Battery case, and battery.

Abstract

DEPCT69 17 / 03 / 2569 The case (100) of the battery, and the battery, the side walls of the case (100) perpendicular to the direction of Width (Y) is defined as the first side wall (101); the side wall of the case (100) perpendicular to the direction of width. The thickness (Z) is defined as the second side wall (102); mounting hole (105) for mounting the explosion-proof valve (104). Formed on each side wall at one (101); in the thickness direction (Z), each mounting hole (105) is located at The center position of the first side wall (101), and the first side wall (101) is connected to the two. The second adjacent side wall (102) is assembled by the curved corner wall (103); the mounting holes (105) are included. First and second sides in the thickness direction (Z); distance between the first side of the mounting holes (105) And the first side of the corresponding curved wall (103) is C, the size of the case (100) in the thickness direction (Z). It is B, the size of the mounting hole (105) in the thickness direction (Z) is E, 0.05B ​​is less than or equal to C is less than or equal to 0.20B, and 0.35B less than or equal to E less than or equal to 0.70B Case (100) of the battery and battery are provided, thus solving the problem in the task. There is already an improper distance between the edge of the explosion-proof valve (104) and the curved wall. (103) After the pressure relief mechanism is adjusted to the side wall of the case (100)

Description

Battery casing and battery

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the China Patent Office on June 28, 2023, with application number 2023107767009 and invention name “Battery casing and battery”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the technical field of lithium-ion batteries, and in particular to a battery casing and a battery. Background Art

[0004] With the continuous development of technology, users' requirements for new energy batteries are becoming increasingly higher. To improve the safety performance of battery cells, pressure relief mechanisms are often installed on battery cells. When a battery cell is operating abnormally and gas is generated inside, the pressure relief mechanism can be used to discharge the gas, thus preventing major safety accidents.

[0005] In the prior art, as shown in Figure 11, explosion-proof valves are installed on the cover plate. During pack assembly, gas vents are reserved at both ends of the battery cell to allow the gas generated by the explosion-proof valve opening in the event of thermal runaway. However, the presence of these gas vents at both ends of the battery cell significantly occupies the pack space, hindering further improvement in the pack's energy density.

[0006] When the explosion-proof valve is adjusted from the cover 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 outlet ducts 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 can remain unchanged, and the size of the pack can be reduced, thereby greatly improving the energy density or volume utilization of the pack.

[0007] Therefore, in order to improve the energy density of the pack, it is very effective to adjust the pressure relief structure from the cover plate to the side wall of the shell.

[0008] 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 prevented from leaking. Specifically, as shown in Figures 2 and 8, in the thickness direction of the shell, if the distance 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 much), the heat generated during the welding of the explosion-proof valve will cause the outer walls of both sides of the shell to deform, and it will be detrimental to the airtightness test of the explosion-proof valve after welding, and it is easy to mistakenly interpret products that fail the airtightness test as normal products (because a sealing ring needs to be installed at the position C during the airtightness test).

[0009] 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.

[0010] Summary of the Invention

[0011] 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 explosion-proof valve edge from the rounded corner wall after the pressure relief mechanism is adjusted to the side wall of the shell.

[0012] According to the 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 by 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, 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 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.

[0013] In any of the above technical solutions, optionally, C ≥ 2 mm.

[0014] In any of the above technical solutions, optionally, the radius of the cross section of the cylindrical surface where the outer circular surface of the rounded wall is located is R, and E=B-2R-2C.

[0015] In any of the above technical solutions, optionally, 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 outside of the first side wall, and the second waist-shaped hole is located on the inside 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.

[0016] In any of the above technical solutions, optionally, a size of the first waist-shaped hole in the width direction is f, a size of the explosion-proof valve in the width direction is e, and f≥e+0.1 mm.

[0017] In any of the above technical solutions, optionally, 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, and the distance from the inner edge of the step portion to the outer edge of the step portion is D, D≤F.

[0018] In any of the above technical solutions, optionally, 0.5 mm ≤ D.

[0019] A second aspect of the present application provides a battery, comprising the battery casing as described above.

[0020] In any of the above technical solutions, optionally, the battery further includes an explosion-proof valve, which is installed in the installation hole, and a dimension of the explosion-proof valve in the longitudinal direction is L, and L / E≤10.

[0021] In any of the above technical solutions, optionally, the battery further 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, and 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.

[0022] 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, and the first side wall is provided with a mounting hole for installing the explosion-proof valve, and in the thickness direction, the mounting hole is located at the center position of the first side wall, and the first side wall is connected to the two adjacent second side walls through 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, and the mounting hole includes a first side and a second side opposite to each other in the thickness direction, and 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.

[0023] To increase the energy density of the pack, this application repositions the explosion-proof valve to the first sidewall of the shell. Furthermore, the following constraints are established: 0.05B≤C≤0.20B, and 0.35B≤E≤0.70B. This limits the proportion of the explosion-proof valve to the entire first sidewall, ensuring that the distance C between the edge of the explosion-proof valve and the rounded corner wall in the thickness direction of the shell is neither too large nor too small.

[0024] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings.

[0025] BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. 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 relevant drawings can be obtained based on these drawings without creative work.

[0027] FIG1 is a schematic diagram showing an overall exploded structure of a battery according to an embodiment of the present application;

[0028] FIG2 is a schematic diagram showing the installation structure of the explosion-proof valve and the housing according to an embodiment of the present application;

[0029] FIG3 shows a side view of a housing according to an embodiment of the present application;

[0030] FIG4 shows a schematic cross-sectional view taken along line AA of FIG3 ;

[0031] FIG5 shows an enlarged schematic diagram of portion B of FIG4 ;

[0032] FIG6 shows a side view of the housing after installing an explosion-proof valve according to an embodiment of the present application;

[0033] FIG7 shows a schematic cross-sectional view taken along line AA of FIG6 ;

[0034] FIG8 shows an enlarged schematic diagram of portion A of FIG7 ;

[0035] FIG9 shows a schematic structural diagram of an explosion-proof valve according to an embodiment of the present application;

[0036] FIG10 shows a schematic cross-sectional view taken along line BB in FIG9 ;

[0037] FIG11 is a schematic structural diagram showing a battery cell group installed in a pack in the prior art.

[0038] Icon: 100- shell; 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; 300- negative electrode cover; 400- battery cell; 500- side panel; 600- insulating protective film; X- length direction; Y- width direction; Z- thickness direction. DETAILED DESCRIPTION

[0039] The following detailed description is provided to help the reader gain a comprehensive understanding of the methods, devices, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, devices, and / or systems described herein will be apparent upon 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. Rather, except for operations that must occur in a particular order, changes may be made that will be apparent upon understanding the disclosure of this application. Furthermore, descriptions of features known in the art may be omitted for clarity and brevity.

[0040] 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 possible ways to implement the methods, devices, and / or systems described herein that will be apparent upon understanding the disclosure of this application.

[0041] Throughout the specification, when an element (such as a layer, region, or substrate) is described as being “on,” “connected to,” “coupled to,” “over,” or “overlaying” another element, it may be directly “on,” “connected to,” “coupled to,” “over,” or “overlaying” 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 coupled to,” “directly over,” or “directly covering” another element, there may be no other elements intervening therebetween.

[0042] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more items.

[0043] 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 used only to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Thus, a first member, component, region, layer, or portion in the examples described herein may also be referred to as a second member, component, region, layer, or portion without departing from the teachings of the examples.

[0044] 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 encompass different orientations of the device in use or operation in addition to the orientations 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 would subsequently be "below" or "lower" relative to the other element. Thus, the term "above" includes both the orientations "above" and "below," 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.

[0045] The terms used herein are intended only to describe various examples and are not intended to limit the present disclosure. Unless the context clearly indicates otherwise, the singular is intended to include the plural. The terms "comprise," "include," and "have" list the presence of stated features, quantities, operations, components, elements, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0046] Due to manufacturing techniques and / or tolerances, variations in the shapes shown in the drawings may occur. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings but include changes in shapes that occur during manufacturing.

[0047] The features of the examples described herein can 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.

[0048] In a first aspect, the present application provides a battery housing, thereby solving the problem that after the pressure relief mechanism is adjusted to the side wall of the housing, the distance between the edge of the explosion-proof valve and the rounded wall is difficult to control.

[0049] According to the shell 100 of the present application, as shown in Figures 2, 5 and 8, the shell 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 shell 100 is the first side wall 101, and the side wall defining the vertical thickness direction Z of the shell 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), the first side wall 101 is provided with a mounting hole 105 for mounting an explosion-proof valve 104 (there are one or more mounting holes 105), and in the thickness direction Z, the mounting hole 105 is located at the center of the first side wall 101 (as shown in Figure 5, 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 the two adjacent second side walls 102 by a rounded wall 103.

[0050] Optionally, as shown in Figures 2, 5, and 8, 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 dimensions of the two rounded walls 103 are equal. Here, the radius of the cross-section of the cylindrical surface on which the outer circular surface of the rounded wall 103 is located is defined as R.

[0051] 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, and 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 dimension of the shell 100 in the thickness direction Z is B, and the dimension of the mounting hole 105 in the thickness direction Z is E. 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.

[0052] To improve the energy density of the pack, this application repositions explosion-proof valve 104 to the first sidewall 101 of the housing. Furthermore, the following constraints are established: 0.05B≤C≤0.20B, and 0.35B≤E≤0.70B. This limits the proportion of explosion-proof valve 104 on the entire first sidewall 101, ensuring that the distance C between the edge of explosion-proof valve 104 and the rounded wall 103 in the housing's thickness direction Z is neither too large nor too small.

[0053] Here, as shown in FIG5 and FIG8, in order to ensure that the heat generated during welding of the explosion-proof valve 104 does not deform the two second side walls 102 of the housing 100, and to reserve a position for installing a sealing ring during airtightness testing, C≥2mm.

[0054] Optionally, in an 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 ability to promptly remove internal gas when the pressure relief mechanism is opened, the specific structure and dimensions of the rounded wall 103, the explosion-proof valve 104, and the mounting hole 105 will be described in detail below with reference to Figures 1 to 11.

[0055] In an embodiment of the present application, as shown in Figure 5, the mounting hole 105 includes a step portion 1051 and a through hole, and 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 dimensions in the thickness direction Z are equal), wherein the step portion 1051 divides the through hole into a first waist-shaped hole 1052 and a second waist-shaped hole 1053, and 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 outside of the first side wall 101, and the second waist-shaped hole 1053 is located on the inside 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.

[0056] In the embodiment of the present application, as shown in FIG5 , 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, where f ≥ e + 0.1 mm. This ensures that the height of the explosion-proof valve 104 does not exceed the first waist-shaped hole 1052, that is, 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 sidewall 101 does not extend beyond the overall housing 100.

[0057] In the embodiment of the present application, as shown in Figures 8 and 10 , a thinned area 1041 is provided at the center of explosion-proof valve 104. The distance from the outer edge of thinned area 1041 to the outer edge of explosion-proof valve 104 is defined as F, and the distance from the inner edge of step 1051 to the outer edge of step 1051 is defined as D, where D ≤ F. This ensures that step 1051 does not affect thinned area 1041 of explosion-proof valve 104, thereby ensuring that when explosion-proof valve 104 is opened, the effective area of ​​thinned area 1041 can expel gas from the housing.

[0058] Alternatively, when 0.5 mm ≥ D, the first sidewall 101 with the step 1051 is difficult to manufacture and the mold is easily damaged. Therefore, in this embodiment, 0.5 mm ≤ D ensures that the first sidewall 101 with the step 1051 is easy to manufacture.

[0059] Optionally, in order to ensure the connection stability and exhaust area of ​​the explosion-proof valve 104, in this embodiment, as shown in Figures 9 and 10, the dimension of the explosion-proof valve 104 in the length direction X is defined as L, then L / E≤10.

[0060] 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.

[0061] Optionally, as shown in Figure 1, 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, and 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, and the positive electrode cover plate 200 and the negative electrode cover plate 300 are respectively installed in the two openings.

[0062] 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 scope of protection 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 scope of protection of the present application.

Claims

DEPCT69 17 / 03 / 2569 1. Battery casing, where the casing has length, width, and thickness directions; The side wall of the case that is perpendicular to the width direction is defined as the first side wall; The side wall of the case that is perpendicular to the thickness direction is defined as the second side wall, and the wall The first side is equipped with mounting holes for securing 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 curved wall; Each of the curved walls consists of the first and second sides; The first side of the curved wall is connected to the first side wall, and the second side of the curved wall is connected to the second side wall. It is connected to the second side wall; The mounting holes are assembled with the first and second sides opposite each other in the direction of rotation. thick; The distance from one side of the mounting hole to the first side of the corresponding curved wall. And the distance from the second side of the mounting hole to the first side of the corresponding curved wall is... Defined as C; The dimension of the case in the thickness direction is defined as B; The dimension of the mounting hole in the thickness direction is defined as E; and 0.05B ​​is less than or equal to C is less than or equal to 0.20B, and 0.35B is less than or equal to E is less than or equal to 0.70B.

2. Battery case according to claim 1, where C is greater than or equal to 2 mm.

3. The case of the battery according to claim 1, where the radius of the cross-section of the cylindrical surface which the surface The exterior of the curved wall is defined as R, and E = B - 2R - 2C 4. Battery case as per claim 1, where mounting holes include stepped sections and holes. Through; the steps are arranged in a direction along the circumference of the through hole; The stepped section divides the through hole into a first constriction and a second constriction; The first constriction is located outside the first side wall, and the second constriction is located inside the second side wall. one; The cross-sectional area of ​​the first constriction is greater than the cross-sectional area of ​​the second constriction; and The explosion-proof valve was securely installed in the first constricted opening.

5. The battery case pursuant to claim 4, where the dimension of the first constriction in the width direction is defined. It is f; The dimension of the explosion-proof valve in the width direction is defined as e; and f is greater than or equal to e + 0.1 mm.

6. Battery case pursuant to claim 4, whereby the center of the explosion-proof valve is provided. Areas that have become thinner; The distance from the outer edge of the thinning area to the outer edge of the explosion-proof valve is... Defined as F; The distance from the inner edge of a stair section to the outer edge of a stair section is defined. It is D, and D is less than or equal to F.

7. Battery case according to claim 6, where 0.5 mm is less than or equal to D.

8. A battery, which includes a battery case as specified in any of Claims 1 through 7.

9. A battery as per claim 8, whereby the battery is incorporated with an additional explosion-proof valve. Securely mount it in the mounting holes; The dimension of the explosion-proof valve in the length direction is defined as L; and L / E less than or equal to 10 10. The battery as per claim 8, whereby the battery is incorporated with an additional positive electrode cover, The negative electrode cover, battery cell, side plates, and insulating protective film; An insulating protective film is worn over the battery cells; The side plates are mounted on the side walls of the battery cell to hold the protective film in place. insulator; The case is placed over the insulating protective film; and Both ends of the case are provided with two openings respectively, and plates covering the positive and negative electrodes. The negative electrode cover plate is securely installed in the two openings, respectively.

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