Experimental investigation of the porous nickel anode in the molten carbonate fuel cell

The electrochemical performance of the porous nickel anode in a molten carb onate fuel cell was experimentally investigated in this study. The electrod e structure was studied by scanning electron microscope and Hg porosimetry. The effect of electrolyte filling, on overpotential at a constant current density, was also examined. Kinetics for the hydrogen reaction was studied by obtaining stationary polarization curves, for porous nickel anodes at va rying temperatures and anode gas compositions. The slopes of these polariza tion curves were analyzed at low overpotentials, with the assumption that t he porous anode was under kinetic control, and the corresponding exchange c urrent densities were determined using a simplified porous electrode model. The obtained partial pressure dependencies of the exchange current density were high, and therefore, difficult to explain by the generally assumed me chanisms. (C) 2001 The Electrochemical Society.