Corrugated structure for fuel cell flow fields

Abstract

A corrugated structure for a fuel cell, comprising a plurality of peaks and valleys. A method of making a structure for a fuel cell, comprising providing a mesh or screen sheet having one or more edges, forming the mesh or screen sheet into a corrugated structure, and treating one or more of the edges. A flow field for a fuel cell, comprising at least one metal mesh or screen, the at least one metal mesh or screen comprising a plurality of peaks and valleys. A fuel cell, comprising a first corrugated mesh or screen located in an anode of the fuel cell, a second corrugated mesh or screen located in a cathode of the fuel cell, and a membrane located between the first and second corrugated mesh or screen.

Description

[Technical Field]

[0001] [1] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 025,615, filed on 15 May 2020, which is incorporated in its entirety by reference. [2] The disclosure of the present invention is directed to the field of polymer electrolyte membrane fuel cells. [Background technology]

[0002] [3] A typical polymer electrolyte membrane (PEM) fuel cell (also known as a proton exchange membrane fuel cell) has several components. Such a fuel cell has a polymer membrane that functions as an electrolyte, which, when sufficiently hydrated, provides the function of proton conduction and, in addition, provides the separation of highly reactive gases, namely hydrogen and oxygen. A catalyst is used to facilitate the electrochemical reaction that enables the battery to produce electricity, specifically, the dissociation of hydrogen at the anode into its constituent electrons and protons and the formation of a species containing activated oxygen at the cathode.

[0003] [4] The anode electrode catalyst and the cathode electrode catalyst are typically applied to respective sides of a cell in one of the following two methods: (1) applied in the form of a gas diffusion electrode (GDE), in which case the catalyst and a support thereof are impregnated onto a gas diffusion medium (typically a matte of pyrolyzed carbon or graphite fibers) disposed between a reactant flow field and the membrane; or (2) applied in the form of a catalytically coated membrane (CCM), in which case the catalyst and a support thereof are immobilized on ionomer-extended portions of the polymer membrane surface on respective sides. Regardless of which form is used, during cell assembly, an electrical connection is established between the gas diffusion medium and the polymer membrane, with the catalyst disposed therebetween. The side of the membrane in contact with the anode catalyst is the anode side, and the side of the membrane in contact with the cathode catalyst is the cathode side.

[0004] [5] A fuel cell also has two separator plates (also known as "bipolar plates"), which function to conduct electricity while separating adjacent fluid compartments. The anode compartment is the space between the anode side of the membrane and a separator plate. The cathode compartment is the space between the cathode side of the membrane and a separator plate.

[0005] [6] A fuel gas, for example a hydrogen-containing gas, is supplied to an anode compartment. A gas containing an oxidant, for example air, is supplied to a cathode compartment. In order to operate a fuel cell, hydrogen must be able to reach the anode side of the membrane, while oxygen must reach the cathode side. Conductive spacers can be used to create passages respectively to the anode compartment or the cathode compartment. These spacers also function, when present, as flow fields through which reactant gases and product water convect. The terms "flow field", "flow field spacer" and "spacer", as used herein, all refer to a component having a plurality of functions, and these are used interchangeably in the present disclosure. Summary of the Invention

[0006] [7] In one embodiment, the present disclosure is directed to a method of making a structure for a fuel cell, the method comprising: providing a mesh or screen sheet having one or more edges; forming the mesh or screen sheet into an undulating structure; and treating one or more of the edges.

[0007] [8] In one embodiment, the structure may include one or more of a current collector mesh or screen, a membrane support mesh or screen, a flow field structure, and a gas diffusion electrode. The method may include providing a mesh or screen sheet having one or more edges. The mesh or screen sheet may be formed from austenitic stainless steel, chromium, niobium, zirconium, nickel, silver, titanium, or alloys thereof. Examples of mesh or screen sheets include woven wire, wire cloth, or expanded metal. The method may include forming the mesh or screen sheet into a corrugated structure. Examples of corrugated structures include a corrugated feature, a serpentine feature, or a pleated feature. The corrugated structure may be formed using a calendering roller, one or more rollers, a textile pleating machine, or cross-corrugation. The method may include processing one or more edges. One or more edges can be treated by hemming, compressing, folding, encapsulating, bending, or brushing one or more freely exposed wires, or by cutting one or more edges using a laser, plasma, or other thermal cutting method. The method may also include pressing or flattening the corrugated structure.

[0008] [9] In another embodiment, the disclosure of the present invention relates to a flow field for a fuel cell, comprising at least one metal mesh or screen, the at least one metal mesh or screen comprising a plurality of peaks and valleys, directed toward the flow field. In a particular form, the plurality of meshes or screens may be metal and may include cross-sectional views having sinusoidal profiles, sawtooth profiles, trapezoidal profiles, or toroidal bead-like profiles.

[0009]

[10] In another embodiment, the disclosure of the present invention is directed toward a fuel cell comprising a first corrugated mesh or screen located within the anode of the fuel cell, a second corrugated mesh or screen located within the cathode of the fuel cell, and a membrane located between the first corrugated mesh or screen and the second corrugated mesh or screen. The fuel cell may also include a 3.0 mm mesh or screen located within the anode of the fuel cell.

[0010]

[11] In a further embodiment, the disclosure of the present invention relates to a fuel cell comprising a cathode, an anode, a membrane inserted between the cathode and the anode, and a first open flow field comprising a first mesh or screen directed toward the fuel cell.

[0011]

[12] In yet another embodiment, the disclosure of the present invention relates to a fuel cell comprising an open flow field having an overall flow direction, wherein the flow permeability in a direction perpendicular to the overall flow direction is higher than the flow permeability in a direction parallel to the overall flow direction.

[0012]

[13] Another embodiment of the disclosure of the present invention is an open flow field for a fuel cell having a flow direction, comprising at least one screen, mesh, foam, or expanded metal and at least one channel, the at least one channel being directed toward the open flow field, extending in a direction intersecting the flow direction.

[0013]

[14] In a further embodiment, the disclosure of the present invention relates to a fuel cell comprising a cathode, an anode, and a membrane inserted between the cathode and the anode, as well as an open flow field comprising a plurality of channels having a wave, zigzag, or sinusoidal shape, wherein the channels are directed toward the fuel cell and repeat across the open flow field.

[0014]

[15] Disclosures of the present invention are also directed to a fuel cell comprising an open flow field at an anode having a plurality of channels having a repeating pattern including a first periodicity, and an open flow field at a cathode having a plurality of channels having a repeating pattern including a second periodicity, wherein the plurality of channels at the open flow field at the anode and the plurality of channels at the open flow field at the cathode are positioned such that the first periodicity and the second periodicity are out of phase by an amount in the range of 90 to 270 degrees. [Brief explanation of the drawing]

[0015] [Figure 1]

[16] Figures 1A, 1B, and 1C illustrate a method for fabricating a corrugated structure for a fuel cell. [Figure 2]

[17] Figures 2 and 2A illustrate various cross-sectional arrangements for corrugated structures of fuel cells. [Figure 3]

[18] Figure 3 illustrates a flow field including the first and second wave-like structures. [Figure 4]

[19] Figure 4 illustrates the overall flow direction through the corrugated structure. [Figure 5]

[20] Figure 5 shows the undulations of a structure arranged in a zigzag pattern. [Figure 6]

[21] Figure 6 illustrates a compression pattern produced by alternating zigzag patterns for the flow field. [Modes for carrying out the invention]

[0016]

[22] Figure 1a illustrates a method for fabricating a structure for a fuel cell according to a first embodiment of the present disclosure. The structure may include any feature, component, or part of a fuel cell. For example, the structure may be used to constitute an entire flow field, or only a portion of a membrane support component, or to constitute all or part of an electrode, current collector mesh or screen, membrane support mesh or screen, spacer, flow field structure, gas diffusion electrode, or any other part of a fuel cell.

[0017]

[23] In some embodiments, the structure may consist of both a structural material and accessible void space, where “structural material” means a solid material and any associated inaccessible space, and “accessible void space” means a void that can support an unrestricted flow of fluid through the porous structure, where the structure is “open” and any two points within the accessible void space of the structure can be connected by a virtual smooth path line that exists throughout the accessible void space of the structure, where the term “smooth” means that the path line has a tangent vector that is uniquely defined at any point along it, and the phrase “supports an unrestricted flow of fluid” means that for all such path lines thereafter, the criterion is non-interference. This means that the criterion is satisfied, which means that for every point on the path line, (a) a circle having the point as its center, (b) a circle in a plane perpendicular to the tangent vector of the path line at the point, and (c) a circle with a radius of 5 micrometers do not intersect any solid material, in which case the term "inside" means inside the convex hull of the structure when it is assembled with the other components in the fuel cell configuration.

[0018]

[24] The structure can be formed from any desirable material depending on its purpose. For example, the structure can be formed from metallic materials such as austenitic stainless steel, chromium, niobium, zirconium, nickel, silver, titanium, or alloys thereof. In another form, the structure may contain nonmetallic components. The nonmetallic components may be conductive and may be, for example, carbon fibers, carbon powder, or carbon coatings. In another form, the structure may be made from polymeric materials suitable for use in fuel cells.

[0019]

[25] As shown in Figure 1a, the structure may begin as a sheet of material 11. The sheet of material 11 may have any dimensions or any shape. The sheet may be supplied as a roll 10. Alternatively, the sheet of material 11 may be supplied flat. Examples of materials include woven wire mesh, screen, perforated metal, metal felt, or expanded metal. The weave or opening spacing may be uniform or varied. The mesh dimensions may range from 30 mesh to 500 mesh, where “mesh” means “number of filaments per linear inch.” For example, in certain embodiments, the mesh dimensions are at least 50 mesh, at least 75 mesh, at least 100 mesh, at least 150 mesh, at least 200 mesh, at least 250 mesh, at least 300 mesh, at least 350 mesh, at least 400 mesh, and at least 450 mesh. Examples of weaves include any style. For example, the weave style may be plain, twill, Dutch, lock-crimp, or any style that allows for the formation of openings or spaces between filaments. The expanded metal can be formed to have gaps or openings of any shape. For example, the gaps or openings may be round, elliptical, square, rectangular, flat, diamond, or any other polygonal or single-sided shape. Alternatively, the openings may include narrow slits or slots. In addition, the material may start in an annealed state, a quarter-hard state, a half-hard state, or any other suitable heat-treated state.

[0020]

[26] The wires constituting the mesh or screen sheet may have diameters ranging from 0.0005 inches to 0.015 inches. For example, in certain embodiments, the diameters may be at least 0.001 inches, at least 0.005 inches, and at least 0.01 inches. The diameters may be consistent or vary across the mesh or screen. For example, wires of a first diameter may constitute a first portion of the weave, while wires of a second diameter may constitute a second portion of the weave. A third wire having a third diameter may constitute a third portion of the weave, and so on. In addition, the wires may have a first diameter in the first portion and a second diameter in the second portion.

[0021]

[27] As illustrated in Figure 1a, the mesh or screen sheet 11 may be supplied on a roll 10. The mesh or screen sheet 11 may include one or more edges and may have any desired shape. However, a square or rectangular shape may be preferred for ease of manufacture. The width of the mesh or screen sheet can be varied depending on the desired use of the structure. For example, when used as or on the cathode side of a fuel cell, the width may be in the range of 10 mm to 1000 mm. In certain embodiments, the width may be at least 10 mm, at least 25 mm, at least 50 mm, at least 75 mm, at least 100 mm, at least 125 mm, at least 150 mm, at least 175 mm, at least 200 mm, at least 250 mm, at least 300 mm, at least 400 mm, or at least 500 mm. In these embodiments, the width may be less than 1000 mm, less than 900 mm, less than 800 mm, less than 750 mm, less than 700 mm, less than 600 mm, less than 500 mm, less than 400 mm, less than 300 mm, less than 250 mm, less than 200 mm, or less than 175 mm. In addition to these embodiments, the range of width is intended to encompass any combination of the lower and upper limits of the ranges disclosed in the two preceding sentences.Therefore, non-limiting exemplary ranges of width include 10mm~800mm, 10mm~600mm, 10mm~400mm, 10mm~250mm, 10mm~200mm, 10mm~175mm, 25mm~1000mm, 25mm~800mm, 25mm~600mm, 25mm~400mm, 25mm~250mm, 25mm~200mm, 25mm~175mm, 50mm~1000mm, 50mm~800mm, 50mm~600mm, 50mm~400mm, 50mm~250mm, 50mm~200mm, 50mm~175mm, 75mm~1000mm, 75mm~800mm, 75mm~600mm, 75mm~400mm, 75mm~250mm, 7 5mm~200mm, 75mm~175mm, 100mm~1000mm, 100mm~800mm, 100mm~600mm, 100mm~400mm, 100mm~250mm, 100mm~200mm, 100mm~1 75mm, 125mm~1000mm, 125mm~800mm, 125mm~600mm, 125mm~400mm, 125mm~250mm, 125mm~200mm, 125mm~175mm, 150mm~1000m m, 150mm~800mm, 150mm~600mm, 150mm~400mm, 150mm~250mm, 150mm~200mm, 150mm~175mm, 175mm~1000mm, 175mm~800mm, 17 Examples include 5mm-600mm, 175mm-400mm, 175mm-250mm, 200mm-1000mm, 200mm-800mm, 200mm-600mm, 200mm-400mm, 200mm-250mm, 250mm-1000mm, 250mm-800mm, 250mm-600mm, 250mm-400mm, 300mm-1000mm, 300mm-800mm, 300mm-600mm, and 300mm-400mm.

[0022]

[28] Alternatively, when used as an anode or on the anode side of a fuel cell, the width may be in the range of 10 mm to 1000 mm. In certain embodiments, the width may be at least 10 mm, at least 25 mm, at least 50 mm, at least 75 mm, at least 100 mm, at least 125 mm, at least 150 mm, at least 175 mm, at least 200 mm, at least 250 mm, at least 300 mm, at least 400 mm, or at least 500 mm. In these embodiments, the width may be 1000 mm or less, 900 mm or less, 800 mm or less, 750 mm or less, 700 mm or less, 600 mm or less, 500 mm or less, 400 mm or less, 300 mm or less, 250 mm or less, 200 mm or less, or 175 mm or less. In addition to these embodiments, the range of width is intended to encompass any combination of the lower and upper limits of the range disclosed in the two preceding sentences.Therefore, non-limiting exemplary ranges of width include 10mm~800mm, 10mm~600mm, 10mm~400mm, 10mm~250mm, 10mm~200mm, 10mm~175mm, 25mm~1000mm, 25mm~800mm, 25mm~600mm, 25mm~400mm, 25mm~250mm, 25mm~200mm, 25mm~175mm, 50mm~1000mm, 50mm~800mm, 50mm~600mm, 50mm~400mm, 50mm~250mm, 50mm~200mm, 50mm~175mm, 75mm~1000mm, 75mm~800mm, 75mm~600mm, 75mm~400mm, 75mm~250mm, 7 5mm~200mm, 75mm~175mm, 100mm~1000mm, 100mm~800mm, 100mm~600mm, 100mm~400mm, 100mm~250mm, 100mm~200mm, 100mm~1 75mm, 125mm~1000mm, 125mm~800mm, 125mm~600mm, 125mm~400mm, 125mm~250mm, 125mm~200mm, 125mm~175mm, 150mm~1000m m, 150mm~800mm, 150mm~600mm, 150mm~400mm, 150mm~250mm, 150mm~200mm, 150mm~175mm, 175mm~1000mm, 175mm~800mm, 17 Examples include 5mm-600mm, 175mm-400mm, 175mm-250mm, 200mm-1000mm, 200mm-800mm, 200mm-600mm, 200mm-400mm, 200mm-250mm, 250mm-1000mm, 250mm-800mm, 250mm-600mm, 250mm-400mm, 300mm-1000mm, 300mm-800mm, 300mm-600mm, and 300mm-400mm.

[0023]

[29] The widths mentioned in the preceding two paragraphs are for illustrative purposes only. It will be understood that rolls according to the disclosure of the present invention can be provided in any width, and a desired width can be achieved by cutting a structure to the desired width.

[0024]

[30] The corrugated structure is formed in the mesh or screen sheet 11 using rollers 12. The rollers 12 may include one or more flutes, ridges, valleys, depressions, or any other raised or lowered portions so as they pass over the mesh or screen 11 a corrugated structure is imparted to it. The rollers 12 may be close to each other or offset from each other. The rollers 12 impart the corrugated structure to the mesh or screen sheet 11 by deforming it. Figure 1b shows an example of a corrugated structure. Figure 1b shows a corrugated structure having multiple peaks and valleys. A mesh or screen sheet 11 is shown having a width w1, a height h1, and a spacing s1 between adjacent valleys. The spacing s1 is shown to be consistent in both peaks and valleys, but may not be consistent as will be discussed below. In one embodiment, the height h1 may be in the range of 0.2 mm to 2.0 mm, and the spacing s1 between adjacent peaks may be in the range of 0.2 mm to 3.0 mm. For example, in a particular embodiment, the height h1 may be at least 0.4 mm, at least 0.6 mm, at least 0.8 mm, at least 1.0 mm, at least 1.2 mm, at least 1.4 mm, at least 1.6 mm, or at least 1.8 mm. Similarly, in a particular embodiment, the spacing s1 between adjacent peaks may be at least 0.4 mm, at least 0.6 mm, at least 0.8 mm, at least 1.0 mm, at least 1.2 mm, at least 1.4 mm, at least 1.6 mm, at least 1.8 mm, at least 2.0 mm, at least 2.2 mm, at least 2.4 mm, at least 2.6 mm, or at least 2.8 mm. The ratio of the height h1 to the spacing s1 may be in the range of 5:1 to 1:15, for example, 3:1, 2:1, 1:1, 1:2, 1:3, 1:5, and 1:10.

[0025]

[31] Although only two rollers 12 are illustrated in Figure 1a, it will be understood that more or fewer rollers may be used. For example, corrugated structures can be formed using a single roller or using three or more rollers. In addition, although Figure 1a shows rollers 12 arranged perpendicular to the roll 10, some embodiments may include rollers 12 arranged parallel to the roll 10 to form corrugated structures parallel to the length of the mesh or screen sheet 11.

[0026]

[32] The mesh or screen sheet 11 may pass through the calender roller 13 in the same line as the roller 12 after passing through the roller 12. The calender roller 13 may include one or more rollers having substantially smooth or flat surfaces. The calender roller 13 may include hard metal rollers on one side and soft felt or paper rollers on the other side. One or more rollers may be adjacent to each other or offset. The calender roller 13 is arranged to press or partially flatten the corrugated features to achieve the desired final height, elastic compliance, yield strength, and / or flow resistance. As can be seen from Figure 1c, the height h2 of the mesh or screen sheet 11 is lower than the height h1 shown in Figure 1b. The height h1 may be about 30% higher than the desired final height. For example, the roller 12 can form a corrugated structure with a height h1 of about 0.67 mm. During calendering, the height h2 may be about 0.52 mm. The width w2 may be substantially similar to the width w1, slightly larger than the width w1, or slightly smaller than the width w1. In one embodiment, the height of the pressed or flattened corrugated structure may be in the range of 0.2 mm to 1.5 mm, for example, 0.2 mm to 1.3 mm, 0.2 mm to 1.1 mm, 0.2 mm to 1.0 mm, 0.2 mm to 0.8 mm, 0.2 mm to 0.6 mm, 0.2 mm to 0.4 mm, 0.4 mm to 1.5 mm, 0.4 mm to 1.3 mm, 0.4 mm to 1.1 mm, 0.4 mm to 1.0 mm, 0.4 mm to 0.8 mm, 0.4 mm to 0. The ranges may also be 0.6mm, 0.6mm~1.5mm, 0.6mm~1.3mm, 0.6mm~1.1mm, 0.6mm~1.0mm, 0.6mm~0.8mm, 0.8mm~1.5mm, 0.8mm~1.3mm, 0.8mm~1.1mm, 0.8mm~1.0mm, 1.0mm~1.5mm, 1.0mm~1.3mm, 1.0mm~1.1mm, 1.1mm~1.5mm, 1.1mm~1.3mm, 1.3mm~1.5mm, etc.Calendering a corrugated structure adjusts the yield strength of the pressed or flattened corrugated structure to 5 kgF / cm. 2 to 200 kgF / cm 2 in the range of, for example, 25 kgF / cm 2 to 200 kgF / cm 2 , 50 kgF / cm 2 to 200 kgF / cm 2 , 75 kgF / cm 2 to 200 kgF / cm 2 , 100 kgF / cm 2 to 200 kgF / cm 2 , 125 kgF / cm 2 to 200 kgF / cm 2 , 150 kgF / cm 2 to 200 kgF / cm 2 , 175 kgF / cm 2 to 200 kgF / cm 2 , 5 kgF / cm 2 to 175 kgF / cm 2 , 25 kgF / cm 2 to 175 kgF / cm 2 , 50 kgF / cm 2 to 175 kgF / cm 2 , 75 kgF / cm 2 to 175 kgF / cm 2 , 100 kgF / cm 2 to 175 kgF / cm 2 , 125 kgF / cm 2 to 175 kgF / cm 2 , 150 kgF / cm 2 to 175 kgF / cm 2 , 5 kgF / cm 2 to 150 kgF / cm 2 , 25 kgF / cm 2 to 150 kgF / cm 2 , 50 kgF / cm 2 to 150 kgF / cm 2 , 75 kgF / cm 2 to 150 kgF / cm 2 , 100 kgF / cm 2 to 150 kgF / cm 2 , 125 kgF / cm 2 to 150 kgF / cm 2, 5 kgF / cm 2 ~125 kgF / cm² 2 , 25 kgF / cm 2 ~125 kgF / cm² 2 , 50 kgF / cm 2 ~125 kgF / cm² 2 , 75 kgF / cm 2 ~125 kgF / cm² 2 , 100 kgF / cm 2 ~125 kgF / cm² 2 , 5 kgF / cm 2 ~100 kgF / cm 2 , 25 kgF / cm 2 ~100 kgF / cm 2 , 50 kgF / cm 2 ~100 kgF / cm 2 , 75 kgF / cm 2 ~100 kgF / cm 2 , 5 kgF / cm 2 ~75 kgF / cm 2 , 25 kgF / cm 2 ~75 kgF / cm 2 , 50 kgF / cm 2 ~75 kgF / cm 2 , 5 kgF / cm 2 ~500 kgF / cm 2 , 25 kgF / cm 2 ~50 kgF / cm 2 , 5 kgF / cm 2 ~25 kgF / cm 2 This could potentially be included in the range.

[0027]

[33] One or more edges of the mesh or screen sheet 11 may be treated before or after passing through the roller 12 or before or after passing through the calender roller 13. Treating the edges will reduce the likelihood of damaged, frayed or otherwise separated filaments appearing on one or more edges. Damaged, frayed or otherwise separated filaments may puncture the electrochemical film or otherwise damage the fuel cell. Treatment may include weaving loose wires or filaments on one or more edges, folding one or more edges, pressing one or more edges, flattening one or more edges, hemming one or more edges, compressing one or more edges, encapsulating one or more edges, or any combination thereof. Processing one or more edges may involve modifying the mesh or screen sheet 11 to include another material, for example, when encapsulating one or more edges. In addition, one or more edges of the mesh or screen sheet 11 may be processed by, for example, laser cutting, laser fusion, thermal cutting, thermal fusion, die cutting, rollerblade cutting, brushing and / or shearing.

[0028]

[34] The process described above can result in the final desired width for the structure, and the structure may be cut to any desired length. Cutting can be performed with any standard cutting equipment that is not expected to damage or alter the corrugated structure.

[0029]

[35] A corrugated structure may include multiple peaks and valleys, or alternating ridges and grooves. A corrugated structure may include pleated features, wave-like features, or serpentine features. Pleated features can be formed by folding or overlapping the mesh or screen sheet in any way. In addition to the processes described above, pleated features can also be formed using a textile pleating machine. Serpentine features can be formed in any of the methods discussed herein and include any irregular or inconsistent patterns of peaks and valleys or alternating ridges and grooves. Figure 2 illustrates cross-sectional views of various corrugated structures. A mesh or screen sheet 15 having multiple sharp peaks and valleys is shown. The peaks and valleys may be uniformly spaced or have irregular spacing. For example, a mesh or screen sheet 25 having a first set 25b of peaks and valleys and a second set 25c of peaks and valleys spaced by gaps 25a is shown. A mesh or screen sheet 16 having multiple peaks and valleys with flat areas is shown. The peaks and valleys may be uniformly spaced or irregularly spaced. For example, a mesh or screen sheet 26 having a first set of peaks and valleys 26b and a second set of peaks and valleys 25c spaced by gaps 26a is shown. A mesh or screen sheet 17 having multiple sinusoidal peaks and valleys is shown. The peaks and valleys may be uniformly spaced or irregularly spaced. For example, a mesh or screen sheet 27 having a first set of peaks and valleys 27b and a second set of peaks and valleys 27c spaced by gaps 27a is shown. A mesh or screen sheet 18 having multiple semicircular peaks is shown. The peaks may be uniformly spaced or irregularly spaced. For example, a mesh or screen sheet 28 having a first set of peaks 28b and a second set of peaks 28c spaced by gaps 28a is shown. Although not shown, the corrugated structure may include only valleys.Furthermore, the corrugated structure may contain more than one cross-sectional shape and may have irregular spacing. For example, the corrugated structure may consist of sharp peaks separated by semicircular valleys.

[0030]

[36] Figure 2A illustrates cross-sectional views of various corrugated structures that have been mechanically processed by pressing, flattening, or calendering. A mesh or screen sheet 50 pressed or flattened perpendicular to the surface of the sheet 50 is shown. A mesh or screen sheet 51 pressed or flattened by a shearing motion is shown. A mesh or screen sheet 52 pressed or flattened at a predetermined angle is shown. The resulting corrugated structure includes three layers of mesh or screen indicated by arrows. A mesh or screen sheet 53 pressed or flattened at a predetermined angle to produce five layers of mesh or screen is shown. The angle at which the corrugated structure can be pressed or flattened may be any angle in the range of 1 to 90 degrees.

[0031]

[37] The method may also include cleaning or passivation of the corrugated structure. Cleaning or passivation may include one or more of ultrasonic treatment, acid cleaning, immersion treatment, and electrochemical treatment. Cleaning and passivation may depend on the material used and the desired use of the corrugated structure. In addition, the corrugated structure may be annealed or otherwise heat-treated.

[0032]

[38] In one embodiment, one or more structures can be used to create a flow field for a fuel cell. The flow field may include one or more metal meshes or screens. Each of the one or more metal meshes or screens may be shaped as discussed above and may include multiple peaks and valleys. Multiple structures may be chemically, mechanically or metallurgically joined to one another or to other structures in the fuel cell, or simply placed adjacent to one another. For example, parts may be joined together by weaving them together by piercing them together or by "hooking" them after the application of compressive force, tying, or encircling. In one embodiment, one or more structures can form an open flow field on both sides of the electrochemical membrane. In another embodiment, one or more structures can be used as an open flow field on one side of the electrochemical membrane. Multiple structures can be used as conductive spacers to create pathways in the anode and cathode compartments, respectively. These spaces may also function as flow fields through which reactant gases and the product water convect. In addition, the electrode catalyst may be deposited on one or more of the multiple structures that form the flow field.

[0033]

[39] Figure 3 illustrates a flow field of a fuel cell including a first corrugated structure 31 and a second corrugated structure 32. The first corrugated structure 31 and the second corrugated structure 32 can be formed according to the process described above. The first corrugated structure may be located within the anode of the fuel cell, while the second corrugated structure 32 may be located within the cathode of the fuel cell. An electrochemical film (not shown) may be located between the first corrugated structure 31 and the second corrugated structure 32. The peaks and valleys of the first corrugated structure 31 are located perpendicular to the peaks and valleys of the second corrugated structure 32. Such an arrangement allows the areas supporting the electromechanical film (not shown) to form a square-dot lattice compression pattern 35, in which case the valleys 34 of the second corrugated structure 32 are in contact with the peaks 33 of the first corrugated structure 31. This arrangement ensures that the electrochemical film (not shown) is adequately supported from both sides and avoids damage to the electrochemical film.

[0034]

[40] Accordingly, according to the fuel cell described in this embodiment, there is a first corrugated mesh or screen located in the anode of the fuel cell, a second corrugated mesh or screen located in the cathode of the fuel cell, and a membrane located between the first corrugated mesh or screen and the second corrugated mesh or screen. The first corrugated mesh or screen may be positioned perpendicular to the second corrugated mesh or screen to create a square dot grid pattern. In some embodiments, the corrugations of the first corrugated mesh or screen constitute a zigzag pattern, and in other embodiments, the corrugations of the second corrugated mesh or screen constitute a zigzag pattern. The zigzag pattern of the first corrugated mesh or screen may be perpendicular to the zigzag pattern of the second corrugated mesh or screen. In other embodiments, the first corrugated mesh or screen and the second corrugated mesh or screen constitute an open flow field on both sides of the membrane. In additional embodiments, the first corrugated mesh or screen or the second corrugated mesh or screen forms one of the current collector mesh or screen, the membrane support mesh or screen, the flow field structure, and the gas diffusion electrode.

[0035]

[41] Another embodiment of the disclosure of the present invention is a fuel cell comprising a cathode, an anode, and a membrane inserted between the cathode and the anode, and a first open flow field comprising a first mesh or screen directed toward the fuel cell. The cathode and / or anode may comprise a plurality of channels. The plurality of corrugations in the open flow field constitute a wavy structure, and the plurality of corrugations may be at a predetermined angle with respect to the plurality of channels. The angle may be at least 45 degrees. In some embodiments, the angle may be 90 degrees or less. For example, the angle may be in the range of 45 to 90 degrees, for example 45 to 75 degrees, 45 to 60 degrees, 60 to 90 degrees, 60 to 75 degrees, and 75 to 90 degrees, etc.

[0036]

[42] In certain embodiments, the fuel cell further includes a second open flow field comprising a second corrugated mesh or screen, wherein the second mesh or screen comprises a plurality of corrugations. In other embodiments, the first or second open flow field comprises a third mesh or screen, wherein the third mesh or screen comprises a plurality of corrugations.

[0037]

[43] In some embodiments, the open flow field may include at least one first mesh or screen having a plurality of corrugations. In some embodiments, the open flow field may include first, second, and third meshes or screens having a plurality of corrugations. In some embodiments, the first mesh or screen and the second mesh or screen may include a zigzag pattern having pattern angles in the range of 1 to 90 degrees, such as 5 to 90 degrees, 10 to 90 degrees, 25 to 90 degrees, 45 to 90 degrees, 60 to 90 degrees, 75 to 90 degrees, 1 to 75 degrees, 5 to 75 degrees, 10 to 75 degrees, 25 to 75 degrees, 45 to 75 degrees, 60 to 75 degrees, 1 to 60 degrees, 5 to 60 degrees, 10 to 60 degrees, 25 to 60 degrees, 45 to 60 degrees, 1 to 45 degrees, 5 to 45 degrees, 10 to 45 degrees, and 25 to 45 degrees. In some embodiments, the pattern angles may be the same for the first mesh or screen and the second mesh or screen. In some embodiments, the pattern angles may be different.

[0038]

[44] In some embodiments, the first mesh or screen includes a first zigzag pattern, and the second mesh or screen includes a second zigzag pattern. The first zigzag pattern and the second zigzag pattern may be the same or different. In some embodiments, the first zigzag pattern is positioned at a predetermined angle to the second zigzag pattern. This angle may be in the range of 1 to 90 degrees, for example, 5 to 90 degrees, 10 to 90 degrees, 25 to 90 degrees, 45 to 90 degrees, 60 to 90 degrees, 75 to 90 degrees, 1 to 75 degrees, 5 to 75 degrees, 10 to 75 degrees, 25 to 75 degrees, 45 to 75 degrees, 60 to 75 degrees, 1 to 60 degrees, 5 to 60 degrees, 10 to 60 degrees, 25 to 60 degrees, 45 to 60 degrees, 1 to 45 degrees, 5 to 45 degrees, 10 to 45 degrees, and 25 to 45 degrees. In some embodiments, the first zigzag pattern is positioned at a predetermined angle to the second zigzag pattern such that the first zigzag pattern is perpendicular to the second zigzag pattern.

[0039]

[45] In one flow configuration, the overall flow direction 40 is perpendicular to the direction of the crests and troughs in the corrugated structure. Non-uniformity in the flow at the inlet and / or outlet of the flow field is rapidly dissipated by the high permeability of the flow field in the direction of corrugation, as shown in Figure 4. In one embodiment, the fuel cell may include an open flow field having an overall flow direction 40, formed by one or more meshes or screens having corrugated structures. Flow permeability in the direction perpendicular to the overall flow direction 40 is higher than flow permeability in the direction parallel to the overall flow direction. Flow permeability correlates with the size of the openings in the mesh or screen containing the corrugated structure, the height of the corrugated structure, the width of the corrugated structure, the spacing between the crests and troughs in the corrugated structure, the thickness of the wires forming the mesh or screen, and any surface treatment applied to the mesh or screen. By adjusting these parameters, the ratio of flow permeability in the direction perpendicular to the overall flow direction to flow permeability in the direction parallel to the overall flow direction can be at least 1.05:1. In some embodiments, the ratio of flow permeability perpendicular to the overall flow direction to flow permeability parallel to the overall flow direction may be in the range of 20:1 to 1.05:1, for example, 15:1, 10:1, 5:1, 3:1, 2:1, 1.5:1, 1.4:1, 1.3:1, 1.25:1, 1.2:1, 1.15:1, and 1.1:1. In some embodiments, flow permeability perpendicular to the overall flow direction may be at least twice as great as flow permeability parallel to the overall flow direction. In some embodiments, the open flow field includes at least one corrugated structure, and in other embodiments, the open flow field includes a corrugated mesh or screen.

[0040]

[46] In Figure 5, a zigzag pattern 50 of peaks and troughs of a corrugated structure in the flow field is illustrated. In such an arrangement, the overall flow direction of both the cathode and anode may be perpendicular to the zigzag direction, and high permeability perpendicular to the overall flow direction is maintained. Although a zigzag pattern is shown, patterns having a wave or sinusoidal shape may also be used. The zigzag pattern 50 may be contained in one or more corrugated structures located in the anode and cathode. Note that multiple corrugated structures may be located in both the anode and cathode. The flow field includes length Fl and width Fw. The zigzag pattern may be offset by a zigzag pattern angle α and may include a zigzag pattern width Zw. The zigzag pattern angle α may be in the range of 1 to 90 degrees, for example, 5 to 90 degrees, 10 to 90 degrees, 25 to 90 degrees, 45 to 90 degrees, 60 to 90 degrees, 75 to 90 degrees, 1 to 75 degrees, 5 to 75 degrees, 10 to 75 degrees, 25 to 75 degrees, 45 to 75 degrees, 60 to 75 degrees, 1 to 60 degrees, 5 to 60 degrees, 10 to 60 degrees, 25 to 60 degrees, 45 to 60 degrees, 1 to 45 degrees, 5 to 45 degrees, 10 to 45 degrees, and 25 to 45 degrees. The peaks and valleys may each contain a predetermined width Cw. If the zigzag pattern is staggered between the anode and cathode, the square dot grid compression pattern is maintained. For example, the square dot grid compression pattern is maintained by shifting the pattern of the second structure along the Fw axis of the first structure by a value of (Zw / 2).

[0041]

[47] In another embodiment, the fuel cell may include an open anode flow field having a plurality of channels having a repeating pattern including a first periodicity, and an open cathode flow field having a plurality of channels having a repeating pattern including a second periodicity, wherein the plurality of channels of the open anode flow field and the plurality of channels of the open cathode flow field are positioned such that the first periodicity and the second periodicity are phase-shifted by an amount in the range of 90 to 270 degrees, for example, 90 to 225 degrees, 90 to 180 degrees, 90 to 135 degrees, 135 to 270 degrees, 135 to 225 degrees, 135 to 180 degrees, 180 to 270 degrees, 180 to 225 degrees, and 225 to 270 degrees. In certain embodiments, the multiple channels of the open flow field at the anode and the multiple channels of the open flow field at the cathode are positioned such that the first periodicity and the second periodicity are 180 degrees out of phase. In some embodiments, the first and second periodicities may be the same. In some embodiments, the first and second periodicities may be different.

[0042]

[48] ​​Figure 6 illustrates a flow field 60 having such an arrangement. As shown, the valleys 61 of the cathode corrugated structure contact the peaks 62 of the anode corrugated structure to form a square dot lattice compression pattern 63. As discussed above, this arrangement ensures that the electrochemical film (not shown) is adequately supported from both sides.

[0043]

[49] In another embodiment, an open flow field for a fuel cell having a flow direction may include at least one screen, mesh, foam, or expanded metal and at least one flow path, the at least one flow path extending in a direction intersecting the flow direction. In some embodiments, the at least one flow path extends across the width of a portion of the flow field. The screen, mesh, foam, or expanded metal may include one or more corrugated structures. The flow path may include a plurality of corrugated structures, and in certain embodiments, these corrugated structures include corrugations or pleats. In one embodiment, at least one flow path is linear. In one embodiment, the flow path may include at least one bend or curve. The bend or curve may be sharp or gentle, and may include a series of curves or bends. In some embodiments, the flow path may be parallel to a plurality of other flow paths, each intersecting the flow direction.

[0044]

[50] In one embodiment, at least one flow path is at an angle in the range of 1 to 180 degrees, for example, 15 to 180 degrees, 30 to 180 degrees, 45 to 180 degrees, 60 to 180 degrees, 75 to 180 degrees, 90 to 180 degrees, 105 to 180 degrees, 120 to 180 degrees, 135 to 180 degrees, 150 to 180 degrees, 165 to 180 degrees, 1 to 135 degrees, 15 to 135 degrees, 30 to 135 degrees, 45 to 135 degrees, 60 to 135 degrees, 75 to 135 degrees, 9 The flow direction may intersect at angles such as 0 to 135 degrees, 105 to 135 degrees, 120 to 135 degrees, 1 to 90 degrees, 15 to 90 degrees, 30 to 90 degrees, 45 to 90 degrees, 60 to 90 degrees, 75 to 90 degrees, 1 to 75 degrees, 15 to 75 degrees, 30 to 75 degrees, 45 to 75 degrees, 60 to 75 degrees, 1 to 60 degrees, 15 to 60 degrees, 30 to 60 degrees, 45 to 60 degrees, 1 to 45 degrees, 15 to 45 degrees, 30 to 45 degrees, 1 to 30 degrees, and 15 to 30 degrees.

[0045]

[51] Further embodiments of the disclosure of the present invention include a cathode, an anode, and a membrane inserted between the cathode and the anode; and an open flow field including a plurality of flow channels having a wave, zigzag, or sinusoidal shape, the flow channels being directed to the fuel cell and repeating across the open flow field. In some embodiments, the channels are arranged to intersect the flow direction of an open flow field, and in further embodiments, the channels intersect the flow direction at angles from 1 to 90 degrees, for example, 15 to 90 degrees, 30 to 90 degrees, 45 to 90 degrees, 60 to 90 degrees, 75 to 90 degrees, 1 to 75 degrees, 15 to 75 degrees, 30 to 75 degrees, 45 to 75 degrees, 60 to 75 degrees, 1 to 60 degrees, 15 to 60 degrees, 30 to 60 degrees, 45 to 60 degrees, 1 to 45 degrees, 15 to 45 degrees, 30 to 45 degrees, 1 to 30 degrees, and 15 to 30 degrees. In some embodiments, the channels are perpendicular to the flow direction of an open flow field. In other embodiments, permeability along the channels is greater than permeability along the flow direction.

[0046]

[52] Exemplary embodiments of the structures have been described herein, but it will be apparent to those skilled in the art that various modifications and variations can be made without departing from the essence of the disclosure of the present invention. [Explanation of Symbols]

[0047] 10 rolls 11. Materials, mesh, or screen sheets 12 rollers 13 Calendar Roller 15-18 mesh or screen sheet 25 mesh or screen sheet 25a Gap 25b The first set of peaks and valleys 25c Mountains and Valleys, second set 26 Mesh or screen sheet 26a Gap 26b The first set of peaks and valleys 27 Mesh or screen sheet 27a Gap 27b The first set of mountains and valleys 27c The second set of mountains and valleys 28 Mesh or screen sheet 28a Gap 28b The first set of the mountain 28c Mountain's second set 50-53 Flattened mesh or screen sheet 31. First wave-like structure 32. Second wave-like structure 33 mountains 34 Valley 35 Square Dot Grid Compression Pattern 40 Flow direction 50 Zigzag Patterns 60 Flow Field 61 Valleys of the wavy structure of the cathode 62. The undulating structure of the anode 63 Square Dot Grid Compression Pattern

Claims

1. A method for manufacturing a structure for a fuel cell, To provide a mesh or screen sheet having one or more edges, Forming the mesh or screen sheet into a corrugated structure using a roller, Processing one or more of the edges, and Next, the corrugated structure is pressed or flattened using a calender roller. Includes, The method relating to one or more of the edges, comprising weaving one or more of the edges, flattening one or more of the edges, hemming one or more of the edges, compressing one or more of the edges, folding one or more of the edges, cutting one or more of the edges, fusing one or more of the edges, brushing one or more of the edges, or sealing one or more of the edges.

2. A method for manufacturing a structure for a fuel cell according to claim 1, wherein the height of the pressed or flattened corrugated structure is 0.2 mm to 1.5 mm.

3. The yield strength of the pressed or flattened corrugated structure is 5 kgF / cm². ２ ~200kgF / cm ２ A method for manufacturing a structure for a fuel cell according to claim 1.

4. A method for manufacturing a structure for a fuel cell according to claim 1, further comprising cleaning or passivating the corrugated structure.

5. A method for producing a structure for a fuel cell according to claim 4, wherein the cleaning or passivation comprises one or more of ultrasonic treatment, acid cleaning, immersion treatment, and electrochemical treatment.

6. A method for manufacturing a structure for a fuel cell according to claim 1, wherein the mesh or screen sheet is woven wire.

7. A method for manufacturing a structure for a fuel cell according to claim 1, wherein the mesh or screen sheet is expanded metal.

8. A method for manufacturing a structure for a fuel cell according to claim 1, wherein the corrugated structure includes pleated features.

9. A method for manufacturing a structure for a fuel cell according to claim 1, wherein the corrugated structure includes a wave-like feature.

10. A method for manufacturing a structure for a fuel cell according to claim 1, wherein the corrugated structure includes snake-like features.

11. A method for manufacturing a structure for a fuel cell according to claim 1, wherein the height of the corrugated structure is in the range of 0.2 mm to 2.0 mm.

12. A method for manufacturing a structure for a fuel cell according to claim 1, wherein the distance between adjacent peaks of the corrugated structure is in the range of 0.2 mm to 3.0 mm.

13. A method for manufacturing a structure for a fuel cell according to claim 1, wherein the screen or mesh sheet is formed from stainless steel, chromium, niobium, zirconium, nickel, silver, titanium, or an alloy thereof.

14. A method for manufacturing a structure for a fuel cell according to claim 13, wherein the stainless steel is austenitic stainless steel.

15. A method for manufacturing a structure for a fuel cell according to claim 1, wherein the screen or mesh sheet includes wires having a diameter of 0.0005 inches (0.00127 cm) to 0.015 inches (0.0381 cm).

16. A method for manufacturing a structure for a fuel cell according to claim 1, wherein the screen or mesh sheet has a mesh size of 30 to 500 mesh (11.8 to 196.9 filaments per cm).

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