Assembly method and assembly device of fuel cell and fuel cell

Abstract

The embodiment of the invention discloses an assembling method and an assembling device of a fuel cell and the fuel cell. The assembly method of the fuel cell comprises the following steps: obtaining the size characteristics of a gas diffusion layer; the size features comprise thickness, length, width and preset thickness variation; wherein the preset thickness variable quantity is the thickness variable quantity of the gas diffusion layer made of the same material after being actually used in the fuel cell for a preset time; according to the size characteristics, the pre-pressing pressure and the pre-pressing frequency are determined; applying pressure to the gas diffusion layer according to the pre-pressing pressure and the pre-pressing times; forming a membrane electrode by using the gas diffusion layer after the pressure is applied; and applying pressure to the membrane electrode, and assembling the membrane electrode subjected to pressure application to form the fuel cell. According to the technical scheme of the embodiment of the invention, the pressure is applied to the gas diffusion layer before the single fuel cell is assembled, and the stress in the fuel cell is released in advance, so that the pressure of the assembled fuel cell is kept stable, and the stability and reliability of the fuel cell are improved.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and in particular to a fuel cell assembly method, assembly apparatus, and fuel cell. Background Technology

[0002] A fuel cell is a device that directly converts the chemical energy of fuel into electrical energy through an electrochemical reaction, while releasing heat and byproducts such as water. The structure of a fuel cell includes an electrolyte membrane, electrodes (anode and cathode) located on both sides of the electrolyte membrane, and bipolar plates.

[0003] However, as the operating time of fuel cells assembled using existing technologies increases, the internal electrolyte membrane ages, the membrane thickness decreases, and the membrane compressibility drops. The internal structure also experiences creep due to concentrated loads, which in turn leads to reduced power generation performance and decreases the stability and reliability of the fuel cell. Summary of the Invention

[0004] This invention provides a fuel cell assembly method, assembly apparatus, and fuel cell to improve the stability and reliability of fuel cells.

[0005] According to one aspect of the present invention, a method for assembling a fuel cell is provided, the method comprising:

[0006] Obtain the dimensional characteristics of the gas diffusion layer; the dimensional characteristics include thickness, length, width, and preset thickness variation; wherein, the preset thickness variation is the thickness variation of the gas diffusion layer of the same material after a preset period of actual use in the fuel cell;

[0007] Based on the dimensional characteristics, determine the preloading pressure and the number of preloading cycles;

[0008] Pressure is applied to the gas diffusion layer based on the pre-compression pressure and the number of pre-compression cycles;

[0009] A membrane electrode is formed using a gas diffusion layer after pressure is applied;

[0010] Pressure is applied to the membrane electrode assembly, and the pressure-adjusted membrane electrode assembly is used to form a fuel cell.

[0011] Optionally, based on dimensional characteristics, the preloading pressure and the number of preloading cycles are determined, including:

[0012] The elastic modulus of the gas diffusion layer is determined based on the thickness and the preset thickness variation.

[0013] The preload pressure and the number of preload cycles are determined based on the thickness, elastic modulus, length, and width.

[0014] Optionally, the preloading pressure and the number of preloading cycles are determined based on the thickness, elastic modulus, length, and width, including:

[0015] The number of preloading cycles is determined based on the elastic modulus and thickness.

[0016] The preload pressure is determined based on the thickness, length, and width.

[0017] Optionally, the number of preloading cycles can be determined based on the elastic modulus and thickness, including:

[0018] The number of preloading cycles is determined based on the following formula.

[0019] n = (σ1 - σ) * E + σ1 / σ * 10;

[0020] Where n is the number of pre-compression cycles, σ1 is the thickness, σ is the center value of the gas diffusion layer thickness, and E is the elastic modulus.

[0021] Optionally, the preload pressure can be determined based on the thickness, length, and width, including:

[0022] The preload pressure is determined according to the following formula.

[0023] F = P / (D1 * D2) * 10 -3 *σ1 / σ;

[0024] Where F is the pre-pressure, P is the theoretical operating pressure of the fuel cell, D1 is the length, D2 is the width, σ1 is the thickness, and σ is the center value of the gas diffusion layer thickness.

[0025] Optionally, pressure may be applied to the membrane electrode, including:

[0026] A preset pressure is applied to the membrane electrode.

[0027] Optionally, after applying pressure to the membrane electrode and assembling the pressure-adjusted membrane electrode to form a fuel cell, the process includes:

[0028] Multiple fuel cells were stacked and assembled, and the assembly forces were recorded.

[0029] Determine the assembly pressure based on the assembly force;

[0030] When the assembly pressure is within the preset pressure range, a fuel cell stack is formed.

[0031] Optionally, after determining the assembly pressure based on the assembly force, the following may also be included:

[0032] When the assembly pressure is not within the preset pressure range, apply pressure to the membrane electrode again.

[0033] According to another aspect of the present invention, an assembly apparatus for a fuel cell is provided, the assembly apparatus comprising:

[0034] The size feature acquisition module is used to acquire the size features of the gas diffusion layer. The size features include thickness, length, width, and preset thickness change. The preset thickness change is the thickness change of the gas diffusion layer of the same material after a preset period of actual use in the fuel cell.

[0035] The preload pressure and preload cycle determination module is used to determine the preload pressure and preload cycle based on dimensional characteristics.

[0036] The pre-compression module is used to apply pressure to the gas diffusion layer according to the pre-compression pressure and the number of pre-compression cycles;

[0037] A membrane electrode forming module is used to form a membrane electrode using a gas diffusion layer under applied pressure;

[0038] A fuel cell assembly module is used to apply pressure to the membrane electrode assembly (MEA) and then assemble the MEA under pressure to form a fuel cell.

[0039] According to another aspect of the present invention, a fuel cell is provided, which is assembled using the fuel cell assembly method of any embodiment of the present invention.

[0040] The technical solution of this invention, based on the dimensional characteristics of the gas diffusion layer, precisely sets the pre-compression pressure and the number of pre-compression cycles. Pressure is applied to the gas diffusion layer according to the pre-compression pressure and the number of pre-compression cycles, releasing internal stress in advance and improving the surface smoothness of the gas diffusion layer. The pressurized gas diffusion layer is then assembled with the catalyst layer and electrolyte membrane to form a membrane electrode assembly (MEA). This results in tighter contact between the gas diffusion layer, catalyst layer, and electrolyte membrane, reducing contact resistance, improving the electrical performance of the MEA, and reducing mechanical wear between the gas diffusion layer and adjacent components. This mitigates the problems of reduced fuel cell power generation performance caused by electrolyte membrane aging, reduced membrane thickness, decreased membrane compressibility, and creep due to concentrated loads. Applying pressure to the MEA and assembling it into a fuel cell eliminates microscopic gaps between layers, reduces interfacial contact resistance, increases the overall mechanical strength of the MEA, reduces the risk of delamination during use, extends the lifespan of the fuel cell, improves the power generation performance of the fuel cell, and ultimately enhances the stability and reliability of the fuel cell.

[0041] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a flowchart of a fuel cell assembly method according to an embodiment of the present invention;

[0044] Figure 2 This is a flowchart of another fuel cell assembly method provided according to an embodiment of the present invention;

[0045] Figure 3 It is provided according to the embodiments of the present invention. Figure 2 The flowchart included in S230;

[0046] Figure 4 This is a flowchart of another fuel cell assembly method provided according to an embodiment of the present invention;

[0047] Figure 5 This is a schematic diagram of the structure of a fuel cell assembly device according to an embodiment of the present invention;

[0048] Figure 6 This is a cross-sectional structural diagram of a fuel cell according to an embodiment of the present invention. Detailed Implementation

[0049] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0050] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0051] Figure 1 This is a flowchart of a fuel cell assembly method according to an embodiment of the present invention. This embodiment is applicable to assembling fuel cells. The fuel cell assembly method can be executed by a fuel cell assembly device, which can be implemented in hardware and / or software. Figure 1 As shown, the assembly method of the fuel cell includes:

[0052] S110. Obtain the dimensional characteristics of the gas diffusion layer; the dimensional characteristics include thickness, length, width, and preset thickness variation; wherein, the preset thickness variation is the thickness variation of the gas diffusion layer of the same material after a preset period of actual use in the fuel cell.

[0053] Specifically, the main structure of the gas diffusion layer is the substrate layer, typically composed of carbon paper or carbon cloth. Carbon paper has a uniform porous thin-layer structure, made of graphitized carbon fibers, and possesses excellent conductivity, chemical stability, and thermal stability. Carbon cloth has bending properties and certain compressive strength, but its dimensional stability is relatively poor. The gas diffusion layer also includes a microporous layer located on one side of the substrate layer. This microporous layer improves the substrate's pore structure, reduces the contact resistance between the substrate and the catalyst layer, guides the reactant gases to pass quickly through the diffusion layer and distribute them uniformly to the catalyst layer surface, and drains the water generated during the reaction to prevent flooding. For example, a membrane electrode assembly (MEA) includes an electrolyte membrane and an anode and cathode located on either side of the electrolyte membrane. The anode includes a gas diffusion layer and a catalyst layer, with the microporous layer of the gas diffusion layer located between the substrate layer and the catalyst layer. The gas diffusion layer provides channels for reactant gases (such as hydrogen and oxygen), allowing the gases to diffuse uniformly to the catalyst layer surface, ensuring the smooth progress of the electrochemical reaction. The gas diffusion layer also serves as a supporting structure for the electrode, providing stable physical support and ensuring that the electrode structure remains stable during battery operation, capable of withstanding certain pressures and mechanical stresses.

[0054] The dimensional characteristics of the gas diffusion layer can be obtained, for example, by measuring the thickness, length, and width of the gas diffusion layer using a laser thickness gauge or high-precision calipers. The preset thickness variation can be determined in advance by performing accelerated aging tests on a gas diffusion layer made of the same material as the gas diffusion layer used in the currently assembled fuel cell. Specifically, the initial thickness of the gas diffusion layer to be tested can be obtained first, then an accelerated aging test can be performed on the gas diffusion layer to be tested, and the thickness after the accelerated aging test can be obtained. The thickness variation rate is determined based on the percentage of the difference between the initial thickness before the accelerated aging test and the thickness of the gas diffusion layer after the accelerated aging test relative to the initial thickness. The preset thickness variation is then determined based on the thickness variation rate and the thickness of the gas diffusion layer used in the currently assembled fuel cell.

[0055] The preset thickness variation can also be determined in advance by conducting accelerated aging tests on a gas diffusion layer of the same size and material as the gas diffusion layer used in the currently assembled fuel cell. Specifically, the initial thickness of the gas diffusion layer to be tested can be obtained first, then an accelerated aging test can be performed on the gas diffusion layer to be tested, and the thickness after the accelerated aging test can be obtained. The preset thickness variation of the gas diffusion layer can be determined based on the difference between the initial thickness of the gas diffusion layer before the accelerated aging test and the thickness of the gas diffusion layer after the accelerated aging test.

[0056] The material of the gas diffusion layer used in accelerated aging testing is the same as that used in the gas diffusion layer during fuel cell assembly. This improves the accuracy of obtaining the preset thickness change of the gas diffusion layer, thereby improving the performance of the assembled fuel cell. The preset time can be the simulated actual usage time of the gas diffusion layer in the accelerated aging test. For example, if the initial thickness of the gas diffusion layer is 0.2 mm, after accelerated aging testing (simulating 3000 hours of actual use), the thickness of the gas diffusion layer decreases by 0.04 mm, from 0.2 mm to 0.16 mm, which is the preset thickness change of 0.04 mm. After obtaining the dimensional characteristics of the gas diffusion layer, it is necessary to determine the pressure applied to the gas diffusion layer and the number of times the pressure is applied based on the dimensional characteristics, thereby applying pressure to the gas diffusion layer and releasing internal stress in advance.

[0057] S120. Determine the preloading pressure and the number of preloading cycles based on the dimensional characteristics.

[0058] Specifically, the pre-compression pressure is the pressure applied to the gas diffusion layer beforehand. The number of pre-compression cycles is the number of times the pressure is applied to the gas diffusion layer beforehand. The pre-compression pressure and the number of pre-compression cycles are determined by simulating the operating environment of a fuel cell (such as vibration or degradation caused by electrochemical reactions) and based on the different size characteristics of the gas diffusion layer. The reason for determining the pre-compression pressure and the number of pre-compression cycles based on size characteristics is that size characteristics affect the uniformity of pressure distribution. Larger gas diffusion layers are prone to edge pressure decay during a single pre-compression, leading to uneven porosity distribution. Applying pressure in sections or using multiple pressure applications can ensure the consistency of the overall structure.

[0059] Insufficient pre-compression pressure and number of pre-compression cycles may lead to uneven pore distribution in the gas diffusion layer, poor adhesion to other components, and increased contact resistance. Excessive pre-compression pressure and number of pre-compression cycles may cause material damage, elastic failure, and reduce the service life and performance of the gas diffusion layer. Determining appropriate pre-compression pressure and number of pre-compression cycles allows for a better balance between the mechanical properties and structural stability of the gas diffusion layer, ensuring the overall performance of the fuel cell.

[0060] S130. Apply pressure to the gas diffusion layer according to the pre-compression pressure and the number of pre-compression cycles.

[0061] Specifically, based on the determined pre-compression pressure and number of pre-compression cycles, a hot press molding machine can be used to apply pressure to the gas diffusion layer. For example, the ambient temperature is set to 85°C (simulating the operating temperature of a fuel cell), the duration of each pressure application is set to 40 seconds (to ensure sufficient stress release), and the pre-compression pressure (e.g., 0.6 MPa) is applied according to the number of pre-compression cycles (e.g., 3 times), with a preset interval (e.g., 15 seconds) between each application to avoid overheating of the material due to continuous pressure application.

[0062] S140, A membrane electrode is formed using a gas diffusion layer after pressure is applied.

[0063] Specifically, the pressurized gas diffusion layer is combined with the catalyst layer and electrolyte membrane via hot-pressing to form a membrane electrode assembly (MEA). The hot-pressing process requires precise control of the bonding pressure, temperature, and time. Matching the dimensions of the resulting MEA to the gas diffusion layer improves the stability of the MEA formation.

[0064] S150. Apply pressure to the membrane electrode and assemble the membrane electrode with the pressure applied to form a fuel cell.

[0065] Specifically, applying pressure to the membrane electrode assembly (MEA) involves applying specific pressure after the MEA has been initially fabricated. This optimizes interfacial contact and structural stability, thereby improving the MEA's electrochemical performance and durability. The pressurized MEA is then bonded to components such as titanium alloy bipolar plates and graphite end plates, and the end plate bolts are tightened to assemble a single fuel cell. The pressure applied to the MEA can be obtained by simulating the stress characteristics of the MEA during fuel cell operation.

[0066] Applying pressure to the membrane electrode assembly (MEA) and assembling the MEA under pressure to form a fuel cell can eliminate microscopic gaps between layers, reduce interfacial contact resistance, allow catalyst particles to bond more tightly with the electrolyte membrane, improve the utilization rate of reactive sites, increase the overall mechanical strength of the MEA, and reduce the risk of delamination during use.

[0067] The technical solution of this invention, based on the dimensional characteristics of the gas diffusion layer, precisely sets the pre-compression pressure and the number of pre-compression cycles. Pressure is applied to the gas diffusion layer according to the pre-compression pressure and the number of pre-compression cycles, releasing internal stress in advance and improving the surface smoothness of the gas diffusion layer. The pressurized gas diffusion layer is then assembled with the catalyst layer and electrolyte membrane to form a membrane electrode assembly (MEA). This results in tighter contact between the gas diffusion layer, catalyst layer, and electrolyte membrane, reducing contact resistance, improving the electrical performance of the MEA, and reducing mechanical wear between the gas diffusion layer and adjacent components. This mitigates the problems of reduced fuel cell power generation performance caused by electrolyte membrane aging, reduced membrane thickness, decreased membrane compressibility, and creep due to concentrated loads. Applying pressure to the MEA and assembling it into a fuel cell eliminates microscopic gaps between layers, reduces interfacial contact resistance, increases the overall mechanical strength of the MEA, reduces the risk of delamination during use, extends the lifespan of the fuel cell, improves the power generation performance of the fuel cell, and ultimately enhances the stability and reliability of the fuel cell.

[0068] Figure 2 This is a flowchart of another fuel cell assembly method according to an embodiment of the present invention. This embodiment is a detailed description of the technical features of the above embodiments. Figure 2 As shown, the assembly method of the fuel cell includes:

[0069] S210. Obtain the dimensional characteristics of the gas diffusion layer; the dimensional characteristics include thickness, length, width, and preset thickness variation; wherein, the preset thickness variation is the thickness variation of the gas diffusion layer of the same material after a preset period of actual use in the fuel cell.

[0070] S220. Determine the elastic modulus of the gas diffusion layer based on the thickness and the preset thickness variation.

[0071] Specifically, the elastic modulus of the gas diffusion layer is related to its compressibility and can be determined based on the ratio of the thickness change to the initial thickness. The elastic modulus of the gas diffusion layer is obtained based on the initial thickness of the gas diffusion layer obtained in S210 and the thickness change of a gas diffusion layer of the same material after a preset period of actual use in the fuel cell. The elastic modulus of the gas diffusion layer reflects its ability to resist elastic deformation.

[0072] S230. Determine the preloading pressure and the number of preloading cycles based on the thickness, elastic modulus, length, and width.

[0073] Specifically, the elastic modulus of the gas diffusion layer can be obtained according to S220. Then, based on the thickness, elastic modulus, length, and width of the gas diffusion layer, the pre-compression pressure and the number of pre-compression cycles are determined. For example, the performance of gas diffusion layers with different thicknesses, elastic moduli, lengths, and widths is tested under different pre-compression pressures and pre-compression cycles. The optimal performance is determined by the pre-compression pressure and number of pre-compression cycles corresponding to the thickness, elastic modulus, length, and width of different gas diffusion layers. Then, based on the thickness, elastic modulus, length, and width of the gas diffusion layer to be assembled, and the previously determined pre-compression pressure and number of pre-compression cycles corresponding to the thickness, elastic modulus, length, and width of different gas diffusion layers, the pre-compression pressure and number of pre-compression cycles are determined.

[0074] The thickness of the gas diffusion layer determines the required compression, the elastic modulus reflects the deformation resistance of the gas diffusion layer, and the length and width of the gas diffusion layer determine the stress area during preloading. By determining the preloading pressure and the number of preloading cycles based on the thickness, elastic modulus, length, and width of the gas diffusion layer, the required preloading pressure and the number of preloading cycles can be determined more accurately, thereby improving the mechanical properties and structural stability of the gas diffusion layer.

[0075] In an optional embodiment of the present invention, Figure 3 It is provided according to the embodiments of the present invention. Figure 2 The flowchart included in S230 is as follows: Figure 3 As shown, S230 includes:

[0076] S2301. Determine the number of preloading cycles based on the elastic modulus and thickness.

[0077] Specifically, the number of preloading cycles is determined according to the following formula:

[0078] n = (σ1 - σ) * E + σ1 / σ * 10;

[0079] Where n is the number of pre-compression cycles, σ1 is the thickness, σ is the center value of the gas diffusion layer thickness, and E is the elastic modulus.

[0080] Specifically, the center thickness σ of the gas diffusion layer can be obtained by referring to the material specifications, for example, by determining the center thickness σ of the gas diffusion layer based on the thickness specified in the carbon paper specifications of a certain brand. σ1 is the initial thickness of the gas diffusion layer measured before treatment. The elastic modulus of the gas diffusion layer reflects its resistance to deformation, and the thickness of the gas diffusion layer determines the required compression. Based on the above relationship, the number of pre-compression cycles for the gas diffusion layer can be determined more accurately, ensuring the microstructural stability of the gas diffusion layer. Insufficient pre-compression cycles may lead to uneven pore distribution in the gas diffusion layer and poor adhesion to other components; excessive pre-compression cycles may lead to material damage, elastic failure, and reduced service life and performance of the gas diffusion layer. Accurately determining the number of pre-compression cycles for the gas diffusion layer allows for a better balance between mechanical properties and structural stability, ensuring the overall performance of the fuel cell.

[0081] S2302. Determine the preload pressure based on the thickness, length, and width.

[0082] Specifically, the preload pressure is determined according to the following formula:

[0083] F = P / (D1 * D2) * 10 -3 *σ1 / σ;

[0084] Where F is the pre-pressure, P is the theoretical operating pressure of the fuel cell, D1 is the length, D2 is the width, σ1 is the thickness, and σ is the center value of the gas diffusion layer thickness.

[0085] Specifically, the theoretical operating pressure P of the fuel cell can also be obtained by referring to the material specifications. The thickness of the gas diffusion layer determines the required compression, while the length and width of the gas diffusion layer determine the stress area during pre-compression. Based on these relationships, the pre-compression pressure on the gas diffusion layer can be determined more precisely, ensuring the microstructural stability of the gas diffusion layer. If the pre-compression pressure is too low, gaps may appear between the gas diffusion layer and other components, increasing contact resistance; if the pre-compression pressure is too high, it may cause material damage (such as carbon paper fiber breakage), elastic failure, and reduce the service life and performance of the gas diffusion layer. Accurately determining the pre-compression pressure on the gas diffusion layer allows for a better balance between mechanical properties and structural stability, ensuring the overall performance stability of the fuel cell.

[0086] S240. Apply pressure to the gas diffusion layer according to the pre-compression pressure and the number of pre-compression cycles.

[0087] S250, A membrane electrode is formed using a gas diffusion layer after pressure is applied.

[0088] S260. Apply pressure to the membrane electrode and assemble the membrane electrode with the pressure applied to form a fuel cell.

[0089] The technical solution of this invention determines the pre-compression pressure and the number of pre-compression cycles based on the thickness, elastic modulus, length, width, and corresponding relationships of the gas diffusion layer. This allows for more accurate determination of the pre-compression pressure and the number of pre-compression cycles for the gas diffusion layer, thereby improving the mechanical properties and structural stability of the gas diffusion layer.

[0090] In an optional embodiment of the present invention, applying pressure to the membrane electrode includes applying a preset pressure to the membrane electrode.

[0091] Specifically, the preset pressure is a fixed value, which can be a pre-set pressure applied to the membrane electrode assembly (MEA). The preset pressure can be obtained based on the stress characteristics of the MEA during fuel cell operation. Determining the preset pressure based on the stress characteristics of the MEA during fuel cell operation can improve the matching and synergistic performance between the MEA and other layer materials, and reduce interfacial impedance.

[0092] Figure 4 This is a flowchart of another fuel cell assembly method provided according to an embodiment of the present invention.

[0093] like Figure 4 As shown, the assembly method of the fuel cell includes:

[0094] S310. Obtain the dimensional characteristics of the gas diffusion layer; the dimensional characteristics include thickness, length, width, and preset thickness variation; wherein, the preset thickness variation is the thickness variation of the gas diffusion layer of the same material after a preset period of actual use in the fuel cell.

[0095] S320. Determine the preloading pressure and the number of preloading cycles based on the dimensional characteristics.

[0096] S330. Apply pressure to the gas diffusion layer according to the pre-compression pressure and the number of pre-compression cycles.

[0097] S340, A membrane electrode is formed using a gas diffusion layer after pressure is applied.

[0098] S350, Apply pressure to the membrane electrode, and use the pressure-applied membrane electrode to assemble a fuel cell.

[0099] S360: Stack and assemble multiple fuel cells and record the assembly force.

[0100] Specifically, S350 assembles a single fuel cell. Following S350, this step involves stacking multiple fuel cells to form a fuel cell stack. During the stacking and compression assembly of multiple fuel cells, the assembly force is recorded in real time.

[0101] S370. Determine the assembly pressure based on the assembly force.

[0102] Specifically, the assembly pressure is determined based on the ratio of the assembly force to the area of ​​the fuel cell.

[0103] S380. Determine the relationship between the assembly pressure and the preset pressure range.

[0104] S390. When the assembly pressure is within the preset pressure range, a fuel cell stack is formed.

[0105] Specifically, the preset pressure range can be a range of assembly pressures that meet the assembly conditions. For example, the preset pressure range is (0.6 ± 0.06) MPa, i.e., 0.54 MPa - 0.66 MPa. The relationship between the assembly pressure and the preset pressure range is determined. When the assembly pressure is within the preset pressure range, it indicates that the assembly pressure meets the design requirements, thus forming the fuel cell stack. For example, if the assembly pressure is 0.60 MPa, it is within the preset pressure range (0.54 MPa - 0.66 MPa), therefore the assembly pressure meets the design requirements, and the assembled fuel cell stack is formed.

[0106] S400. When the assembly pressure is not within the preset pressure range, apply pressure to the membrane electrode again.

[0107] Specifically, the relationship between the assembly pressure and the preset pressure range is determined. When the assembly pressure is not within the preset pressure range, it means that the assembly pressure does not meet the design requirements. Therefore, the fuel cell stack cannot be formed. S350 needs to be executed again to apply pressure to the membrane electrode. The membrane electrode after applying pressure is used to assemble the fuel cell and the subsequent steps are repeated until the assembly pressure is within the preset pressure range, at which point the fuel cell stack is formed.

[0108] The technical solution of this invention applies pressure to the gas diffusion layer before assembling a single fuel cell. By simulating the mechanical environment of fuel cell operation, the internal stress of the fuel cell is released in advance. The pressurized gas diffusion layer is used to form a membrane electrode assembly (MEA). Pressure is then applied to the MEA, and the pressurized MEA is used to assemble the fuel cell. Single fuel cells are stacked to form a fuel cell stack, and the assembly force is recorded. The assembly pressure is determined based on the assembly force. When the assembly pressure is within a preset pressure range, the fuel cell stack is formed. When the assembly pressure is outside the preset pressure range, pressure is applied to the MEA again to ensure that the pressure of the fuel cell stack after assembly remains within a stable range, maintaining a good pressurization state and improving the performance of the fuel cell stack.

[0109] Figure 5 This is a schematic diagram of the structure of a fuel cell assembly device according to an embodiment of the present invention. Figure 5 As shown, the assembly apparatus for the fuel cell includes:

[0110] The size feature acquisition module 100 is used to acquire the size features of the gas diffusion layer; the size features include thickness, length, width and preset thickness change; wherein, the preset thickness change is the thickness change of the gas diffusion layer of the same material after a preset period of actual use in the fuel cell.

[0111] Specifically, the size feature acquisition module 100 is used to acquire the size features of the gas diffusion layer, including thickness, length, width, and a preset thickness change. The thickness after accelerated aging testing can be obtained. The preset thickness change is determined based on the difference between the thickness of the gas diffusion layer before and after the accelerated aging test. The material of the gas diffusion layer used in the accelerated aging test needs to be the same as the material used in the gas diffusion layer during fuel cell assembly to improve the accuracy of acquiring the size features of the gas diffusion layer, thereby improving the performance of the assembled fuel cell. The preset time can be the simulated actual usage time of the gas diffusion layer during the accelerated aging test. For example, if the initial thickness of the gas diffusion layer is 0.2 mm, after accelerated aging testing (simulating 3000 hours of actual use of the gas diffusion layer), the thickness decreases by 0.04 mm, from 0.2 mm to 0.16 mm, i.e., the preset thickness change is 0.04 mm. After acquiring the size features of the gas diffusion layer, the pressure applied to the gas diffusion layer and the number of times the pressure is applied need to be determined based on the size features, thereby applying pressure to the gas diffusion layer and releasing internal stress in advance.

[0112] The pre-compression pressure and pre-compression cycle determination module 200 is used to determine the pre-compression pressure and pre-compression cycle based on dimensional characteristics.

[0113] Specifically, the operating environment of the fuel cell is simulated (such as vibration or degradation caused by electrochemical reactions), and the pre-compression pressure and number of pre-compression cycles applied to the gas diffusion layer are determined based on the different size characteristics of the gas diffusion layer. The pre-compression pressure and number of pre-compression cycles can be determined according to the different thickness characteristics of the gas diffusion layer.

[0114] The pre-compression module 300 is used to apply pressure to the gas diffusion layer according to the pre-compression pressure and the number of pre-compression cycles.

[0115] Specifically, pressure is applied to the gas diffusion layer according to the determined pre-compression pressure and number of pre-compression cycles. For example, the ambient temperature is set to 85°C (simulating the operating temperature of a fuel cell), the duration of each pressure application is set to 40 seconds (to ensure sufficient stress release), and the pre-compression pressure (e.g., 0.6 MPa) is applied according to the number of pre-compression cycles (e.g., 3 times), with a preset interval (e.g., 15 seconds) between each application to avoid overheating of the material due to continuous pressure application.

[0116] The membrane electrode forming module 400 is used to form a membrane electrode using a gas diffusion layer after pressure is applied.

[0117] Specifically, the pressurized gas diffusion layer is combined with the catalyst layer and electrolyte membrane via hot-pressing to form a membrane electrode assembly (MEA). The hot-pressing process requires precise control of the bonding pressure, temperature, and time. Matching the dimensions of the resulting MEA to the gas diffusion layer improves the stability of the MEA formation.

[0118] The fuel cell assembly module 500 is used to apply pressure to the membrane electrode and assemble the pressurized membrane electrode to form a fuel cell.

[0119] Specifically, after the membrane electrode is initially fabricated, the fuel cell assembly module 500 applies specific pressure to the membrane electrode again to optimize the interfacial contact and structural stability, thereby improving the electrochemical performance and durability of the membrane electrode.

[0120] The fuel cell assembly apparatus provided in the embodiments of the present invention can execute the fuel cell assembly method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of executing the method.

[0121] Figure 6 This is a schematic cross-sectional view of a fuel cell according to an embodiment of the present invention. Figure 6 As shown, the fuel cell, from the center to both sides, includes an electrolyte membrane 10, an anode 20 / cathode 30, and a bipolar plate 40. The anode 20 includes a gas diffusion layer and a catalyst layer. This fuel cell is assembled using the fuel cell assembly method of any embodiment of the present invention, and possesses corresponding beneficial effects, which will not be elaborated further here.

[0122] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0123] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A method for assembling a fuel cell, characterized in that, include: Obtain the dimensional characteristics of the gas diffusion layer; The dimensional features include thickness, length, width, and a preset thickness variation; wherein, the preset thickness variation is the thickness variation of the gas diffusion layer of the same material after a preset period of actual use in the fuel cell; Based on the aforementioned dimensional characteristics, determine the preloading pressure and the number of preloading cycles; Pressure is applied to the gas diffusion layer according to the pre-compression pressure and the number of pre-compression cycles; A membrane electrode is formed using the gas diffusion layer after pressure is applied; Pressure is applied to the membrane electrode, and the pressure-applied membrane electrode is used to assemble a fuel cell.

2. The fuel cell assembly method according to claim 1, characterized in that, Based on the stated dimensional characteristics, the preloading pressure and the number of preloading cycles are determined, including: The elastic modulus of the gas diffusion layer is determined based on the thickness and the preset thickness variation. The preload pressure and the number of preload cycles are determined based on the thickness, the elastic modulus, the length, and the width.

3. The fuel cell assembly method according to claim 2, characterized in that, The step of determining the preload pressure and the number of preload cycles based on the thickness, the elastic modulus, the length, and the width includes: The number of pre-compression cycles is determined based on the elastic modulus and the thickness. The preload pressure is determined based on the thickness, the length, and the width.

4. The fuel cell assembly method according to claim 3, characterized in that, Determining the number of preloading cycles based on the elastic modulus and the thickness includes: The number of pre-compression cycles is determined according to the following formula. n = (σ1 - σ) * E + σ1 / σ * 10; Where n is the number of pre-compression cycles, σ1 is the thickness, σ is the center value of the gas diffusion layer thickness, and E is the elastic modulus.

5. The fuel cell assembly method according to claim 3, characterized in that, Determining the preload pressure based on the thickness, length, and width includes: The preload pressure is determined according to the following formula. F=P / (D1*D2)*10 -3 *σ1 / σ; Where F is the pre-pressure, P is the theoretical operating pressure of the fuel cell, D1 is the length, D2 is the width, σ1 is the thickness, and σ is the center value of the gas diffusion layer thickness.

6. The assembly method of a fuel cell according to claim 1, characterized in that, Applying pressure to the membrane electrode includes: A preset pressure is applied to the membrane electrode.

7. The fuel cell assembly method according to claim 1, characterized in that, After applying pressure to the membrane electrode and assembling the pressure-adjusted membrane electrode to form a fuel cell, the process includes: Multiple fuel cells were stacked and assembled, and the assembly forces were recorded. The assembly pressure is determined based on the assembly force. When the assembly pressure is within a preset pressure range, a fuel cell stack is formed.

8. The fuel cell assembly method according to claim 7, characterized in that, After determining the assembly pressure based on the assembly force, the method further includes: When the assembly pressure is not within the preset pressure range, pressure is applied to the membrane electrode again.

9. An assembly apparatus for a fuel cell, characterized in that, include: The size feature acquisition module is used to acquire the size features of the gas diffusion layer; The dimensional features include thickness, length, width, and a preset thickness variation; wherein, the preset thickness variation is the thickness variation of the gas diffusion layer of the same material after a preset period of actual use in the fuel cell; The pre-compression pressure and pre-compression cycle determination module is used to determine the pre-compression pressure and pre-compression cycle based on the dimensional characteristics. A pre-compression module is used to apply pressure to the gas diffusion layer according to the pre-compression pressure and the number of pre-compression cycles; A membrane electrode forming module for forming a membrane electrode using the gas diffusion layer after pressure is applied; A fuel cell assembly module is used to apply pressure to the membrane electrode and assemble the pressurized membrane electrode to form a fuel cell.

10. A fuel cell, characterized in that, The fuel cell is assembled using the assembly method described in any one of claims 1-8.

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