Integrated explosion-proof valve cell cover plate structure

Abstract

The utility model provides an integrated explosion-proof valve cell cover plate structure, which comprises a light aluminum plate, a lower plastic, a positive electrode assembly and a negative electrode assembly, the lower plastic is stacked below the light aluminum plate, and the positive electrode assembly and the negative electrode assembly are positioned on two sides, respectively penetrate through the lower plastic and the light aluminum plate from bottom to top, and are fixedly connected with the light aluminum plate; and a convex or concave integrated anti-explosion valve is formed on the light aluminum plate between the positive electrode assembly and the negative electrode assembly through stamping. The integrally-stamped anti-explosion valve is formed in the mode of stamping the smooth aluminum plate, and anti-explosion valve parts do not need to be manufactured independently. An independent explosion-proof valve film pasting process and an explosion-proof valve and top cover welding process are not needed, so that the part number and the process steps of the cover plate are reduced, the cost of the top cover is reduced, and the yield of the battery cell manufacturing process is also improved.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, in particular to an integrated explosion-proof valve battery cover structure. Background Art

[0002] When conventional lithium batteries and sodium batteries use hard carbon as the negative electrode, the electrode material will produce a volume effect during intercalation and deintercalation, and the battery cell will produce a large amount of gas during the process and service. This will determine the structural form of the corresponding battery cell. According to safety requirements, the square and cylindrical battery cell structures must take this situation into account. Therefore, square and cylindrical battery cells are usually equipped with explosion-proof valves on the outer packaging shell and cover (such as CN 220672792 U; CN 116259920 B; CN308617273 S; CN201910749967.2; CN201811574829.7, etc.). However, for battery systems that do not produce gas and have zero volume effect, the explosion-proof valve can be stamped into an integral part of the bare aluminum plate to reduce the top cover cost and improve the battery cell process yield.

[0003] Typically, the outer packaging components of a prismatic battery cell consist primarily of a top cover and aluminum shell. The explosion-proof valve is welded to the top cover as a separate component. The top cover requires a reserved hole for the corresponding explosion-proof valve, and then the valve and top cover are welded together. The cost of the top cover is related to the cost of the explosion-proof valve and the yield rate of the laser welding process. Therefore, this has been a persistent pain point for the high cost of the top cover. Furthermore, the explosion-proof valve, as a separate component, requires separate mold production, which also increases the cost of the cover. Utility Model Content

[0004] The technical problem to be solved by the utility model is: in order to overcome the shortcomings of the explosion-proof valve in the prior art, the utility model provides an integrated explosion-proof valve battery core cover plate structure.

[0005] The technical solution adopted by the present invention to solve its technical problems is: an integrated explosion-proof valve battery cover structure, including a plain aluminum plate, a lower plastic, a positive electrode assembly and a negative electrode assembly, wherein the lower plastic is stacked below the plain aluminum plate, and the positive electrode assembly and the negative electrode assembly are located on both sides, respectively penetrating the lower plastic and the plain aluminum plate from bottom to top, and are fixedly connected to the plain aluminum plate; an integrated explosion-proof valve with an upward convex or downward concave shape is stamped on the plain aluminum plate between the positive electrode assembly and the negative electrode assembly.

[0006] Preferably, the explosion-proof valve is a convex bulge formed by stamping on a plain aluminum plate, and the top surface of the convex bulge is provided with a stamped notch with an opening, the notch is circumferentially arranged along the outer edge of the bulge, and the opening forms a connection portion with the plain aluminum plate.

[0007] Furthermore, the height of the bulge is 1-2 mm, which is smaller than the height of the positive electrode assembly and the negative electrode assembly protruding from the plain aluminum plate.

[0008] Furthermore, the explosion-proof valve is a groove punched on a plain aluminum plate, and the bottom surface of the groove is provided with a punched notch with an opening, the notch is circumferentially arranged along the outer edge of the groove, and the opening forms a connection portion with the plain aluminum plate.

[0009] Furthermore, the depth of the groove is 1-2 mm, and in order to prevent the electrolyte from flowing into the groove, a protective film is provided above the groove to block the electrolyte.

[0010] Furthermore, the notch is trapezoidal, and the angle α between the two sides of the trapezoid is in the range of 30°-90°.

[0011] Furthermore, the width D of the residual thickness at the bottom of the notch is in the range of 0.05-0.2 mm.

[0012] Furthermore, the residual thickness t of the bottom of the notch ranges from 0.05 to 0.2 mm.

[0013] Furthermore, the pressure relief pressure range of the explosion-proof valve is 0.4-1.2 MPa.

[0014] Furthermore, a large amount of gas will be produced when the battery cell experiences thermal runaway. To facilitate exhaust, an exhaust structure is provided on the lower plastic below the explosion-proof valve. The exhaust structure includes a sink provided on the lower plastic, a plurality of exhaust holes are provided on the bottom surface of the sink, and a plurality of reinforcing ribs connecting the bottom and side surfaces are also provided in the sink.

[0015] The beneficial effects of the present invention are as follows: the present invention provides an integrated explosion-proof valve battery cover structure, (1) forming an integrated stamped explosion-proof valve by stamping a plain aluminum plate, eliminating the need to manufacture separate explosion-proof valve parts; (2) eliminating the explosion-proof valve protective film by forming a convex bulge; and (3) eliminating the need for a separate explosion-proof valve film lamination process and a welding process between the explosion-proof valve and the top cover, thereby reducing the number of parts and process steps of the cover, thereby reducing the cost of the top cover and improving the yield rate of the battery cell process. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0017] Figure 1 It is a schematic diagram of the exploded structure of the battery cover structure of the first embodiment of the present invention.

[0018] Figure 2 yes Figure 1 Schematic diagram of the cross-section structure.

[0019] Figure 3 yes Figure 2 Enlarged structural diagram of the middle explosion-proof valve.

[0020] Figure 4 This is a schematic diagram of the front structure of the bare aluminum plate of Example 1.

[0021] Figure 5 This is a schematic diagram of the back structure of the bare aluminum plate of Example 1.

[0022] Figure 6 It is an enlarged structural diagram of the explosion-proof valve.

[0023] Figure 7 It is a schematic diagram of the structure of the notch.

[0024] Figure 8 It is a structural diagram of the exhaust structure.

[0025] Figure 9 This is a schematic diagram of the bare aluminum plate structure of Example 2.

[0026] In the figure: 1. Plain aluminum plate, 11. Explosion-proof valve, 12. Bump, 13. Groove, 14. Score, 2. Positive electrode upper plastic, 3. Negative electrode upper plastic, 4. Lower plastic, 41. Sink, 42. Exhaust hole, 43. Reinforcement rib, 5. Positive electrode column, 6. Negative electrode column, 7. Positive electrode sealing ring, 8. Negative electrode sealing ring. DETAILED DESCRIPTION

[0027] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating the basic structure of the present invention only in a schematic manner. They therefore only show components relevant to the present invention, and directions and references (e.g., up, down, left, right, etc.) are intended solely to facilitate the description of features in the drawings. The following detailed description is therefore not to be taken in a limiting sense, and the scope of the claimed subject matter is defined solely by the appended claims and their equivalents. Example 1

[0028] like Figure 1-Figure 7As shown, the utility model has an integrated explosion-proof valve 11 battery cover structure, including a plain aluminum plate 1, a lower plastic 4, a positive electrode assembly and a negative electrode assembly, wherein the lower plastic 4 is stacked under the plain aluminum plate 1, and the positive electrode assembly and the negative electrode assembly are located on both sides, respectively penetrating the lower plastic 4 and the plain aluminum plate 1 from bottom to top, and are fixedly connected to the plain aluminum plate 1; the plain aluminum plate 1 between the positive electrode assembly and the negative electrode assembly is stamped to form an upward convex integrated explosion-proof valve 11, that is, the explosion-proof valve 11 is a convex bulge 12 stamped on the plain aluminum plate 1, and the top surface of the convex bulge 12 is provided with a stamped notch 14 with an opening, and the notch 14 is arranged circumferentially along the outer edge of the bulge 12, and the opening forms a connection portion with the plain aluminum plate 1, and the connection portion is not notched 14. In order to prevent the electrolyte from corroding the notch 14, the height of the convex bump 12 (ie, the height protruding from the surface of the plain aluminum plate 1) is 1-2 mm, which is smaller than the height of the positive electrode assembly and the negative electrode assembly protruding from the plain aluminum plate 1. Figure 7 As shown, preferably, the notch 14 is a trapezoid, and the angle α of the two sides of the trapezoid is in the range of 30°-90°. In this embodiment, it is preferably 60°. The width D of the residual thickness at the bottom of the notch 14 is in the range of 0.05-0.2mm. The thickness t of the residual thickness at the bottom of the notch 14 is in the range of 0.05-0.2mm. When the air pressure inside the battery cell reaches a certain value, the integrated explosion-proof valve 11 will rush along the notch 14 to release the pressure. The pressure relief pressure of the explosion-proof valve 11 is controlled by designing the angles of the two sides, the residual width and the residual thickness. The pressure relief pressure of the explosion-proof valve 11 is in the range of 0.4-1.2Mpa.

[0029] The positive electrode assembly includes a positive electrode column 5, a positive electrode sealing ring 7 and a positive electrode upper plastic 2, a lower plastic 4 and a plain aluminum plate 1, which are stacked. The positive electrode column 5 passes through the lower plastic 4 and the plain aluminum plate 1 from bottom to top, and the upper end is fixed by the positive electrode upper plastic 2. The positive electrode sealing ring 7 is set at the junction of the positive electrode column 5 and the lower plastic 4, the plain aluminum plate 1 and the upper plastic to achieve sealing between the positive electrode column 5 and the three.

[0030] The negative electrode assembly includes a negative electrode column 6, a negative electrode sealing ring 8 and a negative electrode upper plastic 3, a lower plastic 4 and a plain aluminum plate 1, which are stacked. The negative electrode column 6 passes through the lower plastic 4 and the plain aluminum plate 1 from bottom to top, and the upper end is fixed by the negative electrode upper plastic 3. The negative electrode sealing ring 8 is set at the junction of the negative electrode column 6 and the lower plastic 4, the plain aluminum plate 1 and the upper plastic to achieve sealing between the negative electrode column 6 and the three.

[0031] like Figure 8 As shown, an exhaust structure is provided on the lower plastic 4 below the explosion-proof valve 11, and the exhaust structure includes a sink 41 provided on the lower plastic 4, a plurality of exhaust holes 42 are provided on the bottom surface of the sink 41, and a plurality of reinforcing ribs 43 connecting the bottom surface and the side surface are also provided in the sink 41. Example 2

[0032] like Figure 9As shown, the difference between this embodiment and the first embodiment lies in the different directions of the convex and concave portions of the explosion-proof valve 11. In this embodiment, a concave, integrated explosion-proof valve 11 is stamped into the plain aluminum plate 1 between the positive and negative electrode assemblies. That is, the explosion-proof valve 11 is a groove 13 stamped into the plain aluminum plate 1. The bottom surface of the groove 13 is provided with a stamped notch 14 having an opening. The notch 14 is arranged circumferentially along the outer edge of the groove 13, and the opening forms a connection with the plain aluminum plate 1. The depth of the groove 13 (i.e., the depth of the depression in the surface of the plain aluminum plate 1) is 1-2 mm. To block the electrolyte, a protective film is provided above the groove 13.

[0033] Pressure relief test:

[0034] The explosion-proof valve 11 on the bare aluminum plate 1 is prepared using a 2mm thick 1060 aluminum plate. The pressure relief pressure obtained by the top cover blasting machine test is shown in Table 1. The following is only a test example and does not mean that the same pressure relief pressure can be achieved by designing according to these parameters.

[0035]

[0036] Based on the above-mentioned ideal embodiment of the present invention, and in accordance with the above description, relevant personnel can make various changes and modifications without departing from the scope of the present invention. The technical scope of this utility model is not limited to the content of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. An integrated explosion-proof valve battery cover structure, characterized by: It includes a bare aluminum plate, a lower plastic, a positive electrode assembly and a negative electrode assembly, wherein the lower plastic is stacked under the bare aluminum plate, and the positive electrode assembly and the negative electrode assembly are located on both sides, respectively penetrating the lower plastic and the bare aluminum plate from bottom to top and fixedly connected to the bare aluminum plate; an integrated explosion-proof valve with an upward convex or downward concave shape is stamped on the bare aluminum plate between the positive electrode assembly and the negative electrode assembly.

2. The integrated explosion-proof valve battery cover structure according to claim 1, characterized in that: The explosion-proof valve is a convex bulge formed by punching on a plain aluminum plate. The top surface of the convex bulge is provided with a stamped notch with an opening. The notch is arranged circumferentially along the outer edge of the bulge, and the opening forms a connection portion with the plain aluminum plate.

3. The integrated explosion-proof valve battery cover structure according to claim 2, characterized in that: The height of the bulge is 1-2 mm, which is smaller than the height of the positive electrode assembly and the negative electrode assembly protruding from the plain aluminum plate.

4. The integrated explosion-proof valve battery cover structure according to claim 1, characterized in that: The explosion-proof valve is a groove punched on a plain aluminum plate. The bottom surface of the groove is provided with a punched notch with an opening. The notch is arranged circumferentially along the outer edge of the groove, and the opening forms a connection portion with the plain aluminum plate.

5. The integrated explosion-proof valve battery cover structure according to claim 4, characterized in that: The depth of the groove is 1-2 mm, and a protective film is provided above the groove.

6. The integrated explosion-proof valve battery cover structure according to claim 2 or 4, characterized in that: The notch is trapezoidal, and the angle α between the two sides of the trapezoid is in the range of 30°-90°.

7. The integrated explosion-proof valve battery cover structure according to claim 6, characterized in that: The width D of the residual thickness at the bottom of the notch is in the range of 0.05-0.2 mm.

8. The integrated explosion-proof valve battery cover structure according to claim 7, characterized in that: The thickness t of the residual thickness at the bottom of the notch is in the range of 0.05-0.2 mm.

9. The integrated explosion-proof valve battery cover structure according to claim 1, characterized in that: The pressure relief pressure range of the explosion-proof valve is 0.4-1.2 MPa.

10. The integrated explosion-proof valve battery cover structure according to claim 1, characterized in that: An exhaust structure is provided on the lower plastic below the explosion-proof valve. The exhaust structure includes a sink provided on the lower plastic. A plurality of exhaust holes are provided on the bottom surface of the sink, and a plurality of reinforcing ribs connecting the bottom surface and the side surfaces are also provided in the sink.

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