Single cell of a membrane electrode assembly, fuel cell stack and method of manufacture

Abstract

The application discloses a kind of single cell of polar plate wrapping film electrode, fuel cell stack and preparation method, and the single cell of polar plate wrapping film electrode includes first polar plate assembly, second polar plate assembly, membrane electrode assembly, first flow channel plate and second flow channel plate;First polar plate assembly includes first lower polar plate, first upper polar plate and first connecting part, and the side of first connecting part is connected to first lower polar plate and first upper polar plate;Second polar plate assembly includes second lower polar plate, second upper polar plate and second connecting part, and the side of second connecting part is connected to second lower polar plate and second upper polar plate;First lower polar plate is inserted into the interior space of second polar plate assembly in parallel and is divided into three interval spaces in vertical direction, and first flow channel plate, membrane electrode assembly and second flow channel plate are sequentially installed in three interval spaces from top to bottom.The convenience of later maintenance is greatly improved, the system complexity is simplified, the flexibility and efficiency of assembly are improved, and the production cost is effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and in particular to a single cell with a membrane electrode wrapped with electrode plates, a fuel cell stack, and a method for its fabrication. Background Technology

[0002] The fuel cell system is assembled using a stacked assembly method, with core components including metal electrode plates, sealing rings, and membrane electrode assemblies (MEAs). The traditional assembly process involves first placing the sealing ring on the metal electrode plate, then covering it with the MEA, and then repeatedly stacking the metal electrode plates, sealing rings, and MEAs until a fuel cell system is formed. In this system, the MEA acts as the carrier for the electrochemical reaction, undertaking the core function of initiating the electrochemical reaction; the sealing ring seals the reactant gases to prevent leakage that could affect reaction efficiency and system safety; and the metal electrode plates are responsible for current and reactant gas conduction, ensuring power output and gas delivery.

[0003] Patent CN 110010924 A discloses a modularly packaged fuel cell metal electrode assembly, which includes a metal electrode, a membrane electrode assembly (MEA), and a packaging structure. One side of the metal electrode covers the MEA. The packaging structure is frame-shaped, positioned along the edges of the metal electrode and the MEA, and connected to both edges, ultimately integrating the metal electrode and the MEA into a complete fuel cell metal electrode assembly. A sealing ring has been added to the basic assembly, specifically including the metal electrode, two sealing rings, the MEA, and the packaging structure. A sealing ring is provided on each of the two sides of the metal electrode, and one side of the metal electrode and its sealing ring together cover the MEA. The packaging structure is also positioned at and connected to the edges of the metal electrode and the MEA, making the metal electrode, the two sealing rings, and the MEA form an integrated fuel cell metal electrode assembly.

[0004] However, the problems are as follows: the processing of metal plates is difficult and costly. As the core conductive component of the module, the metal plate needs to be formed by die stamping to create complex structures such as gas flow channels and current conduction paths. On the one hand, the complex flow channel design requires extremely high precision of the die, necessitating the use of high-precision die processing technology (such as CNC engraving and EDM), with the development cost of a single die reaching hundreds of thousands to millions of yuan. On the other hand, the metal plate material is mostly thin stainless steel, titanium alloy, etc., which are prone to deformation and cracking during the stamping process, requiring specialized stamping equipment (such as precision servo stamping machines) to control pressure and speed, further increasing the initial equipment investment.

[0005] There is a strong demand for specialized equipment for encapsulation structures: the encapsulation structures in the invention have multiple implementation methods, all of which rely on specialized equipment. When using "adhesive curing" to form the encapsulation structure, specialized adhesive application equipment is required; when using "polymer injection molding", customized injection molds and specialized injection molding machines are required, and the injection process requires precise control of temperature and pressure parameters to adapt to the edge dimensions of the metal electrode plate and the membrane electrode. The procurement and debugging cycle of specialized equipment is long, and the initial investment is large.

[0006] Post-maintenance disassembly is difficult: Most of the encapsulation structures are "non-removable" adhesive-cured structures. Once a fault occurs inside the component (such as membrane electrode aging or seal ring damage), the faulty component cannot be disassembled and replaced individually. The entire modular component must be replaced. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the shortcomings of existing metal electrode plates, such as extremely high requirements for flow channel design and manufacturing process, easy deformation and cracking, high cost, and difficulty in later maintenance and disassembly. The invention provides a single cell, fuel cell stack and preparation method of electrode plate wrapped membrane electrode.

[0008] The present invention solves the above-mentioned technical problems through the following technical solution:

[0009] A single cell with a membrane electrode wrapped with plates is characterized in that it includes a first plate assembly, a second plate assembly, a membrane electrode assembly, a first flow channel plate, and a second flow channel plate.

[0010] The first electrode assembly includes a first lower electrode, a first upper electrode, and a first connecting portion. The first lower electrode and the first upper electrode are arranged in parallel relative to each other. The first connecting portion is connected to the side of the first lower electrode and the first upper electrode and can drive the first lower electrode to open relative to the first upper electrode in an opening and closing manner.

[0011] The second electrode assembly includes a second lower electrode, a second upper electrode, and a second connecting portion. The second lower electrode and the second upper electrode are arranged in parallel relative to each other. The second connecting portion is connected to the side of the second lower electrode and the second upper electrode and can drive the second lower electrode to open relative to the second upper electrode in an opening and closing manner.

[0012] During assembly, the first lower electrode plate is inserted parallel to the internal space of the second electrode plate assembly, dividing the space defined by the first electrode plate assembly and the second electrode plate assembly into three space intervals in the vertical direction. The first flow channel plate, the membrane electrode assembly, and the second flow channel plate are installed sequentially in the three space intervals from top to bottom.

[0013] In this solution, the aforementioned structural form is adopted. The first and second connecting parts bend and wrap the first and second electrode assemblies around the membrane electrode assembly. The first and second electrode assemblies respectively perform the dual functions of "anode current collection + cathode current collection," achieving functional integration of current collection and structural support, simplifying system complexity. Simultaneously, the fuel cell stack relies primarily on the deformation force of the first and second electrode assemblies after bending for clamping and fixation, making the fuel cell stack structure detachable. This allows for individual disassembly and replacement of faulty components without requiring the entire stack to be replaced, significantly improving the convenience of later maintenance. Furthermore, it enables modular assembly of the fuel cell stack, enhancing the flexibility and efficiency of assembly. Moreover, the fuel cell stack design employs an asymmetric functional sequence, doubling the reaction area and current intensity while achieving parallel operation with the same polarity. The stacking method has a significant impact on stack performance.

[0014] Meanwhile, the electrode plate and the flow channel plate are designed as independent planar parts, functionally separating the traditional electrode plate by designing the current collection function and the flow channel structure as independent planar parts. This simplifies the design process and manufacturing technology of traditional metal electrode plate flow channels, effectively reducing production costs. Furthermore, compared to traditional stamped metal bipolar plates, this design significantly saves substantial upfront mold-making costs and shortens the development cycle.

[0015] Preferably, both the first flow channel plate and the second flow channel plate are provided with flow guide channels, and the upper and lower plates of the first electrode plate assembly and the second electrode plate assembly are provided with hollowed-out flow channels corresponding to the positions of the flow guide channels.

[0016] In this design, the aforementioned structural form is adopted. By creating perforated flow channels on the electrode plates and designing a flow guiding field on the flow channel plates, the design process and manufacturing process are simplified, effectively reducing production costs. Simultaneously, the first and second flow channel plates act as a reversal force for the fluid and provide insulation between the upper and lower metal electrode plates, achieving forced flow guidance and preventing short circuits between the first and second electrode plate assemblies.

[0017] Preferably, the hollowed-out flow channel is located in the middle region between the upper and lower plates of the first electrode assembly and the second electrode assembly.

[0018] And / or, the shape of the flow channels is serpentine.

[0019] Preferably, the first lower electrode plate, the first upper electrode plate, the second lower electrode plate and the second upper electrode plate are each provided with a first through hole, and the first flow channel plate and the second flow channel plate are each provided with a second through hole, the second through hole corresponding to and communicating with the first through hole;

[0020] And / or, the thickness of the upper and lower plates of the first electrode assembly and the second electrode assembly is 0.1~0.2mm.

[0021] Preferably, the first electrode assembly and the second electrode assembly have the same shape, and the first connecting portion and the second connecting portion are mirror-symmetrically arranged with respect to the vertical plane so that the first electrode assembly and the second electrode assembly intersect each other. In the stacked structure in the vertical direction, from top to bottom, it includes the first upper electrode plate, the first flow channel plate, the second upper electrode plate, the membrane electrode assembly, the first lower electrode plate, the second flow channel plate, and the second lower electrode plate.

[0022] Alternatively, the first connecting part and the second connecting part are disposed on the same side, respectively located at the two ends of the connecting side, and the size of the first connecting part or the second connecting part is less than 1 / 2 of the side length of the connecting side.

[0023] Preferably, the device also includes a sealing assembly comprising a plurality of sealing frames disposed on a contact surface at any location inside the single cell, the sealing frames having a planar profile adapted to the contact surface, and the thickness of the sealing frames being greater than or equal to the compression gap formed between the contact surfaces.

[0024] In this solution, the aforementioned structural form is adopted, with several sealing frames used to seal different reaction chambers, thereby effectively enhancing the sealing effect. Simultaneously, the fuel cell stack structure is detachable, significantly improving the convenience of later maintenance; and modular assembly of the fuel cell stack is achieved, enhancing the flexibility and efficiency of fuel cell stack assembly.

[0025] Preferably, the sealing frame is made of rubber or cured adhesive;

[0026] And / or, the thickness of the sealing frame is less than 0.05 mm;

[0027] Preferably, the thickness of the sealing frame is 5 to 15 micrometers.

[0028] In this solution, the above-mentioned structural form is adopted, which effectively avoids excessive bending deformation of the electrode plate and flow channel plate during stacking due to the excessive thickness of the sealing frame, thus achieving greater stability and reliability.

[0029] Preferably, both the first electrode assembly and the second electrode assembly are made of conductive metal materials;

[0030] And / or, both the first flow channel plate and the second flow channel plate are made of insulating plastic material.

[0031] A fuel cell stack is characterized in that it comprises a plurality of single cells with plate-encapsulated membrane electrodes as described above.

[0032] Preferably, the first electrode assembly and the second electrode assembly are arranged in parallel and cross each other, and the single cells with multiple electrode-encapsulated membrane electrodes are stacked and connected in series.

[0033] In this scheme, the aforementioned structural form is adopted, consisting of parallel connections followed by series connections. While achieving parallel connection with the same polarity, the reaction area and current intensity are doubled, and the system complexity is simplified. Simultaneously, modular assembly of the fuel cell stack is achieved, improving the flexibility and efficiency of fuel cell stack assembly.

[0034] Preferably, an additional membrane electrode assembly is disposed between any two adjacent single cells with the membrane electrode wrapped by the electrode plates.

[0035] A method for preparing a fuel cell stack, characterized in that it is used to prepare the fuel cell stack as described above, the method comprising the following steps:

[0036] Single cell assembly: includes bending the first electrode assembly and the second electrode assembly and arranging them in a cross-shaped manner to divide the space defined by the first electrode assembly and the second electrode assembly into three space intervals in the vertical direction; and installing the first flow channel plate, the membrane electrode assembly and the second flow channel plate in the three space intervals from top to bottom;

[0037] Battery stack assembly: Multiple single cells are stacked in series vertically, and an additional membrane electrode assembly is placed between any two adjacent single cells.

[0038] Preferably, the specific steps of assembling the single cell are as follows:

[0039] Place the second flow channel plate on the second lower electrode plate;

[0040] Place the first lower electrode plate on the second flow channel plate;

[0041] The membrane electrode assembly is placed on the first lower electrode plate;

[0042] The second electrode assembly is bent so that the second upper electrode is parallel to the second lower electrode and clamped against the membrane electrode assembly;

[0043] Place the first flow channel plate on the second upper electrode plate;

[0044] The first electrode assembly is bent so that the first upper electrode is parallel to the first lower electrode and clamped against the first flow channel plate;

[0045] And / or, prior to the assembly of the single cell, the following steps are also included:

[0046] A sealing frame is installed on the contact surface of the upper and lower two electrode plates of the first electrode assembly and the second electrode assembly at any position.

[0047] Preferably, symmetrical rubber screen printing or adhesive curing by heating is performed on the contact surfaces of the upper and lower plates of the first and second electrode assemblies.

[0048] Preferably, the fuel cell assembly further includes the following steps:

[0049] A sealing frame is provided at the contact surface of two adjacent single batteries;

[0050] After stacking, pressure is applied to the fuel cell stack and it is locked with a locking device. The applied pressure is 1~1.5MPa.

[0051] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0052] The positive and progressive effects of this invention are as follows:

[0053] The present invention relates to a single cell, a fuel cell stack, and a fabrication method for a membrane electrode assembly (MEA) wrapped with electrode plates. By bending the first and second electrode plate assemblies through a first connecting portion and a second connecting portion, the MEA assembly is wrapped inside the first and second electrode plate assemblies. The first and second electrode plate assemblies respectively perform the dual functions of "anode current collection + cathode current collection," achieving functional integration of current collection and structural support. Furthermore, under the premise of achieving parallel connection of the same polarity, the reaction area is doubled, effectively increasing the current intensity. This stacking method can significantly affect the performance of the stack. Simultaneously, it allows for the individual disassembly and replacement of faulty components without replacing the entire stack, greatly improving the convenience of later maintenance and simplifying system complexity. It also enables modular assembly of the fuel cell stack, improving the flexibility and efficiency of fuel cell stack assembly. Furthermore, by placing the first and second flow channel plates between the first and second electrode plate assemblies, the current collection function and flow channel structure are designed as independent planar parts, thereby simplifying the design process and manufacturing process of traditional metal electrode plate flow channels and effectively reducing production costs. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of the structure of a single cell with a plate-coated film electrode according to an embodiment of the present invention.

[0055] Figure 2 This is an exploded structural diagram of a single cell with a plate-coated film electrode according to an embodiment of the present invention.

[0056] Figure 3This is a schematic diagram of the internal structure of a single cell with a plate-coated film electrode according to an embodiment of the present invention.

[0057] Figure 4 This is a schematic diagram of the first electrode plate assembly in an embodiment of the present invention when it is opened or closed.

[0058] Figure 5 This is a schematic diagram of a fuel cell stack according to an embodiment of the present invention.

[0059] Figure 6 This is a flowchart illustrating the method for preparing a fuel cell stack according to an embodiment of the present invention.

[0060] Explanation of reference numerals in the attached figures:

[0061] First electrode assembly 1

[0062] First lower electrode plate 11

[0063] First upper electrode plate 12

[0064] First connecting part 13

[0065] Hollowed-out flow channel 14

[0066] First through hole 15

[0067] Second electrode assembly 2

[0068] Second lower electrode plate 21

[0069] Second upper electrode plate 22

[0070] Second connecting part 23

[0071] Membrane electrode assembly 3

[0072] First flow channel plate 4

[0073] Second through hole 41

[0074] Guide channel 42

[0075] Second flow channel plate 5

[0076] Sealing frame 6 Detailed Implementation

[0077] The present invention will be described more clearly and completely below by way of embodiments and in conjunction with the accompanying drawings, but the present invention is not limited to the scope of the embodiments described below.

[0078] This invention discloses a fuel cell stack, which includes a single cell comprising multiple electrode plates encapsulating membrane electrode assemblies. For example... Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5As shown, the single cell with a membrane electrode assembly includes a first electrode assembly 1, a second electrode assembly 2, a membrane electrode assembly 3, a first flow channel plate 4, and a second flow channel plate 5. The first electrode assembly 1 includes a first lower electrode plate 11, a first upper electrode plate 12, and a first connecting portion 13. The first lower electrode plate 11 and the first upper electrode plate 12 are arranged parallel to each other. The first connecting portion 13 is connected to the side of the first lower electrode plate 11 and the first upper electrode plate 12 and can drive the first lower electrode plate 11 to open relative to the first upper electrode plate 12. The second electrode assembly 2 includes a second lower electrode plate 21 and a second upper electrode plate 22. The second connecting part 23, the second lower electrode plate 21 and the second upper electrode plate 22 are arranged in parallel with each other. The second connecting part 23 is connected to the side of the second lower electrode plate 21 and the second upper electrode plate 22 and can drive the second lower electrode plate 21 to open relative to the second upper electrode plate 22 in an opening and closing manner. During assembly, the first lower electrode plate 11 is inserted parallel to the internal space of the second electrode plate assembly 2, dividing the space defined by the first electrode plate assembly 1 and the second electrode plate assembly 2 into three interval spaces in the vertical direction. The first flow channel plate 4, the membrane electrode assembly 3 and the second flow channel plate 5 are installed in the three interval spaces from top to bottom.

[0079] The first electrode assembly 1 and the second electrode assembly 2 are arranged in a cross configuration, such that the first lower electrode 11 is inserted parallel to the interior space of the second electrode assembly 2, and the second upper electrode 22 is inserted parallel to the interior space of the first electrode assembly 1. This results in the first lower electrode 11, the first upper electrode 12, the second lower electrode 21, the second upper electrode 22, the first flow channel plate 4, the membrane electrode assembly 3, and the second flow channel plate 5 being arranged in parallel. The first flow channel plate 4, the membrane electrode assembly 3, and the second flow channel plate 5 are sequentially installed from top to bottom in three spaced intervals, such that the first flow channel plate 4 is located between the first upper electrode 12 and the second upper electrode 22, the second flow channel plate 5 is located between the first lower electrode 11 and the second lower electrode 21, and the membrane electrode assembly 3 is located between the second upper electrode 22 and the first lower electrode 11.

[0080] Compared with existing technologies, the single cell with plate-wrapped membrane electrode assembly in this embodiment often employs a symmetrical layer sequence of "plate-channel plate-MEA-channel plate-plate" or a repetitive stacked structure when multiple MEAs are connected in series, resulting in a large number of components and assembly redundancy. In this embodiment, the single cell with plate-wrapped membrane electrode assembly is designed with an asymmetric functional layer sequence based on the requirement of "a single membrane electrode assembly 3 + parallel connection of the same polarity". Specifically, the upper and lower plates of the first plate assembly 1 and the second plate assembly 2 act as current collectors and respectively conduct the electricity generated by the anode and cathode of the membrane electrode assembly 3, with the upper and lower sides of the core located at the cathode and anode of the membrane electrode assembly 3, respectively. The first channel plate 4 and the second channel plate 5 are the cathode channel plate and the anode channel plate, respectively. The core layer sequence of the single cell with plate-encased membrane electrode assembly (MEA) is simplified: Centered on MEA assembly 3, a composite unit of "flow channel plate-metal electrode plate" is integrated on one side of MEA assembly 3, forming an asymmetric stack of "second lower electrode plate 21 → second flow channel plate 5 → first lower electrode plate 11 (anode side) → MEA assembly 3 → second upper electrode plate 22 (cathode side) → first flow channel plate 4 → first upper electrode plate 12". Compared to existing technologies, this stacking method can double the reaction area while achieving parallel connection of the same polarity, thereby enhancing the current intensity and significantly impacting the performance of the stack.

[0081] The first electrode assembly 1 includes a first lower electrode plate 11, a first upper electrode plate 12, and a first connecting portion 13. The first connecting portion 13 allows the first lower electrode plate 11 to be bent and opened relative to the first upper electrode plate 12, enabling the first lower electrode plate 11 and the first upper electrode plate 12 to be arranged relatively parallel to each other. The second electrode assembly 2 includes a second lower electrode plate 21, a second upper electrode plate 22, and a second connecting portion 23. The second connecting portion 23 allows the second lower electrode plate 21 to be bent and opened relative to the second upper electrode plate 22, enabling the second lower electrode plate 21 and the second upper electrode plate 22 to be arranged relatively parallel to each other.

[0082] The first connecting part 13 and the second connecting part 23 are used to bend and open the first electrode assembly 1 and the second electrode assembly 2 and wrap them around the membrane electrode assembly 3. This allows the membrane electrode assembly 3 to be enclosed within the internal space of the first electrode assembly 1 and the second electrode assembly 2. The first electrode assembly 1 and the second electrode assembly 2 respectively perform the dual functions of "anode current collection + cathode current collection", replacing the separate anode electrode plate, cathode electrode plate and connecting conductor in the prior art. This achieves functional integration of current collection and structural support, simplifying system complexity. At the same time, the first electrode assembly 1 and the second electrode assembly 2 are folded into a specific shape through a bending process, directly wrapping the membrane electrode assembly 3, as well as the first flow channel plate 4 and the second flow channel plate 5 inside. This means that the structural fixation method in the single cell where the electrode plates wrap the membrane electrode no longer relies on glue, but can be achieved mainly by the deformation force of the first electrode assembly 1 and the second electrode assembly 2 after bending to achieve clamping and fixation. The overall fuel cell stack structure allows for the independent disassembly of individual cells, facilitating the replacement of faulty components without requiring the entire stack to be replaced, thus significantly improving the convenience of subsequent maintenance; it also enables modular assembly of the fuel cell stack, enhancing the flexibility and efficiency of fuel cell stack assembly.

[0083] By placing the first flow channel plate 4 and the second flow channel plate 5 within the space defined by the first electrode plate assembly 1 and the second electrode plate assembly 2, the current collection function is designed on the first electrode plate assembly 1 and the second electrode plate assembly 2, and the flow channel structure is designed on the first flow channel plate 4 and the second flow channel plate 5. The electrode plate and the flow channel plate are designed as independent planar parts. This functional decomposition of the traditional electrode plate, with the current collection function and the flow channel structure designed as independent planar parts, simplifies the design process and manufacturing process of traditional metal electrode plate flow channels, effectively reducing production costs. Simultaneously, compared to traditional stamped metal bipolar plates, it significantly saves substantial upfront mold-making costs and shortens the development cycle.

[0084] During fuel cell stack assembly, the first lower electrode plate 11 is inserted parallel to the internal space of the second electrode plate assembly 2, and the second upper electrode plate 22 is inserted parallel to the internal space of the first electrode plate assembly 1. The first flow channel plate 4, the membrane electrode assembly 3, and the second flow channel plate 5 are sequentially installed from top to bottom in the three spaced intervals defined by the first electrode plate assembly 1 and the second electrode plate assembly 2 to form a single cell with the electrode plate wrapping the membrane electrode. This allows the first electrode plate assembly 1 and the second electrode plate assembly 2 to be arranged in parallel with each other, and multiple single cells with the electrode plate wrapping the membrane electrode are stacked vertically in series. Traditional fuel cell stack assembly is composed of single cells connected in series with positive and negative polarities, while the fuel cell stack in this embodiment is changed to positive-negative-negative-positive and positive-negative-negative-positive, first connected in parallel and then in series. Under the premise of achieving the same polarity parallel connection function, the reaction area is doubled and the current intensity is doubled; and the system complexity is simplified. At the same time, modular assembly of the fuel cell stack is realized, improving the flexibility and efficiency of fuel cell stack assembly. In this embodiment, the upper part of the single cell with the electrode plate wrapped in film is the cathode side, and the lower part is the anode side. The stacking and series arrangement of multiple single cells with electrode plate wrapped in film means that the cathode side of multiple single cells with electrode plate wrapped in film is facing upward and the anode side is facing downward, and they are stacked vertically along the height direction.

[0085] An additional membrane electrode assembly is disposed between any two adjacent single cells containing membrane electrodes. Specifically, such as... Figure 5 As shown, the uppermost second lower electrode 21, through the additional membrane electrode assembly, allows the potential of the single cell containing the membrane electrode wrapped by the lower electrode to increase. The potential then flows to the first upper electrode 12 of the single cell containing the membrane electrode wrapped by the lower electrode, and then to the first lower electrode 11. Afterward, it flows through the upper membrane electrode assembly 3 to the second upper electrode 22, where the potential increases again, and then flows to the second lower electrode 21. This process is repeated from top to bottom, increasing the downward-flowing potential through the additional membrane electrode assembly and the membrane electrode assembly 3. Both the first electrode assembly 1 and the second electrode assembly 2 are made of conductive metal materials.

[0086] like Figure 2 and Figure 4As shown, both the first flow channel plate 4 and the second flow channel plate 5 are provided with flow guiding channels 42. The upper and lower electrode plates of the first electrode assembly 1 and the second electrode assembly 2 are each provided with perforated flow channels 14 corresponding to the positions of the flow guiding channels 42. The first flow channel plate 4 and the second flow channel plate 5 are connected to the perforated flow channels 14 on the upper and lower electrode plates through the flow guiding channels 42, forming a flow channel. This allows the reactants transferred in the flow channel to be transferred through the flow channel plate to the reaction interfaces on both sides of the membrane electrode assembly 3. By opening perforated flow channels 14 on the electrode plates and designing a flow guiding field on the flow channel plates, this design simplifies the design process and manufacturing process, effectively reducing production costs. Simultaneously, by placing the first flow channel plate 4 between the first upper electrode plate 12 and the second upper electrode plate 22, and the second flow channel plate 5 between the first lower electrode plate 11 and the second lower electrode plate 21, it serves to reverse the flow of fluid and insulate the upper and lower metal electrode plates, achieving forced flow guidance and preventing short circuits between the first electrode assembly 1 and the second electrode assembly 2.

[0087] In this embodiment, the perforated flow channel 14 is located in the middle region between the upper and lower plates of the first electrode assembly 1 and the second electrode assembly 2. The middle region of the first electrode assembly 1 and the second electrode assembly 2 has a perforated structure, which largely overlaps with the flow channel 42 on the flow channel plate, thereby allowing the reactants transferred in the flow channel plate to be transferred through the flow channel plate to the reaction interfaces on both sides of the membrane electrode assembly 3.

[0088] First through holes 15 are formed on the first lower electrode plate 11, the first upper electrode plate 12, the second lower electrode plate 21, and the second upper electrode plate 22. Second through holes 41 are formed on the first flow channel plate 4 and the second flow channel plate 5. The second through holes 41 correspond to and are connected to the first through holes 15. Specifically, there are four first through holes 15, which are the cathode fluid inlet, cathode fluid outlet, anode fluid inlet, and anode fluid outlet, respectively. That is, each electrode plate has four first through holes 15, which are distributed around the perimeter, with a hollow structure in the middle area. There are two second through holes 41, that is, each flow channel plate has two second through holes 41. When assembling and stacking the fuel cell stack and the single cell with electrode membrane electrode assemblies, positioning is achieved through double through holes or edge alignment, thereby completing the assembly of the single cell with electrode membrane electrode assemblies and the fuel cell stack.

[0089] The thickness of the upper and lower plates of the first electrode assembly 1 and the second electrode assembly 2 is 0.1~0.2mm, that is, the thickness of the first lower electrode 11, the first upper electrode 12, the second lower electrode 21 and the second upper electrode 22 is 0.1~0.2mm. The electrode plates can be formed into a frame-rib-channel integrated plate structure by stamping or etching. The middle connecting part is a connecting plate. During installation, the connecting part is bent 180 degrees to achieve parallel setting of the upper and lower electrode plates.

[0090] The flow channels 42 are all serpentine in shape. Located in the middle region of the first flow channel plate 4 and the second flow channel plate 5, the flow channels 42 primarily serve to reverse the fluid flow and provide insulation between the upper and lower metal plates. The first flow channel plate 4 and the second flow channel plate 5 have through holes around their perimeter for the inflow and outflow of cathode / anode fluid. Both the first flow channel plate 4 and the second flow channel plate 5 are made of insulating plastic material, such as PEEK, PET, or PEI.

[0091] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the fuel cell stack also includes a sealing assembly, which includes several sealing frames 6. Each sealing frame 6 is disposed on a contact surface at any location inside the single cell. The sealing frame 6 has a planar profile adapted to the contact surface, and its thickness is greater than or equal to the compression gap formed between the contact surfaces. Specifically, several sealing frames 6 are respectively installed on the upper and lower plates of the first electrode assembly 1 and the second electrode assembly 2, and are detachably pressed between the upper and lower plates of the first and second electrode assemblies 1 and 2 and the first flow channel plate 4, the membrane electrode assembly 3, and the second flow channel plate 5. Each electrode of the first and second electrode assemblies 1 and 2 has a sealing frame 6 on both its front and back surfaces. These sealing frames 6 are used to seal different reaction chambers, thereby effectively enhancing the sealing effect. Meanwhile, the first electrode assembly 1 and the second electrode assembly 2 are bent and deformed to achieve clamping and fixation and apply force to multiple sealing frames 6, resulting in better sealing effect. The structure of the fuel cell stack is detachable, which greatly improves the convenience of later maintenance. Furthermore, the modular assembly of the fuel cell stack is realized, which improves the flexibility and efficiency of fuel cell stack assembly.

[0092] The thickness of the sealing frame 6 is less than 0.05 mm, meaning the thickness of the sealing frame 6 exposed on the electrode plate is less than 0.05 mm. Preferably, the thickness of the sealing frame 6 is 5-15 micrometers. This very small thickness of the sealing frame 6 effectively prevents excessive bending deformation of the electrode plate and flow channel plate during stacking, resulting in greater stability and reliability. The sealing frame 6 can be manufactured separately or integrated into the electrode plate, making assembly more convenient.

[0093] In this embodiment, each single cell containing a membrane electrode assembly (MEA) has eight sealing frames 6, which are respectively installed on the front and back surfaces of the four MEAs. The sealing frames 6 are made of a sealing material. The sealing frames 6 can be made of rubber, which is installed on the surface of the MEAs. Alternatively, the sealing frames 6 can be made of a curing adhesive. Liquid sealant is applied to the surface of the MEAs, and then cured by heating to form a cured adhesive that adheres to the MEAs. Afterward, the flow channel plate or MEA assembly 3 is installed onto the MEAs and clamped in place, thus achieving a detachable connection.

[0094] In this embodiment, the first electrode assembly 1 and the second electrode assembly 2 have the same shape. The first connecting portion 13 and the second connecting portion 23 are arranged symmetrically with respect to the vertical plane, so that the first electrode assembly 1 and the second electrode assembly 2 intersect each other. In the vertical stacked structure, from top to bottom, it includes a first upper electrode plate 12, a first flow channel plate 4, a second upper electrode plate 22, a membrane electrode assembly 3, a first lower electrode plate 11, a second flow channel plate 5, and a second lower electrode plate 21. The first electrode assembly 1 and the second electrode assembly 2 have the same shape and are respectively located on both sides of the single cell where the electrode plates wrap the membrane electrode, and are stacked crosswise, which makes assembly very convenient. The first connecting portion 13 can be connected to the entire side or most of the side of the first lower electrode plate 11 and the first upper electrode plate 12, so that the connection is stable and reliable.

[0095] Of course, in other embodiments, the first connecting portion 13 and the second connecting portion 23 are disposed on the same side, respectively located at the two ends of the connecting side, and the size of the first connecting portion 13 or the second connecting portion 23 is less than 1 / 2 of the side length of the connecting side. That is, the first connecting portion 13 extends from the same connecting side of the first lower electrode plate 11 and the first upper electrode plate 12 and forms a first clearance notch, and the second connecting portion 23 extends from the same connecting side of the second lower electrode plate 21 and the second upper electrode plate 22 and forms a second clearance notch; the first connecting portion 13 and the second connecting portion 23 intersect and are located on the same side of the first electrode plate assembly 1 and the second electrode plate assembly 2, and the second connecting portion 23 passes through the first clearance notch and the first connecting portion 13 passes through the second clearance notch, so that the first electrode plate assembly 1 and the second electrode plate assembly 2 are clamped between the first flow channel plate 4, the membrane electrode assembly 3 and the second flow channel plate 5 to achieve a stacked arrangement. The first connecting portion 13 is interconnected with a portion of the side of the first lower electrode plate 11 and the first upper electrode plate 12. The unconnected side forms a first clearance notch. Through the first clearance notch and the second clearance notch, the second connecting portion 23 and the first connecting portion 13 are mutually clearanceed and positioned on the same side of the single cell with the electrode plate covering the film electrode, resulting in a more compact overall structure and a smaller footprint. Specifically, the first connecting portion 13 can be within half of the entire side of the first lower electrode plate 11 and the first upper electrode plate 12.

[0096] This invention also discloses a method for preparing a fuel cell stack, which is used to prepare a fuel cell stack as described above. Figure 6 As shown, the method for fabricating the fuel cell stack includes the following steps: Single cell assembly: bending the first electrode assembly 1 and the second electrode assembly 2 and arranging them in a cross configuration to divide the space defined by the first electrode assembly 1 and the second electrode assembly 2 into three space intervals in the vertical direction; and sequentially installing the first flow channel plate 4, the membrane electrode assembly 3, and the second flow channel plate 5 from top to bottom in the three space intervals; Stack assembly: stacking multiple single cells in series in the vertical direction and setting an additional membrane electrode assembly between any two adjacent single cells.

[0097] By having the first electrode assembly 1 and the second electrode assembly 2 respectively perform the dual functions of "anode current collection + cathode current collection," the functions of current collection and structural support are integrated, simplifying system complexity. Through a bending process, the first electrode assembly 1 and the second electrode assembly 2 are folded into specific shapes, directly clamping and enclosing the membrane electrode assembly 3, as well as the first flow channel plate 4 and the second flow channel plate 5 within the internal space. This allows the structural fixation of the fuel cell stack to rely primarily on the deformation force of the first and second electrode assembly 1 and 2 after bending, rather than glue. This makes the fuel cell stack structure detachable, significantly improving the convenience of later maintenance; it also enables modular assembly of the fuel cell stack, improving the flexibility and efficiency of fuel cell stack assembly. Furthermore, the electrode plates and flow channel plates are designed as independent planar parts, functionally separating the traditional electrode plate by designing the current collection function and flow channel structure as independent planar parts. This simplifies the design process and manufacturing process of traditional metal electrode plate flow channels, effectively reducing production costs. At the same time, compared with traditional stamped metal bipolar plates, it has significant advantages in saving a lot of upfront mold-making costs and shortening the development cycle.

[0098] In this embodiment, the specific steps of assembling a single cell are as follows: placing the second flow channel plate 5 on the second lower electrode plate 21; placing the first lower electrode plate 11 on the second flow channel plate 5; placing the membrane electrode assembly 3 on the first lower electrode plate 11; bending the second electrode plate assembly 2 so that the second upper electrode plate 22 is parallel to the second lower electrode plate 21 and clamped against the membrane electrode assembly 3; placing the first flow channel plate 4 on the second upper electrode plate 22; bending the first electrode plate assembly 1 so that the first upper electrode plate 12 is parallel to the first lower electrode plate 11 and clamped against the first flow channel plate 4. When assembling the single cell with the electrode plate enclosing the membrane electrode, the corresponding structures are placed sequentially along the height direction, making installation and connection very convenient. Simultaneously, bending the second electrode plate assembly 2 and the first electrode plate assembly 1 during assembly achieves clamping and fixing, resulting in a tight fit between the structures, good sealing, and high clamping and fixing stability.

[0099] Of course, in other embodiments, during assembly, the first electrode assembly 1 and the second electrode assembly 2 can be bent first, then inserted parallel to each other to achieve mutual intersection, and finally disassembled to install the first flow channel plate 4, the membrane electrode assembly 3, and the second flow channel plate 5 in three spaced spaces. Specifically, to facilitate the installation of the first flow channel plate 4, the membrane electrode assembly 3, and the second flow channel plate 5, it is not necessary to ensure the upper and lower electrode plates are parallel during the first bending of the first electrode assembly 1 and the second electrode assembly 2. After the first flow channel plate 4, the membrane electrode assembly 3, and the second flow channel plate 5 are installed, the first electrode assembly 1 and the second electrode assembly 2 can be clamped and fixed to achieve parallelism between the upper and lower electrode plates.

[0100] Before assembling a single cell, the following steps are included: A sealing frame 6 is installed on the contact surface of either the upper or lower electrode plates of the first electrode assembly 1 and the second electrode assembly 2. Each electrode plate has a sealing frame 6 on both its front and back surfaces. Several sealing frames 6 are used to seal different reaction chambers, thereby effectively enhancing the sealing effect. Simultaneously, the bending deformation force of the first electrode assembly 1 and the second electrode assembly 2 achieves clamping and fixation, applying force to the multiple sealing frames 6, resulting in a better sealing effect. Furthermore, the fuel cell stack structure is detachable, significantly improving the convenience of later maintenance; and modular assembly of the fuel cell stack is achieved, enhancing the flexibility and efficiency of fuel cell stack assembly.

[0101] In one embodiment, symmetrical rubber is screen-printed on the contact surfaces of the upper and lower plates of the first electrode assembly 1 and the second electrode assembly 2 at any position. The rubber can be silicone rubber or other sealing materials. Before bending the electrode, silicone rubber or other sealing materials can be screen-printed symmetrically on both sides of the electrode. The rubber has a thickness of 5 to 15 micrometers.

[0102] In another embodiment, the adhesive is cured by heating at any point on the contact surface of the upper and lower plates of the first electrode assembly 1 and the second electrode assembly 2. By curing the sealant by heating, it can be used as a single unit, eliminating the need for a separate sealing frame 6 and improving assembly efficiency. The temperature for curing the adhesive is 150~180℃.

[0103] The fuel cell stack assembly also includes the following steps: A sealing frame 6 is installed at the contact surface of two adjacent single cells; after stacking, pressure is applied to the stack and it is locked using a locking device, with the applied pressure being 1~1.5 MPa. After applying a pressure of 1~1.5 MPa, it is locked with bolts and steel straps. After stacking, a pressure of 1~1.5 MPa is applied to the single cells with multiple electrode plates wrapping the membrane electrode and the additional membrane electrode assembly through a force-applying mechanism, effectively preventing bending deformation and ensuring high stability; then it is locked and fixed with bolts and steel straps, thus completing the assembly of the fuel cell stack.

[0104] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A single cell with a plate-coated membrane electrode, characterized in that, It includes a first electrode assembly, a second electrode assembly, a membrane electrode assembly, a first flow channel plate, and a second flow channel plate; The first electrode assembly includes a first lower electrode, a first upper electrode, and a first connecting portion. The first lower electrode and the first upper electrode are arranged in parallel relative to each other. The first connecting portion is connected to the side of the first lower electrode and the first upper electrode and can drive the first lower electrode to open relative to the first upper electrode in an opening and closing manner. The second electrode assembly includes a second lower electrode, a second upper electrode, and a second connecting portion. The second lower electrode and the second upper electrode are arranged in parallel relative to each other. The second connecting portion is connected to the side of the second lower electrode and the second upper electrode and can drive the second lower electrode to open relative to the second upper electrode in an opening and closing manner. During assembly, the first lower electrode plate is inserted parallel to the internal space of the second electrode plate assembly, dividing the space defined by the first electrode plate assembly and the second electrode plate assembly into three space intervals in the vertical direction. The first flow channel plate, the membrane electrode assembly, and the second flow channel plate are installed sequentially in the three space intervals from top to bottom.

2. The single cell with a plate-wrapped film electrode as described in claim 1, characterized in that, Both the first flow channel plate and the second flow channel plate are provided with flow guide channels, and the upper and lower electrode plates of the first electrode plate assembly and the second electrode plate assembly are provided with hollow flow channels corresponding to the positions of the flow guide channels.

3. The single cell with a plate-wrapped film electrode as described in claim 2, characterized in that, The hollowed-out flow channel is located in the middle area between the upper and lower plates of the first electrode assembly. And / or, the shape of the flow channel is serpentine.

4. The single cell with a plate-wrapped film electrode as described in claim 1, characterized in that, A first through hole is formed on the first lower electrode plate, the first upper electrode plate, the second lower electrode plate, and the second upper electrode plate. A second through hole is formed on both the first flow channel plate and the second flow channel plate. The second through hole corresponds to and is connected to the first through hole. And / or, the thickness of the upper and lower plates of the first electrode assembly and the second electrode assembly is 0.1~0.2mm.

5. The single cell with a plate-wrapped film electrode as described in claim 1, characterized in that, The first electrode assembly and the second electrode assembly have the same shape. The first connecting portion and the second connecting portion are mirror-symmetrically arranged with respect to the vertical plane so that the first electrode assembly and the second electrode assembly intersect each other. In the stacked structure in the vertical direction, from top to bottom, it includes the first upper electrode plate, the first flow channel plate, the second upper electrode plate, the membrane electrode assembly, the first lower electrode plate, the second flow channel plate, and the second lower electrode plate. Alternatively, the first connecting part and the second connecting part are disposed on the same side, respectively located at the two ends of the connecting side, and the size of the first connecting part or the second connecting part is less than 1 / 2 of the side length of the connecting side.

6. The single cell with a plate-wrapped film electrode as described in claim 1, characterized in that, It also includes a sealing assembly comprising a plurality of sealing frames disposed on a contact surface at any location inside the single cell, the sealing frames having a planar profile adapted to the contact surface, and the thickness of the sealing frames being greater than or equal to the compression gap formed between the contact surfaces.

7. The single cell with a plate-wrapped film electrode as described in claim 6, characterized in that, The sealing frame is made of rubber or adhesive. And / or, the thickness of the sealing frame is less than 0.05 mm; Preferably, the thickness of the sealing frame is 5 to 15 micrometers.

8. The single cell with a plate-wrapped film electrode as described in claim 1, characterized in that, Both the first electrode assembly and the second electrode assembly are made of conductive metal materials; And / or, both the first flow channel plate and the second flow channel plate are made of insulating plastic material.

9. A fuel cell stack, characterized in that, It includes multiple single cells with plate-encapsulated membrane electrodes as described in any one of claims 1-8.

10. The fuel cell stack as described in claim 9, characterized in that, The first electrode assembly and the second electrode assembly are arranged in parallel and cross each other, and the single cells with multiple electrode-wrapped membrane electrodes are stacked and connected in series.

11. The fuel cell stack as described in claim 10, characterized in that, An additional membrane electrode assembly is provided between any two adjacent single cells with membrane electrodes wrapped by the electrode plates.

12. A method for preparing a fuel cell stack, characterized in that, It is used to prepare a fuel cell stack as described in any one of claims 9-11, wherein the method for preparing the fuel cell stack includes the following steps: Single cell assembly: includes bending the first electrode assembly and the second electrode assembly and arranging them in a cross configuration to divide the space defined by the first electrode assembly and the second electrode assembly into three space intervals in the vertical direction; The first flow channel plate, the membrane electrode assembly, and the second flow channel plate are then sequentially installed from top to bottom in the three spaced spaces. Battery stack assembly: Multiple single cells are stacked in series vertically, and an additional membrane electrode assembly is placed between any two adjacent single cells.

13. The method for preparing a fuel cell stack as described in claim 12, characterized in that, The specific steps for assembling the single battery are as follows: Place the second flow channel plate on the second lower electrode plate; Place the first lower electrode plate on the second flow channel plate; The membrane electrode assembly is placed on the first lower electrode plate; The second electrode assembly is bent so that the second upper electrode is parallel to the second lower electrode and clamped against the membrane electrode assembly; Place the first flow channel plate on the second upper electrode plate; The first electrode assembly is bent so that the first upper electrode is parallel to the first lower electrode and clamped against the first flow channel plate; And / or, prior to the assembly of the single cell, the following steps are also included: A sealing frame is installed on the contact surface of the upper and lower two electrode plates of the first electrode assembly and the second electrode assembly at any position. Preferably, symmetrical rubber screen printing or adhesive curing by heating is performed on the contact surfaces of the upper and lower plates of the first and second electrode assemblies.

14. The method for preparing a fuel cell stack as described in claim 12, characterized in that, The assembly of the fuel cell stack also includes the following steps: A sealing frame is provided at the contact surface of two adjacent single batteries; After stacking, pressure is applied to the fuel cell stack and it is locked with a locking device. The applied pressure is 1~1.5MPa.

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