文档名：热失控状态气液两相的锂离子电池建模及修正方法研究
摘要：锂离子电池在应用过程中因滥用而发生热失控现象,导致电池内部产生大量气体,传统的固液两相模型难以准确描述热失控机理.针对以上问题,以18650电池组为研究对象,构建气液两相的锂离子电池模组的电化学-热耦合模型,研究了热失控气体对锂离子电池内部应力、温度、电解液浓度的影响规律,同时利用COMSOLMultiphysics5.5软件进行了有效性验证和理论模型修正.研究结果表明,锂离子电池热失控气体对电池内部应力、温度、电解液浓度有着明显的正反馈影响规律.内部应力的理论修正值与仿真值峰值均在相近时刻出现,且误差为0.04MPa,计算精确率提高了80％.电池内部温度到60℃左右时发生热失控,产生的热失控气体在内部温度升高到160℃时被点燃,640s时达到最高仿真温度,修正温度分别为177、172℃,热失控气体产生的热点现象是影响电池包内部的温度分布不均的主要原因.电解液浓度理论修正值和仿真值从1200mol/m3同步下降至837mol/m3,形成气液两相流,电解液与电极材料反应和分解造成了电解液浓度降低.
Abstract：Lithium-ionbatteries,whicharewidelyusedenergystoragedevicesinmodernelectronicdevicesandelectricvehicles,havebeenidentifiedasakeycomponentinthetransitionfromdepletedfossilfuelstosustainableenergyproductionanduseworldwide.However,duetomisuseandimproperuse,lithium-ionbatteriescanexperiencethermalrunaway,aphenomenonthatmanifestsitselfasasignificantbuild-upofgaseswithinthebattery.Traditionalsolid-liquidtwo-phasemodelspresentchallengesincharacterizingthecomplexityofthermalrunawaymechanisms.Inordertounderstandthemechanismofthermalrunawaymoreaccurately,anelectrochemical-thermalcouplingmodelof18650lithium-ionbatterypackisbuiltbasedongas-liquidtwo-phaseflow,andthevariationlawofinternalstress,temperatureandelectrolyteconcentrationoflithium-ionbatteryduringthermalrunawayiswellstudied.Accordingtothechemicalreactionprocessandthedynamicevolutionofinternalpressureandtemperature,thewholethermalrunawayprocessisdividedintoreactionstage,diffusionstageandequilibriumstage,sothatthecharacteristicsofeachstagecanbestudiedinmoredetail.TheeffectivenessofthetheoreticalanalysisisverifiedbyusingtheCOMSOLMultiphysics5.5software,andthetheoreticalmodelismodified,andtheresultsofthecomparativeanalysisshowtheimportanceandcomplementarityofthetheoreticalanalysisandsimulationexperimentsinthestudyofthermalrunawayoflithium-ionbatteries.Thedifferencebetweenthepeakvalueoftheinternalstresscorrectionvalueandthesimulatedvalueisonly0.04MPa,theerrorissignificantlyreduced,andtheaccuracyisincreasedby80％,whichindicatesthatthemodelcanmoreaccuratelydescribethethermalrunawayprocessoflithium-ionbattery,highlightingtheaccuracyenhancementobtainedbythismodelingmethod.Ourstudyalsorevealsthatthethermalrunawaygascancauseadrasticchangeintheinternaltemperatureofthebattery,andtheamplitudeofthechangeisbasicallysynchronizedwiththeincreaseoftheinternalpressureofthebattery,thethermalrunawayoccursatatemperatureof60℃,andthethermalrunawaygasisignitedwhentheinternaltemperaturerisesto160℃,andthemaximumsimulatedtemperatureandcorrectedtemperatureare177℃and172℃at640seconds,respectively.Theformationofhotspotsisthemaincauseofuneventemperaturedistributionwithinthebattery.Inaddition,Ourstudyshowsthattheelectrolyteconcentrationdecreasesfrom1200mol/m3to837mol/m3simultaneouslyfromthetheoreticalandsimulatedvaluesoftheelectrolyteconcentrationcausedbythethermalrunawaygasthroughoutthethermalrunawayprocess.Thisdynamicevolutiontrendacceleratestheformationofgas-liquidtwo-phaseflowandtheprocessofthermalrunaway,forminggas-liquidtwo-phaseflow,theinteractionbetweentheelectrolyteandtheelectrodematerial,whichleadstothereductionoftheelectrolyteconcentrationtoalargeextent.Theelectrochemical-thermalcouplingmodelbasedongas-liquidtwo-phaseflowandthein-depthstudyofthethermalrunawayprocessdeepensourunderstandingofthemechanismofthermalrunawayoflithium-ionbatteries,andprovidesamorein-depththeoreticalbasisforpreventingorremedyingthethermalrunawayproblemoflithium-ionbatteries.
作者：廖世勇 吴浩 吴胜利 邢文婷 Author：LIAOShiyong WUHao WUShengli XINGWenting
作者单位：重庆交通大学交通运输学院,重庆400074;西安交通工程学院交通运输学院,西安710300重庆交通大学交通运输学院,重庆400074重庆工商大学管理科学与工程学院,重庆400067
刊名：重庆理工大学学报
Journal：JournalofChongqingInstituteofTechnology
年，卷(期)：2024, 38(1)
分类号：TM911.11
关键词：锂离子电池 热失控气体 电化学-热耦合模型 理论修正 正反馈
Keywords：lithium-ionbattery thermalrunawaygas electrochemical-thermalcouplingmodel theoreticalrevision positivefeedback
机标分类号：
在线出版日期：2024年3月6日
基金项目：国家自然科学基金，重庆市自然科学基金，国家社会科学基金热失控状态气液两相的锂离子电池建模及修正方法研究[
期刊论文] 重庆理工大学学报--2024, 38(1)廖世勇 吴浩 吴胜利 邢文婷锂离子电池在应用过程中因滥用而发生热失控现象,导致电池内部产生大量气体,传统的固液两相模型难以准确描述热失控机理.针对以上问题,以18650电池组为研究对象,构建气液两相的锂离子电池模组的电化学-热耦合模型,研究了...参考文献和引证文献
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热失控状态气液两相的锂离子电池建模及修正方法研究 Research on modeling and correction method of gas-liquid two-phase lithium-ion battery in thermal runaway state
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