纳米α-MnO_2的固相制备及电化学性能

The synthesis of nanocrystalline α-MnO_2 by solid-phase reaction technique and its electrochemical performance

用KMnO2和醋酸锰为原料，在室温下固相反应经过热处理和酸处理制备纳米α-MnO2，采用X射线衍射技术和扫描电子显微镜（SEM）分析了MnO2的结晶结构及表面形态；通过循环伏安法、恒流充放电和交流阻抗测试研究了样品的电化学行为。合成的α-MnO2在1．0mol／LNa2S04电解液中，-0．1～0．8V（vs．SCE）范围内，电流密度为300mA／g，3mV／s的扫描速度下的比电容可达222．7F／g，经1000次循环后，容量保持85％以上，有着较好的循环性能和电容稳定性。

Nanocrystalline α-MnO2 was synthesized with solid-phase reaction through heat treatment and acid treatment at room temperature by using KMnO4 and Mn（CHaCOO）2 ·4H2O as raw materials. The sample was characterized by XRD and SEM. The electrochemical characteristics of the sample were characterized by CV and constant current charge-discharge tests. The specific capacitance of the nanoα-MnO2 was 222.7F/g in 1.0 mol/ L Na2SO4 electrolyte at the scan rate of 3mV/s, the current density of 300mA/g, in the range of --0.1-0.8V （vs. SCE） ,after 1000 times cycle, the capacity is maintain of 85%, a good circulation performance and capacitance stability. The nano α-MnO2 was an excellent electrode material for supercapacitor.