通过建立二维热模型对6.5Ah圆柱型Ni/MH动力电池在常规循环和模拟工况循环过程中的热效应进行了分析,并讨论了循环次数对电池热效应的影响.实验采用石英频率微量热仪对电池的热容量及其在不同电流(1C,3C,5C)过充电时的产热速率进行了测量,继而将产热速率曲线拟合成分段函数,以此建立精确的热模型.实验采用有限元方法模拟了电池在不同循环次数时不同电流充电过程中其内部温度场分布.结果表明,电池在常规循环和模拟工况循环时,循环次数与电池内部中心温度之间均近似呈现线性关系;同时,在对电池热效应的测试过程中,充电电流越大,循环次数对热效应的影响越显著.由此,可以预测不同循环次数时电池内部的温度分布,从而对不同循环次数时电池的实际使用条件提供指导.
To analyze the thermal behavior of a 6.5-Ah cylinder Ni/MH battery in the cycle processes,including normal and simulated work-condition cycle processes,a two-dimensional thermal model is provided.Furthermore,the impact of cycle processes on thermal behavior is discussed.Quantities of heat and the heat generation rate of the battery during overcharging at different currents (1,3,5 C) are measured by quartz frequency microcalorimetry.The heat generation rate is fitted by piecewise functions,thus more reliable data is provided to create a precise thermal model.The internal temperature profiles of different cycle numbers during charging at different currents are simulated by FEM.Results show that the relationships between the central battery temperature and the cycle numbers are approximately linear.Meanwhile,the larger the charging currents,the more obvious the effect of cycle numbers on thermal behavior.Thus,the internal temperature profiles at different cycle numbers can be predicted,and suitable battery application conditions are provided.