硫脲作还原剂制备二氧化锰及其电化学性能

通过化学液相法,用硫脲作为还原剂和高锰酸钾反应制备了无定形MnO2。用XRD和SEM研究了产物的结构和形貌,用恒流充放电和循环伏安测试考察了MnO2的电化学性能。结果表明:在0.5mol/L的Na2SO4溶液中,电位窗口为0～0.8V、电流密度为1×10–3A/cm2时,首次放电比容量为248F/g,,经过100次循环后比容量保持在232F/g。在(3～5)×10–3A/cm2的电流密度下放电比容量分别为198和182F/g,具有良好的电容特性。

Synthesis of amorphous manganese dioxide by thiourea as reductant and its electrochemical properties

Amorphous MnO2 was synthesized with chemical co-precipitation method by using KMnO4 and thiourea aqueous solution as raw materials. The sample was characterized by XRD and SEM. The electrochemical characteristics of the sample were characterized by CV and constant current charge-discharge tests. The first discharge specific capacitance of the amorphous MnO2 is 248 F/g in 0.5 mol/L Na2SO4 electrolyte at the current density of 1×10–3 A/cm2 in the range of 0～ 0.8 V. After 100 cycles, the specific capacitance still sustains 232 F/g. The constant current charge-discharge tests at 3×10–3 A/cm2 and 5×10–3 A/cm2 still exhibit a good cycleability, the discharge specific capacitance is 198 F/g and 182 F/g, respectively. The amorphous MnO2 is an excellent electrode material for super-capacitor.