BATTERY 102 • PAGE 1

Battery Chemistries: An Introduction

ADVANCED BATTERIES AND THE CHEVROLET VOLT, HYBRIDS AND EV1

Many different types ofbaerieshavebeen producedover Abaery createselectricity fromachemicalreactioninsidethe the years for a broadarrayofapplications,topowering heart baery cell(s),which createselectricalcurrentusing apositive pacemakers, flashlightsandradios,handheldgames,laptops, electrode (cathode)andanegativeelectrode(anode), connected cell phones andautomobiles. byaliquidorsolidelectrolyte(ionconductor) and aheld apart For decades, cars andtrucksusedasmallbaerytopowerthe byaseparator(electroninsulator.) starter motor, thelightsandtheignitionsystemofthevehicle’s Whenabaery isconnectedtoanelectric circuit, achemical petroleum-powered engine.Butsincethe1990s, theauto reactiontakesplace.Electricalcurrentiscarriedby ions, from the cathode tothe anodeduringcharging,andfrom negative topositiveduringdischarging.Theionsare smalland reside withinthe crystalstructureofthe electrodematerials. Differentelectrode materialshavedifferentcurrent-carrying capacities,andthisaffectsthestoragecapacities of thecells. Thefollowingisasummaryofthe strengths andlimitations ofthreeprimary automotive chemistries –nickelmetal hydride, lithium-ionandleadacid –beingusedinpast,currentand futureGM vehicles.

ead acid baery ept Car utilized a l 512 Electric Conc industry hasbeen using baeriesastheprimary powersource for hybrids, plug-in hybrids, electricvehiclesandfuelcellvehicles. When theChevrolet Voltgoesintoproduction, targeted forlate 2010,it will bepoweredbyabaerypackthatdeliversupto 40miles of gasoline-freeandemissions-free driving. Dependingon the vehicleapplicationandtheenergystorageor power requirements, baerysolutionsandpackaging maydiffer. Chevr olet Volt utilizes a lithium ion baery BATTERY 102 • PAGE 2

Lithium Ion RESOURCES ADVANTAGES •14-30milliontonsoflithiumreservesexiston theplanetasbrine, •Lithiumismostcosteffectivein termsof energydensity, ore,orclay,accordingto FMCLithium, WesternLithium, Orocobre, poweranddurability. Keith Evans,geologist. Thatisestimatedtobeenough forbillionsof •Lithiumion’scyclelifeisthreetofourtimesthatof nickel-metal hybrid andelectricvehicles, basedon a16 kWhbaerypack.Thereis hydride(NiMH).Cyclelifeisthenumberof complete an estimated4pounds/2kilogramsoflithiumineachVoltpack. charge-dischargecyclesa baerycanperformbeforethe baery’senergycapacityfalls below80%of itsinitialrated energycapacity. •Lithiumionhas twotimes theenergydensityof NiMH,andthismeansless baeryisneededforany equivalentapplication. •LithiumislighterthanNiMHandlead-acid. •Evolvingtechnology –newmaterialsandprocessesarebeing Lithium salt flats developedbroadeningthebaeryoptionswithinthelithiumionfamily. LIMITATIONS •Itshouldbenotedthattheglobalannualproductionofallvehicles •Requiresprotectioncircuittomaintainvoltageandcurrent. is approximately70million andthetotalpopulationofvehicleson the roadtodayisapproximately850million. •Lowtolerancetooverdischargeandovercharge. •The currentmethodofchoiceislithiumsaltbrines, which are •Subjecttoagingfasteratelevatedtemperatureand atfullcharge, lessexpensivetominethanhardrocklithiumdeposits. evenif notinuse.(Allbaeriesaresubjecttoaging). •Averagelithiumconsumptionrose8% annuallyfrom2003-2007. •Transportationrestrictions:therearerestrictionsforall (source:Roskill) baeries.Mostbaeriesareregulatedascorrosives(Class8). LithiumbaeriesareregulatedundermiscellaneousClass9. •Currentlythemainconsumption marketforlithiumion Smallshipmentsmay beexemptedfrom regulations. is consumerelectrics,andpharmaceuticalapplications. •Requirespreciseandcleanmanufacturing. BATTERY 102 • PAGE 3

Lithium Ion (cont.) RECYCLING SAFETY •Thereisanexistinginfrastructureandrecyclerscanrecyclethe •Baerysafetyisanintegratedsolutionbetweenthe cellchemistry, lithiumioncellsbeingusedinconsumergoodslikecellphonesand cellpackaging,controls,andpackmechanicaldesign. laptops usinglithiumionbaeries. •GMrigorouslytestslithium-ionbaery packsin GM’sbaery •GM isworkingwithother automakersandrecyclerstodevelop labsandon-roadinearlyengineeringdevelopmentcars. asustainablerecyclingmodel. •Numerousmeasureshavebeentakentohelp prevent issues such •The impactofautomotivelithiumbaerieson therecyclingindustry asshortcircuitingandoverheating,crashintrusionand water is atleastadecadeout.TheVolt’sbaeryisdesignedto last submersion.LGChem,which issupplyingthelithium-ioncellsfor significantlylonger thanaconsumerelectronics baery lifeof theChevroletVolt,usesanexclusiveSafetyReinforced Separator 1-3years.Beyondtheautomotivelifeofthesebaeries, theremay consistingof semi-permeable membranesseparatingtheelectrodes beseconduseopportunitiesinnon-autoapplicationsthatcould inthecells,whicharemechanically andthermallysuperiortocommonly extendtheir useablelifespananother5-10 years. usedseparators.

ENVIRONMENT AND HEALTH ASPECTS •GM hasalong-standingcommitmentto protecthumanhealth, naturalresources andtheenvironment.Ourvehiclesaredesigned tobeasrecyclableandrecoverableasfeasiblypossible.Ourvehicle designsincludeuseofrecycledandbiobasedmaterialsfrom renewablesources,anduponselectingmaterialswecarefully Chevrolet Volt li thium ion baery p andthoroughlyassesshealthandenvironmentalimpacts and ack being tested. strivetousesafematerials forvehicleinteriors,exteriors, partsandsystems. •Lithiumionbaeriesaredesignedtobeusedsafelyassealed units invehicles.Pleasesee therecyclingsection. •LithiumMetalisveryreactive.Lithiumionbaeries conversely donotuselithiummetal.Itcombinesthelithiumwithmetaloxides which stabilizes thestructure.Thelithiumistransferredasions betweenchargeanddischargecycles. BATTERY 102 • PAGE 4

Nickel-metal hydride (NiMH) RESOURCES LIMITATIONS (cont.) •The world’sreserves ofnickelareabout23 billion T/20 billionMT – •Transportationrestrictions:NiMHmaybeexemptedfrom hazardous nickelmetalconstitutes about62 million T/56millionMT. materialsdependingonhowthebaery ismanufactured and tested. •Productionandconsumption ofnickelappearstobesteady. RECYCLING •The mainconsumptionmarketfor nickelisthestainlesssteel •Mostindustrialnickelisrecycled, industry,followedbyelectronicsmanufacturing andbaerysectors. duetotherelatively easy retrieval of themetalfromscrap, anddueto itshighvalue. •Therearebaeryrecyclerswho canrecycleNiMHbaeriestoday. Theserecyclershaveestablished businessesbasedonconsumerbaery cells(e.g.cellphones). •NiMHbaeryrecyclingissetuptorecovernickelprimarily for thestainlesssteelindustryandnotreusedinthebaery. ENVIRONMENT AND HEALTH ASPECTS •GMhasalong-standingcommitmenttoprotecthumanhealth, naturalresourcesandtheenvironment.Ourvehiclesare designed ADVANTAGES tobeasrecyclableandrecoverableasfeasibly possible. Ourvehicle •More tolerantofoverchargethanlithiumion. designsincludeuseof recycledandbiobasedmaterialsfrom •Therearetransportationrestrictionsforallbaeries howeverthere renewablesources,andupon selectingmaterialswecarefully arefewerregulationsforNiMHtransportversuslithiumion. andthoroughly assesshealthandenvironmentalimpactsand LIMITATIONS strivetousesafematerialsforvehicleinteriors,exteriors, •Performancestartstodeteriorateifrepeatedlydeeplycycled. partsandsystems. • Subjecttoagingfasteratelevatedtemperatureandatfull charge, •NiMHbaeriesaredesignedtobeusedsafelyassealed units even ifnotinuse. (Allbaeries aresubjectto aging). in vehicles.Pleaseseetherecyclingsection. •Requiresregularfull dischargetopreventcrystallineformation, SAFETY which canleadtoincreasedself-discharge or electricalshort. •Baerysafetyisanintegratedsolutionbetweenthe cellchemistry, cellpackaging,controls,andpackmechanicaldesign. •Highself-dischargeraterelativeto lithiumion. •Baerycontrolsareusedtokeepthecellsin theproperstatefor safeoperation. •GMrigorouslytestsbaery packsinourlaboratoriesand on-road inearlyengineeringdevelopmentcars. •Numerousmeasureshavebeentakentohelp prevent issues suchas shortcircuiting,overheating,crashintrusion andwater submersion. BATTERY 102 • PAGE 5

LEAD ACID RESOURCES RECYCLING (cont.) •Leadisusuallyfoundinorewithzinc, silver and(mostabundantly) •Thelead-acidbaerygainsitsenvironmentaledgefrom its copper,andisextractedtogetherwiththesemetals.Themainlead closed-looplifecycle. Thetypicalnewlead-acidbaery contains mineralisgalena (PbS), which contains86.6%lead. 60-80percentrecycledleadandplastic.Whenaspentbaery •Productionandconsumption ofleadisincreasingworldwide.Total iscollected,itissenttoapermiedrecyclerwhere,understrict annual productionisabout8million T/7.2million MT;abouthalf environmentalregulations, theleadandplasticarereclaimedandsent is producedfromrecycledscrap. toanewbaerymanufacturer. ADVANTAGES •Therecyclingcyclegoesonindefinitely.Thatmeansthelead and •The majoradvantageof lead-acidbaeriesisthat, afterhaving plasticinthelead-acidbaery inyourcar,truck,boatormotorcycle been usedfor somanyyears,theyarewellunderstoodand havebeen –andwill continuetobe –recycledmany times. This cheaptoproduce. makeslead-acidbaerydisposalextremely successfulfrom both environmentalandcostperspectives.(Source:Baery Council •More tolerantofoverdischargeandoverchargethanlithiumion. International) LIMITATIONS ENVIRONMENT AND HEALTH ASPECTS •Generally,lead-acidbaeries aretooheavy, toobulkyand •GMhasalong-standingcommitmenttoprotecthumanhealth, won'tholdenoughenergyfor sufficienttimeto beusefulinmost naturalresourcesandtheenvironment.Ourvehiclesare designed hybridsandelectriccars. tobeasrecyclableandrecoverableasfeasibly possible. Ourvehicle •Likemostbaeries, lead-acidisclassifiedaClass8corrosive designsincludeuseof recycledandbiobasedmaterialsfrom andhassometransportationrestrictions. renewablesources,andupon selectingmaterialswecarefully and • Subjecttoagingfasteratelevatedtemperatureandatfull charge, thoroughly assesshealthandenvironmentalimpactsand striveto even ifnotinuse. (Allbaeries aresubjectto aging). usesafematerialsforvehicleinteriors,exteriors,partsandsystems. •Lead-acidbaeriesaredesignedtobeusedsafely assealed units invehicles.Leadacidbaeriesshouldberecycledatend-of-life torecovervaluableleadandothermaterials. Pleaseseetherecyclingsection. SAFETY •Baerysafetyisanintegratedsolution ery. lead-acid ba betweenthecell chemistry,cellpackaging, n EV1 used a The First-ge controls,andpackmechanicaldesign. RECYCLING A Chevro •Baerycontrolsareusedtokeepthe co let Covair ncept car electric •Lead-acidbaeriesaretherecyclingsuccessstoryofour time. from the cellsin theproperstateforsafeoperation. 1960s. Morethan97percentofallbaeryleadisrecycled.Comparedto 55%ofaluminumsoftdrinkandbeercans, 45%ofnewspapers, •GMrigorouslytestsbaery packsin ourlaboratories 26%ofglassbolesand26%oftires,lead-acidbaeriestop andon-roadinearly engineeringdevelopmentcars. thelistofthemosthighlyrecycledconsumer product. •Numerousmeasureshavebeentakentohelp prevent issues suchas shortcircuiting,overheating,crashintrusion andwater submersion. BATTERY 102 • PAGE 6

Voltec GM 2-Mode GM Hybrid Hybrid System System

Propulsion Extended-Range Two-ModeParallel Belt-Alternator Technology ElectricVehicle HybridSystem StarterHybridSystem

Battery Type Lithium-Ion NiMH NiMH

Battery •kW–110 •kW–35 •kW –12 Specs •kWh–16 •kWh–2.1 •Wh –720 •Voltage –365 •Voltage–320 •Voltage–40 •181 kg/400lbs. •40 8Vmodules •6 133Vmodules •Morethan200 prismaticcells

GM Vehicles •ChevroletVolt(2010) •CadillacEscaladeHybrid/ •ChevroletMalibu EscaladePlatinumHybrid Hybrid •ChevroletTahoeHybrid •ChevroletSilveradoHybrid •GMCSierraHybrid •GMC YukonHybrid/ YukonDenaliHybrid

Supplier LGChem Panasonic EV Cobasys EnergyLtd. BATTERY 102 • PAGE 7

Next Gen GM GM 2-Mode BEV BEV Hybrid System Plug-In

Propulsion Belt-Alternator Two-ModeParallel Baery Baery Technology StarterHybrid PlugInHybrid Electric Electric System System

Battery Type Lithium-Ion Lithium-Ion NiMH Lead Acid

Battery •kW–morethan15 •kW–55 •kW–105 •kW– 105 Specs •Wh–500 •kWh –8 •kWh–29 •kWh – 16 •Voltage –115 •Voltage–270 •Voltage–343 •Voltage – 312 •30cyndricalcells •Morethan •430kg/948 lbs •450 kg/992 lbs 100prismatic cells •26 13.2Vmodules •26 12V modules

GM Vehicles •Calendaryear •Calendaryear EV1 EV1 2011–models 2011–models tobeannounced tobeannounced

Supplier HitachiVehicle LGChem Panasonic Delco EnergyLtd.