Wetting performance analysis of porosity distribution in NMC111 layered electrodes in lithium-ion batteries using the Lattice Boltzmann Method

Wettability by electrolytes is a crucial yet time-intensive step in manufacturing lithium-ion batteries, with the challenge intensifying for high-density electrodes subjected to calendaring. Achieving complete wetting is vital for battery operation, as it ensures the uniform formation of the solid electrolyte interface essential for ionic transport. This study employs the Lattice Boltzmann Method to investigate the wettability of NMC111 cathodes composed of layers with varying porosities and electrode thicknesses. Utilizing an in-house code, actual contact angles between the electrolyte and battery components are used to identify critical areas prone to gas entrapment. The findings reveal that incorporating high-porosity layers at these interfaces can mitigate gas entrapment in both medium and thick electrodes, particularly under high calendaring conditions, and enhance the imbibition rate under thick electrodes. Conversely, placing high-porosity layers in the middle of the electrode structure compromises electrolyte saturation and significantly increases gas entrapment, though it marginally improves the imbibition rate in medium-thick electrodes. The analysis extends beyond overall wetting performance to include a detailed examination of local wetting behavior, providing insights into homogeneous cathodes and those with varied porosity layers.