介孔CoMn_(2)O_(4)/还原氧化石墨烯复合材料的制备及其超级电容性能

Preparation of Mesoporous CoMn_(2)O_(4)/Reduced Graphene Oxide Composites and Their Supercapacitor Properties

采用共沉淀法制备了CoMn_(2)O_(4)/还原氧化石墨烯(CoMn_(2)O_(4)/rGO)复合电极材料,并研究了石墨烯含量对CoMn_(2)O_(4)/rGO复合材料形貌、微观结构及电化学性能的影响。结果表明:CoMn_(2)O_(4)纳米颗粒沉积在石墨烯纳米片的表面,随着石墨烯含量的增加,CoMn_(2)O_(4)纳米颗粒在r GO表面的分布逐渐均匀,聚集现象消失。CoMn_(2)O_(4)/rGO具有高的比表面积及优良的电化学性能,其中CoMn_(2)O_(4)/rGO20 (rGO质量分数为20%)电容性能最好,在电流密度1 A/g时具有1 420 F/g的比电容。CoMn_(2)O_(4)/rGO30(rGO质量分数为30%)的倍率性能和循环稳定性能最好。2 000次充放电后,样品CoMn_(2)O_(4)/rGO30在5 A/g时的比电容保持率为94%,样品CoMn_(2)O_(4)的比电容保持率为78%。

CoMn_(2)O_(4) nanoparticles on reduced graphene oxide(CoMn_(2)O_(4)/rGO) composites with different graphene contents were synthesized in situ by a coprecipitation method. The effect of graphene content on the morphology, microstructure and electrochemical properties of CoMn_(2)O_(4)/rGO materials was investigated. The results show that CoMn_(2)O_(4) nanoparticles are deposited on the surface of graphene nanosheets. The distribution of CoMn_(2)O_(4) nanoparticles on the surface of rGO is gradually uniform, and the particle aggregation disappears as graphene content increases. CoMn_(2)O_(4)/rGO exhibits a great specific surface area and an excellent electrochemistry. The optimum capacitance performance of CoMn_(2)O_(4)/rGO20(20% rGO, in mass fraction) can be obtained, and the specific capacitance is 1 420 F/g at 1 A/g. CoMn_(2)O_(4)/rGO30(30% rGO, in mass fraction) has the optimum cyclic stability. The specific capacitance retention rate of CoMn_(2)O_(4)/rGO30 is 94% at 5 A/g, while that of CoMn_(2)O_(4) is 78%, after 2 000 cycles of charges and discharges.