Currently the state of the art anode material for SOFCs is Ni-YSZ cermet. This materials show excellent catalytic activity and stability for the H2 oxidation of hydrogen fuel at SOFC operation conditions. However, Ni-YSZ based anode cermets have a number of drawbacks in system where hydrocarbon fuel is used, such as carbon deposition and sulfur poisoning. In addition, Ni-based anodes suffer from instability upon redox cycling due to the volume expansion of the anode by the Ni oxidation to NiO. This drawbacks of Ni-YSZ cermet significantly may reduces the SOFC lifetime.
To overcome these drawbacks of Ni-YSZ based anode, we investigate Ni-free ceramic oxide material as alternative anodes. Developments of Ni-free anode, such as ceria, titanate and lanthanum chromite-based oxides, are required to meet various properties such as high electrochemical performances, tolerance to formation of carbon coking, thermal and redox stability. Among these materials, perovskite-structured materials have been explored to replace Ni-based cermet for SOFCs because they have high tolerance against the carbon deposition and sulfur poisoning with good electrocatalytic performances.
In this work, hence we investigate the performance and durability of Ni-free ceramic-based anode during redox cycles of IT-SOFCs. In addition, various transition metals are doped to cramic-based oxide materials to improve electrocatalytic activity, thus resulting in improving the SOFC performance. After the durability testing of SOFCs, electrochemical properties and physicochemical properties of Ni-free ceramic anode cells are investigate by using various analytic techniques such as EIS, SEM, TEM, and XRD.
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Keywords: anode-supported solid oxide fuel cells, degradation mechanism, Ni-free anode material, redox cycling.