Creating a Digital Bimodal Cathode

The GeoDict tutorial on creating a bimodal cathode provides a practical introduction to the digital modeling of battery electrodes for subsequent degradation simulations. Using the GeoApp “Bimodal Cathode” introduced in GeoDict 2023, the tutorial explains how to create a digital bimodal cathode based on parameters from battery production.

The focus is on the settings and material parameters relevant for subsequent degradation simulations using BatteryDict. The tutorial demonstrates how to define two different particle size distributions for the active cathode material NMC333 and how to interpret the corresponding D-values. In addition, the tutorial explains how to specify the ratio of particle types, the significance of density values, and the selection of suitable materials for the electrolyte and carbon binder. Using the “Criteria to Match” feature, it demonstrates how porosity and loading can be precisely adjusted within specified tolerances. Furthermore, the use of random initial values and the definition of appropriate termination criteria are introduced. Finally, the generated bimodal cathode structure is analyzed in the Results Viewer, where, among other things, voltages and porosity are evaluated, and the NMC particles and the carbon binder are visualized in the 3D structure. The tutorial is intended specifically for GeoDict users who wish to digitally generate bimodal electrodes and prepare them for further battery simulations.

• Creation of a bimodal cathode: Use of the GeoApp “Bimodal Cathode” to digitally generate a bimodal electrode structure; definition of appropriate domain settings for subsequent simulations.
• Particle size distribution and active materials: Defining two NMC333 particle populations with different particle size distributions; understanding and applying D-values; determining the ratio between the two particle types.
• Material and structural properties: Defining material densities, selecting materials for the electrolyte and carbon binder, and setting the material parameters relevant to the cathode structure.
• Target values and generation criteria: Defining “Criteria to Match” based on porosity and loading, defining suitable tolerance ranges, using random initial values, and setting termination criteria for structure generation.
• Evaluation and preparation for battery simulations: Analysis of the generated cathode in the Result Viewer, verification of the achieved structural parameters, and 3D visualization of NMC particles and carbon binder, as well as preparation of the structure for further degradation simulations with BatteryDict.
• Practical application of the workflow in GeoDict to create realistic bimodal cathode structures for battery simulations.