To make the electrochemical methods developed in this work widely accessible, we demonstrate that high-quality kinetic measurements can be obtained using only symmetric coin cells. Symmetric cells are ideal for the most precise EIS measurements; since there are two WEs, there are no artifacts or distortions which can arise from the CE or RE . There is also little ambiguity in the data analysis: the WE impedance is simply half of the cell impedance. The main disadvantage of symmetric cells is that they, by definition, cannot determine the symmetry of the kinetics between the anodic and cathode directions; 3-electrode cells are generally needed for this purpose. Symmetric cells can be assembled by electrochemically pre-cycling two identical electrodes versus any CE (e.g., Li-metal) to the desired SOC, then extracting and rinsing the electrodes, and building them into a coin cell with fresh electrolyte. Although somewhat tedious, this process is simple and reproducible and allows for rapid parallel testing. Advantageously, due to their sloping voltage profile, LCO symmetric cells can be quickly reset to the same SOC between each measurement by a short constant voltage hold at 0 V.