Melt-diffused binary solid–solid ionic mixture in a porous polymeric host as free-standing solid electrolyte for lithium batteries

•Novel ionic liquid based and LiTFSI doped solid electrolyte developed.•Solvent-free approach for free-standing solid electrolyte by melt-diffusion.•Leakage-free solid electrolyte shows excellent electrochemical properties.•Lithium battery assembled showed good cyclability and Coulombic efficiency.