CN220138471U

CN220138471U - Battery case and battery

Info

Publication number: CN220138471U
Application number: CN202321715489.1U
Authority: CN
Inventors: 李龙
Original assignee: Svolt Energy Technology Co Ltd
Current assignee: Svolt Energy Technology Co Ltd
Priority date: 2023-06-30
Filing date: 2023-06-30
Publication date: 2023-12-05
Anticipated expiration: 2033-06-30

Abstract

The utility model relates to the technical field of lithium batteries, in particular to a battery shell and a battery. The shell has length direction, thickness direction and width direction, and the lateral wall that is perpendicular to width direction of inject the shell is first lateral wall, and the lateral wall that is perpendicular to thickness direction of inject the shell is the second lateral wall, and first lateral wall is provided with the mounting hole that is used for installing explosion-proof valve, and first lateral wall passes through the fillet wall with two adjacent second lateral walls to be connected, and wherein, the thickness of first lateral wall is greater than the thickness of second lateral wall, and the thickness of fillet wall equals the thickness of second lateral wall, and the interior round surface of fillet wall is connected with the medial surface of first lateral wall through smooth transition face. According to the shell of the battery and the battery, the problem that stress concentration exists at the transitional connection part of the side walls with different wall thicknesses after the existing shell is designed with unequal wall thicknesses is solved.

Description

Battery case and battery

Technical Field

The utility model relates to the technical field of lithium batteries, in particular to a battery shell and a battery.

Background

With the continuous development of technology, the requirements of users on new energy batteries are getting higher. In order to improve the safety performance of the battery cell, a pressure release mechanism is usually arranged on the battery cell. When the battery unit is abnormal in operation and generates gas, the gas can be discharged through the pressure release mechanism, so that a large safety accident is avoided.

In the prior art, as shown in fig. 6, the explosion-proof valve is arranged on the cover plate, and air outlet channels are reserved at two ends of the battery core respectively during pack assembly, so that gas generated after the explosion-proof valve is opened during thermal runaway of the battery core is discharged. However, due to the existence of the air passages at the two ends of the battery cell, the space of pack is greatly occupied, and the further improvement of pack energy density is not facilitated.

When the explosion-proof valve is adjusted to the side wall of the shell from the cover plate, gas is directly discharged downwards, and gas outlet channels are not required to be reserved at two ends of the battery core when the battery core is assembled into the pack, so that the length of the battery core can be lengthened or the size of the battery core is unchanged, the size of the pack is reduced, and the energy density or the volume utilization rate of the pack is greatly improved.

Therefore, to increase the energy density of pack, it is a very efficient method to adjust the pressure relief structure from the cover plate to the side wall of the housing.

In view of this, after adjusting the relief mechanism to the casing lateral wall, in order to guarantee effective welding of relief mechanism, the thickness of welding the lateral wall of relief mechanism needs more than 0.95mm, if four lateral walls of casing all adopt the equal wall thickness design more than 0.95mm, then can greatly increased the weight of casing.

Therefore, the shell can adopt a design with unequal wall thickness, namely, the thickness of the side wall of the welding pressure relief mechanism is larger than 0.95mm, and other side walls are thinned. However, the transitional connection of the side walls of different wall thicknesses has the problem of stress concentration, which reduces the strength of the shell.

Disclosure of Invention

The utility model aims to provide a battery shell and a battery, so that the problem that stress concentration exists at the transitional connection part of side walls with different wall thicknesses after the existing shell is designed with unequal wall thicknesses is solved.

According to a first aspect of the present utility model, there is provided a housing of a battery, the housing having a length direction, a thickness direction and a width direction, wherein a sidewall perpendicular to the width direction defining the housing is a first sidewall, a sidewall perpendicular to the thickness direction defining the housing is a second sidewall, the first sidewall is provided with a mounting hole for mounting an explosion-proof valve, the first sidewall is connected with two adjacent second sidewalls through a rounded wall, wherein the thickness of the first sidewall is greater than the thickness of the second sidewall, the thickness of the rounded wall is equal to the thickness of the second sidewall, and an inner circumference of the rounded wall is connected with an inner circumference of the first sidewall through a smooth transition surface.

In any of the above technical solutions, further, the transition surface is a plane.

In any of the above technical solutions, further, an included angle between the transition surface and the inner side surface of the first sidewall is 120 ° to 165 °.

In any of the above technical solutions, further, an included angle between the transition surface and the inner side surface of the first sidewall is 135 °.

In any of the above solutions, further, the first sidewall has a symmetry plane, the symmetry plane is perpendicular to the thickness direction, and the two second sidewalls are symmetrical with respect to the symmetry plane.

In any of the above technical solutions, further, the transition surface and the inner side surface of the second sidewall are both tangential to the inner circular surface.

In any of the above technical solutions, further, the housing is an aluminum housing.

In any of the above technical solutions, further, the mounting hole includes a step portion and a through hole, the step portion is disposed along a circumferential direction of the through hole, the step portion separates the through hole into a first waist-shaped hole and a second waist-shaped hole, wherein the first waist-shaped hole is located at an outer side of the first sidewall, the second waist-shaped hole is located at an inner side of the first sidewall, a cross-sectional area of the first waist-shaped hole is larger than a cross-sectional area of the second waist-shaped hole, and the explosion-proof valve is mounted in the first waist-shaped hole.

According to a second aspect of the present utility model there is provided a battery comprising a housing for a battery as described above.

In any of the above technical solutions, further, the battery further includes a positive electrode cover plate, a negative electrode cover plate, a pole group, a side plate and an insulating protective film, the insulating protective film is sleeved on the pole group, the side plate is installed on the side wall of the pole group and is used for fixing the insulating protective film, the shell is sleeved on the insulating protective film, two openings are respectively formed in two ends of the shell, and the positive electrode cover plate and the negative electrode cover plate are respectively installed on the two openings.

According to the shell of the battery, the shell is provided with a length direction, a thickness direction and a width direction, wherein a side wall which is perpendicular to the width direction and defines the shell is a first side wall, a side wall which is perpendicular to the thickness direction and defines the shell is a second side wall, the first side wall is provided with a mounting hole for mounting an explosion-proof valve, the first side wall is connected with two adjacent second side walls through round corner walls, the thickness of the first side wall is larger than that of the second side walls, the thickness of the round corner walls is equal to that of the second side walls, and the inner circular surface of the round corner walls is connected with the inner side surface of the first side walls through smooth transition surfaces.

That is, the present utility model adjusts the explosion proof valve to the first side wall of the housing in order to increase the energy density of the pack. And on the basis, the shell can adopt a design with unequal wall thickness (namely, the thickness of the first side wall is larger than that of the second side wall) so as to reduce the weight of the shell. In view of this, the present utility model has been developed in an effort to reduce the concentrated stresses present at the transitional junctions of sidewalls of different wall thicknesses.

Specifically, the thickness of the fillet wall is equal to the thickness of the second sidewall, and therefore, the transition of the fillet wall and the second sidewall does not have a problem of stress concentration. The connection part of the fillet wall and the first side wall can disperse stress through the transition surface, in particular, the smooth transition surface is used for connecting the thin wall with the thick wall in a transition way (the smooth transition surface is used for connecting the inner side of the first side wall and the inner circular surface of the fillet wall), so that the thickness difference between the thin wall and the thick wall is gradually reduced, namely, the concentrated stress at the connection part is dispersed through the part where the transition surface is located, and the strength of the shell is further increased.

In order to make the above objects, features and advantages of the present utility model more comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present utility model and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 shows a schematic view of the mounting structure of an explosion-proof valve and a housing according to an embodiment of the present utility model;

fig. 2 shows an overall exploded structural schematic view of a battery according to an embodiment of the present utility model;

FIG. 3 shows a side view of a housing according to an embodiment of the utility model;

FIG. 4 shows a schematic cross-section A-A of FIG. 3;

FIG. 5 shows an enlarged schematic view of portion B of FIG. 4;

fig. 6 is a schematic diagram showing a prior art structure in which a cell stack is mounted in a pack.

Icon: 100-a housing; 101-a first sidewall; 102-a second sidewall; 103-rounded walls; 104-an explosion-proof valve; 105-mounting holes; 106-transition surface; 1051-steps; 1052-a first kidney-shaped aperture; 1053-second waist-shaped aperture; 200-an anode cover plate; 300-a negative electrode cover plate; 400-pole group; 500-side plates; 600-insulating protective film; x-length direction; y-width direction; z-thickness direction; s-plane of symmetry.

Detailed Description

The following detailed description is provided to assist the reader in obtaining a thorough understanding of the methods, apparatus, and/or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatuses, and/or systems described herein will be apparent after an understanding of the present disclosure. For example, the order of operations described herein is merely an example, and is not limited to the order set forth herein, but rather, obvious variations may be made upon an understanding of the present disclosure, other than operations that must occur in a specific order. In addition, descriptions of features known in the art may be omitted for the sake of clarity and conciseness.

The features described herein may be embodied in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein have been provided solely 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 present disclosure.

In the entire specification, when an element (such as a layer, region or substrate) is described as being "on", "connected to", "bonded to", "over" or "covering" another element, it may be directly "on", "connected to", "bonded to", "over" or "covering" another element or there may be one or more other elements interposed therebetween. In contrast, when an element is referred to as being "directly on," directly connected to, "or" directly coupled to, "another element, directly on," or "directly covering" the other element, there may be no other element intervening therebetween.

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

Although terms such as "first," "second," and "third" may be used herein to describe various elements, components, regions, layers or sections, these elements, components, regions, layers 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, a first member, component, region, layer or section discussed in examples described herein could also be termed a second member, component, region, layer or section without departing from the teachings of the examples.

For ease of description, spatially relative terms such as "above … …," "upper," "below … …," and "lower" may be used herein to describe one element's relationship to another element as illustrated in the figures. Such spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "upper" relative to another element would then be oriented "below" or "lower" relative to the other element. Thus, the term "above … …" includes both orientations "above … …" and "below … …" depending on the spatial orientation of the device. The device may also be otherwise positioned (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing various examples only and is not intended to be limiting of the disclosure. Singular forms also are intended to include plural forms unless the context clearly indicates otherwise. The terms "comprises," "comprising," and "having" are intended to specify the presence of stated features, integers, operations, elements, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, operations, elements, and/or groups thereof.

Variations from the shapes of the illustrations as a result, of manufacturing techniques and/or tolerances, are to be expected. Accordingly, the examples described herein are not limited to the particular shapes shown in the drawings, but include changes in shapes that occur during manufacture.

The features of the examples described herein may be combined in various ways that will be apparent upon an understanding of the present disclosure. Further, while the examples described herein have a variety of configurations, other configurations are possible as will be apparent after an understanding of the present disclosure.

The first aspect of the utility model provides a battery shell, thereby solving the problem that stress concentration exists at the transitional connection part of side walls with different wall thicknesses after the existing shell adopts the design with unequal wall thicknesses.

The case 100 of the battery according to the present utility model, as shown in fig. 1 and 5, has a length direction X, a thickness direction Z, and a width direction Y, wherein the sidewall perpendicular to the width direction Y defining the case 100 is a first sidewall 101, the sidewall perpendicular to the thickness direction Z defining the case 100 is a second sidewall 102 (the area of the first sidewall 101 is smaller than that of the second sidewall 102), the first sidewall 101 is provided with a mounting hole 105 (one or more mounting holes 105) for mounting an explosion-proof valve 104, the first sidewall 101 and the adjacent two second sidewalls 102 are connected by rounded walls 103 (here, for convenience of processing and to ensure the integrity of the case 100, the case 100 may be approximately rectangular, as shown in fig. 5, the first sidewall 101 has a symmetry plane S on which a center line of the first sidewall 101 extending in the length direction X is on, preferably, the symmetry plane S of the first sidewall 101 and the symmetry plane of the mounting hole 105 are coplanar, wherein the symmetry plane S is perpendicular to the thickness direction Z, and the two second sidewalls 102 may be identical with respect to the symmetry plane S of the case 103, i.e., four rounded walls 100 may have the same structure.

The thickness of the first sidewall 101 is greater than the thickness of the second sidewall 102, the thickness of the rounded wall 103 is equal to the thickness of the second sidewall 102 (here, as shown in fig. 5, if the thickness of the first sidewall 101 is defined as T, the thickness of the second sidewall 102 is defined as T > T, if the radius of the cross section of the cylindrical surface where the outer circular surface of the rounded wall 103 is defined as R1, and the radius of the cross section of the cylindrical surface where the inner circular surface of the rounded wall 103 is defined as R2, r1=r2+t), and the inner circular surface of the rounded wall 103 is connected to the inner side surface of the first sidewall 101 through the smooth transition surface 106.

To sum up, in order to increase the energy density of pack, the present utility model adjusts the explosion proof valve 104 to the first side wall 101 of the housing. And on this basis, the housing may be of a non-uniform wall thickness design (i.e., the thickness of the first side wall 101 is greater than the thickness of the second side wall 102) to reduce the weight of the housing. Based on the above, the utility model is purposefully designed for reducing the concentrated stress existing at the transitional connection part of the side walls with different wall thicknesses.

Specifically, the thickness of the rounded wall 103 is equal to the thickness of the second sidewall 102, and therefore, there is no stress concentration problem in the transition of the rounded wall 103 and the second sidewall. Whereas the connection of the rounded wall 103 and the first sidewall 101 may distribute stress through the transition surface 106, in particular, the smooth transition surface 106 connects the thin wall and the thick wall in a transition (the smooth transition surface 106 connects the inner side of the first sidewall 101 and the inner circular surface of the rounded wall 103), so that the thickness difference between the two is gradually reduced, that is, the concentrated stress is distributed at the portion where the transition surface 106 is located, and the strength of the housing 100 is further increased. The specific structure and dimensions of the first side wall 101, the second side wall 102, the rounded wall 103, and the mounting hole 105 of the present utility model will be described in detail below with reference to fig. 1 to 5.

In an embodiment of the present utility model, as shown in fig. 5, the transition surface 106 is preferably planar, and both the transition surface 106 and the inner side surface of the second sidewall 102 are tangential to the inner circular surface. A smooth transition of the rounded wall 103 with the first side wall 101 and the second side wall 102 is ensured.

Further, the angle a between the transition surface 106 and the inner side surface of the first sidewall 101 is 120 ° to 165 °.

It should be noted that, if the included angle a is smaller than 120 °, the distance between the transition portion of the second side wall 102 and the first side wall 101 is relatively short (i.e., the span of the transition surface 106 is short), and thus the stress concentration therein cannot be effectively dispersed, which has an poor effect of improving the strength of the housing, and in addition, the strength of the manufactured mold is insufficient at the location, and the mold is damaged.

If the included angle a > 165 °, the distance between the transition portion of the second side wall 102 and the first side wall 101 is relatively long (i.e., the span of the transition surface 106 is long), and further, the first thick wall is relatively short (the first side wall 101 with the thickness of T) in the thickness direction Z, which may cause the width of the explosion-proof valve 104 to be reduced, or the width of the explosion-proof valve 104 to be unchanged, and the welding reliability of the welding portion of the explosion-proof valve 104 may be reduced.

Preferably, the angle a is 135 °. Preferably, the housing 100 is an aluminum housing. The tensile strength of the shell 100 after molding is more than or equal to 120Mpa, and the yield strength is more than or equal to 110Mpa.

Further, in the embodiment of the present utility model, as shown in fig. 5, the mounting hole 105 includes a stepped portion 1051 and a through hole, the stepped portion 1051 is provided along a circumferential direction of the through hole (the stepped portion 1051 is provided along an inner wall of the through hole by one circle and is equal in size in a thickness direction Z), wherein the stepped portion 1051 partitions 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 provided along the width direction Y, wherein the first waist-shaped hole 1052 is located outside the first side wall 101, the second waist-shaped hole 1053 is located inside the first side wall 101, a sectional area of the first waist-shaped hole 1052 is larger than a sectional area of the second waist-shaped hole 1053, and the explosion-proof valve 104 is mounted to the first waist-shaped hole 1052.

According to a second aspect of the present utility model there is provided a battery (which may be a secondary battery) comprising a casing 100 of the battery as described above.

Further, as shown in fig. 2, the battery further includes a positive electrode cover plate 200, a negative electrode cover plate 300, a pole group 400, a side plate 500, and an insulation protection film 600, wherein the insulation protection film 600 is sleeved on the pole group 400, the side plate 500 is mounted on a side wall of the pole group 400 and is used for fixing the insulation protection film 600, the casing 100 is sleeved on the insulation protection film 600, two openings are respectively provided at two ends of the casing 100, and the positive electrode cover plate 200 and the negative electrode cover plate 300 are respectively mounted at the two openings.

Finally, it should be noted that: the above examples are only specific embodiments of the present utility model, and are not intended to limit the scope of the present utility model, but it should be understood by those skilled in the art that the present utility model is not limited thereto, and that the present utility model is described in detail with reference to the foregoing examples: any person skilled in the art may modify or easily conceive of the technical solution described in the foregoing embodiments, or perform equivalent substitution of some of the technical features, while remaining within the technical scope of the present disclosure; such modifications, changes or substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present utility model, and are intended to be included in the scope of the present utility model.

Claims

1. A battery case, characterized in that the case has a length direction, a thickness direction and a width direction,

the side wall perpendicular to the width direction defining the housing is a first side wall,

the side wall of the shell, which is 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 first side wall is connected with two adjacent second side walls through a round corner wall,

wherein the thickness of the first side wall is larger than that of the second side wall,

the thickness of the rounded wall is equal to the thickness of the second sidewall,

the inner circular surface of the round corner wall is connected with the inner side surface of the first side wall through a smooth transition surface.

2. The battery housing of claim 1, wherein the transition surface is planar.

3. The battery housing of claim 2, wherein the transition surface is at an angle of 120 ° to 165 ° to the inner side of the first sidewall.

4. A housing for a battery as claimed in claim 3, wherein the transition surface is at an angle of 135 ° to the inner side of the first side wall.

5. The battery case according to claim 1, wherein the first side wall has a symmetry plane perpendicular to the thickness direction, and the two second side walls are symmetrical about the symmetry plane.

6. The battery housing of claim 1, wherein the transition surface and the inner side surface of the second sidewall are both tangential to the inner circular surface.

7. The housing of a battery according to claim 1, wherein the housing is an aluminum case.

8. The battery case according to claim 1, wherein the mounting hole includes a stepped portion and a through hole, the stepped portion being provided along a circumferential direction 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 positioned at the outer side of the first side wall, the second waist-shaped hole is positioned at 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,

the explosion-proof valve is mounted in the first waist-shaped hole.

9. A battery comprising a casing of the battery according to any one of claims 1-8.

10. The battery of claim 9, further comprising a positive electrode cover plate, a negative electrode cover plate, a pole group, a side plate, and an insulating protective film,

the insulating protective film is sleeved on the pole group,

the side plates are arranged on the side walls of the pole groups and are used for fixing the insulating protective film,

the 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 arranged at the two openings.