Using Electrochemical Impedance Spectroscopy and Equivalent Circuit Modeling to Analyze Capacity Fade in Lithium-Ion Batteries Due to Pulse Charging

Abstract

Battery life is a critical and challenging issue for battery development and applications. The capacity of lithium-ion batteries reduces during continuous discharge-charge cycling. This capacity fade or loss occurs due to different mechanisms which are associated with side reactions that occur in these batteries [1]. The objective of this work is to use electrochemical impedance spectroscopy (EIS) to study the effects of pulse charging on the capacity and cycling characteristics of lithium-ion cells and compare it with conventional charging method at constant current-constant voltage (CCCV). Implementing conventional charging and pulse charging at an average of 0.5C and 1C on 18650 Lithium Iron Phosphate batteries separately provides varied results in capacity after few cycles. Equivalent circuit models are extracted from the measured EIS data for both of the charging methods to provide detailed results on capacity and battery performance. Reference: [1] P. Arora, R. E. White, and M. Doyle, “Capacity Fade Mechanisms and Side Reactions in Lithium‐Ion Batteries,” J. Electrochem. Soc. , vol. 145, no. 10, pp. 3647–3667, Oct. 1998. Figure 1