Super P and MoO₂/MoS₂ co-doped gradient nanofiber membrane as multi-functional separator for lithium–sulfur batteries

Lithium–sulfur battery is one of the most promising battery systems for industrialization due to its high theoretical specific capacity and high energy density. Nonetheless, the “shuttle effect” has restrained the advancement of lithium–sulfur batteries. In this work, a gradient-structured nanofiber membrane with pure gelatin on one side and Super P-MoO₂/MoS₂-gelatin on the other side was created using a multi-step electrostatic spinning technique, which was applied for multi-functional separator for lithium–sulfur batteries. The pure gelatin layer facing the anode side primarily homogenizes the lithium flux, whereas the Super P-MoO₂/MoS₂-gelatin layer facing the cathode side primarily adsorbs polysulfides by physical and chemical adsorption and enhancing polysulfide conversion efficiency. The findings demonstrate that even after 150 cycles at 0.2C, the lithium–sulfur battery can still sustain a discharge-specific capacity of 572.3 mAh·g⁻¹. When used with Li||Li symmetric batteries, it has a cycle life of more than 1200 h. The commercialization of lithium–sulfur batteries is given a fresh idea by this straightforward preparation technique.