Effect of Manganese Valence on Specific Capacitance in Supercapacitors of Manganese Oxide Microspheres |
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| Authors: | Dr Xing Chen Lei Li Dr Xiaoli Wang Prof Kun Xie Prof Yuqiao Wang |
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| Institution: | 1. School of Chemistry and Chemical Engineering, Southeast University, 211189 Nanjing, P.?R. China;2. College of Optoelectronic Engineering, Chongqing University, 400044 Chongqing, P.?R. China;3. Chongqing Key Laboratory of Water Environment Evolution and Pollution Control in Three Gorges Reservoir, Chongqing Three Gorges University, 404020 Wanzhou, P.?R. China |
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| Abstract: | Manganese oxides have attracted great interest in electrochemical energy storage due to high theoretical specific capacitance and abundant valence states. The multiple valence states in the redox reactions are beneficial for enhancing the electrochemical properties. Herein, three manganese microspheres were prepared by a one-pot hydrothermal method and subsequent calcination at different temperatures using carbon spheres as templates. The trivalent manganese of Mn2O3 exhibited multiple redox transitions of Mn3+/Mn2+ and Mn4+/Mn3+ during the intercalation/deintercalation of electrolyte ions. The possible redox reactions of Mn2O3 were proposed based on the cyclic voltammetry and differential pulse voltammogram results. Mn2O3 microsphere integrated the advantages of multiple redox couples and unique structure, demonstrating a high specific capacitance and long cycling stability. The symmetric Mn2O3//Mn2O3 device yielded a maximum energy density of 29.3 Wh kg?1 at 250 W kg?1. |
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| Keywords: | manganese oxide Mn2O3 redox couple supercapacitor tervalent |
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