CN220692164U - Explosion-proof casing, electric core and battery package - Google Patents

Abstract

The utility model provides an explosion-proof shell, a battery cell and a battery pack, and relates to the field of battery cell exhaust structures. The explosion-proof shell comprises a plurality of sub-shells, and a closed accommodating cavity is formed after the sub-shells are connected; the connection part of any two adjacent sub-shells is provided with a fastening part and a weak part, and when the battery cell is in a thermal runaway state, the weak part is cracked to form an exhaust channel capable of communicating the accommodating cavity with an external space. When the battery cell is in a thermal runaway state, the weak part is cracked under the action of high-pressure gas to form an exhaust passage from the accommodating cavity to an external space; the weak part is formed in the process of assembling and connecting the sub-shells (namely, the weak part for exhausting belongs to a part of the shells), so that when the sizes of the battery cells are changed, the battery cells do not need to be replaced or redesigned, and the explosion-proof shell can flexibly meet the exhaust requirements of the battery cells with different sizes.

Description

Explosion-proof casing, electric core and battery package

Technical Field

The application relates to the field of battery cell exhaust structures, in particular to an explosion-proof shell, a battery cell and a battery pack.

Background

The battery pack is an essential key component of the new energy automobile, and with the increase of the popularity of the new energy automobile, the safety problem of the battery pack during use is more and more paid attention to. Thermal runaway is one of the common failure modes of battery packs, and is characterized in that a great amount of high-temperature gas is rapidly generated inside the battery cell due to the factors such as chemical reaction process runaway, so that the pressure and the temperature inside the battery cell exceed rated safety values. At present, the explosion-proof valve is arranged on the battery core to carry out air discharge and pressure relief so as to ensure the use safety of the battery core, but for large-size battery cores (such as battery cores with the length dimension of 300-700 mm, the width dimension of 200-300 mm and the thickness dimension of 20-40 mm), the specification of the existing explosion-proof valve on the market is too small to meet the air discharge requirement. If the specification of the explosion-proof valve is changed, the corresponding specification of the structure corresponding to the explosion-proof valve on the battery core shell is also required to be changed correspondingly, and the operation is required to be repeated every time the size of the battery core is changed (i.e. the specification of the explosion-proof valve and other corresponding structures is redesigned), so that the development and production assembly efficiency of the battery core are greatly reduced. That is, the existing venting through the explosion-proof valve cannot flexibly accommodate the variation in cell size.

Disclosure of Invention

Accordingly, an object of the present application is to provide an explosion-proof housing, a battery cell and a battery pack, so as to solve the problem that the conventional exhaust method through an explosion-proof valve cannot flexibly adapt to the change of the battery cell size.

According to the above object, a first aspect of the present utility model provides an explosion-proof housing formed outside a battery cell, wherein the explosion-proof housing includes a plurality of sub-housings, and a closed accommodating cavity is formed after the plurality of sub-housings are connected; the connection part of any two adjacent sub-shells is provided with a fastening part and a weak part, and when the battery cell is in a thermal runaway state, the weak part is cracked to form an exhaust channel capable of communicating the accommodating cavity with an external space.

Preferably, the sub-shells are connected by welding, and the fastening part and the weak part are positioned at the welding seam of any two adjacent sub-shells.

Preferably, the welding pressure of the weak portion is less than 0.9MPa.

Preferably, the welding pressure of the fastening portion is greater than 1.2MPa.

Preferably, when the battery cell is formed into a square battery cell, the welded seam formed by welding the plurality of sub-shells is rectangular, at least one weak portion is formed on each side of the welded seam, and at least one weak portion is formed on each side of the welded seam.

Preferably, the weak portion is formed in an L-shaped structure, and the weak portion is provided at four vertex angles of the weld bead.

Preferably, when the cell is formed as a cylindrical cell, the weld is located at an end of the cell in the axial direction, and the weld is formed as a circle; the weak portion is formed into an arc-shaped structure, and a plurality of weak portions are uniformly arranged at intervals.

Preferably, each of the sub-housings is formed of stainless steel.

According to a second aspect of the present utility model there is provided a cell wherein the cell comprises an explosion proof housing as described above.

According to a third aspect of the present utility model there is provided a battery pack, wherein the battery pack is provided with a cell as described above.

According to the explosion-proof shell, the battery cell and the battery pack, the multiple sub-shells are connected to form the shell of the battery cell, and the multiple sub-shells are connected to form a closed accommodating cavity so as to be capable of accommodating electrolyte and the like; further, the fastening part and the weak part are formed at the joint of any two adjacent sub-shells, so that when the battery cell is in a thermal runaway state, the weak part is cracked under the action of high-pressure gas to form an exhaust passage from the accommodating cavity to the external space; the weak part is formed in the process of assembling and connecting the sub-shells (namely, the weak part for exhausting belongs to a part of the shells), so that when the sizes of the battery cells are changed, the battery cells do not need to be replaced or redesigned, and the explosion-proof shell can flexibly meet the exhaust requirements of the battery cells with different sizes.

In order to make the above objects, features and advantages of the present application 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 application, 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 application and therefore should not be considered limiting the scope, and that other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of an explosion proof housing according to an embodiment of the present utility model;

FIG. 2 is another schematic view of an explosion proof housing according to an embodiment of the present utility model;

fig. 3 is a partially exploded schematic illustration of an explosion proof housing in accordance with an embodiment of the utility model.

Icon: 1-a sub-housing; 2-weaknesses; 3-a fastening part; 4-positive electrode posts; 5-a negative electrode column; 6-liquid injection holes.

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 a review of the disclosure of the present application.

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 after an understanding of the disclosure of the present application. 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.

As shown in fig. 1 to 3, according to a first aspect of the present utility model, there is provided an explosion-proof housing formed outside a battery cell as a housing of the battery cell, the explosion-proof housing being formed by connecting a plurality of sub-housings 1, and hereinafter, a specific structure of each of the above-mentioned portions of the explosion-proof housing according to the present utility model will be described in detail.

In this embodiment, a plurality of sub-housings 1 are connected to form a closed accommodating cavity for filling electrolyte and placing parts such as a pole piece and a diaphragm, so as to ensure that the battery cell has a normal use function. In addition, a fastening part 3 and a weak part 2 are formed at the joint of any two adjacent sub-shells 1, and the fastening part 3 can improve the firmness of the joint of the sub-shells 1, so that the strength and the rigidity of the whole structure of the explosion-proof shell are ensured; the weak portion 2 is used for exhausting, that is, when the battery cell is in a thermal runaway state, under the action of high pressure in the battery cell, the weak portion 2 is propped up to a cracking state by high-temperature gas in the battery cell to form an exhaust channel which is communicated with the accommodating cavity and the external space, so that the high-temperature high-pressure gas in the battery cell can be exhausted from the exhaust channel (that is, the weak portion 2 after cracking).

Further, in order to facilitate better achievement of the above technical effects, the sub-housings 1 in the present embodiment are connected by welding, that is, the above fastening portion 3 and the weak portion 2 are both located at the weld of any adjacent image sub-housing 1. Specifically, in this embodiment, the starting pressure for starting the exhaust of the battery cell is 0.6MPa to 0.9MPa, so the welding pressure at the weak portion 2 should be less than 0.9MPa so that it can be smoothly cracked to form an exhaust passage; the welding pressure at the fastening part 3 should be greater than 1.2MPa to avoid the case of the battery cell from cracking, etc.

More specifically, as shown in fig. 1 to 3, when the battery cell is formed as a square battery cell, the welded seam formed after the welding of the plurality of sub-cases 1 is rectangular, and each side of each rectangular welded seam is respectively formed with at least one weak portion 2, thereby facilitating the uniform discharge of high-temperature and high-pressure gas inside the battery cell. Further, the weak portion 2 is formed in an L-shaped structure, and the weak portion 2 is provided at four apex angles of the rectangular weld, i.e., a plurality of weak portions 2 are located at apex angles of the present explosion-proof housing. In the case of welding the sub-housing 1, the welding at the top corners is most difficult, so that the weak points are arranged at the top corners of the weld joints in the present embodiment, which is the optimal choice based on the characteristics of the housing connection assembly structure. However, the specific size of the weak point, such as the length of the vertical side and the horizontal side, is not particularly limited, and should be flexibly adjusted according to practical situations, such as the specification and the size of the battery cell, when the sub-housing 1 is welded, so that the explosion-proof housing can flexibly meet the exhaust requirements of the battery cells with different sizes.

It should be noted that, the shape, number, etc. of the sub-housings 1 are not particularly limited, as shown in fig. 1 to 3, the explosion-proof housing in this embodiment is provided with two rectangular plate-shaped sub-housings 1 and one hollow sub-housing 1, the former is correspondingly disposed at the hollow portion of the latter, that is, the two rectangular plate-shaped sub-housings 1 are respectively formed into two top covers along the length direction of the battery cell, correspondingly, the two top covers of the battery cell are also formed with a positive electrode post 4 (and a liquid injection hole 6) and a negative electrode post 5, and for the top cover of the battery cell, the positive electrode post 4, the liquid injection hole 6 and the negative electrode post 5 are the conventional arrangement of the battery cell, so that the description is omitted. Alternatively, the explosion-proof housing may be provided with six rectangular parallelepiped plate-shaped sub-housings 1 (not shown in the drawings), each sub-housing 1 is formed as one side portion of the housing of the battery cell, so that each side portion of the battery cell is formed with a weak portion 2 capable of exhausting, and further, the exhaust effect of the battery cell is ensured.

When the battery cell is formed as a cylindrical battery cell, although not shown in the drawings, the weld thereof should be located at the end of the cylindrical battery cell in the axial direction thereof in order to improve the sealability of the receiving chamber, and the weld is formed in a circular shape, i.e., the sub-case 1 of the cylindrical battery cell includes two circular sub-cases 1 and one rectangular sub-case 1. At this time, the weak portions 2 are formed in an arc-shaped structure, and the plurality of weak portions 2 are disposed at uniform intervals.

In addition, the sub-housing 1 is made of stainless steel, so that the explosion-proof housing formed after connection of the sub-housing can avoid being corroded by electrolyte, and meanwhile, the strength of the overall structure of the battery cell is also increased.

According to the explosion-proof housing of the present utility model, a plurality of sub-housings 1 are connected to form a housing of a battery cell, and a closed accommodating chamber is formed after the plurality of sub-housings 1 are connected to enable placement of an electrolyte or the like; further, the fastening part 3 and the weak part 2 are formed at the joint of any two adjacent sub-shells 1, so that when the battery cell is in a thermal runaway state, the weak part 2 is cracked under the action of high-pressure gas to form an exhaust passage from the accommodating cavity to the external space; the weak portion 2 is formed in the process of assembling and connecting the sub-housing 1 (namely, the weak portion 2 for exhausting belongs to a part of the housing), so that when the size of the battery cell is changed, the battery cell does not need to be replaced or redesigned, and the explosion-proof housing can flexibly meet the exhaust requirements of battery cells with different sizes.

According to a second aspect of the present utility model there is provided a battery cell comprising an explosion-proof housing as described above.

According to a third aspect of the present utility model there is provided a battery pack provided with a cell as described above.

Finally, it should be noted that: the foregoing examples are merely specific embodiments of the present application, and are not intended to limit the scope of the present application, but the present application is not limited thereto, and those skilled in the art will appreciate that while the foregoing examples are described in detail, the present application is not limited thereto. Any person skilled in the art may modify or easily conceive of the technical solution described in the foregoing embodiments, or make equivalent substitutions for some of the technical features within the technical scope of the disclosure of the present application; such modifications, changes or substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (10)

1. An explosion-proof shell formed outside an electric core, which is characterized in that the explosion-proof shell comprises a plurality of sub-shells, and a closed accommodating cavity is formed after the sub-shells are connected; the connection part of any two adjacent sub-shells is provided with a fastening part and a weak part, and when the battery cell is in a thermal runaway state, the weak part is cracked to form an exhaust channel capable of communicating the accommodating cavity with an external space.

2. The explosion-proof housing of claim 1, wherein the sub-housings are connected by welding, and the fastening portion and the weakened portion are located at a weld of any adjacent two of the sub-housings.

3. The explosion-proof housing of claim 2, wherein the welding pressure of the weak portion is less than 0.9MPa.

4. The explosion-proof housing according to claim 2, wherein the welding pressure of the fastening portion is greater than 1.2MPa.

5. The explosion-proof housing according to claim 2, wherein when the battery cell is formed as a square battery cell, a weld formed by welding a plurality of the sub-housings is rectangular, and each side of the weld is formed with at least one of the weak portions.

6. The explosion-proof housing according to claim 5, wherein the weak portion is formed in an L-shaped structure, and the weak portion is provided at four apex angles of the weld bead.

7. The explosion-proof housing according to claim 2, wherein when the cell is formed as a cylindrical cell, the weld is located at an end in the axial direction of the cell, and the weld is formed in a circular shape; the weak portion is formed into an arc-shaped structure, and a plurality of weak portions are uniformly arranged at intervals.

8. The explosion-proof housing of claim 1, wherein each of the sub-housings is formed of stainless steel.

9. A battery cell, characterized in that the battery cell comprises an explosion-proof housing according to any one of claims 1 to 8.

10. A battery pack, characterized in that the battery pack is provided with the cell as claimed in claim 9.