Flow field plate, bipolar plate and manufacturing method thereof

Abstract

The present application provides a method for manufacturing a flow field plate for a fuel cell unit. The method includes forming a first flow field for circulating a reactive fluid on a first side of a metal plate, wherein the reaction zone of the first flow field includes a first ridge that defines a first flow channel. Forming the first flow field includes cutting a first pattern corresponding to the first ridge in a first conductive adhesive film and adhering the cut first pattern to the first side of the metal plate so that at least 10% of the height of the first ridge, measured from the top, is formed by the first pattern. The present application also provides a method for manufacturing a bipolar plate for a fuel cell, as well as a flow field plate and bipolar plate manufactured by the above method. According to the present application, the contact conductivity of the flow field plate can be improved, facilitating the manufacture of the flow field plate and reducing the manufacturing cost of the flow field plate.

Description

[Technical Field]

[0001] FIELD OF THE INVENTION This application relates generally to fuel cell technology, and more particularly to flow field plates, bipolar plates for use in fuel cells and methods of making the same. [Background technology]

[0002] Fuel cells, which generate electricity through an electrochemical reaction between a fuel and an oxidant, are increasingly being used to provide electrical power, particularly in the field of electric vehicles. Proton exchange membrane fuel cells (PEMFCs) are a widely used type of fuel cell that utilizes hydrogen as the fuel and oxygen as the oxidant. Typically, a membrane electrode assembly (MEA) is positioned between two flow field plates to form a fuel cell unit. The two flow field plates function as a cathode plate and an anode plate, respectively, and contain flow fields for supplying reactive fluids (i.e., hydrogen, oxygen, or air) to the MEA.

[0003] Metals are commonly used to fabricate flow field plates due to their excellent thermal and electrical conductivity and density. However, in the operating environment of a PEMFC (e.g., low pH, high humidity, and operating temperatures of approximately 80°C), typical metallic materials used for flow field plates (such as stainless steel and titanium) exhibit chemical instability, resulting in corrosion resistance and contact conductivity issues for the metal flow field plates.

[0004] In existing flow field plate manufacturing techniques, carbon-based coatings are typically applied to metal flow field plates to improve their corrosion resistance and contact conductivity. However, applying the carbon-based coating requires a vacuum environment, making the process complex, time-consuming, and expensive, which is not conducive to mass production of flow field plates. Furthermore, to maintain a substantially constant contact resistance between the carbon-coated flow field plate and the MEA, a significant holding force must be maintained between the flow field plate and the MEA. This relies on the fuel cell's piling fixtures. However, due to vibrations in the fuel cell's operating environment, the fixtures can loosen, leading to a reduction in holding force and, consequently, an increase in contact resistance between the flow field plate and the MEA.

[0005] Therefore, there is a need for improvements to existing flow field plate manufacturing techniques. Summary of the Invention [Problem to be solved by the invention]

[0006] SUMMARY OF THE INVENTION The present application aims to provide an improved method for manufacturing flow field plates for fuel cell units to overcome at least one of the aforementioned deficiencies. [Means for solving the problem]

[0007] According to one aspect of the present application, there is provided a method for manufacturing a flow field plate for a fuel cell unit. The method includes forming a first flow field for circulating a reactive fluid on a first side of a metal plate, wherein a reaction zone of the first flow field includes first ridges that define first flow channels. Forming the first flow field includes cutting a first pattern corresponding to the first ridges in a first conductive adhesive film and adhering the cut first pattern on the first side of the metal plate such that at least 10% of the height of the first ridges, measured from the top, is formed by the first pattern.

[0008] According to another aspect of the present application, there is provided a method of manufacturing a flow field plate for a fuel cell unit, the method including: manufacturing a cathode plate using the method described above; manufacturing an anode plate using the method described above; and securing the cathode plate and the anode plate together in a first flow field opposite each other to form a bipolar plate.

[0009] According to yet another aspect of the present application, a flow field plate for a fuel cell unit is provided, the flow field plate comprising: a metal plate; a first flow field formed on a first side of the metal plate for circulating a reactive fluid, the first flow field having a reaction zone including first ridges defining first flow channels; and a first conductive adhesive film, the first conductive adhesive film having a first pattern corresponding to the first ridges and adhered to the first side of the metal plate such that at least 10% of the height of the first ridges measured from the top is formed by the first pattern.

[0010] According to a further aspect of the present application, there is provided a bipolar plate for a fuel cell, comprising an anode plate, which is one of the flow field plates described above, and a cathode plate, which is another of the flow field plates described above, wherein both the anode plate and the cathode plate are secured to a first flow field opposite each other.

[0011] According to the present application, the contact conductivity of the flow field plate can be improved, the manufacturing of the flow field plate is facilitated, and the manufacturing cost of the flow field plate is reduced. [Brief explanation of the drawings]

[0012] These and other aspects of the present disclosure will be more fully understood and appreciated hereinafter in connection with the accompanying drawings, in which it should be noted that the drawings are merely illustrative and are not drawn to scale. [Figure 1] 1 is a schematic diagram of two cell units of an exemplary fuel cell pile, in which flow field plates manufactured in accordance with a preferred embodiment of the present application are used. [Figure 2] 1 is a top view of a flow field plate according to a preferred embodiment of the present application, schematically illustrating a first side of the flow field plate; [Figure 3] 3 is a bottom view of the flow field plate of FIG. 2, schematically illustrating a second side of the flow field plate opposite the first side. [Figure 4] 2 is a schematic cross-sectional view taken along line II of FIG. 1, illustrating a cross-section of one type of flow field plate according to the present application; [Figure 5] 3 is a schematic cross-sectional view similar to FIG. 2, illustrating a cross-section of another type of flow field plate according to the present application. [Figure 6] 1 is a top view diagram illustrating a laminate structure including a first conductive adhesive film disposed between two layers of backing film according to a preferred embodiment of the present application; [Figure 7] FIG. 7 is a side view of the laminated structure of FIG. 6. [Figure 8] 7 is a top view of the laminate structure of FIG. 6, schematically illustrating a first pattern cutout in the laminate structure. [Figure 9] 3 is a top view similar to FIG. 2, but showing the first conductive adhesive film and the second adhesive film not yet bonded to the metal plate of the flow field plate. [Figure 10] 10 is a top view similar to FIGS. 2 and 9, in which a first conductive adhesive film is adhered to the metal plate of the flow field plate, but a second adhesive film has not yet been adhered to the metal plate of the flow field plate. [Figure 11]11 is an enlarged view of dashed area A in FIG. 10, schematically illustrating one type of flow channel structure that may be formed by a manufacturing method according to the present application. [Figure 12] 11 is an enlarged view of dashed area B in FIG. 10, schematically illustrating one type of flow channel structure that may be formed by a manufacturing method according to the present application.

[0013] List of Reference Numbers 1 cell unit 3. Proton Exchange Membrane 5 Cathode diffusion layer 7 Cathode catalyst layer structure 9 Anode diffusion layer 11 Anode catalyst layer structure 100 Flow Field Plate 101 Metal Plate 101a First Aspect 101b The Second Aspect 101c entrance 101d exit 101e entrance 101f exit 101g First opening 101h Second opening 103 First Flow Field 105 Inlet Distribution Zone 107 Reaction Zone 107a1 side wall 107a2 bottom wall 107a First flow channel 107b First Ridge 107b1 Upper part 107b2 bottom 108 Protrusion 109 Exit Collection Zone 111 First conductive adhesive film 113a Second flow channel 113b Second Ridge 113b1 Upper part 115 Second Flow Field 117a Third flow channel 117b Third Ridge 117b1 Upper part 118 Third conductive adhesive film 200 Backing Film 300 laminated structure DETAILED DESCRIPTION OF THE INVENTION

[0014] Some preferred embodiments of the present application will be described in detail below in conjunction with examples. Those skilled in the art will understand that these embodiments are merely illustrative and are not intended to impose any limitations on the present application. Furthermore, the features of the embodiments of the present application may be combined with each other, provided that there is no contradiction. In the accompanying drawings, other components are omitted for the sake of simplicity, but this does not mean that the flow field plate, bipolar plate, fuel cell unit, and fuel cell of the present application cannot include other structures and components. Of course, the dimensions, proportional relationships, and number of components shown in the drawings should not be considered limitations on the present application.

[0015] Fuel cells can be used in vehicles to provide electricity, thereby driving a vehicle's motor or enabling on-board systems to perform various functions. FIG. 1 schematically illustrates two cell units 1 of an exemplary fuel cell pile. The exemplary fuel cells are proton exchange membrane fuel cells (PEMFCs), and the pile is formed by piling multiple cell units 1 together. As described in detail below, flow field plates 100 manufactured in accordance with preferred embodiments of the present application can be used in the cell units 1 to function as cathode plates and / or anode plates. For example, in one cell unit 1, a flow field plate 100 can be used as a cathode plate, and another flow field plate 100 can be used as an anode plate. Furthermore, the flow field plates 100 can be combined with other flow field plates.

[0016] As shown in FIG. 1 , each cell unit 1 typically consists of a cathode plate (flow field plate 100 on the left side of each cell unit 1 in FIG. 1 ), an anode plate (flow field plate 100 on the right side of each cell unit 1 in FIG. 1 ), a proton exchange membrane 3, a cathode diffusion layer 5 and a cathode catalyst layer structure 7 between the cathode plate and the proton exchange membrane 3, and an anode diffusion layer 9 and an anode catalyst layer structure 11 between the anode plate and the proton exchange membrane 3. The cathode diffusion layer 5, the cathode catalyst layer structure 7, the anode diffusion layer 9, the anode catalyst layer structure 11, and the proton exchange membrane 3 are typically integrated into a single unit called a membrane electrode assembly (MEA). The cathode diffusion layer 5 and the anode diffusion layer 9 support the cathode catalyst layer structure 7 and the anode catalyst layer structure 11, respectively, and are used to transport reactive fluids and reaction products (e.g., hydrogen, oxygen / air, water, etc.). As shown in Figures 4 and 5, the cathode flow field and the anode flow field are formed on the cathode plate and the anode plate, respectively. The cathode flow field of the cathode plate of the plurality of cell units 1 can form the cathode flow channel of the pile (not shown), and the anode flow field of the anode plate of the plurality of cell units 1 can form the anode flow channel of the pile (not shown).

[0017] The electrochemical reactions in a PEMFC occur in the MEA and mainly involve the hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR) processes. H2 and O2 are transported through the anode diffusion layer 9 and cathode diffusion layer 5 to the anode catalyst layer structure 11 and cathode catalyst layer structure 7, respectively, where H2 loses electrons under the action of the anode catalyst in the anode catalyst layer structure 11 to form H+. H+ is transferred to the cathode side through the proton exchange membrane 3 and combined with O2 under the action of the cathode catalyst in the cathode catalyst layer structure 7 to form H2O. H2O is transferred to the cathode and anode flow fields through the cathode diffusion layer 5 and anode diffusion layer 9, and then discharged from the PEMFC through the cathode and anode flow channels. Electrons flow to the cathode through an external circuit (not shown), forming an electric current.

[0018] 2-4 schematically illustrate a flow field plate 100 constructed through a manufacturing method according to a preferred embodiment of the present application. As shown in FIGS. 2 and 3, the flow field plate 100 comprises a metal plate 101 having opposing first and second sides 101a and 101b. The metal plate 101 may be made of an iron-based alloy (stainless steel), a light metal, or an alloy thereof (mainly titanium and its alloys, aluminum and its alloys). The metal plate 101 comprises an inlet 101c configured to receive a reactive fluid (a reactive gas in a PEMFC, specifically hydrogen, oxygen, or air) and an outlet 101d configured to discharge a reaction product. The inlet 101c and the outlet 101d are openings extending through the metal plate 101.

[0019] As shown in FIGS. 2 and 4, the flow field plate 100 further includes a first flow field 103 formed on a first side 101a of the metal plate 101 for circulating a reactive fluid. The first flow field 103 includes an inlet distribution zone 105, a reaction zone 107, and an outlet collection zone 109, which are sequentially arranged along the flow direction of the reactive gas. The reaction zone 107 includes a first ridge 107b defining a first flow channel 107a. The first flow channel 107a extends between the inlet distribution zone 105 and the outlet collection zone 109. The inlet distribution zone 105 of the first flow field 103 is disposed near the inlet 101c of the metal plate 101 and is in communication with the inlet 101c, configured to receive the reactive gas from the inlet 101c and distribute the reactive gas to each of the flow channels 107a. The outlet collection zone 109 is configured to collect the reaction products from the first flow channel 107a, is positioned near the outlet 101d of the metal plate 101, and is configured to communicate with the outlet 101d and discharge the reaction products to the outlet 101d.

[0020] Continuing with reference to Figures 2 and 4, the flow field plate 100 further comprises a first conductive adhesive film 111, which corresponds to the first ridge 107b and is patterned to be adhered to the first side 101a of the metal plate 101. This arrangement ensures that at least 10% (e.g., 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, or any value in between of the height of the first ridge 107b) of the first ridge 107b (measured from the top 107b1) (Figure 4) is formed by the first pattern 111. As best shown in Figure 4, when the flow field plate 100 is used as an anode or cathode plate and assembled with an MEA, the first conductive adhesive film 111 can adhere the metal plate 101 to the cathode diffusion layer 5 and anode diffusion layer 9, respectively, of the MEA.

[0021] As specifically described in conjunction with the method for manufacturing the flow field plate 100, the inventors have recognized that the above-described configuration of the flow field plate 100 according to the present application can provide several advantages: (1) the first conductive adhesive film 111 maintains stable adhesion between the metal plate 101 and the cathode diffusion layer 5 and the anode diffusion layer 9, thereby maintaining substantially constant contact resistance during long-term operation of the fuel cell. This helps to improve the contact conductivity of the flow field plate 100, thereby improving the reliability and power generation performance of the fuel cell. (2) By providing the first conductive adhesive film 111, the need for additional holding force between the metal plate 101 and the cathode diffusion layer 5 and the anode diffusion layer 9 can be reduced, improving the reliability of the fuel cell. (3) The first conductive adhesive film 111 covers a portion of the metal plate 101, helping to prevent corrosion on that portion of the metal plate 101, thereby extending the service life of the flow field plate 100. (4) The first conductive adhesive film 111 is fixed to the metal plate 101 by adhesion, eliminating the need for a complex and time-consuming surface modification process on the metal plate 101 and making the flow field plate 100 easier to manufacture, reducing manufacturing costs and therefore facilitating mass production of the flow field plate 100. (5) At least 10% of the height of the first ridge 107b measured from the top portion 107b1 is formed by the first pattern, allowing the first conductive adhesive film 111 to form at least a portion of the flow field of the reaction zone 107. This helps to reduce or even eliminate the stamping operations required to manufacture the reaction zone 107 of the flow field plate 100 and improves flexibility in the design and manufacturing of the flow field plate 100.

[0022] An exemplary method for manufacturing a flow field plate 100 according to the present application will be specifically described in conjunction with Figures 4-10. Figure 9 is a top view of the metal plate 101, schematically illustrating a first side 101a of the metal plate 101. The metal plate 101 is already formed with an inlet 101c and an outlet 101d. The inlet 101c and the outlet 101d of the metal plate 101 may be formed by any process known in the art, such as machining, stamping, etc.

[0023] A method for manufacturing a flow field plate 100 according to the present application includes forming a first flow field 103 for circulating a reactive fluid on a first side 101a of a metal plate 101. As described above, the reaction zone 107 of the first flow field 103 includes a first ridge 107b that defines a first flow channel 107a. The first flow field 103 is formed according to the following steps: (1) cutting a first pattern corresponding to the first ridge 107b in a first conductive adhesive film 111 (FIG. 8); and (2) bonding the cut first pattern to the metal plate 101 on the first side 101a so that at least 10% of the height of the first ridge 107b measured from the top is formed by the first pattern (FIG. 10). It should be understood that the manufacturing method according to the present application can provide the advantages (1) to (5) described above.

[0024] The manufacturing method of the present application improves the design and manufacturing flexibility of the flow field plate 100. For example, FIGS. 11 and 12 show two flow channel structures that can be formed by the manufacturing method of the present application. FIG. 11 shows a first flow channel 107a having a necking structure. The first flow channel 107a is defined by the shape of a first ridge 107b. Specifically, the flow area of the first flow channel 107a first decreases and then increases along the flow direction of the reactive fluid (as indicated by the dashed arrow in the figure), thereby accelerating the flow of the reactive fluid or reaction product. In this specification, unless otherwise specified, "flow area" refers to the effective cross-sectional area of the channel for fluid flow within a component or part. This necking structure can be configured at a desired position in the first flow field 103 to achieve the effect of accelerating the flow of the reactive fluid or reaction product. For example, this necking structure can be configured downstream of the reaction zone of the cathode flow field to accelerate the release of the reaction product. 12 shows a first flow channel 107a having a turbulent structure. Specifically, protrusions 108 may be provided on the sidewalls of the first flow channel 107a (i.e., first ridges 107b) that protrude into the first flow channel 107a to create turbulence in the reactant fluids, which helps to enhance the reaction within the reaction zone 107.

[0025] 11 and 12 are difficult to form by conventional processes such as stamping and machining. In contrast, using the manufacturing method of the present application, first flow channel 107a having a necking structure and a turbulent flow structure can be easily and cost-effectively formed. Of course, the manufacturing method of the present application can also easily and cost-effectively form other flow channel structures that are difficult to form by conventional processes such as stamping and machining, and the present application is not limited thereto.

[0026] Furthermore, compared to conventional processes such as stamping and machining, the manufacturing method of the present application can form a variety of complex flow field patterns simply and cost-effectively, reducing or even eliminating the cost of designing and manufacturing stamping molds.

[0027] Importantly, the manufacturing method according to the present application allows for improved flexibility in the design and manufacture of the flow field plate 100.

[0028] In some embodiments, the entire height (100%) of the first ridge 107b, measured from the upper portion 107b1, can be formed by the first conductive adhesive film 111 (i.e., the first pattern). As shown in FIGS. 5 and 9, the first region of the metal plate 101 corresponding to the reaction zone 107 is substantially flat. As used herein, "substantially flat" means within acceptable manufacturing tolerances. In this case, the first pattern can be configured such that the entire height of the first ridge 107b, measured from the upper portion 107b1, is formed by the first pattern. Thus, the step of adhering the cut first pattern to the first side 101a of the metal plate 101 includes adhering the cut first pattern to the first region of the metal plate 101 on the first side 101a to form the entire first ridge 107b. This method can further improve the flexibility of designing and manufacturing the flow field plate 100. For example, referring to the structure of flow field plate 100 (used as a cathode plate) in the lower part of FIG. 5 , the entire height of first ridge 107b, measured from top 107b1, is formed by first conductive adhesive film 111 (i.e., first pattern). In this case, sidewall 107a1 of first flow channel 107a may be perpendicular to bottom wall 107a2 of first flow channel 107a, i.e., the draft angle is zero. This flow channel structure helps increase the flow channel density in reaction zone 107, thereby improving the performance of flow field plate 100. Such a flow channel structure is difficult to form by conventional processes such as stamping and machining. In contrast, the manufacturing method of the present application allows for simple and cost-effective formation of first flow channels 107a having sidewalls 107a1 perpendicular to bottom wall 107a2 of first flow channel 107a.

[0029] In another partial embodiment, as shown in FIGS. 4 and 5, a portion of the height of the first ridge 107b, measured from the bottom 107b2 opposite the top 107b1, can be formed by stamping the metal plate 101. Specifically, referring to the structure of the flow field plate 100 (used as an anode plate) in the upper part of FIG. 5, the first ridge 107b is composed of a first portion and a second portion. The first portion is formed by stamping the metal plate 101, and the second portion is formed by adhering a first conductive adhesive film 111 to the first portion. That is, forming the first flow field 103 further includes a step of forming the first portion of the first ridge 107b by stamping the metal plate 101, and the step of adhering the cut first pattern to the first side 101a of the metal plate 101 includes adhering the cut first pattern to the first portion to form the second portion, thereby forming the entire first ridge 107b.

[0030] The first conductive adhesive film 111 includes a first adhesive material and first conductive particles dispersed therein. The first conductive particles can be dispersed in the first adhesive material at any suitable weight percentage by any suitable process. This depends in particular on the conductive properties of the first adhesive material itself and the density and conductivity of the first conductive particles. The first adhesive material can be preferably polymethyl methacrylate (PMMA), acrylic adhesive, polypyrrole, epoxy resin, silicone resin, polyamide, polyimide, or fluororubber. The first conductive particles can be preferably gold (Au), graphite, a high-surface-area carbon material (such as Ketjenblack, carbon black, graphene, single-walled carbon nanotubes, multi-walled carbon nanotubes, chromium nitride (CrN), or titanium nitride (TiN)). Of course, the present application is not limited thereto, and it is understood that the first adhesive material and the first conductive particles may be any suitable material that enables the first conductive adhesive film 111 to maintain stable adhesion between the metal plate 101 and each of the cathode diffusion layer 5 and the anode diffusion layer 9, and to maintain a substantially constant contact resistance.

[0031] In some embodiments, the first conductive adhesive film 111 is configured to adhere the metal plate 101 to each of the cathode diffusion layer 5 and the anode diffusion layer 9, providing an adhesive force of at least 2 N / cm (e.g., 2 N / cm, 2.5 N / cm, 3 N / cm, or more) between each of the diffusion layers and the metal plate 101. This helps to maintain stable adhesion and a substantially constant contact resistance between the metal plate 101 and each of the diffusion layers, and also helps to meet the need for additional holding force between the metal plate 101 and each of the diffusion layers.

[0032] 4 and 5, each first flow channel 107a is defined by two side walls 107a1 and a bottom wall 107a2 extending between the two side walls 107a1. The two side walls 107a1 are formed by two adjacent first ridges 107b, and the bottom wall 107a2 is formed by a portion of the metal plate 101 between the two adjacent first ridges 107b. The first pattern (i.e., the conductive adhesive film 111) does not overlap with the portion of the metal plate 101. Of course, the portion of the metal plate 101 between the two adjacent first ridges 107b or the entire metal plate 101 may be surface-treated to have corrosion resistance.

[0033] 6 to 8, the step of cutting out a first pattern corresponding to the first ridges 107b in the first conductive adhesive film 111 can include placing the first conductive adhesive film 111 between two layers of backing film 200 to form a laminate structure 300, and cutting out a first pattern corresponding to the first ridges 107b in the laminate structure 300. FIG. 6 schematically shows a top view of a laminate structure 300 including a first conductive adhesive film 111 placed between two layers of backing film 200, FIG. 7 is a side view of the laminate structure of FIG. 6, and FIG. 8 is a top view of the laminate structure 300 of FIG. 6, schematically showing the first pattern cut out in the laminate structure 300. Then, the step of adhering the cut first pattern to the first side 101a of the metal plate 101 can include peeling the cut out first pattern from the backing film 200 and adhering it to the first side 101a of the metal plate 101 (shown in FIG. 10). The backing film 200 can be made of a material suitable for holding the first conductive adhesive film 111 during cutting of the first pattern from the first conductive adhesive film 111, and for easily peeling the first conductive adhesive film 111 therefrom without damage after the first pattern has been cut.

[0034] 2, the inlet distribution zone 105 and the outlet collection zone 109 of the first flow field 103 may be formed in a manner similar to that of the reaction zone 107. Specifically, at least one of the inlet distribution zone 105 and the outlet collection zone 109 includes a second ridge 113b that defines a second flow channel 113a. The flow field plate 100 further includes a second adhesive film (not shown) that is patterned to correspond to the second ridge 113b and adhered to the first side 101a of the metal plate 101 such that at least a portion (e.g., 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, or any value therebetween) of the height of the second ridge 113b measured from the top 113b1 is formed by the second pattern. In other words, forming the first flow field 103 further includes cutting a second pattern corresponding to the second ridge 113b in the second adhesive film, and adhering the cut second pattern to the first side 101a of the metal plate 101 so that at least a portion of the height of the second ridge 113b measured from the top 113b1 is formed by the second pattern.

[0035] In this way, several advantages can be provided: (1) the second adhesive film can further help maintain stable adhesion between the metal plate 101 and the cathode diffusion layer 5 and the anode diffusion layer 9, thereby keeping the contact resistance substantially constant, which helps to improve the contact conductivity of the flow field plate 100 and therefore improve the performance of a fuel cell using the flow field plate 100; (2) at least a portion of the height of the second ridge 113b measured from the upper portion 113b1 is formed by the second pattern, which allows the second adhesive film to form at least a portion of the flow field in at least one of the inlet distribution zone 105 and the outlet collection zone 109, which helps to reduce or even eliminate stamping operations required in manufacturing at least one of the inlet distribution zone 105 and the outlet collection zone 109 of the flow field plate 100 and improves the flexibility in designing and manufacturing the flow field plate 100.

[0036] Preferably, the second adhesive film can be a polyethylene naphthalate (PEN), polyethylene terephthalate (PET), or polyimide (PI) film having an acrylic adhesive coated on its surface, although the second adhesive film is not limited thereto and can also be made of other suitable materials.

[0037] In some embodiments, as shown in Figure 9, at least one of the second region of the inlet distribution zone 105 and the outlet collection zone 109 of the metal plate 101 is substantially flat. It is contemplated that the second adhesive film may be adhered to the second region (Figure 2) and configured such that the entire height of the second ridge 113b measured from the upper portion 113b1 is formed by the second pattern. In other words, the second pattern is configured such that the entire height of the second ridge 113b measured from the upper portion 107b1 is formed by the second pattern, and the step of adhering the cut second pattern to the first side 101a of the metal plate 101 includes adhering the cut second pattern to the second region of the metal plate 101 on the first side 101a to form the entire second ridge 113b. It is understood that, as described above in connection with the reaction zone 107, the methods described herein can easily and cost-effectively form flow channel structures and flow channel patterns in the inlet distribution zone 105 and the outlet collection zone 109 that are difficult to form by conventional processes such as stamping and machining. It is also understood that, in another partial embodiment, a portion of the second ridge 113b measured from the bottom opposite the top 107b1 can be formed by stamping the metal plate 101, and the remaining portion of the second ridge 113b can be formed by adhering a second adhesive film to that portion, thereby forming the entire second ridge 113b.

[0038] 2 and 3, the metal plate 101 further comprises an inlet 101e configured to receive a cooling fluid and an outlet 101f configured to discharge the cooling fluid. Additionally, the metal plate 101 further comprises a first opening 101g and a second opening 101h configured to communicate with a reactive fluid inlet and a reaction product outlet, respectively, of another metal plate 101. The inlet 101e, the outlet 101f, the first opening 101g, and the second opening 101h are all openings extending through the metal plate 101.

[0039] As shown in FIG. 3, the flow field plate 100 may further include a second flow field 115 formed on a second side 101b of the metal plate 101 opposite the first side 101a and used to circulate a cooling fluid. The second flow field 115 includes a third ridge 117b defining a third flow channel 117a. The third flow channel 117a extends between an inlet 101e and an outlet 101f. The cooling fluid flows from the inlet 101e into the second flow field 115 and exits the second flow field 115 through the outlet 101f.

[0040] It is contemplated that second flow field 115 may be formed in a similar manner to reaction zone 107. Specifically, flow field plate 100 further includes a third conductive adhesive film 118 (FIGS. 4 and 5), which corresponds to third ridge 117b and is patterned to be adhered to second side 101b of metal plate 101. This arrangement ensures that at least 10% (e.g., 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, or any value therebetween) of the height of third ridge 117b, as measured from top 117b1, is formed by the third pattern.

[0041] In other words, the method of the present application for forming flow field plate 100 further includes forming a second flow field 115 for circulating a cooling fluid on a second side 101b of metal plate 101 opposite first side 101a. The step of forming second flow field 115 includes the steps of cutting a third pattern corresponding to third ridge 117b in third conductive adhesive film 118, and adhering the cut third pattern to second side 101b of metal plate 101 such that at least 10% of the height of third ridge 117b measured from top 117b1 is formed by the third pattern.

[0042] In this way, several advantages can be provided: (1) when two flow field plates 100 are fixed together with the first flow field 103 facing each other to form a bipolar plate, the third conductive adhesive film 118 can maintain a stable adhesive force between the two flow field plates 100, thereby keeping the contact resistance substantially constant; and (2) at least 10% of the height of the third ridge 117b measured from the top 117b1 is formed by the third pattern, thereby allowing the third conductive adhesive film 118 to form at least a part of the second flow field 115 for circulating a cooling fluid. This helps to reduce or eliminate the stamping operation required to create the second flow field 115 of the flow field plate 100, improving the flexibility in designing and manufacturing the flow field plate 100.

[0043] The third conductive adhesive film 118 includes a third adhesive material and second conductive particles dispersed within the third adhesive material. The second conductive particles can be dispersed within the third adhesive material in any suitable weight percentage and by any suitable process, depending in particular on the conductive properties of the third adhesive material itself and the density and conductivity of the second conductive particles. The third adhesive material is preferably a phenolic resin or an epoxy resin. The second conductive particles are preferably expanded graphite or other highly conductive carbon materials.

[0044] In some embodiments, the third region of the metal plate 101 corresponding to the second flow field 115 is considered to be substantially flat. The third pattern is adhered to the third region and configured such that the entire height of the third ridge 117b, measured from the upper portion 117b1, is formed by the third pattern. In other words, the third pattern is configured such that the entire height of the third ridge 117b, measured from the upper portion 117b1, is formed by the third pattern, and adhering the cut third pattern to the second side 101b of the metal plate 101 includes adhering the cut third pattern to the third region of the metal plate 101 on the first side 101a to form the entire third ridge 117b. Of course, as described in connection with the reaction zone 107 above, it will be appreciated that the methods described herein can simply and cost-effectively form flow channel structures and flow channel patterns for circulation of a cooling fluid within the second flow field 115 that are difficult to form by conventional processes such as stamping and machining. It should also be understood that in other partial embodiments, a portion of the third ridge 117b measured from the bottom opposite the top 117b1 can be formed by stamping the metal plate 101 (e.g., while stamping the first ridge 107b), and the remaining portion of the third ridge 117b can be formed by adhering the third conductive adhesive film 118 to that portion, thereby forming the entire third ridge 117b.

[0045] The flow field plate 100 manufactured according to the above-described method can be used as an anode plate or a cathode plate. As shown schematically in FIG. 1 , the anode plate of one of two adjacent fuel cell units 1 can be secured together with the cathode plate of another fuel cell unit 1 before the stack is assembled to form a bipolar plate. In other words, the cathode and anode plates manufactured according to the above-described method can be secured together to opposing first flow fields 103 to form a bipolar plate. In some embodiments, both the cathode and anode plates can have a second flow field 115 for circulating a cooling fluid, and the second flow field 115 of the cathode plate and the second flow field 115 of the anode plate can cooperate with each other to collectively form a flow field for circulating a cooling fluid. In other embodiments, only one of the cathode and anode plates has a second flow field 115 for circulating a cooling fluid, and this second flow field 115 is used to circulate the cooling fluid between the cathode and anode plates.

[0046] In some embodiments, for the same bipolar plate, the entire height of the first ridge 107b of the first flow field 103 of the cathode plate is formed by the first conductive adhesive film 111, while 10% to 50% (e.g., 10%, 20%, 30%, 40%, 50%, or any value therebetween) of the height of the first ridge 107b of the first flow field 103 of the anode plate, measured from the top 107b1, is formed by the first conductive adhesive film 111. In this case, the remaining portion of the first ridge 107b of the first flow field 103 of the anode plate is formed by stamping. While forming the remaining portion of the first ridge 107b, at least a portion of the second flow field 115 for circulating a cooling fluid can be formed on the second side 101b opposite the first side 101a on which the first flow field 103 is formed on the anode plate. The first flow field 103 of the cathode plate is used as a cathode flow field, and the first flow field 103 of the anode plate is used as an anode flow field. During the reaction, the reaction products on the cathode side contain water, which needs to be quickly discharged from the reaction zone 107 through the cathode flow field. It is advantageous to form the entire height of the first ridge 107b of the first flow field 103 of the cathode plate (cathode flow field) with the first conductive adhesive film 111, because this enables the formation of various flow channel structures that are useful for draining the cathode flow field, which are difficult to form by conventional stamping.

[0047] The present disclosure discloses a method for manufacturing a flow field plate for a fuel cell unit, a method for manufacturing a bipolar plate for a fuel cell, a flow field plate for a fuel cell unit, and a bipolar plate for a fuel cell. Further embodiments and combinations thereof include:

[0048] Example 1 includes a method of manufacturing a flow field plate for a fuel cell unit, the method including forming a first flow field for circulating a reactive fluid on a first side of a metal plate, wherein a reaction zone of the first flow field includes first ridges defining first flow channels. Forming the first flow field includes cutting a first pattern corresponding to the first ridges in a first conductive adhesive film, and adhering the cut first pattern onto the first side of the metal plate such that at least 10% of the height of the first ridges, measured from the top, is formed by the first pattern.

[0049] Example 2 includes the method of example 1, wherein forming the first flow field further includes forming a first portion of the first ridge by stamping the metal plate, and wherein adhering the cut first pattern onto the first side of the metal plate includes adhering the cut first pattern onto the first portion to form the entire first ridge.

[0050] Example 3 includes the method of Example 1, wherein a first region of the metal plate corresponding to the reaction zone is substantially flat, the first pattern is configured such that the entire height of the first ridge measured from the top is formed by the first pattern, and the step of adhering the cut first pattern onto the first side of the metal plate includes adhering the cut first pattern onto the first region of the metal plate to form the entire first ridge.

[0051] Example 4 includes the method of example 1, wherein each first flow channel is defined by two side walls and a bottom wall extending between the two side walls, the two side walls are formed by two adjacent first ridges, the bottom wall is formed by a portion of the metal plate between the two adjacent first ridges, and the first pattern does not overlap with the portion of the metal plate.

[0052] Example 5 includes the method of example 1, wherein the first conductive adhesive film includes a first adhesive material and first conductive particles dispersed in the first adhesive material.

[0053] Example 6 includes the method of example 5, wherein the first adhesive material is PMMA, acrylic adhesive, polypyrrole, epoxy resin, silicone resin, polyamide, polyimide, or fluororubber, and / or the first conductive particles are gold, graphite, ketjen black, carbon black, graphene, single-walled carbon nanotubes, multi-walled carbon nanotubes, chromium nitride, or titanium nitride.

[0054] Example 7 includes the method of example 1, wherein the fuel cell unit further includes a membrane electrode assembly having a diffusion layer, and the first conductive adhesive film is configured to adhere the metal plate to the diffusion layer and provide an adhesive force of at least 2 N / cm between the diffusion layer and the metal plate.

[0055] Example 8 includes the method described in Example 1, in which the step of cutting a first pattern corresponding to the first ridge in the first conductive adhesive film includes placing the first conductive adhesive film between two backing films to form a laminate structure and cutting a first pattern corresponding to the first ridge in the laminate structure, and the step of adhering the cut first pattern onto the first side of the metal plate includes peeling the cut first pattern from the backing film and adhering it onto the first side of the metal plate.

[0056] Example 9 includes the method of any one of Examples 1-8, wherein the metal plate further comprises an inlet configured to receive a reactive fluid and an outlet configured to discharge a reaction product, the first flow field further comprises an inlet distribution zone in communication with the inlet and an outlet collection zone in communication with the outlet, the reaction zone extends between the inlet distribution zone and the outlet collection zone, and at least one of the inlet distribution zone and the outlet collection zone comprises a second ridge defining a second flow channel. Forming the first flow field further includes cutting a second pattern corresponding to the second ridge in the second adhesive film and adhering the cut second pattern onto the first side of the metal plate such that at least a portion of the height of the second ridge, measured from the top, is defined by the second pattern.

[0057] Example 10 includes the method of example 9, wherein a second region of the metal plate corresponding to at least one of the inlet distribution zone and the outlet collection zone is substantially flat, the second pattern is configured such that the entire height of the second ridge measured from the top is formed by the second pattern, and the step of adhering the cut second pattern onto the first side of the metal plate includes adhering the cut second pattern onto the second region of the metal plate to form the entire second ridge.

[0058] Example 11 includes the method of Example 10, wherein the second adhesive film is a PEN, PET, or PI film having a surface coated with an acrylic adhesive.

[0059] Example 12 includes the method of any one of Examples 1 to 8, further including forming a second flow field for circulating a cooling fluid on a second side of the metal plate opposite the first side, the second flow field including third ridges defining second flow channels. Forming the second flow field includes cutting a third pattern corresponding to the third ridges in a third conductive adhesive film, and adhering the cut third pattern on the second side of the metal plate such that at least 10% of the height of the third ridges, measured from the top, is formed by the third pattern.

[0060] Example 13 includes the method of example 12, wherein a third region of the metal plate corresponding to the second flow field is substantially flat, the third pattern is configured such that the entire height of the third ridge measured from the top is formed by the third pattern, and the step of adhering the cut third pattern onto the second side of the metal plate includes adhering the cut third pattern onto the third region of the metal plate to form the entire third ridge.

[0061] Example 14 includes the method of Example 12, in which the third conductive adhesive film comprises a third adhesive material and second conductive particles dispersed in the third adhesive material, the third adhesive material is preferably a phenolic resin or an epoxy resin, and the second conductive particles are preferably expanded graphite.

[0062] Example 15 includes a method of manufacturing a bipolar plate for a fuel cell, the method including: manufacturing a cathode plate using the method of Example 1; manufacturing an anode plate using the method of Example 1; and securing the cathode plate and the anode plate together in a first flow field opposite each other to form a bipolar plate.

[0063] Example 16 includes the method of example 15, wherein the entire height of the first ridge of the first flow field of the cathode plate is formed by the first conductive adhesive film, and 10% to 50% of the height of the first ridge of the first flow field of the anode plate, measured from the top, is formed by the first conductive adhesive film.

[0064] Example 17 includes a flow field plate for a fuel cell unit, the flow field plate comprising: a metal plate; a first flow field formed on a first side of the metal plate for circulating a reactive fluid, the reaction zone of the first flow field including a first ridge defining a first flow channel; and a first conductive adhesive film, the first conductive adhesive film having a first pattern corresponding to the first ridge, the first pattern being adhered to the first side of the metal plate such that at least 10% of the height of the first ridge measured from the top is formed by the first pattern.

[0065] Example 18 includes the flow field plate of Example 17, wherein the first ridge is composed of a first portion and a second portion, the first portion being formed by stamping a metal plate, and the second portion being formed by adhering a first conductive adhesive film to the first portion.

[0066] Example 19 includes the flow field plate of Example 17, wherein a first region of the metal plate corresponding to the reaction zone is substantially flat, a first conductive adhesive film is adhered to the first region, and the entire height of the first ridge measured from the top is formed by the first pattern.

[0067] Example 20 includes the flow field plate of example 17, wherein each first flow channel is defined by two side walls and a bottom wall extending between the two side walls, the two side walls being formed by two adjacent first ridges, the bottom wall being formed by a portion of the metal plate between the two adjacent first ridges, and the first pattern does not overlap with the second portion of the metal plate.

[0068] Example 21 includes the flow field plate of Example 17, where the first conductive adhesive film includes a first adhesive material and first conductive particles dispersed in the first adhesive material.

[0069] Example 22 includes the flow field plate of example 21, wherein the first viscous material is PMMA, acrylic, polypyrrole, epoxy, silicone, polyamide, polyimide, or fluororubber, and / or the first conductive particles are gold, graphite, ketjen black, carbon black, graphene, single-walled carbon nanotubes, multi-walled carbon nanotubes, chromium nitride, or titanium nitride.

[0070] Example 23 includes the flow field plate of Example 17, wherein the fuel cell unit further includes a membrane electrode assembly having a diffusion layer, and the first conductive adhesive film is configured to adhere the metal plate to the diffusion layer and provide an adhesive force of at least 2 N / cm between the diffusion layer and the metal plate.

[0071] Example 24 includes the flow field plate of Example 17, wherein the flow field plate further comprises an inlet configured to receive reactive fluids and an outlet configured to discharge reaction products; the first flow field further comprises an inlet distribution zone in communication with the inlet and an outlet collection zone in communication with the outlet; the reaction zone extends between the inlet distribution zone and the outlet collection zone; at least one of the inlet distribution zone and the outlet collection zone comprises a second ridge defining a second flow channel; and the flow field plate further comprises a second adhesive film, the second adhesive film having a second pattern corresponding to the second ridge, and the second adhesive film is adhered to the first side of the metal plate such that at least a portion of the height of the second ridge measured from the top is formed by the second pattern.

[0072] Example 25 includes the flow field plate described in Example 24, where the second adhesive film is a PEN, PET, or PI film having a surface coated with an acrylic adhesive.

[0073] Example 26 includes the flow field plate of Example 17, wherein a second region of the metal plate corresponding to at least one of the inlet distribution zone and the outlet collection zone is substantially flat, a second adhesive film is adhered to the second region, and the entire height of the second ridge measured from the top is formed by the second pattern.

[0074] Example 27 includes the flow field plate of Example 17, wherein the flow field plate is formed on a second side of the metal plate opposite the first side and is a second flow field used to circulate a reactive fluid, wherein the reaction zone of the second flow field includes third ridges that define second flow channels; and a third conductive adhesive film, wherein the third conductive adhesive film is adhered to the second side of the metal plate in a third pattern corresponding to the third ridges, and wherein at least 10% of the height of the third ridges measured from the top is formed by the third pattern.

[0075] Example 28 includes the flow field plate of Example 27, wherein the third conductive adhesive film comprises a third adhesive material and second conductive particles dispersed in the third adhesive material, the third adhesive material is preferably a phenolic resin or an epoxy resin, and the second conductive particles are preferably expanded graphite.

[0076] Example 29 includes the flow field plate of example 17, wherein a third region of the metal plate corresponding to the second flow field is substantially flat, and a third pattern is adhered to the third region, and the third pattern is configured to define the entire height of the third ridge measured from the top.

[0077] Example 30 comprises a bipolar plate for a fuel cell, the bipolar plate comprising an anode plate which is a flow field plate according to Example 11, and a cathode plate which is a flow field plate according to Example 11, both of which are secured to a first flow field opposite each other.

[0078] Example 31 includes the bipolar plate of Example 30, wherein the entire height of the first ridge of the first flow field of the cathode plate is formed by the first conductive adhesive film, and 10% to 50% of the height of the first ridge of the first flow field of the anode plate, measured from the top, is formed by the first conductive adhesive film.

[0079] It should be understood that the terms "first," "second," and "third" are used only to distinguish one component or portion from other components or portions, and are not intended to limit these components and / or portions in any way.

[0080] The present application has been described in detail in conjunction with specific embodiments. It is clear that the embodiments illustrated in the above description and the accompanying drawings should be understood as illustrative rather than limiting the present application. Those skilled in the art may make various modifications or changes without departing from the spirit of the present application, and such modifications or changes should not be excluded from the scope of the present application.

Claims

1. 1. A method of manufacturing a flow field plate for a fuel cell unit, comprising: The method comprises: forming a first flow field for circulating a reactive fluid on a first side of a metal plate, the reaction zone of the first flow field including a first ridge defining a first flow channel; forming the first flow field cutting a first pattern corresponding to the first ridge in a first conductive adhesive film; adhering the cut first pattern onto the first side of the metal plate such that at least 10% of the height of the first ridge measured from the top is formed by the first pattern; A method comprising:

2. forming the first flow field further includes forming a first portion of the first ridge by stamping the metal plate, and adhering the cut first pattern onto the first side of the metal plate includes adhering the cut first pattern onto the first portion of the first ridge to form the entire first ridge; Or, a first region of the metal plate corresponding to the reaction zone is substantially flat, the first pattern is configured such that the entire height of the first ridge measured from the top is formed by the first pattern, and the step of adhering the cut first pattern onto the first side of the metal plate includes adhering the cut first pattern onto the first region to form the entire first ridge; 2. The method of claim 1.

3. The first conductive adhesive film includes a first adhesive material and first conductive particles dispersed in the first adhesive material, the first adhesive material is preferably PMMA, an acrylic adhesive, polypyrrole, an epoxy resin, a silicone resin, a polyamide, a polyimide, or a fluororubber, and the first conductive particles are preferably gold, graphite, ketjen black, carbon black, graphene, a single-walled carbon nanotube, a multi-walled carbon nanotube, chromium nitride, or titanium nitride; and / or each first flow channel is defined by two side walls and a bottom wall extending between the two side walls, the two side walls being formed by two adjacent first ridges, the bottom wall being formed by a portion of the metal plate between the two adjacent first ridges, and the first pattern does not overlap with the portion of the metal plate; 2. The method of claim 1.

4. The fuel cell unit further comprises a membrane electrode assembly having a diffusion layer, and the first conductive adhesive film is configured to adhere the metal plate to the diffusion layer and provide an adhesive force of at least 2 N / cm between the diffusion layer and the metal plate; and / or the step of cutting the first pattern corresponding to the first ridge in the first conductive adhesive film includes disposing the first conductive adhesive film between two backing films to form a laminate structure and cutting the first pattern corresponding to the first ridge in the laminate structure, and the step of adhering the cut first pattern onto the first side of the metal plate includes peeling the cut first pattern from the backing film and adhering it onto the first side of the metal plate; 2. The method of claim 1.

5. the metal plate further comprising an inlet configured to receive a reactive fluid and an outlet configured to discharge a reaction product; the first flow field further comprises an inlet distribution zone in communication with the inlet and an outlet collection zone in communication with the outlet, the reaction zone extending between the inlet distribution zone and the outlet collection zone, at least one of the inlet distribution zone and the outlet collection zone comprising a second ridge defining a second flow channel; forming the first flow field cutting a second pattern corresponding to said second ridges in a second adhesive film, said second adhesive film preferably being a PEN, PET or PI film having an acrylic adhesive coating; adhering the cut second pattern onto the first side of the metal plate such that at least a portion of the height of the second ridge measured from the top is formed by the second pattern; Including, 5. The method according to any one of claims 1 to 4.

6. a second region of the metal plate corresponding to at least one of the inlet distribution zone and the outlet collection zone is substantially flat, and the second pattern is configured such that the entire height of the second ridge, measured from the top, is formed by the second pattern; the step of adhering the cut second pattern onto the first side of the metal plate includes adhering the cut second pattern onto the second region of the metal plate to form the entire second ridge; 6. The method of claim 5.

7. The method comprises: forming a second flow field for circulating a cooling fluid on a second side of the metal plate opposite the first side; the second flow field includes a third ridge defining a second flow channel; forming the second flow field cutting a third pattern corresponding to the third ridges in a third conductive adhesive film, the third conductive adhesive film comprising a third adhesive material and second conductive particles dispersed in the third adhesive material, the third adhesive material being preferably a phenolic resin or an epoxy resin, and the second conductive particles being preferably expanded graphite; adhering the cut third pattern onto the second side of the metal plate such that at least 10% of the height of the third ridge measured from the top is formed by the third pattern; Including, 5. The method according to any one of claims 1 to 4.

8. a third region of the metal plate corresponding to the second flow field is substantially flat, and the third pattern is configured such that the entire height of the third ridge, as measured from the top, is formed by the third pattern; the step of adhering the cut third pattern onto the second side of the metal plate includes adhering the cut third pattern onto the third region of the metal plate to form the entire third ridge; 8. The method of claim 7.

9. 1. A method of manufacturing a bipolar plate for a fuel cell, comprising: Manufacturing a cathode plate using the method of claim 1; Manufacturing an anode plate using the method of claim 1; fixing the cathode plate and the anode plate together in the first flow field opposite each other to form a bipolar plate; A method comprising:

10. the entire height of the first ridge of the first flow field of the cathode plate is formed by the first conductive adhesive film; 10% to 50% of the height of the first ridge of the first flow field of the anode plate measured from above is formed by the first conductive adhesive film.

10. The method of claim 9.

11. 1. A flow field plate for a fuel cell unit, comprising: A metal plate and a first flow field formed on a first side of the metal plate for circulating a reactive fluid, the reaction zone of the first flow field including a first ridge defining a first flow channel; a first conductive adhesive film, the first conductive adhesive film having a first pattern corresponding to the first ridge, the first conductive adhesive film being adhered to the first side of the metal plate such that at least 10% of the height of the first ridge measured from the top is formed by the first pattern; A flow field plate comprising:

12. the first ridge is composed of a first portion and a second portion, the first portion being formed by stamping the metal plate, and the second portion being formed by adhering the first conductive adhesive film to the first portion; Or, a first area of the metal plate corresponding to the reaction zone is substantially flat, and the first conductive adhesive film is adhered to the first area and configured such that the entire height of the first ridge measured from the top is formed by the first pattern; 12. The flow field plate of claim 11.

13. The first conductive adhesive film includes a first adhesive material and first conductive particles dispersed in the first adhesive material, the first adhesive material is preferably PMMA, an acrylic adhesive, polypyrrole, an epoxy resin, a silicone resin, a polyamide, a polyimide, or a fluororubber, and the first conductive particles are preferably gold, graphite, ketjen black, carbon black, graphene, a single-walled carbon nanotube, a multi-walled carbon nanotube, chromium nitride, or titanium nitride; and / or each first flow channel is defined by two side walls and a bottom wall extending between the two side walls, the two side walls being formed by two adjacent first ridges, the bottom wall being formed by a second portion of the metal plate between the two adjacent first ridges, and the first pattern does not overlap the second portion of the metal plate; and / or the fuel cell unit further comprises a membrane electrode assembly having a diffusion layer, and the first conductive adhesive film is configured to adhere the metal plate to the diffusion layer and provide an adhesive force of at least 2 N / cm between the diffusion layer and the metal plate.

12. The flow field plate of claim 11 .

14. the flow field plate further comprising an inlet configured to receive a reactive fluid and an outlet configured to discharge a reaction product; the first flow field further comprising an inlet distribution zone in communication with the inlet and an outlet collection zone in communication with the outlet; the reaction zone extends between the inlet distribution zone and the outlet collection zone, at least one of the inlet distribution zone and the outlet collection zone comprising a second ridge defining a second flow channel; the flow field plate further comprises a second adhesive film, the second adhesive film having a second pattern corresponding to the second ridges, the second adhesive film being adhered to the first side of the metal plate such that at least a portion of the height of the second ridges measured from the top is formed by the second pattern; The second adhesive film is preferably a PEN, PET or PI film having an acrylic adhesive coating.

12. The flow field plate of claim 11.

15. a second area of the metal plate corresponding to at least one of the inlet distribution zone and the outlet collection zone is substantially flat, and the second adhesive film is adhered to the second area and configured such that the entire height of the second ridge, measured from the top, is formed by the second pattern; 15. The flow field plate of claim 14.

16. The flow field plate comprises: a second flow field formed on a second side of the metal plate opposite the first side and configured to circulate a cooling fluid, the second flow field including a third ridge defining a second flow channel; and a third conductive adhesive film in a third pattern corresponding to the third ridge, the third conductive adhesive film being adhered to the second side of the metal plate such that at least 10% of the height of the third ridge measured from the top is formed by the third pattern; Furthermore, The third conductive adhesive film comprises a third adhesive material and second conductive particles dispersed in the third adhesive material, the third adhesive material being preferably a phenolic resin or an epoxy resin, and the second conductive particles being preferably expanded graphite.

12. The flow field plate of claim 11.

17. a third region of the metal plate corresponding to the second flow field is substantially flat; the third pattern is adhered to the third region and configured such that the entire height of the third ridge, measured from the top, is formed by the third pattern.

17. The flow field plate of claim 16.

18. 1. A bipolar plate for a fuel cell, comprising: an anode plate, the anode plate being the flow field plate of claim 11; a cathode plate, said cathode plate being another flow field plate according to claim 11; Equipped with The anode plate and the cathode plate are both fixed to the first flow field opposite each other, a bipolar plate.

19. the entire height of the first ridge of the first flow field of the cathode plate is formed by the first conductive adhesive film; 10% to 50% of the height of the first ridge of the first flow field of the anode plate measured from above is formed by the first conductive adhesive film.

19. The bipolar plate of claim 18.

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