石墨烯、石墨烯碳纳米管的制备及其超级电容器性能研究

国内图书分类号：O613.71学校代码：10213国际图书分类号：540密级：公开理学硕士学位论文石墨烯、石墨烯/碳纳米管的制备及其超级电容器性能研究硕士研究生：葛士彬导师：杨春晖教授申请学位：理学硕士学科：无机化学所在单位：化工学院答辩日期：2009年6月授予学位单位：哈尔滨工业大学ClassifiedIndex:O613.71U.D.C:540DissertationfortheMasteralDegreeinSciencePREPARATIONANDSUPERCAPACITORPROPERTIESOFGRAPHENE、GRAPHENE/CARBONNANOTUBESCandidate：GeShibinSupervisor：Prof.YangChunhuiAcademicDegreeAppliedfor：MasterofScienceSpeciality：InorganicChemistryAffiliation：SchoolofChemicalEngineeringDateofDefence：June,2009Degree-Conferring-Institution：HarbinInstituteofTechnology哈尔滨工业大学理学硕士学位论文-I-摘要随着社会经济的发展，人们对于清洁能源以及生态环境越来越关注，超级电容器作为一种新型的储能器件,由于其无污染、高效的优良特性，越来越受到人们的重视。石墨烯自2004年问世以来，已经在诸多领域引起了广泛的关注，各国科学家都在争先恐后的研究石墨烯的各种特殊的性质。石墨烯的理论比表面积高达2630m2/g，而且其导电性非常好，是制造超级电容器的理想材料。采用Hummers还原氧化石墨法制备了石墨烯，使用AFM、SEM、TG表征了其结构与形貌，讨论了干燥温度和溶剂对石墨烯形貌的影响，结果表明，石墨烯样品的厚度为0.59nm，低温干燥可以使石墨烯保持良好的片状结构，有水存在时可以使石墨烯更好的分散。采用石墨烯为电极材料制备出超级电容器，研究了粘结剂含量、石墨烯涂覆量、电极成型压力、电解液对石墨烯电极电容性能的影响，结果表明，随着PVDF含量的增加，掉粉现象消失，等效内阻增大；石墨烯涂覆量太少比容量小，太多容易掉粉；随着电极成型压力的增加，比容量逐渐减小；在6mol/L的KOH溶液中，所制得的电容器比容量可达72F/g。通过循环伏安法、恒流充放电法、交流阻抗法研究了石墨烯超级电容器的电化学性能，结果表明，电容器在不同电压扫描速率下表现出良好的可逆性和双电层电容特性，可大电流充放电，等效串联内阻小。将碳纳米管引入石墨烯体系中，制备出石墨烯/碳纳米管复合材料，扫描电镜结果显示，碳纳米管被成功的负载到了石墨烯上。采用石墨烯/碳纳米管复合材料为电极材料制备出超级电容器，研究了不同碳纳米管种类、碳纳米管含量对石墨烯电极电容性能的影响，结果表明，采用长度为1-2μm、外径10-20nm的多壁碳纳米管制备的电容器表现出最好的电容性能，比容量达112F/g，随着碳纳米管含量的增加，比电容增加，但过多反而使比电容下降。通过循环伏安法、恒流充放电法、交流阻抗法研究了石墨烯/碳纳米管超级电容器的电化学性能，结果表明，电容器在不同电压扫描速率下表现出良好的可逆性和双电层电容特性，甚至60mV/s时仍表现出很好的电容特性，可大电流充放电，充放电效率高，等效串联内阻小。关键词石墨烯；超级电容器；碳纳米管；比容量哈尔滨工业大学理学硕士学位论文-II-AbstractWiththeeconomicdevelopment,thereisenvironment-friendlyenergy,andecologicalenvironmenthasbecomeincreasinglyconcernedaboutanewtypeofsuper-capacitorsastheenergystoragedevices,becauseofitsnon-polluting,high-performancecharacteristicsofthefine,ithasgainedmoreandmoreattention.GrapheneSinceitsinceptionin2004,causedinmanyfieldshasbeenwidespreadconcern,thescientistsarescramblinggrapheneresearchthenatureofthevariousspecial.Thetheoryofgraphenesurfaceareaashighas2630m2/g,anditsverygoodelectricalconductivityistheidealmaterialforsupercapacitor.UsingHummersmethodtorestoregraphiteoxidetopreparegraphene,theuseofAFM,SEM,TGcharacterizationofthestructureandmorphology,discussedthedryingtemperatureandsolventonthemorphologyofgraphene.Resultsshowthatthicknessofthegraphenesampleis0.59nm,low-temperaturedryingcanmaintaingoodgraphenesheetstructure,thepresenceofwatercanmakeabetterdispersionofgraphene.Preparingsupercapacitorsbyusinggrapheneforelectrodematerials,studyingeffectofthebindercontent,thevolumeofgraphenecoated,electrodeformingpressureoncapacitancecharacteristicsofsupercapacitor.TheresultsshowedthatwiththeincreaseofPVDFcontentequivalentresistanceincreasesandamostdon’tdroppowder;thespecificcapacitanceincreasewiththecoatedgrapheneweightbutwhenit’stoomuchgraphenewilleasytodroppowder;withtheelectrodeformingpressureincreases,thespecificcapacitancein6mol/LofKOHsolutionobtainedto72F/g.Cyclicvoltammetry,constantcurrentcharge-discharge,ACimpedancemethodwereusedtostudythegrapheneelectrochemicalsupercapacitorperformance,resultsshowthatatdifferentscanratesshowedgoodreversibilityandcharacteristicsofelectricdoublelayercapacitor,canbehigh-currentcharge-dischargeandhasasmallequivalentseriesresistance.Theintroductionofthecarbonnanotubestographenesystem,preparedgraphene/carbonnanotubecomposites,scanningelectronmicroscopyshowedthatcarbonnanotubeshavebeensuccessfullyloadonthegraphene.Graphene/carbonnanotubescompositeelectrodematerialswereusedforpreparingsupercapacitors,studiedthedifferenttypesofcarbonnanotubes,carbonnanotubecontentoneffectoftheelectrode哈尔滨工业大学理学硕士学位论文-III-capacitance,theresultsshowthatsupercapccitorusethelengthof1-2μm,diameterof10-20nmmulti-walledcarbonnanotubeshowthebestperformanceofthecapacitanceandhasthespecificcapacityof112F/g.Thecontentofcarbonnanotubeswithanincreaseinspecificcapacitance,butitdeclinedwhenit’stoomuch.Cyclicvoltammetry,constantcurrentcharge-discharge,ACimpedancemethod,werewereusedtostudygraphene/carbonnanotubeselectrochemicalsupercapacitorperformance,resultsshowthatatdifferentvoltagescanratesthecapacitorshowedgoodreversibilityanddouble-layercapacitancecharacteristics,andeven60mV/swasstillshowaverygoodperformancecharacteristicsofthecapacitor,canchargeanddischargecurrent,hasahighcharge-dischargeefficiency,andasmallequivalentseriesresistance.Keywordsgraphene,supercapacitor,carbonnanotube,specificcapacitance哈尔滨工业大学理学硕士学位论文-IV-目录摘要..............................................................................................................................IAbstract........................................................................................................................II第1章绪论................................................................................................................11.1石墨烯概述.......................................................................................................11.2石墨烯制备方法进展及应用............................................................................21.2.1石墨烯研究进展...................................................................