A Multifunctional MoC-Decorated Dual-Carbon Nanofiber Host for High-Performance Lithium-Sulfur Batteries

The practical application of lithium-sulfur batteries is limited by the severe shuttle effect of lithium polysulfides (LiPSs) and slow sulfur conversion kinetics, resulting in accelerated capacity decay and limited cycle life. To address these challenges, we designed a multifunctional sulfur host, named VGS@MoC/NCNF, in which MoC-modified, nitrogen-doped carbon nanofibers are coated with a layer of vertically aligned graphene sheets. The hierarchically designed dual-carbon architecture provides sufficient sulfur loading space and establishes efficient pathways for rapid electron/ion transport, while the uniformly dispersed MoC nanoparticles provide dual adsorption-catalysis functions. The VGS@MoC/NCNF-S effectively confines LiPSs through combined physical-chemical interactions and catalytically accelerates LiPS redox kinetics. Consequently, the VGS@MoC/NCNF-S displays an initial capacity of 1070.8 mAh g^-1 and maintains a capacity of 798.5 mAh g^-1 after 400 cycles with only 0.063% capacity fade per cycle at 1 C rate, presenting excellent cycling stability. This work provides a rational design strategy for designing high-efficiency sulfur hosts with the integrated functionality of polysulfide confinement and catalytic conversion for advanced lithium-sulfur batteries.