A new configuration of hydrogen ion supercapacitors was reported. A positive electrode composed of pseudocapacitive MnO2, highly dispersed into active porous carbon through an impregnation method, was combined with a nitrogen-doped highly ordered mesoporous carbon with enhanced electrochemical hydrogen insertion capacity as a negative electrode. During the operation, hydrogen ion shuttled between MnO2 and carbon electrodes. The MnO2 was formed on the surface of nanostructured carbon through a spontaneous redox reaction. Operating in an aqueous neutral solution, the hybrid device demonstrated an extended working voltage to ∼2.1 V with good cycle life.
Keywords: electrochemical hydrogen insertion; highly ordered mesoporous carbon; hydrogen ion supercapacitor; pseudocapacitive MnO2 electrode.