The voltage loss in a single cell of a segmented-in-series flat-tube-type solid oxide fuel cell (SOFC) stack was evaluated. The stack exhibits a particular configuration, and the current flows along an in-plane direction in the anode and cathode; this differs from conventional planar-type SOFCs. Distributions of the current in the cell were studied in detail for many parameters such as the length of electrodes and conductivities of the cell components. Gas diffusion in a porous substrate and anode and the fuel utilization affect the concentration polarization; thus, they were also considered. By using the simulation results, appropriate configurations for the cell and stack were designed, and the simulation was validated by performance tests for a practical fuel cell stack. The stack exhibited a high performance of 0.76 V at 0.2 A/cm2 at Uf = 81.6% with dry H2 fuel, yielding a DC energy conversion efficiency of 53.6% HHV. Moreover, a bundle comprising 34 stacks was also fabricated, and excellent values of output voltage (342.5 V), output power (338.3 W), and electrical efficiency (49.5% HHV) at a current density of 0.2 A/cm2 were obtained.

This content is only available via PDF.
You do not currently have access to this content.