Three-dimensional modeling of polarization characteristics in molten carbonate fuel cells using peroxide and superoxide mechanisms

► A detailed three-dimensional, mathematical model of an MCFC was presented. ► Both peroxide and superoxide mechanisms predicted the linear region of the polarization curve accurately. ► Both mechanisms showed a concave tendency for the cathode reaction rate as the carbon-dioxide mole fraction is decreased when the current density increases. ► None of these mechanisms showed a downward bent in the polarization curve.