Electrolytic bath pole plate

Abstract

The utility model discloses a polar plate of an electrolytic bath, which relates to the technical field of bipolar plates of electrolytic baths and comprises a back plate and a noble metal plate, a hollow area is arranged in the middle of the back plate and penetrates through the back plate in the thickness direction of the back plate. The precious metal plate comprises a base material layer and a coating, the base material layer is made of titanium alloy or metal titanium, the coating is located on the outer surface of the base material layer, the precious metal plate is embedded in the hollow area, the precious metal plate and the hollow area are sealed, and an electrochemical reaction area is arranged on the surface of the precious metal plate. The polar plate is divided into the back plate and the precious metal plate, the back plate is made of a stainless steel plate which is cheap, the surface of the back plate is not provided with a precious metal coating, the middle part of the back plate is provided with a hollow area for embedding the precious metal plate, and only the surface of the precious metal plate is coated with the precious metal coating, so that the use amount of the precious metal coating is greatly reduced; and the cost and the workload of the plating layer are reduced, and the polar plate has low resistance, high strength and corrosion resistance.

Description

Technical Field

[0001] The utility model relates to the technical field of PEM and AEM electrolyzers, in particular to a bipolar plate for a PEM electrolyzer. Background Art

[0002] The main technologies for hydrogen production by water electrolysis include alkaline water electrolyzers (AE), proton exchange membrane water electrolyzers (PEM), alkaline ion exchange membrane electrolyzers (AEM), and solid oxide water electrolyzers (SOE). Currently, both PEM and AEM electrolyzers contain bipolar plates. Bipolar plates are cut from a single metal plate, with water inlets and outlets designed around the plate. Flow fields or flow channels are also designed within the active electrochemical reaction area of ​​the same metal plate, or they may not be designed within the active electrochemical reaction area.

[0003] For PEM electrolyzers or AEM electrolyzers, the effective electrochemical reaction area will be in a relatively high temperature and corrosive environment for a long time when the electrochemical reaction occurs, and low resistance must be ensured at the same time. The current common design is that the plate material is made of metal titanium, which has excellent strength, low resistivity, high thermal conductivity and low hydrogen permeability. However, titanium is easily corroded, especially on the anode side. The potential may exceed 2V, which will cause the accumulation of surface oxides, thereby increasing the contact resistance and reducing the thermal conductivity. In order to avoid this situation, a thin layer of platinum or other precious metals can be applied to the outer wall of the plate to reduce the surface resistance. At this time, plating is required. The plating can be carried out before processing the inlet and outlet and the flow field of the flow channel, or after the finished product is processed. Regardless of the type of plating, the entire plate is plated. That is to say, the general design uses a whole piece of titanium plate or other metal plate for coating, but in fact only the area where effective electrochemical reaction occurs requires lower resistance, high strength, corrosion resistance, etc. In the area where no effective electrochemical reaction occurs, there is no need for such high requirements for corrosion. It is only necessary to ensure normal water flow and air flow in and out.

[0004] For example, Chinese invention patent number CN108546935A discloses a method for preparing a platinum-coated anode plate, including the following steps: selecting a titanium plate as a raw material; (1) shearing, meshing, and punching the raw material into a substrate according to requirements; (3) washing the raw material; (4) roughening the substrate; (5) preparing a precious metal solution; and (6) applying the precious metal solution multiple times to the heat-treated substrate surface. Therefore, this patent involves coating the entire titanium plate with precious metal, resulting in a large amount of precious metal used and high production costs.

[0005] Furthermore, Chinese invention patent number CN116791126A discloses a bipolar plate for a proton exchange membrane electrolyzer and a method for manufacturing the same. The bipolar plate comprises a laminated substrate layer and a coating layer; the substrate layer is made of titanium or a titanium alloy; and the coating layer is a single metal or alloy layer. This patent also involves applying the coating layer to a single substrate layer.

[0006] Therefore, it is urgent to invent a plate that reduces the amount of precious metal coating used to save production material costs. Utility Model Content

[0007] Based on this, it is necessary to provide a plate with low precious metal usage to address the above technical problems.

[0008] To achieve the above objectives, the present invention provides the following technical solutions:

[0009] An electrolytic cell plate, comprising a back plate and a precious metal plate;

[0010] A hollow area is provided in the middle of the back plate, and the hollow area penetrates the back plate along the thickness direction of the back plate;

[0011] The precious metal plate includes a substrate layer and a coating. The substrate layer is made of titanium alloy or metallic titanium. The coating is located on the outer surface of the substrate layer. The precious metal plate is embedded in the hollow area. The precious metal plate and the hollow area are sealed. An electrochemical reaction area is provided on the surface of the precious metal plate.

[0012] By adopting the above technical solution, the electrode plate is divided into two parts: the back plate and the precious metal plate. The back plate does not need to be plated and only serves to carry water and air and to support the plate, so its cost is low. The precious metal layer is only plated on the precious metal plate, so the amount of precious metal used is small, the cost of plating is low, and the workload of coating the precious metal plate is saved. The precious metal plate is embedded in the hollow area of ​​the back plate to form a electrode plate, which is easy to install.

[0013] Preferably, the back plate is made of a thin stainless steel plate.

[0014] By adopting the above technical solution, the backplane does not work in a high temperature and corrosive environment, and the use requirements can be met by selecting a stainless steel plate, and the cost is relatively low.

[0015] Preferably, a water inlet and outlet channel and an air inlet and outlet channel are provided on the outer side of the back plate, and both the water inlet and outlet channel and the air inlet and outlet channel pass through the back plate along the thickness direction of the back plate.

[0016] By adopting the above technical solution, the water inlet and outlet channels and the air inlet and outlet channels play the role of water flow and air flow in and out.

[0017] Preferably, the coating is one of a platinum coating, a tantalum coating, a niobium coating or a tantalum-niobium alloy coating.

[0018] By adopting the above technical solution, the coating can improve the conductivity, oxidation resistance and electrochemical corrosion resistance of the precious metal plate.

[0019] Preferably, the precious metal plate and the back plate have the same thickness.

[0020] By adopting the above technical solution, when the precious metal plate is embedded in the hollow area of ​​the back plate, the surfaces of the precious metal plate and the back plate are flush, which facilitates the flow of water and air between the precious metal plate and the back plate.

[0021] Compared with the related art, the electrolytic cell plate provided by the present invention has the following beneficial effects:

[0022] The utility model divides the electrode plate into two parts, a back plate and a precious metal plate. The back plate adopts a cheaply available stainless steel plate, and its surface does not need precious metal coating. A hollow area for embedding the precious metal plate is designed in the middle of the back plate. The precious metal coating is only applied on the surface of the precious metal plate, which greatly reduces the use of the precious metal coating, reduces the cost and workload of the coating, and the electrode plate has low resistance, high strength and corrosion resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A three-dimensional diagram of the back plate of the present invention;

[0024] Figure 2 A three-dimensional diagram of the anode plate of the present invention;

[0025] Figure 3 A top view of the anode plate of the present invention;

[0026] Figure 4 A three-dimensional diagram of the cathode plate of the present invention;

[0027] Figure 5 It is a top view of the cathode plate of the present invention.

[0028] Reference numerals: 10, back plate; 101, hollow area; 20, noble metal plate; 30, anode plate; 40, cathode plate. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0030] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", and "right" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0031] Example

[0032] See also Figures 1 to 3 As shown, an embodiment of the present invention provides an electrolytic cell plate, which is suitable for the anode plate 30 and the cathode plate 40 of PEM and AEM electrolytic cells. The plate includes a back plate 10 and a precious metal plate 20. A rectangular hollow area 101 is provided in the middle of the back plate 10, and the hollow area 101 passes through the back plate 10 along the thickness direction of the back plate 10. The hollow area 101 is used to install the precious metal plate 20. The outer surface of the back plate 10 is not coated, and the back plate 10 can adopt an inexpensive thin-sheet stainless steel plate.

[0033] The precious metal plate 20 includes a substrate layer and a coating. The material of the substrate layer is titanium alloy or metallic titanium, which has excellent strength, low resistivity, high thermal conductivity and low hydrogen permeability. In order to improve the corrosion resistance of the substrate layer, the coating is applied to the outer surface of the substrate layer. The coating is made of precious metal material. The outer surface of the precious metal plate 20 has an electrochemical reaction area.

[0034] During actual production and processing, water inlet and outlet channels and air inlet and outlet channels are designed on the back plate 10. Both the water inlet and outlet channels and the air inlet and outlet channels penetrate the back plate 10 along the thickness direction of the back plate 10 and are used to input and output water and air. When the precious metal plate 20 is manufactured, a flow field or flow channel is first designed within the effective electrochemical reaction area of ​​the precious metal plate 20, and then a coating is plated on the outer surface of the substrate layer. Then, the precious metal plate 20 is embedded in the hollow area 101 of the back plate 10, and the outer edge of the precious metal plate 20 is tightly fitted with the inner wall of the hollow area 101, so that a sealed connection is formed between the precious metal plate 20 and the hollow area 101 of the back plate 10, thereby preventing water and air from leaking between the precious metal plate 20 and the back plate 10.

[0035] Compared with the traditional method of coating a precious metal layer on a whole titanium plate, the electrode provided in the present application has a coating only on the precious metal plate 20 and no coating on the back plate 10, which can significantly reduce the use of precious metal coating materials and reduce the material cost of the coating.

[0036] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation and protection scope of the present invention.

[0037] The present invention also has the following implementation methods based on the above:

[0038] Furthermore, the coating is one of platinum coating, tantalum coating, niobium coating or tantalum-niobium alloy coating. Coatings of these materials can improve the electrical conductivity, oxidation resistance and electrochemical corrosion resistance of the precious metal plate 20 .

[0039] In addition, the precious metal plate 20 and the back plate 10 have the same thickness. When the precious metal plate 20 is embedded in the hollow area 101 of the back plate 10, the surfaces of the precious metal plate 20 and the back plate 10 are flush, which facilitates the flow of water and air between the precious metal plate 20 and the back plate 10.

[0040] like Figures 2 to 5 As shown, the electrode plates include an anode plate 30 and a cathode plate 40. The back plates 10 of the anode plate 30 and the cathode plate 40 are the same. The difference between the two lies in the different flow channel or flow field structures in the electrochemical reaction area on the precious metal plate 20. The specific structural form of the flow channel or flow field on the anode plate 30 and the cathode plate 40 is not limited here.

[0041] It should be noted that, in this article, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements that are inherent to such process, method, article or apparatus.

[0042] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An electrolytic cell plate, Features: The electrode plate comprises a back plate (10) and a noble metal plate (20); A hollow area (101) is provided in the middle of the back plate (10), and the hollow area (101) penetrates the back plate (10) along the thickness direction of the back plate (10); The precious metal plate (20) comprises a substrate layer and a coating layer, the substrate layer is made of a titanium alloy or metallic titanium, the coating layer is located on the outer surface of the substrate layer, the precious metal plate (20) is embedded in a hollow area (101), the precious metal plate (20) and the hollow area (101) are sealed, and an electrochemical reaction area is provided on the surface of the precious metal plate (20).

2. The electrolytic cell plate according to claim 1, Features: The back plate (10) is made of a thin stainless steel plate.

3. The electrolytic cell plate according to claim 1, Features: The outer side of the back plate (10) is provided with a water inlet and outlet channel and an air inlet and outlet channel, and the water inlet and outlet channel and the air inlet and outlet channel both penetrate the back plate (10) along the thickness direction of the back plate (10).

4. The electrolytic cell plate according to claim 1, Features: The coating is one of a platinum coating, a tantalum coating, a niobium coating or a tantalum-niobium alloy coating.

5. The electrolytic cell plate according to claim 1, Features: The thickness of the noble metal plate (20) and the back plate (10) are the same.

Images