Preparation of alkaline solid polymer electrolyte based on PVA-TiO2-KOH-H2O and its performance in Zn-Ni battery

A novel composite alkaline polymer electrolyte based on poly(vinyl alcohol) (PVA) polymer matrix, titanium dioxide (TiO2) ceramic fillers, KOH, and H2O was prepared by a solution casting method. The properties of PVA-TiO2-KOH alkaline polymer electrolyte films were studied by X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and AC impedance techniques. DSC and XRD results showed that the domain of amorphous region in the PVA polymer matrix augmented when TiO2 filler was added. The SEM result showed that TiO2 particles dispersed into the PVA matrix although some TiO2 aggregates of several micrometers were formed. The alkaline polymer electrolyte showed excellent electrochemical properties. The room temperature (20 °C) ionic conductivity values of typical samples were between 0.102 and 0.171 S cm−1. The Zn-Ni secondary battery with the alkaline polymer electrolyte PVA-TiO2-KOH had excellent electrochemical property at the low charge-discharge rate.