Towards a 3D-resolved model of Si/Graphite composite electrodes from manufacturing simulations

Abstract

Composite graphite/silicon (Si) electrodes with low Si weight percentages are considered as a promising anode for next generation Li-ion batteries. In this context, understanding the mesostructural changes due to Si volume expansion and the complex electrochemical interplay between graphite and Si becomes crucial to unlock real-life applications of such composite electrodes. This work presents, for the first time, a three-dimensional (3D) physics-based model for graphite/Si composite electrodes, coupling electrochemistry and mechanics, using as input electrode mesostructures obtained from manufacturing-related Coarse-Grained Molecular Dynamics models. The slurry and dried electrode mesostructure are first generated by considering graphite and additives only, while the Si is included in an additional step. The model herein presented is a step further into obtaining a fundamental understanding of the complex processes happening in graphite/Si composite electrodes, paving the way towards their optimization.