Li-ion Battery introduction锂离子电池介绍演示幻灯片

BattreyChemistryFundamentalsandCharacteristics,SinowealthBPwxl,Page2,CONTENTS,Introduction,01,Li-ionBatteryFundamentalsandElectricalBehavior,02,MonitoringandSafety,04,GeneralBatteryCharacteristics,03,Page3,1.2Li-ionBatteryFundamentalsandElectricalBehavior,1.2.1BatteryStructure1.2.2Fundamentals1.2.3Materialsandtheirinfluences1.2.3Electricalbehavior1.2.4Equivalentcircuit,Page4,Li-ionBatteryStructure,CylindricalLi-ionBatterystructure,Separator,cathodeandanodearearoundthecolumn.,18650,Page5,Li-ionBatteryStructure,PrismaticLi-ionBatteryStructure,Page6,Li-ionBatteryStructure,CoinLi-ionBatterystructure,Page7,Li-ionBatteryStructure,ThinFilmLi-ionBatteryStructure,10-100umthinkness.formicrominiaturedevice,Page8,Li-ionBatteryStructure,Page9,Li-ionBatteryStructure,Li-ionBatteryStructure:AnodeCathodeSeparatorElectrolyteEnclosureandpackage,Page10,Li-ionBatteryPerformancerequirementsofanodematerials,highspecificenergyhighspecificpowerlowself-dischargeratiolowcostlonglifehighsafetylevel,Page11,CapacityCalculation：1molLi+,Q=96500C（F=NA*e=96500C/mol）1C=1AsTakeLiFePO4forexample:TheformulaweightofLiFePO4is157.756g/mol,(1g/157.756g/mol)*96500C/mol/3600s=170mAh/gTheformulaweightofLiCoO2is97.88g/mol,(1g/97.88g/mol)*96500C/mol/3600s=274mAh/g,Li-ionBatteryCapacityCalculationforAnode,Page12,Li-ionBatteryanodematerialsandtheirpeformances,Page13,LiCoO2,LiMn2O4,poorsafety,highcost,Synthesisdifficult,seriousattenuation,LiNiO2,Li-ionbatteryanodematerials,Page14,Li-ionbatteryanodematerialdevelopment,powerfield,communicationfield,LiFePO4LiMn2O4,Li-ternarycompoundLiNiO2,Ni-H,lead-acid,LiCoO2,powerfield:LiFePO4andLiMn2O4havetheadvantagesoflowcost,minocationfield:Li-ternarycompoundandLiNiO2havehigherspecificenergy.,Li-ionbatteryanodematerial,Page15,Li-ionbatteryPerformancerequirementsofcathodematerials,Li+canbeembedandseperatedrapidly.goodreversibilityofLi+reactionwithseldomcrystalstructurechange.weakelectricpotentialchangeinthereactionprocess.goodsurfacetexture(SolidElectrolyteInterfaceFilm,SEI)stabilityandcompactedlargediffusioncoefficientforLi+diffusionincells,easytochargequickly.,Page16,Li-ionbatteryCathodematerials,Page17,syntheticgraphite,siliconcarbonalloy,Li-ionbatterycathodematerialsperformance,Page18,carbonmaterialspotentialriskLi4Ti5O12,largemountofcapacity,lessexpension,longcyclelifeandstoragelife,surpportquickcharge.etc.,Metallithiumisdepositedonthecarbonsurface.Itcanexplosivelyreactwithavarietyofmaterials.Burning,explodeandgasexpansionareallprotentialsafetyproblems.,carbonmaterials,Li4Ti5O12,Fig.Li4Ti5O12SEMphotoanditschg/dsgperformance,Li-ionbatterycathodematerials,Page19,二次锂电池正负极材料电压-容量分布图Voltageversuscapacityforpositive-andnegative-electrodematerialspresentlyusedorunderseriousconsiderationsforthenextgenerationofrechargeableLi-basedcells.,Li-ionbatteryelectrodeVoltage-Capacitydistribution,Page20,Fig.2electrolyteproductmanufactureprocess,Li-ionbatteryelectrolyte,ElectrolyteisoneoffourmajorpartoftheLi-ionbattery,whichplaysanimportantroleinLi+transferandhasaneffectonCapacity,worktemperaturerangecycleandsafetyofthebattery.Electrolyteisusually15%ofthetotalweightand32%oftotalvolume,anditspurityisworthattentioninthemanufacturingprocess.,Page21,keepliquidstateinlargetemperaturerange,highLi+conductivity(10-2S/cm).goodchemicalandheatstability,hardtoevaporationandreactionwithothers.highprotentialupto4.5V(vs.Li/Li+)。non-toxiceasytoprepare,lowcost,Li-ionbatteryPerformancerequirementsofelectrolytematerials,Page22,safety,stability,compatibilitywithcathode,conductivity,highdielectricconstant,posedbysolventandadditive,solvent,Li-ionbatteryelectrolytesolvent,Page23,Li-ionbatteryelectrolyteadditive,Page24,1.liquidstate,solution.highpuritysolvent,electrolyte(LiPF6),additive.2.solidstate,ploymer.polymerlithiumionbattery,LIP.,Li-ionbatteryelectrolyte,Page25,playanimprotantrolein:keepanodeandcathodeseparateallowiontopassthroughitselfandchargetotransfer,Li-ionbatteryseparator,Page26,Li-ionbatteryseparatorperformance,Page27,porousploymerthinfilm（PP,PE,PP/PE/PP）mechanicalproperty,wettablity,poreclosetemppointandfusingpointconflictnon-wovenfabrics,Separion无纺布型highporositynanofiberfilmSeparionthinfilmploymerelectrolytesolid,gel,Li-ionBatterySeparator,Page28,Celgard2400separator，PP，25m，37%porosity，0.117m*0.042mporesize,Li-ionbatteryseparatorexample,Page29,Li-ionBatteryCharacteristics,ChemicalCapacityandEnergyBatteryImpedanceUsableCapacityPowerCapabilityCycleLife,Durability,ShelfLifeSelf-DischargeProperties,Page30,Li-ionBatteryChemicalCapacity/Energy,Qmax：Amountofchargecanbeextractedfromthefullychargedcelltotheendofdischargevoltage(EDV).Batterychemicalcapacity(noload)InUnitof:Ah/kg,Ah/l,Wh/kg,Wh/l/l,/kg-protableequipments(phone,pad,etc.),ploymerLi-ionBatteryAh,Wh-comparingdifferentbatterywithsamechemicalmaterialsinAh,butWhfordifferentchemicalbattery.,Fig.xVoltageprofileduringlow-ratedischargeofbattery,Page31,Li-ionBatteryBatteryImpedance,BatteryImpedance：dV=I*R,aftertransientprocessNyquistplot:VoltageresponsesoncurrentofdifferentfrequencyA1:impedance,stretchingrealvalueofA2,3,5A5:0.51sA6:1000s,Relaxationtime,Page32,Li-ionbatteryBatteryImpedance,BatteryImpedance：dV=I*R,aftertransientprocessNyquistplot:VoltageresponsesoncurrentofdifferentfrequencyA1:1000s.realsesistancestopincreasing，IRdropconstant，DCresistance.,Relaxationtime,Page33,BatteryImpedance：dV=I*R,aftertransientprocessNyquistplot:Voltageresponsesoncurrentofdifferentfrequency40m6070m100mA1A2A3A4A5A61000sNOTE：Cellmakersoftenreportcellimpendanceat1kHz,itsnotrealcellresistance.realresistance(DCresistance)is2.7timeslargerthanthatat1kHz.Relaxationtimeincreasing，realresistancekeepconstantbutimaginaryincreacing,asifseriallyconnectedcapacitorandcapatanceishuge.notethatcellimpedancevariesfromSOC,resultingfromactiveparticalsandionschanges.Equivalentcircuitrefertopage6Fig.3.,Li-ionbatteryBatteryImpedance,Page34,Qusable:batteryvoltages.fullychargedvoltage,endofdischargevoltage。CellvoltagedependingonSOCanddischargecurrent(IRdrop).IRdropobservedtakeabout500s.(Nyquistplot1000s)IRdrop:current，temperature，cyclelife，differentfromdiffferentSOC.Note:DonotestimateIRdropbyresistancefromcellmakers.1kHzvsDCestimateusablecapacityinrealdischargeprocessinthermalbox,heatexchange,muchmoreclosetorealusablecapacitywhynottestcelltemperaturedirectly？self-heatingofcelland,moreimportant,electronicdevicesresultinenviromenttemperaturearoundthecellsrising,abundantheatexchange(putinthermalbox)isnessanaryformonitoring.,Li-ionbatteryUsableCapacity,Page35,RagonePlot:PowerDensity(W/kg)-EnergyDensity(Wh/kg)./kg,/l,/m2EnergyDensity(Wh/kg):batteryenneryforbatteryonecycleusePowerDensity(W/kg):batterypowerforbatteryproviodenneryeveryunittime,Li-ionbatteryPowerCapabilityandRagonePlot,Page36,cellaged：chemicalcapacitylossandimpedanceincreasechemicalcapacityloss：reason：crystalstructureofactivechangeinflunce：highandlow-ratedischargeapplicationsimpedanceincrease：primaryreason：passivatinglayergrowandelectrolytelossinflunce：high-ratedischargeapplication.deeperIRdrop，usablecapacitydecrease。,Li-ionbatteryCycleLife,Page37,Li-ionBatteryCycleLife,Analyze：Experimentalresults-impedanceincreaseinflunceismuchlargerthanthatofcapacityloss.100cyclelater，capcityloss5%，impedanceincrease60%.(DCresistanceincreasedbutnot1kHzresistance(almostconstant),DCresistanceisworthyofourattention)internalresistance：R=(V-OCV)/I,Page38,Shelflifedependsonstoragevoltage(storageSOC)andstoragetemperature.Experimentalresult：lead-acidbatterybenefitfromhighSOCstorage,andLi-ionbatterypreferlowSOCstorageAgedanalyzedissimilartothatofcyclelife,currentexsitanceaccelaratetheagedandparasticreactioncurrentcausecrackingofpassivatinglayer,andthelayerregrowwilluseupsomeactiveLi,theextrareactionparticleswilljamupporestodecreasetheconductivity.currentappearanddisappearmakethepassivatinglayerexpansionandshrinkage,themachanicalchangecausetheelectricaldisconnect.duringsametime，cycleaged510timeslargerthanstorage.,Li-ionBatteryShelfLife(StorageLife),Page39,Li-ionBatteryShelfLife(StorageLife),Inthesametemperature,thelowervoltage,thelowerbatterycapacityloss,thelongerstoragelifeofthebattery.Underthesamevoltagecondition,thelowertemperature,thelowerbatterycapacityloss,thelongerstoragelifeofthebattery.Underthesamechargecurrentcondition,thelowerchargevoltage,thelongercyclelifeofthebattery.,Page40,Li-ionbatterySelf-Discharge,Self-dischargeMechanism:ParasiticconductanceDendriticcrystalgrowsinchargeprocess,decreasingthesufaceofanode.Saperatorwillbepokedandcrackedbymoredendriticcrystal,leadingtoelectrodedirectcontecttoeachother.Precautions:nanoporoussaparatorshavebeenusedtoreducethiseffect.shuttlemoleculessomemoleculescanbecomeoxidizedoncathode,diffusetoanode,andbecomereducedthere,andbacktocathode.Similareffectofelectrontransfer.Precautions:avoidbringinginimpuritiesincellmanufactureprocess.utilize:underthehighvoltageconditon,theredoxreactionofshuttlemoleculescanpreventovercharge.,Page41,Li-ionbatterySelf-Discharge,Self-dischargeMechanism:Recombinationofoxygen-hydrogenH2andO2generatebyelectrolysisofwater,gassesthendiffusethroughtheseparatorandreactsincesaparatorsarenotairtight.Anotherredoxreactiongeneratewhichissimilartotheeffectofelectrontransfer.Recombinationofoxygen-hydrogengeneratesheatandbecomesnoticeableclosetotheendofcharge.Otherredoxreactionsbyimpuritiesinelectrolyte.,Page42,Li-ionbatterySelf-Discharge,Temperature：thehighertemperature,thehigherself-discahrgerateTemperaturerisewillaccelerateallredoxreactions.Age：themoreage,thehigherself-discahrgeratetheage,themorecrackofactivematerials,thehighersurfacearea,themoremattersofredoxreactions.Note:cellstructuredesignThereactionsbetweenelectrolyteandelectrodealwaysexsitintheprocessofself-discharge,whichmakespoorthematerialactivityandchangesitsstructure,leadingtodecreasetheennergy(voltage)ofthecellundertheconstantcapacity.,Page43,1.4MonitoringandSafety,1、safetyLi-ionbatterysafetyproblemsneedmoreanntention:moreactivityofLi,reactionwithmountsofmaterialhighspecificennergyConsequence:Thermalrunaway(热逃逸，热失控)：Thetemperaturerise,themoreadditiveheat.thermalpositivefeedbackbatteryexplode(expansionbyheatormuchmoregas)Sources:Mernalshortcircuit,metalparticlesAgeprocess.cellimbalance,electrodeimbalanceunreasonableoperation,overdischarge/charge.crystalstructurechange,dendriticcrystal,internalshortcircuit,Page44,1.4MonitoringandSafety,2、safetyproblemexampleexternalshortcircuit,exter