Lithium-ion battery cell protection assembly, battery cell, battery, power device

Abstract

The utility model provides a lithium ion electric core protection assembly, electric core, battery, power equipment, including the casing, the casing includes a plurality of wall surfaces, wherein the bottom wall is C surface, C surface installs the explosion -proof valve, is B surface and B' surface in C surface both ends, is fixed in B surface or B' surface cover plate unit, the cover plate unit includes the cover plate body, is opened in the cover plate body and pours the liquid hole, the cover plate body still is fixed with riveting piece, pours the liquid hole and riveting piece between through the boss barrier, the boss extends and forms the closed loop boss along the cover plate body edge, and the riveting piece is located in the closed loop boss. When injecting electrolyte to the electric core, the boss can block the overflowed electrolyte, guarantees riveting piece and pole post are not contaminated. When the external force is applied to the riveting piece, its periphery closed loop boss can act as the reinforcing rib, avoids the partial deformation of cover plate. When the cover plate body and the casing are laser welded, even if the local heat has the deformation tendency, but under the action of boss, the deformation greatly reduces, reduces the welding process difficulty. If the cover plate body or casing is deflected when laser welding, the boss can prevent the laser from causing the burn of the plastic riveting piece.

Description

Technical Field

[0001] This utility model relates to the field of battery cell safety protection technology, specifically a lithium-ion battery cell protection component, battery cell, battery, and power equipment. Background Technology

[0002] With the increasing maturity of lithium-ion battery technology, lithium-ion batteries are widely used as power batteries in electric vehicles and energy storage, and the requirements for the performance and safety of lithium-ion batteries are becoming increasingly stringent.

[0003] Lithium-ion battery cells are core components for battery pack safety and assembly, and their structural design is crucial to cell safety. Conventional cell explosion-proof valves are located on the cover plate, thus requiring a relatively thick aluminum plate. To save costs and improve cell space utilization, thinner aluminum plates are generally used for the cell casing. The problems with this structure are as follows:

[0004] 1. The exhaust path of the battery cell is relatively long, which is not the optimal exhaust path.

[0005] 2. The structure of the perforated area of ​​the casing is relatively weak, and plastic deformation is prone to occur during the laser welding of the cover plate and the casing, which affects the use of the battery cell.

[0006] 3. The heat generated during welding accumulates near the weld and cannot dissipate quickly, thus exacerbating the deformation.

[0007] 4. Due to the large-scale deformation and unevenness of the casing, it cannot fully fit with the supporting fixture. This results in a slight misalignment of the battery cell. During laser welding of the casing, there is a chance that the laser will hit the upper plastic surface, causing burns and affecting the appearance and performance of the battery cell.

[0008] In summary, the existing battery cell casing welding process is difficult, and the location of the explosion-proof valve is not the optimal choice. Utility Model Content

[0009] The technical problem to be solved by this utility model is how to improve the protection level of the battery cell while reducing the difficulty of the welding process.

[0010] This utility model solves the above-mentioned technical problems through the following technical means:

[0011] A lithium-ion battery cell protection assembly includes a housing; the housing includes multiple walls, wherein the bottom wall is surface C, an explosion-proof valve is installed on surface C, and surfaces B and B' are located at both ends of surface C. A cover plate unit is fixed on surface B or B'; the cover plate unit includes a cover plate body, on which a liquid injection hole is opened, and a rivet block is fixed on the cover plate body outside the liquid injection hole; the liquid injection hole and the rivet block are separated by a boss, the boss extends along the edge of the cover plate body to form a closed-loop boss, and the rivet block is located inside the closed-loop boss.

[0012] Based on the boss design, when electrolyte is injected into the cell, if electrolyte flows out from the injection hole, it can be blocked by the boss, ensuring that the riveting block and the terminal are not contaminated. Secondly, when external force is applied to the riveting block, its surrounding closed-loop boss can act as a reinforcing rib, preventing local deformation of the cover plate. Furthermore, during laser welding of the cover plate body and the shell, even if there is a tendency for localized deformation due to heat, the deformation is greatly reduced and can be ignored under the action of the boss, ensuring flat alignment of the cover plate body and the shell during laser welding and reducing the difficulty of the welding process. In addition, even if the cover plate body or the shell is misaligned during laser welding, the boss can prevent the laser from burning the plastic riveting block.

[0013] Furthermore, the closed-loop boss is integrally formed with the cover plate body.

[0014] Furthermore, the thickness of surface C is greater than the thickness of other wall surfaces.

[0015] Furthermore, the thickness of the C-surface is greater than 0.8 mm.

[0016] Furthermore, the width A of the boss is ≥ 1 mm.

[0017] Furthermore, 0.3≤H / W<0.5, where H is the height of the boss above the cover plate body, and W is the thickness of the boss formed by the extrusion of the cover plate body edge.

[0018] Furthermore, 0.7mm≤(L+H)-W<1.45mm, where L is the thickness of the cover plate body.

[0019] This utility model also provides a battery cell, including the above-mentioned lithium-ion battery cell protection component.

[0020] This utility model also provides a battery, including the above-mentioned battery cell.

[0021] This utility model also provides a power device, including the battery described above.

[0022] The advantages of this utility model are:

[0023] Based on the boss design, when electrolyte is injected into the cell, if electrolyte flows out from the injection hole, it can be blocked by the boss, ensuring that the riveting block and the terminal are not contaminated. Secondly, when external force is applied to the riveting block, its surrounding closed-loop boss can act as a reinforcing rib, preventing local deformation of the cover plate. Furthermore, during laser welding of the cover plate body and the shell, even if there is a tendency for localized deformation due to heat, the deformation is greatly reduced and can be ignored under the action of the boss, ensuring flat alignment of the cover plate body and the shell during laser welding and reducing the difficulty of the welding process. In addition, even if the cover plate body or the shell is misaligned during laser welding, the boss can prevent the laser from burning the plastic riveting block. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of a protective component according to an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of a cover plate unit according to an embodiment of the present utility model;

[0026] Figure 3 This is a schematic diagram showing two cross-sectional positions of a cover plate unit according to an embodiment of the present utility model;

[0027] Figure 4 for Figure 3 Enlarged cross-sectional schematic diagrams of two sections in the middle;

[0028] Figure 5 This is a schematic diagram of the structure of the shell and cover plate unit during welding in accordance with the present invention.

[0029] 1-Housing; 2-Explosion-proof valve; 3-Cover plate unit; 31-Cover plate body; 32-Injection hole; 33-Riveting block; 34-Boss. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below in conjunction with the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0031] Example 1

[0032] This embodiment describes a lithium-ion battery cell protection component, such as... Figure 1 As shown, it includes a housing 1; for blade batteries or prismatic batteries, housing 1 is a cuboid structure with six walls, as shown below. Figure 1 As shown, these are surfaces A, A', B, B', C, and C', respectively. An explosion-proof valve 2 is installed on surface C, the bottom wall of housing 1 (after the battery is installed in the vehicle body, the bottom wall of housing 1 is considered the bottom wall). Figure 1 (C-side). The shell 1 is extruded and features an unequal wall structure. The C-side of the welded explosion-proof valve 2 has a thick wall structure, with a wall thickness > 0.8 mm. Considering both cost and the welding requirements of the explosion-proof valve 2, a thickness of 0.9 mm or 1 mm is typically used. This improves the resistance to deformation during laser welding of the shell 1 and increases the safety threshold for deformation resistance on the explosion-proof valve 2 side of the battery cell. The explosion-proof valve 2 is mounted on the battery cell shell 1, resulting in a shorter path for venting air in the event of thermal runaway of the battery cell, thus enhancing the safety performance of the battery cell.

[0033] The cover plate unit 3 is fixed to surface B or B' of the housing 1. For example... Figure 1 , Figure 2 As shown, in this embodiment, the cover plate unit 3 is fixed on side B and includes a cover plate body 31, which is a rectangular aluminum plate. An injection hole 32 is formed on the cover plate body 31, and a plastic riveting block 33 for the electrode post is fixed on the cover plate body 31 outside the injection hole 32. A boss 34 separates the injection hole 32 from the riveting block 33. The boss 34 extends along the edge of the cover plate body 31 to form a closed-loop boss 34, and the riveting block 33 is located within the closed-loop boss 34. In this embodiment, the boss 34 and the cover plate body 31 are integrally extruded. The area on the back of the cover plate body 31 corresponding to the boss 34 is raised, forming a step with the other plates of the cover plate body 31. Based on the design of the boss 34, when electrolyte is injected into the cell, if the electrolyte flows out from the injection hole, it can be blocked by the boss 34, ensuring that the riveting block 33 and the electrode post are not contaminated. Secondly, when an external force is applied to the rivet block 33, the closed-loop boss 34 around it can act as a reinforcing rib, preventing local deformation of the cover plate. Furthermore, during laser welding of the cover plate body 31 and the housing 1, even if there is a tendency for localized deformation due to heat, the deformation is greatly reduced and negligible under the action of the boss 34, ensuring the flat alignment of the cover plate body 31 and the housing 1 during laser welding and reducing the difficulty of the welding process. Additionally, even if the cover plate body 31 or the housing 1 becomes misaligned during laser welding, the boss 34 can prevent the laser from burning the plastic rivet block 33.

[0034] This embodiment obtained the dimensional relationships of various parts in the experiment, as well as the welding yield under these dimensional relationships. The experimental conditions were as follows: the shell 1 and the explosion-proof valve 2 were made of MXF2 (imported material), and the length and width of the explosion-proof valve 2 were both 60*15mm; the welding power was 1050W. Examples and comparisons are shown in Table 1.

[0035] Table 1

[0036]

[0037]

[0038] In summary, as Figure 3 , Figure 4As shown, under the premise of ensuring welding yield and cost, the design parameters are standardized to avoid misalignment and burning of the upper plastic during laser welding due to unevenness of the large surface of the shell 1 (in relation to the support fixture). It is necessary to meet the following requirements: 0.7mm ≤ (L+H) - W < 1.45mm (cost and process considerations); and 0.3 ≤ H / W < 0.5 (process and cost considerations); 0.3mm ≤ H < 0.5mm; A ≥ 1mm. Where A is the width of the boss 34, H is the height of the boss 34 above the cover plate body 31, W is the thickness of the boss 34 formed by the edge extrusion of the cover plate body 31, and L is the thickness of the cover plate body 31 excluding the area where the boss 34 is formed by extrusion. Figure 4 C represents the chamfer on the back edge of the boss, typically 0.3mm. For example... Figure 5 As shown, when welding the cover plate and the shell, placing them on the support fixture allows for good alignment. Even if there is localized heating during welding, the deformation of the cover plate and the shell is very small under the action of the boss 34, and they can still be well aligned, reducing welding difficulty and improving yield.

[0039] Example 2

[0040] This embodiment provides a battery cell that uses the lithium-ion battery cell protection component described in Embodiment 1.

[0041] Example 3

[0042] This embodiment provides a battery composed of the battery cells described in Embodiment 2.

[0043] Example 4

[0044] This embodiment provides a power device, including the battery described in Embodiment 3.

[0045] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A lithium-ion battery cell protection component, characterized in that, The device includes a housing; the housing includes multiple walls, with the bottom wall being surface C, on which an explosion-proof valve is installed; the two ends of surface C are surfaces B and B', and a cover plate unit is fixed on surface B or B'; the cover plate unit includes a cover plate body, on which an injection hole is opened, and a rivet block is also fixed on the cover plate body; the injection hole and the rivet block are separated by a boss, which extends along the edge of the cover plate body to form a closed-loop boss, and the rivet block is located inside the closed-loop boss.

2. The lithium-ion battery cell protection assembly according to claim 1, characterized in that, The closed-loop boss is integrally formed with the cover plate body.

3. The lithium-ion battery cell protection assembly according to claim 1 or 2, characterized in that, The thickness of the shell C surface is greater than the thickness of the other wall surfaces.

4. The lithium-ion battery cell protection assembly according to claim 3, characterized in that, The thickness of surface C is greater than 0.8 mm.

5. The lithium-ion battery cell protection assembly according to claim 1 or 2, characterized in that, The width A of the boss is ≥ 1 mm.

6. The lithium-ion battery cell protection assembly according to claim 1 or 2, characterized in that, 0.3≤H / W<0.5, where H is the height of the boss above the cover plate body, and W is the thickness of the boss formed by the extrusion of the cover plate body edge.

7. The lithium-ion cell protection assembly according to claim 6, characterized in that, 0.7mm≤(L+H)-W<1.45mm, where L is the thickness of the cover plate body.

8. A battery cell, characterized in that, Includes the lithium-ion battery cell protection component as described in any one of claims 1 to 7.

9. A battery, characterized in that, Includes the battery cell as described in claim 8.

10. A power equipment, characterized in that, Includes the battery as described in claim 9.

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