A current-sensor electrochemical device for accurate gas diffusivity measurement in fuel cells

In the previous diffusivity measurements via the electrochemical devices designed by the authors, the electronic conduction contribution of electrolyte materials was neglected, and an error in the subsequent evaluations of limiting current density and concentration polarization was consequently induced. In this report, a current-sensor and oxygen-sensor based electrochemical cell was designed for accurate diffusivity measurements in fuel cells. Our analytical investigation shows that diffusivity measurements via the new device lead to accurate analytical evaluations of limiting current density and concentration polarization in fuel cells. With the improved accuracy, one can reliably pre-evaluate the limiting current density and concentration polarization of fuel cell electrodes with different thicknesses ranging from several nanometers to a few millimeters at different operating temperatures.