Current collector, preparation method thereof and electrolytic bath

Abstract

The current collector comprises a bipolar plate, the bipolar plate comprises a disc and a circular ring, the circular ring surrounds the periphery of the disc, one or more alkali liquor inlets are formed in the first end of the circular ring, and one or more alkali liquor outlets are formed in the second end of the circular ring; the flow field material is arranged on the disc, and the flow field material comprises a plurality of expansion metal grid plates which are sequentially arranged at intervals. The manufacturing method comprises the steps that the diameter of a disc is obtained, and the length and the width of each expansion metal grid plate are determined according to the diameter of the disc, the preset number of the expansion metal grid plates and the preset distance between the adjacent expansion metal grid plates; according to the length and the width of each expansion metal grid plate and the edge contour of the corresponding disc, the raw material is cut to obtain a preset number of expansion metal grid plates; and according to the preset position of each expansion metal grid plate on the disc, the expansion metal grid plates are welded to the disc. According to the invention, the uniformity of the alkali liquor distributed on the bipolar plate can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of alkaline water electrolysis, and particularly to a current collector, a preparation method thereof, and an electrolytic cell. Background Art

[0002] Inside a water electrolyzer, under the action of an electric current, water molecules are converted into gaseous hydrogen (H2) and gaseous oxygen (O2). This process occurs in an electrolytic cell formed by stacking multiple components layer by layer. A diaphragm is provided between the cathode and anode of the electrolytic cell to effectively separate the hydrogen and oxygen generated during the electrolysis process. Current collectors are arranged on both sides of these electrodes, and the current collectors are located between the electrodes and the bipolar plates.

[0003] The entire electrolytic cell system is stacked between two distribution plates. The distribution plates not only provide the necessary power input and distribution for the electrolytic cell but also ensure the stable operation of the entire system. The end plates at both ends of the electrolytic cell separate the various components of the electrolytic cell. At the same time, a seal is provided between the end plates and the electrolytic cell components to ensure the clamping and sealing of the system and prevent leakage.

[0004] The functions of the current collector in the electrolytic cell are as follows: First, they greatly increase the contact area between the bipolar plate and the electrode, thereby improving the efficiency of current transmission; second, the current collector serves as a bridge for the current, ensuring that the current can be transmitted to the electrode smoothly and providing continuous power for the electrolysis of water; finally, they also guide the alkali solution to flow in the most uniform manner inside the electrolytic cell, from the alkali solution inlet to the alkali solution outlet, ensuring the high efficiency and stability of the entire electrolysis process. Therefore, the larger the contact area between the current collector and the electrode, the more current passes through the system, which in turn promotes the dissociation of more water molecules and can improve the overall performance of the electrolytic cell. In addition, in order to cope with the possible corrosion problems during the electrolysis process, the current collector is usually made of corrosion-resistant materials, or stainless steel materials that have been specially treated and coated with corrosion-resistant coatings to ensure the long-term stable operation of the electrolytic cell.

[0005] The types of current collectors in the electrolysis market are: (1) a flow field material with a complex structure is welded on the bipolar plate; (2) an embossed bipolar plate with unique textures. Although the designs are different, the core functions are the same, that is, by increasing the direct contact area and multiple contact points, optimizing current transmission and alkali solution flow. Compared with the embossed bipolar plate (2000 points / m 2 ), the flow field material shows significant advantages in increasing the current density and reducing the overall resistance of the battery stack due to its higher contact point density (about 3000 points / m 2 ).

[0006] It should be emphasized that the flow field material is an expanded metal plate, on which a diamond-shaped structure is designed, which can further optimize current collection and the flow path of the lye. After cutting and stretching, the expanded metal plate forms a regular mesh structure, and the size of the acute angles therein directly affects the resistance of lye flow and the distribution flow path. As the acute angle increases, the apparent density of the expanded metal plate decreases, the flow resistance decreases, and the lye flows in these holes along a specific distribution flow path, ensuring the efficiency and uniformity of the electrolysis process.

[0007] Reference Figure 7 , in the application scenario where an expanded metal plate is welded to the bipolar plate 2 as a current collector, the prior art is as follows: For the special requirements of a circular electrolytic cell, two raw materials 90 (rectangular expanded metal plates with relatively large sizes) are cut into two semi-circular structures 92, and the two semi-circular structures can fit with the disc of the circular bipolar plate. Subsequently, around the circular ring of the bipolar plate, welding techniques such as resistance welding or gas tungsten arc welding (TAG) are used to weld these two semi-circular structures to the bipolar plate. In actual application, in order to obtain the semi-circular structure, raw materials of a larger size are required, and a large amount of cut-off corner materials are generated, which not only causes waste of materials but also increases costs. In addition, as Figure 7 shown, the lye on the surface of this current collector flows from the lye inlet 211 along the V-axis direction to the lye outlet 212. This flow pattern seems efficient, but in fact, it leads to uneven distribution of lye on the surface of the bipolar plate. The non-uniformity of fluid flow on the surface of the electrolytic cell will reduce the performance of the entire system because not all surfaces of the electrolytic cell can be in the optimal working state. The specific impacts brought about by the non-uniformity of lye flow include: (1) Uneven temperature distribution on the surface of the electrolytic cell: The lye needs to be maintained at the optimal temperature before entering the electrolytic cell to promote the chemical reaction of water electrolysis. However, in the stagnant area and the area with insufficient supply, due to the lack of fluid renewal, the temperature in these areas will drop, resulting in a temperature difference on the surface of the electrolytic cell. The non-uniformity of temperature will reduce the reaction kinetics, thereby reducing the production amount of gaseous dihydrogen. (2) Uneven distribution of reactants: The reactants (OH - ) required for the water electrolysis reaction exist in the lye and are gradually consumed on the electrode surface. In the stagnant area, the lye cannot be renewed, resulting in insufficient supply of reactants, reduced reaction kinetics, and reduced production amount of dihydrogen. (3) Poor evacuation of products: The gaseous products generated by the chemical reaction need to be effectively collected. In the stagnant area, due to the non-renewal of the lye, the generated bubbles cannot be timely carried to the outlet channel, resulting in limited separation of the reaction products on the surface of the bipolar plate and a decrease in reaction kinetics.

[0008] To solve at least one of the above technical problems, the present invention proposes a current collector, a preparation method thereof, and an electrolytic cell. Summary of the Invention

[0009] The object of the present invention is to provide a current collector, a preparation method thereof and an electrolytic cell, which can improve the uniformity of the distribution of the lye on the bipolar plate.

[0010] The object of the present invention is achieved by the following technical solutions:

[0011] In the first aspect, the present invention provides a current collector, comprising:

[0012] A bipolar plate, the bipolar plate includes a disc and a ring, the ring surrounds the circumference of the disc, one or more lye inlets are provided at the first end of the ring, and one or more lye outlets are provided at the second end of the ring;

[0013] A flow field material, the flow field material is arranged on the disc, and the flow field material includes a plurality of expanded metal grid plates arranged at intervals in sequence.

[0014] Further, the number of the expanded metal grid plates is 3 to 6;

[0015] The distance between adjacent expanded metal grid plates is less than or equal to half of the diameter of the bipolar plate.

[0016] Further, there is a preferred lye flow path between the lye inlet and the lye outlet.

[0017] The wide side of the expanded metal grid plate is arc-shaped and matches the edge contour of the disc;

[0018] The width of the expanded metal grid plate is less than or equal to the diameter of the disc.

[0019] Further, the preferred lye flow path extends along the V axis or forms an angle of ±45° with the V axis, and the V axis is parallel to the bipolar plate;

[0020] The expanded metal grid plate rotates around the T axis (-180°, 180°], and the T axis is perpendicular to the bipolar plate.

[0021] Further, the expanded metal grid plate includes a plurality of hole structures;

[0022] The short axis length of the hole structure is 10 to 20 mm, and the long axis of the hole structure is 20 to 30 mm.

[0023] In the second aspect, the present invention provides a manufacturing method of a current collector, and the manufacturing method obtains the above-mentioned current collector;

[0024] The manufacturing method includes the following steps:

[0025] Obtain a plurality of expanded metal grid plates and rotate the expanded metal grid plates;

[0026] Weld the expanded metal grid plate to the disc of the bipolar plate to form the flow field material.

[0027] Further, the obtaining of multiple expanded metal grid plates and the rotation of the expanded metal grid plates include:

[0028] Obtain multiple raw materials, lay the multiple raw materials on the disc, after rotating the raw materials, cut the raw materials according to the edge contour of the disc to obtain the rotated expanded metal grid plates;

[0029] Further, obtain multiple expanded metal grid plates, lay the multiple expanded metal grid plates on the disc, and rotate the expanded metal grid plates.

[0030] Further, the central axis of the flow field material is parallel to the preferred caustic solution flow path;

[0031] Further, the central axis of the flow field material is not parallel to the preferred caustic solution flow path.

[0032] In a third aspect, the present invention provides a method for manufacturing a current collector, and the manufacturing method obtains the current collector as described above;

[0033] The manufacturing method includes the following steps:

[0034] Obtain the diameter of the disc, and determine the length and width of each expanded metal grid plate according to the diameter of the disc, the preset number of expanded metal grid plates, and the preset spacing between adjacent expanded metal grid plates;

[0035] Cut the raw materials according to the length and width of each expanded metal grid plate and the edge contour of the corresponding disc to obtain the preset number of expanded metal grid plates;

[0036] Weld the expanded metal grid plates to the disc according to the preset positions of each expanded metal grid plate on the disc.

[0037] In a fourth aspect, the present invention provides an electrolytic cell, and the electrolytic cell includes the current collector as described above or the current collector obtained by the manufacturing method as described above.

[0038] Further, the current collector is provided at the anode of the electrolytic cell;

[0039] Further, the current collector is provided at the cathode of the electrolytic cell.

[0040] Further, the rotation direction of the expanded metal grid plate of the cathode around the T axis is opposite to the rotation direction of the expanded metal grid plate of the anode around the T axis.

[0041] Further, the rotation direction of the expanded metal grid plate of the cathode around the T axis is the same as the rotation direction of the expanded metal grid plate of the anode around the T axis;

[0042] Further, the rotation direction of the expanded metal grid plate of the cathode around the V-axis is opposite to that of the expanded metal grid plate of the anode around the V-axis;

[0043] Further, the rotation direction of the expanded metal grid plate of the cathode around the V-axis is the same as that of the expanded metal grid plate of the anode around the V-axis.

[0044] Further, the rotation angle of the expanded metal grid plate of the cathode around the T-axis is the same as that of the expanded metal grid plate of the anode around the T-axis;

[0045] Further, the rotation angle of the expanded metal grid plate of the cathode around the T-axis is different from that of the expanded metal grid plate of the anode (around the T-axis;

[0046] Further, the rotation angle of the expanded metal grid plate of the cathode around the V-axis is the same as that of the expanded metal grid plate of the anode around the V-axis;

[0047] Further, the rotation angle of the expanded metal grid plate of the cathode around the V-axis is different from that of the expanded metal grid plate of the anode around the V-axis.

[0048] Compared with the prior art, the beneficial effects of the present invention at least include:

[0049] By arranging a plurality of expanded metal grid plates arranged at intervals in the current collector of the present invention, the dimensional requirements for raw materials can be reduced.

[0050] The size of the raw materials used in the manufacturing method of the present invention is much smaller than the dimensional requirements for raw materials in the prior art, significantly reducing the difficulty of obtaining raw materials; and the scrap generated by the manufacturing method of the present invention is much less than that generated by the prior art, significantly saving the production cost.

[0051] By using expanded metal grid plates with different rotation angles on the cathode and anode of the electrolytic cell of the present invention, the distribution of the lye on the bipolar plate can be made more uniform, thereby improving the efficiency and performance of the electrolytic cell. Description of the Drawings

[0052] Figure 1 is a schematic structural diagram of an embodiment of the present invention.

[0053] Figure 2 is a schematic structural diagram of a preparation method of a current collector of an embodiment of the present invention.

[0054] Figure 3 is a schematic structural diagram of the cathode and anode of an electrolytic cell of an embodiment of the present invention.

[0055] Figure 4 It is another structural schematic diagram of the current collector in the embodiment of the present invention.

[0056] Figure 5 It is a structural schematic diagram of the expanded metal mesh plate in the embodiment of the present invention.

[0057] Figure 6 It is another structural schematic diagram of the expanded metal mesh plate in the embodiment of the present invention.

[0058] Figure 7 It is a structural schematic diagram of a preparation method of a current collector in the prior art.

[0059] In the figure: 10, hole structure; 101, concave area; 1011, concave point; 102, convex area; 1021, convex point; 103, minor axis; 104, major axis; 110, second hole; 120, first hole; 130, third hole; 2, bipolar plate; 21, circular ring; 211, lye inlet; 212, lye outlet; 22, disc; 6, electrolytic cell; 61, cathode; 62, anode; 81, preferred lye flow path; 82, central axis; 83, stagnant area; 9, flow field material; 90, raw material; 901, first material plate; 902, second material plate; 903, third material plate; 904, fourth material plate; 91, scrap; 92, semi-circular structure; 93, additional scrap; 94, expanded metal mesh plate; 941, first mesh plate; 942, second mesh plate; 943, third mesh plate; 944, fourth mesh plate; 951, width; 952, length; 96, spacing. Detailed implementation manners

[0060] Now, example embodiments will be described more comprehensively with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present invention will be more complete and comprehensive, and the concept of the example embodiments will be fully conveyed to those skilled in the art. Like reference numerals in the figures denote the same or similar structures, and thus their repeated description will be omitted.

[0061] In the present invention, the words expressing position and direction are described with reference to the accompanying drawings as examples, but can be changed according to needs, and all changes made are included in the protection scope of the present invention.

[0062] In order to reduce the manufacturing cost and improve the flow uniformity of the lye, so as to improve the efficiency and performance of the electrolytic cell, the present invention introduces a current collector and its preparation method and an electrolytic cell.

[0063] The current collector of the present invention includes: a bipolar plate 2 and a flow field material 9.

[0064] ReferenceFigure 1 The bipolar plate 2 of the present invention includes a disc 22 and a ring 21. The ring 21 surrounds the circumference of the disc 22. One or more lye inlets 211 are provided at the first end of the ring 21, and one or more lye outlets 212 are provided at the second end of the ring 21. There is a preferred lye flow path between the lye inlet 211 and the lye outlet 212. The preferred lye flow path extends along the V-axis direction or forms an angle of ±45° with the V-axis, and the V-axis is parallel to the bipolar plate 2.

[0065] During application, at least two lye inlets 211 are arranged in parallel on the ring 21, and two lye outlets 212 are arranged in parallel. The lye flows directly from the lye inlet 211 to the lye outlet 212 along the V-axis direction, that is, the flow path of the lye is the preferred lye flow path 81.

[0066] The flow field material 9 of the present invention is arranged on the disc 22. There are several welding methods available for welding the flow field material 9 around the ring 21 of the bipolar plate 2, such as resistance welding or gas tungsten arc welding (TAG). The size of the flow field material 9 can be slightly larger than the size of the disc 22. For example, the diameter of the flow field material 9 is slightly larger than the diameter of the disc 22 of the bipolar plate 2. In this case, the flow field material 9 partially covers the ring 21 of the bipolar plate 2, but does not block the lye inlets 211 and the lye outlets 212, and makes the welding points close to the periphery of the ring 21 to ensure a stable structure and unobstructed fluid channels. Further, in order to reduce material waste, the diameter of the flow field material 9 can also be equal to or slightly smaller than the diameter of the disc 22. When the flow field material 9 is a non-circular structure, the length of the flow field material 9 is greater than or equal to the diameter of the disc 22, and the width 951 of the flow field material 9 is less than or equal to the diameter of the disc 22.

[0067] Reference Figure 1 The flow field material 9 of the present invention includes a plurality of expanded metal grid plates 94 arranged at intervals in sequence. Specifically, the width 951 of the expanded metal grid plate 94 is less than or equal to the diameter of the disc 22, and the wide side of the expanded metal grid plate 94 is arc-shaped and matches the edge contour of the disc 22. During application, the number of the expanded metal grid plates 94 is 3 to 6. Reference Figure 2 Compared with Figure 7 the prior art, the present invention has a larger number of expanded metal grid plates 94 provided in the current collector. Therefore, the requirements for the size of the raw material 90 are low, reducing the difficulty of obtaining the raw material 90. At the same time, during the manufacturing process, since small-sized raw materials 90 are used, the generated scraps 91 are relatively few, reducing waste and capable of saving 6% to 20% of the raw material 90 cost.

[0068] In some embodiments, the present invention can overlap adjacent expanded metal grid plates 94 through a welding process, that is, the spacing 96 between adjacent expanded metal grid plates 94 is less than or equal to 0. In some other embodiments, a certain spacing is formed between adjacent expanded metal grid plates 94 of the present invention, that is, the spacing 96 between adjacent expanded metal grid plates 94 is greater than 0. During application, the spacing 96 between adjacent expanded metal grid plates 94 can be equal or unequal, but is less than the width 951 of the expanded metal grid plate 94 and is usually less than or equal to half of the diameter of the bipolar plate 2. In actual application, the spacing 96 between adjacent expanded metal grid plates 94 is greater than 0 and less than or equal to 150 mm.

[0069] To meet the requirements of different scenarios, engineers can set the width 951 of each expanded metal grid plate 94 of the present invention to be equal or unequal, and can also set the length 952 of each expanded metal grid plate 94 to be equal or unequal. To reduce production costs, the length 952 and width 951 of each expanded metal grid plate 94 can be set to be unequal. Alternatively, the expanded metal grid plate 94 is set into two groups of symmetric expanded metal grid plates 94, and each group has at least two expanded metal grid plates 94.

[0070] In some embodiments, the extension direction of the long side or short side of the expanded metal grid plate 94 is along the V-axis direction.

[0071] To improve the uniformity of the caustic solution flow, the expanded metal grid plate 94 of the present invention includes a plurality of hole structures 10. The hole structures 10 can be diamond-shaped or polygonal, but the hole structures 10 include a short diagonal (SWM) and a long diagonal (LWM). The short diagonal is the shorter diagonal length 952 from the center of one pitch point of a hole structure 10 to the center of an adjacent pitch point, reflecting the dimension in the direction of the short axis 103 of the hole structure 10. The long diagonal is the longer diagonal length 952 from the center of one pitch point of a hole structure 10 to the center of another pitch point of a hole structure 10, reflecting the dimension in the direction of the long axis 104 of the hole structure 10. In application, the length 952 of the short axis 103 of the hole structure 10 is 10 - 20 mm, and the long axis 104 of the hole structure 10 is 20 - 30 mm. In addition, each hole structure 10 has four corners - two opposite acute angles and two opposite obtuse angles. In application, each hole structure 10 includes: a raised area 102 forming an obtuse angle and a corresponding sunken area 101 forming another obtuse angle. The lowest point of the sunken area 101 is the concave point 1011, and the highest point of the raised area 102 is the convex point 1021. The concave point 1011 of one hole is connected to the convex point 1021 of another hole structure 10, and the convex point 1021 of one hole is connected to the concave point 1011 of another hole structure 10. In application, the connection line between the convex point 1021 and the concave point 1011 is along the V-axis direction. Since the flow field formed by the expanded metal grid plate 94 is not completely symmetric, the raised area 102 forms a right-angle surface, the sunken area 101 forms an oblique-angle surface, and the hole structure 10 makes the distribution flow path of the flow field form an acute angle, so that when the caustic solution flows through the straight surface or the inclined surface in different directions, it will be subject to different hydrodynamic effects, and then flow along any direction on the surface of the disc 22, thus realizing the uniform distribution of the caustic solution flow within 360°. In actual application, this three-dimensional structure with half (section) bulging upward and the other half (strand) sunken has the following functions:

[0072] (1) Increase surface contact: The raised sections effectively increase the contact area between the bipolar plate 2 and the electrode, thereby improving the efficiency and stability of current transmission. (2) Current transmission and feeding: These sections serve as bridges for current, ensuring that current can be evenly and efficiently transmitted to the electrode, providing the necessary power for the electrolysis process. (3) Guide the flow of caustic solution: The raised sections also play a role in blocking the flow of caustic solution in a specific direction, forcing the caustic solution to advance along a specific distribution flow path. Such as Figure 5 and Figure 6As shown, when the lye passes through the expanded metal plate, the advancing distribution flow path is as follows: starting from entering the first hole 120, after the lye is blocked by the bump 1021, it flows out through the left and right strands of the hole structure 10 (i.e., the raised area 102 of another hole), and then continues to enter another hole, namely the second hole 110. The lye is blocked by the bump 1021 again and flows out through the raised area 102 of the next hole, and then continues to enter the next hole, namely the third hole 130, and so on until it flows out of the entire system. It can be seen that the flow path of the lye is closely related to the acute angle of the hole, and the lye will be guided to flow in two specific directions corresponding to the acute angle.

[0073] (2) Refer to Figure 7 , the central axis 82 of the flow field material 9 formed by the two semi-circular structures 92 overlaps with the preferred lye flow path 81. The lye from the left and right lye inlets 211 flows from the lye inlets 211 to the lye outlet 212 in a left-right separated flow direction through a direct manner (preferred lye flow path 81) and passes through the surface of the disc 22 of the bipolar plate 2. Therefore, no new lye from the lye inlet 211 enters the stagnant areas 83 adjacent to both sides of the preferred lye flow path on the surface of the bipolar plate 2. The non-uniformity of the fluid flow on the surface of the electrolytic cell will reduce the overall performance of the system. In fact, if the fluid distribution on the surface of the bipolar plate 2 is non-uniform, it will also cause non-uniformity in other components (such as electrodes) of the electrolytic cell.

[0074] To further improve the uniformity of the lye flow, the expanded metal grid plate 94 of the present invention rotates around the T axis within (-180°, 180°], for example: -170°, -160°, -150°, -140°, -130°, -120°, -110°, -100°, -90°, -80°, -70°, -60°, -50°, -40°, -30°, -20°, -10°, 0°, 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80°, 90°, 100°, 110°, 120°, 130°, 140°, 150°, 160°, 170° or 180°. During application, the T axis is perpendicular to the bipolar plate 2. In actual application, in order to meet the requirements of different scenarios, engineers can rotate each expanded metal grid plate 94 by the same or different angles, so that the lye flow direction reaches the originally inaccessible stagnant areas 83, covering most of the surface of the disc 22, significantly reducing the stagnant areas 83 of the fluid, thereby ensuring a more uniform distribution of the lye on the entire surface of the electrolytic cell 6, and further improving the fluid mixing efficiency and the uniformity of the electrolysis reaction in the entire electrolytic cell 6, and optimizing the operating conditions of the electrolytic cell 6.

[0075] When the preferred flow path 81 of the alkali solution in the electrolytic cell 6 coincides with the central axis 82, the stagnant region 83 of the fluid often causes the accumulation of the products (H2, O2) of the water electrolysis reaction, thereby affecting the effective utilization of the active sites of the electrodes. In the present invention, since the flow rate of the stagnant region 83 of the fluid is significantly increased, these gaseous products can be more smoothly dragged away from the surface of the bipolar plate 2 and discharged smoothly through the alkali solution outlet 212, increasing the collection area of the electrolysis reaction. In addition, since the alkali solution contains the reactant OH - ions necessary for the water electrolysis reaction, the present invention optimizes the dispersion degree of the alkali solution on the entire surface of the electrolytic cell 6, that is, realizes the uniform distribution of OH - ions, not only enhances the contact tightness of the active substances on the electrodes, but also pushes the reaction kinetics to the optimal state by continuously supplying OH - ions, thereby further improving the generation efficiency and output of gaseous substances (H2, O2).

[0076] In some preferred embodiments, in order to ensure the smooth progress of the electrolysis process, the present invention is also provided with a heat exchanger to control the temperature of the alkali solution so that the alkali solution is maintained within a preset temperature range, such as 80-90 °C, to ensure the high efficiency and stability of the electrolysis reaction. At the same time, by improving the distribution of the alkali solution on the surface of the disc 22, the uniform supply and transfer of heat of the entire electrolytic cell 6 are realized, which not only promotes the water electrolysis reaction to proceed under the optimal kinetic conditions, but also ensures that the water electrolysis reaction can be efficiently carried out at every place on the surface of the disc 22.

[0077] The manufacturing method of the current collector of the present invention may include: step SS21-step SS22.

[0078] Step SS21: Obtain multiple expanded metal mesh plates 94 and rotate the expanded metal mesh plates 94.

[0079] In application, the implementation of step SS21 includes two methods:

[0080] Method 1: Obtain multiple raw materials 90, lay the multiple raw materials 90 on the disc 22, after rotating the raw materials 90, cut the raw materials 90 according to the edge contour of the disc 22 to obtain the rotated expanded metal mesh plates 94.

[0081] Method 2: Obtain multiple expanded metal mesh plates 94, lay the multiple expanded metal mesh plates 94 on the disc 22, and rotate the expanded metal mesh plates 94.

[0082] Step SS22: Weld the expanded metal mesh plates 94 on the disc 22 of the bipolar plate 2 to form the flow field material 9.

[0083] During application, the central axis of the flow field material 9 can be parallel to the preferred lye flow path or non-parallel to the preferred lye flow path.

[0084] In addition, the manufacturing method of the current collector of the present invention includes steps SS21 - SS23.

[0085] Step SS21: Obtain the diameter of the disc 22, and determine the length 952 and width 951 of each expanded metal grid plate 94 according to the diameter of the disc 22, the preset quantity of the expanded metal grid plates 94, and the preset spacing 96 between adjacent expanded metal grid plates 94.

[0086] During application, the preset quantity is greater than 2.

[0087] Step SS22: Cut the raw material 90 according to the length 952 and width 951 of each expanded metal grid plate 94 and the edge contour of the corresponding disc 22 to obtain the preset quantity of expanded metal grid plates 94.

[0088] During application, the size of the raw material 90 used in the manufacturing method of the present invention is much smaller than the size requirement of the raw material 90 in the prior art, significantly reducing the difficulty of obtaining the raw material 90; and the scrap 91 generated by the manufacturing method of the present invention is much less than the scrap 91 generated by the prior art, significantly saving the production cost.

[0089] Step SS23: Weld the expanded metal grid plates 94 to the disc 22 according to the preset positions of each expanded metal grid plate 94 on the disc 22.

[0090] During application, the expanded metal grid plates 94 cannot block the lye inlet and the lye outlet 212.

[0091] The electrolytic cell 6 of the present invention includes an anode 62 and a cathode 61, and a current collector is provided on the anode 62 and / or the cathode 61. And the anode 62 and the cathode 61 can be symmetrically arranged or asymmetrically arranged. When the anode 62 and the cathode 61 are symmetrically arranged: the current collectors of the anode 62 and the cathode 61 are both the above-mentioned current collectors or the current collectors obtained by the above-mentioned manufacturing method. When the anode 62 and the cathode 61 are asymmetrically arranged: the current collector on one side (the anode 62 or the cathode 61) adopts the above-mentioned current collector or the current collector obtained by the above-mentioned manufacturing method, and the current collector on the other side adopts a traditional current collector. For example, the current collector of the cathode 61 uses the above-mentioned current collector, while the current collector of the anode 62 uses a woven mesh current collector.

[0092] Reference Figure 3, To improve the electrolysis efficiency of the electrolytic cell 6, the rotational direction of the expanded metal grid plate 94 of the cathode 61 of the present invention around the T-axis is the same as or opposite to the rotational direction of the expanded metal grid plate 94 of the anode 62 around the T-axis, so that the alkali solution is evenly distributed on the entire surface of the electrolytic cell 6, which not only reduces the fluid stagnant area 83, but also enhances fluid mixing, thereby improving the mass transfer efficiency during the electrolysis process. Due to the uniformity of the alkali solution distribution and the improvement of fluid dynamics, the current distribution in the electrolytic cell 6 becomes more uniform, reducing the phenomena of local overheating and uneven electrolysis, and further increasing the generation rate of gaseous products (such as H2 and O2), thus improving the overall electrolysis efficiency of the electrolytic cell 6.

[0093] In addition, by optimizing the flow of the alkali solution, the erosion and corrosion on the electrode surface are reduced, and the service life of the electrode is prolonged.

[0094] During application, the rotational direction of the expanded metal grid plate 94 of the cathode 61 around the V-axis is the same as or opposite to the rotational direction of the expanded metal grid 94 of the anode 62 around the V-axis. The rotational angle of the expanded metal grid plate 94 of the cathode 61 around the V-axis is the same as or different from the rotational angle of the expanded metal grid plate 94 of the anode 62 around the V-axis.

[0095] During actual application, the expanded metal grid plate 94 of the cathode 61 and / or the anode 62 rotates around the V-axis within (-180°, 180°], and preferably, the expanded metal grid plate 94 of the cathode 61 and / or the anode 62 rotates around the V-axis within (-45°, 45°].

[0096] In some embodiments, the rotational angle of the expanded metal grid plate 94 of the cathode 61 around the V-axis is +10°, and the rotational angle of the expanded metal grid plate 94 of the anode 62 around the V-axis is -10°.

[0097] In some embodiments, the rotational angle of the expanded metal grid plate 94 of the cathode 61 around the V-axis is -15°, and the rotational angle of the expanded metal grid plate 94 of the anode 62 around the V-axis is +15°.

[0098] In some embodiments, the rotational angle of the expanded metal grid plate 94 of the cathode 61 around the V-axis is -15°, and the rotational angle of the expanded metal grid plate 94 of the anode 62 around the V-axis is +45°.

[0099] In some embodiments, the rotational angle of the expanded metal grid plate 94 of the cathode 61 around the V-axis is +45°, and the rotational angle of the expanded metal grid plate 94 of the anode 62 around the V-axis is -45°.

[0100] In some embodiments, the rotational angle of the expanded metal grid plate 94 of the cathode 61 around the V-axis is 0°, and the rotational angle of the expanded metal grid plate 94 of the anode 62 around the V-axis is +45°.

[0101] To meet the requirements of different scenarios, engineers can set the number, width 951, length 952, and spacing 96 of the expanded metal grid plates 94 of the cathode 61 and anode 62 of the present invention to be the same or different.

[0102] To make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, Examples 1-6 are used to further elaborate on the present invention. It should be understood that the specific examples described herein are only used to explain the present invention and are not used to limit the present invention.

[0103] In the electrolytic cells 6 of Examples 1-6, both the anode 62 and the cathode 61 are provided with current collectors.

[0104] Reference Figure 4 , the radius of the disc 22 in Examples 1-6 is 1795 mm, and the preset number of expanded metal grid plates 94 is 4.

[0105] Select 4 suitable raw materials 90, namely the first material plate 901, the second material plate 902, the third material plate 903, and the fourth material plate 904 in sequence. According to the preset installation positions of each raw material 90, cut the 4 raw materials 90, remove the scraps 91, and obtain 4 expanded metal grid plates 94, namely the first grid plate 941, the second grid plate 942, the third grid plate 943, and the fourth grid plate 944 in sequence. The first grid plate 941, the second grid plate 942, the third grid plate 943, and the fourth grid plate 944 are arranged along the L axis in sequence.

[0106] Compared with the prior art, the size requirements for the raw materials 90 in Examples 1-4 of the present invention are smaller, and less scrap 91 is generated. Relative to the present application, the prior art will generate 6% - 20% additional scraps 93. It can be seen that the present application can at least reduce the material cost by 6% - 20%.

[0107] The expanded metal grid plate 94 includes an A side and a B side. When the A side contacts the disc 22, the state of the expanded metal grid plate 94 is recorded as A. When the B side contacts the disc 22, the state of the expanded metal grid plate 94 is recorded as B.

[0108] In Example 1, the states of the first grid plate 941 and the fourth grid plate 944 of both the anode 62 and the cathode 61 are A, and the states of the second grid plate 942 and the third grid plate 943 of both the anode 62 and the cathode 61 are B. That is, in Example 1, both the anode 62 and the cathode 61 are ABBA, and preferably the lye flow path 81 and the central axis 82 are both arranged along the V axis.

[0109] In Example 2, the states of the first grid plate 941 and the third grid plate 943 of the anode 62 and the cathode 61 are both A, and the states of the second grid plate 942 and the fourth grid plate 944 of the anode 62 and the cathode 61 are both B. That is, in Example 2, both the anode 62 and the cathode 61 are ABAB, and preferably the alkali liquid flow path 81 and the central axis 82 are both arranged along the V axis.

[0110] In Example 3, the first grid plate 941 and the fourth grid plate 944 of the anode 62 both rotate -10° around the V axis, and their states are both A. The second grid plate 942 and the third grid plate 943 of the anode 62 both rotate 170° around the V axis, and their states are both B. The first grid plate 941 and the fourth grid plate 944 of the cathode 61 both rotate 10° around the V axis, and their states are both A. The second grid plate 942 and the third grid plate 943 of the cathode 61 both rotate -170° around the V axis, and their states are both B. That is, in Example 3, both the anode 62 and the cathode 61 are ABBA, and preferably the alkali liquid flow path 81 intersects with the central axis 82.

[0111] In Example 4, the first grid plate 941 and the fourth grid plate 944 of the cathode 61 both rotate -45° around the V axis, and their states are both A. The second grid plate 942 and the fourth grid plate 944 of the cathode 61 both rotate 135° around the V axis, and their states are both B. The first grid plate 941 and the fourth grid plate 944 of the anode 62 both rotate 45° around the V axis, and their states are both A. The second grid plate 942 and the fourth grid plate 944 of the anode 62 both rotate -135° around the V axis, and their states are both B. That is, in Example 4, both the anode 62 and the cathode 61 are ABBA, and preferably the alkali liquid flow path 81 intersects with the central axis 82.

[0112] In Example 5, the first grid plate 941 and the fourth grid plate 944 of the anode 62 both rotate -10° around the T axis, and their states are both A. The second grid plate 942 and the third grid plate 943 of the anode 62 both rotate 170° around the T axis, and their states are both B. The first grid plate 941 and the fourth grid plate 944 of the cathode 61 both rotate 10° around the T axis, and their states are both A. The second grid plate 942 and the third grid plate 943 of the cathode 61 both rotate -170° around the T axis, and their states are both B. That is, in Example 5, both the anode 62 and the cathode 61 are ABBA, and preferably the alkali liquid flow path 81 intersects with the central axis 82.

[0113] In Example 6, both the first grid plate 941 and the fourth grid plate 944 of the cathode 61 rotate -45° around the T axis, and their states are both A. Both the second grid plate 942 and the fourth grid plate 944 of the cathode 61 rotate 135° around the T axis, and their states are both B. For the anode 62, both the first grid plate 941 and the fourth grid plate 944 rotate 45° around the T axis, and their states are both A. Both the second grid plate 942 and the fourth grid plate 944 of the anode 62 rotate -135° around the T axis, and their states are both B. That is, in Example 6, both the anode 62 and the cathode 61 are ABBA, and preferably the lye flow path 81 intersects with the central axis 82.

[0114] Examples 1-6 can all improve the uniformity of the lye distribution on the disk 22.

[0115] Examples 1-6 can all generate hydrogen and oxygen. Moreover, the yield and production efficiency of Example 4 are greater than those of Example 3, the yield and production efficiency of Example 3 are greater than those of Example 2, and the yield and production efficiency of Example 3 are greater than those of Example 1.

[0116] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limitations on the present invention. Without departing from the principles and purposes of the present invention, those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the invention, and all these changes should fall within the protection scope of the claims of the present invention.

Claims

1. A current collector, characterized in that: include: A bipolar plate (2), the bipolar plate (2) comprising a disc (22) and a ring (21), the ring (21) surrounding the circumference of the disc (22), one or more alkali solution inlets (211) being provided at a first end of the ring (21), and one or more alkali solution outlets (212) being provided at a second end of the ring (21); A flow field material (9), wherein the flow field material (9) is disposed on the disc (22), and the flow field material (9) comprises a plurality of expanded metal mesh plates (94) arranged in sequence and spaced apart from each other.

2. The current collector according to claim 1, characterized in that: The number of the expanded metal mesh plates (94) is 3 to 6; The spacing (96) between adjacent expanded metal mesh plates (94) is less than or equal to half the diameter of the bipolar plate (2).

3. The current collector according to claim 1, characterized in that: A preferred alkali solution flow path (81) is provided between the alkali solution inlet (211) and the alkali solution outlet (212). The connecting line is along the V axis; 4. The current collector according to claim 1, characterized in that: The wide side of the expanded metal mesh plate (94) is arc-shaped and matches the edge profile of the disk (22); The length (952) of the expanded metal mesh plate (94) is less than or equal to the diameter of the disk (22).

5. The current collector according to claim 4, characterized in that: The preferred alkali solution flow path (81) extends along the V-axis direction; The expanded metal mesh plate (94) is rotated about a V axis (-180°, 180°], and the V axis is parallel to the bipolar plate (2).

6. The current collector according to claim 5, characterized in that: The expanded metal mesh plate (94) is rotated around the V axis (-45°, 45°].

7. The current collector according to claim 1, characterized in that: The expanded metal mesh plate (94) comprises a plurality of hole structures (10); the short axis (103) of the hole structure (10) is 10 to 20 mm, and the long axis (104) of the hole structure (10) is 20 to 30 mm.

8. A method for manufacturing a current collector, characterized in that: The manufacturing method obtains the current collector according to any one of claims 1 to 7; The production method comprises the following steps: Obtaining a plurality of expanded metal mesh plates (94), and rotating the expanded metal mesh plates (94); An expanded metal mesh plate (94) is welded to the disc (22) of the bipolar plate (2) to form a flow field material (9).

9. The method for manufacturing a current collector according to claim 8, characterized in that: The step of obtaining a plurality of expanded metal mesh plates (94) and rotating the expanded metal mesh plates (94) comprises: Obtaining a plurality of raw materials (90), and laying the plurality of raw materials (90) on a disc (22), rotating the raw materials (90), and then cutting the raw materials (90) according to the edge profile of the disc (22) to obtain a rotated expanded metal mesh plate (94); Alternatively, obtain a plurality of expanded metal mesh plates (94), lay the plurality of expanded metal mesh plates (94) on a disc (22), and rotate the expanded metal mesh plates (94).

10. The method for manufacturing a current collector according to claim 8, characterized in that: The central axis of the flow field material (9) is parallel to the preferred alkali solution flow path; Alternatively, the central axis of the flow field material (9) is not parallel to the preferred alkali solution flow path.

11. A method for manufacturing a current collector, characterized in that: The manufacturing method obtains the current collector according to any one of claims 1 to 7; The production method comprises the following steps: Obtaining the diameter of the disk (22), and determining the length (952) and width (951) of each expanded metal mesh plate (94) according to the diameter of the disk (22), the preset number of expanded metal mesh plates (94), and the preset spacing (96) between adjacent expanded metal mesh plates (94); Cutting the raw material (90) according to the length (952) and width (951) of each expanded metal mesh plate (94) and the edge profile of the corresponding disk (22) to obtain a preset number of expanded metal mesh plates (94); According to the preset position of each expanded metal mesh plate (94) on the disc (22), the expanded metal mesh plate (94) is welded to the disc (22).

12. An electrolytic cell, characterized in that: The electrolytic cell (6) comprises the current collector according to any one of claims 1 to 7, or the current collector obtained by the manufacturing method according to any one of claims 8 to 10, or the current collector obtained by the manufacturing method according to claim 11.

13. The electrolytic cell according to claim 12, characterized in that The anode (62) of the electrolytic cell (6) is provided with the current collector; And / or, the cathode (61) of the electrolytic cell (6) is provided with the current collector.

14. The electrolytic cell according to claim 13, characterized in that The rotation direction of the expanded metal mesh plate (94) of the cathode (61) around the V axis is opposite to the rotation direction of the expanded metal mesh plate (94) of the anode (62) around the V axis; Alternatively, the rotation direction of the expanded metal mesh plate (94) of the cathode (61) around the V axis is the same as the rotation direction of the expanded metal mesh plate (94) of the anode (62) around the V axis.

15. The electrolytic cell according to claim 13, characterized in that The rotation angle of the expanded metal mesh plate (94) of the cathode (61) around the V axis is the same as the rotation angle of the expanded metal mesh plate (94) of the anode (62) around the V axis; Alternatively, the rotation angle of the expanded metal mesh plate (94) of the cathode (61) around the V axis is different from the rotation angle of the expanded metal mesh plate (94) of the anode (62) around the V axis.

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