Battery case and battery
By differentiating the side wall thickness and connection design of the lithium-ion battery casing, the problem of stress concentration in the battery casing during charge and discharge cycles is solved, enhancing the structural strength and safety of the battery and extending its service life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SVOLT ENERGY TECHNOLOGY CO LTD
- Filing Date
- 2025-07-16
- Publication Date
- 2026-07-21
Smart Images
Figure CN224537155U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of battery technology, and in particular to a battery casing and a battery. Background Technology
[0002] With the gradual maturation of lithium-ion battery technology, its application as a power battery in electric vehicles and energy storage is becoming increasingly widespread. The safe operation of lithium-ion batteries is not only related to the normal operation of equipment, but also directly affects the life and property safety of users. However, due to structural design defects, the existing cell casing is prone to deformation when gas is generated in the cell. This deformation can disrupt the stable environment inside the cell, posing a serious threat to cell safety.
[0003] In prismatic battery cells, the casing is primarily formed using a stamping and stretching process, resulting in variations in wall thickness across the large, narrow, and bottom surfaces. The wall thickness changes drastically at the edge transitions, making these areas stress concentration points. During the entire charge-discharge cycle, the edges of the prismatic casing frequently experience stress changes, becoming the weakest points in the entire casing structure. These edges are highly susceptible to fatigue cracking, significantly reducing battery life and safety. Utility Model Content
[0004] The purpose of this application is to provide a battery casing and battery to solve, to a certain extent, the technical problem in the prior art that during the charge and discharge cycle of the entire package, the edges of the square casing are frequently subjected to stress changes, becoming the weakest part of the entire casing structure, which is very easy to crack due to fatigue, greatly reducing the service life and safety of the battery.
[0005] According to a first aspect of this application, a battery housing is provided, including a plurality of sidewalls, the plurality of sidewalls being arranged to form a receiving space; Two adjacent sidewalls are defined as the first sidewall and the second sidewall, respectively, and the wall thickness of the first sidewall is greater than the wall thickness of the second sidewall. The battery housing further includes a connecting portion that connects the first sidewall and the second sidewall. The connecting portion includes a rounded section, a first transition section, and a second transition section. Wherein, the rounded section is connected to the second sidewall, the first transition section is connected to the first sidewall, and the second transition section connects the rounded section and the first transition section; The wall thickness of both the rounded section and the second transition section is equal to the wall thickness of the second sidewall; The first transition segment includes a first end and a second end that are opposite to each other, the first end being connected to the second transition segment, and the second end being connected to the first sidewall; In the direction from the first end to the second end, the wall thickness of the first transition section gradually increases.
[0006] Preferably, the maximum wall thickness of the first transition section is equal to the wall thickness of the first sidewall; The minimum wall thickness of the first transition section is equal to the wall thickness of the second sidewall.
[0007] Preferably, the outer walls of the first transition section, the second transition section, and the first sidewall are aligned. The inner wall surface of the first transition section is an inclined plane.
[0008] Preferably, on a plane that is perpendicular to both the first sidewall and the second sidewall, the extension direction of the first sidewall is a first direction, and the extension direction of the second sidewall is a second direction. In the first direction, the size of the first transition segment is H1; in, ,in, Let be the wall thickness of the first sidewall. α is the wall thickness of the second sidewall, and ∠α is the angle between the inner wall surface and the outer wall surface of the first transition section.
[0009] Preferably, the value of ∠α is in the range of 10° to 30°.
[0010] Preferably, the difference between the wall thickness of the first sidewall and the wall thickness of the second sidewall is 0.1 mm to 1.0 mm.
[0011] Preferably, in the first direction, the size of the second transition segment is equal to the size of the first transition segment; And / or, the battery casing satisfies: 0.35mm ≤ (H1 + H2) ≤ 11.34mm, where H2 is the size of the second transition section in the first direction.
[0012] Preferably, the battery casing includes a casing body; The shell body is a one-piece molded square box; The shell body is formed by two large sidewalls, two narrow sidewalls and a bottom wall. The two large sidewalls are arranged opposite each other along the thickness direction, and the two narrow sidewalls are arranged opposite each other along the width direction. Each narrow sidewall is connected to the two large sidewalls at both ends in the thickness direction. The bottom wall is connected to the same end of the two large sidewalls and the two narrow sidewalls in the length direction. Wherein, the wall thickness of the large sidewall is less than the wall thickness of the narrow sidewall and the wall thickness of the bottom wall; Both the large sidewall and the narrow sidewall, both the large sidewall and the bottom wall, and both the narrow sidewall and the bottom wall are connected via the connecting portion.
[0013] Preferably, the battery housing further includes a cover plate disposed at one end of the housing body in the length direction away from the bottom wall.
[0014] According to a second aspect of this application, a battery is provided, comprising the battery casing described in any of the above technical solutions, and thus possessing all the beneficial technical effects of the battery casing, which will not be repeated here.
[0015] Compared with the prior art, the beneficial effects of this application are as follows: The battery casing provided in this application, through differentiated sidewall thickness settings, provides stronger support during cell gas generation. Thicker sidewalls effectively resist internal pressure, reduce casing deformation, maintain a stable internal environment within the cell, and lower safety risks caused by casing deformation. The battery casing connection section employs a design with a rounded section, a second transition section, and a first transition section, with the first transition section gradually increasing in wall thickness, resulting in a smoother transition at the edges. This design effectively disperses stress at the edges, avoiding stress concentration caused by abrupt changes in wall thickness. This significantly improves the fatigue resistance of the edges during charge-discharge cycles, reduces cracking, and enhances the overall structural strength of the battery casing. It effectively reduces the risk of casing deformation and edge cracking, providing more reliable protection for the cell, reducing battery failures caused by casing issues, thereby extending battery life and improving the safety and stability of lithium-ion batteries in electric vehicles and energy storage applications.
[0016] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0018] Figure 1 This is a partial structural schematic diagram of the battery casing provided in an embodiment of this application; Figure 2 This is an isometric structural diagram of the shell body provided in an embodiment of this application; Figure 3 for Figure 2 A schematic diagram of the cross-sectional structure obtained by cutting the shell body along the AA direction; Figure 4 for Figure 3An enlarged structural diagram of the shell body at point D is provided. Figure 5 for Figure 2 A schematic diagram of the cross-sectional structure obtained by cutting the shell body along the BB direction; Figure 6 for Figure 5 An enlarged structural diagram of the shell body at point E is provided. Figure 7 for Figure 2 A schematic diagram of the cross-sectional structure obtained by cutting the shell body along the CC direction; Figure 8 for Figure 7 The provided enlarged structural diagram of the shell body at point F.
[0019] Figure label: 101-First sidewall; 102-Second sidewall; 11-Large surface sidewall; 12-Narrow sidewall; 13-Bottom wall; 2-Connecting part; 21-First transition section; 22-Second transition section; 23-Rounded section; F1 - First direction; F2 - Second direction; L - Length direction; W - Width direction; T - Thickness direction. Detailed Implementation
[0020] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this application, but not all embodiments.
[0021] The components of the embodiments of this application described and shown in the accompanying drawings can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of this application provided in the drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application.
[0022] Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0023] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0024] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0025] The following reference Figures 1 to 8 This application describes a battery casing and a battery according to some embodiments.
[0026] See Figures 1 to 8 As shown, an embodiment of the first aspect of this application provides a battery casing including multiple sidewalls that enclose a receiving space. Two adjacent sidewalls are defined as a first sidewall 101 and a second sidewall 102, with the wall thickness of the first sidewall 101 being greater than that of the second sidewall 102. The battery casing also includes a connecting portion 2 that connects the first sidewall 101 and the second sidewall 102. The connecting portion 2 includes a rounded section 23, a first transition section 21, and a second transition section 22. The rounded section 23 is connected to the second sidewall 102, the first transition section 21 is connected to the first sidewall 101, and the second transition section 22 connects the rounded section 23 and the first transition section 21. The wall thickness of both the rounded section 23 and the second transition section 22 is equal to the wall thickness of the second sidewall 102. The first transition section 21 includes a first end and a second end opposite to each other. The first end is connected to the second transition section 22, and the second end is connected to the first sidewall 101. The wall thickness of the first transition section 21 gradually increases in the direction from the first end to the second end.
[0027] The battery casing provided by the aforementioned technical features, through differentiated setting of sidewall thickness, provides stronger support when the cell generates gas. This effectively resists internal pressure, reduces casing deformation, maintains a stable internal environment within the cell, and lowers safety risks caused by casing deformation. The battery casing connection portion 2 adopts a design with a rounded section 23, a second transition section 22, and a first transition section 21, with the wall thickness of the first transition section 21 gradually increasing, resulting in a smoother transition at the edges. This design effectively disperses stress at the edges, avoids stress concentration caused by abrupt changes in wall thickness, significantly improves the fatigue resistance of the edges during charge-discharge cycles, reduces cracking, and enhances the overall structural strength of the battery casing. This effectively reduces the risk of casing deformation and edge cracking, providing more reliable protection for the cell, reducing battery failures caused by casing problems, thereby extending battery life and improving the safety and stability of lithium-ion batteries in electric vehicles and energy storage applications.
[0028] It should be noted that, as Figures 1 to 8As shown, the rounded segment 23 can be an inverted arc, that is, the two ends of the inverted arc are tangent to the second sidewall 102 and the second transition segment 22, respectively.
[0029] like Figure 1 As shown in the figure, a schematic diagram of the cross-sectional structure obtained by cutting the first sidewall 101 and the second sidewall 102 along a plane perpendicular to the intersection line of the first sidewall 101 and the second sidewall 102 is presented. Figure 1 From the viewpoint shown, the first sidewall 101 can extend along the first direction F1, and the second sidewall 102 can extend along the second direction F2. Preferably, Figure 1 The example shown is where the first sidewall 101 and the second sidewall 102 are perpendicular to each other. In other words, the first direction F1 is perpendicular to the second direction F2 to accommodate most square battery structures. However, it is not limited to this. The angle between the first direction F1 and the second direction F2 can also be an obtuse angle or an acute angle to accommodate battery structures of other shapes.
[0030] Preferably, such as Figure 1 As shown, the maximum wall thickness of the first transition section 21 (i.e., the wall thickness of the end of the first transition section 21 connected to the first side wall 101) can be equal to the wall thickness of the first side wall 101, so as to ensure a smooth connection between the first transition section 21 and the first side wall 101.
[0031] Similarly, such as Figure 1 As shown, the minimum wall thickness of the first transition section 21 (i.e., the wall thickness of the end of the first transition section 21 that connects to the second transition section 22) can be equal to the wall thickness of the second sidewall 102. This ensures that the wall thickness of the end of the first transition section 21 that connects to the second transition section 22 is equal to the wall thickness of the second transition section 22, thus guaranteeing a smooth connection between the first transition section 21 and the second transition section 22.
[0032] Preferably, such as Figure 1 As shown, the outer walls of the first transition section 21, the second transition section 22, and the first side wall 101 are aligned to ensure the smoothness and cleanliness of the outer surface of the battery casing.
[0033] Preferably, such as Figure 1 As shown, the inner wall surface of the first transition section 21 can be an inclined plane to facilitate the manufacturing and shaping of the first transition section 21.
[0034] like Figure 1 As shown, in the first direction F1, the size of the first transition segment 21 is H1, where, ,in, The wall thickness of the first sidewall 101, ∠α is the wall thickness of the second sidewall 102, and ∠α is the angle between the inner wall surface and the outer wall surface of the first transition section 21.
[0035] Preferably, the value of ∠α can be in the range of 10° to 30°, which can effectively ensure the smooth transition of the connecting part 2 and make the battery casing have good fatigue resistance.
[0036] Preferably, the difference between the wall thickness of the first sidewall 101 and the wall thickness of the second sidewall 102 can be 0.1mm to 1.0mm, so as to accommodate the wall thickness difference between adjacent sidewalls formed during the stamping process of most battery casings.
[0037] Preferably, such as Figure 1 As shown, in the first direction F1, the dimensions of the second transition segment 22 (i.e., Figure 1 The dimensions of H2 shown are the same as those of the first transition segment 21. Figure 1 The dimensions of the second transition segment 22 and the first transition segment 21 in the first direction F1 are equal, meaning H1 = H2. This makes the structure of the connecting portion 2 more regular, allowing stress to be transmitted more evenly and stably from the first transition segment 21 to the second transition segment 22. This avoids localized stress concentration or disorder caused by dimensional differences, ensuring that stress can smoothly transition along a preset path, further improving the stability of the battery casing under complex stress conditions.
[0038] Preferably, the battery casing satisfies the following condition: 0.35mm≤(H1+H2)≤11.34mm. This ensures a smooth transition of the connecting part 2, facilitates the processing and forming of the battery casing, and effectively improves the fatigue resistance of the battery casing.
[0039] In an embodiment, such as Figures 2 to 8 As shown in the figure, an example of a square battery casing is presented. Correspondingly, the battery casing may include a casing body, which is a square box.
[0040] Preferably, the shell body can be a one-piece molded square box. Here, one-piece molding can be understood as a one-piece molded part formed by processing methods such as stamping and deep drawing.
[0041] Preferably, such as Figures 2 to 8 As shown, the shell body is formed by two large sidewalls 11, two narrow sidewalls 12, and a bottom wall 13. Specifically, as... Figures 2 to 8As shown, two large sidewalls 11 are arranged opposite each other along the thickness direction T, and two narrow sidewalls 12 are arranged opposite each other along the width direction W. The two ends of each narrow sidewall 12 in the thickness direction T are respectively connected to the two large sidewalls 11. The bottom wall 13 is connected to the same end of the two large sidewalls 11 and the two narrow sidewalls 12 in the length direction L.
[0042] like Figures 2 to 8 As shown in the figure, L can be an example of the length direction L mentioned above, W can be an example of the width direction W mentioned above, and T can be an example of the thickness direction T mentioned above.
[0043] Preferably, the wall thickness of the large sidewall 11 is less than the wall thickness of the narrow sidewall 12 and less than the sidewall thickness of the bottom wall 13, so as to adapt to the forming characteristics of the square box formed by stamping and deep drawing.
[0044] like Figure 4 As shown in the figure, an example is shown where the aforementioned narrow sidewall 12 and bottom wall 13 are connected by the aforementioned connecting part 2.
[0045] like Figure 6 As shown in the figure, an example is shown where the aforementioned large sidewall 11 and bottom wall 13 are connected by the aforementioned connecting part 2.
[0046] like Figure 8 As shown in the figure, an example is shown where the large sidewall 11 and the narrow sidewall 12 are connected by the connecting part 2.
[0047] Referring to Table 1, the results of molding were shown below for shell bodies of the same specifications and dimensions, with changes made to the wall thicknesses of the large sidewall 11, the narrow sidewall 12, and the bottom wall 13, as well as the value of ∠α.
[0048] Table 1:
[0049] As shown in Table 1, when ∠α is in the range of 10° to 30°, the corresponding value of the transition length (i.e., H1+H2) satisfies 0.35mm≤(H1+H2)≤11.34mm, which makes the transition of the connection part 2 smooth and the fatigue resistance of the shell body is good. If (H1+H2)<0.35, the transition is too aggressive, losing the significance of the transition fillet and the fatigue resistance; if (H1+H2)>11.34mm, the transition length is too large, occupying the original wall length, which not only makes the process forming difficult and the stamping and stretching material feeding difficult, but also makes the required thickness of the original wall thinner, resulting in a loss of overall wall strength.
[0050] In an embodiment, preferably (not shown in the figure), the battery casing may further include a cover plate disposed at one end of the casing body in the length direction L away from the bottom wall 13, so as to seal the casing body and ensure the airtightness of the battery casing.
[0051] The second aspect of this application also provides a battery including the battery casing described in any of the above embodiments, and thus has all the beneficial technical effects of the battery casing, which will not be repeated here.
[0052] Preferably, the battery may further include an electrode assembly, which may be sealed within the battery casing.
[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application 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 or all of the technical features therein. Such 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 battery casing, characterized in that, It includes multiple sidewalls, which enclose and form an accommodating space; Two adjacent sidewalls are defined as the first sidewall and the second sidewall, respectively, and the wall thickness of the first sidewall is greater than the wall thickness of the second sidewall. The battery housing further includes a connecting portion that connects the first sidewall and the second sidewall. The connecting portion includes a rounded section, a first transition section, and a second transition section. Wherein, the rounded section is connected to the second sidewall, the first transition section is connected to the first sidewall, and the second transition section connects the rounded section and the first transition section; The wall thickness of both the rounded section and the second transition section is equal to the wall thickness of the second sidewall; The first transition segment includes a first end and a second end that are opposite to each other, the first end being connected to the second transition segment, and the second end being connected to the first sidewall; In the direction from the first end to the second end, the wall thickness of the first transition section gradually increases.
2. The battery casing according to claim 1, characterized in that, The maximum wall thickness of the first transition section is equal to the wall thickness of the first sidewall; The minimum wall thickness of the first transition section is equal to the wall thickness of the second sidewall.
3. The battery casing according to claim 1, characterized in that, The outer walls of the first transition section, the second transition section, and the first sidewall are aligned. The inner wall surface of the first transition section is an inclined plane.
4. The battery casing according to claim 3, characterized in that, On a plane that is perpendicular to both the first sidewall and the second sidewall, the extension direction of the first sidewall is the first direction, and the extension direction of the second sidewall is the second direction. In the first direction, the size of the first transition segment is H1; in, ,in, Let be the wall thickness of the first sidewall. α is the wall thickness of the second sidewall, and ∠α is the angle between the inner wall surface and the outer wall surface of the first transition section.
5. The battery casing according to claim 4, characterized in that, The value of ∠α ranges from 10° to 30°.
6. The battery casing according to claim 1, characterized in that, The difference between the thickness of the first sidewall and the thickness of the second sidewall is 0.1 mm to 1.0 mm.
7. The battery casing according to claim 4, characterized in that, In the first direction, the size of the second transition segment is equal to the size of the first transition segment; And / or, the battery casing satisfies: 0.35mm ≤ (H1 + H2) ≤ 11.34mm, where H2 is the size of the second transition section in the first direction.
8. The battery casing according to any one of claims 1 to 7, characterized in that, The battery casing includes a casing body; The shell body is a one-piece molded square box; The shell body is formed by two large sidewalls, two narrow sidewalls and a bottom wall. The two large sidewalls are arranged opposite each other along the thickness direction, and the two narrow sidewalls are arranged opposite each other along the width direction. Each narrow sidewall is connected to the two large sidewalls at both ends in the thickness direction. The bottom wall is connected to the same end of the two large sidewalls and the two narrow sidewalls in the length direction. Wherein, the wall thickness of the large sidewall is less than the wall thickness of the narrow sidewall and the wall thickness of the bottom wall; Both the large sidewall and the narrow sidewall, both the large sidewall and the bottom wall, and both the narrow sidewall and the bottom wall are connected via the connecting portion.
9. The battery casing according to claim 8, characterized in that, The battery casing also includes a cover plate disposed at one end of the casing body in the length direction away from the bottom wall.
10. A battery, characterized in that, The battery casing includes any one of claims 1 to 9.