CN216720096U - End cover, battery monomer, battery and power consumption device - Google Patents

Abstract

The application provides an end cover, battery monomer, battery and power consumption device relates to battery technical field. The end cover is used in a battery monomer, the end cover is provided with an upper surface and a lower surface, the lower surface and the upper surface are oppositely arranged along the thickness direction of the end cover, a first wall and a second wall are arranged on the lower surface along the circumferential direction of the end cover, mounting grooves distributed along the circumferential direction of the end cover are defined between the first wall and the second wall, and the mounting grooves are used for mounting the side wall of a shell of the battery monomer. The improvement of the mounting groove structure is utilized to improve the strength of the heat affected zone after the end cover and the shell are welded, and the possibility that the heat affected zone is cracked in the service life of the battery monomer is reduced.

Description

End cover, battery monomer, battery and power consumption device

Technical Field

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

Background

At present, in the production process of the lithium battery, laser welding of the top cover and the battery shell (usually an aluminum shell) is carried out, but the strength of a heat affected zone is insufficient after welding of the end cover and the shell, so that the phenomenon that the heat affected zone below a welding line is broken possibly occurs in the service life of a battery monomer.

SUMMERY OF THE UTILITY MODEL

An object of the present invention is to provide an end cap, a battery cell, a battery and an electric device, which can improve the strength of a heat affected zone and reduce the possibility of cracking of the heat affected zone during the lifetime of the battery cell.

In a first aspect, the present application provides an end cap for a battery cell, where the end cap has an upper surface and a lower surface, the lower surface and the upper surface are arranged opposite to each other in a thickness direction of the end cap, the lower surface is provided with a first wall and a second wall along a circumferential direction of the end cap, mounting grooves distributed along the circumferential direction of the end cap are defined between the first wall and the second wall, and the mounting grooves are used for mounting a side wall of a housing of the battery cell.

In the technical scheme of the embodiment of the application, the installation groove distributed along the circumferential direction of the end cover is defined between the first wall and the second wall, and when the shell is assembled into a single battery, on one hand, the installation groove can accurately position the shell, so that the assembly precision is improved; on the other hand, after the side wall of the shell is embedded in the mounting groove, the side wall can be respectively contacted with the first wall and the second wall to increase the contact area, and further when the shell and the side wall are welded to be connected into a whole, heat generated by welding can be transmitted along the first wall, the second wall and the side wall along a plurality of directions, so that the heat transmission quantity in each direction is weakened, the strength of a heat affected zone on the lower side of a welding joint is increased, and the possibility of cracking of the heat affected zone in the service life of the battery monomer is reduced.

In some embodiments, the depth of the mounting groove is not less than 0.5mm in the thickness direction of the end cap. Under this condition, be favorable to improving the welding strength of casing and end cover, avoid the fracture, if the mounting groove degree of depth is less than 0.5 mm's recess, welding strength is not enough, and the casing is easy to be cracked with the welded junction of end cover.

In some embodiments, the upper surface is provided with a positioning groove corresponding to the mounting groove, and the positioning groove is used for enabling the laser to directionally weld the side wall and the end cover. Because the lateral wall inlays and locates in the mounting groove after actual assembly, the top cap is non-transparent material, therefore can't the accurate lateral wall position of judgement during the welding, consequently utilizes the upper surface to be equipped with the constant head tank that corresponds with the mounting groove, utilizes the constant head tank can fix a position lateral wall position fast during the welding to make directional and accurate welding lateral wall of laser and end cover.

In some embodiments, the thickness of the end cap between the bottom wall of the positioning groove and the bottom wall of the mounting groove in the thickness direction of the end cap is 0.3-0.7 mm. The thickness meets the requirements of a welding process, and the welding strength after welding can be ensured. If the thickness is thin, the situation of welding through is easy to occur during welding, the process difficulty is high, if the thickness is too thick, the welding process difficulty is high, and more heat is accumulated in the welding process, so that the strength of a heat affected zone is insufficient.

In a second aspect, the present application provides a battery cell comprising an electrode assembly, an end cap in the above embodiments, and a housing. The end cover is provided with a side surface distributed in the circumferential direction, and the side surface is connected with the upper surface and the lower surface; the shell is used for accommodating the electrode assembly, the shell is provided with an opening and a side wall surrounding the periphery of the opening, and at least part of the side wall is embedded in the mounting groove, so that the side wall is welded with the end cover and forms a welding part.

In the technical scheme of the embodiment of the application, the end cover provided by the embodiment is matched with the shell, so that on one hand, the mounting groove on the end cover can accurately position the shell, and the assembly precision is improved; on the other hand, after the side wall of the shell is embedded in the mounting groove, the side wall can be respectively contacted with the first wall and the second wall to increase the contact area, and then when the shell and the side wall are welded to be connected into a whole, heat generated by welding can be transmitted along the first wall, the second wall and the side wall along a plurality of directions, so that the heat transmission quantity in each direction is weakened, the strength of a heat affected zone on the lower side of a welding joint is increased, and the possibility of cracking of the heat affected zone in the service life of the battery monomer is reduced.

In some embodiments, the side wall has an integrally formed body and a mounting portion, the mounting portion is embedded in the mounting groove, and the outer surface of the body is flush with the side surface. The arrangement mode that the outer surface of the body is flush with the side face is adopted, the appearance of the battery monomer cannot be obviously changed, and the battery can be conveniently assembled with other parts.

In some embodiments, the side wall has a body and a mounting portion, the body and the mounting portion are integrally formed, the mounting portion is embedded in the mounting groove, and the side surface protrudes out of the outer surface of the body. By adopting the mode, the original structure of the side wall is not required to be changed, and the processing flow of the side wall of the shell is reduced. In some embodiments, the welding portion is spaced apart from the side surface by a first predetermined distance, the welding portion is spaced apart from the lower surface by a second predetermined distance in the thickness direction, and the first predetermined distance and the second predetermined distance are both greater than zero. The strength of the welding part is enhanced, the phenomenon that the electrode assembly is damaged due to the fact that molten materials flow into the interior of the battery cell in the welding process is avoided, and the phenomenon that the molten materials flow out of the end cover in the welding process can be avoided.

In a third aspect, the present application provides a battery comprising a plurality of battery cells of the above embodiments.

In some embodiments, any two adjacent battery cells are arranged at intervals and form a mounting gap; the battery is including setting up the heat insulating mattress in the installation gap, and the heat insulating mattress can effectual isolated two adjacent free heat transfer of battery to when making arbitrary one battery monomer thermal runaway, can not influence adjacent battery monomer.

In some embodiments, the shape of the insulation mat is complementary to the shape of the mounting slot. Therefore, when the side face protrudes out of the outer surface of the body, the shape of the heat insulation pad can be improved when the appearance of the battery monomer is changed, the shape of the heat insulation pad is complementary to that of the installation gap, the heat insulation pad can support two adjacent battery monomers, and the stability of assembling of the battery monomers in the battery is guaranteed.

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

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 according to some embodiments of the present application;

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

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

fig. 4 is a schematic cross-sectional view of a battery cell according to some embodiments of the present disclosure;

FIG. 5 is an enlarged partial view of the end cap and shell of FIG. 4 prior to welding;

FIG. 6 is a schematic structural view of an end cap according to some embodiments of the present application;

FIG. 7 is a schematic illustration in partial cross-section of an end cap according to some embodiments of the present application;

FIG. 8 is a schematic structural view of the end cap and housing of some embodiments of the present application after welding;

FIG. 9 is a schematic structural view of the end cap and housing of some embodiments of the present application after welding;

FIG. 10 is a schematic structural view of the end cap and housing of some embodiments of the present application after welding;

FIG. 11 is a schematic view of the assembly of a battery cell with an insulation mat according to some embodiments of the present application;

fig. 12 is a schematic view of the assembly of a battery cell and an insulation mat according to some embodiments of the present application.

An icon: 1000-a vehicle; 100-a battery; 200-a controller; 300-a motor; 10-a box body; 11-a first part; 12-a second part; 20-a battery cell; 21-end cap; 21 a-electrode terminal; 22-a housing; 23-an electrode assembly; 24-mounting a gap; 30-a heat insulation mat; 211-upper surface; 212-lower surface; 213-mounting groove; 2131-a first wall; 2133-a second wall; 2134-third wall; 215-a positioning groove; 2151-a fourth wall; 216-flank; 221-opening; 222-a side wall; 2221-body; 2223-a mounting portion; 218 — a weld.

Detailed Description

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

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

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

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

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

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

In the description of the embodiments of the present application, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the directions or positional relationships indicated in the drawings, and are only for convenience of description of the embodiments of the present application and for simplicity of description, but do not indicate or imply that the referred device or element must have a specific direction, be constructed and operated in a specific direction, and thus, should not be construed as limiting the embodiments of the present application.

In the description of the embodiments of the present application, unless otherwise explicitly stated or limited, the terms "mounted," "connected," "fixed," and the like are used in a broad sense, and for example, may be fixedly connected, detachably connected, or integrated; mechanical connection or electrical connection is also possible; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the embodiments of the present application can be understood by those of ordinary skill in the art according to specific situations.

At present, the application of the power battery is more and more extensive from the development of market situation. The power battery is not only applied to energy storage power supply systems such as hydraulic power, firepower, wind power and solar power stations, but also widely applied to electric vehicles such as electric bicycles, electric motorcycles, electric automobiles and the like, and a plurality of fields such as military equipment and aerospace. With the continuous expansion of the application field of the power battery, the market demand is also continuously expanding.

The inventor of the invention notices that, in the present lithium cell production process, all can carry out end cover and casing laser welding, but no matter trapezoidal top cap, still directly carry out seam welding to top cap and casing, all exist because welding heat affected zone intensity is not enough, lead to electric core in life-span term, probably take place the phenomenon that heat affected zone broke.

The inventors have studied and found that the cause of the above problems is mainly: during welding, heat is mainly transmitted from top to bottom of the shell, the transmission path is narrow, the heat is large, and therefore the strength of a heat affected zone of the shell is still insufficient.

Based on the above consideration, in order to solve the problem that the heat-affected zone has insufficient strength and cracks in the heat-affected zone during the life of the battery cell, the inventor designs an end cap, wherein a mounting groove distributed along the circumferential direction of the end cap is defined between a first wall and a second wall of the lower surface of the end cap, when the housing is assembled into the battery cell, a side wall of the housing can be embedded in the mounting groove, and the side wall can be respectively contacted with the first wall and the second wall to increase the contact area, and further when the housing and the side wall are welded to be connected into a whole, heat generated by welding can be transmitted along the first wall, the second wall and the side wall along multiple directions, so that the amount of heat in each direction is weakened, the strength of the heat-affected zone at the lower side of the welding joint is increased, and the possibility of the heat-affected zone cracking in the life of the battery cell is reduced.

The battery cell disclosed in the embodiment of the application can be used in electric devices such as vehicles, ships or aircrafts, but not limited thereto. The power supply system who possesses this power consumption device of constitution such as battery monomer, battery that this application is disclosed can be used, like this, is favorable to alleviating and automatically regulated electric core bulging force worsens, and supplementary electrolyte consumes, promotes the stability and the battery life of battery performance.

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

For convenience of description, the following embodiments are described by taking an electric device according to an embodiment of the present application as an example of a vehicle 1000.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a vehicle 1000 according to some embodiments of the present disclosure. The vehicle 1000 may be a fuel automobile, a gas automobile, or a new energy automobile, and the new energy automobile may be a pure electric automobile, a hybrid electric automobile, or a range-extended automobile, etc. The battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom or the head or the tail of the vehicle 1000. The battery 100 may be used for power supply of the vehicle 1000, 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 be used not only as an operating power source of the vehicle 1000, but also as a driving power source of the vehicle 1000, instead of or in part of fuel or natural gas, to provide driving power for the vehicle 1000.

Referring to fig. 2, fig. 2 is an exploded view of a battery 100 according to some embodiments of the present disclosure. The battery 100 includes a case 10, a battery cell 20, and a heat insulating sheet 30, and the battery cell 20 and the heat insulating sheet 30 are accommodated in the case 10.

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

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

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

The heat insulation pad 30 is disposed between two adjacent battery cells 20, and the heat insulation pad 30 can effectively isolate heat transfer between two adjacent battery cells 20, so that when any one battery cell 20 is out of control due to heat, the adjacent battery cell 20 is not affected. Wherein, the heat insulation pad 30 is adhered between two adjacent battery cells 20 via the glue coated on the front and back surfaces.

The material of the heat insulation pad 30 may be at least one of aerogel composite material, inorganic fiber cotton, mica and its composite material, thermosetting resin foam, inorganic foam, etc., and those skilled in the art can select the material according to actual needs, which is not limited herein.

Referring to fig. 3 and fig. 4, fig. 3 is an exploded structural schematic view of a battery cell 20 according to some embodiments of the present disclosure, and fig. 4 is a cross-sectional structural schematic view of the battery cell 20. The battery cell 20 refers to the smallest unit constituting the battery 100. As shown in fig. 3, the battery cell 20 includes an end cap 21, a case 22, an electrode assembly 23, and other functional components.

The end cap 21 refers to a member that covers the opening 221 of the case 22 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 21 may be adapted to the shape of the housing 22 to fit the housing 22. Alternatively, the end cap 21 may be made of a material (e.g., an aluminum alloy) having a certain hardness and strength, so that the end cap 21 is not easily deformed when being impacted, and the battery cell 20 may have a higher structural strength and improved safety. The end cap 21 may be provided with functional components such as the electrode terminals 21 a. The electrode terminals 21a may be used to be electrically connected with the electrode assembly 23 for outputting or inputting electric energy of the battery cells 20. In some embodiments, the end cap 21 may further include a pressure relief mechanism for relieving the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold value. The material of the end cap 21 may also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not limited in this embodiment. In some embodiments, insulation may also be provided on the inside of the end cap 21, which may be used to isolate the electrical connection components within the housing 22 from the end cap 21 to reduce the risk of short circuits. Illustratively, the insulator may be plastic, rubber, or the like.

The case 22 is an assembly for mating with the end cap 21 to form an internal environment of the battery cell 20, wherein the formed internal environment may be used to house the electrode assembly 23, electrolyte, and other components. The housing 22 and the end cap 21 may be separate components, and an opening 221 may be formed in the housing 22, and the opening 221 may be covered by the end cap 21 at the opening 221 to form the internal environment of the battery cell 20. The housing 22 may be a variety of shapes and sizes, such as rectangular parallelepiped, cylindrical, hexagonal prism, etc. Specifically, the shape of the case 22 may be determined according to the specific shape and size of the electrode assembly 23. The material of the housing 22 may be various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not limited in the embodiments of the present invention.

The electrode assembly 23 is a part in which electrochemical reactions occur in the battery cell 20. One or more electrode assemblies 23 may be contained within the case 22. The electrode assembly 23 is mainly formed by winding or stacking a positive electrode sheet and a negative electrode sheet, and a separator is generally disposed between the positive electrode sheet and the negative electrode sheet. The portions of the positive and negative electrode sheets having the active material constitute the body portion of the electrode assembly 23, and the portions of the positive and negative electrode sheets having no active material each constitute a tab 23 a. The positive electrode tab and the negative electrode tab may be located at one end of the main body portion together or at both ends of the main body portion, respectively. During the charge and discharge of the battery 100, the positive and negative electrode active materials react with the electrolyte, and the tab 23a connects the electrode terminal 21a to form a current loop.

Please refer to fig. 4-7 according to some embodiments of the present application; the application provides an end cover 21 for a battery unit 20, the end cover 21 is provided with an upper surface 211 and a lower surface 212, the lower surface 212 and the upper surface 211 are arranged oppositely along the thickness direction of the end cover 21, the lower surface 212 is provided with a first wall 2131 and a second wall 2133 along the circumferential direction of the end cover 21, mounting grooves 213 distributed along the circumferential direction of the end cover 21 are defined between the first wall 2131 and the second wall 2133, and the mounting grooves 213 are used for mounting side walls 222 of a shell 22 of the battery unit 20.

The housing 22 has an opening 221, and the "side wall 222" of the housing 22 refers to a peripheral wall of the housing 22 surrounding the opening 221.

"lower surface 212" refers to a surface of the end cap 21 facing the housing 22 after the end cap 21 is assembled with the housing 22, and "upper surface 211" refers to a surface of the end cap 21 facing away from the housing 22 after the end cap 21 is assembled with the housing 22, and a distance between the upper surface 211 and the lower surface 212 is a thickness of the end cap 21, wherein the upper surface 211 and the lower surface 212 are substantially parallel, that is, a thickness of the end cap 21 between the upper surface 211 and the lower surface 212 is substantially constant.

The first wall 2131 and the second wall 2133 are used to form the wall of the mounting groove 213, wherein the first wall 2131 and the second wall 2133 are both located on the lower surface 212, the first wall 2131 is located on the periphery of the second wall 2133, one ends of the first wall 2131 and the second wall 2133 are connected to each other, and the other end (the end connected to the lower surface 212) serves as the opening end of the mounting groove 213. Since the thickness of the end cap 21 between the upper surface 211 and the lower surface 212 is substantially constant, as shown in fig. 5 and 7, the mounting groove 213 is actually a groove recessed in the lower surface 212, that is, the distance between the upper surface 211 and the lower surface 212 is taken as the thickness a1, based on the installation of the mounting groove 213, the thickness of the end cap 21 between the upper surface 211 and the mounting groove 213 is a2, and a1 is greater than a2, meanwhile, it should be noted that the thickness of the portion of the end cap 21 surrounded by the mounting groove 213, that is, the thickness of the middle portion of the end cap 21, may be actually greater than a1 or less than a1, and the thickness of the middle portion of the end cap 21 in fig. 7 is equal to a 1.

By defining the mounting grooves 213 distributed along the circumferential direction of the end cap 21 between the first wall 2131 and the second wall 2133, when the housing 22 is assembled into the single battery 20, on one hand, the mounting grooves 213 can precisely position the housing 22, which is beneficial to improving the assembly precision; on the other hand, after the side wall 222 of the housing 22 is embedded in the mounting groove 213, the inner and outer surfaces of the side wall 222 can be respectively in contact with the first wall 2131 and the second wall 2133 to increase the contact area, and further, when the end cap 21 and the side wall 222 are welded to be connected into a whole, heat generated by welding can be transmitted along the first wall 2131, the second wall 2133 and the side wall 222 in multiple directions, so that the heat transmission amount in each direction is weakened, the strength of the heat affected zone on the lower side of the welding joint is increased, and the problem of cracking of the heat affected zone in the life of the battery cell 20 is alleviated. The heat affected zone is a zone where the base materials at two sides of the welding seam in a solid state have obvious structure and performance changes under the action of welding heat circulation.

In order to ensure the strength of the end cap 21, the thickness a1 of the end cap 21 is 2-2.7mm, for example, the thickness a1 of the end cap 21 is 2mm, 2.3mm, 2.5mm, 2.6mm, or 2.7 mm.

It should be noted that the shape of the mounting groove 213 should match the shape of the sidewall 222 of the housing 22, for example, when the housing 22 is a cylinder, the mounting groove 213 is circular on the lower surface 212. As shown in fig. 6, when the housing 22 has a square shape, the mounting groove 213 has a rectangular shape on the lower surface 212.

The sectional shape of the mounting groove 213 may be semicircular, trapezoidal, rectangular, V-shaped, etc., where the sectional shape refers to a section parallel to the paper, and in order to facilitate the insertion of the side wall 222 into the mounting groove 213, the sectional area of the open end of the mounting groove 213 should be not smaller than the end of the mounting groove 213 near the upper surface 211, where the sectional area of the open end of the mounting groove 213 refers to a section perpendicular to the paper.

As shown in fig. 7, the mounting groove 213 has a rectangular cross-sectional shape, and in this case, the mounting groove 213 further includes a third wall 2134 as a bottom wall of the mounting groove, wherein the third wall 2134 faces an open end of the mounting groove 213, and the third wall 2134 connects one ends of the first wall 2131 and the second wall 2133 close to the upper surface 211, respectively.

According to some embodiments of the present application, optionally, the depth of the mounting groove 213 in the thickness direction of the end cover 21 is not less than 0.5 mm.

The depths here are actually: the distance between the third wall 2134 and the extending surface of the lower surface 212 in the thickness direction of the end cap 21.

The depth of the mounting groove 213 is not less than 0.5mm, so that the welding strength of the shell 22 and the end cover 21 is improved, cracking is avoided, if the depth of the mounting groove 213 is less than 0.5mm, the welding strength is insufficient, and the welding part of the shell 22 and the end cover 21 is easy to break.

According to some embodiments of the present application, referring to fig. 7, optionally, the upper surface 211 is provided with a positioning groove 215 corresponding to the mounting groove 213, and the positioning groove 215 is used for directionally welding the laser beam to the side wall 222 and the end cover 21, that is, when the laser beam is irradiated downwards from the upper surface 211 of the end cover 21, the positioning groove 215 facilitates the path of the laser beam to correspond to the position of the mounting groove 213 on the lower surface 212 of the end cover 21.

The positioning groove 215 is a groove concavely formed on the upper surface 211.

The positioning groove 215 corresponding to the mounting groove 213 is formed on the upper surface 211, and the positioning groove 215 is used to quickly position the side wall 222 during welding, so that the laser can be directed and accurately weld the side wall 222 and the end cover 21.

The cross-sectional shape of the positioning slot 215 may be a semicircle, a V-shape, a rectangle, etc., and those skilled in the art can select the cross-sectional shape according to actual requirements, which is not limited herein, and as shown in the figure, the cross-sectional shape of the positioning slot 215 is a rectangle.

Referring to fig. 5 and fig. 7, in an actual use process, laser passes through the positioning groove 215 to precisely weld the side wall 222 and the end cover 21, so that the side wall 222 and the end cover 21 are welded, wherein the welding position of the side wall 222 and the end cover 21 may be only the side wall 222 and the third wall 2134, or on the basis of the side wall 222 and the third wall 2134, a part of the first wall 2131 and/or the second wall 2133 is also welded with the side wall 222.

Alternatively, when the side wall 222 is welded to the end cap 21 only at the side wall 222 and the third wall 2134, the center line of the positioning groove 215 coincides with the center line of the mounting groove 213.

According to some embodiments of the present application, the thickness of the end cap 21 between the bottom wall of the seating groove 215 and the bottom wall of the mounting groove 213 is 0.3-0.7mm in the thickness direction of the end cap.

Wherein the third wall 2134 is a bottom wall of the mounting groove, as shown in fig. 7, the cross section of the positioning slot 215 is rectangular, the positioning slot 215 has a fourth wall 2151 substantially parallel to the lower surface 212, that is, the fourth wall 2151 is a bottom wall of the positioning slot 215, therefore, the thickness of the end cap 21 between the bottom wall of the positioning slot 215 and the bottom wall of the mounting groove 213 refers to: the third wall 2134 and the fourth wall 2151 are spaced apart in the thickness direction.

The thickness meets the requirements of the welding process, and the welding strength after welding can be ensured. If the thickness is thin, the situation of welding through is easy to occur during welding, the process difficulty is high, if the thickness is too thick, the welding process difficulty is high, and more heat is accumulated in the welding process, so that the strength of a heat affected zone is insufficient.

In order to avoid the problem that the depth of the mounting groove 213 is too large, which results in a thinner thickness between the third wall 2134 and the upper surface 211, which is likely to cause welding-through during welding, and a difficulty in the process is high, when the upper surface 211 is not provided with the positioning groove 215 corresponding to the mounting groove 213, the thickness between the third wall 2134 and the upper surface 211 can be 0.3-0.7 mm.

According to some embodiments of the present application, referring to fig. 3 to 10, a battery cell 20 is further provided, which includes an electrode assembly 23, an end cap 21 in the above embodiments, and a case 22. End cap 21 has its circumferentially disposed sides 216, sides 216 connecting upper surface 211 and lower surface 212; the case 22 is used for accommodating the electrode assembly 23, the case 22 has an opening 221 and a side wall 222 surrounding the periphery of the opening 221, and at least a portion of the side wall 222 is embedded in the mounting groove 213, so that the side wall 222 is welded to the end cap 21 and forms a welded portion 218.

When the end cap 21, the electrode assembly 23 and the case 22 are assembled, the general operation process is as follows: the electrode assembly 23 is first put into the case 22 through the opening 221, the electrode assembly 23 is electrically connected to the electrode terminal 21a provided on the end cap 21, at least part of the side wall 222 of the case 22 is fitted into the mounting groove 213 to cover the end cap 21 on the opening 221, and then the end cap 21 and the case 22 are welded to each other by welding a laser beam from the upper surface 211 toward the third wall 2134.

The weld 218 refers to the joint formed by the sidewall 222 and the end cap 21 after welding. Optionally, the welding portion 218 is an annular structure surrounding the battery cell 20, and the welding portion 218 is used to weld the side wall 222 and the end cap 21 together to achieve sealing of the battery cell 20.

By utilizing the matching between the end cover 21 and the shell 22 provided by the embodiment, on one hand, the mounting groove 213 on the end cover 21 can accurately position the shell 22, which is beneficial to improving the assembly precision; on the other hand, after the side wall 222 of the housing 22 is embedded in the mounting groove 213, the side wall 222 can be respectively contacted with the first wall 2131 and the second wall 2133 to increase the contact area, and further, when the housing 22 and the side wall 222 are welded to be connected into a whole, heat generated by welding can be transmitted along the first wall 2131, the second wall 2133 and the side wall 222 along multiple directions, so that the heat transmission amount in each direction is weakened, the strength of the heat affected zone at the lower side of the welding joint is increased, and the possibility of cracking of the heat affected zone in the life time of the battery cell 20 is reduced.

The cross-sectional shape of the welding portion 218 gradually narrows from the upper surface 211 toward the third wall 2134, and the welding of the end cap 21 and the housing 22 may be laser welding, specifically laser transmission welding. The laser transmission welding may be performed by using a laser such as a semiconductor pulse laser, a fiber laser, a semiconductor/fiber composite laser, and the like, which is not limited herein.

The material of the end cap 21 is not limited, but it is necessary to ensure the same material. And can be selected as a metal material having good thermal conductivity while being lightweight. Such metallic materials include, but are not limited to, aluminum, stainless steel, and nickel plated steel. In the welding method of this example, the housing 22 and the end cap 21 are made of aluminum.

According to some embodiments of the present disclosure, referring to fig. 8 and 9, the sidewall 222 has a body 2221 and a mounting portion 2223 that are integrally formed, the mounting portion 2223 is embedded in the mounting groove 213, and an outer surface of the body 2221 is flush with the side surface 216.

In fig. 8 and 9, the "main body 2221" and the "mounting portion 2223" are separated into two parts in the height direction of the side wall 222, and are located at the boundary between the "main body 2221" and the "mounting portion 2223" by the dotted line in the side wall 222, the mounting portion 2223 is provided at the top end of the main body 2221, and the top end of the main body 2221 refers to one end of the main body 2221 close to the cover plate. Since the outer surface of the body 2221 is flush with the side surface 216, the mounting portion 2223 is offset from the top end of the body 2221. In fig. 8 and 9, the dashed lines within the weld 218 indicate the contact interface between the mounting portion 2223 and the mounting slot when not welded.

With the outer surface of the body 2221 flush with the side surface 216, as shown in fig. 8, the inner surface of the mounting portion 2223 may be flush with the inner surface of the body 2221, where the thickness of the body 2221 is greater than the thickness of the mounting portion 2223. Or on the premise that the outer surface of the body 2221 is flush with the side surface 216, as shown in fig. 9, the inner surface of the mounting portion 2223 protrudes from the inner surface of the body 2221, and at this time, the thickness of the body 2221 may be the same as that of the mounting portion 2223, which may improve the utilization rate of space.

According to some embodiments of the present application, referring to fig. 10, the sidewall 222 has a body 2221 and a mounting portion 2223 that are integrally formed, the mounting portion 2223 is embedded in the mounting groove 213, and the side surface 216 protrudes from the outer surface of the body 2221.

In fig. 10, the dashed lines within the weld 218 represent the contact interface of the mounting portion 2223 and the mounting slot when not welded. In fig. 10, "main body 2221" and "mounting portion 2223" are two parts separated from each other in the height direction, and are located at the boundary between "main body 2221" and "mounting portion 2223" defined by the dotted line in the side wall 222, the mounting portion 2223 is provided at the top end of the main body 2221, and the top end of the main body 2221 refers to one end of the main body 2221 close to the cover plate.

As shown in fig. 10, the outer surface of the body 2221 is flush with the outer surface of the mounting portion 2223, the outer surface of the body 2221 may be recessed in the side surface 216, and the inner surface of the body 2221 is flush with the inner surface of the mounting portion 2223.

With the arrangement shown in fig. 10, the original structure of the side wall 222 of the housing 22 can be directly adopted without modification of the shape thereof, thereby reducing the process flow for the side wall 222. According to some embodiments of the present application, the welding portion 218 is spaced a first predetermined distance from the side surface 216, and the welding portion 218 is spaced a second predetermined distance from the lower surface 212 in the thickness direction, wherein the first predetermined distance and the second predetermined distance are both greater than zero. The first preset distance and the second preset distance may be set according to actual requirements, and are not limited herein.

The arrangement is beneficial to enhancing the strength of the welding part 218, and simultaneously prevents the melted material from flowing into the inside of the battery cell 20 and damaging the electrode assembly 23 during welding, and also prevents the melted material from flowing out of the end cover 21 during welding.

Any two adjacent battery cells 20 are arranged at intervals and form a mounting gap 24; the battery 100 includes an insulation pad 30 disposed within the mounting aperture 24, the insulation pad 30 having a shape complementary to the shape of the mounting aperture 24.

Referring to fig. 2, 11 and 12, according to some embodiments of the present application, a battery 100 including a plurality of battery cells 20 according to the above embodiments is also provided.

In some embodiments, any two adjacent battery cells 20 are spaced apart and form a mounting gap 24; the battery 100 includes an insulating mat 30 disposed within the mounting slot 24.

Wherein, the installation gap 24 means: since the two battery cells 20 are spaced apart, a gap for mounting the heat insulation mat 30 is formed between opposite sides (the side surface 216 and the outer surface of the body 2221) of the two battery cells 20.

The arrangement of the heat insulation pad 30 can effectively isolate the heat transfer of two adjacent battery cells 20, so that when any one battery cell 20 is out of control thermally, the adjacent battery cell 20 is not affected.

As shown in fig. 7 and 8, when the side surface 216 is flush with the outer surface of the body 2221, the shape of the heat insulating mat 30 is substantially uniform in the thickness of the heat insulating mat 30 (in the direction from the bottom to the top of the battery cell 20) as shown in fig. 11.

In some embodiments, the shape of the insulation mat 30 is complementary to the shape of the mounting slot 24.

Complementary shape means that the outer contour of the heat insulation pad 30 is the same as the contour of the mounting gap 24, so that the heat insulation pad 30 can be embedded and filled in the mounting gap 24.

As shown in fig. 12, when the side surface 216 protrudes from the outer surface of the body 2221 to change the appearance of the battery cell 20, the shape of the heat insulation pad 30 may be modified to be complementary to the shape of the mounting slit 24, so that the heat insulation pad 30 can support two adjacent battery cells 20, and the stability of the assembly of the plurality of battery cells 20 in the battery 100 is ensured.

As shown in fig. 12, the insulation mat 30 is thinner in the portion corresponding to the end cap 21 and thicker in the portion corresponding to the side wall 222.

According to some embodiments of the present application, there is also provided an electric device, which includes the battery in the above embodiments, wherein the battery is used for providing electric energy.

According to some embodiments of the present application, referring to fig. 3, and 6-9, the present application provides a battery cell 20 including an electrode assembly 23, an end cap 21, and a case 22. An upper surface 211, a lower surface 212 and a side surface 216 distributed along the circumferential direction of the end cover 21, wherein the lower surface 212 and the upper surface 211 are arranged oppositely along the thickness direction of the end cover 21, and the side surface 216 is connected with the upper surface 211 and the lower surface 212; the lower surface 212 is provided with a first wall 2131 and a second wall 2133 along the circumferential direction of the end cover 21, mounting grooves 213 distributed along the circumferential direction of the end cover 21 are defined between the first wall 2131 and the second wall 2133, the upper surface 211 is provided with positioning grooves 215 corresponding to the mounting grooves 213, and the positioning grooves 215 are used for enabling the laser to directionally weld the side wall 222 and the end cover 21. In the thickness direction of the end cap 21, the depth of the mounting groove 213 is not less than 0.5mm, and the thickness of the end cap 21 between the positioning groove 215 and the mounting groove 213 is 0.3-0.7 mm. The case 22 is used for accommodating the electrode assembly 23, the case 22 has an opening 221 and a side wall 222 surrounding the periphery of the opening 221, the side wall 222 is embedded in the mounting groove 213, the side wall 222 is welded with the end cap 21 to form a welded part 218, the welded part 218 is a first preset distance away from the side surface 216, and the welded part 218 is a second preset distance away from the lower surface 212 in the thickness direction. The side wall 222 has a body 2221 and a mounting portion 2223 that are integrally formed, the mounting portion 2223 is inserted into the mounting groove 213, and the outer surface of the body 2221 is flush with the side surface 216.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; these modifications and substitutions do not depart from the spirit of the embodiments of the present application, and they should be construed as being included in the scope of the claims and description of the present application. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. The present application is not intended to be limited to the particular embodiments disclosed herein but is to cover all embodiments that may fall within the scope of the appended claims.

Claims (12)

1. An end cap (21) for a battery cell (20), the end cap (21) having:

an upper surface (211);

the lower surface (212) and the upper surface (211) are arranged oppositely in the thickness direction of the end cover (21), a first wall (2131) and a second wall (2133) are arranged on the lower surface (212) along the circumferential direction of the end cover (21), mounting grooves (213) distributed along the circumferential direction of the end cover (21) are defined between the first wall (2131) and the second wall (2133), and the mounting grooves (213) are used for mounting side walls (222) of a shell (22) of the battery unit (20).

2. The end cap (21) according to claim 1, wherein the depth of the mounting groove (213) is not less than 0.5mm in the thickness direction of the end cap (21).

3. The end cap (21) of claim 1, wherein the upper surface (211) is provided with a detent (215) corresponding to the mounting groove (213), the detent (215) for laser-directed welding of the side wall (222) to the end cap (21).

4. The end cap (21) of claim 3, wherein the thickness of the end cap (21) between the bottom wall of the positioning groove (215) and the bottom wall of the mounting groove (213) in the thickness direction of the end cap (21) is 0.3-0.7 mm.

5. A battery cell (20), comprising:

an electrode assembly (23);

the end cap (21) of any of claims 1-4, said end cap (21) having circumferentially distributed sides (216) thereof, said sides (216) connecting said upper surface (211) and said lower surface (212); and

and the shell (22) is used for accommodating the electrode assembly (23), the shell (22) is provided with an opening (221) and a side wall (222) surrounding the periphery of the opening (221), and at least part of the side wall (222) is embedded in the mounting groove (213) so that the side wall (222) is welded with the end cover (21) and forms a welding part (218).

6. The battery cell (20) of claim 5, wherein the side wall (222) has an integrally formed body (2221) and a mounting portion (2223), the mounting portion (2223) is embedded in the mounting groove (213), and an outer surface of the body (2221) is flush with the side surface (216).

7. The battery cell (20) of claim 5, wherein the side wall (222) has a body (2221) and a mounting portion (2223) that are integrally formed, the mounting portion (2223) is embedded in the mounting groove (213), and the side surface (216) protrudes from the outer surface of the body (2221).

8. The battery cell (20) of claim 5, wherein the weld (218) is a first predetermined distance from the side surface (216), and the weld (218) is a second predetermined distance from the lower surface (212) in the thickness direction, the first and second predetermined distances each being greater than zero.

9. A battery (100) comprising a plurality of battery cells (20) according to any one of claims 5-8.

10. The battery (100) according to claim 9, wherein any two adjacent battery cells (20) are arranged at intervals and form a mounting gap (24);

the battery (100) includes an insulating mat (30) disposed within the mounting slot (24).

11. The battery (100) of claim 10, wherein the shape of the thermal insulation mat (30) is complementary to the shape of the mounting slot (24).

12. An electric consumer, characterized in that it comprises a battery (100) according to any of claims 9-11, said battery (100) being intended to be powered.

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