In this work, we have presented the first steps towards a 3D modelling approach to capture manufacturing-performance relationships of graphite/Si composite electrodes. We presented a workflow for the generation of the graphite/Si electrodes using Coarse-Grained Molecular Dynamics (CGMD), where the location of the Si particles was resolved by an ad hoc decoration approach, followed by a relaxation run. Then, these microstructures were used as inputs for simulating the electrochemical performance of the graphite/Si composite electrodes by coupling electrochemistry and mechanics, given that Si suffers a ~300% volume expansion upon lithiation.