Integrated current collector for vanadium redox flow battery

Abstract

The integrated current collector comprises a single pole plate and a copper plate connected to the single pole plate, the single pole plate is provided with a plurality of convex parts, the copper plate is provided with concave parts for embedding the convex parts, and after the convex parts are embedded in the concave parts, the single pole plate is attached to the copper plate. After the convex part is embedded in the concave part, the contact area of the monopolar plate and the copper plate is increased, and the contact resistance is reduced after the contact area is increased, so that the heat loss of current in the conductor is reduced, and the efficiency of the whole circuit is improved.

Description

Technical Field

[0001] The present application relates to the field of vanadium redox flow batteries, and in particular to an integrated current collector for vanadium redox flow batteries. Background Art

[0002] An all-vanadium flow battery is a redox battery with vanadium as the active material in a circulating liquid state. The electrical energy in a vanadium battery is stored as chemical energy in a sulfuric acid electrolyte containing vanadium ions of varying valences. The electrolyte is pumped into the battery stack via an external pump and mechanically forced to circulate through a closed loop of different storage tanks and half-cells. Using a proton exchange membrane as the separator of the battery pack, the electrolyte solution flows parallel to the electrode surfaces, generating an electrochemical reaction. The current is collected and conducted by dual electrode plates, converting the chemical energy stored in the solution into electrical energy.

[0003] The existing Chinese invention patent with publication (announcement) number CN112952136A discloses an integrated monopolar plate electrode frame and a vanadium liquid flow battery containing the same, including a battery end plate, a current collector, an integrated electrode frame with a monopolar plate stacked by a monopolar plate and an electrode frame with a central through hole, an electrode, a sealing gasket, a diaphragm, and an integrated electrode frame with a monopolar plate stacked by a monopolar plate and two electrode frames with central through holes.

[0004] In the aforementioned technologies, the monopolar plate and current collector are in planar contact, and pressure is used to maintain contact. However, vanadium flow batteries are inherently heavy, and relying solely on external pressure often creates gaps between the two contact surfaces. This reduces the contact area between the two conductors and increases contact resistance. Furthermore, reducing the contact area between the two conductors degrades the contact quality and increases contact resistance. Utility Model Content

[0005] In order to increase the contact area and reduce the resistance, the present application provides an integrated current collector for a vanadium flow battery using the following technical solution:

[0006] An integrated current collector for a vanadium liquid flow battery includes a monopolar plate and a copper plate connected to the monopolar plate. The monopolar plate is provided with a convex portion, and the copper plate is provided with a concave portion for embedding the convex portion. After the convex portion is embedded in the concave portion, the monopolar plate and the copper plate are bonded together.

[0007] Preferably, a groove that does not penetrate the thickness direction of the copper plate (2) is provided on the upper surface of the copper plate, and the lower surface of the copper plate is arranged horizontally, with the protrusion embedded in the groove.

[0008] Preferably, the copper plate is partially deformed downward to form a depression, the lower surface of the copper plate is protruding, and the convex portion is embedded in the depression.

[0009] Preferably, there are at least four recesses.

[0010] Preferably, the plurality of recesses are distributed in a rectangular array.

[0011] Preferably, the projection of the recess on the copper plate is a square, and the total projection area of the recesses accounts for more than 8% of the area of the copper plate.

[0012] Preferably, the depth of the recess is 0.2-0.25 mm.

[0013] Preferably, a first conductive adhesive layer is provided in the recess, and the first conductive adhesive layer is located between the copper plate (2) and the monopolar plate.

[0014] Preferably, a circle of sealing grooves is provided on the copper plate, a sealing ring embedded in the sealing groove is provided on the monopolar plate, and the plurality of recesses are all surrounded by the sealing grooves.

[0015] Preferably, a second conductive adhesive layer is provided in the sealing groove, and the second conductive adhesive layer is located between the monopolar plate and the copper plate.

[0016] In summary, this application includes at least one of the following beneficial technical effects:

[0017] 1. After the convex part is embedded in the concave part, the contact surface between the monopolar plate and the copper plate is increased. When the contact area is increased, the contact resistance is reduced, and the heat loss generated by the current in the conductor is reduced, thereby improving the efficiency of the entire circuit;

[0018] 2. The sealing ring and the sealing groove are used to isolate the outside air from entering, thus preventing the copper plate from oxidizing and affecting the contact resistance.

[0019] 3. Fix the monopolar plate and copper plate into one with conductive glue. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the overall structure of the monopolar plate of Example 1 of the present application;

[0021] Figure 2 This is a schematic diagram of the overall structure of the copper plate of Example 1 of the present application;

[0022] Figure 3 Schematic diagram of the back structure of the monopolar plate and copper plate of Example 1 of the present application;

[0023] Figure 4 Schematic diagram of the back structure of the monopolar plate of Example 2 of the present application;

[0024] Figure 5 This is a schematic diagram of the front structure of the monopolar plate of Example 2 of the present application;

[0025] Figure 6 This is a schematic diagram of the front structure of the copper plate of Example 2 of the present application;

[0026] Figure 7This is a schematic diagram of the back structure of the copper plate of Example 2 of the present application.

[0027] Explanation of the accompanying reference numerals: 1. Monopolar plate; 11. Sealing ring; 2. Copper plate; 21. Sealing groove; 3. Conductive plate; 31. Mounting hole; 4. Filling block; 5. Groove; 6. Protrusion; 7. Depression. DETAILED DESCRIPTION

[0028] The following is combined with Figure 1-7 This application is described in further detail.

[0029] Example 1

[0030] Reference Figure 1 、 Figure 2 An integrated current collector for a vanadium flow battery includes a monopolar plate 1 and a copper plate 2. Both the monopolar plate 1 and the copper plate 2 are rectangular parallelepipeds with identical length, width, and height dimensions of 705mm × 382mm × 3mm. 144 rectangular filler blocks 4 are fixed to the front of the monopolar plate 1. These filler blocks 4 project a square shape onto the monopolar plate 1 and measure 8.94mm × 8.94mm × 2mm. The 144 filler blocks 4 are arranged in an array of 9 rows and 16 columns, with equal distance between adjacent filler blocks 4.

[0031] Reference Figure 1 、 Figure 2 Two conductive plates 3 are provided on either side of the copper plate 2 for connecting to external circuits. These plates are provided with several mounting holes 31. A groove 5, the same size as the filler block 4, is provided on the top surface of the copper plate 2. The groove 5 is 2 mm deep. A ring of sealing grooves 21 is formed on the surface of the copper plate 2 where the grooves 5 are located. The sealing grooves 21 have a rectangular cross-section and surround all 144 grooves 5. A sealing ring 11 is provided on the monopolar plate 1, corresponding to the sealing grooves 21. The sealing ring 11 and the filler block 4 are located on the same plane as the monopolar plate 1.

[0032] Reference Figure 1 、 Figure 2 A first conductive adhesive layer (not shown in the drawings) is provided in the groove 5 and is located between the copper plate 2 and the monopolar plate 1. A second conductive adhesive layer (not shown in the drawings) is provided in the sealing groove 21 and is located between the monopolar plate 1 and the copper plate 2.

[0033] refer to Figure 3 , the backs of the copper plate 2 and the monopolar plate 1 are flat.

[0034] The implementation principle of an integrated current collector for a vanadium flow battery in Example 1 of the present application is as follows:

[0035] 1. Apply conductive glue to the groove 5 and the sealing groove 21.

[0036] 2. Align the filling block 4 with the corresponding groove 5 and press until the copper plate 2 and the monopolar plate 1 fit together.

[0037] Example 2

[0038] refer to Figure 4 、 Figure 5 The overall size and material of the monopolar plate 1 are the same as those in Example 1, and the only difference is that the monopolar plate 1 is stamped to form 144 protrusions 6. The array of the 144 protrusions 6 is the same as that in Example 1. The shape of the protrusion 6 is a rectangular parallelepiped, the height of the protrusion 6 is 2 mm, the length and width are both 8.94 mm, and the edges of the protrusion 6 are rounded.

[0039] refer to Figure 6 、 Figure 7 The copper plate 2 is stamped to form 144 depressions 7, the dimensions of the depressions 7 are 2 mm in depth, 8.94 mm in length and width, and a sealing groove 21 is also provided on the copper plate 2. A sealing ring 11 corresponding to the sealing groove 21 is provided on the monopolar plate 1. The copper plate 2 and the monopolar plate 1 are also fixed and sealed with conductive glue.

[0040] Example 3: The copper plate 2 in Example 1 and the monopolar plate 1 in Example 2 are assembled into an integrated current collector.

[0041] Example 4: The copper plate 2 in Example 2 and the monopolar plate 1 in Example 1 are assembled into an integrated current collector.

[0042] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. An integrated current collector for a vanadium redox flow battery, characterized in that: The invention comprises a monopolar plate (1) and a copper plate (2) connected to the monopolar plate (1); the monopolar plate (1) is provided with a convex portion, and the copper plate (2) is provided with a concave portion for embedding the convex portion; after the convex portion is embedded in the concave portion, the monopolar plate (1) and the copper plate (2) are bonded together.

2. The integrated current collector for vanadium redox flow battery according to claim 1, characterized in that: The upper surface of the copper plate (2) is provided with a groove (5) which does not penetrate the thickness direction of the copper plate (2); the lower surface of the copper plate (2) is arranged horizontally, and the protrusion is embedded in the groove (5).

3. The integrated current collector for vanadium redox flow battery according to claim 1, characterized in that: The copper plate (2) is partially deformed downward to form a depression (7), the lower surface of the copper plate (2) is protruding, and the protrusion is embedded in the depression (7).

4. The integrated current collector for vanadium redox flow battery according to claim 2 or 3, characterized in that: There are at least four recesses.

5. The integrated current collector for vanadium redox flow battery according to claim 4, characterized in that: The plurality of recesses are distributed in a rectangular array.

6. The integrated current collector for vanadium redox flow battery according to claim 5, characterized in that: The projection of the recess on the copper plate (2) is a square, and the total projection area of several recesses accounts for more than 8% of the area of the copper plate (2).

7. The integrated current collector for vanadium redox flow battery according to claim 6, characterized in that: The depth of the recess is 0.2-0.25 mm.

8. The integrated current collector for vanadium redox flow battery according to claim 7, characterized in that: A first conductive adhesive layer is provided in the recess, and the first conductive adhesive layer is located between the copper plate (2) and the monopolar plate (1).

9. The integrated current collector for vanadium redox flow battery according to claim 8, characterized in that: A circle of sealing grooves (21) is provided on the copper plate (2), a sealing ring (11) embedded in the sealing groove (21) is provided on the monopolar plate (1), and the plurality of recesses are surrounded by the sealing groove (21).

10. The integrated current collector for vanadium redox flow battery according to claim 9, characterized in that: A second conductive adhesive layer is provided in the sealing groove (21), and the second conductive adhesive layer is located between the monopolar plate (1) and the copper plate (2).

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