Comparison of different current collecting modes of anode supported micro-tubular SOFC through mathematical modeling

A two-dimensional model comprising fuel channel, anode, cathode and electrolyte layers for anode-supported micro-tubular solid oxide fuel cell (SOFC), in which momentum, mass and charge transport are considered, has been developed. By using the model, tubular cells operating under three different modes of current collection, including inlet current collector (IC), outlet current collector (OC) and both inlet and outlet collector (BC), are proposed and simulated. The transport phenomena inside the cell, including gas flow behavior, species concentration, overpotential, current density and current path, are analyzed and discussed. The results depict that the model can well simulate the diagonal current path in the anode. The current collecting efficiency as a function of tube length is obtained. Among the three proposed modes, the BC mode is the most effective mode for a micro-tubular SOFC, and the IC mode generates the largest current density variation at z-direction.