“…The charge transfer resistances, R 1 and R 2 , result from the interface resistance of both anode/electrolyte and cathode/electrolyte. Researchers have reported the growth of the surface films on the anode and the formation of defect in cathode material, but usually conclude that the cathode contributes more to the increase of overall cell impedance [20,22,24,25]. Nagasubramanian observed that the cathode contributed the most to the second semicircle from 3-electrode impedance test [18].…”