掺钴MnO2电极的电化学电容行为研究

采用化学共沉淀法制备了超级电容器电极材料化学掺杂Co的MnO2电极,借助XRD测试对电极材料进行了物理结构表征,表明掺Co量影响材料的晶体结构和活性。电化学测试结果得出化学掺杂的配比对电化学性能影响很大,掺杂量为n(Co)：n(Co Mn)大于或小于0．1时,其循环伏安、充放电和电容特性较差。而适量的掺入Co,改善了电极的电容性能,降低了电极内阻,提高了活性物质的利用率,并使得电极能够在大电流下进行充放电。经1000次循环,适量掺杂的MnO2电极比未掺杂的MnO2电极具有更高的电容性能,掺杂的MnO2电极循环性能相对较差,但是其比电容仍然大干未掺杂MnO2电极。

Study on capacitance performance of MnO2 electrodes chemically doped with Co3+

Cobalt chemically doped MnO2 used as electrode materials for supercapacitors were preparedby chemical co- precipitation method. The result of XRD shows that the values of doped Co affect the crystal structure and electroactive property of these materials. The electrochemical measurements show that the ratios of cobalt have great influence on their electrochemical capacities. When the mole ratio of n(Co):n(Co+ Mn) is higher or lower than 0.1, their electrodes present the worse charge- discharge properties and capacity. The electrode doped with Co has better capacity property,low impedance and high usage rate, and can be charge- discharged at high current of 40mA. After 1000 cycles, specific capacitance of modified MnO2 electrode is higher than that of MnO2 electrode, but its cycling charge- discharge property is relatively worse.