Abstract: This invention is directed to aqueous redox flow batteries comprising ionically charged redox active materials and separators, wherein the separator is less than about 100 microns and the flow battery is capable of operating with high energy densities and voltage efficiencies.

Abstract: The invention concerns flow batteries comprising: a first aqueous electrolyte comprising a first redox active material; a second aqueous electrolyte comprising a second redox active material; a first electrode in contact with the first aqueous electrolyte; a second electrode in contact with the second aqueous electrolyte and a separator disposed between the first aqueous electrolyte and the second aqueous electrolyte; the flow battery having an open circuit potential of at least 1.4 V, and is capable of operating or is operating at a current density at least about 50 mA/cm2, wherein both of the first and second redox active materials remain soluble in both the charged and discharged states. In certain embodiments, the redox active materials are metal ligand coordination compounds. The disclosure also describes systems comprising these flow batteries and methods of them.

Abstract: This invention is directed to aqueous redox flow batteries comprising ionically charged redox active materials and ionomer membranes, wherein the charge of the redox active materials is of the same sign as that of the ionomer, so as to confer specific improvements.

Abstract: The invention concerns flow batteries comprising: a first half-cell comprising: (i) a first aqueous electrolyte comprising a first redox active material; and a first carbon electrode in contact with the first aqueous electrolyte; (ii) a second half-cell comprising: a second aqueous electrolyte comprising a second redox active material; and a second carbon electrode in contact with the second aqueous electrolyte; and (iii) a separator disposed between the first half-cell and the second half-cell; the first half-cell having a half-cell potential equal to or more negative than about ?0.3 V with respect to a reversible hydrogen electrode; and the first aqueous electrolyte having a pH in a range of from about 8 to about 13, wherein the flow battery is capable of operating or is operating at a current density at least about 25 mA/cm2.

Abstract: This invention is directed to aqueous redox flow batteries comprising ionically charged redox active materials and separators, wherein the separator is about 100 microns or less and the flow battery is capable of (a) operating with a current efficiency of at least 85% with a current density of at least about 100 mA/cm2; (b) operating with a round trip voltage efficiency of at least 60% with a current density of at least about 100 mA/cm2; and/or (c) giving rise to diffusion rates through the separator for the first active material, the second active material, or both, of about 1×10?7 mol/cm2-sec or less.

Abstract: This invention is directed to aqueous redox flow batteries comprising redox-active metal ligand coordination compounds. The compounds and configurations described herein enable flow batteries with performance and cost parameters that represent a significant improvement over that previous known in the art.

Abstract: A unitized electrode assembly (9) for use in the fuel cell comprises a first GDL (23), a PEM (28), and a second GDL (12), with electrode catalysts (27, 30) disposed between said PEM and each of said GDLs, said layers (23, 27, 30, 12) being impregnated with a thermoplastic polymer a sufficient distance from each edge of the UEA so as to form a fluid seal (13). The UEA is formed by a process which comprises making a sandwich of some or all of said layers (23, 27, 28, 30 and 33), with thermoplastic polymer film (22, 25, 32, 35) extending inwardly from the edges of said sandwich a sufficient distance to form the seal, said thermoplastic polymer film being disposed between each electrode and the adjacent GDL and/or between each GDL and release film (21, 36) on the top and bottom of the sandwich.

Abstract: A unitized electrode assembly (9) for use in the fuel cell comprises a first GDL (23), a PEM (28), and a second GDL (12), with electrode catalyst (27, 30) disposed between said PEM and each of said GDLs, said layers (23, 27, 30, 12) being impregnated with a thermoplastic polymer a sufficient distance from each edge of the UEA so as to form a fluid seal (13). The UEA is formed by a process which comprises making a sandwich of some or all of said layers (23, 27, 28, 30 and 33), with thermoplastic polymer film (22, 25, 32, 35) extending inwardly from the edges of said sandwich a sufficient distance to form the seal, said thermoplastic polymer film being disposed between each electrode and the adjacent GDL and/or between each GDL and release film (21, 36) on the top and bottom of the sandwich.

Abstract: The present invention generally relates to nanostructures and compositions comprising nanostructures, methods of making and using the nanostructures, and related systems. In some embodiments, a nanostructure comprises a first region and a second region, wherein a first photocatalytic reaction (e.g., an oxidation reaction) can be carried out at the first region and a second photocatalytic reaction (e.g., a reduction reaction) can be carried out at the second region. In some cases, the first photocatalytic reaction is the formation of oxygen gas from water and the second photocatalytic reaction is the formation of hydrogen gas from water. In some embodiments, a nanostructure comprises at least one semiconductor material, and, in some cases, at least one catalytic material and/or at least one photosensitizing agent.

Abstract: To mitigate bubble blockage in water passageways (78, 85), in or near reactant gas flow field plates (74, 81) of fuel cells (38), passageways are configured with (a) intersecting polygons, obtuse angles including triangles, trapezoids, or (b) hydrophobic surfaces (111), or (c) differing adjacent channels (127, 128), or (d) water permeable layers (93, 115, 116, 119) adjacent to water channels or hydrophobic/hydrophilic layers (114, 120).

Abstract: A method for making a membrane electrode assembly includes the steps of providing a membrane electrode assembly including an anode including a hydrogen oxidation catalyst; a cathode; a membrane disposed between the anode and the cathode; and depositing a peroxide decomposition catalyst in at least one position selected from the group consisting of the anode, the cathode, a layer between the anode and the membrane and a layer between the cathode and the membrane wherein the peroxide decomposition catalyst has selectivity when exposed to hydrogen peroxide toward reactions which form benign products from the hydrogen peroxide. The peroxide decomposition catalyst can also be positioned within the membrane. Also disclosed is a power-generating fuel cell system including such a membrane electrode assembly, and a process for operating such a fuel cell system.

Abstract: A membrane electrode assembly includes an anode including a hydrogen oxidation catalyst; a cathode; a membrane disposed between the anode and the cathode; and a peroxide decomposition catalyst positioned in at least one position selected from the group consisting of a layer between the anode and the membrane and a layer between the cathode and the membrane wherein the peroxide decomposition catalyst has selectivity when exposed to hydrogen peroxide toward reactions which form benign products from the hydrogen peroxide. The peroxide decomposition catalyst can also be positioned within the membrane. Also disclosed is a power-generating fuel cell system including such a membrane electrode assembly, and a process for operating such a fuel cell system. The assembly components contain ionomer material which can be perfluorinated or non-perfluorinated, high temperature, hydrocarbon, and the like.

Abstract: To mitigate bubble blockage in water passageways (78, 85), in or near reactant gas flow field plates (74, 81) of fuel cells (38), passageways are configured with (a) cross sections having intersecting polygons or other shapes, obtuse angles including triangles and trapezoids, or (b) hydrophobic surfaces (111), or (c) differing adjacent channels (127, 128), or (d) water permeable layers (93, 115, 116, 119) adjacent to water channels or hydrophobic/hydrophilic layers (114, 120), or (e) diverging channels (152).

Abstract: To mitigate bubble blockage in water passageways (78, 85), in or near reactant gas flow field plates (74, 81) of fuel cells (38), passageways are configured with (a) intersecting polygons, obtuse angles including triangles, trapezoids, or (b) hydrophobic surfaces (111), or (c) differing adjacent channels (127, 128), or (d) water permeable layers (93, 115, 116, 119) adjacent to water channels or hydrophobic/hydrophilic layers (114, 120).

Abstract: A unitized electrode assembly (9) for use in the fuel cell comprises a first GDL (23), a PEM (28), and a second GDL (12), with electrode catalyst (27, 30) disposed between said PEM and each of said GDLs, said layers (23, 27, 30, 12) being impregnated with a thermoplastic polymer a sufficient distance from each edge of the UEA so as to form a fluid seal (13). The UEA is formed by a process which comprises making a sandwich of some or all of said layers (23, 27, 28, 30 and 33), with thermoplastic polymer film (22, 25, 32, 35) extending inwardly from the edges of said sandwich a sufficient distance to form the seal, said thermoplastic polymer film being disposed between each electrode and the adjacent GDL and/or between each GDL and release film (21, 36) on the top and bottom of the sandwich.

Abstract: A membrane electrode assembly includes an anode, a cathode, a membrane disposed between the anode and the cathode, and an extended catalyzed layer between the cathode and the membrane, the extended catalyzed layer being adapted to consume oxygen and decompose hydrogen peroxide to produce water.

Abstract: A membrane electrode assembly includes an anode; a cathode; a membrane disposed between the anode and the cathode; and an extended catalyzed layer between the membrane and at least one electrode of the anode and the cathode. The extended catalyzed layer includes catalyst particles embedded in membrane material and preferably includes a first plurality of particles which are electrically connected to the at least one electrode. The extended catalyzed layer may further preferably have a second plurality of particles which are electrically disconnected from the at least one electrode.

Abstract: A decontamination procedure for a fuel cell power plant (10) includes operating the plant to produce electrical power for an operating period, and then terminating operation of the plant (10) for a decontamination period, and then, whenever optimal electrical production of a plant fuel cell (12) is reduced by at least 5% by contaminants adsorbed by fuel cell electrodes (24, 42), decontaminating the fuel cell (12) of the plant (10) during the decontamination period by oxidizing contaminants adsorbed by electrodes (24, 42) of the fuel cell. Oxidizing the contaminants may be accomplished by various steps including exposing the electrodes (24, 42) to flowing oxygen; to heated flowing oxygen; to a sequence of start-stop cycles; and, to varying controlled potentials.

Abstract: A membrane electrode assembly includes an anode including a hydrogen oxidation catalyst; a cathode; a membrane disposed between the anode and the cathode; and a peroxide decomposition catalyst positioned in at least one position selected from the group consisting of the anode, the cathode, a layer between the anode and the membrane and a layer between the cathode and the membrane wherein the peroxide decomposition catalyst has selectivity when exposed to hydrogen peroxide toward reactions which form benign products from the hydrogen peroxide. The peroxide decomposition catalyst can also be positioned within the membrane. Also disclosed is a power-generating fuel cell system including such a membrane electrode assembly, and a process for operating such a fuel cell system.

Abstract: A fuel cell power plant (10) having a fuel concentration sensor cell (54) is disclosed for detecting a concentration of fuel in a fuel cell (12) of the plant (10). A portion of a fuel exhaust stream is directed to flow through the sensor cell (54) adjacent to a membrane electrode assembly (60) of the sensor cell (54). A power circuit (62) may or may not deliver an electrical current to the cell (12), while changes in voltage across the cell (12) that are proportional to changes in hydrogen concentrations within the fuel exhaust stream are detected by a detector (68) which communicates the changes to a controller (108) for controlling a rate of fuel supply to the fuel cell (12). A porous sensor water transport plate (74) cools, humidifies delivers and removes liquid from the sensor cell (12).