New method for the preparation of solid polymer electrolyte based on poly(vinylidene fluoride-co-hexafluoropropylene)

A novel solid polymer electrolyte (pore-gel SPE) has been found to provide superior SPE having a high conductivity, good mechanical strength and low solution leakage. This pore-gel SPE was prepared from gelation in pores of polymer membrane with electrolyte solution including solvent. The conductivity of pore-gel type PVDF-HFP/ TEABF4 (Tetraethylammomium tetrafluoroborate) membrane can reach 1.6×10-1 Scm-1. The tensile strength of this membrane was 4,000 kPa, which is about 23 times larger than that of gel-type SPE with the same composition. Poregel SPE reduced solution leakage to 0%, compared with 2% of hybrid-type SPE after 2.0 hr leakage test in PVDFHFP/ TEABF4 membrane.