Low Temperature Lithium Batteries-Saft

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1、LOWTEMPERATURELITHIUMBATTERIESKamenNechevandRobertStaniewiczSAFTAmericaLOWTEMPERATURERECHARGEABLEBATTERIESWhatScientificLawsGovernBatteries’ColdTemperaturePerformance?!ThermodynamictemperatureterminNernstEquation.!Electrochemicalkineticsdependenceontemperature.!Presenceofsolidelectrolyteinterface

2、attheanodeandpossiblythecathode.SEIionicconductivityshowsalogresponsewithtemperature.!Electrolyteionicconductivitydependencyontemperature.!Solidstatediffusionintoahostelectrodestructure.LithiumInorganicPrimaryBatteriesSAFTisthelargestsupplieroflithiumprimarybatteriesfortheUSspaceanddefensemarket!

3、ThionylChloride–generallycanoperateat–40oCto–50oCinconventionallydesignedcells.Forextremeoperation–80oChasbeenachievedwithreducedsaltconcentration.UltimatelythefreezingpointofSOCl(-100oC)isthe2limitingfactor.!SulfurDioxide–generallycanoperateat–40to–50oC.Thesamelimitingfactorsapply–freezingpointo

4、facetonitrile/SOsolvent(-46oC/-73oC).2LOWTEMPERATURERECHARGEABLEBATTERIESSAFTLowTemperatureEfforts!SAFTstartedlowtemperaturelithium-ioncelldevelopmentinmid1990’s!Underautomotive(PNGV)programswithDOEandUSABC!UnderTRPprogramwithUSAirForceandUSArmy!OngoingVeryHighPowerdevelopmenteffortwithUSAirForce

5、!FormostapplicationsSAFTtargetsdevelopmentoflowtemperaturecapabilitieswithlimitedornoimpactoncalendarandcyclelifeLOWTEMPERATURERECHARGEABLEBATTERIESStepsInvolvedinCharge/DischargeForLithium-ionElectrochemistry!Inliquidelectrolyteelectroactivespecies(ions)aretransportedbetweenelectrodesbymigration

6、and/ordiffusion.!WhentheyreachthesurfaceSEI,thesespecieschangephases(heterogeneousreactions).!TheionsundergosolidstateionicdiffusionthroughtheSEItoreachactiveelectrodesite.!Attheactiveelectrodesiteanelectrontransferstep(Faradaicreaction)takesplace.!Finallylithiumhastodiffuseintothehostlattice(met

7、aloxidefordischargeandcarbonforcharge).Allofthesestepsareinfluencedbytemperature.Theyinduceconsequentpolarizationtermsthatlowertheoperatingvoltageandlimitmaterialutilizationatlowtemperature.Neteffectisreducedenergyandp