Flow battery electrode frame and stack

Abstract

This invention provides a flow battery electrode frame and stack. The electrode frame includes a flat electrode frame body. The electrode frame body has an outwardly extending flange on one side surface. The flange extends continuously along the edge of the electrode frame body, and an obtuse angle is formed between the flange and the electrode frame body. When multiple electrode frames are stacked, for two adjacent electrode frames, the flange of the lower electrode frame is engaged with the side surface of the upper electrode frame corresponding to the thickness of the electrode frame body, and the inner surface of the flange is in close contact with the side surface of the electrode frame body to form a welding surface. Based on the technical solution of this invention, by providing a flange at the edge of the electrode frame body, a welding surface located on the outermost side of the electrode frame is formed between the flange and the corresponding side surface of the electrode frame body when the electrode frames are stacked, facilitating welding operations and improving the efficiency of stack assembly.

Description

Technical Field

[0001] This invention relates to the field of flow battery technology, and particularly to a flow battery electrode frame and stack. Background Technology

[0002] Flow batteries are a new type of energy storage battery, and the electrode frame is a crucial component. It provides channels for electrolyte flow, secures the electrodes, bipolar plates, and ion-conducting membrane, and can be stacked to form a flow battery stack. Simultaneously, the electrode frame also serves as the stack's outer shell. To ensure the stack's internal sealing, adjacent electrode frames in the stacked structure need to be welded together.

[0003] In existing technologies, welding is performed directly on the contact surfaces of adjacent electrode frames or by using sealing materials for connection. For electrode frames, this welding method allows only one frame to be stacked and welded at a time, affecting work efficiency. Furthermore, since flow batteries require a certain degree of pressure compression during stack assembly, the existing welding methods are not only difficult to perform welding operations under compression, but also make it difficult to guarantee the strength of the welded structure in the free state after each electrode frame is welded and released from compression. Summary of the Invention

[0004] To address the problems in the prior art, this application proposes a flow battery electrode frame and stack. By setting a baffle at the edge of the electrode frame body, when the electrode frames are stacked, a welding surface is formed between the baffle and the side corresponding to the thickness of the electrode frame body, which is located on the outermost side of the electrode frame. This facilitates the welding operation and improves the efficiency of stack assembly.

[0005] The present invention provides a flow battery electrode frame, comprising a flat electrode frame body, wherein one side surface of the electrode frame body has an outwardly extending flange, the flange extends continuously along the edge of the electrode frame body, and the flange and the electrode frame body have an angle that is obtuse.

[0006] When multiple electrode frames are stacked, for two adjacent electrode frames, the retaining edge of the lower electrode frame is fastened to the outer side of the electrode frame body of the upper electrode frame, and the inner side surface of the retaining edge is in close contact with the outer side surface of the electrode frame body to form a welding surface.

[0007] In one embodiment, the vertical height of the retaining edge relative to the surface of the electrode frame body is less than the thickness of the electrode frame body, and the surface is the surface of the electrode frame body on the side corresponding to the retaining edge. This embodiment ensures that the range of a welding surface does not exceed the range of the side corresponding to the thickness of the electrode frame body. If the range of the welding surface exceeds the range of the side corresponding to the thickness of the electrode frame body, then in the stacked structure of the electrode frames, the lower welding surface will cover the outer surface of the upper retaining edge. During welding, both the inner and outer surfaces of the upper retaining edge will be welded, which can easily affect the stability of the retaining edge structure itself.

[0008] In one embodiment, the thickness of the retaining edge is greater than 1 mm and less than the thickness of the electrode frame body.

[0009] In one embodiment, the outer surface of the electrode frame body and the outer surface of the retaining edge smoothly transition and are located in the same plane. With this embodiment, the outer surface corresponding to the thickness of the electrode frame body and the outer surface of the retaining edge form a plane, resulting in a cleaner appearance and simpler structure for the electrode frame. This facilitates the stacking of electrode frames and also makes welding operations easier.

[0010] In one embodiment, a welding flux is applied to the outer surface of the electrode frame body by injection molding, printing, or spraying. With this embodiment, after the electrode frames are stacked, the welding flux is located at the welding surface, which helps to improve the weld strength.

[0011] In one embodiment, when multiple electrode frames are stacked, adjacent electrode frames are welded on the welding surface by means of laser, ultrasound or hot plate.

[0012] In one embodiment, the electrode frame body and the edge are made of polypropylene, polyethylene, polyvinyl chloride, acrylonitrile-butadiene-styrene copolymer, polyvinylidene fluoride, or a modified polymer thereof.

[0013] The present invention provides a flow battery stack, the stack being composed of a plurality of flow single cells, the flow single cell including the flow battery electrode frame described above.

[0014] The above-mentioned technical features can be combined in various suitable ways or replaced by equivalent technical features, as long as the purpose of the present invention can be achieved.

[0015] The flow battery electrode frame and stack provided by the present invention have at least the following advantages compared with the prior art:

[0016] This invention discloses a flow battery electrode frame and stack. The electrode frame has a retaining edge at its edge. Between adjacent electrode frames in the stack, a welding surface is formed between the inner surface of the retaining edge and the outer surface corresponding to the thickness of the respective electrode frame body. Compared to the welding surface formed between electrode frame bodies in the prior art, the welding surface of the electrode frame in this invention is located on the outermost side of the electrode frame, facilitating welding operations and improving the efficiency of stack assembly. Furthermore, the connection and sealing of adjacent electrode frames in the stack through welding eliminates the need for locking structures in prior art stacks, simplifying the overall structure of the stack. Attached Figure Description

[0017] The invention will now be described in more detail with reference to embodiments and the accompanying drawings.

[0018] Figure 1 A schematic diagram of the electrode frame of the present invention is shown;

[0019] Figure 2 This shows a schematic diagram of the structure of the electrode stack of the present invention;

[0020] Figure 3 A partial cross-sectional view of the stacked structure of the electrode frame of the present invention is shown.

[0021] In the accompanying drawings, the same parts use the same reference numerals. The drawings are not to scale.

[0022] Figure label:

[0023] 1-Electrode frame body, 11-Protrusion, 2-Side guard, 3-Welding surface. Detailed Implementation

[0024] The invention will now be further described with reference to the accompanying drawings.

[0025] The present invention provides a flow battery electrode frame, including a flat electrode frame body 1, with a baffle 2 extending outward from the edge of one side surface of the electrode frame body 1. The baffle 2 extends continuously along the edge of the electrode frame body 1, and there is an angle between the baffle 2 and the electrode frame body 1, and the angle is an obtuse angle.

[0026] When multiple electrode frames are stacked, for two adjacent electrode frames, the guard edge 2 of the lower electrode frame is fastened to the outer side of the electrode frame body 1 of the upper electrode frame, and the inner side surface of the guard edge 2 is in close contact with the outer side surface of the electrode frame body 1 to form a welding surface 3.

[0027] Specifically, as shown in the attached figure, the electrode frame body 1 within the electrode frame is flat, and has other structures on it for assembling components such as the bipolar plates, ion separator, and positive and negative electrodes of the flow battery. These structures will not be described in detail here. The retaining edge 2 within the electrode frame is located at the edge of the electrode frame body 1 and extends continuously along the edge, thus forming a ring shape. The retaining edge 2 has an obtuse angle with the electrode frame body 1, therefore, the retaining edge 2 presents a similar bent-off state relative to the electrode frame body 1, as shown in the attached figure. Figure 1 and Figure 3 As shown, the flange 2 is a "flanged edge" located around the edge of the electrode frame body 1.

[0028] Multiple electrode frames are stacked to form the flow battery stack, as shown in the attached figure. Figure 2 As shown in the attached figure, in the stacked structure of two adjacent electrode frames, the flange 2 of one electrode frame wraps around and fastens to the outer side of the electrode frame body 1 of the other electrode frame corresponding to its thickness. Figure 3 As shown. At this point, the inner surface of the retaining edge 2 is in close contact with the outer surface corresponding to the thickness of the electrode frame body 1, thus forming the welding surface 3. After welding the welding surface 3, the inner surface of the retaining edge 2 and the outer surface corresponding to the thickness of the electrode frame body 1 are connected as one and sealed. Thus, the edge of the electrode frame body 1 and the corresponding retaining edge 2 constitute the sealed shell of the fuel cell stack, completely preventing electrolyte leakage. At the same time, multiple electrode frames can be connected as one and maintain a seal through the welding structure of the welding surface 3, ensuring the stability of the fuel cell stack structure. This eliminates the need for the original bolts, bolts, and springs used in the fuel cell stack for locking.

[0029] In existing technologies, where electrode frames are welded together to form a fuel cell stack, the welding between adjacent electrode frames is performed on a plane corresponding to the electrode frame body 1 of this invention, and the welding position is some distance from the edge of the electrode frame body 1. Therefore, after two electrode frames are stacked, the welding position is far from the edge, making the welding operation difficult. Because of this difficulty, only one electrode frame can be stacked and welded at a time, resulting in very low work efficiency. Furthermore, the fuel cell stack requires a certain degree of pressure compression during the welding process. However, existing welding methods require multiple welding operations followed by pressure application and release, which means the strength of the welded structure cannot be effectively guaranteed in the free state after pressure release.

[0030] In the electrode frame structure of the present invention, the welding surface 3 is formed by the inner surface of the retaining edge 2 and the outer surface corresponding to the thickness of the electrode frame body 1, as shown in the attached figure. Figure 3As shown, welding surface 3 is located at the outermost edge of the electrode frame, which is very convenient for welding operations. Furthermore, during welding, all electrode frames of the fuel cell stack can be stacked and compressed uniformly, and then the welding surfaces 3 between each electrode frame can be welded one by one. This results in high work efficiency and ensures the strength of the welded structure.

[0031] Preferably, a protrusion 11 is provided on the edge of the other side surface of the electrode frame body 1 on the side opposite to the stop 2.

[0032] Specifically, as shown in the attached diagram. Figure 3 After multiple electrode frames are stacked, the protrusion 11 is located between adjacent electrode frames, which allows for a certain width of gap between adjacent electrode frames, and thus a certain width of gap at the welding surface 3. This provides a certain forming space for the welded structure to meet different welding requirements. The width of the gap is controlled by controlling the height of the protrusion 11. Generally, the height of the protrusion 11 is very small, a few tenths of a millimeter or even smaller.

[0033] Furthermore, the protrusion 11 is an annular shape that extends continuously along the edge of the electrode frame body 1.

[0034] In one embodiment, the vertical height of the stop 2 relative to the surface of the electrode frame body 1 is less than the thickness of the electrode frame body 1, and the surface is the surface of the electrode frame body 1 on the side where the stop 2 is located.

[0035] Specifically, as shown in the attached diagram. Figure 3 As shown, the relative height of the retaining edge 2 is controlled so that after the electrode frames are stacked, the retaining edge 2 in one electrode frame can only correspond to the outer side surface corresponding to the thickness of the electrode frame body 1 of the adjacent electrode frame. In this way, for a welding surface 3, it can be ensured that its range does not exceed the range of the outer side surface corresponding to the thickness of its corresponding electrode frame body 1, thereby ensuring the reliability of the electrode frame stacking structure.

[0036] Specifically, if the area of ​​welding surface 3 exceeds the area of ​​the side corresponding to the thickness of electrode frame body 1, then for the attached figure... Figure 3 In the stacked structure of the electrode frame shown, the lower welding surface 3 will cover the outer surface of the upper retaining edge 2. During welding, both the inner and outer surfaces of the upper retaining edge 2 will be welded, which may easily affect the stability of the retaining edge 2 structure itself.

[0037] In one embodiment, the thickness of the retaining edge 2 is greater than 1 mm and less than the thickness of the electrode frame body 1.

[0038] Preferably, the thickness of the retaining edge 2 is 2-4 mm.

[0039] In one embodiment, the outer side of the electrode frame body 1 and the outer side of the retaining edge 2 are smoothly transitioned and both are located in the same plane.

[0040] Specifically, as shown in the attached diagram. Figure 3 As shown, the outer side of the electrode frame body 1 corresponding to its thickness and the outer side of the retaining edge 2 form a plane. This makes the electrode frame look neater and the structure simpler. It is also suitable for stacking electrode frames and facilitates welding operations.

[0041] In one embodiment, a welding aid is attached to the side corresponding to the thickness of the electrode frame body 1 by injection molding, printing or spraying.

[0042] Specifically, after the electrode frames are stacked, the welding flux is located at welding surface 3, which helps to improve the welding strength. For laser welding, laser welding absorbent is used as the welding flux, while for hot plate and ultrasonic welding, other appropriate fluxes are used.

[0043] In one embodiment, when multiple electrode frames are stacked, adjacent two electrode frames are welded on the welding surface 3 by means of laser, ultrasonic, or hot plate.

[0044] In one embodiment, the electrode frame body 1 and the edge 2 are made of a modified polymer material selected from polypropylene (PP), polyethylene (PE), polyvinyl chloride (PVC), acrylonitrile-butadiene-styrene copolymer (ABS), and polyvinylidene fluoride (PVDF).

[0045] Specifically, the electrode frame body 1 and the edge 2 can be made of one of the above-mentioned materials, or a modified material based on the above-mentioned materials, or a weldable polymer material composed of the above-mentioned materials and other rigid molecular fibers.

[0046] The present invention provides a flow battery stack, which is composed of multiple flow single cells, each of which includes the aforementioned flow battery electrode frame, thereby possessing all of its technical effects.

[0047] Specifically, the flow cell also includes other components, including an ion separator, bipolar plates, electrodes, and other components assembled on the electrode frame.

[0048] This membrane allows ions to pass through during the positive and negative electrode reactions, while blocking the passage of other ions and solvents. The ions that can be conducted include, but are not limited to, H+. + Na + K + Li + Cl - OH - Plasma.

[0049] The electrodes include a positive electrode and a negative electrode, where the positive and negative electrode reactions of the battery occur, respectively. The positive electrode reaction includes redox reactions involving other redox pairs, such as the interconversion of pentavalent and tetravalent vanadium ions, and the interconversion of trivalent and divalent ferric ions. The negative electrode reaction includes redox reactions involving other redox pairs, such as the interconversion of trivalent and tetravalent vanadium ions, and the interconversion of trivalent and divalent chromium ions.

[0050] In the description of this invention, it should be understood that the terms "upper", "lower", "bottom", "top", "front", "rear", "inner", "outer", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and 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. Therefore, they should not be construed as limitations on this invention.

[0051] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A flow battery electrode frame, comprising a flat electrode frame body, characterized in that, The edge of one side surface of the electrode frame body has an outwardly extending flange, the flange extends continuously along the edge of the electrode frame body, and there is an angle between the flange and the electrode frame body, and the angle is an obtuse angle. When multiple electrode frames are stacked, for any two adjacent electrode frames, the guard edge of the lower electrode frame is fastened to the outer side of the electrode frame body of the upper electrode frame, and the inner side surface of the guard edge is in close contact with the outer side surface of the electrode frame body to form a welding surface; there is a preset interval between the outer side surface of the guard edge of the upper electrode frame and the guard edge of the lower electrode frame to form an open operating space, and the operating space is adjacent to the outer end of the welding surface. A protrusion is provided on the edge of the other side surface of the electrode frame body on the side where the opposite side guard is located.

2. The flow battery electrode frame according to claim 1, characterized in that, The vertical height of the stop relative to the surface of the electrode frame body is less than the thickness of the electrode frame body, and the surface is the surface of the electrode frame body on the side corresponding to the stop.

3. The flow battery electrode frame according to claim 1, characterized in that, The thickness of the retaining edge is greater than 1 mm and less than the thickness of the electrode frame body.

4. The flow battery electrode frame according to claim 1, characterized in that, The outer side of the electrode frame body and the outer side of the retaining edge are smoothly transitioned and are located in the same plane.

5. The flow battery electrode frame according to claim 1, characterized in that, Welding aid is applied to the outer surface of the electrode frame body by injection molding, printing or spraying.

6. The flow battery electrode frame according to any one of claims 1 to 5, characterized in that, When multiple electrode frames are stacked, adjacent electrode frames are welded on the welding surface by means of laser, ultrasound or hot plate.

7. The flow battery electrode frame according to any one of claims 1 to 5, characterized in that, The electrode frame body and the edge are made of one of the following materials: polypropylene, polyethylene, polyvinyl chloride, acrylonitrile-butadiene-styrene copolymer, polyvinylidene fluoride, or a modified polymer thereof.

8. A flow battery stack, said stack being composed of a plurality of flow single cells, characterized in that, The flow cell includes the flow cell electrode frame as described in any one of claims 1 to 7.

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