YAN Dongliang

(School of Material Science and Engineering, Guilin University of Electronic Technology, Guilin Guangxi ****0042, China)

Abstract:Amorphous hydrous MnO2 was synthesized by the chemical precipitation method by mixing potassium permanganate and polyethylene glycol （PEG400） aqueous solution. XRD, TEM, BET, cyclic voltammetry and chronoptentiometry were carried our for physical and chemical characterization. The results showed the obtained MnO2 had a amorphous nature and exhibited the ideal capacitive behaviors within the potential window of -0.2 to 0.8 V (vs. SCE) in 1 M Na2SO4. The sample obtained at the potassium permanganate/polyethylene glycol of 1:2.5 （wt%）showed the highest BET. The highest specific capacitance of 200.5 Fg-1 was also obtained at a current density of 0.5 Ag-1.

Key words: supercapacitor; manganese dioxide; specific capacitance