Expanded Vanadium Oxide Interlayers Accelerating Bidirectional Polysulfide Redox in Li–S Batteries

Abstract Vanadium‐based compounds with potent chemical interactions and catalytic activity for lithium polysulfides (LiPSs) are deployed worldwide to suppress the shuttle effect of LiPSs in cost‐effectiveness, high‐capacity, and eco‐friendly lithium‐sulfur batteries (LSBs). In this work, layer structured NH 4 V 4 O 10 (NVO) is fabricated by a simple hydrothermal method and employed as a functional layer on the surface of the PP separator. The nanoscale laminar structure and increased layer spacing of NVO afford abundant physical/chemical adsorption sites and fast ion/electron channels for adsorption and catalytic conversion of LiPSs, and thus improve the electrochemical performance of the lithium sulfur battery. The NVO‐modified separator enables the sulfur cathode to deliver an initial discharge capacity of 1059.9 mAh g −1 at 1 C with an average capacity attenuation of 0.06% per cycle over 1000 cycles, and the cell exhibits a relative high capacity of 1328.3, 1085.3, 896.9, 763.8, and 626.6 mAh g −1 at 0.5, 1, 2, 3, and 4 C, respectively. This work provides an effective way to suppress the shuttle effect of LiPSs and accelerate the electrochemical kinetics of the lithium–sulfur battery.