Battery cell current collector disc explosion-proof pressure relief structure and explosion-proof valve

Abstract

This utility model relates to the field of battery cell explosion protection, and more particularly to a battery cell current collector explosion-proof pressure relief structure and explosion-proof valve. The explosion-proof pressure relief structure includes a current collector body; the current collector body has a central hole penetrating its opposite sides, and the inner wall of the central hole has at least one notch; one side of the current collector body has a first groove and a second groove, the first groove extending circumferentially, and the second groove extending from the notch to the first groove; the explosion-proof valve includes the aforementioned current collector body, which is connected to the battery cell; an explosion-proof sheet covering the current collector body; and a cover plate connected to the battery cell and used to fix the explosion-proof sheet. The battery cell current collector explosion-proof pressure relief structure and explosion-proof valve disclosed in this utility model can achieve a good pressure relief effect.

Description

Technical Field

[0001] This utility model relates to the field of battery cell explosion protection, and more particularly to a battery cell current collector explosion-proof pressure relief structure and explosion-proof valve. Background Technology

[0002] The safety of lithium-ion batteries remains a key research focus for battery cell manufacturers. As battery cell capacity increases, so does the overall size (height and width). To address the safety issue of heat spread in the module due to explosion-proof valve failure, the industry has primarily adopted methods such as increasing the number of explosion-proof valves or enlarging their body structures to achieve pressure relief and heat dissipation. However, the current trend in battery cell development is to increase energy density by reducing the weight of structural components. Clearly, increasing the number of explosion-proof valves or enlarging their structures contradicts this trend. Therefore, improvements to existing battery cell explosion-proof structures are necessary. Utility Model Content

[0003] In order to overcome the shortcomings of the existing technology, this utility model provides an explosion-proof pressure relief structure for the current collector of the battery cell and an explosion-proof valve.

[0004] One of the objectives of this utility model is to provide an explosion-proof pressure relief structure for a battery cell current collector, including a current collector body; the current collector body is provided with a central hole penetrating its opposite sides, and the inner wall of the central hole is provided with at least one notch; one side of the current collector body is provided with a first groove and a second groove, the first groove extending circumferentially along the circumference, and the second groove extending from the notch to the first groove.

[0005] Preferably, the inner wall of the central hole is provided with at least two notches, and the notches, the first notch, and the second notch correspond one-to-one.

[0006] Preferably, a plurality of the first grooves are arranged in a circumferential array along the circumference, with a gap between two adjacent first grooves; the second grooves extend radially along the circumference.

[0007] Preferably, a through hole is provided at the intersection of the first and second notches.

[0008] The second objective of this utility model is to provide a battery cell explosion-proof valve, comprising: The aforementioned current collector body is connected to the battery cell; the explosion-proof sheet is covered on the current collector body; and the cover plate is connected to the battery cell and used to fix the explosion-proof sheet.

[0009] Preferably, it also includes a dustproof membrane, which is connected to the cover plate. The dustproof membrane and the explosion-proof sheet are placed on opposite sides of the cover plate, and a through hole is provided in the center of the dustproof membrane.

[0010] Preferably, a first sink groove is provided on one side of the cover plate, and the explosion-proof sheet is fixedly connected to the first sink groove; a second sink groove is provided on the other side of the cover plate, and the dustproof membrane is fixedly connected to the second sink groove.

[0011] Preferably, the cover plate is further provided with a third notch, which is provided around the explosion-proof sheet.

[0012] Preferably, the explosion-proof sheet has a fourth groove.

[0013] This utility model has the following technical effects: In this patent, the manifold body, explosion-proof plate, and cover plate are all equipped with explosion-proof structures. These explosion-proof structures work together to achieve graded pressure relief. Specifically, the fourth notch on the explosion-proof plate is the first layer of pressure relief explosion-proof structure, which can cope with the relatively slow process of cell thermal runaway; the third notch on the cover plate is the second layer of pressure relief explosion-proof structure, which provides pressure relief when the cell thermal runaway is very rapid and the explosion-proof plate is insufficient; the first and second notches on the manifold are the third layer of explosion-proof structure, which expands the airflow discharge channel when the size of the central hole on the manifold restricts airflow and thus limits the opening speed during pressure relief. This multi-layered pressure relief structure improves the explosion-proof pressure relief effect without increasing the number or size of the explosion-proof valves. Attached Figure Description

[0014] Figure 1 A structural schematic diagram of a battery cell from a first-person perspective; Figure 2 A structural schematic diagram of the battery cell from a second perspective; Figure 3 Exploded view of the structure of the manifold body, explosion-proof sheet, cover plate and dustproof membrane; Figure 4 This is a schematic diagram of the structure of side A of the collector plate body; Figure 5 This is a schematic diagram of the structure of the collector plate body on side B. Figure 6 This is a structural diagram of side A of the explosion-proof sheet; Figure 7 This is a structural diagram of side B of the explosion-proof sheet; Figure 8 This is a cross-sectional view of the explosion-proof sheet. Figure 9 This is a structural schematic diagram of side A of the cover plate; Figure 10 This is a structural schematic diagram of side B of the cover plate; Figure 11 This is a diagram showing the effect of the first and second grooves in the collector plate body cracking. Figure 12 for Figure 8Enlarged view of the structure at point F.

[0015] In the diagram, 100. Collector plate body; 101. Center hole; 102. Notch; 103. First notch; 104. Second notch; 105. Gap; 106. Through hole; 200. Battery cells; 300, explosion-proof sheet; 301, fourth notch; 400. Cover plate; 401. First settling groove; 402. Second settling groove; 403. Third notch; 500, dustproof film; 501, small holes; Detailed Implementation

[0016] The principles and features of this utility model are described below with reference to the embodiments; the examples given are only for explaining this utility model and are not intended to limit the scope of this utility model.

[0017] Example 1 This embodiment provides an explosion-proof and pressure-relief structure for a battery cell current collector, including a current collector body 100. In this embodiment, the current collector body 100 is a circular, thin sheet, used in a cylindrical battery. In other embodiments, the current collector body 100 can be designed in other shapes. A central hole 101 is provided at the center of the current collector body 100, penetrating its opposite sides. The opposite sides refer to the... Figure 4 and attached Figure 5 The A and B sides of the central hole 101 are provided. At least one notch 102 is provided on the inner wall of the central hole 101. In this embodiment, four notches 102 are designed. In other embodiments, one, two, three, etc., can be designed. One side (B side) of the collector plate body 100 is provided with a first notch 103 and a second notch 104. The notches 102, the first notch 103, and the second notch 104 correspond one-to-one in number. That is, in this embodiment, four first notches 103 and four second notches 104 are also designed. The four first notches 103 are arranged in a circular array with the central hole 101 as the array center. However, no two first notches 103 are connected. That is, a gap 105 should be left between any two adjacent first notches 103 to prevent too many or too long notches from affecting the conductive area. The first notches 103 are arc-shaped, and the four first notches 103 surround a circle. The central hole 101 is located within this circle. The second notch 104 extends from the notch 102 to the first notch 103, and a through hole 106 is provided at the intersection of the first notch 103 and the second notch 104.

[0018] The central hole 101 allows airflow to pass through during cell depressurization. When the airflow velocity is too high, the central hole 101 tears starting from the notch 102. The tear then extends from the second notch 104 to the first notch 103, enlarging the central hole 101 and thus ensuring depressurization efficiency. The effect of the first notch 103 and the second notch 104 breaking apart is shown in the attached figure. Figure 12 As shown.

[0019] Example 2 This second embodiment provides a battery cell explosion-proof valve, including the manifold body 100, explosion-proof sheet 300, cover plate 400, and dustproof membrane 500 of the first embodiment. Except for the manifold body 100, the explosion-proof sheet 300, cover plate 400, and dustproof membrane 500 are all generally circular thin sheets.

[0020] The current collector body 100 is connected to the battery cell 200. This patent improves the structure of the current collector body 100, not the connection structure between the current collector body 100 and the battery cell 200. Therefore, the connection method between the current collector body 100 and the battery cell 200 can refer to existing technology. (See attached diagram) Figure 9 and attached Figure 10 A first recess 401 and a second recess 402 are respectively provided on both sides (side A and side B) of the cover plate 400, wherein the first recess 401 is provided on side A of the cover plate 400 and the second recess 402 is provided on side B of the cover plate 400. A dustproof film 500 is provided on side B of the cover plate 400 and adhered to the second recess 402, and a through hole 501 is provided on the dustproof film 500; an explosion-proof sheet 300 is covered on the manifold body 100, provided on side A of the cover plate 400, and welded and fixed to the first recess 401. Specifically, refer to the attached drawing. Figure 6 and attached Figure 7 The A side of the explosion-proof plate 300 faces the main body 100 of the manifold, and the B side of the explosion-proof plate 300 faces the cover plate 400.

[0021] The cover plate 400 has a third notch 403 around the explosion-proof sheet 300. The explosion-proof sheet 300 has a fourth notch 301.

[0022] When pressure relief is initiated, the explosion-proof disc 300 tears based on the fourth notch 301 to complete the pressure relief. This pressure relief method is suitable for the relatively slow process of cell 200 runaway. When cell thermal runaway is obvious and rapid, the pressure relief of the explosion-proof disc 300 is insufficient, and the cover plate 400 tears based on the third notch 403 to further accelerate the pressure relief. When the pressure relief airflow (or solid flow) is too large and the diameter of the central hole 101 is too small, affecting the pressure relief, the collector plate body 100 tears at the notch 102 and extends to the first notch 103 and the second notch 104 to expand the flow area of ​​the airflow (or solid flow). Achieving layered pressure relief can ensure the pressure relief explosion-proof effect without increasing the structural volume of the explosion-proof valve.

[0023] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A cell current collector explosion-proof pressure relief structure, characterized in that, The device includes a collector plate body; the collector plate body is provided with a central hole penetrating its opposite sides, and the inner wall of the central hole is provided with at least one notch; one side of the collector plate body is provided with a first groove and a second groove, the first groove extending circumferentially along the circumference, and the second groove extending from the notch to the first groove.

2. The explosion-proof pressure relief structure for the current collector of the battery cell according to claim 1, characterized by, The inner wall of the central hole is provided with at least two notches, and the notches, the first notch, and the second notch correspond one-to-one.

3. The explosion-proof pressure relief structure for the current collector of the battery cell according to claim 2, characterized by, Multiple first serrations are arranged in a circumferential array along the circumference, with a gap between two adjacent first serrations; the second serrations extend radially along the circumference.

4. The explosion-proof pressure relief structure for the current collector of the battery cell according to claim 3, characterized by, A through hole is provided at the intersection of the first and second notches.

5. An explosion relief valve for an electrochemical cell, characterized by include: The current collector body according to any one of claims 1 to 4, wherein the current collector body is connected to the battery cell; Explosion-proof sheet, the explosion-proof sheet being covered on the manifold body; A cover plate, which is connected to the battery cell and is used to fix the explosion-proof sheet.

6. The cell explosion-proof valve according to claim 5, characterized in that, It also includes a dustproof membrane, which is connected to the cover plate. The dustproof membrane and the explosion-proof sheet are placed on opposite sides of the cover plate, and a through hole is provided in the center of the dustproof membrane.

7. The electrochemical cell explosion vent of claim 6, wherein, A first sink groove is provided on one side of the cover plate, and the explosion-proof sheet is fixedly connected to the first sink groove; a second sink groove is provided on the other side of the cover plate, and the dustproof membrane is fixedly connected to the second sink groove.

8. The electrochemical cell explosion vent of claim 7, wherein, The cover plate is also provided with a third notch, which is arranged around the explosion-proof sheet.

9. The electrochemical cell explosion vent of claim 5, wherein, The explosion-proof sheet has a fourth groove.

Images