针对常用的电动汽车动力电池容量衰减循环充放电检测方法由于忽略了电池在充放电过程中所发生的“伴随有电荷转移的化学反应”的特点，而导致其难以正确、非破坏性地检测其动力电池容量及其衰减状况的难题，根据电池电化学和计算机层析图像测量原理，以电动汽车车用磷酸铁锂动力电池容量衰减为研究对象，研究了处于电化学反应过程中的动力电池电性能参数与其内部活性物质结构形态之间的关系，提出了电动汽车动力电池容量衰减层析图像检测方法，在此基础上，建立了动力电池容量衰减检测实验系统，并以此对某款典型的纯电动汽车车用磷酸铁锂动力电池容量衰减进行了实验验证，结果表明，该方法具有实用、正确和非破坏性地检测动力电池容量衰减的特点。

The commonly used method of power battery capacity detection of electric vehicle neglects the characteristic of chemical reaction with charge transfer which occurs in the process of charging and discharging of the battery, so it is difficult to detect the power battery capacity and its fading accurately and nondestructively. We proposed the tomography image detecting method of the capacity fading of power battery. The detection technique of tomography image and the commonly electrochemical performance detection technique were integrated. The experiment system of power battery capacity fading was established. The object of the research was the capacity fading of LiFePO4 power battery which used in pure electric vehicle usually. The relationship between the electric performance parameters of power battery and its structure morphological parameters was studied based on the principle of battery electrochemical and computer tomography. The experimental result shows that the tomography image method is practical, correct and non-destructively.