Recycling of solid-state batteries

Solid-state batteries (SSBs) are expected to provide higher energy densities, faster charging performance and greater safety than lithium-ion batteries (LIBs). Introducing a solid electrolyte (SE) results in changes in materials, manufacturing processes and cell characteristics. Compared to LIBs, however, there is a limited understanding of the recyclability of SSBs. Here we review the present strategies for indirect recycling of various SSBs, such as resynthesis, and direct recycling, such as reconditioning, focusing on promising SEs including oxides, sulfides/thiophosphates/halides and polymers. We consider the recycling routes adapted to different SEs, consisting of pretreatment as well as mechanical and metallurgical processes. Future recycling solutions will need to meet the demands for robust, energy-efficient methods with minimal environmental impact, while delivering high recycling rates and good secondary material quality.