Battery casing and battery

Abstract

This application relates to the field of lithium-ion battery technology, and more particularly to a battery casing and a battery. A first sidewall is defined as a sidewall perpendicular to the width direction of the casing, and a second sidewall is defined as a sidewall perpendicular to the thickness direction of the casing. The first sidewall has a mounting hole for mounting an explosion-proof valve. In the thickness direction, the mounting hole is located at the center of the first sidewall. The first sidewall is connected to two adjacent second sidewalls via rounded corner walls. The mounting hole includes a first side and a second side in the thickness direction. The distance from the first side of the mounting hole to the first side of the corresponding rounded corner wall is C. The dimension of the casing in the thickness direction is B, and the dimension of the mounting hole in the thickness direction is E, where 0.05B≤C≤0.20B and 0.35B≤E≤0.70B. The battery casing and battery of this application solve the problem that, in existing designs where the pressure relief mechanism is adjusted to the sidewall of the casing, the distance between the edge of the explosion-proof valve and the rounded corner wall is inappropriate.

Description

Technical Field

[0001] The present application relates to the technical field of lithium-ion batteries, and in particular to a battery casing and a battery. Background Art

[0002] With the continuous development of technology, users have higher and higher requirements for new energy batteries. In order to improve the safety performance of battery cells, a pressure relief mechanism is usually set on the battery cells. When the battery cells operate abnormally and produce gas inside, the gas can be discharged through the pressure relief mechanism to avoid major safety accidents.

[0003] In the prior art, such as Fig.11 As shown in the figure, the explosion-proof valve is set on the cover plate, and when the pack is assembled, air outlets are reserved at both ends of the battery cell to discharge the gas generated after the explosion-proof valve opens when the battery cell is thermally runaway. However, due to the existence of the air outlets at both ends of the battery cell, the space of the pack is greatly occupied, which is not conducive to further improving the energy density of the pack.

[0004] When the explosion-proof valve is adjusted from the cover plate to the side wall of the shell, the gas is discharged directly downward. When the battery cells are assembled into a pack, there is no need to reserve air outlets at both ends of the battery cells. In this way, the length of the battery cells can be lengthened or the size of the battery cells remains unchanged, and the size of the pack can be reduced, thereby greatly improving the energy density or volume utilization of the pack.

[0005] Therefore, in order to improve the energy density of the pack, it is a very effective method to adjust the pressure relief structure from the cover plate to the side wall of the shell.

[0006] In view of this, after the pressure relief mechanism is adjusted to the side wall of the shell, the pressure relief mechanism and the shell need to be reliably fixed and connected to prevent air leakage. Figure 2 and Figure 8 As shown, in the thickness direction of the shell, if the dimension C between the edge of the explosion-proof valve and the rounded wall is too small (or the width of the explosion-proof valve accounts for too large a proportion), the heat generated during the welding of the explosion-proof valve will cause the outer walls on both sides of the shell to deform, and it is not conducive to the detection of the airtightness of the explosion-proof valve after welding, and it is easy to cause products that fail the airtightness test to be mistakenly interpreted as normal products (because when testing the airtightness, a sealing ring needs to be installed at the position of C).

[0007] If the dimension C between the edge of the explosion-proof valve and the rounded wall is too large (or the width of the explosion-proof valve is too small), when the explosion-proof valve is opened, the effective exhaust area is small, and the gas inside the shell cannot be discharged in time, resulting in a high internal pressure of the shell, which brings safety risks. Summary of the invention

[0008] The purpose of the present application is to provide a battery casing and a battery, thereby solving a series of problems caused by the inappropriate size of the edge of the explosion-proof valve from the rounded wall after the pressure relief mechanism is adjusted to the side wall of the shell.

[0009] According to a first aspect of the present application, a battery shell is provided, the shell having a length direction, a width direction and a thickness direction, the side wall of the shell perpendicular to the width direction is defined as a first side wall, the side wall of the shell perpendicular to the thickness direction is defined as a second side wall, the first side wall is provided with a mounting hole for mounting an explosion-proof valve, the mounting hole is located at the center of the first side wall in the thickness direction, the first side wall is connected to two adjacent second side walls through a rounded wall, each of the rounded walls includes a first side and a second side, the first side of the rounded wall is connected to the first side wall, the second side of the rounded wall is connected to the second side wall, the mounting hole includes a first side and a second side opposite to each other in the thickness direction, the distance from the first side of the mounting hole to the first side of the corresponding rounded wall, and the distance from the second side of the mounting hole to the first side of the corresponding rounded wall is C, the size of the shell in the thickness direction is B, the size of the mounting hole in the thickness direction is E, 0.05B≤C≤0.20B, 0.35B≤E≤0.70B.

[0010] In any of the above technical solutions, further, C ≥ 2 mm.

[0011] In any of the above technical solutions, further, the radius of the cross section of the cylindrical surface where the outer circular surface of the fillet wall is located is R, and E=B-2R-2C.

[0012] In any of the above technical solutions, further, the mounting hole includes a step portion and a through hole, the step portion is arranged along the circumference of the through hole, and the step portion divides the through hole into a first waist-shaped hole and a second waist-shaped hole, wherein the first waist-shaped hole is located on the outer side of the first side wall, and the second waist-shaped hole is located on the inner side of the first side wall, the cross-sectional area of ​​the first waist-shaped hole is larger than the cross-sectional area of ​​the second waist-shaped hole, and the explosion-proof valve is installed in the first waist-shaped hole.

[0013] In any of the above technical solutions, further, the size of the first waist-shaped hole in the width direction is f, the size of the explosion-proof valve in the width direction is e, and f≥e+0.1 mm.

[0014] In any of the above technical solutions, further, a thinning zone is provided in the middle of the explosion-proof valve, the distance from the outer edge of the thinning zone to the outer edge of the explosion-proof valve is F, the distance from the inner edge of the step portion to the outer edge of the step portion is D, and D≤F.

[0015] In any of the above technical solutions, further, 0.5mm≤D.

[0016] A second aspect of the present application provides a battery, comprising the battery casing as described above.

[0017] In any of the above technical solutions, further, the battery also includes an explosion-proof valve, the explosion-proof valve is installed in the installation hole, and the size of the explosion-proof valve in the length direction is L, L / E≤10.

[0018] In any of the above technical solutions, further, the battery also includes a positive electrode cover plate, a negative electrode cover plate, a battery cell, a side plate and an insulating protective film, the insulating protective film is sleeved on the battery cell, the side plate is installed on the side wall of the battery cell for fixing the insulating protective film, the outer shell is sleeved on the insulating protective film, two openings are respectively provided at both ends of the outer shell, and the positive electrode cover plate and the negative electrode cover plate are respectively installed on the two openings.

[0019] According to the shell of the present application, the shell has a length direction, a width direction and a thickness direction, wherein the side wall defining the vertical width direction of the shell is the first side wall, and the side wall defining the vertical thickness direction of the shell is the second side wall, the first side wall is provided with a mounting hole for installing the explosion-proof valve, in the thickness direction, the mounting hole is located at the center of the first side wall, the first side wall is connected to the two adjacent second side walls by a rounded wall, wherein each rounded wall includes a first side and a second side, the first side of the rounded wall is connected to the first side wall, and the second side of the rounded wall is connected to the second side wall, the mounting hole includes a first side and a second side opposite to each other in the thickness direction, the distance from the first side of the mounting hole to the first side of the corresponding rounded wall, and the distance from the second side of the mounting hole to the first side of the corresponding rounded wall is defined as C, the size of the shell in the thickness direction is B, and the size of the mounting hole in the thickness direction is E, then 0.05B≤C≤0.20B, 0.35B≤E≤0.70B.

[0020] In order to improve the energy density of the pack, the explosion-proof valve is adjusted to the first side wall of the shell. On this basis, 0.05B≤C≤0.20B and 0.35B≤E≤0.70B are defined. That is, the proportion of the explosion-proof valve on the entire first side wall is limited, ensuring that the dimension C of the explosion-proof valve edge from the rounded corner wall in the thickness direction of the shell is not too large or too small.

[0021] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A schematic diagram showing an overall exploded structure of a battery according to an embodiment of the present application is shown;

[0024] Figure 2 A schematic diagram of the installation structure of the explosion-proof valve and the housing according to an embodiment of the present application is shown;

[0025] Figure 3 A side view of a housing according to an embodiment of the present application is shown;

[0026] Figure 4 Show Figure 3 AA cross-sectional diagram of ;

[0027] Figure 5 Show Figure 4 An enlarged schematic diagram of part B;

[0028] Figure 6 A side view showing a housing after an explosion-proof valve is installed according to an embodiment of the present application;

[0029] Figure 7 Show Figure 6 AA cross-sectional diagram of ;

[0030] Figure 8 Show Figure 7 A magnified schematic diagram of part A;

[0031] Fig. 9 A schematic structural diagram of an explosion-proof valve according to an embodiment of the present application is shown;

[0032] Fig.10 Show Fig. 9 BB cross-sectional diagram;

[0033] Fig.11 A schematic diagram showing the structure of a battery cell group installed in a pack in the prior art is shown.

[0034] Icons: 100-housing; 101-first side wall; 102-second side wall; 103-rounded wall; 104-explosion-proof valve; 1041-thinning area; 105-mounting hole; 1051-step portion; 1052-first waist-shaped hole; 1053-second waist-shaped hole; 200-positive electrode cover plate; 300-negative electrode cover plate; 400-battery cell; 500-side panel; 600-insulating protective film; X-length direction; Y-width direction; Z-thickness direction. DETAILED DESCRIPTION

[0035] The following specific embodiments are provided to help the reader obtain a comprehensive understanding of the methods, devices and / or systems described herein. However, after understanding the disclosure of the present application, various changes, modifications and equivalents of the methods, devices and / or systems described herein will be apparent. For example, the order of operations described herein is merely an example, and is not limited to the order set forth herein, but in addition to the operations that must occur in a particular order, changes that will be apparent after understanding the disclosure of the present application may be made. In addition, in order to improve clarity and brevity, descriptions of features known in the art may be omitted.

[0036] The features described herein may be implemented in different forms and should not be interpreted as being limited to the examples described herein. Rather, the examples described herein have been provided only to illustrate some of the many possible ways of implementing the methods, devices and / or systems described herein that will be apparent after understanding the disclosure of the present application.

[0037] Throughout the specification, when an element (such as a layer, a region, or a substrate) is described as being “on”, “connected to”, “bound to”, “over”, or “covering” another element, it may be directly “on”, “connected to”, “bound to”, “over”, or “covering” another element, or one or more other elements may be present between them. In contrast, when an element is described as being “directly on”, “directly connected to”, “directly bound to”, “directly over”, or “directly covering” another element, there may be no other elements present between them.

[0038] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more items.

[0039] Although terms such as "first," "second," and "third" may be used herein to describe various members, components, regions, layers, or portions, these members, components, regions, layers, or portions are not limited by these terms. Rather, these terms are only used to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Therefore, without departing from the teachings of the examples described herein, the first member, component, region, layer, or portion referred to may also be referred to as the second member, component, region, layer, or portion.

[0040] For ease of description, spatial relational terms such as "above", "upper", "below", and "lower" may be used herein to describe the relationship of one element to another element as shown in the accompanying drawings. Such spatial relational terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, an element described as being "above" or "upper" relative to another element will subsequently be "below" or "lower" relative to the 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 relational terms used herein will be interpreted accordingly.

[0041] The terms used herein are only used to describe various examples and are not used to limit the present disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms "include", "comprise" and "have" list the stated features, quantities, operations, components, elements and / or their combinations that exist, but do not exclude the existence or addition of one or more other features, quantities, operations, components, elements and / or their combinations.

[0042] Variations in the shapes shown in the 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 drawings but include variations in shapes that occur during manufacturing.

[0043] The features of the examples described herein may be combined in various ways that will be apparent after understanding the disclosure of the present application. In addition, although the examples described herein have various configurations, other configurations are possible as will be apparent after understanding the disclosure of the present application.

[0044] In a first aspect, the present application provides a battery casing, thereby solving the problem that after the pressure relief mechanism is adjusted to the side wall of the casing, the distance between the edge of the explosion-proof valve and the rounded wall is difficult to control.

[0045] According to the housing 100 of the present application, Figure 2 , Figure 5 and Figure 8As shown, the housing 100 has a length direction X, a width direction Y and a thickness direction Z, wherein the side wall defining the vertical width direction Y of the housing 100 is the first side wall 101, and the side wall defining the vertical thickness direction Z of the housing 100 is the second side wall 102 (the area of ​​the first side wall 101 is smaller than the area of ​​the second side wall 102), and the first side wall 101 is provided with a mounting hole 105 for mounting the explosion-proof valve 104 (the mounting hole 105 is one or more), and in the thickness direction Z, the mounting hole 105 is located at the center of the first side wall 101 (such as Figure 5 As shown, the symmetry plane of the mounting hole 105 is coplanar with the symmetry plane of the first side wall 101 , and the first side wall 101 is connected to two adjacent second side walls 102 via a rounded wall 103 .

[0046] Furthermore, if Figure 2 , Figure 5 and Figure 8 As shown, the symmetry plane of the mounting hole 105 is coplanar with the symmetry plane of the housing 100 (the symmetry plane is perpendicular to the thickness direction Z), that is, the structures and sizes of the two rounded walls 103 are equal. Here, the radius of the cross section of the cylindrical surface where the outer circular surface of the rounded wall 103 is located is defined as R.

[0047] Among them, each rounded wall 103 includes a first side and a second side (extending from the first side along an arc to the second side), the first side of the rounded wall 103 is connected to the first side wall 101, and the second side of the rounded wall 103 is connected to the second side wall 102, the mounting hole 105 includes a first side and a second side opposite to each other in the thickness direction Z, and the distance from the first side of the mounting hole 105 to the corresponding first side of the rounded wall 103 and the distance from the second side of the mounting hole 105 to the corresponding first side of the rounded wall 103 are defined as C (that is, the shortest distance from the edge of the mounting hole 105 to the rounded wall 103 is C), the size of the shell 100 in the thickness direction Z is B, the size of the mounting hole 105 in the thickness direction Z is E, and in the thickness direction Z of the shell 100, taking the outer side surface of the shell 100 as an example, E=B-2R-2C.

[0048] In order to improve the energy density of the pack, the explosion-proof valve 104 is adjusted to the first side wall 101 of the shell. On this basis, 0.05B≤C≤0.20B and 0.35B≤E≤0.70B are defined. That is, the proportion of the explosion-proof valve 104 on the entire first side wall 101 is defined, ensuring that the dimension C between the edge of the explosion-proof valve 104 and the rounded wall 103 in the thickness direction Z of the shell is not too large or too small.

[0049] Here, if Figure 5 and Figure 8As shown, in order to ensure that the heat generated during the welding of the explosion-proof valve 104 does not deform the two second side walls 102 of the housing 100, and during the airtightness test, a position is reserved for installing a sealing ring, then C≥2mm.

[0050] Further, in the embodiment of the present application, in order to meet the manufacturability of the connection between the pressure relief mechanism and the housing 100, the helium testability of the connection, and the timely discharge of the internal gas when the pressure relief mechanism is opened, the following will refer to Figures 1 to 11 , the specific structure and size of the rounded wall 103, the explosion-proof valve 104, and the mounting hole 105 are described in detail.

[0051] In the embodiments of the present application, Figure 5 As shown, the mounting hole 105 includes a step portion 1051 and a through hole, the step portion 1051 is arranged along the circumference of the through hole (the step portion 1051 is arranged along the inner wall of the through hole for a circle, and the size in the thickness direction Z is equal), wherein the step portion 1051 divides the through hole into a first waist-shaped hole 1052 and a second waist-shaped hole 1053, the first waist-shaped hole 1052 and the second waist-shaped hole 1053 are arranged along the width direction Y, wherein the first waist-shaped hole 1052 is located on the outer side of the first side wall 101, and the second waist-shaped hole 1053 is located on the inner side of the first side wall 101, the cross-sectional area of ​​the first waist-shaped hole 1052 is larger than the cross-sectional area of ​​the second waist-shaped hole 1053, and the explosion-proof valve 104 is installed in the first waist-shaped hole 1052.

[0052] In the embodiments of the present application, Figure 5 As shown, the dimension of the first waist-shaped hole 1052 in the width direction Y is defined as f (i.e., the distance from the upper surface of the step portion 1051 to the outer side surface of the first waist-shaped hole 1052 is f), and the dimension of the explosion-proof valve 104 in the width direction Y is defined as e, wherein f≥e+0.1mm. This ensures that the height of the explosion-proof valve 104 does not exceed the first waist-shaped hole 1052, i.e., the height of the explosion-proof valve 104 does not exceed the overall housing 100, thereby ensuring that the weld between the explosion-proof valve 104 and the first side wall 101 does not exceed the overall housing 100.

[0053] In the embodiments of the present application, Figure 8 and Fig.10 As shown, a thinning area 1041 is provided at the center of the explosion-proof valve 104, and the distance from the outer edge of the thinning area 1041 to the outer edge of the explosion-proof valve 104 is defined as F, and the distance from the inner edge of the step portion 1051 to the outer edge of the step portion 1051 is defined as D, and D≤F. That is, it is ensured that the step portion 1051 will not affect the thinning area 1041 of the explosion-proof valve 104, and further ensured that when the explosion-proof valve 104 is opened, the effective area of ​​the thinning area 1041 can remove the gas inside the shell.

[0054] Furthermore, when 0.5 mm ≥ D, the first side wall 101 provided with the step portion 1051 is difficult to manufacture, and the mold used for manufacturing is easily damaged. Therefore, in this embodiment, 0.5 mm ≤ D. This ensures that the first side wall 101 provided with the step portion 1051 is easy to manufacture.

[0055] Furthermore, in order to ensure the connection stability and exhaust area of ​​the explosion-proof valve 104, in this embodiment, Fig. 9 and Fig.10 As shown, the dimension of the explosion-proof valve 104 in the length direction X is defined as L, then L / E≤10.

[0056] According to a second aspect of the present application, a battery (which may be a secondary battery) is provided, comprising the battery casing as described above.

[0057] Furthermore, if Figure 1 As shown, the battery also includes a positive electrode cover plate 200, a negative electrode cover plate 300, a battery cell 400, a side plate 500 and an insulating protective film 600. The insulating protective film 600 is sleeved on the battery cell 400. The side plate 500 is installed on the side wall of the battery cell 400 for fixing the insulating protective film 600. The outer shell 100 is sleeved on the insulating protective film 600. Two openings are respectively provided at both ends of the outer shell 100. The positive electrode cover plate 200 and the negative electrode cover plate 300 are respectively installed in the two openings.

[0058] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application rather than to limit them. The protection scope of the present application is not limited thereto. Although the present application has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that any technician familiar with this technical field can still modify the technical solutions recorded in the aforementioned embodiments within the technical scope disclosed in the present application, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be covered by the protection scope of the present application.

Claims

1. A battery, characterized in that: The battery comprises a housing and an explosion-proof valve, wherein the housing has a length direction, a width direction and a thickness direction. The side wall of the housing perpendicular to the width direction is defined as a first side wall, The side wall of the housing perpendicular to the thickness direction is defined as the second side wall, and the first side wall is provided with a mounting hole for mounting the explosion-proof valve. In the thickness direction, the mounting hole is located at the center of the first side wall. The first side wall is connected to two adjacent second side walls via a rounded wall. Each of the rounded walls comprises a first side and a second side, The first side of the rounded wall is connected to the first side wall, and the second side of the rounded wall is connected to the second side wall. The mounting hole includes a first side and a second side opposite to each other in the thickness direction, The distance from the first side of the mounting hole to the first side of the corresponding rounded wall, and the distance from the second side of the mounting hole to the first side of the corresponding rounded wall are C, The dimension of the shell in the thickness direction is B, The dimension of the mounting hole in the thickness direction is E, 0.05B≤C≤0.20B, 0.35B≤E≤0.70B; C≥2mm; The radius of the cross section of the cylindrical surface where the outer cylindrical surface of the fillet wall is located is R, E = B-2R-2C; The mounting hole includes a step portion and a through hole, wherein the step portion is arranged along the circumference of the through hole. The step portion divides the through hole into a first waist-shaped hole and a second waist-shaped hole. Wherein, the first waist-shaped hole is located on the outer side of the first side wall, and the second waist-shaped hole is located on the inner side of the first side wall. The cross-sectional area of ​​the first waist-shaped hole is greater than the cross-sectional area of ​​the second waist-shaped hole. The explosion-proof valve is installed in the first waist-shaped hole; A thinning area is provided in the middle of the explosion-proof valve. The distance from the outer edge of the thinning area to the outer edge of the explosion-proof valve is F, The distance from the inner edge of the step portion to the outer edge of the step portion is D, D≤F; 0.5mm≤D; The dimension of the first waist-shaped hole in the width direction is f, the dimension of the explosion-proof valve in the width direction is e, and f≥e+0.1 mm; The dimension of the explosion-proof valve in the length direction is L. L / E≤10.

2. The battery according to claim 1, characterized in that The battery also includes a positive electrode cover plate, a negative electrode cover plate, a battery cell, a side plate and an insulating protective film. The insulating protective film is sleeved on the battery core, The side plate is mounted on the side wall of the battery cell and is used to fix the insulating protective film. The outer shell is sleeved on the insulating protective film. Two openings are respectively arranged at two ends of the shell, and the positive electrode cover plate and the negative electrode cover plate are respectively installed in the two openings.

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