【摘要】 在不同的pH值下,以KMnO₄氧化Mn（NO₃）₂分别合成2种化学MnO₂。晶体结构和晶型经X射线衍射仪和X射线扫描电镜检测,表明pH值对晶体形成有一定的影响。在-0.3～0.6V（相对Hg/HgO电极电位）范围用循环伏安法研究两种材料的电化学性能,结果显示它们具有静电电容特征。活性炭作为对电极组成混合型电化学电容器与MnO₂相同电极对称型电化学电容器相比,工作电压窗口和比电容都得到了提高。恒流充放电显示,对称结构电极比电容分别为262和302F/g;不对称结构电极比电容为348和342F/g,具有较好的大电流放电能力和循环寿命。更多还原

【Abstract】 Two chemical manganese oxides were synthesized by oxidation of Mn(NO3)2 salts with KMnO4 under different pH values. The crystal structure and crystal pattern were characterized by mean of X-ray diffraction and X-ray scan microscope, which demonstrated that pH values determined the formation of crystal structure. The electrochemical performance of the two materials was studied by cycling voltammetry in the range -0.3-0.6 V (Hg/HgO), which indicated their capacitive behaviors. Comparison of capacitor with activated carbon as electrode material constructing asymmetric configuration to that with MnO2 constructing symmetric configuration, showed that both working voltage and specific capacitance of hybrid capacitors were increased. Galvanostatic charge/ discharge indicated that the specific capacitance of symmetry structure of electrochemical capacitor were 262 and 302 F/g, respectively, and those of asymmetry structure of electrochemical capacitor were 348 and 342 F/g, respectively. These materials possess better capability of high current discharge and cyclicity.更多还原