Battery

Abstract

The utility model provides a battery which comprises a shell structure and a battery cell arranged in the shell structure, the shell structure comprises a middle frame, a first cover plate and a second cover plate, one side wall of the middle frame is connected with the battery cell, the first cover plate and the second cover plate are arranged on two opposite sides of the middle frame, and the first cover plate and the second cover plate are connected with the middle frame. And an anti-explosion pressure relief part is arranged on the second cover plate. According to the battery disclosed by the utility model, the explosion-proof pressure relief part is arranged on the cover plate which is relatively close to the bent part of the tab of the internal roll core, so that the difficulty of a shell processing and assembling process is reduced, meanwhile, the technical effect of pressure relief is achieved, the reliable packaging process of a hard-shell battery cell in the consumption field is realized, and the purposes of improving the energy density and simultaneously reducing the cost are achieved. And the thermal runaway of the cell is effectively controlled.

Description

Technical Field

[0001] This utility model relates to the field of lithium-ion battery technology, and in particular to a battery. Background Technology

[0002] Existing hard-shell batteries mainly employ stretch forming. A metal stretching mold is created based on the product specifications. Then, the bare battery cells are laser- or ultrasonically welded onto a terminal post that penetrates the casing or cover plate, followed by laser welding for encapsulation. Hard-shell cells produced in this way typically consist of a casing, a cover plate, and a first terminal post connecting the positive electrode to the bare battery cell, and a second terminal post connecting the negative electrode to the bare battery cell. The thermal reliability of this type of hard-shell cell is superior to that of pouch cells. To promptly release pressure in the event of thermal runaway, pressure relief devices are usually installed on the first and second terminal post surfaces. The placement of these devices on the side where the terminals are located prevents the manufacture of thinner cells. Utility Model Content

[0003] In view of the above technical problems, this utility model proposes a battery.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a battery, comprising a housing structure and a battery cell disposed in the housing structure, the housing structure comprising a middle frame, a first cover plate and a second cover plate, one side wall of the middle frame being connected to the battery cell, the first cover plate and the second cover plate being disposed on opposite sides of the middle frame, and the second cover plate being provided with an explosion-proof pressure relief part.

[0005] Furthermore, the electrode sheet of the battery cell is connected to the tab via a bent tab portion, which is disposed adjacent to the second cover plate.

[0006] Furthermore, the middle frame is formed by bending, cutting, and stamping.

[0007] Furthermore, the inner cavity formed by the middle frame, the first cover plate, and the second cover plate is a receiving cavity, and the battery cell is disposed in the receiving cavity.

[0008] Furthermore, the burst pressure of the explosion-proof pressure relief section is less than the burst pressure of the shell structure.

[0009] Furthermore, the explosion-proof pressure relief part can be either arc-shaped or straight-shaped.

[0010] Furthermore, the depth of the explosion-proof pressure relief section is 50%-90% of the thickness of the second cover plate.

[0011] Furthermore, the explosion-proof pressure relief part is 0.5mm-10mm away from the edge of the second cover plate.

[0012] The battery of this utility model has an explosion-proof pressure relief part set on the cover plate that is relatively close to the bending part of the inner core electrode tab. This reduces the difficulty of the casing processing and assembly process, while also achieving the technical effect of pressure relief. This enables the use of the reliable packaging process of hard-shell battery cells in the consumer field, thereby improving energy density while effectively controlling the thermal runaway of the battery cell. Attached Figure Description

[0013] Figure 1 This is an exploded view of the battery of this utility model;

[0014] Figure 2 for Figure 1 The diagram shows the fitting relationship between the second cover plate and the bent part of the electrode tab of the battery.

[0015] Legend: 1. First cover plate; 2. Second cover plate; 3. Middle frame; 4. First pole post; 5. Explosion-proof pressure relief part; 6. Electrode plate; 7. Electrode tab; 8. Electrode tab bending part. Detailed Implementation

[0016] Please see Figures 1-2 This utility model discloses a battery, including a housing structure and a battery cell disposed in the housing structure. The housing structure includes a middle frame 3, a first cover plate 1 and a second cover plate 2. One side wall of the middle frame is connected to the battery cell. The first cover plate and the second cover plate are disposed on opposite sides of the middle frame. An explosion-proof pressure relief part 5 is provided on the second cover plate.

[0017] In one embodiment, the electrode sheet 6 of the battery cell is connected to the electrode tab 7 via a tab bending portion 8, the tab bending portion being disposed adjacent to the second cover plate.

[0018] The positive and negative terminals of the battery cell are connected to at least one terminal post that penetrates the middle frame to enable charging and discharging of the battery cell. For example, the first terminal post and the second terminal post can be located on either side wall of the middle frame, with the first terminal post connected to the positive terminal post of the battery cell and the second terminal post connected to the negative terminal post of the battery cell.

[0019] In one embodiment, the middle frame is formed by bending, cutting, and stamping. The second cover plate containing the explosion-proof pressure relief section is encapsulated by laser welding after the battery cell is installed in the casing.

[0020] In one embodiment, the cavity formed by the middle frame, the first cover plate, and the second cover plate is a receiving cavity, and the battery cell is disposed in the receiving cavity. Specifically, the first cover plate, the second cover plate, and the middle frame are welded to form a closed receiving cavity, and the battery cell is placed inside the receiving cavity.

[0021] In one embodiment, the burst pressure of the explosion-proof pressure relief section is less than the burst pressure of the shell structure.

[0022] In one embodiment, the explosion-proof pressure relief part is either arc-shaped or straight-shaped.

[0023] In one embodiment, the depth of the explosion-proof pressure relief section is 50%-90% of the thickness of the second cover plate.

[0024] In one embodiment, the explosion-proof pressure relief part is 0.5mm-10mm away from the edge of the second cover plate.

[0025] Specifically, in one embodiment, the tab of the bare cell of the battery is transferred to a tab by ultrasonic welding and laser welding of foil material from the uncoated area of ​​the electrode sheet 6; the bare cell tab is connected to a terminal post penetrating the middle frame by laser welding; and simultaneously, a bending mechanism is used to bend it into a bent tab 8. The explosion-proof pressure relief part 5 is disposed on the second cover plate 2 relatively close to the bent tab 8. The depth of the explosion-proof pressure relief part 5 is 50%-90% of the thickness of the second cover plate 1. During the thermal shock process of the hard-shell battery, when the gas pressure generated inside the battery exceeds the explosion-proof pressure relief part's burst value, the explosion-proof pressure relief part 5 can be opened in time to release the gas inside the casing, thereby avoiding further heat accumulation and thermal runaway, which could affect the personal safety of consumers.

[0026] Table 1: Data from Explosion-Proof Scratching Thermal Shock Test

[0027] Scratching surface First cover plate Second cover plate Blast value (Kpa) 35 35 Thermal shock (135℃ for 30 min) 3 / 5 Pass 5 / 5 Pass

[0028] Please refer to the table above. Tests have shown that placing the explosion-proof pressure relief section on the second cover plate, which is relatively close to the bent electrode tab, can improve the pass rate of the cell thermal shock test.

[0029] The battery of this utility model has a pressure relief section located on the cover plate relatively close to the bending part of the internal core electrode tab, which reduces the difficulty of casing processing and assembly, while achieving the technical effect of pressure relief. This enables the use of the reliable packaging process of hard-shell cells in the consumer field, thereby improving energy density while effectively controlling cell thermal runaway.

[0030] Finally, it should be noted that the above are merely preferred embodiments of the present utility model and are not limited to the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. 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, characterized by, The shell structure comprises a middle frame, a first cover plate and a second cover plate, one side wall of the middle frame is connected with the battery cell, the first cover plate and the second cover plate are arranged on opposite sides of the middle frame, and the second cover plate is provided with an anti-explosion pressure relief part.

2. The battery of claim 1, wherein: The electrode tab of the battery cell is connected through an ear bending part, and the ear bending part is arranged adjacent to the second cover plate.

3. The battery of claim 1, wherein: The middle frame is formed by bending, cutting and stamping.

4. The battery of claim 1, wherein: An inner cavity formed by the middle frame, the first cover plate and the second cover plate is a containing cavity, and the battery cell is arranged in the containing cavity.

5. The battery of claim 1, wherein: The burst pressure of the anti-explosion pressure relief part is less than the burst pressure of the shell structure.

6. The battery of claim 1, wherein: The anti-explosion pressure relief part is in one of an arc shape and a straight line shape.

7. The battery of claim 1, wherein: The depth of the anti-explosion pressure relief part is 50%-90% of the thickness of the second cover plate.

8. The battery of claim 1, wherein: The anti-explosion pressure relief part is 0.5mm-10mm away from the edge of the second cover plate.

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