Diagnostic approach reveals how temperature shapes battery aging in electric vehicles
This new study shows how advanced diagnostic techniques can track and explain battery degradation in electric vehicles, revealing that lower temperatures significantly preserve battery health while exposing hidden aging pathways.
As electric vehicles expand globally, understanding how batteries age under real-world conditions is essential for improving performance, safety, and durability. Within the NEMO project framework, researchers at Vrije Universiteit Brussel (VUB) investigated the degradation of 75 Ah NMC631 lithium-ion cells, focusing on the impact of temperature using a combined diagnostic approach based on incremental capacity analysis (ICA) and electrochemical impedance spectroscopy (EIS).
Cells were tested under identical cycling conditions while varying only the temperature, allowing a clear assessment of temperature-driven aging. The results show that lower temperatures significantly slow degradation, with cells maintaining stable electrochemical behavior and retaining over 90% state of health even after 1600 cycles. In contrast, higher temperatures accelerate aging and intensify internal changes.
The study reveals that multiple degradation mechanisms occur simultaneously, including lithium inventory loss, reduced conductivity, and active material degradation. It also shows that internal differences within cells grow over time, leading to distinct aging pathways—even under identical operating conditions.
By combining ICA and EIS, the researchers provide a more complete understanding of battery health, enabling clearer differentiation between gradual degradation and potential failure modes. This approach offers valuable insights for improving battery management systems, enhancing safety, and extending the lifetime of EV batteries.
Read the full study here.
Picture by Vardan Papikyan on Unsplash
