大型软包锂离子电池的热物性实验研究

Experimental investigation on thermophysical parameters of large-format pouch lithium-ion battery

针对大型软包锂离子电池热物性参数的测定问题,提出适用于该型电池的热参数表征方法.基于准稳态导热原理,建立电池的传热理论模型.开展实验研究电池的比定压热容和导热系数与温度的依变关系,分析热损对测试结果的影响,对测试方法的有效性进行验证.结果表明,电池比定压热容随着温度的升高而线性增大,导热系数受温度的影响较小.在900 s内可以测得电池热参数在10~60℃下的变化状况,实验验证结果显示测算精度高于92.3%,具有测算周期短、准确度高和测试灵活等优势.

A thermal parameter characterization method suitable for this battery was proposed aiming at the problem of the thermophysical parameters determination for large-format pouch lithium-ion battery cell.A theoretical model of heat transfer of the battery was established based on the principle of quasi-steady-state heat conduction.Experiments were conducted to analyze the dependence of the specific heat capacity at constant pressure and thermal conductivity of the battery on the temperature.The influence of heat loss on the test results was analyzed,and the validity of the test method was verified.Results show that the cell specific heat increases linearly as the increasing temperature,and the temperature has a minor effect on the cell thermal conductivity.The thermal parameters in the temperature range of 10~60℃ for the cell can be measured within 900 s.The experimental results show that the test precise overtops 92.3%,which has the advantages of short measurement cycle,high accuracy and flexible testing.