超级电容器用无定形MnO_2的制备及性能

Synthesis and Electrochemical Performance of Amorphous MnO_2 for Supercapacitor

采用液相氧化还原法制备了无定形态MnO2。通过XRD、SEM、循环伏安及恒电流充放电测试对产物的物理及电化学特性进行了研究。结果表明:200℃热处理后的材料仍保持无定形态,呈形貌规则的球形。以3 mol·L-1 KOH为电解液,充放电电流为200 mA·g-1,未热处理的材料50周期比电容达到332.1 F·g-1,但500周期容量保持率仅为57.5%。200℃热处理后的材料比电容稍有下降,50周期为231.2 F·g-1,但循环性能明显提高,500周期容量保持率高达97.9%,能够满足超级电容器的需要。

Amorphous MnO2 was synthesized by a redox reaction in liquid. Physical and electrochemical characterization of the synthesized material were performed using XRD, SEM, cyclic voltammograms and galvanostatic charge-discharge tests. Results indicated that material by heat treated at 200℃ remained amorphous and had regular spheric shapes. In a 3 mol.L-1 KOH electrolyte and with charge-discharge current of 200 mA.g-1, the 50e specific capacitance reached 332.1 F-gt without heat treatment, but conservation rate of the 500th was only 57.5 %. Heat treatment at 200℃ resulted in a decline of the 50th specific capacitance to 231.2 F-g1 and an improvement of cycle performance of the 500th to 97.9 %, which could meet requirement of supercapacitors.