Battery cell shell and battery cell

Abstract

The application relates to the technical field of batteries, in particular to a battery cell shell and a battery cell. The battery cell shell comprises a shell main body including an annular side wall enclosing a containing cavity, the containing cavity has an opening, the side wall is formed with a turned-in flange part at the opening, the turned-in flange part is used for crimping a sealing ring in a cover cap to a top cap in the cover cap, a rolling groove part is arranged on the side wall and recessed inward in a first direction, so that a protrusion is formed on a cavity wall of the containing cavity, the protrusion is arranged in a second direction and is spaced from the turned-in flange part, the distance between one end of the turned-in flange part facing an axis of the side wall and an outer wall of the side wall in the first direction is w2, the distance between one end of the protrusion facing the axis of the side wall and an inner wall of the side wall in the first direction is w4, and 1.8*w4<=w2<=2.2*w4. The application guarantees that the turned-in flange part has sufficient crimping strength, guarantees the sealing performance of the cover cap, improves the assembly quality of the battery cell shell and the cover cap, and thus improves the use performance and service life of the battery cell.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a battery cell shell and a battery cell. BACKGROUND

[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 fields, and the use performance and safety of lithium ion batteries are increasingly required.

[0003] The current battery includes a shell and a cap, and after the cap is assembled with the shell, part of the sealing ring in the cap of the shell is bent inward, so that the bent part of the shell can press the sealing ring on the top cover of the cap to achieve battery sealing. The insufficient press-fit strength of the sealing ring after the shell is bent will affect the sealing performance of the cap, thereby affecting the use performance and service life of the battery. In addition, the shell is processed into an inner boss by edge rolling for positioning and supporting the cap. The structure of the inner boss affects the supporting strength, and if the strength is insufficient, the risk of fracture failure will increase. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a battery cell shell and a battery cell to solve the problem that the existing battery cell shell has insufficient press-fit strength of the sealing ring after bending, which affects the sealing performance, thereby reducing the use performance and service life of the battery cell.

[0005] The first aspect of the present application provides a battery cell shell, wherein the battery cell shell comprises:

[0006] A shell body comprising an annular side wall enclosing a receiving cavity, the receiving cavity having an opening, the side wall forming a turned-in edge portion at the opening and extending in a first direction, the side wall being provided with a rolling groove portion recessed inwardly in the first direction, so that a protrusion is formed on the cavity wall of the receiving cavity; the protrusion is spaced apart from the turned-in edge portion in a second direction, and the first direction is perpendicular to the second direction;

[0007] The distance between one end of the turned-in edge portion facing the axis of the side wall and the outer wall of the side wall in the first direction is w2; the distance between one end of the protrusion facing the axis of the side wall and the inner wall of the side wall in the first direction is w4, and 1.8xw4≤w2≤2.2xw4.

[0008] Preferably, the size of the side wall in the first direction is w1, and 0.05xw1≤w4≤0.08xw1.

[0009] Preferably, the size of the protrusion in the second direction is w3, and 1.1xw3≤w4≤1.2xw3.

[0010] Preferably, the thickness of the side wall is equal everywhere, and the thickness of the side wall is g, in mm;

[0011] 6xg≤w3≤7xg; 11.88xg≤w2≤18.48xg; 6.6xg≤w4≤8.4xg;

[0012] The size of the side wall in the first direction is w1, and 132xg≤w1≤168xg.

[0013] Preferably, in the second direction, the accommodation cavity forms a first accommodation space for accommodating a cover cap on the side of the convex part facing the outside of the battery;

[0014] In the second direction, the accommodation cavity forms a second accommodation space for accommodating a pole group on the side of the convex part facing the inside of the battery.

[0015] Preferably, the thickness of the flange part in the second direction is g1, in mm; the thickness of the side wall surrounding the first accommodation space in the first direction is g2, in mm; the thickness of the groove bottom of the rolling groove part in the first direction is g3, in mm; and the thickness of the side wall surrounding the second accommodation space in the first direction is g4, in mm;

[0016] At least two of g1, g2, g3, and g4 are not equal.

[0017] Preferably, G1=min{g1, g2, g3, g4}, 0.15mm≤G1≤0.3mm; and G2=max{g1, g2, g3, g4}, 0.15mm≤G2≤0.3mm.

[0018] Preferably, 6xG1≤w3≤7xG2; 11.88xG1≤w2≤18.48xG2; and 6.6xG1≤w4≤8.4xG2.

[0019] The outer surface of the side wall surrounding the first accommodation space extending in the second direction is arranged coplanar with the outer surface of the side wall surrounding the second accommodation space extending in the second direction; and the size of the side wall in the first direction is w1, and 132xG1≤w1≤168xG2.

[0020] Preferably, the shell body further comprises:

[0021] A bottom wall arranged on the side of the side wall away from the opening in the second direction.

[0022] The second aspect of the present application provides an electric core comprising the electric core shell of any of the above technical solutions.

[0023] Compared with the prior art, the application has the following beneficial effects:

[0024] The shell body of the battery cell comprises an annular side wall enclosing a receiving cavity, the receiving cavity has an opening, the side wall is formed with a flange portion at the opening, the flange portion is inwardly folded and extends in a first direction, and is used for crimping a sealing ring in the cover cap to a top cap in the cover cap; a rolling groove portion is arranged on the side wall and recessed inwardly in the first direction, so that a protrusion is formed on a cavity wall of the receiving cavity to play a supporting role on the cover cap; the protrusion is arranged in a second direction and is spaced from the flange portion, the first direction is perpendicular to the second direction; a distance between one end of the flange portion facing an axis of the side wall and an outer wall of the side wall in the first direction is w2; a distance between one end of the protrusion facing the axis of the side wall and an inner wall of the side wall in the first direction is w4, and 1.8xw4≤w2≤2.2xw4, so that the flange portion has sufficient crimping strength, the sealing property of the cover cap is ensured, the assembly quality of the shell body of the battery cell and the cover cap is improved, and the use performance and service life of the battery cell are improved.

[0025] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the following preferred embodiments are described in detail below, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or the prior art description. Obviously, the drawings described below are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0027] Figure 1 The structural schematic diagram of the battery cell shell provided by the embodiment of the present application is shown in the figure;

[0028] Figure 2 The structural schematic diagram of the battery cell shell provided by the embodiment of the present application is shown in the figure;

[0029] Figure 3 The structural sectional view of the battery cell shell provided by the embodiment of the present application is shown in the figure;

[0030] Figure 4 The local enlarged structural sectional view of the battery cell shell provided by the embodiment of the present application is shown in the figure, when the wall thickness is equal;

[0031] Figure 5 The local enlarged structural sectional view of the battery cell shell provided by the embodiment of the present application is shown in the figure, when the wall thickness is not equal.

[0032] Icon: 1 - housing body; 10 - accommodation cavity; 100 - opening; 101 - first accommodation space; 102 - second accommodation space; 1000 - protrusion; 11 - side wall; 111 - flange portion; 112 - roll groove portion; 12 - bottom wall; D1 - first direction; D2 - second direction. DETAILED DESCRIPTION

[0033] The following detailed description is presented to help the reader understand the methods, devices, and / or systems described herein. However, various changes, modifications, and equivalents can be made as would be obvious to a person of ordinary skill in the art having the benefit of this disclosure. For example, the order in which operations are described is not necessarily the order in which the operations are performed. Additionally, the various operations described herein can be combined or divided into sub-operations, and / or some operations can be performed concurrently. Additionally, some operations can be performed by hardware components or software components, including digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), and / or other integrated components.

[0034] The features described herein can be implemented in different forms and should not be construed as limited to the examples described herein. Rather, these examples have been provided so that this disclosure will be thorough and complete, and will fully convey the scope of the methods, devices, and / or systems to be implemented. Further, the description should not be construed as limiting the described features to the precise forms disclosed. Rather, the examples described herein are provided so that this disclosure will satisfy applicable legal requirements.

[0035] Throughout the specification, when an element (such as a layer, region, or substrate) is referred to as being “on” another element, “connected to” another element, “coupled to” another element, “adjacent to” another element, or “covering” another element, it can be directly on, connected, coupled, adjacent to, or covering the other element or one or more other elements can be interposed therebetween. In contrast, when an element is referred to as being “directly on,” “directly connected to,” “directly coupled to,” “directly adjacent to,” or “directly covering” another element, there are no other elements interposed therebetween.

[0036] As used herein, the term “and / or” includes any one of the listed items and any combination of two or more of the listed items.

[0037] Although terms such as "first", "second", and "third" can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. Rather, these terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, terms of a first element, component, region, layer or section described in the examples herein could also be termed a second element, component, region, layer or section without departing from the teachings of the examples.

[0038] For ease of description, spatial relationship terms such as "on", "upper", "under", and "lower" can be used herein to describe the relationship between one element and another element as shown in the drawings. Such spatial relationship terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the drawings. For example, if the device in the drawings is turned over, an element described as on "upper" or "upper" relative to another element would then be oriented "under" or "lower" relative to the other element. Accordingly, the term "on" encompasses both an "on" and "under" orientation based on the spatial orientation of the device. The device can be oriented in other ways (e.g., rotated 90 degrees or at other orientations) and an appropriate re-interpretation of the spatial relationship terms used herein will be made.

[0039] The terminology used herein is for the purpose of describing various examples only and is not intended to be limiting of the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises", "comprising", "includes", "including" and "has", "having" as used herein, are specifically intended to be construed as open-ended terms, i.e., to mean "including, but not limited to", "including, but not limited to", "including, but not limited to" and "including, but not limited to", respectively.

[0040] Variations in shapes depicted in the drawings can occur as a result of manufacturing processes and / or tolerances. Thus, the examples described herein are not limited to the specific shapes described herein but include variations in shapes that occur during manufacturing.

[0041] The features of the examples described herein can be combined in a variety of ways as will be apparent after the disclosure of the application is understood. In addition, although the examples described herein have a variety of configurations, other configurations are possible as will be apparent after the disclosure of the application is understood.

[0042] According to a first aspect of the present application, there is provided an electrode housing, which specifically includes a housing main body 1.

[0043] Hereinafter, the specific structure of the electrode housing according to the present embodiment will be described as described above.

[0044] In this embodiment, as Figures 1 to 3 As shown, the housing body 1 includes an annular sidewall 11 surrounding a receiving cavity 10. The sidewall 11 can be a cylindrical annular structure. The receiving cavity 10 has an opening 100. The sidewall 11 has an inwardly folded flange 111 at the opening 100, which extends along a first direction D1, for pressing the sealing ring in the cap onto the top cover of the cap. The sidewall 11 is provided with a groove 112 that is recessed inward along the first direction D1, so that a protrusion 1000 is formed on the cavity wall of the receiving cavity 10 to support the cap. The groove 112 can be formed by a rolling process.

[0045] Specifically, the flange 111 is formed into an annular plate structure, and the groove 112 is formed into an annular groove structure. It should be noted that the relationship between the groove 112 and the protrusion 1000 can be understood as follows: after the sidewall 11 is processed by the rolling process, the groove wall of the groove 112 is formed on the outer wall of the sidewall 11, and the protrusion 1000 is formed on the inner wall of the sidewall 11.

[0046] In this embodiment, the protrusion 1000 and the flange 111 are spaced apart on the second direction D2. The first direction D1 is perpendicular to the second direction D2. When the cell is a cylindrical cell, the first direction D1 is the radial direction of the cell and the second direction D2 is the axial direction of the cell.

[0047] Preferably, the main body 1 of the shell is a steel shell.

[0048] In this embodiment, as Figure 4 As shown, the distance between the end of the flange 111 facing the axis of the side wall 11 and the outer wall of the side wall 11 in the first direction D1 is w2; the distance between the end of the protrusion 1000 facing the axis of the side wall 11 and the inner wall of the side wall 11 in the first direction D1 is w4, 1.8×w4≤w2≤2.2×w4, thus ensuring that the flange 111 has sufficient crimping strength, ensuring the sealing of the cap, improving the assembly quality of the cell housing and the cap, thereby improving the performance and service life of the cell.

[0049] Furthermore, in this embodiment, as Figure 4 As shown, the dimension of the sidewall 11 in the first direction D1 is w1, 0.05×w1≤w4≤0.08×w1, thus ensuring that the protrusion 1000 has sufficient support strength to meet the assembly requirements of the cap and the battery cell housing.

[0050] In this embodiment, as Figure 4 As shown, the size of the protrusion 1000 in the second direction D2 is w3, 1.1×w3≤w4≤1.2×w3, which ensures that the protrusion 1000 has sufficient rigidity to prevent the protrusion 1000 from easily deforming.

[0051] In one alternative implementation, such as Figure 4 As shown, the battery cell housing is formed as a housing structure with equal wall thickness, that is, the thickness of the side wall 11 is equal everywhere. The thickness dimension of the side wall 11 is g, 6×g≤w3≤7×g, which reduces the processing difficulty of the groove 112 and reduces the risk of the protrusion 1000 breaking and failing.

[0052] Furthermore, 11.88×g≤w2≤18.48×g ensures that the flange 111 has sufficient pressing strength, while also facilitating the bending of the main body 1 of the housing to form the flange 111, thereby improving the sealing performance and ensuring reliable sealing.

[0053] Furthermore, 6.6×g≤w4≤8.4×g ensures that the protrusion 1000 has sufficient support strength, while reducing the processing difficulty and facilitating the forming of the groove 112.

[0054] Furthermore, 132×g≤w1≤168×g, thus ensuring the structural strength of sidewall 11.

[0055] It should be noted that the units for w1, w2, w3, w4 and g are all mm.

[0056] The reliability of the limiting conditions of 1.8×w4≤w2≤2.2×w4, 6×g≤w3≤7×g, 11.88×g≤w2≤18.48×g, 6.6×g≤w4≤8.4×g, and 132×g≤w1≤168×g in this invention is verified through multiple sets of tests. Each set of tests includes multiple battery cells, and the test results are shown in Table 1.

[0057] Table 1

[0058]

[0059] As shown in Table 1, in Examples 1 to 7, w1, w2, w3, and w4 are respectively within the ranges of 1.8×w4≤w2≤2.2×w4, 132×g≤w1≤168×g, 11.88×g≤w2≤18.48×g, 6×g≤w3≤7×g, and 6.6×g≤w4≤8.4×g. The dimensional relationships are reasonable and do not affect the assembly of the battery cell housing. The sealing and safety of the assembled battery cell meet the requirements. However, in Comparative Example 1, because the size of w2 is too small, it cannot effectively press the cap, resulting in sealing failure. In Comparative Example 2, because the size of w2 is too large, it will squeeze the explosion-proof valve in the cap, affecting the opening of the explosion-proof valve, resulting in the failure of the valve opening of 3 battery cells, and failing to guarantee the safety performance of the battery cells. In Comparative Example 3, because the size of w4 is too large, it will squeeze the sealing ring in the cap, causing the sealing ring to crack and the sealing failure.

[0060] In this embodiment, as Figures 3 to 5 As shown, in the second direction D2, the receiving cavity 10 forms a first receiving space 101 for receiving the cap on the side of the protrusion 1000 facing the outside of the battery; in the second direction D2, the receiving cavity 10 forms a second receiving space 102 for receiving the electrode assembly on the side of the protrusion 1000 facing the inside of the battery. The first receiving space 101 and the second receiving space 102 are arranged in the second direction D2. The electrode tabs on the electrode assembly can extend into the first receiving space 101 and connect with the cap, thus realizing the transmission of electrical energy.

[0061] In another alternative implementation, such as Figure 5 As shown, the battery cell housing is formed as a housing structure with unequal wall thickness. Specifically, the thickness of the flange 111 in the second direction D2 is g1 (in mm); the thickness of the sidewall 11 forming the first receiving space 101 in the first direction D1 is g2 (in mm); the thickness of the bottom of the groove 112 in the first direction D1 is g3 (in mm); and the thickness of the sidewall 11 forming the second receiving space 102 in the first direction D1 is g4 (in mm). At least two of g1, g2, g3, and g4 are not equal, so that there are multiple locations with unequal thicknesses on the sidewall 11, thus satisfying the strength requirements of the wall thickness at different locations of the battery cell housing. Preferably, g1≠g2≠g3≠g4.

[0062] Furthermore, such as Figure 5 As shown, G1=min{g1,g2,g3,g4}, that is, G1 is the minimum value among g1, g2, g3 and g4, 0.15mm≤G1≤0.3mm; G2=max{g1,g2,g3,g4}, that is, G2 is the maximum value among g1, g2, g3 and g4, 0.15mm≤G2≤0.3mm.

[0063] Furthermore, such as Figure 5 As shown, 6×G1≤w3≤7×G2 reduces the processing difficulty of the grooved part 112 and reduces the risk of breakage failure of the protrusion 1000; 11.88×G1≤w2≤18.48×G2 ensures that the flanged part 111 has sufficient pressing strength, and at the same time facilitates the bending of the housing body 1 to form the flanged part 111, thereby improving the sealing performance and ensuring reliable sealing; 6.6×G1≤w4≤8.4×G2 ensures that the protrusion 1000 has sufficient supporting strength, and at the same time reduces the processing difficulty and facilitates the processing and forming of the grooved part 112.

[0064] Preferably, 2.1×w3≤w2≤2.5×w3 and w4>w3, so that the cap is reliably fixed and the flange 111 or the groove 112 is prevented from breaking or collapsing.

[0065] Furthermore, the outer surface of the sidewall 11 forming the first receiving space 101 extending in the second direction D2 and the outer surface of the sidewall 11 forming the second receiving space 102 extending in the second direction D2 are coplanar with each other. That is, the thickness difference between g2 and g4 is reflected in the inner surface of the sidewall 11. The dimension of the sidewall 11 in the first direction D1 is w1, 132×G1≤w1≤168×G2, thus ensuring the structural strength of the sidewall 11.

[0066] It should be noted that the units for w1, w2, w3 and w4 are all mm.

[0067] Furthermore, in this embodiment, such as Figure 2 and Figure 3 As shown, the housing body 1 also includes a bottom wall 12, which is formed as a plate-like structure perpendicular to the second direction D2. The bottom wall 12 is disposed on the side of the side wall 11 away from the opening 100 in the second direction D2, and its circumferential side wall 11 is connected to the side wall 11, so that after the battery cell is assembled, one end of the side wall 11 in the second direction D2 is closed by the bottom wall 12, and the other end is closed by the cap.

[0068] According to the present invention, a battery cell housing includes an annular sidewall forming a receiving cavity. The receiving cavity has an opening, and the sidewall has an inwardly folded flange extending in a first direction at the opening for pressing a sealing ring in a cap onto a top cover in the cap. A groove is provided on the sidewall that is recessed inward in the first direction, causing a protrusion to be formed on the cavity wall of the receiving cavity to support the cap. The protrusion and the flange are spaced apart in a second direction, and the first direction is perpendicular to the second direction. The distance between the end of the flange facing the axis of the sidewall and the outer wall of the sidewall in the first direction is w2; the distance between the end of the protrusion facing the axis of the sidewall and the inner wall of the sidewall in the first direction is w4, where 1.8×w4≤w2≤2.2×w4. This ensures that the flange has sufficient pressing strength, guarantees the sealing of the cap, improves the assembly quality of the battery cell housing and the cap, and thus improves the performance and service life of the battery cell.

[0069] 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.

[0070] 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. A battery cell housing, characterized in that, The battery cell housing includes: The housing body includes an annular sidewall that forms a receiving cavity, the receiving cavity having an opening, the sidewall having an inwardly folded flange extending in a first direction at the opening, and a groove recessed inward in the first direction on the sidewall, such that a protrusion is formed on the cavity wall of the receiving cavity; the protrusion is spaced apart from the flange in a second direction, and the first direction is perpendicular to the second direction. The dimension of the sidewall in the first direction is w1; the distance between the end of the flange facing the axis of the sidewall and the outer wall of the sidewall in the first direction is w2; the dimension of the protrusion in the second direction is w3; the distance between the end of the protrusion facing the axis of the sidewall and the inner wall of the sidewall in the first direction is w4, 1.8×w4≤w2≤2.2×w4; The thickness of the sidewall is equal at all points, and the thickness of the sidewall is in g, with the unit being mm. 6×g≤w3≤7×g; 11.88×g≤w2≤18.48×g; 6.6×g≤w4≤8.4×g; 132×g≤w1≤168×g; Alternatively, in the second direction, the receiving cavity forms a first receiving space for receiving a cap on the side of the protrusion facing the outside of the battery; in the second direction, the receiving cavity forms a second receiving space for receiving an electrode assembly on the side of the protrusion facing the inside of the battery. The thickness of the flanged portion in the second direction is g1, in mm; the thickness of the sidewall forming the first accommodating space in the first direction is g2, in mm; the thickness of the bottom of the groove in the first direction is g3, in mm; and the thickness of the sidewall forming the second accommodating space in the first direction is g4, in mm. At least two of the values ​​of g1, g2, g3, and g4 are not equal; G1=min{g1,g2,g3,g4}, 0.15mm≤G1≤0.3mm; G2=max{g1,g2,g3,g4}, 0.15mm≤G2≤0.3mm; 6×G1≤w3≤7×G2;11.88×G1≤w2≤18.48×G2;6.6×G1≤w4≤8.4×G2; The outer surface of the sidewall forming the first accommodating space extending in the second direction and the outer surface of the sidewall forming the second accommodating space extending in the second direction are coplanar with each other; 132×G1≤w1≤168×G2.

2. The cell housing according to claim 1, characterized in that, 0.05×w1≤w4≤0.08×w1.

3. The cell housing according to claim 1, characterized in that, 1.1×w3≤w4≤1.2×w3.

4. The cell housing according to claim 1, characterized in that, The main body of the shell also includes: The bottom wall is disposed in the second direction on the side of the side wall away from the opening.

5. A battery cell, characterized in that, The battery cell housing includes any one of claims 1 to 4.

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