李伟 刘桂雄

摘要：为研究锂离子电池充放电下温度迅速升高触发热失控的热行为，以18650型三元锂电池单体为研究对象， 耦合电化学产热模型与热滥用模型，对其进行数值仿真试验，研究不同充放电倍率、环境温度、散热系数条件下，电芯从正常工作温度范围到高温范围的热特性。试验结果表明，电池在触发热失控反应开始阶段会出现温升速率拐点特性，温升速率骤降，随后电池温度急剧升高;电池高充放电倍率、高温环境、低散热系数均严重影响电池热稳定性，其中充放电倍率对电池热稳定性影响最大，散热条件对电池峰值温度有一定影响，电池未触发热失控时环境温度对电池峰值温度影响较小。

关键词：电化学产热模型;热滥用模型;充放电倍率;热行为

中图分类号： TH811文献标志码： A文章编号：1674–5124（2021）12–0157–06

Lithium battery local thermal dispersion simulation test technology based on coupled electrochemical and thermal abuse models

LI Wei，LIU Guixiong

（School of Mechanical and Automotive Engineering， South China University ofTechnology， Guangzhou 510640， China）

Abstract： In order to study the thermal behavior of thermal runaway triggered by rapid temperature increase under charge and discharge of lithium ion battery， the 18650 lithium ternary battery monomer was used as the object of study， coupled with electrochemical heat generation model and thermal abuse model， and numerical simulationtestwascarriedouttostudythethermalcharacteristicsof thecellsfromnormaloperating temperature range to high temperature range under different charge and discharge rates， ambient temperature andheatdissipationcoefficient. Thetestresultsshowthatthebatterywillshowtheinflection pointof temperature rise at the beginning of the thermal runaway reaction， with the temperature rise rate dropping abruptly and then the temperature of the battery rising sharply; the high charge/discharge rate， high temperature environment and low heat dissipation coefficient of the battery all have a serious impact on the thermal stabilityof the battery， in which the charge/discharge rate has the greatest impact on the thermal stability of the battery， and the heat dissipation conditions have a certain impact on the peak temperature of the battery， when the battery has not triggered thermal runaway， the thermal stability of the battery will be affected by the high charge/discharge rate， high temperature environment and low heat dissipation coefficient. Ambient temperature has less influence on peak battery temperature.

Keywords ： electrochemical heat generation model; thermal abuse model; charge and discharge rate; thermal behavior

0引言

鋰离子动力电池具有能量密度高、稳定性强、循环寿命长、无记忆效应等特点，在新能源汽车中得到广泛应用[1-3]，然而电池在充放电过程中产生大量热量，使其内部温度上升直接影响动力电池的性能、寿命，过高温度触发电池内部活性材料分解引发热失控[4]，严重时甚至会导致动力电池模组热失控引发安全事故[5]。研究锂离子动力电池热特性，开展锂离子动力电池局部热扩散仿真试验，对于提升电池安全性具有重要意义[6-7]。

国内外许多学者对锂电池热特性开展有益探索研究[8]。彭鹏等（2013）基于高温下电池内部活性材料分解反应，建立……