CN218887348U

CN218887348U - End cover, battery monomer, battery and consumer

Info

Publication number: CN218887348U
Application number: CN202222745944.4U
Authority: CN
Inventors: 陈圣旺; 郭志君; 王鹏
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2022-10-18
Filing date: 2022-10-18
Publication date: 2023-04-18
Anticipated expiration: 2032-10-18

Abstract

The embodiment of the application provides an end cover, a single battery, a battery and electric equipment, and belongs to the technical field of batteries. The end cover is used for closing the opening of the shell of the battery cell and comprises an abutting part and a first convex part. The abutting part is provided with an abutting surface which is used for abutting against one end of the shell setting opening. The first convex part is connected with the abutting part and protrudes out of the abutting surface, and the first convex part is used for extending into the shell. The abutting surface is provided with a groove, the groove is arranged around the first convex portion, and the peripheral surface of the first convex portion is connected with the groove wall surface of the abutting surface through the groove. The risk that the end cover interferes with the shell is caused because the round angle is formed between the outer peripheral surface of the first convex part and the connecting position of the abutting surface, so that the abutting surface can abut against one end of the shell with an opening, and the firmness of the end cover connected to the shell is improved.

Description

End cover, battery monomer, battery and consumer

Technical Field

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

Background

Batteries are widely used in electronic devices such as mobile phones, notebook computers, battery cars, electric automobiles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, electric tools, and the like.

In the battery cell, an end cap is connected to the case and closes an opening of the case, and the end cap and the case together form a space for accommodating the electrode assembly, the electrolyte, and other components. In order to ensure the service life of the battery monomer, the firmness of the end cover after being connected with the shell needs to be ensured. Therefore, how to improve the firmness of the end cap after being connected with the shell is an urgent technical problem to be solved.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides an end cover, single battery, battery and consumer, can improve the fastness after end cover and casing are connected.

In a first aspect, an embodiment of the present application provides an end cap for closing an opening of a housing of a battery cell, the end cap including an abutting portion and a first protrusion; the abutting part is provided with an abutting surface which is used for abutting against one end of the shell setting opening; the first convex part is connected with the abutting part and protrudes out of the abutting surface, and the first convex part is used for extending into the shell; wherein, the face of leaning on is provided with the recess, and the recess encircles first convex part setting, and the outer peripheral face of first convex part links to each other with the groove wall face that the face of leaning on passes through the recess.

Among the above-mentioned technical scheme, leaning on to be provided with the recess on the face, the outer peripheral face of first convex part links to each other with the groove wall face that leans on the face to pass through the recess, has reduced because of the outer peripheral face of first convex part and the hookup location who leans on the face forms the fillet, and causes end cover and casing to take place the risk of interfering for leaning on the face can lean on and set up open-ended one end in the casing, improve the fastness of end cover connection behind the casing.

In some embodiments, the groove wall surface includes a first groove side surface connected to the abutting surface, the first groove side surface being disposed at an obtuse angle to the abutting surface. The crowded material volume when having increased the stamping forming recess, the extrusion force that first groove side received when stamping forming can improve to support to the face and support to hang down straightness between the lateral surface of portion, and can make to support to the face more level and smooth, and the increase supports to support the area of contact of face and casing, is convenient for support to portion and casing welding.

In some embodiments, the pocket wall surface comprises a second pocket side surface and a first fillet surface; the side surface of the second groove is connected with the peripheral surface; the first fillet connects the first slot side and the second slot side. First fillet face can realize first groove side and second groove side rounding off, and difficult appearance stress concentration improves the intensity of end cover in the connection region of first groove side and second groove side.

In some embodiments, the groove side comprises a second groove side, a groove bottom, and a first fillet; the side surface of the second groove is connected with the peripheral surface; the bottom surface of the groove is connected with the side surface of the first groove; the first fillet connects the second groove flank and the groove bottom. The first fillet face can realize the circular arc transition of the side face of the second groove and the bottom face of the groove, stress concentration is not easy to occur, and the strength of the end cover in the connecting area of the side face of the second groove and the bottom face of the groove is improved. In addition, because the first groove side face connected with the groove bottom face and the abutting face are arranged at an obtuse angle, the groove of the structure has larger groove width, the width of the abutting face is reduced, and the abutting face can be in good contact with the shell.

In some embodiments, the groove bottom face is parallel to the abutment face.

In some embodiments, the radius of the first fillet surface is R, satisfying: r is more than or equal to 0.2mm. Under the condition of reducing the risk of stress concentration of the end cover, the forming difficulty of the first fillet surface is reduced.

In some embodiments, the distance from the position where the second groove side surface is connected with the first fillet surface to the abutting surface along the direction perpendicular to the abutting surface is H, and the following conditions are satisfied: h is more than or equal to 0.05mm. The risk that the first fillet surface abuts against one end of the shell where the opening is arranged is reduced.

In some embodiments, the second groove side surface is located within the same cylinder as the outer peripheral surface. The structure of the groove is simpler, and the forming difficulty of the groove is reduced.

In some embodiments, the outer peripheral surface extends in a direction perpendicular to the abutment surface. When the outer peripheral surface of the first convex part and the inner peripheral surface of the shell form positioning fit, the contact area between the abutting surface and the shell can be increased.

In some embodiments, the first protrusion has an end surface facing away from the abutment surface, the end surface being connected to the outer peripheral surface by a second rounded surface. The second fillet surface is arranged, so that on one hand, the connection position of the end surface of the first convex part and the peripheral surface is prevented from forming a sharp corner; on the other hand, when the end cover is assembled with the shell, the first convex part can enter the shell conveniently.

In some embodiments, the end cap further includes a body portion, and the first protrusion is disposed around an outer side of the body portion, and protrudes from the body portion in a direction facing an inside of the housing in a thickness direction of the body portion. The first convex part can reinforce the body part and improve the deformation resistance of the body part.

In some embodiments, the body portion has a first outer surface facing away from the housing in a thickness direction of the body portion, the first outer surface being a surface of the end cap furthest from the housing, the abutment portion has a second outer surface disposed opposite the abutment face, the first outer surface being further from the abutment face than the second outer surface. First surface can be as the free holding surface of battery, because first surface is farther away from than the second surface and is in leaning on the face, even lean on the portion of leaning on and the welding of casing formation protrusion in the welding slag of holding surface, the welding slag is difficult for protrusion in first surface also, has reduced the influence of welding slag to first surface for first surface can contact with the outside part large tracts of land when battery monomer places in the outside part, has improved the free stability of battery.

In some embodiments, the body portion has a weak portion configured to be broken when the battery cell is decompressed to discharge a pressure inside the battery cell. The end cover has the pressure relief function due to the arrangement of the weak part, and can be used as a pressure relief component of a single battery, so that the safety of the single battery is improved.

In some embodiments, the body portion is provided with a score groove, and the body portion forms a weak portion at a position corresponding to the score groove. The body part is correspondingly formed with the weak part in a way of arranging the mark engraving groove, so that the thickness of the weak part is thinner than that of other areas, the weak part is easier to damage, and the forming way of the weak part is simple.

In some embodiments, the body portion has a relief area bounded by the score groove, the relief area being provided with a reinforcement rib. When in pressure relief, the pressure relief area can be opened by taking the notch groove as a boundary, and the pressure relief area is larger. The pressure relief area is provided with the strengthening rib, and the strengthening rib plays the reinforcing action to the pressure relief area, improves the anti deformability of pressure relief area, and when battery monomer internal pressure changed, the pressure relief area was difficult for taking place to warp, reduced the risk that the pressure relief area was opened in battery monomer normal use.

In some embodiments, the stiffener includes a first stiffener and a second stiffener, the first stiffener and the second stiffener both having a circular arc shape, and the opening of the first stiffener is disposed opposite to the opening of the second stiffener. The reinforcing rib has the advantages that the radiation range of the reinforcing rib is larger, the reinforcing range of the pressure release area can be enlarged, the arc-shaped first reinforcing part and the arc-shaped second reinforcing part have better deformation resistance, the pressure release area can be better reinforced, and the deformation resistance and the fatigue resistance of the pressure release area are further improved.

In some embodiments, the scored groove is a groove extending along the closed track. When the single battery is decompressed, the part of the body part in the area limited by the notch groove can be opened in a mode of separating from the outside of the single battery, so that the single battery has a large decompression area, and the decompression efficiency is improved.

In some embodiments, the scored groove is a circular groove. The circular groove has simple structure and convenient forming.

In some embodiments, the body portion has a first outer surface facing away from the interior of the housing in a thickness direction of the body portion, the first outer surface being a surface of the end cap furthest from the housing, the first outer surface being provided with a recess, a projection of a bottom surface of the recess covering the weakened portion. The arrangement of the concave part enables a certain distance to exist between the weak part and the first outer surface, when the first outer surface is in contact with an external component, the influence of the external component on the weak part can be reduced, the weak part can be smoothly damaged when the internal pressure of the single battery reaches normal detonation pressure, and the risk that the detonation pressure of the single battery is increased due to the blocking effect of the external component on the weak part is reduced.

In some embodiments, the body portion has a first inner surface opposite to the first outer surface along a thickness direction of the body portion, and the first inner surface is provided with a second convex portion at a position corresponding to the concave portion. The provision of the second convex portion can increase the strength of the region where the main body portion is provided with the concave portion.

In a second aspect, an embodiment of the present application provides a battery cell, including a housing and the end cap provided in any one of the embodiments of the first aspect; the shell is provided with an opening; the first convex part extends into the shell, the abutting surface abuts against one end, provided with an opening, of the shell, and the end cover closes the opening.

In some embodiments, the abutment is welded to the housing. The mode of realizing the fixed connection of the end cover and the shell is simple, and the firmness and the sealing property of the end cover and the shell after connection can be ensured.

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

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 illustration of a vehicle according to some embodiments of the present application;

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

fig. 3 is an exploded view of a battery cell provided in some embodiments of the present application;

fig. 4 is a schematic structural view of the battery cell shown in fig. 3;

FIG. 5 is a schematic structural view of the end cap shown in FIG. 4;

FIG. 6 is an enlarged fragmentary view of the end cap shown in FIG. 5 at A;

FIG. 7 is an enlarged partial view of the end cap of FIG. 6 at B;

FIG. 8 is an enlarged, fragmentary view of an end cap provided in accordance with other embodiments of the present application;

fig. 9 is a schematic structural diagram of a battery cell according to still other embodiments of the present application;

FIG. 10 is a schematic structural view of the end cap of FIG. 9;

FIG. 11 is an enlarged fragmentary view of the end cap shown in FIG. 10 at C;

FIG. 12 is an isometric view of the end cap shown in FIG. 10;

fig. 13 is a top view of the end cap shown in fig. 12.

Icon: 1-a shell; 2-an electrode assembly; 21-a first tab; 22-a second tab; 3-end cover; 31-an abutment; 311-a rest surface; 312-an outer side; 313-a second outer surface; 32-a first projection; 321-outer peripheral surface; 322-end face; 323-second fillet face; 33-a groove; 331-a first slot side; 332-a second slot side; 333-first fillet surface; 334-groove bottom; 34-a body portion; 341-first outer surface; 342-a weakening; 343-notching grooves; 344-pressure relief zone; 345-reinforcing ribs; 3451-first stiffener; 3452-second stiffener; 346-a recess; 347-a first inner surface; 348-a second projection; 4-an electrode terminal; 5-a current collecting member; 10-a battery cell; 20-a box body; 201-a first portion; 202-a second portion; 100-a battery; 200-a controller; 300-a motor; 1000-vehicle.

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 herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "including" and "having," and any variations thereof, in the description and claims of this application and the description of the above figures are intended to cover non-exclusive inclusions. 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.

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

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

In 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 cylindrical battery monomer, the square battery monomer and the soft package battery monomer are also 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 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, wherein 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 lug. 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 cell, an end cap is connected to the case and closes an opening of the case, and the end cap and the case together form a space for accommodating the electrode assembly, the electrolyte, and other components. The inventor notices that after the end cover is connected with the shell, the phenomenon of looseness is easy to occur, and the firmness of the end cover after being connected with the shell is poor.

For a general end cover, the end cover has an abutting portion and a first convex portion, when the end cover is installed, the first convex portion extends into the housing, and an abutting surface of the abutting portion abuts against one end of the housing, where the opening is provided. The inventor notices that the abutting surface of the abutting portion and the outer peripheral surface of the first convex portion generally pass through a fillet, when the end cover is installed, the fillet can interfere with the shell, the abutting surface cannot abut against one end, provided with an opening, of the shell, and the firmness of the end cover after being connected with the shell is poor.

In view of this, embodiments of the present application provide an end cap, in which a groove surrounding a first protrusion is provided on an abutting surface of an abutting portion, and an outer circumferential surface of the first protrusion is connected to the abutting surface through a groove wall surface of the groove.

In such end cover, support to be provided with the recess on the face, the outer peripheral face of first convex part with support to link to each other through the groove wall face of recess by the face, reduced because of the outer peripheral face of first convex part with support to support the hookup location formation fillet of face, and cause the risk that end cover and casing take place to interfere for support to set up open-ended one end in the casing, improve the fastness of end cover connection behind the casing.

The end cover described in the embodiment of the application is suitable for a battery cell, a battery and electric equipment 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, spacecraft, and the like; 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 particularly limit the above electric devices.

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

The end cap 3 described in the embodiment of the present application is suitable for the battery cell 10, the battery 100, and the electric device using the battery 100.

The powered device may be a vehicle 1000, a cell phone, a portable device, a laptop, a boat, a spacecraft, a motorized toy, a power tool, and the like. The vehicle 1000 may be a fuel automobile, a gas automobile or a new energy automobile, and the new energy automobile may be a pure electric automobile, a hybrid electric automobile or a range-extended automobile, etc.; 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.

For convenience of description, the following embodiments will be described by taking an electric device as the vehicle 1000.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a vehicle 1000 according to some embodiments of the present disclosure. The 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, and 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 power requirements for operation during starting, navigation, and traveling of the vehicle 1000.

In some embodiments of the present application, the battery 100 may not only serve as an operating power source of the vehicle 1000, but also serve 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 an accommodating 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 cover each other to define a receiving space for receiving the battery cell 10. The first portion 201 and the second portion 202 may be in various 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 also be a hollow structure with one side open, and the open side of the second portion 202 is covered on the open side of the first portion 201, so as to form the box body 20 with 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 receiving 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, one or more battery cells 10 may be provided. If there are a plurality of battery cells 10, the plurality of battery cells 10 may be connected in series, 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 case 20. Or all the single batteries 10 can 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 20.

Referring to fig. 3 and 4, fig. 3 is an exploded view of a battery cell 10 according to some embodiments of the present disclosure; fig. 4 is a schematic structural view of the battery cell 10 shown in fig. 3. The battery cell 10 may include a case 1, an electrode assembly 2, and an end cap 3.

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

The electrode assembly 2 in the case 1 may be one or more.

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 in which the positive electrode sheet, the separator, and the negative electrode sheet are wound, or a lamination type structure in which the positive electrode sheet, the separator, and the negative electrode sheet are stacked. The electrode assembly 2 has a first tab 21 and a second tab 22, one of the first tab 21 and the second tab 22 is a positive tab, and the other is a negative tab, and the positive tab may be a portion of the positive tab not coated with a positive active material layer, and the negative tab may be a portion of the negative tab not coated with a negative active material layer.

The end cap 3 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 3 defines a space for accommodating the electrode assembly 2, the electrolyte, and other components together with the case 1. The shape of the end cap 3 can be adapted to the shape of the housing 1, for example, the housing 1 has a rectangular parallelepiped structure, the end cap 3 has a rectangular cover plate adapted to the housing 1, and for example, as shown in fig. 3 and 4, the housing 1 has a cylindrical structure, and the end cap 3 has a circular end cap adapted to the housing 1. The end cap 3 may be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc., and the material of the end cap 3 may be the same as or different from that of the housing 1.

In the battery cell 10, one or two end caps 3 may be provided. For example, the housing 1 is a hollow structure with two opposite ends forming an opening, two end covers 3 may be correspondingly disposed, and the two end covers 3 respectively close the two openings of the housing 1; for another example, as shown in fig. 3 and 4, the housing 1 is a hollow structure with one end open, one end cap 3 may be correspondingly disposed, and one end cap 3 closes one opening of the housing 1.

The battery cell 10 may further include an electrode terminal 4, and the electrode terminal 4 is used to be electrically connected to the electrode assembly 2 to output electric power of the battery cell 10. The electrode terminal 4 may be attached to the case 1 or may be attached to the end cap 3. As shown in fig. 3 and 4, taking the case 1 as an example of a hollow structure with one open end, the electrode terminal 4 is disposed on a wall portion of the case 1 facing the end cap 3, the electrode terminal 4 is electrically connected to the first tab 21 of the electrode assembly 2, and the end cap 3 is electrically connected to the second tab 22 of the electrode assembly 2.

Of course, the electrode terminal 4 and the first tab 21 may be directly or indirectly connected, and the end cap 3 and the second tab 22 may be directly or indirectly connected. Illustratively, the electrode terminal 4 is indirectly connected to the first tab 21 via one current collecting member 5, and the end cap 3 is indirectly connected to the second tab 22 via another current collecting member 5. The current collecting member 5 is a metal conductor, such as copper, iron, aluminum, steel, aluminum alloy, or the like, and the current collecting member 5 may have a disk shape.

Referring to fig. 5 and 6, fig. 5 is a schematic structural view of the end cap 3 shown in fig. 4; fig. 6 is a partially enlarged view of the end cap 3 shown in fig. 5 at a. The embodiment of the application provides an end cover 3 for closing an opening of a shell 1 of a battery single body 10, wherein the end cover 3 comprises an abutting part 31 and a first convex part 32; the abutting portion 31 has an abutting surface 311, and the abutting surface 311 is used for abutting against one end of the housing 1 provided with the opening; the first convex part 32 is connected to the abutting part 31 and protrudes from the abutting surface 311, and the first convex part 32 is used for extending into the housing 1; the abutting surface 311 is provided with a groove 33, the groove 33 is arranged around the first protrusion 32, and the outer peripheral surface 321 of the first protrusion 32 is connected with the abutting surface 311 through the groove wall surface of the groove 33.

The abutting portion 31 is a portion of the end cap 3 for abutting against the housing 1, the abutting portion 31 surrounds the outer side of the first protrusion 32, and the abutting portion 31 may be an edge portion of the end cap 3.

The first protrusion 32 is a portion of the end cap 3 extending into the housing 1, and the first protrusion 32 may form a positioning fit with the housing 1, that is, an outer circumferential surface 321 of the first protrusion 32 contacts an inner circumferential surface of the housing 1. Taking the case where the end cap 3 is a circular end cap as an example, a part of the area of the end cap 3 inside the abutting portion 31 may be the first protrusion 32, or all of the area of the end cap 3 inside the abutting portion 31 may be the first protrusion 32 in the radial direction of the end cap 3. Taking as an example that all of the regions of the end cap 3 located inside the abutting portion 31 are first protrusions 32, the first protrusions 32 are circular regions located at the middle position of the end cap 3, and the abutting portion 31 is an annular region located at the edge position of the end cap 3.

The groove 33 surrounds the outer side of the first protrusion 32, and the abutting surface 311 surrounds the outer side of the groove 33. The recess 33 may be formed by stamping. The recess 33 may be an annular groove surrounding the outer side of the first protrusion 32, and the groove wall surface of the recess 33 defines an inner space of the recess 33. The abutting surface 311 is an inner surface of the abutting portion 31 and is used for abutting against one end of the housing 1 where the opening is arranged, and the abutting surface 311 may be an annular plane surrounding the outer side of the groove 33.

For a general end cap 3, the abutting surface 311 of the abutting portion 31 and the outer circumferential surface 321 of the first protrusion 32 are in rounded transition, and the rounded corner interferes with the housing 1, so that the abutting surface 311 cannot abut against the end of the housing 1 with the opening, and the firmness of the end cap 3 connected with the housing 1 is poor. For example, the end cap 3 is welded to the housing 1 and then has poor connection strength, so that the end cap 3 is easily separated from the housing 1.

In the embodiment of the present application, since the groove 33 is disposed on the abutting surface 311, the outer peripheral surface 321 of the first convex portion 32 is connected to the abutting surface 311 through the groove wall surface of the groove 33, a fillet between the outer peripheral surface 321 of the first convex portion 32 and the abutting surface 311 is eliminated, a risk of interference between the end cover 3 and the housing 1 due to a fillet formed at a connection position of the outer peripheral surface 321 of the first convex portion 32 and the abutting surface 311 is reduced, so that the abutting surface 311 can abut against one end of the housing 1 where the opening is disposed, and firmness of the end cover 3 connected to the housing 1 is improved.

In addition, in a general end cap 3, after the fillet interferes with the case 1, a gap is formed between the abutting surface 311 of the abutting portion 31 and one end of the case 1 where the opening is provided, and when the abutting portion 31 is welded to the end cap 3, welding laser is emitted into the case 1, which damages internal components of the battery cell 10 and affects the service life of the battery cell 10. In the embodiment of the present application, the groove 33 is provided to enable the abutting surface 311 to abut against the opening of the housing 1, so as to reduce the risk of the welding laser entering the interior of the housing 1.

In some embodiments, referring to fig. 7, fig. 7 is a partial enlarged view of the end cap 3 shown in fig. 6 at B. The groove wall surface comprises a first groove side surface 331, the first groove side surface 331 is connected with the abutting surface 311, and the first groove side surface 331 and the abutting surface 311 are arranged at an obtuse angle.

The first groove side 331 is a groove side where the concave groove 33 is connected to the abutting surface 311, the first groove side 331 is disposed obliquely, and the first groove side 331 surrounds the outer side of the first protrusion 32. Taking the concave groove 33 as an annular groove, the first groove side surface 331 may be a conical surface surrounding the outer side of the first convex portion 32.

The first slot side 331 makes an angle a with the abutment surface 311, 90 < a < 180. a may be 100 °, 110 °, 120 °, 130 °,135 °, 140 °, 150 °, 160 °, 170 °, etc. Illustratively, 135 < a < 180.

In this embodiment, the first slot side surface 331 and the abutting surface 311 are arranged at an obtuse angle, so as to reduce the risk of a sharp corner at the connection position of the first slot side surface 331 and the abutting surface 311, so that the connection position is not too sharp.

In addition, the end cover 3 may be formed by stamping from a base material, and after the abutting portion 31 is stamped and formed, the abutting portion 31 may deform along with the release of stress, so that the abutting surface 311 of the abutting portion 31 is not flat and the perpendicularity between the abutting surface 311 and the outer side surface 312 of the abutting portion 31 is not required.

In the embodiment, since the first groove side surface 331 and the abutting surface 311 are arranged at an obtuse angle, the first groove side surface 331 is in an inclined state, so that the extrusion amount during the punch forming of the groove 33 is increased, the extrusion force applied to the first groove side surface 331 during the forming can improve the verticality between the abutting surface 311 and the outer side surface 312 (shown in fig. 6) of the abutting portion 31, and can make the abutting surface 311 smoother, increase the contact area between the abutting surface 311 and the housing 1, and facilitate the welding of the abutting portion 31 and the housing 1. When 135 ° < a < 180 °, the abutting surface 311 can be made more flat, further improving the perpendicularity between the abutting surface 311 and the outer side surface 312 of the abutting portion 31.

It should be noted that, in other embodiments, the first groove side 331 and the abutting surface 311 may be disposed at other angles, for example, a right angle or an acute angle.

In some embodiments, with continued reference to fig. 7, the groove sides include a second groove side 332, a first radiused surface 333, and a groove bottom 334, the second groove side 332 being connected to the peripheral surface 321, the groove bottom 334 being connected to the first groove side 331, and the first radiused surface 333 connecting the second groove side 332 and the groove bottom 334.

The second slot side 332 is the slot side where the recess 33 connects to the second slot side 332. The second groove side surface 332 and the outer peripheral surface 321 may be coplanar, e.g., both located in the same cylinder; the second groove side surface 332 and the outer peripheral surface 321 may be arranged at an obtuse angle, for example, the outer peripheral surface 321 is a cylindrical surface, and the second groove side surface 332 is a conical surface. The boundary position between the second groove side surface 332 and the outer peripheral surface 321 is located in the plane of the abutting surface 311. The position indicated by the dotted line in fig. 7 is the boundary position between the second groove side surface 332 and the outer peripheral surface 321.

The slot bottom 334 may be planar, and the slot bottom 334 may be disposed at an obtuse angle to the first slot side 331. The angle between the slot bottom surface 334 and the first slot side surface 331 may be equal to or different from the angle between the abutting surface 311 and the first slot side surface 331, if equal, the slot bottom surface 334 is parallel to the abutting surface 311, if unequal, the slot bottom surface 334 is not parallel to the abutting surface 311. The first rounded surface 333 is a chamfered surface connecting the second groove side surface 332 and the groove bottom surface 334, and both the second groove side surface 332 and the groove bottom surface 334 may be tangent to the first rounded surface 333.

The first rounded surface 333 enables arc transition between the second groove side surface 332 and the groove bottom surface 334, so that stress concentration is not likely to occur, and the strength of the end cover 3 in the connection region between the second groove side surface 332 and the groove bottom surface 334 is improved.

In addition, if the abutting surface 311 is too wide, the area of the abutting surface 311 is large, and it is difficult to ensure the flatness of the abutting surface 311, which makes the forming difficult. In the embodiment, since the first groove side 331 connected to the groove bottom 334 is arranged at an obtuse angle with the abutting surface 311, the groove 33 with this structure has a larger groove width, reduces the width of the abutting surface 311, and ensures the flatness of the abutting surface 311 more easily, so that the abutting surface 311 can be in good contact with the housing 1.

In some embodiments, with continued reference to fig. 7, the slot bottom surface 334 is parallel to the abutment surface 311. Illustratively, the groove bottom surface 334 is an annular flat surface that surrounds the outside of the first protrusion 32.

In other embodiments, referring to fig. 8, fig. 8 is a partially enlarged view of the end cap 3 according to other embodiments of the present application. The groove wall surface includes a second groove side surface 332 and a first rounded surface 333, the second groove side surface 332 being connected to the outer circumferential surface 321, and the first rounded surface 333 connecting the first groove side surface 331 and the second groove side surface 332.

The first and second slot sides 331, 332 may each be tangent to the first fillet surface 333.

The first rounded surface 333 enables smooth transition between the first groove side surface 331 and the second groove side surface 332, prevents stress concentration from occurring, and improves the strength of the end cap 3 at the connection region between the first groove side surface 331 and the second groove side surface 332.

In some embodiments, with continued reference to fig. 7 and 8, the radius of the first fillet surface 333 is R, which satisfies: r is more than or equal to 0.2mm.

R may be 0.2mm, 0.3mm, 0.4mm, 0.5mm, etc.

If R is smaller than 0.2mm, the molding difficulty of the first fillet surface 333 is large, and there is a risk of stress concentration. Therefore, R is larger than or equal to 0.2mm, and the forming difficulty of the first fillet surface 333 is reduced under the condition of reducing the risk of stress concentration of the end cover 3.

In some embodiments, with continued reference to fig. 7 and 8, the distance H from the abutting surface 311 to the position where the second groove side surface 332 is connected to the first fillet surface 333 along the direction perpendicular to the abutting surface 311 satisfies: h is more than or equal to 0.05mm.

In fig. 7 and 8, the Z direction is a direction perpendicular to the abutting surface 311.

Taking the first rounded surface 333 as an example of being tangent to the second groove side surface 332, the position where the second rounded surface 323 is tangent to the second groove side surface 332 is the connecting position of the second groove side surface 332 and the first rounded surface 333. Taking the second groove side surface 332 as a cylindrical surface extending in the Z direction as an example, the distance H from the position where the second groove side surface 332 is connected to the first fillet surface 333 to the abutting surface 311 is the height of the second groove side surface 332 in the Z direction.

H may be 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, etc. Further, H is more than or equal to 0.2mm.

When the end cap 3 is assembled with the housing 1, the surface of the housing 1 for contacting the abutting surface 311 may be uneven, and there is still a possibility that the uneven structure of the end of the housing 1 where the opening is provided abuts against the first rounded surface 333. Therefore, H is greater than or equal to 0.05mm, and the risk that the first rounded surface 333 abuts against the end of the housing 1 where the opening is provided is reduced.

In some embodiments, referring to fig. 7 and 8, the second groove side surface 332 and the outer peripheral surface 321 are located in the same cylinder.

Understandably, the second groove side surface 332 and the outer circumferential surface 321 are both cylindrical surfaces, the second groove side surface 332 and the outer circumferential surface 321 are coaxially arranged, and the radius of the second groove side surface 332 is equal to the radius of the outer circumferential surface 321.

In this embodiment, the second groove side surface 332 and the outer peripheral surface 321 are located in the same cylindrical surface, so that the structure of the groove 33 is simpler, and the difficulty in forming the groove 33 is reduced.

In some embodiments, with continued reference to fig. 7 and 8, the outer circumferential surface 321 extends in a direction perpendicular to the abutting surface 311.

For example, the outer circumferential surface 321 is a cylindrical surface, the extending direction of the outer circumferential surface 321 is the axial direction of the outer circumferential surface 321, and the axial direction of the outer circumferential surface 321 is perpendicular to the abutting surface 311.

When the outer peripheral surface 321 of the first convex portion 32 is in positioning fit with the inner peripheral surface of the housing 1, the contact area of the abutting surface 311 with the housing 1 can be increased.

In some embodiments, with continued reference to fig. 6, the first protrusion 32 has an end surface 322 facing away from the abutting surface 311, and the end surface 322 is connected to the outer circumferential surface 321 through a second rounded surface 323.

The second rounded surface 323 is a chamfered surface connecting the end surface 322 and the outer peripheral surface 321. The end cap 3 and the outer peripheral surface 321 may each be tangent to the second rounded surface 323.

In the present embodiment, the second rounded surface 323 is provided to avoid the connection position between the end surface 322 of the first protrusion 32 and the outer peripheral surface 321 from forming a sharp corner; on the other hand, when the end cap 3 is assembled with the housing 1, the first projection 32 is facilitated to enter into the housing 1.

In some embodiments, please refer to fig. 9 and 10, fig. 9 is a schematic structural diagram of a battery cell 10 according to still other embodiments of the present application; fig. 10 is a schematic structural view of the end cap 3 shown in fig. 9. The end cap 3 further includes a body 34, and the first protrusion 32 is disposed around the outer side of the body 34, and in the thickness direction of the body 34, the first protrusion 32 protrudes from the body 34 in the direction facing the inside of the housing 1.

The body portion 34 is a main body portion of the end cap 3, and the body portion 34 is located inside the first protrusion 32. Taking the circular structure of the end cap 3 as an example, the body portion 34 may be a circular area located inside the first protrusion 32, and the first protrusion 32 is farther from the central axis of the end cap 3 than the body portion 34 along the radial direction of the end cap 3.

The first protrusion 32 may serve as a portion where the end cap 3 is electrically connected to the electrode assembly 2. For example, in embodiments where the second pole piece 22 of the electrode assembly 2 is directly connected to the end cap 3, the first protrusion 32 of the end cap 3 may abut against the second pole piece 22 to achieve a large area of flow-through between the end cap 3 and the second pole piece 22; as another example, in an embodiment in which the second tab 22 of the electrode assembly 2 and the end cap 3 are indirectly connected by the current collecting member 5, the first protrusion 32 of the end cap 3 may abut against the current collecting member 5 to achieve a large area of flow-through between the end cap 3 and the current collecting member 5.

In fig. 9 and 10, the Z direction is a thickness direction of the body portion 34, and it can be understood that the thickness direction of the body portion 34 coincides with a direction perpendicular to the abutting surface 311.

In the present embodiment, since the first protrusion 32 is disposed around the outer side of the main body 34, and the first protrusion 32 protrudes from the main body 34 along the direction facing the inside of the housing 1, the first protrusion 32 can reinforce the main body 34, and the deformation resistance of the main body 34 is improved.

Further, when the end cap 3 is electrically connected to the electrode assembly 2, an open area between the end cap 3 and the current collecting member 5 or the tab of the electrode assembly 2 may be secured by the first protrusions 32 abutting against the current collecting member 5 or the tab of the electrode assembly 2.

In some embodiments, referring to fig. 11, fig. 11 is a partial enlarged view of the end cap 3 shown in fig. 10 at C. Along the thickness direction of the body portion 34, the body portion 34 has a first outer surface 341 facing away from the housing 1, the first outer surface 341 is a surface of the end cover 3 farthest from the housing 1, the abutting portion 31 has a second outer surface 313 disposed opposite to the abutting surface 311, and the first outer surface 341 is farther from the abutting surface 311 than the second outer surface 313.

The first outer surface 341 may be planar. Taking the circular configuration of the end cap 3 as an example, the first outer surface 341 may be a circular plane or an annular plane located in a central region of the end cap 3. The first outer surface 341 may serve as a support surface for the battery cell 10.

The second outer surface 313 is a surface of the abutting portion 31 opposite to the abutting surface 311, and the second outer surface 313 may be a plane. The second outer surface 313 is connected to the abutment surface 311 by an outer side surface 312 of the abutment 31. Since the first outer surface 341 is farther from the abutting surface 311 than the second outer surface 313, the first outer surface 341 and the second outer surface 313 have a certain distance in the thickness direction of the body portion 34. When the abutting surface 311 abuts against the end of the housing 1 where the opening is provided, the abutting portion 31 is closer to the housing 1 as a whole than the first outer surface 341 in the thickness direction of the body portion 34.

The first outer surface 341 can be used as a supporting surface of the single battery 10, and because the first outer surface 341 is farther from the abutting surface 311 than the second outer surface 313, even if the abutting portion 31 and the housing 1 are welded to form welding slag protruding from the supporting surface, the welding slag is not easy to protrude from the first outer surface 341, and a height difference between the first outer surface 341 and the second outer surface 313 provides an avoidance space for the welding slag, so that the influence of the welding slag on the first outer surface 341 is reduced, the first outer surface 341 can be in large-area contact with an external component when the single battery 10 is placed on the external component, and the stability of the single battery 10 is improved. The external component may be a bottom wall of the case 20 of the battery 100, a thermal management component, or the like. The thermal management means is a means for managing the temperature of the battery cell 10, and may be a water-cooled panel.

In some embodiments, with continued reference to fig. 10, the body portion 34 has a weak portion 342, and the weak portion 342 is configured to be broken when the battery cell 10 is depressurized to release the pressure inside the battery cell 10.

The weakened portion 342 is a portion of the main body portion 34 that is weaker, and the weakened portion 342 is weaker and more easily broken than other areas of the main body portion 34. A local area of the body portion 34 may be weakened to form the weakened portion 342. For example, the thickness of a local region of the body portion 34 is reduced to correspondingly form the weak portion 342; for another example, an annealing process is performed on a local region of the body portion 34 to correspondingly form the weak portion 342. The weakening 342 can be broken in various ways, such as by breaking, breaking away, etc.

When the pressure inside the battery cell 10 reaches the detonation pressure, the weak portion 342 is broken by the discharge (gas, electrolyte, etc.) inside the battery cell 10, and the battery cell 10 is depressurized.

The end cap 3 has a pressure relief function due to the arrangement of the weak portion 342, and the end cap 3 can serve as a pressure relief component of the single battery 10, so that the safety of the single battery 10 is improved.

In some embodiments, with continued reference to fig. 10, the body portion 34 is provided with a score groove 343, and the body portion 34 is formed with a weakened portion 342 at a position corresponding to the score groove 343.

The scored groove 343 may be a groove extending along a straight track or a groove extending along a curved track. If the scored groove 343 is a groove extending along the bending track, the scored groove 343 may be a groove extending along a closed track or a groove extending along a non-closed track. Of course, the score line 343 may be a cylindrical line or a rectangular parallelepiped line.

The weak portion 342 is correspondingly formed by providing the notch 343 on the body portion 34, so that the thickness of the weak portion 342 is thinner than that of other regions, and is easier to break, and the weak portion 342 is formed in a simple manner.

In some embodiments, referring to fig. 12 and 13, fig. 12 is an isometric view of the end cap 3 shown in fig. 10; fig. 13 is a plan view of the end cap 3 shown in fig. 12. The body portion 34 has a relief area 344 bounded by a score groove 343, the relief area 344 being provided with a rib 345.

The pressure relief region 344 is a portion of the body portion 34 that opens with the notch 343 as a boundary when the battery cell 10 is relieved of pressure. When the pressure relief area 344 is opened, the body portion 34 forms a discharge port at a position corresponding to the pressure relief area 344, and the discharge inside the battery cell 10 can be discharged through the discharge port to relieve the pressure inside the battery cell 10. The pressure relief area 344 may be opened in an outwardly flipped or disengaged manner.

The reinforcing ribs 345 can increase the rigidity of the bleeding area 344 and enhance the deformation resistance of the bleeding area 344. The rib 345 may have various shapes, such as a straight line shape, a circular arc shape, a circular ring shape, a U shape, a circular shape, a rectangular shape, and the like. The stiffener 345 may be integrally formed with the body 34, for example, by forming the stiffener 345 on the body 34 by stamping, so that the stiffener 345 is integrally formed with the body 34; the rib 345 may be provided separately from the body portion 34 and connected thereto, for example, by welding. When the rib 345 is formed in the body portion 34 by pressing, a pressing groove having the same shape as the rib 345 is formed in the body portion 34 at a position facing the rib 345.

When the pressure is released, the pressure release area 344 can be opened by the notch 343 as a boundary, and has a large pressure release area. The pressure relief area 344 is provided with the reinforcing rib 345, the reinforcing rib 345 reinforces the pressure relief area 344, the deformation resistance of the pressure relief area 344 is improved, when the internal pressure of the single battery 10 changes, the pressure relief area 344 is not easy to deform, and the risk that the pressure relief area 344 is opened in the normal use process of the single battery 10 is reduced.

In some embodiments, with continued reference to fig. 12 and 13, the stiffener 345 includes a first reinforcement part 3451 and a second reinforcement part 3452, the first reinforcement part 3451 and the second reinforcement part 3452 are both circular arc-shaped, and the opening of the first reinforcement part 3451 is opposite to the opening of the second reinforcement part 3452.

The first reinforcement portion 3451 and the second reinforcement portion 3452 each protrude from the relief area 344. The first reinforcement part 3451 has both ends in the extending direction, and a line (straight line) position of both ends of the first reinforcement part 3451 forms an opening of the first reinforcement part 3451. The second reinforcement part 3452 has both ends in the extending direction, and a connecting line (straight line) position of both ends of the second reinforcement part 3452 forms an opening of the second reinforcement part 3452.

In some embodiments, as shown in fig. 12 and 13, the first reinforcement portion 3451 and the second reinforcement portion 3452 may be directly connected. In other embodiments, the first reinforcement part 3451 and the second reinforcement part 3452 may be spaced apart, for example, the first reinforcement part 3451 and the second reinforcement part 3452 are spaced apart along the radial direction of the end cap 3.

Because the first reinforcement part 3451 and the second reinforcement part 3452 are both circular arc-shaped, and the openings of the first reinforcement part 3451 and the second reinforcement part 3452 are oppositely arranged, the radiation range of the reinforcing rib 345 of the structure is larger, the reinforcing range of the pressure release area 344 can be enlarged, the circular arc-shaped first reinforcement part 3451 and the circular arc-shaped second reinforcement part 3452 have better deformation resistance, can play a better reinforcing effect on the pressure release area 344, and further improve the deformation resistance and the fatigue resistance of the pressure release area 344.

In some embodiments, score groove 343 is a groove that extends along a closed trajectory.

The closed track may be a variety of shapes, such as a circular track, a rectangular track, an elliptical track, and the like. In this embodiment, the pressure relief area 344 is an enclosed area of the body portion 34 defined by the score groove 343.

When the single battery 10 is decompressed, the portion of the body portion 34 in the region defined by the notch groove 343 may be opened in a manner of being separated from the outside of the single battery 10, so that the single battery 10 has a large decompression area, and the decompression efficiency is improved.

In some embodiments, score groove 343 is a circular groove.

It will be appreciated that the score groove 343 is a groove extending along a circular trajectory. In this embodiment, the relief area 344 is a circular area of the body portion 34 defined by the score groove 343. The circular groove has simple structure and convenient forming.

In other embodiments, score groove 343 can be a groove that extends along a non-closed path to define relief area 344, such as an arcuate groove, a U-shaped groove, or the like.

In some embodiments, with reference to fig. 10, in the thickness direction of the body portion 34, the body portion 34 has a first outer surface 341 facing away from the inside of the housing 1, the first outer surface 341 is a surface of the end cap 3 farthest from the housing 1, the first outer surface 341 is provided with a recess 346, and a projection of a bottom surface of the recess 346 covers the weak portion 342.

The recess 346 may be a cylindrical groove, a rectangular parallelepiped groove, or the like provided in the first outer surface 341. The bottom surface of the recess 346 may be planar. It is understood that the projection of the weak portion 342 in the thickness direction of the body portion 34 is located in the bottom surface of the recess 346.

The recess 346 is arranged to have a certain distance between the weak portion 342 and the first outer surface 341, so that when the first outer surface 341 contacts an external member, the influence of the external member on the weak portion 342 can be reduced, the weak portion 342 can be smoothly broken when the internal pressure of the battery cell 10 reaches a normal initiation pressure, and the risk that the initiation pressure of the battery cell 10 is increased due to the blocking effect of the external member on the weak portion 342 is reduced.

In some embodiments, with reference to fig. 10, the body portion 34 has a first inner surface 347 opposite to the first outer surface 341 along a thickness direction of the body portion 34, and the first inner surface 347 is provided with a second protrusion 348 at a position corresponding to the recess 346.

The first inner surface 347 is a surface of the body portion 34 opposite to the first outer surface 341 in the thickness direction, and the distance between the first inner surface 347 and the first outer surface 341 is the thickness of the body portion 34.

The shape of the second protrusion 348 may be the same as the shape of the recess 346. Taking the shape of the concave portion 346 as a cylindrical groove as an example, the second convex portion 348 may be a cylindrical boss protruding from the first inner surface 347. The concave portion 346 may be formed by stamping, and when the concave portion 346 is stamped on the first outer surface 341, a second convex portion 348 protruding from the first inner surface 347 is correspondingly formed.

The ribs 345 may protrude from the surface of the convex portion facing away from the first inner surface 347, or may protrude from the bottom surface of the concave portion 346. In the embodiment shown in fig. 10, the rib 345 protrudes from the bottom surface of the recess 346, and the rib 345 does not protrude beyond the end surface 322 of the first protrusion 32 in the thickness direction of the body portion 34.

In embodiments where the body portion 34 is provided with the scored groove 343, the scored groove 343 may be provided on a bottom surface of the recess 346 and/or a surface of the protrusion facing away from the first inner surface 347.

In the present embodiment, the provision of the second protrusion 348 can increase the strength of the area of the main body 34 where the recess 346 is provided, and improve the breakage resistance of the area of the main body 34 where the recess 346 is provided.

The embodiment of the application provides a battery cell 10, which comprises a shell 1 and an end cover 3 provided by any one of the above embodiments. The housing 1 has an opening, the first protrusion 32 extends into the housing 1, the abutting surface 311 abuts against one end of the housing 1 where the opening is located, and the end cover 3 closes the opening.

Illustratively, the housing 1 is a cylindrical housing and the end cap 3 is a circular end cap.

In some embodiments, the abutment 31 is welded to the housing 1.

The welding area formed by the welding connection of the abutting part 31 and the shell 1 is arranged around the abutting part 31, and the abutting part 31 and the shell 1 are connected in a sealing mode.

In this embodiment, the abutting portion 31 and the housing 1 are connected by welding, so that the end cover 3 and the housing 1 are fixedly connected in a simple manner, and the firmness and the sealing performance of the end cover 3 and the housing 1 after connection can be ensured.

The embodiment of the application provides a battery 100, which comprises the battery cell 10 provided by any one of the above embodiments.

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

In addition, the embodiment of the present application further provides a circular end cap for closing the opening of the housing 1 of the battery cell 10, and the end cap 3 includes the abutting portion 31, the first protrusion 32 and the body portion 34. The abutting portion 31 has an abutting surface 311, and the abutting surface 311 is used for abutting one end of the housing 1 where the opening is provided. The first protrusion 32 is connected to the abutting portion 31 and protrudes from the abutting surface 311, and the first protrusion 32 is configured to extend into the housing 1. The abutting surface 311 is provided with a groove 33, the groove 33 is arranged around the first protrusion 32, and the outer peripheral surface 321 of the first protrusion 32 is connected with the abutting surface 311 through the groove wall surface of the groove 33. The groove wall surface includes a first groove side surface 331, a second groove side surface 332, a groove bottom surface 334, and a first fillet surface 333. The first groove side surface 331 is connected with the abutting surface 311, and the first groove side surface 331 and the abutting surface 311 form an obtuse angle. The second groove side surface 332 is connected to the outer peripheral surface 321, and the second groove side surface 332 and the outer peripheral surface 321 are located in the same cylindrical surface. The slot bottom surface 334 is parallel to the abutment surface 311, the slot bottom surface 334 being connected to the first slot side surface 331. The first fillet 333 connects the second groove side 332 and the groove bottom 334, the radius of the first fillet 333 is R, R is more than or equal to 0.2mm. The distance from the position where the second groove side surface 332 is connected with the first fillet surface 333 to the abutting surface 311 along the direction perpendicular to the abutting surface 311 is H, and H is more than or equal to 0.05mm. The first protrusion 32 is disposed around the outer side of the main body 34, and the first protrusion 32 protrudes from the main body 34 in a direction facing the inside of the housing 1 along a direction perpendicular to the abutting surface 311.

Wherein the body portion 34 is provided with a notch groove 343, the body portion 34 is formed with a weak portion 342 at a position corresponding to the notch groove 343, the notch groove 343 is an annular groove and defines a pressure relief area 344, and the pressure relief area 344 is provided with a rib 345. The reinforcing rib 345 includes a first reinforcing portion 3451 and a second reinforcing portion 3452, the first reinforcing portion 3451 and the second reinforcing portion 3452 are both circular arc-shaped, and the opening of the first reinforcing portion 3451 is opposite to the opening of the second reinforcing portion 3452. In a direction perpendicular to the abutting surface 311, the body portion 34 has a first outer surface 341 facing away from the interior of the housing 1, the first outer surface 341 is a surface of the end cap 3 farthest from the housing 1, the first outer surface 341 is provided with a concave portion 346, a projection of a bottom surface of the concave portion 346 covers the weak portion 342, the body portion 34 has a first inner surface 347 opposite to the first outer surface 341, and a position of the first inner surface 347 corresponding to the concave portion 346 is provided with a second convex portion 348.

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

The above embodiments are merely for illustrating the technical solutions of the present application and are not intended to limit the present application, and those skilled in the art can make various modifications and variations of the present application. 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 for closing an opening of a housing of a battery cell, the end cap comprising:

an abutting portion having an abutting face for setting one end of the opening against the housing;

the first convex part is connected with the abutting part and protrudes out of the abutting surface, and the first convex part is used for extending into the shell;

the abutting surface is provided with a groove, the groove is arranged around the first convex portion, and the peripheral surface of the first convex portion is connected with the abutting surface through the groove wall surface of the groove.

2. The end closure of claim 1, wherein said channel wall surface includes a first channel side surface, said first channel side surface being contiguous with said abutment surface, said first channel side surface being disposed at an obtuse angle to said abutment surface.

3. The end closure of claim 2, wherein said channel wall surface comprises:

a second groove side surface connected to the outer peripheral surface;

a first radiused surface connecting the first slot side and the second slot side.

4. The end closure of claim 2, wherein said channel side comprises:

a second groove side surface connected to the outer peripheral surface;

the groove bottom surface is connected with the side surface of the first groove;

a first fillet connecting the second groove side and the groove bottom.

5. The end closure of claim 4, wherein said groove bottom surface is parallel to said abutment surface.

6. The end closure of claim 4, wherein said first radiused surface has a radius R satisfying: r is more than or equal to 0.2mm.

7. An end closure according to claim 4, wherein the second channel side surface is connected to the first radiused surface at a distance H from the abutment surface in a direction perpendicular to the abutment surface such that: h is more than or equal to 0.05mm.

8. An end cap according to claim 4, wherein the second groove side surface is located in the same cylindrical surface as the outer peripheral surface.

9. An end cap according to any one of claims 1-8, wherein the peripheral surface extends in a direction perpendicular to the abutment surface.

10. An end cap according to any of claims 1-8, wherein the first protrusion has an end face facing away from the abutment face, the end face being connected to the peripheral face by a second rounded face.

11. The end cap of any one of claims 1-8, further comprising:

the first protruding portion is arranged around the outer side of the body portion, and protrudes out of the body portion in a direction facing the inside of the housing in the thickness direction of the body portion.

12. An end cap according to claim 11, wherein the body portion has a first outer surface facing away from the housing in a thickness direction of the body portion, the first outer surface being a surface of the end cap furthest from the housing, the abutment portion has a second outer surface disposed opposite the abutment face, the first outer surface being further from the abutment face than the second outer surface.

13. An end cap according to claim 11, wherein the body portion has a weakened portion configured to be broken upon venting of the cell to vent pressure inside the cell.

14. An end closure as claimed in claim 13, in which the body portion is provided with a score groove, the body portion forming the weakened portion at a location corresponding to the score groove.

15. An end closure according to claim 14, wherein the body portion has a pressure relief region bounded by the score groove, the pressure relief region being provided with a reinforcing rib.

16. The end closure of claim 15, wherein said reinforcing bead comprises a first reinforcing portion and a second reinforcing portion, said first reinforcing portion and said second reinforcing portion each having a circular arc shape, said first reinforcing portion opening being disposed opposite said second reinforcing portion opening.

17. An end closure according to claim 14, wherein the score groove is a groove extending along a closed path.

18. The end closure of claim 14, wherein said score groove is a circular groove.

19. An end cap according to claim 13, wherein the body portion has a first outer surface facing away from the interior of the housing in a thickness direction of the body portion, the first outer surface being a surface of the end cap furthest from the housing, the first outer surface being provided with a recess, a projection of a bottom surface of the recess covering the weakened portion.

20. An end cap according to claim 19, wherein the body portion has a first inner surface opposite to the first outer surface in a thickness direction of the body portion, and a second convex portion is provided at a position of the first inner surface corresponding to the concave portion.

21. A battery cell, comprising:

a housing having an opening;

the end cap of any one of claims 1-20, the first protrusion extending into the housing, the abutment surface abutting an end of the housing at which the opening is disposed, the end cap closing the opening.

22. The battery cell as recited in claim 21 wherein the abutment is welded to the housing.

23. A battery comprising a cell according to claim 21 or 22.

24. An electrical device comprising the battery of claim 23.