State-of-Health Estimation of Lithium-ion Batteries by Fusing an Open-Circuit-Voltage Model and Incremental Capacity Analysis
Xiaolei Bian, Zhongbao GAE Wei, Weihan Li, Josep Pou, Dirk Uwe Sauer, Longcheng Liu, IEEE Transactions on Power Electronics, 13 August 2021.
The state of health (SOH) is a vital parameter enabling the reliability and life diagnostic of lithium-ion batteries (LIBs). A novel fusion-based SOH estimator is proposed in this study, which combines an open-circuit-voltage (OCV) model and the incremental capacity analysis (ICA). Specifically, a novel OCV model is developed to extract the OCV curve and the associated features-of-interest (FOI), from the measured terminal voltage during constant-current (CC) charge. With the determined OCV model, the disturbance-free incremental capacity (IC) curves can be derived, which enables the extraction of a set of IC morphological FOIs. The extracted model FOI and IC morphological FOIs are further fused for SOH estimation through an artificial neural network. Long-term degradation data obtained from different battery chemistries are used for validation. Results suggest that the proposed fusion-based method manifests itself with high estimation accuracy and high robustness.