Damage Analysis of Lithium Iron Phosphate Batteries for Pure Electric Vehicles

Charge and discharge experiments of Lithium iron phosphate (LiFePO4) battery packs have been performed on an experimental platform, and electrochemical properties and the damage mechanism of LiFePO4 batteries are also analyzed in extreme cases. Our results indicate that over-charge has little impact on utilizable capacity of the battery in the short term. Over-discharge has a huge impact on utilizable capacity of the battery. Based on these results, a battery pack management method for reducing battery damage is proposed. Namely, by detecting voltage, temperature and other parameters of each cell, charge and discharge processes of the battery pack are monitored and controlled. This management method can avoid the battery pack damage problems arising from over-charge, over-discharge and over-temperature. At the same time, this method can also slow the rate of the battery pack capacity attenuation and extend the cycle life of the battery pack