Coin cells were built with CR2032 cases and contained a wave spring, a top (1 mm thick) and bottom (0.6 mm thick) Al spacer (both 16.2 mm diameter), one ¾" diameter ceramic-coated polyolefin separator (Celgard, H1409, 14 μm), 40 μL of electrolyte, and two 16 mm diameter LCO electrodes. For each symmetric cell, the two electrodes were paired to ensure they had a nearly identical mass (< 2% difference). Symmetric cells with pristine LCO electrodes were assembled to measure the pore resistance of the electrodes under blocking conditions. LCO symmetric cells with electrochemically delithiated LCO electrodes were prepared by pre-cycling the LCO electrodes versus Li-metal counter electrodes in Swagelok cells. The LCO was charged at a ~ 2C rate to 4.15 V vs. Li/Li + , then held at 4.15 V until a C/50 current cutoff. After extracting the electrodes from Swagelok cells, they were rinsed thoroughly with DMC and dried under vacuum to remove the residual solvent, then two delithiated LCO electrodes were used to build a symmetric coin cell with fresh electrolyte.