LiS-Based Composite Cathode with in Situ-Generated LiPS Electrolyte on LiS for Advanced All-Solid-State Lithium-Sulfur Batteries.

All-solid-state lithium-sulfur batteries (ASSLSBs) are considered to be a promising solution for the next generation of energy storage systems due to their high theoretical energy density and improved safety. However, the practical application of ASSLSBs is hindered by several critical challenges, including the poor electrode/electrolyte interface, sluggish electrochemical kinetics of solid-solid conversion between S and LiS in the cathode, and big volume changes during cycling. Herein, the 85(92LiS-8PS)-15AB composite cathode featuring an integrated structure of a LiS active material and LiPS solid electrolyte is developed by in situ generating a LiPS glassy electrolyte on LiS active materials, resulting from a reaction between LiS and PS. The well-established composite cathode structure with an enhanced electrode/electrolyte interfacial contact and highly efficient ion/electron transport networks enables a significant enhancement of redox kinetics and an areal LiS loading for ASSLSBs. The 85(92LiS-8PS)-15AB composite demonstrates superior electrochemical performance, exhibiting 98% high utilization of LiS (1141.7 mAh g) with both a high LiS active material content of 44 wt % and corresponding areal loading of 6 mg cm. Moreover, the excellent electrochemical activity can be maintained even at an ultrahigh areal LiS loading of 12 mg cm with a high reversible capacity of 880.3 mAh g, corresponding to an areal capacity of 10.6 mAh cm. This study provides a simple and facile strategy to a rational design for the composite cathode structure achieving fast Li-S reaction kinetics for high-performance ASSLSBs.