(1. 北京科技大學(xué) 新材料技術(shù)研究院,北京 100083;2. 山西長征動力科技有限公司, 山西 048400;
3. 北京智行鴻遠(yuǎn)汽車有限公司,北京 102202)
摘 要: 從仿真建模的角度出發(fā),對一款40 A?h軟包疊片式動力電池建立電化學(xué)-熱耦合模型,并對該構(gòu)型電池的極耳結(jié)構(gòu)進(jìn)行了相關(guān)研究及優(yōu)化工作。仿真結(jié)果顯示,極耳與電芯間由于產(chǎn)熱率的差異而引起的熱流交換是電芯域內(nèi)出現(xiàn)溫度梯度分布的主要因素。在對極耳尺寸的優(yōu)化中發(fā)現(xiàn),電芯的最高溫度隨極耳寬度和厚度的增大而逐漸減小;電芯的最大溫差隨極耳寬度和厚度的增大在一定范圍內(nèi)逐漸減小,而當(dāng)兩者超過一定閾值(極耳寬度大于70 mm,極耳厚度大于0.5 mm)后,電芯的最大溫差反而呈現(xiàn)出增大的趨勢。原因在于極耳產(chǎn)熱率的降低以及散熱率的增加,使得在放電中后期極耳溫度低于電芯溫度,起到給電芯持續(xù)散熱的效果,但這種散熱作用隨極耳尺寸的增大反而惡化了電芯溫度分布的均勻性。
關(guān)鍵字: 電化學(xué)-熱耦合模型;熱參數(shù);極耳尺寸;溫度梯度
(1. School of Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China;
2. Shanxi Changzheng Power Technology Co., Ltd., Shanxi 048400, China;
3. Beijing Idrive Automotive Co., Ltd., Beijing 102202, China)
Abstract:A forward design method based on the electrochemical-thermal model was adopted for a 40 A?h laminated lithium-ion cell. Then, the tab structure of this cell was studied and optimized based on the validated model. It is found from the numerical results that the heat flux between the tab and the cell core caused by heat generation rate difference is the main factor that resulting in the temperature gradient distribution of the cell core. Optimization results of tab size show that the maximum temperature of the cell core gradually decreases with the increase in tab width and thickness. Besides, the maximum temperature difference in the cell core decreases with the increase of tab width and thickness in a certain range. But when the two parameters both exceed the threshold values (the tab width is more than 70 mm, and the tab thickness is greater than 0.5 mm), the index tends to increase. The main reason is that the decrease of the heat generation rate and the increase of the heat radiation rate of the tabs makes its temperature lower than that of the cell core, further playing a cooling effect on the cell core. However, the heat dissipation plays a bad effect on the uniformity of the cell temperature distribution to the increase in the tab size.
Key words: electrochemical-thermal model; thermal parameter; tab size; temperature gradient


