Electrospun nanofiber polyacrylonitrile coated separators to suppress the shuttle effect for long-life lithium–sulfur battery

Polymeric coating on the separator with effective polysulfides diffusion inhibition can provide intimate contact between intermediate polysulfides and conductive layer of separator for high-energy lithium–sulfur (Li–S) batteries. Herein, polyacrylonitrile–poly(1,5-diaminoanthraquinone) (PAN/PDAAQ) and PAN-potassium functionalized graphene (PAN/K-FGF) nanofibers are synthesized via electrospinning method and act as effective separators for Li–S batteries to minimize polysulfides diffusion toward the anode. PAN/K-FGF coated separator shows capacity retention of 768 mAh g⁻¹ after 100 cycles at 1C. The capacity maintains at 419 mAh g⁻¹ after 500 cycles. PAN/PDAAQ nanofibers are coated on glass fiber separator functions as physical and chemical barrier for polysulfides diffusion. Therefore, the cell with PAN/PDAAQ coating on the separator demonstrates capacity retention of 881 mAh g⁻¹ after 100 cycles at 1C and small capacity decay rate of 0.11% per cycle resulted in 800 cycles at 1C. PAN/PDAAQ could define as an ideal separator material for Li–S batteries.