Alkali water electrolysis hydrogen production electrolytic cell and gas-liquid transmission layer

Abstract

The utility model discloses an alkaline water electrolysis hydrogen production electrolytic bath and a gas-liquid transmission layer, and relates to the technical field of alkaline water electrolysis hydrogen production, the gas-liquid transmission layer is a three-dimensional porous metal net structure, and comprises a primary structure and a secondary structure; the primary structure is a polygonal planar net structure made of metal wires; and the second-level structure is three-dimensional processing on the basis of the plane net with the first-level structure. The gas-liquid transmission layer is applied to a cathode and / or an anode of an alkaline water electrolysis hydrogen production electrolytic cell. In order to solve the problem that the number of contact points between mastoid points and electrodes in a traditional alkaline water electrolytic tank is small, the three-dimensional porous gas-liquid transmission layer is beneficial for increasing the contact area between the electrodes and a bipolar plate, the contact resistance and ohmic polarization phenomena of the electrolytic tank are reduced, and therefore the running current density is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of hydrogen production by alkaline water electrolysis, and in particular to an electrolytic cell for hydrogen production by alkaline water electrolysis and a gas-liquid transmission layer. Background Art

[0002] In the wave of transformation of the global energy structure, hydrogen energy, as a clean and efficient form of energy, is gradually occupying an important position in the energy field. With the increasing awareness of environmental protection, hydrogen energy, as an important component of future energy, has broad development prospects. As one of the current mainstream hydrogen production technologies, the efficiency and stability of alkaline water electrolysis hydrogen production technology are directly related to the production cost and market competitiveness of hydrogen energy. However, alkaline water electrolysis hydrogen production technology currently faces many challenges, one of which is that there are many problems with the gas-liquid transmission layer in the traditional electrolyzer.

[0003] The gas-liquid transmission layer in the traditional alkaline water electrolysis hydrogen production electrolyzer often has problems such as low gas-liquid transmission efficiency, easy clogging, and easy damage. These problems directly lead to low electrolysis efficiency and rising hydrogen production costs, which are difficult to meet the needs of large-scale commercial applications. Specifically, traditional gas-liquid transmission layer materials are mostly porous materials, such as foam metals and porous ceramics. Although these materials have certain gas-liquid transmission capabilities, their single structure and limited surface area result in low gas-liquid transmission efficiency. In addition, these materials are susceptible to corrosion in alkaline environments, have a short service life, and need to be replaced frequently, further increasing the cost of hydrogen production. Utility Model Content

[0004] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is how to provide an efficient, durable, and structurally optimized gas-liquid transmission layer for improving the efficiency and stability of alkaline water electrolysis hydrogen production technology and reducing the cost of hydrogen production.

[0005] To achieve the above objectives, the first aspect of the utility model provides a gas-liquid transmission layer for an alkaline water electrolysis hydrogen production cell, wherein the gas-liquid transmission layer is a three-dimensional porous metal mesh structure, specifically a planar mesh structure that has been three-dimensionally processed.

[0006] Preferably, the porous metal mesh structure includes a primary structure and a secondary structure; the primary structure is a polygonal planar mesh structure made of metal wire; the secondary structure is a three-dimensional treatment based on the planar mesh with the primary structure. The porous gas-liquid transmission layer must have both a primary structure and a secondary structure. The primary structure is a structural feature in the X and Y axis directions. As the gas-liquid transmission layer of the alkaline water electrolyzer, it ensures the uniformity of gas-liquid distribution on the electrode surface and the function of rapid separation of liquid and foam; the secondary structure is a structural feature in the Z axis direction. Its function in supporting the electrode in the alkaline water electrolyzer is to

[0007] Preferably, the diameter of a single metal wire used in the primary structure ranges from 0.01 to 0.5 mm, the aperture size of the metal mesh ranges from 1.0 to 15 mm, and the number of metal wires contained in the woven mesh skeleton unit is 1 to 5.

[0008] Preferably, the diameter of a single metal wire used in the primary structure ranges from 0.1 to 0.25 mm, and the aperture size of the metal mesh ranges from 2 to 8 mm.

[0009] Preferably, the secondary structure is wavy, the height difference between the crest and the trough is in the range of 3.0 to 30 mm, and the ratio of the distance between two adjacent troughs to the height difference between the crest and the trough is in the range of 0.5 to 10.

[0010] Preferably, the secondary structure is wavy and undulating, and the height difference between the crest and the trough is in the range of 5 to 15 mm; the ratio of the distance between two adjacent troughs to the height difference between the crest and the trough is in the range of 1 to 3.

[0011] Preferably, the gas-liquid transmission layer contains nickel, and alloys containing elements such as Fe, Mn, Ti, Fe, C, Cr, Ta, W, Mo, and Nb are not excluded.

[0012] The second aspect of the utility model provides an alkaline water electrolysis hydrogen production electrolyzer, comprising the aforementioned gas-liquid transmission layer, wherein the gas-liquid transmission layer is applied to the cathode and / or anode of the alkaline water electrolysis hydrogen production electrolyzer; the number of the gas-liquid transmission layers placed is 1 to 10 layers.

[0013] Preferably, the number of gas-liquid transmission layers placed is 1 to 3.

[0014] The third aspect of the utility model provides an alkaline water electrolysis hydrogen production electrolyzer, comprising the aforementioned gas-liquid transmission layer, the alkaline water electrolysis hydrogen production electrolyzer also comprising a bipolar plate, an electrode and a diaphragm; the gas-liquid transmission layer is in contact with the bipolar plate and / or the electrode and / or the diaphragm.

[0015] Technical effects of the utility model:

[0016] (1) In order to address the problem of the small number of contact points between the nipple points and the electrodes in traditional alkaline water electrolyzers, the three-dimensional porous gas-liquid transport layer helps to increase the contact area between the electrodes and the bipolar plates, reduce the contact resistance and ohmic polarization phenomenon of the electrolyzer, and thus increase the operating current density.

[0017] (2) In order to solve the problem of uneven gas-liquid distribution caused by the small number of papillary points and the long distance between them in the traditional alkaline water electrolyzer, the three-dimensional porous gas-liquid transport layer has a rich void structure, which helps to improve the uniformity of gas-liquid distribution and current distribution.

[0018] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the primary structure of Example 1 of the utility model;

[0020] Figure 2 It is a schematic diagram of the structure of Embodiment 1 of the present utility model;

[0021] Figure 3 It is a structural schematic diagram of Embodiment 2 of the present utility model;

[0022] Figure 4 It is a structural schematic diagram of embodiment 3 of the present utility model. DETAILED DESCRIPTION

[0023] The following describes several preferred embodiments of the utility model with reference to the drawings in the specification, so that the technical content is clearer and easier to understand. The utility model can be embodied in many different forms of embodiments, and the protection scope of the utility model is not limited to the embodiments mentioned in the text.

[0024] In the drawings, components with the same structure are indicated by the same numerical labels, and components with similar structures or functions are indicated by similar numerical labels. The size and thickness of each component shown in the drawings are arbitrarily shown, and the utility model does not limit the size and thickness of each component. In order to make the illustration clearer, the thickness of the components is appropriately exaggerated in some places in the drawings.

[0025] The utility model develops an efficient, durable, and structurally optimized gas-liquid transmission layer, which becomes the key to the development of alkaline water electrolysis hydrogen production technology. The utility model proposes a three-dimensional porous metal mesh gas-liquid transmission layer and its application in an alkaline water electrolysis hydrogen production electrolyzer, aiming to solve the problems existing in the traditional gas-liquid transmission layer and improve the efficiency and stability of alkaline water electrolysis hydrogen production.

[0026] The utility model provides a gas-liquid transmission layer for an alkaline water electrolysis hydrogen production cell. The gas-liquid transmission layer is a three-dimensional porous metal mesh structure with efficient gas-liquid transmission capability and excellent durability, and can significantly improve the efficiency and stability of alkaline water electrolysis hydrogen production.

[0027] The porous metal mesh structure includes a primary structure and a secondary structure; the primary structure is a polygonal planar mesh structure made of metal wire; the secondary structure is a three-dimensional treatment based on the planar mesh with the primary structure. Specifically: the primary structure is a mesh structure with polygonal holes made of metal wire through weaving, crocheting and other processes; the secondary structure is a three-dimensional treatment based on the planar mesh with the primary structure, and the typical structure is a corrugated structure.

[0028] The diameter of a single metal wire used in the primary structure ranges from 0.01 to 0.5 mm, the aperture size of the metal mesh ranges from 1.0 to 15 mm, and the number of metal wires contained in the woven mesh skeleton unit is 1 to 5. Preferably, the diameter of a single metal wire used in the primary structure ranges from 0.1 to 0.25 mm, and the aperture size of the metal mesh ranges from 2 to 8 mm.

[0029] The secondary structure is wavy, the height difference between the crest and the trough is in the range of 3.0 to 30 mm, and the ratio of the distance between two adjacent troughs to the height difference between the crest and the trough is in the range of 0.5 to 10. Preferably, the secondary structure is wavy, the height difference between the crest and the trough is in the range of 5 to 15 mm, and the ratio of the distance between two adjacent troughs to the height difference between the crest and the trough is in the range of 1 to 3.

[0030] The porous gas-liquid transmission layer contains at least nickel, and alloys containing Fe, Mn, Ti, Fe, C, Cr, Ta, W, Mo, Nb and other elements are not excluded. By adding nickel to the metal mesh, not only can its corrosion resistance and durability be increased, but also its gas-liquid transmission efficiency can be further improved. This three-dimensional porous metal mesh gas-liquid transmission layer containing nickel can operate stably for a long time in an alkaline environment, reduce the replacement frequency, and reduce the cost of hydrogen production.

[0031] In addition to nickel wire, other metal materials with high conductivity and corrosion resistance can also be considered, such as stainless steel, titanium alloy, etc. These materials can ensure that the gas-liquid transmission layer can maintain stable performance under long-term operation.

[0032] The choice of weaving process has a great influence on the performance of the gas-liquid transmission layer. Advanced weaving technology, such as 3D printing technology, can be considered to produce three-dimensional porous metal mesh with complex structure.

[0033] The corrugated structure can increase the surface area of ​​the gas-liquid transmission layer and improve the gas-liquid contact area, thereby enhancing the gas-liquid transmission efficiency. When designing, it is necessary to consider parameters such as the height and wave distance of the corrugation, and determine the optimal structural design through simulation and optimization.

[0034] The utility model also provides an alkaline water electrolysis hydrogen production electrolyzer, in which a gas-liquid transmission layer is applied to the cathode and / or anode of the alkaline water electrolysis hydrogen production electrolyzer; the number of gas-liquid transmission layers placed is 1 to 10 layers, and preferably, the number of gas-liquid transmission layers placed is 1 to 3 layers.

[0035] The alkaline water electrolysis hydrogen production electrolyzer also includes a bipolar plate with the function of dividing a single chamber, an electrode with a catalytic reaction function and a diaphragm with the function of dividing anode and cathode; the gas-liquid transmission layer is in contact with the bipolar plate and / or the electrode and / or the diaphragm.

[0036] In the alkaline water electrolysis hydrogen production electrolyzer, the three-dimensional porous metal mesh gas-liquid transmission layer as part of the electrode can significantly improve the electrolysis efficiency. Its porous structure provides a large number of channels for the flow of gas and electrolyte, ensuring full contact and uniform distribution of gas and electrolyte. At the same time, the metal mesh has excellent electrical conductivity, which can reduce resistance and energy loss.

[0037] The utility model provides a method for preparing a three-dimensional porous metal mesh gas-liquid transmission layer. First, a metal wire of suitable diameter, such as nickel wire, is selected and made into a planar mesh structure of a primary structure through a weaving process. Then, the primary structure is three-dimensionally processed, such as using a stamping or pressing process to form a corrugated secondary structure. By adjusting parameters such as the height and wave distance of the corrugation, the performance of the gas-liquid transmission layer is optimized. Finally, the prepared gas-liquid transmission layer is cleaned, dried, and other post-processed to prepare for use in an electrolyzer for hydrogen production by alkaline water electrolysis.

[0038] The utility model provides an assembly method of an electrolyzer for producing hydrogen by electrolysis of alkaline water. First, prepare bipolar plates, electrodes, diaphragms, and a three-dimensional porous metal mesh gas-liquid transmission layer prepared according to the above embodiment. Then, assemble in the order of bipolar plates-electrodes-gas-liquid transmission layer-electrodes-diaphragms to form a single-section chamber. Repeat the above steps to assemble an electrolyzer with multiple chambers as needed. Finally, seal and inspect the assembled electrolyzer to ensure its normal operation.

[0039] Example 1

[0040] like Figure 1 and Figure 2 As shown, the three-dimensional space mesh is woven with a single layer of a single nickel wire with a wire diameter of 0.19 mm, a mesh diameter of 4 mm, a corrugation height of 7 mm, and a wave distance of 14 mm to obtain a single-layer three-dimensional space metal mesh.

[0041] Two porous gas-liquid transmission layers were stacked to assemble an alkaline water electrolyzer. The performance of the electrolyzer was tested at 80°C and 30wt% KOH solution, and the results showed that it was 6000A / m-2@2.0V, which was significantly improved compared to the performance of the electrolyzer with traditional structure (2500A / m-2@2.0V).

[0042] Example 2

[0043] like Figure 3 As shown, the three-dimensional space mesh is double-woven using a single 0.09mm diameter nickel wire, with a mesh diameter of 9mm, a corrugation height of 7mm, and a wave distance of 14mm to obtain a single-layer three-dimensional space metal mesh.

[0044] A single-piece porous gas-liquid transmission layer was stacked to assemble an alkaline water electrolyzer. The performance of the electrolyzer was tested in a 30wt% KOH solution at 80°C and was 4000A / m-2@2.0V. The performance was significantly improved compared to the performance of the electrolyzer with a traditional structure (2500A / m-2@2.0V). However, the performance of the electrolyzer was lower than that of the structure in Example 1 where the corrugation size was within the preferred range.

[0045] Example 3

[0046] like Figure 4 As shown, the three-dimensional space mesh is double-woven with two 0.25mm diameter nickel wires, with a mesh diameter of 6mm, a corrugation height of 8mm, and a wave distance of 20mm to obtain a single-layer three-dimensional space metal mesh.

[0047] The alkaline water electrolyzer was assembled by adopting the assembly method of plate-electrode-gas-liquid transmission layer-electrode-diaphragm. The performance of the electrolyzer was tested at 80°C and 30wt% KOH solution and was found to be 6000A / m-2@1.98V.

[0048] The preferred specific embodiments of the utility model are described in detail above. It should be understood that ordinary technology in the field can make many modifications and changes according to the concept of the utility model without creative work. Therefore, any technical solution that can be obtained by a technician in the technical field based on the concept of the utility model through logical analysis, reasoning or limited experiments on the basis of the existing technology should be within the scope of protection determined by the claims.

Claims

1. A gas-liquid transmission layer for an alkaline water electrolysis hydrogen production cell, characterized in that: The gas-liquid transmission layer is a three-dimensional porous metal mesh structure, which includes a primary structure and a secondary structure; the primary structure is a polygonal planar mesh structure made of metal wire; the secondary structure is a three-dimensional treatment on the basis of a planar mesh with a primary structure, and the gas-liquid transmission layer contains nickel elements.

2. The gas-liquid transmission layer according to claim 1, characterized in that: The wire diameter of a single metal wire used in the primary structure ranges from 0.01 to 0.5 mm, the aperture size of the metal mesh ranges from 1.0 to 15 mm, and the number of metal wires contained in a woven mesh skeleton unit ranges from 1 to 5.

3. The gas-liquid transmission layer according to claim 2, characterized in that: The diameter of a single metal wire used in the primary structure ranges from 0.1 to 0.25 mm, and the aperture size of the metal mesh ranges from 2 to 8 mm.

4. The gas-liquid transmission layer according to claim 1, characterized in that: The secondary structure is wavy, the height difference between the wave crest and the wave trough is in the range of 3.0 to 30 mm, and the ratio of the distance between two adjacent wave troughs to the height difference between the wave crest and the wave trough is in the range of 0.5 to 10.

5. The gas-liquid transmission layer according to claim 4, characterized in that: The secondary structure is particularly wavy, with the height difference between the wave crest and the wave trough ranging from 5 to 15 mm; the ratio of the distance between two adjacent wave troughs to the height difference between the wave crest and the wave trough ranging from 1 to 3.

6. An alkaline water electrolysis hydrogen production electrolyzer, comprising the gas-liquid transmission layer according to any one of claims 1 to 5, characterized in that: The gas-liquid transmission layer is applied to the cathode and / or anode of an electrolytic cell for producing hydrogen by electrolysis of alkaline water; the number of the gas-liquid transmission layers placed is 1 to 10.

7. The alkaline water electrolysis hydrogen production electrolytic cell according to claim 6, characterized in that: The number of the gas-liquid transmission layers is 1 to 3.

8. An alkaline water electrolysis hydrogen production electrolyzer, comprising the gas-liquid transmission layer according to any one of claims 1 to 5, characterized in that: The alkaline water electrolysis hydrogen production electrolyzer also includes a bipolar plate, an electrode and a diaphragm; the gas-liquid transmission layer is in contact with the bipolar plate and / or the electrode and / or the diaphragm.

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