Westinghouse Electric Corporation

David M Moon

Subhash C Singhal

George R Folser

Uday B Pal

A dense, electronically conductive interconnection layer 26 is bonded on a porous, tubular, electronically conductive air electrode structure 16, optionally supported by a ceramic support 22, by (A) forming a layer of oxide particles of at least one of the metals Ca, Sr, Co, Ba or Mg on a part 24 of a first surface of the air electrode 16, (B) heating the electrode structure, (C) applying a halide vapor containing at least lanthanum halide and chromium halide to the first surface and applying a source of oxygen to a second opposite surface of the air electrode so that they contact at said first surface, to cause a reaction of the oxygen and halide and cause a dense lanthanum-chromium oxide structure to grow, from the first electrode surface, between and around the oxide particles, where the metal oxide particles get incoporated into the lanthanum-chromium oxide structure as it grows thicker with time, and the metal ions in the oxide particles diffuse into the bulk of the lanthamum-chromium oxide structure, to provide a dense, top, interconnection layer 26 on top of the air electrode 16. A solid electrolyte layer 18 can be applied to the uncovered portion of the air electrode, and a fuel electrode 20 can be applied to the solid electrolyte, to provide an electrochemical cell 10.

Method of doping interconnections for electrochemical cells

This is a process for producing a ferroboron containing 0.5-20% silicon and up to 4.5% carbon. This process utilizes the silicon reduction of B.sub.2 O.sub.3 and avoids excessive losses due to volatilization of B.sub.2 O.sub.3. It also results in a ferroboron which is substantially free from aluminum impurity. The process uses a mixture, which includes an iron-containing constituent, a silicon containing constituent, and boric acid. Preferably a molten pool is prepared and controlled to a temperature of 1100-1550 (and preferably 1100.degree.-1450.degree. C.) prior to the addition of the boric acid. At least some of the silicon constituent can also be injected into the molten pool along with the boric acid.

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Pittsburgh, PA, United States of America

David M Moon