89 results about "Gas diffusion layer" patented technology

This invention discloses a method for preparing a diffusion layer to improve the peak power of a fuel cell. During the operation of a proton exchange membrane fuel cell, the water vapor required for humidification during the reaction process is transported counter-currently to the water generated in the reaction. When the water generated in the reaction is not drained in time, a "flooding" phenomenon occurs, which severely affects the peak power of the fuel cell. To reduce flooding and optimize gas-liquid transport in the fuel cell, this invention discloses a method for preparing a diffusion layer that enhances water-gas mass transfer and improves the peak power of the fuel cell. This method has advantages such as simple process, low cost, and ease of industrialization.

This invention discloses a fuel cell and its application. The bipolar plate includes a connecting structure with a cross-flow channel and a narrowing structure. The hydraulic diameter of the narrowing structure is smaller than that of the non-narrowing structure. The non-narrowing structure of the flow channel has a connecting structure corresponding to at least one of two adjacent ridges. Furthermore, the resistance of the gas in the first direction through the narrowing structure is R1, and the resistance in the second direction through the connecting structure is R2, where R1 / R2 ≥ 20. The first direction is the flow direction of the gas entering the flow field, and the second direction is perpendicular to the first direction. Therefore, the fuel cell bipolar plate provided by this invention can more fully utilize the pressure drop generated by the narrowing structure to create a larger pressure difference between adjacent flow channels. This allows a smaller flow field pressure drop to create the same or higher level of under-ridge gas convection and permeation effect within the gas diffusion layer or membrane electrode, thereby improving the under-ridge mass transfer and drainage performance of the fuel cell.

A gas diffusion layer composed of a sheet of composite powder, the composite powder includes: conductive particles; conductive fibers; and a polymer resin, wherein a grain boundary of the composite powder is present on a surface or a cross section of the gas diffusion layer.

This invention relates to an air-cooled fuel cell stack with a coupled three-dimensional porous structure and its adaptive oxygen supply method. The stack includes multiple membrane electrode assemblies (MEAs), bipolar plates, anode plates, current collectors, and end plates. Each MEA includes a catalyst-coated membrane and gas diffusion layers (GDLs) on both sides. A three-dimensional porous conductive structure layer is disposed between the outer surface of the GDL gas diffusion layer on the cathode side of each MEA and the adjacent bipolar plate. This three-dimensional porous conductive structure layer is made of a porous metallic material with high porosity, high conductivity, high thermal conductivity, and corrosion resistance, and at least a portion of its surface is coated with a catalytic / conductive coating. This invention integrates a high-porosity, high-conductivity / thermal-conductivity, and corrosion-resistant three-dimensional porous material in situ on the cathode side, constructing a multifunctional interface layer that combines physical support, current conduction, thermal diffusion, aqueous phase regulation, and gas redistribution functions. This achieves self-breathing, self-humidification, self-drainage, and synergistic adaptive local micro-reactions. The process is simple and suitable for large-scale production.

The electrode has a catalyst layer and a gas diffusion layer. The catalyst layer is formed by a skeleton and pores. The skeleton is formed from a metal. The gas diffusion layer covers the catalyst layer. The gas diffusion layer is formed from a porous material. The gas diffusion layer has a first surface and a second surface. The first surface faces the skeleton. The second surface is opposite from the first surface. The contact angle of ultrapure water dripped onto the second surface is 115-140°. Part of the gas diffusion layer is inside the pores.

This invention belongs to the field of battery gas diffusion layer preparation, and in particular, a high-temperature fuel cell gas diffusion layer structure and its preparation method. Addressing the problem that in existing high-temperature proton exchange membrane fuel cells, the operating environment easily leads to oxidation and acid corrosion of the gas diffusion layer, causing damage and failure, reduced durability, and consequently, a sharp decline in battery performance, the invention includes the following steps: S1: Preparation of high-temperature graphitized carbon black: Weigh ordinary carbon black and pretreat it at 300–500°C for 10–30 minutes to remove surface impurities. This invention performs high-temperature graphitization treatment on the carbon black used in the microporous layer and prepares a microporous layer slurry with good coating quality. Then, using a hydrophobic agent with superior performance compared to traditional PTFE, its oxidation and acid corrosion resistance are greatly improved, and its durability is enhanced. This makes it suitable for application in high-temperature proton exchange membrane fuel cells, enabling long-term, undiminished battery performance.

This invention discloses a gas diffusion layer with multi-level mass transfer channels, its preparation method, and its application. The gas diffusion layer with multi-level mass transfer channels includes a substrate layer and a microporous layer on the substrate layer; wherein the microporous layer comprises carbon black, hollow porous carbon nanofibers, and optionally a hydrophobic binder. This invention uses hollow porous carbon nanofibers as a novel MPL carbon material to synergistically construct a gas diffusion layer with better water vapor management capabilities in conjunction with carbon black particles. The resulting gas diffusion layer exhibits excellent comprehensive performance; its hollow porous structure provides additional water transport channels, improving water vapor transport capacity, thereby enabling the assembled membrane electrode to have better output performance.

The application discloses a kind of fuel cell ionomer evaluation method and application based on thin liquid film electrode, belong to automobile fuel cell technical field.The method in the application first disperses catalyst and ionomer to be measured in solvent to form electrode slurry, is coated to the surface of gas diffusion layer and forms gas diffusion electrode;Gas diffusion electrode is assembled into working electrode with sealing gasket and graphite flow field plate again and is fixed in electrolytic cell;Add electrolyte to electrolytic cell, adopt lifting method or steam wetting method to construct continuous uniform thin liquid film on the surface of catalytic layer of working electrode, form gas-liquid-solid three-phase interface;Reaction gas is introduced to carry out electrochemical test, and the performance of ionomer is evaluated according to test result.The application simulates the three-phase interface environment in real fuel cell catalytic layer by constructing thin liquid film electrode, realizes the decoupling evaluation of ionomer intrinsic performance and three-phase interface construction effect, and can be applied to fuel cell ionomer screening.

The application relates to the technical field of mass spectrometry in-situ cell, and discloses a membrane electrode in-situ cell for differential electrochemical mass spectrometry working condition characterization, which comprises a transition plate, a through hole is formed in the transition plate, a hydrophobic air-permeable membrane is arranged in the through hole, and the membrane electrode in-situ cell further comprises a membrane electrode assembly, the membrane electrode assembly comprises a proton exchange membrane and catalytic layers arranged on the two sides of the proton exchange membrane, and the two sides of the proton exchange membrane are connected with polar plates through gas diffusion layers, and flow channels are arranged in the polar plates; the physical barrier of the hydrophobic air-permeable membrane fundamentally prevents a large amount of water vapor from entering the mass spectrometer, protects the instrument, and improves the detection sensitivity and accuracy of trace gas products; and the standard MEA without modification is directly tested, the real working state is maintained, and the obtained data can better reflect the actual application performance; in addition, an external cold trap, a drying tube and a long-distance transmission pipeline are omitted, the path of the gas from generation to entering the mass spectrometer is extremely short, the response time is fast, and the system dead volume is small.

This application discloses a gas diffusion layer-free fuel cell based on a carbon-based porous support and its preparation method. The core of this fuel cell is the carbon-based porous support, prepared by co-pyrolysis of coal or biomass with enzymatically hydrolyzed lignin. Pretreatment using nickel-catalyzed hydrodesulfurization reduces the residual sulfur content in the support to <10 ppb, eliminating the risk of sulfur poisoning of the precious metal catalyst. A solvent-circulating vacuum-pressure impregnation method is used to embed precious metal nanoparticles into the pores of the support, achieving physical confinement and chemical anchoring. The catalyst is directly coated onto the surface of the bipolar plate flow channel to form an integrated electrode, replacing the traditional gas diffusion layer. This fuel cell eliminates the need for a gas diffusion layer (GDL), reduces contact resistance and cost, improves catalyst durability, enhances water management, and solves the technical challenge of sulfur poisoning of precious metals with low-cost carbon supports. It provides a new pathway for the large-scale application of high-performance, long-life, and low-cost fuel cells.

This invention discloses a testing system for the water breakthrough pressure of a fuel cell gas diffusion layer and a method for measuring the water breakthrough pressure of the gas diffusion layer. This method evaluates the gas-liquid transport capacity of the gas diffusion layer by measuring its water breakthrough pressure. The water breakthrough pressure measurement system includes a water tank, a gas diffusion layer holder, a pressure loading device, a differential pressure detector, a detection unit, and a thermostat. This invention enables the measurement of the pressure difference across the gas diffusion layer without initiating a fuel cell reaction, allowing for analysis of the water breakthrough pressure and thus assessing the diffusion layer's performance. This detection method ensures sampling accuracy while shortening detection time, saving detection costs, and improving detection efficiency.

An integrated gas diffusion layer for a fuel cell, and a preparation method and use thereof are provided. In the integrated gas diffusion layer, a flow field plate and a gas diffusion layer are integrated into an integral structure, including processing a surface of the gas diffusion layer by etching or pressing to form a flow field structure with a flow channel and a rib, so that the surface of the gas diffusion layer also has the function of a flow field, thereby forming the integrated gas diffusion layer. By adopting the technical solution of the present application, the structure having the flow channel with high porosity and the microchannel rib is engraved on the surface of the existing gas diffusion layer by methods such as lase engraving, machining, mechanical pressing and the like, to realize integration of the flow field plate and the gas diffusion layer.

This invention provides a catalyst slurry for fuel cells and its preparation method, relating to the field of fuel cells. The catalyst slurry for fuel cells, by weight, comprises catalyst particles, perfluorosulfonic acid resin ionomer, ultrapure water, lower alcohol, and carbon powder. By employing porous carbon powder with specific properties, which interacts with the perfluorosulfonic acid resin ionomer, this invention can significantly improve the viscosity and stability of the catalyst slurry. Furthermore, the CCM formed after coating this catalyst slurry exhibits good performance and will not produce any adverse effects when in contact with the carbon in the microporous layer of the gas diffusion layer during fuel cell use.

A gas-phase electrochemical module includes a separation membrane, and a cathode structure and an anode structure on both sides of the separation membrane. The cathode structure includes a cathode electrode plate, a gas diffusion layer (GDL), and a cathode catalyst layer. A portion of the GDL away from the cathode electrode plate is a hydrophilic structure. The cathode catalyst layer is formed in the hydrophilic structure, and a depth of the cathode catalyst layer penetrating into the GDL is greater than 10 μm. The metal content of the cathode catalyst layer is greater than 95%. The cathode catalyst layer includes a first coating layer and a second coating layer on the surface of the first coating layer, and the first coating layer is a copper metal layer. The second coating layer is a single-layer or multi-layer structure, in which the material of the second coating layer includes silver, gold, indium, or an alloy thereof.

This invention provides a gas diffusion layer, its preparation method, and its application. The gas diffusion layer includes a substrate and a microporous layer, with the microporous layer disposed on at least a portion of the surface of the substrate. The microporous layer comprises gas diffusion material particles, a binder, and a hydrophobic agent. The particle sizes of the gas diffusion material particles are: D10 of 50–100 nm, D50 of 10–80 μm, and D90 of 100–300 μm. Along the thickness direction of the substrate, the average particle size of the gas diffusion material particles in the microporous layer decreases sequentially from the side closest to the substrate surface to the side furthest from the substrate surface. The surface pore size of the gas diffusion layer ranges from 50–100 nm. This gas diffusion layer not only ensures sufficient gas mass transfer but also maintains uniform pressure as the gas passes through it, effectively preventing the formation of carbonates and bicarbonates and mitigating flooding issues, thereby ensuring stable electrode operation and improving electrode current efficiency.

Proposed is a fuel cell separator. More particularly, proposed is a fuel cell separator having a point contact channel structure, in which the channel structure of the separator is formed inclinedly to ensure smooth transfer and discharge of condensed water, and an overlapping portion of opposite anode separator and cathode separator forms a point contact to have a minimum area so that water accumulation caused by a pressed gas diffusion layer and electrode performance degradation can be minimized.

The present application relates to a kind of gradient microporous layer gas diffusion layer for carbon dioxide reduction and its preparation method.The gas diffusion layer includes substrate layer and gradient microporous layer;The gradient microporous layer includes multiple microporous sublayers with different hydrophilic-hydrophobic along its thickness direction;Along the direction of away from substrate layer, the hydrophobicity of each microporous sublayer shows gradient decreasing trend.The gradient microporous layer gas diffusion layer presented in the present application is suitable for carbon dioxide reduction technical field, and the microporous layer with the gradient change of hydrophobicity is constructed using microporous sublayer with different hydrophobic agent content, and the small hole smaller than 0.1 μm is formed using the mutual filling of carbon material between different microporous sublayer, and the gradient microporous layer gas diffusion layer is simple and repeatable in preparation operation, and has very high application value.

The application discloses a kind of gas diffusion layer and preparation method, electrode and battery, it is related to battery technical field, to solve the problem that existing microporous layer is easy to drop powder after high-temperature sintering.The gas diffusion layer includes support layer and microporous layer formed on the surface of the support layer, and the microporous layer contains at least hydroxyl-terminated polyester resin and curing agent.The preparation method is used to prepare the gas diffusion layer, and the electrode uses the gas diffusion layer, and the battery uses the gas diffusion layer.The gas diffusion layer and preparation method, electrode and battery provided by the application are used to improve the bonding strength of microporous layer and support layer, reduce the surface defects of microporous layer, and improve the water vapor heat transfer efficiency.

This application provides a proton exchange membrane fuel cell (100), characterized in that it comprises: a catalyst-coated membrane (101), the catalyst-coated membrane (101) including a proton exchange membrane (101a) and a cathode catalyst layer (101b1) and an anode catalyst layer (101b2) respectively coated on opposite surfaces of the proton exchange membrane (101a); a gas diffusion layer positioned on the outer surface of the catalyst-coated membrane (101); an electrode plate positioned on the outer surface of the gas diffusion layer; and a hydrophilic conductive sheet (110), the hydrophilic conductive sheet (110) being capable of being disposed on the surface of the gas diffusion layer.

A gas diffusion layer includes: a porous member containing conductive particles, conductive fibers, and a polymer resin, wherein the polymer resin has polymer resin particles presenting in particulate form, and the polymer resin includes two or more polymer resin particles fused together in part.

The present invention provides a method for manufacturing a gas diffusion layer substrate that has high normal permeability in the thickness direction, a low contact resistance per unit thickness, and a fuel cell that exhibits high power generation performance. [Solution] The present invention provides a method for manufacturing a gas diffusion layer substrate for fuel cells, comprising, in order: a water-containing sheet manufacturing step, which involves using a slurry containing carbon fibers, graphite particles having a particle diameter of 120 μm or more, fibrillated organic fibers that will be carbonized in a later carbonization step, and water to produce a water-containing sheet containing carbon fibers, graphite particles, and fibrillated organic fibers; a composite sheet manufacturing step, which involves squeezing the water from the water-containing sheet and drying it to produce a composite sheet; a resin impregnation step, which involves impregnating the composite sheet with a carbon precursor resin that will be carbonized in a later carbonization step to produce a resin-impregnated sheet; a compression step, which involves compressing the resin-impregnated sheet to produce a thin-walled sheet; and a carbonization step, which involves heating and firing the thin-walled sheet in a non-oxidizing atmosphere.

To easily manufacture a gas diffusion layer having a microporous layer.SOLUTION: A method for manufacturing a gas diffusion layer for a fuel cell includes a stirring step of stirring a solution containing copper methylacetylide as precursors to form the precursors into a wire-like shape and entangle the precursors with each other in the solution, an adding step of adding the precursor to a surface layer of a porous substrate sheet so as to fill pores in the surface layer, and a firing step of baking the substrate sheet and the precursor at 1000°C or more and 1200°C or less to grow a graphene multilayer film from the precursor and thermally remove copper, thereby forming porous carbon that is composed of the graphene multilayer films, has mesoporosity, and has a hollow wire-like crystal structure.SELECTED DRAWING: Figure 11

The application belongs to the technical field of gas diffusion layer preparation, and particularly relates to a preparation method of a water management film for an electrochemical hydrogen compressor and application thereof. The method solves the dual challenges of anode side film dehydration and mechanical durability in an EHC under low humidity conditions. After laser drilling treatment, N element-containing groups modified on the surface of the hole wall can form hydrogen bonds with water molecules and promote water adsorption, thereby realizing stable film hydration and reducing the in-plane resistance. The method is simple and convenient to operate, has strong practicability, and the prepared water management film for the electrochemical hydrogen compressor can effectively improve the performance and mechanical strength of the EHC under extreme humidity conditions after being assembled into the EHC.

Provided are: a gas diffusion layer comprising a carbon fiber layer and a microporous layer that contains an aromatic polyamide pulp, a water-dispersed resin, and a carbon-based electroconductive substance and is provided upon the carbon fiber layer; a gas diffusion electrode; a membrane electrode assembly; a fuel cell; a production method for the gas diffusion layer; a production method for the gas diffusion electrode; and a production method for the membrane electrode assembly.

The application discloses an in-situ polymerization-based proton exchange membrane integrated bidirectional gradient porous gas diffusion layer and a manufacturing method thereof, and belongs to the technical field of fuel cells. In the prior art, the interlayer contact loss of the proton exchange membrane is high, the pore distribution is single, and the process is complicated. In the method, photodegradable polymer microspheres PLA-PEG, NaCl crystals, aniline monomers and graphene are dissolved in an N-methyl pyrrolidone solution, and after being mixed sufficiently, a gas diffusion layer coating is obtained; the gas diffusion layer coating is scraped on the surface of a proton exchange membrane substrate; the gas diffusion layer coating on the surface of the proton exchange membrane substrate is irradiated with ultraviolet light; and template removal and activation work are performed on the surface of the proton exchange membrane semi-finished product. The method has the advantages that the porous layer has the functions of a gas diffusion layer and a micro-reaction interface, realizes the triple optimization of gas transmission, electron conduction and water management, and is suitable for high-power-density fuel cell systems.

To provide a new gas diffusion layer with high liquid water discharge performance and a manufacturing method thereof.SOLUTION: A gas diffusion layer includes a base material, and a carbon nanotube film formed on the surface of the base material. The base material is made of a conductive porous material. The carbon nanotube film includes in-plane oriented carbon nanotubes. The thickness of the base material is preferably 90 μm or more and 250 μm or less. The thickness of the carbon nanotube film is preferably 0.1 μm or more and 30 μm or less. Furthermore, the contact angle of water on the surface of the carbon nanotube film is preferably 40° or more and 140° or less.SELECTED DRAWING: Figure 3

The utility model relates to fuel cell technical field, concretely provides a kind of fuel cell bipolar plate.The fuel cell bipolar plate includes: anode surface and cathode surface, wherein: the cathode surface is equipped with multiple open air straight flow channel;And, in each open air straight flow channel, the bottom surface of at least one open air straight flow channel is high-low undulating bottom along air flow direction;The anode surface is equipped with hydrogen gas access and multiple hydrogen gas bending flow channel communicated with the hydrogen gas access.In this way, since the cathode surface of the fuel cell bipolar plate in each open air straight flow channel, the bottom surface of at least one open air straight flow channel is high-low undulating bottom along air flow direction, air can produce a speed component in the process of flowing in the open air straight flow channel towards membrane electrode direction, and then air can better penetrate into the gas diffusion layer of membrane electrode, thereby solve the problem in the prior art.