Modulating ionic conduction and accelerating sulfur conversion kinetics through oxygen vacancy engineering for high-performance solid-state lithium-sulfur batteries

Poly(ethylene oxide) (PEO)-based solid-state lithium-sulfur batteries (SSLSBs) have garnered considerable attention as potential energy storage solutions owing to their exceptional specific energy, ease of processing, and economic viability. Nevertheless, the inherently low Li${}^{+}$ conductivity of the PEO electrolyte and the inevitable dissolution of lithium polysulfides (LiPSs) within the sulfur cathode hinder the solid-state sulfur conversion kinetics and lead to significant loss of active materials, thus posing challenges for practical applications. Herein, these concerns are addressed by incorporating oxygen vacancy enriched-Nb${}_{22}$W${}_{20}$O${}_{102-x}$ (NWO${}_x$) nanorods as cathode additives in high-performance PEO-based SSLSBs. The uniformly dispersed NWO${}_x$ nanorods effectively modify the coordination environment of Li ions by increasing the concentration of free Li ions in the PEO catholyte and alleviating the shuttle effect of dissolved LiPSs. Consequently, the developed SSLSB demonstrates excellent cyclic stability and rate capability. Specifically, it achieves a high discharge capacity of 1208.6 mAh g${}^{-1}$ during the initial cycle and maintains 927.8 mAh g${}^{-1}$ after 200 cycles at 0.1 C. Moreover, such a configuration can accommodate a high loading of active materials with stable capacity retention. Overall, this study presents an effective approach for developing solid-state sulfur cathodes in PEO-based SSLSBs. (© 2024 Wiley‐VCH GmbH)