CN216720095U - End cover assembly, battery monomer, battery and power consumption device - Google Patents

Abstract

The application relates to an end cover assembly, a battery monomer, a battery and an electric device. The end cover assembly is used for a single battery and comprises a pressure relief structure and an end cover. The pressure relief mechanism is configured to actuate to relieve pressure when pressure inside the battery cell reaches a threshold. The end cover comprises a main body part, a buffering part and an installation part, the pressure relief mechanism is installed on the installation part, the buffering part is arranged on the outer side of the installation part in a surrounding mode and is connected with the main body part and the installation part, and the buffering part is used for deforming when the end cover is impacted so as to reduce acting force transmitted to the pressure relief mechanism. The application provides an end cover assembly can strengthen the free security of battery.

Description

End cover assembly, battery monomer, battery and power consumption device

Technical Field

The present application relates to the field of battery technology, and more particularly, to an end cap assembly, a battery cell, 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 comprise 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 an end cover assembly, battery monomer, battery and power consumption device, can strengthen the free security of battery.

In a first aspect, an embodiment of the present application provides an end cap assembly for a battery cell, where the end cap assembly includes a pressure relief structure and an end cap. The pressure relief mechanism is configured to actuate to relieve pressure when pressure inside the battery cell reaches a threshold. The end cover comprises a main body part, a buffering part and an installation part, the pressure relief mechanism is installed on the installation part, the buffering part is arranged on the outer side of the installation part in a surrounding mode and is connected with the main body part and the installation part, and the buffering part is used for deforming when the end cover is impacted so as to reduce acting force transmitted to the pressure relief mechanism.

Among the above-mentioned technical scheme, when the free end cover of battery received the effort, the buffer can take place to warp to make the effort obtain the release of certain degree in the buffer, thereby reduce the effort that transmits to pressure relief mechanism, with this opening threshold value of guaranteeing pressure relief mechanism, the free security of reinforcing battery and use reliability.

In some embodiments, at least a portion of the cushioning portion protrudes from the body portion in a thickness direction of the end cap to form an arch.

Among the above-mentioned technical scheme, when the end cover received the effort, the effort acted on domes, and domes can take place tensile deformation or compressive deformation to can release the effort to a certain extent, reduce the effort that transmits to pressure relief mechanism.

In some embodiments, at least a portion of the buffer protrudes in a direction away from the electrode assembly of the battery cell in a thickness direction of the end cap to form an arch structure. In the embodiment of the application, the buffer part does not additionally occupy the internal space of the battery cell, and the occupied volume of the electrode assembly or the electrolyte can be increased, so that the energy density of the battery cell is increased.

In some embodiments, the buffer portion is provided in a plurality, and the plurality of buffer portions are respectively arranged around the outer side of the mounting portion. In the embodiment of the application, the plurality of buffer parts can further improve the buffer deformation capacity and further enhance the safety of the battery cells.

In some embodiments, the plurality of buffering parts are arranged continuously, and transition fillets are arranged at the joints of two adjacent buffering parts. In this application embodiment, the junction of two adjacent buffers is equipped with the transition fillet, can avoid producing stress concentration in the junction, improves the structural stability of buffers.

In some embodiments, the plurality of buffers are spaced apart; the end cover further comprises a reinforcing part, and the reinforcing part is arranged between the two adjacent buffer parts. In this application embodiment, the reinforcing part can play the additional strengthening to the end cover to set up the reinforcing part and be favorable to fixing a position when processing buffer, improve its machining precision.

In some embodiments, the plurality of buffers includes a first buffer and a second buffer, and the protruding directions of the first buffer and the second buffer are opposite in the thickness direction of the end cap. In this application embodiment, the different protruding direction of first buffer portion and second buffer portion, one of them tensile deformation of first buffer portion and second buffer portion, another compression deformation, the two different deformation modes can maintain the main part and be invariable in the size of length direction row to guarantee the structural stability of main part, improve the holistic structural stability of end cover.

In some embodiments, the thickness of the mounting portion is greater than the thickness of the body portion. In this application embodiment, the thickness of installation department is greater than the thickness of main part, and the intensity of installation department also correspondingly improves, even the end cover receives the effort, also is difficult for taking place to warp in installation department to can further improve pressure relief mechanism's structural stability, guarantee its threshold value of opening.

In some embodiments, at least a portion of the buffer protrudes in a direction of an electrode assembly of the battery cell in a thickness direction of the end cap to form an arch structure, the buffer including a first edge near the electrode assembly in the thickness direction; the mounting part includes a second edge adjacent to the electrode assembly in a thickness direction, wherein the first edge is flush with or exceeds the second edge in the thickness direction. In the embodiment of the application, when the first edge and the second edge are flush, and the end cover is subjected to the acting force in the battery monomer, the acting force can act on the first edge and the second edge at the same time, the buffer part is deformed, and the acting force transmitted to the pressure relief mechanism is reduced; because the intensity of installation department is higher, can bear the effort of great intensity, be difficult to take place to warp, also can reduce the effort that transmits to pressure relief mechanism. Buffering portion and installation department two synergism reduce the effort that transmits to pressure relief mechanism jointly, improve pressure relief mechanism's structural stability. When the first edge exceeds the second edge, when the end cover is subjected to the acting force in the single battery, the acting force acts on the buffer part firstly, and the buffer part is deformed in advance, so that the acting force can be released at the buffer part to a certain extent, and the acting force transmitted to the pressure relief mechanism is reduced; and can, reduce the risk that the installation department takes place to warp to improve pressure relief mechanism's structural stability.

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

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

In a fourth aspect, an embodiment of the present application provides an electric device, which includes the battery of the third aspect, and the battery is used for providing 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 structural diagram of a battery cell provided in some embodiments of the present application;

FIG. 6 isbase:Sub>A schematic cross-sectional view of the battery cell shown in FIG. 5 taken along line A-A;

FIG. 7 is a left side structural schematic view of an end cap assembly provided by some embodiments of the present application;

FIG. 8 is a schematic cross-sectional view of the end cap assembly shown in FIG. 7 taken along line B-B;

FIG. 9 is an enlarged schematic view of the endcap assembly, at I, of FIG. 8;

FIG. 10 is a perspective view of an end cap assembly provided by some embodiments of the present application;

FIG. 11 is another enlarged schematic view of the endcap assembly, at I, of FIG. 8;

FIG. 12 is a schematic perspective view of an end cap assembly according to further embodiments of the present application;

FIG. 13 is a further enlarged schematic view of the endcap assembly of FIG. 8 at I;

FIG. 14 is a perspective view of an end cap assembly according to further embodiments of the present application;

FIG. 15 is a further enlarged schematic view of the endcap assembly of FIG. 8 at I;

FIG. 16 is a perspective view of an end cap assembly according to further embodiments of the present application;

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

Wherein, in the figures, the respective reference numerals:

x, the thickness direction; y, length 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;

8. an electrode assembly; 81. a body portion; 82. a lug portion; 83. a current collecting member;

9. a housing assembly; 91. a housing; 92. an end cap assembly; 921. an electrode terminal;

10. an end cap; 11. a main body portion; 111. a first surface; 112. a second surface; 12. a buffer section; 12a, a first edge; 121. a first buffer section; 122. a second buffer section; 13. an installation part; 13a, a second edge; 14. a reinforcing portion;

20. a pressure relief mechanism.

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, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within 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 foregoing 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 the case may be.

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 preceding and following associated objects are in an "or" relationship.

In the embodiments of the present application, like reference numerals denote like components, and in the different embodiments, detailed descriptions of the like components are omitted 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 cylindrical battery monomer, the square battery monomer and the soft package battery monomer are not limited in the embodiment of the application.

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 charge or discharge of battery cells.

The battery cell includes an electrode assembly including a positive electrode tab, a negative electrode tab, and a separator, and an electrolyte. 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 current collector and a positive active substance layer, and the positive active substance layer is coated on the surface of the positive current collector; the positive current collector comprises a positive current collecting part and a positive electrode lug protruding out of the positive current collecting part, the positive current collecting part is coated with a positive active substance layer, and at least part of the positive electrode lug is not coated with the positive 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 high current can be passed through without fusing, a plurality of positive electrode tabs are stacked together, and a plurality of 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 one side opened, and the end cover assembly covers the opening of the shell and is in sealing connection with the opening of the shell to form a containing cavity for containing the electrode assembly and the electrolyte. The end cap assembly includes an end cap and a pressure relief mechanism.

The development of battery technology requires consideration of various design factors, such as energy density, cycle life, discharge capacity, charge/discharge rate, and other performance parameters, as well as battery safety.

The pressure relief mechanism on the battery cell has an important influence on the safety of the battery. For example, when a short circuit or an overcharge occurs, thermal runaway may occur inside the battery cell, which may cause a sudden increase in pressure or temperature. In this case, the pressure release mechanism is actuated to release the internal pressure and temperature to prevent the battery cell from exploding, firing, etc.

The pressure relief mechanism refers to an element or a component that is actuated to relieve internal pressure or temperature when the internal pressure of the battery cell reaches a predetermined threshold. The threshold design varies according to design requirements. The threshold may depend on the material of one or more of the positive electrode sheet, the negative electrode sheet, the electrolyte and the separator within the cell. The pressure relief mechanism may take the form of, for example, an explosion-proof valve, a gas valve, a pressure relief valve, or a safety valve, and may specifically employ a pressure-sensitive or temperature-sensitive element or configuration, that is, when the internal pressure or temperature of the battery cell reaches a predetermined threshold value, the pressure relief mechanism performs an action or a weak structure provided in the pressure relief mechanism is broken, thereby forming an opening or a passage through which the internal pressure can be released.

As used herein, "activation" refers to the action or activation of the pressure relief mechanism to a state such that the internal pressure of the battery cell is released. The actions generated by the pressure relief mechanism may include, but are not limited to: at least a portion of the pressure relief mechanism ruptures, fractures, is torn or opened, or the like. When the pressure relief mechanism is actuated, high-temperature and high-pressure substances in the battery cells are discharged outwards from the actuated part as emissions. In this way, the cells can be vented under controlled pressure or temperature, thereby avoiding potentially more serious accidents.

Reference herein to emissions from the battery cell includes, but is not limited to: electrolyte, dissolved or split positive and negative electrode plates, fragments of separators, high-temperature and high-pressure gas generated by reaction, flame and the like.

The inventor finds that the explosion and pressure relief problem of the battery cell occurs when the battery cell does not reach the preset thermal runaway condition in the circulation process of the battery cell, and analyzes and researches the structure and the use environment of the battery cell. The inventor finds that, in the use process of the battery cell, the end cover is subjected to a force inside or outside the battery cell, so that a local area of the end cover is deformed, the deformation of the end cover gives a tensile stress to the pressure relief mechanism, and therefore a weak structure of the pressure relief mechanism is broken, the opening threshold of the pressure relief mechanism is reduced, and the safety risk of the battery cell is caused.

In view of this, the present application provides a technical solution, in which an end cap assembly for a battery cell is provided, the end cap assembly includes an end cap and a pressure relief mechanism. The pressure relief mechanism is configured to actuate to relieve pressure when pressure inside the battery cell reaches a threshold value. The end cover comprises a main body part, a buffering part and an installation part, the pressure relief mechanism is installed on the installation part, the buffering part is arranged on the outer side of the installation part in a surrounding mode and is connected with the main body part and the installation part, and the buffering part is used for deforming when the end cover is impacted so as to reduce acting force transmitted to the pressure relief mechanism. The end cover assembly with the structure can deform at the buffering part when being impacted, so that the acting force is released at the position, the acting force transmitted to the pressure relief mechanism can be reduced, the opening threshold value of the pressure relief mechanism can be ensured, and the safety of a battery cell can be enhanced.

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 power tools include metal cutting electric power tools, grinding electric power tools, assembly electric power tools, and electric power 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 specifically limit the above power utilization device.

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 illustration of a vehicle according to 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 be used not only as an operating power source of the vehicle 1, but also 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 casing part 52 may be a hollow structure with one open end, the first casing part 51 is a plate-shaped structure, and the first casing part 51 covers the open side of the second casing part 52 to form the casing 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.

Assuming that 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 body.

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, the number of the battery cells is multiple, and the multiple battery cells are connected in series or in parallel or in series-parallel to form the battery module 6. A 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; fig. 5 is a schematic structural diagram of a battery cell provided in some embodiments of the present application; fig. 6 isbase:Sub>A schematic cross-sectional view of the battery cell shown in fig. 5 taken along linebase:Sub>A-base:Sub>A.

As shown in fig. 4 to 6, the battery cell 7 provided in the embodiment of the present application includes an electrode assembly 8 and a case assembly 9, and the electrode assembly 8 is accommodated in the case assembly 9.

In some embodiments, the housing assembly 9 may also be used to contain an electrolyte, such as an electrolyte. The housing assembly 9 may be of various constructions.

In some embodiments, the housing assembly 9 may include a housing 91 and an end cap assembly 92, the housing 91 is a hollow structure with one side open, and the end cap assembly 92 covers the opening of the housing 91 and forms a sealing connection to form a receiving cavity for receiving the electrode assembly 8 and the electrolyte.

In some embodiments, the end cap assembly 92 includes an end cap 10, and the end cap 10 covers the opening of the shell 91. The end cap 10 may have various structures, for example, the end cap 10 has a plate-shaped structure, a hollow structure with one end open, and the like. Illustratively, in fig. 4, the housing 91 has a rectangular parallelepiped structure, the end cap 10 has a plate-like structure, and the end cap 10 covers an opening at the top of the housing 91.

The end cap 10 may be made of an insulating material (e.g., plastic) or a conductive material (e.g., metal). When end cap 10 is made of a metallic material, end cap assembly 92 may further include an insulating member (not shown) on a side of end cap 10 facing electrode assembly 8 to insulate and separate end cap 10 from electrode assembly 8.

In some embodiments, the end cap assembly 92 may further include an electrode terminal 921, the electrode terminal 921 being mounted on the end cap 10. The two electrode terminals 921 are defined as a positive electrode terminal and a negative electrode terminal, respectively, each of which is used to electrically connect with the electrode assembly 8 to output electric energy generated by the electrode assembly 8.

In other embodiments, the housing assembly 9 may have other structures, for example, the housing assembly 9 includes a housing 91 and two end cap assemblies 92, the housing 91 is a hollow structure with two opposite open sides, and one end cap assembly 92 is correspondingly covered on one open side of the housing 91 and forms a sealing connection to form a containing cavity for containing the electrode assembly 8 and the electrolyte. In such a configuration, two electrode terminals 921 may be provided on one end cap assembly 92, while the electrode terminals 921 are not provided on the other end cap assembly 92, or one electrode terminal 921 may be provided on each of the two end cap assemblies 92.

In the battery cell 7, the electrode assembly 8 housed in the case assembly 9 may be one or a plurality of.

The electrode assembly 8 includes a positive electrode tab, a negative electrode tab, and a separator. The electrode assembly 8 may be a wound electrode assembly, a laminated electrode assembly, or other form of electrode assembly.

In some embodiments, electrode assembly 8 is a wound electrode assembly. The positive pole piece, the negative pole piece and the separator are all of a belt-shaped structure. The positive electrode plate, the separator and the negative electrode plate can be sequentially stacked and wound for more than two turns to form the electrode assembly 8.

In other embodiments, electrode assembly 8 is a laminated electrode assembly. Specifically, the electrode assembly 8 includes a plurality of positive electrode tabs and a plurality of negative electrode tabs, which are alternately laminated in a direction parallel to the thickness direction of the positive electrode tabs and the thickness direction of the negative electrode tabs.

The electrode assembly 8 includes a body part 81 and a tab part 82 connected to the body part 81, from the external appearance of the electrode assembly 8. Illustratively, tab portion 82 extends from an end of body portion 81 proximate end cap assembly 92.

In some embodiments, there are two tab portions 82, and the two tab portions 82 are defined as a positive tab portion and a negative tab portion, respectively. The positive electrode lug and the negative electrode lug may extend from the same end of the body part 81, or may extend from opposite ends of the body part 81.

The body 81 is a core part of the electrode assembly 8 that performs a charge and discharge function, and the tab 82 is used to draw out a current generated by the body 81. The body portion 81 includes a positive current collecting portion of a positive current collector, a positive active material layer, a negative current collecting portion of a negative current collector, a negative active material layer, and a separator. The positive pole lug portion comprises a plurality of positive pole lugs, and the negative pole lug portion comprises a plurality of negative pole lugs.

The pole ear portion 82 is for electrical connection to the electrode terminal 921. The lug part 82 may be directly connected to the electrode terminal 221 by welding or the like, or may be indirectly connected to the electrode terminal 921 by another member. For example, the battery cell 7 further includes a current collecting member 83, and the current collecting member 83 is used to electrically connect the electrode terminal 921 and the tab portion 82. The two current collecting members 83 are defined as a positive current collecting member for electrically connecting the positive electrode terminal and the positive electrode tab and a negative current collecting member for electrically connecting the negative electrode terminal and the negative electrode tab, respectively.

FIG. 7 is a left side structural schematic view of an end cap assembly provided by some embodiments of the present application; FIG. 8 is a schematic cross-sectional view of the end cap assembly shown in FIG. 7 taken along line B-B; FIG. 9 is an enlarged schematic view of the endcap assembly shown in FIG. 8 at I; FIG. 10 is a perspective view of an end cap assembly provided in accordance with some embodiments of the present application.

In some embodiments, as shown in fig. 7-10, the end cap assembly 92 includes an end cap 10 and a pressure relief mechanism 20. The end cap 10 comprises a main body 11, a buffer part 12 and a mounting part 13, the pressure relief mechanism 20 is mounted on the mounting part 13, the buffer part 12 is arranged around the outer side of the mounting part 13 and is connected with the main body 11 and the mounting part 13, and the buffer part 12 is used for deforming when the end cap 10 is impacted so as to reduce acting force transmitted to the pressure relief mechanism 20. The pressure relief mechanism 20 is configured to actuate to relieve pressure when the pressure inside the battery cell reaches a threshold.

The pressure relief mechanism 20 is configured to actuate to relieve the internal pressure of the battery cell when the internal pressure reaches a threshold value. When the battery monomer produced more gas and made casing internal pressure rise and reach the threshold value, the weak structure that is equipped with in the pressure relief mechanism 20 execution action or the pressure relief mechanism 20 was broken, and then avoided the battery monomer to explode. A weakened structure refers to a portion of the pressure relief mechanism 20 that is weak relative to the remainder of the pressure relief mechanism 20 and is susceptible to rupture, fracture, tear, or open. Illustratively, a predetermined region of the pressure relief mechanism 20 is thinned, and the thinned portion forms a weak structure. Alternatively, a predetermined region of the pressure relief mechanism 20 may be treated so that the strength of the region is weaker than the strength of other regions, and the region of lower strength may form a weak structure.

The pressure relief mechanism 20 may be any of a variety of possible pressure relief mechanisms 20, and the embodiments of the present application are not limited in this respect. For example, pressure relief mechanism 20 may be a pressure sensitive pressure relief mechanism configured to rupture when the internal air pressure of a cell in which the pressure sensitive pressure relief mechanism is disposed reaches a threshold value.

The end cap 10 may be made of an insulating material or a conductive material for insulating the electrolyte from the external environment. When the end cap 10 is made of a conductive material (e.g., copper, iron, aluminum, stainless steel, aluminum alloy, etc.), an insulating member may be disposed between the end cap and the electrode assembly 8 to isolate the end cap 10 from the electrode assembly, thereby reducing the risk of short circuit between the end cap 10 and the electrode assembly 8. In the embodiment of the present application, the insulating member is made of an insulating material, and the insulating member may be made of rubber, plastic, or the like. The end cap 10 may be a conductive material such as copper, iron, aluminum, stainless steel, aluminum alloy, or the like. It should be noted that in the embodiment of the present application, in the case where the end cap assembly 92 is not provided with an insulating member, the end cap 10 may be made of an insulating material.

The end cap 10 includes a main body portion 11, a buffer portion 12, and a mounting portion 13. The mount 13 is used to mount the pressure relief mechanism 20, and the pressure relief mechanism 20 may be mounted on the mount 13 by welding or the like. The buffer portion 12 is disposed around the outer side of the mounting portion 13 and connects the main body portion 11 and the mounting portion 13.

The cushioning portion 12 refers to a portion of the end cap 10 having a deformability relative to the rest of the end cap 10, and is easily deformed when receiving a force. Illustratively, a predetermined region of the end cap 10 is subjected to a punching process, and the punched portion forms the buffer portion 12. Alternatively, a predetermined region of the end cap 10 is subjected to a material treatment so that the region has a higher deformability than the remaining region, for example, an elastic material or the like is used.

During the transportation, temperature change or charging and discharging of the battery cell, the following situations may exist in the battery cell: the end cap 10 is subjected to an internal impact force, such as electrolyte inside the cell, etc., causing impact to the end cap 10, the end cap 10 is subjected to an external impact force, such as force outside the cell, causing impact to the end cap 10, etc. In the presence of one or more of the above conditions, the end cap 10 may be deformed by creep deformation, and the pressure relief mechanism 20 may be actuated prematurely when the pressure inside the battery cell reaches a threshold value, so that the battery cell has poor use reliability and poor safety performance.

In this embodiment, when the end cap 10 of the battery cell receives an acting force, the buffer portion 12 can deform, so that the acting force can be released to a certain extent at the buffer portion 12, thereby reducing the acting force transmitted to the pressure relief mechanism 20, ensuring the opening threshold of the pressure relief mechanism 20, and enhancing the safety and the use reliability of the battery cell.

With continued reference to fig. 9 and 10, in some embodiments, at least a portion of the buffer portion 12 is an arch structure, and at least a portion of the buffer portion 12 protrudes from the main body portion 11 along the thickness direction X of the end cap 10 to form the arch structure. The arch structure has a cavity, and may be a semicircular structure, a polygonal structure, an arc structure, an elliptical structure, a parabolic structure, or a pointed arch structure, etc., and exemplarily, at least a portion of the buffer portion 12 is a V-shaped structure or a U-shaped structure. The buffer portion 12 may have a partially arch structure or a fully arch structure, and is not limited in this application.

When the end cap 10 is acted upon by an acting force, the acting force acts on the arch structure, and the arch structure can be subjected to tensile deformation or compressive deformation, so that the acting force can be released to a certain extent, and the acting force transmitted to the pressure relief mechanism 20 is reduced.

The X direction shown in fig. 9 indicates the thickness direction of the end cap 10. The main body portion 11 includes a first surface 111 and a second surface 112 opposite to each other in the thickness direction X, the first surface 111 being disposed facing the electrode assembly, and the second surface 112 being disposed facing away from the electrode assembly.

The buffer portion 12 may be provided in one or more. When the plurality of buffer portions 12 are provided, the plurality of buffer portions 12 are provided around the outer side of the mounting portion 13. The plurality of buffer portions 12 can further improve the buffer deformability and further enhance the safety of the battery cell.

As some examples, when one or more buffers 12 are provided, at least a portion of each buffer 12 may protrude in a direction away from the electrode assembly to form an arch, in other words, at least a portion of each buffer 12 protrudes from the second surface 112 in the thickness direction X. When receiving an external impact force, the cushioning portion 12 is deformed in a direction away from the center axis of the cushioning portion 12; when receiving the internal impact force of the battery cell, the cushioning portion 12 is compressively deformed in the direction of the center axis of the cushioning portion 12. The buffer part 12 is arranged to protrude toward a direction away from the electrode assembly, so that the buffer part 12 does not occupy the inner space of the battery cell, the occupied volume of the electrode assembly or the electrolyte can be increased, and the energy density of the battery cell can be increased.

FIG. 11 is another enlarged schematic view of the endcap assembly shown in FIG. 8 at I; FIG. 12 is a perspective view of an endcap assembly according to still other embodiments of the present application.

As another example, as shown in fig. 11 and 12, when the buffer parts 12 are provided in one or more, at least a portion of each buffer part 12 may protrude in a direction of the electrode assembly to form an arch structure, in other words, at least a portion of the buffer part 12 protrudes from the first surface 111 in the thickness direction X. When receiving an external impact force, the cushioning portion 12 is compressively deformed in the direction of the central axis of the cushioning portion 12; when receiving the internal impact force of the battery cell, the cushioning portion 12 is deformed in a direction away from the center axis of the cushioning portion 12. The buffer part 12 is protruded toward the electrode assembly, so that the buffer part 12 does not additionally occupy the entire assembly space of the battery cell, and the assembly of the battery cell and an external member is facilitated.

Of course, when the cushioning portion 12 is provided in plural, a part of the cushioning portion 12 may protrude from the first surface 111 of the main body portion 11 in the thickness direction X, and another part of the cushioning portion 12 may protrude from the second surface 112 of the main body portion 11 in the thickness direction X.

FIG. 13 is a further enlarged schematic view of the endcap assembly of FIG. 8 at I; FIG. 14 is a perspective view of an endcap assembly according to still other embodiments of the present application.

As shown in fig. 13 and 14, the plurality of buffer portions 12 exemplarily include a first buffer portion 121 and a second buffer portion 122, and the protruding directions of the first buffer portion 121 and the second buffer portion 122 are opposite in the thickness direction X. For example, the first buffer portion 121 protrudes from the first surface 111 of the body portion 11, the second buffer portion 122 protrudes from the second surface 112 of the body portion 11, and when an external impact force is applied, the first buffer portion 121 is compressed and deformed in a direction toward a central axis of the buffer portion 12, and the compression deformation may cause a reduction in size of the body portion 11 in the longitudinal direction Y; the second cushioning portion 122 is subjected to tensile deformation in a direction away from the central axis of the cushioning portion 12 while being subjected to an external impact force, and the tensile deformation may cause an increase in the size of the main body portion 11 in the longitudinal direction Y; the provision of the first buffer portion 121 and the second buffer portion 122 at the same time can maintain the dimension of the main body portion 11 in the longitudinal direction Y to be constant, thereby ensuring the structural stability of the main body portion 11 and improving the structural stability of the entire end cap. The Y direction shown in fig. 13 indicates the longitudinal direction of the main body 11, and the longitudinal direction Y is perpendicular to the thickness direction X.

The connection manner between the plurality of buffer portions 12 has various forms, such as a continuous arrangement or an interval arrangement.

As some examples, the plurality of buffer portions 12 are continuously disposed, transition fillets are disposed at the joints of two adjacent buffer portions 12, and the transition fillets are disposed at the joints of two adjacent buffer portions 12 on the basis of ensuring the buffer deformation capability of the plurality of buffer portions 12, so that stress concentration at the joints can be avoided, and the structural stability of the buffer portions 12 can be improved.

As another example, referring to fig. 13 and 14, the plurality of buffer portions 12 are disposed at intervals. The end cover further comprises a reinforcing part 14, the reinforcing part 14 is arranged between two adjacent buffer parts 12 (for example, two adjacent second buffer parts 122), the reinforcing part 14 can play a role in reinforcing the end cover 10, and the arrangement of the reinforcing part 14 is beneficial to positioning when the buffer parts 12 are machined, so that the machining precision is improved.

FIG. 15 is a further enlarged schematic view of the endcap assembly, at I, of FIG. 8; FIG. 16 is a perspective view of an end cap assembly according to still other embodiments of the present application.

As shown in fig. 15 and 16, in some embodiments, the thickness of the mounting portion 13 is greater than that of the main body portion 11 in order to further ensure the structural stability of the pressure relief mechanism 20 based on the deformability of the cushioning portion 12 of the end cap 10. Installation department 13 is used for installing pressure relief mechanism 20, improves the thickness of installation department 13 here, and the intensity of installation department 13 also correspondingly improves, even the end cover receives the effort, also is difficult for taking place the deformation in installation department 13 to can further improve pressure relief mechanism 20's structural stability, guarantee its threshold value of opening.

The thickness of the mounting portion 13 is greater than that of the main body portion 11, and a portion of the mounting portion 13 protrudes from the first surface 111 of the main body portion 11 along the thickness direction X, a portion of the mounting portion 13 protrudes from the second surface 112 of the main body portion 11 along the thickness direction X, or both the first surface 111 and the second surface 112 of the main body portion 11 along the thickness direction X.

The mounting portion 13 includes a second edge 13a and a fourth edge that oppose each other in the thickness direction X. Wherein the second edge 13a is disposed adjacent to the electrode assembly and the fourth edge is disposed away from the electrode assembly.

The cushioning portion 12 includes a first edge 12a and a third edge that are opposed to each other in the thickness direction X. Wherein the first edge 12a is disposed adjacent to the electrode assembly and the third edge is disposed away from the electrode assembly.

As some examples, when at least a portion of the cushioning portion 12 protrudes from the first surface 111 of the main body portion 11 in the thickness direction X to form an arch structure, the first edge 12a is flush with the second edge 13a in the thickness direction X. Because the first edge 12a and the second edge 13a are flush, when the end cap 10 is subjected to the acting force inside the battery cell, the acting force can simultaneously act on the first edge 12a and the second edge 13a, the buffer part 12 is deformed, and the acting force transmitted to the pressure relief mechanism 20 is reduced; since the strength of the mounting portion 13 is high, it is possible to simultaneously receive a large strength of the acting force, so that it is not easily deformed, and the acting force transmitted to the pressure release mechanism 20 can be reduced. The buffer portion 12 and the mounting portion 13 cooperate to reduce the acting force transmitted to the pressure relief mechanism 20, thereby improving the structural stability of the pressure relief mechanism 20.

Alternatively, when at least a portion of the cushioning portion 12 protrudes from the first surface 111 of the main body portion 11 in the thickness direction X to form an arch structure, the first edge 12a exceeds the second edge 13a in the thickness direction X. When the end cover 10 is subjected to the acting force in the battery cell, the acting force acts on the buffer part 12 firstly, and the buffer part 12 deforms in advance, so that the acting force can be released in the buffer part 12 to a certain extent, and the acting force transmitted to the pressure relief mechanism 20 is reduced; and the strength of the acting force impacting other parts of the end cover, such as the mounting part 13, can be reduced, the risk of deformation of the mounting part 13 is reduced, and the structural stability of the pressure relief mechanism 20 is improved.

As other examples, when at least a portion of the cushioning portion 12 protrudes from the second surface 112 of the main body portion 11 in the thickness direction X to form an arch structure, the third edge is flush with the fourth edge in the thickness direction X. The buffer portion 12 and the mounting portion 13 cooperate with each other to reduce the force transmitted to the pressure relief mechanism 20, thereby improving the structural stability of the pressure relief mechanism 20.

Alternatively, when at least a portion of the cushioning portion 12 protrudes from the second surface 112 of the main body portion 11 in the thickness direction X to form an arch structure, the third edge exceeds the fourth edge in the thickness direction X. The buffer part 12 can play a role in deformation release, and can also reduce the risk of deformation of the mounting part 13, thereby improving the structural stability of the pressure relief mechanism.

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 particularly, features described in connection with the 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 rather to cover all embodiments falling within the scope of the appended claims.

Claims (12)

1. An end cap assembly for a battery cell, the end cap assembly comprising:

a pressure relief mechanism configured to actuate to relieve pressure inside the battery cell when the pressure reaches a threshold; and

the end cover comprises a main body part, a buffering part and an installation part, wherein the pressure relief mechanism is installed on the installation part, the buffering part is arranged around the outer side of the installation part and is connected with the main body part and the installation part, and the buffering part is used for deforming when the end cover is impacted so as to reduce and transmit acting force of the pressure relief mechanism.

2. An end cap assembly according to claim 1, wherein at least a portion of the bumper portion protrudes from the body portion in a thickness direction of the end cap to form an arch.

3. The end cap assembly according to claim 2, wherein at least a portion of the buffer protrudes in a direction away from an electrode assembly of the battery cell in a thickness direction of the end cap to form the arch structure.

4. An end cap assembly according to claim 2,

the buffer part sets up to a plurality ofly, and is a plurality of the buffer part encircles respectively set up in the outside of installation department.

5. The end cap assembly of claim 4,

the buffer parts are continuously arranged, and transition fillets are arranged at the joints of the two adjacent buffer parts.

6. The end cap assembly of claim 4,

a plurality of the buffer parts are arranged at intervals;

the end cover further comprises a reinforcing part, and the reinforcing part is arranged between two adjacent buffer parts.

7. The end cap assembly of claim 4, wherein the plurality of bumpers includes a first bumper and a second bumper, the direction of projection of the first bumper and the second bumper being opposite in the thickness direction of the end cap.

8. An end cap assembly according to any one of claims 1 to 7, wherein the mounting portion has a thickness greater than a thickness of the body portion.

9. An end cap assembly according to claim 8,

at least a portion of the buffer part protrudes in a direction of an electrode assembly of the battery cell in a thickness direction of the end cap to form an arch structure, the buffer part including a first edge near the electrode assembly in the thickness direction;

the mounting part includes a second edge adjacent to the electrode assembly in the thickness direction,

wherein the first edge is flush with or exceeds the second edge in the thickness direction.

10. A battery cell comprising the end cap assembly of any one of claims 1-9.

11. A battery comprising the cell of claim 10.

12. An electrical device comprising the battery of claim 11, wherein the battery is configured to provide electrical energy.

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