The kinetically induced memory effect can be explained by the difference in multi-particle dynamics during the reading step. Specifically, under high applied rates, the increased active population results in a higher number of nucleated particles at the end of the writing step (50% SOC). Consequently, these nucleated particles become more accessible to the system during the subsequent reading step, having already surmounted the nucleation energy barrier. Notably, these nucleated particles persist during the resting period. Conversely, under low applied writing rates reaches 50% SOC following a mosaic scheme, where the majority of the particles are either uncharged (lithiated) or completely charged (delithiated). In the subsequent reading step, the need to overcome the nucleation barrier for a larger quantity of particles requires greater overpotentials while the maximum available active particle population is lower. As a consequence, higher potentials are observed throughout the remaining charging process as shown in Fig 1b . Previous work described the formation of a metastable solid solution phase transition in LFP, such that, during a fast (dis)charge, the particle cannot proceed toward phase separation due to the mismatch in characteristic times between reaction and diffusion kinetics. In contrast, no solution phase transition at 5C was observed within this study, which can be attributed to a fundamental distinction in particle shape. Specifically, leveraging the [010] crystalline direction for 1D fast diffusion kinetics, plateletshaped LFP particles demonstrate a reaction-limited behavior. On the other hand, the spheroidal commercial particles employed in this work (Figs. S7-S9), characterized by higher defect concentrations and, consequently, quasi-isotropic diffusivity, exhibit an effectively diffusion-limited behavior resulting in a more favorable phase separation. Moreover, the presence of the kinetically induced memory effect in a wide set of phase-separating materials (Fig. and Figs. ) shows that the presence of a metastable solid solution transition in LFP is not a decisive factor in explaining the observed memory effect.