The Influence of Testing Conditions on State of Health Estimations of Electric Vehicle Lithium-Ion Batteries Using an Incremental Capacity Analysis

Abstract

The increasing growth of the second-hand electric vehicle market demands reliable methods for evaluating the state of health of deployed electric vehicle batteries. Among these methods, incremental capacity analysis is a commonly used technique for state of health evaluation via the quantification of degradation modes. While the optimal conditions for its application typically involve low currents and a controlled temperature, this cannot be easily applied to deployed batteries. It is therefore essential to understand the impact of varying charging rates and temperatures on the accuracy of the analysis. In this study, the characteristics and behavior of incremental capacity features for seven electric vehicle batteries tested under different calendar aging conditions were investigated. The results show that accurate state of health estimations under different test conditions could be obtained using specific electrochemical features.