ICRC 2024 - Session 4

Dr. Benjamin Balke-Grünewald
Fraunhofer IWKS 

Awareness of the importance of sustainability and environmental impacts in the battery sector is increasing following decades of focus almost solely on improving performance of batteries. The need for sustainability is present along the full value chain, from resources to cell production and recycling. This contribution addresses sustainable battery production in the context of a design for recycling concept supporting direct recycling. In particular, the contribution of the Fraunhofer Research and Development Center for Electromobility (FZEB) at the Fraunhofer Institute for Silicate Research ISC will be highlighted.

To create better and more sustainable battery chemistries, it is important to consider all aspects of the battery cycle. This includes factors such as raw materials and their supply chain, manufacturing processes of materials, electrodes and cells, performance properties, and recycling or end-of-life processes. This presentation will discuss the importance of both critical and non-critical materials in batteries and their use in different battery chemistries. Lithium-ion batteries often contain high value elements such as cobalt or nickel which means that the current recycling processes are more viable, however for lower value materials such as lithium iron phosphate or the sodium-ion cathode materials lower cost recovery processes are required. If the materials can be recovered easily with low-cost processes routes and in a form that can be directly re-used in a battery, direct recycling, the economics should be more favourable than returning to the elements to either their metallic or precursor salt as is done in pyrometallurgical and hydrometallurgical routes. When developing new battery technologies, there's a chance to design in recycling from the start, rather than retrospectively, as is currently the case for lithium-ion batteries. Additionally, this presentation will explore design principles for creating a more sustainable battery technology.

Generation and load peaks from renewable energy sources are a challenge for energy grids. There is no single energy storage solution that is ideal for every grid-scale application. Combining storage components into a complex system allows to benefit on their advantages and to suppress weak points of the single components. Hybrid energy storage systems (HESS) refer to several types of storage components of different characteristics that are combined to form an integral entity, preferably controlled by a mutual energy management system. Usually, an electrochemical energy storage system is designed either for high-power or high-energy applications and if not used in intended ways, the user must cope with penalties by lifetime, performance, and cost. In this talk, an example of a flexible and sustainable storage system which is being developed within ResHy project (ResHy: Ressourcenschonende Hybridbatterie, English: Sustainable hybrid battery) by EnBW AG and Fraunhofer ISE will be presented. ResHy aims the development of an electrochemical hybrid storage system containing a 2nd life lithium-ion battery (LiB) and a sodium-based component. To improve the efficiency and benefit on synergies of the single components, an energy management system (EMS) and a highly flexible control system will be developed. This will allow a high degree of control and adaptability, as well as better adjustment to a variety of system environments. The developed hybrid storage system will be implemented and tested at a solar park of 62 MWp in a proximity of Gundelsheim planned by EnBW.

Various recycling methods of lithium-ion batteries (LIBs) have already reached the industrial stage. However, there is a vast need to improve these processes toward greater sustainability. Commercial recycling of LIBs currently focuses mainly on the recovery of precious metals, especially cobalt, copper and nickel, while recovery of other valuable elements and components such as lithium or graphite still maintains in the laboratory scale. Direct recycling is a method that directly recovers the active materials preserving their original structure. Advantages of the direct recycling approach include significantly lower emissions and less secondary pollution compared to pyrometallurgical and hydrometallurgical processes. However, there are many challenges to overcome to make direct recycling viable. In this work we show various aspects and problems of direct recovery of anode and cathode materials. One of the challenges is separation of electrode layers from current collectors because they are made with the requirement of long-lasting adhesion. The recovered active materials exhibit electrochemical performance comparable to the commercial counterparts.

Although the benefits of recycling spent lithium-ion batteries (LIBs) are widely acknowledged, many challenges and issues persist. Spent LIBs are expected to be collected, sorted, dismantled, and finally converted into black mass (BM). This is the so-called pre-treatment in recycling processes. While BM producing and processing technologies have been gaining momentum in recent years, the BM market is still in its infancy and requires for improvements in terms of economic feasibility and environmental footprint. Moreover, relevant regulatory frameworks need to be updated concerning the widespread use and advancement of LIBs. The technical challenges lie in the post-treatment during leaching of BM and precipitation of the valuable metals to revive the spent LIBs. BM is typically dissolved in an acidic or alkaline solution and followed by selective but complex extraction of valuable metal compounds. Various complex separation processes are necessary in the post-process phase to bring BM back into the battery production. In the post-treatment, two main challenges are increasingly apparent nowadays due to political and/or economic circumstances. One is the significant investment required for building the infrastructure. The other one is creating sustainable cycles and finding the pathways to the decarbonized recycling processes, while embracing the challenges of tomorrow. Thus, a holistic view of the current recycling process is vital to minimize negative effects on the environment. As an alternative to the current hydrometallurgy, direct recycling has emerged but commercialization of those lab-scale processes still needs to be validated from industrial perspectives. Finding solutions for these challenges in the end requires efforts not only from the scientists and researchers, but also from industrial stakeholders with growing interests and long-term patient engagement for the technical breakthrough. However, this is understandably very difficult as making a profit is an essential component of a successful business. Due to declining profitability and income, the LIB recycling industry is facing an increasingly severe struggle for survival. In this regard, battery regulations and legal supports are eagerly anticipated for the industries to keep high levels of commitments to long-term investments. Moreover, it is urgent to strengthen the competitiveness by closely monitoring geopolitical policy movements mainly in China, U.S.A., and Europe by deepening cooperation with local and overseas companies and governments. In this contribution, current achievements and remaining challenges in LIB recycling carried out in Fraunhofer IWKS will be presented. Our exploration of alternative hydrometallurgical processes using deep eutectic solvents (DES) will be covered. Finally, the advancements and challenges for sustainable BM recovery will be discussed.

Details to follow soon