Lithium dendrites suppressed by low temperature in-situ anti-perovskite coated garnet solid-state electrolyte

Abstract

Garnet-type solid-state electrolyte (SSE) has attracted much attention due to its wide electrochemical window, high mechanical strength, and chemically compatible with lithium metal. Nonetheless, the high sintering temperature and poor ability to suppress lithium dendrite strongly limit its application. Herein, we report a simple aqueous method to prepare in-situ lithium rich anti-perovskites (LiRAPs) coated garnet SSEs, and successfully reduce the sintering temperature from 1200 °C to 350 °C. The composite SSEs deliver a higher ionic conductivity (3.67 × 10−4 vs. 1.20 × 10−4 S cm−1) and a better cycling stability (84.8% capacity retention after 200 cycles vs. short-circuit after 90 cycles) than the pristine garnet SSEs. Moreover, the composite SSEs exhibit an improved ability to suppress lithium dendrite (over 200 h working for Li symmetrical cell and 0.7 mA cm−2 critical current density). This work demonstrates that in-situ LiRAPs coating strategy can effectively reduce the sintering temperature and suppress the Li dendrite growth inside the garnet electrolyte.