2D/1D V2O5 Nanoplates Anchored Carbon Nanofibers as Efficient Separator Interlayer for Highly Stable Lithium-Sulfur Battery

Abstract

Quick capacity loss due to the polysulfide shuttle effects is a critical challenge for high-performance lithium-sulfur (Li-S) batteries. Herein, a novel 2D/1D V2O5 nanoplates anchored carbon nanofiber (V-CF) interlayer coated on standard polypropylene (PP) separator is constructed, and a stabilization mechanism derived from a quasi-confined cushion space (QCCS) that can flexibly accommodate the polysulfide utilization is demonstrated. The incorporation of the V-CF interlayer ensures stable electron and ion pathway, and significantly enhanced long-term cycling performances are obtained. A Li-S battery assembled with the V-CF membrane exhibited a high initial capacity of 1140.8 mAh g-1 and a reversed capacitance of 1110.2 mAh g-1 after 100 cycles at 0.2 C. A high reversible capacity of 887.2 mAh g-1 is also maintained after 500 cycles at 1 C, reaching an ultra-low decay rate of 0.0093% per cycle. The excellent electrochemical properties, especially the long-term cycling stability, can offer a promising designer protocol for developing highly stable Li-S batteries by introducing well-designed fine architectures to the separator.