Flow field plate, bipolar plate and manufacturing method thereof

Abstract

A method of manufacturing a flow field plate for a fuel cell is provided. The method includes forming a first flow field on a first side of a metal plate for circulation of a reaction fluid, a reaction zone of the first flow field including a first ridge defining a first flow channel. Forming the first flow field includes the steps of: cutting a first pattern corresponding to the first ridge in a first conductive adhesive film; and adhering the cut-out first pattern to the metal plate on the first side such 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 of manufacturing a bipolar plate for a fuel cell, and a flow field plate and a bipolar plate manufactured by the aforementioned method. According to the flow field plate, the contact conductivity of the flow field plate can be improved, the flow field plate is easy to manufacture, and the manufacturing cost of the flow field plate is reduced.

Description

Flow field plate, bipolar plate and manufacturing method thereof Technical Field

[0001] The present invention relates generally to fuel cell technology, and more particularly to flow field plates, bipolar plates and methods of manufacturing the same for fuel cells. Background Art

[0002] Fuel cells, which generate electricity by electrochemically reacting a fuel with an oxidant, are increasingly being used to provide electricity, particularly in the field of electric vehicles. A proton exchange membrane fuel cell is a widely used fuel cell that uses hydrogen as fuel and oxygen as an oxidant. Typically, a membrane electrode assembly (MEA) is arranged between two flow field plates to form a fuel cell unit. The two flow field plates serve as cathode and anode plates, respectively, and include a flow field for supplying a reactant fluid (i.e., hydrogen, oxygen, or air) to the MEA.

[0003] Metals are commonly used to manufacture flow field plates (FFPs) due to their excellent thermal and electrical conductivity and compactness. However, in the operating environment of proton exchange membrane fuel cells (e.g., low pH, high humidity, and an operating temperature of approximately 80°C), typical metal materials used for FFPs (e.g., stainless steel and titanium) are chemically unstable, resulting in issues with corrosion resistance and contact conductivity.

[0004] In existing flow field plate manufacturing technology, the corrosion resistance and contact conductivity of metal flow field plates are usually improved by applying a carbon-based coating to them. However, applying the carbon-based coating needs to be carried out in a vacuum environment. This process is complicated, time-consuming and costly, which is not conducive to large-scale production of flow field plates. In addition, in order to maintain a substantially constant contact resistance between the flow field plate with the carbon-based coating and the MEA, a large holding force needs to be maintained between the flow field plate and the MEA. This relies on the fuel cell stack fixture. However, due to the vibration in the working environment of the fuel cell, the fixture may become loose, resulting in a reduction in the holding force, which in turn causes the contact resistance between the flow field plate and the MEA to increase.

[0005] Therefore, it is necessary to improve the existing flow field plate manufacturing technology.

[0006] Summary of the Invention

[0007] The present application aims to provide an improved method for manufacturing a flow field plate for a fuel cell unit to overcome at least one of the above-mentioned drawbacks.

[0008] According to one aspect of the present application, a method for manufacturing a flow field plate for a fuel cell unit is provided. 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 a first ridge defining a first flow channel. Forming the first flow field includes the steps of cutting a first pattern corresponding to the first ridge in a first conductive adhesive film; and adhering the cut first pattern to the metal plate on the first side such that at least 10% of the height of the first ridge, measured from the top, is formed by the first pattern.

[0009] According to another aspect of the present application, a method for manufacturing a bipolar plate for a fuel cell is provided, comprising: manufacturing a cathode plate using the aforementioned method; manufacturing an anode plate using the aforementioned method; and fixing the cathode plate and the anode plate together in such a manner that the first flow field faces back to back with each other to form a bipolar plate.

[0010] According to another aspect of the present application, a flow field plate for a fuel cell unit is provided, comprising: a metal plate; a first flow field formed on a first side of the metal plate and used to circulate a reaction fluid, the reaction area of ​​the first flow field comprising 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 and being bonded to the metal plate on the first side so that at least 10% of the height of the first ridge measured from the top is formed by the first pattern.

[0011] According to another aspect of the present application, a bipolar plate for a fuel cell is provided, comprising: an anode plate, which is one of the aforementioned flow field plates; and a cathode plate, which is another of the aforementioned flow field plates; wherein the anode plate and the cathode plate are fixed together in such a manner that the first flow field is facing each other.

[0012] According to the present application, the contact conductivity of the flow field plate can be improved, and the flow field plate can be easily manufactured, thereby reducing the manufacturing cost of the flow field plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above and other aspects of the present application will be more thoroughly understood and appreciated with reference to the accompanying drawings. It should be noted that the drawings are for illustrative purposes only and are not drawn to scale. In the drawings:

[0014] FIG1 schematically shows two battery cells of an exemplary fuel cell stack, wherein flow field plates manufactured according to a method according to a preferred embodiment of the present application are used in these battery cells;

[0015] 2 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;

[0016] 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;

[0017] 4 is a schematic cross-sectional view along line II of FIG. 1 , schematically illustrating a cross-section of a flow field plate according to a type of the present application;

[0018] FIG5 is a schematic cross-sectional view similar to FIG2 , schematically showing a cross-section of another type of flow field plate according to the present application;

[0019] 6 schematically shows a top view of a laminate structure including a first conductive adhesive film disposed between two backing films according to a preferred embodiment of the present application;

[0020] FIG7 is a side view of the laminated structure of FIG6;

[0021] FIG. 8 is a top view of the laminate structure of FIG. 6 , schematically illustrating a first pattern cut out in the laminate structure.

[0022] 9 is a top view similar to FIG. 2 , wherein the first conductive adhesive film and the second adhesive film have not yet been bonded to the metal plate of the flow field plate;

[0023] 10 is a top view similar to FIG. 2 and FIG. 9 , wherein the first conductive adhesive film is bonded to the metal plate of the flow field plate, while the second adhesive film has not yet been bonded to the metal plate of the flow field plate;

[0024] FIG11 is an enlarged view of a dotted line area A in FIG10 , schematically illustrating a flow channel structure that can be formed by the manufacturing method according to the present application; and

[0025] FIG12 is an enlarged view of a dotted line area B in FIG10 , schematically illustrating another flow channel structure that can be formed by the manufacturing method according to the present application.

[0026] Reference Signs List

[0027] 1 battery cell

[0028] 3 Proton exchange membrane

[0029] 5 Cathode diffusion layer

[0030] 7 Cathode Catalytic Layer Structure

[0031] 9 Anode diffusion layer

[0032] 11 Anode Catalytic Layer Structure

[0033] 100 Flow Field Plate

[0034] 101 Metal Plate

[0035] 101a First side

[0036] 101b Second side

[0037] 101c Entrance

[0038] 101d Exit

[0039] 101e Entrance

[0040] Exit 101f

[0041] 101g First Opening

[0042] 101h Second opening

[0043] 103 First Flow Field

[0044] 105 Entrance Distribution Area

[0045] 107 Reaction Zone

[0046] 107a1 Side wall

[0047] 107a2 bottom wall

[0048] 107a First flow channel

[0049] 107b First Ridge

[0050] 107b1 Top

[0051] 107b2 bottom

[0052] 108 protrusion

[0053] 109 Export Collection Area

[0054] 111 first conductive adhesive film

[0055] 113a Second flow channel

[0056] 113b Second ridge

[0057] 113b1 Top

[0058] 115 Second Flow Field

[0059] 117a Third flow channel

[0060] 117b Third Ridge

[0061] 117b1 Top

[0062] 118 third conductive adhesive film

[0063] 200 back film

[0064] 300 laminated structure DETAILED DESCRIPTION

[0065] Some preferred embodiments of the present application are described in detail below with reference to examples. Those skilled in the art will appreciate that these embodiments are merely exemplary and are not intended to limit the present application in any way. In addition, the features in the embodiments of the present application may be combined with each other unless they conflict. In the accompanying drawings, other components are omitted for brevity, but this does not mean that the flow field plates, bipolar plates, fuel cell units, and fuel cells of the present application cannot include other structures and components. It should be understood that the dimensions, proportional relationships, and number of components of the various structures and components in the accompanying drawings are not intended to limit the present application.

[0066] Fuel cells can be used in vehicles to provide electricity to drive the vehicle motor to provide power or enable the on-board system to perform various functions. Figure 1 schematically shows two battery cells 1 of an exemplary fuel cell stack. The exemplary fuel cell is a proton exchange membrane fuel cell (PEMFC), and its stack is composed of a plurality of battery cells 1 stacked. As will be described in detail below, the flow field plate 100 manufactured according to the method of the preferred embodiment of the present application can be used in the battery cell 1 to serve as a cathode plate and / or an anode plate. For example, in one battery cell 1, one flow field plate 100 can be used as a cathode plate, and another flow field plate 100 can be used as an anode plate. For another example, the flow field plate 100 can be combined with other flow field plates.

[0067] As shown in FIG1 , each battery cell 1 is typically composed of a cathode plate (a flow field plate 100 on the left side of each battery cell 1 in FIG1 ), an anode plate (a flow field plate 100 on the right side of each battery cell 1 in FIG1 ), 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 and are referred to as a membrane electrode assembly (MEA). The cathode diffusion layer 5 and the anode diffusion layer 9 are used to support the cathode catalyst layer structure 7 and the anode catalyst layer structure 11, respectively, and to transport the reaction fluid and reaction products (hydrogen, oxygen / air, water, etc.). As schematically shown in FIG4 and FIG5 , a cathode flow field and an anode flow field are formed on the cathode plate and the anode plate, respectively. The cathode flow fields of the cathode plates of the multiple battery cells 1 can constitute the cathode flow channel (not shown) of the battery stack, and the anode flow fields of the anode plates of the multiple battery cells 1 can constitute the anode flow channel (also not shown) of the battery stack.

[0068] The electrochemical reaction of PEMFC occurs in MEA, mainly involving hydrogen oxidation (HOR) and oxygen reduction (ORR). H2 and O2 are respectively transferred to the anode catalyst layer structure 11 and the cathode catalyst layer structure 7 through the anode diffusion layer 9 and the cathode diffusion layer 5. H2 loses electrons under the action of the anode catalyst in the anode catalyst layer structure 11 to form H + . H + The electrons are transferred to the cathode side through the proton exchange membrane 3, where they combine with O2 under the action of the cathode catalyst in the cathode catalytic layer structure 7 to form H2O. The H2O is transferred to the cathode flow field and the anode flow field through the cathode diffusion layer 5 and the anode diffusion layer 9, and then discharged from the PEMFC through the cathode flow channel and the anode flow channel. Electrons flow to the cathode through an external circuit (not shown), forming an electric current.

[0069] Figures 2 to 4 schematically illustrate a flow field plate 100 constructed by a manufacturing method according to a preferred embodiment of the present application. As shown in Figures 2 and 3, the flow field plate 100 includes a metal plate 101 having opposite first and second sides 101a and 101b. The metal plate 101 can be made of an iron-based alloy (stainless steel), a light metal and its alloys (mainly titanium and its alloys, aluminum and its alloys). The metal plate 101 includes an inlet 101c configured to receive a reaction fluid (reaction gas in PEMFC, specifically hydrogen, oxygen or air) and an outlet 101d configured to discharge reaction products. The inlet 101c and outlet 101d are openings extending through the metal plate 101.

[0070] As shown in Figures 2 and 4, the flow field plate 100 also includes a first flow field 103 formed on the first side 101a of the metal plate 101 and configured to circulate the reactant fluid. The first flow field 103 includes an inlet distribution area 105, a reaction area 107, and an outlet collection area 109, sequentially arranged along the flow direction of the reactant gas. The reaction area 107 includes a first ridge 107b defining a first flow channel 107a. The first flow channel 107a extends between the inlet distribution area 105 and the outlet collection area 109. The inlet distribution area 105 of the first flow field 103 is positioned near and in communication with the inlet 101c of the metal plate 101 to receive the reactant gas from the inlet 101c and distribute the reactant gas to each of the flow channels 107a. The outlet collection area 109 is configured to collect reaction products from the first flow channel 107a and is positioned near and in communication with the outlet 101d of the metal plate 101 to discharge the reaction products to the outlet 101d.

[0071] Continuing with Figures 2 and 4 , the flow field plate 100 further includes a first conductive adhesive film 111 having a first pattern corresponding to the first ridges 107b and bonded to the metal plate 101 on the first side 101a such that at least 10% (e.g., 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, or any value therebetween) of the height of the first ridges 107b, as measured from the top 107b1 ( Figure 4 ), is formed by the first pattern. As best shown in Figure 4 , when the flow field plate 100 is used as an anode plate or a cathode plate and assembled with an MEA, the first conductive adhesive film 111 can bond the metal plate 101 to the corresponding one of the cathode diffusion layer 5 and the anode diffusion layer 9 of the MEA.

[0072] As will be described in detail below in conjunction with the method for manufacturing the flow field plate 100, the inventors have realized that the aforementioned configuration of the flow field plate 100 according to the present application can provide a number of advantages: (1) the first conductive adhesive film 111 can maintain a stable adhesive force between the metal plate 101 and the corresponding diffusion layer in the cathode diffusion layer 5 and the anode diffusion layer 9 during the long-term operation of the fuel cell to keep the contact resistance basically constant, which 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) the provision of the first conductive adhesive film 111 can reduce the need for applying additional holding force between the metal plate 101 and the corresponding diffusion layer in the cathode diffusion layer 5 and the anode diffusion layer 9, thereby improving the reliability of the fuel cell; (3) the first conductive adhesive film 111 covers the metal plate 101 and the corresponding diffusion layer in the cathode diffusion layer 5 and the anode diffusion layer 9, thereby improving the reliability of the fuel cell; (4) The first conductive adhesive film 111 is fixed to the metal plate 101 by bonding, eliminating the complex and time-consuming surface modification process of the metal plate 101, which makes the flow field plate 100 easy to manufacture and reduces the manufacturing cost, thereby facilitating the large-scale production of the flow field plate 100; (5) At least 10% of the height of the first ridge 107b measured from the top 107b1 is formed by the first pattern, which enables the first conductive adhesive film 111 to form at least a part of the flow field of the reaction zone 107, which helps to reduce or even eliminate the stamping work required when manufacturing the reaction zone 107 of the flow field plate 100, and improves the design and manufacturing flexibility of the flow field plate 100.

[0073] An exemplary method for manufacturing a flow field plate 100 according to the present application will be described in detail below with reference to Figures 4 to 10. Figure 9 is a top view of a metal plate 101, schematically illustrating a first side 101a of the metal plate 101. The metal plate 101 is formed with an inlet 101c and an outlet 101d. The inlet 101c and outlet 101d of the metal plate 101 can be formed by any process known in the art, such as machining or stamping.

[0074] The method for manufacturing a flow field plate 100 according to the present application includes forming a first flow field 103 for circulating a reaction fluid on a first side 101a of a metal plate 101. As described above, the reaction area 107 of the first flow field 103 includes a first ridge 107b defining a first flow channel 107a. Forming the first flow field 103 includes 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 can be understood that the manufacturing method according to the present application can provide the above-mentioned advantages (1) to (5).

[0075] The manufacturing method according to the present application improves the flexibility of design and manufacture of flow field plate 100. For example, Figure 11 and Figure 12 show two flow channel structures that can be formed by the manufacturing method of the present application. Figure 11 shows a first flow channel 107a with a constriction structure. The first flow channel 107a is defined by the shape of the first ridge 107b. Specifically, the flow area of ​​the first flow channel 107a decreases first and then increases along the direction of flow of the reaction fluid (as indicated by the dotted arrow in the figure), thereby accelerating the flow of the reaction fluid or reaction product. In this article, unless otherwise specified, "flow area" refers to the effective cross-sectional area of ​​the channel of the component or part for circulating fluid. This constriction structure can be set at a desired position in the first flow field 103 to achieve the effect of accelerating the flow of the reaction fluid or reaction product. For example, this constriction structure can be set at the downstream position of the reaction zone of the cathode flow field to accelerate the discharge of reaction products. Figure 12 shows the first flow channel 107a with a turbulent structure. Specifically, a protrusion 108 protruding into the first flow channel 107 a may be provided on the sidewall of the first flow channel 107 a (ie, the first ridge 107 b ) to disturb the reaction fluid, thereby helping to enhance the reaction in the reaction zone 107 .

[0076] The flow channel structures shown in Figures 11 and 12 are both difficult to form using traditional processes such as stamping and machining. In contrast, the manufacturing method of the present application allows for easy and low-cost formation of the first flow channel 107a having a necking structure and a flow-disturbing structure. It should be understood that the manufacturing method of the present application can also easily and low-costly form other flow channel structures that are difficult to form using traditional processes such as stamping and machining, and the present application is not limited thereto.

[0077] In addition, compared with traditional processes such as stamping and machining, the manufacturing method of the present application can easily and inexpensively form various complex flow field patterns, and reduce or even eliminate the cost of stamping die design and manufacturing.

[0078] Importantly, the manufacturing method of the present application can improve the flexibility in designing and manufacturing the flow field plate 100 .

[0079] In some embodiments, the entire (100%) height of the first ridge 107b measured from the top 107b1 can be formed by the first conductive adhesive film 111 (i.e., the first pattern). As shown in Figures 5 and 9, the first area of ​​the metal plate 101 corresponding to the reaction zone 107 is substantially flat. As used in this article, "substantially flat" refers to within the range allowed by manufacturing tolerances. In this case, the first pattern can be configured so that the entire height of the first ridge 107b measured from the top 107b1 is formed by the first pattern. Accordingly, the step of bonding the cut-out first pattern to the metal plate 101 on the first side 101a includes bonding the cut-out first pattern to the first area 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 the flow field plate 100 (which is used as a cathode plate) in the lower portion of FIG5 , the entire height of the first ridge 107b measured from the top 107b1 is formed by the first conductive adhesive film 111 (i.e., the first pattern). In this case, the sidewall 107a1 of the first flow channel 107a can be perpendicular to the bottom wall 107a2 of the first flow channel 107a, that is, the draft angle is 0. This flow channel structure helps to increase the flow channel density of the reaction zone 107, thereby improving the performance of the flow field plate 100. This flow channel structure is difficult to form by traditional processes such as stamping and machining. On the contrary, by means of the manufacturing method of the present application, the first flow channel 107a with the sidewall 107a1 perpendicular to the bottom wall 107a2 of the first flow channel 107a can be easily and inexpensively formed.

[0080] In other partial embodiments, as shown in Figures 4 and 5, a portion of the height of the first ridge 107b measured from the bottom 107b2 opposite to the top 107b1 can be formed by stamping the metal plate 101. Specifically, referring to the structure of the flow field plate 100 (the flow field plate 100 is used as an anode plate) in the upper part of Figure 5, the first ridge 107b is composed of a first part and a second part. The first part is formed by stamping the metal plate 101, and the second part is formed by bonding the first conductive adhesive film 111 to the first part. That is, forming the first flow field 103 also includes a step of forming the first part of the first ridge 107b by stamping the metal plate 101, and the step of bonding the cut first pattern to the metal plate 101 on the first side 101a includes bonding the cut first pattern to the first part to form the second part, thereby forming the entire first ridge 107b.

[0081] The first conductive adhesive film 111 includes a first viscous material and first conductive particles dispersed in the first viscous material. The first conductive particles can be dispersed in the first viscous material in any suitable weight percentage by any suitable process. This specifically depends on the conductive properties of the first viscous material itself and the density and conductivity of the first conductive particles. Preferably, the first viscous material can be polymethyl methacrylate (PMMA), acrylic glue, polypyrrole, epoxy resin, silicone resin, polyamide, polyimide or fluororubber. Preferably, the first conductive particles can be gold (Au), graphite, a high specific surface carbon material such as Ketjen black, carbon black, graphene, single-walled carbon nanotubes, multi-walled carbon nanotubes, chromium nitride (CrN), titanium nitride (TiN). It should be understood that the present application is not limited to this, and the first viscous material and the first conductive particles can be any suitable material that enables the first conductive adhesive film 111 to maintain a stable bonding force and a substantially constant contact resistance between the metal plate 101 and the corresponding diffusion layers in the cathode diffusion layer 5 and the anode diffusion layer 9.

[0082] In some embodiments, the first conductive adhesive film 111 is configured to bond the metal plate 101 to the corresponding diffusion layer in the cathode diffusion layer 5 and the anode diffusion layer 9 to provide an adhesion force of at least 2 N / cm (e.g., 2 N / cm, 2.5 N / cm, 3 N / cm, or higher) between the corresponding diffusion layer and the metal plate 101. This helps maintain a stable adhesion force and a substantially constant contact resistance between the metal plate 101 and the corresponding diffusion layer. Furthermore, this also helps eliminate the need for applying additional holding force between the metal plate 101 and the corresponding diffusion layer.

[0083] As shown in Figures 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 the 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 any portion of the metal plate 101. It should be understood that 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 provide corrosion resistance.

[0084] In some embodiments, as shown in Figures 6 to 8 , cutting a first pattern corresponding to the first ridge 107 b in the first conductive adhesive film 111 may include placing the first conductive adhesive film 111 between two backing films 200 to form a laminated structure 300, and cutting a first pattern corresponding to the first ridge 107 b in the laminated structure 300. Figure 6 schematically illustrates a top view of the laminated structure 300 including the first conductive adhesive film 111 disposed between two backing films 200, Figure 7 is a side view of the laminated structure of Figure 6 , and Figure 8 is a top view of the laminated structure 300 of Figure 6 , schematically illustrating the first pattern cut out in the laminated structure 300. Subsequently, the step of bonding the cut first pattern to the metal plate 101 on the first side 101 a may include peeling the cut first pattern from the backing film 200 and bonding it to the metal plate 101 on the first side 101 a (as shown in Figure 10 ). The backing film 200 may be made of a material suitable for holding the first conductive adhesive film 111 during cutting the first pattern therefrom and easily peeling the first conductive adhesive film 111 therefrom without damage after cutting the first pattern therefrom.

[0085] 2 , the inlet distribution region 105 and the outlet convergence region 109 of the first flow field 103 can be formed in a manner similar to the reaction region 107. Specifically, at least one of the inlet distribution region 105 and the outlet convergence region 109 includes a second ridge 113b defining a second flow channel 113a. The flow field plate 100 further includes a second adhesive film (not shown) having a second pattern corresponding to the second ridge 113b and bonded to the metal plate 101 on the first side 101a 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 as measured from the top 113b1 is formed by the second pattern. In other words, forming the first flow field 103 also includes the following steps: cutting a second pattern corresponding to the second ridge 113b in the second adhesive film; and bonding the cut second pattern to the metal plate 101 on the first side 101a 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.

[0086] In this way, many advantages can be provided: (1) the second adhesive film can further help maintain a stable bonding force between the metal plate 101 and the corresponding diffusion layers in the cathode diffusion layer 5 and the anode diffusion layer 9, thereby keeping the contact resistance basically constant, which helps to improve the contact conductivity of the flow field plate 100, thereby improving the performance of the fuel cell using the flow field plate 100; (2) at least a portion of the height of the second ridge 113b measured from the top 113b1 is formed by the second pattern, which enables the second adhesive film to form at least a portion of the flow field of at least one of the inlet distribution area 105 and the outlet collection area 109, which helps to reduce or even eliminate the stamping work required when manufacturing at least one of the inlet distribution area 105 and the outlet collection area 109 of the flow field plate 100, and improve the design and manufacturing flexibility of the flow field plate 100.

[0087] Preferably, the second adhesive film can be a polyethylene naphthalate (PEN), polyethylene terephthalate (PET) or polyimide (PI) film coated with acrylic adhesive on the surface. It should be understood that the second adhesive film is not limited thereto and can also be made of other suitable materials.

[0088] In some embodiments, as shown in FIG9 , the second region of at least one of the inlet distribution area 105 and the outlet collection area 109 of the metal plate 101 is substantially flat. It is contemplated that a second adhesive film can be bonded to the second region ( FIG2 ) and configured such that the entire height of the second ridge 113b, measured from the top 113b1, is formed by the second pattern. In other words, the second pattern is configured such that the entire height of the second ridge, measured from the top 107b1, is formed by the second pattern, and the step of bonding the cut-out second pattern to the metal plate 101 on the first side 101a includes bonding the cut-out second pattern to the second region of the metal plate 101 on the first side 101a to form the entire second ridge 113b. It should be understood that, as described above in conjunction with the reaction zone 107, the methods described herein enable easy and cost-effective formation of flow channel structures and flow channel patterns in the inlet distribution area 105 and the outlet collection area 109 that are difficult to form using traditional processes such as stamping and machining. It should also be understood that in some other embodiments, a portion of the second ridge 113b measured from the bottom opposite to 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 bonding the second adhesive film to this portion. In this way, the entire second ridge 113b can be formed.

[0089] Referring back to Figures 2 and 3 , the metal plate 101 further includes an inlet 101e configured to receive a cooling fluid, and an outlet 101f configured to discharge the cooling fluid. Furthermore, the metal plate 101 includes a first opening 101g and a second opening 101h configured to communicate with the reaction fluid inlet and reaction product outlet, respectively, of the mating metal plate 101. The inlet 101e, outlet 101f, first opening 101g, and second opening 101h are all openings extending through the metal plate 101.

[0090] As shown in FIG3 , 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 configured 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 into the second flow field 115 from the inlet 101e and exits the second flow field 115 from the outlet 101f.

[0091] It is contemplated that the second flow field 115 can be formed in a similar manner to the reaction zone 107. Specifically, the flow field plate 100 further includes a third conductive adhesive film 118 (FIGS. 4 and 5) having a third pattern corresponding to the third ridges 117b and bonded to the metal plate 101 on the second side 101b such that at least 10% (e.g., 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, or any value therebetween) of the height of the third ridges 117b as measured from the top 117b1 is formed by the third pattern.

[0092] In other words, the method for forming the flow field plate 100 of the present application further includes forming a second flow field 115 for circulating a cooling fluid on a second side 101b of the metal plate 101, opposite to the first side 101a. Forming the second flow field 115 includes the following steps: cutting a third pattern corresponding to the third ridge 117b in the third conductive adhesive film 118; and adhering the cut third pattern to the metal plate 101 on the second side 101b such that at least 10% of the height of the third ridge 117b, as measured from the top 117b1, is formed by the third pattern.

[0093] In this way, many advantages can be provided: (1) when the two flow field plates 100 are fixed together in a manner that the first flow fields 103 are back to back to form a bipolar plate, the third conductive adhesive film 118 can maintain a stable bonding force between the two flow field plates 100, thereby keeping the contact resistance basically constant; (2) at least 10% of the height of the third ridge 117b measured from the top 117b1 is formed by the third pattern, which enables the third conductive adhesive film 118 to form at least a portion of the second flow field 115 for circulating the cooling fluid, which helps to reduce or even eliminate the stamping work required when manufacturing the second flow field 115 of the flow field plate 100, and improves the design and manufacturing flexibility of the flow field plate 100.

[0094] The third conductive adhesive film 118 includes a third viscous material and second conductive particles dispersed in the third viscous material. The second conductive particles can be dispersed in the third viscous material using any suitable process and in any suitable weight percentage. This depends on the conductive properties of the third viscous material itself and the density and conductivity of the second conductive particles. Preferably, the third viscous material is a phenolic resin or an epoxy resin. Preferably, the second conductive particles are expanded graphite or other highly conductive carbon materials.

[0095] It is contemplated that in some embodiments, the third region of the metal plate 101 corresponding to the second flow field 115 is substantially flat. The third pattern is bonded to the third region and is configured such that the entire height of the third ridge 117b, measured from the top 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 top 117b1, is formed by the third pattern, and the step of bonding the cut third pattern to the metal plate 101 on the second side 101b includes bonding the cut third pattern to three regions of the metal plate 101 on the second side 101b to form the entire third ridge 117b. It should be understood that, as described above in conjunction with the reaction zone 107, the method described herein can easily and inexpensively form a flow channel structure and flow channel pattern for the second flow field 115 for circulating a cooling fluid, which is difficult to form using traditional processes such as stamping and machining. It should also be understood that in some other embodiments, a portion of the third ridge 117b measured from the bottom opposite to the top 117b1 can be formed by stamping the metal plate 101 (for example, at the same time as the first ridge 107b is stamped), and the remaining portion of the third ridge 117b is formed by adhering the third conductive adhesive film 118 to this portion. In this way, the entire third ridge 117b can be formed.

[0096] The flow field plate 100 manufactured according to the aforementioned method can be used as an anode plate or a cathode plate. As schematically shown in Figure 1, the anode plate of one of the two adjacent fuel cell units 1 can be fixed together with the cathode plate of the other fuel cell unit 1 before assembling the stack to form a bipolar plate. In other words, the cathode plate and the anode plate manufactured using the aforementioned method can be fixed together in a manner that the first flow field 103 is back to back with each other to form a bipolar plate. In some embodiments, the cathode plate and the anode plate can both 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 form a flow field for circulating a cooling fluid. In other embodiments, only one of the cathode plate and the anode plate has a second flow field 115 for circulating a cooling fluid, and the second flow field 115 is used to circulate a cooling fluid between the cathode plate and the anode plate.

[0097] 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 remainder of the first ridge 107b of the first flow field 103 of the anode plate is formed by stamping. Simultaneously with the formation of the remainder 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 of the anode plate, opposite the first side 101a where the first flow field 103 is formed. The first flow field 103 of the cathode plate serves as the cathode flow field, and the first flow field 103 of the anode plate serves as the anode flow field. During the reaction, the cathode-side reaction products include water, which needs to be quickly drained from the reaction zone 107 via the cathode flow field. It is advantageous to form the entire height of the first ridge 107b of the first flow field 103 (cathode flow field) of the cathode plate from the first conductive adhesive film 111 because it allows the formation of various flow channel structures in the cathode flow field that are conducive to drainage, which are difficult to form by conventional stamping.

[0098] Disclosed herein are 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 examples and combinations thereof include the following:

[0099] Example 1 includes a method for manufacturing a flow field plate for a fuel cell unit, the method comprising: 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 a first ridge defining a first flow channel. Forming the first flow field comprises the steps of: cutting a first pattern corresponding to the first ridge in a first conductive adhesive film; and adhering the cut first pattern to the metal plate on the first side such that at least 10% of the height of the first ridge, measured from the top, is formed by the first pattern.

[0100] Example 2 includes the method of Example 1, wherein: forming the first flow field also includes a step of forming a first portion of the first ridge by stamping the metal plate; and the step of bonding the cut first pattern to the metal plate on the first side includes bonding the cut first pattern to the first portion to form the entire first ridge.

[0101] Example 3 includes the method of Example 1, wherein: a first area 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 bonding the cut first pattern to the metal plate on the first side includes bonding the cut first pattern to the first area of ​​the metal plate on the first side to form the entire first ridge.

[0102] Example 4 includes the method of Example 1, wherein each of the first flow channels 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, and the bottom wall being formed by a portion of the metal plate between the two adjacent first ridges, the first pattern not overlapping the portion of the metal plate.

[0103] Example 5 includes the method of Example 1, wherein the first conductive adhesive film includes a first viscous material and first conductive particles dispersed in the first viscous material.

[0104] Example 6 includes the method of Example 5, wherein: the first adhesive material is PMMA, acrylic glue, 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, titanium nitride.

[0105] 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 bond the metal plate to the diffusion layer to provide an adhesion force of at least 2 N / cm between the diffusion layer and the metal plate.

[0106] Example 8 includes the method of Example 1, wherein: the step of cutting out the first pattern corresponding to the first ridge in the first conductive adhesive film includes positioning the first conductive adhesive film between two layers of backing films to form a laminate structure, and cutting out the first pattern corresponding to the first ridge in the laminate structure, and the step of bonding the cut first pattern to the metal plate on the first side includes peeling the cut first pattern from the backing film and bonding it to the metal plate on the first side.

[0107] Example 9 includes the method of any one of Examples 1 to 8, wherein the metal plate further includes an inlet configured to receive a reaction fluid and an outlet configured to discharge a reaction product; the first flow field further includes an inlet distribution area for communicating with the inlet and an outlet collection area for communicating with the outlet, the reaction zone extends between the inlet distribution area and the outlet collection area, and at least one of the inlet distribution area and the outlet collection area includes a second ridge defining a second flow channel. Forming the first flow field further includes the steps of: cutting a second pattern corresponding to the second ridge in a second adhesive film; and adhering the cut second pattern to the metal plate on the first side such that at least a portion of the height of the second ridge measured from the top is formed by the second pattern.

[0108] Example 10 includes the method of Example 9, wherein: a second area of ​​the metal plate corresponding to the at least one of the inlet distribution area and the outlet collection area 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 bonding the cut second pattern to the metal plate on the first side includes bonding the cut second pattern to the second area of ​​the metal plate on the first side to form the entire second ridge.

[0109] Example 11 includes the method of Example 10, wherein the second adhesive film is a PEN, PET, or PI film with an acrylic adhesive coated on the surface.

[0110] Example 12 includes the method of any one of Examples 1 to 8, wherein the method further 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 comprising a third ridge defining a second flow channel. Forming the second flow field comprises the steps of: cutting a third pattern corresponding to the third ridge in a third conductive adhesive film; and adhering the cut third pattern to the metal plate on the second side such that at least 10% of the height of the third ridge, as measured from the top, is formed by the third pattern.

[0111] Example 13 includes the method of Example 12, wherein: a third area 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 bonding the cut-out third pattern to the metal plate on the second side includes bonding the cut-out third pattern to the three areas of the metal plate on the second side to form the entire third ridge.

[0112] Example 14 includes the method of Example 12, wherein the third conductive adhesive film includes a third viscous material and second conductive particles dispersed in the third viscous material, the third viscous material is preferably a phenolic resin or an epoxy resin, and the second conductive particles are preferably expanded graphite.

[0113] Example 15 includes a method for manufacturing a bipolar plate for a fuel cell, the method comprising: manufacturing a cathode plate using the method of Example 1; manufacturing an anode plate using the method of Example 1; and fixing the cathode plate and the anode plate together in a manner such that the first flow field faces back to back with each other to form a bipolar plate.

[0114] 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.

[0115] 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 and for circulating a reaction fluid, the reaction area of ​​the first flow field comprising 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 and being bonded to the metal plate on the first side so that at least 10% of the height of the first ridge measured from the top is formed by the first pattern.

[0116] 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 the metal plate, and the second portion being formed by bonding the first conductive adhesive film to the first portion.

[0117] Example 19 includes the flow field plate of Example 17, wherein a first area of ​​the metal plate corresponding to the reaction zone is substantially flat, the first conductive adhesive film is adhered to the first area, and is configured such that the entire height of the first ridge measured from the top is formed by the first pattern.

[0118] Example 20 includes the flow field plate of Example 17, wherein each of the first flow channels 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, and the bottom wall being formed by a second portion of the metal plate between the two adjacent first ridges, the first pattern not overlapping the second portion of the metal plate.

[0119] Example 21 includes the flow field plate of Example 17, wherein the first conductive adhesive film includes a first viscous material and first conductive particles dispersed in the first viscous material.

[0120] Example 22 includes the flow field plate of Example 21, wherein the first viscous material is PMMA, acrylic glue, 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, titanium nitride.

[0121] 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 bond the metal plate to the diffusion layer to provide a bonding force of at least 2 N / cm between the diffusion layer and the metal plate.

[0122] Example 24 includes the flow field plate of Example 17, wherein the flow field plate further includes an inlet configured to receive a reaction fluid, and an outlet configured to discharge a reaction product; the first flow field further includes an inlet distribution area for communicating with the inlet, and an outlet collection area for communicating with the outlet, the reaction zone extends between the inlet distribution area and the outlet collection area, and at least one of the inlet distribution area and the outlet collection area includes a second ridge defining a second flow channel; the flow field plate further includes a second adhesive film, the second adhesive film has a second pattern corresponding to the second ridge, and is bonded to the metal plate on the first side so that at least a portion of the height of the second ridge measured from the top is formed by the second pattern.

[0123] Example 25 includes the flow field plate of Example 24, wherein the second adhesive film is a PEN, PET, or PI film with acrylic adhesive coated on the surface.

[0124] Example 26 includes the flow field plate of Example 17, wherein a second area of ​​the metal plate corresponding to at least one of the inlet distribution area and the outlet collection area is substantially flat, and the second adhesive film is bonded 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.

[0125] Example 27 includes the flow field plate of Example 17, wherein the flow field plate further comprises: a second flow field formed on a second side of the metal plate opposite to the first side and for circulating a cooling fluid, the second flow field comprising a third ridge defining a second flow channel; and a third conductive adhesive film having a third pattern corresponding to the third ridge and bonded to the metal plate on the second side such that at least 10% of the height of the third ridge measured from the top is formed by the third pattern.

[0126] Example 28 includes the flow field plate of Example 27, wherein the third conductive adhesive film includes a third viscous material and second conductive particles dispersed in the third viscous material, the third viscous material is preferably a phenolic resin or an epoxy resin, and the second conductive particles are preferably expanded graphite.

[0127] 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, the third pattern is bonded to the third region, and is configured such that the entire height of the third ridge measured from the top is formed by the third pattern.

[0128] Example 30 includes a bipolar plate for a fuel cell, comprising: an anode plate, which is a flow field plate according to Example 11; a cathode plate, which is a flow field plate according to Example 11; wherein the anode plate and the cathode plate are fixed together in a manner such that the first flow field is facing each other.

[0129] 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.

[0130] It will be understood that the terms “first”, “second” and “third” are merely used to distinguish one element or portion from another element or portion, but these elements and / or portions should not be limited by such terms.

[0131] The present application has been described in detail above with reference to specific embodiments. It is apparent that the above description and the embodiments shown in the accompanying drawings are to be understood as illustrative only and do not constitute limitations on the present application. Those skilled in the art may make various modifications or alterations to the present application without departing from the spirit of the present application, and such modifications or alterations do not depart from the scope of the present application.

Claims

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

2. The method according to claim 1, wherein: Forming the first flow field further includes the step of forming a first portion of the first ridge by stamping the metal plate, and the step of bonding the cut first pattern to the metal plate on the first side includes bonding the cut first pattern to the first portion of the first ridge to form the entire first ridge; or A first area 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 bonding the cut first pattern to the metal plate on the first side includes bonding the cut first pattern to the first area on the first side to form the entire first ridge.

3. The method according to claim 1, wherein: The first conductive adhesive film comprises a first viscous material and first conductive particles dispersed in the first viscous material, wherein the first viscous material is preferably PMMA, acrylic glue, polypyrrole, epoxy resin, silicone resin, polyamide, polyimide or fluororubber, and the first conductive particles are preferably gold, graphite, Ketjen black, carbon black, graphene, single-walled carbon nanotubes, multi-walled carbon nanotubes, chromium nitride, 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, and the bottom wall being formed by a portion of the metal plate between the two adjacent first ridges, the first pattern not overlapping the portion of the metal plate.

4. The method according to claim 1, wherein: The fuel cell unit further comprises a membrane electrode assembly having a diffusion layer, the first conductive adhesive film being configured to bond the metal plate to the diffusion layer to provide an adhesive force of at least 2 N / cm between the diffusion layer and the metal plate; and / or The step of cutting out the first pattern corresponding to the first ridge in the first conductive adhesive film includes setting the first conductive adhesive film between two backing films to form a laminated structure, and cutting out the first pattern corresponding to the first ridge in the laminated structure, and the step of bonding the cut first pattern to the metal plate on the first side includes peeling the cut first pattern from the backing film and bonding it to the metal plate on the first side.

5. The method according to any one of claims 1 to 4, characterized in that The metal plate further includes an inlet configured to receive a reaction fluid, and an outlet configured to discharge a reaction product; The first flow field further includes an inlet distribution area for communicating with the inlet, and an outlet convergence area for communicating with the outlet, the reaction zone extends between the inlet distribution area and the outlet convergence area, at least one of the inlet distribution area and the outlet convergence area includes a second ridge defining a second flow channel, and forming the first flow field further includes the following steps: cutting a second pattern corresponding to the second ridge in a second adhesive film, wherein the second adhesive film is preferably a PEN, PET or PI film with acrylic adhesive coated on the surface; and The cut-out second pattern is bonded to the metal plate on the first side such that at least a portion of the height of the second ridge measured from the top is formed by the second pattern.

6. The method according to claim 5, characterized in that: a second area of ​​the metal plate corresponding to the at least one of the inlet distribution area and the outlet collection area being substantially flat, the second pattern being configured such that the entire height of the second ridge measured from the top is formed by the second pattern; as well as The step of bonding the cut-out second pattern to the metal plate on the first side includes bonding the cut-out second pattern to the second area of ​​the metal plate on the first side to form the entire second ridge.

7. The method according to any one of claims 1 to 4, characterized in that The method further includes forming a second flow field for circulating a cooling fluid on a second side of the metal plate opposite to the first side, the second flow field including a third ridge defining a second flow channel, wherein forming the second flow field comprises the following steps: cutting a third pattern corresponding to the third ridge in a third conductive adhesive film, wherein the third conductive adhesive film comprises a third adhesive material and second conductive particles dispersed in the third adhesive material, wherein the third adhesive material is preferably phenolic resin or epoxy resin, and the second conductive particles are preferably expanded graphite; and The cut-out third pattern is bonded to the metal plate on the second side such that at least 10% of the height of the third ridge measured from the top is formed by the third pattern.

8. The method according to claim 7, wherein: A third area of ​​the metal plate corresponding to the second flow field is substantially flat, the third pattern being configured such that the entire height of the third ridge measured from the top is formed by the third pattern; as well as The step of bonding the cut third pattern to the metal plate on the second side includes bonding the cut third pattern to the three areas of the metal plate on the second side to form the entire third ridge.

9. A method for manufacturing a bipolar plate for a fuel cell, comprising: Manufacturing a cathode plate using the method according to claim 1; Manufacturing an anode plate using the method according to claim 1; as well as The cathode plate and the anode plate are fixed together with the first flow fields facing away from each other to form a bipolar plate.

10. The method according to claim 9, characterized in that: 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 a 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.

11. A flow field plate for a fuel cell unit, comprising: Metal sheets; a first flow field formed on a first side of the metal plate and used for circulating a reaction fluid, wherein a reaction zone of the first flow field includes a first ridge defining a first flow channel; as well as A first conductive adhesive film has a first pattern corresponding to the first ridge and is bonded to the metal plate on the first side such that at least 10% of a height of the first ridge measured from a top is formed by the first pattern.

12. The flow field plate according to claim 11, characterized in that: the first ridge portion is composed of a first portion and a second portion, the first portion being formed by punching 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.

13. The flow field plate according to claim 11, wherein: The first conductive adhesive film comprises a first viscous material and first conductive particles dispersed in the first viscous material, wherein the first viscous material is preferably PMMA, acrylic glue, polypyrrole, epoxy resin, silicone resin, polyamide, polyimide or fluororubber, and the first conductive particles are preferably gold, graphite, Ketjen black, carbon black, graphene, single-walled carbon nanotubes, multi-walled carbon nanotubes, chromium nitride, titanium nitride; and / or Each of the first flow channels 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, and the bottom wall being formed by a second portion of the metal plate between the two adjacent first ridges, the first pattern not overlapping the second portion of the metal plate; and / or The fuel cell unit further includes a membrane electrode assembly having a diffusion layer, and the first conductive adhesive film is configured to bond the metal plate to the diffusion layer to provide an adhesive force of at least 2 N / cm between the diffusion layer and the metal plate.

14. The flow field plate according to claim 11, wherein: The flow field plate further includes an inlet configured to receive a reaction fluid, and an outlet configured to discharge a reaction product; The first flow field further includes an inlet distribution area for communicating with the inlet, and an outlet convergence area for communicating with the outlet, the reaction zone extends between the inlet distribution area and the outlet convergence area, and at least one of the inlet distribution area and the outlet convergence area includes a second ridge defining a second flow channel; the flow field plate further comprising a second adhesive film in a second pattern corresponding to the second ridges and bonded to the metal plate on the first side such that at least a portion of the height of the second ridges measured from the top is formed by the second pattern; and The second adhesive film is preferably a PEN, PET or PI film with acrylic adhesive coated on the surface.

15. The flow field plate according to claim 14, wherein: A second area of ​​the metal plate corresponding to at least one of the inlet distribution area and the outlet collection area is substantially flat, and the second adhesive film is bonded to the second area and configured so that the entire height of the second ridge measured from the top is formed by the second pattern.

16. The flow field plate according to claim 11, wherein The flow field plate further comprises: a second flow field formed on a second side of the metal plate opposite to the first side and for circulating a cooling fluid, the second flow field including a third ridge defining a second flow channel; and a third conductive adhesive film having a third pattern corresponding to the third ridge and being bonded to the metal plate on the second side such that at least 10% of the height of the third ridge measured from the top is formed by the third pattern, wherein the third conductive adhesive film includes 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.

17. The flow field plate according to claim 16, wherein: A third area of ​​the metal plate corresponding to the second flow field is substantially flat, and the third pattern is bonded to the third area and configured such that the entire height of the third ridge measured from the top is formed by the third pattern.

18. A bipolar plate for a fuel cell, comprising: an anode plate, said anode plate being a flow field plate according to claim 11; a cathode plate, said cathode plate being another flow field plate according to claim 11; The anode plate and the cathode plate are fixed together in a manner that the first flow field faces back to back with each other.

19. The bipolar plate according to claim 18, characterized in that: 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 a 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.

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