Interfacial Layers to Enable Recyclability of All-Solid-State Lithium Batteries

Abstract

All-solid-state batteries (ASSBs) with lithium metal anodes are promising energy storage devices due to their high energy density and safety. Their potential massive production and lack of recycling methods necessitate the development of strategies to address the problem of spent batteries. Current recycling methods rely on organic solvents or high-temperature furnaces, which are not environmentally friendly. Here, we proposed a design for recyclable all-solid-sate lithium batteries by introducing interfacial layers at electrode interfaces. Flexible lithium perchlorate doped polypropylene carbonate (PPC-LiClO4) thin-films improve contacts between metallic lithium and Li7La3Zr2O12 (LLZO)-based composite electrolytes, LLZO–PPC–LiClO4, thus lowering interfacial resistance. Half cells with modified interfaces exhibit a critical current density of 1.0 mA cm−2 and outstanding cycling stability at a current density of 0.1 mA cm–2. In addition, polymer-salt layers serve as sacrificial layers to enable clean separation of cathodes and solid-state electrolytes. Recovered cathodes and composite electrolytes show high purity of LiFePO4 and LLZO ceramic materials that allows further direct recycling.