Breakthrough in battery technology: unraveling the mystery of electrolyte wetting in advanced lithium-ion batteries

As the world transitions from fossil fuels to clean energy storage systems, lithium-ion batteries (LIBs) have become increasingly vital across multiple industries. While larger battery structures offer promising solutions for enhanced energy density, they present significant challenges in electrolyte filling and wetting processes. Researchers from the Tsinghua University have now conducted groundbreaking research to understand the complex relationship between electrode microstructure and electrolyte wetting, addressing a critical bottleneck in battery manufacturing.

The study employed advanced X-ray computed tomography to reconstruct three-dimensional electrode structures, allowing researchers to evaluate key parameters affecting electrolyte wetting. Their findings reveal that manufacturing processes significantly impact wetting behavior through two primary mechanisms:

•  Manufacturing Process Effects: Increasing calendering pressure and active material content reduces electrode porosity, which decreases permeability and penetration rate while enhancing capillary action. This creates a complex interplay that determines overall wetting effectiveness.

•  Incomplete Wetting Causes: The research identified two primary factors behind incomplete electrolyte wetting: partial closure of pores during the calendering process that blocks electrolyte access, and non-wetting phase gases that become trapped within the electrolyte during wetting, hindering complete penetration.

The study provides quantitative assessments of permeability and capillary forces—critical factors that determine both the degree and rate of electrolyte wetting. These insights offer battery manufacturers concrete guidance for optimizing production processes to achieve more efficient and complete wetting, potentially reducing manufacturing costs while improving battery performance and longevity.

This research opens several promising avenues for battery technology advancement:

•  Development of optimal geometric configurations for electrodes and separators during the wetting phase, enhancing battery structural design during manufacturing

•  Creation of multi-scale, multi-physics numerical models to comprehensively examine various influencing mechanisms and their interactions

•  Establishment of macro-scale process simulation models based on the micro-scale findings to accurately determine saturation immersion times, potentially reducing production costs

•  Application of vibration inputs during the immersion process to facilitate the expulsion of trapped gases, thereby increasing actual electrolyte infiltration volume

This innovative research provides unprecedented insights into the complex mechanisms governing electrolyte wetting in lithium-ion batteries. By elucidating the relationship between manufacturing parameters, electrode microstructure, and wetting behavior, the study offers a scientific foundation for optimizing battery production processes. As the demand for high-energy-density batteries continues to grow in applications ranging from electric vehicles to renewable energy storage systems, these findings will play a crucial role in developing more efficient, higher-performing, and more reliable battery technologies to power our clean energy future.