Sulzer Metco (us) Inc.

Sulzer Hexis Ag

Sulzer Innotec Ag

Hexis Ag

Kaspar Honegger

Emad Batawi

Andreas Franz-Josef Kaiser

Rajiv J Damani

The porous, gas permeable layer substructure () for a thin, gas tight layer () can in particular be used as a functional component in high temperature fuel cells (). This layer substructure has a smooth surface () which is suitable for an application of the gas tight layer or a multi-layer system including the gas tight layer, with the application being carried out by means of a screen printing method or other coating methods. The smooth surface is formed by a compacted edge zone (). The edge zone and a carrier structure () adjacent to this are made from sinterable particles of a uniform substance mixture. The porosity of the carrier structure is greater than 30 volume percent, preferably greater than 40 volume percent. The pore size of the edge zone is smaller than 10 &#x3bc;m, preferably smaller than 3 &#x3bc;m.

Porous, gas permeable layer substructure for a thin, gas tight layer for use as a functional component in high temperature fuel cells

The spray powder can be used for the manufacture of a thermally insulating layer which is resistant to high temperatures. A coating of this kind, a so-called TBC, can be produced on a substrate by means of a thermal spraying process. The substrate can already be coated with a single- or multi-layered part coating, in particular a primer. At least one thermally insulating functional material is used, which on the one hand has a lower thermal conductivity than the substrate and on the other hand forms a chemically and thermally stable phase at high temperatures. The spray powder comprises particles () which respectively have an agglomerate-like micro-structure () which is formed by a plurality of granules () adhering to each other. These granules are made up of the functional material or the functional materials. At least one further component is present made of an additive () or a plurality of additives. This further component is distributed finely dispersed on the surfaces () of the functional material granules (), i.e. primarily in the boundary zones. The further component in the given form or in a transformed form exerts a retarding or eliminating effect with regard to sintering compounds, which can form at high temperatures between the functional material granules.

Spray powder for the manufacture of a thermally insulating layer which remains resistant at high temperatures

A fuel cell having a solid electrolyte layer () forms together with two electrode layers () a plate-like multiple layer system (). The layers are applied by means of coating procedures to an open-pored, electrically conducting carrier structure () in the sequence anode (), electrolyte () and cathode (). This multiple layer system () has an outer edge which is exposed during a current generating operation of the fuel cell to an external environment () which contains molecular oxygen. The material of the carrier structure assumes an oxidized or a reduced state in thermodynamic equilibrium at the operating temperature of the fuel cell depending on the environment. The outer edge () of the multiple layer plate is covered over with an inert material. At the operating temperature of the fuel cell this edge covering () forms a barrier which inhibits or prevents the transport of molecular oxygen out of the external environment () into the carrier structure. The material is in particular YSZ, i.e. zirconium dioxide ZrOwhich is stabilized with yttrium oxide YO.

Fuel cell comprising a solid electrolyte layer

The high temperature fuel cell with a thin film electrolyte has an electrochemically active element which is executed as a planar multi-layer structure. At least the electrolyte and cathode layers are deposited on a porous, gas-permeable carrier structure, by means of a thin film technique. The carrier structure is a sintered body of metal ceramic material which comprises a highly porous base layer as well as a fine pored cover layer of anode material placed on the base layer. The pores of the base layer are open with respect to one another and have an average diameter of the order of magnitude of at least about 300 .mu.m. The pores of the cover layer have diameters which are not substantially greater than 1 to 3 .mu.m. The coefficient of thermal expansion of the carrier structure is substantially the same as that of the solid electrolyte.

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Wallenwil, Switzerland

Kaspar Honegger