Exploring the Relationship Between Electrode Structure and Wetting

Scientists from Tsinghua University have addressed a key challenge in battery manufacturing by conducting research to understand the relationship between electrode microstructure and electrolyte wetting.

The use of lithium-ion batteries (LIBs) has grown in importance across various industries as the world shifts from fossil fuels to clean energy storage technologies.

While larger battery structures offer promising solutions for increased energy density, they present significant challenges for the electrolyte filling and wetting processes.

To assess important factors influencing electrolyte wetting, the study used sophisticated X-ray computed tomography to reconstruct three-dimensional electrode structures. According to their findings, there are two main ways that manufacturing processes affect wetting behavior:

• Manufacturing Process Effects: Increasing the active material content and calendering pressure reduces electrode porosity, which enhances capillary action but also lowers permeability and penetration rates. The overall effectiveness of wetting results from the complex interaction of these factors.
• Incomplete Wetting Causes: The study identifies two main causes of incomplete electrolyte wetting: trapped non-wetting phase gases in the electrolyte that hinder full penetration, and partial pore closure during the calendering process that limits electrolyte access.

The study offers quantitative evaluations of capillary forces and permeability, two important variables that affect the extent and rate of electrolyte wetting.

These observations provide battery manufacturers with specific recommendations for streamlining production procedures to accomplish more thorough and effective wetting, which could lower manufacturing costs while enhancing battery longevity and performance.

This study opens up several exciting new directions for battery technology development:

• Improvement of battery structural design during manufacturing through the creation of ideal geometric configurations for electrodes and separators during the wetting phase.
• Multi-scale, multi-physics numerical models are being developed to thoroughly investigate different influencing mechanisms and their interactions.
• Using micro-scale results to develop macro-scale models that can accurately predict saturation immersion times and potentially lower production costs.
• Vibration inputs are applied during the immersion process to help release trapped gases, increasing the actual volume of electrolyte infiltration.

This groundbreaking study provides new insights into the complex processes controlling electrolyte wetting in lithium-ion batteries. It offers a scientific foundation for improving battery production by clarifying the relationship between wetting behavior, electrode microstructure, and manufacturing parameters.

These findings will be crucial in developing more efficient, higher-performing, and more reliable battery technologies to support the growing demand for high-energy-density batteries in applications ranging from electric vehicles to renewable energy storage systems.

Journal Reference:

Chen, F., et al. (2025) Unraveling Mechanisms of Electrolyte Wetting Process in Three-Dimensional Electrode Structures: Insights from Realistic Architectures. Green Energy and Intelligent Transportation. doi.org/10.1016/j.geits.2024.100248.