【摘要】 用化学共沉淀法和水热法制备了海胆型和纳米线型的Mn O2。采用X射线衍射仪(XRD)、扫描电镜(SEM)对电极材料的物相和形貌进行表征。采用电化学阻抗、循环伏安和恒电流充放电对其进行电化学性能测试。结果表明,采用相同材料不同制备方法得到的Mn O2具有不同的形貌。化学共沉淀法制备的海胆型Mn O2,其直径约为300~500 nm;水热法制备的纳米线型Mn O2,其直径约为10~30 nm,长度约为100~500 nm。两种形貌的Mn O2在6 mol·L-1KOH溶液中具有良好的电容特性,1 A·g-1的电流密度下,海胆型Mn O2的比电容为539 F·g-1;纳米线型Mn O2的比电容为375 F·g-1。经过1000圈的循环后,海胆型Mn O2仅损失了15%的比容量。更多还原

【Abstract】 MnO2 powder with urchin sphere and nanowire were prepared by chemical coprecipitation method and hydrothermal method. The structure and morphology of the products were characterized by Xray diffraction( XRD) spectrometry and scanning electron microscopy( SEM). Their electrochemical performance as a supercapacitor electrode material was investigated comparatively by cyclic voltammetry( CV),electrochemical impedance spectroscopy( EIS),and galvanostatic charge-discharge( CP). The results indicate that MnO2 powder prepared by different preparation methods with the same material displayed different morphologies. Urchin type MnO2 prepared by chemical coprecipitation has a diameter about 300-500 nm. The diameter of nanowire MnO2 prepared by hydrothermal method is about 10-30 nm,with a length of about 100-500 nm. Both of the MnO2 powders have excellent capacitance behaviors in 6mol · L-1KOH solution. The specific capacitance of urchin sphere-structured MnO2 and nanowirestructured MnO2 at the current density of 1 A·g-1were 539 F·g-1and 375 F·g-1,respectively. When the urchin sphere-structured MnO2 was recycled for 1000 times,only 15% of its specific capacity was lost.更多还原