The cell resistance was 324 mΩ cm 2 , of which the anode contributed a surprisingly low 61 mΩ cm 2 while the cathode contributed a much higher 263 mΩ cm 2 . Thus, while the anode had a notably higher onset potential than the cathode, consistent with the more sluggish nature of the oxygen-evolution reaction (OER) relative to the hydrogen-evolution reaction (HER), it produced far smaller increases in voltage as the current density increased, than the cathode.