CN216213915U - Battery cell, battery and power consumption device - Google Patents

Abstract

The embodiment of the application relates to a battery monomer, a battery and an electric device. The battery cell of the embodiment of the application comprises: a housing including an opening and a first recess recessed with respect to an outer end surface of the housing surrounding the opening; the end cover is used for covering the opening of the shell; and a gas permeable member at least partially accommodated in the first recess and located between the end cap and the case, the gas permeable member connecting the end cap and the case, and the gas permeable member being configured to release internal gas to the outside through the gas permeable member when the gas pressure inside the battery cell is greater than the gas pressure outside the battery cell. The single battery of this application embodiment can maintain the single internal and external pressure balance of battery, and the atress of casing and end cover is balanced, is difficult for taking place local deformation, improves the single security performance of battery.

Description

Battery cell, battery and power consumption device

Technical Field

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

Background

The battery cell is widely used in electronic devices such as a mobile phone, a notebook computer, a battery car, an electric airplane, an electric ship, an electric toy car, an electric toy ship, an electric toy airplane, an electric tool, and the like. The battery monomer can include a cadmium-nickel battery monomer, a hydrogen-nickel battery monomer, a lithium ion battery monomer, a secondary alkaline zinc-manganese battery monomer and the like.

In addition to improving the performance of the battery cell, safety issues are also a considerable problem in the development of battery technology. If the safety problem of the battery cell cannot be guaranteed, the battery cell cannot be used. Therefore, how to enhance the safety of the battery cell is a technical problem to be solved urgently in the battery technology.

SUMMERY OF THE UTILITY MODEL

The application provides a battery monomer, battery and power consumption device, aims at improving the security performance of battery.

In a first aspect, embodiments of the present application provide a battery cell, which includes a housing, an end cap, and a gas permeable member. The housing includes an opening and a first recess recessed with respect to an outer end face of the housing surrounding the opening. The end cover is used for covering the opening of the shell. The gas permeable member is at least partially accommodated in the first recess and located between the end cover and the housing, the gas permeable member connects the end cover and the housing, and the gas permeable member is configured to release gas inside to the outside through the gas permeable member when the gas pressure inside the battery cell is greater than the gas pressure outside the battery cell.

In the above technical solution, the ventilation member is at least partially accommodated in the first recess, and the first recess can support and position the ventilation member, thereby facilitating the assembly of the ventilation member. When the inside atmospheric pressure of battery monomer is greater than the outside atmospheric pressure of battery monomer, the inside gas of battery monomer can release to the outside through ventilative component to can maintain the free internal and external pressure balance of battery, the atress of casing and end cover is balanced, is difficult for taking place local deformation, thereby can prolong the free life of battery, and then improves the free security performance of battery. The gas in the single battery can be released through the ventilating member at any time, and the internal too high pressure of difficult accumulation of single battery to can avoid the internal too high pressure of single battery to a certain extent to lead to single battery to break or even explode the phenomenon etc. and further improve single battery's security performance.

In some embodiments, the gas permeable member includes a body portion sandwiched between the end cap and the case, and a first protrusion portion protruding from a surface of the body portion facing the end cap, and abutting against a surface of the end cap facing the electrode assembly of the battery cell. The first projection can support the end cap and facilitate a sealed connection between the first projection and the end cap.

In some embodiments, the air-permeable member is configured to deform when pressed against the bottom wall of the first recess to form the first protrusion. The mode is favorable for flexibly adjusting the size of the abutting force between the ventilating member and the end cover, thereby being capable of adjusting the sealing performance between the ventilating member and the end cover.

In some embodiments, the body portion includes a stress portion configured to deform when the gas permeable member is pressed against the bottom wall of the first recess to relieve the stress. When the ventilation component is deformed, the stress is released through the deformation of the stress part, so that the problem that the local area of the ventilation component generates stress concentration can be avoided to a certain extent, and the service life of the ventilation component can be prolonged.

In some embodiments, the stress portion and the first projecting portion are disposed opposite to each other in a thickness direction of the body portion. The stress part and the first protruding part are oppositely arranged, so that the stress can be released when the ventilation member is formed to deform, and the first protruding part can be formed.

In some embodiments, the stress section includes an aperture formed within the body section. The structure form of hole is simple, and easy processing, the ventilative component warp the stress that produces and can release through the hole to can avoid the stress concentration problem of deformation department to a certain extent.

In some embodiments, the gas permeable member further comprises a second projection projecting from a surface of the body portion facing the end cap, the second projection being located on a side of the end cap facing away from the electrode assembly to limit movement of the end cap. Under the spacing of second bulge, even the end cover receives the gaseous impact force in battery monomer, also be difficult for breaking away from the casing to improve the structural stability of end cover.

In some embodiments, the end cap includes a first end that abuts the first projection; the first end has a size in a first direction gradually decreasing in a direction from the end cap toward the electrode assembly, the first direction being perpendicular to a direction from the end cap toward the electrode assembly. The surface of the end cap near the electrode assembly is fitted with the first projection, which is advantageous in improving the sealing performance between the end cap and the first projection.

In some embodiments, the housing comprises two first sides and two second sides, wherein the two first sides are oppositely arranged, the second sides are connected between the two first sides, and the area of the first sides is larger than that of the second sides; the two ventilation components are arranged oppositely, and each ventilation component is arranged between the first side surface and the end cover or each ventilation component is arranged between the second side surface and the end cover. Each ventilation member sets up respectively between first side and end cover, and the area of first side is great relatively, sets up ventilation member between first side and end cover and is favorable to increasing ventilative area, improves ventilative speed to improve the speed that the internal and external pressure of battery monomer adjusted. Each ventilating member is arranged between the second side face and the end cover, the area of the second side face is relatively small, the ventilating members are arranged between the second side face and the end cover, and the ventilating members do not occupy more space inside the single battery, so that the energy density of the single battery is guaranteed.

In some embodiments, the gas permeable member is an annular structure that surrounds the outside of the end cap. The gas in the single battery can be released outwards through the circumferential direction outside the end cover, the gas release area is relatively large, and the gas pressure in the single battery can be quickly adjusted.

In some embodiments, the gas permeable member is connected to the end cap and the housing in a physisorptive manner. The mode of physical adsorption is difficult for producing debris such as welding slag, welding bits, has reduced the safe risk that the welding course of working caused, can improve the free security performance of battery.

In some embodiments, the gas permeable member is chemically bonded to the end cap and the housing. The ventilation component can be directly connected with the end cover and the shell, and processing and assembly are facilitated.

In some embodiments, the air-permeable member abuts a bottom wall of the first recess. The bottom wall of the first concave portion is abutted to the air permeable member, so that the air permeable member is convenient to mount and position and is convenient to assemble into the shell.

In some embodiments, a projection of the bottom wall of the first recess overlaps a projection of the end cap in a direction from the end cap toward the electrode assembly of the battery cell. The bottom wall of the first recess can provide a supporting force to the end cap, and further improve the supporting effect on the end cap.

In a second aspect, embodiments of the present application provide a battery, including a battery cell as in any of the embodiments of the first aspect.

In a third aspect, an embodiment of the present application provides an electric device, including the battery of the second aspect, where the battery is used to provide electric energy.

Drawings

Features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic illustration of a vehicle according to some embodiments of the present application;

fig. 2 is an exploded schematic view of a battery provided by some embodiments of the present application;

fig. 3 is a schematic structural view of the battery module shown in fig. 2;

fig. 4 is an exploded schematic view of a battery cell provided by some embodiments of the present application;

fig. 5 is a schematic cross-sectional view of a battery cell provided by some embodiments of the present application;

fig. 6 is an enlarged schematic view of the cell shown in fig. 5 at I;

FIG. 7 is another enlarged schematic view of the battery cell shown in FIG. 5 at I;

FIG. 8 is a further enlarged schematic view of the cell shown in FIG. 5 at I;

fig. 9 is a further enlarged schematic view of the cell shown in fig. 5 at I;

in the drawings, the drawings are not necessarily drawn to scale.

Wherein, in the figures, the various reference numbers:

y, a first direction; x, a second direction;

1. a vehicle; 2. a battery; 3. a controller; 4. a motor; 5. a box body; 51. a first tank portion; 52. a second tank portion; 53. an accommodating space; 6. a battery module; 7. a battery cell; 10. an electrode assembly; 20. a housing assembly;

21. a housing; 21a, an opening; 21b, outer end face; 211. a first recess; 211a, a bottom wall; 211b, sidewalls; 212. a first side surface; 213. a second side surface;

22. an end cap assembly; 23. an end cap; 231. a first end;

30. a ventilation member; 31. a body portion; 31a, a first surface; 32. a first projecting portion; 33. a stress section; 34. a second projection.

Detailed Description

To make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without making any creative effort belong to the protection scope of the present application.

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 in the description of the application in the present application 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. The terms "first," "second," and the like in the description and claims of this application or in the above-described drawings are used for distinguishing between different elements and not for describing a particular sequential or chronological order.

Reference in the specification 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 specification. 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.

In the description of the present application, it should be noted that, unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "attached" are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

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

In the embodiments of the present application, like reference numerals denote like parts, and a detailed description of the same parts is omitted in different embodiments for the sake of brevity. It should be understood that the thickness, length, width and other dimensions of the various components in the embodiments of the present application and the overall thickness, length, width and other dimensions of the integrated device shown in the drawings are only exemplary and should not constitute any limitation to the present application.

The appearances of "a plurality" in this application are intended to mean more than two (including two).

In this application, the battery cell may include a lithium ion secondary battery cell, a lithium ion primary battery cell, a lithium sulfur battery cell, a lithium sodium ion battery cell, a magnesium ion battery cell, or the like, which is not limited in this application. The battery cell may be a cylinder, a flat body, a rectangular parallelepiped, or other shapes, which is not limited in the embodiments of the present application. The battery cells are generally divided into three types in an encapsulation manner: the single battery of cylindricality battery, square battery monomer and laminate polymer battery monomer, this application embodiment is also not limited to this.

Reference to a battery in embodiments of the present application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in the present application may include a battery module or a battery pack, etc. Batteries generally include a case for enclosing one or more battery cells. The box can avoid liquid or other foreign matters to influence the charging or discharging of battery monomer.

The battery cell includes an electrode assembly and an electrolyte, the electrode assembly including a positive electrode tab, a negative electrode tab, and a separator. The battery cell mainly depends on metal ions to move between the positive pole piece and the negative pole piece to work. The positive pole piece comprises a positive pole current collector and a positive pole active substance layer, and the positive pole active substance layer is coated on the surface of the positive pole current collector; the positive electrode current collector comprises a positive electrode current collecting portion and a positive electrode lug protruding out of the positive electrode current collecting portion, the positive electrode current collecting portion is coated with a positive electrode active substance layer, and at least part of the positive electrode lug is not coated with the positive electrode active substance layer. Taking a lithium ion battery monomer as an example, the material of the positive electrode current collector may be aluminum, the positive electrode active material layer includes a positive electrode active material, and the positive electrode active material may be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, or the like. The negative pole piece comprises a negative pole current collector and a negative pole active substance layer, and the negative pole active substance layer is coated on the surface of the negative pole current collector; the negative current collector comprises a negative current collecting part and a negative electrode lug protruding out of the negative current collecting part, the negative current collecting part is coated with a negative electrode active substance layer, and at least part of the negative electrode lug is not coated with the negative electrode active substance layer. The material of the negative electrode current collector may be copper, the negative electrode active material layer includes a negative electrode active material, and the negative electrode active material may be carbon, silicon, or the like. In order to ensure that the fuse is not fused when a large current is passed, the number of the positive electrode tabs is multiple and the positive electrode tabs are stacked together, and the number of the negative electrode tabs is multiple and the negative electrode tabs are stacked together. The material of the spacer may be PP (polypropylene) or PE (polyethylene). In addition, the electrode assembly may have a winding structure or a lamination structure, and the embodiment of the present application is not limited thereto.

The battery cell may further include a housing assembly having a receiving cavity therein, the receiving cavity being a closed space provided by the housing assembly for the electrode assembly and the electrolyte. The shell assembly comprises a shell and an end cover assembly, wherein the shell is of a hollow structure with an opening at one side, the end cover assembly comprises an end cover, and the end cover covers the opening of the shell and is in sealing connection with the opening to form a containing cavity for containing the electrode assembly and electrolyte.

The inventor finds that gas can be generated in the single battery in the processes of transportation, temperature change or charging and discharging of the single battery, the gas in the single battery cannot be discharged in time, and a large amount of gas can be accumulated in the single battery, so that the gas pressure in the single battery is too high, impact is caused to the local area of the single battery, and the single battery is broken or even explodes, so that potential safety hazards are caused.

In view of this, the inventors provide a solution in which a battery cell includes a case, an end cap, and a gas permeable member. The housing includes an aperture and a first recess recessed relative to an outer end face of the housing surrounding the aperture. The end cover is used for covering the opening of the shell. The gas permeable member is at least partially accommodated in the first recess and located between the end cover and the housing, the gas permeable member connects the end cover and the housing, and the gas permeable member is configured to release gas inside to the outside through the gas permeable member when the gas pressure inside the battery cell is greater than the gas pressure outside the battery cell. The battery monomer with the structure is provided with the ventilating component between the shell and the end cover, and gas in the battery monomer can be released out of the battery monomer through the ventilating component, so that the internal and external pressure balance of the battery monomer is maintained, the service life of the battery monomer is prolonged, and the safety performance of the battery monomer is improved.

The technical scheme described in the embodiment of the application is suitable for the single battery, the battery containing the single battery and the electric device using the battery.

The electric device can be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy, an electric tool and the like. The vehicle can be a fuel oil vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or a range extending vehicle and the like; spacecraft include aircraft, rockets, space shuttles, and spacecraft, among others; the electric toys include stationary or mobile electric toys, such as game machines, electric car toys, electric ship toys, electric airplane toys, and the like; the electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and electric tools for railways, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, electric impact drills, concrete vibrators, and electric planers. The embodiment of the present application does not particularly limit the above power utilization apparatus.

For convenience of explanation, the following embodiments will be described with an electric device as an example of a vehicle.

FIG. 1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application. As shown in fig. 1, a battery 2 is provided inside a vehicle 1, and the battery 2 may be provided at the bottom or the head or the tail of the vehicle 1. The battery 2 may be used for power supply of the vehicle 1, and for example, the battery 2 may serve as an operation power source of the vehicle 1.

The vehicle 1 may further comprise a controller 3 and a motor 4, the controller 3 being adapted to control the battery 2 to power the motor 4, e.g. for start-up, navigation and operational power demands while driving of the vehicle 1.

In some embodiments of the present application, the battery 2 may not only serve as an operating power source of the vehicle 1, but also serve as a driving power source of the vehicle 1, instead of or in part of fuel or natural gas, to provide driving power for the vehicle 1.

Fig. 2 is an exploded schematic view of a battery provided in some embodiments of the present application. As shown in fig. 2, the battery 2 includes a case 5 and a battery cell (not shown in fig. 2) accommodated in the case 5.

The case 5 is used for accommodating the battery cells, and the case 5 may have various structures. In some embodiments, the box body 5 may include a first box body portion 51 and a second box body portion 52, the first box body portion 51 and the second box body portion 52 cover each other, and the first box body portion 51 and the second box body portion 52 jointly define a receiving space 53 for receiving the battery cells. The second box portion 52 may be a hollow structure with one open end, the first box portion 51 is a plate-shaped structure, and the first box portion 51 covers the open side of the second box portion 52 to form the box 5 with the accommodating space 53; the first casing portion 51 and the second casing portion 52 may be hollow structures each having one side opened, and the opening side of the first casing portion 51 may be covered with the opening side of the second casing portion 52 to form the casing 5 having the accommodating space 53. Of course, the first and second casing portions 51 and 52 may be various shapes, such as a cylinder, a rectangular parallelepiped, or the like.

In order to improve the sealing property after the first casing portion 51 and the second casing portion 52 are connected, a sealing member, such as a sealant or a gasket, may be provided between the first casing portion 51 and the second casing portion 52.

If the first box portion 51 covers the top of the second box portion 52, the first box portion 51 may also be referred to as an upper box cover, and the second box portion 52 may also be referred to as a lower box cover.

In the battery 2, one or more battery cells may be provided. If the number of the battery monomers is multiple, the multiple battery monomers can be connected in series or in parallel or in series-parallel, and the series-parallel refers to that the multiple battery monomers are connected in series or in parallel. The plurality of battery monomers can be directly connected in series or in parallel or in series-parallel, and the whole formed by the plurality of battery monomers is accommodated in the box body 5; of course, a plurality of battery cells may be connected in series or in parallel or in series-parallel to form the battery module 6, and a plurality of battery modules 6 may be connected in series or in parallel or in series-parallel to form a whole and accommodated in the box 5.

Fig. 3 is a schematic structural view of the battery module shown in fig. 2. As shown in fig. 3, in some embodiments, there are a plurality of battery cells, and the plurality of battery cells are connected in series or in parallel or in series-parallel to form the battery module 6. The plurality of battery modules 6 are connected in series or in parallel or in series-parallel to form a whole and are accommodated in the case.

The plurality of battery cells in the battery module 6 may be electrically connected to each other through the bus member, so as to realize parallel connection, series connection, or parallel-series connection of the plurality of battery cells in the battery module 6.

Fig. 4 is an exploded schematic view of a battery cell provided in some embodiments of the present application, and fig. 5 is a cross-sectional schematic view of the battery cell provided in some embodiments of the present application; fig. 6 is an enlarged schematic view of the battery cell shown in fig. 5 at I.

As shown in fig. 4 to 6, the battery cell 7 provided in the embodiment of the present application includes a case 21, an end cap 23, and a gas permeable member 30. The housing 21 includes an opening 21a and a first concave portion 211, and the first concave portion 211 is recessed with respect to an outer end surface 21b of the housing 21 surrounding the opening 21a. The end cap 23 is used to cover the opening 21a of the housing 21. The gas permeable member 30 is at least partially accommodated in the first recess 211 and located between the end cap 23 and the case 21, the gas permeable member 30 connects the end cap 23 and the case 21, and the gas permeable member 30 is configured such that when the gas pressure inside the battery cell is greater than the gas pressure outside the battery cell, the gas inside is released to the outside through the gas permeable member 30.

The shell 21 is a hollow structure with an opening 21a, and the end cover 23 covers the opening 21a of the shell 21 to form a sealing connection and form an accommodating cavity. The receiving cavity may be used to receive the electrode assembly and the electrolyte. In the single battery, the electrode assembly is a core part of the single battery for realizing the charging and discharging functions, and one or more electrode assemblies can be accommodated in the accommodating cavity. Illustratively, in fig. 4, there are four electrode assemblies. The electrode assembly includes a positive electrode tab, a negative electrode tab, and a separator. The electrode assembly may be a wound electrode assembly, a laminated electrode assembly, or other form of electrode assembly. For example, the electrode assembly is a wound electrode assembly. The positive pole piece, the negative pole piece and the separator are all in a strip structure, and the positive pole piece, the separator and the negative pole piece can be sequentially stacked and wound for more than two circles to form an electrode assembly. Also for example, the electrode assembly is a laminated electrode assembly. Specifically, the electrode assembly includes a plurality of positive electrode tabs and a plurality of negative electrode tabs which are alternately stacked in a direction parallel to a thickness direction of the positive electrode tabs and a thickness direction of the negative electrode tabs.

The housing 21 may take a variety of configurations. Illustratively, the housing 21 is a hollow structure with an opening 21a at one side, and the end cap 23 covers the opening 21a of the housing 21 and forms a sealed connection. Or the housing 21 may be a hollow structure with two opposite side openings 21a. The end covers 23 are oppositely arranged in two, and one end cover 23 correspondingly covers one opening 21a of the shell 21 and forms a sealing connection.

The end cap 23 is used to cover the opening 21a of the housing 21, and the end cap 23 may have various structures. Illustratively, the housing 21 is a rectangular parallelepiped structure, the end cap 23 is a plate structure, and the end cap 23 covers the opening 21a at the top of the housing 21. Alternatively, the housing 21 has a cylindrical structure, the end cap 23 has a plate-like structure, and the end cap 23 covers the opening 21a at the top of the housing 21.

The end cap 23 may be made of an insulating material (e.g., plastic) or a conductive material (e.g., metal). When the end cap 23 is made of a metal material, an insulating member (not shown) may be further disposed between the end cap 23 and the electrode assembly to insulate and separate the end cap 23 and the electrode assembly.

The gas permeable member 30 has gas permeability, which means that gas in the battery cell 7 can be released to the outside of the battery cell through the gas permeable member 30 to maintain pressure balance between the inside and the outside of the battery cell 7, as the name suggests. Of course, gas outside the battery cell 7 can also flow into the battery cell 7 through the gas permeable member 30.

The air permeable member 30 may be made of an organic polymer material. The organic high molecular material is selected from one or more of polypropylene PP, polypropylene derivative, polyethylene terephthalate PET, ethylene propylene copolymer EAA, cast polypropylene CPP, polytetrafluoroethylene PTFE, polyvinylidene fluoride PVDF, polyacrylonitrile PAN, polyethylene PE, polyethylene derivative, polyphenylene sulfide PPS, polyphenylene oxide PPO, polyphthalamide PPA, polybutylene terephthalate PBT, acrylonitrile-butadiene-styrene copolymer ABS and liquid crystal high molecular polymer LCP. The gas in the battery cell 7 may be dissolved in the organic polymer material, and then diffused from the high concentration region to the low concentration region in the organic polymer material, and evaporated. If the organic polymer material has free channels (e.g., crystal defects, etc.), gas can also flow through the free channels.

In the present embodiment, the air permeable member 30 is at least partially received in the first recess 211, and the first recess 211 can support and position the air permeable member 30, thereby facilitating the assembly of the air permeable member 30. When the inside atmospheric pressure of battery monomer 7 is greater than the outside atmospheric pressure of battery monomer 7, the inside gas of battery monomer 7 can release to the outside through ventilative member 30 to can maintain the internal and external pressure balance of battery monomer 7, the atress of casing 21 and end cover 23 is balanced, difficult local deformation takes place, thereby can prolong the life of battery monomer 7, and improve the security performance of battery monomer 7. In the charging and discharging process, the gas inside the single battery 7 can be released through the ventilating member 30 at any time, and the too high pressure is not easy to accumulate in the single battery 7, so that the phenomena that the single battery 7 is broken or even explodes due to the too high pressure inside the single battery 7 can be avoided to a certain extent, and the safety performance of the single battery 7 is further improved.

In the embodiment of the present application, the arrangement position of the air permeable member 30 includes various forms, and the specific arrangement position of the air permeable member 30 can be flexibly arranged according to the structural form of the housing 21.

With continued reference to fig. 4 to fig. 6, in some examples, the housing 21 has a rectangular parallelepiped structure, the housing 21 includes two first side surfaces 212 disposed opposite to each other and two second side surfaces 213 disposed opposite to each other, the second side surfaces 213 are connected between the two first side surfaces 212, and an area of the first side surfaces 212 is larger than an area of the second side surfaces 213. The two ventilation members 30 are disposed oppositely, and each ventilation member 30 is disposed between the first side surface 212 and the end cover 23. The area of the first side surface 212 is relatively large, and the ventilation member 30 is arranged between the first side surface 212 and the end cover 23, so that the ventilation area is increased, the ventilation speed is increased, and the speed of adjusting the internal pressure and the external pressure of the battery unit 7 is increased.

Alternatively, the air-permeable members 30 are provided in four, two air-permeable members 30 are provided between the first side surface 212 and the end cap 23, respectively, and two air-permeable members 30 are provided between the second side surface 213 and the end cap 23, respectively. In other words, the air-permeable member 30 is disposed around the outside of the end cap 23, further increasing the air-permeable area and increasing the air-permeable rate.

Alternatively, each air permeable member 30 is disposed between the second side 213 and the end cap 23, respectively. The area of the second side surface 213 is relatively small, and the ventilation member 30 is disposed between the second side surface 213 and the end cap 23, so that the ventilation member 30 does not occupy more space inside the battery cell 7 while ensuring the ventilation function, thereby facilitating to ensure the energy density of the battery cell 7.

In other examples, the housing 21 is a cylindrical structure and the air permeable member 30 is an annular structure surrounding the outside of the end cap 23. The gas in the battery cell 7 can be released outwards through the circumference of the outer side of the end cover 23, the gas release area is relatively large, and the gas pressure in the battery cell 7 can be quickly adjusted.

Referring to fig. 5 and 6, in the embodiment of the present application, the air permeable member 30 is made of an organic polymer material, and the organic polymer material can be combined with the housing 21 and the end cap 23 in various ways.

In order to further enhance the safety performance of the battery cell 7, in some embodiments, the air permeable member 30 is connected to the end cover 23 and the housing 21 in an adhesion manner, which is not easy to generate welding slag, welding scraps, and other impurities, reduces the safety risk caused by the welding process, and can improve the safety performance of the battery cell.

In some examples, the air permeable member 30 is connected to the end cap 23 and the housing 21 in a physisorptive manner. In the present embodiment, the air-permeable member 30 may connect itself to the air-permeable member 30 between the end cap 23 and the housing 21 by glue. The glue may include at least one of polyacrylic acid PAA and polyacrylic acid derivative, and the material of the glue may be other materials commonly used in the art.

In other examples, the gas permeable member 30 is chemically bonded to the end cap 23 and the housing 21. The air permeable member 30 may be directly connected to the end cap 23 and the housing 21, facilitating the manufacturing assembly. In the present embodiment, the air-permeable member 30 is selected from at least one of polypropylene PP, polypropylene derivative, polyethylene terephthalate PET, ethylene propylene copolymer EAA, cast polypropylene CPP, polytetrafluoroethylene PTFE, polyvinylidene fluoride PVDF, and polyacrylonitrile PAN. Chemical bonding means that the functional groups included in the gas permeable member 30 are connected to the housing 21 by van der waals force, molecular force, or even atomic force; accordingly, the gas permeable member 30 and the end cap 23 are bonded by van der waals force, molecular force, or even atomic force between the functional group included in the gas permeable member 30 and the housing 21. This connection method has high connection strength, and can significantly improve the connection strength between the ventilation member 30, the end cover 23, and the housing 21, and improve the sealing property between the three.

The connection manner of the ventilation member 30 and the first concave portion 211 when the ventilation member 30 is assembled to the housing 21 has various forms.

With continued reference to fig. 5 and 6, in some embodiments, the air permeable member 30 abuts against the bottom wall 211a of the first concave portion 211, and the abutment of the bottom wall 211a of the first concave portion 211 and the air permeable member 30 facilitates the installation and positioning of the air permeable member 30, so as to facilitate the assembly of the air permeable member 30 into the housing 21.

Alternatively, the bottom wall 211a of the first concave portion 211 and the air permeable member 30 may be connected by chemical bonding on the basis that the air permeable member 30 is abutted against the bottom wall 211a of the first concave portion 211, and a certain abutting force exists between the bottom wall 211a of the first concave portion 211 and the air permeable member 30, so that the bonding force of the chemical bonding can be further enhanced.

In other embodiments, the air permeable member 30 is connected to the bottom wall 211a of the first recess 211. For example, the bottom wall 211a of the first concave portion 211 and the air permeable member 30 may be connected by physical absorption. Of course, chemical bonding may also be used for attachment.

In some embodiments, a projection of the bottom wall 211a of the first recess 211 overlaps a projection of the end cap 23 in a direction from the end cap 23 toward the electrode assembly of the battery cell. The bottom wall 211a of the first recess 211 can give a supporting force to the end cap 23, and the supporting function to the end cap 23 is further improved.

It should be noted that the X direction shown in fig. 6 indicates a direction from the end cap 23 to the electrode assembly of the battery cell, and may be referred to as a second direction. The Y direction denotes a direction perpendicular to the electrode assembly directed from the end cap 23 to the battery cell, and may be referred to herein as a first direction. The second direction X is perpendicular to the first direction Y.

The structural form of the ventilation member 30 itself has some influence on the strength of connection between the housing 21 and the end cap 23, and the structural form of the ventilation member 30 will be described next.

With continued reference to fig. 5 and 6, in some embodiments, the ventilation member 30 includes a body portion 31 and a first protruding portion 32, the body portion 31 is clamped between the end cap 23 and the case 21, the first protruding portion 32 protrudes from a surface of the body portion 31 facing the end cap 23, the first protruding portion 32 abuts against a surface of the end cap 23 facing the electrode assembly of the battery cell, the first protruding portion 32 abuts against the end cap 23, and the first protruding portion 32 can support the end cap 23 and facilitate a sealed connection between the first protruding portion 32 and the end cap 23. The surface of the body 31 facing the end cap 23 is a first surface 31a.

As some examples, the ventilation member 30 is configured to deform when pressed against the bottom wall 211a of the first concave portion 211 to form the first convex portion 32. The gas permeable member 30 abuts against the bottom wall 211a of the first recess 211, the gas permeable member 30 is deformed when the gas permeable member 30 abuts against the bottom wall 211a of the first recess 211, and protrudes toward the end cap 23 to form the first protruding part 32, and the first protruding part 32 abuts against the surface of the end cap 23 facing the electrode assembly of the battery cell. This is advantageous in that the magnitude of the abutting force between the air-permeable member 30 and the end cap 23 can be flexibly adjusted, thereby enabling the sealing performance between the air-permeable member 30 and the end cap 23 to be adjusted.

Alternatively, the ventilation member 30 may also be deformed toward the side wall 211b of the first concave portion 211 when deformed against the bottom wall 211a of the first concave portion 211, thereby increasing the frictional force between the ventilation member 30 and the side wall 211b of the first concave portion 211, and further improving the sealing performance between the ventilation member 30 and the housing 21.

With continued reference to fig. 5 and 6, in some embodiments, the end cap 23 includes a first end 231 abutting the first protrusion 32; the first end 231 is reduced in size stepwise in the first direction Y in a direction toward the electrode assembly, i.e., the second direction X, by the end cap 23. The surface of the end cap 23 adjacent to the electrode assembly is fitted to the first protrusions 32, which is advantageous in improving the sealing performance between the end cap 23 and the first protrusions 32. Here, the gradual decrease may be a size of the first end 231 in the first direction Y, which is stepped down, or may be a linear decrease.

When the ventilation member is deformed, stress concentration may occur at the deformed portion, so that fatigue failure is likely to occur at the deformed portion of the ventilation member, thereby shortening the service life of the ventilation member.

Fig. 7 is another enlarged schematic view of the battery cell shown in fig. 5 at I.

In order to extend the service life of the air permeable member 30, as shown in fig. 7, in some embodiments, the body portion 31 may further include a stress portion 33, and the stress portion 33 is configured to be deformed when the air permeable member 30 presses against the bottom wall 211a of the first concave portion 211 to release the stress. When the ventilation member 30 is deformed, the stress is released by the deformation of the stress portion 33, so that the problem of stress concentration in a local region of the ventilation member 30 can be avoided to some extent, and the service life of the ventilation member 30 can be prolonged. And because the ventilation component 30 can release stress when being deformed, the whole surface fit between the ventilation component 30 and the end cover 23 is facilitated, and the sealing performance between the ventilation component 30 and the end cover 23 is improved. And also facilitates the entire surface fit between the ventilation member 30 and the side wall 211b of the first concave portion 211, improving the sealing performance between the ventilation member 30 and the side wall 211b of the first concave portion 211.

Alternatively, the stress portion 33 and the first projecting portion 32 are disposed oppositely in the thickness direction of the body portion 31. The deformation region of the ventilation member 30 mainly occurs at a portion close to the bottom wall 211a of the first concave portion 211, and the stress portion 33 and the first convex portion 32 are oppositely arranged, so that the stress can be released when the ventilation member 30 is formed and deformed, and the formation of the first convex portion 32 can be facilitated; and the sealing performance between the ventilation member 30, the end cover 23, and the housing 21 can be further improved. In the present embodiment, the thickness direction of the body portion 31 is parallel to the second direction X.

Illustratively, the stress portion 33 includes a hole formed inside the body portion 31. The holes are used as stress holes, the structure form is simple, the processing is convenient, the forms can be circular holes, strip-shaped holes, polygonal holes and the like, and the forms of the holes are not limited. Stress generated by deformation of the ventilation member 30 can be released through the holes, so that the problem of stress concentration at the deformation can be avoided to some extent.

When the air pressure inside the battery cell is too high during the use of the battery cell, a certain impact force may be given to the end cap, the end cap has a tendency to move outward, and the end cap has a risk of being detached from the housing.

Fig. 8 is a further enlarged schematic view of the cell shown in fig. 5 at I.

In order to protect the end cap 23, as shown in fig. 8, in some embodiments, the gas permeable member 30 further includes a second protrusion 34, the second protrusion 34 protrudes from a surface of the body portion 31 facing the end cap 23, i.e., the first surface 31a, and the second protrusion 34 is located on a side of the end cap 23 facing away from the electrode assembly to limit movement of the end cap 23. Under the limit of the second protrusion 34, even if the end cap 23 receives the impact force of the gas inside the battery cell, the end cap 23 is not easy to detach from the case 21, thereby improving the structural stability of the end cap 23.

Fig. 9 is a further enlarged schematic view of the cell shown in fig. 5 at I.

As shown in fig. 9, optionally, the second protruding portion 34 may also be located on the outer end face 21b of the housing 21, and the second protruding portion 34 is configured to improve the sealing performance among the ventilation member 30, the end cover 23 and the housing 21, and prevent foreign matters outside the battery cell from entering the inside of the battery cell through the joints among the components, so that pollution to the battery cell is avoided to a certain extent, and the safety performance of the battery cell is improved.

In other embodiments, the first protrusion 32 may also be connected to a surface of the end cap 23 facing the electrode assembly of the battery cell. The first projecting portion 32 and the end cap 23 are directly connected as one body and then assembled into the housing 21 as a whole, and the assembly process can be simplified.

Referring to fig. 4, 5 and 7, as an embodiment of the present application, a battery cell includes a case 21, an end cap 23 and a gas permeable member 30. The housing 21 includes an opening 21a and a first recess 211, and the end cap 23 covers the opening 21a of the housing 21. The first recess 211 is recessed with respect to an outer end surface 21b of the housing 21 surrounding the opening 21a, the air permeable member 30 is accommodated in the first recess 211 between the end cover 23 and the housing 21, and the air permeable member 30 connects the end cover 23 and the housing 21 in a chemical bonding manner. The ventilation member 30 includes a body 31 and a first protrusion 32, and a stress hole, the body 31 is clamped between the end cap 23 and the case 21, and the first protrusion 32 protrudes from a surface of the body 31 facing the end cap 23 and abuts against an electrode assembly of the end cap 23 facing the battery cell. The first projecting portion 32 also abuts against the bottom wall 211a of the first recess 211. The stress hole and the first projecting portion 32 are disposed opposite to each other in the thickness direction of the body portion 31. In this embodiment, the two air-permeable members 30 are oppositely disposed, and the two air-permeable members 30 are respectively disposed between the first side surface 212 and the end cap 23.

While the present application has been described with reference to preferred embodiments, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the present application, and in particular, features shown in the various embodiments may be combined in any manner as long as there is no structural conflict. The present application is not intended to be limited to the particular embodiments disclosed herein but is to cover all embodiments that may fall within the scope of the appended claims.

Claims (16)

1. A battery cell, comprising:

a housing including an opening and a first recess recessed with respect to an outer end face of the housing surrounding the opening;

the end cover is used for covering the opening of the shell; and

a gas permeable member at least partially received within the first recess and located between the end cap and the housing, the gas permeable member connecting the end cap and the housing, and the gas permeable member being configured to release gas inside the battery cell to the outside through the gas permeable member when the gas pressure inside the battery cell is greater than the gas pressure outside the battery cell.

2. The battery cell of claim 1,

the gas permeable member includes a body portion sandwiched between the end cap and the case, and a first protrusion portion protruding from a surface of the body portion facing the end cap and abutting against a surface of the end cap facing the electrode assembly of the battery cell.

3. The battery cell of claim 2,

the air-permeable member is configured to deform when pressed against a bottom wall of the first recess to form the first projection.

4. The battery cell of claim 3,

the body portion includes a stress portion configured to deform to release stress when the gas permeable member is pressed against the bottom wall of the first recess.

5. The battery cell according to claim 4, wherein the stress portion and the first projecting portion are disposed opposite to each other in a thickness direction of the body portion.

6. The battery cell as recited in claim 4 wherein the stress portion comprises an aperture formed within the body portion.

7. The battery cell of claim 2,

the gas permeable member further includes a second projection projecting from a surface of the body portion facing the end cap, the second projection being located on a side of the end cap facing away from the electrode assembly to restrict movement of the end cap.

8. The battery cell of claim 2,

the end cover comprises a first end which is abutted against the first bulge;

the first end has a size that decreases stepwise in a first direction perpendicular to a direction from the end cap toward the electrode assembly in a direction from the end cap toward the electrode assembly.

9. The battery cell according to any one of claims 1 to 8,

the shell comprises two first side surfaces which are oppositely arranged and two second side surfaces which are oppositely arranged, the second side surfaces are connected between the two first side surfaces, and the area of the first side surfaces is larger than that of the second side surfaces;

the two air permeable members are arranged oppositely, and each air permeable member is arranged between the first side face and the end cover or each air permeable member is arranged between the second side face and the end cover.

10. The battery cell according to any one of claims 1 to 8,

the air permeable member is an annular structure surrounding the outer side of the end cover.

11. The battery cell according to any one of claims 1 to 8,

the air-permeable member is connected to the end cap and the case in a physisorptive manner.

12. The battery cell according to any one of claims 1 to 8,

the gas permeable member is chemically bonded to the end cap and the housing.

13. The battery cell according to any one of claims 1 to 8,

the ventilation member abuts against a bottom wall of the first recess.

14. The battery cell according to any one of claims 1 to 8,

a projection of a bottom wall of the first recess overlaps a projection of the end cap in a direction from the end cap toward an electrode assembly of the battery cell.

15. A battery comprising a plurality of cells according to any one of claims 1 to 14.

16. An electrical device comprising a battery as claimed in claim 15 for providing electrical energy.

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