INTEGRATED FABRICATION PROCESS FOR SOLID OXIDE FUELCELLS USING HYBRID PLASMA SPRAYING

Abstract The central components for solid oxide fuel cells (SOFC) are the electrodes-electrolyte multilayer arrangement (PEN) and the separating bipolar plates. The PEN (Positive electrode- Electrolyte-Negative electrode) assembly consists of a dense gastight yttria-stabilized zirconia (YSZ) electrolyte and porous electrodes for which usually Ni-YSZ cermet anode and Sr-doped LaMnO3 cathode layers are used. The various PEN units are connected in a cell stack by bipolar plates which are either metallic or ceramic ones. Furthermore, a protective layer on the metallic bipolar plates consisting of a chromium alloy is required to prevent chromium evaporation leading to a rapid and strong degradation of the SOFC performance. At the DLR Stuttgart both the DC and the RF vacuum plasma spraying technique have been further developed and adapted to meet the requirements for the manufacture of the different SOFC components. The DCVPS process using specially developed Laval-like nozzles is especially appropriate to the production of thin and dense coatings as required for the electrolyte and the protective layers. However, applying special spray parameters and nozzles it is also possible to deposit porous electrode layers. The production of the entire PEN arrangement in one consecutive DC-VPS process is the objective of the actual development. On the other hand, the RF plasma spray technique is suitable for the near net-shape production of bulk components such as the metallic bipolar plate. The development of the deposition processes for the production of SOFC components using DC and RF plasma spray methods and the results obtained concerning PEN fabrication, deposition of protective layers and the near net-shape production of metallic bipolar plates are presented in the paper.

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Microstructures and Characterization of Zirconia Coatings Formed by Laser Combined Plasma Spraying

Thermal Spray 1998: Proceedings from the International Thermal Spray Conference ◽

10.31399/asm.cp.itsc1998p1663 ◽

1998 ◽

Author(s):

Z. Zhou ◽

N. Eguchi ◽

H. Shirasawa ◽

A. Ohmori

Keyword(s):

Laser Irradiation ◽

Plasma Spraying ◽

Barrier Properties ◽

Thermal Barrier ◽

Irradiation Treatment ◽

Hybrid Plasma ◽

Sprayed Coating ◽

Steel Substrates ◽

High Temperature Erosion

Abstract Hybrid plasma spraying combined with YAG laser irradiation was studied in order to obtain the optimum zirconia coatings for thermal barrier use. Zirconia coatings of approximately 150 ;Um in thickness were formed on the NiCrAlY under coated steel substrates both by means of conventional plasma spraying and hybrid plasma spraying under a variety of conditions. Post-laser irradiation was also conducted on the plasma as-sprayed coating for comparison. The microstructure of each coating was studied in detail and, for some representative coatings, thermal barrier properties were evaluated by hot erosion and a hot oxidation test. With hybrid spraying, performed under optimum conditions, it was found that a microstructure with appropriate partial densification and without connected porosities was formed and that cracks, which are generally produced in the post-laser irradiation treatment, were completely inhibited. In addition, hybrid spraying formed a smooth coating surface. These microstructural changes resulted in improved coating properties with regard to hardness, high temperature erosion resistance and oxidation resistance.

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Influence of Post-Treatment on the Performances of Plasma Spraying La0.8Sr0.2CrO3 Coating Layer on Ferritic Stainless Steel as Interconnects for Solid Oxide Fuel Cells

Asian Journal of Chemistry ◽

10.14233/ajchem.2014.17365 ◽

2014 ◽

Vol 26 (6) ◽

pp. 1816-1818

Author(s):

Xiaoqin Ren ◽

Weitao Bao

Keyword(s):

Stainless Steel ◽

Fuel Cells ◽

Solid Oxide Fuel Cells ◽

Plasma Spraying ◽

Ferritic Stainless Steel ◽

Coating Layer ◽

Post Treatment ◽

Solid Oxide ◽

Oxide Fuel

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Characterization of Ni–YSZ anodes for solid oxide fuel cells fabricated by suspension plasma spraying with axial feedstock injection

Journal of Power Sources ◽

10.1016/j.jpowsour.2013.05.174 ◽

2013 ◽

Vol 243 ◽

pp. 172-180 ◽

Cited By ~ 21

Author(s):

Craig Metcalfe ◽

Joel Kuhn ◽

Olivera Kesler

Keyword(s):

Fuel Cells ◽

Solid Oxide Fuel Cells ◽

Plasma Spraying ◽

Suspension Plasma Spraying ◽

Solid Oxide ◽

Oxide Fuel

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Shrinkage Control of the Sealing Layer for the Cube-Type Solid Oxide Fuel Cell Bundle

Journal of Fuel Cell Science and Technology ◽

10.1115/1.3182728 ◽

2010 ◽

Vol 7 (2) ◽

Author(s):

S. Sakuragi ◽

Y. Funahashi ◽

T. Suzuki ◽

Y. Fujishiro ◽

M. Awano

Keyword(s):

Sheet Thickness ◽

Solid Oxide ◽

Fabrication Process ◽

Glass Layer ◽

Oxide Fuel ◽

Glass Composites ◽

Porous Cathode ◽

Composite Glass ◽

Sealing Layer ◽

Shrinkage Behavior

Currently, microtubular solid oxide fuel cells (SOFC) bundles are under development, which consist of microtubular SOFCs (diameter=0.8–2 mm) and porous cathode matrix where the SOFCs are integrated. In this study, a new fabrication process of the sealing layer for the microtubular SOFC bundles was examined using MgO-magnesium boro-silicate glass composites. A sheet and paste of these composites were prepared, and the microstructure and shrinkage behavior of the composite glass layers were investigated to minimize the deformation of the layer during fabrication process. The results indicated that using 100% glass sheet with the composite glass pastes appeared to be effective in reducing the shrinkage of the glass layer. In addition, the effect of sheet thickness on the shrinkage behavior was investigated and showed that the shrinkage ratio reduced as the sheet thickness decreased, and the shrinkage of about 0.2% was achieved at the sheet thickness of about 200 μm without defects or shape deformations. Thus, this fabrication method turned out to be effective for constructing a sealing layer for the microtubular SOFC bundles.

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