Preparation and proton conductivity of poly(vinylidene fluoride)/ layered double hydroxide nanocomposite gel electrolytes

Layered double hydroxide (LDH) was synthesized in the presence of sodium dodecyl sulfate. X-ray diffraction (XRD) and infrared spectrum revealed that dodecyl sulfate (DS) anions were successfully intercalated into the interlayers of LDH. Poly(vinylidene fluoride)/LDH nanocomposite membranes were prepared by mixing the DS intercalated LDH with poly(vinylidene fluoride) (PVDF) in N,N’0-dimethylformamide solution followed by the solvent evaporation. The nanocomposite membranes were further swollen with a H3PO4 solution in ethylene carbonate-propylene carbonate to obtain the proton conducting nanocomposite gel electrolytes. XRD and transmission electron microscope results showed that LDH particles were well-dispersed in the polymer matrix and partially intercalated by polymer chains. The proton conductivity was highly enhanced in the nanocomposite gel electrolyte systems. In the case of the nanocomposite gel electrolyte containing 7.40 wt.% LDH, the proton conductivity increased by about 2.5 times compared to pure PVDF gel electrolyte.