Figure (b) shows the evolution of the electrode thickness upon discharge, as we can see, the thickness of the electrodes increases faster when the Si is dominating the reaction. Additionally, small variations exist between 1C and 0.1C, where the latter results in slightly bigger thickness changes, given the higher SOC of the Si phase. Furthermore, we also found the expansion degree of the AM to be inhomogeneous. Figure shows that the volumes ratios of the solid phases at the end of discharge vary across the electrode thickness. It is evident that, at 1C, due to the SOC distribution caused by mass transfer limitations, leads to solid volume ratios that are larger near the separator side. Meanwhile, at 0.1C, the same volume ratios are maintained at both ends of the electrode. It is noteworthy that at both, 0.1C and 1C operation, the volume ratios in the middle of the electrode are always higher. This can be explained by a heterogeneous distribution of the graphite and Si content across the electrode thickness, as shown in Figure . Indeed, the higher Si content in the middle of the electrode results in a more severe expansion in this region.