Shell, single battery and battery pack
By incorporating welds off-center from the centerline and adding recesses and corners within the casing, the problem of casing deformation or cracking under varying internal battery pressure is solved, thus improving battery safety.
Patent Information
- Application Number
- CN202520075185.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-13
- Publication Date
- 2026-01-23
- Estimated Expiration
- 2035-01-13
AI Technical Summary
The existing casing is prone to deformation or cracking at the welded positions when the internal pressure of the battery increases or negative pressure is generated.
The weld seams of the shell are designed to be offset from the centerline, and recesses and corners are provided on the side walls to reduce the stress on the weld seams and enhance the structural stability and compressive strength.
This reduces the possibility of weld deformation or cracking, thus improving battery safety.
Smart Images
Figure CN223828537U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of batteries, and particularly relates to a shell, a single battery and a battery pack. BACKGROUND
[0002] The battery comprises a shell and an electric core, and the electric core is arranged in the shell. The existing shell is generally formed into a cylindrical shape by means of bending and splicing a base material, and then welding is performed at the splicing position. In the case that the internal pressure of the battery increases or negative pressure is generated, the welding position is prone to deformation or cracking. CONTENT OF THE UTILITY MODEL
[0003] The utility model aims to solve the technical problem that the welding position is prone to deformation or cracking in the case that the internal pressure of the battery increases or negative pressure is generated. Another object of the application is to provide a single battery. A third object of the application is to provide a battery pack.
[0004] TECHNICAL SCHEME The shell provided in the embodiments of the application comprises:
[0005] The shell surrounds a containing cavity, and is provided with an opening along one side in a first direction and communicating with the containing cavity. The shell comprises a first side wall, the first side wall has a welding seam, and the welding seam extends to the opening. The first side wall has a center line, the center line is arranged along the first direction, and the welding seam has a spacing from the center line.
[0006] In some embodiments, the shell comprises a plurality of inner wall surfaces and a plurality of recesses. The plurality of inner wall surfaces surround the containing cavity, and two adjacent inner wall surfaces are connected by the recess. The recess is recessed in a direction away from the containing cavity.
[0007] In some embodiments, the two adjacent inner wall surfaces abut each other.
[0008] In some embodiments, the two adjacent inner wall surfaces are spaced apart on a side connected with the recess.
[0009] In some embodiments, the shell comprises a plurality of inner wall surfaces connected end to end. Each inner wall surface surrounds the containing cavity. In a second direction perpendicular to the first direction, the minimum distance between the welding seam and the inner wall surface adjacent and closest to the welding seam is H. The wall thickness of the shell is D1, the length of the first side wall is D2, and the following is satisfied: D1≤H<D2 / 2.
[0010] In some embodiments, the wall thickness of the shell is D1, and the depth of the recess is L, and the following is satisfied: 0
[0011] In some embodiments, the recess extends along an arc or a polygon.
[0012] In some embodiments, the side wall of the shell is provided with a plurality of corners, the corners are correspondingly arranged with the recess, and the corners extend along an arc.
[0013] Correspondingly, the shell of the application is provided.
[0014] Correspondingly, the shell of the application is provided.
[0015] Beneficial effects: the shell of the application offsets the weld from the center line of the first side wall. Since the center area of the side wall of the shell is subjected to the greatest force when the internal pressure of the battery changes, offsetting the weld from the center line can relatively reduce the force acting on the weld and reduce the possibility of deformation or cracking of the weld.
[0016] The battery of the application includes the shell described above, and thus can have all the technical features and beneficial effects of the shell described above.
[0017] The battery pack of the application includes the shell described above or the single battery described above, and thus can have all the technical features and technical effects of the shell or the single battery described above. BRIEF DESCRIPTION OF DRAWINGS
[0018] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort.
[0019] Figure 1 A front view of the shell provided by the embodiments of the application;
[0020] Figure 2 A side view of the shell provided by the embodiments of the application;
[0021] Figure 3 A structure schematic view of the inner wall surface and the recess provided by the embodiments of the application;
[0022] Figure 4 Another structure schematic view of the inner wall surface and the recess provided by the embodiments of the application;
[0023] Figure 5 A structure schematic view of the recess provided by the embodiments of the application;
[0024] Figure 6 A schematic view of the weld position distribution provided by the embodiments of the application;
[0025] Reference numerals: 1. Outer shell; 10. Receiving cavity; 100. Opening; 11. First side wall; 111. Weld; 12. Inner wall surface; 13. Recess; 14. Corner. Detailed Implementation
[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.
[0027] In the description of this application, it should be understood that the terms "height," "thickness," "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In the description of this application, "a plurality of" means two or more, and "at least one" can mean one, two, or more, unless otherwise explicitly specified. In the description of this application, "perpendicular" means completely perpendicular to 90° or almost completely perpendicular, for example, an angle within the range of 85° to 95° is considered perpendicular. Similarly, "parallel" means completely parallel or almost completely parallel, for example, a completely parallel range within 10° is considered parallel.
[0028] In this application, the centerline refers to the axis of symmetry or central axis of a geometric figure or curve. It is a special line segment of the figure or curve that divides it into two symmetrical parts. For geometric figures such as rectangles, squares, and circles, the centerline is a line passing through the center point of the figure and perpendicular to the axis of symmetry. It divides the figure into two symmetrical parts, each of which is a mirror image of the other.
[0029] It should also be noted that in the accompanying drawings of the embodiments of this application, the arrow marked with X represents the first direction X, and the arrow marked with Y represents the second direction Y. The first direction X and the second direction Y are introduced to more clearly illustrate the structure and relative positional relationship of each component in the housing. In practical applications, the first direction X and the second direction Y may change depending on the placement of the housing.
[0030] As a preamble to the embodiments of this application, the battery includes a casing and a cell. The casing is rectangular, and the cell is manufactured using a stacking process and disposed within the casing. Existing casings generally use a bending and splicing method to form a hollow cylindrical structure from the substrate, and then welding is performed at the splice. For ease of manufacturing, the weld is usually located at the center of the wide side (the side corresponding to the shorter side) of the casing. When the internal pressure of the battery increases or a negative pressure is generated, due to the symmetrical design of the casing, the internal pressure is evenly distributed in all directions. The central area is located at the center of each side, and it can be subjected to relatively uniform pressure in all directions. Therefore, the central area of each side wall of the casing is subjected to the greatest force, and the weld position will also be subjected to relatively large pressure, which will make the weld prone to deformation or cracking.
[0031] Please combine them together Figure 1 and Figure 2 The housing in this embodiment includes an outer shell 1, which is bent to form a receiving cavity 10. The outer shell 1 is rectangular, and an opening 100 communicating with the receiving cavity 10 is provided on one side of the outer shell 1 along the first direction X. The outer shell 1 includes a first sidewall 11, which has a weld 111 extending to the opening 100. The position of the weld 111 is the position where the outer shell 1 is bent and spliced. The first sidewall 11 has a center line M, which is arranged along the first direction X, that is, the center line M is parallel to the first direction X. There is a gap between the weld 111 and the center line M.
[0032] The centerline is represented by M in the attached figure. It passes through the midpoint of the length of the first sidewall 11 in the second direction Y. The second direction Y is perpendicular to the first direction X and parallel to the first sidewall 11. That is, the two sides of the first sidewall 11 along the second direction Y are symmetrically distributed about the centerline M.
[0033] Please combine them together Figure 1 and Figure 6 In this application, the outer shell 1 includes two large surfaces and two wide surfaces. The area of the wide surfaces is smaller than that of the large surfaces. The first sidewall 11 corresponds to the wide surface, that is, the weld 111 is set on the wide surface of the outer shell 1. In some other embodiments, the first sidewall 11 may also correspond to the large surface.
[0034] Because the weld 111 is set off from the center line M, avoiding the central area of the first side wall 11, when the pressure inside the battery increases or a negative pressure is formed inside the battery, the pressure load on the weld 111 is relatively reduced, which reduces the possibility of the weld 111 deforming or cracking and helps to improve the safety performance of the battery.
[0035] Please combine them together Figure 3 and Figure 4In some embodiments, the outer shell 1 includes a plurality of inner wall surfaces 12 and a plurality of recesses 13. The plurality of inner wall surfaces 12 form a receiving cavity 10. Two adjacent inner wall surfaces 12 are connected by a recess 13, and the recess 13 is recessed in a direction away from the receiving cavity 10.
[0036] The recess 13 is a structure that is recessed into the wall thickness of the outer casing 1. The recess 13 connects the two inner wall surfaces 12, thereby increasing the size of the receiving cavity 10 in the recessed direction of the recess 13. On the one hand, it allows the outer casing 1 to produce small displacements or deformations between the inner wall surfaces 12 when it is bent or subjected to internal pressure of the battery, thereby reducing the risk of stress concentration and damage. On the other hand, it can provide an expanded space for the receiving cavity 10 to accommodate cells of different sizes or shapes, increasing the flexibility and fault tolerance of the outer casing 1 structure.
[0037] Please refer to Figure 3 In some embodiments, two adjacent inner wall surfaces 12 abut against each other. That is, after the outer shell 1 is bent and formed, the two inner wall surfaces 12 on both sides of the recess 13 can come into contact with each other. By abutting against each other, a tight connection is formed between the inner wall surfaces 12, which helps to increase the overall rigidity and stability of the outer shell 1 and improve its compressive strength.
[0038] Please refer to Figure 4 In some embodiments, two adjacent inner wall surfaces 12 are spaced apart on the side connected to the recess 13. In this embodiment, the battery cell uses a stacking process, that is, the positive and negative electrode sheets and the separator are stacked alternately by a feeding mechanism to form a stacked core, so the battery cell is approximately rectangular in shape. The spaced arrangement of the two adjacent inner wall surfaces 12 ensures that after the battery cell is placed into the receiving cavity 10, the bent portion of the battery cell is contained within the receiving cavity 10, thereby avoiding direct contact with the inner wall surfaces 12 and preventing the battery cell from being squeezed.
[0039] Please refer to Figure 1 In some embodiments, in the second direction Y, the minimum distance between the weld 111 and its adjacent and closest inner wall surface 12 is H. The second direction Y is perpendicular to the first direction X and parallel to the first sidewall 11. The wall thickness of the outer shell 1 is D1, and the length of the first sidewall 11 in the second direction Y is D2, satisfying: D1≤H<D2 / 2. By limiting the distance between the weld 111 and its adjacent inner wall surface 12, the strength of the weld 111 can be maintained within a stable range, while also providing a certain allowance for bending and welding of the outer shell 1, facilitating processing.
[0040] The minimum distance of weld 111, the wall thickness of outer shell 1, and the length of the first sidewall 11 can be measured using measuring tools. These tools can include vernier calipers, rulers, and coordinate measuring machines. Taking the measurement of the wall thickness of outer shell 1 as an example, a vernier caliper is selected. During measurement, the two measuring jaws of the vernier caliper are respectively attached to the inner wall surface 12 and the sidewall of outer shell 1, keeping the caliper perpendicular to the inner wall surface 12. The scale lines on the vernier caliper are observed, and the dimension value corresponding to the position of the measuring jaws is read; this is the wall thickness of outer shell 1. Alternatively, measurements can be taken using image processing or projection measurement equipment (such as optical projectors and contour projectors).
[0041] Please refer to Figure 5 In some embodiments, the wall thickness of the outer shell 1 is D1, and the depth of the recess 13 is L, satisfying: 0 < L ≤ D1 - a, where a is the pressure-resistant melting depth of the outer shell 1, which can be adjusted according to different design requirements. Limiting the depth of the recess 13 ensures the structural strength of the outer shell 1 at this location, preventing the material strength of the recess 13 from becoming too weak. The measurement of the recess 13 can refer to the method for measuring the wall thickness of the outer shell 1 described above, and will not be repeated here.
[0042] Please refer to Figure 5 In some embodiments, the recess 13 extends along an arc or polygon. Specifically, the shape of the recess 13 can be fan-shaped, semi-circular, square, rectangular, etc. When the recess 13 extends along a polygon, it does not mean that the recess 13 is a closed shape, but rather that the inner contour of the recess 13 has multiple sequentially connected segments, with the first and last segments respectively connecting to an inner wall surface 12, forming the opening of the recess 13. The different forms of the recess 13 increase the flexibility of the bending structure of the outer shell 1.
[0043] Please refer to Figure 1 In some embodiments, the outer side wall of the outer shell 1 is provided with multiple corners 14, which are corresponding to the recesses 13 and extend in an arc shape. The corners 14 are formed by bending the outer shell 1. The arc shape can reduce stress concentration and increase the deformation resistance of the outer shell 1 at this point, so that the weld 111 is as close as possible to the corner 14 while deviating from the center line M, thereby stabilizing the weld 111 to fix the splice of the outer shell 1.
[0044] Accordingly, the single-cell battery provided in this application includes the casing of the above embodiments. Therefore, the single-cell battery can have all the technical features and beneficial effects of the casing described above, which will not be repeated here.
[0045] Accordingly, the battery pack provided in this application includes the housing of the above embodiments, or includes the single cell of the above embodiments, and thus can have all the technical features and technical effects of the housing or single cell, which will not be repeated here.
[0046] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.
[0047] The casing, single battery cell, and battery pack provided in the embodiments of this application have been described in detail above, and specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
Claims
1. A housing, characterized in that, include: The outer shell (1) surrounds a receiving cavity (10). The outer shell (1) has an opening (100) communicating with the receiving cavity (10) on one side along a first direction (X). The outer shell (1) includes a first sidewall (11). The first sidewall (11) has a weld (111) and the weld (111) extends to the opening (100). The first sidewall (11) has a center line (M) which is arranged along the first direction (X). There is a gap between the weld (111) and the center line (M).
2. The housing according to claim 1, characterized in that, The outer shell (1) includes multiple inner wall surfaces (12) and multiple recesses (13). The multiple inner wall surfaces (12) form the receiving cavity (10). Two adjacent inner wall surfaces (12) are connected by the recesses (13). The recesses (13) are recessed in a direction away from the receiving cavity (10).
3. The housing according to claim 2, characterized in that, The two adjacent inner wall surfaces (12) abut against each other.
4. The housing according to claim 2, characterized in that, Two adjacent inner wall surfaces (12) are spaced apart on the side connected to the recess (13).
5. The housing according to claim 2, characterized in that, In the second direction (Y), the minimum distance between the weld (111) and its adjacent and closest inner wall surface (12) is H. The second direction (Y) is perpendicular to the first direction (X). The wall thickness of the outer shell (1) is D1, and the thickness of the outer shell (1) is D2, satisfying: D1≤H<D2 / 2.
6. The housing according to any one of claims 2 to 5, characterized in that, The outer shell (1) has a wall thickness of D1 and the recess (13) has a depth of L, satisfying: 0<L≤D1-a.
7. The housing according to claim 2, characterized in that, The recess (13) extends along an arc or polygon.
8. The housing according to claim 2, characterized in that, The sidewall of the outer shell (1) is provided with a plurality of corners (14), the corners (14) are provided corresponding to the recesses (13), and the corners (14) extend in an arc shape.
9. A single-cell battery, characterized in that, Includes the housing as described in any one of claims 1 to 8.
10. A battery pack, characterized in that, It includes the housing as described in any one of claims 1 to 8, or the single cell as described in claim 9.