CN218215488U

CN218215488U - End cover assembly, battery monomer, battery and consumer

Info

Publication number: CN218215488U
Application number: CN202221919496.9U
Authority: CN
Inventors: 程启; 陈新祥; 林蹬华; 陈龙; 黄守君; 雷育永; 李全坤; 郑于炼; 王鹏
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2022-07-22
Filing date: 2022-07-22
Publication date: 2023-01-03
Anticipated expiration: 2032-07-22

Abstract

The embodiment of the application provides an end cover assembly, a single battery, a battery and electric equipment, and belongs to the technical field of batteries. The end cap assembly includes an end cap, a connector, and an electrode terminal. The end cover is used for sealing the opening of the single battery shell and is provided with a terminal leading-out hole. The connecting piece sets up in the end cover and deviates from one side of casing in the thickness direction. And the electrode terminal penetrates through the terminal leading-out hole and is connected to the connecting piece, and the electrode terminal is used for connecting the electrode assembly of the battery cell so as to realize the electrical connection of the connecting piece and the electrode assembly. The circumference of the outer surface of the end cap is L along the thickness direction of the end cap ₁ The connecting piece has an abutment surface facing away from the end cap, the abutment surface having a circumference L ₂ ，L ₂ /L ₁ Not less than 0.25. When the battery monomer with the end cover assembly is connected with another battery monomer, the connection track of the connecting pieces of the two battery monomers can be increased, the bonding strength of the connecting pieces of the two battery monomers is enhanced, and the stability of electric connection of the two battery monomers is improved.

Description

End cover assembly, battery monomer, battery and consumer

Technical Field

The application relates to the technical field of batteries, in particular to an end cover assembly, a battery monomer, a battery and electric equipment.

Background

With the development of new energy technology, batteries are more and more widely used, for example, in mobile phones, notebook computers, battery cars, electric automobiles, electric airplanes, electric ships, electric toy cars, electric ships, electric toy airplanes, electric tools, and the like.

In order to meet the voltage requirement, a plurality of battery cells are generally connected in series, in parallel or in series-parallel, and the stability of the electrical connection between the battery cells needs to be considered. Therefore, how to improve the stability of the electrical connection between the battery cells is an urgent problem to be solved in the battery technology.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides an end cover assembly, single battery, battery and consumer, is favorable to promoting the stability of electric connection between the single battery.

In a first aspect, an embodiment of the present application provides an end cap assembly, which includes an end cap, a connecting member, and an electrode terminal; the end cover is used for sealing the opening of the single battery shell and is provided with a terminal guideAn outlet hole; the connecting piece is arranged on one side of the end cover, which deviates from the shell in the thickness direction; the electrode terminal penetrates through the terminal leading-out hole and is connected to the connecting piece, and the electrode terminal is used for connecting an electrode assembly of the battery monomer so as to realize the electrical connection of the connecting piece and the electrode assembly; wherein, along the thickness direction of the end cover, the perimeter of the outer surface of the end cover is L ₁ The connecting piece has an abutment surface facing away from the end cap, the abutment surface having a circumference L ₂ The butt joint surface is used for being electrically connected with an external component, and satisfies the following conditions: l is ₂ /L ₁ ≥0.25。

In the technical scheme, the ratio of the perimeter of the butt joint surface of the connecting piece to the perimeter of the outer surface of the end cover is not less than 0.25, so that the perimeter of the butt joint surface of the connecting piece is longer, when the battery cell with the end cover assembly is connected with other battery cells, the connection track of the connecting pieces of the two battery cells can be increased, the bonding strength of the connecting pieces of the two battery cells is enhanced, and the stability of electric connection of the two battery cells is favorably improved.

In some embodiments, 0.5 ≦ L ₂ /L ₁ Less than or equal to 1. Therefore, under the condition that the connecting pieces of the two battery monomers have longer connecting tracks when being connected, the perimeter of the butt joint surface of the connecting pieces is not too large, so that the sufficient bonding strength between the connecting pieces of the two battery monomers is ensured, and the connecting efficiency is improved.

In some embodiments, 0.5 ≦ L ₂ /L ₁ Less than or equal to 0.7. The connection efficiency of the connecting pieces of the two battery cells is further improved.

In some embodiments, the electrode terminal is welded to the connector, and a first welding part is formed at a welding position of the electrode terminal to the connector, the first welding part not exceeding the abutting surface. The electrode terminal and the connecting piece are welded, so that the connection strength of the electrode terminal and the connecting piece can be improved, and stable overcurrent is guaranteed. The first welding part does not exceed the butt joint surface, and the risk that the butt joint surfaces of the connecting pieces of the two battery cells cannot be attached to each other due to the first welding part formed by welding the electrode terminal and the connecting piece is reduced.

In some embodiments, the connection member is provided with a through-hole through which the electrode terminal is inserted; along the thickness direction of end cover, the through-hole runs through the butt joint face, and electrode terminal has first terminal surface, and first terminal surface and butt joint face lie in the same one side of end cover, and first terminal surface is closer to the end cover than the butt joint face. Like this, guarantee that the butt joint face of two free connecting pieces of battery can laminate by a large scale, guarantee connection quality, increase the area of overflowing between two battery monomers.

In some embodiments, the through hole comprises a first hole section and a second hole section which are arranged in sequence along the direction of the connecting piece pointing to the end cover, the aperture of the first hole section is larger than that of the second hole section, the first hole section penetrates through the abutting surface, and the inner circumferential surface of the first hole section is connected with the inner circumferential surface of the second hole section through a first connecting surface; wherein the first end surface is flush with the first connecting surface; or, the first end surface is closer to the end cover than the first connecting surface along the thickness direction of the end cover. Therefore, the first end face and the butt joint face at least keep the distance of the first hole section, and the influence of the electrode terminal on the butt joint face of the connecting piece of the two battery cells in mutual fitting is reduced.

In some embodiments, the thickness of the connector in the thickness direction of the end cap is L ₃ The distance between the first end surface and the butt joint surface is L ₄ And satisfies the following conditions: l is more than or equal to 0.1 ₄ /L ₃ Less than or equal to 0.2. Mixing L with ₄ /L ₃ The setting is in reasonable within range, on the one hand for distance between first terminal surface and the butt joint face can not the undersize, reduces the influence that electrode terminal laminated each other to the butt joint face of two free connecting pieces of battery, and on the other hand makes distance between first terminal surface and the butt joint face can not too big, makes electrode terminal partly be located the through-hole more, increases electrode terminal and connecting piece's flow area, and has improved electrode terminal and connecting piece's stability of being connected.

In some embodiments, the end cap assembly further comprises a first insulator at least partially positioned between the connector and the end cap in a thickness direction of the end cap to insulate the connector from the end cap. The first insulating part plays a role in separating the connecting part from the end cover so as to realize insulation between the connecting part and the end cover and reduce the risk of short circuit of the battery monomer.

In some embodiments, the first insulator is a flat plate structure disposed between the connector and the end cap. The first insulating part is simple in structure and easy to mold and manufacture.

In some embodiments, the first insulator comprises a body portion and an edge portion; the body part is positioned between the connecting piece and the end cover along the thickness direction of the end cover; the edge part is arranged around the edge of the body part, and the edge part and the body part jointly define an accommodating space; wherein the connector portion is accommodated in the accommodating space. Like this, the edge part sets up around the connecting piece, and the edge part can increase the creepage distance of connecting piece and end cover, strengthens the insulating properties between connecting piece and the end cover.

In some embodiments, the thickness of the portion of the connecting member protruding outside the first insulating member in the thickness direction of the end cap is H ₁ The thickness of the first insulating member is H ₂ The thickness of the end cap is H ₃ And satisfies the following conditions: h is more than or equal to 1 ₁ /H ₂ Less than or equal to 5, and/or, less than or equal to 1, H ₁ /H ₃ Less than or equal to 3. This allows the connector to have a larger connectable area.

In some embodiments, the abutment surface is planar.

In some embodiments, the projection of the edge of the connector in the thickness direction of the end cap is located entirely on the end cap. The connecting piece is completely positioned in the area range limited by the edge of the end cover, the connecting piece is not easy to interfere the installation of the end cover, and the end cover is easier to fix on the shell.

In some embodiments, the projections of the connecting piece and the end cover along the thickness direction of the end cover are both rectangular, the length direction of the connecting piece is consistent with the length direction of the end cover, and the width direction of the connecting piece is consistent with the width direction of the end cover. The connecting piece and the end cover of the structure are simple in structure, the connecting piece can be made large, and large-area overcurrent after the connecting pieces of the two battery monomers are connected is achieved.

In a second aspect, embodiments of the present application provide a battery cell, including a case, an electrode assembly, and the end cap assembly provided in any one of the embodiments of the first aspect; the shell is provided with an opening; the electrode assembly is accommodated in the case; the end cap closes the opening, and the electrode terminal is electrically connected to the electrode assembly.

In a third aspect, an embodiment of the present application provides a battery, which includes a plurality of battery cells provided in any one of embodiments of the second aspect.

In some embodiments, the plurality of battery cells include a first battery cell and a second battery cell, and the abutting surface of the first battery cell and the abutting surface of the second battery cell abut against and are connected to each other along the thickness direction of the end cover, so that the first battery cell is electrically connected with the second battery cell. The connecting piece of the first battery cell and the connecting piece of the second battery cell are connected together, so that stable overcurrent of the connecting piece of the first battery cell and the connecting piece of the second battery cell can be realized.

In some embodiments, the connection member of the first battery cell is welded to the connection member of the second battery cell and a second welding portion is formed at the welding position, the second welding portion extending along an edge of the butting face. Because the ratio of the perimeter of the butt joint surface of the connecting piece to the perimeter of the outer surface of the end cover is set within a reasonable range, the perimeter of the butt joint surface of the connecting piece is longer, the perimeter of the second welding part is increased, the bonding strength of the connecting piece of the first battery monomer and the connecting piece of the second battery monomer is enhanced, and the stability of electric connection of the first battery monomer and the second battery monomer is improved.

In some embodiments, the end cap assembly further comprises a first insulator at least partially between the connector and the end cap in a thickness direction of the end cap to insulate and isolate the connector and the end cap; the sum of the thickness of the part of the connecting piece of the first battery cell, which protrudes out of the first insulating piece, and the thickness of the part of the connecting piece of the second battery cell, which protrudes out of the first insulating piece, in the thickness direction of the end cover is H ₄ The width of the second welding part is H ₅ Satisfies the following conditions: h is more than or equal to 0.25 ₅ /H ₄ Less than or equal to 1. Will H ₅ /H ₄ The setting has great welding to melt wide after can guaranteeing that free connecting piece of first battery and the free connecting piece welding of second battery have in reasonable within range, has further increased the joint strength of the free connecting piece of first battery and the free connecting piece of second battery.

In a fourth aspect, an embodiment of the present application provides an electric device, including the battery provided in any one of the embodiments of the third aspect.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.

FIG. 1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

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

fig. 3 is a cross-sectional view of a battery cell provided by some embodiments of the present application;

FIG. 4 is a schematic structural view of an end cap assembly provided in accordance with certain embodiments of the present application;

FIG. 5 is a top view of the end cap assembly shown in FIG. 4;

FIG. 6 is an enlarged view of a portion A of FIG. 4;

FIG. 7 is a partial view of the connector shown in FIG. 4;

FIG. 8 is a schematic structural view of an end cap assembly provided in accordance with further embodiments of the present application;

FIG. 9 is a schematic view of the first insulator shown in FIG. 8;

fig. 10 is a schematic connection diagram of a first battery cell and a second battery cell provided in an embodiment of the present application;

fig. 11 is a partially enlarged view of fig. 10 at B.

Icon: 1-a shell; 2-an electrode assembly; 21-positive tab; 22-negative tab; 3-an end cap assembly; 31-end cap; 310-an outer surface; 311-terminal leading-out hole; 32-a connector; 321-a through hole; 3211-a first bore section; 3212-a second pore section; 3213-first connection face; 3214-a third hole section; 3215-a second connection face; 322-a docking surface; 323-inner surface; 33-electrode terminals; 331-a terminal body; 3311-first stage; 3312-second stage; 332-a limiting part; 333-a first end face; 34-a first weld; 35-a first insulator; 351-a body portion; 352-edge portion; 353-an accommodating space; 36-a second insulator; 37-a seal; 10-a battery cell; 10 a-a first battery cell; 10 b-a second battery cell; 20-a box body; 201-a first portion; 202-a second portion; 30-a second weld; 100-a battery; 200-a controller; 300-a motor; 1000-a vehicle; z-thickness direction.

Detailed Description

In order to make the objects, 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 figures above, 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 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 thicknesses, lengths, widths, and the like of the various components in the embodiments of the present application, and the overall thicknesses, lengths, widths, and the like of the integrated devices shown in the drawings are merely illustrative, 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 the present application, the battery cell may include a lithium ion secondary battery, a lithium ion primary battery, a lithium sulfur battery, a sodium lithium ion battery, a sodium ion battery, a magnesium ion battery, or the like, which is not limited in the embodiments of the present 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 to this also not limited.

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 monomer comprises an electrode assembly and electrolyte, wherein the electrode assembly comprises a positive plate, a negative plate and an isolating membrane. The battery cell mainly depends on metal ions moving between the positive plate and the negative plate to work. The positive plate comprises a positive current collector and a positive active substance layer, the positive active substance layer is coated on the surface of the positive current collector, the positive current collector which is not coated with the positive active substance layer protrudes out of the positive current collector which is coated with the positive active substance layer, and the positive current collector which is not coated with the positive active substance layer is used as a positive tab. Taking a lithium ion battery as an example, the material of the positive electrode current collector may be aluminum, and the positive electrode active material may be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, or the like. The negative pole piece includes negative pole mass flow body and negative pole active substance layer, and the surface of negative pole mass flow body is scribbled to the negative pole active substance layer, and the negative pole mass flow body protrusion in the negative pole mass flow body of having scribbled the negative pole active substance layer of not scribbling the negative pole active substance layer, and the negative pole mass flow body of not scribbling the negative pole active substance layer is as negative pole ear. The material of the negative electrode current collector may be copper, 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, a plurality of positive electrode tabs are stacked, and a plurality of negative electrode tabs are stacked. The material of the isolation film 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.

In the battery, in order to meet the requirements of large current or large voltage, a plurality of battery monomers in a box body need to be connected in series, in parallel or in series-parallel. At present, the single electric connection of two batteries is realized to the part that generally adopts to converge, and the part that converges needs to occupy inside some spaces of box, has reduced the utilization ratio of box inner space, has reduced the energy density of battery.

In order to increase the utilization ratio of the internal space of the box body and improve the energy density of the battery, the confluence part can be removed, and the output parts of the two battery monomers for outputting electric energy are directly welded together. For example, to connect two cells in series, the negative output member of one cell may be welded to the positive output member of the other cell.

The inventor notices that in a vibration environment, the welding positions of the output parts of the two battery cells are stressed greatly, the output parts of the two battery cells are prone to being in failure connection, and the stability of the electrical connection of the two battery cells is poor.

In view of this, the present application provides an end cap assembly including an end cap, a connecting member, and an electrode terminal. The end cap is provided with a terminal leading-out hole. The connecting piece sets up in the end cover and deviates from one side of casing in the thickness direction. The electrode terminal passes through the terminal lead-out hole and is connected to the connector. Along the thickness direction of end cover, the girth of the surface of end cover is L1, and the connecting piece has the butt joint face that deviates from the end cover, and the girth of butt joint face is L2, and the butt joint face is used for being connected with the external component electricity, satisfies: L2/L1 is more than or equal to 0.25.

In the end cover assembly, the ratio of the perimeter of the butt joint surface of the connecting piece to the perimeter of the outer surface of the end cover is not less than 0.25, so that the perimeter of the butt joint surface of the connecting piece is longer, when the battery cell with the end cover assembly is connected with another battery cell, the connecting track of the connecting piece (output part) of the two battery cells can be increased, the bonding strength of the connecting piece of the two battery cells is enhanced, and the stability of electric connection of the two battery cells is improved.

The end cover assembly described in the embodiments of the present application is suitable for a battery cell, a battery, and an electric device using the battery.

The electric equipment can be vehicles, mobile phones, portable equipment, notebook computers, ships, spacecrafts, electric toys, electric tools 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-extended 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-mentioned electric devices.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a vehicle 1000 according to some embodiments of the present disclosure. The battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom or the head or the tail of the vehicle 1000. The battery 100 may be used for power supply of the vehicle 1000, for example, the battery 100 may serve as an operation power source of the vehicle 1000.

The vehicle 1000 may further include a controller 200 and a motor 300, the controller 200 being configured to control the battery 100 to supply power to the motor 300, for example, for starting, navigation, and operational power requirements while the vehicle 1000 is traveling.

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

Referring to fig. 2, fig. 2 is an exploded view of a battery 100 according to some embodiments of the present disclosure. The battery 100 includes a battery cell 10 and a case 20, and the case 20 accommodates the battery cell 10.

The case 20 is a component for accommodating the battery cell 10, the case 20 provides a storage space for the battery cell 10, and the case 20 may have various structures. In some embodiments, the case 20 may include a first portion 201 and a second portion 202, and the first portion 201 and the second portion 202 are covered with each other to define a receiving space for receiving the battery cell 10. The first portion 201 and the second portion 202 may be a variety of shapes, such as a rectangular parallelepiped, a cylinder, and the like. The first portion 201 may be a hollow structure with one side open, the second portion 202 may be a hollow structure with one side open, and the open side of the second portion 202 is closed to the open side of the first portion 201, thereby forming the case 20 having a receiving space. The first portion 201 may have a hollow structure with one side open, the second portion 202 may have a plate-like structure, and the second portion 202 may cover the open side of the first portion 201 to form the case 20 having the housing space. The first portion 201 and the second portion 202 may be sealed by a sealing element, which may be a sealing ring, a sealant, or the like.

In the battery 100, there may be a plurality of battery cells 10, and the plurality of battery cells 10 may be connected in series or in parallel or in series-parallel, where in series-parallel refers to that the plurality of battery cells 10 are connected in series or in parallel. A plurality of battery cells 10 may be connected in series, in parallel, or in series-parallel to form a battery module, and a plurality of battery modules may be connected in series, in parallel, or in series-parallel to form a whole, and may be accommodated in the box 20. All the single batteries 10 can also be directly connected in series or in parallel or in series-parallel, and the whole formed by all the single batteries 10 is accommodated in the box body 20.

Referring to fig. 3, fig. 3 is a cross-sectional view of a battery cell 10 according to some embodiments of the present disclosure. Battery cell 10 includes a housing 1, an electrode assembly 2, and an end cap assembly 3.

The case 1 is a member for accommodating the electrode assembly 2, the case 1 may be a hollow structure having one end formed to be open, and the case 1 may be a hollow structure having opposite ends formed to be open. The housing 1 may be in various shapes, such as a cylinder, a rectangular parallelepiped, etc. The material of the housing 1 may be various, such as copper, iron, aluminum, steel, aluminum alloy, etc.

The electrode assembly 2 is a component in the battery cell 10 where electrochemical reactions occur. The electrode assembly 2 may include a positive electrode tab, a negative electrode tab, and a separator. The electrode assembly 2 may have a winding type structure formed by winding a positive electrode sheet, a separator, and a negative electrode sheet, or a lamination type structure formed by stacking a positive electrode sheet, a separator, and a negative electrode sheet. The electrode assembly 2 has a positive electrode tab 21 and a negative electrode tab 22, and the positive electrode tab 21 may be a portion of the positive electrode sheet not coated with the positive electrode active material layer, and the negative electrode tab 22 may be a portion of the negative electrode sheet not coated with the negative electrode active material layer.

The end cap assembly 3 is used to close the opening of the case 1 to isolate the internal environment of the battery cell 10 from the external environment. In the battery cell 10, the number of the end cap assemblies 3 may be one or two. Taking the case 1 as an example of a hollow structure with two opposite ends forming openings, the number of the end cap assemblies 3 is two, the two end cap assemblies 3 respectively close the two openings of the case 1, and the positive electrode tab 21 and the negative electrode tab 22 of the electrode assembly 2 are respectively electrically connected with the two end cap assemblies 3. The specific structure of the end cap assembly 3 will be described in detail below with reference to the accompanying drawings.

Referring to fig. 4, fig. 4 is a schematic structural view of an end cap assembly 3 according to some embodiments of the present disclosure. The embodiment of the application provides an end cap assembly 3, which comprises an end cap 31, a connecting piece 32 and an electrode terminal 33. The end cap 31 is used to close the opening of the case 1 of the battery cell 10, and the end cap 31 is provided with a terminal drawing hole 311. The connecting piece 32 is arranged on the side of the end cap 31 facing away from the housing 1 in the thickness direction Z. The electrode terminal 33 passes through the terminal drawing hole 311 and is connected to the connection member 32, and the electrode terminal 33 is used to connect the electrode assembly 2 of the battery cell 10 to achieve electrical connection of the connection member 32 with the electrode assembly 2. Wherein, along the thickness direction Z of the end cap 31, the perimeter L of the outer surface 310 of the end cap 31 is ₁ The circumference of the abutting surface 322 of the connecting member 32 is L ₂ The butt-joint surface 322 is used for electrically connecting with an external component, and satisfies the following conditions: l is ₂ /L ₁ ≥0.25。

The end cap 31 is a member that closes the opening of the case 1 to isolate the internal environment of the battery cell 10 from the external environment. The end cap 31 may be fixed to the housing 1 by welding, crimping, or the like.

The outer surface 310 is a surface of the end cap 31 located outside the battery cell 10 in the thickness direction Z, and is also a surface of the end cap 31 facing the connecting member 32 in the thickness direction Z, and the outer surface 310 is connected to an outer side surface of the end cap 31, which is parallel to the thickness direction Z of the end cap 31. The outer surface 310 may be a variety of shapes, such as rectangular, circular, etc. For example, the outer surface 310 is rectangular, and four edges of the outer surface 310 are connected to four outer side surfaces. The outer surface 310 may be planar, curved, etc.

The connection member 32 is an output member of the battery cell 10 for outputting electric power. If the connecting member 32 is connected to the positive tab 21 of the electrode assembly 2 through the electrode terminal 33, the connecting member 32 is a positive electrode output member of the battery cell 10; if the connector 32 is connected to the negative electrode tab 22 of the electrode assembly 2 through the electrode terminal 33, the connector 32 is a negative electrode output member of the battery cell 10. After the end cap 31 is connected to the housing 1 and closes the opening of the housing 1, the connecting member 32 is located on the side of the end cap 31 facing away from the housing 1 in the thickness direction Z, i.e., the connecting member 32 is located outside the battery cell 10. The connecting member 32 may be a metal conductor, such as copper, iron, aluminum, steel, aluminum alloy, or the like.

The mating face 322 is a surface where the connector 32 is electrically connected to an external component. The external component may be the connector 32 of the other end cap assembly 3. For example, when the connecting members 32 of two battery cells 10 are connected, the abutting surface 322 of the connecting member 32 of one battery cell 10 can be connected with the abutting surface 322 of the connecting member 32 of another battery cell 10 to electrically connect the two battery cells 10. The abutment surface 322 can also be understood as an end surface of the connecting piece 32 facing away from the end cap 31 in the thickness direction Z of the end cap 31. The interface 322 can be a variety of shapes, such as rectangular, circular, etc. If the outer surface 310 is rectangular, the abutting surface 322 may also be rectangular; if the outer surface 310 is circular, the abutment surface 322 may also be circular. The abutment surface 322 may be planar, curved, etc.

The terminal lead-out hole 311 penetrates through the through hole 321 on the inner and outer surfaces in the thickness direction Z of the end cap 31. The electrode terminal 33 is a member that passes through the terminal drawing hole 311 and connects the electrode terminal 33 and the electrode assembly 2. A sealing member 37 may be disposed between the electrode terminal 33 and the end cap 31 to seal the terminal drawing hole 311. The electrode terminals 33 and the connection members 32 may be connected by various means, such as welding, riveting, bonding, integral molding, etc. The electrode terminal 33 may be a metal conductor, such as copper, iron, aluminum, steel, aluminum alloy, or the like.

Illustratively, as shown in fig. 4, the electrode terminal 33 includes a terminal body 331 and a limiting portion 332, the terminal body 331 is disposed through the terminal lead-out hole 311, the connecting element 32 is connected to the terminal body 331, and the limiting portion 332 is connected to an end of the terminal body 331 away from the connecting element 32. The stopper 332 and the connecting member 32 are respectively located on both sides of the end cap 31 in the thickness direction Z of the end cap 31 to fix the electrode terminal 33 and the connecting member 32 to the end cap 31. The terminal body 331 and the stopper 332 may be integrally formed. The stopper 332 is used to electrically connect to the positive electrode tab 21 or the negative electrode tab 22 of the electrode assembly 2. Of course, the stopper 332 and the positive electrode tab 21 or the negative electrode tab 22 of the electrode assembly 2 may be directly connected, for example, welded. The stopper 332 may be indirectly connected to the positive electrode tab 21 or the negative electrode tab 22 of the electrode assembly 2, for example, via a current collecting member. The current collecting member may be a metal conductor, such as copper, iron, aluminum, steel, aluminum alloy, or the like.

The perimeter of the outer surface 310 is the circumferential length of the edge of the outer surface 310 and the perimeter of the interface 322 is the circumferential length of the edge of the interface 322. As shown in fig. 5, fig. 5 is a top view of the end cap assembly 3 shown in fig. 4. For example, where the outer surface 310 and the abutting surface 322 are both rectangular, the length of the outer surface 310 is a ₁ The width of the outer surface 310 is b ₁ The length of the abutting surface 322 is a ₂ The width of the butt-joint surface 322 is b ₂ Then L is ₁ ＝2(a ₁ +b ₁ )，L ₂ ＝2(a ₂ +b ₂ )。L ₂ /L ₁ And may be any value not less than 0.25, such as 0.25, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, etc.

In the embodiment of the present application, a ratio of a circumference of the abutting surface 322 of the connecting member 32 to a circumference of the outer surface 310 of the end cap 31 is not less than 0.25, so that the circumference of the abutting surface 322 of the connecting member 32 is longer, and when the battery cell 10 having the end cap assembly 3 is connected to another battery cell 10, a connection track of the connecting member 32 of the two battery cells 10 can be increased, a bonding strength of the connecting member 32 of the two battery cells 10 is enhanced, and the stability of electrical connection between the two battery cells 10 is improved. For example, when the connecting members 32 of two battery cells 10 are welded, the welding may be performed along the circumferential direction of the edge of the abutting surface 322, so as to increase the welding track when the two are welded.

In some embodiments, 0.5 ≦ L ₂ /L ₁ ≤1。

In this embodiment, L ₂ /L ₁ And can be any value between 0.5 and 1, such as 0.5, 0.6, 0.7, 0.8, 0.9, 1, and the like.

In this embodiment, L is ₂ /L ₁ Is arranged within a reasonable range, and ensures the connection of two single batteries 10Under the condition that the connecting pieces 32 have longer connecting tracks during connection, the perimeter of the butt joint surface 322 of the connecting pieces 32 is not too large, so that enough welding strength between the connecting pieces 32 is ensured, and the welding efficiency is improved.

In some embodiments, 0.5 ≦ L ₂ /L ₁ Less than or equal to 0.7. The connection efficiency of the connection members 32 of the two battery cells 10 is further improved.

In some embodiments, please refer to fig. 6, wherein fig. 6 is a partially enlarged view of a point a in fig. 4. The electrode terminal 33 is welded to the connector 32, and a first welding portion 34 is formed at a welding position of the electrode terminal 33 to the connector 32, the first welding portion 34 not exceeding the abutting surface 322.

The first welding portion 34 is a portion where the electrode terminal 33 and the connection member 32 are welded to form a weld, and the electrode terminal 33 and the connection member 32 are fixed by the first welding portion 34.

In the present embodiment, welding the electrode terminal 33 to the connection member 32 can improve the connection strength between the electrode terminal 33 and the connection member 32, and ensure stable overcurrent. The first welding part 34 does not exceed the abutting surface 322, and the risk that the abutting surfaces 322 of the connecting parts 32 of the two battery cells 10 cannot be attached to each other due to the welding of the electrode terminal 33 and the connecting part 32 to form the first welding part 34 is reduced.

In some embodiments, referring to fig. 6 and 7, fig. 7 is a partial view of the connecting member 32 shown in fig. 4. The connector 32 is provided with a through hole 321, and the electrode terminal 33 is inserted into the through hole 321. The through hole 321 penetrates the abutting surface 322 in the thickness direction Z of the end cap 31, the electrode terminal 33 has a first end surface 333, the first end surface 333 and the abutting surface 322 are located on the same side of the end cap 31, and the first end surface 333 is closer to the end cap 31 than the abutting surface 322.

The connecting member 32 also has an inner surface 323 facing the end cap 31 in the thickness direction Z of the end cap 31, and a through hole 321 penetrates the inner surface 323. The through hole 321 may be a constant diameter hole penetrating the inner surface 323 and the abutting surface 322, or may be a variable diameter hole, for example, a stepped hole, penetrating the inner surface 323 and the abutting surface 322.

The first end surface 333 is an end surface of the electrode terminal 33 located on the same side of the end cap 31 in the thickness direction Z as the abutting surface 322 of the connection member 32. In an embodiment where the electrode terminal 33 includes the terminal body 331 and the position-limiting portion 332, the terminal body 331 is inserted into the through hole 321, and the first end surface 333 is an end surface of the terminal body 331 that is away from the position-limiting portion 332 along the thickness direction Z of the end cap 31.

In this embodiment, the first end surface 333 is closer to the end cap 31 than the abutting surface 322, so that the electrode terminal 33 does not protrude out of the abutting surface 322 of the first end surface 333, the abutting surfaces 322 of the connecting members 32 of the two single batteries 10 can be attached in a large area, the connection quality is ensured, and the flow area between the two single batteries 10 is increased.

In some embodiments, with continued reference to fig. 6 and fig. 7, in a direction toward the end cover 31 (shown in fig. 4) along the connecting member 32, the through hole 321 includes a first hole segment 3211 and a second hole segment 3212, a hole diameter of the first hole segment 3211 is larger than a hole diameter of the second hole segment 3212, the first hole segment 3211 penetrates the abutting surface 322, and an inner circumferential surface of the first hole segment 3211 is connected with an inner circumferential surface of the second hole segment 3212 by a first connecting surface 3213. Wherein the first end surface 333 is flush with the first connection surface 3213; alternatively, the first end surface 333 is closer to the end cover 31 than the first connection surface 3213 along the thickness direction Z of the end cover 31.

The through hole 321 is a stepped hole, the aperture of the first hole segment 3211 is larger than that of the second hole segment 3212, and the first hole segment 3211 and the second hole segment 3212 may be coaxially disposed. An inner circumferential surface of the first hole segment 3211 is a hole wall surface of the first hole segment 3211, and an inner circumferential surface of the second hole segment 3212 is a hole wall surface of the second hole segment 3212. The first connection surface 3213 is a flat surface connecting an inner circumferential surface of the first hole section 3211 and an inner circumferential surface of the second hole section 3212. If the first end surface 333 is closer to the end cover 31 than the first connection surface 3213 along the thickness direction Z of the end cover 31, the distance between the first end surface 333 and the abutment surface 322 of the connection member 32 is greater than the depth of the first hole segment 3211, so that the first end surface 333 is farther from the abutment surface 322 of the connection member 32. As shown in fig. 7, if the first end surface 333 is flush with the first connection surface 3213, the first end surface 333 is located on the same plane as the first connection surface 3213, and the distance between the first end surface 333 and the abutment surface 322 of the connection member 32 is equal to the depth of the first hole segment 3211.

In an embodiment in which the electrode terminal 33 is welded to the connection member 32 and the first welding part 34 is formed, the first welding part 34 may extend along an edge of the first end surface 333, and the fixation of the electrode terminal 33 and the connection member 32 is achieved by the first welding part 34. The first hole segment 3211 is configured to receive a portion of the first welding portion protruding from the first connection surface 3213, such that the first welding portion 34 does not extend beyond the abutting surface 322.

Illustratively, the through hole 321 may further include a third hole segment 3214, and the hole diameters of the first, second, and

third hole segments

3211, 3212, and 3214 decrease in sequence in a direction in which the connecting member 32 points toward the end cover 31, the first and

third hole segments

3211 and 3214 respectively penetrate the abutting surface 322 and the inner surface 323 of the connecting member 32, and an inner circumferential surface of the third hole segment 3214 is connected to an inner circumferential surface of the second hole segment 3212 through a second connecting surface 3215. The terminal body 331 includes first section 3311 and second section 3312, along the thickness direction Z of end cover 31, first section 3311 and spacing portion 332 are connected respectively in the both ends of second section 3312, first section 3311 and the coaxial setting of second section 3312, the diameter of first section 3311 is greater than the diameter of second section 3312, the one end that first section 3311 deviates from second section 3312 forms first terminal surface 333, second section 3312 wears to locate in third hole section 3214, first section 3311 is located second hole section 3212 and supports and lean on in second connection face 3215.

In the present embodiment, the first end surface 333 and the abutting surface 322 are at least spaced apart from the first hole segment 3211, so that the electrode terminal 33 is less likely to be attached to the abutting surfaces 322 of the connecting members 32 of the two battery cells 10.

In some embodiments, with continued reference to fig. 6 and 7, the connecting member 32 has a thickness L along the thickness direction Z of the end cap 31 ₃ The distance between the first end surface 333 and the abutting surface 322 is L ₄ And satisfies the following conditions: l is more than or equal to 0.1 ₄ /L ₃ ≤0.2。

The thickness of the connecting member 32 is the distance between the abutting surface 322 of the connecting member 32 and the inner surface 323 in the thickness direction Z of the end cap 31.

L ₄ /L ₃ And may be any value between 0.1 and 0.2, such as 0.1, 0.12, 0.14, 0.16, 0.18, 0.2, etc.

In this embodiment, L is ₄ /L ₃ Are arranged within a reasonable range, on the one hand, such that the first end surface 333 is in contact with the abutment surface 322, the influence of the electrode terminal 33 on the abutment surfaces 322 of the connectors 32 of the two battery cells 10 is reduced, and the risk that the first welding portion 34 formed by welding the electrode terminal 33 and the connector 32 protrudes beyond the abutment surfaces 322 of the connectors 32 is reduced. On the other hand, the distance between the first end surface 333 and the abutting surface 322 is not made excessively large, so that the electrode terminal 33 is more partially located in the through hole 321, the flow area of the electrode terminal 33 and the connection member 32 is increased, and the connection stability of the electrode terminal 33 and the connection member 32 is improved.

In some embodiments, with continued reference to fig. 4, the end cap assembly 3 may further include a first insulating member 35, and the first insulating member 35 is at least partially located between the connecting member 32 and the end cap 31 along the thickness direction Z of the end cap 31 to insulate and isolate the connecting member 32 and the end cap 31.

The first insulating member 35 is made of an insulating material, such as plastic, rubber, etc. The first insulator 35 may be partially located between the connector 32 and the end cap 31, or may be completely located between the connector 32 and the end cap 31.

In the present embodiment, the first insulating member 35 functions to separate the connecting member 32 and the end cap 31, so as to insulate the connecting member 32 from the end cap 31, and reduce the risk of short circuit of the battery cell 10.

In some embodiments, the end cap assembly 3 may further include a second insulating member 36, the second insulating member 36 is disposed on a side of the end cap 31 facing away from the connecting member 32 along the thickness direction Z of the end cap 31, and the second insulating member 36 is used for insulating and isolating the end cap 31 and the electrode assembly 2 (shown in fig. 3).

The second insulating member 36 is a member that separates the end cap 31 and the electrode assembly 2 to achieve insulation of the electrode assembly 2 from the end cap 31. The second insulating member 36 is made of an insulating material, such as plastic rubber. In an embodiment where the electrode terminal 33 has the stopper portion 332, the second insulating member 36 may be partially located between the stopper portion 332 of the electrode terminal 33 and the end cap 31 to separate the stopper portion 332 and the end cap 31 to insulate and isolate the stopper portion 332 from the end cap 31. The second insulating member 36, the end cap 31, and the first insulating member 35 are restrained between the connecting member 32 and the restraining portion 332.

In some embodiments, as shown in fig. 4, the first insulating member 35 is a flat plate structure disposed between the connecting member 32 and the end cap 31.

The shape of the first insulating member 35 may be the same as that of the connection member 32. For example, the first insulating member 35 and the connecting member 32 are rectangular; as another example, the first insulating member 35 and the connecting member 32 are both circular. The edge of the first insulating member 35 may be flush with the edge of the connecting member 32, or the edge of the first insulating member 35 may be beyond the edge of the connecting member 32, so that the projection of the edge of the connecting member 32 in the thickness direction Z of the end cap 31 is completely located in the first insulating member 35, thereby achieving better insulation between the connecting member 32 and the end cap 31.

In this embodiment, the first insulating member 35 has a flat plate structure, and is simple in structure and easy to mold and manufacture.

In some embodiments, please refer to fig. 8 and 9, fig. 8 is a schematic structural diagram of an end cap assembly 3 according to still other embodiments of the present application; fig. 9 is a schematic structural view of the first insulating member 35 shown in fig. 8. The first insulating member 35 includes a body portion 351 and an edge portion 352. The body portion 351 is along the thickness direction Z of the end cap 31, and the body portion 351 is located between the connector 32 and the end cap 31. The edge portion 352 surrounds the edge of the body portion 351, and the edge portion 352 and the body portion 351 together define an accommodating space 353. Wherein the connecting member 32 is partially received in the receiving space 353.

The body portion 351 is a portion where the first insulating member 35 is disposed between the connecting member 32 and the end cap 31, and the body portion 351 may be a flat plate structure. The edge portion 352 is a portion of the first insulating member 35 surrounding the edge of the main body 351, the edge portion 352 is an annular structure extending along the edge of the main body 351, and the edge portion 352 covers the periphery of the connecting member 32. The ring shape referred to herein may be a circular ring, a rectangular ring, or the like. The edge portion 352 and the body portion 351 may be integrally formed.

The accommodation space 353 is formed inside the first insulating member 35 and is defined by the edge portion 352 and the body portion 351 together, and the accommodation space 353 forms an opening on a side of the edge portion 352 facing away from the body portion in the thickness direction Z of the end cover 31, through which the insulating member can enter the accommodation space 353.

In the present embodiment, the connection member 32 is partially accommodated in the accommodation space 353 such that the rim portion 352 is disposed around the connection member 32, and the rim portion 352 can increase the creepage distance between the connection member 32 and the end cap 31 and enhance the insulation performance between the connection member 32 and the end cap 31.

In some embodiments, referring to fig. 4 and 8, the thickness of the portion of the connecting member 32 protruding outside the first insulating member 35 along the thickness direction Z of the end cap 31 is H ₁ The first insulator 35 has a thickness H ₂ The thickness of the end cover 31 is H3, and the following conditions are satisfied: h is more than or equal to 1 ₁ /H ₂ Less than or equal to 5, and/or, less than or equal to 1, H ₁ /H ₃ ≤3。

H ₁ /H ₂ And may be any number between 1 and 5, such as 1, 2, 3, 4, 5, etc. H ₁ /H ₃ And can be any number between 1 and 3, such as 1, 2, 3, etc.

As shown in fig. 4, in the embodiment that the first insulating member 35 is of a flat plate structure, the connecting member 32 is located on the side of the first insulating member 35 away from the end cap 31, the connecting member 32 integrally protrudes out of the first insulating member 35, and the thickness of the portion of the connecting member 32 protruding out of the first insulating member 35 is the thickness of the connecting member 32, i.e., H ₁ ＝L ₃ . The thickness of the first insulating member 35 is the distance between the surface of the first insulating member 35 facing the connecting member 32 and the surface facing the end cap 31.

As shown in fig. 8, in the embodiment where the first insulating member 35 includes the body portion 351 and the edge portion 352, since the connecting member 32 is partially located in the accommodating space 353, the thickness of the portion of the connecting member 32 protruding outside the first insulating member 35 is the thickness of the portion of the connecting member 32 located outside the accommodating space 353. The thickness of the first insulating member 35 is the distance between the surface of the edge portion 352 facing away from the end cap 31 and the surface of the body portion 351 facing the end cap 31.

In this example, H is ₁ /H ₂ And/or H ₁ /H ₃ Are provided within a reasonable range so that the connecting member 32 has a large connectable area. Taking the welding of the connecting members 32 of two battery cells 10 as an example, such a structure can increase the welding area of the connecting members 32 to facilitate the welding.

In some embodiments, the interface 322 is planar. The structure of the connecting member 32 is simplified to reduce the difficulty in manufacturing the connecting member 32.

In some embodiments, the projection of the edge of the connecting piece 32 in the thickness direction Z of the end cap 31 is entirely located on the end cap 31.

The edge of the connecting piece 32 does not exceed the edge of the end cover 31, so that the connecting piece 32 is completely positioned in the area limited by the edge of the end cover 31, and the connecting piece 32 is not easy to interfere with the installation of the end cover 31, so that the end cover 31 is easier to be fixed on the shell 1. For example, when welding end cover 31 in casing 1, welding position is end cover 31's border position, and above-mentioned structure can reduce the influence of connecting piece 32 to end cover 31 and casing 1 when the welding, and the rosin joint phenomenon is difficult to appear, guarantees the fastness after end cover 31 and casing 1 weld.

In some embodiments, the projections of the connecting member 32 and the end cap 31 along the thickness direction Z of the end cap 31 are both rectangular, the length direction of the connecting member 32 coincides with the length direction of the end cap 31, and the width direction of the connecting member 32 coincides with the width direction of the end cap 31. The connecting piece 32 and the end cover 31 with the structure are simple in structure, the connecting piece 32 can be made large, and large-area overcurrent after the connecting pieces 32 of the two single batteries 10 are connected is realized.

The embodiment of the application provides a battery cell 10, which comprises a shell 1, an electrode assembly 2 and an end cover assembly 3 provided by any one of the above embodiments. The housing 1 has an opening. The electrode assembly 2 is accommodated in the case 1. The end cap 31 closes the opening, and the electrode terminal 33 is electrically connected to the electrode assembly 2.

The embodiment of the present application provides a battery 100, which includes a plurality of battery cells 10 provided in any one of the above embodiments.

In some embodiments, please refer to fig. 10, and fig. 10 is a schematic connection diagram of a first battery cell 10a and a second battery cell 10b according to an embodiment of the present disclosure. The plurality of battery cells 10 include a first battery cell 10a and a second battery cell 10b, and along the thickness direction Z of the end cover 31, the abutting surface 322 of the first battery cell 10a and the abutting surface 322 of the second battery cell 10b abut against and are connected to each other, so that the first battery cell 10a and the second battery cell 10b are electrically connected.

The connection member 32 of the first battery cell 10a and the connection member 32 of the second battery cell 10b may be connected in various ways, such as welding, adhesion, etc.

The number of cells 10 in the battery 100 may be two, three, five, or the like. The first battery cell 10a and the second battery cell 10b are two battery cells 10 in the battery 100. The first battery cell 10a and the second battery cell 10b may be connected in series, and the polarities of the two connection members 32 connected to each other in both the first battery cell 10a and the second battery cell 10b are opposite.

By connecting the connection member 32 of the first battery cell 10a and the connection member 32 of the second battery cell 10b together, stable overcurrent of the connection member 32 of the first battery cell 10a and the connection member 32 of the second battery cell 10b can be achieved.

In some embodiments, as shown in fig. 11, fig. 11 is a partial enlarged view at B in fig. 10. The connection member 32 of the first battery cell 10a is welded to the connection member 32 of the second battery cell 10b and a second welding part 30 is formed at the welding position, the second welding part 30 extending along the edge of the butting face 322.

The second welding part 30 is a portion where the connection member 32 of the first battery cell 10a and the connection member 32 of the second battery cell 10b are welded to form a weld, and the two connection members 32 are fixed by the second welding part 30. The second weld 30 is wrapped around the connection 32.

Since the ratio of the circumference of the abutting surface 322 of the connection member 32 to the circumference of the outer surface 310 of the end cap 31 is set within a reasonable range, the circumference of the abutting surface 322 of the connection member 32 is longer, so that the circumference of the second welding part 30 is increased, the bonding strength of the connection member 32 of the first battery cell 10a and the connection member 32 of the second battery cell 10b is enhanced, and the stability of the electrical connection of the first battery cell 10a and the second battery cell 10b is improved.

In the embodiment where the end cap assembly 3 includes the first insulating member 35, the sum of the thickness of the portion of the connecting member 32 of the first battery cell 10a protruding outside the first insulating member 35 and the thickness of the portion of the connecting member 32 of the second battery cell 10b protruding outside the first insulating member 35 in the thickness direction Z of the end cap 31 is H4, and the width of the second welding portion 30 is H5, satisfying: h is more than or equal to 0.25 ₅ /H ₄ ≤1。

H ₅ /H ₄ And can be any number between 0.25 and 1, such as 0.25, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, and the like.

Will H ₅ /H ₄ The setting is in reasonable within range, can guarantee that the connecting piece 32 of first battery monomer 10a has great welding to melt wide with the connecting piece 32 welding back of second battery monomer 10b, has further increased the joint strength of the connecting piece 32 of first battery monomer 10a and the connecting piece 32 of second battery monomer 10 b.

The embodiment of the present application further provides an electric device, including the battery 100 provided in any one of the above embodiments.

In addition, as shown in fig. 4 and 5, an end cap assembly 3 is further provided in an embodiment of the present application, and includes an end cap 31, a connecting member 32, an electrode terminal 33, a first insulating member 35, and a second insulating member 36, where the connecting member 32, the end cap 31, the first insulating member 35, and the second insulating member 36 are sequentially stacked. The end cap 31 is used to close the opening of the case 1 of the battery cell 10, and the end cap 31 is provided with a terminal drawing hole 311. The electrode terminal 33 includes a terminal body 331 and a limiting portion 332, the terminal body 331 penetrates through the terminal lead-out hole 311, the connecting piece 32 is connected to the terminal body 331, the limiting portion 332 is connected to one end of the terminal body 331, which is far away from the connecting piece 32, and the limiting portion 332 is matched with the connecting piece 32 to limit the first insulating piece 35, the end cover 31 and the second insulating piece 36. The projections of the end cap 31 and the connecting piece 32 along the thickness direction Z of the end cap 31 are both rectangular, the length direction of the end cap 31 is consistent with the length direction of the connecting piece 32, and the width direction of the end cap 31 is consistent with the width direction of the connecting piece 32. The edge of the connecting piece 32 is located entirely on the end cap 31 in a projection in the thickness direction Z of the end cap 31. The perimeter L of the outer surface 310 of the end cap 31 along the thickness direction Z of the end cap 31 ₁ The connecting element 32 has an abutment surface 322 facing away from the end cap 31, the abutment surface 322 having a circumference L ₂ The butt-joint surface 322 is used for electrically connecting with an external component, and satisfies the following conditions: l is a radical of an alcohol ₂ /L ₁ ≥0.25。

It should be noted that, in the present application, the embodiments and features of the embodiments may be combined with each other without conflict.

The above embodiments are only used to illustrate the technical solutions of the present application, and are not used to limit the present application, and various modifications and changes may be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An end cap assembly, comprising:

the end cover is used for sealing an opening of a shell of the battery cell and is provided with a terminal leading-out hole;

the connecting piece is arranged on one side, deviating from the shell, of the end cover in the thickness direction;

the electrode terminal penetrates through the terminal leading-out hole and is connected to the connecting piece, and the electrode terminal is used for connecting an electrode assembly of the battery cell so as to realize the electrical connection of the connecting piece and the electrode assembly;

wherein, along the thickness direction of the end cover, the circumference of the outer surface of the end cover is L ₁ The connecting piece is provided with an abutting surface deviating from the end cover, and the circumference of the abutting surface is L ₂ The butt joint surface is used for being electrically connected with an external component, and meets the following requirements: l is a radical of an alcohol ₂ /L ₁ ≥0.25。

2. The end cap assembly of claim 1, wherein 0.5 ≦ L ₂ /L ₁ ≤1。

3. The end cap assembly of claim 2, wherein 0.5 ≦ L ₂ /L ₁ ≤0.7。

4. The end cap assembly according to claim 1, wherein the electrode terminal is welded to the connector, and a first welding portion is formed at a welding position of the electrode terminal to the connector, the first welding portion not exceeding the abutting surface.

5. The end cap assembly of claim 1, wherein the connector is provided with a through hole through which the electrode terminal is disposed;

along the thickness direction of end cover, the through-hole runs through the butt joint face, electrode terminal has first terminal surface, first terminal surface with the butt joint face is located same one side of end cover, first terminal surface than the butt joint face is closer to the end cover.

6. An end cap assembly according to claim 5, wherein the through hole comprises a first hole section and a second hole section arranged in sequence along a direction in which the connecting member points to the end cap, the first hole section has a larger hole diameter than the second hole section, the first hole section penetrates through the abutting surface, and an inner circumferential surface of the first hole section is connected with an inner circumferential surface of the second hole section through a first connecting surface;

wherein the first end surface is flush with the first connection surface; or, along the thickness direction of the end cover, the first end face is closer to the end cover than the first connection face.

7. An end cap assembly according to claim 5, wherein the connector has a thickness L in the direction of the thickness of the end cap ₃ The distance between the first end surface and the butt joint surface is L ₄ And satisfies the following conditions: l is more than or equal to 0.1 ₄ /L ₃ ≤0.2。

8. The end cap assembly of any of claims 1-7, further comprising:

the first insulating piece is at least partially positioned between the connecting piece and the end cover along the thickness direction of the end cover so as to insulate and separate the connecting piece and the end cover.

9. The end cap assembly of claim 8, wherein the first insulator member is a flat plate structure disposed between the connector member and the end cap.

10. The end cap assembly of claim 8, wherein the first insulator comprises:

a body portion located between the connector and the end cap in a thickness direction of the end cap;

the edge part is arranged around the edge of the body part, and the edge part and the body part jointly define an accommodating space;

wherein the connector portion is accommodated in the accommodating space.

11. An end cap assembly according to claim 8, wherein the thickness of the portion of the connecting member protruding outside the first insulating member in the thickness direction of the end cap is H ₁ The thickness of the first insulating part is H ₂ The thickness of the end cover is H ₃ And satisfies the following conditions: h is more than or equal to 1 ₁ /H ₂ Less than or equal to 5, and/or, less than or equal to 1, H ₁ /H ₃ ≤3。

12. An end cap assembly according to any one of claims 1 to 7 wherein the abutment surface is planar.

13. An end cap assembly according to any one of claims 1 to 7, wherein the projection of the edge of the connector in the direction of the thickness of the end cap is located entirely on the end cap.

14. An end cap assembly according to any one of claims 1 to 7, wherein the projections of the connector and the end cap in the thickness direction of the end cap are both rectangular, the length direction of the connector coincides with the length direction of the end cap, and the width direction of the connector coincides with the width direction of the end cap.

15. A battery cell, comprising:

a housing having an opening;

an electrode assembly accommodated in the case;

the end cap assembly of any one of claims 1-14, the end cap closing the opening, the electrode terminal being electrically connected to the electrode assembly.

16. A battery comprising a plurality of cells according to claim 15.

17. The battery of claim 16, wherein the plurality of battery cells comprises a first battery cell and a second battery cell, and the abutting surface of the first battery cell and the abutting surface of the second battery cell abut against and are connected to each other along a thickness direction of the end cap to electrically connect the first battery cell and the second battery cell.

18. The battery of claim 17, wherein the connection member of the first battery cell is welded to the connection member of the second battery cell and is formed with a second weld at the welding location, the second weld extending along an edge of the mating face.

19. The cell defined in claim 18, wherein the end cap assembly further comprises a first insulator at least partially between the connector and the end cap in a thickness direction of the end cap to insulate and isolate the connector and the end cap;

the sum of the thickness of the part of the connecting piece of the first battery cell protruding out of the first insulating piece and the thickness of the part of the connecting piece of the second battery cell protruding out of the first insulating piece along the thickness direction of the end cover is H ₄ The width of the second welding part is H ₅ And satisfies the following conditions: h is more than or equal to 0.25 ₅ /H ₄ ≤1。

20. An electrical device comprising a battery as claimed in any one of claims 16 to 19.