All-Solid Electrochemical Capacitors Using Proton Conducting Polymer Electrolytes

A novel polymer electrolyte, comprised of a heteropoly acid (ionic conductor) and poly(vinyl-alcohol) (polymer matrix), has been developed for all-solid electrochemical capacitors. The proton conductivity of this polymer electrolyte has reached 0.01 S/cm at room temperature and showed good stability. The solid ECs have demonstrated high rate performance (up to 100 V/s in cyclic voltammetry and a time constant of 10 ms), which exceeded their liquid-based counterpart. Material characterization revealed that crystallized water facilitate the proton conductivity of the polymer electrolyte.