End-of-Life Processing of Electric Vehicle Batteries: Disassembly as a key requirement for efficient circularity

Summary:

The growth in electric vehicle sales is associated with a huge amount of batteries. Once these systems reach the end-of-life (EoL) phase, they will be directed towards different EoL strategies, which require disassembly as a key technology. However today, disassembly still represents a bottleneck process that requires optimization in terms of costs, safety, and throughput. Taking advantage of automation and digitalization can offer very promising solutions considering the improvement of disassembly processes. That is why different research projects are addressing these aspects, such as the project DeMoBat. To show the importance of disassembly infrastructures, we built an agent-based model to forecast the number of batteries that have to be entirely disassembled. A case study shows an exemplary application of the developed model for Baden-Württemberg. The electric vehicle fleet since 2010 is taken into account under consideration of one optimistic and one pessimistic market scenario to illustrate the appearance of the end-of-life landscape. Thereby, the circular economy strategies repurposing, remanufacturing, and recycling are considered. Reusing defective batteries after being repaired is out of scope for planning disassembly capacities, as repair is not seen as an industrial process here. Our initial results show that per year more than 450.000 batteries could reach the end-of-life phase in Baden-Württemberg by 2050. All these batteries would have to be disassembled as a preparatory step for circular economy strategies and hence require the implementation of disassembly networks consisting of interconnected disassembly factories. Thereby, the focus must be on reducing transport costs, as they currently represent 50 % of the total recycling costs. Disassembly factories will have to deal with several challenges to ensure their competitiveness and sustainability in the long term. Handling the following challenges will be essential: the wide range of battery variants, the increasing return volumes, the uncertainties regarding quality, quantity, and timing of returns, the short life cycle of cell technologies, and the diversity of circular economy strategies, which require different disassembly methods. That is why disassembly systems must meet high flexibility and transformation requirements. In this context, we identify five main enablers for flexibility and transformation relevant for disassemblers. These are: First, scalability, which
consists of spatial and personnel expansion and covers technological transformation based on automation and digitalization. Second, universality through the consideration of the variants‘ diversity. Third, modularity, using standardized disassembly units. Fourth, compatibility, which ensures the interconnectivity between machines and their environment. Finally, the stations‘ mobility, which ensures an efficient layout when new disassembly equipment is added to the disassembly factory. In view of the mentioned challenges and derived requirements, we propose a general design for a disassembly factory using a net configuration with disassembly stations arranged in matrix form.