A mono-comb poly (siloxane-g-ethylene oxide) electrospun fiber membrane for solid-state sodium ion batteries

•A novel mono-comb electrospun fiber membrane is successfully prepared.•The fiber membrane has outstanding thermal stability and strength.•Sodium ion batteries with the membrane exhibit excellent electrochemical performance. Replacing organic liquid electrolytes with solid-state electrolytes (SSEs) can effectively improve safety in conventional rechargeable sodium ion batteries. Herein, a mono-comb poly(siloxane-g-ethylene oxide) fiber membrane is proposed to construct fast sodium ion channels for solid electrolyte based on electrospinning polyacrylonitrile (PAN) fiber and the polymerization reaction between polymethylhydrosiloxane (PMHS) and methoxypolyethylene glycols (MPEG). The fiber membrane exhibits a high room-temperature ionic conductivity of 1.06 mS cm−1, an electrochemical stability window of 4.8 V, and outstanding thermal stability and mechanical strength. A rechargeable Na/Na3V2(PO4)3 solid-state full cell based on the polymer electrolyte membrane exhibits a high initial discharge capacity of 114.3 mAh g−1 at 0.2C and a discharge capacity retention of 86.5% after 1000 cycles at 1C. These advantages make the mono-comb poly(siloxane-g-ethylene oxide) fiber membrane have a good prospect in safety sodium ion batteries.