活性石墨烯的制备及其电化学电容特性的研究

Preparation and Electrochemical Capacitive Properties of Activated Graphene

将超声分散处理的氧化石墨直接与氢氧化钾按一定比例混合,经过高温活化处理,制备得到活性石墨烯。采用XRD、TEM以及氮气吸脱附对活性石墨烯的微观结构、表面形貌以及比表面积进行表征分析,并考察材料的电化学电容特性。结果表明:经过直接活化制备得到的活性石墨烯具有很高的比表面积(高达1220m^2/g)和较大的孔容积(0.995cm^3/g)。电化学性能测试结果表明:在1A/g电流密度下,6mol/L KOH溶液中活性石墨烯电极材料的质量比电容能达到111F/g,经过5000次充放电循环后,电容保持率仍为99.2%。

After the ultrasonic dispersion treatment, graphite oxide is mixed with potassium hydroxide directly at a certain percentage, and is activated at a high temperature to prepare activated graphene. The morphology, structure and BET surface area of activated graphene are characterized by X-ray diffraction, transmission electron microscopy and nitrogen ad- sorption-desorption is analyzed. Furthermore, the electrochemical capacitance of the material is investigated. It was found that the activated graphene has a high specific surface area （up to 1220m2/g） and large pore volume （0. 995cm3/g）. The discharge capacitance of the ma- terial in a 6mol/L KOH aqueous electrolyte is lllF/g and the capacitance retention is 99.2% after 5000 cycles at a current density of 1A/g.