Rational\nDesigned Mixed-Conductive Sulfur Cathodes for All-Solid-State Lithium\nBatteries

Abstract

All-solid-state\nlithium–sulfur batteries (ASSLSBs) hold great promise for safe\nand high-energy-density energy storage. However, developing high-performance\nsulfur cathodes has been proven difficult due to low electronic and\nionic conductivities and large volume change of sulfur during charge\nand discharge. Here, we reported an approach to synthesize sulfur\ncathodes with a mixed electronic and ionic conductivity by infiltrating\na solution consisting of Li₃PS₄ (LPS) solid\nelectrolyte and S active material into a mesoporous carbon (CMK-3).\nThis approach leads to a uniform dispersion of amorphous Li₃PS₇ (L3PS) catholyte in an electronically conductive carbon\nmatrix, enabling high and balanced electronic/ionic conductivities\nin the cathode composite. The inherent porous structure of CMK-3 also\nhelps to accommodate the strain/stress generated during the expansion\nand shrinkage of the active material. In sulfide-based all-solid-state\nbatteries with Li metal as the anode, this cathode composite delivered\na high capacity of 1025 mAh g^–1 after 50 cycles\nat 60 °C at 1/8C. This work highlights the important role of\nhigh and balanced electronic and ionic conductivities in developing\nhigh-performance sulfur cathodes for ASSLSBs.