All-in-One Homogenized Sulfur/Cobalt Disulfide Composite Cathodes for Harmonious Interface All-Solid-State Lithium–Sulfur Batteries

The development of high-performance all-solid-state lithium-sulfur batteries (ASSLSBs) has garnered considerable attention due to their potential for high energy density and enhanced safety. However, significant challenges such as poor cycling stability, interface incompatibility, and reaction kinetics hinder severely their practical application. In this work, an all-in-one sulfur/cobalt disulfide (S/CoS₂) composite cathode is proposed by integrating sulfur and homogenized cobalt disulfide (CoS₂) as the sulfur-based cathode materials with the sulfide solid electrolyte (Li₆PS₅Cl) through ball milling. This strategy combines the homogenization effect and catalytic effect of CoS₂ to improve the interfacial compatibility and reaction kinetics of the sulfur-based cathode, thereby reducing interfacial resistance and enhancing overall battery performance. It is confirmed that the introduction of homogenized CoS₂ can significantly improve interfacial lithium-ion transport, enhancing the rate performance. More importantly, it promotes the conversion of S to Li₂S, improving the utilization rate and reaction kinetics of the ASSLSBs. The S/CoS₂ cathode delivers an impressive initial discharge capacity of 1584 mA h g^-1 with a capacity utilization of 99% at a current density of 0.25 mA cm^-2 and maintains 915 mA h g^-1 after 100 cycles. Even at 1.28 mA cm^-2, the cathode exhibits a specific capacity of 474 mA h g^-1. This all-in-one strategy provides valuable insights into the design of next-generation ASSLSBs and holds significant potential for future energy storage technologies.