VDMA Battery Production Lyoner Str. 18 60528 Frankfurt am Main Phone +49 69 6603-1592 Fax +49 69 6603-2592 E-Mail
[email protected] Internet http://battprod.vdma.org
Battery Production
Roadmap
Battery Production Equipment 2030
http://battprod.vdma.org/
150831VDMA_Roadmap_TI_RT_K1.indd 2-4
26.09.14 12:08
The VDMA "Battery Production" Industry Circle is a multi-industry-segment activity under the auspices of the VDMA Electromobility Forum E-MOTIVE, in which users, manufacturers, machine builders and researchers work together. In view of the synergy effects with electronics and photovoltaic production, the VDMA Productronic Association (Electronics Production) acts as the leader of the Industry Circle. The members of this Industry Circle include 15 industry segments and six German regional VDMA associations; these contribute the specific know-how of their members and thus help to maximise synergy effects. http://battprod.vdma.org http://elektromobilitaet.vdma.org
The Chair of Production Engineering of E-Mobility Components (PEM) of the RWTH Aachen University is a synonym for successful and futureoriented research and innovation in the field of emobility production. The Battery Production group within Professor Kampker's department is concerned with production processes for lithiumion cells and the assembly processes for battery packs. The focus is on approaches which will allow integrated product and process development in order to optimise the cost and quality drivers in the manufacturing and assembly process. Thanks to its participation in a number of international industrial projects and its central position in wellknown research projects, the PEM of the RWTH Aachen University offers a broad-based expertise in the areas of battery cells and battery packs.
The Fraunhofer Institute of System and Innovation Research ISI analyses the development and effects of innovations. We research the short- and longterm development of innovation processes and the social effects of new technologies and services. Based on this, we offer our clients from the worlds of industry, politics and science recommendations for action and information to assist with important decision-making. Our expertise is in our solidlyfounded scientific competency and our interdisciplinary and systematic approach to research. http://www.isi.fraunhofer.de
http://www.pem.rwth-aachen.de
About this book Publisher VDMA Battery Production Lyoner Str. 18 60528 Frankfurt am Main Phone +49 69 6603-1592 Fax +49 69 6603-2592 E-mail
[email protected] Website http://battprod.vdma.org Authors VDMA Batterieproduktion Dr. Eric Maiser, Dr. Sarah Michaelis, Daniel Müller PEM der RWTH Aachen Prof. Dr. Achim Kampker, Dr. Christoph Deutskens, Heiner Heimes, Nemanja Sarovic, Niklas Klusmann Fraunhofer ISI Dr. Axel Thielmann, Andreas Sauer Editors Dr. Eric Maiser, Dr. Sarah Michaelis, Daniel Müller Peter Haan, Paul Merz, Volker Eberlein, Dr. Stefan Jakschik, Dr. Florian Schott, Christian Werner Publishing house and production VDMA Verlag GmbH, Frankfurt am Main Printing h. reuffurth gmbh, Mühlheim am Main Copyright 2014 This work and all parts of it are protected by copyright law. Picture credits Cover picture
Other pictures
© jaflippo bei Fotolia.com “All the signals are at green“: German manufacturers of battery production equipment aim to be the leaders of the industry.. See individual picture credits
Battery Production
Roadmap
Battery
Production Equipment
2030
In cooperation with
Chair of Production Engineering of E-Mobility Components (PEM)
Fraunhofer Institute for Systems and Innovation Research ISI
2
CONTENTS
Contents
Executive Summary
3
Introduction
4
Roadmapping: The whole picture Technology roadmapping in the production equipment industry Methodology
4 4 6
The biggest challenges
9
Red brick walls: an overview Grand Challenges
Roadmap for battery production equipment User markets The demand for electrical energy storage devices up to 2030 Lithium ion technology as a reference scenario Product requirements and specifications The requirements placed on battery manufacturers Solutions offered by machinery and production equipment builders today Where technological breakthroughs are required in the future – red brick walls in detail Beyond lithium ion technology
Conclusion and recommendations for action Conclusion Recommendations for action
9 11
13 13 15 19 21 25 26 28 48
56 56 58
Appendix
60
References Participants
60 64
EXECUTIVE SUMMARY
Executive Summary
Electrical energy storage devices are the key components for the success of electromobility and stationary applications, such as the buffering of energy from renewable supplies. Worldwide, the battery industry is now looking for reliable estimates of market and technological factors. Up to now, discussions have centred on the reduction of costs and the choice of battery technology. This present roadmap is focusing on production technology for the first time. It is the result of a broad-based objective-oriented dialogue between German machinery and production equipment builders and battery producers, user industries and production researchers. This was initiated by VDMA Battery Production and moderated by this together with members and partners from the field of research. The aim was to formulate solutions to be offered by German players in the field of battery production equipment for the large-scale production of high-capacity energy storage devices in the period up to 2030. In five workshops, with contributions from 240 experts from the entire field of battery production, the present situation in the industry was analysed and technological alternatives for production technology were evaluated and projected forward for the period up to 2030. This was carried out using the roadmapping methodology of the semiconductor industry. The main focus was on large-sized lithium ion batteries. A comparison of the solutions offered by machinery and production equipment builders with the requirements of battery manufacturers underlined the necessity for technological breakthroughs, breaking down the so-called "red brick walls". On this basis, a list was compiled of the areas of production technology requiring concrete research. This present roadmap describes research needs for 15 core areas. The biggest challenges proved to be process stability coupled with a simultaneous increase in production throughput, scalability with regard to volume production, sustainability
and above all enhanced quality together with a simultaneous reduction of costs. The following recommendations for action were made: the need for research which has been revealed should be met in a targeted way through cooperation between industrial partners and research organisations. Pilot lines are important platforms for machinery and production equipment builders, since these allow innovations to be tested in production environments which are very similar to genuine production lines and refined to make them suitable for volume production. At the same time, the German players require access to large projects in order to gain experience directly in high-volume production. They should aim at being able to offer customers complete production lines. It will be possible to make significant progress towards this aim through cooperation between players in consortiums or associations and by accompanying measures such as line integration, life-cycle cost studies and joint publicity work. This will allow the battery production equipment industry to achieve international competitiveness across a broad front. It is also important in general to conduct positive public relations work in order to encourage investment in battery production. Finally, the roadmapping process which has been initiated should be continued. Activities have already begun in all these areas within the VDMA. VDMA Battery Production will continue to actively drive forward the roadmapping process which has been initiated and the implementation of this.
3
4
INTRODUCTION
Introduction
Electromobility and renewable energy have become megatrends. This has in recent times generated new interest in electrical energy storage devices. The worlds of industry, politics and research are looking worldwide for strategies which will allow them to position themselves successfully in this field. Roadmaps are a well-proved method of creating clarity: they provide a coherent picture of a future vision, represent in ideal cases a consensus across a broad industrial front, act as an investment guide and facilitate pre-competition collaboration between all the players concerned within the roadmapping process.
Roadmapping: The whole picture Technology roadmapping is a strategic tool used by innovation management. It links scenarios describing technological developments and capacity to the implementation of these in terms of corporate objectives and market opportunities. Forecasts of future megatrends and markets1 ("know why") can benefit everyone who is able to generate concrete requirements [Phaal2003a] for products ("know what"), the Timeline (know-when) Time
Purpose (know-why) Purpose (know-what) Purpose (know-how) Implementation
Vision/ Market
M1
P1
Product
M2
P3
P2
P4
T3
R&D programmes
If we adapt this to our present case, the following picture emerges: electro mobility and stationary energy storage devices represent the blue route "Market", while the green route "Product" is the battery, the yellow route specifies the production technology, and the red route designates battery or production research as appropriate.
Technology roadmapping in the production equipment industry The development of user markets and research into battery technologies has already been studied worldwide in numerous roadmaps. In Germany, too, roadmaps with details of marketrelated and technological factors have been published within the NPE4 and in projects organised by the innovation alliance LiB20155 of the Federal German Ministry of Education and Research (BMBF) [LiB 2015].
T2
T1
Technology
technologies to be deployed ("know how") and the required research and development programmes over a defined period of time. This generates separate "travel routes" which can be considered in each case with separate but related roadmaps2: requirements are formulated by working from top to bottom, while solutions are created working from bottom to top. The overall roadmapping process accordingly leads from an overarching scenario through to products and feasibility and on to concrete needs for research, which can be visualised in a milestone chart3 [Phaal2003b].
RD1
RD2
RD4 RD3
T4
2
RD6
3
RD5
Roadmapping: from an overarching scenario through to products and feasibility and on to concrete needs for research. Development paths in a milestone chart [Phaal2003b] 1
Popular examples include theageing society, shortages of raw materials, sustainability, climate change, etc.
Identified by different colours in the milestone chart
Strictly speaking, our roadmapping follows the development paths shown in the milestone chart in reverse
4 The National Platform for Electromobility (NPE) is a German Government advisory committee. http://www.bmub.bund.de/themen/luft-laermverkehr/verkehr/elektromobilitaet/nationale-plattformelektromobilitaet/ 5
http://www.lib2015.de
INTRODUCTION
There have as yet been no roadmaps available which focus on battery production beyond the horizon of the internal plans of individual companies. VDMA Battery Production began already in 2011 to initiate a broad public objective -oriented dialogue between battery producers, production researchers and machinery and production equipment builders and to encourage exchanges of ideas between suppliers. This present study describes the results of this process.
Starting point, objectives and target groups VDMA Battery Production conducts roadmapping from the point of view of machinery and production equipment builders. A previous study [Schlick2011] has already described the strengths and weaknesses of the industry with regard to battery production. The major conclusions of the study were as follows: • German machinery and production equipment builders offer solutions applicable to the entire process chain of battery manufacturing. Individual companies have already offered complete solutions, particularly in the field of module production. • Asian players have a lead over German companies in experience, due to the many years in which they have equipped factories for consumer batteries. They are currently dominant as suppliers of production equipment. In view, however, of the necessity for new concepts for high-capacity energy storage devices, opportunities are emerging to make good this lead. • Experience from related industries, such as semiconductor, photovoltaics and automobile production, and also the food and packaging industry, has already been successfully applied. The excellent German position in the automation industry creates a
starting point with good prospects for success. The roadmapping process should therefore aim to achieve the following: • Determination of the position of German machinery and production equipment builders in the field of battery production and technological further development through collaboration with production research. The result will provide both a coherent picture for a shared development vision and also a comprehensive catalogue of solutions for customers and will enhance the international competitiveness of the suppliers concerned. • Gain in know-how for new suppliers among machinery and production equipment builders by illustrating the interrelationships throughout the process chain. This will make it possible for participating companies to position their own product portfolios appropriately. Benchmarks will be created allowing comparison with (international) competitors, resulting in opportunities to expand companies' own product portfolios. • Research needs of production technology will be identified. The aim should be to identify not only the required machine solutions but also the points in time at which these must be available. This will result in a guideline for public and private finance providers. • Recommendations for action for all players will be derived from the results. These will be aimed both at the manufacturers of production equipment and at research service providers, the world of politics and investors. They will also form a guideline for the work of associations in the VDMA. This present roadmap in itself can represent only a part of the results which emerged from the dialogue initiated within the roadmapping process between production equipment
5
6
INTRODUCTION
whole industry. The basic principles and parameters are described in detail in [Garcia1997]. In this study, we describe the basic pillars supporting the method to which we have orientated ourselves.
VDMA roadmapping workshop: dialogue between production equipment manufacturers, battery producers, users and research organisations. Photo: VDMA
manufacturers, battery producers, users and research organisations. As a general principle, those who will benefit the most will be the participants in this dialogue [Groenveld1997, Phaal2009]. It is important to involve all the relevant players in the dialogue and proceed in a structured way.
Methodology The VDMA's experience with roadmapping [adria2005, VDMA-PV2010] has underlined the importance of clearly specified methodology for the roadmapping process. Particularly with new technologies, there is a wide range of possible paths. As with previous activities, we adapted the roadmapping process used in the semiconductor industry to the needs of battery production:
The concept of separate roadmaps for customers and production equipment builders One of the most important conclusions of the ITRS process is: "Technology roadmapping is driven by needs, not by solutions" [Garcia1998]. In roadmapping workshops in the past, we often observed the following attitudes: producers made the formulation of requirements placed on machine builders dependent on the feasibility (as imagined at the present time) of process technology for volume production. This did not lead to the ambitious objectives which should have resulted from the product requirements of the end customers. On the contrary, technology suppliers felt able to make statements on the development of new process solutions only when there were prospects of high-volume production. This in turn did not lead to the generation of proactive innovative machine solutions. In cases of this kind, no fruitful discussion takes place. It is possible to achieve a breakthrough here only if the two sides – producers and machine builders – each formulate separate roadmaps.
Roadmapping in the semiconductor industry One of the best-known technology roadmapping methods is the ITRS1. The global semiconductor industry uses this to coordinate the wide range of development work aimed at increasing performance and cutting costs in chip production. Over 1,200 experts worldwide are participating in the creation of this method today. It is to a very high degree binding for the 1 International Technology Roadmap for Semiconductors http://www.itrs.net Milestones are referred to here as “Technology Nodes”.
Manufacturers analyse critical system parameters and define specifications for their products, in our case batteries. This results in "non-negotiable" requirements placed on the manufacturers of production equipment. Parallel to and independently of this step, the manufacturers of production equipment extrapolate the process technologies available today, develop technological alternatives and in this way formulate future feasibility from their point of view. In this way, a wide range of possible ideas for machine solutions is created. Only after this are the individual roadmaps combined together. It is important in this
INTRODUCTION
process to define a harmonising time grid. In our dialogue, we have defined the following time grid in order to obtain comparability: (1) „State of Art“, (2) Up to 2015, (3) Up to 2020, (4) Up to 2030.
The importance of "red brick walls" The bringing-together of the requirements placed on battery manufacturers and on feasibility from the point of view of process development within the defined time grid reveals the following for each individual process step: (1) Process solutions which are already available in the field, (2) Process solutions which are available only at a pilot stage (3) Process solutions which have been demonstrated or exist as part-solutions, and (4) Process solutions which are unknown from the present-day point of view. Cases of this last kind are marked in the tables in red ("red brick"). If solutions are Value chain
Lead acid Ni-MH Li-ionen Li-S Li-air
Future prospects for other battery technologies markets and products
Existing mechanical engineering roadmap, lithium ion technology
Today
2030
Time
Battery technology
If we regard a milestone chart as roadmapping for production technology, further charts emerge for each battery technology. This present book is concerned with the challenges associated with the volume production of lithium ion technology. We do however also consider the future market and product prospects of alternative battery technologies. Source: VDMA
unknown in several process steps required to meet a manufacturer requirement, then in metaphorical terms a so-called "red brick wall" arises. This indicates that technological breakthroughs are necessary. Research efforts must now be targeted at overcoming the "red brick walls" in order to fulfil the manufacturers' requirements. The identification of red brick walls is thus a core task within the roadmapping process. From this it is possible to derive clearly stated concrete research requirements.
Multi-dimensional roadmaps – focus on the production equipment industry A holistic roadmapping approach "from the overarching scenario through products and feasibility and down to concrete research requirements" as shown in the milestone chart above would have been too complex for our purposes. We wished to focus explicitly on machinery and production equipment builders. We have thus interpreted "research" to mean "production research". Continuing to think in terms of the milestone chart, a separate chart results for each battery technology, creating a multidimensional roadmap. To allow an intensive study of the process chain, we have accordingly focused on the battery technology which appears most promising at the present time, lithium ion technology. In view of the competitive environment for German companies, we shall furthermore limit ourselves to considering large-sized cells for high-capacity applications. In conclusion, we shall take a look ahead at the market and product prospects for future alternative battery technologies, which in certain cases exist today only at the demonstration stage.
7
8
INTRODUCTION
Workshops at the VDMA For the dialogue, we selected an expert-based approach [Kostoff2001], featuring five workshops in which first the manufacturers of production equipment discussed issues with each other, to be joined in the last workshop by representatives of companies in client industries. Among those participating right from the start were experts from the PEM of the RWTH Aachen (production technology research) and the Fraunhofer-Institute of System and Innovation Research ISI (customer roadmaps, particularly LiB 2015 roadmapping). The compilation of this present roadmap was a joint activity. In the discussion of the production technology solutions offered and the evaluation of these, we pursued a strictly systematic approach: standardised EXCEL tables were used to examine production methods with a high degree of detail for their suitability for large-scale production1. For this purpose, the competency fields of the participating machine builders were evaluated and, on this basis, four task forces were formed along the process chain2. The participants in the task forces compiled ideas for solutions in separate workshops, using this systematic approach. This ensured comparability at all
times – one of the critical factors for highquality roadmaps [Kostoff2001]3. The EXCEL tables could also be filled out by members outside of the workshops. The tables were then validated, consolidated4 and discussed with customers and researchers. The results of these discussions were used to define the red brick walls which form the basis for this roadmap.
To sum up: this present roadmap formulates solutions offered by German machinery and production equipment builders and describes the need for research for the high-volume production of high-capacity lithium ion energy storage devices in the period up to 2030.
1
Multi-dimensional matrix for the evaluation of solutions for machines, production equipment and components with the following criteria: Degree of maturity: Demonstrator, prototype, pilot production, volume production. When will the solution be ready for volume production? "State of the art", 2020, 2030 Relevance for volume production: Seven evaluation criteria, including costs, quality, time. Data related to the process step under consideration compared with the present-day standard process. Obstacles to introduction? Who is driving the introduction? Seven further evaluation criteria What customer need is being met? Evaluation according to type and measured variables 2
TF1: Front end cell production: from mixing to calendaring TF2: Back end cell production: from separation to formation and clean room technology TF3: Module and pack assembly TF4: Overarching topics: measuring and testing, automation, software, safety technology
3
[Kostoff2001] defines further critical factors for the creation of high-quality roadmaps, which we also considered.
4
The details were known only to participants in the roadmapping workshops and the people who contributed to the contents of the tables.
THE BIGGEST CHALLENGES
The biggest challenges
Red brick walls: an overview A large part of the added value of a battery pack is created in the production of the battery cells. It is this area that requires the most investment [Kampker2012a], offers the greatest potential for reducing costs [Schlick2012] and ultimately presents the biggest opportunities and risks with regard to business success. At the same time, a number of different technological alternatives are available today for cell production, which means that battery manufacturers are faced with a bewildering choice of options for the equipment of a cell line. On the other hand, there are only a few production equipment manufacturers which are able to offer complete cell lines. In our roadmapping workshops, too, we found that the biggest challenges and potentials from the point of view of German machinery and production equipment builders lie in the production of battery cells. We thus attached particular importance to the identification of possible red brick walls for the production technology of lithium ion foil cells. A total of nine red brick walls were found in this area alone. The production process of a battery cell is divided into three main processes: the production of electrodes, cell assembly, and formation and testing [Kampker2012a]. In the area of electrode production, three red brick walls were identified. These are associated with the mixing of slurry and the challenges of the coating process. Five red brick walls relate to the area of cell-assembly. Here, we found that special requirements apply to the separation and stacking of the electrode sheets. We also found red brick walls relating to the production and sealing of the cell housings. Filling with liquid electrolyte was the subject of a further red brick wall. In the last main process, two red brick walls were identified. These are concerned with ways of speeding up the formation process and forecasting the service life of individual cells.
The area of module and pack assembly requires considerably less investment. There are not as many process alternatives [Kampker2012b] and line suppliers are already enjoying success, including suppliers from Germany. There are, however, a number of decisions to be taken and challenges to be met, resulting from the different form factors and the absence of standards [Maiser2014], but solutions are already available today in certain cases. Nonetheless, a red brick wall was identified in the workshops in the area of pack assembly whose core concern was to replace the laboriously welded aluminium housings. Above and beyond this, there are five further red brick walls which relate to non-process-specific topics. These include, for example, the high operating costs of clean rooms and drying rooms, recycling processes and standardisation. The presentation of the red brick walls is oriented to the sequence of the main process steps. A total of 15 red brick walls (RBW) were identified: •
RBW 1: Mixing - continuous process operation
•
RBW 2: Coating - increasing speed and width
•
RBW 3: Coating – double sided and simultaneous
•
RBW 4 Separating – contamination during process step
•
RBW 5: Stacking – increasing speed
•
RBW 6: Cell assembly - deep-drawing more than 11 mm
•
RBW 7: Cell assembly - sealing of foil cells
9
10 THE BIGGEST CHALLENGES
•
RBW 8: Filling - increasing speed
•
RBW 9: Formation – a more reliable and faster process
•
RBW 10: Long-term forecast – statements concerning service life
•
RBW 11: Pack assembly – plastic pack housings
•
RBW 12 Overarching topic – clean rooms and drying rooms
•
RBW 13: Overarching topic – recycling
•
RBW 14: Overarching topic – standardisation
RBW
RBW
high
9
RBW
RBW
15
10
RBW
RBW
13
5
RBW
RBW
medium
1
3
RBW
8
RBW
RBW
2
11
RBW
7
low
Benefit
14
RBW
•
RBW 15: Overarching topic – relevant parameters for process control
In the chapters which follow, these 15 red brick walls relating to future battery production will be discussed in depth. Basic principles and challenges will be analysed in detail and approaches proposed to overcome the various red brick walls. Notwithstanding that it is important all in all for the success of process technology that all the red brick walls should be addressed at the correct point in time, there is always the question for the individual suppliers of production equipment of the cost and benefits associated with the development of a solution. This applies in particular to new entrants. In order to visualise the individual red brick walls, these have been shown and evaluated in a new reference system, the portfolio matrix1. The knowledge of the existence of red brick walls is valuable in itself. However, the discussion above has also shown that the implementation of measures to counteract each red brick wall involves a high level of research costs. Notwithstanding this, the portfolio matrix allows the 15 red brick walls which we have derived to be related to each other - from 'low hanging fruits' (upper right corner) to 'hard to handle' (lower left corner). This results in a qualitative representation of attractiveness from the point of view of the suppliers of production technology.
RBW
12
4
RBW
6
medium
high
low
Cost
Key:
2020
2030
Portfolio matrix: comparison of time horizons, cost and benefit for the overcoming of the identified red brick walls. Source: RWTH Aachen
1
Benefits and costs were evaluated by awarding points from 1-9 (low being 1…3 and high being 7…9). The values for benefits and costs are inversely related to the attractiveness of each red brick wall. For benefits, values which are as high as possible are advantageous, while for costs, the value should be as low as possible. This is the reason why the value 1 for benefits and 9 for costs lie at the origin of the matrix. At the top right-hand corner of the matrix are the so-called lowhanging fruits – challenges which offer high benefits and can be achieved at acceptable cost.
THE BIGGEST CHALLENGES 11
Grand Challenges Increasing quality while simultaneously reducing costs Process stability with higher throughput
Scale up of production
RBW 4 RBW 7 RBW 10 RBW 12 RBW 15
RBW 2 RBW 3 RBW 5 RBW 6 RBW 14
RBW 9
Sustainability
RBW 1 RBW 8 RBW 11
RBW 13
The Grand Challenges for battery production and their relationship to the identified red brick walls. Source: RWTH Aachen, VDMA
Grand Challenges We have described the biggest challenges facing battery production on the basis of the "Grand Challenges" defined for the semiconductor industry. All the red brick walls which have been identified can be correlated to four overarching grand challenges. • The first grand challenge is the scaling-up of production solutions from the demonstrator level through to pilot lines and volume production. Many working steps are not yet ready for volume production and have a high potential for automation. Particular attention must be paid to scalability in the case of new process steps. In order to be able to meet the increased future demand for batteries, the throughput time must be significantly reduced. • The second grand challenge is process stability with a simultaneous increase in production throughput. In comparison with related industries, present-day battery production lines have a very high reject rate. Against the background of the high material costs of a battery cell, which are multiplied as
this is processed further to form part of a module and battery pack, this represents a significant cost driver. A simple increase in process speed has a negative effect on process stability. Wider process windows or more precise control systems allow higher process speeds with the same process stability as before and lower reject rates. • The third grand challenge is sustainability in battery production. The phrase "green production" relates both to environmental friendliness and the safe processing of the raw materials in a product and to the materials and solvents used in the process: a further important factor is also energy and resource efficiency in production. An important aspect of recycling, however, is closed-loop production: this ensures that as much of battery raw material as possible is fed back into battery production after recycling and not converted into other waste products which are left to decay. • The fourth overarching grand challenge for battery production is achieving higher quality while at the same time reducing costs. This is the core challenge by which the manufacturers and suppliers of production technology must measure themselves in the long term. For one thing, the success of electromobility depends crucially on this. Related industries such as the semiconductor, display and photovoltaic industries have succeeded in meeting this challenge over a period of decades. The aim is to achieve this for battery production, too.
12 THE BIGGEST CHALLENGES
Coating technology is an important process technology for battery production. Seen here: a pilot production line at the RWTH Aachen. This coating machine was selected as an example in the VDMA workshop series entitled "Total Cost of Ownership for Battery Production." Source: PEM of RWTH Aachen
Cost evaluation facilitates cost reduction A reduction of the costs of battery production demands knowledge of the individual cost components. Only through a holistic evaluation is it possible to identify and eliminate cost drivers. More and more manufacturers are asking their suppliers for details of the consequential costs of an investment. Understanding costs fully requires an evaluation over the complete life-cycle1 of products (development, operation and recycling). Differences in manufacturers' cost models, however, make it difficult to obtain an overview. The VDMA publication 34160:2006 provides a standard for uniform calculation which is matched to the needs of battery machine builders. Since this would have exceeded the limits of the roadmapping workshops, VDMA Battery Production initiated a series of workshops entitled "Total Cost of Ownership for Battery Production" in 2012. This series will shortly be completed. The results will be published separately.
1
Also referred to as "Total Cost of Ownership".
ROADMAP FOR BATTERY PRODUCTION EQUIPMENT 13
Roadmap for battery production equipment
In this section, we will now describe the results of the roadmapping process in detail. As a starting point, it was necessary to answer the following: is our involvement justified by the expected size of the battery market? Which battery technology will be dominant in the coming decades and will represent the biggest demand for production solutions? What is the driving factor behind the requirements placed by battery manufacturers on their suppliers? These questions can be answered by studying markets and the product specifications on the user side. The user applications determine the requirements placed on battery manufacturers. From this, it is possible to derive and understand the requirements placed by battery manufacturers on the suppliers of production technologies. For this purpose, we made reference to existing roadmaps.
User markets The possible applications of electrical energy storage technologies lie not only in the area of electromobility but also in many forms in the field of stationary energy storage [Schlick2012, Thielmann2012a]. Small electric vehicles demand storage devices of a few kilowatt hours (kWh) capacity, while large electric vehicles require ratings of up to 25 kWh and more1. The available range of stationary storage devices, for example for use as buffers with renewable energy supplies or for mobile phone masts, runs from small (100 kWh) centralised systems. Stationary electrical energy storage devices with capacities up to the megawatt hour range are already commercially available. As applications become larger, the level of distribution in both
1
The range of available devices is varied, including everything from bicycles already available in the mass-market, small guided conveyor vehicles, boats, electric vehicles and buses through to hybrid rail vehicles, various working machines and even ships.
electromobility and stationary energy storage becomes smaller, as does the speed of market diffusion
Developments in the electric car market In the electric car market, there is a particular focus on the development of plug-in hybrid vehicles (PHEVs) and battery-driven electric vehicles (BEVs), with the automobile industry, both in Germany and elsewhere, acting as the driver for the development of other applications, such as small commercial vehicles. The time at which this market will take off depends very heavily on the development of external variables acting on cost/benefit calculations, for example the prices of crude oil or generated electricity [Plötz2013]. An equally critical factor is the need for cost-reduction targets to be met with regard to vehicle batteries and for broader social acceptance to be built up through positive experiences with electromobility in the population at large. In general, all present-day forecasts include a high level of elements of uncertainty. The sales figures for more heavily electrified electric vehicles (PHEVs and BEVs) have exhibited very promising growth in recent years, from 45,000 vehicles in the year 2011 to 113,000 vehicles in 2012 [IEA2013] and more than 210,000 vehicles in 2013 [ICCT2013]. This means, however, that the total number of electric vehicles in operation worldwide is still well below half a million and thus below the global target figures specified in [IEA2013]. This represents far less than 1% of all cars worldwide. Nonetheless, optimists believe that the high rate of growth will continue [King2013].
14 ROADMAP FOR BATTERY PRODUCTION EQUIPMENT
The market share of PHEVs and BEVs in 2030 will lie between low single-digit values and approximately 50% of all new-vehicle registrations in the countries included in the study.
Target values for regional market shares for electric vehicles (PHEVs and BEVs) in the world's major markets 2010-2020[IEA2013].
One of the current challenges is the lack of diversity among the vehicle models available with regard to different price classes and functionality. The present products on offer are very far from being able to cover all customer segments and their special requirements. As the result of the dominance of hybrid cars (HEVs), the lion's share of all electric vehicles is currently being produced in Japan, followed by the USA. Much further back in the field are Korea, France and Germany [Marklines2014]. Estimates published by research institutions and corporate consultants as to the size of the market for electric vehicles in the year 2020 often seem to be characterised by the optimism described above [Martin2013, Frost2014].1 In general, however, all studies are based on a number of assumptions regarding influential variables and the development of these, for example the price of crude oil or batteries. This then results in a considerable bandwidth of possible market development scenarios. The results may accordingly deviate sharply from one another. The forecasts generally do not attempt to describe the most probable development scenario.
1
The innovation report "Electromobility and its Importance for Industry, Society and the Environment" (Working Report No. 153), [Peters2012] includes an overview and comparison of current studies which are concerned with the future market penetration of electric and hybrid vehicles.
If we consider the entire worldwide pool of vehicles, there is a giant market potential for electromobility. In the year 2012, internationally a total of around 77 million vehicles were sold, which represents an increase of 6% over the previous year [ICCT2013]. This figure includes 50 million cars. The three largest markets in terms of numbers of sold vehicles in 2012 were China (19 million), the USA (15 million) and the EU 27 (14 million). The expectation for electromobility is also that the most important markets will be in Asia, the USA and the EU.
Year
EU-27
U.S.
China
2020
7%
10%
9%
2030
30%
35%
40%
Forecast market shares for electric vehicles (PHEVs and BEVs) in the most important markets. Quelle: [ICCT2013, IEA2013]
One very large potential is predicted to be electric vehicles deployed in large fleets (for example, car sharing providers or large companies). These vehicles account for 30% of annual new-vehicle registrations in Germany. Similar values are reported from other European countries.
ROADMAP FOR BATTERY PRODUCTION EQUIPMENT 15
US-Dollar
44 bn
43 bn
36 bn 13 bn
32 bn
11.4 bn
19.9 bn
Developments in the market for stationary applications
11 bn 8 bn 2.9 bn
3 bn
4 bn 1.6 bn
878 m
The wide bandwidth of forecasts for the worldwide development of the market for lithium ion batteries in unit sales [Thielmann2012a].
Development in the market for heavy-duty hybrid (commercial) vehicles In addition to the particularly promising passenger car applications, there are further applications which have begun to be adopted but are as yet far less significant in terms of unit sales. These are generally summarised under the heading "Heavy-duty hybrid (commercial) vehicles". While, for example, there is a relatively large market potential for electrified buses and trucks, non-road mobile machinery generally involves niche applications with comparatively low unit sales.1 The market for heavy-duty hybrid (commercial) vehicles has progressed beyond the prototype phase and is now, particularly in the case of buses and trucks, either at the demonstration stage or just about to undergo successful commercialisation.
1
One exception is, for example, fork-lift trucks, which continue to use lead acid batteries as before.
In this field, the popular discussion is of products as buffers for energy from renewable sources [Hollinger2013, Fürstenwerth2014]. This market ranges from photovoltaic installations for private users to large containers for wind power generators or companies with production facility. Mobile phone masts represent a further market for batteries which is less often discussed in public. The position with stationary applications of electrical energy storage devices is similar to that for electromobility: smaller concepts such as solar power storage devices are already available on the market [Märtel2013b]. However, the larger an electrochemical storage medium for a given application is, the lower the expected unit sales and the further away such devices are from their market launch, not to mention massmarket success. However, demonstration projects already exist for all kinds of applications.
The demand for electrical energy storage devices up to 2030 For a number of years, numerous new sales forecasts have been appearing from time to time relating to the development of the worldwide market volume for electrical energy storage devices in general and lithium ion batteries in particular. Notwithstanding that there are significant differences between these in terms of absolute values, all forecasts predict healthy growth. The market for lithium ion batteries worldwide is predicted to grow by several multiples, the exact number depending on the source, driven both by a wider choice of products on the market and falling production costs.
16 ROADMAP FOR BATTERY PRODUCTION EQUIPMENT
The market for rechargeable batteries from 2000 to 2025 in MWh
180000
120000
HEVs will gradually be replaced by PHEVs [Anderman2013, Pillot2013, Global2013]. The lithium ion battery market for electric vehicles will grow more strongly in future years than the market for other applications, such as consumer goods or the industrial sector (see graphic on left).
60000
0 2000
2010
2020
Ni-Cd
Ni-MH without cars
LIB without cars
LIB for HEV
LIB for P-HEV
LIB for EV
2025 Ni-MH for HEV
The market for rechargeable batteries from 2000 to 2025 in MWh according to battery technologies, including beyond lithium ion technology. The average annual growth rate is 12 percent. Data taken from [Pillot2013]
It is estimated that the value of the global lithium ion battery market in 2013 was approximately US$18 billion [Sapru2014, Frost2010, Yano11]. The estimates for the period up to 2020 vary from US$15 bn [Statista2014] to over US$70 bn. As, however, the latter figure is based on estimates from the years 2008 to 2011 (see graphic on previous page) and is quoted increasingly frequently, it can be assumed that the size of the market of the future will be subject to an upward trend [Oyama2011, Trans2013, Pillot2013]. As described in the previous chapter, this growth will be a consequence of the forecast rising demand in all areas in which lithium ion batteries are used, namely in stationary applications as buffers for energy from renewable sources, in electric vehicles, and also as before in numerous types of consumer goods (mobile communications and tools) and in the industrial sector (electric tools and accessories). A further factor is that all assumptions are that lithium ion batteries will gradually take the place of nickel metal hydride batteries, which were the main type previously used in HEVs. In the period up to 2030, it can be expected that nickel metal hydride batteries will have completely disappeared from the market – linked to the fact that
A particularly important role will be played by the expected development in battery prices – the production capacities of large battery manufacturers, which have been built up worldwide and are not currently fully utilised, have already in recent months led to a significant fall in battery prices and may in the medium term lead to a pronounced amalgamation process among suppliers [Anderman2013]. While battery prices remain low, the market will grow faster and the remaining manufacturers will be able to make healthy profits even with low profit margins.
Size of market for consumer batteries and other small and medium-sized batteries The value of the market for batteries for portable consumer goods, such as mobile tools and communication devices1, in 2014 will be between US$9bn [Yano2011] and US$12bn [Frost 2010]. Then there are the small and mediumsized batteries which are not used directly by consumers but are used, for example, in medical technology. The size of this market was approxymately US$3bn in 2014 [Yano2011]. The expectations for the year 2020 are that the market for consumer batteries will grow to a value of between US$12 bn and US$19 bn, while the market for other small and medium-sized batteries will have a value of approximately US$5 billion.
1
Referred to in the following as "consumer batteries"
ROADMAP FOR BATTERY PRODUCTION EQUIPMENT 17
Global LiB markets (consumer batteries) in bn. $
Global LiB markets (vehicle batteries) in bn. $
20
40 35 30
15
25 20
10
15 10
5
5 0
0 2015
2020
2015 AAB - Anderman (2013)
Avicenne (2013)
2020 Navigant (2014)
Avicenne (2013)
Yano (2011)
Frost&Sullivan (2012)
Frost&Sullivan (2014)
Yano (2011)
Frost&Sullivan (2010)
Frost&Sullivan (2014)
Frost&Sullivan (2010)
Global Data (2013)
Navigant (2012)
Global LiB markets (industrial batteries) in bn. $
Global LiB markets (stationary energy storage) in bn. $
10
20
15
5
10
5
0
0 2015 Yano (2011)
Frost&Sullivan (2010)
2020 Frost&Sullivan (2014)
2015
2020
iSupply (2011)
Pike (2010)
Frost&Sullivan (2014)
Global markets for lithium ion batteries (LIB) in total and according to applications. Sources: see individual graphics
•
[Anderman2013] forecasts a worldwide market for large-sized lithium ion batteries for HEVs, PHEVs and BEVs at pack level of just under US$4 billion as early as 2014. The prediction is that this market will be worth over US$9 billion in the year 2020. If we consider the statements made at cell level, these agree closely with [Pillot2013].
•
[Pillot2013] forecasts a value for the market at cell level of just under US$3 billion for the year 2014. The forecast for the year 2020 is over US$7 billion. Both these figures agree with [Anderman2013].
•
[Global2013] goes well beyond this and forecasts a market size of over US$12 billion for the year 2014 and US$36 billion for the year 2020.
•
[Frost2010] as an older publication is more conservative than [Global2013] regarding the market size in the year 2014 at just under $7 billion but forecasts the same figure of US$37 billion for the year 2020.
The size of the market for lithium ion batteries for electromobility applications Particularly in the next several years, electric vehicles will represent a central application for large-sized lithium ion batteries in the mass market. Since, in addition to this, various degrees of electrification of the vehicle drivetrains are possible, the question must always be considered in studying the market as a whole as to the size of the market shares of the individual degrees of electrification (HEVs, PHEVs, BEVs). This information will allow statements to be made regarding the market development of the various lithium ion cells chemistries1. Further details on the battery technologies used will be given in the chapter "Product requirements and specifications". The figures for the market volume for lithium ion batteries for electromobility in the years 2014 and 2020 vary widely in the currentlyavailable studies:
1
The various vehicle types require different types of lithium ion batteries, among other things with different cell chemistries. The growth rates of the various degrees of electrification therefore have an influence on the market for the various types of lithium ion batteries. Market data is, however, not usually broken down on the basis of cell chemistries.
18 ROADMAP FOR BATTERY PRODUCTION EQUIPMENT
As already mentioned, there are also a number of further estimates and forecasts [Navigant 2013, Navigant2014, Yano2011, Roland 2011].
The size of the market for industrial batteries With regard to the batteries used in the industrial sector, and thus, for example, in electrical tools and accessories, the expectation is that the market in 2014 will have been worth approximately US$3 billion [Frost2010]. This market is also expected to grow, to a value of US$7 billion.
The size of the market for stationary energy storage devices There have as yet been few market analyses for stationary electrochemical storage devices. At the transmission network level, demand for this type of storage device is expected to develop only in the long term together with the widespread expansion of fluctuating energy supplies from renewable sources as part of the changing energy policy in Germany [Fürstenwerth2014]. Energy balancing and/or other more economic types of storage devices will also prevent or at least limit the adoption of lithium ion batteries as electrical energy storage devices at transmission network level in the coming decades, since they will then be economically viable only in special cases such as island solutions [VDE 2012]. At the distribution network level, lithium ion batteries may have a part to play in photovoltaics or in the storage of solar energy in private households, photovoltaics or wind energy parks and network stabilisation systems [Younicos2013]. The prediction for the market volume of electrical energy storage devices in photovoltaic or home solar applications up to 2020 is for a value of €2.4 billion, with lithium ion batteries expected to be preferred to lead acid batteries through standardisation on the basis of calculations of total cost of ownership. Further studies also predict markets for lithium ion batteries up to 2020 of several billion US dol-
lars worldwide for on- and off-grid applications. The applications of lithium ion batteries in the field of stationary storage devices are however many and various and it is expected that a variety of business models will be developed in the coming years. A dependable estimate of market developments in this as yet young field of the future, even beyond photovoltaics, is barely possible at the present time. There is however no doubt, that lithium ion batteries will also play a significant role in this field. It is as a general principle interesting to see how the market for batteries can be estimated for a given customer sector. One example: the development of the worldwide sales figures for electric vehicles varies between conservative estimates of around 1 million PHEVs/BEVs up to 2020 [Anderman 2013, Pillot2013] and the target values which may be achieved by this time of around 5 - 6 million vehicles [IEA 2013]. This translates directly via the relevant assumptions regarding battery sizes (e.g. 8 - 12 kWh for typical PHEVs or 20 - 25 kWh for typical BEVs) into demand for batteries and via assumptions regarding price developments with PHEV/BEV batteries (in US$/kWh, PHEV batteries are more expensive than BEV batteries, typical assumptions for the period up to 2020 are 200 - 300 US$/kWh at cell level) into the billion-dollar markets described in the market studies. These studies reflect bandwidths varying from US$6 9 bn for vehicle batteries up to 5 times this value. The position is similar with regard to estimates for other sub-markets for lithium ion batteries, such as the still young area of stationary electrical energy storage devices. All these figures show clearly that while in general exceptionally high growth is expected, the precise magnitude of this up to a certain point in time fluctuates within the broad bandwidth covering the various estimates.
ROADMAP FOR BATTERY PRODUCTION EQUIPMENT 19
Lithium ion technology as a reference scenario
4-volt lithium ion batteries as a current reference technology
As consumer batteries, they are a vital part of our daily lives, but lithium ion batteries do not as yet have the same degree of technological maturity as conventional lead acid or nickel metal hydride batteries. Depending on the dimensioning of the cells, however, they can offer significantly higher energy and power densities and are thus regarded mainly for this reason as the battery systems of choice for mobile and stationary applications. In the following, therefore, we will describe the current state of the art, using the present-day reference system. This firstly represents the starting point for our focus area of production technology and secondly serves as a basis for a look ahead into the further development of battery technology overall (see chapter "Beyond lithium ion technology") [Peters 2012, Thielmann2012b].1 The progress which has been achieved in the field of electromobility is also the driver for the development of energy storage devices for stationary applications. Since, however, these must in certain cases meet significantly different performance requirements; we will at various points deal explicitly and separately with these two areas of applications.
The current reference system of "classic" lithium ion batteries for use both in electromobility and stationary applications is the already very highly developed four-volt lithium ion battery with an energy density of over 110 Wh/kg (gravimetric) or 179 Wh/l (volumetric), a service life of more than 5000 cycles, equivalent to 10 - 15 years, reliability at a maximum of EUCAR level 42 and costs which at the moment, depending on the quantities produced, lie between 300-400 €/kWh.3 In electrochemical terms, the current reference system is based on a cathode made of nickel manganese cobalt (NMC) or lithium iron phosphate (LFP) and an anode made of graphite. Lithium titanate is also suitable as an alternative anode material, particularly for use in largesized stationary storage devices or energy storage devices for HEVs in the field of electromobility [Korthauer2013].
Rechargeable batteries differ one from another in the choice of chemical storage system, the cathode and anode material, electrolyte and separators used and various other characteristic features, such as operating temperature.
1
Our remarks are based on the technological overview contained in the innovation report "Electromobility and its Importance for Business, Society and the Environment" (Working Report No. 153)“ [Peters2012] and on the "Technology Roadmap: Energy Storage Devices for Electromobility 2030“ [Thielmann2012b]
The declared aim of the industry is to lower the cost of this system, realistic forecasts name a figure of 250€/kWh for the year 20204. This objective was also the main motivation for this present book. Among the tools for reducing costs are not only industrial volume production and the associated learning-curve effect and economies of scale [Schlick2011] but also progress in the production of materials and an improvement in quality [Roland2011]. The increasingly tough competition between global battery producers and the current production
2 European Council for Automotive R&D (EUCAR); This is an association of interested parties, including Europe's major car and commercial vehicle manufacturers, which defines hazard levels for electrical energy storage technologies, based on the resistance of a technology to abuse. Manufacturers and suppliers must develop and test their batteries accordingly in order to be sure of achieving the necessary EUCAR level. 3
All parameter specifications at system level and for use in BEVs
4 See chapter entitled "Developments to be expected in central performance parameters".
20 ROADMAP FOR BATTERY PRODUCTION EQUIPMENT
overcapacity1 in large-sized cells [Andermann 2013] have caused prices to fall and have increased the cost pressure on manufacturers. The latitude for the improvement of system parameters, such as an increase in energy density, is intrinsically limited by the system itself. Breakthroughs can be expected not in the current generation but the next generation of lithiumbased batteries (see chapter entitled "beyond lithium ion technology"). Nonetheless, we have in the VDMA roadmapping process focused on lithium ion technology.
Large-sized lithium ion batteries as a suitable reference system for the introduction of volume production As has been shown in the preceding chapters, lithium ion technology has reached an advanced stage of development and an adequate degree of penetration of mass markets. Large-sized cells for high energy and high-capacity applications are already available in the market. It can be assumed that areas which are currently dominated by other technologies such as lead acid or nickel metal hydride2 will be taken over by lithium ion technology. Current cell chemistries and packaging allow sufficient latitude for the various requirements of electromobility and stationary energy storage devices. The overall picture in battery technology research and development shows that the current generation of "classic" large-sized lithium ion batteries is being improved on an evolutionary
1
The production overcapacity should be regarded as temporary, since the markets mentioned above have not yet "come alive" and the expected demand is not yet present. Falling prices will activate the market. As the rate of growth increases, overcapacity will soon be eliminated and, due to the lead time in the building of factors, production bottlenecks will result. There has been experience of this in numerous industries, particularly the semiconductor and photovoltaic cell industries.
2
Lead acid in the stationary energy storage market or as traction batteries in mobile machinery, nickel metal hydride especially for use in HEVs. This is discussed in more detail in the chapter entitled "beyond lithium ion technology".
basis, thus gradually closing the gap in energy density relative to consumer batteries (250 Wh/kg). Within the next 10 years, it is likely that no fundamentally different battery technologies will be available on a commercial scale, which is why the upcoming rise in the market for electric vehicles (particularly BEVs) up to the year 2020 and beyond will be based on the current lithium ion battery generation. For the period after 2025 and beyond 2030, lithium sulphur batteries can be considered as the most promising battery technology for use in electromobility, together with completely different energy storage solutions such as fuel cells, which may possibly deliver decisive advantages with regard to energy density and thus to the working range of BEVs. These however, have not yet been sufficiently evaluated and made available in the market. For use in stationary applications requiring small to medium storage capacities and cycles, the current lithium ion battery generation will continue for many years to represent the reference system, due to the dimensioning breadth and the consequent wide variety of applications which it offers. For large-sized cells, however, lithium ion technology has not yet succeeded in making the leap into volume production. Quality must be increased and costs must be reduced. This is the great challenge for production technology. We have accordingly decided to focus the VDMA roadmapping process on lithium ion technology.
ROADMAP FOR BATTERY PRODUCTION EQUIPMENT 21
Product requirements and specifications The investment costs for electrical energy storage devices are a crucial factor in gaining acceptance by end customers and are accordingly at centre stage from the point of view of the suppliers of electric vehicles and stationary storage systems. In the case of electromobility, further important factors include a large working range, fast acceleration and fast charging. For stationary applications, the crucial factors are a long service life and low total cost of ownership throughout the battery life cycle. These and other requirements mean that it is important to select the right electrical energy storage device for a specific application. They ultimately lead to concrete requirements for the performance parameters of batteries.
Central performance parameters The most important technical performance parameters are listed below: •
Energy density, gravimetrically in Wh/kg and volumetrically in Wh/l,
•
Power density, gravimetrically in W/kg and volumetrically in W/l,
•
Service life, operating service life in cycles and calendar service life in years,
•
Environmental conditions or acceptable maximum and minimum temperatures in °C,
•
Safety expressed by a EUCAR level,
•
Costs in €/kWh,
•
Efficiency in percent.
Further criteria for the selection of the most suitable battery system are charging capacity,
voltage stability during discharge, the duration of a charging operation and degradation effects which lead to a reduction in calendar service life. In addition to fulfilling technical specifications, modern battery systems are expected to be capable of being produced in an environmentally-friendly way and allowing inexpensive and environmentally-friendly disposal. Linkage at an early point in time between product development and later battery recycling will allow the logical design of a sustainable and ecological battery technology. What is more, the development of processes for the reclamation of lithium and cobalt is of strategic importance for the safeguarding of suppliers of raw materials for battery production in Germany [Peters2012]. A comparison of the performance data listed above is useful in deriving the requirements which are to be placed on machinery and production equipment builders and on which the roadmapping process is based. It should, however, be noted that different priorities should be defined for electromobility and stationary applications.
Performance parameters for electromobility applications In the case of the electric bicycles and scooters already available on the mass market, the most important factors with regard to acceptance and cost-effectiveness are calendar service life, safety and investment and operating costs. HEVs are subject to stringent requirements regarding power density, service life and safety. The importance of lower costs will increase as market diffusion becomes more widespread. This trend can also be observed with PHEVs, however here the explicit emphasis is on volumetric energy and power density rather than calendar service life and safety. In the case of BEVs and small commercial vehicles, the emphasis is on energy density instead of power density. The various performance parameters
22 ROADMAP FOR BATTERY PRODUCTION EQUIPMENT
Cell manufacturer
Voltage
Weight
Volume
Energy density
Specific energy
V
kg
l
Wh/l
WH/kg
Firma
Modell
Pouch
3,75
0,80
0,40
309
155
Nissan
Leaf
36
Pouch
3,75
0,86
0,49
275
157
Renault
Zoe
52
Pouch
3,65
1,25
0,60
316
152
Daimler
Smart
50
Prismatic
3,7
1,70
0,85
218
109
Mitsubishi
i-MiEV
64
Prismatic
3,7
1,80
0,97
243
132
Fiat
500
16
Prismatic
3,25
0,45
0,23
226
116
Coda
EV
20
Prismatic
2,3
0,52
0,23
200
89
Honda
Fit
Tesla
Model S
Chemistry
Capacity
Anode/ Cathode
Ah
AESC
G/LMONCA
33
LG Chem
G/NMCLMO
Li-Tec
G/NMC
Li Energy Japan
G/LMONMC G/LMONMC G-LFP
Samsung Lishen Tianjin Toshiba
LTO-NMC
Panasonic
G/NCA
3,1
Form
Cylindrical
3,6
0,045
0,018
630
248
Used in:
Performance parameters of lithium ion battery cells used in commercially available BEVs, including cell chemistries [Andermann 2013].
can be considerably influenced by the choice of cell chemistry. The following cell chemistries are the most important ones for battery cells which are used in BEVs such as the Nissan Leaf, Tesla Model S and Renault Zoë (see table above): graphite anodes are in certain cases mixed with LMO or NMC and combined with cathodes made of NCA, LMO or NMC in prismatic or pouch cells. Lishen Tianjin battery cells have an LFP cathode, which results in a cell chemistry with low energy density, which is still installed today, particularly by Chinese companies, due to its safety advantages. Toshiba uses cells with an LTO anode and NMC cathode, which results in a lower specific energy density in comparison with other cell chemistries. The cylindrical 18650 battery cell from Panasonic uses an extremely low capacity cell design with a graphite anode and an NCA Cell manufacturer
Sanyo Samsung LEJ LG A123 AESC
Chemistry
Capacity
Anode/ cathode
Ah
NMC
22
Form
Prismatic
Voltage
Weight
Specific energy
V
kg
Wh/kg
3,68
0,73
112
NMCLMO
26
Prismatic
3,7
0,85
113
LFP
21
Prismatic
3,3
0,64
108
LMONMC
15
Pouch
3,7
0,38
148
LFP
20
Pouch
3,3
0,49
135
LMO-NCA
23
Pouch
3,75
0,57
151
Performance parameters for lithium ion cells installed in commercially-available PHEVs, including cell chemistries [Andermann 2013].
cathode. The difference is due to compromises made in favour of greater safety, reliability, service life and energy density and lower costs [Anderman2013]. The result is, however, also by far the highest energy density. For battery cells used in PHEV models such as the Chevy Volt, Toyota Prius PHEV and Mitsubishi Outlander PHEV, similar cell chemistries play a dominant role – notwithstanding that significantly lower capacity can be expected (see graphic on left). In the case of hybrid buses, there are stringent requirements regarding power density and costs. The reason for this latter requirement is that these buses are ordered in the main by public and private transportation companies and therefore need to be cost-effective both as investments and in operation. Coupled with this is a requirement for long service life and a high level of safety.
Performance parameters for stationary applications Even when dealing with individual segments of the stationary storage device market, such as large cyclically operated storage devices, it is important to know what specific application is concerned. It is generally assumed that the requirements regarding service life and costs will be stringent and will need to be studied in calculations of total cost of ownership throughout the service life of the product in question.
ROADMAP FOR BATTERY PRODUCTION EQUIPMENT 23 The objectives of the world's leading countries with regard to energy densities (Wh/kg) for large-sized LIB cells of the third battery generation (use in BEVs/PHEVs)
The objectives of the world's leading countries with regard to the costs (€/kWh) for large-sized LIB cells of the third battery generation (use in BEVs/PHEVs)
Energy density in Wh/kg
Cost in €/kWh
Japan (NEDO) South Korea (MKE) China (MOST/MIT) USA (DOE) Germany (BMBF/ISI)
In certain cases, different definitions of market maturity and quantities have been taken as a basis (e.g. differences such as prototypes with low volume and market launch/short production runs with high volume).
Target values based on roadmaps of governments and industrial associations worldwide [Thielmann2012b]
The level of investment and operating costs will be influenced very strongly by the way in which the requirements for long cycle life of energy storage device technologies are fulfilled. The efficiency of electrical energy storage systems is also an important factor.
Performance parameters of battery technologies which appear promising for the future Lithium high-energy and high voltage batteries are planned for use in electromobility applications in the medium and long term as an evolutionary further development of current lithium ion batteries. For the distant future the concept of lithium sulphur batteries can also be regarded as highly promising for the period after 2020 due to the high possible energy density of these batteries, particularly for BEVs. In addition to lithium-based batteries, however, fuel cell technology can also be considered as relevant to electromobility, in particular proton exchange membrane fuel cells (PEM-FC, hydrogen-based). Particularly for large vehicles and long working ranges, these cells offer good technological properties, fast tank filling and an easy means of providing air-conditioning for passenger cells.
An approach other than the further development of large-sized cells is being adopted by Tesla Motors Inc. with the use of conventional 18650 round cells in its electric vehicles. These cells are used, for example, in laptops and are already being produced in large quantities. Automakers can benefit in this way from the performance parameters already achieved (e.g. energy density) and economies of scale. In this case, the need for innovations shifts in particular to battery management systems and system integration. In the case of stationary applications, lithiumbased batteries are in competition in particular with lead acid, redox flow and sodium sulphur batteries with capacities in the kWh to MWh range (and possibly also the rechargeable zinc air batteries of the future). In addition to these electrochemical storage systems, mechanical energy storage technologies such as compressed air reservoirs may offer alternatives to lithium ion technology, particularly in the field of home solar systems Since the main emphasis regarding requirements is completely different in stationary application fields compared with electromobility, cell chemistries other than lithium ion technology are used, see the chapter "Beyond lithium ion technology“.
Developments which can be expected in central performance parameters A comparison of the roadmaps of different governments worldwide provides a good overview of the different philosophies which apply to individual technical parameters, such as energy density and costs. It can be seen that the USA has had very ambitious objectives even up to 2015, as reflected in the government's generally risk-loving attitude and promotional policy, which is based on research into and development of potentially disruptive technologies. While South Korea orientates itself
24 ROADMAP FOR BATTERY PRODUCTION EQUIPMENT
very closely to the target values specified by the Japanese NEDO, China intends to achieve more, particularly in the long term. The roadmaps published by the NDEO in 2006, 2008, 2010 and 2013 are at the centre of all published strategy documents and provide orientation for the entire battery community worldwide, due to, among other things, traditional reasons associated with Japan's role as the longstanding technological leader in electrical energy storage devices. The German roadmap for the NPE [NPE2010] adopts a significantly more conservative attitude (see graphic), with data stated for the system level. With regard to energy density, there has indeed been a gradual rise in recent years by approximately 10 to 15% to the present values of 150 160 Wh/kg at cell level and 110 - 120 Wh/kg at system level. While this evolutionary development will continue, lithium sulphur batteries could allow three times more energy density [Thielmann2012b]. Progress with regards to
Volumetric energy (Wh/l)
Gravimetric energy (Wh/kg)
Peak power (Wh/l)
Quality (failure rates in % as average per year over 10 years)
Safety (EUCAR level)
Costs > 250,000 Euros/year (Euro/kWh
Cold start power (W/kg) Service life (years)
The development of major parameters for a BEV from the point of view of the NPE om the point of view of the NPE[Peters2012]
service life and in particular numbers of cycles will decide if and when lithium sulphur battery technology will be ripe for market launch. The use of conventional 18650 consumer cells in electric vehicles in the case of Tesla Motors Inc. results even today in a significantly higher energy density of approximately 250 Wh/kg. The gap between the 160 Wh/kg of present-day large-sized lithium ion batteries and the 250 Wh/kg of consumer cells must be closed in order to allow future use of electric energy storage devices in electromobility applications. With regard to stationary applications, the emphasis is on other performance parameters. Here, even within the current generation of large-sized lithium ion batteries, there is great potential for improvement, since there are high losses at all points from the materials/components used through to the cells and fully developed systems [Köhler2013]. Given a continuous reduction of costs, lithium ion batteries could gradually replace lead acid batteries completely in home solar applications. The falling battery prices which can be expected, together with longer service life, should result in significant advantages for lithium ion batteries over their total life cycle [Schlick2011].
ROADMAP FOR BATTERY PRODUCTION EQUIPMENT 25
The requirements placed on battery manufacturers While we were able to obtain product requirements, and the performance parameters derived from these, for high-energy and high-capacity applications from existing sources and incorporate these into the roadmapping process, we were not able to obtain battery manufacturers' specifications. We have therefore incorporated the battery manufacturers into the roadmapping process and, in this way, compiled a list of the requirements placed on machinery and production equipment builders. The highest priorities are for the following areas: The requirements placed by battery manufacturers on machine builders are based first and foremost on the objective of achieving a significant reduction in the costs of lithium ion batteries. The aim is to increase the degree of automation, exploit economies of scale and avoid rejects. At the same time, the field of stationary and electromobility applications demands high quality standards. In view of this, stable processes are essential if quantities to be increased. Continuous process operation in a mixed process would save time and money. It is, however, first necessary to develop better concepts for changes to processes. High-quality slurry must also be ensured for the purposes of continuous process operation. As regards the coating process, the aim is to increase speed from the current value of 30 m/min. to 70 to 100 m/min. A further increase in output can be obtained by implementing simultaneous double-sided coating. There must be no loss of quality as the result of either a speed increase or simultaneous doublesided coating. The stacking process is regarded as one of the most time-critical steps in the process chain. Here, the use of reliable grippers which operate
cleanly, quickly and gently should make it possible to achieve a stacking speed of one second per sheet. As regards filling with electrolyte, the crucial factor is good wetting of the surface. This must be achieved in future even with higher filling speeds. There is considerable potential in the formation and ageing process for saving time and money. The target is formation times of two hours instead of 24 hours and a significant reduction in the ageing time, which currently takes several weeks. It is vitally important here to avoid affecting service life and quality adversely. For customers, a further crucial factor is to be able to predict service life correctly both at cell level and system level. The obstacle to be overcome here is the reduction of reject rates by using non-destructive test methods while simultaneously reducing the test duration. In addition to increasing process speeds, customers have other wishes, aimed at reducing costs. One of these wishes is concerned with larger cells, together with an increased level of standardisation of interfaces. Further advantages can be achieved by reducing drying rooms to mini environments. In the medium term, battery manufacturers expect that machines and production equipment can also be adapted to changes in the materials used to manufacture products. It would be conceivable to use plastic housings instead of aluminium. With all processes, it is important to take into account the recycling factor. It is possible to save money here if cells are designed right from the start for recycling ("design for recyclability"). In this way, the recycling of the raw materials used can generate a financial return even at an early stage.
26 ROADMAP FOR BATTERY PRODUCTION EQUIPMENT
The general wish of manufacturers is that stable processes should make quality checks superfluous. Furthermore, for a higher degree of automation, it is important to guarantee fail-safe operation. Only under these conditions is it meaningful to fully interlink the individual process steps. In order to meet this customer wish, it is first necessary to achieve an adequate understanding of the processes. By no means all the parameters are known which may have an effect on the quality of the end product. It is thus all the more important to get to grips with known process-critical parameters. For the separation process, this means dealing successfully with the particle contamination which can impair quality. It is also necessary to avoid leakages during the cell sealing process.
Supplier of cell production equipment
Process steps
Machine and plant manufacturer
Experts
High Potentials
Supplier of module and pack assembly equipment
Process steps
Machine and plant manufacturer
Experts
High Potentials
Competencies of the German suppliers of production technology for lithium ion batteries. Particularly in cell manufacturing, the structure of the value chain is heavily sub-divided. Source: Heimes, PEM of RWTH Aachen.
Solutions offered by machinery and production equipment builders today The disruptive change from conventional to electrified drive trains [Kampker2014] is creating attractive opportunities in the newly-emerging electromobility market. Growing markets are also expected for stationary energy storage devices, due among other things to changes in energy sources. In addition to battery manufacturers, a number of machinery and production equipment builders are attempting to gain a share of the value creation process in these new markets. The industry is focusing on the most promising battery technology, lithium ion technology. By providing intelligent production technology, machinery and production equipment industry is offering a major tool with which to achieve urgently-needed cost reductions. German players offer solutions for all points along the process chain. Competencies in the industry cover a broad front, the main distinction being between cell production on the one hand and module and pack assembly on the other. Particularly in the case of module production, individual German companies are already offering complete solutions. A few of them have even succeeded in winning out against established process technologies with new solutions. In cell production, on the other hand, there is a heavily sub-divided value creation structure. Experience from related industries, such as the semiconductor and photovoltaic industries and automobile production, and also the food and packaging industries [Schlick2011], is already being successfully applied in both areas. The solid foundation of the German industry and the future prospects in the automation industry (Industry 4.01) provide German companies with an excellent starting point.
1
The next step in automation technology, under the heading "Industry 4.0", is being actively driven forward, particularly by German companies. Production operations increasingly
Mixing principle
Intensive mixer
Classic mixer
Tempering
With air conditiong system
Without air conditioning system
Chargierung Batch system
Continuous
Discontinuous
Atmosphäre Atmosphere
Vaccuum
Shielding gas
Normal atmosphere
Auftragswerkzeug Application tool
Commabar
Slot nizzle
Roller application
Bahnlage Track position
Longitudial
Transverse
Beschichtungsart Type of coating
Laser
Z-folding (two sided)
Individual
Contactless (ultrasound) Laser welding
Friction welding
Kühlen Cooling
Cooling roller
Colling zone Charge dissipation
Number of rollerpairs
1
2
Line pressure
300 kN
500 kN
Track widths Bahnbreite
300 mm
500 mm
Cast iron
Chromed steel
chromed
Trockenraum Drying room
Installed
Not installed
Slitting Slitting
Blade
Laser beam
Pulse joining
Ultrasound welding
Deep drawn foil
Folded foil
Foil bag
Cleaning of joints
Chlorine
Laser
None
Type of olive
Ohne
Tempering
Formation
Cleaning
Filling
Long
Vacuum Induction roller plating
Layering method
Pulse sealing
Filling technology
Short
None
Wedge
Z-folding (one sided)
HeatedmetauscherFoil seal
Fresh air
Edges
Stamping
Layering method Gripper technology
Packing
Circulating air
Surface
Cutting principle
Welding
Overall length Gesamtlänge
Walzenmaterial Roller material
Cleaning
Separating Stacking
Floating Double sided
Degas sing
Erwärmungsprinzip Heating principle
Suction jet dryer
Single sided
Ageing
Drying
Roller conveyor
Verfahrensart Type of process
Pre-treatment
Calendaring
Shielding gas
Atmosphäre Atmosphere
Type of conveyor Bahnführung
Morphological chart of battery production
Strips
Normal atmosphere
Monitoring
Coating
Mixing
ROADMAP FOR BATTERY PRODUCTION EQUIPMENT 27
Contact sealing
Injection Narrow
Hot sealing Cell stack insertion
Wide
Fan nozzle
Metering method
Fixed quantity
Metering pump
Position of cells
Horizontal
Vertical
Contact making
Connection to cell
Cell to connection
Type of contact
Gripper
Spring contact pins
Damage allowed
Yes
Feedback
Cell to cell
No To network
None
Current intensity
25 A
50 A
Connection of cells
Individual circuits
Cell dropout system
Process temperature
Low
Piercing principle
Laser
Needle
Rolling of cells
With
Without
Position of cells Storage zone temperature
High
Horizontal High
Vertical Low
Time-variable
Ageing period
Two weeks
Four weeks
Weight measurement
Comparative measurement
Absolute measurement
Dimensions
Coordinate measuring device
Gauges
Density measurement
Gas outflow
Weight differences
Capacitance measurement
High current discharge
Laser measurement Pressure differences Standard current discharge
Morphological chart for battery production. Numerous technological alternatives are available today for each individual process step. Source: PEM of RWTH Aachen
Asian players have a lead in experience over German companies thanks to the fact that they have for many years equipped factories producing consumer batteries. They are currently dominant as providers of production equipment. However, the requirements for the production of large-sized the batteries are also a challenge for these players. Accordingly, German suppliers of production equipment have a realistic opportunity of catching up the Asian lead [Schlick2011]. Lithium ion battery cells are of special importance in view of their major influence on the cost of complete systems [Kampker2013a]. It is therefore on these that the world is focusing with regard to production technology. By drawing on the existing competencies gained in other industries, German machinery and production equipment builders are also in a position to make a valuable contribution within the production process for lithium ion battery cells. The investment costs for battery cells are due to the sub-divided value creation structure in the machinery and production equipment industry [Kampker2012a]. An analysis of more than 200 national and international machinery and production equipment builders has shown that, within cell production, these companies focus on selected sub-process steps according to their existing competencies. This means a challenge when it comes to the formation of technology chains. This is made more difficult by the large control themselves through a network of machines and workpieces. For further information, see http://www.plattform-i40.de
number of interfaces. German machinery and production equipment builders will, however, be able to master this challenge through close corporation and will be able to offer holistic solutions. The heterogeneous competency profile of machinery and production equipment builders has led to a wide bandwidth of alternative solutions or technical implementations (e.g. single-sheet stacking or Z folding, ultrasound welding or laser welding, stamping or laser cutting) [Kampker2013c]. It is a characteristic feature of cell production that reference needs to be made to a variety of technological production processes. These include not only coating and cutting but also shaping, joining and the modification of materials characteristics. As a result, cell manufacturers have a variety of solutions at their disposal which can be implemented in various production resources. This is both a blessing and a curse. For manufacturers, the selection of processes for a complete line is very complex. Each of these alternative solutions is, however, characterised by individual advantages. A study showed that it was possible to identify over 100 alternative production resources in the area of cell production and classify these in the morphological charts shown above [Kampker2012c].
28 ROADMAP FOR BATTERY PRODUCTION EQUIPMENT
Production resources vary in terms of their performance characteristics (time, costs, quality, flexibility and degree of maturity). Cell manufacturers therefore need to take the performance characteristics of an overall process into account when selecting production resources. In addition to this, so manufacturers must ensure that the selected production resources are able both to deliver the required product characteristics (e.g. the required layer thickness) and also to harmonise together in a process chain [Kampker2013b]. The selection of alternative production resources is thus particularly important within the production planning for lithium ion battery cells. The preceding description of the present situation shows clearly that it will be possible to offer a holistic technologically harmonised production concept at the present time only by drawing on the products offered by a number of different companies. A core challenge for cell manufacturers is thus to integrate different production resources to form a single overall process. "Operators of production facilities for lithium ion cells are thus confronted with the challenge of identifying a suitable machinery and production equipment builders for each process step." [Kampker2013c] Our task is to change this situation by deploying existing and newly-developed know-how in the field of battery production equipment in a targeted way and further developing this.
Where technological breakthroughs are required in the future – red brick walls in detail In the following, the 15 identified red brick walls are discussed in detail on the basis of milestone charts adapted for our purposes.
Visualisation in a milestone chart As described in the introduction, we use milestone charts with parallel "routes" to visualise and analyse forecast technological development paths. The green route contains critical system parameters for the battery and symbolises the requirements of the battery manufacturers. The yellow route represents production technology and stands for the solutions offered by machinery and production equipment builders. Finally, the red route represents battery production research. The milestone charts show the networking of the individual routes. From top to bottom, requirements are formulated, while from bottom to top solutions are shown. The charts which follow show only battery manufacturer requirements for which no production solutions as yet exist – by definition, these are the red brick walls. In the interests of clarity, a milestone chart has been produced for each red brick wall. In view of the fact that the discussion did not reveal any short-term red brick walls (time horizon 2015); we have limited ourselves to medium- to long-term time horizons. The present state of the art in production technology for volume production has been discussed in the preceding check and is the starting point "Today" in the milestone chart1.
1
In the roadmapping workshops, 2012 was defined as "today". Here, we have taken as a basis the situation which developed in the course of the roadmapping process 2011 – 2013.
ROADMAP FOR BATTERY PRODUCTION EQUIPMENT 29
Target system
RBW 1: Mixing – Continuous process operation
Time
The development of a continuous mixer will increase the degree of automation in the process. Changes in the mixing ratio of active and passive material will be necessary. Quality
Requirements of manufacturer
Continuous mixing process
Batch by batch mixing
Engineering solutions
Industrial continuous mixing
Continuous mixing in laboratory operation
Alternative mixers
R&D programs
Water-based solvents Reduced binder content
Today Key:
Costs
State of the art
Extruders
2020 Research projects
2025 Pilot facilities, demonstrators
Four symbols are used to represent the milestones in the development path. The circle represents the process technology currently used. The hexagon stands for the need for research or research properties. The rectangles with rounded corners represent pilot production lines or demonstrated approaches to solutions, while technologies suitable for mass production are identified by a rectangle with sharp corners1.
Potential for improvement in the target system The milestone chart is supplemented by a graphic showing the potential for improvement for volume production which would result from overcoming the red brick wall2. This is a simplified representation of the assessment criteria by which each process technology was measured in the roadmapping workshop. In this present roadmap, we have limited ourselves to three categories which cover the target system. "Time" designates an increase in process speed, i.e. a faster throughput time. "Quality" stands for an improvement of the product, e.g. the performance parameters or the service life of batteries, or a reduction in the reject rate. "Costs" represent investment and/or operating costs.
1
2
Graphic: Design RWTH Aachen based on [Phaal2003b].
Improvement of process steps – in the case of overarching topics, improvement of an entire production phase.
2030 Technology suitable for volume production
RBW 1 Mixing: Continuous process operation Challenges and basic principles Mixing is the first process step in battery production, and in this step active material, carbon, binder, solvents and additives are used to produce a slurry. The input of energy, the process temperature and also the order in which active and passive materials are added (dry mixing, wet mixing) considerably influence the characteristics of the slurry. The challenges on the process side are to avoid air enclosures and to ensure consistent physical properties across the individual fractions. The viscometry in particular, to which the subsequent coating process is matched, must be kept constant. Above and beyond this, it is crucial to avoid the formation of agglomerates and to ensure that further processing of the slurry takes place immediately, in order to avoid sedimentation effects. After as little as an hour, de-mixing of the binder and the rest of the slurry can occur. Currentlyused mixing technologies operate with batch production. These include planetary mixing systems and single- or multi-shaft mixing systems with and without vacuum extraction. The aim is to develop a continuous mixing process in the laboratory by 2020 and to be able by 2030 to offer machine solutions for stable large-scale production.
30 ROADMAP FOR BATTERY PRODUCTION EQUIPMENT
Continuous process operation, which has already been practised in other industries for many years, allows a significantly higher degree of automation of the process. It makes it possible to significantly reduce costs, since the throughput time is reduced, the need for human labour is reduced and susceptibility to faults is minimised. Moreover, with this type of process operation, it is possible to produce slurry in accordance with the needs of the downstream processes and feed this in an ideal way directly to the coating machine. This allows the occurrence of inhomogeneities due to long waiting times to be avoided. At the present time, the quality losses with regard resulting from a changeover of the mixing principle are too high. What is more, the required engineering work for continuous process operation is considerably more complex. Any necessary interventions and corrections can be made only at the end of the process. In continuous operation, the demands on the instrumentation and control equipment to be used are therefore higher. There is a need for research so that continuous mixing technologies for battery operation with consistent slurry quality can be developed. Possible solutions The requirements for a continuous mixer are based on the current mixing process. This means that allowance must be made for developments directly in the mixing process. In order to increase the power density of the electrodes, it is an attractive idea to reduce the use of passive materials, in particular binder (generally polyvinylidene fluoride, or PVDF). It would also be desirable to replace the use of the toxic and explosive solvent n-methyl pyrrolidone (NMP) by cheaper water-based solutions. Research efforts are also being driven by the current discussion of a possible general ban of NMP as a solvent. This may become even more necessary, since NMP appears on the ECHA list of materials giving particular cause for concern. It is therefore possible that a general ban on use may be imposed through the REACH decree [ECHA2014].
However, even without a ban on use, there are incentives to change to water-based systems. The use of these is not only cheaper but also speeds up the drying time, as they evaporate more quickly (see also RBW 12) [Guerfi2007]. It will also be necessary to develop valid highspeed tests for the slurry. At the present time, it is possible to detect incorrect parameter settings only later in the process chain. With batch-bybatch mixing operation, this would lead to a discrete quantity of reject material. Incorrect parameter settings must be regarded significantly more critically in a continuous mixing process. It has already been possible to achieve progress in the production of anodes. It is possible here to significantly reduce the proportion of binder by adding a fluid. The exploitation of capillary effects allows the adhesion properties of the slurry on the collector foil to be improved. The fluid evaporates completely during the drying process [Bitsch2014]. In the Asian region, the use of a water-based solvent is already the state of the art. On the cathode side, it is more difficult to implement the use of water-based solvents, since the lithium which is present must be prevented from reacting with the water [Mossbauer2010]. For the production of lithium ion phosphate batteries (LFP), progress has already been achieved by using a water-soluble elastomer as a binder. No solutions are as yet available for the further permutations of lithium ion batteries (NMC, NCA). Research in this area is focusing primarily on materials. Since this work in the main involves internal company developments and patented applications, machinery and production equipment builders have only limited information available. In order to ensure the necessary quality and reproducibility for a water-based electrode production process using production technology relevant to industrial needs, it is necessary to design production equipment technology and processes specifically for the use of water as a solvent.
ROADMAP FOR BATTERY PRODUCTION EQUIPMENT 31
Target system
RBW 2: Coating – Increasing speed and width
Time
It will be possible to increase production throughput by a step-by-step increase in belt speed to 100 m/min and by increasing the width of the foil to 2 m. Process must be maintained after every increase. Quality
Requirements of manufacturer
Costs Coating 100m/min 2m width
Coating 70-100m/min 1,3m width
Coating 30m/min 0,6m width
Engineering solutions
Coating 30m/min 1,3m width
R&D programs
Coating 70-100m/min 1,3m width
Laser drying
Coating 70-100m/min 2m width
Coating 70-100m/min 2m width
New coating technologies Production of a foil wider than 2m
Today Key:
State of the art
2020 Research projects
2025 Pilot facilities, demonstrators
A complete abandonment of solvents would further reduce costs and make the subsequent drying process, and possibly the calendaring process, obsolete. It will be possible to use a mixer based on the functional principle of an extruder for this purpose. Due to the physical working principle of an extruder, it would seem possible in general to dispense with the use of solvents. There has, however, as yet been no concrete expression of this development direction.
RBW 2 Coating: Increasing speed and width Challenges and basic principles During the coating process, the slurry is applied either continuously or intermittently to a substrate for made of copper (for the anode) or aluminium (for the cathode) using an applicator system and to a thickness of 50 - 300 µm, depending on the cell type and variant. Among the coating technologies used are slot nozzles, comma wipers and gridded rollers, with slot nozzles offering the greatest advantages. Present-day coating machines operate at a speed of 30 m/min. and a width of approximately 0.6 m. The critical factors for quality are precise metering of the slurry in the applicator tool and an even coating thickness across the width of the foil. An uneven coating thickness will lead to differing line pressures in the calendaring process. These will in turn lead to
2030 Technology suitable for volume production
differences in the porosity of the material and thus to a loss of quality. Projecting edges can produce the same effect in intermediate operation. Edge sharpness is a further quality criterion. Moreover, a crucial factor for cyclical service life and subsequent battery performance is the adhesion of the coating to the substrate foil. In order to exploit economies of scale and meet rising demand, future coating machines in the period up to 2030 must be capable of stable operation in the order of magnitude of 100 m/min across a width of 2 m. At the same time, it must be ensured that the increase in width and conveyor belt speed is not at the expense of electrode quality. Possible solutions An initial pilot production lines with a slot nozzle operates at a speed of 30 m/min. over a doubled width of 1.2 m. However, it is not yet possible to guarantee stability of the even lateral distribution of the coating thickness. Only when this has been achieved by adapting process parameters will it then be possible to increase the speed. An increase in speed would have a direct effect on the length of the drying machine, since the two processes are directly coupled. New drying technologies such as laser drying deliver faster results than conventional machines. However, it remains to be determined to what extent the new drying technologies will influence coating
32 ROADMAP FOR BATTERY PRODUCTION EQUIPMENT
Target system
RBW 3: Coating – Double-sided and simultaneous A double-sided, simultaneous coating system halves the throughput time compared with serially operating machines. There are further positive effects on the subsequent drying process, through only one pass is required. Requirements of manufacturer Serial coating and drying
New coating systems
R&D programs
New job tools
Pilot facility for double-sided coating and drying
Non-contact drying
Extruder
2020 Research projects
2025 Pilot facilities, demonstrators
compositions (keyword "de-mixing") and surface quality. An increase in width from 1.2 to 2.0 m using a slot nozzle as an applicator system should be regarded as critical. The formation of a meniscus is necessary for the application process. It should be determined whether it is possible to coat across a width of 2.0 m with existing nozzle systems or whether this technology is at its limit even with a lesser width. It is necessary to develop new coating systems. The following coating methods have already been considered but had to be rejected: sputtering, CVD coating, evaporation, ink-jet printing and powder coating. The coating thicknesses produced are in this case in the nanometre range and are thus too
[m/min] 100
[m] 2,0
Speed
70
1,2
Coating width
30 Status quo
2020
Costs
Industrial double-sided process line
Today State of the art
Quality
Double-sided coating and drying simultaneously
Engineering solutions
Key:
Time
2025
0,6 2030
Development in speed and width of collector foil in the coating process. Source: PEM of RWTH Aachen
2030 Technology suitable for volume production
thin to store the necessary energy density. Depending on the application, a coating thickness of 200 µm is applied to the cathode of foil. The graphic at bottom left illustrates the development in the speed and width of the collector foil in the coating process. In order to increase width, it is necessary to adapt the relevant substrate foils. It is currently not possible to produce 10 - 20 µm thick foils with a width of 2.0 m in an adequate quality. Here, too, appropriate development is required.
RBW 3 Coating: Double-sided and simultaneous Challenges and basic principles A double-sided simultaneous coating machine would halve throughput time compared with serially-operating machines. There are further positive effects on the subsequent drying process, through which only one pass is required. In this process, one electrode side passes through the drying process twice. With simultaneous double-sided coating, there is no second pass, resulting in time and cost advantages. A suitable coating machine should be ready for market launch by 2020. In addition to the existing challenges presented by the coating process, such as achieving even lateral distribution of the slurry (see RBW 2), it is
ROADMAP FOR BATTERY PRODUCTION EQUIPMENT 33
RBW 4: Separation – Contamination in process step
Target system Time
The particle contamination resulting from the separation process may cause short-circuits in the cells. The particle size varies, depending on the separation technology used. Quality
Requirements of manufacturer
Costs
No damaging particle contamination
Stamping
Engineering solutions
Integration of quality assurance into process
Laser cutting
Extraction of particles (silver technology)
R&D programs
Particle detection Further development of existing technology
Pilot plants for new separation technologies
Today Key:
Avoidance of particles, with detection if necessary
State of the art
2020 Research projects
2025 Pilot facilities, demonstrators
also necessary to avoid running of the slurry after application due to the effect of gravity. Possible solutions In order to implement double-sided simultaneous coating, there must be developments in various areas. New coating machines will require an alternative routing of the foil in order to prevent running of the slurry. It would also be possible to introduce innovative applicator systems which are designed for double-sided coating and can operate independently of the effects of gravity. The drying technology must also be changed to allow double-sided simultaneous operation. One possible solution is contactless drying machines. Floating dryers are a commonly-use system for contactless drying. With this solution, the foil floats over air cushions in a sinusoidal shape created by air cushions. It will be necessary to identify a suitable design, providing nondamaging floating and drying characteristics, in order to meet the high quality requirements of electrode coating. Slurries which are able to operate without solvent cannot run, which has a positive effect on the development of simultaneous doublesided coating. Possible solutions include the extruder already described in connection with RBW 1 or a form of powder pressing. There have as yet been no concrete implementations. An
2030 Technology suitable for volume production
Asian machinery and production equipment builders has already shown a double-sided coating machine at a trade fair. It was not possible to determine whether this machine meets quality requirements and is suitable for industrial operation.
RBW 4 Separation: Contamination in process step Challenges and basic principles During separation, the electrode coils are cut into sheets. A critical quality factor is particle contamination of the sheets resulting from the cut, which may damage the separator and lead to a short-circuit. The objective is to stabilise the process sufficiently by 2030 so that qualitydamaging particle contamination is avoided. The state of the art is represented by two separation technologies – stamping and laser cutting. In the case of stamping, the quality of the cut edges depends on tool wear. The quality of the cut edges decreases over time, which means that particle contamination increases. In the case of laser cutting, the tool does not wear and no change in quality therefore takes place. Furthermore, changing the geometry involves only low additional cost [Kronthaler2012].
34 ROADMAP FOR BATTERY PRODUCTION EQUIPMENT
Target system
RBW 5: Stacking – Increasing speed
Time
The stacking process is a bottleneck in foil cell production, due to the lower speeds involved. The process involves a trade-off between speed, positioning accuracy, cleanliness and gentle material handling. Quality
Requirements of manufacturer
Costs
Stacking operation
