New time-frequency model sheds light on stress-driven behavior in lithium-ion batteries

A new study offers a clearer view of how mechanical stress and electrochemical processes interact inside lithium-ion batteries, providing a multi-scale framework that could support better battery design and stress monitoring. By combining time-domain and frequency-domain analysis, the research helps explain how diffusion-induced stress influences lithium transport from individual particles up to the electrode level.

Lithium-ion batteries are expected to deliver high energy density, long cycle life, and reliable safety in applications ranging from portable electronics to electric vehicles. Yet battery performance is shaped not only by electrochemical reactions, but also by mechanical changes inside active materials as lithium ions move in and out. One persistent challenge has been to understand this coupling in both directions: how lithium diffusion generates stress, and how that stress in turn alters diffusion.

To address that problem, the researchers established a two-way coupled electro-chemo-mechanical model for lithium-ion batteries and solved its responses in both the time and frequency domains. The work examined the coupling mechanism across multiple scales, from active particles to porous electrodes, with the aim of linking local mechanical effects to system-level battery behavior.

The analysis showed that diffusion-induced stress does not influence lithium transport in a uniform way throughout discharge. In the time-domain analysis, stress enhanced lithium diffusion during the early and middle stages of discharge, but inhibited diffusion near the end of discharge. In the frequency-domain analysis, stress was found to affect solid-phase diffusion more strongly than electrolyte-phase diffusion. Taken together, the results suggest that stress plays a dynamic and stage-dependent role in shaping battery transport behavior.

The study also indicates that particle-scale changes can carry through to the electrode scale, helping explain how local stress-diffusion interactions affect the broader electrochemical response of the cell. By quantitatively connecting these scales, the model provides a more complete picture of the mechanical-electrochemical coupling mechanism in lithium-ion batteries.

This framework could be useful for battery manufacturing, diagnostics, and stress monitoring, particularly in efforts to better predict internal battery states and performance evolution. Because the work is primarily theoretical and model-based, further studies will still be needed to connect these insights to experimental validation and long-term battery aging in practical systems.

Reference

Author:

Zihan Meng ^a, Yuxuan Bai ^a, Fangzhou Zhang ^{a b}, Jiujun Zhang ^a, Qiu-An Huang ^{a c}

Title of original paper:

A joint time-frequency analysis of the mechanical-electrochemical coupling mechanism from particles to electrodes for the Li-ion battery

Article link:

https://www.sciencedirect.com/science/article/pii/S2773153725000726

Journal:

Green Energy and Intelligent Transportation

DOI:

10.1016/j.geits.2025.100322

Affiliations:

^a College of Sciences/Institute for Sustainable Energy, Shanghai University, Shanghai 200444, China

^b Institute of Materials/School of Materials Science and Engineering, Shanghai University, Shanghai 200072, China

^c College of Sciences/Faculty of Physics, Shanghai University, Shanghai 200444, China

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