用于超级电容器电极材料的聚苯胺基碳-英文-

11,*1,21111(1,,411105;2,510170)().、、X、、.、.,800℃,(325m2·g-1),0.5A·g-1153F·g-1.(),..;;;X;O646Polyaniline-BasedCarbonforaSupercapacitorElectrodeLILi-Min1LIUEn-Hui1,*LIJian1,2YANGYan-Jing1SHENHai-Jie1HUANGZheng-Zheng1XIANGXiao-Xia1(1KeyLaboratoryofEnvironmentallyFriendlyChemistryandApplications,MinistryofEducation,CollegeofChemistry,XiangtanUniversity,Xiangtan411105,HunanProvince,P.R.China;2GuangzhouZhenxingIndustrialCo.,Ltd.,Guangzhou510170,P.R.China)AbstractNovelcarbonmaterialscontainingheteroatoms(nitrogenandoxygen)werepreparedbycarbonizingH2SO4-dopedpolyanilineatdifferenttemperatures.Themorphology,elementalcomposition,surfacechemicalcomposition,andsurfaceareaoftheas-preparedsampleswereinvestigatedbyscanningelectronmicroscopy(SEM),elementalanalyzer,X-rayphotoelectronspectroscopy(XPS)andBrunauer-Emmett-Teller(BET)measurements.Electrochemicalpropertieswerestudiedbycyclicvoltammetry(CV),galvanostaticcharge/dischargeandelectrochemicalimpedancespectroscopy(EIS).Theresultsshowthatthecarbonpreparedbycarbonizingpolyanilineat800℃hasgoodelectrochemicalperformanceanditsspecificcapacitancevalueisashighas153F·g-1underacurrentdensityof0.5A·g-1,althoughithasalowspecificsurfacearea(325m2·g-1).Thehighspecificcapacitanceofthiscarbonisbelievedtobeduetoitsproperproportionofheteroatoms(nitrogenandoxygen),whichprovidealargeamountofpseudo-capacitance.Thiskindofcarbonmaterialcanthusbeusedasapromisingelectrodematerialinsupercapacitors.KeyWordsSupercapacitor;Polyaniline;Carbon;X-rayphotoelectronspectroscopy;Electrochemicalimpedancespectroscopy[Article](WuliHuaxueXuebao)ActaPhys.-Chim.Sin.,2010,26(6)1521-1526JuneReceived:January25,2010;Revised:March19,2010;PublishedonWeb:April30,2010.*Correspondingauthor.Email:[e-mail];Tel:[phone].TheprojectwassupportedbytheNaturalScienceFoundationofHunanProvince,China(07JJ6015).(07JJ6015)鬁EditorialofficeofActaPhysico-ChimicaSinica1521ActaPhys.-Chim.Sin.,2010Vol.26Supercapacitorshavebeenknownoverthirtyyears,whichareoneofthemostpromisingelectrochemicalenergystoragesys-tems.Theyhaveattractedconsiderableattentionsincetheycanprovidemuchhigherenergydensitiesthanconventionaldielec-triccapacitors,andtheycanalsoprovidehigherpowerdensitiesandhavealongercyclelifethanbatteries[1-2].Basedondifferentchargestoragemechanisms,therehavebeentwomajortypesofsupercapacitorsincludingelectricaldouble-layercapacitors(EDLCs)andpseudocapacitors.ThecapacitanceofEDLCsarisesfromthechargeseparationattheelectrode/electrolyteinterface,whilethecapacitanceofpseudocapacitorarisesfromfaradicredoxreactionsattheelectrode/electrolytesurface,forexample,transition-metaloxides[3-7]andelectroactivepolymers[8-11].Thenoblemetaloxides[1,12]andpolymers[10,13]aselectrodematerialshavehigherspecificcapacitancethancarbonmaterials,butthecostofnoblemetalishighandthecyclingstabilityofpolymersisshort,whichlimittheirapplication.Carbonmaterialsarethoughttobethemostattractiveelectrodematerialsbecauseoftheirexcellentelectrochemicalproperty,highsurfacearea,rela-tivelylowcost,andgoodavailability[14].Variouscarbon-enrichedprecursorswereusedtopreparecarbonmaterials,forexample,formaldehyderesin,sucrose,pitchandsoon[15-17].However,onlyseveralresearchers[18-19]usedpolyanilineastheprecursorofcarbonmaterials.Theythoughtthecarbonmaterialpreparedfrompolyanilinehadlowelectricalconductivities,andtheydidnotfurtherresearchtheelectro-chemicalpropertiesofthecarbonmaterial.Thecarbonmaterialscontainingheteroatoms(nitrogenandox-ygen)bycarbonizingpolyanilineaselectrodematerialsforsu-percapacitorswereinvestigatedinthisarticle.Becausepolyani-lineiscommerciallyavailableandverycheap,thepreparationprocessofcarbonmaterialsissimple,webelievethatitisapromisingcarbonmaterialforsupercapacitors.Theelementalcomposition,surfaceareaandelectrochemicalcharacteristicsofthesamplesatdifferentcarbonizationtemperaturesweredis-cussed.1Experimental1.1PreparationofpolyanilineAniline(analyticalgrade)wasredistilledbeforeuse,deionizedwaterwasusedinthisinvestigation.Firstly,16.8mLanilinewasinjectedto100mL1mol·L-1H2SO4(analyticalgrade),and100mL1mol·L-1(NH4)2S2O8(ana-lyticalgrade)wasaddeddrop-wiseintotheaboveacidsolutioncontaininganilinewithin3hunderconstantstirring.Thepoly-merizationwascontinuedfor4hatroomtemperature.Thesolidproductwascollected,washedwithdeionizedwater,anddriedat80℃for48hundervacuumcondition.TheH2SO4-dopedpolyanilinewasobtained.1.2PreparationofcarbonmaterialsThepolyanilinewascarbonizedfor2hinatubularfurnace(SG2-6-1,XiangtanHuafengCo.,Ltd.,China)undernitrogenat-mosphereat700,800,and900℃,respectively.Theheatingratefromroomtemperaturewas5℃·min-1.Theobtainedcarbonspreparedat700,800,and900℃weredenotedbyC700,C800,andC900,respectively.1.3MaterialscharacterizationThemorphologyofthesampleswasexaminedusingascan-ningelectronmicroscope(SEM,HitachiS5200,Japan).Carbon,hydrogen,nitrogen,andsulphurcontentsofthesamplesweredeterminedusingaelementalanalyzer(CHNStypeVarioEL,ElementarCorporation,Germany).Oxygencontentwascalcu-latedbydifference.Beforetheanalysis,allthesam