CN218482275U

CN218482275U - Integrated structure for fuel cell and proton exchange membrane fuel cell

Info

Publication number: CN218482275U
Application number: CN202222393842.0U
Authority: CN
Inventors: 张颖慧; 张浩然; 冯春平; 薛文闯; 文龙; 罗森源
Original assignee: Shenzhen Shenke Pengwo Technology Co ltd
Current assignee: Shenzhen Shenke Pengwo Technology Co ltd
Priority date: 2022-09-08
Filing date: 2022-09-08
Publication date: 2023-02-14
Anticipated expiration: 2032-09-08

Abstract

The utility model discloses an integral structure and proton exchange membrane fuel cell for fuel cell, wherein, integral structure includes foam metal layer and metal fiber layer for fuel cell, the metal fiber layer is laid foam metal layer one side on the surface. The utility model discloses technical scheme replaces traditional flow field board, adopts the metal fiber layer to replace traditional graphite gas diffusion layer through adopting the foam metal layer to with foam metal layer and metal fiber layer integrated design, improved gas distribution homogeneity in the fuel cell working process, thereby the battery performance that improves.

Description

Integrated structure for fuel cell and proton exchange membrane fuel cell

Technical Field

The utility model relates to a fuel cell technical field especially relates to an integrated structure and proton exchange membrane fuel cell for fuel cell.

Background

The proton exchange membrane fuel cell is a power generation device which directly converts chemical energy in fuel into electric energy, and has the advantages of high power density, high energy conversion efficiency, low working temperature, quick start, zero greenhouse gas emission and the like. However, large-scale commercialization of pem fuel cells is still limited by cost, performance, and reliability and durability.

The proton exchange membrane fuel cell stack mainly comprises a membrane electrode, a flow field plate, a current collecting plate, an end plate, an insulating plate and the like. Wherein, the membrane electrode is composed of a gas diffusion layer, a proton exchange membrane and a catalyst layer. The flow field plates function to provide flow channels for reactant gases and product water, prevent permeation of reactant materials between the two electrodes, collect current, transfer heat, mechanically support and reinforce the cell, etc., and have a mass of about 40-80% of the fuel cell stack and a cost of about 30-37% of the total cost of the stack. The Gas Diffusion Layer (GDL) in the membrane electrode is used as a transition layer between a bipolar plate flow field and a catalyst layer and mainly used for transmitting substances and electrons, the flow field and the GDL jointly determine the transmission of gas, liquid water and electrons, the gas diffusion layer plays a vital role in the mass transfer of reactants and products, the structure of the gas diffusion layer determines the uniformity of the gas distribution of the reactants to a great extent, and whether the water energy of the products is discharged in time or not, so that the performance and the stability of a fuel cell are influenced, and the development of the flow field and the GDL layer in the proton exchange membrane fuel cell is always the key point of research and development attention of the fuel cell technology.

The current commonly used bipolar plate flow field is that a channel is processed on graphite and graphite composite materials by methods of carving or stamping and forming on a metal polar plate. The groove-ridge structure is high in processing cost, the ridge structure is completely attached to the gas diffusion layer, gas cannot easily reach the catalyst layer below the ridge, liquid water is easily accumulated in the GDL below the ridge, water logging occurs, and the effective active area of the catalyst layer is reduced. GDL adopts the carbon paper material that carbon fiber processing made more, and the production technology of this material is complicated, and the price is higher, is brittle material moreover, takes place the fibre fracture easily in assembling process, makes its structure suffer destruction, influences gas transmission and drainage efficiency. Although the carbon paper GDL has certain porosity and good conductivity, the thickness of the carbon paper GDL is between 150 and 200 mu m, which still causes the limited mass transfer and increases the ohmic resistance (the resistance of the material per se and the contact resistance between the material and the adjacent catalyst layer and flow field plate).

The above is only for the purpose of assisting understanding of the technical solution of the invention, and does not represent an admission that the above is the prior art.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide an integrated structure for fuel cell aims at improving the gas distribution homogeneity in the fuel cell use to improve fuel cell's performance.

In order to achieve the above object, the present invention provides an integrated structure for fuel cell, including:

a foam metal layer;

and the metal fiber layer is laid on the surface of one side of the foam metal layer.

In one embodiment, the metal fiber layer covers the entire surface of one side of the metal foam layer.

In one embodiment, the metal fibers in the metal fiber layer are spread on the foam metal surface according to a felting method with gradually reduced fiber length and fiber radius gradient.

In one embodiment, the metal fiber layer has a plurality of through holes, and the size of the through holes gradually decreases from one end close to the foam metal layer along the thickness direction of the foam metal layer.

In an embodiment, the material of the foamed metal layer may be selected from any one of foamed aluminum, foamed nickel, foamed copper, foamed titanium, foamed alloy, and foamed stainless steel.

In one embodiment, the metal fiber layer may be made of any one of aluminum fiber, copper fiber, nickel fiber, titanium fiber, alloy fiber, and stainless steel fiber.

In one embodiment, the foam metal layer has a porosity of 80-98%, a pore size of 80-200 μm, and a thickness of 0.2-2mm.

In one embodiment, the metal fibers in the metal fiber layer have a diameter of 1 to 20 μm and a length of 0.5 to 10mm.

In one embodiment, the metal fiber layer has a porosity of 70-90%, a pore size of 5-30 μm, and a thickness of 0.05-0.2mm.

The utility model also provides a proton exchange membrane fuel cell, including above-mentioned integrated structure for fuel cell, still include the catalyst layer, the catalyst layer is located the metal fiber layer dorsad one side of foam metal layer, the catalyst layer with the surface laminating on metal fiber layer is in the same place.

The utility model discloses technical scheme replaces traditional flow field board, adopts the metal fiber layer to replace traditional graphite gas diffusion layer through adopting the foam metal layer to with foam metal layer and metal fiber layer integrated design, improved gas distribution homogeneity in the fuel cell working process, thereby the battery performance that improves. In the technical scheme of the utility model, because the foam metal in the foam metal layer has three-dimensional pore structure, it has the characteristics that the porosity is big, with low costs, adopts foam metal to replace traditional "groove-ridge" formula flow field plate structure, has favorable to promoting the discharge of water that generates in the fuel cell, has avoided the flooding phenomenon, can also improve the homogeneity of gas distribution, is favorable to increasing the utilization area of catalyst layer, makes the electrochemical reaction more even; moreover, because the metal fiber has the characteristics of high strength and good toughness, the metal fiber layer is adopted to replace the traditional carbon paper gas diffusion layer, the structural damage caused by overhigh assembly pressure in the assembly process can be avoided, and the cost can be reduced; on the other hand, after the foam metal layer and the metal fiber layer are integrally sintered, the contact resistance between the gas diffusion layer and the flow field plate in the traditional structure can be eliminated; on the other hand, because the densities of the foam metal and the metal fiber are lower, the total mass of the fuel cell can be reduced, and the mass power density of the fuel cell is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

Fig. 1 is a schematic structural view of an integrated structure for a fuel cell according to an embodiment of the present invention.

The reference numbers illustrate:

reference numerals	Name (R)	Reference numerals	Name (R)
				10	Foamed metal layer	20	Metal fiber layer

The objects, features and advantages of the present invention will be further described with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that, if directional indications (such as up, down, left, right, front, back, 8230; \8230;) are provided in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship between the components, the motion situation, etc. in a specific posture (as shown in the attached drawings), and if the specific posture is changed, the directional indications are correspondingly changed.

In addition, if there is a description relating to "first", "second", etc. in the embodiments of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, if appearing throughout the text, "and/or" is meant to include three juxtaposed aspects, taking "a and/or B" as an example, including either the a aspect, or the B aspect, or both the a and B aspects. In addition, the technical solutions in the embodiments may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should not be considered to exist, and is not within the protection scope of the present invention.

The utility model provides an integrated structure for fuel cell.

Referring to fig. 1, in the embodiment of the present invention, the integrated structure for a fuel cell includes a metal foam layer 10 and a metal fiber layer 20, the metal foam layer 10 is used as a base layer, the metal fiber layer 20 is disposed on a surface of one side of the metal foam layer 10, in one embodiment, the metal fiber layer 20 is disposed on a surface of one side of the metal foam layer 10 by a sintered mat, but a person skilled in the art may also dispose the metal fiber layer 20 on a surface of one side of the metal foam layer 10 by other methods, which are not limited herein. In the integrated structure for the fuel cell, the foamed metal layer 10 can replace a traditional flow field plate, and the metal fiber layer 20 can replace a traditional graphite gas diffusion layer, that is, in the assembly process of the fuel cell, one side of the metal fiber layer 20, which is opposite to the foamed metal layer 10, is attached to a catalyst layer, and in the operation process of the fuel cell, gas passes through the foamed metal layer 10, the metal fiber layer 20 and the catalyst layer in sequence.

The foam metal is a special metal material containing foam pores, and has small density, high porosity (the pore diameter can reach millimeter level) and certain strength and rigidity. The foam metal has high air permeability, almost all are interconnected pores, the specific surface area of pores is large, and the volume weight of the material is small.

The metal fiber is a fiber-shaped material which has high metal content, continuously distributes metal materials and has a transverse dimension in a micron order. The metal fiber has good mechanical properties, high fracture specific strength and tensile specific modulus, good bending resistance and toughness, good chemical corrosion resistance, difficult oxidation in air and the like.

The utility model discloses technical scheme replaces traditional flow field board, adopts metal fiber layer 20 to replace traditional graphite gas diffusion layer through adopting foam metal layer 10 to with foam metal layer 10 and the design of metal fiber layer 20 integration, improved gas distribution homogeneity in the fuel cell working process, thereby the battery performance that improves. In the technical scheme of the utility model, because the foam metal in the foam metal layer 10 has a three-dimensional pore structure, it has the characteristics of porosity factor is big, with low costs, adopt the foam metal layer 10 to replace traditional "groove-ridge" formula flow field plate structure, be favorable to promoting the discharge of water that generates in the fuel cell, avoided the flooding phenomenon, can also improve the homogeneity of gas distribution, be favorable to increasing the utilization area of catalyst layer, make the electrochemical reaction more even; moreover, because the metal fiber has the characteristics of high strength and good toughness, the metal fiber layer 20 is adopted to replace the traditional carbon paper gas diffusion layer, the structural damage caused by overhigh assembly pressure in the assembly process can be avoided, and the cost can be reduced; on the other hand, the foam metal layer 10 and the metal fiber layer 20 are designed integrally, so that the contact resistance between the gas diffusion layer and the flow field plate in the traditional structure can be eliminated; on the other hand, because the densities of the foam metal and the metal fibers are lower, the total mass of the fuel cell can be reduced, and the mass power density of the fuel cell is improved.

The metal fiber layer 20 may partially cover or entirely cover the surface of the metal foam layer 10, and in order to further improve the uniformity of gas diffusion and facilitate the discharge of water generated in the fuel cell, it is preferable that the metal fiber layer 20 entirely cover the surface of the metal foam layer 10.

Further, the metal fibers in the metal fiber layer 20 are flatly laid on the surface of the metal foam layer 10 according to a felting method with an excessive gradient of gradually decreasing fiber length and fiber radius, so that the pore size of the through holes of the metal fiber layer 20 is gradually decreased from the end close to the metal foam layer 10 along the thickness direction thereof, or the porosity of the end of the metal fiber layer 20 close to the metal foam layer 10 is larger than the porosity of the end of the metal fiber layer 20 opposite to the metal foam layer 10, that is, the pore size of the side of the metal fiber layer 20 close to the catalyst layer is smaller than the pore size of the side of the metal fiber layer 20 close to the metal foam layer 10. In the working process of the fuel cell, gas diffuses from one side of the metal fiber layer 20 close to the foam metal layer 10 to the catalyst layer, and because the aperture of one end of the metal fiber layer 20 close to the foam metal layer 10 is relatively large, the resistance in the gas diffusion process is reduced, so that the gas diffusion efficiency is improved; and, since the pore diameter of the metal fiber layer 20 on the side close to the catalyst layer is small, the contact resistance between the metal fiber layer 20 and the catalyst layer is reduced.

Considering various factors such as gas diffusion efficiency, support stability and resistance, furthermore, the porosity of the foam metal layer 10 is 80% -98%, that is, the overall porosity of the foam metal layer 10 is 80%, 90%, 98% or any value therebetween; the pore size of the foam metal layer 10 is 80-200 μm, that is, the pore size can be 80 μm, 100 μm, 150 μm, 200 μm or any value therebetween; the thickness of the foamed metal layer 10 is 0.2-2mm, i.e. the thickness of the foamed metal layer 10 may be 0.2mm, 0.5mm, 1mm, 1.5mm, 2mm or any value in between. Too large porosity or too large pore diameter of the metal foam layer 10 can weaken the support stability of the metal foam layer, and too small porosity or too small pore diameter of the metal foam layer 10 can increase gas mass transfer resistance and improve gas pressure drop; an excessive thickness of the metal foam layer 10 increases the electrical resistance of the metal foam layer 10.

Similarly, in consideration of various factors such as gas diffusion efficiency, support stability, and electrical resistance, the diameter of the metal fibers in the metal fiber layer 20 is 1-20 μm, that is, the diameter of the metal fibers in the metal fiber layer 20 may be 1 μm, 10 μm, 20 μm, or any value therebetween; the length of the metal fibers in the metal fiber layer 20 is 0.5-10mm, i.e. the length of the metal fibers can be 0.5mm, 5mm, 10mm or any value therebetween. The porosity of the metal fiber layer 20 is 70-90%, i.e. the porosity may be 70%, 80%, 90% or any value in between; the pore size of the metal fiber layer 20 is 5-30um, that is, the pore size may be 5um, 10um, 20um, 30um or any value therebetween, in an embodiment, the pore size of the metal fiber layer 20 on the side close to the catalyst layer is closer to 5 μm, and the pore size of the metal fiber layer 20 on the side close to the foam metal layer 10 is closer to 30 μm; the thickness of the metal fiber layer 20 is 0.05-0.2mm, i.e. the thickness may be 0.05mm, 0.1mm, 0.15mm, 0.2mm or any value in between.

In an embodiment of the integrated structure for a gas fuel cell of the present invention, the material of the foamed metal layer 10 may be selected from one or more of foamed aluminum, foamed nickel, foamed copper, foamed titanium, foamed alloy, and foamed stainless steel.

Different kinds of foamed metal have different characteristics, for example, foamed aluminum and its alloy are light, and have the characteristics of sound absorption, heat insulation, vibration reduction, impact energy absorption and electromagnetic wave absorption; the foam nickel has communicated pore structure and high porosity, so that the foam nickel has high air permeability, high specific surface area and capillary force; the copper foam has good conductivity and ductility, lower preparation cost than nickel foam, better conductivity, but lower corrosion resistance than nickel foam. The skilled person can select a suitable foamed metal material according to the specific requirements of the product, and perform a suitable corrosion-resistant treatment on the selected foamed metal material, which is not limited herein.

The metal fiber layer 20 can be made of any one or a combination of a plurality of materials selected from aluminum fibers, copper fibers, nickel fibers, titanium fibers, alloy fibers and stainless steel fibers; of course, the metal fiber layer 20 may also be made of other metal fiber materials known to those skilled in the art, and is not limited herein. In one embodiment, the material of the metal fiber layer 20 is selected from stainless steel metal fibers, the stainless steel fiber drawing wires are long wire bundles, each bundle contains thousands to tens of thousands of stainless steel fibers, and the stainless steel fibers have good flexibility, good mechanical properties and corrosion resistance, and are completely resistant to the corrosion of nitric acid, phosphoric acid, alkali and organic chemical solvents; before the stainless steel metal fibers are laid on the surface of the foamed metal layer 10, the stainless steel metal fibers may be subjected to a suitable corrosion-resistant treatment, which may be selected from a corrosion-resistant treatment method for metals commonly used by those skilled in the art, and is not particularly limited.

The utility model discloses still provide a proton exchange membrane fuel cell, this proton exchange membrane fuel cell include that fuel cell uses the integral structure, and this fuel cell refers to above-mentioned embodiment with the concrete structure of integral structure, because this proton exchange membrane fuel cell has adopted the whole technical scheme of above-mentioned all embodiments, consequently has all beneficial effects that the technical scheme of above-mentioned embodiment brought at least, and the repeated description is no longer given here. The proton exchange membrane fuel cell also comprises a catalyst layer, wherein the catalyst layer is arranged on one side of the metal fiber layer 20, which is back to the foam metal layer 10, and the catalyst layer is attached to the surface of the metal fiber layer 20.

The foregoing examples are merely illustrative and serve to explain some of the features of the method of the present invention. The appended claims are intended to claim as broad a scope as can be conceived and the examples presented herein are merely illustrative of selected implementations in accordance with all possible combinations of examples. Accordingly, it is applicants' intention that the appended claims are not to be limited by the choice of examples illustrating features of the invention. Where the claims recite a range of values, such ranges are intended to include all sub-ranges subsumed therein, and variations within the ranges are intended to be encompassed by the claims as appended hereto where possible.

Claims

1. An integrated structure for a fuel cell, comprising:

a foam metal layer;

2. The integrated structure for a fuel cell according to claim 1, wherein the metal fiber layer covers the entire surface of one side of the metal foam layer.

3. The integrated structure for a fuel cell according to claim 2, wherein the metal fibers in the metal fiber layer are laid on the surface of the metal foam by a felting method with an excessive gradient in which the fiber length and the fiber radius are gradually decreased.

4. The integrated structure for a fuel cell according to claim 3, wherein the metal fiber layer has a plurality of through holes, and the size of the through holes is gradually reduced from an end near the metal foam layer in the thickness direction thereof.

5. The integrated structure for a fuel cell according to claim 1, wherein the material of the foamed metal layer is selected from any one of foamed aluminum, foamed nickel, foamed copper, foamed titanium, foamed alloy, and foamed stainless steel.

6. The integrated structure for a fuel cell according to claim 1, wherein the metal fiber layer is made of any one of aluminum fibers, copper fibers, nickel fibers, titanium fibers, alloy fibers, and stainless steel fibers.

7. The integrated structure for a fuel cell according to any one of claims 1 to 6, wherein the foamed metal layer has a porosity of 80% to 98%, a pore size of 80 to 200 μm, and a thickness of 0.2 to 2mm.

8. The integrated structure for a fuel cell according to any one of claims 1 to 6, wherein the metal fibers in the metal fiber layer have a diameter of 1 to 20 μm and a length of 0.5 to 10mm.

9. The integrated structure for a fuel cell according to claim 7, wherein the metal fiber layer has a porosity of 70 to 90%, a pore diameter of 5 to 30 μm, and a thickness of 0.05 to 0.2mm.

10. A proton exchange membrane fuel cell comprising the integrated structure for a fuel cell according to any one of claims 1 to 9, further comprising a catalyst layer, wherein the catalyst layer is disposed on a side of the metal fiber layer opposite to the foam metal layer, and the catalyst layer is attached to a surface of the metal fiber layer.