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以KMn O4和Mn SO4为原料,采用水热法合成超级电容器电极材料纳米MnO_2,采用X射线衍射(XRD)、扫描电镜(SEM)、比表面积测试、循环伏安、恒流充放电和电化学阻抗等方法测试MnO_2的结构和电容性能。结果表明,采用水热法可以合成直径为10~90 nm,长度为1~3 cm的α-MnO_2纳米线;水热温度对MnO_2纳米线的晶粒和形貌影响显著,但不改变MnO_2的晶型;随水热温度升高,MnO_2纳米线的晶粒逐渐长大,同时变长变粗,导致比表面逐渐降低;MnO_2纳米线的比电容随水热温度升高呈先增大后减小,当水热温度为140℃时比电容最大,为227 F/g,同时表现出良好的倍率性能。
Nanometer MnO 2 electrode material was synthesized by hydrothermal method using KMn O 4 and Mn SO 4 as raw materials. XRD, SEM, specific surface area, cyclic voltammetry, constant current charge-discharge and electrochemical Impedance and other methods to test the structure and capacitance properties of MnO_2. The results show that α-MnO 2 nanowires with diameter of 10 ~ 90 nm and length of 1 ~ 3 cm can be synthesized by hydrothermal method. The hydrothermal temperature has a significant effect on the grain and morphology of MnO 2 nanowires, With the increase of hydrothermal temperature, the grain size of MnO 2 nanowires gradually grows and becomes longer and thicker, which leads to the decrease of specific surface area. The specific capacitance of MnO 2 nanowires firstly increases and then decreases with the increase of hydrothermal temperature, When the hydrothermal temperature of 140 ℃, the largest specific capacitance of 227 F / g, while showing good rate performance.