Fabrication of Mn/Mn oxide core-shell electrodes with three-dimensionally ordered macroporous structures for high-capacitance supercapacitors

Three-dimensionally ordered macroporous (3DOM) metallic Mn films have been prepared with ordered polystyrene (PS) templates on electrodeposition from an ionic liquid (IL). A 3DOM Mn core-Mn oxide shell film was prepared on anodizing a 3DOM Mn film in KCl aqueous solution. The varied anodization courses were confirmed to cause variations of the material characteristics of the prepared 3DOM Mn/Mn oxide electrodes and thereby in their pseudocapacitive performance. The 3DOM Mn/Mn oxide electrodes anodized with the cyclic voltammetric method showed the most promising specific capacitance, 1200 +/- 60 F g(-1) (based on the mass of 3DOM Mn/Mn oxides), with a satisfactory rate capability and cycling performance. Such electrodes can be potentially applied for lithium batteries and supercapacitors.