Much research on solid oxide fuel cells (SOFCs) has adopted the configuration of button cells or symmetric half cells, which enable the investigations of SOFC constituents, such as the electrolyte and electrodes. The performance of SOFCs of a full-cell size (e.g. 10 cm ´ 10 cm) or a stack is highly dependent upon the cathode current collector, which bonds the cathode with a metallic interconnect. The requirements for the contact material are (1) sufficiently high electrical conductance, (2) compatibility with the cathode and interconnect materials with respect to CTE, (3) chemical stability under high current conditions, (4) ability to buffer the interactions between interconnect oxide and electrode oxide, and (5) stability with both interconnect and cathode and not adversely affect the formation of the interconnect protective oxide. In this presentation, we will describe the mechanism that the cathode current collector affects the cell performance by using full-size cells and short-stacks. The area specific resistance of the cathode current collector was studied by changing the contact material, gas distribution in the interconnect, anode contact materials, gas flow rate, fuel utilization ration and operation temperature.

The author would like to thank the financial support from Natural Science Foundation of China (No. 51502316) and Excellent Members of Youth Innovation Promotion Association, CAS (No. Y50708WR28). The work was partially supported by US DOE through DE-FE0026097.