We develop novel membrane electrolytes comprising h-BN-doped poly(ethylene oxide) modified poly(vinylidene fluoride-co-hexafluoropropylene)-nanofibers (h-BN@PEO/PVH) with high ionic conductivity (3.3 × 10-4 S cm-1) and Li+ transference number (0.74), endowing solid LiFePO4//Li...