Nano-silica doped composite polymer chitosan/poly(ethylene oxide)-based electrolyte with high electrochemical stability suitable for quasi solid-state lithium metal batteries

•Nano-silica doped composite polymer chitosan/poly(ethylene oxide)-based electrolytes show high ionic conductivity and high Lithium ion transference number.•Nano-silica doped composite polymer chitosan/poly(ethylene oxide)-based electrolytes show the good mechanical properties and relatively good thermal stability.•Nano-silica doped composite polymer chitosan/poly(ethylene oxide)-based electrolytes show a high initial cathode capacity of 134 mA h g−1 at a current density of 0.2C for 300 cycles at room temperature.