A Universal Solid Reaction Enabling Nanosized Li₂S in an Amorphous Matrix for All-Solid-State Li–S Batteries

Lithium sulfide (Li2S), a key cathode material for all-solid-state lithium–sulfur (Li–S) batteries, faces challenges such as low electronic and ionic conductivities and limited active material utilization during cycling. In this study, we developed a new cathode featuring nanosized Li2S embedded in an amorphous LiFeS2 matrix (92Li2S@8LiFeS2). Benefiting from the mixed electronic and ionic conductivities of LiFeS2 along with its catalytic effect and the nanosized Li2S that shortens electron and ion transport distances, this 92Li2S@8LiFeS2 cathode exhibits long-term cycling stability with a capacity retention of over 99% after 320 cycles. With an active material content of 48% and a mass loading of 19.1 mg/cm2, the cathode achieves an areal capacity of 13.2 mAh/cm2. This work presents a facile and novel approach to designing Li2S-based cathodes for high-performance, all-solid-state Li–S batteries.