High areal capacitance of Mn3O4-carbon nanotube electrodes

This paper reports the fabrication of Mn3O4-multiwalled carbon nanotube (MWCNT) electrodes for supercapacitors with a high active mass loading of 35 mg cm−2, which showed high capacitance of 3.5 F cm−2, good capacitance retention at high charge-discharge rates and low impedance. Good electrochemical performance was achieved using non-covalent modification of MWCNT with an anionic steroid dispersant, which allowed excellent MWCNT dispersion and facilitated the fabrication of Mn3O4-MWCNT nanocomposites with uniform distributions of individual components. The electrodes showed activation behavior, related to capacitance increase, impedance reduction and enrichment of the Mn3+ and Mn4+ oxidation states.