The common denominator in the aforementioned studies is the possibility of explaining the phenomena through the lenses of the complex kinetic behavior of phase-separating active materials. For the active materials that (de)lithiate following a solid-solution path, such as LiCoO2 (LCO) and LiNixCoyMn1-x-yO2 (NMC), Li diffuses inside the particles uniformly such that, when the current is stopped, the concentration inside the particles quickly equilibrates. Thus, the system evolves without substantial intra or inter-particle heterogeneities, relying solely on the particle's size distribution and position with respect to the electrode's depth as a source of heterogeneities. In contrast, LiFePO4 (LFP) and Li4Ti5O12 (LTO) undergo phase separation during the (de)lithiation process due to their physio-mechanical properties. At a given state of charge, even under equilibrium conditions, these particles exhibit coexisting Li-poor and Li-rich phases. This fundamental difference in reaction behavior, evident in a flat voltage plateau and a voltage hysteresis , is intricately linked to inter-particle heterogeneities.