Unraveling the reversible redox mechanism of Li6PS5Cl solid electrolyte in all-solid-state lithium–sulfur batteries

Abstract

We reveal the reversible redox mechanism of Li₆PS₅Cl in composite cathodes for practical all-solid-state lithium–sulfur batteries. The limited electrochemical reactivity of the non-conducting sulfur-based active material induces the formation of Li₆PS₅Cl decomposition products, which allows the recrystallization of Li₆PS₅Cl through a reversible redox process, contributing to the composite cathode capacity.