Facile one-pot synthesis of Co3Mo3N-loaded inside hierarchical porous bead-on-string as cathode host material for high-performance lithium-sulfur batteries

Abstract

A critical factor impeding the development of lithium-sulfur batteries is the deleterious shuttle effect. To address the issue, we devise a facile electrospinning approach to integrate catalysts and hierarchically porous structures into bead-on-string carbon host material as the host material. Compared to the traditional preparation of hierarchical porous structures, the upgraded electrospinning eliminates the need for etching templates, providing a larger specific surface area (333.39 m2 g−1) and tremendous potential for large-scale production. The cathode utilizing bead-on-string Co3Mo3N as host material exhibits a remarkable capacity of 1257 mAh g−1 at 0.2 C and maintains a capacity retention rate of 90 % after 100 cycles. Even at 4.0 C, the capacity remains at 648 mAh g−1 with minimal capacity loss. Under harsh conditions (including high sulfur loading, high areal loading, and lean electrolyte), the composite cathode consistently delivers a capacity of 8 mAh cm−2. Simultaneously, systematic electrochemical testing, in-situ assessments, and DFT calculations unveil the dual-metal synergistic effects of Co3Mo3N in suppressing the shuttle effect and catalyzing the conversion of lithium polysulfides. Co3Mo3N provides chemical adsorption to significantly promote the reaction kinetics of polysulfides. This work establishes a neoteric technique and a theoretical strategy for exploring the catalytic efficacy of dual-metal nitrides for Li-S batteries.