【摘要】 采用机械化学法,在高锰酸钾和乙酸锰摩尔配比为1/1的条件下制备了弱结晶性α-MnO2。采用循环伏安、交流阻抗等方法对MnO2电极进行测试;对MnO2超级电容器在6mol/L KOH溶液中以1.2V放电窗口、200mA/g电流密度下进行充放电过程研究。结果表明,超级电容器在低电位范围表现出双电层电容,在高电位范围表现为法拉第假电容;Mn3O4电化学惰性物质主要在初始40次充放电过程中生成,其使循环伏安图中氧化还原峰逐渐消失、高电位法拉第假电容逐渐减小、放电曲线逐渐接近直线,表现为双电层电容特征。电极最大比容量为416F/g,200次循环后为240F/g,等效串联电阻由17Ω逐渐增到41Ω。更多还原

【Abstract】 α-MnO₂ has been prepared by mechanochemical method,starting from equivalent KMnO₄ and（Mn（CH₃COO）₂.） The electrochemical performance of MnO₂ electrode was investigated by cyclic voltammograms,（A.C.） impedance,etc.The charge-discharge process of MnO₂ supercapacitor in 6mol/L KOH was studied within 1.2V,at（200mA/g.） The results suggest that the supercapacitor displays double layer capability at low potential,while pseudocapacitance properties at high potential;the electrochemical inert（Mn₃O₄） formed mainly during the initial 40 charging and discharging processes.In the charge-discharge cycling,the pseudocapacitance properties disappeared gradually;the discharge curves were close to be linear,which indicating the characteristic of double-layer capability;the maximum capacitance of MnO₂ electrode was as high as 416F/g,retained 240F/g after 200 cycles;the equivalent series resistance（ESR） increased from 17Ω to 41Ω.更多还原