2015-WM-PN-A-Guide-to-Lithium-ion-safety-Jim-McDowall.pdfVIP专享VIP免费原创优质

AGuidetoLithium-IonBatterySafetyJimMcDowallBattcon2014Whatissafety?Safetyisnotabsolute!…orintrinsic(tobatteries)SafetyisrelativeandisexpressedstatisticallyAGuidetoLithium-IonBatterySafety-Battcon20142Definitionssafety–‘freedomfromunacceptablerisk’hazard–‘apotentialsourceofharm’risk–‘thecombinationoftheprobabilityofharmandtheseverityofthatharm’tolerablerisk–‘riskthatisacceptableinagivencontext,basedonthecurrentvaluesofsociety’AGuidetoLithium-IonBatterySafety-Battcon20143Safetystatistics–IEC61508“Functionalsafetyofelectrical/electronic/programmableelectronicsafety-relatedsystems”SafetyIntegrityLevels:SILHighdemandorcontinuousmode:probabilityofdangerousfailureperhour1≥10-6to<10-52≥10-7to<10-63≥10-8to<10-74≥10-9to<10-8AGuidetoLithium-IonBatterySafety-Battcon20144GoodsafetyphilosophySafetyeventscannotbeentirelyeliminatedReducetheprobabilityofasafetyeventMinimizethelevel/severityofthateventLimittheconsequencesoftheeventAGuidetoLithium-IonBatterySafety-Battcon20145Lithium-ionhazardcategoriesOverchargingOvertemperatureMechanicalabuseAGuidetoLithium-IonBatterySafety-Battcon20146Lithium-ionbasicsSafetycharacteristicsvarybyLi-ionelectrochemistryOvercharged(delithiated)positivecanbecomeunstablePassivationlayer(SEI)canbreakdownabove100°CAGuidetoLithium-IonBatterySafety-Battcon20147Battcon2008–“UnderstandingLithium-IonTechnology”OverchargingAGuidetoLithium-IonBatterySafety-Battcon20148ThemostseriousofLi-ionsafetyevents…butalsotheleastlikelyWouldrequireveryhighvoltageAround65Vfora48VsystemAround160Vfora125VsystemMultiplelayersofcontrolReliablechargingsystemsAlarmmanagementBattery-levelswitchesOvertemperatureAGuidetoLithium-IonBatterySafety-Battcon20149CausesHighambienttemperatureI2RheatingfromdutycycleInternalshortcircuitMechanicalabuseAGuidetoLithium-IonBatterySafety-Battcon201410CrushingorpenetrationofcellsCancauseshort-circuitingandovertemperatureMostlikelyduringtransportationandinstallationShipmentinpartiallychargedstateRoadsidecabinetscouldbehitbyavehiclePartialprotectionfromcabinetstructureSellingsafetyAGuidetoLithium-IonBatterySafety-Battcon201411Frequentpromotionof‘single-shot’safetysolutionsElectrochemistryCeramic-coatedseparatorsThermal-managementdevicesElectrochemistryLithiumironphosphateLithiumtitanateEachhasprosandconsNointrinsicsafety!“Priusfireforensics”reportHolisticsafety–thefourpillarsAGuidetoLithium-IonBatterySafety-Battcon201412Celldesign–ventingAGuidetoLithium-IonBatterySafety-Battcon201413ReliesongaspressurebuildupwithincellMayalsohaveacircuit-interruptfunctionEffectsofcellventingSaft'sapproachtoLi-ionsafety-Confidential-Donotdistribute14TheseverityofathermalrunawayeventcanbelimitedifthechainisinterruptedHEATSOURCELOWTEMPREACTIONSHIGHTEMPREACTIONSTHERMITEREACTIONSTEMPERATURETIMESystemdesign–moduleAGuidetoLithium-IonBatterySafety-Battcon201415AvoidheatpropagationfromacellinthermalrunawayAirgapThermalinsulationPhase-changematerialModulemountingmustallowformanagementofventedgasSystemdesign–batterymanagementAGuidetoLithium-IonBatterySafety-Battcon201416LayeredapproachtosafetymanagementMeasurementanddetectionCellbalancingSwitches(contactors;MOSFETs)AlgorithmsAlarmmanagementMiddlewareApplicationHWMiddlewarecomponentDriverscomponentApplicationsequencerDataLow-levelLink&TransportPresentationMiddlewaremoduleDriversmodulePhysicalmoduleBMSSoftwareBMULibraryBMSFunctionsFaçadeLibrarysequencerIMD/IMRSOC/SOHCasestudy–BoeingDreamlinerAGuidetoLithium-IonBatterySafety-Battcon201417FirstlargecommercialjetwithLi-ionbatteriesTwoincidentsofbatteryfiresgroundedthefleetformonthsExtensiveNTSBinvestigationDreamlinerbatterydesignAGuidetoLithium-IonBatterySafety-Battcon201418DreamlinercellconstructionAGuidetoLithium-IonBatterySafety-Battcon201419DreamlinerbatteryfixAGuidetoLithium-IonBatterySafety-Battcon201420StandardsandspecificationsAGuidetoLithium-IonBatterySafety-Battcon201421TwoapproachesSpecifysafetydesignfeaturesSpecifyfunctionalsafetyunderapplicationconditionsSpecifyingfunctionalsafetyisfarbetterAllowsuseofstandardsIEC61508–SILlevelTelcordiaGR-3150IEEEStd1679providesframeworkforevaluatingsafetyandotherfunctionalityofnewtechnologiesSummaryAGuidetoLithium-IonBatterySafety-Battcon201422RecognizethatsafetyisneverabsoluteHolisticapproachthrough“fourpillars”conceptSafetymaxim:“Doeverythingpossibletoeliminateasafetyevent,andthenassumeitwillhappen”ProperlydesignedLi-ionbatteriescanbeoperatedconfidentlywithahighdegreeofsafetyThanksforlistening…AGuidetoLithium-IonBatterySafety-Battcon201423jim.mcdowall@saftbatteries.com