Hexamethylene diisocyanate-modified Al2O3 as inorganic fillers enabling low resistance and high stable cross-linked polymer electrolyte of lithium metal batteries

Abstract

In this work, we first utilized hexamethylene diisocyanate-modified Al2O3 as inorganic fillers to construct a double-network solid polymer electrolytes based on the interpenetrated poly(vinylidene fluoride) and poly(ethylene oxide) (PEO@PVDF). The hexamethylene diisocyanate can promote the uniform dispersion of Al2O3 in PEO@PVDF polymer electrolytes. Consequently, the PEO@PVDF polymer electrolyte with hexamethylene diisocyanate-modified Al2O3 (PPH@Al2O3) exhibited a perfect room temperature ionic conductivity (9.19 × 10−5 S cm−1), excellent electrochemical stability voltage (4.7 V). The LiFePO4//PPH@Al2O3//Li cell delivers an initial capacity of 139.2 mAh g−1 at 0.2 C and with a capacity retention close to 100% after 100 cycles.