氧化石墨烯(或石墨烯)-MnO2复合体的合成及超级电容中应用

氧化石墨烯(或石墨烯)-MnO2复合体的合成及电化学性能SynthesisandElectrochemicalPerformanceofGrapheneOxide(orGraphene)-MnO2Composites氧化石墨烯/石墨烯-MnO2复合体的合成及电化学研究-I-摘要近年来，氧化石墨烯和石墨烯以其独特的结构和优异的性能，在化学、物理和材料学界引起了广泛的研究兴趣。它们与过渡金属氧化物形成的纳米复合材料是一种很有发展前景的新型材料。在过渡金属氧化物中，二氧化锰由于其资源广泛、价格低廉、环境友好，受到了国内外研究者的关注。用二氧化锰作为电极改性材料，首先是由于纳米二氧化锰具有很大的比表面积，其次MnO2本身也会发生氧化还原反应形成赝电容，有助于提高电容器的电容量。本文采用改进的Hummers法对天然石墨进行氧化处理制备氧化石墨，在水溶剂或醇溶剂中经超声分散，加入KMnO4和MnCl2形成氧化石墨烯-MnO2复合材料。另一方面，将制得的氧化石墨在水合肼的作用下加热还原制备石墨烯，同样加入KMnO4和MnCl2形成石墨烯-MnO2复合材料。实验采用三电极体系，0.5mol/LNa2SO4作为电解液，通过循环伏安、恒流充放电、交流阻抗测试，考察并讨论了溶剂种类、KMnO4和MnCl2的加入量、反应时间以及还原过程中水合肼用量等对氧化石墨烯/石墨烯-MnO2电化学性能的影响。关键词：氧化石墨烯；石墨烯；MnO2；电化学性能氧化石墨烯/石墨烯-MnO2复合体的合成及电化学研究-II-SynthesisandElectrochemicalPerformanceofGrapheneOxide(orGraphene)-MnO2CompositesAbstractInrecentyears,grapheneoxideandgraphemehaveattractedwideinterestduetotheiruniquestructuresandexcellentperformancesinchemistry,physicsandmaterials.Thegrapheneoxide(orgraphene)-metaloxidecompositesarenewpromisingmaterialsforsupercapacitors.Amongtransitionmetaloxides,manganeseoxide(MnO2)ispaidmuchattentionbecauseofitsnaturalabundance,lowcost,andenvironmentalfriendliness.TheuseofMnO2astheelectrodematerialismainlyascribedtoitslargesurfaceareaandpseudocapacitance.ThegraphiteoxidewaspreparedfromnaturalflakegraphitebythemodifiedHummersmethod.Aftertheultrasonicdispersioninwatersolventoralcoholsolvent,thegrapheneoxide-MnO2compositewassynthesizedbyaddingKMnO4andMnCl2.Thegraphenewaspreparedbyrefluxingtheabovementionedgraphiteoxideinthepresenceofhydrazinehydrate.Andthen,thegraphene-MnO2compositewaspreparedwiththeadditionofKMnO4andMnCl2.UsingthethreeelectrodessystemandNa2SO4electrolyte,theeffectofsolvents,amountofMn,reactiontimeandamountofhydrazinehydrateontheelectrochemicalperformancewereinvestigatedforthecompositesofgrapheneoxide-MnO2andgraphene-MnO2bycyclicvoltammetry,constantcurrentcharge/discharge,andelectrochemicalimpedancespectroscopy.KeyWords：Grapheneoxide；Graphene；MnO2；Electrochemicalperformance氧化石墨烯/石墨烯-MnO2复合体的合成及电化学研究-III-目录摘要.....................................................................................................................................IAbstract.....................................................................................................................................II1文献综述.........................................................................................................................-1-1.1引言......................................................................................................................-1-1.2电化学电容器概况..............................................................................................-2-1.2.1电容器的原理及结构...............................................................................-2-1.2.2超级电容器的性能特点...........................................................................-3-1.2.3超级电容器的主要特性...........................................................................-4-1.2.4超级电容器恒流充电特性分析...............................................................-5-1.2.5常用电容器...............................................................................................-8-1.2.6超级电容器发展动态...............................................................................-9-1.3超级电容器材料................................................................................................-11-1.3.1碳材料.....................................................................................................-11-1.3.2金属氧化物.............................................................................................-12-1.3.3导电聚合物.............................................................................................-12-1.4超级电容器电解液............................................................................................-12-1.4.1水系电解液.............................................................................................-12-1.4.2有机电解液.............................................................................................-13-1.4.3固态电解质.............................................................................................-13-1.4.4离子液体(ionicliquid)............................................................................-14-2电极材料的性能测试方法...........................................................................................-16-2.1循环伏安特性曲线............................................................................................-16-2.1.1循环伏安特性曲线测试原理.................................................................-16-2.2恒电流充放电法................................................................................................-17-2.3交流阻抗法........................................................................................................-18-3实验方法.......................................................................................................................-19-3.1主要化学试剂和仪器设备................................................................................-19-3.1.1化学试剂.................................................................................