Uniquely nanofibrillated hollow carbon nanofibers with decoration of 2D MOF-derived Co[sbnd]Mo sulfides: An efficient cathode material for Lithium sulfur batteries

The employment of electrocatalysts provides a substantial method for mitigating the shuttle effect of lithium polysulfides (LiPSs), improves the kinetics of conversion and overall electrochemical performance. Herein, a simple strategy is executed to grow 2-dimensional cobalt metal organic frameworks (2D Co-MOF) on nanofibrillated hollow carbon nanofibers (N_fib-HCNFs) followed by Mo-etching and sulfidation to develop Co₄S₃/MoS₂@N_fib-HCNFs as an efficient cathode material for lithium‑sulfur batteries (LiSBs). After S-loading, as prepared cathode material Co₄S₃/MoS₂@N_fib-HCNFs show good electrochemical performance, high specific discharge capacity at 0.1C (1282 mAh g⁻¹), commendable cycling stability over 500 cycles at 1C with discharge capacity retention ∼61.3 % and Coulombic efficiency 92.3 %. The Co₄S₃/MoS₂ heterostructure in N_fib-HCNFs matrix enhances sulfur utilization, suppresses the polysulfide shuttle, and accelerates redox kinetics. The Co₄S₃/MoS₂@N_fib-HCNFs electrode outperforms N_fib-HCNFs in charge/discharge capability, with a high Coulombic efficiency and low voltage hysteresis (151.1 mV). Enhanced polysulfide conversion, improved long-term stability, and polysulfide trapping are enabled by its porous structure, high conductivity, and abundant catalytic sites. This work provides a method for the modification of N_fib-HCNFs and promotes the development of LiSBs for future applications. Additionally, this approach of polysulfide transformation via Co₄S₃/MoS₂ heterostructure can deliver a more configured design strategy for next generation energy storage systems.