An investigation of the proton conductivities of hydrated poly(vinyl alcohol)/boric acid complex electrolytes

Proton-conducting polymer complex electrolytes were prepared by incorporation of boric acid, H3BO3 into poly(vinylalcohol), PVA, to form hydrated PVAxH3BO3 where x denotes the number of moles of boric acid per polymer repeat unit. The dried materials were characterized via Fourier transform infrared spectroscopy, thermogravimetry, and X-ray diffraction. The proton conductivity of the hydrated complex electrolytes was measured by AC impedance spectroscopy. PVA2H3BO3 with RH ∼25% was found to be optimum composition that exhibited proton conductivity of 1.3 × 10−3 S/cm at 80 °C.