Abstract: A PEM based water electrolysis stack consists of a number of cells connected in series by using interconnects. Water and electrical power (power supply) are the external inputs to the stack. Water supplied to the oxygen electrodes through flow fields in interconnects is dissociated into oxygen and protons. The protons are transported through the polymer membrane to the hydrogen electrodes, where they combine with electrons to form hydrogen gas. If the electrolysis stack is required to be used exclusively as an oxygen generator, the hydrogen gas generated would have to be disposed off safely. The disposal of hydrogen would lead to a number of system and safety related issues, resulting in the limited application of the device as an oxygen generator. Hydrogen can be combusted to produce heat or better disposed off in a separate fuel cell unit which will supply electricity generated, to the electrolysis stack to reduce power input requirements.

Abstract: A method of construction of an electrochemical interconnect plate, the method comprising the steps of: (a) etching predetermined fluid flow channels in a first conductive sheet; and (b) coating the first conductive sheet with a corrosion resistant layer of nickel and tin.

Abstract: A PEM based water electrolysis stack consists of a number of cells connected in series by using interconnects. Water and electrical power (power supply) are the external inputs to the stack. Water supplied to the oxygen electrodes through flow fields in interconnects is dissociated into oxygen and protons. The protons are transported through the polymer membrane to the hydrogen electrodes, where they combine with electrons to form hydrogen gas. If the electrolysis stack is required to be used exclusively as an oxygen generator, the hydrogen gas generated would have to be disposed off safely. The disposal of hydrogen would lead to a number of system and safety related issues, resulting in the limited application of the device as an oxygen generator. Hydrogen can be combusted to produce heat or better disposed off in a separate fuel cell unit which will supply electricity generated, to the electrolysis stack to reduce power input requirements.

Abstract: A method of construction of an electrochemical interconnect plate, the method comprising the steps of: (a) etching predetermined fluid flow channels in a first conductive sheet; and (b) coating the first conductive sheet with a corrosion resistant layer of nickel and tin.

Abstract: An electrochemical device including a series of interconnected electrochemical units, each of the electrochemical units including a membrane electrode assembly arranged between a first conductive surface and a second conductive surface and wherein: the first conductive surface preferably can include at least one conductive tab overlapping a conductive tab of the second conductive surface of an adjacent electrochemical unit, the first and second conductive tabs being electrically interconnected to one another.

Abstract: A bipolar interconnect plate for a fuel cell, including: a first surface having a series of conductive interconnect posts for forming a conductive interconnect for conductively interconnecting, in use, with a cathode surface of a MEA; the plate including a series of ridges surrounding the first surface having air access slots therein in fluid communication with the first surface.

Abstract: A method of forming a bipolar interconnect for a polymer electrolyte membrane fuel cell or electrolyser stack. The method includes providing a planar electrically-conductive blank, and deforming a portion of the conductive blank to provide a raised part on the blank defining an electrical contact and a fluid flow channel.

Abstract: An electrochemical cell having a central active area and a perimeter area, the electrochemical cell including: a membrane electrode assembly (MEA) having a first electrode, a proton exchange membrane, and a second electrode of opposite electrical polarity to the first electrode; a pressed metal interconnect having on a first side a raised portion in electrical contact with the first electrode; the interconnect and the first electrode defining at least one fluid channel between the interconnect and the first electrode in the central active area, such that a fluid conveyed in the fluid channel is in fluid communication with the first electrode; a gasket interposed between the membrane and the interconnect in the perimeter area, such that the fluid is sealed within the fluid channel; and a fluid opening in the gasket allowing fluid communication between the fluid channel and a manifold in the perimeter area.

Abstract: A membrane electrode assembly (MEA) for an electrochemical cell including: a first electrode; a second electrode; and a proton exchange membrane (PEM) interposed between the first and second electrodes such that protons can pass between the first and second electrodes across the PEM; wherein the first electrode has a foraminous metallic substrate to provide support for the PEM.

Abstract: An electrical interconnect device for a planar fuel cell having solid oxide electrolyte, a cathode and a nickel-containing anode comprises a plate-like chromium-containing substrate having fuel gas-flow channels on one side and an oxidation-resistant coating on surfaces of the one side adapted to contact the anode. The coating comprises an outer oxygen barrier layer for electrically contacting the anode comprising Ni, a noble metal except Ag or an alloy of one or more of these metals and an electrically conductive metal barrier layer comprising Nb, Ta, Ag or alloys of one or more of these metals between the substrate and the outer layer.

Abstract: An electrical interconnect device for a planar fuel cell, comprising solid oxide electrolyte (44), an anode and a cathode (42), is described. The interconnect device comprises a plate-like chromium-containing substrate (22) having gas-flow channels (28) on the cathode-side and a coating on the cathode-side. The coating comprises an oxide surface layer comprising at least one metal M selected from Mn, Fe, Co and Ni, and an M, Cr spinel layer intermediate the substrate and the oxide surface layer. The intermediate spinel layer is formed by reaction of M oxide with surface chromium oxide on the substrate. The coating material may be applied as oxide or as salt or metal, or a mixture, and then converted to oxide. The M-metal(s) may be mixed with non-M metal or be doped. Methods of application are described in which the oxide surface layer is partially reacted to form the intermediate spinel layer.

Abstract: A composite electrode material for use in solid electrolyte devices, which comprises a mixture of a noble metal and a semiconducting metal oxide with either electronic (n-type) or hole (p-type) conductivity.

Abstract: An electrode for a solid electrolyte oxygen sensor, characterized in that the electrode comprises a surface layer on the solid electrolyte, said surface layer consisting of or containing a solid solution in urania of one or more other metal oxides with oxygen/metal atom ratio equal to or less than two, provided that at least one of said other metal oxides has an oxygen/metal atom ratio less than two.

Abstract: A method of measuring the oxygen partial pressure in an atmosphere in which a temperature T.sub.c at which the free energy of formation of an oxide of a metal such as palladium in contact with the atmosphere is determined to provide a measure of the partial pressure of oxygen. Apparatus for use in the method comprises an electrolytic cell including an electrode of the said metal and an electrolyte such as yttria stabilized zirconia having ionic oxygen mobility.

Abstract: A method of measuring the oxygen partial pressure in an atmosphere in which a temperature T.sub.c at which the free energy of formation of an oxide of a metal such as palladium in contact with the atmosphere is determined to provide a measure of the partial pressure of oxygen. Apparatus for use in the method comprises an electrolytic cell including an electrode of the said metal and an electrolyte such as yttria stabilized zirconia having ionic oxygen mobility.

Abstract: A method of determining the oxygen partial pressure in an atmosphere at a known temperature, in which the magnitude of a critical potential equal and opposite to the free energy of formation of an oxide of a metal such as palladium in contact with the atmosphere is determined to provide a measure of the partial pressure of oxygen. Apparatus for use in the method comprises an electrolytic cell including an electrode of the said metal, an electrolyte such as yttria stabilized zirconia having ionic oxygen mobility and means to apply a potential to the cell to modify the resistance characteristics of the electrode.