Influence of slurry drying machinery conditions on lithium-ion battery cathode microstructural properties: Multiscale modelling insights

The performance of lithium-ion battery (LIB) electrodes is significantly influenced by the manufacturing parameters selected during their production. A key step involving high energy consumption and cost is the slurry drying. This stage can cause the carbon additive and binder to undesirably migrate across the electrode thickness, reducing electrochemical performance and durability during LIB cell operation. This study introduces a novel modelling approach that couples multiple scales in order to address the impact of heterogeneous drying conditions on the microstructure of dried electrodes. The framework integrates a macroscale model of the drying machine with a 3D mesoscale model to predict the final microstructural properties across the electrode film. These models are interconnected by a 1D model that monitors local solvent evaporation and drying time. This novel methodology allows for a detailed investigation into how variations in chamber temperature influence binder migration. As a proof-of-concept, this framework demonstrates that the drying stage in pilot lines involves heterogeneities that result in variable drying rates across the slurry film. The reported methodology also quantifies the extent of in-plane variability in electrode properties resulting from drying heterogeneities, providing key insights for process optimisation.