Superior Low-Temperature All-Solid-State Battery Enabled by High-Ionic-Conductivity and Low-Energy-Barrier Interface

All-solid-state batteries (ASSBs) working at room and mild temperature have demonstrated inspiring performances over recent years. However, the kinetic attributes of the interface applicable to the subzero temperatures are still unidentified, restricting the low-temperature interface design and operation. Herein, a host of cathode interfaces are constructed and investigated to unlock the critical interface features required for cryogenic temperatures. The unstable interface between LiNi_0.90Co_0.05Mn_0.05O₂ (Ni90) and Li₆PS₅Cl (LPSC) sulfide solid electrolyte (SE) results in unfavorable cathode-electrolyte interphase (CEI) and sluggish lithium-ion transport across the CEI. After inserting a Li₂ZrO₃ (LZO) coating layer, the activation energy of the Ni90@LZO/sulfide SE interface can be reduced from 60.19 kJ mol^-1 to 41.39 kJ mol^-1 owing to the suppressed interfacial reactions. Through replacing the LPSC SE and LZO coating layer by the Li₃InCl₆ (LIC) halide SE, both a highly stable interface and low activation energy (25.79 kJ mol^-1) can be achieved, thus realizing an improved capacity retention (26.9%) at -30 °C for the Ni90/LIC/LPSC/Li-In ASSB. Moreover, theoretical evaluation clarifies that cathode/SE interfaces with high ionic conductivity and low energy barrier are favorable to the Li⁺ conduction through the interphase and the Li⁺ transfer across the cathode/interphase interface. These critical understandings may provide guidance for low-temperature interface design in ASSBs.