High-performance Li6PS5Cl-based all-solid-state lithium-ion batteries

All-solid-state lithium-ion batteries (ASSLIBs) owing to their advantage of enhanced safety are considered to be a promising candidate for next-generation energy storage devices. However, the poor cycling performance and low areal capacities of ASSLIBs with S, Li2S or traditional oxide cathodes hinder the development of high-energy-density ASSLIBs. Herein, a Li6PS5Cl solid-state electrolyte has been systematically investigated for use as a cathode active material in ASSLIBs for the first time. ASSLIBs employing Li6PS5Cl as both the active material and electrolyte with a Li-In alloy anode are fabricated. A Li6PS5Cl-based cell with an active material loading of 3.1 mg cm(-2) exhibits a high discharge capacity of around 535 mA h g(-1) after 650 cycles at 56 mA g(-1) (similar to 0.1C) at room temperature, which is the highest value among ASSLIBs using sulfide SSEs as active materials and is even comparable with those of cells with S, Li2S or transition metal sulfides as the active material. This superior long-term cycling performance is attributed to the highly reversible electrochemical activity of Li6PS5Cl revealed by ex situ XRD and XPS analyses.