锂电池寿命模拟

JournalofPowerSources196(2011)3942–3948ContentslistsavailableatScienceDirectJournalofPowerSourcesjournalhomepage:∗,PingLiua,JocelynHicks-Garnera,ElenaShermana,SourenSoukiaziana,MarkVerbruggeb,HarshadTatariab,JamesMusserc,PeterFinamorecaHRLLaboratories,LLC,Malibu,CA90265,UnitedStatesbGeneralMotorsCorp.,Warren,MI48092,UnitedStatescJohnDeereSoutheastEngineeringCenter,Charlotte,NC28241,UnitedStatesarticleinfoArticlehistory:Received25October2010Receivedinrevisedform22November2010Accepted23November2010Availableonline1December2010Keywords:LiFePO4batteryLifemodelCellagingCyclelifeabstractInthisreport,cyclinginducedcapacityfadeofaLiFePO4batterywasstudiedandcycle-lifemodelswereestablished.Celllifedataforestablishingthemodelwerecollectedusingalargecycle-testmatrix.Thetestmatrixincludedthreeparameters,temperature(−30to60◦C),depthofdischarge(DOD)(90–10%),anddischargerate(C-rate,rangingfromC/2to10C,withthe1Cratecorrespondingto2A).AtthelowC-rates,experimentalresultsindicatedthatthecapacitylosswasstronglyaffectedbytimeandtemperature,whiletheDODeffectwaslessimportant.AtthehighC-rates,thecharge/dischargerateeffectsbecamesignificant.Toestablishalifemodel,weadoptapowerlawequationinwhichthecapacitylossfollowedapowerlawrelationwithtimeorchargethroughputwhileanArrheniuscorrelationaccountedforthetemperatureeffect.Thismodel,whenparameterswereallowedtochangewithC-rates,wasfoundtorepresentalargearrayoflifecycledata.Finally,wediscussourattemptsinestablishingageneralizedbatterylifemodelthataccountsforAhthroughput(time),C-rate,andtemperature.©2010ElsevierB.V.Allrightsreserved.1.IntroductionAtpresent,lithium-ionbatteriesareincreasinglybeingusedtomeettheenergyandpowerdemandsofcurrentconsumerelectron-ics.Thesebatteriesarealsobeingtargetedforuseintheautomotiveandspaceindustries.However,notknowingabattery’srateofcapacitylossorusefullifeintheseapplicationsposesasignificantbusinessrisk.Fortheautomotiveindustry,thisinformationiscriti-calindeterminingtheperformanceanddurabilityofthebatteryintractionapplications;forthespaceindustry,thebatterymustlastforthelifeofthemissionasserviceand/orreplacementisrarelyanoption.Overthepastfewyearstherehavebeensubstantialeffortsfocusedonthedevelopmentofmodelstopredictcapacityfadeinlithiumionbatteries[1–12].Differentmodelshavebeendevelopedtoaccountforvariousscenariosresponsibleforcapacityfadesuchasparasiticsidereactions[5,13,14],SEIformation[6],andresis-tanceincrease[1,15,10].However,experimentaldataareessentialforthestudyoftheagingprocessesofabatterysystemandtheval-idationofthecapacityfadingmechanisms.Toprovidetherequiredinformation,asignificantamountoftestingandasystematicmod-elingeffortisneededtodevelopareliablemodeltodescribethefactorseffectingbatterylife.Veryfewgroupshaveattemptedto∗Correspondingauthor.Tel.:[phone];fax:[phone].E-mailaddress:[e-mail](J.Wang).developalifepredictionmodelusingalargeexperimentaldataset.Wrightetal.,[16–18]presentedthetestingresultsandlifemodelingoflithium-ionbatterieswithNibasedlithiuminsertioncathodesincludingLiNi0.8Co0.2O2andLiNi0.8Co0.15Al0.05O2.Theseresultsunderscoretheimportanceofusinglargetestingmatrixtoinvestigateandvalidatethelifemodelingoflithiumionbatteries.LiFePO4(lithiumironphosphate)basedlithiumionbatteryhasbeenconsideredasoneofmostpromisingcandidatesforlargescaleapplicationsintheautomotiveandspaceindustriesbecauseofitsexcellentchemicalandthermalstabilityandlowcost[19–23].However,capacityfadebehaviorandlifemodelingforthisbat-teryhasnotbeenwellestablished.Moreimportantly,thereislittleinsightregardingtheagingmechanismsassociatedwiththistypeofbattery[24–28].WeevaluatedtheagingmechanismsofLiFePO4lithiumionbatterycellsusingbothdestructivephysicalanalysisandnon-destructiveelectrochemicalanalysis.Theresultsindicatethatcapacityfadeisprimarilytheresultoflossofactivelithiumthatismostlikelyassociatedwithanodedegradation[28].Thispaperfocusesondevelopingasemi-empiricallifemodelbasedonthismechanism.Theeffectsoffourexperimentalparameters—time,temperature,depthofdischarge(DOD),anddis-chargerate—wereinvestigated.Atlowcharge/dischargerates,theresultssuggestcapacitylossisstronglyaffectedbytimeandtem-perature,andtheDODeffectislessimportant.AgeneralpowerlawequationdescribedbyBloometal.[29],wherecapacityfadefollowsapowerlawrelationwithtime,wasadoptedasastart-ingpointtodevelopourmodel.Initialresultsdemonstratedthat0378-7753/$–seefrontmatter©2010ElsevierB.V.Allrightsreserved.doi:10.1016/j.jpowsour.2010.11.134J.Wangetal./JournalofPowerSources196(2011)3942–39483943Fig.1.Testmatrixforacceleratedcyclelifestudy.Twocellsweretestedateachcondition.Thenumbersinthetestmatrixindicatethenumberofcyclesattainedbythecell.Cellshighlightedingreenwerestillcyclingwhenthismanuscriptwaswritten,andcellshighlightedinredhavereachedthedefinedendoflifecondition.(Forinterpretationofthereferencestocolorinthisfigurelegend,thereaderisreferredtothewebversionofthearticle.)thepowerlawrelationshipcanrepresentmostofthelifecycledata.Fur