Sandwich-structured electrospun all-fluoropolymer membranes with thermal shut-down function and enhanced electrochemical performance

High safety and rate capability of lithium-ion batteries (LIBs) remain challenging. In this study, sandwich-structured poly(vinylidene fluoride)/poly(vinylidene fluoride-co-hexafluoropropylene)/poly(vinylidene fluoride) (PVDF/PVDF-HFP/PVDF) membranes with thermal shut-down function were successfully prepared through electrospinning. The effects different weight ratios PVDF PVDF-HFP in a composite membrane on the physical electrochemical properties explored. It was found that 36 wt% (P/H2/P) showed excellent electrolyte absorption (367%) ionic conductivity (2.5 × 10?3 S/cm). Half-cell P/H2/P as separator exhibited higher discharge capacity better cycle performance than commercial PP membrane. More importantly, thermally stable high melting-temperature chosen outer layer, while low used inner layer. Self-shutdown achieved when heated at 140 °C, providing measure for LIBs. These results indicate PVDF/PVDF-HFP/PVDF is promising candidate LIBs applications.