In this work, exhaustive characterizations of 3D geometries of LiNi1/3Mn1/3Co1/3O2 (NMC), LiFePO4 (LFP), and NMC/LFP blended electrodes are undertaken for rational interpretation of their measured electrical properties and electrochemical performance. X‐ray tomography and focused ion beam in combination with scanning electron microscopy tomography are used for a multiscale analysis of electrodes 3D geometries. Their multiscale electrical properties are measured by using broadband dielectric spectroscopy. Finally, discharge rate performance are measured and analyzed by simple, yet efficient methods. It allows us to discriminate between electronic and ionic wirings as the performance limiting factors, depending on the discharge rate. This approach is a unique exhaustive analysis of the experimental relationships between the electrochemical behavior, the transport properties within the electrode, and its 3D geometry. Multiscale characterizations of 3D geometries and electrical properties of Li‐ion electrodes made of LiNi1/3Mn1/3Co1/3O2 (NMC), LiFePO4 (LFP), and NMC/LFP blend allow the rational interpretation of their electrochemical performance by discriminating between electronic and ionic wirings as the performance limiting factors, depending on the discharge rate.