High-Safety All-Solid-State Lithium-Metal Battery with High-Ionic-Conductivity Thermoresponsive Solid Polymer Electrolyte.

Lithium-metal batteries (LMB) are very attractive owing to their high theoretical energy density, but significant challenges such as low ionic conductivity and safety risks prevent their widespread application. Herein, we report a new design of high-safety all-solid-state LMB by using high-ionic-conductivity thermoresponsive solid-polymer electrolyte (TSPE), providing a smart and active approach to realize thermally induced autonomic shutdown of LMBs by efficiently inhibiting the ionic conduction between electrodes beyond an unsafe temperature. The as-obtained TSPE exhibits a high ionic conductivity (2 × 10-4 S cm-1 at 30 °C), which enables a significantly improved capacity of 160 mA h g-1 at 0.2 C and outstanding high rate capability up to 5 C as well as a super-long cycle life of over 400 cycles for the constructed all-solid-state Li||LiFePO4 batteries. The present study opens up a new avenue for the fabrication of self-protective all-solid-state batteries with inherent intelligent thermal management to ensure battery-series safety.