Electrochemical reaction component and PEM stack device

Abstract

The invention belongs to the technical field of water electrolysis hydrogen production galvanic piles, and discloses an electrochemical reaction component and a PEM galvanic pile device. The electrochemical reaction component comprises a flow field plate, and a flow channel is formed in the inner plate surface of the flow field plate; the membrane electrode comprises an edge sealing inner edge; the diffusion layer is cushioned between the inner plate surface of the flow field plate and the surface of the membrane electrode; wherein the flow field plate, the diffusion layer and the membrane electrode are sequentially stacked along the surface vertical direction of the membrane electrode, and a non-flow-channel part on the inner plate surface of the flow field plate is aligned and propped against the inner edge of the sealing edge along the surface vertical direction. By optimally designing the mounting structure of the membrane electrode and adjusting the mounting position relationship among the membrane electrode, the flow field plate and the diffusion layer, the chemical performance of the stack is improved, the problem that the stress of the membrane electrode is too large and uneven is solved, and the purposes of improving the chemical performance of the stack and prolonging the service life of the membrane electrode are achieved.

Description

Technical Field

[0001] This application belongs to the field of water electrolysis hydrogen production stack technology, specifically, it relates to a PEM stack device and its electrochemical reaction components. Background Technology

[0002] When hydrogen is produced by proton exchange membrane (PEM) water electrolysis, electricity and water are introduced. The PEM water electrolyzer produces oxygen at the anode and high-purity hydrogen at the cathode. This method of producing "green hydrogen" using PEM fuel cell stacks is increasingly being used for storing renewable energy sources such as solar and wind power. As a highly efficient and environmentally friendly hydrogen production method, PEM fuel cell stacks typically use proton exchange membranes, which possess strong chemical stability, high proton conductivity, and excellent gas separation capabilities, as proton transport conductors. The produced hydrogen is of high purity and effectively prevents electron transfer, offering advantages such as high safety and high efficiency.

[0003] Among them, the membrane electrode assembly (MEA), as a core component, is under constant pressure during the use of the fuel cell stack, undergoing electrochemical reactions and heat, mass, and electrical transport. This makes the MEA prone to deformation, wrinkling, displacement, or even overflow, leading to a decrease in fuel cell stack efficiency or even failure, which seriously affects the fuel cell stack's performance and service life. Summary of the Invention

[0004] To address the aforementioned deficiencies or shortcomings, this application discloses an electrochemical reaction component and a PEM stack device to improve stack efficiency and service life.

[0005] To achieve the above objectives, this application proposes an electrochemical reaction component for a PEM fuel cell stack device, the electrochemical reaction component comprising: A flow field plate, wherein flow channels are formed on the inner plate surface of the flow field plate; The membrane electrode includes the inner edge of the sealing edge; A diffusion layer is disposed between the inner surface of the flow field plate and the surface of the membrane electrode. In this configuration, the flow field plate, the diffusion layer, and the membrane electrode are stacked sequentially along the direction perpendicular to the surface of the membrane electrode, and the non-flow channel portion on the inner plate surface of the flow field plate is aligned and presses against the inner edge of the sealing edge along the direction perpendicular to the surface.

[0006] In some embodiments, the non-channel portion is the channel ridge of the flow field plate or the solid portion of the plate surface.

[0007] In some embodiments, along the electrode extension direction of the membrane electrode, a first adjacent flow channel and a second adjacent flow channel are respectively adjacent to both sides of the non-flow channel portion that is aligned and pressed against the inner edge of the seal. Wherein, along the electrode extension direction, the distance between the first adjacent flow channel and the inner edge of the sealing edge and the distance between the second adjacent flow channel and the inner edge of the sealing edge are both greater than zero; Alternatively, along the electrode extension direction of the membrane electrode, the two sides of the non-flow channel portion that is aligned and pressed against the inner edge of the sealing edge are respectively adjacent to the flow channel and the solid portion of the flow field plate edge; Wherein, along the electrode extension direction, the distance between the adjacent flow channel and the inner edge of the sealing edge, and the distance between the solid part of the flow field plate edge and the inner edge of the sealing edge are all greater than zero.

[0008] In some embodiments, the membrane electrode includes a proton exchange membrane distributed along the electrode extension direction. The proton exchange membrane includes a body segment with a catalyst coating and a sealing segment with a sealing film on its surface. The inner edge of the sealing film is the connecting edge between the body segment and the sealing segment.

[0009] In some embodiments, the diffusion layer completely covers the body segment and its outer end extends beyond the inner edge of the sealing edge, at least partially covering the sealing edge segment.

[0010] In some embodiments, the electrochemical reaction component includes: An outer layer plate is stacked on one side of the outer plate surface of the flow field plate; A frame is provided at the electrode extension end of the membrane electrode; A sealing gasket is disposed between the inner surface of the end of the outer layer plate and the surface of the frame and is used to seal the end of the electrochemical reaction component; The inner surface of the end of the outer layer plate and / or the surface of the frame are provided with receiving grooves for accommodating the overflow of the membrane electrode. The receiving grooves are located inside the sealing gasket and are spaced apart from the inner edge of the sealing edge along the electrode extension direction of the membrane electrode.

[0011] In some embodiments, the inner surface of the flow field plate and / or the surface of the frame are formed with guide grooves for guiding the inner edge of the sealing edge to the receiving groove.

[0012] In some embodiments, the flow field plate includes a first flow field plate and a second flow field plate, and the diffusion layer includes a first diffusion layer and a second diffusion layer. The first flow field plate, the first diffusion layer, the membrane electrode, the second diffusion layer, and the second flow field plate are stacked sequentially. A support groove for accommodating and mounting the second flow field plate and the second diffusion layer is formed on the inner side of the frame.

[0013] In some embodiments, the surface of the frame is provided with a support pad for supporting the sealing section of the membrane electrode.

[0014] In some embodiments, the electrochemical reaction component includes a first outer plate covering the outer plate surface of the first flow field plate, and a flow field plate positioning groove for positioning and mounting the first flow field plate is formed on the inner plate surface of the end of the first outer plate, the flow field plate positioning groove being located inside the receiving groove.

[0015] In addition, this application also provides a PEM stack device, which includes the electrochemical reaction components described above according to this application.

[0016] In some embodiments, the cathode side of the electrochemical reaction component is provided with a cathode end plate, a cathode insulating plate and a cathode current collector stacked sequentially from the outside to the inside, and the anode side of the electrochemical reaction component is provided with an anode end plate, an anode insulating plate and an anode current collector stacked sequentially from the outside to the inside.

[0017] In the electrochemical reaction components and PEM stack device of this application, the self-mounting structure of the membrane electrode and its installation position relationship with the flow field plate are optimized. This allows the non-flow channel portion of the flow field plate to directly press against the inner edge of the membrane electrode's sealing edge. The pressure from the outside to the inside is transmitted sequentially through the flow field plate and the diffusion layer to the inner edge of the membrane electrode's sealing edge via a layer-by-layer solid contact method. This results in a balanced and stable force on the inner edge of the sealing edge, placing it in a compressed and non-free state, thus enabling more reliable positioning and greater resistance to impact during operation. While the inner edge of the sealing edge is more firmly positioned, the compressed and non-free state of the membrane electrode edge prevents it from freely swelling and deforming, thus reducing the likelihood of wrinkles. This allows for a larger contact area of ​​the membrane electrode during operation, improving the stack's efficiency and extending its service life.

[0018] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0019] The accompanying drawings are provided to illustrate the present application and form part of the specification. They are used together with the following detailed description to explain the present application, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the structure of a PEM stack device according to a specific embodiment of this application; Figure 2 A schematic diagram of the structure of a membrane electrode according to one embodiment; Figure 3 This is a schematic diagram of the structure of an electrochemical reaction component according to a specific embodiment of this application; Figure 4 This is a schematic diagram of the structure of an electrochemical reaction component according to a specific embodiment of this application. For clarity, the diffusion layer, membrane electrode, and second flow field plate are omitted from the diagram.

[0020] Explanation of reference numerals in the attached figures Detailed Implementation

[0021] The specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of this application.

[0022] The PEM stack device and its electrochemical reaction components according to this application are described below with reference to the accompanying drawings.

[0023] To address the defects such as membrane electrode deformation and displacement that occur in existing PEM stack devices during operation, this application specifically discloses a novel electrochemical reaction component for use in PEM stack devices, which optimizes the installation structure of the membrane electrode to improve the normal operating time of the membrane electrode.

[0024] like Figure 3 As shown, in one specific embodiment, the electrochemical reaction component 4 of this application includes: A flow field plate, on the inner surface of which flow channels 421 are formed; The membrane electrode 44 includes the inner edge of the sealing edge 444; A diffusion layer is placed between the inner surface of the flow field plate and the surface of the membrane electrode 44; In this process, along the vertical direction Y of the surface of the membrane electrode 44, the flow field plate, the diffusion layer and the membrane electrode 44 are stacked in sequence, and the non-flow channel portion 422 on the inner plate surface of the flow field plate is aligned and pressed against the inner edge 444 of the sealing edge along the vertical direction Y of the surface.

[0025] This application aims to solve the problem of wrinkling and deformation of the membrane electrode 44 during use. The impact of various factors such as heat, mass transfer, and electrical transport generated during electrochemical reactions easily causes deformation of the membrane electrode 44. To address this, the inventors, through continuous observation and analysis, discovered that the inner edge 444 of the membrane electrode 44 (see...) Figure 2 The area most susceptible to impact and swelling can lead to displacement, deformation, and wrinkles, resulting in a reduction in the contact area of ​​the membrane electrode and a decrease in its working efficiency.

[0026] Therefore, this application innovatively optimizes the installation structure of the membrane electrode 44, so that the non-flow channel part 422 of the flow field plate is directly pressed on the inner edge 444 of the sealing edge of the membrane electrode 44. The sealing load can keep the inner edge 444 under pressure and in a non-free state, so that the inner edge 444 has no swelling space, the positioning is more reliable and more impact resistant. With the position of the inner edge 444 fixed, the membrane electrode 44 is in a stable and uniform stress state, and it is not easy to produce wrinkles.

[0027] See Figure 4The non-flow channel portion 422 is the solid part of the flow field plate, acting on the inner edge 444 of the membrane electrode 44 through the diffusion layer. The force transmission process involves solid contact, with the pressure from the outer plate and the weight of the non-flow channel portion 422 of the flow field plate applied evenly and evenly to the inner edge 444 of the membrane electrode 44. Comparatively, if... Figure 3 When the inner edge 444 of the sealing edge is aligned with the flow channel 421, the liquid in the flow channel 421 of the flow field plate interacts with the diffusion layer and then acts on the inner edge 444 of the sealing edge through the diffusion layer. In this way, not only is the force transmission process non-physical contact, but the liquid in the flow channel 421 is fluid, which causes the force to fluctuate and the distribution to be uneven. Ultimately, this will lead to unstable pressure acting on the inner edge 444 of the sealing edge. The inner edge 444 of the sealing edge is easily displaced by impact, and the inner side of the inner edge 444 of the membrane sealing edge will swell and deform, producing obvious wrinkles.

[0028] Therefore, when assembling the electrochemical reaction component 4, it is necessary to precisely control the non-flow channel portion 422 of the flow field plate and the inner edge 444 of the sealing edge to form a solid abutment along the vertical direction Y of the surface of the membrane electrode 44, so as to better position the inner edge 444 of the sealing edge of the membrane electrode 44 and help prevent the membrane electrode from wrinkling and deforming.

[0029] It should be noted that the directional terms "inner" and "outer" used here are relative to the membrane electrode 44 or the PEM water electrolyzer. The flow field plate, diffusion layer, and membrane electrode 44 are stacked sequentially from the outside to the inside. See [link to relevant documentation]. Figure 3 , Figure 4 The electrode extension direction X indicated in the diagram is the inside-out direction of the membrane electrode 44.

[0030] As is known to those skilled in the art, the inner surface of the flow field plate is precision-machined with flow channels 421, and flow channel ridges are formed on both sides of the flow channels 421. The flow channels 421 can be of various shapes, such as serpentine, parallel, interdigitated, etc., through which liquid flows for uniform distribution to the reaction area. Therefore, specifically, the non-flow channel portion 422 in this application can be either the flow channel ridges of the flow field plate or the solid portion of the plate surface.

[0031] See Figure 3 In this embodiment, the non-flow channel portion 422, with its cross-sectional lines drawn, is solidly aligned and pressed against the inner edge of the seal 444. Along the electrode extension direction X of the membrane electrode 44, a first adjacent flow channel and a second adjacent flow channel are respectively adjacent to both sides of the non-flow channel portion 422 that is aligned and pressed against the inner edge of the seal 444; wherein, along the electrode extension direction X, the distance between the first adjacent flow channel and the inner edge of the seal 444, and the distance between the second adjacent flow channel and the inner edge of the seal 444, are both greater than zero. See also... Figure 3 That is, L in the diagram 01 >0 or L 02>0, meaning that the ridge of the flow channel or the solid part of the plate is pressed on the inner edge 444 of the sealing edge of the membrane electrode 44.

[0032] Of course, those skilled in the art will understand that when the non-flow channel portion 4242, which is aligned and pressed against the inner edge of the sealing edge 444 along the electrode extension direction X of the membrane electrode 44, is located outside the edge flow channel, the two sides of the non-flow channel portion 442 are respectively adjacent to the adjacent flow channel and the solid portion of the flow field plate edge. Furthermore, along the electrode extension direction X, the distances between the adjacent flow channel and the inner edge of the sealing edge 444, and between the solid portion of the flow field plate edge and the inner edge of the sealing edge 444, are all greater than zero.

[0033] See Figure 2 For reference, one structural form of the membrane electrode 44 may include a proton exchange membrane 442 distributed along the electrode extension direction. The proton exchange membrane 442 includes a body segment 443 with a catalyst coating (the black part at the left end of the figure) and a sealing segment with a sealing film 441 on its surface (the white part at the right end of the figure). The inner edge 444 of the sealing film is the connecting edge between the body segment 443 and the sealing segment. In other words, the inner edge 444 of the sealing film is the outer edge of the body segment 443 or the inner edge of the sealing segment, or the boundary between the two. The proton exchange membrane 442 of the membrane electrode 44 is integrally extended, continuously passing through the body segment 443 and the sealing segment from the inside. Of course, another structural form of the membrane electrode 44 may only have a catalyst-coated body segment 443 without a sealing segment, or a catalyst-coated body segment 443 and an unsealed membrane edge segment, i.e., without a sealing film 441.

[0034] In Figure 2 When assembling the membrane electrode 44 with the sealed edge section into the electrochemical reaction component 4 of this application, in addition to accurately positioning the inner edge 444 of the sealed edge, attention should also be paid to the mounting position of the diffusion layer relative to the membrane electrode 44. Figure 3 In the illustrated embodiment, the diffusion layer completely covers the body segment 443, and its outer end extends beyond the inner edge 444 of the sealing edge, at least partially covering the sealing edge segment. This is true for both the first diffusion layer 43 and the second diffusion layer 47 illustrated. Thus, see [link to illustration]. Figure 3 The encapsulation load is transferred to the inner and outer sides of the membrane electrode 44 through the anode and cathode bipolar plates and the diffusion layer. This structure reflects the supporting role of the sealing section 441. Regardless of the supporting position, the stress area will improve the stress on the membrane electrode 443 in the reaction zone. Another factor is that if a sealing membrane structure is used, the sealing membrane 441 has a certain hardness and thickness, which can protect the membrane electrode from excessive stress. This will make the overall stress on the body section 443 of the membrane electrode 44 smaller, thereby improving the service life of the membrane electrode 44.

[0035] exist Figure 3In the illustrated embodiment, as an example, along the electrode epitaxial direction X of the membrane electrode 44, the size of the first diffusion layer 43 is designated as L1, the size of the body segment 443 of the membrane electrode 44 is designated as L2, and the total size of the membrane electrode 44 is designated as L3. The size L1 of the first diffusion layer 43 should be greater than or equal to the size L2 of the body segment 443 of the membrane electrode 44, and less than or equal to the total size L3 of the membrane electrode 44, i.e., L2 ≤ L1 ≤ L3. Similarly, the size L5 of the second diffusion layer 47 should also satisfy: L2 ≤ L5 ≤ L3.

[0036] exist Figure 3 , Figure 4 In the electrochemical reaction component 4, the following are also included: The outer layer plate is stacked on one side of the outer plate surface of the flow field plate; The frame 46 is disposed at the electrode extension end of the membrane electrode 44; A sealing gasket 50 is disposed between the inner end surface of the outer layer plate and the surface of the frame 46 and is used to seal the end of the electrochemical reaction component 4. The inner surface of the end of the outer layer plate and / or the surface of the frame 46 are provided with a receiving groove 461 for accommodating the overflow of the membrane electrode. The receiving groove 461 is located inside the sealing gasket 50 and is spaced apart from the inner edge 444 of the sealing edge along the electrode extension direction X of the membrane electrode 44.

[0037] Existing PEM fuel cell stacks not only experience swelling and deformation after assembly, but also, after long-term service, the membrane electrode 44 may undergo adhesive deformation and creep due to thermal stress, swelling stress, and external sealing forces. These cumulative deformations can easily lead to membrane electrode overflow after prolonged service, especially for membrane electrodes without sealing edges. Therefore, this embodiment specifically adds a receiving groove 461 to accommodate overflowing membrane electrodes 44, preventing fuel cell stack failure due to membrane overflow.

[0038] Specifically Figure 4 In this process, the aforementioned receiving groove 461 is provided between the outside of the electrochemical reaction region and the inside of the outermost sealing region. Figure 3 The distance L from the inner edge of the receiving trench 461 to the inner edge 444 of the sealing edge of the membrane electrode 44 is shown. 03 Greater than 0, the distance L from the outer edge of the groove to the outermost sealing area. 04 Greater than 0, i.e., L 03 >0, L 04 >0.

[0039] The receiving groove 461 can be set alone on the flow field plate, alone on the frame 46, or both on the frame 46 and the flow field plate. The width and height of the receiving groove 461 can be determined according to the thickness of the frame 46 and the flow field plate, so as not to affect the structural strength and sealing performance.

[0040] Furthermore, guide grooves 423 for guiding the inner edge 444 of the sealing edge to the receiving groove 461 can also be formed on the inner plate surface and / or the surface of the frame 46 of the flow field plate. Figure 4 The guide groove 423 is shown as a stepped groove, but this is just an example; other shapes of guide grooves are also possible. This design prevents the membrane electrode from overflowing, leading to seal leakage or fuel cell failure. During long-term service, the membrane electrode 44 (black portion) will undergo various cumulative deformations such as creep and viscoplastic deformation. These cumulative deformations cause the membrane electrode 44 to be extruded and moved outward along the inner surface of the first diffusion layer 43, such as... Figure 4 As shown by the arrow group in the image, and then via Figure 4 The guide groove 423 provided at the end of the first flow field plate 42 shown guides the material more smoothly to the receiving groove 461, and it is ultimately contained by the receiving groove 461, without subsequently expanding outwards and deforming to squeeze components such as the sealing gasket 50. In this way, if the membrane electrode overflows outwards due to deformation under stress during the operation of the fuel cell stack, the membrane electrode has an overflow receiving space, which will not affect the structural seal, avoid serious structural damage, and prevent fuel cell stack failure, thereby helping to extend the service life of the fuel cell stack.

[0041] Of course, those skilled in the art will understand that in other embodiments, the guide groove 423 may not be provided, and this should also be within the scope of protection of this application. Even without the guide groove 423, the overflowing membrane electrode 44 will always have its overflow path, and it is easy to cause structural damage, leading to sealing failure, liquid overflow, etc. However, because a guide groove 423 is provided at the end of the flow field plate... Figure 4 As shown in the receiving trench 461, any overflowing membrane electrode 44 will eventually fall into the receiving trench 461 and be contained therein, without causing further overflow.

[0042] In the electrochemical reaction component 4, the upper and lower sides of the membrane electrode 44 are the cathode and anode, respectively. Therefore, the flow field plate includes the first flow field plate 42 and the second flow field plate 48 shown in the figure, and the diffusion layer also includes the first diffusion layer 43 and the second diffusion layer 47. Figure 3 The first flow field plate 42, the first diffusion layer 43, the film electrode 44, the second diffusion layer 47, and the second flow field plate 48 shown are sequentially stacked; wherein, a support groove 462 for accommodating and mounting the second flow field plate 48 and the second diffusion layer 47 is formed on the inner side of the frame 46. Figure 4 As shown, a support groove 462 is defined by the inner end of the frame 46 and the second outer layer plate 49, which can be used to support and position the second flow field plate 48 and the second diffusion layer 47.

[0043] See Figure 3The support groove 462 has a slot size of L4, and a membrane electrode 44, a second flow field plate 48, and a second diffusion layer 47 are mounted on the groove. The size L5 of the second diffusion layer 47 is greater than or equal to the total size L2 of the membrane electrode body section 443, and less than or equal to the slot size L4 of the support groove 462, i.e., L2≤L5≤L4. The size L6 of the second flow field plate 48 is the same as the slot size L4 of the support groove 462, i.e., L6≤L4.

[0044] The surface of the frame 46 is also provided with a support pad 45, which supports the sealing section of the membrane electrode 44 to prevent it from being suspended in the air and to provide better support, especially when the second diffusion layer 47 applies force to the sealing section of the membrane electrode 44. At the same time, the support pad 45 also acts as a sealing gasket to prevent hydrogen and oxygen from crossing between the anode and cathode of the membrane electrode, thus avoiding dangers such as explosions.

[0045] exist Figure 3 In the process, the first outer plate 41 and the first flow field plate 42, the second flow field plate 48 and the second outer plate 49 respectively form a complete flow field structure. The first outer plate 41 and the first flow field plate 42 can be integrated as one piece, and the second flow field plate 48 and the second outer plate 49 can also be integrated as one piece.

[0046] See Figure 3 , Figure 4 Because a guide groove 423 for guiding the inner edge 444 of the sealing edge 444 to the receiving groove 461 is formed on the inner plate surface of the first flow field plate 42, there is a gap between the outer end of the first flow field plate 42 and the frame 46, which is not conducive to the positioning of the outer end of the first flow field plate 42. Therefore, when the first outer layer plate 41 covers the outer plate surface of the first flow field plate 42, a flow field plate positioning groove for positioning and installing the first flow field plate 42 is specially formed on the inner plate surface of the end of the first outer layer plate 41. Figure 4 As shown, a groove can be machined on the inner surface of the first outer plate 41. The groove is suitable for accommodating the entire first flow field plate 42 along the electrode extension direction X, but the groove depth along the perpendicular direction Y of the surface shown in the figure is less than the thickness of the flow field plate. This groove is the flow field plate positioning groove, which can ensure that the first flow field plate 42 is installed in a certain position and prevent the first flow field plate 42 from being misaligned.

[0047] In this case, since the depth of the groove in the perpendicular direction Y along the surface shown in the figure is less than the thickness of the flow field plate, when the first flow field plate 42 is installed on the flow field plate positioning groove, the two form a stop positioning fit, thereby limiting the movement of the first flow field plate 42 along the electrode extension direction X. Figure 4 As can be seen, along the electrode extension direction X, the positioning groove of the flow field plate is located inside the receiving groove 461.

[0048] It should be noted that the electrochemical reaction component 4 in this embodiment can be either a structural component with a frame 46 or a structural component without a frame, neither of which affects the design and implementation of this application. Figure 3 , Figure 4 The diagram shows a cross-sectional view of the various components in the electrolytic cell, including the first flow field plate 42, the first diffusion layer 43, the membrane electrode 44, the second diffusion layer 47, and the second flow field plate 48. When the electrolytic cell is rectangular, each dimension is indicated in both the horizontal length and width directions, and the size comparisons are also between the length and width directions. If the cell is circular, the dimensions are indicated as the radial diameter or radius, and the size comparisons are also between the diameter and radius.

[0049] It should be noted that, although not shown in the figure, the solid parts of the first flow field plate 42 and the second flow field plate 48 should also be aligned and press against the inner edge 444 of the membrane electrode 44 at the inlet and outlet to ensure their secure pressing and positioning. In other words, at the inlet and outlet, the gas-liquid tank is a groove structure with a bottom plate, and the solid part of the flow field plate with the bottom plate should be pressed against the inner edge 444 of the membrane electrode 44.

[0050] As can be seen, this application optimizes the structural dimensions, positional relationships, and dimensional matching relationships of each element in the electrochemical reaction component 4, thereby directly affecting the service life of the membrane electrode, reducing the generation of membrane electrode defects, and minimizing membrane electrode wrinkling and deformation to achieve the optimal membrane electrode service life. Specifically, by ensuring that the membrane electrode edges are essentially wrinkle-free, electrochemical performance can be improved; by reducing the stress on the membrane electrode structurally, service life can also be improved; and by providing membrane electrode housing space to prevent membrane electrode overflow, the lifespan of the fuel cell stack can be directly extended.

[0051] Based on the above, this application also discloses a PEM stack device. For example... Figure 1 The PEM stack device shown includes the electrochemical reaction component 4 described above in this application. By adopting the improved novel electrochemical reaction component 4, the generation of membrane electrode defects is greatly reduced, membrane electrode wrinkling and deformation and membrane electrode creep are prevented, the stress on the membrane electrode is minimized, and the optimal service life of the membrane electrode is obtained.

[0052] See Figure 1 The cathode side of the electrochemical reaction component 4 is provided with a cathode end plate 1, a cathode insulating plate 2, and a cathode current collector plate 3 stacked sequentially from the outside to the inside. The anode side of the electrochemical reaction component 4 is provided with an anode end plate 7, an anode insulating plate 6, and an anode current collector plate 5 stacked sequentially from the outside to the inside, thus forming a complete fuel cell stack structure that can be used for hydrogen production by water electrolysis. Since this fuel cell stack structure is well known to those skilled in the art, the other components besides the electrochemical reaction component 4 and their functions will not be described in detail here.

[0053] In summary, based on the existing problems of obvious wrinkles at the edge of the membrane electrode, membrane electrode creep, and insufficient service life of the membrane electrode in the existing fuel cell stack device, this application improves the electrochemical performance and reduces the stress on the membrane electrode by optimizing the reasonable installation structure, structural size, and size matching relationship between the various components of the electrochemical reaction component 4, thereby achieving the goal of improving the chemical performance of the fuel cell stack and extending the service life of the membrane electrode.

[0054] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0055] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0056] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0057] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. An electrochemical reaction component for use in a PEM fuel cell stack, characterized in that, The electrochemical reaction component (4) includes: A flow field plate, wherein a flow channel (421) is formed on the inner plate surface of the flow field plate. The membrane electrode (44) includes the inner edge of the sealing edge (444). A diffusion layer is placed between the inner surface of the flow field plate and the surface of the membrane electrode (44); In this process, the flow field plate, the diffusion layer and the membrane electrode (44) are stacked sequentially along the vertical direction (Y) of the surface of the membrane electrode (44), and the non-flow channel portion (422) on the inner plate surface of the flow field plate is aligned and presses against the inner edge (444) of the sealing edge along the vertical direction (Y) of the surface.

2. The electrochemical reaction component according to claim 1, characterized in that, The non-flow channel portion (422) is the flow channel ridge or the solid part of the plate surface of the flow field plate.

3. The electrochemical reaction component according to claim 1, characterized in that, Along the electrode extension direction (X) of the membrane electrode (44), the two sides of the non-flow channel portion that is aligned and pressed against the inner edge of the sealing edge (444) are respectively adjacent to a first adjacent flow channel and a second adjacent flow channel. Wherein, along the electrode epitaxial direction (X), the distance between the first adjacent flow channel and the inner edge of the sealing edge (444) and the distance between the second adjacent flow channel and the inner edge of the sealing edge (444) are both greater than zero; Alternatively, along the electrode extension direction (X) of the membrane electrode (44), the two sides of the non-flow channel portion that is aligned and pressed against the inner edge of the sealing edge (444) are respectively adjacent to the solid portion of the flow field plate edge; Wherein, along the electrode extension direction (X), the distance between the adjacent flow channel and the inner edge of the sealing edge (444) and the distance between the solid part of the flow field plate edge and the inner edge of the sealing edge (444) are both greater than zero.

4. The electrochemical reaction component according to any one of claims 1 to 3, characterized in that, The membrane electrode (44) includes a proton membrane (442) distributed along the electrode extension direction. The proton membrane (442) includes a body section (443) with a catalyst coating and a sealing section with a sealing film (441) on its surface. The inner edge (444) of the sealing film is the connecting edge between the body section (443) and the sealing section.

5. The electrochemical reaction component according to claim 4, characterized in that, The diffusion layer completely covers the body segment (443) and its outer end extends beyond the inner edge of the sealing edge (444) to at least partially cover the sealing edge segment.

6. The electrochemical reaction component according to any one of claims 1 to 3, characterized in that, The electrochemical reaction component (4) includes: An outer layer plate is stacked on one side of the outer plate surface of the flow field plate; A frame (46) is disposed at the electrode extension end of the membrane electrode (44); A sealing gasket (50) is disposed between the inner end surface of the outer layer plate and the surface of the frame (46) and is used to seal the end of the electrochemical reaction component (4). The inner surface of the end of the outer layer plate and / or the surface of the frame (46) are provided with a receiving groove (461) for accommodating the overflow of the membrane electrode. The receiving groove (461) is located inside the sealing gasket (50) and is spaced apart from the inner edge of the sealing edge (444) along the electrode extension direction (X) of the membrane electrode (44).

7. The electrochemical reaction component according to claim 6, characterized in that, The inner surface of the flow field plate and / or the surface of the frame (46) are formed with guide grooves (423) for guiding the inner edge (444) of the sealing edge to the receiving groove (461).

8. The electrochemical reaction component according to claim 6, characterized in that, The flow field plate includes a first flow field plate (42) and a second flow field plate (48), and the diffusion layer includes a first diffusion layer (43) and a second diffusion layer (47). The first flow field plate (42), the first diffusion layer (43), the membrane electrode (44), the second diffusion layer (47) and the second flow field plate (48) are stacked in sequence. The inner side of the frame (46) is formed with a support groove (462) for accommodating the installation of the second flow field plate (48) and the second diffusion layer (47).

9. The electrochemical reaction component according to claim 8, characterized in that, The surface of the frame (46) is provided with a support pad (45), which is used to support the sealing section of the membrane electrode (44).

10. The electrochemical reaction component according to claim 8, characterized in that, The electrochemical reaction component includes a first outer plate (41) that covers the outer plate surface of the first flow field plate (42). A flow field plate positioning groove for positioning and installing the first flow field plate (42) is formed on the inner plate surface of the end of the first outer plate (41). The flow field plate positioning groove is located inside the receiving groove (461).

11. A PEM fuel cell stack device, characterized in that, The PEM stack device includes an electrochemical reaction component (4) according to any one of claims 1 to 10.

12. The PEM stack device according to claim 11, characterized in that, The cathode side of the electrochemical reaction component (4) is provided with a cathode end plate (1), a cathode insulating plate (2) and a cathode current collector plate (3) stacked sequentially from the outside to the inside. The anode side of the electrochemical reaction component (4) is provided with an anode end plate (7), an anode insulating plate (6) and an anode current collector plate (5) stacked sequentially from the outside to the inside.

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