The effects of the interconnect rib contact resistance on the performance of planar solid oxide fuel cell stack and the rib design optimization

Optimization of the Interconnect Ribs for a Cathode-Supported Solid Oxide Fuel Cell

“…Figure 1a shows a repeating cell unit of a cathode-supported cell stack. As demonstrated before [19,23], a 2D model is equivalent to a 3D model when discussing the effects of rib widths on the fuel cell performance as they provide essentially the same results. Therefore, a 2D model (Figure 1b) is used here.…”

“…Previous studies have already shown very different effects of the cathode and anode ribs on the mass transport in the electrodes. For anode-supported SOFC, the anode gas transport was only mildly affected by the anode rib, which is benefit from thick anode, while an oxygen depletion zone of 0.46 mm was found with a cathode rib width of only 0.8 mm due to thin cathode thickness limiting the oxygen diffusion to the area under rib [19]. On the contrary, for cathode-supported SOFCs, the anode rib has an important influence on the anode gas transport; the minimum hydrogen concentration under anode rib is only about one third of that under anode channel [22].…”

“…However, these formulae are only valid for an anode-supported SOFC. The effects of the cathode and anode ribs on the mass transport for cathode-supported SOFC are different to that for anode-supported SOFC, which are demonstrated by references [19,22].…”

“…Noh et al [18] showed that by modifying the current collection configuration, cell performance was improved by more than 30%. Based on systematic examination of the stack cell performance as a function of various influencing factors, Liu et al [19] proposed a simple expression for the optimal rib width as a function of the pitch width and ASR contact that was independent of the porosity, layer thickness and conductivity of the electrode and easy for SOFC engineers to use. Unfortunately, the existing numerical studies on the rib design optimization have been carried out with two assumptions: (i) equal ASR contact for the anode-interconnect and cathode-interconnect interfaces and (ii) equal width of the optimal anode and cathode rib widths.…”

“…However, as demonstrated experimentally by Kornely et al [12] and Dey et al [20], ASR contact for the anode-interconnect and cathode-interconnect interfaces can be very different. Therefore, the optimal anode rib width isn't equivalent to the optimal cathode rib width as the optimal rib width depends on ASR contact [19,21]. Even if ASR contact for the anode-interconnect and cathode-interconnect interfaces are equal, the optimal rib widths for anode and cathode should be different.…”