Partition plate for bipolar electrode water electrolysis hydrogen production device and manufacturing method

Abstract

The invention discloses a partition plate for a bipolar electrode water electrolysis hydrogen production device and a manufacturing method. The partition plate comprises nickel foil and foamed nickel layers attached to the two side faces of the nickel foil in the assembling process. Meanwhile, during assembly, an insulating film is fixed on the foamed nickel layer in a stacking manner; the manufacturing method comprises the following steps: preparing slurry containing the active material, the binder and the conductive agent through ball milling; foamed nickel is placed in a funnel, the surface of the foamed nickel is evenly coated with the slurry, and the slurry is sucked into micropores of the foamed nickel under negative pressure suction of a pump; after drying, the foamed nickel loaded with the active material is embedded into a customized steel mold, and the steel mold is fed into a hydraulic machine to be pressed to obtain a foamed nickel layer; in the assembling process, two foam nickel layers are taken, and a nickel foil is clamped between the two foam nickel layers to form a partition plate. By using the solid ECPBs without using a diaphragm, the purpose of saving the cost can be achieved, and meanwhile, the resistance caused by the diaphragm can be reduced, and the electrode performance can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of water electrolysis hydrogen production devices, and in particular relates to a separator for a bipolar electrode water electrolysis hydrogen production device and a manufacturing method thereof. Background Art

[0002] Hydrogen energy is a recognized clean energy with advantages such as light density, good thermal conductivity and good combustion performance. Hydrogen energy is a secondary energy source. It is produced by using other energy sources through certain methods, unlike coal, oil and natural gas which can be mined directly. Commonly used industrial hydrogen production methods include natural gas steam reforming hydrogen production, methanol steam conversion hydrogen production, water electrolysis hydrogen production, and hydrocarbon oxidation reforming hydrogen production.

[0003] The electrolysis of water to produce hydrogen is relatively simple to operate, the technology is relatively mature, and the hydrogen production process is pollution-free, making it an important means to achieve large-scale production of hydrogen. In the current hydrogen production industry, alkaline water electrolysis technology has early industrialization, mature technology, and low equipment cost, so alkaline water electrolysis occupies a dominant position in the water electrolysis industry.

[0004] Conventional water electrolysis hydrogen production requires the use of ion exchange membranes to separate hydrogen and oxygen. Ion exchange membranes are expensive, which increases the cost of electrolytic hydrogen production. At the same time, the use of membranes increases the internal resistance of the system and improves energy consumption. The membrane also faces problems such as hydrogen purity and safety caused by the mutual penetration of hydrogen and oxygen. Based on this, CN114108015B discloses a filter-pressed membraneless water electrolyzer, which realizes hydrogen production and oxygen production in separate chambers by using a partition assembly composed of bipolar electrode plates arranged on the partition body, and prepares high-purity hydrogen without the presence of any membrane, replacing the traditional ion exchange membrane, reducing costs, and solving the safety problems caused by the mutual penetration of hydrogen and oxygen faced by the traditional water electrolysis hydrogen production technology. It can be seen that how to prepare the partition assembly is not disclosed in the prior art. Summary of the invention

[0005] The object of the present invention is to provide a separator for a bipolar electrode water electrolysis hydrogen production device and a manufacturing method thereof, so as to solve the problem that the prior art does not disclose how to prepare the separator assembly.

[0006] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0007] The invention discloses a separator for a bipolar electrode water electrolysis hydrogen production device, comprising a nickel foil and a foam nickel layer attached to both sides of the nickel foil during assembly; an insulating film is fixed on one side of the foam nickel layer in a stacked manner during assembly.

[0008] Furthermore, the thickness of the nickel foil is 0.2 mm, the thickness of the nickel foam layer is 4 mm; and the insulating film is a porous PE film or a non-woven fabric.

[0009] A method for preparing a separator comprises the following steps:

[0010] Step 1, preparing a slurry containing an active material, a binder and a conductive agent by ball milling;

[0011] Step 2, placing a 27 cm diameter and 4 mm thick nickel foam in a 28 cm diameter funnel, evenly coating the slurry on the surface of the nickel foam, and sucking the slurry into the micropores of the nickel foam under the negative pressure suction of the pump;

[0012] Step 3: After drying, the nickel foam loaded with active materials is embedded in a customized steel mold, sent into a hydraulic press, and pressed under a high pressure of 700 tons to obtain the nickel foam layer;

[0013] Step 4: During assembly, two nickel foam layers are taken and a nickel foil is sandwiched between the two to form the partition, and the partition has a sandwich structure.

[0014] Furthermore, the slurry preparation in step 1 includes: dissolving a binder in an organic solvent to form a precursor solution, adding an active material and a conductive agent to the precursor solution, stirring, and then adding a dispersant, and continuing to stir to obtain a uniform and fluid slurry.

[0015] Furthermore, the preparation of the active material comprises the following steps:

[0016] Step 01, dissolving cobalt nitrate hexahydrate, nickel nitrate hexahydrate, and sodium dodecyl sulfate by stirring with a solvent to obtain a solution referred to as solution A;

[0017] Step 02, taking urea and a solvent and mixing them into a solution, which is recorded as solution B;

[0018] Step 03, mixing the obtained solution A and solution B, reacting at 90°C-110°C for 4h, cooling to room temperature, and discharging to obtain a sample solution;

[0019] Step 04, filter out the sample from the sample solution, wash both sides with NMP detergent for 10 times without drying to obtain the active material;

[0020] The solvent is prepared by mixing water and ethanol in a volume ratio of 1:1.

[0021] Furthermore, the usage ratio of the cobalt nitrate hexahydrate to the nickel nitrate hexahydrate is 1:4.

[0022] Furthermore, in step 1, the binder is polyvinylidene fluoride, the conductive agent is acetylene black powder, and the dispersant is polyvinyl pyrrolidone.

[0023] Furthermore, in the step 3, the nickel foam loaded with active materials is embedded in a customized steel mold, and after being sent into a hydraulic press, the pressure is controlled to increase by 50 tons per minute until it reaches 700 tons. After maintaining the pressure for 5 minutes, the pressure is released to obtain the nickel foam layer.

[0024] Furthermore, the amount ratio of the active material, the conductive agent, the binder and the dispersant is 15-18:1-2:1-2:1-2.

[0025] The present invention has the following beneficial effects:

[0026] The present invention uses a solid electron-proton buffer medium and does not require a diaphragm, thereby achieving the purpose of cost saving. At the same time, it can also reduce the resistance caused by the diaphragm and improve electrode performance. A bipolar electrode water electrolysis hydrogen production device assembled on the basis of the diaphragm of the present invention can achieve spatial separation and temporal synchronization of hydrogen production and oxygen production, which will greatly improve the efficiency of water electrolysis. At the same time, based on the diaphragm structure of the electron-proton buffer medium, the membrane permeation problem of gas is fundamentally solved in practice, HER and OER are spatially decoupled, and channels through which hydrogen and oxygen gases can permeate each other are eliminated, thereby ensuring high purity of gas under high pressure and renewable energy power supply, obtaining multiple benefits of high-pressure water electrolysis, and being more adaptable to the power fluctuation of wind and solar power plants.

[0027] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0029] Figure 1 This is a schematic diagram of the partition structure of the present invention;

[0030] Figure 2 The flowchart of the preparation method of the separator of the present invention is as follows;

[0031] Figure 3 The figure is a flow chart of the preparation method of the active material of the present invention. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In the description of the present invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inside", "all around" and the like indicating orientation or positional relationship are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the components or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0034] See also Figure 1 As shown, the present invention is a separator for a bipolar electrode water electrolysis hydrogen production device, comprising a nickel foil 1 with a thickness of 0.2 mm, and a nickel foam layer 2 with a thickness of 4 mm attached to both sides of the nickel foil 1 during assembly; at the same time, during assembly, an insulating film made of a non-woven fabric is fixed in a laminated manner on the nickel foam layer 2;

[0035] Of course, in the present invention, the insulating film 3 may also be a porous PE film or other porous plastic films.

[0036] like Figure 2 The present invention also provides a method for preparing a separator, comprising the following steps:

[0037] Step 1: Dissolve the binder in an organic solvent to form a precursor solution, add the active material and the conductive agent to the precursor solution, stir, then add the dispersant, and prepare a slurry containing the active material, the binder and the conductive agent by ball milling, and the slurry is uniform and has fluidity.

[0038] Step 2, placing a 27 cm diameter and 4 mm thick nickel foam in a 28 cm diameter funnel, evenly coating the slurry on the surface of the nickel foam, and sucking the slurry into the micropores of the nickel foam under the negative pressure suction of the pump;

[0039] Step 3: After drying, the nickel foam loaded with active materials is embedded in a customized steel mold, and then put into a hydraulic press, and the pressure is increased by 50 tons per minute until it reaches 700 tons. After maintaining the pressure for 5 minutes, the pressure is released to obtain the nickel foam layer 2;

[0040] Step 4: During assembly, two nickel foam layers 2 are taken and a nickel foil 1 is sandwiched between the two to form a partition, and the partition has a sandwich structure.

[0041] It can be known that in the present application, that is, in step 1, the binder is polyvinylidene fluoride, the conductive agent is acetylene black powder, and the dispersant is polyvinyl pyrrolidone.

[0042] The dosage ratio of active material, conductive agent, binder and dispersant is 8:1:1:1.

[0043] Of course, when Ni(OH)2 powder is selected as the active material or Ni(OH)2 containing water is obtained as in Example 2 below.

[0044] Specifically, Figure 3 As shown, a method for preparing an active material is provided, which specifically comprises:

[0045] Step 01, dissolving cobalt nitrate hexahydrate, nickel nitrate hexahydrate, and sodium dodecyl sulfate by stirring with a solvent to obtain a solution referred to as solution A;

[0046] Step 02, taking urea and a solvent and mixing them into a solution, which is recorded as solution B;

[0047] Step 03, mixing the obtained solution A and solution B, reacting at 90°C-110°C for 4h, cooling to room temperature, and discharging to obtain a sample solution;

[0048] Step 04, filter out the sample from the sample solution, wash both sides with NMP detergent for 10 times without drying to obtain the active material;

[0049] The solvent is prepared by mixing water and ethanol in a volume ratio of 1:1.

[0050] Specifically, considering the actual product recovery rate and other issues, the present application provides the following four groups of formulation examples, which are carried out in a 50L reactor, as shown in the following table:

[0051]

[0052] In the above, the solution system volume is the mixed volume of solution B and solution A.

[0053] At the same time, when formula 4 is selected for preparation, the preparation method of the active material is specifically as follows:

[0054] a) 485 g of cobalt nitrate hexahydrate, 1937 g of nickel nitrate hexahydrate, and 37.5 g of SDS were mixed with a solvent (water and ethanol in a volume ratio of 1:1) to form a 10 L solution, which was recorded as solution A;

[0055] b) 1800 g of urea was mixed with the solvent to form 5 L of solution, which was recorded as solution B;

[0056] c) reacting at 90-110°C for 4 hours, cooling to room temperature and discharging;

[0057] d) Filter out the sample from the sample solution and wash it with NMP detergent without drying.

[0058] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0059] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A separator for a bipolar electrode water electrolysis hydrogen production device, characterized in that: It comprises a nickel foil (1) and a foam nickel layer (2) which is attached to two side surfaces of the nickel foil (1) during assembly; during assembly, an insulating film is fixed on one side of the foam nickel layer (2) in a stacked manner.

2. A separator for a bipolar electrode water electrolysis hydrogen production device according to claim 1, characterized in that: The thickness of the nickel foil (1) is 0.2 mm, and the thickness of the nickel foam layer (2) is 4 mm.

3. A separator for a bipolar electrode water electrolysis hydrogen production device according to claim 1, characterized in that: The insulating film (3) is a porous PE film or a non-woven fabric.

4. A method for preparing a separator for a bipolar electrode water electrolysis hydrogen production device as claimed in any one of claims 1 to 3, characterized in that: The steps include: Step 1, preparing a slurry containing an active material, a binder and a conductive agent by ball milling; Step 2, placing a 27 cm diameter and 4 mm thick nickel foam in a 28 cm diameter funnel, evenly coating the slurry on the surface of the nickel foam, and sucking the slurry into the micropores of the nickel foam under the negative pressure suction of the pump; Step 3: After drying, the nickel foam loaded with active materials is embedded in a customized steel mold, sent into a hydraulic press, and pressed under a high pressure of 700 tons to obtain the nickel foam layer (2); Step 4: During assembly, two nickel foam layers (2) are taken and a nickel foil (1) is sandwiched between the two to form the partition, and the partition is in a sandwich structure.

5. The method for preparing a separator for a bipolar electrode water electrolysis hydrogen production device according to claim 4, characterized in that: The slurry preparation in step 1 includes: dissolving a binder in an organic solvent to form a precursor solution, adding an active material and a conductive agent to the precursor solution, stirring, and then adding a dispersant, and continuing to stir to obtain a uniform and fluid slurry.

6. The method for preparing a separator for a bipolar electrode water electrolysis hydrogen production device according to claim 5, characterized in that: The preparation of the active material comprises the following steps: Step 01, stirring and dissolving cobalt nitrate hexahydrate, nickel nitrate hexahydrate, and sodium dodecyl sulfate with a solvent to obtain a solution referred to as solution A; Step 02, taking urea and a solvent and mixing them into a solution, which is recorded as solution B; Step 03, mixing the obtained solution A and solution B, reacting at 90°C-110°C for 4h, cooling to room temperature, and discharging to obtain a sample solution; Step 04, filter out the sample from the sample solution, wash both sides with NMP detergent for 10 times without drying to obtain the active material; The solvent is prepared by mixing water and ethanol in a volume ratio of 1:

1.

7. The method for preparing a separator for a bipolar electrode water electrolysis hydrogen production device according to claim 6, characterized in that: The usage ratio of the cobalt nitrate hexahydrate to the nickel nitrate hexahydrate is 1:

4.

8. The method for preparing a separator for a bipolar electrode water electrolysis hydrogen production device according to claim 5, characterized in that: In the step 1, the binder is polyvinylidene fluoride, the conductive agent is acetylene black powder, and the dispersant is polyvinyl pyrrolidone.

9. The method for preparing a separator for a bipolar electrode water electrolysis hydrogen production device according to claim 4, characterized in that: In step 3, the nickel foam loaded with active materials is embedded in a customized steel mold, and after being sent into a hydraulic press, the pressure is controlled to increase by 50 tons per minute until it reaches 700 tons. After maintaining the pressure for 5 minutes, the pressure is released to obtain the nickel foam layer (2).

10. The method for preparing a separator for a bipolar electrode water electrolysis hydrogen production device according to claim 5, characterized in that: The dosage ratio of the active material, the conductive agent, the binder and the dispersant is 15-18:1-2:1-2:1-2.

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