Fundamental understanding of heat generation of lithium-ion batteries during operations is crucial to the cost-effective and efficient design of a thermal management system (TMS) in electric vehicles. Accurate characterization of the heat requires a calorimeter that meets inherent dynamics of the heat with accuracy. Therefore, we have developed an isothermal calorimeter using the thermoelectric assemblies (TEAs) along with the temperature control and Kalman filter, which is used to measure the heat generation rate (HGR) of large format pouch type lithium-ion batteries as an example. The measured HGR is a function of charge and discharge rates, state-of-charge (SOC), and temperatures. Analysis has shown that both the HGR and the ratio of the total heat generation to the total energy stored or released (p_heat) of the tested cells increase as the current increases or the temperature decreases. In addition, a new calorimetric method is developed which enables a simultaneous determination of the entropy coefficient and internal resistance in the reversible and irreversible heat source terms in the frequency domain. The method can reduce the testing time about 92% compared with those by the conventional potentiometric method and electrochemical impedance spectroscopy (EIS) analysis, respectively, and the determined parameters are in good accordance with the reference values. Moreover, the calculated reversible and irreversible heat sources terms are compared with the experimental measurement and matched each other.

对锂离子电池在运行过程中产生热量的基本了解对于电动汽车热管理系统（TMS）的经济高效设计至关重要。热量的准确表征需要一个热量表，该热量表能够准确地满足热量的内在动力学。因此，我们开发了一种使用热电组件（TEA）以及温度控制和卡尔曼滤波器的等温量热仪，以测量大型袋式锂离子电池的发热量（HGR）为例。测得的HGR是充电率和放电率，充电状态（SOC）和温度的函数。分析表明，HGR和总热量与储存或释放的总能量之比（p_热当电流增加或温度降低时，被测电池的）会增加。此外，开发了一种新的量热方法，该方法可以同时确定频域中可逆和不可逆热源项的熵系数和内阻。与常规电位法和电化学阻抗谱（EIS）分析相比，该方法可减少约92％的测试时间，确定的参数与参考值良好。此外，将计算出的可逆和不可逆热源项与实验测量值进行比较，并相互匹配。