有机硅电解液：安全性和高电压性能研究进展

有机硅电解液：安全性和高电压性能研究进展1、BackgroundSafetyissuesrelatedwithLi-ionBatteriesSafeelectrolytesforhigh-voltagebatteries2、OrganosiliconbasedelectrolytesHigh-voltageOS-basedelectrolytesOS-basedelectrolytesforSianodes4、SummaryOutlineSafetyissuesofLIBs:Highflammabilityofcarbonateelectrolytes!LiFePO4batteryNotsafeenough！SafetyofLithium-IonBatteriesSafety(abusetolerance):•Whenovercharged,thermalrunawayleadstofiresetc.•Runawayreactioncausedbyreleaseofoxygenfromcathodematerials(e.g.,LiCoO2).ThedevelopmentofnewSafeelectrolytematerials!OOORRDMC:R=CH3DEC:R=CH2CH3OOECOHighVoltageCathodeMaterialsDischargepotential(V)RedoxcoupleTheoreticalCapacity(mAh/g)PotentialRange(V)LiCoPo44.82+/3+Co1673.0–5.1LiNiPo4～5.12+/3+Ni1673.0–5.5Li3V2(PO4)3LiMPO43.83+/4+/5+V1973.0–4.8Li2CoP2O74.92+/3+Cob1092.0–5.5Li2MnP2O74.452+/3+Mnb1102.0–4.7Li2NiPO4F～5.12+/3+Nib1433.0–5.5LiNiSO4FC5.2–5.42+/3+Ni149—Li2NiSiO4LiNiMnC4.8O42+/3+Nib163—1.5LiNi0.5Mn1.5O44.72+/3+/4+Ni1473.5–5.0LiFe0.5Mn1.5O44.53+/4+3+/4+Fe,Mn1483.0–5.3xLi2MnO3·(1-x)LiMeO2(0X1,Me=Ni,Co,Mn)3.52+/3+/4+3+/4Ni,Co3+/4+Mnd～3142.0–4.8Es=Qcapacity*Vvoltage1.Safety!2.High-voltageStability!J.PowerSources,237(2013)229.High-voltagecathodesrequirecompatibleelectrolytesElectrolyteChallenges:NSAdditivesDinitrilesIonicliquidsSulfoneFluorinatedsolventInorganiccompoundsSulfonateestersCarboxylanhydridesPhosphidesCCNNnOFCOOOOOCF3FFCF3R4N+R2OCFR1OFR1N+R2O-CFFFR1N+R2R3OSFOOSSOOOOSOOOOSOOOOSOOSOCF3CF3F3CF3CF3CCF3OPOOOOOBOOOOOLiBOOOOFFLiElectrolytesolventsandadditivesforhigh-voltageSolventsLiBOBLiODFBCNHHCnCNLiNi0.5Mn1.5O4/Li,3.5-4.9V,1/12CJElectrochemSoc,156(2009)A60.;159(2012)A370;160(2013)A838.JPowerSources,189(2009)576.Aproticaliphaticdinitrilesolventsn=3ADN,n=5PMNn=6SUN,n=8SENAdvantages:Electrochemicalwindow(7-8V)Flashpoint(110℃,163℃forADN)Dielectricconstant(20-30,55forSCN)Disadvantages:PoorcompatibilitywithgraphitePoorsolubilityofLiPF6LiTFSI(V4.3V,corrodescollector)LiBF4(inferiorability,poorlowtemperatureperformance)JElectrochemSoc,149(2002)A920;JPhysChemB,115(2011)12120.ElectrochemCommun,11(2009)1418;11(2009)1073.Sulfone-BasedElectrolytesAdvantages:HighoxidationpotentialLowflammableHighmeltingpoint;Poorcompatibilitywithgraphite;WettingproblemwithseparatorLi4Ti5O12/1MLiPF6FEC/DMC/D23/4/3/LiNi0.5Mn1.5O4(DatafromANL,USA)OFRf1Rf2OD2OFEC1Cat55oCFluorinatedBasedElectrolytesAdvantages:HighoxidativestabilityHighflashpoint/lowflammability(Safe)CompatiblewithgraphiteODisadvantages:Badperformanceatelevatedtemperatures(FEC)Harshsynthesisconditions/highcost1MLiPF6EC/DEC(3/7)1MLiPF6EC/DMC/MFA(3/3/4)FOHCCOCH3FMFA1MLiPF6MFALiCo2/Graphitecell(1Ahcell);Daikindata(Japan)FluorinatedBasedElectrolytesEnergy&EnvironmentalScience,6(2013)1806;ElectrochemCommun,10(2008)783.HighLowflammabilityHighoxidationresistanceHighviscosity(lowconductivity&ratecapability)PoorwettingHighcostJPowerSources,189(2009)331;225(2013)113;233(2013)115.Mixwithcarbonateorotherco-solventperformanceIonicLiquidElectrolytesthermalstabilityVerylowrotationbarrieraroundSi-Oaxis,(ca.0.8KJ/mol)lowlinearisationenergyoftheSi-O-Siangle(~1.3kJ/mol).Organosilicon(OS)Electrolytes:HighionicconductivityNon-flammability:BiocompatibleExcellentwettingcapabilityWideliquidphaserange(-40–200oC)Lowviscosity-comparablewithalkylcarbonatesMediumwideelectrochemicalwindowVerylowglasstransitiontemperaturegoodthermalstabilityAlternative:OrganosiliconElectrolytesOOOOOR2R2R1R1=H,CH3R2=CH3,CH3CH2CarbonateelectrolytesHighlyflammable!OJ.Mater.Chem.,2008,18(31),3713-17;2010,20,8224-26.Chem.Mater.,2007,19,5734-5741.Implantneuro-stimulatormicrocell(27.53.2mm2,1g)OrganosiliconasSafeElectrolytes1.Excellentcyclability；2.Electrochemicallystable3.Nonflammable/Safe;4.EnvironmentalbenignConventionalelectrolytesOSelectrolytesMCMB/LiNi0.8Co0.15Al0.05O2,0.8MLiBOBOSelectrolytesC/5,3.0to4.0V;100%efficiencyJPowerSources,228(2013)32;196(2011)2255ElectrochemCommun,8(2006)429;ChemCommun,49(2013)1190ProgressonOrganosiliconElectrolytes(Lit.)IonicconductivityCompatibilitywithgraphiteOxidationpotential(4.2V)ChallengesofOSelectrolytes:Compoundsη/cPεoT/Cg-σ/mScm1(0)25CE/VcathodicE/VanodicEW/VSN1SN2SN3BNSTNS2.884.627.163.604.6011.612.312.815.717.3-118-111-98.4-107-1061.101.521.201.281.030.00.00.01.111.095.125.115.055.605.205.125.115.054.494.11NCH2CH2CH2CSiOCH2CH2OCH3nCNCH2CH2Si(CH3)(3-m)(OCH2CH2OCH3)mCH3dielectricconstantoxidationpotentialIncreaseddielectricconstantIncreasedoxidationpotentialHighconductivityOrganosiliconCompoundswithNitrileGroupCH3DischargeCapacity(mAh/g)Efficiency(%)Potenial/VSpecificCapacity/mAhg-1Specificcapacity/mAhg-1Capacityretention(%)Specificcapacity/mAhg01401201008060105100959085803000.7CCCto4.4V,0.5CDCto3.0V274cycles:85.2%LCO/OSco-solvent/Graphite50100150200250Cyclenumber016014012010080604020180LCO/graphite,2.7-4.4V,0.2CBNS/0.4MLiODFB+0.6MLiPF6TNS/0.4MLiODFB+0.6MLiPF6SN1/0.4MLiODFB+0.6MLiPF640801201600525300309060120180150101520Cyclenumber0204060100800.2C2C1.5C1C0.5C0.2CMisciblewellwithcarbonateEnhancedhighrateperformance01002003004005006000.01.00.