Discrete Element Method Modeling of an Extrusion Process with Recirculation for Dry Manufacturing of Lithium‐Ion Battery Electrodes

Herein, a computational modeling study is reported to enhance the understanding of the solvent‐free extrusion process employed to produce filaments for the 3D printing of lithium‐ion battery electrodes. This study is supported by a newly developed dynamic, 3D‐resolved numerical model, designed as a methodological framework to explore mesoscopic particle dynamics in a twin‐screw extruder (TSE). Based on the discrete element method, this granular model accounts for the main features of the TSE, allowing the simulation of several recirculation cycles and extrusion of active material, carbon additive, and binder mixtures. This study also discusses how different electrode material formulations, material injection sequences, twin‐screw rotation speeds, and residence time in the extruder barrel affect the microstructure and particle distribution of the extruded filament. Finally, parameters including the porosity, tortuosity factor, effective diffusivity, and electrical conductivity of the filament microstructures are calculated.