Abstract: An electrochemical fuel cell comprises a pair of separator plates and a pair of fluid distribution layers interposed between the separator plates. At least one of the fluid distribution layers comprises a sealing region and an electrically conductive, fluid permeable active region, and a preformed sheet material extending into each of the sealing region and the active region. An ion exchange membrane is interposed between at least a portion of the fluid distribution layers, and a quantity of electrocatalyst is interposed between at least a portion of each of the fluid distribution layers and at least a portion of the membrane, thereby defining the active region. Compression of the preformed sheet material by urging of the pair of plates towards each other renders the at least one fluid distribution layer substantially fluid impermeable in a direction parallel to the major planar surfaces, in the sealing region.

Abstract: A method and apparatus detects and locates perforations in membranes used in electrochemical cells. The membrane has first and second oppositely facing major planar surfaces. The first surface is exposed to a first reactant fluid, preferably a gaseous mixture comprising hydrogen, while the second surface is exposed to a second reactant fluid, preferably ambient air comprising oxygen. The first and second reactant fluids are substantially fluidly isolated from each other by the membrane when no perforations are present in the membrane. The first reactant fluid contacts the second reactant fluid when at least one perforation is present in the membrane. The first and second reactant fluids exothermically react upon contact, preferably in the presence of a catalyst, to generate heat, which is then detected using an infrared thermal detector or thermal imaging device or a layer of thermally sensitive film positioned in proximity with the membrane.

Abstract: An embossed fluid flow field plate for electrochemical cells comprises two sheets of compressible, electrically conductive material. Each sheet has two oppositely facing major surfaces. At least one of the major surfaces has an embossed surface which has a fluid inlet formed therein. The embossed surface has at least one open-faced channel embossed therein extending from the fluid inlet for conducting pressurized fluid introduced at the fluid inlet. A metal sheet is interposed between each of the compressible sheets. The compressible, electrically conductive sheet preferably comprises graphite foil. A method of fabricating an embossed separator plate for use in conjunction with an electrochemical fuel cell comprises (1) providing two sheets of compressible, electrically conductive sheet material, (2) interposing a metal sheet between each of the compressible sheets, and (3) embossing an open-faced channel in at least one of the surfaces of the sheets facing away from the metal sheet.

Abstract: An embossed fluid flow field plate for electrochemical cells comprises two sheets of compressible, electrically conductive material. Each sheet has two oppositely facing major surfaces. At least one of the major surfaces has an embossed surface which has a fluid inlet formed therein. The embossed surface has at least one open-faced channel embossed therein extending from the fluid inlet for conducting pressurized fluid introduced at the fluid inlet. A metal sheet is interposed between each of the compressible sheets. The compressible, electrically conductive sheet preferably comprises graphite foil.

Abstract: A method and apparatus selectively oxidizes, within the fuel cell assembly, the carbon monoxide present in a fuel stream fed to the assembly. A quantity of catalyst is contained within at least a portion of a fuel stream passageway within the stack. The carbon monoxide is selectively oxidized by the catalyst to carbon dioxide, and carbon monoxide produced by the reverse water-shift reaction is also oxidized.

Abstract: An electrochemical fuel cell assembly includes a membrane electrode assembly which comprises an anode, a cathode having a surface thereof exposed to ambient air, and an ion exchange membrane interposed between the anode and the cathode. A seal forms a gas-impermeable barrier around the anode to which a gaseous fuel stream is supplied. The assembly further includes a thermally conductive plate having a plurality of thermally conductive members or fins extending from a major surface of the plate. The thermally conductive members contact portions of the exposed cathode surface. Adjacent thermally conductive members cooperate with the plate and the exposed cathode surface to form air conducting channels. Heat generated exothermically in the membrane electrode assembly is dissipated to the atmosphere through the thermally conductive members.

Abstract: A method and apparatus oxidizes the carbon monoxide present in an incoming reactant fuel stream and/or carbon monoxide produced by the reverse water-shift reaction to carbon dioxide in a reactant stream introduced to an electrochemical fuel cell. The reactant stream comprises hydrogen, carbon dioxide and carbon monoxide. A first oxygen-containing gas stream is introduced into the reactant stream through a first port disposed between the reactant stream inlet and the reactant stream outlet. A further oxygen-containing gas stream is introduced into the reactant stream through at least one secondary port located between the first port and the reactant stream outlet.