Electrochemical characterization of MnO₂ as the cathode material for a high voltage hybrid capacitor

Jian-ling Li1),Fei Gao1),Yan Jing1),Rui-ying Miao1),Ke-zhong Wu2),and Xin-dong Wang1) 1) School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China 2) Department of Chemistry and Material Science,Hebei Normal University,Shijiazhuang 050016,China

摘 要：Manganese dioxide（MnO2） was prepared using the ultrasonic method.Its electrochemical performance was evaluated as the cathode material for a high voltage hybrid capacitor.And the specific capacitance of the MnO2 electrode reached 240 F·g-1.The new hybrid capacitor was constructed,combining Al/Al2O3 as the anode and MnO2 as the cathode with electrolyte for the aluminum electrolytic capacitor to solve the problem of low working voltage of a supercapacitor unit.The results showed that the hybrid capacitor had a high energy density and the ability of quick charging and discharging according to the electrochemical performance test.The capacitance was 84.4 μF,and the volume and mass energy densities were greatly improved compared to those of the traditional aluminum electrolytic capacitor of 47 μF.The analysis of electrochemical impedance spectroscopy（EIS） showed that the hybrid capacitor had good impedance characteristics.

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