An advanced electro-thermal cycle-lifetime estimation model for LiFePO4 batteries

Abstract

Electric vehicles (EVs) have been considered as one of the effective solutions to current energy and environment concerns. One of the challenges regarding the energy storage system (ESS) of today's electric vehicles, which are batteries, is the capacity fade. It is of great importance to identify and analyze the factors contributing to the capacity loss and predict the cell degradation. In this manuscript, an advanced systematic Lithium iron phosphate (LiFePO4) battery cell model is proposed to estimate the battery cell State-of-Charge (SOC), cell internal temperature, and battery cycle-lifetime. The accuracy of the proposed model is examined and verified through comparative analyses. Based on the proposed battery model, the impact of various factors, such as discharge current rate, temperature, peak discharge current and Depth-of-Discharge (DoD) and their effects on battery cell capacity loss and cycle-lifetime are investigated and studied.