Halide/sulfide composite solid-state electrolyte for Li-anode based all-solid-state batteries

Li2ZrCl6 (LZC) solid-state electrolytes (SSEs) have been recognized as a candidate halide SSEs for allsolid-state Li batteries (ASSLBs) with high energy density and safety due to its great compatibility with 4 V-class cathodes and low bill-of-material (BOM) cost. However, despite the benefits, the poor chemical/electrochemical stability of LZC against Li metal causes the deterioration of Li/LZC interface, which has a detrimental inhibition on Li+ transport in ASSLBs. Herein, we report a composite SSE combining by LZC and argyrodite buffer layer (Li6PS5Cl, LPSC) that prevent the unfavorable interaction between LZC and Li metal. The Li/LPSC-LZC-LPSC/Li symmetric cell stably cycles for over 1000 h at 0.3 mA/cm(2) (0.15 mAh/cm(2)) and has a high critical current density (CCD) value of 2.1 mA/cm(2) at 25 degrees C. Under high temperature (60 degrees C) which promotes the reaction between Li and LZC, symmetric cell fabricated with composite SSE also display stable cycling performance over 1200 h at 0.3 mAh/cm(2). Especially, the Li/NCM ASSLBs fabricated with composite SSE exhibit a high initial coulombic efficiency, as well as superior cycling and rate performance. This simple and efficient strategy will be instrumental in the development of halidebased high-performance ASSLBs. (c) 2023 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

Automated summary

Li2ZrCl6(LZC) solid-state electrolytes (SSEs) have potential as a halide SSE for all-solid-state Li batteries (ASSLBs) due to their compatibility with cathodes and low cost. However, the instability of LZC against Li metal affects Li+ transport in ASSLBs.