Battery cell explosion-proof valve structure

Abstract

The utility model relates to a kind of electric core explosion-proof valve structure, especially a kind of electric core explosion-proof valve structure with different opening pressure, first explosion-proof valve and second explosion-proof valve are arranged at the end of electric core shell, first explosion-proof valve and second explosion-proof valve have different opening pressure, the end surface of electric core shell has the first score of waist shape, first score and the part of electric core shell enclosed by it form first explosion-proof valve, opening is arranged at the other end of electric core shell, second explosion-proof valve is welded to opening place.The electric core explosion-proof valve structure disclosed in the utility model can realize graded pressure relief.

Description

Technical Field

[0001] This utility model relates to a battery cell explosion-proof valve structure, and more particularly to a battery cell explosion-proof valve structure with different opening pressures. Background Technology

[0002] Lithium-ion batteries are currently the most widely used commercial battery products. With the improvement of cell energy sealing, cell safety has become a key focus in cell structural design. The explosion-proof valve on the cell is one of the important structures to ensure cell safety. Currently, there are various structures for explosion-proof valves. In terms of quantity, there are examples of designing explosion-proof valves on one side of the cell, as well as on both sides. Designing explosion-proof valves on both sides requires welding two explosion-proof plates, increasing the cost of the structural components; while designing explosion-proof valves on one side increases the design area of ​​the valve and results in poor valve opening stability.

[0003] Therefore, it is necessary to improve the existing explosion-proof valve structure. Utility Model Content

[0004] In order to overcome the shortcomings of the existing technology, this utility model provides a battery cell explosion-proof valve structure with different opening pressures.

[0005] To achieve the above objectives, this utility model discloses a battery cell explosion-proof valve structure, in which a first explosion-proof valve and a second explosion-proof valve are provided at the end of the battery cell shell, and the first explosion-proof valve and the second explosion-proof valve have different opening pressures.

[0006] Preferably, the first explosion-proof valve and the second explosion-proof valve are located at opposite ends of the battery cell housing.

[0007] Preferably, the end face of the battery cell casing has a waist-shaped first notch, and the first notch and the portion of the battery cell casing enclosed by it form a first explosion-proof valve.

[0008] Preferably, the first explosion-proof valve is located at an eccentric position at the end of the battery cell casing, and the long side of the first groove is perpendicular to the radial direction of the battery cell casing.

[0009] Preferably, a through opening is provided at the end of the battery cell housing, the second explosion-proof valve is in the form of a thin-walled sheet, the second explosion-proof valve is welded to the battery cell housing and covers the opening, and a second groove is provided on the inner side of the second explosion-proof valve.

[0010] Preferably, the residual thickness of the first groove is greater than the residual thickness of the second groove.

[0011] Preferably, the second explosion-proof valve is circular and stepped, and the second groove is provided on the stepped surface of the second explosion-proof valve.

[0012] Preferably, the opening is provided with an outer sinking trough and an inner sinking trough, the second explosion-proof valve is welded to the inner sinking trough, the outer sinking trough is connected with a protective plate, and the protective plate covers the top of the second explosion-proof valve.

[0013] Preferably, the diameter of the outer settling tank is defined as d1, and the diameter of the second explosion-proof valve is defined as d2, where d2-d1=0.2~0.5mm.

[0014] This utility model has the following technical effects: (1) The explosion-proof valve structure of this patent is placed at both ends of the battery cell, and the first explosion-proof valve structure is integrally formed with the outer shell of the battery cell, instead of using a welded explosion-proof sheet. This ensures pressure relief efficiency while saving processing costs.

[0015] (2) The first explosion-proof valve and the second explosion-proof valve have different opening pressures to achieve graded pressure relief and improve the pressure relief capability of the battery cell.

[0016] (3) The first explosion-proof valve adopts a waist-shaped structure and the second explosion-proof valve adopts a circular structure design to avoid the electrode plate becoming arched during the release process, which would block the pressure release channel and thus improve the pressure release smoothness of the explosion-proof valve. Attached Figure Description

[0017] Figure 1 A structural schematic diagram of a battery cell from a first-person perspective; Figure 2 This is a structural schematic diagram of a battery cell from a second perspective. Figure 3 This is a schematic diagram of the structure of the first explosion-proof valve; Figure 4 This is an exploded view of the structure at the second explosion-proof valve. Figure 5 This is a cross-sectional view of the structure of the second explosion-proof valve.

[0018] In the diagram, 100. Cell casing; 101. Opening; 102. Outer recess; 103. Inner recess; 200. First explosion-proof valve; 201. First notch; 300, Second explosion-proof valve; 301, Second notch; 302, Protective plate. Detailed Implementation

[0019] 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.

[0020] A battery cell explosion-proof valve structure is disclosed. In this embodiment, the diameter of the battery cell is between 35mm and 60mm, and the battery cell is cylindrical. A first explosion-proof valve 200 and a second explosion-proof valve 300 are provided at the ends of the battery cell housing 100. The first explosion-proof valve 200 and the second explosion-proof valve 300 have different opening pressures. Specifically, in this embodiment, the opening pressure of the first explosion-proof valve 200 is 1.05 to 1.2 times the opening pressure of the second explosion-proof valve 300. During pressure relief, the second explosion-proof valve 300 opens first. When the pressure relief capacity of the second explosion-proof valve 300 is limited and cannot relieve the pressure generated by the battery cell in time, the first explosion-proof valve 200 opens to achieve staged pressure relief. The first explosion-proof valve 200 and the second explosion-proof valve 300 are respectively located on the two end faces of the battery cell housing 100. Specifically: The first explosion-proof valve 200 is integrally formed with the battery cell housing 100. A waist-shaped first notch 201 is provided on the end face of the battery cell housing 100. The first notch 201 and the portion of the battery cell housing it encloses form the first explosion-proof valve 200. This design reduces the impact on the strength of the battery cell housing 100 compared to a welded explosion-proof valve. The first explosion-proof valve 200 is located at an eccentric position at the end of the battery cell housing 100. (See attached diagram) Figure 1 The radial direction of the battery cell housing 100 is defined as the X direction, and the long side of the first notch 101 is perpendicular to the radial direction of the battery cell housing 100. In this embodiment, the area of ​​the first explosion-proof valve 200 is designed to be 60 mm². 2 ~130mm 2 .

[0021] An opening 101 is provided at the center of the other end face of the battery cell casing 100. An outer recess 102 and an inner recess 103 are provided at the opening 101, where "inner" and "outer" refer to their relative positions to the battery cell. The second explosion-proof valve 300 is a circular, thin-walled valve with a thickness of 0.25mm to 0.35mm. The second explosion-proof valve 300 is fixed in the inner recess 103 by welding. The second explosion-proof valve 300 is stepped, a shape that reduces the fatigue effect of the battery cell's breathing effect during charging and discharging, thereby improving its resistance to deformation. A second notch 301 is provided on the inner side of the step of the second explosion-proof valve 300. A protective sheet 302 is welded to the outer recess 102, covering the top of the second explosion-proof valve 300. To ensure the required welding strength of the explosion-proof valve, the diameter of the outer countersink 102 is defined as d1, and the diameter of the second explosion-proof valve 300 is defined as d2, where d2-d1 = 0.2~0.5mm. This ensures that the welding position of the second explosion-proof valve 300 is not too thin. In this embodiment, the area of ​​the second explosion-proof valve 300 is 70mm². 2 ~130mm 2 .

[0022] In this embodiment, different opening pressures are achieved by controlling the different residual thicknesses of the first notch 201 and the second notch 301. To facilitate the explanation of the meaning of residual thickness, the outer shell thickness of the battery cell is defined as D1, and the depth of the first notch 201 is defined as D2. Then, the residual thickness of the first notch D3 is D3 = D1 - D2. The thickness of the second explosion-proof valve is defined as D4, and the depth of the second notch 301 is defined as D5. Then, the residual thickness of the second notch D6 is D6 = D4 - D5.

[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 battery cell explosion-proof valve structure, characterized in that, A first explosion-proof valve (200) and a second explosion-proof valve (300) are provided at the end of the battery cell housing (100), and the first explosion-proof valve (200) and the second explosion-proof valve (300) have different opening pressures.

2. The cell explosion-proof valve structure according to claim 1, characterized in that, The first explosion-proof valve (200) and the second explosion-proof valve (300) are respectively placed at both ends of the battery cell housing (100).

3. The cell explosion-proof valve structure according to claim 1 or 2, characterized in that, The end face of the battery cell housing (100) has a waist-shaped first notch (201), and the first notch (201) and the portion of the battery cell housing enclosed by it form a first explosion-proof valve (200).

4. The cell explosion-proof valve structure according to claim 3, characterized in that, The first explosion-proof valve (200) is located at an eccentric position at the end of the cell housing (100), and the long side of the first groove (201) is perpendicular to the radial direction of the cell housing (100).

5. The cell explosion-proof valve structure according to claim 3, characterized in that, An opening (101) is provided at the end of the battery cell housing (100). The second explosion-proof valve (300) is in the shape of a thin-walled sheet. The second explosion-proof valve (300) is welded to the battery cell housing (100) and covers the opening (101). A second groove (301) is provided on the inner side of the second explosion-proof valve (300).

6. The cell explosion-proof valve structure according to claim 5, characterized in that, The residual thickness of the first notch (201) is greater than the residual thickness of the second notch (301).

7. The cell explosion-proof valve structure according to claim 5, characterized in that, The second explosion-proof valve (300) is circular and stepped, and the second groove (301) is provided on the stepped surface of the second explosion-proof valve (300).

8. The cell explosion-proof valve structure according to claim 7, characterized in that, An outer sinking groove (102) and an inner sinking groove (103) are provided at the opening (101). The second explosion-proof valve (300) is welded to the inner sinking groove (103). A protective plate (302) is connected to the outer sinking groove (102). The protective plate (302) covers the top of the second explosion-proof valve (300).

9. The cell explosion-proof valve structure according to claim 8, characterized in that, The diameter of the outer settling tank (102) is defined as d1, and the diameter of the second explosion-proof valve (300) is defined as d2, where d2-d1=0.2~0.5mm.

Images