Battery Reliability of fast Electric Vehicle Charging Systems

Fast electric vehicle charging systems (FEVCSs) are becoming popular, but to assure long-term operation, further research on battery lifetime is necessary. This is because FEVCSs use high charging currents, and consequently subject Li-Ion batteries to high levels of average state of charge (SOC) and temperatures within a short period of time. Thus, degradation mechanisms, such as Lithium plating and electrolyte breakdown, are inevitable in Li-Ion batteries, leading to reduced battery capacity and lifetime. Therefore to investigate the battery reliability of FEVCSs, this paper proposes a two-stage modeling approach. Using the proposed model, the impact of SOC and temperature on the reliability of the battery as well as the reliability of a Li-Ion battery under typical fast EV charging conditions are investigated, and results are presented to show how the battery reliability deteriorates under fast charging conditions.