Synergistic Regulation of Single-Atom Catalysis and Conductive Enhancement in All-Solid-State Li–S Batteries

The electrochemical performance of all-solid-state lithium–sulfur batteries (ASSLSBs) remains inadequate for commercial viability due to the inherently low electronic conductivity of elemental sulfur, which results in sluggish reaction kinetics. Here, we propose a dual modification strategy combining doping and catalysis to promote solid-state conversion reactions in the sulfur cathode. This synergistic approach has been shown to enhance the electrical conductivity of the sulfur cathode, thereby improving the reaction kinetics. Through XPS and ⁷Li ssNMR analysis, we reveal the sequential formation and quantitative evolution of various lithium polysulfide intermediates during the sulfur reduction process. The ASSLSBs demonstrated an areal capacity of 6.3 mAh cm^–2 and a capacity retention of 95.9% after 100 cycles. Furthermore, the ASSLSBs paired with a Li metal anode achieved an electrode energy density of 818.4 Wh kg^–1. These findings provide valuable insights into the solid-phase conversion process of sulfur and establish a promising strategy for developing high-performance ASSLSBs.