Recycling Strategies for Sulfide-Based All-Solid-State Lithium-Ion Batteries

All-solid-state lithium-ion batteries (ASSBs) are an up-and-coming alternative to conventional lithium-ion batteries with liquid electrolytes. A high potential lies in higher energy densities with high lifetime and long-term stability, avoiding safety hazards such as thermal runaway concerning liquid electrolyte systems. Battery cell concepts with sulfidic electrolytes represent a promising candidate due to their high plasticity and ionic conductivity compared to competing systems with oxide and polymer-based electrolytes.

Currently, research primarily focuses on material development and production processing to enable an industrial implementation of ASSBs. However, barely any recycling concepts have been published, taking into account the necessity for a sustainable raw materials supply in the scope of a circular economy for these novel cell concepts.

This study investigates the feasibility of transferring existing recycling concepts for commercial lithium-ion batteries to sulfide-based ASSBs.

Cell chemistry raises unique challenges, such as the hazardous gas occurrence (H2S and SO2) in contact with air or moisture, which are addressed in the transfer of concepts. As a result, a process route is presented based on thermal pretreatment, subsequent crushing and sorting, early lithium removal, and extractive hydrometallurgy. In parallel, direct recycling approaches will be discussed, where the electrolyte can be recovered for reuse in new ASSB cells.