Battery cell shell and battery cell
By incorporating a grooved pressure relief component inside the cell casing, the production complexity and contamination issues caused by the explosion-proof valve in existing battery structures are resolved, enabling safe pressure relief and efficient production of the cells.
Patent Information
- Application Number
- CN202511222439.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-29
- Publication Date
- 2026-08-04
- Estimated Expiration
- 2045-08-29
AI Technical Summary
Existing battery structures place the explosion-proof valve on the cap or outside the casing, which leads to complex production processes, low yield rates, and the explosion-proof valve is easily contaminated, affecting the product quality and safety performance of the battery.
Design a battery cell housing in which a pressure relief component is installed in a groove-shaped structure inside the housing body. The bottom wall is recessed into the cavity. When the battery cell experiences thermal runaway, the pressure relief component breaks through to achieve internal and external communication, eliminating the need for welding and directly forming it on the housing. The pressure relief component is coaxially arranged with the side wall to ensure sufficient safety distance and opening area.
This enables timely pressure relief of the battery cells, improving production yield and safety performance, reducing the risk of external contamination, simplifying processing steps, and saving costs.
Smart Images
Figure CN120999202B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of battery technology, and in particular to a cell housing and a cell. 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] Current batteries consist of two parts: the main casing and the cap. To ensure safe pressure release in the event of thermal runaway, an explosion-proof valve is required within the battery structure. Existing battery structures place the explosion-proof valve on the cap and connect it using welding. This increases the number of production steps, reduces production efficiency, and results in a low welding yield. Furthermore, some battery structures place the explosion-proof valve on the outside of the casing, making it susceptible to external contamination, which can affect the battery's product quality and safety performance. Summary of the Invention
[0004] In view of this, the purpose of this application is to provide a cell housing and a cell to solve the problem that the existing battery structure places the explosion-proof valve on the cap or the outside of the housing, which leads to a complicated production process and low yield of the cell, and the explosion-proof valve is easily contaminated, thereby affecting the product quality and safety performance of the battery.
[0005] A first aspect of the present invention provides a battery cell housing, wherein the battery cell housing comprises: The housing body has a bottom wall and side walls, the bottom wall and side walls forming an accommodating cavity; The pressure relief component is formed as a groove-shaped structure disposed inside the housing body, and is formed by an inward recess from the surface of the bottom wall facing the accommodating cavity; The thickness of the sidewall in the first direction is g, in mm; the distance between the end of the pressure relief component facing the sidewall and the surface of the sidewall facing away from the accommodating cavity in the first direction is w1, in mm, where 5×g≤w1≤6×g.
[0006] Preferably, the distance between the bottom of the pressure relief component and the surface of the bottom wall facing away from the accommodating cavity in the second direction is d, where 50 µm ≤ d ≤ 100 µm.
[0007] Preferably, the pressure relief component is cut along the second direction and the cross section is formed as a trapezoidal structure with an upper bottom and a lower bottom. The length dimension of the upper bottom in the first direction is smaller than the length dimension of the lower bottom in the first direction. The upper bottom is disposed at the bottom of the groove of the pressure relief component in the groove structure.
[0008] Preferably, the dimension of the lower bottom in the first direction is w2, in mm, and the dimension of the upper bottom in the first direction is w3, in mm, where 0.4×w2≤w3≤0.7×w2.
[0009] Preferably, 0.4mm≤w2≤0.5mm. Preferably, the cross-section of the pressure relief component along the second direction is formed into a triangular structure with a sharp angle, and the sharp angle is located at the bottom of the groove of the groove-shaped pressure relief component. Preferably, the pressure relief component is formed as an annular groove structure with an opening, the length of which is G, 1mm≤G≤2mm.
[0010] Preferably, the pressure relief component is disposed on the negative electrode side of the battery cell, and / or the pressure relief component is formed by stamping on the bottom wall. Preferably, the axis of the pressure relief component extending in the second direction is coaxial with the axis of the housing body extending in the second direction; And / or, the shape of the pressure relief element is the same as the shape of the sidewall.
[0011] A second aspect of the present invention provides a battery cell comprising the battery cell housing described in any of the above technical solutions.
[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: The battery cell housing of the present invention includes a housing body having a bottom wall and side walls, the bottom wall and side walls forming an accommodating cavity; the pressure relief component is formed as a groove-shaped structure disposed inside the housing body, and is formed by inward indentation from the surface of the bottom wall facing the accommodating cavity. In the event of thermal runaway and internal gas generation in the battery cell, the pressure will increase and rupture the pressure relief component, making the inside and outside of the battery cell connected, so as to achieve timely pressure relief and ensure the safety performance of the battery cell. The pressure relief component is disposed inside the housing body so that the housing body protects the pressure relief component, reducing the risk of external contamination. Moreover, the pressure relief component is directly formed on the bottom wall of the housing body, which is convenient for processing and eliminates the welding process, saving costs and improving the production yield of the battery cell; the thickness of the side wall in the first direction is g, in mm; the distance between the end of the pressure relief component facing the side wall and the surface of the side wall facing away from the accommodating cavity in the first direction is w1, in mm, 5×g≤w1≤6×g, so as to form a sufficient safety distance, while ensuring that there is sufficient pressure relief area after the pressure relief component is opened, thereby improving the production quality and safety performance of the battery cell.
[0013] 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
[0014] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in 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 the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0015] Figure 1 This is a schematic diagram of the battery cell housing provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the battery cell housing from another perspective, provided in an embodiment of the present invention. Figure 3 This is a partial cross-sectional view of the battery cell casing provided in an embodiment of the present invention; Figure 4 for Figure 3 Enlarged structural diagram at point A in the middle.
[0016] Icons: 10-Main body of the shell; 11-Bottom wall; 12-Side wall; 100-Accommodation cavity; 20-Pressure relief component; 21-Opening; 201-Upper bottom; 202-Lower bottom; D1-First direction; D2-Second direction. Detailed Implementation
[0017] The following detailed embodiments are provided to help the reader gain a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and / or systems described herein will be apparent after understanding the disclosure of this application. For example, the order of operations described herein is merely illustrative and is not limited to the order set forth herein; changes that will be apparent after understanding the disclosure of this application are possible, except for operations that must occur in a specific order. Furthermore, for clarity and brevity, descriptions of features known in the art may be omitted.
[0018] The features described herein may be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many feasible ways of implementing the methods, apparatus, and / or systems described herein that will be apparent upon understanding the disclosure of this application.
[0019] Throughout the specification, when an element (such as a layer, region, or substrate) is described as being "on" another element, "connected to" another element, "bonded to" another element, "on" another element, or "covering" another element, it may be directly "on" another element, "connected to" another element, "bonded to" another element, "on" another element, or "covering" another element, or there may be one or more other elements in between. In contrast, when an element is described as being "directly on" another element, "directly connected to" another element, "directly bonded to" another element, "directly on" another element, or "directly covering" another element, there may be no other elements in between.
[0020] As used herein, the term “and / or” includes any one of the relevant items listed and any combination of any two or more items.
[0021] Although terms such as “first,” “second,” and “third” may be used herein to describe individual components, assemblies, regions, layers, or parts, these components, assemblies, regions, layers, or parts are not limited by these terms. Rather, these terms are used only to distinguish one component, assembly, region, layer, or part from another. Therefore, without departing from the teachings of the examples described herein, the first component, assembly, region, layer, or part referred to as the second component, assembly, region, layer, or part may also be referred to as the second component, assembly, region, layer, or part.
[0022] For ease of description, spatial relation terms such as “above,” “upper,” “below,” and “lower” are used herein to describe the relationship between one element and another, as shown in the accompanying drawings. Such spatial relation terms are intended to include not only the orientation depicted in the drawings but also different orientations of the device during use or operation. For example, if the device in the drawings is flipped, an element described as being “above” or “upper” relative to another element will subsequently be “below” or “lower” relative to that other element. Therefore, the term “above” includes both “above” and “below” orientations depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relation terms used herein will be interpreted accordingly.
[0023] The terminology used herein is for the purpose of describing various examples only and is not intended to limit this disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms “comprising,” “including,” and “having” enumerate the stated features, quantities, operations, components, elements, and / or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.
[0024] Variations in the shapes shown in the accompanying drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the accompanying drawings, but include changes in shape that may occur during manufacturing.
[0025] The features of the examples described herein can be combined in various ways that will be apparent upon understanding the disclosure of this application. Furthermore, although the examples described herein have a wide variety of constructions, other constructions are possible, as will be apparent upon understanding the disclosure of this application.
[0026] According to a first aspect of the present invention, a battery cell housing is provided, which specifically includes a housing body 10 and a pressure relief component 20.
[0027] The specific structure of the battery cell housing according to this embodiment, as described above, will be described below.
[0028] In this embodiment, as Figure 1 and Figure 2 As shown, the housing body 10 has a bottom wall 11 and a side wall 12. The side wall 12 forms an annular shape, and the bottom wall 11 closes one end of the annular shape formed by the side wall 12. The bottom wall 11 and the side wall 12 together form a receiving cavity 100. The receiving cavity 100 is used to carry components such as electrode groups that are located inside the battery cell. The battery cell cap closes the other end of the annular shape formed by the side wall 12, that is, it closes the receiving cavity 100.
[0029] like Figures 1 to 3As shown, the pressure relief component 20 can open to achieve communication between the inside and outside of the battery cell when the cell experiences thermal runaway. Specifically, in this embodiment, the pressure relief component 20 is formed as a groove-shaped structure inside the housing body 10, and is formed by the inward indentation of the bottom wall 11 facing the accommodating cavity 100, thereby reducing the thickness of the bottom wall 11. When gas is generated inside the battery cell and the pressure is high enough to open the pressure relief component 20, it can break through the pressure relief component 20, causing the bottom wall 11 to crack along the shape of the groove-shaped structure of the pressure relief component 20, thereby achieving communication between the inside and outside of the battery cell, achieving the purpose of timely pressure relief and ensuring the safety performance of the battery cell. The pressure relief component 20 is set inside the housing body 10 so that the housing body 10 protects the pressure relief component 20, reducing the risk of external contamination. The pressure relief component 20 is directly formed on the bottom wall 11 of the housing body 10 without the need for additional welding, which has the advantages of easy processing and eliminating the welding process, saving costs and improving the production yield of the battery cell.
[0030] Preferably, the pressure relief component 20 is formed by stamping on the bottom wall 11, so that the pressure relief component 20 and the housing body 10 can be integrally formed, which is convenient for processing and also improves the situation where the production yield of the battery cell is reduced due to defects caused by welding.
[0031] In this embodiment, the sidewall 12 can be a cylinder to suit cylindrical battery cells; the sidewall 12 can also be a cuboid to suit prismatic battery cells. When the battery cell is cylindrical, the pressure relief component 20 is disposed on the negative electrode side of the battery cell, that is, the negative electrode of the battery cell is located on the side of the bottom wall 11 relative to the housing body 10. In this embodiment, as Figure 3 and Figure 4 As shown, the thickness of the sidewall 12 in the first direction D1 is g, in mm; the distance between the end of the pressure relief component 20 facing the sidewall 12 and the surface of the sidewall 12 facing away from the accommodating cavity 100 in the first direction D1 is w1, in mm, 5×g≤w1≤6×g, to form a sufficient safety distance, while ensuring that the pressure relief component 20 has a sufficient pressure relief area after opening, thereby improving the production quality and safety performance of the battery cell.
[0032] Preferably, 0.1mm≤g≤0.3mm.
[0033] In this embodiment, the pressure relief member 20 is formed as a ring structure, such that its axis extending in the second direction D2 is coaxial with the axis extending in the second direction D2 of the housing body 10, so as to ensure that the distance between the pressure relief member 20 and the side wall 12 is equal at all points.
[0034] Preferably, the shape of the pressure relief component 20 is the same as the shape of the side wall 12. For example, when the projection of the side wall 12 onto the plane perpendicular to the axial direction is circular, the pressure relief component 20 is formed as a ring; for example, when the projection of the side wall 12 onto the plane perpendicular to the axial direction is rectangular, the pressure relief component 20 is a proportionally reduced rectangular ring.
[0035] In a preferred embodiment, such as Figure 1 and Figure 2 As shown, the pressure relief component 20 is formed as an annular groove structure with an opening 21. When the pressure relief component 20 is opened, the area inside the annulus on the bottom wall 11 is lifted outwards and remains connected to the area outside the annulus after being lifted. This avoids the risk of short circuit caused by metal contact due to splashing when the pressure relief component 20 is opened. Specifically, the length of the opening 21 is G, where 1mm≤G≤2mm. This ensures that the pressure relief component 20 can be opened smoothly and has a sufficient opening area, and effectively avoids splashing caused by the pressure relief component 20 detaching from the housing body 10 after being opened.
[0036] Furthermore, in this embodiment, as Figure 3 and Figure 4 As shown, the distance between the bottom of the groove of the pressure relief component 20 and the surface of the bottom wall 11 facing away from the accommodating cavity 100 in the second direction D2 is d, 50 µm≤d≤100 µm, thus ensuring the strength of the housing body 10 and ensuring that the pressure relief component 20 can be opened smoothly.
[0037] It should be noted that the first direction D1 is perpendicular to the second direction D2; when the shell body 10 is a cylinder, the first direction D1 is the radial direction of the shell body 10, and the second direction D2 is the axial direction of the shell body 10; when the shell body 10 is a cuboid, the first direction D1 can be the width direction or the thickness direction of the shell body 10, and the second direction D2 is the length direction of the shell body 10 (i.e., the depth direction of the accommodating cavity 100).
[0038] In a preferred embodiment, such as Figure 3 and Figure 4 As shown, the cross-section of the pressure relief component 20 along the second direction D2 is formed into a trapezoidal structure with an upper bottom 201 and a lower bottom 202, preferably an isosceles trapezoid. The upper bottom 201 and the lower bottom 202 are spaced apart and parallel to each other in the second direction D2. The length dimension of the upper bottom 201 in the first direction D1 is smaller than the length dimension of the lower bottom 202 in the first direction D1. The upper bottom 201 is disposed at the bottom of the groove of the pressure relief component 20 with the groove structure.
[0039] Furthermore, such as Figure 4 As shown, the dimension of the lower bottom 202 in the first direction D1 is w2, in mm, and the dimension of the upper bottom 201 in the first direction D1 is w3, in mm. 0.4×w2≤w3≤0.7×w2, thus ensuring that the pressure relief component 20 will open smoothly only when the internal pressure of the battery cell reaches the preset parameter. This will prevent premature opening from affecting the service life of the battery cell, and will also prevent delayed opening or failure to open, which could lead to the rupture of the casing body 10 and affect the safety performance of the battery cell.
[0040] Furthermore, such as Figure 4 As shown, 0.4mm≤w2≤0.5mm. In another preferred embodiment, the cross-section of the pressure relief member 20 along the second direction D2 is formed into a triangular structure with sharp corners, and the sharp corners are located at the bottom of the groove of the pressure relief member 20.
[0041] The following tests verify the reliability of the limiting conditions of 5×g≤w1≤6×g, 0.4mm≤w2≤0.5mm, and 0.4×w2≤w3≤0.7×w2 in this invention. Each test group includes multiple cells, and the test results are shown in Table 1.
[0042] Table 1
[0043] Note: A test result of OK indicates that the test is qualified, and a test result of NG indicates that the test is unqualified.
[0044] As shown in Table 1, in Examples 1 to 9, w1, w2, and w3 are respectively within the limits of 5×g≤w1≤6×g, 0.4mm≤w2≤0.5mm, and 0.4×w2≤w3≤0.7×w2. The size design of the pressure relief component 20 is reasonable, and the exhaust area and opening pressure can match the exhaust requirements. However, in Comparative Example 1, the pressure relief component 20 opens prematurely because the size of w2 is too small, and the pressure relief component 20 opens prematurely because the size of w1 is too small, and the part that falls off after opening flies out of the cell casing, increasing the safety risk. In Comparative Examples 2 and 3, the pressure relief component 20 opens late or not at all because the size of w2 and w3 is too large, and the main body of the casing 10 has cracked, affecting the safety performance of the cell.
[0045] According to the present invention, a battery cell housing includes a housing body having a bottom wall and side walls, the bottom wall and side walls forming an accommodating cavity; a pressure relief component is formed as a groove-shaped structure disposed inside the housing body, and is formed by inward indentation from the surface of the bottom wall facing the accommodating cavity. In the event of thermal runaway and internal gas generation in the battery cell, the pressure will increase and rupture the pressure relief component, making the inside and outside of the battery cell interconnected, so as to achieve timely pressure relief and ensure the safety performance of the battery cell. The pressure relief component is disposed inside the housing body so that the housing body protects the pressure relief component, reducing the risk of external contamination. Moreover, the pressure relief component is directly formed on the bottom wall of the housing body, which is convenient for processing and eliminates the welding process, saving costs and improving the production yield of the battery cell; the thickness of the side wall in the first direction is g, in mm; the distance between the end of the pressure relief component facing the side wall and the surface of the side wall facing away from the accommodating cavity in the first direction is w1, in mm, 5×g≤w1≤6×g, so as to form a sufficient safety distance, while ensuring that there is sufficient pressure relief area after the pressure relief component is opened, thereby improving the production quality and safety performance of the battery cell.
[0046] The battery cell provided by the present invention includes the battery cell housing as described above, and thus has all the above-mentioned beneficial effects, which will not be repeated here.
[0047] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the technical scope disclosed in this application. Such modifications, changes, 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 application, and should all be covered within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims.
Claims
1. An electric cell housing, characterized by, The cell housing includes: The housing body has a bottom wall and side walls, the bottom wall and side walls forming an accommodating cavity; The pressure relief component is formed as a groove-shaped structure disposed inside the housing body, and is formed by an inward recess from the surface of the bottom wall facing the accommodating cavity; The thickness of the sidewall in the first direction is g, in mm; the distance between the end of the pressure relief component facing the sidewall and the surface of the sidewall facing away from the accommodating cavity in the first direction is w1, in mm, where 5×g≤w1≤6×g, and 0.1mm≤g≤0.3mm. The pressure relief component is cut along the second direction and its cross-section is formed into a trapezoidal structure with an upper bottom and a lower bottom. The length dimension of the upper bottom in the first direction is smaller than the length dimension of the lower bottom in the first direction. The upper bottom is disposed at the bottom of the groove of the pressure relief component in the groove structure. The dimension of the lower bottom in the first direction is w2 in mm, and the dimension of the upper bottom in the first direction is w3 in mm. 0.4×w2≤w3≤0.7×w2, 0.4mm≤w2≤0.5mm.
2. The cell case of claim 1, wherein, The distance between the bottom of the pressure relief component and the surface of the bottom wall facing away from the accommodating cavity in the second direction is d, 50µm≤d≤100µm.
3. The cell case of claim 1, wherein, The pressure relief component is cut along the second direction and its cross-section is formed into a triangular structure with sharp corners, the sharp corners being located at the bottom of the groove of the groove-shaped pressure relief component.
4. The cell case of claim 1, wherein, The pressure relief component is formed as an annular groove structure with an opening, the length of which is G, 1mm≤G≤2mm.
5. The cell case of claim 1, wherein, The pressure relief component is disposed on the negative electrode side of the battery cell, and / or the pressure relief component is formed by stamping on the bottom wall.
6. The cell case of claim 1, wherein, The axis of the pressure relief component extending in the second direction is coaxial with the axis of the housing body extending in the second direction; And / or, the shape of the pressure relief element is the same as the shape of the sidewall.
7. An electric cell characterized by The cell housing includes any one of claims 1 to 6.