Comparative SOH Diagnosis and Forecasting of LFP and NMC Lithium-Ion Batteries in Electric Vehicles under Realistic Operating Conditions

Abstract

Accurate State of Health (SOH) diagnosis and forecasting are critical for ensuring the safety, efficiency, and longevity of batteries in electric vehicles (EVs). This novel research provides a comprehensive simulation-based comparative analysis of two Lithium Iron Phosphate (LFP) and Nickel Manganese Cobalt Oxide (NMC) batteries' degradation under realistic EV cycling conditions across an extended temperature range (25°C to 65°C). The design model used in this research, rigorously parameterized using published experimental data, tracks capacity fade and internal resistance growth, as well as coulombic efficiency decline, as key SOH indicators. Results of this novel and useful study demonstrate that both chemistries degrade faster with rising temperature, but NMC exhibits significantly accelerated aging above 50°C, reaching 80% SOH in fewer than half the cycles of LFP at 65°C. LFP maintains superior thermal resilience in a perfect manner, retaining higher SOH and lower resistance, including more stable coulombic efficiency across all temperatures. Achieved results also confirm and show greater degradation variability in NMC under thermal stress as well as increasing failure risk. This useful research quantifies critical temperature thresholds of batteries for end-of-life (SOH = 80%) and provides clear, data-driven guidance for battery selection and thermal management in EVs, particularly in hot climates or high-duty applications. By establishing a validated, multi-temperature simulation benchmark, this novel research work fills a major gap in chemistry-specific degradation forecasting and supports the design of adaptive battery management systems tailored to regional operating environments.