In-Situ Construction of Ceramic–Polymer All-Solid-State Electrolytes for High-Performance Room-Temperature Lithium Metal Batteries

High-performance solid-state lithium batteries require not only solid-state electrolytes with high room temperature ionic conductivity, but also low interfacial resistance. Here, we report the preparation of a composite solid-state polymer electrolyte (CSE) based on ceramic nanowires with scandium-initiated in situ ring-opening polymerization of ether-based monomer inside lithium–metal batteries (LMBs), allowing good interfacial contact between the components of the solid-state cells. The polymerization of ether-based monomers enables the transport of Li+ as a solid-state electrolyte, and the ceramic membrane constructed by ceramic nanowires serves to prevent short-circuiting of the cell, inhibit crystallization of the polymer, and build fast ion channels at the interface of the polymer and nanowires. The CSE has a tunable room-temperature ionic conductivity (10–3–10–5 S cm–1), lithium-ion transference number (0.36–0.54), and electrochemcial window (4.3–5.18 V) based on monomer conversion. Owing to the low interfacial resistance of in situ polymerization, the assembled solid-state LMBs have good cycling and rate performance. Our research provides a promising direction for advancing the development of high-performance CSEs and corresponding devices.