基于钴酸钙电极的固态对称超级电容器

Solid state symmetric supercapacitor based on calcium cobalt oxide electrode

采用柠檬酸盐法制备钻酸钙(Ca2Co2O5)。XRD、SEM分析表明,制备的粉体为单相组成,属于片状团聚体。用循环伏安、恒流充放电及交流阻抗法测试产物在5mol/LKOH电解液中的电化学性能。Ca2Co2O5材料通过法拉第电化学反应及可能的电解液中阴离子的插入反应存储电荷,在0~0.5V充放电,1A/g电流下的比电容可达440.3F/g,以5A/g循环1500次的电容保持率为69.3%。将Ca2Co2O5电极与聚乙烯醇(PVA)-KOH凝胶电解质装配成全固态对称电化学电容器「该电容器在比功率为750W/kg时的比能量可达31.0Wh/kg,以5A/g在0~1.5V循环3000次的电容保持率为77.1%。

Calcium cobalt oxide (Ca2Co2O5) was prepared by citric acid method. XRD, SEM analysis results revealed that the prepared Ca2Co2O5 was single phase composed, the powder was aggregated into flake like shape. The electrochemical performance of the product in 5 mol/L KOH electrolyte was tested by means of cyclic voltammetry, galvanostatic charge-discharge and impedance measurements. The charge storage of Ca2Co2O5 was mainly associated with the faradic reaction and the possible intercalation of electrolyte oxygen ions. The specific capacitance of Ca2Co2O5 electrode reached 440.3 F/g at 1 A/g (0-0.5V). The specific capacitance of Ca2Co2O5 electrode retained 69. 3% after 1500 cycles at 5 A/g (0 - 0.5V). Polyvinyl alcohol(PVA)-KOH gel was used as electrolyte in the all solid Ca2Co2O5 -based symmetric supercapacitor. The specific energy of the supercapacitor was 31.0 Wh/kg at the specific power of 750 W/kg, the capacitance retention was 77.1 % after 3 000 cycles at 5 A/g (0-1.5 V).