温升是影响锂离子电池力学性能和使用寿命的主要参数。研究了热辐射效应对温度的影响,首先建立了圆柱型电池传热模型,针对ICR65/400锂离子电池数值分析了热辐射系数对电池内部温度场变化的影响;然后讨论了放电倍率、对流换热系数和环境温度对热辐射的影响;最后在高放电倍率、自然对流和低温环境下,对有无热辐射效应的温度场进行了比较。结果表明：圆柱型锂离子电池放电过程中最高温度出现在电池中心处,最低温度在电池表面;当放电倍率、环境温度和对流换热系数不变时,热辐射系数越大,电池散热越快,体系降温速率越快,达到热平衡时间越短;电池放电倍率越高,其生热速率越快,热辐射的散热效果越显著;当对流换热系数和放电倍率不变时,环境温度越低,其与电池温差越大,热辐射的散热效果越显著;当环境温度和放电倍率不变时,对流换热系数越小,热辐射的散热效果越显著;热辐射效应可有效降低电池内部温度。

Temperature rising is a major parameter affecting the mechanical properties and service life of lithium ion batteries. In this work, taking into account the thermal radiation effect, a heat transfer model of cylindrical batteries was developed, and the influence of thermal radiation coefficient on the temperature field in ICR65/400 lithium-ion batteries was analyzed numerically. Then the effects of the discharge rate, convective heat transfer coefficient and ambient temperature on the thermal radiation effect were discussed. The comparison of the temperature field affected by thermal radiation effect and no thermal radiation was carried out under the conditions of high discharge rate, natural convection and low temperature. The results show that the maximum temperature of cylindrical lithium-ion batteries occurs in the center of the batteries and the minimum temperature is on the surface of the batteries during the discharge process; when the discharge rate, ambient temperature and convective heat transfer coefficient are given, the larger the thermal radiation coefficient, the faster the heat dissipation of the battery, the faster the temperature decrease rate of the system and the shorter the time to reach the thermal equilibrium; the higher the discharge rate of the battery, the faster the heat generation rate and the more obvious the heat radiation effect; when the convective heat transfer coefficient and the discharge rate are given, the lower the ambient temperature, the greater the temperature difference of the environment and the battery, and the more significant the convective heat transfer effect; when the ambient temperature and discharge rate are given, the smaller the convective heat transfer coefficient, and the more obvious the heat dissipation effect of thermal radiation. The thermal radiation can effectively decrease the temperature of the lithium ion batteries.