Preparation and electrochemical characterization of the alkaline polymer gel electrolyte polymerized from acrylic acid and KOH solution

An alkaline polymer gel electrolyte (PGE) film was prepared by solution polymerization of acrylate–KOH–H2O at room temperature, and the preparation conditions were optimized in view of the mechanical properties and ionic conductivity of the film. The PGE film with the optimized composition of 0.02% K2S2O8, 16.75% acrylic acid and 83.23 wt.% 4 mol l−1 KOH solution is transparent, rubber-like and dimensionally stable with improved mechanical properties as compared with gelled electrolyte. The specific conductivity of the film is 0.288 s cm−1 at room temperature and the conductivity values follow the Arrhenius equation with the activation energy of ∼10 kJ mol−1. These data suggest that the ionic conduction proceeds in the same mechanism as in aqueous alkaline solution. Experimental results from the laboratory Zn/Air, Zn/MnO2 and Ni/Cd cells using the PGE film as electrolyte demonstrate that the PGE film has almost the same chemical and electrochemical stability as aqueous alkaline solution, and shows good performance characteristics for application of alkaline primary and secondary battery systems.