Fig. 4: Electrochemical characterizations of microelectrodes.
From: The role of oxygen-permeable ionomer for polymer electrolyte fuel cells
a Inverse of the limiting current density as a function of the ionomer thickness at 333 K and 30% RH. The bulk (Rbulk) and interfacial (Rin) resistances are determined by the slope and intercept of the linear line, respectively. b Interfacial (open symbols with solid lines) and bulk (solid symbols with dashed lines) oxygen permeation resistance of ionomer thin films measured by the microelectrode technique. c, d Oxygen solubility and diffusion coefficient of ionomer thick films measured by the microelectrode technique. In b, the bulk resistance was calculated assuming an ionomer thickness of 5 nm. The error bars shown in (b) were calculated from fitting errors assuming the normal error distributions, and the error bars shown in (c) and (d) show the differences between two measurements.
