Rapidly In Situ Cross-Linked Poly(butylene oxide) Electrolyte Interface Enabling Halide-Based All-Solid-State Lithium Metal Batteries

Halide-based solid-state halide electrolytes (SSEs) wererecentlyrevived as promising candidates for next-generation all-solid-statebatteries due to their superionic conductivity, direct compatibilitywith high-voltage cathodes, and scalable production. However, theincompatibility between halide SSEs and lithium metal anodes remainsa main challenge to achieve high energy density. Herein, we demonstratea thin cross-linked poly(butylene oxide) solid polymer electrolyte(xPBO SPE) interlayer on the superionic Li3InCl6 SSE to enable lithium metal compatibility. A rapid and solvent-freein situ cross-linking process is developed by reaction between a 0.5s pulse of trimethylaluminum vapor and the hydroxyl terminal groupsof poly(butylene oxide). The Li-Li symmetric cells using xPBO-SPE@Li3InCl6 demonstrate a highly stable cycling performanceover 1100 h and up to 1.0 mA cm(-2) and 1.0 mAh cm(-2). All-solid-state lithium metal battery (ASSLMB) performancewith a LiCoO2 cathode is presented. This new rapid cross-linkingstrategy shall inspire more possibilities for lithium metal anodeintegration in ASSLMBs.