A Universal Solid Reaction Enabling Nanosized Li 2 S in an Amorphous Matrix for All-Solid-State Li–S Batteries

Lithium sulfide (Li 2 S), 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 Li 2 S embedded in an amorphous LiFeS 2 matrix (92Li 2 S@8LiFeS 2 ). Benefiting from the mixed electronic and ionic conductivities of LiFeS 2 along with its catalytic effect and the nanosized Li 2 S that shortens electron and ion transport distances, this 92Li 2 S@8LiFeS 2 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/cm 2, the cathode achieves an areal capacity of 13.2 mAh/cm 2 . This work presents a facile and novel approach to designing Li 2 S-based cathodes for high-performance, all-solid-state Li–S batteries.