169results about How to "Improve fuel cell performance" patented technology

An active solid polymer electrolyte membrane provides an enhancement in power-generating performance. The active solid polymer electrolyte membrane in a solid polymer electrolyte fuel cell includes a solid polymer electrolyte element, and a plurality of noble metal catalyst grains which are carried by an ion exchange in a surface layer located inside a surface of the solid polymer electrolyte element and which are dispersed uniformly in the entire surface layer. The surface layer has a thickness t2 equal to or smaller than 10 μm. An amount CA of noble metal catalyst grains carried is in a range of 0.02 mg / cm2≦CA<0.14 mg / cm2.

A stop method for a fuel cell system that includes a fuel cell unit in which hydrogen is supplied to an anode, and air is supplied to a cathode so as to generate electrical power via an electrochemical reaction. The stop method includes the steps of stopping supply of hydrogen to the anode, and supplying air to the anode so as to discharge water remaining at the anode.

An anion transport membrane is provided enabling efficient anion exchange across the membrane, which could be used in applications like fuel cells, water electrolyzers, or water filtration systems. The structural membrane morphology is based on a hydrophobic polysulfone membrane backbone and co-grafted thereon hydrophilic poly(ethylene glycol) grafts and anion conducting quaternary ammonium species. This structure defines a bi-continuous morphology with locally phase-separated hydrophobic-hydrophilic domains, and a co-localization of the anion conducting quaternary ammonium species with respect to the hydrophilic poly(ethylene glycol) grafts enabling efficient and continuous ion transport channels for facilitating anion transport.

A fuel cell system which includes: a fuel cell (1); a supply system (Sc) for supplying fuel gas to the fuel cell (1); a recirculation system (Rc) for recirculating unused fuel gas from the fuel cell (1), in which the fuel gas therein may contain nitrogen; a purge valve (8) for purging nitrogen contained in the fuel gas in the recirculation system (Rc); and a controller (100) for adjusting a valve opening of the purge valve (8) so that a nitrogen concentration of the fuel gas in the recirculation system (Rc) is kept constant.

An electro-catalyst composition for use as an electrode, gas diffusion layer-supported electrode, catalytic electrode-coated solid electrolyte layer, and / or membrane-electrode assembly in a proton exchange membrane (PEM) type fuel cell. The composition comprises: (a) a proton- and electron-conducting polymer having at least one heteroatom per backbone monomer unit thereof and a plurality of neutral transition metal atoms covalently bonded to at least a portion of the heteroatoms; wherein the polymer has an electronic conductivity no less than 10−4 S / cm and a proton conductivity no less than 10−5 S / cm. Preferably, the electro-catalyst composition further comprises (b) a plurality of catalytically active particles of a transition metal, nucleated around the covalently bonded transition metal atoms. Also preferably, additional catalytically active catalyst particles with an average dimension smaller than 2 nm (most preferably smaller than 1 nm) are physically dispersed in such a polymer and typically not chemically bonded thereto. A hydrogen-oxygen PEM fuel cell or a direct methanol fuel cell (DMFC) featuring such an electro-catalyst composition in a thin-film electrode exhibits a superior current-voltage response.

A stop method for a fuel cell system including a fuel cell unit in which hydrogen is supplied to an anode, and air is supplied to a cathode so as to generate electrical power via an electrochemical reaction. The stop method includes the steps of stopping supply of hydrogen to the anode, electrically connecting the anode and the cathode via an electrical load, and supplying air to the anode.

A diffusion medium for use in a PEM fuel cell comprising a thin perforated layer having variable size and frequency of perforation patterns incorporated into a microporous layer on a first side of a porous substrate layer, wherein the diffusion medium is adapted to improve water management and performance of the fuel cell.

A solid oxide fuel cell comprising a solid oxide electrolyte layer, a cathode layer on a cathode side of the electrolyte layer and an anode layer on an anode side of the electrolyte layer, and wherein a hydrocarbon reforming layer is also disposed on the anode side of the electrolyte layer, said hydrocarbon reforming layer having a composition different from that of the anode layer and comprising a catalyst for promoting a hydrocarbon steam reforming reaction and a component, or a precursor of such a component for alleviating carbon deposition on the hydrocarbon reforming layer.

A flow field forming one wall of a channel in a flow field plate of a solid oxide fuel cell, the flow field includes a flat substrate having a patterned array of differently-shaped flow barriers projecting from the substrate into the channel, the flow field channel decreases in cross-sectional area in a flow direction.

A covalent crosslinking of ion-conducting materials via sulfonic acid groups can be applied to various low cost electrolyte membrane base materials for improved fuel cell performance metrics relative to such base material. This proposed approach is due, in part, to the observation that many aromatic and aliphatic polymer materials have significant potential as proton exchange membranes if a modification can increase their physical and chemical stabilities without sacrificing electrochemical performance or significantly increasing the material and production costs.

An electric power generation system has elements that improve the cold start capability and freeze tolerance of a constituent fuel cell stack cooperate to reduce the amount of water remaining within the passages of the stack. The system includes a purge system that is connectable to the oxidant supply, fuel supply and / or coolant passages upstream of the stack. When the stack is shut down, the stack is disconnected from an external circuit, and purge fluid is transmitted by the purge system through the stack before the stack falls below the freezing point of water. In systems where fuel and / or oxidant streams are humidified prior to entry into the stack, a humidifier bypass system may be provided in place of the purge system. The humidifier bypass system transmits reactant fluid to the stack in fluid isolation from the humidifier, so that the inlet reactant streams are unhumidified.

An electrocatalyst contains a conductive support which loads a noble metal thereon. In the electrocatalyst of the present invention, the noble metal is formed by adding a reducing agent for an ion of the noble metal to a reversed micellar solution containing an aqueous solution of the noble metal ion, and the noble metal is loaded with a mean particle diameter ranging from 1 to 10 nm.

A fuel cell of the invention has a hydrogen permeable metal layer, which is formed on a plane of an electrolyte layer that has proton conductivity and includes a hydrogen permeable metal. The amount of a catalyst supported on a catalyst layer in the fuel cell is regulated according to an uneven temperature distribution in the fuel cell, which is caused by operating conditions of the fuel cell including temperatures and flow directions of fluids supplied to the fuel cell. Such regulation effectively equalizes an uneven temperature distribution in the fuel cell and thus advantageously prevents the lowered durability and the deteriorating performance of the fuel cell due to the uneven temperature distribution in the fuel cell having the hydrogen permeable metal layer.

The specification discloses a fuel cell comprising stacked unit cells, each of the unit cells including a pair of electrodes having a catalytic reaction layer and a gas diffusion layer, an electrolyte layer disposed between the pair of electrodes, a separator having a flow path for supplying a fuel gas to one electrode and a separator having a flow path for supplying an oxidant gas to the other electrode, the separators being placed on the outer side of the electrodes and the unit cells being stacked with the separators placed therebetween, wherein at least the catalytic reaction layer, the gas diffusion layer or the flow path has water-repelling properties. Thereby, a fuel cell having a superior cell performance is obtained.

Disclosed are a polymer electrolyte membrane, a method for manufacturing the same and a membrane-electrode assembly comprising the same, the polymer electrolyte membrane includes a hydrocarbon-containing ion conductive layer; and a fluorine-containing ion conductor discontinuously dispersed on the hydrocarbon-containing ion conductive layer.

In an air supply unit for a fuel cell stack comprising a compressor for compressing air that is fed via a feed line to the fuel cell stack and to a turbine to which also exhaust gas of a combustion chamber can be supplied and wherein an exhaust gas from the combustion chamber is supplied to the turbine, the feed line to the fuel cell stack is in communication with a branch line by way of which compressed air can be fed also to the combustion chamber. The invention further relates to a method for operating an air supply unit for the fuel cell system.

A plurality of electrical current sensors for a set of fuel cell stacks in series independently measure electrical current in a fuel cell, and an acceptability status is determined for each electrical current sensor by independent comparison of each sensor measurement to the individual values of the other sensor measurements. A characteristic current measurement is derived from all electrical current sensors having an acceptability status which is trustworthy.

A polymer electrolyte membrane for a fuel cell includes a polymer matrix comprising a cross-linked curable oligomer with nano-sized proton conductive polymer particles in the polymer matrix. The curable oligomer may include unsaturated functional groups at each end of a chain, and may further include 3 to 14 ethylene oxides. The proton conductive polymer nano particles may include fluorine-based proton conductive polymer nano particles, non-fluorine-based proton conductive polymer nano particles, hydrocarbon-based proton conductive polymer nano particles, and combinations.

The present invention is a grafted polymer electrolyte membrane prepared by first preparing a precursor membrane comprising a polymer which is capable of being graft polymerized, exposing the surface of the precursor membrane to a plasma in an oxidative atmosphere, then graft-polymerizing a side chain polymer to the plasma treated precursor membrane and introducing a proton conductive functional group to the side chain. The resulting grafted polymer electrolyte membrane has excellent stability and performance when used in a proton-exchange membrane fuel cell or for electrolysis of water.

The present invention relates to a porous electrode used in a polymer electrolyte membrane fuel cell, and more particularly to a method of preparing a membrane-electrode assembly by forming a self-stand electrode layer by coating catalyst ink on a non-conductive substrate having a macropore and then joining it to a polymer electrolyte membrane. The porous self-stand electrode according to the present invention allows moisture and gas to be smoothly discharged and inflowed in a high current density operation region to improve the performance of a fuel cell, and can be freely cutted to simplify the preparation process of the membrane-electrode assembly.

An electric insulator for a fuel cell stack with a plurality of fuel cell plates is provided. The electric insulator includes an insulation layer having a water management feature adapted to militate against liquid water contacting the fuel cell plates. Fuel cell stacks having the water management feature are also described.

An electrocatalyst contains a conductive support which loads a noble metal thereon. In the electrocatalyst of the present invention, the noble metal is formed by adding a reducing agent for an ion of the noble metal to a reversed micellar solution containing an aqueous solution of the noble metal ion, and the noble metal is loaded with a mean particle diameter ranging from 1 to 10 nm.

A fuel cell cathode comprising a cathode body having rib regions and base regions which connect the rib regions, the rib regions being of greater thickness and of less porosity than the base regions.

A duct interconnecting two channels in a fuel-cell flowfield is disclosed. In use, responsive to a flow velocity differential as between the two channels, reaction product water (in the case of a PEM fuel cell) is drawn from one channel to the other via the duct so as to aid in the removal of reaction product accumulations in one or the other of the channels. Each of the two channels may have an associated flow-velocity-increasing means (such as an in-line venturi) associated with each end of the duct. Depending on the location of the duct within a flowfield, the duct may also help to maintain a desired pressure drop and flow of reactant gas along each channel, which helps propel excess water along the channels, and, when the oxidant is oxygen in air, helps prevent localized oxygen depletion.

A polymer blend useful as an ion conductor in fuel cells includes a first polymer that includes a non-ionic segment and a second polymer that includes a sulfonic acid group.

There is described a method of flowing reactants through a fuel cell stack having a plurality of fuel cells, the method comprising: dividing the stack into a plurality of groups, each of the groups connected together electrically in series; selecting a number of the groups and a number of cells in each of the groups to maintain a substantially constant stoichiometry for each of the groups, wherein a number of the fuel cells in each of said groups is decreasing from upstream to downstream; and distributing the reactants in series to each of the groups and in parallel within each of the groups.

Disclosed are an electro-catalyst composition and a precursor electro-catalyst composition (e.g., ink or suspension) for use in a fuel cell that exhibits improved power output. The electro-catalyst composition comprises: (a) a catalyst un-supported or supported on an electronically conducting carrier (e.g., carbon black particles); and (b) an ion-conducting and electron-conducting coating material in physical contact with the catalyst and / or coated on a surface of the carrier, wherein the coating material has an electronic conductivity no less than 10−4 S / cm ( preferably no less than 10−2 S / cm) and an ion conductivity no less than 10−5 S / cm (preferably no less than 10−3 S / cm). Also disclosed are a fuel cell electrode comprising this composition, a membrane-electrode assembly (MEA) comprising this composition, and a fuel cell comprising this composition.

By providing a coloring agent, which is brought in contact with the liquid fuel leaked from an outer peripheral portion of the liquid fuel holding section that is configured to hold the liquid fuel and by which the contact portion is changed in color, in at least part of the outer peripheral portion, the leakage of the liquid fuel from the liquid fuel holding section can be visually detected swiftly and easily without providing any special detection device.

A solid oxide fuel cell comprising a solid oxide electrolyte layer, a cathode layer on a cathode side of the electrolyte layer and an anode layer on an anode side of the electrolyte layer, and wherein a hydrocarbon reforming layer is also disposed on the anode side of the electrolyte layer, said hydrocarbon reforming layer having a composition different from that of the anode layer and comprising a catalyst for promoting a hydrocarbon steam reforming reaction and a component, or a precursor of such a component for alleviating carbon deposition on the hydrocarbon reforming layer.

The present invention relates to a polymer blend electrolyte membrane comprising an inorganic polymer having polydimethylsiloxane as a main chain, which has a pore structure at both ends formed by condensation reaction between 3-aminopropyltriethoxysilane and tetraethylorthosilicate, wherein phosphoric acid is chemically linked to an amino group of the pore structure; and a proton-conducting polymer having a cation exchange group at the side chain thereof, as well as a manufacturing method thereof. Generally, proton-conducting electrolyte membranes have significantly reduced ion conductivity at high temperatures. However, proton-conducting electrolyte membranes have advantages in terms of efficiency and cost, and thus it is needed to develop an electrolyte membrane, which has excellent ion conductivity even at high temperature. Accordingly, the present invention aims to provide a polymer blend electrolyte membrane for use at high temperature and a manufacturing method thereof.