Characteristics of MnOx electrochemical capacitors with solid electrolyte (CsHSO4) operated at elevated temperatures

An all solid-state electrochemical capacitor operated in the temperature range of 150–180 °C was fabricated with MnO2 thin film electrode and CsHSO4 proton-conductive electrolyte. The sample has a cell structure of Au/MnO2/CsHSO4/MnO2/Au. The electrochemical behavior of the capacitor was characterized by cyclic voltammetry technique. It was found that such electrochemical capacitor exhibited a typical cyclic voltammogram of electrochemical capacitors with the average capacity of 1.30×102 F g−1 (at 180 °C) and showed a significant increase of the capacity by elevating the operation temperature. This result can be explained by the enhancement of proton diffusion into the MnO2 electrode.