Innovative Incremental Capacity Analysis Implementation for C/LiFePO4 Cell State-of-Health Estimation in Electrical Vehicles

Resumen

This paper presents a fully embedded state of health (SoH) estimator for widely used C/LiFePO₄ batteries. The SoH estimation study was intended for applications in electric vehicles (EV). C/LiFePO₄ cells were aged using pure electric vehicle cycles and were monitored with an automotive battery management system (BMS). An online capacity estimator based on incremental capacity analysis (ICA) is developed. The proposed estimator is robust to depth of discharge (DoD), charging current and temperature variations to satisfy real vehicle requirements. Finally, the SoH estimator tuned on C/LiFePO₄ cells from one manufacturer was tested on C/LiFePO₄ cells from another LFP (lithium iron phosphate) manufacturer.