Electron and Ion Co-Conductive Catalyst Achieving Instant Transformation of Lithium Polysulfide towards Li S.

Most of the catalysts in lithium sulfur (Li-S) batteries present low electronic conductivity and the lithium polysulfides (LiPSs) must diffuse onto the surface of the carbon materials to achieve their conversion reaction. It is a significant challenge to achieve the instantaneous transformation of LiPSs to Li S in Li-S batteries to suppress the shuttle effect of LiPSs. Herein, a unique electron and ion co-conductive catalyst of carbon-coated Li Al Ti (PO ) (C@LATP) is developed, which not only possesses strong adsorption to LiPSs, but, more importantly, also promotes the instantaneous conversion reaction of LiPSs to Li S. The C@LATP nanoparticles as catalytic active sites can synchronously and efficiently provide both Li ions and electrons to facilitate the conversion reaction of LiPSs. The conversion reaction path of LiPSs using C@LATP changes from traditional "adsorption-diffusion-conversion" to novel "adsorption-conversion," which effectively lowers the decomposition barrier of Li S and promotes faster conversion of LiPSs. The shuttle effect of LiPSs is considerably suppressed and utilization of sulfur is greatly improved. The Li-S batteries using C@LATP present excellent rate, cycling, and self-discharge properties. This work highlights the significance of electron and ion co-conductive solid-state electrolytes for the instantaneous transformation of LiPSs in advanced Li-S batteries.