In recent years, electric vehicles have developed rapidly. However, as the power source of electric vehicles, lithium battery has poor performance at low temperature, and has some problems such as reduced capacity and increased internal resistance. In this paper, two thermal environments, including natural convection condition and near‐adiabatic condition, are established, and discharge capacity test and cyclic dynamic stress test (DST) are conducted for lithium iron phosphate batteries. The actual effect of near‐adiabatic conditions is analyzed from three perspectives: battery surface temperature, terminal voltage and EIS. The results show that the near‐adiabatic working condition has almost no effect on the discharge capacity at the standard discharge current (0.5 °C) under the same temperature conditions, ranging from −15 to 25 °C. In the low‐temperature − 10 and − 15 °C cyclic dynamic stress test, compared with the natural convection working condition, the near‐adiabatic condition has a rapid rise in terminal voltage one cycle earlier, causing the cycle to stop. Also, the polarization impedance increases at least twice after the cycle under the near‐adiabatic condition. Finally, according to the analysis of variance (ANOVA), the near‐adiabatic condition has a significant effect on voltage and polarization resistance at low temperatures. Still, it has almost no effect on ohmic resistance and discharge capacity. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

中文翻译：

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电动汽车锂电池低温绝热性能研究

近年来，电动汽车发展迅速。然而，作为电动车辆的动力源，锂电池在低温下性能较差，并且具有诸如容量减小和内部电阻增加的一些问题。本文建立了自然对流和近绝热两个热环境，并对磷酸铁锂电池进行了放电容量测试和循环动态应力测试（DST）。从三个方面分析了绝热条件的实际影响：电池表面温度，端电压和EIS。结果表明，在绝热条件下，在-15至25°C的相同温度条件下，标准放电电流（0.5°C）下的放电容量几乎没有影响。在低温-10和-15°C循环动应力测试中，与自然对流工作条件相比，近绝热条件在一个循环的早期使端子电压快速升高，从而导致循环停止。同样，在绝热条件下，极化阻抗在循环后至少增加两次。最后，根据方差分析（ANOVA），接近绝热条件对低温下的电压和极化电阻具有显着影响。尽管如此，它对欧姆电阻和放电容量几乎没有影响。©2021日本电气工程师学会。由Wiley Periodicals LLC发布。在接近绝热的状态下，端子电压会在一个周期之前迅速上升，从而导致该周期停止。同样，在绝热条件下，极化阻抗在循环后至少增加两次。最后，根据方差分析（ANOVA），接近绝热条件对低温下的电压和极化电阻具有重大影响。尽管如此，它对欧姆电阻和放电容量几乎没有影响。©2021日本电气工程师学会。由Wiley Periodicals LLC发布。在接近绝热的状态下，端子电压会在一个周期之前迅速上升，从而导致该周期停止。同样，在绝热条件下，极化阻抗在循环后至少增加两次。最后，根据方差分析（ANOVA），接近绝热条件对低温下的电压和极化电阻具有显着影响。尽管如此，它对欧姆电阻和放电容量几乎没有影响。©2021日本电气工程师学会。由Wiley Periodicals LLC发布。接近绝热的条件对低温下的电压和极化电阻具有显着影响。尽管如此，它对欧姆电阻和放电容量几乎没有影响。©2021日本电气工程师学会。由Wiley Periodicals LLC发布。接近绝热的条件对低温下的电压和极化电阻具有显着影响。尽管如此，它对欧姆电阻和放电容量几乎没有影响。©2021日本电气工程师学会。由Wiley Periodicals LLC发布。