Niobium Phosphide-Induced Sulfur Cathode Interface with Fast Lithium-Ion Flux Enables Highly Stable Lithium-Sulfur Catalytic Conversion.

Research on the Li-S catalytic chemistry primarily focus on the development of high-performance catalysts and the exploration of their reaction mechanisms, with limited attention given to the impact on the interface at the cathode. Moreover, regulating the Li flux at the cathode interface can enhance LiS conversion kinetics without compromising the intrinsic catalytic activity of catalyst. This work presents a paradigm that employs interface regulation to enhance Li-S battery (LSB) cycling stability. A novel phosphorus doped carbon supported niobium phosphide nanocrystals (NbP/PC) catalyst is developed and demonstrates exceptional intrinsic activity for lithium polysulfide conversion while it facilitates lithium salt dissociation through intermolecular hybridization. The NbP-induced functional interface layer with abundant LiF and LiN provides efficient Li transport channel for LiS decomposition, which further mitigates the passivation of active sites. In consequence, the assembled LSB exhibits a capacity retention rate of 0.04 % per cycle after 1100 cycles at a 1 C. Furthermore, the pouch battery with an energy density of 451 Wh kg maintains stable performance over 20 cycles. This strategy addresses the limitations of traditional catalytic material design in the chemical regulation of the cathodic interface for promising future of LSBs.