A method for forming an elliptical concave and convex electrode plate of a large water electrolysis hydrogen production electrolyzer

Abstract

The present invention discloses a method for forming an elliptical concave-convex electrode plate for a large-scale water electrolysis hydrogen production electrolyzer. The outer contour of the electrode plate is an ellipse, and the minor axis of the ellipse is along the width direction of the rolled slab. The maximum minor axis length can be close to the maximum width of the rolled slab, and the major axis of the ellipse is along the length direction of the rolled slab, so the major axis length is theoretically not limited by the width of the rolled slab, which solves the problem that the traditional circular electrode plate is limited by the maximum width of the rolled slab and the effective working area of ​​the electrode plate cannot be further increased. The present invention adopts a progressive stamping forming method to solve the technical problems of high mold material cost, high mold processing cost, high mold processing and matching precision requirements, the inability of the overall mold to adapt to the changes of protrusions and pits, and the need for large countertops and large-tonnage special equipment, breaking through the limitations of the electrode plate diameter and effective working area and greatly reducing the production and manufacturing costs of the electrode plate.

Description

Technical Field

[0001] The invention relates to a concave-convex pole plate of an electrolyzer and a forming method thereof, and in particular to an elliptical concave-convex pole plate of a large-scale water electrolysis hydrogen production electrolyzer and a forming method thereof. Background Art

[0002] my country is building a clean, low-carbon, safe and efficient energy system by replacing traditional fossil energy with renewable energy. Hydrogen is an ideal energy source to replace traditional fossil fuels because of its outstanding advantages such as high energy density, wide sources, renewable, non-toxic and clean. At present, hydrogen mainly comes from hydrogen production from fossil raw materials, industrial by-products and water electrolysis, among which water electrolysis is the most ideal way to produce hydrogen. However, the current production capacity of water electrolysis is seriously insufficient, and it is necessary to increase research and development from the perspectives of technology and equipment to rapidly expand the production capacity of water electrolysis.

[0003] The electrolyzer is the core component of the water electrolysis hydrogen production equipment. The size of the electrolyzer directly determines the hydrogen production of a single water electrolysis hydrogen production equipment, while the plate structure, size, material and gas production pressure in the electrolyzer directly affect the service life and electrolysis efficiency of the electrolyzer. At the same time, since the number of plates in a single electrolyzer is often as many as 300, the manufacturing cost of the plates largely determines the cost of the entire electrolyzer and even the electrolysis hydrogen production equipment.

[0004] Traditional electrolytic cell plates are all circular, with nipples or protrusions distributed according to a specific pattern formed on the front and back of the circular thin-walled slab, and the height of the protrusions is generally 3 to 5 mm. At present, the diameter d of the circular plate ranges from 580 mm to 1800 mm and has only a few fixed specifications. The maximum hydrogen production of a single device is 1000 cubic meters per hour, see invention patent ZL201020668648.3. If the hydrogen production capacity of a single device is to be expanded, the size of the plate needs to be expanded, which inevitably requires the use of a larger circular slab. However, due to the limitations of the rolling process, the maximum width of the thin-walled cold-rolled plate (such as DC04, 304 stainless steel, etc.) commonly used for electrolytic cell plates is only 2000 mm. Since it is necessary to reserve a processing allowance on the outer edge of the circular slab when forming the plate, the use of a 2000 mm wide thin-walled slab can only form a diameter of about 1800 mm and an effective working area of ​​about 2.54 m 2 How to manufacture concave and convex plates with larger diameter or effective working area has become a bottleneck problem restricting the large-scale development of water electrolysis hydrogen production equipment.

[0005] In addition to the limited size of the plates, there are also many difficulties in the forming and manufacturing of large-size plates, which further limits the development of large-scale water electrolysis hydrogen production equipment. It can be seen from the invention patent (application number: 202210267373.X) that the concave and convex plates are currently usually manufactured by stamping an integral mold that matches the size specifications of the plates, see. On the surface of the overall upper and lower molds, protrusions and pits distributed according to a specific pattern are processed. When the overall upper and lower molds are closed, the required protrusions will be formed on the front and back sides of the thin-walled slab at one time. This integral die stamping method has the advantages of high efficiency and good consistency, but it also has many disadvantages or limitations, mainly including: (1) The mold processing cost is extremely high. Taking a circular plate with a diameter of d = 1800 mm as an example, the total number of protrusions on both sides of the plate exceeds 5000, and a corresponding number of protrusions and pits need to be processed on the upper and lower mold surfaces; (2) The mold material cost is very high. The initial circular plate blank used for the plate with a diameter of d = 1800 mm has a diameter greater than 1800 mm, while the corresponding integral forming mold diameter exceeds 2000 mm. In order to reduce the wear problem of the mold in mass production, the mold needs to be made of expensive wear-resistant materials and needs to be heat treated; (3) The dimensional accuracy of the protrusions and pits is largely determined by the processing accuracy and matching accuracy of the mold. In order to ensure the accuracy and consistency of a large number of small protrusions and small pits with a height of 3 to 5 mm and a diameter of 15 to 20 mm, very high requirements are placed on the processing and matching accuracy of the upper and lower integral molds with a diameter of nearly 2000 mm. The processing is difficult and costly; (4) A set of integral molds can only be used to form a circular electrode plate of a fixed specification. When the diameter of the electrode plate changes, the size of the protrusion or pit changes, or the thickness of the electrode plate changes, a new integral forming mold needs to be reprocessed, which can be said to be "a chain reaction"; (5) The use of integral molds to form electrodes must be carried out on large-scale, large-tonnage special equipment, which requires very high accuracy of the equipment. Taking a circular electrode with a diameter of d=1800mm as an example, the forming equipment needs to provide a clamping force of more than 10000kN (1000 tons), and the work surface needs to be more than 2500mm×2500mm.

[0006] In summary, the manufacturing of convex and concave plates for large-scale water electrolysis hydrogen production electrolyzers, on the one hand, is limited by the width of thin-walled cold-rolled plates, which results in the inability to increase the diameter of the plates and the insufficient effective working area. On the other hand, due to the use of an integral mold stamping process, there are problems such as high mold material costs, high mold processing costs, high mold processing and matching accuracy requirements, the overall mold cannot adapt to the changes in protrusions and pits, and the need for large tables and large-tonnage special equipment. It is urgent to propose a new plate design method and forming and manufacturing method to break through the limitations of plate diameter and effective working area and significantly reduce the production and manufacturing cost of the plates. Summary of the invention

[0007] In order to solve the problems that the diameter of the circular concave-convex pole plates of the existing large-scale water electrolysis hydrogen production electrolyzer is limited, the effective working area cannot be further increased, and the cost of manufacturing large-size pole plates using integral mold forming technology is extremely high, the present invention proposes a forming method for the elliptical concave-convex pole plates of the large-scale water electrolysis hydrogen production electrolyzer.

[0008] The present invention is to solve the above problems, the technical solution of the present invention is:

[0009] A method for forming an elliptical concave-convex electrode plate of a large-scale water electrolysis hydrogen production electrolyzer, the steps are as follows:

[0010] Step 1, elliptical plate design: the outer contour of the plate is elliptical, the ratio of the length of the major axis a to the length of the minor axis b of the ellipse is in the range of 1 to 3, the protrusions on the front side of the plate corresponding to the pits on the back side or the pits on the front side of the plate corresponding to the protrusions on the back side are decomposed into several groups along the short axis direction of the plate, and each group of protrusions or pits is on a straight line; each group of protrusions and pits on the front side of the plate are equally spaced and alternately distributed along the long axis direction of the elliptical plate, that is, a row of protrusions is adjacent to a row of pits, the maximum number of protrusions in a single row in the short axis direction of the plate is N, and the maximum number of pits is N-1, and the effective working area of ​​a single plate is π×a×b as the design target, and the outer dimensions of the elliptical plate and the size and distribution of the protrusions and pits are determined;

[0011] Step 2: Design and process the progressive stamping die: According to the outer dimensions of the elliptical plate and the distribution of protrusions and pits determined in step 1, the die is designed with the maximum number of protrusions N in a single row in the short axis direction of the elliptical plate; the upper die of the progressive stamping die is composed of N discrete punch units, an upper die discrete punch connecting plate, and an upper die pressing plate. The discrete punch units are connected to the upper die discrete punch connecting plate by threads and can move downward synchronously with the upper die discrete punch connecting plate. The N discrete punch units move along the upper die discrete punch. The head connecting plates are evenly spaced in the length direction, and the slab pressing plate is connected to the upper die discrete punch connecting plate through connecting bolts and nitrogen springs; the lower die of the progressive stamping die is composed of N-1 discrete punch units, a lower die discrete punch connecting plate, and a lower die pressing plate, and the structure and mutual connection relationship of the lower die are the same as those of the upper die; the length of the upper die pressing plate and the lower die pressing plate is 100 to 200 mm longer than the short axis length of the elliptical plate, and the width of the upper die pressing plate and the lower die pressing plate is 3 to 7 times the spacing of the straight lines where the adjacent groups of protrusions are located;

[0012] Step 3, elliptical slab design: According to the elliptical plate designed in step 1, the shape and size of the initial slab are optimized and designed in combination with the theoretical calculation and simulation analysis of the forming process; the shape of the initial slab is elliptical, the length of its major axis is 1.01 to 1.10 times the length of the major axis of the elliptical plate to be formed, and the length of its minor axis is 1.01 to 1.05 times the length of the minor axis of the elliptical plate to be formed;

[0013] Step 4, stamping the first group of concave and convex features: according to the first group of protrusions N and the first group of pits N-1 on the elliptical plate designed in step 1, the corresponding number of discrete punch units are fixed to the upper die discrete punch connecting plate and the lower die discrete punch connecting plate respectively, and the major axis and minor axis of the elliptical slab are adjusted and aligned with the width direction and the length direction of the progressive stamping die respectively, and the slab is stamped; during the stamping and die closing process, the upper die pressing plate and the lower die pressing plate are first contacted with the elliptical slab to fix the slab, and a surface pressure of 3 to 50 MPa is provided in the peripheral adjacent area of ​​the first group of protrusions and pits to be stamped, and then the upper die discrete punch connecting plate and the lower die discrete punch connecting plate respectively drive the upper die discrete punch and the lower die discrete punch to stamp the slab to obtain a group of protrusions and pits;

[0014] Step 5, progressive stamping of the elliptical plate blank: the elliptical plate blank is moved along the long axis direction in a stepping manner, and the stepping distance is the distance between adjacent rows of protrusions of the elliptical plate to be formed along the long axis direction; after each step of the elliptical plate blank, a group of protrusions and pits are formed by a progressive stamping die; before each stamping, the number of discrete punches of the upper die and the lower die is adjusted according to the number of protrusions and pits to be formed on the elliptical plate; the die closing stamping process is the same as step 4;

[0015] Step 6. Removal of excess material from the outer periphery of the plate blank: According to the outer dimensions of the elliptical plate to be formed and the distribution of protrusions and pits, laser cutting or mechanical cutting is used to remove excess material from the outer periphery to obtain an elliptical plate product with shape, size and concave-convex features that meet the requirements.

[0016] The beneficial effects of the present invention are:

[0017] 1. The present invention proposes a method for forming an elliptical concave-convex electrode plate for a large-scale water electrolysis hydrogen production electrolyzer. The outer contour of the electrode plate is an ellipse, and the minor axis of the ellipse is along the width direction of the rolled slab. The maximum minor axis length can be close to the maximum width of the rolled slab, and the major axis of the ellipse is along the length direction of the rolled slab. Therefore, the major axis length is theoretically not limited by the width of the rolled slab. When the ratio of the major axis to the minor axis length of the manufactured elliptical electrode plate is 3 using a thin-walled slab with a width of 2000 mm, the effective working area of ​​the electrode plate reaches 7.62 m 2 The effective working area of ​​the circular plate (1800mm in diameter) is 3 times that of the traditional circular plate (maximum diameter 1800mm). The effective working area of ​​the circular plate is 2.54m 2 ). This solves the problem that the traditional circular plate is limited by the maximum width of the rolled slab and cannot further increase the effective working area of ​​the plate.

[0018] 2. The present invention proposes a method for forming an elliptical concave-convex plate of a large-scale water electrolysis hydrogen production electrolyzer, wherein the outer contour of the plate is an ellipse, which is symmetrical about the major axis and the minor axis of the ellipse, and the protrusions and pits on the plate are regularly distributed at equal intervals along the major axis direction of the elliptical plate. Therefore, when using a progressive stamping die for forming, after completing the forming of a group of protrusions and pits in the direction of the major axis of the ellipse, there is no need to adjust the discrete stamping die to complete the forming of a group of protrusions and pits on the other side that are symmetrical about the minor axis of the ellipse. This avoids the problem of low production efficiency when the distribution of protrusions and pits on the plate is irregular or unequally spaced and asymmetrically distributed along the major axis of the ellipse, requiring discrete punch adjustment when forming each group of protrusions and pits.

[0019] 3. The present invention proposes a method for forming an elliptical concave-convex pole plate for a large-scale water electrolysis hydrogen production electrolyzer. The outer contour of the pole plate is an ellipse. A progressive stamping forming method is adopted. A single mold can adapt to the forming of elliptical pole plates with the same width and different major axis and minor axis ratios, and the mold has strong adaptability. In addition, by adjusting the number of discrete punches, a set of progressive stamping forming dies can also be used to form elliptical slabs of different widths. If the progressive stamping forming die used can form an elliptical pole plate with a minor axis length of 1800 mm, then the set of dies can complete the forming of other elliptical pole plates with a minor axis length of less than 1800 mm. This solves the problem that traditional integral stamping forming dies can only be used for the forming of circular pole plates of specific sizes.

[0020] 4. The present invention proposes a method for forming an elliptical concave-convex electrode plate for a large-scale water electrolysis hydrogen production electrolyzer. The outer contour of the electrode plate is elliptical, and a progressive stamping method is adopted. The length of the upper mold plate and the lower mold plate is 100 to 200 mm longer than the short axis length of the elliptical electrode plate, and the width of the upper mold plate and the lower mold plate is only 3 to 7 times the spacing between the straight lines where adjacent rows of protrusions are located. The size of the progressive stamping mold is significantly smaller than that of the traditional integral stamping mold, which greatly reduces the mold cost and the electrode plate production cost.

[0021] 5. The present invention proposes a method for forming an elliptical concave-convex plate for a large-scale water electrolysis hydrogen production electrolyzer. The outer contour of the plate is elliptical. The progressive stamping method is used. The number of protrusions and pits formed by a single stamping is only 1 / 20 to 1 / 50 of that during the integral mold stamping, and the required stamping force is much smaller than that of the integral mold stamping. At the same time, the maximum width of the progressive stamping die only needs to be consistent with the short axis length of the elliptical plate, and the width is less than 2500mm. Therefore, the table of the equipment required for forming is also much smaller than that required for the integral mold stamping, and the one-time investment in equipment is significantly reduced, thereby effectively reducing the manufacturing cost of the plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1It is a schematic diagram of the elliptical concave and convex plates of the electrolytic cell for producing hydrogen by water electrolysis;

[0023] Figure 2 It is a schematic diagram of the main process of the elliptical concave-convex pole plate and its progressive stamping forming;

[0024] Figure 3 Schematic diagram of the elliptical concave-convex pole plate and its blank at different stages of progressive stamping forming, where Figure 3 (a) is an elliptical slab. Figure 3 (b) is the plate blank after the first set of concave-convex features are stamped. Figure 3 (c) is the slab during the progressive stamping process. Figure 3 (d) is the part after progressive stamping;

[0025] Figure 4 It is a schematic diagram of the structure of an elliptical concave-convex pole plate and its progressive stamping forming die;

[0026] Figure 5 It is a schematic diagram of the edge pressing action of the elliptical concave-convex pole plate and its progressive stamping forming die;

[0027] Figure 6 It is a schematic diagram of the stamping action of the elliptical concave and convex pole plate and its progressive stamping forming die.

[0028] In the figure: 1 elliptical pole plate, 1-1 protrusion, 1-2 pit, 3 guide column, 4 connecting bolt, 5 nitrogen spring, 6 upper die discrete punch connecting plate, 7 upper die pressing plate, 8 cover plate, 9 discrete punch unit, 10 lower die pressing plate, 11 lower die discrete punch connecting plate, 12 return spring. DETAILED DESCRIPTION

[0029] The following combination Figures 1 to 6 and technical solutions to further illustrate the specific implementation methods of the present invention.

[0030] Specific implementation method 1: Combination Figures 1 to 6 The oval concave-convex pole plate of a large-scale water electrolysis hydrogen production electrolyzer and the forming method thereof proposed by the present invention are carried out according to the following steps:

[0031] Step 1: Elliptical plate design: The outer contour of the plate is elliptical, with a major axis length of 2700mm and a minor axis length of 1800mm. The ratio of the major axis to the minor axis of the ellipse is 1.5. The plate thickness is 1.8mm. The height of all protrusions is 5mm and the diameter is 25mm. The protrusions on the front or back of the plate can be decomposed into several groups along the minor axis of the plate and each group of protrusions is on a straight line. The spacing between the straight lines of adjacent groups of protrusions is 40mm. The maximum number of protrusions in a single row in the minor axis direction of the plate is 35, and the maximum number of pits is 34.

[0032] Step 2: Design and process the progressive stamping die: According to the outer dimensions of the elliptical plate and the distribution of protrusions and pits determined in step 1, the die is designed with a maximum number of protrusions of 35 in a single row in the short axis direction of the elliptical plate; the upper die of the progressive stamping die is composed of 35 discrete punch units, an upper die discrete punch connecting plate, and an upper die pressing plate. The discrete punch units are connected to the upper die discrete punch connecting plate by threads and can move downward synchronously with the upper die discrete punch connecting plate. The 35 discrete punch units are arranged along the upper die discrete punch connecting plate. The punch connecting plates are evenly spaced in the length direction, and the slab pressing plate is connected to the upper die discrete punch connecting plate through connecting bolts and nitrogen springs; the lower die of the progressive stamping die is composed of 34 discrete punch units, a lower die discrete punch connecting plate, and a lower die pressing plate, and the structure and mutual connection of the lower die are the same as those of the upper die; the length of the upper die pressing plate and the lower die pressing plate is 100 to 200 mm longer than the short axis length of the elliptical plate, and the width of the upper die pressing plate and the lower die pressing plate is times the spacing of the straight lines where the adjacent groups of protrusions are located, that is, 280 mm;

[0033] Step 3, elliptical slab design: According to the elliptical plate designed in step 1, the shape and size of the initial slab are optimized and designed in combination with the theoretical calculation and simulation analysis of the forming process; the shape of the initial slab is elliptical, and the length of its major semi-axis is 1.05 times the major axis length of the elliptical plate to be formed, that is, 2835mm, and the length of its minor axis is 1.02 times the minor axis length of the elliptical plate to be formed, that is, 1800mm, that is, 1836mm;

[0034] Step 4, stamping the first group of concave and convex features: according to the first group of 35 protrusions and 34 pits on the elliptical plate designed in step 1, the corresponding number of discrete punch units are fixed to the upper die discrete punch connecting plate and the lower die discrete punch connecting plate respectively, and the major axis and minor axis of the elliptical slab are adjusted and aligned with the width direction and length direction of the progressive stamping die respectively, and the slab is stamped; during the stamping and clamping process, the upper die pressing plate and the lower die pressing plate first contact with the elliptical slab to fix the slab, and provide a surface pressure of 3 to 50 MPa in the peripheral adjacent area of ​​the first group of protrusions and pits to be stamped, and then the upper die discrete punch connecting plate and the lower die discrete punch connecting plate respectively drive the upper die discrete punch and the lower die discrete punch to stamp the slab to obtain the first group of protrusions and pits;

[0035] Step 5, progressive stamping of the elliptical slab: the elliptical slab is moved along the long axis direction in a stepping manner, and the stepping distance is 40 mm along the long axis direction of the adjacent rows of protrusions of the elliptical plate to be formed; after each step of the elliptical slab, a group of protrusions and pits are formed by a progressive stamping die; before each stamping, the number of discrete punches of the upper die and the lower die is adjusted according to the number of protrusions and pits to be formed on the elliptical plate; the die closing stamping process is the same as step 4;

[0036] Step 6. Removal of excess material from the periphery of the plate blank: According to the outer dimensions of the elliptical plate to be formed and the distribution of protrusions and pits, laser cutting or mechanical cutting is used to remove excess material from the periphery to obtain an elliptical plate product with shape, size and concave-convex features that meet the requirements.

[0037] The beneficial effect of this embodiment is that the elliptical outer contour plate is adopted, which breaks through the limitation of the width size of the traditional circular plate which cannot be produced and manufactured with a diameter of more than 1800mm and an area of ​​more than 2.54m 2 The problem of electrode plates. In addition, the electrode plates are formed in a progressive forming manner, and a single mold can adapt to the same width and multiple axial length ratios of the electrode plates. By adjusting the number of discrete punches, the forming of electrode plates of different widths can also be achieved. In addition, by using progressive forming, the mold size required for a single forming is small, and the mold manufacturing, maintenance, and repair costs are low. In addition, the progressive forming method has a small number of protrusions and pits in a single forming, a small forming force, and low requirements for forming equipment, which can significantly reduce equipment costs.

[0038] Specific implementation method 2: Combination Figure 4 Note that in step two, elastic materials such as polyurethane are used instead of nitrogen springs. While providing load to the upper and lower die plates during mold closing, the mold can continue to move downward until the punch completes the forming of protrusions and pits.

[0039] The beneficial effects of this embodiment are: elastic materials such as polyurethane are inexpensive and easy to process and replace. When the load of the upper mold plate and the lower mold plate on the slab needs to be changed, it can be achieved by adjusting the thickness and hardness of the elastic material.

[0040] Specific implementation method three: Combination Figure 4 Note that in step 2, when designing the mold, the upper mold plate and the lower mold plate are made of flexible materials such as polytetrafluoroethylene, and the other steps are the same as the specific implementation method one.

[0041] The beneficial effect of this embodiment is that the upper mold plate and the lower mold plate are made of flexible materials such as polytetrafluoroethylene, and the plate can produce a certain elastic deformation under the action of the mold clamping force, which effectively solves the problem that the flatness of the mold surface is difficult to ensure when processing large-size molds, resulting in uneven force on the slab and abnormal material flow during the mold pressing process due to local contact. Since the uniform pressure on the surface of the slab is achieved, the protrusions and pits are deformed evenly during the forming process, so that the residual stress in the plane of the slab can be evenly distributed.

[0042] Specific implementation method four: Combination Figure 3 , Figure 4Note that in step 4 and step 5, the progressive stamping process is to start from one end and gradually move toward the other end along the long axis direction of the elliptical plate. The stamping of the entire plate can be completed by sequentially moving the slab along the long axis direction.

[0043] The beneficial effect of this embodiment is that: by adopting the method of stepwise feeding along the long axis direction, the slab can be stamped in a single direction along the long axis direction to achieve high forming efficiency.

[0044] Specific implementation method five: Combination Figure 3 , Figure 4 Note that in step four and step five, the progressive stamping process adopts a symmetrical stamping method, that is, first the stamping of the first column of protrusions and pits located in the center of the plate is completed, and then the left and right stamping are performed alternately along the first column of protrusions as the symmetry axis until the stamping of the entire plate is completed. The other steps are the same as the specific implementation method one.

[0045] The beneficial effect of this embodiment is that by adopting the method of alternating symmetrical stamping from the center column to both sides, the material is deformed symmetrically within the entire plate surface, and the material flow and residual stress are symmetrically distributed about the protrusions and pits of the center column, thereby reducing the overall warping of the plate after stamping and improving the flatness and other forming accuracy of the parts.

Claims

1. A method for forming an elliptical concave and convex electrode plate for a large-scale water electrolysis hydrogen production electrolyzer, characterized in that: Here are the steps: Step 1, elliptical plate design: the outer contour of the plate is elliptical, the ratio of the length of the major axis a to the length of the minor axis b of the ellipse is in the range of 1 to 3, the protrusions on the front side of the plate corresponding to the pits on the back side or the pits on the front side of the plate corresponding to the protrusions on the back side are decomposed into several groups along the short axis direction of the plate, and each group of protrusions or pits is on a straight line; each group of protrusions and pits on the front side of the plate are equally spaced and alternately distributed along the long axis direction of the elliptical plate, that is, a row of protrusions is adjacent to a row of pits, the maximum number of protrusions in a single row in the short axis direction of the plate is N, and the maximum number of pits is N-1, and the effective working area of ​​a single plate is π×a×b as the design target, and the outer dimensions of the elliptical plate and the size and distribution of the protrusions and pits are determined; Step 2: Design and process the progressive stamping die: According to the outer dimensions of the elliptical plate and the distribution of protrusions and pits determined in step 1, the die is designed with the maximum number of protrusions N in a single row in the short axis direction of the elliptical plate; the upper die of the progressive stamping die is composed of N discrete punch units, an upper die discrete punch connecting plate, and an upper die pressing plate. The discrete punch units are connected to the upper die discrete punch connecting plate by threads and can move downward synchronously with the upper die discrete punch connecting plate. The N discrete punch units move along the upper die discrete punch. The head connecting plates are evenly spaced in the length direction, and the slab pressing plate is connected to the upper die discrete punch connecting plate through connecting bolts and nitrogen springs; the lower die of the progressive stamping die is composed of N-1 discrete punch units, a lower die discrete punch connecting plate, and a lower die pressing plate, and the structure and mutual connection relationship of the lower die are the same as those of the upper die; the length of the upper die pressing plate and the lower die pressing plate is 100 to 200 mm longer than the short axis length of the elliptical plate, and the width of the upper die pressing plate and the lower die pressing plate is 3 to 7 times the spacing of the straight lines where the adjacent groups of protrusions are located; Step 3, elliptical slab design: According to the elliptical plate designed in step 1, the shape and size of the initial slab are optimized and designed in combination with the theoretical calculation and simulation analysis of the forming process; the shape of the initial slab is elliptical, the length of its major axis is 1.01 to 1.10 times the length of the major axis of the elliptical plate to be formed, and the length of its minor axis is 1.01 to 1.05 times the length of the minor axis of the elliptical plate to be formed; Step 4: Stamping the first set of concave and convex features: According to the first group of protrusions N and the first group of pits N-1 designed on the elliptical plate in step 1, the corresponding number of discrete punch units are fixed to the upper die discrete punch connecting plate and the lower die discrete punch connecting plate, respectively, and the major axis and minor axis of the elliptical slab are adjusted and aligned with the width direction and the length direction of the progressive stamping die, respectively, and the slab is stamped; during the stamping and die closing process, the upper die pressing plate and the lower die pressing plate first contact with the elliptical slab to fix the slab, and a surface pressure of 3 to 50 MPa is provided in the peripheral adjacent area of ​​the first group of protrusions and pits to be stamped, and then the upper die discrete punch connecting plate and the lower die discrete punch connecting plate respectively drive the upper die discrete punch and the lower die discrete punch to stamp the slab to obtain a group of protrusions and pits; Step 5, progressive stamping of the elliptical plate blank: the elliptical plate blank is moved along the long axis direction in a stepping manner, and the stepping distance is the distance between adjacent rows of protrusions of the elliptical plate to be formed along the long axis direction; after each step of the elliptical plate blank, a group of protrusions and pits are formed by a progressive stamping die; before each stamping, the number of discrete punches of the upper die and the lower die is adjusted according to the number of protrusions and pits to be formed on the elliptical plate; the die closing stamping process is the same as step 4; Step 6. Removal of excess material from the outer periphery of the plate blank: According to the outer dimensions of the elliptical plate to be formed and the distribution of protrusions and pits, laser cutting or mechanical cutting is used to remove excess material from the outer periphery to obtain an elliptical plate product with shape, size and concave-convex features that meet the requirements.

2. The method for forming an elliptical concave-convex electrode plate for a large-scale water electrolysis hydrogen production electrolyzer according to claim 1, characterized in that: The nitrogen spring is replaced by polyurethane material.

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