不同晶型MnO2超级电容器电极材料的电化学特性
Electrochemical Properties of Supercapacitor Electrode Materials Prepared by MnO2 with Different Crystal Forms
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摘要: 用不同晶型的MnO2粉体制备了β-MnO2和γ-MnO2电极, 用循环伏安和恒流充放电试验研究了上述两种电极的电化学特性。结果表明: β-MnO2和γ-MnO2电极都具有良好的电容性能, 但后者具有更为良好的倍率放电性能, 适合大电流充放电; 在300 mA·g-1的电流密度下, 经5 000个循环充放电之后, β-MnO2电极已失效, 而γ-MnO2电极的容量保持率还高达89.2%。Abstract: The β-typed and γ-typed electrodes were prepared by MnO2 powders with different crystal forms, and the electrochemical properties of the above-mentioned electrodes were studied by cyclic voltammetry method and constant-current charge and discharge test. The results show that both the β-typed and γ-typed electrodes had good capacitance property, and the γ-MnO2 electrode had better rate discharge property and was more suitable for charge-discharge of larger current. Under the condition of the current density of 300 mA·g-1, the β-MnO2 electrode became invalid but the capacitance retention of γ-MnO2 electrode was still as high as 89.2% after circulatory charge-discharge 5 000 cycles.
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