Fuel cell and fuel cell manufacturing method

Abstract

The invention discloses a fuel cell and a manufacturing method of the fuel cell. The fuel cell includes two fixing parts, two external electrode plates and multiple internal electrode plates, multiple titanium mesh structures, multiple membrane electrode assembly, multiple catalyst layers and multiple sealing rings. A titanium mesh structure is fixed on one side of each external electrode plate through diffusion bonding technology. Two titanium mesh structures are fixed on both sides of each internal electrode plate through diffusion bonding technology. A catalyst layer is provided on one side of each titanium mesh structure. Each membrane electrode assembly is located between two titanium mesh structures, and each titanium mesh structure serves as a gas diffusion layer.

Description

[Technical Field]

[0001] This invention relates to a fuel cell and a method for manufacturing a fuel cell, particularly a fuel cell without carbon cloth and a method for manufacturing the same. [Previous Technology]

[0002] Existing common fuel cells use carbon cloth as a gas diffusion layer, and the carbon cloth, electrode plates and membrane electrode assembly are only in contact with each other. Therefore, after long-term use, the carbon cloth is prone to corrosion, which will lead to an increase in the contact resistance between the carbon cloth and the electrode plates, thereby reducing the power generation capacity of the fuel cell. [Summary of the Invention]

[0003] This invention discloses a fuel cell and a method for manufacturing a fuel cell, mainly to improve the problem that existing fuel cells with carbon cloth are prone to corrosion after long-term use, which leads to a decrease in the power generation capacity of the fuel cell.

[0004] One embodiment of the present invention discloses a fuel cell, which includes: multiple electrode plates, multiple titanium mesh structures, multiple catalyst layers, multiple membrane electrode assemblies, multiple sealing rings, and two fixing members. Each electrode plate has multiple flow channels on at least one side; the two electrode plates located at both ends of the fuel cell are respectively defined as an outer electrode plate, and the remaining electrode plates are respectively defined as an inner electrode plate. Each outer electrode plate, with multiple flow channels on one side, is fixed to a titanium mesh structure using diffusion welding technology. Each inner electrode plate, with one side also fixed to a titanium mesh structure using diffusion welding technology, has its other side fixed to another titanium mesh structure using the same technology. Each titanium mesh structure comprises multiple titanium wires, with multiple sections of each wire overlapping different titanium wires. Each mesh structure contains multiple mesh openings. These sections of the titanium wires are fused to the electrode plates, and at each point where the electrode plate is fused to a titanium wire, a conductive path can be established through at least one titanium wire. Sections of the titanium wires not fused to the electrode plates are overlapped on one side of another titanium wire. Each catalyst layer is disposed on at least a portion of one of the titanium mesh structures and on the side of one of the electrode plates where the titanium mesh structure is located. Multiple membrane electrode assemblies are disposed between two titanium mesh structures. A sealing ring is provided between each electrode plate and each membrane electrode assembly, and the periphery of each titanium mesh structure is surrounded by the sealing ring. Two fasteners are used to hold multiple electrode plates, multiple titanium mesh structures, multiple catalyst layers, multiple membrane electrode assemblies, and multiple sealing rings. Each fastener and multiple electrode plates together form a gas channel, and each gas channel is connected to multiple flow channels of the electrode plates.

[0005] One embodiment of the present invention discloses a method for manufacturing a fuel cell, which is used to manufacture a fuel cell. The fuel cell includes multiple electrode plates, multiple titanium mesh structures, multiple catalyst layers, multiple membrane electrode assemblies, and two fixing members. The two electrode plates located at both ends of the fuel cell are defined as an outer electrode plate, and the remaining electrode plates are defined as an inner electrode plate. Each titanium mesh structure includes multiple titanium wires, and multiple segments at different positions of each titanium wire are respectively arranged to overlap with different titanium wires. Each titanium mesh structure includes multiple mesh holes. The method for manufacturing the fuel cell includes the following steps: an outer electrode plate manufacturing step: using diffusion welding technology, a titanium mesh structure is fixed on one side of each outer electrode plate, so that the position where each outer electrode plate is fused with the titanium wire can be penetrated by up to A conductive path is established by removing one titanium wire. Sections of titanium wires not fused to the outer electrode plate are stacked on one side of another titanium wire. An inner electrode plate manufacturing step involves using diffusion welding technology to fix a titanium mesh structure to both sides of each inner electrode plate. This ensures that at least one titanium wire can establish a conductive path at the location where the inner electrode plate is fused to the titanium wire. Sections of titanium wires not fused to the inner electrode plate are stacked on one side of another titanium wire. A catalyst layer formation step involves depositing a catalyst layer on one side of each titanium mesh structure and the electrode plate fixed to it. An assembly step involves fixing two fasteners together to hold multiple electrode plates, multiple titanium mesh structures, and multiple membrane electrode assemblies. Each membrane electrode assembly is located between two titanium mesh structures.

[0006] In summary, the fuel cell and fuel cell manufacturing method of the present invention, by using diffusion welding technology to fix the titanium mesh structure to the electrode plate and forming the catalyst layer on the surface of the titanium mesh structure and the surface of the electrode plate, can ensure that the titanium wires of each titanium mesh structure connected to the electrode plate can still maintain electrical conductivity after long-term use, thereby maintaining the operating efficiency of the fuel cell.

[0007] To further understand the features and technical content of the present invention, please refer to the following detailed description and drawings of the present invention. However, these descriptions and drawings are only used to illustrate the present invention and are not intended to limit the scope of protection of the present invention in any way.

Implementation Method

[0020] In the following description, if it is indicated that a specific drawing is referred to or shown in a specific drawing, it is only to emphasize that most of the relevant content mentioned in the following description appears in that specific drawing, but it does not limit the following description to referring only to that specific drawing. The dimensions and proportions of the various structures presented in the drawings of this embodiment are only drawn for the convenience of the description, and the dimensions and proportions drawn in the drawings do not represent the actual dimensions and proportions in actual application.

[0021] Please refer to Figures 1 to 6 together, which are respectively a perspective view, an exploded view, a schematic diagram of the outer electrode plate, the titanium mesh structure and the sealing ring, a schematic diagram of the inner electrode plate, the titanium mesh structure and the sealing ring, and a partially enlarged schematic diagram of the outer electrode plate of the first embodiment of the fuel cell of the present invention.

[0022] The fuel cell 100 of this embodiment includes three electrode plates, four titanium mesh structures 3, four catalyst layers 4, two membrane electrode assemblies (MEAs) 5, four sealing rings 6, and two fixing members 7. The two electrode plates located at both ends of the fuel cell 100 are defined as an outer electrode plate 1, and the remaining electrode plates are defined as an inner electrode plate 2. In the drawings of this embodiment, for ease of explanation, only a single inner electrode plate 2 is shown, but in actual applications, the number of inner electrode plates 2 is not limited to a single piece.

[0023] As shown in Figures 3 and 4, each external electrode plate 1 has multiple flow channels C on one side. For example, one side 11 of each external electrode plate 1 may have multiple protruding pillar structures 12, which together form multiple flow channels C on one side of the external electrode plate 1, and the multiple flow channels C are interconnected. The formation of the multiple flow channels C on one side of each external electrode plate 1 is not limited to the above description, and the multiple flow channels C on one side of each external electrode plate 1 are not limited to being completely interconnected. In different embodiments, the multiple flow channels C on one side of each external electrode plate 1 may also be formed by an inward concavity on one side of the external electrode plate 1. The side of each external electrode plate 1 with multiple flow channels C is fixed to a titanium mesh structure 3 using diffusion bonding technology.

[0024] As shown in Figures 5 and 6, each inner electrode plate 2 has multiple flow channels C on one side, and one side of each inner electrode plate 2 is fixed to a titanium mesh structure 3 using diffusion welding technology. The other side of each inner electrode plate 2 also has multiple flow channels C, and the other side of each inner electrode plate 2 is fixed to another titanium mesh structure 3 using diffusion welding technology. The shape and forming method of the multiple flow channels C on each side of the inner electrode plate 2 can be designed according to requirements. The content shown in the figures of this embodiment is only one example.

[0025] As shown in Figures 4 and 6, each titanium mesh structure 3 includes multiple titanium wires 31. Multiple segments of each titanium wire 31 are arranged in overlapping configurations with different titanium wires 31. Each titanium mesh structure 3 includes multiple mesh openings 32. Simply put, each titanium mesh structure 3 is a three-dimensional woven mesh structure formed by the interweaving of multiple titanium wires 31. In practical applications, the aperture of the mesh openings 32 can be between 0.05 and 0.5 millimeters (mm).

[0026] Multiple sections of each titanium wire 31 are fused to the outer electrode plate 1 (inner electrode plate 2). At each location where the outer electrode plate 1 (inner electrode plate 2) is fused to the titanium wire 31, a conductive path can be established through at least one titanium wire 31. Sections of each titanium wire 31 that are not fused to the outer electrode plate 1 (inner electrode plate 2) are overlapped on one side of another titanium wire 31. It should be noted that the overlapping and interlacing patterns of the multiple titanium wires 31 contained in each titanium mesh structure 3 shown in the figures of this embodiment are only one example. In practical applications, the weaving pattern of the multiple titanium wires 31 contained in each titanium mesh structure 3 can be varied according to requirements.

[0027] It should be noted that, in Figures 4 and 6, the example is that a portion of each titanium wire 31 included in the titanium mesh structure 3 is fused to the protruding pillar structure 12 of the outer electrode plate 1 (the protruding pillar structure 22 of the inner electrode plate 2). However, the titanium mesh structure 3 is not limited to being fused only to the multiple protruding pillar structures 12 of the outer electrode plate 1 (the protruding pillar structures 22 of the inner electrode plate 2). In another embodiment where multiple protruding pillar structures 12 and 22 are respectively provided on the sides 11 and 21 of the outer electrode plate 1 and the inner electrode plate 2, a portion of each titanium wire 31 of the titanium mesh structure 3 can also be fused to the side 11 of the outer electrode plate 1 or the side 21 of the inner electrode plate 2.

[0028] In one preferred embodiment, the material of each outer electrode plate 1 and each inner electrode plate 2 may include titanium, and each outer electrode plate 1 and each inner electrode plate 2 may be, for example, a titanium alloy plate or a pure titanium plate. This strengthens the connection strength at the fusion points between the titanium wires 31 and the electrode plates (outer electrode plate 1, inner electrode plate 2), making the fusion points less prone to breakage. In other embodiments, the material of each outer electrode plate 1 and each inner electrode plate 2 may also be stainless steel.

[0029] As shown in Figure 7, at least a portion of each titanium mesh structure 3 is provided with a catalyst layer 4, and each outer electrode plate 1 is provided with a portion of the side surface of the titanium mesh structure 3, and each inner electrode plate 2 is provided with a portion of the side surface of the titanium mesh structure 3, and is also provided with a catalyst layer 4. Specifically, in practical applications, the titanium mesh structure 3 can be fixed to one side of the outer electrode plate 1 using diffusion welding technology, and then the catalyst layer 4 can be plated on the side of the titanium mesh structure 3 opposite to the outer electrode plate 1. Alternatively, the outer electrode plate 1 with the titanium mesh structure 3 fixed can be placed in an electroplating tank for electroplating. Similarly, the two titanium mesh structures 3 can be fixed to both sides of the inner electrode plate 2 using diffusion welding technology, and then the catalyst layer 4 can be plated on the two titanium mesh structures 3 fixed to the inner electrode plate 2. Alternatively, the inner electrode plate 2 with the titanium mesh structures 3 fixed to both sides can be directly placed in an electroplating tank for electroplating. In practical applications, the catalyst layer 4 can be, for example, a material containing platinum, gold, or iridium oxide, etc., and is not limited thereto.

[0030] In different embodiments, a catalyst layer 4 may be deposited on the surface of each titanium mesh structure 3 first, and then diffusion welding technology may be used to fuse the titanium mesh structure 3 with the catalyst layer 4 to the side of each electrode plate with the flow channel C.

[0031] As shown in Figures 2, 3, and 5, a sealing ring 6 is provided between each membrane electrode assembly 5 and the adjacent outer electrode plate 1 or inner electrode plate 2, and the periphery of each titanium mesh structure 3 is surrounded by the sealing ring 6. The sealing ring 6 is mainly used to restrict the flow range of gas and liquid after reaction. The number and shape of the sealing ring 6 provided between each membrane electrode assembly 5 and the adjacent outer electrode plate 1 or inner electrode plate 2 are not limited to those shown in the figures and can be varied according to requirements.

[0032] Two fasteners 7 hold multiple electrode plates (outer electrode plate 1, inner electrode plate 2), multiple titanium mesh structures 3, multiple catalyst layers 4, multiple membrane electrode assemblies 5, and multiple sealing rings 6. In practical applications, the two fasteners 7 can be mutually fixed by multiple screws or other components.

[0033] Furthermore, it is worth mentioning that each outer electrode plate 1 may have two through holes 13, each through hole 13 penetrating the outer electrode plate 1; each inner electrode plate 2 may have two through holes 23, each through hole 23 penetrating the inner electrode plate 2; one fixing member 7 has a gas inlet 71, and the other fixing member 7 has a gas outlet 72. The gas inlet 71 of the fixing member 7, one through hole 13 of each outer electrode plate 1, and one through hole 23 of each inner electrode plate 2 will together form a gas channel, and the gas outlet 72 of the fixing member 7, the other through hole 13 of each outer electrode plate 1, and the other through hole 23 of each inner electrode plate 2 will together form another gas channel. Each gas channel is connected to the flow channel C of each electrode plate, and one gas channel is used to provide hydrogen into the fuel cell 100, and the other gas channel is used to provide oxygen (or air) into the fuel cell 100. The formation method, shape, size, etc. of the two gas channels can be designed according to requirements and are not limited to the above description.

[0034] As described above, the fuel cell 100 of the present invention uses a titanium mesh structure 3 to replace the carbon cloth (gas diffusion layer) in conventional fuel cells, and uses diffusion welding technology to fuse the titanium mesh structure 3 to one side of the outer electrode plate 1 and both sides of the inner electrode plate 2. Since some sections of the multiple titanium wires 31 contained in the titanium mesh structure 3 are fused to each other with the outer electrode plate 1 or the inner electrode plate 2, the contact resistance between the titanium mesh structure 3 and each electrode plate can still be maintained in a relatively good state after long-term use.

[0035] On the contrary, in conventional fuel cells, since the carbon cloth and the electrode plate are only in physical contact (the two only touch each other), after a long period of use, the carbon cloth is prone to erosion in some areas, which will cause the area to lose conductivity. This will increase the contact resistance between the carbon cloth and the electrode plate, thereby affecting the overall operating efficiency of the fuel cell.

[0036] In other words, after prolonged use, the fuel cell 100 of the present invention, with each electrode plate (outer electrode plate 1, inner electrode plate 2) and the multiple titanium wires 31 contained in the adjacent titanium mesh structure 3 jointly establishing multiple conductive paths, will mostly remain in a state where it can still conduct normally. In contrast, in conventional fuel cells, after prolonged use, the areas where the carbon cloth is eroded will cause some conductive paths to fail.

[0037] Furthermore, it is worth mentioning that one side of the carbon cloth in conventional fuel cells is usually coated with a catalyst, which makes the overall manufacturing cost of the carbon cloth relatively expensive. In contrast, the manufacturing cost of the titanium mesh structure 3 and the catalyst layer 4 included in the fuel cell 100 of the present invention is relatively cheap, and the fuel cell 100 of the present invention also has the advantage of relatively low manufacturing cost compared with conventional fuel cells.

[0038] Please refer to Figures 8 to 10, which respectively show an exploded view of the second embodiment of the fuel cell of the present invention, a partially enlarged view of the titanium mesh structure and the auxiliary titanium mesh structure, and a cross-sectional view of the fuel cell. The biggest difference between this embodiment and the previous embodiment is that the fuel cell 200 also includes four auxiliary titanium mesh structures 8. Each auxiliary titanium mesh structure 8 is fixed to one of the titanium mesh structures 3 on the side opposite to the electrode plate (outer electrode plate 1 or inner electrode plate 2) using diffusion welding technology.

[0039] Each auxiliary titanium mesh structure 8 includes multiple auxiliary titanium wires 81. Multiple segments at different positions of each auxiliary titanium wire 81 are arranged overlapping with different auxiliary titanium wires 81. Each auxiliary titanium mesh structure 8 includes multiple mesh openings 82. The maximum aperture of the mesh openings 82 included in each titanium mesh structure 3 is larger than the maximum aperture of the mesh openings 82 included in each auxiliary titanium mesh structure 8. Multiple segments at different positions of each auxiliary titanium wire 81 are fused to one segment of the multiple titanium wires 31 included in the titanium mesh structure 3. At the connection points between each electrode plate (outer electrode plate 1 or inner electrode plate 2) and the titanium wire 31, a conductive path can be established through at least one titanium wire 31 and multiple auxiliary titanium wires 81.

[0040] As shown in Figure 10, at least a portion of the mutually fused auxiliary titanium mesh structure 8, titanium mesh structure 3, and electrode plates (outer electrode plate 1 and inner electrode plate 2) are provided with a catalyst layer 4. In practical applications, diffusion welding technology can be used to fix the titanium mesh structure 3 and auxiliary titanium mesh structure 8 to one side of each outer electrode plate 1, and then the catalyst layer 4 can be electroplated on the side of the auxiliary titanium mesh structure 8 opposite to the outer electrode plate 1. Alternatively, the outer electrode plate 1 with the fixed titanium mesh structure 3 and auxiliary titanium mesh structure 8 can be directly placed in the electroplating tank for the electroplating of the catalyst layer 4. Similarly, diffusion welding technology can be used to fix the titanium mesh structure 3 and auxiliary titanium mesh structure 8 to both sides of each inner electrode plate 2, and then the catalyst layer 4 can be electroplated on one side of the auxiliary titanium mesh structure 8 fixed on the titanium mesh structure 3 of the inner electrode plate 2. Alternatively, the inner electrode plate 2 with two fixed titanium mesh structures 3 and two auxiliary titanium mesh structures 8 can be directly placed in the electroplating tank for the electroplating of the catalyst layer 4.

[0041] In one embodiment, the maximum aperture of each mesh 32 of each titanium mesh structure 3 can be 2 to 20 times the maximum aperture of each mesh 82 of each auxiliary titanium mesh structure 8. In one embodiment, the aperture of each mesh 32 of each titanium mesh structure 3 can be between 0.1 and 1.0 mm, while the aperture of each mesh 82 of each auxiliary titanium mesh structure 8 can be between 0.05 and 0.5 mm.

[0042] In one embodiment, the overall size of each titanium mesh structure 3 is the same as the overall size of each auxiliary titanium mesh structure 8 (i.e., the overall length and width of the titanium mesh structure 3 are the same as the overall length and width of the auxiliary titanium mesh structure 8), and the number of mesh openings 82 included in each auxiliary titanium mesh structure 8 is 1.6 to 100 times the number of mesh openings 32 included in each titanium mesh structure 3. For example, the mesh count of each auxiliary titanium mesh structure 8 may be between 80 and 5000 meshes, while the mesh count of each titanium mesh structure 3 may be between 50 and 500 meshes.

[0043] It should be noted that, in the drawings of this embodiment, the fuel cell 200 includes two auxiliary titanium mesh structures 8 as an example, but the number of auxiliary titanium mesh structures 8 included in the fuel cell 200 is not limited to two. In embodiments where two or more auxiliary titanium mesh structures 8 are provided between the membrane electrode assembly 5 and the titanium mesh structure 3, the pore size of the mesh 82 of the auxiliary titanium mesh structure 8 closer to the membrane electrode assembly 5 is smaller.

[0044] Please refer to Figures 2 to 7 and Figure 11 together. Figure 11 shows a schematic flowchart of the first embodiment of the fuel cell manufacturing method of the present invention. The fuel cell manufacturing method of the present invention is used to manufacture a fuel cell 100. The fuel cell 100 includes multiple electrode plates, multiple titanium mesh structures 3, multiple catalyst layers 4, multiple sealing rings 6, multiple membrane electrode assemblies 5, and two fixing members 7. The two electrode plates located at both ends of the fuel cell 100 are respectively defined as an outer electrode plate 1, and the remaining electrode plates are respectively defined as an inner electrode plate 2. For a detailed description of the titanium mesh structure 3, please refer to the foregoing embodiments, which will not be repeated here.

[0045] The method for manufacturing a fuel cell includes the following steps:

[0046] External electrode plate manufacturing step S11: Using diffusion welding technology, a titanium mesh structure 3 is fixed on one side of each external electrode plate 1, so that the position where each external electrode plate 1 is fused with the titanium wire 31 can establish a conductive path through at least one titanium wire 31, and the section where each titanium wire 31 is not fused with the external electrode plate 1 is stacked on one side of another titanium wire 31.

[0047] Inner electrode plate manufacturing step S12: Using diffusion welding technology, a titanium mesh structure 3 is fixed on both sides of each inner electrode plate 2, so that the position where each inner electrode plate 2 is fused with the titanium wire 31 can establish a conductive path through at least one titanium wire 31, and the section where each titanium wire 31 is not fused with the inner electrode plate 2 is stacked on one side of another titanium wire 31.

[0048] Step S13: A catalyst layer 4 is deposited on one side of each titanium mesh structure 3 and the electrode plate (outer electrode plate 1 or inner electrode plate 2) fixed thereto.

[0049] Assembly step S14: Fix the two fixing members 7 to each other so that multiple electrode plates (outer electrode plate 1 or inner electrode plate 2), multiple titanium mesh structures 3, multiple sealing rings 6, and multiple membrane electrode groups 5 are held by the two fixing members 7; wherein, each membrane electrode group 5 is located between the two titanium mesh structures 3.

[0050] In practical applications, in the outer electrode plate manufacturing step S11, the outer electrode plate 1 can be first placed on the platform of the diffusion welding equipment, then the titanium mesh structure 3 can be placed on the outer electrode plate 1, and finally, diffusion welding technology can be used to fuse different sections of each titanium wire 31 of the titanium mesh structure 3 with the outer electrode plate 1. Similarly, in the inner electrode plate manufacturing step S12, the inner electrode plate 2 can be first placed on the platform of the diffusion welding equipment, then the titanium mesh structure 3 can be placed on the inner electrode plate 2, and finally, diffusion welding technology can be used to fuse different sections of each titanium wire 31 of the titanium mesh structure 3 with the inner electrode plate 2.

[0051] In practical applications, in the catalyst layer formation step S13, the catalyst layer 4 may be plated only on one side of each titanium mesh structure 3 and the electrode plate (outer electrode plate 1 or inner electrode plate 2) fixed therewith, or the titanium mesh structure 3 and the electrode plate (outer electrode plate 1 or inner electrode plate 2) fixed therewith may be directly placed in the electroplating tank for electroplating.

[0052] In practical applications, in assembly step S14, for example, multiple screws and multiple nuts can be used to lock the two fasteners 7 together, but the fastening method of the two fasteners 7 is not limited to this. In addition, assembly step S14 also includes the step of setting a sealing ring 6 between the membrane electrode assembly 5 and the adjacent electrode plate.

[0053] As described above, the fuel cell manufacturing method of the present invention has the advantages of simple manufacturing process and relatively low manufacturing cost compared with the traditional fuel cell manufacturing method containing carbon cloth.

[0054] Please refer to Figures 8 to 10 and Figure 12 together. Figure 12 shows a schematic flowchart of a second embodiment of the fuel cell manufacturing method of the present invention. One difference between the fuel cell manufacturing method of this embodiment and the first embodiment described above is that the fuel cell 100 manufactured by the fuel cell manufacturing method of this embodiment further includes a plurality of auxiliary titanium mesh structures 8. For a detailed description of the auxiliary titanium mesh structures 8, please refer to the aforementioned embodiments, and will not be repeated here.

[0055] The fuel cell manufacturing method of this embodiment includes: an external electrode plate manufacturing step S21, an internal electrode plate manufacturing step S22, a catalyst layer forming step S23, and an assembly step S24. The external electrode plate manufacturing step S21 of this embodiment differs from the external electrode plate manufacturing step S11 of the aforementioned embodiment in that: in the external electrode plate manufacturing step S21, diffusion welding technology is used to fix a titanium mesh structure 3 on one side of each external electrode plate 1, and an auxiliary titanium mesh structure 8 is fixed on the side of the titanium mesh structure 3 opposite to the external electrode plate 1. At the position where each external electrode plate 1 is connected to the titanium wire, a conductive path can be established through at least one titanium wire 31 and multiple auxiliary titanium wires 81. Specifically, in practical applications, the outer electrode plate 1 can be placed flat on the platform of the diffusion welding equipment, and the titanium mesh structure 3 can be placed on the outer electrode plate 1. Then, the auxiliary titanium mesh structure 8 can be placed on the titanium mesh structure 3. Next, the diffusion welding technology can be used to fuse the outer electrode plate 1, the titanium mesh structure 3 and the auxiliary titanium mesh structure 8 together in one go. Then, the outer electrode plate 1 with the titanium mesh structure 3 and the auxiliary titanium mesh structure 8 fixed is flipped over, and another titanium mesh structure 3 and another auxiliary titanium mesh structure 8 are placed on the outer electrode plate 1 one after another. Finally, the diffusion welding technology can be used again to fuse the outer electrode plate 1 with the other titanium mesh structure 3 and the other auxiliary titanium mesh structure 8 together in one go.

[0056] The difference between the inner electrode plate manufacturing step S21 of this embodiment and the inner electrode plate manufacturing step S12 of the aforementioned embodiment is that, in the inner electrode plate manufacturing step S21, diffusion welding technology is used to fix a titanium mesh structure 3 on both sides of each inner electrode plate 2, and an auxiliary titanium mesh structure 8 is fixed on the side of the titanium mesh structure 3 opposite to the inner electrode plate 2. Specifically, in practical applications, the inner electrode plate 2 can be placed flat on the platform of the diffusion welding equipment, and the titanium mesh structure 3 can be placed on the inner electrode plate 2 first, and then the auxiliary titanium mesh structure 8 can be placed on the titanium mesh structure 3. Then, the inner electrode plate 2, the titanium mesh structure 3 and the auxiliary titanium mesh structure 8 can be fused together at one time using diffusion welding technology. After that, the inner electrode plate 2 with the titanium mesh structure 3 and the auxiliary titanium mesh structure 8 fixed is flipped over, and another titanium mesh structure 3 and another auxiliary titanium mesh structure 8 are placed on the inner electrode plate 2 one after another. Finally, the inner electrode plate 2 is fused together with the other titanium mesh structure 3 and the other auxiliary titanium mesh structure 8 at one time again using diffusion welding technology.

[0057] The difference between the inner electrode plate manufacturing step S23 of this embodiment and the inner electrode plate manufacturing step S13 of the aforementioned embodiment is that, in the catalyst layer forming step S23, the catalyst layer 4 is deposited on the side of each auxiliary titanium mesh structure 8 opposite to the titanium mesh structure 3 and on the side of each titanium mesh structure 3 opposite to the electrode plate (outer electrode plate 1 or inner electrode plate 2). In practical applications, in the catalyst layer forming step S23, the catalyst layer 4 may be deposited only on the side of each outer electrode plate 1 where the titanium mesh structure 3 and the auxiliary titanium mesh structure 8 are fixed, or the outer electrode plate 1 and the titanium mesh structure 3 and the auxiliary titanium mesh structure 8 fixed thereto may be directly placed into the relevant electroplating tank for electroplating. Similarly, in the catalyst layer forming step S23, the catalyst layer 4 may be deposited only on the side of each inner electrode plate 2 where the titanium mesh structure 3 and the auxiliary titanium mesh structure 8 are fixed, or the inner electrode plate 2 and the titanium mesh structure 3 and the auxiliary titanium mesh structure 8 fixed thereto may be directly placed into the relevant electroplating tank for electroplating.

[0058] In assembly step S24, the two fixing members 7 are fixed to each other so that multiple electrode plates (outer electrode plate 1 or inner electrode plate 2), multiple titanium mesh structures 3, multiple auxiliary titanium mesh structures 8, multiple sealing rings 6, and multiple membrane electrode groups 5 are held by the two fixing members 7; wherein, each membrane electrode group 5 is located between two titanium mesh structures 3.

[0059] In summary, the fuel cell of the present invention, by using a titanium mesh structure as a gas diffusion layer and fusing the titanium mesh structure and the electrode plate together using diffusion welding technology, ensures that the contact resistance between the titanium mesh structure and the electrode plate does not increase significantly after long-term use. This allows the fuel cell to maintain relatively good operating efficiency, and the overall service life of the fuel cell of the present invention is greater than that of conventional fuel cells using carbon cloth as a gas diffusion layer. The manufacturing method of the fuel cell of the present invention, by using diffusion welding technology to fix the titanium mesh structure (replacing conventional carbon cloth) to the electrode plate and by electroplating a catalyst layer onto the titanium mesh structure, effectively reduces the manufacturing cost of the fuel cell.

[0060] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Therefore, all equivalent technical changes made based on the description and drawings of the present invention are included within the protection scope of the present invention. [Simplified Explanation of the Diagram]

[0008] Figure 1 is a perspective view of the first embodiment of the fuel cell of the present invention.

[0009] Figure 2 is an exploded view of the first embodiment of the fuel cell of the present invention.

[0010] Figure 3 is a schematic diagram of the external electrode plate, titanium mesh structure and sealing ring of the first embodiment of the fuel cell of the present invention.

[0011] Figure 4 is a partially enlarged schematic diagram of Figure 3.

[0012] Figure 5 is a schematic diagram of the internal electrode plate, titanium mesh structure and sealing ring of the first embodiment of the fuel cell of the present invention.

[0013] Figure 6 is a partially enlarged schematic diagram of Figure 5.

[0014] Figure 7 is a cross-sectional view of Figure 1 along section line VII-VII.

[0015] Figure 8 is an exploded view of the second embodiment of the fuel cell of the present invention.

[0016] Figure 9 is a partially enlarged schematic diagram of the titanium mesh structure and auxiliary titanium mesh structure of the second embodiment of the fuel cell of the present invention.

[0017] Figure 10 is a cross-sectional schematic diagram of a second embodiment of the fuel cell of the present invention.

[0018] Figure 11 is a schematic flowchart of the first embodiment of the fuel cell manufacturing method of the present invention.

[0019] Figure 12 is a schematic flowchart of a second embodiment of the fuel cell manufacturing method of the present invention.

Claims

1. A fuel cell comprising: a plurality of electrode plates, each electrode plate having at least one side having a plurality of flow channels; two electrode plates located at both ends of the fuel cell being defined as an outer electrode plate, and the remaining electrode plates being defined as an inner electrode plate; a plurality of titanium mesh structures, each outer electrode plate having one side having the plurality of flow channels being fixed to one of the titanium mesh structures using diffusion welding technology, each inner electrode plate having one side being fixed to one of the titanium mesh structures using diffusion welding technology, and each inner electrode plate having the other side being fixed to another titanium mesh structure using diffusion welding technology; each titanium mesh structure comprising a plurality of titanium wires, each titanium wire having multiple segments at different positions overlapping with different titanium wires, each titanium mesh structure having a plurality of mesh openings; multiple segments at different positions of each titanium wire being fused to the electrode plate, and at the positions where each electrode plate is fused to the titanium wire, a conductive path can be established through at least one titanium wire; and the segments of each titanium wire not fused to the electrode plate are correspondingly overlapped on one side of another titanium wire. Multiple catalyst layers, each catalyst layer being disposed on at least a portion of one of the titanium mesh structures and on one side of one of the electrode plates where the titanium mesh structure is disposed; multiple membrane electrode assemblies, disposed between two of the titanium mesh structures; multiple sealing rings, each sealing ring being disposed between each electrode plate and the membrane electrode assembly, and the periphery of each titanium mesh structure being surrounded by the sealing ring; two fixing members for fixing the multiple electrode plates, the multiple titanium mesh structures, the multiple catalyst layers, the multiple membrane electrode assemblies and the multiple sealing rings, each fixing member and the multiple electrode plates forming a gas channel, each gas channel communicating with the multiple flow channels of the electrode plate.

2. The fuel cell as claimed in claim 1, wherein, The aperture of each mesh is between 0.05 and 0.5 mm.

3. The fuel cell as claimed in claim 1, wherein, The electrode plates are made of titanium or stainless steel; the catalyst layer is made of platinum, gold or iridium oxide.

4. The fuel cell as claimed in claim 1, wherein, The fuel cell further includes multiple auxiliary titanium mesh structures. Each auxiliary titanium mesh structure is fixed to the side opposite to the electrode plate using diffusion welding technology. Each auxiliary titanium mesh structure includes multiple auxiliary titanium wires, with multiple segments at different positions of each auxiliary titanium wire overlapping with different auxiliary titanium wires. Each auxiliary titanium mesh structure includes multiple mesh openings, and the maximum aperture of the mesh openings in each titanium mesh structure is larger than the maximum aperture of the mesh openings in each auxiliary titanium mesh structure. Multiple segments at different positions of each auxiliary titanium wire are fused to one segment of the multiple titanium wires included in the titanium mesh structure. At the connection points between each electrode plate and the titanium wires, a conductive path can be established through at least one titanium wire and multiple auxiliary titanium wires.

5. The fuel cell as claimed in claim 4, wherein, Each of the catalyst layers is also disposed on at least a portion of each of the auxiliary titanium mesh structures.

6. The fuel cell as claimed in claim 4, wherein, The maximum aperture of each mesh of each of the titanium mesh structures is 2 to 20 times the maximum aperture of each mesh of each of the auxiliary titanium mesh structures.

7. The fuel cell as claimed in claim 4, wherein, The aperture of each mesh in each of the titanium mesh structures is between 0.1 and 1.0 mm, and the aperture of each mesh in each of the auxiliary titanium mesh structures is between 0.05 and 0.5 mm.

8. The fuel cell as claimed in claim 4, wherein, The overall size of each of the titanium mesh structures is the same as the overall size of each of the auxiliary titanium mesh structures, and the number of mesh openings contained in each of the auxiliary titanium mesh structures is 1.6 to 100 times the number of mesh openings contained in each of the titanium mesh structures.

9. A method for manufacturing a fuel cell, comprising a plurality of electrode plates, a plurality of titanium mesh structures, a plurality of catalyst layers, a plurality of membrane electrode assemblies, and two fixing members, wherein two electrode plates located at both ends of the fuel cell are defined as an outer electrode plate, and the remaining electrode plates are defined as an inner electrode plate; each titanium mesh structure comprises a plurality of titanium wires, and multiple segments at different positions of each titanium wire are respectively arranged overlapping with different titanium wires; each titanium mesh structure comprises a plurality of mesh openings; the method for manufacturing the fuel cell comprises the following steps: an outer electrode plate manufacturing step: using diffusion welding technology, fixing a titanium mesh structure on one side of each outer electrode plate, such that at the position where each outer electrode plate is fused with the titanium wire, a conductive path can be established through at least one titanium wire; and the segments of each titanium wire that are not fused with the outer electrode plate are overlapped on one side of another titanium wire. A manufacturing step for an inner electrode plate: using diffusion welding technology, a titanium mesh structure is fixed to both sides of each inner electrode plate, such that at the location where each inner electrode plate is fused with the titanium wire, a conductive path can be established through at least one titanium wire. Sections of each titanium wire not fused with the inner electrode plate are overlapped on one side of another titanium wire. A catalyst layer formation step: a catalyst layer is deposited on one side of each titanium mesh structure and the electrode plate fixed thereto. An assembly step: two fixing members are fixed together so that multiple electrode plates, multiple titanium mesh structures, and multiple membrane electrode assemblies are held in place by the two fixing members. Each of the membrane electrode assemblies is located between the two titanium mesh structures.

10. A method for manufacturing a fuel cell as described in claim 9, wherein, The fuel cell manufactured by the method described above further includes multiple auxiliary titanium mesh structures. Each auxiliary titanium mesh structure includes multiple auxiliary titanium wires, with multiple segments at different positions of each auxiliary titanium wire overlapping with different auxiliary titanium wires. Each auxiliary titanium mesh structure includes multiple mesh openings, and the maximum aperture of the mesh openings in each titanium mesh structure is larger than the maximum aperture of the mesh openings in each auxiliary titanium mesh structure. In the outer electrode plate manufacturing step, diffusion welding technology is used to fix one side of each outer electrode plate with a titanium mesh structure, and an auxiliary titanium mesh structure is fixed on the side of the titanium mesh structure opposite to the outer electrode plate. Each outer electrode plate is connected to the titanium wires. The position allows for the establishment of a conductive path through at least one titanium wire and multiple auxiliary titanium wires. In the inner electrode plate manufacturing step, diffusion welding technology is used to fix a titanium mesh structure to both sides of each inner electrode plate, and an auxiliary titanium mesh structure is fixed to the side of the titanium mesh structure opposite to the inner electrode plate. In the catalyst layer formation step, the catalyst layer is deposited on the side of each auxiliary titanium mesh structure opposite to the titanium mesh structure and on the side of each titanium mesh structure opposite to the electrode plate. In the assembly step, two fixing members are mutually fixed so that multiple electrode plates, multiple titanium mesh structures, multiple auxiliary titanium mesh structures, and multiple membrane electrode assemblies are held by the two fixing members.

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