利用KMnO4氧化MnCO3微米球前躯体制备MnO2微米球.X射线衍射(XRD)、扫描电子显微镜(SEM)、循环伏安(CV)法等测试表明:该MnO2微米球由弱结晶α-MnO2构成,粒径为0.5~2μm.测试样品的MnO2微米球载量为5 mg.cm-2时,在2 mol.L-1(NH4)2SO4溶液中表现出良好的电容性能:其于2 mV.s-1的扫速下比电容达到了135.6 F.g-1;即使是100 mV.s-1的高扫速,比电容仍保持为118.8 F.g-1.500次循环过程中充放电效率保持在87.8%以上.第500次循环的比电容为110.5 F.g-1.

The MnO2 microspheres were prepared through the oxidation of KMnO4 and MnCO3 microspheres precursor.The microstructure and supercapacitor properties of MnO2 were characterized by XRD,SEM and CV.The results show that MnO2 was in a poorly crystalline state with α-crystallographic form,the size of microspheres typically ranged from 0.5 to 2 μm.Loading 5 mg·cm-2 MnO2 microspheres had excellent capacitance behaviors in 2 mol·L-1(NH4)2SO4 solution.The specific capacitance was 135.6 F·g-1 with the scan rate at 2 mV·s-1,and 118.8 F·g-1 with the large scan rate at 100 mV/s.Coulumbic efficiency was still above 87.8% in the 500 cycles,and the specific capacitance of the 500th cycle was 110.5 F·g-1.