CN216648450U - Cover structure, battery monomer, battery and power consumption device - Google Patents

Abstract

The application relates to a lid structure, battery monomer, battery and power consumption device includes: a cover, a weakening portion and a balancing portion. The weakened portion is formed on the cover body and is configured to break when an internal pressure of the battery or the battery cell reaches a threshold value. The balancing portion communicates the outside with the inside of the battery or the battery cell, and is configured to allow gas to enter and exit and to block water vapor from the outside from entering the inside of the battery or the battery cell. This application is with the shaping of weakening portion on the lid, and the weakening portion can be at the fracture and the pressure release when battery or the free internal pressure of battery is too big, avoids battery or the explosion of battery monomer, causes the safety problem. Meanwhile, an explosion-proof valve does not need to be additionally installed on the cover structure, the cost of the cover structure can be reduced, the installation can be simplified, and the time and labor are saved during the installation of the cover structure. In addition, the cover structure is also provided with a balancing part which can balance the small pressure difference existing inside and outside the battery or the single battery, so that the formation of the large pressure difference is relieved, and the service life of the battery or the single battery is prolonged.

Description

Cover structure, battery monomer, battery and power consumption device

Technical Field

The application relates to the technical field of battery manufacturing, in particular to a cover structure, a battery monomer, a battery and an electric device.

Background

Energy conservation and emission reduction are the key points of sustainable development of the automobile industry, and electric vehicles become important components of the sustainable development of the automobile industry due to the advantages of energy conservation and environmental protection. For electric vehicles, battery technology is an important factor in its development.

In the development of battery technology, in addition to improving the performance of the battery, the safety problem is a considerable problem, and how to improve the safety of the battery is still a technical problem to be solved urgently in the battery technology.

SUMMERY OF THE UTILITY MODEL

In view of the above problems, the present application provides a cover structure, a battery cell, a battery, and an electric device, which are intended to improve the safety performance of the battery.

In a first aspect, the present application provides a cover structure for a battery or cell, the cover structure comprising a cover body, a weakening portion and a balancing portion. The weakened portion is formed on the cover body and is configured to break when an internal pressure of the battery or the battery cell reaches a threshold value. The balancing portion communicates the outside with the inside of the battery or the battery cell, and is configured to allow gas to enter and exit and to block water vapor from the outside from entering the inside of the battery or the battery cell.

In the technical scheme of this application embodiment, the weakening portion shaping of lid structure is on the lid, and the weakening portion can be at the fracture and the pressure release when battery or the free internal pressure of battery is too big, avoids battery or the explosion of battery monomer, causes the safety problem. Meanwhile, when the cover structure is used in practice, an explosion-proof valve does not need to be additionally installed on the cover structure, the cost of the cover structure can be reduced, the installation can be simplified, and the time and labor are saved during the installation of the cover structure. In addition, the cover structure is also provided with a balancing part which can balance the small pressure difference existing inside and outside the battery or the single battery, so that the formation of the large pressure difference is relieved, and the service life of the battery or the single battery is prolonged.

In some embodiments, the weakened portion includes a weakened portion and an intermediate portion, the weakened portion being disposed around a periphery of the intermediate portion and connected between the cover and the intermediate portion. The weak portion has a thickness smaller than that of the intermediate portion and is configured to break when an internal pressure of the battery or the battery cell reaches a threshold value. In this case, the weakened portion can be obtained by forming an annular weak groove in the lid body during actual processing, and the weakened portion can be easily formed.

In some embodiments, the balance portion is provided on the intermediate portion. Because the thickness of middle part is thinner than weak portion thickness, the structural strength of middle part is higher, and the installation reliability and the steadiness of balance portion can be improved to the balance portion on locating the middle part.

In some embodiments, the balancing part includes a vent hole formed at the weakening part and a vent member covering the vent hole. The balance part is formed by the air holes and the air permeable piece, and during actual operation, the air holes can be formed in the process of forming the weakening part, and then the air permeable piece is covered. Compared with the mode of additionally punching holes at the gas position of the cover body to form the air holes, the processing procedure of the cover structure can be simplified, and the processing efficiency is improved.

In some embodiments, the gas permeable member is located on a side of the weakened portion that faces the interior of the battery or battery cell. At this time, when the cover body is used for the battery or the battery monomer, the ventilation piece is positioned in the battery or the battery monomer and is not exposed outside the battery or the battery monomer, so that the appearance is attractive, and the ventilation piece can be prevented from being separated from the weakening part under external collision to cause the failure of the balance part.

In some embodiments, the air-permeable member is affixed to the weakened portion. The ventilation piece is installed in a sticking mode, operation is convenient, other connecting parts do not need to be processed on the ventilation piece and the weakening part, and processing of the cover structure can be simplified and cost can be reduced.

In some embodiments, the cover structure further includes a bursting element, which is deformable and provided at the weakening portion, and is configured to apply a bursting force assisting the weakening portion to break when deformed by an internal pressure of the battery or the battery cell. At this moment, when the internal pressure of battery or battery monomer increases, the blasting piece can provide the cracked explosive force of weak part with higher speed when the pressure effect is down deformed, guarantees the weak part and splits smoothly and the pressure release when battery or battery monomer inside reaches the pressure threshold value when helping promoting the structural strength of weak part, avoids the explosion. When the strength of the weak portion is slightly high, it is helpful to prevent the weak portion from being broken in a non-thermal failure state to damage the battery or the battery cell, and the structural reliability of the battery or the battery cell can be improved.

In some embodiments, the rupture member comprises an energy-resilient member configured to contract under pressure inside the battery or cell and expand when contracted to a critical degree to apply a burst force to the weakened portion. At the moment, the elastic energy absorbing piece not only provides bursting force for assisting the fracture of the weakened part, but also can delay the fracture time of the weakened part, and is beneficial to prolonging the service life of the battery or the single battery.

In some embodiments, the energy absorbing elastic element covers the area of the weakening section other than the area where the balance section is located. Therefore, when the elastic energy-absorbing piece does not reach the shrinkage critical degree of the elastic energy-absorbing piece, the weakening part can not be influenced by the internal pressure of the battery or the single battery, the time for delaying the fracture of the weakening part can be improved, and the service life of the battery or the single battery can be prolonged.

In some embodiments, the blasting element is affixed to the weakened portion. The blasting piece is installed in a sticking mode, so that the operation is convenient, other connecting parts do not need to be processed on the blasting piece and the weakening part, and the processing of the cover structure can be simplified and the cost can be reduced.

In a second aspect, the present application provides a battery cell, which includes a housing, a cell assembly and a cover structure in any of the above embodiments, wherein the housing encloses a first cavity with a first opening, the cell assembly is accommodated in the first cavity, and the cover structure covers the first opening.

In a third aspect, the present application provides a battery, which includes a box body and a battery cell, wherein the box body includes a box body and a cover structure in any of the above embodiments, the box body encloses a second cavity with a second opening, the cover structure covers the second opening, and the battery cell is accommodated in the second cavity.

In some embodiments, the battery cell includes a housing, a cell assembly, and a cover structure as described in any one of the above embodiments, the housing encloses a first cavity with a first opening, the cell assembly is accommodated in the first cavity, and the cover structure covers the first opening.

In a fourth aspect, the present application provides an electric device, which includes the battery in the above embodiments, and the battery is used for providing electric energy.

The above description is only an overview of the technical solutions of the present application, and the present application may be implemented in accordance with the content of the description so as to make the technical means of the present application more clearly understood, and the detailed description of the present application will be given below in order to make the above and other objects, features, and advantages of the present application more clearly understood.

Drawings

Various additional advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the application. Moreover, like reference numerals are used to refer to like elements throughout. In the drawings:

FIG. 1 is a schematic structural diagram of a vehicle according to an embodiment of the present application;

FIG. 2 is an exploded view of a battery according to an embodiment of the present application;

fig. 3 is an exploded view of a battery cell according to an embodiment of the present disclosure;

FIG. 4 is a schematic structural diagram of a cover structure according to an embodiment of the present disclosure;

FIG. 5 is an enlarged view taken at A in FIG. 4;

FIG. 6 is a schematic view of a portion of the lid structure shown in FIG. 4;

FIG. 7 is an enlarged view at B in FIG. 6;

FIG. 8 is a front view of the cover structure shown in FIG. 4;

fig. 9 is a cross-sectional view at C-C in fig. 8.

The reference numerals in the detailed description are as follows:

1000. a vehicle;

100. a battery; 200. a controller; 300. a motor;

10. a box body; 11. a first portion; 12. a second portion;

20. a battery cell; 21. an end cap; 21a, electrode terminals; 22. a housing; 23. an electrical core assembly;

30. a cover structure; 31. a cover body; 32. a weakened portion; 32a, a weakened portion; 32b, an intermediate portion; 33. a balancing section; 33a, air holes; 33b, a ventilation member; m, a breathable film; 34. a blasting element; 34a, an elastic energy absorbing member; k. avoiding the hole.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are merely used to more clearly illustrate the technical solutions of the present application, and therefore are only examples, and the protection scope of the present application is not limited thereby.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "including" and "having," and any variations thereof, in the description and claims of this application and the description of the above figures are intended to cover non-exclusive inclusions.

In the description of the embodiments of the present application, the technical terms "first", "second", and the like are used only for distinguishing different objects, and are not to be construed as indicating or implying relative importance or to implicitly indicate the number, specific order, or primary-secondary relationship of the technical features indicated. In the description of the embodiments of the present application, "a plurality" means two or more unless specifically defined otherwise.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

In the description of the embodiments of the present application, the term "and/or" is only one kind of association relationship describing an associated object, and means that three relationships may exist, for example, a and/or B, and may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

In the description of the embodiments of the present application, the term "plurality" refers to two or more (including two), and similarly, "plural sets" refers to two or more (including two), and "plural pieces" refers to two or more (including two).

In the description of the embodiments of the present application, the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate orientations and positional relationships that are based on the orientations and positional relationships shown in the drawings, and are used for convenience in describing the embodiments of the present application and for simplification of the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be configured and operated in a specific orientation, and thus, should not be construed as limiting the embodiments of the present application.

In the description of the embodiments of the present application, unless otherwise explicitly specified or limited, the terms "mounted," "connected," "fixed," and the like are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrated; mechanical connection or electrical connection is also possible; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the embodiments of the present application can be understood by those of ordinary skill in the art according to specific situations.

The present applicant has noticed that, upon thermal failure, the battery and the battery cells are liable to explode and cause safety problems due to internal heat and pressure, resulting in low safety performance of the battery. The explosion-proof valve that is equipped with alone usually on the box of traditional battery and the free end cover of traditional battery, under the thermal failure state, battery inside and battery monomer internal pressure unbalance to when reaching the threshold value of explosion-proof valve, the explosion-proof valve initiative is opened with balanced battery and the interior external differential pressure of battery monomer to avoid the explosion. The mode of setting up explosion-proof valve alone, explosion-proof valve structure complicacy makes its cost higher, and needs the explosion-proof valve of extra installation and wastes time and energy.

In order to improve the safety performance of the battery, the applicant researches and discovers that the local strength of the box body and the end cover can be weakened to form a weakened part, and when the internal pressure of the battery and the battery monomer is too high and needs to be relieved, the weakened part can be broken under the action of the internal pressure of the battery and the battery monomer so as to relieve the pressure. Further, the balance part is arranged on the weakening part, the balance part can maintain the balance of the pressure difference between the inside and the outside of the battery and the pressure difference between the inside and the outside of the battery monomer, relieve the accumulation of large pressure, delay the fracture of the weakening part and prolong the service life of the battery and the battery monomer.

In view of the above, the applicant has conducted extensive studies to improve the safety performance of a battery, and has devised a cap structure in which a weakened portion is formed in a cap body, so that the weakened portion is broken and released when the pressure inside the cap body reaches a threshold value, and a balance portion is provided to maintain the balance of the pressure difference between the inside and the outside of the cap body, thereby alleviating the accumulation of large pressure.

The cover structure disclosed in the embodiment of the application can be used for members which need to maintain the internal and external pressure difference and can prevent explosion, such as a box body of a battery, an end cover of a battery cell and the like.

The battery cell disclosed in the embodiment of the application can be used in electric devices such as vehicles, ships or aircrafts, but not limited thereto. A power supply system including the electric device composed of the battery cell, the battery, and the like disclosed in the present application may be used.

The embodiment of the application provides an electric device using a battery as a power supply, wherein the electric device can be but is not limited to a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, a battery car, an electric automobile, a ship, a spacecraft and the like. The electric toy may include a stationary or mobile electric toy, such as a game machine, an electric car toy, an electric ship toy, an electric airplane toy, and the like, and the spacecraft may include an airplane, a rocket, a space shuttle, a spacecraft, and the like.

For convenience of description, the following embodiments take an example in which a power consuming apparatus according to an embodiment of the present application is a vehicle 1000.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a vehicle 1000 according to some embodiments of the present disclosure. The vehicle 1000 may be a fuel automobile, a gas automobile, or a new energy automobile, and the new energy automobile may be a pure electric automobile, a hybrid electric automobile, or an extended range automobile, etc. The battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom or the head or the tail of the vehicle 1000. The battery 100 may be used for power supply of the vehicle 1000, for example, the battery 100 may serve as an operation power source of the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300, the controller 200 being configured to control the battery 100 to supply power to the motor 300, for example, for starting, navigation, and operational power requirements while the vehicle 1000 is traveling.

In some embodiments of the present application, the battery 100 may be used not only as an operating power source of the vehicle 1000, but also as a driving power source of the vehicle 1000, instead of or in part of fuel or natural gas, to provide driving power for the vehicle 1000.

Referring to fig. 2, fig. 2 is an exploded view of a battery 100 according to some embodiments of the present disclosure. The battery 100 includes a case 10 and a battery cell 20, and the battery cell 20 is accommodated in the case 10. The case 10 is used to provide a receiving space for the battery cells 20, and the case 10 may have various structures. In some embodiments, the case 10 may include a first portion 11 and a second portion 12, the first portion 11 and the second portion 12 cover each other, and the first portion 11 and the second portion 12 together define a receiving space for receiving the battery cell 20. The second part 12 may be a hollow structure with one open end, the first part 11 may be a plate-shaped structure, and the first part 11 covers the open side of the second part 12, so that the first part 11 and the second part 12 jointly define a containing space; the first portion 11 and the second portion 12 may be both hollow structures with one side open, and the open side of the first portion 11 may cover the open side of the second portion 12. Of course, the case 10 formed by the first and second portions 11 and 12 may have various shapes, such as a cylinder, a rectangular parallelepiped, and the like.

In the battery 100, the number of the battery cells 20 may be multiple, and the multiple battery cells 20 may be connected in series or in parallel or in series-parallel, where in series-parallel refers to both series connection and parallel connection among the multiple battery cells 20. The plurality of battery cells 20 can be directly connected in series or in parallel or in series-parallel, and the whole formed by the plurality of battery cells 20 is accommodated in the box body 10; of course, the battery 100 may also be formed by connecting a plurality of battery cells 20 in series, in parallel, or in series-parallel to form a battery module, and then connecting a plurality of battery modules in series, in parallel, or in series-parallel to form a whole, and accommodating the whole in the case 10. The battery 100 may further include other structures, for example, the battery 100 may further include a bus member for achieving electrical connection between the plurality of battery cells 20.

Wherein each battery cell 20 may be a secondary battery or a primary battery; but is not limited to, a lithium sulfur battery, a sodium ion battery, or a magnesium ion battery. The battery cell 20 may be cylindrical, flat, rectangular parallelepiped, or other shape.

Referring to fig. 3, fig. 3 is an exploded schematic view of a battery cell 20 according to some embodiments of the present disclosure. The battery cell 20 refers to the smallest unit constituting the battery. Referring to fig. 3, the battery cell 20 includes an end cap 21, a housing 22, a battery cell assembly 23, and other functional components.

The end cap 21 refers to a member that covers an opening of the case 22 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 21 may be adapted to the shape of the housing 22 to fit the housing 22. Alternatively, the end cap 21 may be made of a material (e.g., an aluminum alloy) having a certain hardness and strength, so that the end cap 21 is not easily deformed when being impacted, and the battery cell 20 may have a higher structural strength and improved safety. The end cap 21 may be provided with functional components such as the electrode terminals 21 a. The electrode terminals 21a may be used to be electrically connected with the electric core assembly 23 for outputting or inputting electric power of the battery cells 20. In some embodiments, the end cap 21 may further include a pressure relief mechanism for relieving the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold value. The material of the end cap 21 may also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not limited in this embodiment. In some embodiments, insulation may also be provided on the inside of the end cap 21, which may be used to isolate the electrical connection components within the housing 22 from the end cap 21 to reduce the risk of short circuits. Illustratively, the insulator may be plastic, rubber, or the like.

The housing 22 is an assembly for mating with the end cap 21 to form an internal environment of the battery cell 20, wherein the formed internal environment may be used to house the cell assembly 23, electrolyte, and other components. The housing 22 and the end cap 21 may be separate components, and an opening may be formed in the housing 22, and the opening may be covered by the end cap 21 to form the internal environment of the battery cell 20. Without limitation, the end cap 21 and the housing 22 may be integrated, and specifically, the end cap 21 and the housing 22 may form a common connecting surface before other components are inserted into the housing, and when it is necessary to enclose the inside of the housing 22, the end cap 21 covers the housing 22. The housing 22 may be a variety of shapes and sizes, such as rectangular parallelepiped, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 22 may be determined according to the specific shape and size of the electric core assembly 23. The material of the housing 22 may be various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not limited in the embodiments of the present invention.

The cell assembly 23 is a component in the battery cell 20 where electrochemical reactions occur. One or more electrical core assemblies 23 may be contained within the housing 22. The core assembly 23 is mainly formed by winding or stacking a positive electrode sheet and a negative electrode sheet, and a separator is generally provided between the positive electrode sheet and the negative electrode sheet. The parts of the positive plate and the negative plate with the active materials form the main body part of the electric core assembly, and the parts of the positive plate and the negative plate without the active materials form the tabs respectively. The positive electrode tab and the negative electrode tab may be located at one end of the main body portion together or at both ends of the main body portion, respectively. During the charging and discharging process of the battery, the positive active material and the negative active material react with the electrolyte, and the tabs are connected with the electrode terminals to form a current loop.

According to some embodiments of the present application, referring to fig. 4, 6 and 8, the present application provides a cover structure 30 for a battery 100 or a battery cell 20, the cover structure 30 including a cover body 31, a weakening portion 32 and a balancing portion 33. The weakened portion 32 is formed on the lid body 31, and is configured to break when the internal pressure of the battery 100 or the battery cell 20 reaches a threshold value. The balancing portion 33 communicates the outside with the inside of the battery 100 or the battery cell 20, and is configured to allow gas to enter and exit and to block water vapor from the outside from entering the inside of the battery 100 or the battery cell 20.

The cover 31 may be an end cap 21 of the battery cell 20 for cooperating with the housing 22 to form an internal environment of the battery cell 20. The cover 31 may also be a part of the case 10 of the battery 100, which defines a receiving space for receiving the battery cell 20 together with other parts of the case 10.

The weakened portion 32 is a portion having a structural strength weaker than that of the lid body 31. The weakened portion 32 is formed on the lid body 31, and means that the weakened portion 32 is formed on the lid body 31 at the same time when the lid body 31 is manufactured, and may be formed integrally by injection molding or machining, or in other forms. Specifically, the weakening portion 32 may include a groove formed on the cover 31, and the groove may be recessed toward the inside of the battery 100 or the battery cell 20 or may be recessed toward the outside of the battery 100 or the battery cell 20. Optionally. The groove is formed concavely in the thickness direction of the lid body 31. Of course, the groove may be formed to be recessed in another direction having an acute angle with the thickness direction of the lid 31, as long as the inside and the outside of the battery 100 or the battery cell 20 can be communicated with each other at the time of breakage.

When the internal pressure of the battery 100 or the battery cell 20 reaches a threshold value, the weakened portion 32 is broken. Specifically, the connection between the weakened portion 32 and the lid body 31 may be broken, and the connection between the weakened portion 32 and the lid body 31 may be the weakest point. The weakened portion 32 itself may be broken, and in this case, the weakened portion 32 may be a weakened film, a weakened sheet, or the like molded on the lid body 31. It will be appreciated that the "pressure threshold" referred to in this application is determined by the strength of the weakened portion 32.

The balancing unit 33 can balance the internal and external pressures of the battery 100 or the battery cell 20. When the internal pressure of the battery 100 or the battery cell 20 is small, external gas is allowed to enter the inside of the battery 100 or the battery cell 20. When the internal pressure of the battery 100 or the battery cell 20 is large, the gas inside the battery 100 or the battery cell 20 is allowed to flow out to the outside. Meanwhile, the balancing unit 33 can prevent external water vapor from entering the battery 100 or the battery cell 20, thereby preventing corrosion of components inside the battery 100 or the battery cell 20 and reducing the service life. The balancing portion 33 may be, but is not limited to, a balancing valve commonly used in the art, and a specific configuration of the balancing valve is not described herein.

In the cover structure 30, the weakened portion 32 is formed on the cover body 31, and the weakened portion 32 can be broken and released when the internal pressure of the battery 100 or the battery cell 20 is too high, so that the safety problem caused by explosion of the battery 100 or the battery cell 20 is avoided. Meanwhile, during actual use, an explosion-proof valve does not need to be additionally installed on the cover structure 30, the cost of the cover structure 30 can be reduced, installation can be simplified, and time and labor are saved in the installation of the cover structure 30. In addition, the cover structure 30 is further provided with a balancing portion 33 capable of balancing a small pressure difference existing inside and outside the battery 100 or the battery cell 20, so that the formation of a large pressure difference is alleviated, and the service life of the battery 100 or the battery cell 20 is prolonged.

In some embodiments, referring to fig. 5 and 7, and also to fig. 9, the weakened portion 32 includes a weakened portion 32a and an intermediate portion 32b, and the weakened portion 32a is disposed around the periphery of the intermediate portion 32b and is connected between the cover 31 and the intermediate portion 32 b. The weak portion 32a has a thickness smaller than that of the intermediate portion 32b and is configured to break when the internal pressure of the battery 100 or the battery cell 20 reaches a threshold value.

The thickness of the weak portion 32a and the thickness of the intermediate portion 32b refer to dimensions in the thickness direction of the lid body 31. The thickness of the weak portion 32a is smaller than that of the intermediate portion 32b, that is, the strength of the weak portion 32a is smaller than that of the intermediate portion 32 b. When the internal pressure of the battery 100 or the battery cell 20 is excessively large, the weak portion 32a is broken, and the intermediate portion 32b maintains the connection with the weak portion 32 a. Understandably, since the thickness of the weak portion 32a is smaller than that of the intermediate portion 32b and the thickness of the weak portion 32a is smaller than that of the cover 31, the intermediate portion 32b, the weak portion 32a and the cover 31 collectively define an annular weak groove. As for the relationship between the thickness of the intermediate portion 32b and the thickness of the cover 31, the thickness of the intermediate portion 32b may be smaller than the thickness of the cover 31, or the thickness of the cover 31 may be equal to the thickness of the intermediate portion 32b, and is not particularly limited. Alternatively, the intermediate portion 32b is provided flush with both sides of the lid body 31 in the thickness direction (i.e., both are equal in thickness).

In actual processing, the weakened portion 32 can be obtained by forming an annular weak groove in the lid body 31, and the weakened portion 32 can be easily formed.

Of course, in other embodiments, the weakened portion 32 may take other configurations. For example, the thickness of the weakened portion 32 is smaller than that of the cap body 31 as a whole, and the thickness of the weakened portion 32 is gradually reduced from the outer edge connected to the cap body 31 toward the middle, where the thickness of the middle is the lowest, and the middle of the weakened portion 32 is broken when the internal pressure of the battery 100 or the battery cell 20 is excessively increased. For another example, when the thickness of the weakened portion 32 is smaller than the thickness of the lid body 31 as a whole and the thickness of the weakened portion 32 is gradually increased from the outer edge to the middle portion, the edge thickness is the lowest, and the edge position of the weakened portion 32 is broken when the internal pressure of the battery 100 or the battery cell 20 is excessively increased.

In some embodiments, referring to fig. 6 and 7, the balance portion 33 is disposed on the middle portion 32 b. Since the intermediate portion 32b is thicker than the weak portions 32a, the intermediate portion 32b has higher structural strength, and the provision of the balance portion 33 on the intermediate portion 32b can improve the mounting reliability and stability of the balance portion 33. Of course, in other embodiments, the balancing part 33 may be provided on the cover 31.

In some embodiments, referring to fig. 5, 6 and 7, the balancing part 33 includes a vent hole 33a and a vent member 33b, the vent hole 33a is formed in the weakening part 32, and the vent member 33b covers the vent hole 33 a.

The vent hole 33a communicates the inside and outside of the battery 100 or the battery cell 20, and allows gas to enter and exit. Alternatively, the vent holes 33a may be plural, the plurality of vent holes 33a are formed at intervals on the weakened portion 32, and the vent member 33b covers all of the vent holes 33 a. The portion of the weakened portion 32 between the airing holes 33a can effectively support the airing 33b, thereby improving the mounting stability and reliability of the airing 33 b. Of course, only one vent hole 33a may be provided, and a larger vent hole 33a may achieve the above-mentioned effects.

The air-permeable member 33b allows gas to flow therethrough and blocks water vapor from entering the battery 100 or the battery cell 20 from the outside. The air-permeable member 33b may be made of a material having air permeability and hydrophobicity, such as a polymer material, such as expanded polytetrafluoroethylene, polyurethane, or the like. Specifically, the air permeable member 33b may include an air permeable film m, which is a common component in the art and can be purchased directly, which helps to reduce the design cost. The air permeable membrane m can be a polyurethane air permeable membrane m (PU membrane for short) or an expanded polytetrafluoroethylene membrane (PTFE membrane for short).

At this time, the balance part 33 is formed of the airing hole 33a and the airing member 33b, and in practice, the airing hole 33a may be formed in the process of forming the weakened part 32 and then the airing member 33b may be covered. Compared to the method of forming the ventilation holes 33a separately in the gas position of the lid body 31, the present embodiment can simplify the processing steps of the lid structure 30 and improve the processing efficiency.

In some embodiments, the air-permeable member 33b is located on a side of the weakened portion 32 facing the inside of the battery 100 or the battery cell 20. At this time, when the cover body is used for the battery 100 or the battery cell 20, the air-permeable member 33b is located inside the battery 100 or the battery cell 20 and is not exposed to the outside of the battery 100 or the battery cell 20, which not only provides an aesthetic appearance, but also prevents the air-permeable member 33b from being separated from the weakened portion 32 by an external impact, resulting in a failure of the balance portion 33.

In some embodiments, the air-permeable member 33b is affixed to the weakened portion 32. Specifically, the air-permeable member 33b itself has a back adhesive surface, and is bonded to the weakened portion 32 through the back adhesive of itself, so that the operation is convenient. In particular, it is also possible to bond the gas permeable member 33b and the weakened portion 32 by additional application of glue.

The ventilation member 33b is mounted in a sticking manner, so that the operation is convenient, other connecting parts do not need to be processed on the ventilation member 33b and the weakening part 32, and the processing of the cover structure 30 can be simplified and the cost can be reduced.

Specifically, the weakened portion 32 may include the weakened portion 32a and the middle portion 32b, and the vent hole 33a may be formed in the middle portion 32 b.

Of course, in other embodiments, the air permeable member 33b may be fixed to the weakening portion 32 by fastening, welding, clamping, or the like.

In some embodiments, referring to fig. 5 and 9, the cover structure 30 further includes a bursting element 34, and the bursting element 34 is deformable and disposed on the weakening portion 32, and is configured to apply a bursting force to the weakening portion 32 to assist the weakening portion 32 in breaking when deformed by the internal pressure of the battery 100 or the battery cell 20.

The rupture 34 is a member that can be deformed by pressure inside the battery 100 or the battery cell 20. The deformable blasting element 34 means that the shape of the blasting element 34 is changed, and the deformation modes include expansion, bending and the like. Specifically, optionally, the blasting element 34 includes a mounting post, a mounting piece and a spike portion, the mounting post is disposed on the middle portion 32b in the above embodiment, the mounting piece is connected to one end of the mounting post away from the weakened portion 32, and the spike portion is disposed on the mounting piece and has a spike head disposed toward the weakened portion 32a in the above embodiment. When the internal pressure of the battery 100 or the battery cell 20 is high, the two sides of the mounting piece corresponding to the weak part 32a are folded towards the weak part 32a, and the spike part on the mounting piece is driven to pierce the weak part 32a, so that the fracture of the weak part 32a is accelerated. Of course, the blasting element 34 is not limited to the above-mentioned manner, and is not limited and described herein.

At this time, when the internal pressure of the battery 100 or the battery cell 20 increases, the blasting element 34 can provide a blasting force for accelerating the fracture of the weak portion 32a when being deformed under the pressure, which helps to improve the structural strength of the weak portion 32a and simultaneously ensures that the weak portion 32a is smoothly fractured and decompressed when reaching a pressure threshold value inside the battery 100 or the battery cell 20, thereby avoiding explosion. When the strength of the weak portion 32a is slightly high, it helps to avoid damage to the battery 100 or the battery cell 20 due to breakage of the weak portion 32a in a non-thermal failure state, and the structural reliability of the battery 100 or the battery cell 20 can be improved.

In some embodiments, the bursting element 34 comprises an elastic energy absorbing element 34a, and the elastic energy absorbing element 34a is configured to contract under pressure inside the battery 100 or the battery cell 20 and expand to apply a bursting force to the weakened portion 32 when contracting to a critical degree.

The elastic energy absorbing member 34a may be made of elastic soft rubber, such as elastomer like silicone rubber, etc., and is not limited in particular.

The elastic energy absorbing member 34a can convert the pressure inside the battery 100 or the battery cell 20 into energy absorption (expressed as contraction) first, and at this time, the pressure received by the weakened portion 32 is small, so that the time for breaking the weakened portion 32 can be delayed, and the service life of the battery 100 or the battery cell 20 can be prolonged. When the elastic energy-absorbing member 34a contracts to a critical degree, it expands and converts the absorbed energy into a bursting force acting on the weakened portion 32, accelerating the fracture of the weakened portion 32.

At this time, the elastic energy absorber 34a not only provides a bursting force for assisting the weakened portion 32 in breaking, but also delays the time for breaking the weakened portion 32, which is helpful for prolonging the service life of the battery 100 or the battery cell 20.

In some embodiments, referring to FIGS. 5 and 9, the energy absorbing elastic element 34a covers the area of the weakened portion 32 where the balance 33 is removed. Thus, when the elastic energy absorbing member 34a does not reach the contraction limit, the weakened portion 32 may not be affected by the internal pressure of the battery 100 or the battery cell 20, so that the time for delaying the fracture of the weakened portion 32 may be increased, and the service life of the battery 100 or the battery cell 20 may be prolonged.

Specifically, optionally, the elastic energy absorbing member 34a has an avoiding hole, and the balance portion 33 is exposed to the avoiding hole to ensure the normal function of the balance portion 33.

In some embodiments, the explosive element 34 is affixed to the weakened portion 32. Specifically, the blasting element 34 may have a back adhesive surface, and may be adhered to the weakened portion 32 through the back adhesive of the blasting element, so that the operation is convenient. In particular, it is also possible to bond the bursting element 34 and the weakening 32 by means of an additional glue application.

The blasting piece 34 is mounted in a sticking mode, so that the operation is convenient, other connecting parts do not need to be processed on the blasting piece 34 and the weakening part 32, and the processing of the cover structure 30 can be simplified and the cost can be reduced.

In one embodiment, referring to fig. 4 to 9 together, the cover structure 30 includes a cover 31, a weakened portion 32 formed on the cover 31, a balance portion 33 disposed on the weakened portion 32, and an elastic energy absorbing member 34 a. The weakening portion 32 includes a weakening portion 32a and an intermediate portion 32b, the weakening portion 32a connects the intermediate portion 32b and the lid body 31 and defines an annular weakening groove, and the balance portion 33 includes an air hole 33a formed in the intermediate portion 32b and a permeable membrane m adhered to the intermediate portion 32b and covering the air hole 33 a. The energy absorbing elastic member 34a is adhered to and covers the area of the weakened portion 32 excluding the airing holes 33 a. When the internal pressure of the battery 100 or the battery cell 20 is normal, the internal and external pressure difference of the battery 100 or the battery cell 20 is maintained to be balanced through the air vent 33a and the air permeable film m, when the internal pressure of the battery 100 or the battery cell 20 is increased to a certain degree, the elastic energy absorbing piece 34a absorbs energy and contracts firstly, expands when contracting to a critical degree and applies a bursting force assisting the fracture of the elastic energy absorbing piece to the weakened portion 32, the weakened portion 32 is communicated with the inside and the outside of the battery 100 or the battery cell 20 when being fractured, and the internal pressure of the battery 100 or the battery cell 20 can be diffused outwards quickly to realize pressure relief.

On the other hand, according to some embodiments of the present application, the present application further provides a battery cell 20, which includes a housing 22, a cell assembly 23, and the cover structure 30 in any of the above embodiments, wherein the housing 22 encloses a first cavity with a first opening, the cell assembly 23 is accommodated in the first cavity, and the cover structure 30 covers the first opening. The battery cell 20 has the cap structure 30, so that it can be smoothly decompressed when its internal pressure reaches a pressure threshold value, thereby preventing explosion.

On the other hand, according to some embodiments of the present application, the present application also provides a battery 100 including the battery cell 20 described above. Because the battery cell 20 is provided with the cover structure 30, the pressure can be smoothly released when the internal pressure of the battery cell reaches a pressure threshold value, and explosion is avoided.

On the other hand, according to some embodiments of the present application, the present application further provides a battery 100, which includes a box body 10 and a battery cell, where the box body 10 includes a box body and the cover structure 30 in any of the above embodiments, the box body encloses a second cavity with a second opening, the cover structure 30 covers the second opening, and the battery cell is accommodated in the second cavity. The case 10 of the battery 100 includes the lid structure 30, which can smoothly release the pressure when the internal pressure of the case 10 reaches a pressure threshold value, thereby preventing explosion.

In some embodiments, the battery cell included in the battery 100 includes a housing 22, a battery cell assembly 23, and the cover structure 30 in any of the above embodiments, wherein the housing 22 encloses a first cavity with a first opening, the battery cell assembly 23 is accommodated in the first cavity, and the cover structure 30 covers the first opening. At this time, the battery 100 can be double explosion-proof, and has better safety performance.

In other embodiments, the battery cells included in the battery 100 may also include only common battery cells, which is not limited herein.

On the other hand, according to some embodiments of the present application, the present application further provides an electric device, including the battery 100 in any of the above embodiments, where the battery 100 is used for providing electric energy. The electric device has all the above beneficial effects, which are not described herein.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several implementation modes of the present application, and the description thereof is specific and detailed, but not construed as limiting the scope of the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (16)

1. A cover structure for a battery or cell, comprising:

a cover body;

a weakened portion formed on the cover body and configured to break when an internal pressure of the battery or the battery cell reaches a threshold value; and

a balancing part communicating an outside with an inside of the battery or the battery cell and configured to allow gas to enter and exit and block water vapor from entering the inside of the battery or the battery cell from the outside.

2. The cover structure according to claim 1, wherein the weakened portion includes a weakened portion and an intermediate portion, the weakened portion being disposed around a periphery of the intermediate portion and connected between the cover body and the intermediate portion;

the weak portion has a thickness smaller than that of the intermediate portion and is configured to break when an internal pressure of the battery or the battery cell reaches a threshold value.

3. The cover structure according to claim 2, wherein the balance portion is provided on the intermediate portion.

4. The lid structure according to any one of claims 1 to 3, wherein the balance portion includes an air-permeable hole formed in the weakened portion and an air-permeable member covering the air-permeable hole;

the air-permeable member is configured to allow air flow in and out and to block water vapor from entering the interior of the battery or the battery cell from the outside.

5. The cover structure of claim 4, wherein the air permeable member comprises an air permeable membrane covering the air permeable vent.

6. The cover structure according to claim 4, wherein the gas permeable member is located on a side of the weakened portion that faces the inside of the battery or the battery cell.

7. A cover structure according to claim 4, wherein the air permeable member is adhered to the weakened portion.

8. The cover structure according to any one of claims 1 to 3, further comprising a blasting member deformable to the weakened portion and configured to apply a blasting force to the weakened portion to assist the weakened portion in breaking when deformed by an internal pressure of the battery or the battery cell.

9. The cover structure according to claim 8, wherein the bursting element comprises an elastic energy absorbing member configured to contract under pressure inside the battery or the battery cell and expand when contracted to a critical degree to apply the bursting force to the weakened portion.

10. The cover structure according to claim 9, wherein said elastic energy absorbing member covers the area of said weakened portion other than the area where said balance portion is located.

11. The lid structure of claim 8, wherein the blasting element is affixed to the weakened portion.

12. A battery cell, comprising:

the shell is enclosed to form a first cavity with a first opening;

an electric core assembly accommodated in the first cavity; and

a cover structure as claimed in any one of claims 1 to 11, covering the first opening.

13. A battery comprising the cell of claim 12.

14. A battery, comprising:

a box body comprising a box body and a cover structure as claimed in any one of claims 1 to 11, the box body enclosing a second cavity forming a second opening, the cover structure covering the second opening; and

and the battery monomer is accommodated in the second cavity.

15. The battery of claim 14, wherein the battery cell comprises a housing enclosing a first cavity forming a first opening, a cell assembly contained within the first cavity, and a cover structure according to any one of claims 1 to 11 covering the first opening.

16. An electrical device comprising a battery as claimed in any one of claims 13 to 15 for providing electrical energy.

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