ESSCAP’2008–LithiumIoncapacitorcharacterizationandmodelingAbstractTodevelopelectricalbussesforapplicationswithafastrechargesysteminstations,PVIhasbeentestingsomeelectricalenergycomponentslikesupercapacitorsandbatterieswithhighpowerdensity.Neverthless,supercapacitorslimitaverageautonomybetweentworechargepoints,duetotheirpoorenergydensity.Ontheothersidecyclelifeofbatteriesareverydependentoncurrent.Tosurmounttheseproblems,PVIincollaborationwiththeFCLABlaboratoryandtheAMPERElaboratory,arestudyingLithium-ioncapacitor(LIC)forapplicationswithfastrecharge.Wetaketoassesshowthestoragesystemmeetsbussespowerandenergyrequirementsinheavyelectricvehicles.WenotethattheadvantageofLICtechnologycomparedtoconventionalsupercapacitorliesinthefactthattheenergydensityandthenominalvoltagearehigher.Inthisstudy,theLi-ioncapacitorischaracterizedandmodelled.Thecharacterizationandmodellingmethodsarethesameofsupercapacitorwithdoublelayeractivatedcarbontechnology.TheLICefficiencywillbediscussed.I.INTRODUCTIONLithiumIoncapacitorisanewstoragedevicewhichcombineshighpowerdensityandhighenergydensitycomparedtoconventionalsupercapacitorofthemarket.Ithasfourtimehigherenergydensitythanconventionalsupercapacitor.ThestructureoftheLICiscomposedbytwoelectrodes.Thepositiveoneisformedbyactivatedcarbonasindoublelayercapacitor.Thenegativeelectrodeuseslithiumiondopedcarbon.Thisnewelectrodetechnologybooststhecapacityofthenegativeelectrodeandincreasestheelectricalpotentialdifference.TheelectrolyteisbasedontheLiIon.Figure1showstheelementarystructureofEDLCandLi-ioncapacitorstructure.ItcanbeseenthatthenegativeLICelectrodeisformedbyLidopedCarbone.TheequivalentcapacitanceisformedbythepositiveelectrodecapacitanceCdlinserieswiththenegativeoneCli.Theequivalentcapacitorcanbeexpressedasfollowing:（1）whereCli>>Cdl⇒Ceq≈Cdl（2）Fig.1:ElementarystructureofEDLCandLi-ioncapacitor(JMEnergy[1])TheLiIoncapacitorstudiedinthispaper(figure2)isfabricatedbyJMEnergy.Theirparametersare:nominalcapacitance:2000F;vol