Aging Characterization of Lithium Iron Phosphate Batteries Considering Temperature and Direct Current Undulations as Degrading Factors

This article presents the aging characterization and modeling of lithium iron phosphate (LiFePO4) batteries. The research work suggested here aims to characterize the aging of the resistances and the capacities of the batteries as a function of using temperature and direct current undulations. The proposed model of the LiFePO4 batteries is for multisource systems, such as distributed power generation systems-based renewable energies. The performances of the batteries used in these systems can be affected by the temperature and the dc-current undulations. The characterization system takes into account the temperature and the dc-current undulations as thermal and electric constraints for batteries. The experimental tests are performed through charging and discharging operations using calibrated fluctuating dc-current waveforms. The experimental measurements and simulations results obtained are similar with a deviation less than 1%. Hence, the proposed model is very appropriate to predict the degradation of battery parameters caused by the combined impacts of direct current undulations and the temperature.