From interface engineering to recycling-oriented design: A review of oxide-based all-solid-state batteries

Abstract

All-solid-state lithium batteries based on oxide solid electrolytes have attracted extensive attention due to their high safety, wide electrochemical stability window, excellent thermal stability and superior mechanical strength. However, their practical application is still limited by poor solid–solid contact, high interfacial resistance, elemental interdiffusion, space-charge-layer effects, and mechanical mismatch at the cathode/OSE interface. Interface engineering strategies, including surface coating, wetting-layer construction, co-sintering, sintering additives, three-dimensional structure design, composite electrolytes, and in situ polymerization, have been widely developed to improve interfacial compatibility and electrochemical performance. However, these strategies may also increase cell complexity and create new challenges for end-of-life disassembly, separation, and regeneration. This review summarizes the structural features, failure mechanisms, interface optimization strategies, and recycling feasibility of representative OSEs, including garnet, NASICON, perovskite, anti-perovskite, LISICON, LiPON, and oxychloride electrolytes. The applicability of pyrometallurgy, hydrometallurgical extraction, and direct regeneration to different OSE systems is critically discussed. Furthermore, emerging recycling-friendly electrolyte and interphase designs, such as removable interlayers, soluble or degradable polymer phases, reprocessable electrolytes, and closed-loop regeneration strategies, are highlighted. By linking interface engineering with green recycling, this review provides a full-life-cycle perspective for the sustainable development of OSE-based all-solid-state batteries.