The project aims to create a representative volume element model (RVE) to predict the mechanical properties of the electrode active layer. The first part of the study was capable of capturing linear-elastic properties of a positive NMC electrode active layer. The DOI number of the outcome paper from the first chapter of the project is below. https://doi.org/10.1016/j.ijsolstr.2022.111602 In the second chapter, it is intended to include the viscoelastic effect of binders and fracture in active particles with electrochemical cycling in the RVE model. The extended RVE model aims to explore the two competing mechanisms, namely, diffusion-induced swelling, and particle fracture that cause mechanical degradation in Li-on battery electrodes.