With 0.1M LiTDI, the impedance growth is much less severe (1% increase every ~ 6 h) and is highly linear with time, regardless of whether high-current measurements are conducted. Severe impedance growth of LCO symmetric cells has been observed previously, and is likely caused by chemical reactions of the AM surface with protic impurities in the electrolyte (e.g., H2O, HF), which may otherwise be consumed at the anode in half or full cells . The kinetic measurements conducted in this work generally require many data points collected across a wide range of current density and/or frequency, and each dataset takes several hours to collect. To mitigate the effects of this time-dependent impedance growth, the measurement conditions for each technique were optimized to reduce the total measurement time to < 5 h, ensuring a < 1% change in impedance over the course of the measurement. However, the irreversible impedance growth still leads to minor differences in the I0 value measured between the different techniques, since the datasets were collected sequentially for the same cells.