采用水热法,在不同的水热反应温度和反应时间条件下制备了两种晶型和形貌的二氧化锰,并将之用于超级电容器电极材料.借助X射线衍射、扫描电镜、透射电镜以及比表面分析仪等测试手段对二氧化锰材料进行物理结构表征.结果表明:100℃水热反应12h的产品为纳米片状的ē-MnO2,其BET比表面积为23.2 m2/g;200℃水热反应36h的产品为纳米线状的α-MnO2,其BET比表面积为14.6 m2/g.通过循环伏安、恒电流充放电和电化学阻抗研究了二氧化锰材料的电化学行为.结果表明:δ-MnO2纳米片的循环伏安曲线比α-MnO2纳米线电极更接近于矩形;在0.5 Mg电流密度下,δ-MnO2纳米片的比电容高达283.5 F/g,而α-MnO2纳米线只有227.5 F/g.%Two kinds of manganese dioxide with different crystal shapes and morphologies were prepared by hydrothermal method under different reaction temperatures and times,and they were used as the electrode material for supercapacitors.The physical structures of the manganese dioxide were characterized by X-ray diffractometer,scanning electron microscopy,transmission electron microscopy,and surface area analyzer.The results showed that the δ-MnO2 nanosheets and α-MnO2 nanowires were synthesized under 100 ℃ for 12 h and 200 ℃ for 36 h,respectively.And the BET surface areas of the δ-MnO2 nanosheets and a-MnO2 nanowires were 23.2 m2/g and 14.6 m2/g,respectively.The electrochemical behaviors of the manganese dioxide were investigated by cyclic voltammetry,galvanostatic charge-discharge,and electrochemical impedence spectra.Results showed that the cyclic voltammetry curve of the δ-MnO2nanosheet electrode was more similar to a rectangle than that of α-MnO2 nanowires'.And the δ-MnO2 nanosheets electrode delivered a specific capacitance of 283.5 F/g at the current density of 0.5 A/g,while the α-MnO2 nanowires electrode only delivered a specific capacitance of 227.5 F/g.
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