Development of Anode Materials for P-Sofc Application(3/3)

The aim of this project is to develop high performance anode materials for Proton conducting solid oxide fuel cell (P-SOFC). During practical operation, the anode material of a SOFC suffers from the delamination and warping between the metallic catalysts and the ceramic electrolyte. In addition, carbon may deposits on the electrode when using syngas. We propose a bimetallic alloy (Ni1-xMx; M=Fe, Co) to replace nickel (Ni) in the anode. Ba(Ce0.6Zr0.2Y0.2)O3 will be used as the protonic conductor. We will investigate the effects of different alloying ratios of the bimetallic alloy coupled with Ba(Ce0.6Zr0.2Y0.2)O3 perovskite ceramic structure on the cell performance. To reduce the ohmic resistance and improve the cell performance, the anode-supported cell (ASC) type has become an emphasis. Anode needs to be porous so that hydrogen can diffuse and facilitate oxidation reaction. The mechanical strength is therefore usually weak. At present, the bottleneck of ASC type P-SOFC is poor stability. The main reason for poor stability is due to the porous anode. Compared to electrolyte-supported cell (ESC) and cathode-supported cell (CSC), the anode of ASC is more prone to volume expansion and phase change. The alloy (Ni1-xMx) has several advantages over Ni alone. (1) Reduce the mismatch between nickel oxide (NiO) and ceramic electrolyte. (2) Increase the catalytic activity. (3) Inhibit the carbon deposition. (4) Higher oxidation resistance. Therefore, we will utilize these advantages of bimetallic alloy to develop high performance anode materials with high electron/proton conductivity, good stability and suitable gas transport channels. In addition, we will use FIB-SEM 3D reconstruction to analyze the density and distribution of three-phase boundary.In the first year, nickel-iron (NiFe) and nickel-cobalt (NiCo) alloy anode materials with various ratios will be synthesized. The physical and chemical properties (conductivity, catalytic activity, thermal expansion and microstructure) will be studied. In the second year, the thermal cycling and syngas chemical stabilities of NiFe and NiCo anode materials will be investigated. In the final year, the optimized anode alloy materials will be assembled to test the ASC half-cell performance, investigate the difference between alloy anode and traditional anode by AC impedance spectroscopy and study the long-term cell performance (fuel: hydrogen and syngas). In addition, we will also investigate the changes in the material properties, microstructure and mechanical properties of anode material before and after long-term cell performance test.