(144g) DEM Modelling of Battery Electrode Structures from X-Ray Tomography-Structure Analysis Under Different Calendering Conditions

The calendering process is an essential step in the manufacture of electrodes for lithium ion batteries. Calendering strongly affects the microstructure and end-product performance, however the relationship between the various component material properties and operating conditions of the calendering process on electrode microstructure and performance is not well understood.

In this work, Discrete Element Method (DEM) was used to investigate the electrode structure evolution under different calendering conditions. The initial positions of active material (AM) particles are obtained from an uncalendered electrode microstructure characterized experimentally by X-ray tomography, and imported into DEM simulations. Simulated electrode structures under varying calendering conditions are obtained by uniaxial compression tests in DEM. The Edinburgh Elastic Plastic Adhesive (EEPA) model and bond model are used to describe the mechanical properties of AM particles and binder phase within electrodes. Detailed stress and structural evolutions at microscopic scale are further analysed. The results demonstrate that DEM provides a promising way to investigate and optimize the particle arrangements within battery electrodes during calendering.