LithiumBatteryResearchforVehicleTechnologyatBrookhavenNationalLab.X.Q.Yang,K.W.Nam,X.J.Wang,Y.N.Zhou,H.S.Lee,O.Haas,L.Wu,andY.Zhu

BrookhavenNationalLab.Upton,NY11973,USA

H.Li,X.HuangandL.ChenInstituteofPhysics,ChineseAcademyofSciences,Beijing,ChinaTobepresentedat2009InternationalForumonLi-ionBatteryTechnology&IndustrialDevelopment

Beijing,China,October16-18,20091CenterforFunctionalNano-materialsatBNL2NSLSexperimentalfloor34455667788ExperimentalSetupatX7B(NSLS)withImage

PlateDetector(IPD)andinsitucellMylarsheetBoltholesX-raywindowGasketSeparator

CucurrentcollectorAlcurrentcollectorCathode

Anodeinsitucell91010111112121313141415151616171718181919Latticeparameterchangesduring1stcharge:halfcell

Spinel,

LayeredandMixedCathode

SpinelLayered20Discharge/chargecurveandinsituXRDscans:pouchcell

MixedCathode&CarbonAnode

Cathode:MixedLiMn2O4+Li[Co1/3Ni1/3Mn1/3]O2,Anode:Carbon,Voltagerange:2.5V–4.2V,Chargerate:C/2(capacity=10mAh),Blue&greenlines:beforedischarge&charge,Red&purplelines:afterdischarge&charge,S:Spinelphase,L:LayeredphaseDischargeCharge21SpinelLayeredLatticeparameterchangesduringdischarge/charge:pouchcell

MixedCathode&CarbonAnode

Cathode:MixedLiMn2O4+Li[Co1/3Ni1/3Mn1/3]O2,Anode:Carbon,Voltagerange:2.5V–4.2V,Chargerate:C/2(capacity=10mAh),22Unitcellvolumechangesduringcharge:

ComparisonofhalfcellandpouchcellSpinelLayeredHalfcell:MixedLiMn2O4+Li[Co1/3Ni1/3Mn1/3]O2cathode+LifoilanodePouchcell:MixedLiMn2O4+Li[Co1/3Ni1/3Mn1/3]O2cathode+Carbonanode23LatticeparameterchangesduringdischargeatC/2and4Crates:

Pouchcell:MixedCathode&CarbonAnode

SpinelLayered24UnitcellvolumechangesduringdischargeatC/2and4Crates:

Pouchcell:MixedCathode&CarbonAnode

SpinelLayered25Summaries-I?InthehalfcellcomposedofmixedcathodeandLifoilanode,structuralchangescanbedividedintothreetypicalregionswithxintheLi1-xMOmixedcathode(LiCo1/3Ni1/3Mn1/3O2+LiMn2O4)uponfirstchargeupto5.2Vvs.Li/Li+.RegionI(x=0.0to~0.1):StructuralchangesofLiCo1/3Ni1/3Mn1/3O2componentonlyRegionII(x=0.1to~0.4)

:DominantstructuralchangesbyspinelcomponentoverlayeredcomponentRegionIII(x=0.4to~1.0):Continuousstructuralchangesoflayeredcomponentonlyaftercompletionofspinelcomponentphasetransition?Inthepouchcellcomposedofmixedcathodeandcarbonanode,themixedcathodeshowscompletelyreversiblestructuralchangesduringcharge/discharge.26Summaries-II?Inthepouchcellcomposedofmixedcathodeandcarbonanode,mostofthestructuralchanges(i.e.,capacity)ofpouchcellareattributedtothespinelcomponentwhenoperatedbetween2.5~4.2V.?WhendischargerateincreasesfromC/2to4C,kineticallyinducedtwophaseregionclearlyisseenintheinsituXRD,whichwasnotobservedintheinsituXRDatC/2.?WhendischargerateincreasesfromC/2to4C,spinelcomponentinthemixedpouchcellfollowswellthestructuralchangesshownatC/2whereaslayeredcomponentdoesn’t,indicatingbetterhighratecapabilityofthespinelcomponent.?ThetimeresolvedXRDtechniquedevelopedatBNLisaverypowerfultoolforstudyingthestructuralchangesofthenewmixedca