It was quantitatively shown that neither irreversible impedance growth, resistive heating, ohmic resistance, nor harmonic distortions are appreciable sources of error in the data analysis. Despite the differences in the measured I0 values between EIS and DC techniques, there is excellent agreement between the α value measured with S3E-CP and LA-GEIS. It is extremely unlikely that this deviation from α ≈ 0.5 for LCO is a measurement error. An apparent α value of ~ 0.43 may seem at surface level to have little physical significance. However, the equations developed in this work predict that at either very high or very low current densities, a multi-step reaction will behave as a one-step reaction with apparent values of the BV kinetic parameters. The apparent α value for a two-step reaction with α1 = 0.5 and α2 = 3 is predicted to be 0.429, which agrees extremely well with the S3E-CP and LA-GEIS measurements in this work, and with S3E-CP measurements of LFP in our previous work . Furthermore, the differential charge-transfer resistance known that due to their thermodynamic instability with the electrolyte at high SOC, lithium layered oxide cathodes typically form both a surface reconstruction (i.e., rock-salt) layer, as well as a surface film of electrolyte decomposition products, which together constitute the SEI .