Experimental Investigation of Fast−Charging Effect on Aging of Electric Vehicle Li−Ion Batteries

Abstract

A huge increase in fast−charging stations will be necessary for the transition to EVs. Nevertheless, charging a battery pack at a higher C−rate impacts its state of health, accelerating its degradation. The present paper proposes a different and innovative approach that considers the daily routine of an EV Li−ion battery based on a standard driving cycle, including charging phases when the depth of discharge is 90%. Through dynamic modeling of the EV battery system, the state of charge evolution is determined for different charging C−rates, considering both real discharging and charging current profiles. Finally, by applying a suitable post−processing procedure, aging test features are defined, each being related to a specific EV battery working mode, including charging at a particular C−rate, considering the global battery operation during its lifespan. It is demonstrated that, according to the implemented procedure, fast−charging cycles at 50 kW reduce battery lifespan by about 17% with respect to charge in a 22 kW three−phase AC column, in parity with the discharge rate. Thus, this work can provide a deep insight into the expected massive penetration of electric vehicles, providing an estimate of battery useful life based on charging conditions.

Research on Optimum Charging Current Profile with Multi-Stage Constant Current Based on Bio-Inspired Optimization Algorithms for Lithium-Ion Batteries

“…They possess numerous advantages, including high energy density, compact size, long cycle life, high discharge current tolerance, and the absence of memory effects. As a result, many high-power energy storage systems have begun to focus on the research and development of high-capacity LiBs [1][2][3]. Charging techniques play a crucial role in the performance and lifespan of LiBs.…”

“…Factors directly affected include the following: (1) Charging time: the charging technique employed dominates the time required to fully charge LiBs. Efficient charging algorithms can optimize the charging process and reduce the overall CT. (2) Charging efficiency: the charging technique influences the efficiency of energy transfer during the charging process. Higher CE means less energy loss and more effective utilization of the charging power.…”

“…The main contributions of this paper include the following: (1) Without the need for numerous and long-lasting experimental processes, the OCCP search can be quickly achieved only through the ECM-based computation platform established. (2) The OCCP searching procedure is completed based on the consideration of multi-objective optimization. (3) The JSA applied to the OCCP search of LiBs is first proposed.…”