Degradation Evaluation of Lithium-Ion Batteries in Plug-In Hybrid Electric Vehicles: An Empirical Calibration

Battery life management is critical for plug-in hybrid electric vehicles (PHEVs) to prevent dangerous situations such as overcharging and over-discharging, which could cause thermal runaway. PHEVs have more complex operating conditions than EVs due their dual energy sources. Therefore, the SOH estimation PHEV needs consider specific characteristics of make calibrations accordingly. Firstly, we estimated initial by combining data-driven empirical models. The method used was incremental state charge (SOC)-capacity method, model Arrhenius model. This can obtain battery degradation trend predict well in realistic applications. Then, according multiple PHEV, conducted a correlation analysis selected UF calibration factor because has highest with SOH. Finally, calibrated parameters using fuzzy logic way, so that fitting trends be closer true proposed verified dataset included 11 vehicles. experiment results show root mean square error (RMSE) after decreased 0.2–14% coefficient determination (R2) improved 0.5–32%. provides reliable guidance safe operation batteries.