Improved Electrochemical Properties of an Ni-Based YSZ Cermet Anode for the Direct Supply of Methane by Co Alloying with an Impregnation Method

To avoid the proneness to degradation due to coking in the operation of solid oxide fuel cells (SOFCs) directly running on methane (CH4) fuels, a modified porous anode of the Ni1−XCoX/YSZ (yttria-stabilized zirconia) cermet prepared by an impregnation method is presented. The influence of the Co alloying content on the cermet microstructure, SOFC characteristics, and prolonged cell performance stability has been studied. Co was incorporated into Ni and formed a solid solution of Ni1−XCoX alloy connected with the YSZ as the cermet anode. The porous microstructure of the Ni1−XCoX/YSZ cermet anode formed by sintering exhibited a grain growth with an increase in the Co alloying content. The electrochemical performance of the cells consisting of the Ni1−XCoX/YSZ cermet anode, the YSZ electrolyte, and the LSM (La0.8Sr0.2MnO3) cathode showed an enhancement by the Ni1−XCoX impregnation treatment for the respective supply of H2 and CH4 to the anode. The cell using the Ni0.75Co0.25/YSZ cermet anode (the Ni0.75Co0.25 cell) showed the highest cell performance among the cells tested. In particular, the performance enhancement of this cell was found to be more significant for CH4 than that for H2; a 45% increase in the maximum power density for CH4 and a 17% increase for H2 at 750 °C compared with the performance of the cell using the Ni/YSZ cermet anode. Furthermore, the prolonged cell performance stability with a continuous CH4 supply was found for the Ni0.85Co0.15 and Ni0.75Co0.25 cells at least for 60 h at 750 °C. These enhancement effects were caused by the optimum porous microstructure of the cermet anode with the low anodic polarization resistance.

Joint strength of Ag–9Pd–9Ga brazed interconnect and anode-supported electrolyte for solid-oxide fuel cell applications

A newly developed Ag–9Pd–9Ga active filler was vacuum brazed, and the mechanical properties between the metallic interconnects (SS430, Crofer22 APU, Crofer22 H) and a Ni–yttria-stabilized zirconia cermet anode were systematically investigated. The results indicate that the bonding between metal and cermet is well established and that the interface is smooth. The joint strength evaluated at both 25 ℃ and 800 ℃ under shear and tensile loading conditions confirmed that the brazed Ag–9Pd–9Ga sealant compared favorably with its commercially available glass-ceramic GC-9 counterpart.

A high-performance spectrally-selective solar absorber based on a yttria-stabilized zirconia cermet with high-temperature stability

We demonstrate a W–Ni–YSZ cermet-based solar absorber with high solar absorptance, low infrared emittance and high thermal stability up to 600 °C.

Perovskite Based Anode Materials for Solid Oxide Fuel Cell Application: A Review

Perovskites have gained attraction as electrode and interconnect materials for Solid Oxide Fuel Cells (SOFCs) due to their catalytic, ionic and electrical conductivities, chemical and thermal stabilities at higher temperatures. The operation and efficiency of SOFC depends mainly on the electrodes. Each electrode, anode and cathode, has demanding materials selection criteria. State of the art nickel-yittria stabilized zirconia cermet anodes are unable to work efficiently with hydrocarbon fuels and at intermediate operating temperature range (600-800°C). Hence, there is an increasing demand for the development of alternate anode materials to improve the fuel flexibility and efficiency of SOFCs. Perovskite based materials have oxygen ion vacancies depending on composition, temperature, and surrounding crystalline environment that impart mixed ionic and electronic conductivities to them. Since perovskite can accommodate all the elements in the periodic table they can offer excellent catalytic properties. The report is about the present status of perovskites based anode materials for SOFC application.