Westinghouse Electric Corporation

Siemens Westinghouse Power Corporation

The United States of America As Represented by the United States

Siemens Energy, Inc.

Westinghouse Electric Company LLC

George R Folser

Uday B Pal

Subhash C Singhal

Srikanth Gopalan

Douglas S Schmidt

Arnold O Isenberg

Roswell J Ruka

Paolo R Zafred

Jeffrey T Dederer

Prabhakar Singh

Edward S Buzzelli

Lewis J Kuo

Charles J Spengler

Shailesh D Vora

Walter J Dollard

Von L Richards

Charles A Hager

Norman F Bessette

Gregory W Tomlins

James M Toms

David M Moon

Carl C Hardman

Nichols J Maskalick

A plasma sprayed ceramic-metal fuel electrode is provided. The fuel electrode has particular application in connection with a solid oxide fuel cell used within a power generation system. The fuel cell advantageously comprises an air electrode, an electrolyte formed on at least a portion of the air electrode, a plasma sprayed ceramic-metal fuel electrode formed on at least a portion of the electrolyte, and an interconnect layer to connect adjacent cells in a generator.

Plasma sprayed ceramic-metal fuel electrode

A plasma sprayed ceria-containing interlayer is provided. The interlayer has particular application in connection with a solid oxide fuel cell used within a power generation system. The fuel cell advantageously comprises an air electrode, a plasma sprayed interlayer disposed on at least a portion of the air electrode, a plasma sprayed electrolyte disposed on at least a portion of the interlayer, and a fuel electrode applied on at least a portion of the electrolyte.

Plasma sprayed ceria-containing interlayer

A tubular fuel cell ( ) contains an air electrode ( ), an electrolyte ( ), and a fuel electrode ( ) where an interlayer material ( ) is disposed between the air electrode and the electrolyte, the interlayer ( ) containing a two-phase particle mixture, where the particles have a size range from 0.5-5 micrometers, but where at least 50 wt % of the particles are less than 3 micrometers and where the interlayer ( ) is from 15-40 micrometers thick and from 5-50% porous.

High power density solid oxide fuel cells having improved electrode-electrolyte interface modifications

A solid oxide fuel cell (,) having a closed end (,) and an open end (,) operates in a fuel cell generator (,) where the fuel cell open end (,) of each fuel cell contains a sleeve (,) fitted over the open end (,), where the sleeve (,) extends beyond the open end (,) of the fuel cell (,) to prevent degradation of the interior air electrode of the fuel cell by fuel gas during operation of the generator (,).

Open end protection for solid oxide fuel cells

A dense, substantially gas-tight, electrically conductive interconnection layer is formed on an air electrode structure of an electrochemical cell by (A) providing an electrode surface; (B) forming on a selected portion of the electrode surface, a layer of doped LaCrO.sub.3 particles doped with an element selected from Ca, Sr, Ba, Mg, Co, Ni, Al and mixtures thereof by plasma spraying doped LaCrO.sub.3 powder, preferably compensated with chromium as Cr.sub.2 O.sub.3 and/or dopant element, preferably by plasma arc spraying; and, (C) heating the doped and compensated LaCrO.sub.3 layer to about 1100.degree. C. to 1300.degree. C. to provide a dense, substantially gas-tight, substantially hydration-free, electrically conductive interconnection material bonded to the electrode surface. A solid electrolyte layer can be applied to the unselected portion of the air electrode, and a fuel electrode can be applied to the solid electrolyte, to provide an electrochemical cell.

Method of forming a plasma sprayed interconnection layer on an electrode

A method to form an electrochemical cell (12) is characterized by the steps of thermal spraying stabilized zirconia over a doped lanthanum manganite air electrode tube (14) to provide an electrolyte layer (15), coating conductive particles over the electrolyte, pressurizing the outside of the electrolyte layer, feeding halide vapors of yttrium and zirconium to the outside of the electrolyte layer and feeding a source of oxygen to the inside of the electrolyte layer, heating to cause oxygen reaction with the halide vapors to close electrolyte pores if there are any and to form a metal oxide coating on and between the particles and provide a fuel electrode (16).

Solid oxide electrochemical cell fabrication process

An electrochemical cell containing an air electrode (16), contacting electrolyte and electronically conductive interconnection layer (26), and a fuel electrode, has the interconnection layer (26) attached by: (A) applying a thin, closely packed, discrete layer of LaCrO.sub.3 particles (30), doped with an element selected from the group consisting of Ca, Sr, Co, Ba, Mg and their mixtures on a portion of the air electrode, and then (B) electrochemical vapor depositing a dense skeletal structure (32) between and around the doped LaCrO.sub.3 particles (30).

Method of bonding an interconnection layer on an electrode of an

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

An electrode 6 bonded to a solid, ion conducting electrolyte 5 is made, where the electrode 6 comprises a ceramic metal oxide 18, metal particles 17, and heat stable metal fibers 19, where the metal fibers provide a matrix structure for the electrode. The electrolyte 5 can be bonded to an air electrode cathode 4, to provide an electrochemical cell 2, preferably of tubular design.

Low resistance fuel electrodes

Disclosed is an energy efficient electrolyzer for the production of hydrogen. The electrolyzer consists of an inner container, a plurality of electrolytic cells within the container and means for passing electric current in series through the electrolytic cells. Each cell consists of the anode half of one inert impervious conducting bipolar plate, in contact with an inert conductive anode bed of large surface area separated from the facing cathode half of another inert impervious conducting bipolar plate by a porous insulating separator. The anode is impregnated with an anolyte of about 10 to about 60% aqueous sulfuric acid saturated with sulfur dioxide and the cathode is bathed in a catholyte of about 10 to about 60% aqueous sulfuric acid. The anode is preferably carbon pellets which have been obtained from vegetable matter and which contain about 1 to about 5% platinum.

Energy efficient electrolyzer for the production of hydrogen

Electrodes for use in an electrolytic cell, which are liquid-permeable and have low electrical resistance and high internal surface area are provided of a rigid, porous, carbonaceous matrix having activated carbon uniformly embedded throughout. The activated carbon may be catalyzed with platinum for improved electron transfer between electrode and electrolyte. Activated carbon is mixed with a powdered thermosetting phenolic resin and compacted to the desired shape in a heated mold to melt the resin and form the green electrode. The compact is then heated to a pyrolyzing temperature to carbonize and volatilize the resin, forming a rigid, porous structure. The permeable structure and high internal surface area are useful in electrolytic cells where it is necessary to continuously remove the products of the electrochemical reaction.

Liquid-permeable electrode

A self-supporting electrode structure consisting of active material particles is made by: (1) mixing 100 parts of metallic iron particles, with between about 0.5 part to about 5.0 parts of a water soluble metal sulfate selected from MgSO.sub.4, CdSO.sub.4, MnSO.sub.4, ZnSO.sub.4, BaSO.sub.4, Cr.sub.2 (SO.sub.4).sub.3, CuSO.sub.4, CaSO.sub.4, Li.sub.2 SO.sub.4, their hydrates and mixtures, as an electrochemical activator, and an amount of water effective to form a thin coating of metal sulfate on the metallic iron particles, (2) sizing the mixture to between about 10 microns to about 275 microns average particle size, (3) pressing the coated iron particles, and (4) reducing and sintering the coated iron particles at between about 700.degree. C to about 1,000.degree. C, in a reducing atmosphere; to provide an interconnected self-supporting metallic electrode structure consisting solely of fully charged iron active material particles coated with the metal of the additive, said electrode being capable of immediate discharge.

Growing community of inventors

Lower Burrell, PA, United States of America

George R Folser