基于红外热成像技术的锂离子电池热特性试验研究

为了深入研究锂离子电池在工作状态下的热特性,通过试验与理论分析手段,结合红外成像技术与非接触式可视化观测方法,研究了锂离子电池单体在不同放电倍率下的表面温度分布特征及不同荷电状态(State of charge,SOC)下的温度均衡性和不同测量点的温升特性。结果表明:锂离子电池极耳附近区域为主要的产热源,且放电倍率越高,产热量越大;电池温度上升越快,最高温度越高,电池温度均衡性越差; 1C放电时,电池表面的温度梯度以多个类半圆形温区呈现;并以正极区为圆心向整个电池扩展; 2C放电时,初期形成的两个半圆形温区重合为一个以圆弧为下边的类矩形温区,直至扩展到电池下边缘;不同放电倍率下,电池温升速率均呈现先减小后增大的趋势。根据以上分析及研究成果,可以合理改进电池单体结构,设计电池组或电池包散热方案,提高锂离子电池在工作过程中的高效性和安全性。

Experimental study on thermal characteristics of lithium-ion battery based on infrared thermal imaging technology

In order to study the thermal characteristics of lithium-ion battery under working condition, the surface temperature distribution characteristics of lithium-ion battery cells under different discharge rates and temperature balance under different SOC and temperature rise characteristics of different measurement points were studied by means of experimental and theoretical analysis, combined with infrared thermal imaging technology and non-contact visual observation method. The results show that the vicinity of the ear of the lithium-ion battery is the main source of heat generation, and the higher the discharge rate, the higher the heat generation, the faster the battery temperature rises, the higher the maximum temperature, the worse the battery temperature balance; 1C discharge, the battery The temperature gradient of the surface is presented in a plurality of semi-circular temperature zones, and extends to the entire battery with the positive electrode as the center; when the 2C discharges, the two semi-circular temperature zones formed at the beginning coincide with each other with a circular arc as the lower side. The rectangular temperature zone is extended to the lower edge of the battery; under different discharge rates, the temperature rise rate of the battery first decreases and then increases. According to the above analysis and research results, the battery cell structure can be reasonably improved, and the heat dissipation scheme of the battery pack or the battery pack can be designed to improve the efficiency and safety of the lithium ion battery in the working process.