The following document covers the determination of the diffusion coefficient of two powder materials: LiFePO₄ and LiMn₂O₄ by using potentiostatic intermittent titration technique (PITT) and impedance spectroscopy methodology and compares relevant results with the following relation: D = \fracR² I₀ 3aQD = \frac{{R^2 I_0 }}{{3\alpha Q}}, which is obtained by solving Fick’s spherical coordinate equation (where I ₀ is the initial step current in the PITT experiment, R is the particle radius, Q is the charge that intercalated during the step, and α is the percentage of the theoretical intercalated charge). This procedure allowed the verification of the validity of the spherical model for the powder materials, the accuracy of the expression proposed for the diffusion coefficient determination, and the correctness of the measures that had been taken.