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

In this work, we first utilized hexamethylene diisocyanate-modified Al 2 O 3 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 Al 2 O 3 in PEO@PVDF polymer electrolytes. Consequently, the PEO@PVDF polymer electrolyte with hexamethylene diisocyanate-modified Al 2 O 3 (PPH@Al 2 O 3 ) exhibited a perfect room temperature ionic conductivity (9.19 × 10 −5 S cm −1 ), excellent electrochemical stability voltage (4.7 V). The LiFePO 4 //PPH@Al 2 O 3 //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.