混合超级电容器AC/LiMn_2O_4体系的电化学性能

Study on the Electrochemical Performance of Hybrid Aqueous Electro-chemical Supercapacitor in AC/LiMn_2O_4 System

对AC/LiMnO4体系混合电容器进行研究,以活性炭(AC)为负极材料,尖晶石结构的LiMn2O4为正极材料,Li2SO4为电解液。该体系的原理与锂离子电池很相似,从本质上说属于一种特殊的锂离子电池。改变正负极的质量配比,根据其电化学性能确定了该体系最佳的正负极质量配比。对不同电解液浓度的电容器进行不同电流密度充放电测试,发现电解液浓度增加,会使容量和大电流性能得到明显改善,极化电阻的增大会大大降低放电电压平台。实验表明该体系具有较高的能量密度和功率密度,同时保持了良好的循环性能。

A hybrid aqueous electrochemical supereapaeitor technology was studied in which lithium-ion intercalated compound LiMn2O4 was used as an anode and active carbon as a cathode in a Li2SO4 aqueous electrolyte. The mechanism of this system is similar to that of lithium ion batteries. In essence, this is a special kind of lithium-ion battery. The ratio of anode mass to cathode mass were optimized according to the electrochemical performance of the supercapacitors with diferrent ratio of anode mass to cathode mass. The electrochemical performance in different current concentrations with different electrolyte concentrations was investigated. It was found that the high current performanee of supercapaeitor was obviously improved when electrolyte concentrations was increased, it was also noticed that the augmentation of polarization resistance will greatly reduce the discharge voltage flat. Experiment data indicate that this system exhibit high energy density and power density and maintain nice circulation performance.