An experimentally-validated 3D electrochemical model revealing electrode manufacturing parameters’ effects on battery performance

Abstract

The Lithium Ion Battery electrodes microstructures and their electrochemical performance are determined by the adopted manufacturing process parameters. However, in view of the strong interdependencies between these parameters, evaluating their influence on the performance is not a trivial task. In our previous publications, we have reported a series of computational models able to predict the influence of manufacturing parameters (e.g. slurry formulation, drying rate, calendering pressure) on the LIB electrodes microstructures. We have also demonstrated 3D-resolved models receiving as an input such predicted microstructures and predicting their electrochemical performance. While the manufacturing models have been experimentally validated by us and that the performance model provided performance predictions close to the experimental ones, a 1-to-1 quantitative comparison between the performance model predictions and experimental discharge curves was not yet explored by us. In this work we present an experimentally validated 3D-resolved electrochemical model of a NMC111-based electrode which reveals how slurry formulation and calendering degree affect the electrode performance. We found that the major factors linking manufacturing parameters and electrode performance are the carbon and binder domain distribution within the electrode volume, and the electrostatic potential difference between the electrode and the current collector. A well-connected electronic conductive network throughout the electrode is vital for ensuring full utilization of active material, and it was found that increasing calendering degree is effective in reducing interfacial impedance. This work uncovers, based on a dual modeling/experimental approach, the essence of how electrode manufacturing process takes effect on electrode performance by influencing its microstructure.