Metal Supported SOFCs: Electrochemical Performance under Various Testing Conditions

Abstract

To demonstrate the performance and reliability of MSCs (Metal Supported SOFCs), a systematic electrochemical characterization on button cells has been performed. The cell conditioning during the first heating-up is described in detail, since there is a significant difference to ESCs (Electrolyte Supported Cell) and ASCs (Anode Supported Cell). The focus of the present work is to show the influence of different anode materials, gas-flow rates, and operation temperatures on recorded i-V-curves. In some cases, fuel utilization rates were used, which are higher than commonly applied in button cell experiments. However, under these harsh conditions, the anode and the metal substrate must handle e.g. high humidity. This paper summarizes recent results on (i) manufacturing, (ii) appropriate test procedures, (iii) electrochemical testing, and (iv) influence of different anode layer materials for MSCs.

The Relation of Microstructure, Materials Properties and Impedance of SOFC Electrodes: A Case Study of Ni/GDC Anodes

“…In addition to the electrode transmission line, this circuit model also includes the element L wire , representing the wire inductance, R YSZ for the electrolyte resistance, CPE int as a constant phase element for interfacial capacitance and R int for the interfacial resistance. The interfacial resistances and capacitances depend on the cell preparation procedure; they are likely different for symmetrical model cells, in which the electrodes are sintered on a dense electrolyte, and full SOFCs, in which the electrolyte is sputter-deposited on top of the already sintered anodes (Plansee MSC concept [3,4,7,55,56]) or co-sintered with the anodes (in typical anode supported cells). However, when the ion conducting phase in the electrode is the same as the electrolyte, e.g., Ni/YSZ [24,30,34,57] anodes or for LSM/YSZ cathodes [33], the interfacial resistance is often negligible.…”

“…Subsequently the samples were sintered at 1100 • C for 3 h in H 2 . The same paste and sintering conditions were also used for fabrication of high-performance metal-supported SOFCs [6,7,55].…”

Dual-Phase Cathodes for Metal-Supported Solid Oxide Fuel Cells: Processing, Performance, Durability

“…Porous, 3-D-printed alumina stamps and zirconia felts were placed between the tubes and the meshes (anode -Ni, cathode -Au) contacting the cell, in order to provide reliable contact and homogeneous distribution of fuel and air. 16 Post-test analysis was performed by SEM cross-sectional imaging (Ultra 55, Zeiss, Germany).…”

“…11,13 Since 2008, Plansee SE (PSE, Reutte, Austria) has developed an MSC concept based on its ITM (intermediate temperature metal) oxide-dispersion-strengthened ferritic steel support in close cooperation with Forschungszentrum Jülich GmbH (Jülich, Germany). [14][15][16][17][18] While the fabrication of anode, electrolyte, and diffusion barrier layers (DBLs) can be adapted to applications on the metal substrate, a separate cathode sintering step has not yet been implemented in the state-of-the-art process. This is due to the contradicting requirements of the metal substrate and the cathode with regard to the sintering atmosphere.…”

Degradation Mechanisms of Metal-Supported Solid Oxide Cells and Countermeasures: A Review

“…Ni [ 71 , 72 , 73 , 74 ], Ni-Fe alloys [ 75 , 76 , 77 , 78 , 79 ], and ferritic stainless steels [ 57 , 80 , 81 , 82 , 83 ] have been mostly used as metal supports from 2000 to 2020. Table 1 shows a comparison between Ni, Ni-Fe, and 400-series stainless steels (ferritic stainless steels) in the coefficient of thermal expansion (CTE) and relative oxidation resistance [ 5 ].…”