Closed‐loop Recycling of Sulfide Solid Electrolytes from Spent Solid‐State Sodium Batteries

ABSTRACT All‐solid‐state sodium batteries (ASSSBs) are promising for large‐scale energy storage due to sodium abundance and intrinsic safety. However, from a sustainability perspective, the recyclability of solid electrolytes is critical but largely unexplored, as many mature solid electrolytes rely on low‐abundance, high‐cost elements, limiting long‐term scalability. Herein, we firstly report a closed‐loop recycling strategy for Na 3 SbS 4 (NAS) solid electrolytes guided by the DFT calculations, enabling efficient recovery and regeneration from spent all‐solid‐state sodium batteries via a mild dissolution–recrystallization–thermal treatment process. The recycled NAS (R‐NAS) fully preserves the long‐range crystal structure, local coordination environment, and chemical states of the pristine material. The R‐NAS delivers good ionic conductivity, electrochemical stability, reduced polarization, enhanced rate performance, and superior cycling stability comparable to pristine NAS (P‐NAS). This work demonstrates the feasibility and importance of the recycling of high‐performance sulfide solid electrolytes from spent devices without compromising structural integrity or functionality. The proposed recycling strategy offers a generalizable and sustainable pathway for the reutilization of advanced solid electrolytes, contributing to the circular economy of all‐solid‐state battery technologies.