The interplay between stack pressure, mechanical expansion and degradation pathways in lithium-ion batteries
Heng Wang1,2, Rui Wang1,2, Christopher A O'Keefe3
1Department of Engineering, University of Cambridge, Cambridge, United Kingdom.
Nature Energy
|July 24, 2026
Summary
Optimizing stack pressure in lithium-ion batteries can double their lifespan. Applying consistent pressure prevents mechanical degradation, enhancing battery cycling stability and performance.
Area of Science:
- Materials Science
- Electrochemistry
- Mechanical Engineering
Background:
- Electrochemical degradation in lithium-ion batteries is well-understood.
- The impact of mechanical factors on battery degradation is less explored.
- Mechanical stress can influence battery performance and longevity.
Purpose of the Study:
- To investigate the role of mechanical stack pressure in lithium-ion battery degradation.
- To develop a method for precise control and application of stack pressure.
- To determine the optimal stack pressure for maximizing battery lifetime.
Main Methods:
- Development of a high-precision stack-pressure control and dilatometry tool.
- Application of uniform and constant stack pressure on battery electrodes.
- Testing of graphite ‖ LiNi0.8Mn0.1Co0.1O2 cells under varying stack pressures.
Main Results:
- Doubling the operational lifetime of lithium-ion cells by increasing stack pressure fourfold.
- Identification of distinct degradation mechanisms at low (cathode cracking) and high (lithium plating) stack pressures.
- Demonstration that optimal stack pressure enhances cycling stability without altering battery chemistry.
Conclusions:
- Mechanical factors, specifically stack pressure, significantly impact lithium-ion battery degradation.
- Optimal stack pressure is crucial for maximizing battery lifespan and performance.
- Stack pressure optimization presents a practical strategy for improving battery cycling stability.
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