An approximate analytical solution of transport model in electrodes for anode-supported solid oxide fuel cells

On the basis of the one-dimensional, isothermal mechanistic model in the anode of an anode-supported solid oxide fuel cell using binary mixture as fuel, two approximate analytical solutions considering both mass and charge transfer were developed in this article. First, by dividing the anode into the inactive and active zones, the regular perturbation method was used to approximate the distribution of the fuel concentration and overpotential. Then the approximate solution using the singular perturbation method reflects both the boundary-layer effects of current density at the two boundaries of the anode. Both the two approximate solutions agree, well with the numeric solution in the case of medium and low electric load. By introducing the concept of the boundary-layer thickness at the anode/electrolyte interface, the two approximate solutions can be combined to get an explicit expression in a wide range of operation. The result in this article is useful to system-level modeling anti dynamic analysis. (C) 2007 American Institute of Chemical Engineers.