Simulation of the Calendering Process of NMC‐622 Cathodes for Lithium‐Ion Batteries

Abstract

Calendering is the final step in electrode production during the manufacturing of lithium‐ion batteries. It is a crucial process that significantly influences the electrodes’ mechanical and electrochemical properties and is decisive in defining their volumetric energy density and performance. Herein, a discrete element method modeling approach is proposed to predict the process parameters of the calendering process. In particular, the roll gap width is required for a given target porosity. For this purpose, a particle bed of 9 mm in length is compacted using a roll section enabling a deeper look into the compaction behavior of the microstructure. Six NMC‐622 electrodes with different thicknesses are produced and compacted to different porosities. In the experimental investigation, the roll gap width is set and measured allowing a simulative replica of the process. With the process simulation, the force propagation within the electrode can be observed on a particle level. Furthermore, nanoindentation measurements with NMC‐622 cathodes provide information on the densification behavior of cathodes and support the parameterization of the particle bed. The particle‐based simulation of the compaction process is experimentally validated using nanoindentation measurements on NMC‐622 cathodes.