活性炭細孔構造を反映した電気二重層キャパシタ等価回路モデルの開発

抄録

In this study, an equivalent circuit model of electric double-layer capacitors (EDLCs) reflecting a branched-pore structure for activated carbon was developed. Geometrical parameters such as pore diameter, pore depth, and branch number of the macro pore, meso pore, and micro pore were estimated from the analysis of the electrochemical impedance for EDLCs, combining theoretical equations and an equivalent circuit model. The developed equivalent circuit model was applied to charge/discharge simulations of EDLCs. The experimental and simulated cell voltages during pulsed-current charge were found to be in excellent agreement. Distributions of currents and voltages in the macro pore, meso pore, and micro pore during pulsed-current charges were discussed using equivalent circuit simulations. Electric-double layers were charged in order of the macro pore, the meso pore, and the micro pore. It was suggested that charge delays of the meso pore and the micro pore originated from both solution resistances in pores and the branch structure of the pore for activated carbon.