Electrolytic water hydrogen production bipolar plate with corrosion-resistant multi-comb double-tooth flow field

Abstract

This invention provides a bipolar plate for hydrogen production via water electrolysis with a corrosion-resistant multi-comb double-tooth flow field, belonging to the technical field of bipolar plates. The bipolar plate of this invention is made of corrosion-resistant metal and includes a cathode plate and an anode plate, both of which are provided with a multi-comb double-tooth flow field. The multi-comb double-tooth flow field is disposed within the flow field grooves of the cathode and anode plates and consists of periodically arranged comb-like ribs and double-tooth protrusions, with the double-tooth protrusions located between the comb-like ribs. The multi-comb double-tooth flow fields on the cathode and anode plates are symmetrically arranged, and at least two gas-liquid channels are provided diagonally across the flow field grooves. The multi-comb double-tooth flow field can actively generate turbulence and enhance shearing action to break up and remove bubbles on the electrode surface, improving the heat and mass transfer processes within the groove. Through synergistic innovation in material and flow field structure, this invention effectively improves the corrosion resistance and mass transfer efficiency of the bipolar plate, reduces the risk of H2 / O2 gas cross-contamination, and extends the performance stability and service life of the bipolar plate.

Description

Technical Field

[0001] This invention relates to the field of water electrolysis hydrogen production technology, and in particular to a bipolar plate for water electrolysis hydrogen production with a corrosion-resistant multi-comb double-tooth flow field. Background Technology

[0002] Electrolysis of water to produce hydrogen, as a clean hydrogen production method, has attracted much attention in recent years and is of strategic significance in promoting green energy transformation and achieving emission reduction targets. The electrolyzer, as the core device of green hydrogen production, electrochemical synthesis, and energy storage systems, is of paramount importance. Among the many components of an electrolyzer, the bipolar plate is a key component, undertaking multiple functions such as efficient current conduction, precise distribution of reactant gases / liquid electrolytes, stable support of membrane electrodes, and maintenance of structural integrity. The performance of the bipolar plate directly determines the energy conversion efficiency, service life, and manufacturing cost of the electrolyzer. However, existing bipolar plate technology still faces severe challenges, mainly manifested in two major bottlenecks: insufficient corrosion resistance and low system energy efficiency, which seriously restrict the efficient and stable operation of the electrolyzer. In highly corrosive electrolysis environments, bipolar plates are prone to corrosion, which not only shortens their own lifespan but also causes dissolved metal ions to poison the catalyst layer and ion exchange membrane. Simultaneously, inefficient flow field design leads to impeded mass transfer and a large accumulation of bubbles, significantly increasing system energy consumption and limiting the performance and long-term operational stability of the electrolyzer.

[0003] Currently, traditional bipolar plates are mostly made of stainless steel or graphite, but these materials pose significant corrosion risks. Stainless steel is prone to electrochemical corrosion in acidic or strongly alkaline electrolytes, and its corrosion products contaminate the catalyst and electrolyte, leading to increased cell voltage, decreased efficiency, and a sharp reduction in lifespan. Graphite plates, on the other hand, are insufficient in mechanical strength and are brittle, making them unsuitable for high-pressure operating environments. Crucially, existing bipolar plate materials are typically optimized only for specific electrolytes, lacking universal corrosion-resistant materials compatible with acidic, alkaline, and neutral electrolytes, severely limiting the adaptability of a single electrolyzer to diverse application scenarios. At the flow field design level, the geometry and dimensional parameters of the flow field directly influence the reactant transport efficiency, product discharge rate, current distribution uniformity, and voltage drop loss within the electrolyzer. However, existing bipolar plate technology, especially flow field design, still has many shortcomings: traditional parallel flow channel designs fail to fully consider the characteristics of rapid bubble formation, large size, and strong adhesion under high current densities, leading to uneven reactant distribution, retention of product gases (such as H2 / O2), bubble accumulation, and blockage of mass transfer channels. Improper flow channel design can also lead to imbalances in electrolyte flow rate distribution and abnormal reactant concentration gradients, thereby inducing current density "hot spots," accelerating local catalyst deactivation and corrosion processes, and even affecting the bipolar plate itself. Gas coverage on the electrode surface can obscure active sites, increase polarization overpotential and system energy consumption, and hinder the efficient and stable operation of the electrolyzer; product gas retention prolongs its residence time in the reaction zone, exacerbating the risk of transmembrane permeation and threatening gas purity and system safety. Although improved flow field designs exist, they often fail to achieve optimal overall performance due to excessive pressure drop, complex processing techniques, or over-reliance on empirical parameters.

[0004] Therefore, there is an urgent need to develop novel flow field structures based on fluid mechanics principles that can actively guide and break up large bubbles and achieve uniform mass transfer, while simultaneously pursuing a two-pronged approach. Collaborative innovation from both materials science and fluid mechanics dimensions is needed to develop bipolar plates that combine excellent corrosion resistance, superior conductivity, and optimized flow field configuration, thereby comprehensively improving the overall performance, service life, and economy of electrolyzers. Summary of the Invention

[0005] In view of this, to address the corrosion risks and shortcomings in the flow field design of traditional bipolar plates, this invention provides a bipolar plate for hydrogen production via water electrolysis with a corrosion-resistant multi-comb double-tooth flow field. Made of corrosion-resistant metal, the flow field is designed based on fluid mechanics principles, consisting of periodically arranged comb-like ribs and double-tooth protrusions, actively generating turbulence and enhancing shearing to break up and remove bubbles, thus improving heat and mass transfer within the tank. Through synergistic innovation in material and flow field structure, this invention effectively improves the corrosion resistance and mass transfer efficiency of the bipolar plate, reduces the risk of H2 / O2 gas cross-contamination, and extends the performance stability and service life of the bipolar plate.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A bipolar plate for hydrogen production via water electrolysis, featuring a corrosion-resistant multi-comb double-tooth flow field, is made of corrosion-resistant metal and includes a cathode plate and an anode plate. Both the cathode and anode plates are equipped with multi-comb double-tooth flow fields. These flow fields are located within the flow field grooves of the cathode and anode plates and consist of periodically arranged comb-like ribs and double-tooth protrusions, with the double-tooth protrusions positioned between the comb-like ribs. The multi-comb double-tooth flow fields on the cathode and anode plates are symmetrically arranged, and at least two gas-liquid channels are provided diagonally across the flow field grooves. The multi-comb double-tooth flow fields can actively generate turbulence and enhance shearing action to break up and peel away bubbles on the electrode surface, thereby improving heat and mass transfer processes within the groove.

[0007] This invention utilizes a multi-comb bi-tooth flow field designed based on fluid mechanics principles. This effectively breaks up and guides large bubbles generated on the electrode surface, achieving uniform supply of reactants and rapid discharge of products. This significantly reduces mass transfer overpotential, increases the upper limit of current density, enhances long-term operational stability, and ultimately achieves high corrosion resistance, high efficiency, and high safety in water electrolysis for hydrogen production. The bipolar plates are made of corrosion-resistant metals, giving them excellent electrical and thermal conductivity, high mechanical strength and good mechanical properties, and excellent corrosion resistance and high-temperature resistance. This allows the electrolyzer to maintain stable operating performance, a long service life, improved electrolysis efficiency, and reduced operating costs under harsh working environments such as high corrosion, high temperature, and high pressure. The fluid mechanics-based flow field design and the selection of corrosion-resistant, low-cost bipolar plate materials result in a high-performance, highly stable electrolyzer device, offering the following advantages compared to existing technologies: (1) The multi-comb double-tooth flow field designed in this invention can greatly increase the contact area between the cathode and anode catalysts and the reaction surface, thereby improving the hydrogen production efficiency and purity; (2) The multi-comb double-tooth flow field designed in this invention can improve heat and mass transfer capabilities, reduce gas cross-contamination problems, and allow the gas generated by the reaction to escape more smoothly. (3) Effectively reduces corrosion on the surface of bipolar plates in electrolytic cells, improving their corrosion resistance and durability. It overcomes the technical difficulties of easy corrosion of bipolar plates and low hydrogen production efficiency in existing technologies.

[0008] In summary, thanks to the aforementioned technological advantages, the electrolyzer hydrogen production system exhibits excellent oxygen evolution activity and stability, and has broad application prospects. Attached Figure Description

[0009] Figure 1 3D design model of bipolar plate for multi-comb double-tooth flow field electrolyzer; Figure 2 A physical image of the bipolar plate of a multi-comb double-tooth flow field electrolyzer; Figure 33D design model of bipolar plate for blank flow field electrolytic cell; Figure 4 The images are electron microscope images of the bipolar plates in a multi-comb double-tooth flow field electrolytic cell before testing. In the images, (a) shows the surface morphology of the cathode plate at 100x magnification, (b) shows the surface morphology of the cathode plate at 200x magnification, (c) shows the surface morphology of the cathode plate at 1000x magnification, (d) shows the surface morphology of the anode plate at 100x magnification, (e) shows the surface morphology of the anode plate at 200x magnification, and (f) shows the surface morphology of the anode plate at 1000x magnification. Figure 5 The images show electron microscope images of the bipolar plates in a multi-comb double-tooth flow field electrolytic cell after testing. In the images, (a) shows the surface morphology of the cathode plate at 100x magnification, (b) shows the surface morphology of the cathode plate at 200x magnification, (c) shows the surface morphology of the cathode plate at 1000x magnification, (d) shows the surface morphology of the anode plate at 100x magnification, (e) shows the surface morphology of the anode plate at 200x magnification, and (f) shows the surface morphology of the anode plate at 1000x magnification. Figure 6 The images are electron microscope images of the bipolar plates in a blank flow field electrolytic cell before testing. In the images, (a) shows the surface morphology of the cathode plate at 100x magnification, (b) shows the surface morphology of the cathode plate at 200x magnification, (c) shows the surface morphology of the cathode plate at 1000x magnification, (d) shows the surface morphology of the anode plate at 100x magnification, (e) shows the surface morphology of the anode plate at 200x magnification, and (f) shows the surface morphology of the anode plate at 1000x magnification. Figure 7 The images are electron microscope images after testing the bipolar plates in a blank flow field electrolytic cell. In the images, (a) shows the surface morphology of the cathode plate at 100x magnification, (b) shows the surface morphology of the cathode plate at 200x magnification, (c) shows the surface morphology of the cathode plate at 1000x magnification, (d) shows the surface morphology of the anode plate at 100x magnification, (e) shows the surface morphology of the anode plate at 200x magnification, and (f) shows the surface morphology of the anode plate at 1000x magnification. Figure 8 This is a schematic diagram of a membrane electrode. Figure 9 LSV curves of multi-comb double-tooth type and blank flow field (control group) electrolyzers in 1 M KOH electrolyte at 60℃; Figure 10 LSV curves of multi-comb double-tooth type and blank flow field (control group) electrolyzers in 1 M KOH electrolyte at room temperature; Figure 11 For multi-comb double-tooth type and blank flow field (control group) electrolyzers at 100 mA cm -2 Stability of 1 MKOH electrolyte at current density; Figure 12 For multi-comb double-tooth type and blank flow field (control group) electrolyzers at 100 mA cm -2Stability retention rate in 1 M KOH electrolyte after 100 h at current density; Figure 13 The Faraday efficiency of a multi-comb double-tooth electrolyzer in 1 M KOH electrolyte; Figure 14 A simulation diagram of gas-liquid discharge in a multi-comb double-tooth electrolyzer in 1 M KOH electrolyte; In the figure, 1 is the bipolar plate; 2 is the bolt hole; 3 is the sealing ring; 4 is the multi-comb double-tooth flow field; 5.1 is the gas-liquid channel one; 5.2 is the gas-liquid channel two; 6 is the comb-shaped rib; and 7 is the double-tooth boss. Detailed Implementation

[0010] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0011] like Figure 1 As shown, this invention provides a bipolar plate 1 for hydrogen production by water electrolysis with a corrosion-resistant multi-comb double-tooth flow field. Made of corrosion-resistant metal, it includes a cathode plate and an anode plate, both of which are provided with multi-comb double-tooth flow fields 4. The multi-comb double-tooth flow fields 4 are disposed within the flow field grooves of the cathode and anode plates, and are composed of periodically arranged comb-like ribs 6 and double-tooth protrusions 7, with the double-tooth protrusions 7 located between the comb-like ribs 6. The multi-comb double-tooth flow fields 4 on the cathode and anode plates are symmetrically arranged, and at least two gas-liquid channels (gas-liquid channel 1 5.1 and gas-liquid channel 2 5.2) are provided diagonally in the flow field grooves. The multi-comb double-tooth flow fields 4 can actively generate turbulence and enhance shearing action to break and peel bubbles from the electrode surface, improving the heat and mass transfer process within the tank.

[0012] In this technical solution, the cathode and anode plates are made of corrosion-resistant metal. A symmetrical flow field consisting of periodic comb-shaped ribs 6 and double-toothed protrusions 7 is set in the flow field grooves of the plates. The flow field breaks up and removes bubbles on the electrode surface through active turbulence and enhanced shearing, thereby improving heat and mass transfer within the cell. By synergistically improving the corrosion resistance and mass transfer efficiency of the bipolar plates 1 through material and flow field, the risk of H2 / O2 gas cross-contamination is reduced, and the stability and lifespan of the electrolytic cell are extended.

[0013] In this invention, the comb-like ribs 6 are periodically arranged parallel strip structures. The periodic parallel arrangement of the comb-like ribs 6 forms a strip structure, guiding the electrolyte to flow regularly and generating stable turbulence. This enhances the regularity of the flow field, strengthens the bubble breaking effect, and improves product discharge efficiency.

[0014] In this invention, the gas-liquid channel includes at least a gas-liquid channel 5.1 for electrolyte inflow and a gas-liquid channel 5.2 for product gas and electrolyte outflow. This ensures a continuous supply of reactants and smooth product discharge, avoids channel blockage, and maintains reaction stability.

[0015] In this invention, the corrosion-resistant metal material is at least one of titanium alloy, low-carbon steel, nickel-plated plate, or nickel alloy, which resists corrosion from electrolyte environments such as acids, alkalis, and seawater. It is compatible with multiple electrolyte systems, broadening the application scenarios of electrolytic cells and extending the service life of bipolar plates.

[0016] In this invention, the titanium alloy is either TC8 or TC4 titanium alloy. TC8 / TC4 titanium alloys possess high strength and excellent corrosion resistance, making them suitable for harsh electrolytic environments. Further optimization of material properties enhances the structural stability and corrosion resistance of the bipolar plate under high temperature / high pressure.

[0017] In this invention, the flow field trenches are square, and together with the diagonal gas-liquid channels, form a symmetrical fluid distribution structure. This uniformly covers the active area of ​​the electrode, eliminates flow dead zones, and improves reaction uniformity.

[0018] In this invention, the side length of the flow field trench is 16~4160 mm, adaptable to different electrolytic cell sizes, balancing mass transfer efficiency and space utilization. This enhances design versatility, allowing the size to be adjusted according to application scenarios to meet the needs from pilot-scale to industrialization.

[0019] In this invention, the cathode plate and anode plate are symmetrically arranged and are both square, with a length and width of 38~10000mm and a thickness of 5~1300mm. The symmetrical arrangement of the square cathode and anode plates ensures assembly consistency and uniform distribution of current and electrolyte. This simplifies the assembly process, avoids localized current "hot spots," and reduces polarization losses.

[0020] In this invention, the width of the comb-shaped ribs 6 is 0.75~195 mm, and the height of the double-toothed bosses 7 is 0.425~110 mm. The appropriate comb-shaped rib width and boss height enhance the flow field shearing effect, effectively breaking up bubbles. This optimizes the turbulence effect, reduces bubble adhesion to the electrode surface, and lowers the polarization overpotential.

[0021] In this invention, the diameter of the gas-liquid channel is 0.75~195 mm. The gas-liquid channel diameter is adapted to the electrolyte flow rate and product discharge requirements, balancing flow resistance and mass transfer efficiency. It adapts to different current density scenarios, ensuring smooth fluid transport and improving the overall performance of the electrolyzer.

[0022] The bipolar plate 1 for hydrogen production via water electrolysis, provided by the present invention, featuring a corrosion-resistant multi-comb double-tooth flow field, is assembled in an electrolyzer system. Preferably, this electrolyzer system includes the bipolar plate provided by the present invention. The assembly of the electrolyzer system is as follows: From left to right, the assembly consists of a cathode plate designed based on fluid dynamics, a cathode plate sealing ring 3, a left insulating pad, a cathode diffusion layer, a cathode catalyst, an anion exchange membrane, an anode catalyst, an anode diffusion layer, a right insulating pad, an anode plate sealing ring, and an anode plate corresponding to the flow field. The components on the left and right sides are symmetrically arranged with the anion exchange membrane as the central plate. The cathode plate and the anode plate are fixed by eight screws, which, together with the insulating pad, pass through the bolt holes 2 and are locked with nuts. The flow field is designed as a multi-comb double-tooth type.

[0023] The design of the multi-comb double-tooth flow field is based on a 3D model established from fluid dynamics results. The prepared corrosion-resistant metal plate is then processed according to the design drawings, ultimately forming an electrolytic cell bipolar plate with both a multi-comb double-tooth flow field 4 and a blank flow field. Specifically: the cathode and anode plates of the electrolytic cell with the multi-comb double-tooth and blank flow fields (serving as a control group) are each two symmetrical bipolar plates, square in shape, with dimensions of 38–10000 mm and a thickness of 5–1300 mm. The bipolar plate 1 has the following features from the outside in: eight bolt holes 2 around its perimeter, with a diameter of 3.5–900 mm; and a concave square annular ring 3 for the cathode and anode plates, with an outer ring side length of 18.75–4875 mm, an inner ring side length of 17.5–4550 mm, and a rib width of 1.25–325 mm. The bipolar plate of the electrolytic cell with a multi-comb double-tooth flow field on the inner side of the ring channel has flow field grooves designed based on fluid dynamics. Both the cathode plate and the anode plate are designed with a multi-comb double-tooth flow field 4. The square flow channel of the flow field has a side length of 16~4160mm. The width of each comb-shaped rib is 0.75~195mm, and the double-tooth boss is 0.425~110mm. Two gas-liquid channels (gas-liquid channel 1 5.1 and gas-liquid channel 2 5.2) with a diameter of 0.75~195mm are provided at the diagonal of the square flow channel. The electrolyte flows into the electrolytic cell through gas-liquid channel 1 at both ends of the bipolar plate. After the electrolyte continuously undergoes electrode reactions inside the anode and cathode of the electrolytic cell, the generated gas flows out and is collected together with the electrolyte through gas-liquid channel 2. Among them, gas-liquid channel 2 of the cathode plate is the H2 outlet, and gas-liquid channel 2 of the anode plate is the O2 outlet. Except for the absence of flow field grooves, the internal dimensions of the electrolytic cell with blank flow field are identical to those of the bipolar plate with flow field design.

[0024] Both the left and right insulating pads are preferably made of polytetrafluoroethylene (PTFE). The assembly holes on the insulating pads are in the same position and size as the bolt holes on the bipolar plates, with a diameter of 3.5~900 mm, and are fixed between the two bipolar plates. The insulating pads have a hollow square in the middle, which is in the same position and size as the sealing rings of the cathode and anode plates, with a length of 18.75~4875 mm.

[0025] The cathode catalyst layer is a cathode catalyst (20 wt% platinum-carbon Pt / C) sprayed onto nickel foam using ultrasonic spraying and directly contacted with the anion exchange membrane, with a thickness of 17.5~4550 mm. The cathode diffusion layer is a layer of pure nickel foam.

[0026] The anode catalyst layer is an anode catalyst (FeCoNi LDH) that is sprayed onto nickel foam using ultrasonic spraying and is attached to and in direct contact with the anion exchange membrane. The thickness is set to 17.5~4550 mm, and the anode diffusion layer is a layer of pure nickel foam.

[0027] The anion exchange membrane was fixed between the cathode and anode catalysts, and was designed as a square with a side length approximately 19–4880 mm longer than the sealing ring. The newly prepared anion exchange membrane was pretreated with 1 M NaCl for 72 h, and then pretreated with 1 M KOH solution for 1 h to ensure thorough wetting before testing.

[0028] The electrolyte used in bipolar plate assembled electrolyzers includes at least one of alkaline, acidic, or seawater.

[0029] The bipolar plate is preferably prepared using the following method: Prepare appropriate amounts of pure titanium and other alloying element powders (such as aluminum, iron, etc.), and mix the powders of various alloying elements evenly according to the specified proportions. Place the mixed powder into a mold with a multi-comb double-tooth flow field and perform isostatic pressing or hot pressing to form a billet. Place the pressed billet at a high temperature for sintering, so that the powder particles bond together to form a strong billet. The sintered billet then undergoes further hot working to improve its mechanical properties and shape. Finally, the prepared bipolar plate is surface treated to obtain the final product.

[0030] The technical solution of the present invention will be clearly and thoroughly described below with reference to the accompanying drawings and specific embodiments.

[0031] Example 1 The bipolar plates of the electrolytic cell based on the multi-comb double-tooth flow field and blank flow field (control group) were made of TC8 titanium alloy. The assembly sequence was as follows: anode plate, anode diffusion layer, anode catalyst (FeCoNi LDH), insulating gasket, anion exchange membrane, insulating gasket, cathode catalyst (20 wt% platinum carbon Pt / C), cathode diffusion layer, and cathode plate. The device was assembled in the above order and fixed together with eight bolts. The four apex bolts faced the same direction, and the four apex end bolts faced the opposite direction. The remaining four bolts were arranged in the opposite direction.

[0032] The cathode and anode plates of the multi-comb double-tooth flow field electrolytic cell are two symmetrical bipolar plates, square in shape, with a length and width of 76 mm and a thickness of 10 mm. Eight bolt holes, each 7 mm in diameter, are provided around the perimeter of the bipolar plates from the outside in. The sealing rings of the cathode and anode plates are concave square annular channels, with an outer ring side length of 37.5 mm, an inner ring side length of 35 mm, and a rib width of 2.5 mm. Flow field grooves based on fluid dynamics design are provided on the inner side of this annular channel. Both the cathode and anode are designed as periodically arranged multi-comb double-tooth flow channels, with a side length of 22 mm, a rib width of 1.5 mm per comb, a rib spacing of 0.85 mm, and a double-tooth boss height of 0.85 mm. Two gas-liquid channels, each 1.5 mm in diameter, are provided diagonally across the square flow channels. The inlet and outlet / gas outlet of the electrolytic cell are connected to the electrolyte and gas collection device respectively via rigid corrosion-resistant rubber tubes. The inlet is connected to a peristaltic pump and is connected to the electrolyte, while the outlet / gas outlet is placed in the gas collection device, where H2 / O2 escapes with the electrolyte and is collected.

[0033] The blank flow field (control group) electrolytic cell bipolar plate serves as the control group. Its cathode and anode plates are two symmetrical bipolar plates, square in shape, with a length and width of 76 mm and a thickness of 10 mm. The bipolar plate has eight bolt holes of 7 mm diameter around its perimeter from the outside in. The sealing rings of the cathode and anode plates are concave square annular channels, with an outer ring side length of 37.5 mm, an inner ring side length of 35 mm, and a rib width of 2.5 mm. The inner side of this annular channel is a square structure without flow channels, with a side length of 22 mm. Two gas-liquid channels of 1.5 mm diameter are located at opposite corners of this square. The inlet and outlet / gas outlet of the electrolytic cell are connected to the electrolyte and gas collection device respectively via rigid corrosion-resistant rubber tubes. The inlet is connected to a peristaltic pump and enters the electrolyte, while the outlet / gas outlet is placed in the gas collection device, where H2 / O2 escapes with the electrolyte and is collected.

[0034] Figure 1-3 This invention presents a 3D design model of the bipolar plate of an electrolytic cell with a multi-comb double-tooth flow field and a blank flow field (control group) based on fluid dynamics design, as well as a physical diagram of the multi-comb double-tooth flow field. The electrolytic cell consists of two symmetrical cathode and anode plates, both made of TC8 titanium alloy. The bipolar plates are arranged sequentially to form a multi-comb double-tooth flow field and a blank flow field (control group), and the flow fields of both bipolar plates are symmetrical. The tooth shape and flow channel of the multi-comb double-tooth flow field electrolytic cell bipolar plate are designed to optimize the discharge efficiency for specific bubble sizes. This flow channel design consists of periodically arranged comb-like ribs and double-tooth protrusions. Each comb rib is 1.5 mm wide, the rib spacing is 1.2 mm, and the protrusion is 0.85 mm wide, located between the comb-like ribs. This periodically arranged comb-like ribs and double-tooth protrusions in the multi-comb double-tooth flow field facilitate turbulence and bubble breakage.

[0035] Figure 4-7 Electron micrographs of the bipolar plates in the electrolytic cell with the multi-comb double-tooth flow field and the blank flow field (control group) prepared according to this invention are shown before and after testing. The results show that after a relatively long stability test in 1 M KOH electrolyte, the bipolar plate of the electrolytic cell with the multi-comb double-tooth flow field has a smoother surface and a smaller corrosion area, while the bipolar plate of the electrolytic cell with the blank flow field (control group) has a rougher surface and a larger corrosion area. Therefore, the multi-comb double-tooth flow field with fluid dynamics design can more effectively reduce the corrosion of the surface of the electrolytic cell bipolar plate, thereby improving its corrosion resistance, durability and operating efficiency.

[0036] Figure 8 The image shows the membrane electrode assembly prepared according to the present invention. From left to right, the assembly consists of an anode catalyst, an anion exchange membrane, and a cathode catalyst. The anode and cathode catalysts are coated onto the nickel foam using an ultrasonic spraying method, resulting in a uniform distribution and tight bonding with the three-dimensional framework of the nickel foam.

[0037] Figure 9-10 The LSV test results of the bipolar plate of the electrolytic cell with multi-comb double-tooth flow field and blank flow field (control group) prepared by this invention in 1 M KOH electrolyte are shown in the figure. The experiment shows that the bipolar plate with multi-comb double-tooth design can achieve LSV at 100 mA cm⁻¹. -2 At the specified current density, the cell voltages of the multi-comb double-tooth flow field at 60℃ and room temperature were 1.72 V and 1.84 V, respectively. While the blank flow field (control group) exhibited lower cell voltages at 60℃ and room temperature (1.60 V and 1.72 V, respectively), the lack of a flow field resulted in significant fluctuations in its polarization curve, making reactant supply and product removal extremely difficult during the reaction process. Gas bubbles accumulated on the electrode surface and could not be effectively removed. To address this issue and the large, highly adhesive nature of oxygen bubbles in the anode of the electrolyzer, the multi-comb double-tooth flow field design employs a periodically arranged comb-like rib and double-tooth protrusion structure. This structure shears and guides large bubbles, breaking them up and directing them to the main flow channel, significantly improving mass transfer. Therefore, the core function of the flow field is to enhance mass transfer through convection, enabling a continuous supply of reactants and efficient product removal, thus creating more favorable conditions for the long-term stable operation of the electrolyzer.

[0038] Figure 11-12 The figures show the OER stability test results of the bipolar plates of the multi-comb bitooth flow field electrolyzer and the blank flow field (control group) prepared in this invention in 1M KOH electrolyte. The multi-comb bitooth flow field electrolyzer is in an alkaline environment at 100 mAcm. -2The electrolyzer exhibited superior stability with only a 20% performance degradation after approximately 760 hours of continuous catalytic oxygen evolution (COE) at the same current density, maintaining a maintenance rate of about 80%. This stability is attributed to the multi-comb bi-tooth flow field structure, which reduces local gas coverage and significantly improves mass transfer. The timely removal of bubbles also prevents the formation of insulating layers on the electrode or membrane surfaces, ensuring unobstructed ion conduction pathways. In contrast, the electrolyzer in the blank flow field (control group) showed significant performance fluctuations during continuous COE testing at the same current density, with a performance degradation of approximately 40% after only 100 hours and a maintenance rate of only 60%, indicating poor stability. These results demonstrate that the multi-comb bi-tooth flow field effectively improves the overall performance and durability of the hydrogen production system, achieving a maintenance rate 1.6 times that of the blank flow field (control group). This design, through optimized channel shape and structure distribution, effectively controls flow resistance, providing sufficient lateral distribution while maintaining a clear mainstream direction, thus ensuring efficient transport of reactants and products. This solves the problem of rapid performance degradation and instability caused by poor gas management in the blank flow field.

[0039] Figure 13-14 The image shows the Faraday efficiency test and gas-liquid discharge simulation of the bipolar plate of the multi-comb double-tooth flow field electrolyzer prepared in this invention in 1 M KOH electrolyte. The results show that the multi-comb double-tooth flow field electrolyzer has good reaction efficiency, which is attributed to its periodically distributed comb-like ribs and double-tooth protrusion structure flow field design. This design effectively forces the electrolyte to split and redistribute as it flows through each unit, thereby ensuring that the electrolyte uniformly covers the entire electrode active area and avoiding "edge effects" and flow dead zones. Simultaneously, it can promptly discharge H2 and O2 generated during the electrolysis reaction, thus improving the overall performance of the hydrogen production system.

[0040] Example 2 The bipolar plates of the multi-comb double-tooth flow field and blank flow field electrolytic cells are made of TC4 titanium alloy. The assembly sequence is as follows: anode plate, anode diffusion layer, anode catalyst (FeCoNi LDH), insulating gasket, anion exchange membrane, insulating gasket, cathode catalyst (20 wt% platinum carbon Pt / C), cathode diffusion layer, cathode plate. The device is assembled and fixed together with bolts. The four apex bolts face the same direction, and the four apex end bolts face another direction. The remaining four bolts are reversed.

[0041] The cathode and anode plates of the multi-comb double-tooth flow field electrolytic cell are each two symmetrical bipolar plates, square in shape, with a length and width of 38 mm and a thickness of 5 mm. Eight bolt holes, each 3.5 mm in diameter, are provided around the perimeter of the bipolar plates from the outside in. The sealing rings of the cathode and anode plates are concave square annular channels, with an outer ring side length of 18.75 mm, an inner ring side length of 17.5 mm, and a rib width of 1.25 mm. Flow field grooves based on fluid dynamics design are provided on the inner side of this annular channel. Both the cathode and anode are multi-comb double-tooth square flow channels with a side length of 16 mm, each comb rib width of 0.75 mm, and a boss width of 0.425 mm. Two gas-liquid channels, each 0.75 mm in diameter, are provided diagonally across the square flow channels. The electrolytic cell uses an alkaline electrolyte. Its inlet and outlet / gas outlet are connected to the electrolyte and gas collection device respectively via rigid corrosion-resistant rubber tubes. The inlet is connected to a peristaltic pump and is connected to the electrolyte, while the outlet / gas outlet is placed in the gas collection device, where H2 / O2 escapes with the electrolyte and is collected.

[0042] The blank flow field electrolytic cell serves as a control group. Its cathode and anode plates are two symmetrical bipolar plates, square in shape, with dimensions of 38 mm in length and width, and a thickness of 5 mm. Eight bolt holes, each 3.5 mm in diameter, are provided around the perimeter of the bipolar plates from the outside in. The sealing rings for the cathode and anode plates are concave square annular channels, with an outer side length of 18.75 mm, an inner side length of 17.5 mm, and a rib width of 1.25 mm. The inner side of this annular channel is a square structure without flow channels, with a side length of 16 mm. Two gas-liquid channels, each 0.75 mm in diameter, are located at opposite corners of this square. The electrolytic cell uses an alkaline electrolyte. Its inlet and outlet / gas outlet are connected to the electrolyte and gas collection device respectively via rigid, corrosion-resistant rubber tubing. The inlet is connected to a peristaltic pump and enters the electrolyte, while the outlet / gas outlet is placed in the gas collection device, where H2 / O2 escapes with the electrolyte and is collected.

[0043] Example 3 The bipolar plates of the multi-comb double-tooth flow field and blank flow field electrolytic cells are made of nickel-plated plates. The assembly sequence is as follows: anode plate, anode diffusion layer, anode catalyst (FeCoNi LDH), insulating gasket, anion exchange membrane, insulating gasket, cathode catalyst (20 wt% platinum carbon Pt / C), cathode diffusion layer, cathode plate. The device is assembled and fixed together with bolts. The four apex bolts face the same direction, and the four apex end bolts face another direction. The remaining four bolts are reversed.

[0044] The cathode and anode plates of the multi-comb double-tooth flow field electrolytic cell are each two symmetrical bipolar plates, square in shape, with a length and width of 1000 mm and a thickness of 130 mm. Eight bolt holes, each 90 mm in diameter, are provided around the perimeter of the bipolar plate from the outside in. The sealing rings of the cathode and anode plates are concave square annular channels, with an outer ring side length of 487.5 mm, an inner ring side length of 455 mm, and a rib width of 32.5 mm. Flow field grooves based on fluid dynamics design are provided on the inner side of this annular channel. Both the cathode and anode are multi-comb double-tooth square flow channels with a side length of 416 mm, each comb rib width of 19.5 mm, and a boss width of 11 mm. Two gas-liquid channels, each 19.5 mm in diameter, are provided diagonally across the square flow channels. The electrolytic cell uses an acidic electrolyte. Its inlet and outlet / gas outlet are connected to the electrolyte and gas collection device respectively via rigid corrosion-resistant rubber tubes. The inlet is connected to a peristaltic pump and is connected to the electrolyte. The outlet / gas outlet is placed in the gas collection device, where H2 / O2 escapes with the electrolyte and is collected.

[0045] The blank flow field electrolytic cell serves as a control group. Its cathode and anode plates are two symmetrical bipolar plates, square in shape, with a length and width of 1000 mm and a thickness of 130 mm. Eight bolt holes, each 90 mm in diameter, are provided around the perimeter of the bipolar plates from the outside in. The sealing rings of the cathode and anode plates are concave square annular channels, with an outer side length of 487.5 mm, an inner side length of 455 mm, and a rib width of 32.5 mm. The inner side of this annular channel is a square structure without flow channels, with a side length of 416 mm. Two gas-liquid channels, each 19.5 mm in diameter, are located at opposite corners of this square. The electrolytic cell uses an acidic electrolyte. Its inlet and outlet / gas outlet are connected to the electrolyte and gas collection device respectively via rigid corrosion-resistant rubber tubes. The inlet is connected to a peristaltic pump and enters the electrolyte, while the outlet / gas outlet is placed in the gas collection device, where H2 / O2 escapes with the electrolyte and is collected.

[0046] Example 4 The bipolar plates of the multi-comb double-tooth flow field and blank flow field electrolytic cells are made of low-carbon steel. The assembly sequence is as follows: anode plate, anode diffusion layer, anode catalyst (FeCoNi LDH), insulating gasket, anion exchange membrane, insulating gasket, cathode catalyst (20 wt% platinum carbon Pt / C), cathode diffusion layer, cathode plate. The device is assembled and fixed together with bolts. The four apex bolts face the same direction, and the four apex end bolts face another direction. The remaining four bolts are reversed.

[0047] The cathode and anode plates of the multi-comb double-tooth flow field electrolytic cell are each two symmetrical bipolar plates, square in shape, with a length and width of 760 mm and a thickness of 100 mm. Eight bolt holes, each 70 mm in diameter, are provided around the perimeter of the bipolar plate from the outside in. The sealing rings of the cathode and anode plates are concave square annular channels, with an outer ring side length of 375 mm, an inner ring side length of 350 mm, and a rib width of 25 mm. Flow field grooves based on fluid dynamics design are provided on the inner side of this annular channel. Both the cathode and anode are multi-comb double-tooth shaped square flow channels, with a side length of 320 mm, a rib width of 15 mm for each comb, and a boss width of 8.5 mm. Two gas-liquid channels, each 15 mm in diameter, are provided diagonally across the square flow channels. The electrolytic cell uses an acidic electrolyte. Its inlet and outlet / gas outlet are connected to the electrolyte and gas collection device respectively via rigid corrosion-resistant rubber tubes. The inlet is connected to a peristaltic pump and is connected to the electrolyte. The outlet / gas outlet is placed in the gas collection device, where H2 / O2 escapes with the electrolyte and is collected.

[0048] The blank flow field electrolytic cell serves as a control group. Its cathode and anode plates are two symmetrical bipolar plates, square in shape, with a length and width of 760 mm and a thickness of 100 mm. Eight bolt holes, each 70 mm in diameter, are provided around the perimeter of the bipolar plates from the outside in. The sealing rings of the cathode and anode plates are concave square annular channels, with an outer side length of 375 mm, an inner side length of 350 mm, and a rib width of 25 mm. The inner side of this annular channel is a square structure without flow channels, with a side length of 320 mm. Two gas-liquid channels, each 15 mm in diameter, are located at opposite corners of this square. The electrolytic cell uses an acidic electrolyte. Its inlet and outlet / gas outlet are connected to the electrolyte and gas collection device respectively via rigid, corrosion-resistant rubber tubing. The inlet is connected to a peristaltic pump and enters the electrolyte, while the outlet / gas outlet is placed in the gas collection device, where H2 / O2 escapes with the electrolyte and is collected.

[0049] Example 5 The bipolar plates of the multi-comb double-tooth flow field and blank flow field electrolytic cells are made of nickel alloy. The assembly sequence is as follows: anode plate, anode diffusion layer, anode catalyst (FeCoNi LDH), insulating gasket, anion exchange membrane, insulating gasket, cathode catalyst (20 wt% platinum carbon Pt / C), cathode diffusion layer, cathode plate. The device is assembled and fixed together with bolts. The four apex bolts face the same direction, and the four apex end bolts face another direction. The remaining four bolts are reversed.

[0050] The cathode and anode plates of the multi-comb double-tooth flow field electrolytic cell are two symmetrical bipolar plates, square in shape, with a length and width of 10000 mm and a thickness of 1300 mm. Eight bolt holes, each 900 mm in diameter, are provided around the perimeter of the bipolar plates from the outside in. The sealing rings of the cathode and anode plates are concave square annular channels, with an outer side length of 4875 mm, an inner side length of 4550 mm, and a rib width of 325 mm. Flow field grooves based on fluid dynamics design are provided on the inner side of this annular channel. Both the cathode and anode are multi-comb double-tooth square flow channels with a side length of 4160 mm, each comb rib width of 195 mm, and a boss width of 110 mm. Two gas-liquid channels, each 195 mm in diameter, are located diagonally opposite each other in the square flow channel. The electrolytic cell uses seawater as the electrolyte. Its inlet and outlet / gas outlet are connected to the electrolyte and gas collection device respectively through rigid corrosion-resistant rubber tubes. The inlet is connected to a peristaltic pump and is connected to the electrolyte. The outlet / gas outlet is placed in the gas collection device, and H2 / O2 escapes with the electrolyte and is collected.

[0051] The blank flow field electrolytic cell serves as a control group. Its cathode and anode plates are two symmetrical bipolar plates, square in shape, with dimensions of 10000 mm in length and width, and a thickness of 1300 mm. Eight bolt holes, each 900 mm in diameter, are located around the perimeter of the bipolar plates from the outside in. The sealing rings for the cathode and anode plates are concave square annular channels, with an outer side length of 4875 mm, an inner side length of 4550 mm, and a rib width of 325 mm. The inner side of this annular channel is a square structure without flow channels, with a side length of 4160 mm. Two gas-liquid channels, each 195 mm in diameter, are located at opposite corners of this square. The electrolytic cell uses seawater as the electrolyte. The inlet and outlet / gas outlet are connected to the electrolyte and gas collection device respectively via rigid, corrosion-resistant rubber tubing. The inlet is connected to a peristaltic pump and enters the electrolyte, while the outlet / gas outlet is placed in the gas collection device, where H2 / O2 escapes with the electrolyte and is collected.

[0052] The above description is merely a preferred embodiment of the present invention. However, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention should be covered within the scope of protection of the present invention.

Claims

1. A bipolar plate for hydrogen production via water electrolysis with a corrosion-resistant multi-comb double-tooth flow field, characterized in that, Made of corrosion-resistant metal, the device includes a cathode plate and an anode plate, both of which are provided with a multi-comb double-tooth flow field. The multi-comb double-tooth flow field is located in the flow field grooves of the cathode and anode plates and is composed of periodically arranged comb-like ribs and double-tooth protrusions, with the double-tooth protrusions located between the comb-like ribs. The multi-comb double-tooth flow fields on the cathode and anode plates are symmetrically arranged, and at least two gas-liquid channels are provided diagonally in the flow field grooves. The multi-comb double-tooth flow field can actively generate turbulence and enhance shearing to break and peel off bubbles on the electrode surface, thereby improving the heat and mass transfer process within the groove.

2. The bipolar plate for hydrogen production via water electrolysis with a corrosion-resistant multi-comb double-tooth flow field according to claim 1, characterized in that, The comb-like ribs are strip-shaped structures arranged in parallel periodically.

3. The bipolar plate for hydrogen production via water electrolysis with a corrosion-resistant multi-comb double-tooth flow field according to claim 1, characterized in that, The gas-liquid channel includes at least one gas-liquid channel for electrolyte inflow and another gas-liquid channel for product gas and electrolyte outflow.

4. The bipolar plate for hydrogen production via water electrolysis with a corrosion-resistant multi-comb double-tooth flow field according to claim 1, characterized in that, The corrosion-resistant metal material is at least one of titanium alloy, low carbon steel, nickel-plated plate, or nickel alloy.

5. The bipolar plate for hydrogen production via water electrolysis with a corrosion-resistant multi-comb double-tooth flow field according to claim 4, characterized in that, The titanium alloy is either TC8 titanium alloy or TC4 titanium alloy.

6. The bipolar plate for hydrogen production via water electrolysis with a corrosion-resistant multi-comb double-tooth flow field according to claim 1, characterized in that, The flow field trench is square.

7. A bipolar plate for hydrogen production via water electrolysis with a corrosion-resistant multi-comb double-tooth flow field according to claim 6, characterized in that, The side length of the flow field groove is 16~4160 mm.

8. The bipolar plate for hydrogen production via water electrolysis with a corrosion-resistant multi-comb double-tooth flow field according to claim 1, characterized in that, The cathode plate and anode plate are symmetrically arranged and are both square, with a length and width of 38~10000 mm and a thickness of 5~1300 mm.

9. A bipolar plate for hydrogen production via water electrolysis with a corrosion-resistant multi-comb double-tooth flow field according to claim 1, characterized in that, The width of each comb-shaped rib is 0.5~195 mm, and the height of the double-toothed boss is 0.425~110 mm.

10. A bipolar plate for hydrogen production via water electrolysis with a corrosion-resistant multi-comb double-tooth flow field according to any one of claims 1-9, characterized in that, The diameter of the gas-liquid channel is 0.5~195 mm.

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