| 摘 要： | To improve the electrochemical performances of α-MnO_2 as electrode materials for supercapacitors, Sn-doped α-MnO_2 in the presence of the doping amount of 1%-4% was successfully synthesized by hydrothermal method. As-prepared α-MnO_2 presents nanorod shape and no other impurities exist. By ultraviolet-visible absorption spectroscopy, it is convinced that the band gaps of α-MnO_2 decrease with increasing Sn-doping amount. Cyclic voltammetry investigation indicates that undoped and doped α-MnO_2 all have regular capacitive response. As the scan rate enlarged, the profiles of curves gradually deviate from rectangle. Compared with undoped α-MnO_2, doped α-MnO_2 has larger specific capacitance. The specific capacitance of 3% doped α-MnO_2 reaches 241.0 F/g while undoped α-MnO_2 only has 173.0 F/g under 50 m A/g current density in galvanostatical charge-discharge measurement. Enhanced conductivity by Sn-doping is considered to account for doped sample's enhanced electrochemical specific capacitance.
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