Enhanced electrochemical performance of the activated carbon electrodes with a facile and in-situ phosphoric acid modification

Abstract

Abstract A facile and in-situ modification approach is proposed to significantly improve the electrochemical performance of the commercial activated carbon (AC) electrode used in supercapacitor. After the phosphoric acid modification, the pore structure, specific surface area and conductivity of the AC electrode are almost unchanged, while the percentage composition of O and P is apparently increased, consequently the corresponding wettability and effective surface area are significantly improved. Electrochemical measurements show that the specific capacitance of the modified AC electrode is high up to 249 F g−1, almost increasing 35% compared with that of the commercial AC electrode, and the capacitance retention after 10,000 cycles at 4 A g−1 still can reaches up to 97%, indicating a preferable cycling stability. Most importantly, the simple phosphoric acid modification used in this work results in such a significant improvement in the electrochemical performance on the premise of the commercial AC electrode, so the facile and in-situ modification method might be a promising approach to improving the electrochemical performance of the commercial AC electrode for the supercapacitor in the future.