Electrolysis plate for hydrogen production and method for manufacturing the electrolysis plate

Abstract

The present invention relates to an electrolysis plate (1), in particular an electrolysis plate (1) for hydrogen production, a method for manufacturing the electrolysis plate (1) and the use of the electrolysis plate (1), the electrolysis plate (1) comprising at least one embossed metal plate (2), the metal plate (2) being shaped to define flow channels and having individual embossed elements (10, 24) in the shape of droplets.

Description

Technical Field

[0001] The present invention relates to an electrolysis plate suitable for use in an electrolysis apparatus for producing hydrogen. Further, the present invention relates to a method for manufacturing the electrolysis plate.

Background Art

[0002] An apparatus for producing hydrogen using electrolysis is described, for example, in European Patent No. 2507410. The described electrolysis plant must be adapted to operate using water taken from a salt water source, a steam water source, or a fresh water source. In that case, the water is supplied to a carrier gas stream so that at least a portion of the water is incorporated into the carrier gas stream in a vaporized form. The carrier gas stream introduced in this way is ultimately supplied to the electrolysis apparatus.

[0003] Various electrochemical systems described in International Publication No. 2019 / 121947 and International Publication No. 2020 / 030644 each have an arrangement consisting of a plurality of separator plates that define fluid chambers. The described electrochemical system may be a fuel cell or an electrolyzer.

[0004] European Patent Application Publication No. 3725916 discloses an electrolysis plate provided for use in an apparatus for generating hydrogen, the electrolysis plate having an opening for a gas to penetrate, and the edge of the opening being coated with a non-conductive material.

[0005] According to European Patent Application Publication No. 3575442, a bipolar electrolyzer intended for producing hydrogen is known. The anode and / or cathode of the cell is formed as a porous electrode. The membrane of the bipolar cell is a porous membrane made of an inorganic material. The apparatus based on European Patent Application Publication No. 3575442 needs to be adapted to alkaline electrolysis.

[0006] A method for integrating a hydrogen electrolysis system into a more comprehensive system in which an energy flow and / or a medium flow occurs is described, for example, in WO 2014 / 144556 and German Utility Model No. 20 2011 102525. SUMMARY OF THE INVENTION PROBLEM TO BE SOLVED BY THE INVENTION

[0007] The problem of the present invention is to further develop the production of electrolysis plates as compared with the prior art, and in this case, the manufacturing technology aspects should be considered as well as the fluid technology aspects. MEANS FOR SOLVING THE PROBLEM

[0008] This problem is solved according to the invention, in particular, by an electrolysis plate according to claim 1, which is adapted for hydrogen electrolysis. Similarly, this problem is solved by a method for manufacturing an electrolysis plate according to claim 10. The embodiments and advantages of the present invention described below in connection with the manufacturing method also apply in accordance with the meaning of the present invention to the present apparatus, i.e., the electrolysis plate, and an electrolysis plant comprising a plurality of such metal plates.

[0009] The electrolysis plate includes at least one embossed metal plate, which is formed to define a flow path and has individual embossed elements in the shape of droplets.

[0010] The droplet-shaped, i.e., substantially streamline-shaped, embossed elements in the plan view of the plate surface can be reasonably produced by a forming method and substantially contribute to the mechanical stability of the electrolysis plate. This is particularly important in the case of large-scale electrolysis plants for producing hydrogen. Similarly, the electrolysis plate can be used in a fuel cell or a redox flow cell.

[0011] According to various possible embodiments, each droplet-shaped embossing element has a point of maximum embossing depth, and the distance from that point to one end of the droplet shape is at least 1.2 times, and at most 2.4 times, the distance to the other end of the droplet shape. Instead of a localized region where the maximum embossing depth is given, in this case, there may also be a planar region where the embossing depth is continuously maximum. In this case, the relationships shown between the various distances will be measured longitudinally, on the one hand, between the tip of the embossing element of the droplet shape and the location of the maximum width of the embossing element, and on the other hand, between this location of the maximum width and the rear end of the embossing element. Considering the embossing element as a falling droplet, the so-called rear end of the droplet will be on the upper side. Overall, in any case, a three-dimensional, streamlined design is imparted to the embossing element. Inside the embossing structure of the electrolytic plate, all the embossing elements may have a uniform form. Similarly, embodiments of electrolytic plates with various embossing elements inside the embossing structure are feasible.

[0012] Thereby, in particular, appropriate streamlines are enabled, especially at the location where the fluid is introduced into or discharged from the active field. If there are various embossing elements formed on the electrolytic plate, these embossing elements may be geometrically similar, i.e., they may only be scaled up or down with the same dimensional ratio. Similarly, the embossing elements of the same electrolytic plate may basically have different characteristics, especially the ratio of length to width. In both cases, the contour of the embossing element starting from the end of the embossing element having a shorter distance to the point of the maximum protrusion, i.e., the so-called front end, may, for example, describe a parabola. An acute-angled structure is avoided inside the embossing element, as well as at the transition between the embossing element and the flat region of the electrolytic plate surrounding the entire embossing element, in advantageous embodiments not only in terms of fluid technology but also in terms of manufacturing technology. The embossing elements may form a row-column arrangement, with a small overlap between the embossing elements provided in at least one direction. In particular, the rows in which the embossing elements are arranged may overlap, or the columns formed in contact with the embossing elements for each column may overlap. In this way, an embossing structure can be provided in which the electrolytic plate has particular resistance to bending loads.

[0013] Regarding the alignment of the individual embossing elements of the droplet shape on the electrolysis plate, there are numerous possible deformation patterns. In the simplest case, all the embossing elements are aligned in the same direction, typically in the desired flow direction of the fluid. Similarly, a deformation pattern is achievable where the embossing elements are aligned alternately in each row, i.e., aligned in the longitudinal direction of the metal plate from which the electrolysis plate being manufactured is derived or in the opposite direction. With this deformation pattern, a particularly dense packing of the embossing elements can be achieved on a given plane, which results in a particularly large total surface area of the electrolysis plate compared to its bottom surface. Alternatively, the embossing elements may be inclined with respect to the longitudinal direction of the electrolysis plate. In particular, a pattern of alternately inclined individual elements, at least slightly elongated, may be formed by the embossing elements in each row. In particular, a distinct liquid flow effect can be achieved by such a pattern where the inclined embossing elements in a row fit into the adjacent row of alternately inclined embossing elements in a zipper-like manner.

[0014] According to a possible development that can be combined with all the geometric features of the electrolysis plate already described, one part of the embossing element is formed as a protrusion, while the other part of the embossing element is formed as a recess formed in the same way. Thereby, the same fluid-technical conditions can be established on both sides of the electrolysis plate. The individually measured embossing depth of the embossing elements for each side of the metal plate, i.e., for example, the upper and lower sides in the case of a horizontal structure, is, in a general embodiment, at least three times the thickness of the metal plate extended to the non-embossed area of the metal plate, but not more than ten times. Thereby, on the one hand, a surface that is highly structured, i.e., embossed, with respect to the outer dimensions of the electrolysis plate is provided, and on the other hand, a significant reduction in material strength in the forming area of the electrolysis plate is avoided.

[0015] Inside the manufactured electrochemical cell, a gas diffusion coating may be present on the embossed structure of the electrolytic plate formed by the embossing elements. Regardless of the arrangement in which the individual embossing elements are separated from each other, in that case, the gas diffusion coating actually lies flat on the embossed structure, and by the droplet-shaped embodiment, the desired flow is brought about in the direction of the gas diffusion coating throughout the embossed region. Regarding the form and arrangement of the embossing elements to be adapted to individual cases, in particular, the dynamic pressure is important, and the structure of the electrochemical cell is determined by that dynamic pressure. The electrolytic plate can, in particular, provide the bipolar plate of the electrochemical device.

[0016] The electrolytic plate can be reasonably manufactured by forming a metal plate, and inside the metal plate, an embossed structure is produced in the form of individual embossing elements in the shape of droplets separated from each other. This forming can be carried out, in particular, in a continuous process, for example, a rolling process.

[0017] Hereinafter, a plurality of embodiments of the present invention will be described in more detail with reference to the drawings.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

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Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0019] The following description relates to all embodiments unless otherwise stated differently. Parts and contours that correspond to each other or act equivalently in principle are given the same reference numerals in all the figures.

[0020] In all embodiments, the electrolytic plate 1 is formed as a formed metal plate 2 having a frame-shaped connection region 3 and a rectangular forming region 4 located within this region 3. The formed metal plate 2 is a steel plate that may be coated.

[0021] On the surface of the forming region 4, a medium, in particular an acidic or alkaline aqueous liquid, flows substantially in the longitudinal direction LR of the formed metal plate 2. The width of the formed metal plate 2 is represented by B2, and the height of the formed metal plate 2 is represented by H2. The forming region 4 has a width B4 and a height H4.

[0022] Inside the connection region 3, there are an opening 6 that allows the passage of the medium and a hole 5 that is smaller compared to the circular opening 6. By inserting a clamp anchor (not shown) through the hole 5, a number of electrolytic plates 1 can be mechanically interconnected inside the stack.

[0023] In the shaping area 4, a shaping process in the form of an embossing pattern 8 is formed. The shaping process formed as the embossing pattern 8 has, on the one hand, a function in fluid technology and, on the other hand, enhances the mechanical stability of the electrolytic plate 1 compared to a flat metal plate. The embossing pattern 8 is in the form of individual embossing elements 10, 24 that form rows 7 and columns 9. In that case, each row 7 is arranged transversely to the longitudinal direction LR of the shaping area 4, while the columns 9 are aligned in the longitudinal direction LR. The gaseous or liquid medium flowing through the shaping area 4 flows substantially in the longitudinal direction LR. In FIGS. 2 and 4, the longitudinal direction LR coincides with the x-direction.

[0024] The embossing elements 10, 24 are formed in a droplet shape and contribute significantly to the fact that the fluid medium accumulates and flows predominantly within the active field formed by the embossing pattern 8 and flows without generating cavitation. The gas diffusion coating placed on the shaped metal plate 2 is indicated at 11.

[0025] The elongation of each embossing element 10, 24 in the longitudinal direction LR is represented by B 10 In the transverse direction, an elongation H 10 of the embossing elements 10, 24 is provided. The embossing depth of the embossing elements 10, 24 is represented by H8, regardless of whether they are protruding embossing elements 10 or recessed embossing elements 24. The embossing depth H8 is at least three times the metal plate thickness d of the shaped metal plate 2, and the metal plate thickness d needs to be measured within the flat area indicated at 14 of the metal plate 2.

[0026] The mold pressing elements 10, 24 have a streamlined shape, also referred to as a droplet shape. The tip of each mold pressing element 10, 24 is indicated by 12, and the rear end portion of the mold pressing elements 10, 24 is indicated by 13. The front region 21 of the mold pressing elements 10, 24, which emanates from the tip 12, extends into the rear region 22 that extends to the end 13. The point of the maximum mold pressing depth indicated by 17 is at the boundary between the front region 21 and the rear region 22. Depending on the embodiment, a uniform mold pressing depth may be imparted over a relatively extended region, and thus, generally, the region 17 of the maximum mold pressing depth is mentioned. The length of the front region 21 is denoted by L 21 and the length of the region 22 is denoted by L 22 . The lengths L 21 , L 22 of the regions 21, 22 together correspond to the elongation B 10 of the mold pressing elements 10, 24. The length L 21 of the front region 21 measured between the tip 12 and the dot-like region 17 is 30 - 45% of the total elongation B 10 of the mold pressing elements 10, 24 in the longitudinal direction LR.

[0027] From the tip 12, a front contour 18 that is at least partially parabolic or approximates the form of a parabola emanates. The side portions 19 within the rear region 22, which are part of the outer contour of the mold pressing elements 10, 24, merge into a rear contour 20 that curves towards the end 13. A finite radius of curvature is given at each point of the rear contour 20, and the situation where the mold pressing elements 10, 24 break off at the tip is avoided in all cases.

[0028] The row-column arrangement of the mold pressing elements 10, 24 gives an overlapping region 15 between rows 7 and an overlapping region 16 between columns 9. The width of the overlapping region 15 is represented by U 15 and the width of the overlapping region 16 is represented by U 16 . In the examples described in FIGS. 1 - 7, all the mold pressing elements 10 are equally aligned.

[0029] The embodiment described in FIG. 8 is distinguished from the embodiments described in FIGS. 1 to 7 in that the embossing elements 10 in the first column 9 are aligned in the first direction, and the embossing elements 10 in the next column 9 are aligned in the opposite direction. As a result, the alternately aligned embossing elements 10 are in adjacent columns 9. This alignment of the embossing elements 10 has the advantage that a particularly large part of the forming area 4 can be filled by the embossing elements 10, i.e., the flat area 14 inside the embossing pattern 8 is minimized. This is particularly useful for the mechanical stability of the formed metal plate 2, while at the same time providing favorable fluid-technical properties and maximizing the entire surface of the electrolytic plate 1, which is also an advantage with regard to the electrical properties.

[0030] In the embodiment described in FIG. 9, all the embossing elements 10 are inclined with respect to the longitudinal direction LR such that a pattern 23 is formed in which the embossing elements 10 are alternately in inclined positions for each column as a whole. The advantage of this configuration is, in particular, that a particularly large contact surface is occupied with respect to the gas diffusion coating.

[0031] The embodiment described in FIG. 10 is different from the embodiment described in FIG. 1 in that the rows 7 are staggered, and within each row 7, the embossing elements 10 are formed as protrusions, while in the next row 7, the embossing elements 24 are recesses. The shapes of the embossing elements 10, 24 protruding in opposite directions from the flat area 14 are identical. Also in the case of FIG. 10, an overlap is provided both between adjacent rows 7 and between adjacent columns 9.

Explanation of Reference Numerals

[0032] 1 Electrolytic plate 2 Formed metal plate 3 Connection area 4 Forming area 5 Hole 6 Opening 7 Row 8 Embossing pattern 9 Column 10 Embossing element, protrusion 11 Gas diffusion coating Tip of the 12 - type pressing element Rear end of the 13 - type pressing element Flat area of the 14 - shaped metal plate Overlap area between rows Overlap area between columns Area of the maximum pressing depth Parabolic front contour Side part Curved rear contour Front area Rear area Pattern where the pressing element is in an inclined position Pressing element, indentation Width of the B2 - shaped metal plate Width of the B4 - forming area B 10 Longitudinal extension of the pressing element d - Metal plate thickness Height of the H2 - shaped metal plate Height of the H4 - forming area Pressing depth of the H8 - pressing pattern H 10 Lateral extension of the pressing element L 21 Length of the front area L 22 Length of the rear area LR - Longitudinal direction U 15 Width of the overlap area between rows U 16 Width of the overlap area between columns

Claims

1. A plate (1) adapted for hydrogen electrolysis, comprising at least one embossed metal plate (2), wherein the embossed metal plate (2) is formed to define flow channels and has a flat region (14) and individual embossed elements (10, 24) in the shape of droplets formed within the flat region (14). On both sides of the plate (1), so that the same fluid conditions are obtained, with respect to the flat region (14) of the metal plate (2), one part of the embossed element (10) is formed as a protrusion, and the other part of the embossed element (24) is formed as a recess having the same shape as the protrusion, characterized in that the plate (1).

2. Each of the drop-shaped embossing elements (10, 24) has a maximum embossing depth area (17) formed as a localized area, and the distance (L) of the maximum embossing depth area (17) to one end (13) of the drop-shaped embossing element (10, 24) is ２２ ) is the distance (L) to the other end (12) of the embossing element (10, 24). ２１ 2. The plate (1) according to claim 1, characterized in that the thickness is 1.2 to 2.4 times the thickness of the plate (1).

3. Each of the droplet-shaped embossing elements (10, 24) has a location of the maximum width of the embossing element (10, 24) at only one point, and the distance (L ２２ ) from the location of the maximum width of the embossing element (10, 24) to one end (13) of the embossing element (10, 24) having a droplet shape is ２１ 1.2 times to 2.4 times the distance (L ) to the other end (12) of the embossing element (10, 24), and the plate (1) according to claim 1 is characterized in that.

4. Said distance (L) shorter than to said region (17) of the maximum protrusion ２１ The profile (18) of said profiling element (10, 24) issuing from the end (12) of said profiling element (10, 24) having ) is parabolic, the plate (1) according to claim 2 or 3.

5. The plate (1) according to any one of claims 1 to 4, characterized in that the row-column arrangement of the embossed elements (10, 24) provides for little overlap between the embossed elements (10, 24) in at least one direction.

6. The plate (1) according to claim 5, characterized in that the embossed elements (10, 24) are arranged in an alternating direction for each column, that is, they are aligned in the longitudinal direction (LR) of the metal plate (2) and in the opposite direction, respectively.

7. The plate (1) according to claim 5 or 6, characterized in that the embossed elements (10, 24) are arranged in an alternatingly inclined pattern (23) for each column.

8. The embossing depth (H ８ ) of the embossing element (10, 24) is at least three times the thickness (d) of the metal plate (2), and the plate (1) according to any one of claims 1 to 7 is characterized thereby.

9. Use of the plate (1) according to any one of claims 1 to 8 in an electrolysis device for producing hydrogen.

10. A method for manufacturing a plate (1) adapted for hydrogen electrolysis, comprising forming a metal plate (2), wherein within the metal plate (2), in a continuous process, an embossing pattern (8) is produced in the form of individual embossed elements (10, 24) in the shape of droplets spaced apart from each other within the flat region (14) of the metal plate (2). On both sides of the plate (1), so that the same fluid conditions are obtained, with respect to the flat region (14) of the metal plate (2), one part of the embossed element (10) is formed as a protrusion, and the other part of the embossed element (24) is formed as a recess having the same shape as the protrusion, method.

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