基于多尺度、电化学-热耦合模型的锂离子电池生热特性分析
Analysis of Heat Generation in a Li-Ion Battery Based on a Multi-Scale and Electrochemical-Thermal Coupled Model

为实现精确的电池热管理，选取正、负极材料分别为LiyMn2O4和LixC6的层叠式锂离子电池为研究对象， 建立了微观-宏观尺度耦合、电化学-热耦合模型，分析了不同放电倍率下单体电池的放电特性及电池包的平均温 升、单体电池内部生热机理及变化特性，并详细定量分析了生热量各组成部分所占的比例及变化．分析结果表明： 高放电倍率下，电池放电性能变差，温升显著提高，5C 放电倍率下，温度升高63,℃．低放电倍率下，可逆热是主 要的生热来源，高放电倍率下，液相中的欧姆热是主要的生热来源；相比之下，负极生热量最高，其主要来源于负 极的可逆热，隔膜中所占百分比次之，正极最少，其主要来源于正极的不可逆热和欧姆热．
To achieve accurate battery thermal management，a micro-macroscopic and electrochemical-thermal coupled model for a laminated Li-ion battery with the couple LiyMn2O4|LixC6 was developed in this paper．Based on the modeling results，average temperature rise，characteristics of discharge，as well as mechanism and evolution of heat generation in the battery were investigated．In addition，the proportion of each part of heat generation and its evolution with discharge rate were analyzed quantitatively in details．The results show that battery discharge performance deteriorates at a high discharge rate，which causes significant temperature rise．The average temperature rises by about 63,℃ when the discharge rate is 5,C．Reversible heat is the main heat source at lower discharge rates，but the proportion of Ohmic heat in the liquid phase increases greatly with increasing discharge rate．By contrast，heat generation in the negative electrode is higher than in other regions，which is mainly attributed to the reversible heat. Following the separator，the heat generation in the positive electrode is the least，which is mainly due to the irreversible heat and Ohmic heat