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1、ElectrochimicaActa45(1999)67±86www.elsevier.nl/locate/electactaOnthecorrelationbetweensurfacechemistryandperformanceofgraphitenegativeelectrodesforLiionbatteriesa,aaabD.Aurbach*,B.Markovsky,I.Weissman,E.Levi,Y.Ein-EliaDepartmentofChemistry,Bar-IlanUniversity,Ramat-Gan52900,IsraelbElectricFuelL
2、td.,P.O.Box641,BeitShemesh9900,IsraelReceived3February1999;receivedinrevisedform13April1999AbstractThispaperdiscussessomeimportantaspectsofthecorrelationbetweensurfacechemistry,3Dstructure,andtheelectrochemicalbehavioroflithiatedgraphiteelectrodes.Byreviewingresultsobtainedwithdierentelectroly
3、tesolutions(e.g.ethylenecarbonate-basedsolutions,propylenecarbonatesolutions,andether-basedsystems),wedescribethestabilizationandcapacityfadingmechanismsofgraphiteelectrodes.Oneofthefailuremechanisms+occursatpotentials>0.5VLi/Li,andrelatestoanincreaseintheelectrode'simpedanceduetoimproperpassi
4、vationandasimultaneouschangeintheelectrode'smorphology,probablyduetogasformation.Atlowpotentials(dependingontheelectrolytesolutioninvolved),phenomenasuchasexfoliationandamorphizationofthegraphiteelectrodescanbeobserved.Stabilizationmechanismsarealsodiscussed.Ingeneral,surfacestabilizationofthe
5、graphiteisessentialforobtainingreversiblelithiationandalongelectrodecyclelife.Thelatterusuallyrelatestoprecipitationofhighlycompactandinsolublesurfacespecies,whichadherewell,andirreversibly,totheactivesurface.Hence,thechoiceofappropriateelectrolytesolutionsintermsofsolvents,saltsandadditivesis
6、verycriticalfortheuseofgraphiteanodesinLibatteries.ThemajoranalyticaltoolsforthisstudyincludedFTIRandimpedancespectroscopies,XPS,andinsituandexsituXRDinconjunctionwithstandardelectrochemicaltechniques.#1999ElsevierScienceLtd.Allrightsreserved.Keywords:Lithiumelectrodes;Lithiatedgraphite;Limeta
7、landLiionbatteries;Surfacechemistry;FTIR;XPS;EDAX;InsituXRD;EIS1.Introductionelectrochemicalscience,becausethesesystemsarehighlycomplexandthus,theirbasicstudyisverychal-Liionbatteriesarebecomingincreasinglyimportantlenging.Reviewingtheh