SiO2 blending polyetherimide separator modified with acetylene black/polyvinylpyrrolidone coating layer to enhance performance for lithium-sulfur batteries

Summary The dissolution and diffusion of intermediate product polysulfide in lithium-sulfur battery (Li-S) between electrodes pose great challenge for the further application of Li-S batteries. Herein, we first prepared nano SiO 2 blending polyetherimide (PEI) separator modified with acetylene black/polyvinylpyrrolidone (PVP) coating layer. Joint effect of acetylene black and PVP on polysulfide contribute to outstanding cycle performance. The Li-S cell with CP55 separator presents superior cycle performance (650 mAh g −1 ) than the Li-S cells with the Celgard 2320 and PEI-4 separator after 200 cycles. In addition, the SiO 2 blending PEI separator modified with acetylene black/PVP coating layer for Li-S cells shows higher ionic conductivity (2.02 mS cm −1 ), excellent compatibility with lithium and better thermal stability. This work presents a convenient and economical strategy to alleviate polysulfide dissolution and the CP55 separator is a promising candidate for the further application of Li-S batteries.