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

Abstract

This article presents the aging characterization and modeling of lithium iron phosphate (LiFePO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> ) 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 LiFePO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> 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.