Electric Vehicle Technology

Strategies in Cell Chemistry & Recycling

What Drives Battery Development in Germany

9 min
Electromobility reaches the next stage of maturity - with advances in cell chemistry, 800V technology, thermal management, and battery recycling. New standards and circular economy are increasingly coming into focus for the industry. But that's not all.

Battery technology is entering a new era: In the strategies of German players, topics such as higher energy density, 800V, battery recycling, re-use, and data passports dominate. What are the next steps? Find the answers here.

Electromobility is reaching a new level of maturity, driven by fundamental advances in battery technology and the increasing importance of a well-thought-out circular economy.  Ahead of the upcoming Automotive Battery Conference on July 9–10 in Munich, leading industry experts share insights into the current developments in Germany’s battery sector.

Cell Chemistry and Charging Performance: BMW's Gen6 

An outstanding example of current technological progress is provided by the BMW Group with the sixth generation of its eDrive technology (GEN6). According to Dr. Juliane Kluge, Head of Cell Chemistry and Methods at the Battery Cell Competence Centre (BCCC) of the BMW Group, this marks a "technological leap forward". The large-scale production of the cylindrical BMW Gen6 cells, starting in 2025, will enable "up to 30 percent faster charging speed and around 30 percent more range," according to their information. Even greater increases are possible depending on the model.

Battery Circular Economy at a Glance

What is circular economy in batteries - and why is it essential?

Instead of fossil single-use resources, electromobility relies on the management of valuable technical materials. Recycling, second-life strategies, and the digital battery passport reduce the ecological footprint and ensure raw material availability.

What challenges exist in recycling high-voltage batteries?

Non-uniform cell and pack architectures cause high manual disassembly costs. Automation, standardized interfaces, and design-for-disassembly are key levers for greater efficiency.

How does modern battery thermal management work?

Multifunctional cooling structures made of aluminium or fibreglass ensure safe cell temperature control and structural stability. They combine low weight with high performance and enable compact pack-to-chassis designs.

What is special about BMW's Gen6 battery technology?

The sixth eDrive generation uses cylindrical cells, 800V architecture, and cell-to-pack integration. It offers more range, shorter charging times, and significant cost reduction - with higher sustainability and scalability.

How is Europe preparing for the recycling future?

In the short term, battery returns mainly come from production, but from 2030, end-of-life volumes will increase significantly. Investments in large hydrometallurgical plants, digital twins, and second-life markets are considered strategically necessary.

Pack-to-open-Body and 800-Volt Technology: Rethinking Vehicle Integration

A key element of this technology is the new cylindrical cells, which have a 20 percent higher energy density compared to the prismatic battery cells of the previous generation (Gen5). Integration is carried out via a cell-to-pack process, where the cylindrical cells are directly integrated into the high-voltage battery.

Dr. Juliane Kluge, BMW Group: "The new Gen6 cell enables up to 30 percent more range and charging speed."

The Gen6 high-voltage batteries also feature a flatter design, allowing flexible integration into various vehicle models. A significant structural innovation is that the high-voltage battery in the bodies of the New Class takes on the role of a structural component - a concept referred to as pack-to-open-body.

Charging Efficiency and Control: 800V Technology and BMW Energy Master

Another highlight is the introduction of the new 800-volt technology from this year in the New Class, which will drive the fully electric product portfolio of the BMW Group in the future. This architecture also enables bidirectional charging.

The control of all these complex functions and energy systems is managed by the BMW Energy Master - the hardware and software system developed in-house by the BMW Group sits on the high-voltage battery and acts as a central interface for high and low-voltage power supply as well as for battery data. The Energy Master also controls the power supply of the E-machine and the onboard network and is intended to ensure safe and intelligent operation of the high-voltage battery.

Parallel to technological development, BMW is also addressing costs. Through comprehensive in-house expertise, the team from development, production, and procurement was able to significantly reduce the costs for the Gen6 high-voltage storage, with an expected reduction of 40 to 50 percent compared to the current Gen5 high-voltage storage with comparable e-range.

Maximilian Schirp, ivilion GmbH: "Our multifunctional cooling structures are particularly well-suited for a pack-to-chassis approach."

The global production strategy 'local for local' envisages the assembly of Gen6 high-voltage batteries in five nearby production sites (Lower Bavaria, Hungary, China, Mexico, and USA) to ensure stable production. BMW has awarded contracts worth billions of euros to cell manufacturers for this purpose. The entire external electricity demand worldwide is sourced from renewable sources, and the use of green electricity has also been contractually agreed with many suppliers.

Structural Cooling by ivilion as Key Technology

In addition to cell chemistry and pack integration, battery thermal management and battery pack structure play a crucial role in performance, safety, and lifespan. Maximilian Schirp, CTO & co-founder of ivilion, explains his company's focus on these areas: ivilion develops multifunctional cooling structures that temper the cells and are also mechanically load-bearing. In doing so, ivilion uses standard solutions for the battery management system (BMS) and focuses on topics such as thermal runaway on examining the properties of their structures as a thermal barrier.

Construction of a battery pack - from cell structure to integration to the complete multifunctional battery package.

Materials and Cooling: Aluminium, GRP and Water-Glycol Compared

The cooling structures can be made from both glass fibre reinforced plastic and aluminium, with aluminium requiring an electrically insulating cell wrapping. In both cases, indirect cooling with water/glycol as the cooling fluid is used. Compared to dielectric fluids, water/glycol has better properties in terms of thermal conductivity, heat capacity, and viscosity, although, according to Schirp, a dielectric fluid could be used for special safety requirements (e.g., to prevent short circuits in case of leaks).

Due to the functional integration of structure and thermal management, this concept is, according to model calculations, more cost-effective than existing solutions. In terms of weight and cooling performance (thermal resistance), it is at least on par with immersion cooling solutions. “The solution is particularly well-suited for a pack-to-chassis approach,” emphasises Maximilian Schirp. “This brings additional weight advantages; there is no tipping point in terms of cost/weight.” However, ivilion identified a disadvantage in the higher pressure loss with the same mass flow compared to immersion cooling.

Circular Economy in the Battery Industry

Tilmann Vahle, Quantis Germany: "The management of technical materials replaces the one-time burning of fossil fuels."

The transformation to electromobility equally leads to more circular economy. As Tilmann Vahle, Head of Consulting for Chemicals and Industrial Markets, Quantis Germany, explains, the - always unique - burning of fossil fuels is replaced by the management of technical materials: A typical petrol car burns about 12,000 litres of fuel over 200,000 km - equivalent to around 28 tonnes of CO₂ emissions. An electric car, on the other hand, uses electricity, which is about three times more efficiently converted in the drive - and in countries like Germany, this already comes from renewable sources by over 50 percent (as of 2023). Even today, electric cars are therefore in any case more environmentally friendly; depending on the electricity mix, even up to 80 percent.

At the same time, the footprint of the materials used increases, particularly due to the approximately 50 kilograms of battery materials per electric vehicle. The high-quality closure of material cycles thus gains significantly greater relevance, both from an economic perspective and for the benefit of maintaining a human-friendly climate.

This is not only a strategic goal of the BMW Group, which pursues a closed-loop approach for cobalt, nickel, and lithium and aims to establish this in China, Europe (partner SK tes), and by 2026 also in North America, but also a regulatory necessity driven by the EU Battery Regulation (2024) and the expected ELV revision (from 2025).

Scalable Recycling Processes: Business Models, Start-ups, and Second Life

For recycling, used batteries are mechanically shredded, and the valuable materials are recovered through hydrometallurgy. Dr. Matthias Ballweg, co-founder of Circular Republic, part of UnternehmerTUM, emphasizes the importance of scalable business models in this area. He mentions the re-use of parts, which is already being profitably demonstrated (e.g., "The Future Is Neutral" in France), and the hydrometallurgical recycling of battery material (e.g., start-ups Cylib and Tozero).

Dr. Matthias Ballweg, Circular Republic: "Re-use of parts is already being profitably demonstrated - for example, at 'The Future Is Neutral' in France."

A particular focus is on the automated dismantling of vehicles. Currently, dismantling for recycling and reuse is mostly done manually, which limits value creation. According to Ballweg, there is enormous potential for Germany to take on a global leadership role.

A central instrument for the circular economy is the digital battery passport, which will become mandatory from February 2027 according to the EU Battery Regulation. Experts like Tilmann Vahle, who leads the work of the LCA specialist Quantis Germany in the field of chemicals and industrial sector, and Dr. Matthias Ballweg emphasize the importance of structuring its datasets (including cell chemistry, module topology, safety disconnects) so that recyclers can automatically recognize and dismantle heterogeneous pack architectures.

For closed loops, three aspects are particularly crucial:

  • A clean and validated calculation of the CO2 footprint, enabling producers to reliably credit the CO2 advantage of using used or recycled material over new material.
  • A usage footprint for relevant used parts to determine the relevance of residual value retention.
  • For recyclable material, both the disassembly information and the upstream material footprint (relevant for disclosure obligations under chemical regulations such as REACH).

Challenges in Battery Recycling: Architectures, Costs, and Volume

Dr. Dominik Lembke, Chief Business Development Officer of Librec AG, highlights the challenges and opportunities in the recycling of high-voltage batteries. He assumes that before 2030, the quantities of battery material for recycling plants will mainly come from production scrap from gigafactories. From around 2030, these quantities will be surpassed by the significantly increasing return of end-of-life (EOL) batteries from the field (0.8 to 1.3 million per year, based on Germany).

Dr. Dominik Lembke, Librec: "The requirements for traction batteries leave little room to prioritise recycling aspects."

It is already commercially viable to operate recycling plants, as the quantities from production waste are significant, and numerous batteries need to be recycled due to defects or accidents before reaching the EOL. The production of black mass, the first process step in recycling, can be scaled down and is already profitable today. It is different with hydrometallurgical refineries, where economy-of-scale effects play a much larger role due to process technology and energy intensity. Here, it is worthwhile to build fewer but larger plants. According to Dr. Dominik Lembke, the question is how many of these can be operated profitably in Europe in the medium term - also in competition with existing large plants in Asia. In the long term, however, the development of the corresponding infrastructure in Europe (including pCAM and CAM production) is indispensable to close the material cycle. 

An important addition on the way to a sustainable battery value chain is second-life programmes. Establishing these is currently more determined by the demand for second-life storage systems than by the availability of suitable battery material, experts like Lembke are convinced. Currently, there are enough battery modules to meet the demand for second-life products.

Design-for-Disassembly and Digitalisation 

An important challenge in recycling is the still existing proliferation of cell, module, and pack architectures, which causes high manual dismantling costs. While cell-to-pack and cell-to-chassis concepts save mass and costs in production, they massively drive up decommissioning costs at the end of life. 

So where are the biggest levers to reduce the typical 30 percent dismantling costs per kilowatt hour to under ten percent? Experts discuss design-for-disassembly standards, robot-assisted disassembly, and chemical-thermal shortcut processes. Cylib is already working on a semi-automated human-robot cell for unloading and disassembling HV traction batteries. 

From the perspective of Dr. Lembke, who spent ten years in battery product development at OEMs and cell manufacturers before his role at Librec, the requirements for traction batteries (safety, weight, performance, lifespan, costs) are very extensive and leave little room to prioritise recycling aspects. He argues that product performance should not be sacrificed for disassemblability. Instead of relying on standardised connectors or robot-friendly pack designs - which he believes will only come if they serve production - he sees the biggest lever in making the digital twins already developed for assembly ("reverse assembly instructions") accessible to battery recyclers. This could ease the work for recyclers like Librec, who can quickly and cost-effectively dismantle packs of any design. 

Digital Tools for Dismantling: Battery Passport as a Disassembly Booster

Matthias Breidenbach, Cylib: "For efficient robot-assisted disassembly, the digital battery passport should provide comprehensive data."

The spin-off from RWTH Aachen, Cylib, founded in 2022 in Aachen, is already working on a semi-automated human-robot cell for unloading and dismantling HV traction batteries. Matthias Breidenbach, Head of Business Development at the Bosch-supported company, describes how the future digital battery passport must be structured so that robots can 'blindly' recognise heterogeneous pack architectures from classic module stacks to cell-to-chassis frames and dismantle them in one-minute cycle times: 'For efficient robot-assisted disassembly, the digital battery passport should provide comprehensive data: state of charge, cell-specific state of health, and relevant error codes. Precise information on connection elements (position, type, torque), component dimensions, and cooling system details are crucial. The integration of recycling companies into the battery passport system is essential. The battery passport can serve as a tool for an efficient circular economy and grant recycling companies access to valuable information about quantities and material compositions.'

Cost Reduction through Robotics

The greatest lever for cost reduction of the current typical 30 percent disassembly cost share lies, according to Breidenbach, "in the combination of robot-assisted disassembly and consistent design-for-disassembly." Not only manual disassembly capability, but also designs for robot-optimised disassembly are in demand. His recommendation: The standardisation and approvals of interfaces to the battery management system (BMS) enable quick assessments of the battery condition. 

"A safe deep discharge through continuous BMS monitoring," Breidenbach continues, "significantly reduces disassembly costs. Current practices such as full bonding or foaming of the packs massively hinder efficient recycling." 

Chemical-thermal shortcut processes may offer potential for certain applications, but according to Cylib's assessment, they are unlikely to significantly influence overall costs. "For high-quality recycling with maximum material recovery, standardised discharge-and-disassembly and mechanical processes still appear more advantageous," emphasises Breidenbach. 

Cooperation as the Key to Recycling Transformation

The challenge: Design-for-disassembly is being discussed, but has so far been implemented too rarely. It is evident that close collaboration within the ecosystem is crucial: "Partnerships between manufacturers, recycling companies, and other stakeholders can help achieve common goals such as improved recyclability and the creation of a true circular economy," motivates Matthias Breidenbach. 

Cylib is working together with various partners on projects where not only batteries are recycled, but also the recyclability of batteries is assessed. These experiences show that design-for-disassembly not only offers ecological and economic advantages but also lays the foundation for innovative approaches in disassembly and reuse.

Electromobility needs Circular Economy and Disassembly Intelligence

The German automotive and supplier industry is at an exciting point in the value chain positioning in battery development. Technological progress, exemplified by BMW's Gen6 technology with higher energy density, faster charging, and innovative pack concepts, promises more powerful and cheaper electric vehicles. At the same time, the need for a well-thought-out circular economy is coming into sharper focus, driven by regulation and the goal of ecological and economic added value.

While second-life programs already play an important role today and are supported by the demand for storage systems, high-voltage battery recycling faces challenges such as the diversity of architectures and high manual disassembly costs. Automated disassembly and the effective use of the digital battery passport will be crucial to implementing life-extending measures cost-effectively, efficiently recovering valuable materials, and reducing lifecycle costs. The establishment of large-scale hydrometallurgical refineries in Europe is necessary in the medium to long term to close the material cycle and increase raw material independence. 

The discussions about design-for-disassembly standards versus the use of digital twins and the scaling of recycling capacities show that there are still open questions and different paths being pursued. These topics will shape central debates at the Automotive Battery and require continued intensive collaboration and innovation along the entire value chain. The course for future sustainable electromobility is being set now.

This article was first published at all-electronics.de