针状MnO_2超级电容导电剂添加剂研究

Study on electrochemical performance of acicular MnO_2 by adding conductive additive

利用水热法合成了纳米级针状α型MnO2,在导电剂添加剂占电极材料15%的条件下,添加了AB、MWCNTs、GO,以不同比例复合构建导电网络并制得超级电容电极材料;采用X射线衍射、扫描电镜分析了纳米复合物的形貌和结构;并利用循环伏安法、计时电位法及交流阻抗测定了纳米复合材料的电化学性质和电容性质。结果表明:引入5%MWCNTS和10%AB比电容最好为83.50F/g(电流密度0.25A/g);引入10%AB与5%GO循环性能最佳,1000次循环保持率为87.1%;最后发现添加过多的MWCNTs会过度吸附溶液中离子,导致失效。

A type of acicular manganese dioxide（MnO2 ） via a facile chemical method was demonstrated. By adding 15 % of conductive additive in the electrodes with the materials of AB, MWCNTs,GO, which were added in different pro- portions, the materials constructed of conductive net were got. The morphology and structure of electrodes were systemati- cally characterized by scanning electron microscope（SEM） and X-ray diffraction（XRD）. Cyclic voltammetry（CV） measure- ment,Galvanostatic charge-discharge（DCG） measurement and electrochemical impedance spectroscopy（EIS） were carried out to got the performance of different electrodes. The electrode with 5% MWCNTs and 10 % AB had a great specific ca- pacity of 83.50F/g（under the current density of 0.25A/g）. Electrode with 5% GO and 10% AB had a great cycling per- formance of 87. 1% capacitance retention over 1000 cycles. Electrode with 15 % MWCNTs was easy to out of work because the diffusion of the ions in the electrolyte was restrained by special interior structure.