PVDF-HFP/PMMA-coated PE separator for lithium ion battery

Microporous poly(vinylidenefluoride-co-hexafluoropropylene) (PVDF-HFP)/poly(methyl methacryate) (PMMA)-coated polyethylene (PE) separators were prepared by a simple dip-coating process with various compositions of PVDF-HFP/PMMA mixture under 40% relative humidity condition. The results indicate that the porosity, liquid electrolyte uptake, and ionic conductivity of the coated separators are largely affected by a ratio of PVDF-HFP/PMMA mixture and the highest porosity, electrolyte uptake, and ionic conductivity can be achieved at a composition of PVDF-HFP/PMMA (5/5). The results of the cell performance tests also reveal that the PE separator coated with PVDF-HFP/PMMA in a ratio of 5:5 provides better rate capability and cycle stability than other PE separators coated with different ratios.