Vanadium-BromineRedoxFlowBattery

FlowBatterieKolloquiuminKarlsruheam27.September2017

H.FrankGibbard,Ph.D.CEOWattJouleCorporationDevens,MassachusettsUSA

StationaryEnergyStorage–WhyNow?

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In the past few years the demand for large-scale energy storage has increased for several applications

•  Renewables integration •  Ancillary services •  Arbitrage •  Grid asset optimization •  T&D deferral •  Telecommunications – substitute for diesel

RenewablesIntegration

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ArizonaSolarFarm10-80%in5min

OregonWindFarm10-100%in1hour

Wind&SolarVariabilityProblem

WhyRedoxFlowBatteries?

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§  SeparationofPOWERandENERGY§ MorePOWER=largerstack§ MoreENERGY=largertank§  Competitiveenergyefficiency

§  Highlydurable:10,000+cycles§  Safe,non-flammableliquid§  LowestCapEx&OpEx§  Largeapplicationspace

ProductDevelopmentApproach

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•  Startwithaprovenchemistrytolowerrisk:vanadiumredox

•  Engineeranext-genOEMplatform:quantumimprovement

•  Identifykeybarrierspreventingfullcommercialization

•  UtilizeopeninnovationapproachtosecurebestIP

•  Leveragethebestexpertisewhereveritis

•  Developamulti-generationalpipelineofproductimprovements

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CURRENTPROBLEMSET WATTJOULEIMPROVEMENT

Electrochemicalstacksarelargeanduseexpensivematerials

Newbreakthroughsnowallowmajorreductionsinstacksize

Electrolyteenergydensityislowandrequireslargetanks

Wehavetechnologythatincreasestheenergywecanstoreineveryliter

Systemneedsrefrigeratedcoolingtherebyincreasingcostsandloweringefficiency

WecannoweliminateACandchillerequipmentwithourplatform

Lifetimesystemefficiencyneedsimprovement

Wenowaddmajorefficiencyimprovementswithnoaddedcost

Needforcostly,highpurityactivematerialslikevanadium

Wehaveapathwaytoutilizinglessandthennovanadiumovertime

Relativelyhighcostvs.attractiveeconomics

Alloftheaboveimprovementstranslatetosignificantlylowercost

BuildingaSuperiorProduct

KeyMetric SOA1 Gen1 Gen2V-Br CoreBenefit

ConverterStackPowerDensity 1X 6X 7X Lowermaterialcost

ElectrolyteEnergyDensity 1X 2X 3X Lessliquidrequired

ElectrolyteTemperatureRange 1X 3X 3.2X Noactivecoolingneeded

RoundtripEfficiency 1X 1.1X 1.2X Lowerlifecyclecost

VanadiumCostReduction 1X 1.4X 2.2X Lowervanadiumcost

DCSystemCapitalCost($/kWh) 600 200 150 SignificantlylowerCapEx

PathwaytoBetterVRBMetrics

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QuantumImprovementFactors

1State-of-the-ArtRedoxFlowBattery

ElectriStor™ES10TestSystem2kW,10kWhEngineeringPrototypeII,DCOnly

1,000-foldincreaseinpowerandenergyfrom2014-2016

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So...What‘sNext?

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•  We believe that the improvements made in the chemistry, materials and design of our Gen 1 all-vanadium redox flow battery have pushed this system nearly to its maximum performance and minimum cost limits.

•  Further improvements in our RFB platform will require a change in the basic system chemistry.

•  With financial and technical support from ICL, we have chosen the vanadium-bromine redox flow battery for further development.

V-BrRedoxFlowBattery

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Performance

•  Electrolyteenergydensityof≥50Wh/kg•  Operatingelectrodecurrentdensityof≥200mA/cm2

•  Maximumpowerdensityof≥1000mW/cm2

•  Standardoperatingtemperatureof45°C•  Round-tripDCelectricalefficiencyof80%

Cost•  $150/kWhforDCenergystoragesystem

V-BrRedoxFlowBattery

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•  DecreaseamountofVanadiumbynearly50%

•  Increasedelectrolyteenergydensity

•  Technologydemonstratedinlab-scalehardware

•  UtilizesGen1high-powerdensitycelltechnology

•  Proprietarycomplexingagentprovidesmultiplesystembenefits

•  StrongWattJouleIPposition

V-BrRedoxFlowBatteryAdvantagesOverAll-Vanadium

V-BrRedoxFlowBatteryAdvantagesOverOtherChemistries

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ALTERNATIVEFLOWCHEMISTRIES VANADIUMBROMINE

Hydrogenbrominerequireslargehighpressuretankstostoreflammableandexplosivegaseoushydrogen,andneedsexpensivecatalystthatdegradesovertime

Requiresnocatalystandalltheenergyissafelystoredinliquidform.Electrolytecontainsover60%waterandcannotburnorexplode.

Zincbrominehasdendriteproblemsonelectrodesthatrequirestrippingandhavedurabilityissues.Powerandenergycoupledsincehybridflow.Lowpowerdensity.

Trueredoxflowbatterythatrequiresnoplatingandthereforehasnodendriteproblems.Powerandenergycapabilitycompletelyuncoupled.

Ironchromiumhasasignificanthydrogenandchlorinegassingproblemundernormaloperationandhaslowenergydensity.

Virtuallynogassingpotentialduetoelectrochemicaloperatingmode.Muchhigherenergydensitycanbeachieved.

Vanadium-vanadiumrequireslargestacksandtanksandthehighercostofvanadium,alsohasalimitedtemperaturerange.

Muchhigherpowerandenergydensitycanbeachievedwhilecuttingvanadiumuseby50%.Temperaturerangenotanissue.

y=-0.0415x+1.3373

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0.6

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1.2

1.4

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0 5 10 15 20 25

CellVo

ltage,V

DischargeCurrent,A

InitialResultsofPolarizationTestonGen2At45°Cin25-cm2Cell

V-BrTestResults

Gen2PowerCapabilityin25-cm2cellat45°CVanadiumConcentration2.0Mol/L

Membrane Pmax,mW/cm2 SpecificResistance,Ωcm2

FluorinatedIon-Exchange

431 1.0375

PowerPerformanceSimilartoGen1inFirstExperiments

V-BrTestResults

TypicalUNSWCyclingwithBromineComplexationCurrentDensityonly10mA/cm2

V-BrTestResults

WattJouleCyclingResultsat200mA/cm22MVat45°C

2MV

V-BrTestResults

Dr.FrankGibbardCEO&Founderfrank@wattjoule.com603-502-3234

GregCiprianoVPBusinessDevelopment&Foundergreg@wattjoule.com508-942-8995

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WattJouleexpressesitssincerethankstoICLforitsfinancialandtechnicalassistanceincarryingouttheworkontheV-Brredox

flowbatterysystem.