The effect of pressure gradient on anode micro modeling of solid oxide fuel cell

A theoretical mathematical model is established to investigate the effect of pressure gradient on electrochemical characteristics of anode in solid oxide fuel cell (SOFC) running on pre-reformed methane fuel. The model adopts micro modeling approach in which anode is treated as porous composite structure of electronic and ionic conducting particles. It includes mass conservation, mass transfer, chemical and electrochemical reactions, and charges transfer. Besides, the electrochemical characteristics of anode have been discussed with and without pressure gradient in the dusty-gas model. It can be found that the pressure increases along the anode depth. The molar fractions of fuel species are different under the consideration of pressure gradient. The results revealed by the developed model verify the point of treating a SOFC electrode as two finite layers. Only in the reaction zone layer, the pressure gradient can obviously influence electronic and ionic current densities, electronic and ionic potentials, and anode activation overpotential.