Battery-grade graphite from direct recycling: effect of the thermal treatment on the properties of the regenerated anode material

Scalable and sustainable lithium-ion battery recycling routes could be crucial for the future economic and ecological landscape of Europe. Although graphite is a critical raw material for the EU, the recycling of graphite from spent cells is currently limited to a small scale and is less developed than the recovery of cathode elements. In this study, we present a process for regenerating anode active material from spent lithium-ion cells with electrochemical performance comparable to that of commercial battery-grade graphite. The study is based on a direct recycling concept that employs green solvents and thermal treatment. The focus is on the direct impact of the applied temperature on the quality of the recycled graphite. The temperature range used for thermal treatment affects the physical and chemical properties of the particles, primarily impacting the surface functionalities, which are crucial for electrochemical performance. We demonstrate the electrochemical performance of regenerated graphite active materials by validating the short closed loop from spent cells to new anodes with high-performance. • Graphite from spent cells is recovered by thermal treatment with high purity. • Battery-grade recycled materials are achieved by short treatment above 2000 °C. • Surface regeneration enables initial coulombic efficiency like benchmark. • Physicochemical analysis shows clear temperature-dependent trends. • Validation in new cells supports direct recycling development.