Alkaline poly(vinyl alcohol)/poly(acrylic acid) polymer electrolyte membrane for Ni-MH battery application

Alkaline polymer electrolyte membrane with high ionic conductivity of 0.019 S cm(-1) at room temperature was prepared from poly(vinyl alcohol) and acrylic acid through solution polymerization. The structure and morphology of the membrane were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The electrochemical properties were measured by the alternating current impedance (AC impedance) and the cyclic voltammetry (CV) techniques. Simulated Ni-MH batteries using Mg-based hydrogen storage alloy produced by the hydriding combustion synthesis and mechanical milling (HCS + MM) technique as negative electrode were assembled by using the experimental PVA-PAA-KOH polymer membrane (polymer Ni-MH batteries) and 6 mol L-1 KOH aqueous (traditional Ni-MH batteries) as electrolytes, respectively. After 10 cycles, the capacity retention rate of the traditional Ni-MH battery was only 3.9 %, but the corresponding value of polymer Ni-MH battery was 14.7 %.