光纤传感原位监测锂离子电池热失控过程

王青松、梅文昕、刘誌、郭团中国科学技术大学火灾科学国家重点实验室暨南大学2 3I 电动汽车智能电网电动汽车智能电网电化学储能电站便携电子航空航天电化学储能电站便携电子航空航天亟需监测并深入理解热失控全过程，并实现早期I质量损失内置热电偶内置压力传感器体积大电动汽车和储能：多点监测会增加系统复杂性和能量密度体积大难以植入电池内部难以在热失控高温、高压等极端环境中存活发展新型灵活、小巧的可植入电池内部的传感Energ.Convers.Manage.2022,252,11505I工作原理：以布拉格光栅FiberBraggGrating(FBG)为例λB工作原理：以布拉格光栅FiberBraggGrating(FBG)为例λBλB=2neffΛ温度变化引起光栅周期和折射率的变化，进而引起中心波长变化λBneffΛ纤芯有效折射率光栅周期导致的λB结构及优势灵活，柔性好体积小，重量轻（纤芯直径9μm）耐高温高压不导电耐电解液腐蚀电磁绝缘…I测量电池内部的温度和压力，监测测量电池内部的温度和压力，监测SEI膜生成飞秒激光制备FBG，实现电池内部温度监测首次将FBG植入电池内部，监测电池内部温度一根光纤布置5个FBG测点，测试电池一根光纤布置5个FBG测点，测试电池多点表面温度电池内部植入FBG传感器，监测锂硫电池内部应力变化首次提出多功能光纤，实现电池温度和应变的解耦7 812mm +OpticalfiberCellCrosssectionSideviewCrosssectionSideviewll------------i10mmii-------------0.8mmCladdingCore0.1mmCoreCladdingCladdingWavelength B=2neffWavelengthFP=4nml/(2k+*Wavelength折射率(nm)λFP=4nmLΤ(2k+1)9-10-15-20-25154015451550155515601565Wavelength(nm)0.2MPa1.4MPa154515501555Wavelength(nm)653210WavelengthresponseLinearfitting0.40.20.0-0.2-0.4Wavelengthresponse0100Wavelengthresponse0100200300400500600Temperature(°C)0.00.51.01.52.0Pressure(MPa)Peak1:0.5pm°CPeak1:0.5pm°C-1LinearfittingPeak2:0.5pm°C-1LinearfittingPeak3:0.5pm°C-1Lineafittring420Peak1Peak2Peak3Temperature(°C)Temperature(°C)0.00.20.40.60.80.00.20.40.60.82.0MPaMPaMPaMPaMPaMPaMPaMPaMPaMPaMPa152015401560158016001620Wavelength(nm)86420Peak1:4176.6pmMPa-1Peak2:4185.3pmMPa-1Peak3:4196.1pmMPa-1LinearfittingPressure(MPa) 循环性能评估循环性能评估0.5C140013001200SOH<80%Cellwithsensors020406080100Cyclenumber倍率性能评估倍率性能：不同倍率下的充放电循环0.5C-1C-1热失控前，中，后的FBG光谱信号AfterTRsWavelength(nm)热失控前，中，后的FPI光谱信号BeforeTRDuringTRAfterTRWavelength(nm)热失控前后光谱一致性良好，确保了热失控后光纤的回收 123412345+-热电偶及光纤传感器布置热电偶及光纤传感器布置152523344Temperature(ºC)Temperature(ºC)50040030020000-2-4-6-8416016023603801400340surface@TCsurface@TCTinternal@FBGPinternal@FPI32100.50.00100200300400500600Time(s)温度-压力-电压-质量损失变化曲线安全阀开启温度阶跃第一个压力峰值第二个压力峰值温度峰值温度阶跃第一个压力峰值热失控行为及特征I4.热失控原位监测及预警特征符号(单位)温度/℃TISC,avg(℃ሻ安全阀开启温度Tvent,avg(℃ሻ热失控触发温度TTR,avg(℃ሻTmax(℃ሻTmax,sTmax,inan+ca+elean+binder289.4℃an+binder289.4℃decomposition84.4℃an+ca+eleTemperature(ºC)Temperature(ºC)电压掉落温度TISC,avg对应于隔膜Temperature(ºC)Temperature(ºC)5004003002000103210321033Tsurface@TCTinternal@FBGVoltageMassPinternal@FPI..Internalpressure(M32100.50.00100200300400500600700Temperature(ºC)Temperature(ºC)3002000-1-2-3-4-5StageStageIVenting33Venting33273.3℃0.3℃0.3℃1.651.65MPa020040060080010001200Internalpressure(MPa)2102.00.50.0InternalInternalpressure(MPa)temperature(ºC)微分dT/dt&dP/dt组合温度&压力曲线WarningSmooth@TSmooth@P0.60.30.00100200300400Time(s)InternalInternalpressure(MPa)temperature(ºC)微分dT/dt&dP/dt组合温度&压力曲线WarningSmooth@TSmooth@P0.60.30.00100200300400Time(s)温度&压力变化率转折点30200.10.0-0.1-0.7 0100200300400500600700Time0100200300400500600700Time(s)I4.热失控原位监测及预警HeatGraphiteLiFePO4LiionLiHeatGraphiteLiFePO4LiionLisiteSeparatorSEIfilmElectrolytevaporPdominant户户Tdominant早期预警区间：始于电解液蒸发，止于SEI膜分解，并96TriseratePriserate96TriseratePriserateWarningWarning30TemperatureTemperatureriserate(ºC/s)0.60.30.0-0.3PressurePressureriserate(kP950%SOCWarning6Warning300100200300400Time(s)TemperatureTemperatureriserate(ºC/s)0.60.30.0PressurePressureriserate(kP6Warning4Warning200100200300400Time(s)Tturn(℃)Tturn,STturn,inTturn,avg Temperature(ºC)Pressure(MPa)Temperature(ºC)Pressur