Unveiling Real-world Aging Mechanisms of Lithium-ion Batteries in Electric Vehicles

Strategic Insights -

A recent research study led by Ohio State University has made significant strides in understanding the degradation mechanisms of lithium-ion batteries in electric vehicles. The study, which has been peer-reviewed, aims to contribute to the development of future electric vehicle technology by identifying the key factors that influence battery degradation. The research, funded by Australian Wool Innovation, utilized comprehensive electrochemical analysis to identify and quantify major degradation mechanisms of electric vehicle battery cells.

Key Takeaways:

  • The study found that cathode performance was the major limiting factor of overall cell capacity, with the N/P ratio exceeding 1.0.
  • The impact of Li loss and active material loss mechanisms on performance degradation with total driven distance from 0 to 250 km was visualized using simple, customized electrochemical methods.
  • Li loss predominantly governed the initial performance degradation of EV cells, while after 150 km driving distance, active material loss started to dominate the degradation.
  • The degradation mechanism of cell impedance was analyzed using symmetric cell through electrochemical impedance spectroscopy (EIS) and distribution of relaxation times (DRT) techniques.
  • The cathode suffered from charge transfer resistance, while the anode suffered from contact impedance, with increasing mileage affecting cell performance.
  • The study demonstrated effective experimental strategies to reveal Li-ion battery degradation mechanisms in EVs, contributing to the continued development of future EV technology.
  • The research team included Jung-Hyun Kim, Jun Wei Yap, Michael Lee, Faissal El Idrissi, Prashanth Ramesh, Marcello Canova, Hanna Cho, Dal Young Yoon, and Chun Yong Kang.

Statistics:

  • The study analyzed the degradation mechanisms of EV battery cells with total driven distances ranging from 0 to 250 km.
  • Li loss governed the initial performance degradation of EV cells, while active material loss dominated the degradation after 150 km driving distance.
  • The study used electrochemical impedance spectroscopy (EIS) and distribution of relaxation times (DRT) techniques to analyze the degradation mechanism of cell impedance.
  • The cathode suffered from charge transfer resistance, while the anode suffered from contact impedance, with increasing mileage affecting cell performance.

Sources:

  • Unveiling Real-world Aging Mechanisms of Lithium-ion Batteries In Electric Vehicles. Journal of Energy Storage, 2025;130.
  • Jung-Hyun Kim, Ohio State University, Ctr Automot Res Mech & Aerosp Engn, Columbus, OH 43210, United States.
  • Jun Wei Yap, Michael Lee, Faissal El Idrissi, Prashanth Ramesh, Marcello Canova, Hanna Cho, Dal Young Yoon, and Chun Yong Kang.
  • Australian Wool Innovation.