The Model of Electrochemical Noise of a Hydrogen-Air Fuel Cell

Abstract

The electrochemical noise of a hydrogen-air fuel cell was measured at different current loads. Frequency dependencies of power spectral densities of the noise were calculated for all load currents. For the first time, the phenomenological model describing the behavior of the noise was proposed for a fuel cell. The model is based on two sources of electrochemical noise. One of them is associated with a Faradic resistance of the cathodic reaction of oxygen electroreduction shunted by a parallel double layer capacitance. The values of impedance elements are obtained for each load from the data of electrochemical impedance method. Proposed model describes in detail and with a high accuracy the dependencies of noise power spectral densities obtained for all values of load currents. The usage of the model made it possible to calculate the amplitudes of the electrochemical noise current sources and to plot those dependencies on the fuel cell load current.