Composite bipolar plate

Abstract

The utility model relates to a kind of composite bipolar plate.The composite bipolar plate includes titanium metal bipolar plate, electrolyte reaction area is opened in its thickness direction two sides, and electrode groove is opened around electrolyte reaction area on two sides respectively;Two polymer-based composite material electrode frames, oppositely set on the two sides of titanium metal bipolar plate;First porous electrode and second porous electrode, oppositely set on the electrode groove on two sides, and respectively covered in the outside of electrolyte reaction area.The utility model proposes a kind of composite bipolar plate, not easy to be corroded, and can basically eliminate bypass current, improves the current efficiency of electrolytic cell.

Description

Technical Field

[0001] This utility model relates to the field of electrolytic cell stacks, and in particular to a composite bipolar plate suitable for all-vanadium redox flow electrolytic cell stacks. Background Technology

[0002] Bipolar plates are the core component of an electrolytic cell stack, responsible for conducting electrons, isolating the electrolyte, and supporting the flow field. In all-vanadium liquid flow electrolysis systems, the electrolyte is an acidic vanadium ion solution, and traditional bipolar plates have several drawbacks:

[0003] 1. Although carbon steel electrode frames have high strength, they are prone to corrosion in high-temperature and high-concentration acidic environments, and the metal material is heavy and has high processing costs;

[0004] 2. Existing composite bipolar plates (such as metal-graphite composites) can improve some performance, but the manufacturing process is complicated, the sealing is poor, and bypass current is easily generated, resulting in reduced current efficiency.

[0005] Therefore, there is an urgent need to design a composite bipolar plate with high integration, strong corrosion resistance, good sealing performance, and reduced energy consumption. Utility Model Content

[0006] To address the aforementioned problems in the prior art, this invention proposes a composite bipolar plate that is not easily corroded and can essentially eliminate bypass current, thereby improving the current efficiency of the electrolytic cell stack.

[0007] Specifically, this utility model proposes a composite bipolar plate, comprising,

[0008] A titanium bipolar plate has an electrolyte reaction zone formed on two sides in the thickness direction, and electrode grooves surrounding the electrolyte reaction zone are formed on the two sides respectively.

[0009] Two polymer-based composite material electrode frames are arranged opposite each other on both sides of the titanium bipolar plate;

[0010] The first porous electrode and the second porous electrode are disposed opposite to each other on the electrode grooves on the two sides, and respectively cover the outside of the electrolyte reaction zone.

[0011] According to one embodiment of the present invention, the polymer-based composite material electrode frame is bonded and fixed to the edge of the titanium bipolar plate by a polymer-based hot melt adhesive.

[0012] According to one embodiment of the present invention, the electrolyte reaction zones on the two sides are a positive electrolyte reaction zone and a negative electrolyte reaction zone, the first porous electrode is located outside the positive electrolyte reaction zone, and the second porous electrode is located outside the negative electrolyte reaction zone.

[0013] According to one embodiment of the present invention, the surface of the positive electrode electrolyte reaction zone is provided with a noble metal iridium-tantalum composite coating, and the surface of the negative electrode electrolyte reaction zone is provided with a Magnesite phase titanium suboxide composite coating.

[0014] According to one embodiment of the present invention, the Magneille phase titanium suboxide composite coating contains Ti4O7, and the single crystal conductivity of Ti4O7 is 1500 S / cm.

[0015] According to one embodiment of the present invention, the polymer-based composite electrode frame is made of a composite material of polypropylene and glass fiber.

[0016] According to one embodiment of the present invention, the insulation performance and mechanical strength of the polymer-based composite electrode frame are adjusted by adjusting the ratio of polypropylene and glass fiber in the polymer-based composite electrode frame material.

[0017] According to one embodiment of the present invention, the polymer-based composite material electrode frame is manufactured by compression molding or injection molding.

[0018] According to one embodiment of the present invention, the composite bipolar plate further includes two polymer-based composite material cover plates, which are respectively attached to the outside of the two polymer-based composite material electrode frames.

[0019] According to one embodiment of the present invention, the titanium bipolar plate is made of a 0.3-0.5mm thick titanium substrate and is integrally formed by precision stamping.

[0020] The present invention provides a composite bipolar plate, which adopts a polymer-based composite bipolar plate, fundamentally solving the corrosion problem of the flow channel of the electrolytic cell stack, and basically eliminating bypass current, thus greatly improving the current efficiency of the electrolytic cell stack.

[0021] It should be understood that the above general description and the following detailed description of the present invention are exemplary and illustrative, and are intended to provide further explanation of the present invention as described in the claims. Attached Figure Description

[0022] The accompanying drawings are included to provide a further explanation of the present invention. They are incorporated in and constitute a part of this application. The drawings illustrate embodiments of the present invention and, together with this specification, serve to explain the principles of the present invention. In the drawings:

[0023] Figure 1 A schematic diagram of the structure of a composite bipolar plate according to an embodiment of the present invention is shown.

[0024] The above figures include the following reference numerals:

[0025] Composite bipolar plate 100

[0026] Titanium bipolar plate 101

[0027] Polymer-based composite electrode frame 102

[0028] First porous electrode 103

[0029] Second porous electrode 104

[0030] Polymer hot melt adhesive 105

[0031] Polymer-based composite cover plate 106

[0032] Manifold 107. Detailed Implementation

[0033] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0034] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0035] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0036] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0037] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0038] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application. In addition, although the terminology used in this application is selected from commonly known and used terms, some terms mentioned in this application's specification may have been chosen by the applicant according to his or her judgment, and their detailed meanings are explained in the relevant sections of this description. Moreover, this application should be understood not only through the actual terms used, but also through the meaning implied by each term.

[0039] Figure 1 A schematic diagram of the structure of a composite bipolar plate according to an embodiment of the present invention is shown. As shown in the figure, a composite bipolar plate 100 mainly includes a titanium metal bipolar plate 101, two polymer-based composite material electrode frames 102, a first porous electrode 103, and a second porous electrode 104.

[0040] The titanium bipolar plate 101 serves as the core conductive component, with electrolyte reaction zones on both sides along its thickness direction. These zones are the primary areas where electrochemical reactions occur. Electrode grooves surrounding the electrolyte reaction zones are also formed on both sides for positioning and mounting the first porous electrode 103 and the second porous electrode 104.

[0041] Two polymer-based composite electrode frames 102 are arranged opposite each other on both sides of the titanium bipolar plate 101. The polymer-based composite electrode frames 102 not only serve as supports and fixation, but also act as a common flow field plate, providing channels for the flow of electrolyte and ensuring the uniform distribution of reactants.

[0042] The first porous electrode 103 and the second porous electrode 104 are disposed opposite each other on electrode grooves on two sides, respectively covering the outer side of the electrolyte reaction zone. The first porous electrode 103 and the second porous electrode 104 are located between the titanium metal bipolar plate 101 and the polymer-based composite material electrode frame 102. As carriers for the electrochemical reaction, the first porous electrode 103 and the second porous electrode 104 can increase the reaction contact area, promote the exchange of matter and electron transfer between the electrolyte and the electrode, and ensure the efficient conduction of the electrolysis reaction.

[0043] The composite bipolar plate 100 provided by this invention adopts a polymer-based composite structure. Leveraging the corrosion resistance of polymer materials, it fundamentally solves the problem of easy corrosion in the flow channels of electrolytic stacks, effectively extending the service life of the stack. Simultaneously, the polymer-based material possesses excellent insulation properties, which can virtually eliminate the generation of bypass current, reducing unnecessary energy loss and thus significantly improving the current efficiency of the electrolytic stack, making the stack operation more efficient and stable.

[0044] In some examples, the polymer-based composite electrode frame 102 is bonded and fixed to the edges of the titanium bipolar plate 101 using polymeric hot melt adhesive 105. This connection method ensures a tight bond between the two, enhances the stability of the overall structure, and improves the sealing of the joints by utilizing the properties of the hot melt adhesive, effectively preventing electrolyte leakage and ensuring the stable operation of the bipolar plate.

[0045] In some examples, the electrolyte reaction zones on the two sides of the titanium bipolar plate 101 correspond to the positive and negative electrolyte reaction zones, respectively. The first porous electrode 103 is adapted to be located outside the positive electrolyte reaction zone, and the second porous electrode 104 is located outside the negative electrolyte reaction zone. This arrangement allows the electrochemical reactions of the positive and negative electrodes to proceed in an orderly manner in their respective independent regions, ensuring both the targetedness and efficiency of the reactions. Furthermore, the precise coordination between the porous electrodes and the reaction zones promotes electron transfer and mass exchange, facilitating the smooth progress of the electrolysis process.

[0046] In some examples, the surface of the positive electrode electrolyte reaction zone is coated with a noble metal iridium-tantalum composite coating. Iridium, as a noble metal, possesses excellent catalytic activity and chemical stability, while tantalum enhances the structural strength and corrosion resistance of the coating. The composite coating formed by these two elements synergistically optimizes the oxygen evolution reaction process at the positive electrode, reducing energy consumption during electrolysis by lowering the oxygen evolution overpotential and maintaining long-term stable catalytic performance in acidic electrolyte environments. The surface of the negative electrode electrolyte reaction zone is coated with a Magnesite-phase titanium suboxide composite coating. Titanium suboxide itself possesses good conductivity and acid corrosion resistance. As a coating material, it significantly improves the corrosion resistance of the negative electrode, while its chemical properties inhibit the occurrence of hydrogen evolution side reactions, ensuring the continuous and stable progress of the electrolysis reaction.

[0047] In some examples, the Magneli phase titanium suboxide composite coating includes Ti4O7. Ti4O7, as one of the most conductive phases in the Magneli phase, possesses a single-crystal conductivity of 1500 S / cm, which significantly enhances the coating's electronic conductivity. This high conductivity stems from the electron transport channels formed by its unique crystal structure, promoting efficient electron transfer in the negative electrode reaction region, reducing energy loss during electron transfer, and further improving the efficiency of the electrode reaction.

[0048] In some examples, the polymer-based composite electrode frame 102 is made of polypropylene and glass fiber. The good chemical stability of polypropylene allows it to withstand the corrosion of electrolytes, while its processing fluidity facilitates the molding of complex structures. The addition of glass fiber can significantly enhance the structural strength and rigidity of the material. The composite material formed by the combination of the two overcomes the shortcomings of the mechanical properties of pure plastics while maintaining the corrosion resistance of the polymer. This provides a reliable material basis for the polymer-based composite electrode frame 102, which can stably support the overall structure of the bipolar plate and adapt to the functional requirements of the flow field.

[0049] In some examples, the material properties can be flexibly controlled by adjusting the ratio of polypropylene to glass fiber in the polymer-based composite electrode frame 102. For example, increasing the proportion of glass fiber can improve the mechanical strength and dimensional stability of the electrode frame, ensuring its structural stability under pressure during stack assembly and temperature changes during operation; adjusting the proportion of polypropylene can optimize the insulation properties of the material, reduce current loss in non-reactive regions, and precisely match the performance of the electrode frame with the operational requirements of the electrolytic stack.

[0050] In some examples, the polymer-based composite electrode frame 102 is manufactured using compression molding or injection molding processes. These processes can fully utilize the properties of composite materials, precisely shape fine structures such as flow channels, ensure the dimensional accuracy and consistency of the electrode frame, meet the needs of mass production, and reduce processing costs, thus providing feasibility for its industrial application.

[0051] In some examples, the composite bipolar plate 100 also includes two polymer-based composite material cover plates 106, which are respectively attached to the outer sides of the two polymer-based composite material electrode frames 102. The cover plates and electrode frames can be made of the same material, so that the outer layer structure of the bipolar plate is uniform in material. This not only enhances the overall structural sealing and effectively prevents electrolyte leakage, but also avoids electrochemical corrosion or performance interference that may occur when different materials come into contact, further ensuring the stability of the bipolar plate operation.

[0052] In some examples, the titanium bipolar plate 101 uses a titanium substrate with a thickness of 0.3 to 0.5 mm. Titanium itself has excellent conductivity, which can efficiently conduct electrons, and its corrosion resistance can adapt to the electrolytic environment. Through a precision stamping integrated molding process, the flow field and the bipolar plate body are integrated into one. This structural design reduces the gaps caused by component splicing, improves the compactness and integration of the overall structure, ensures the precise shape of the flow channel, and helps the electrolyte to be evenly distributed in the reaction zone, creating favorable conditions for the efficient electrochemical reaction.

[0053] In some examples, a current collector 107 is also provided on the outside of the polymer-based composite cover plate 106. The current collector 107 can efficiently collect the current generated by the electrode reaction, reduce the loss in the current transmission process, and at the same time provide additional structural support for the composite bipolar plate 100, enhance the overall structural stability, and ensure smooth and stable current conduction during the operation of the fuel cell stack.

[0054] It will be apparent to those skilled in the art that various modifications and variations can be made to the exemplary embodiments of the present invention without departing from the spirit and scope of the present invention. Therefore, it is intended that the present invention cover modifications and variations falling within the scope of the appended claims and their equivalents.

Claims

1. A composite bipolar plate, characterized by, include, A titanium bipolar plate has an electrolyte reaction zone formed on two sides in the thickness direction, and electrode grooves surrounding the electrolyte reaction zone are formed on the two sides respectively. Two polymer-based composite material electrode frames are arranged opposite each other on both sides of the titanium bipolar plate; The first porous electrode and the second porous electrode are disposed opposite to each other on the electrode grooves on the two sides, and respectively cover the outside of the electrolyte reaction zone.

2. The composite bipolar plate as described in claim 1, characterized in that, The polymer-based composite electrode frame is bonded and fixed to the edge of the titanium bipolar plate by a polymer-based hot melt adhesive.

3. The composite bipolar plate of claim 1, wherein The electrolyte reaction zones on the two sides are the positive electrolyte reaction zone and the negative electrolyte reaction zone. The first porous electrode is located outside the positive electrolyte reaction zone, and the second porous electrode is located outside the negative electrolyte reaction zone.

4. The composite bipolar plate of claim 3, wherein The surface of the positive electrode electrolyte reaction zone is provided with a noble metal iridium-tantalum composite coating, and the surface of the negative electrode electrolyte reaction zone is provided with a Magnesite phase titanium suboxide composite coating.

5. The composite bipolar plate of claim 4, wherein The Magneille phase titanium suboxide composite coating contains Ti4O7, and the single crystal conductivity of Ti4O7 is 1500 S / cm.

6. The composite bipolar plate of claim 1, wherein The polymer-based composite electrode frame is made of a composite material of polypropylene and glass fiber.

7. The composite bipolar plate of claim 6, wherein The insulation performance and mechanical strength of the polymer-based composite electrode frame can be adjusted by changing the ratio of polypropylene and glass fiber in the material.

8. The composite bipolar plate of claim 6, wherein The polymer-based composite electrode frame is manufactured using compression molding or injection molding processes.

9. The composite bipolar plate of claim 1, wherein The composite bipolar plate also includes two polymer-based composite material cover plates, which are respectively attached to the outside of the two polymer-based composite material electrode frames.

10. The composite bipolar plate as described in claim 1, characterized in that, The titanium bipolar plate is made of 0.3-0.5mm thick titanium substrate and is integrally formed by precision stamping.

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