Composite PEM electrolyzed water polar plate structure

Abstract

The utility model relates to the technical field of water electrolysis hydrogen production, in particular to a composite PEM water electrolysis polar plate structure. Comprising an anode frame, a cathode frame and an embedded non-full-size titanium bipolar plate, sinking grooves are formed in the anode frame and the cathode frame to limit the non-full-size titanium bipolar plate, and efficient sealing is achieved through staggered sealing design. The non-full-size titanium bipolar plate adopts a runner-free design, so that the processing cost is reduced, and meanwhile, the effective utilization rate of the polar plate is improved to more than 80%. The anode frame and the cathode frame are made of stainless steel or high polymer materials, and the design of an integrally-formed distribution area (an anode straight flow channel and a cathode dendritic bionic flow channel) is combined, so that water flow distribution is optimized, and flow resistance is reduced. The utility model obviously reduces the titanium material consumption and the precious metal coating cost, and is suitable for the large-scale production of the PEM electrolytic bath.

Description

Technical Field

[0001] This utility model relates to the field of hydrogen production technology through water electrolysis, specifically to a composite PEM water electrolysis electrode structure. Background Technology

[0002] PEM electrolyzers possess advantages such as high reaction sensitivity, high integration, high efficiency, and high current density, enabling efficient coupling of fluctuating power sources like wind and solar power, making them the optimal choice for producing green hydrogen. However, due to their reaction mechanism, the electrode materials for the electrolyzers must possess corrosion resistance and high conductivity. Titanium plates with precious metal plating are typically used as electrode materials; however, the large areas of titanium and the corresponding precious metal plating are expensive, resulting in high costs for PEM electrolyzers. Therefore, optimizing the structure to reduce electrode area and improve electrode utilization, indirectly reducing the amount of precious metal plating, is of great significance for cost reduction and efficiency improvement in PEM electrolyzers.

[0003] Current conventional PEM electrolyzer electrode designs typically include inlet / outlet water areas, hydrogen outlet areas, and corresponding bridge areas. Combined with reserved sealing areas, this necessitates extending the electrode area beyond the inlet / outlet water / gas ports, resulting in low electrode utilization, usually less than 60%. Current precious metal coating processes for electrodes, such as PVD, CVD, and electrochemical electroplating, often involve coating a single piece to avoid defects and ensure adhesion. This leads to increased coating costs with increasing electrode area, resulting in high PEM electrolyzer costs and significantly limiting their widespread adoption. Application number CN202123155395.7 discloses an injection-molded, one-piece non-metallic frame bipolar plate. The non-metallic frame material is injection-molded PP or ABS, both of which have poor mechanical strength and are not resistant to hydrolysis, acids, or alkalis. Furthermore, the invention employs a circular design, indirectly leading to low membrane electrode utilization and potentially increasing costs. Application number CN202410839350.0 discloses an electrolytic cell with a metal / plastic composite flow field plate and its manufacturing method. This structure uses a full-size plastic plate and a full-size plastic electrode plate, and can only construct a small single-chamber experimental cell, without considering cost control factors. Application number CN202420219739.0 discloses a stack electrode plate and frame for a PEM electrolytic cell. This design uses a single metal electrode plate, resulting in low metal plate utilization.

[0004] Therefore, optimizing the design of the PEM electrolysis plate structure to reduce coating costs and lower the cost of the PEM electrolyzer will be more conducive to the widespread use of clean hydrogen energy. Utility Model Content

[0005] The problem this invention aims to solve is to reduce coating costs by optimizing the design of the PEM electrolysis plate structure, thereby reducing the cost of the PEM electrolyzer.

[0006] To address the shortcomings of existing technologies, the technical solution adopted by this utility model is as follows: a composite PEM electrolysis water electrode plate structure, comprising sequentially adjacent anode frames, non-full-size titanium bipolar plates, and cathode frames. The middle area of ​​the anode and cathode frames is a square hollow structure. A recessed groove 1 is provided around the square hollow structure of the anode frame, and a recessed groove 2 is provided around the square hollow structure of the cathode frame. The non-full-size titanium bipolar plate is sealed and embedded in the recessed groove 1 and recessed groove 2 on both sides, respectively. The total depth of the recessed groove 1 and recessed groove 2 is equal to the thickness of the non-full-size titanium bipolar plate.

[0007] Preferably, the non-full-size titanium bipolar plate has a sealing groove 1 and a sealing groove 2 on both sides for placing the sealing ring. The sealing groove 1 and the sealing groove 2 have the same depth. The distance between the anode sealing groove 1 and the edge of the non-full-size titanium bipolar plate is less than the distance to the active area, and the distance between the cathode sealing groove 2 and the edge of the non-full-size titanium bipolar plate is greater than the distance to the active area.

[0008] Preferably, the anode frame includes an anode frame A surface and an anode frame B surface, with a recessed groove disposed on the anode frame B surface; the anode frame A surface also includes an anode water inlet sealing groove, an anode water inlet, an anode distribution area, and a hydrogen inlet sealing groove.

[0009] Preferably, the cathode frame includes a cathode frame B surface and a cathode frame A surface, with a recessed groove located on the cathode frame A surface. The cathode frame A surface is also provided with an A surface water inlet sealing groove. The cathode frame B surface is also provided with a B surface water inlet sealing groove, a cathode water inlet, a hydrogen-side active area sealing groove, and a hydrogen inlet, with the hydrogen inlet connected to the cathode distribution area.

[0010] Preferably, the anode distribution area includes a straight flow channel and a lattice cylindrical flow channel. The straight flow channel is connected to the anode nozzle. The ratio of the groove width of the straight flow channel to the diameter of the lattice cylindrical flow channel is 1:1.5-1.5:1. The ratio of the groove width of the straight flow channel to the rib width is 1:2-2:1. The ratio of the distance between adjacent centers of the lattice cylindrical flow channel to the diameter of the lattice cylindrical flow channel is 1.5:2-2:1.5. The cathode distribution area is a dendritic biomimetic flow channel.

[0011] Preferably, the anode frame and the cathode frame are respectively provided with positioning structure one and positioning structure two, which are respectively located at the four corners of the corresponding frame.

[0012] Preferably, the anode frame and the cathode frame are respectively provided with chiral error-proofing structure one and chiral error-proofing structure two.

[0013] The beneficial effects of this utility model are as follows: The structure of this utility model reduces the cost of bipolar plates. A non-full-size titanium bipolar plate is sealed between the anode and cathode frames. The anode and cathode frames are made of stainless steel or polymer materials. Compared with traditional full-size bipolar plates, the amount of titanium material used is reduced by 40%-60%, the area of ​​the precious metal coating is reduced, and the cost is reduced by 40%-60%. Due to the simple structure of the plate, the cost of traditional etching is further reduced. Combined with the multi-in-one welding process of plate-flow channel-diffusion layer, the overall cost of the tank is reduced by more than 10%. The recessed grooves of the anode and cathode frames and the staggered sealing groove design of the non-full-size titanium bipolar plate achieve efficient sealing with a pressure resistance of ≥7MPa. The multi-nozzle design of the anode, combined with the straight flow channel, greatly reduces the flow resistance and reduces the energy consumption of the system pump. The simple biomimetic flow channel design of the cathode reduces the processing difficulty while ensuring efficient hydrogen production. The positioning structure and chiral error-proof design (notch / round hole) on the anode and cathode frames bring the assembly error rate close to zero, making assembly convenient and improving production efficiency. The materials of the anode and cathode frames can be replaced with stainless steel or polymer materials to adapt to different working conditions and expand application scenarios. Attached Figure Description

[0014] Figure 1 This is a structural schematic diagram and an exploded view of the present invention;

[0015] Figure 2 These are top views of the anode frame A and the anode frame B of this utility model;

[0016] Figure 3 These are top views of the A and B sides of the non-full-size titanium bipolar plate of this utility model;

[0017] Figure 4 These are top views of the cathode frame A and cathode frame B of this utility model;

[0018] Figure 5 for Figure 1 A schematic diagram of the cross-section along the water flow direction at point AA;

[0019] Figure 6 This is a schematic diagram and exploded view of the anode frame side structure of this utility model;

[0020] Figure 7 This is an enlarged schematic diagram of the anode frame of this utility model;

[0021] Figure 8 for Figure 7 Schematic diagram at point A in the middle;

[0022] Explanation of reference numerals in the attached drawings: 1. Anode frame; 101. Anode frame A-side; 102. Anode frame B-side; 10. Positioning structure one; 11. Chiral error-proofing structure one; 12. Hydrogen port; 13. Anode water inlet sealing groove; 14. Anode water inlet; 15. Anode distribution area; 151. Straight flow channel; 152. Lattice cylindrical flow channel; 16. Hydrogen port sealing groove; 17. Recessed groove one; 2. Non-full-size titanium bipolar plate; 201. Non-full-size titanium bipolar plate A-side; 202. Non-full-size titanium bipolar plate, B side; 20. Sealing groove one; 21. Sealing groove two; 3. Cathode frame; 301. Cathode frame, B side; 302. Cathode frame, A side; 30. Positioning structure two; 31. Chiral error-proofing structure two; 32. B side nozzle sealing groove; 33. Cathode nozzle; 34. Hydrogen-side active area sealing groove; 35. Hydrogen port; 36. Cathode distribution area; 37. Hydrogen port sealing groove; 38. A side nozzle sealing groove; 39. Recessed groove two. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the present invention to the disclosed forms. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described to better illustrate the principles and practical applications of the present invention, and to enable those skilled in the art to understand the present invention and design various embodiments with various modifications suitable for a particular purpose.

[0024] To reduce the coating cost of PEM electrolyzers, this invention proposes a composite PEM electrolysis electrode structure. By using a non-titanium electrode frame, the electrode area is reduced, the effective utilization rate of the electrode is improved, and thus the cost of precious metal coatings is reduced, achieving the goal of lowering electrode costs. Simultaneously, the non-full-size titanium bipolar plate 2 uses a channelless design and can be used with a titanium mesh, further saving on bipolar plate processing costs.

[0025] See Figure 1The composite electrode assembly of this invention, from bottom to top, consists of an anode frame 1, a non-full-size titanium bipolar plate 2, and a cathode frame 3. The anode frame 1 and cathode frame 3 serve as the main frame structure, supporting and fixing the non-full-size titanium bipolar plate 2, and providing water and air channels and a sealing structure. Specifically, the bonding sequence from top to bottom is: anode frame A-side 101 - anode frame B-side 102 - non-full-size titanium bipolar plate A-side 201 - non-full-size titanium bipolar plate B-side 202 - cathode frame B-side 301 - cathode frame A-side 302, where anode frame B-side 102 and cathode frame B-side 301 are also bonded together. The area between the anode frame 1 and cathode frame 3 is a square hollowed-out area, adapted to the active area of ​​the membrane electrode, retaining only the necessary conductive area and reducing waste of titanium material in the inactive area. This area corresponds to the active area on the non-full-size titanium bipolar plate 2 and the membrane electrode, and spatially serves as the placement area for the anode and cathode diffusion layers.

[0026] The outer contour dimension of the non-full-size titanium bipolar plate 2 is less than or equal to the outer contour of the recessed groove 17 in the anode frame 1 and the recessed groove 39 in the cathode frame 3, so that the non-full-size titanium bipolar plate 2 can be embedded in the recessed groove 17 and the recessed groove 39 and be limited in position. The non-full-size titanium bipolar plate 2 is embedded in the recessed groove 17 and the recessed groove 39, which restricts the displacement of the non-full-size titanium bipolar plate 2, reduces the outer extension area of ​​the plate, reduces the amount of titanium material used and the area of ​​the precious metal coating, and directly reduces the cost. The non-full-size titanium bipolar plate 2 is the core conductive component of the electrolytic reaction, which transmits current and supports the active area of ​​the membrane electrode. The non-full-size titanium bipolar plate 2 has a sealing groove 20 on its A-side 201 and a sealing groove 21 on its B-side 202. The sealing grooves 20 and 21 are used to house a sealing ring. Through press fitting, the anode frame 1, the non-full-size titanium bipolar plate 2, and the cathode frame 3 are effectively sealed, resulting in a composite PEM water electrolysis electrode plate structure. The sealing grooves 20 and 21 on both the anode and cathode sides of the non-full-size titanium bipolar plate 2 have the same width and depth. The distance between the anode sealing groove 20 and the edge of the non-full-size titanium bipolar plate 2 is less than the distance to the active region, while the distance between the cathode sealing groove 21 and the edge of the non-full-size titanium bipolar plate 2 is greater than the distance to the active region. Furthermore, the staggered arrangement of sealing groove 21 and sealing groove 20 achieves efficient sealing, such as... Figure 3 As shown, the length and width of sealing groove 20 are both greater than the length and width of sealing groove 21. The sum of the sinking depths of the recessed groove 17 in the anode frame 1 and the recessed groove 39 in the cathode frame 3 should be equal to the thickness of the non-full-size titanium bipolar plate 2, ensuring that the plate embedding does not create axial gaps that could lead to sealing failure.

[0027] The anode frame 1 and cathode frame 3 can be made of one of the following materials: stainless steel, including but not limited to 304, 304L, 316, and 316L; or polymeric materials, including but not limited to PPS, PEEK, PSU, PI, EP, and their modified blends. Using non-titanium materials for the anode frame 1 and cathode frame 3 can reduce titanium usage by 40%-60%, reduce the area of ​​the precious metal coating by 40%-60%, and lower the overall cost by more than 10%. The anode frame 1 and cathode frame 3 have positioning structures 10 and 30 at their four corner edges. These structures ensure precise alignment of the anode frame 1 and cathode frame 3, preventing assembly misalignment. The anode frame 1 and cathode frame 3 also have chiral error-proofing structures 11 and 31 in the hydrogen flow direction. These structures, through asymmetrical notch design, prevent reverse installation of the anode frame 1 and cathode frame 3, reducing human error. The positioning structures 10 and 30 include, but are not limited to, circular holes, while the chiral error-proofing structures 11 and 31 employ notch-based error prevention, including, but not limited to, semi-circular notches.

[0028] See Figure 2 The anode frame 1 has a mirror-symmetrical structure, consisting of an anode inlet sealing groove 13, an anode inlet 14, and an anode distribution area 15 from left to right. Multiple anode inlets 14 are provided. This design, along with the distribution area, ensures uniform distribution of circulating water in the active region, effectively reducing flow resistance and indirectly lowering pump costs. The anode inlets 14 and hydrogen inlets 12 on the anode frame 1 are perpendicular to each other. The anode inlet sealing groove 13 and hydrogen inlet sealing groove 16 of the anode frame 1 are mutually exclusive and do not interfere with each other in the planar direction. Figure 7 As shown, the anode distribution area 15 of the anode frame 1 also functions as a bridge. The anode distribution area 15 is directly machined onto the anode frame 1. The bridge channel of the anode distribution area 15 is a straight channel 151, which connects to the anode nozzle 14. A lattice cylindrical channel 152 is located after the straight channel 151. The ratio of the width of the straight channel 151 to the diameter of the lattice cylindrical channel 152 is 1:1.5-1.5:1. Figure 8 The straight flow channel 151 shown has a groove width of L, and the diameter of the lattice cylindrical flow channel 152 is d, with L:d ranging from 1:1.5 to 1.5:1. The ratio of the groove width L of the straight flow channel 151 to its rib width is 1:2 to 2:1, and the rib width of the straight flow channel 151 is D, with L:D ranging from 1:2 to 2:1. The distance between adjacent centers of the lattice cylindrical flow channel 152 is M, and the diameter of the lattice cylindrical flow channel 152 is d, with the ratio of the distance between adjacent centers of the lattice cylindrical flow channel 152 to its diameter being 1.5:2 to 2:1.5, i.e., M:d ranging from 1.5:2 to 2:1.5.

[0029] See Figure 4 The cathode frame 3 has a mirror-symmetric structure. From top to bottom, the cathode frame B-side 301 consists of a hydrogen-side active region sealing groove 34, a hydrogen port 35, and a cathode distribution area 36. The cathode ports 33 and 35 of the cathode frame 3 are through holes, positioned in the same spatial distribution as the anode frame 1. The cathode distribution area 36 of the cathode frame A-side 302 is directly machined onto the cathode frame 3, and its flow channel is a dendritic biomimetic flow channel with a width ratio of 1:1.5-1.5:1 to the straight flow channel 151 of the anode. The B-side port sealing groove 32 and the hydrogen-side active region sealing groove 34 on the cathode frame B-side 301 are mutually exclusive and do not interfere with each other in the planar direction. Specifically, the B-side port sealing groove 32 is symmetrical on both sides, and each side must include all ports; the hydrogen-side active region sealing groove 34 is symmetrical vertically, and includes the hydrogen port 35, the active region, and the cathode distribution area 36.

[0030] The A-side water inlet sealing groove 38 and hydrogen port sealing groove 37 on the cathode frame A-side 302 are mutually exclusive and do not interfere with each other in the planar direction. Specifically, the A-side water inlet sealing groove 38 is symmetrical on both sides, and each side must include all water inlets; the A-side water inlet sealing groove 38 is symmetrical vertically and must include the hydrogen port. Here, the sealing of the cathode frame B-side 301 is mainly for fitting with the anode frame B-side 102. During installation, the cathode frame B-side 301 faces upward. This design can effectively prevent the sealing material from falling off due to gravity and potential external interference during installation.

[0031] Figure 5 This is a schematic diagram of the sealing structure in cross-section along the water flow direction, which more intuitively shows the embedding and sealing structure of the non-full-size titanium bipolar plate.

[0032] The recessed groove design of the non-titanium anode frame 1 and cathode frame 3 allows the non-full-size titanium bipolar plate 2 to be embedded within the recessed groove, achieving a sealing effect. The non-full-size titanium bipolar plate 2 is positioned by the recessed grooves of the anode frame 1 and cathode frame 3, and is effectively connected and sealed by a sealing ring in conjunction with the electrolyzer's clamping force. The anode frame 1 and cathode frame 3 simultaneously provide water and gas transport and distribution, structural support, sealing, positioning, and error prevention functions. This structure can be applied to the electrode plates of PEM water electrolysis for hydrogen production. Combined with lower-cost non-titanium uncoated electrode frame materials, it effectively increases the utilization rate of titanium electrode plates, significantly reduces electrode plate processing and material costs, indirectly reduces the cost of precious metal plating on the electrode plates, and thus lowers the cost of the electrolyzer.

[0033] This invention provides a composite PEM electrolysis electrode plate structure. By embedding a non-full-size titanium bipolar plate in a recessed groove, employing an asymmetrical sealing groove layout and a mirror-symmetrical distribution area design, the effective utilization rate of the titanium electrode plate is significantly improved to over 80%. The anode and cathode frames utilize low-cost materials (stainless steel / polymer), and the combination of straight and biomimetic flow channels optimizes water flow distribution, reducing flow resistance and energy consumption. A chiral error-proof structure ensures precise assembly, reducing production losses. In practical applications, this structure reduces the overall cost of the PEM electrolyzer by 10%, providing a cost-effective technical solution for the large-scale production of green hydrogen, and possesses broad market prospects.

Claims

1. A composite PEM electrolysis water electrode plate structure, characterized by: The anode frame (1), the non-full-size titanium bipolar plate (2), and the cathode frame (3) are arranged in sequence. The middle area of ​​the anode frame (1) and the cathode frame (3) is a square hollow structure. The square hollow structure of the anode frame (1) is provided with a first recessed groove (17) around its perimeter, and the square hollow structure of the cathode frame (3) is provided with a second recessed groove (39) around its perimeter. The non-full-size titanium bipolar plate (2) is sealed and embedded in the first recessed groove (17) and the second recessed groove (39) on both sides respectively. The total depth of the first recessed groove (17) and the second recessed groove (39) is equal to the thickness of the non-full-size titanium bipolar plate (2).

2. The composite PEM electrolysis water electrode structure of claim 1, wherein: The non-full-size titanium bipolar plate (2) has a sealing groove 1 (20) and a sealing groove 2 (21) on both sides for placing the sealing ring. The sealing groove 1 (20) and the sealing groove 2 (21) have the same depth. The distance between the anode sealing groove 1 (20) and the edge of the non-full-size titanium bipolar plate (2) is less than the distance from the active area. The distance between the cathode sealing groove 2 (21) and the edge of the non-full-size titanium bipolar plate (2) is greater than the distance from the active area.

3. The composite PEM electrolysis water electrode structure of claim 1, wherein: The anode frame (1) includes an anode frame A surface (101) and an anode frame B surface (102), and a recessed groove (17) is provided on the anode frame B surface (102); the anode frame A surface (101) also includes an anode water inlet sealing groove (13), an anode water inlet (14), an anode distribution area (15), and a hydrogen inlet sealing groove (16).

4. The composite PEM electrolysis water electrode plate structure of claim 3, wherein: The cathode frame (3) includes a cathode frame B surface (301) and a cathode frame A surface (302). The second recessed groove (39) is located on the cathode frame A surface (302). The cathode frame A surface (302) is also provided with an A surface water inlet sealing groove (38). The cathode frame B surface (301) is also provided with a B surface water inlet sealing groove (32), a cathode water inlet (33), a hydrogen side active area sealing groove (34), and a hydrogen port (35). The hydrogen port (35) is connected to the cathode distribution area (36).

5. The composite PEM electrolysis water electrode structure of claim 4, wherein: The anode distribution area (15) includes a straight flow channel (151) and a lattice cylindrical flow channel (152). The straight flow channel (151) is connected to the anode nozzle (14). The ratio of the groove width of the straight flow channel (151) to the diameter of the lattice cylindrical flow channel (152) is 1:1.5-1.5:

1. The ratio of the groove width of the straight flow channel (151) to the rib width is 1:2-2:

1. The ratio of the distance between adjacent centers of the lattice cylindrical flow channel (152) to the diameter of the lattice cylindrical flow channel (152) is 1.5:2-2:1.

5. The cathode distribution area (36) is a dendritic biomimetic flow channel.

6. The composite PEM electrolysis water electrode structure of claim 1, wherein: The anode frame (1) and the cathode frame (3) are respectively provided with positioning structure one (10) and positioning structure two (30), and positioning structure one (10) and positioning structure two (30) are respectively located at the four corners of the corresponding frames.

7. The composite PEM electrolysis water electrode structure of claim 1, wherein: The anode frame (1) and the cathode frame (3) are respectively provided with a chiral error-proofing structure one (11) and a chiral error-proofing structure two (31).

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