Enhanced electrochemical performance of lithium-sulfur batteries using a V2O5/graphene interlayer

Abstract To improve the electrochemical performance of lithium-sulfur (Li-S) batteries, we develop a new strategy to construct the V2O5 yolk-shell microspheres/graphene nanosheets (V2O5/G) layer on commercial polypropylene (PP) separator as a vice-electrode. On one hand, the V2O5/G interlayer can act as a barrier to block polysulfides diffusion and then suppress the troublesome shuttle effect. On the other hand, lithium ions can insert in and extract from V2O5 during discharge/charge processes, and thus contribute extra cathode capacity and large voltage window to the batteries. As expected, the Li-S batteries with a V2O5/G interlayer deliver a large voltage window of 2.0 V (3.6-1.6 V) and a significantly improved electrochemical performance. The work provides a new idea for the design of the high-performance Li-S battery.