CN216648533U

CN216648533U - Current collecting member, battery cell, battery, and power consumption device

Info

Publication number: CN216648533U
Application number: CN202220605178.9U
Authority: CN
Inventors: 柯海波; 陈文伟; 李全坤; 郑于炼; 王鹏; 邢承友
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2022-03-21
Filing date: 2022-03-21
Publication date: 2022-05-31
Anticipated expiration: 2032-03-21

Abstract

The application discloses a current collecting member, a battery cell, a battery and an electric device. The current collecting member is used to electrically connect an electrode assembly of a battery cell and an electrode terminal, and includes: a body and a plurality of protrusions; the protrusions are used for increasing the surface roughness of the body and protrude out of the body in the thickness direction of the body, so that the thickness of the current collecting component at the protrusions is larger than that of the body. The application provides a collecting member can reduce and take place the perforation risk of welding between collecting member and the electrode terminal, improves production goodness and efficiency to energy absorption rate when laser welding simultaneously.

Description

Current collecting member, battery cell, battery, and power consumption device

Technical Field

The application relates to the field of batteries, in particular to a current collecting component, a battery monomer, a battery and electric equipment.

Background

The lithium ion battery has the advantages of high energy density, high power density, more recycling times, long storage time and the like, so the lithium ion battery is widely used on portable electronic equipment such as mobile phones, digital cameras, portable computers and the like; and has wide application prospect in the aspects of large and medium-sized electric equipment such as electric vehicles, electric bicycles and other electric vehicles and energy storage facilities.

The battery generally comprises a plurality of battery cells, current collecting members of the battery cells are assembled with electrode terminals of an end cover assembly by welding, and the connection strength of the welding affects the connection stability of the battery cells at a later stage, so that a technical scheme for improving the connection strength of the current collecting members with the electrode terminals is needed.

SUMMERY OF THE UTILITY MODEL

In view of the above, the present application provides a current collecting member capable of improving the strength of welding between the current collecting member and an electrode terminal.

In a first aspect, the present application provides a current collecting member for electrically connecting an electrode assembly of a battery cell and an electrode terminal, the current collecting member including:

a body;

the protrusions are used for increasing the surface roughness of the body and protrude out of the body in the thickness direction of the body, so that the thickness of the current collecting component at the protrusions is larger than that of the body.

In the technical scheme of this application embodiment, set up a plurality of archs and can increase body roughness, the high anti-problem of laser when improving laser welding improves the absorptivity to laser energy to improve welding efficiency and welding strength, and through setting up a plurality of archs, the part increases the thickness of mass flow component, reduces the risk of welding when welding and wearing, improves the welding goodness.

In some embodiments, the body comprises:

a base;

the terminal connecting part protrudes out of the base part along the thickness direction of the base part, the terminal connecting part is provided with a first surface and a second surface which are arranged oppositely, the first surface is farther away from the base part than the second surface, the first surface is connected with the electrode terminal, and the plurality of protrusions are arranged on the second surface.

In the scheme, the terminal connecting part is arranged to protrude towards the electrode terminal, so that the welding stability of the current collecting component and the electrode terminal is improved, at least part of the current collecting component is accommodated in the mounting hole of the electrode terminal, the occupation of the internal space of a single battery is reduced, and the energy density of the battery is improved.

In some embodiments, the second surface is configured to be distant from the base in a direction in which the terminal connecting portion protrudes and form a recess, and the second surface is a bottom surface of the recess. The concave part provides accommodation space for the plurality of bulges, further reduces the occupation of the inner space of the single battery, improves the energy density of the battery, provides operation space for welding, and avoids the influence of laser energy on other parts in the single battery during laser welding.

In some embodiments, a protruding dimension of the plurality of protrusions with respect to the second surface in a thickness direction of the body is smaller than a depth of the recess. The height of the protrusions is set in a proper range, the manufacturability of the protrusions on the processing position of the current collecting member is improved, and the production cost is reduced while the requirements of reducing the laser height reflection and improving the welding goodness are met. And the protruding dimension is less than the depth of the concave part, so that the interference between the protrusion and other structures in the battery single body can be avoided, and the safety of the battery is ensured.

In some embodiments, the projections of the plurality of projections are equal in size. The energy distribution of each area is balanced during laser welding, and the connection reliability of a welding position is improved.

In some embodiments, the second surface is provided with a reflection reducing region, the plurality of protrusions are uniformly distributed in the reflection reducing region, the area A of the reflection reducing region and the area B of the second surface satisfy a relation, and A is greater than or equal to 70% B. The area of the antireflection region satisfies the above requirements, and the connection reliability of the current collecting member and the electrode terminal can be ensured.

In some embodiments, the shape of the orthographic projection of the protrusion on the bottom surface of the recess is: square or oval. The square or oval bulge is convenient for production and manufacture, and ensures the production efficiency.

In some embodiments, the protrusions of the plurality of protrusions have a height H in the thickness direction of the base, 0.03mm ≦ H ≦ 0.5 mm. Set up reasonable protruding height and can be under the circumstances of guaranteeing welding strength, control material and manufacturing cost.

In some embodiments, the shortest distance between two adjacent convex boundaries is L, and L is more than or equal to 0.5mm and less than or equal to 2 mm. Through setting up bellied interval distance scope, can be with the high anti-control in reasonable scope of welding surface's laser, improve the production goodness.

In some embodiments, the area of the orthographic projection of each protrusion on the first surface is S, 0.09mm ≦ S ≦ 1 mm. Through setting up bellied salient area scope, can reduce the risk of welding through when laser welding, control manufacturing cost simultaneously in reasonable within range.

In some embodiments, the plurality of protrusions are integrally formed with the body. By means of the scheme, the protrusions can be arranged on the body when the current collecting component is manufactured, production and manufacturing are facilitated, and production efficiency is improved.

In a second aspect, the present application provides a battery cell comprising:

a housing provided with an accommodating chamber;

an electrode terminal provided in the case;

the electrode assembly is accommodated in the accommodating cavity and comprises a main body part and a tab led out from the main body part; and

the current collecting member in the above-described embodiments is provided between the electrode terminal and the main body portion of the electrode assembly, and is used to electrically connect the electrode terminal and the tab, and the plurality of protrusions are used to increase the surface roughness of the body of the current collecting member.

In a third aspect, the present application provides a battery including the battery cell of the above embodiment.

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

The foregoing description is only an overview of the technical solutions of the present application, and the present application can be implemented according to the content of the description in order to make the technical means of the present application more clearly understood, and the following detailed description of the present application is given in order to make the above and other objects, features, and advantages of the present application more clearly understandable.

Drawings

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

FIG. 1 is a schematic 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 structural view of a current collecting member according to some embodiments of the present application;

FIG. 5 is a schematic structural view of a current collecting member according to other embodiments of the present application;

fig. 6 is a schematic structural view of a current collecting member according to still further embodiments of the present application;

FIG. 7 is a dimensional structure diagram of a protrusion according to some embodiments of the present disclosure.

Detailed description of the reference numerals

1000. A vehicle;

100. a battery; 200. a controller; 300. a motor;

10. a box body; 11. a first portion; 12. a second portion;

20. a battery cell; 21. an end cap assembly; 22. a housing; 23. an electrical core assembly; 2301. an electrode assembly; 24. an explosion-proof valve; 25. an electrode terminal;

26. a current collecting member; 2601. a body; 2602. a protrusion; 2603. a base; 2604. a terminal connecting portion; 2605. a first surface; 2606. a second surface; 2607. and an antireflection region.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are merely used to more clearly illustrate the technical solutions of the present application, and therefore are only 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 figures above, 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.

In recent years, batteries have been widely used to power high-power devices, such as electric vehicles, electromechanical devices, and the like. The battery realizes larger capacity or power by connecting a plurality of battery cells in series or in parallel.

In the battery cell, it is generally necessary to configure a current collecting member to achieve electrical connection of the electrode assembly and the electrode terminal. The electrode terminals and the current collecting member are mostly connected by laser welding, but the laser is reflected when being irradiated onto the current collecting member, and the smoother the surface to which the laser is applied, the higher the reflectivity is, that is, the laser is highly reflected, that is, the energy of the laser is not absorbed as much as possible and converted into heat for welding, thereby causing the efficiency of the laser welding to be reduced, and causing the waste of energy.

The inventors found that if the surface of the current collecting member for laser action is subjected to rough treatment for material reduction or a concave portion is machined, the thickness of the current collecting member is reduced, resulting in a weak portion. The weak portion is easily welded through during the laser welding.

The inventor provides a class of current collection component, and its surface that bears laser is provided with a plurality of archs, so not only can strengthen class of current collection component part regional thickness, greatly reduced welds the risk of wearing, guarantees the welding goodness, can also effectively improve the high reflection phenomenon of laser when welding, improves the problem that energy absorption rate is low when laser welding promptly.

The current collecting member, the battery cell containing the current collecting member, and the battery disclosed in the embodiments of the present application may be used in, but not limited to, an electric device for a vehicle, a ship, an aircraft, or the like. The power supply system with the electric device can be composed of the current collecting component, the single battery, the battery and the like, so that the probability of welding perforation between the current collecting component and the end cover assembly can be reduced, the laser high-reflectivity problem during welding is improved, and the production efficiency and the optimal rate are improved while the structural welding strength is ensured.

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, and the like, and the spacecraft may include an airplane, a rocket, a space shuttle, a spacecraft, and the like.

For convenience of description, the following embodiments take an example in which a power consuming apparatus according to an embodiment of the present application is 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 starting, navigation, and operational power requirements while the vehicle 1000 is traveling.

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

Referring to fig. 2, fig. 2 is an exploded view of a battery 100 according to some embodiments of the present disclosure. The battery 100 includes a case 10 and a battery cell 20, and the battery cell 20 is accommodated in the case 10. The case 10 is used to provide a receiving space for the battery cell 20, and the case 10 may have various structures.

In some embodiments, the case 10 includes 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 an 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 may be directly connected in series or in parallel or in series-parallel, and the whole body formed by the plurality of battery cells 20 is accommodated in the case 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 accommodating the whole in the case 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 shapes.

Referring to fig. 3, fig. 3 is an exploded schematic view of a battery cell 20 according to some embodiments of the present disclosure. The battery cell 20 refers to the smallest unit constituting the battery. Referring to fig. 3, the battery cell 20 includes an end cap assembly 21, a housing 22, a battery cell assembly 23, and other functional components.

The end cap assembly 21 refers to a member that covers an opening 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 assembly 21 may be adapted to the shape of the housing 22 to fit the housing 22. Alternatively, the end cap assembly 21 may be made of a material (e.g., an aluminum alloy) having certain hardness and strength, so that the end cap assembly 21 is not easily deformed when being extruded and collided, and thus the battery cell 20 may have higher structural strength and the safety performance may be improved. The end cap assembly 21 may be provided with functional components such as the electrode terminals 25. The electrode terminals 25 may be used to electrically connect with the electric core assembly 23 for outputting or inputting electric power of the battery cells 20. In some embodiments, a pressure relief mechanism for relieving the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold value may be further disposed on the end cap assembly 21. The material of the end cap assembly 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 assembly 21, which may be used to isolate the electrical connection components within the housing 22 from the end cap assembly 21 to reduce the risk of short circuits. Illustratively, the insulator may be plastic, rubber, or the like.

The case 22 is a component for mating with the end cap assembly 21 to form the internal environment of the battery cell 20. The internal environment formed may be used to house, among other things, the cell assembly 23, electrolyte, and other components. The housing 22 and the end cap assembly 21 may be separate components, and an opening may be provided in the housing 22, and the opening may be covered by the end cap assembly 21 to form the internal environment of the battery cell 20. Without limitation, the end cap assembly 21 and the housing 22 may be integrated, and specifically, the end cap assembly 21 and the housing 22 may form a common connecting surface before other components are inserted into the housing, and when it is required to enclose the inside of the housing 22, the end cap assembly 21 covers the housing 22. The housing 22 may be a variety of shapes and sizes, such as rectangular parallelepiped, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 22 may be determined according to the specific shape and size of the electric core assembly 23. The material of the housing 22 may be various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present invention is not limited thereto.

The cell assembly 23 is a component in the battery cell 100 where electrochemical reactions occur. One or more electrical core assemblies 23 may be contained within the housing 22. The core assembly 23 is mainly formed by winding or stacking a positive electrode sheet and a negative electrode sheet, and a separator is generally provided between the positive electrode sheet and the negative electrode sheet. The parts of the positive plate and the negative plate with the active materials form the main body part of the electric core assembly, and the parts of the positive plate and the negative plate without the active materials form the tabs respectively. 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 charging and discharging process of the battery, the positive active material and the negative active material react with the electrolyte, and the tabs are connected with the electrode terminals to form a current loop.

In some embodiments of the present application, the end cap assembly 21 further includes a current collecting member 26, and the current collecting member 26 is used to connect the electrode terminal 25 on the end cap assembly 21 with the electrode assembly 2301 of the electric core assembly 23. The electrode terminals 25 and the electrode assemblies 2301 are respectively provided on both sides of the current collecting member 26. The current collecting member 26 is connected to the electrode terminal 25 and the electrode assembly 2301 by welding.

Referring to fig. 4 to 7, fig. 4 is a schematic structural view of the current collecting member 26 of the battery cell 20 according to some embodiments of the present disclosure; fig. 5 is a schematic view of the current collecting member 26 of a battery cell 20 according to other embodiments of the present disclosure; fig. 6 is a schematic structural view of the current collecting member 26 of the battery cell 20 according to still further embodiments of the present application; fig. 7 is a dimensional structure diagram of a protrusion 2602 according to some embodiments of the present application.

As shown in fig. 4, the current collecting member 26 of the battery cell 20 in the embodiment of the present application includes: a body 2601 and a plurality of protrusions 2602. A plurality of protrusions 2602 for increasing surface roughness of the body 2601, the plurality of protrusions 2602 protruding from the body 2601 in a thickness direction of the body 2601 such that at the protrusions 2602, a thickness of the current collecting member 26 is greater than a thickness of the body 2601.

It should be noted that the roughness of the surface of the object means the small pitch and the unevenness of the minute peaks and valleys of the processed surface. Roughness is a dimension parameter in a projecting direction, and the unevenness of the body 2601 can be increased by providing a plurality of projections 2602 on the surface of the body 2601 to raise the roughness of the surface of the body 2601 by the minute peaks and valleys on the surface of the body 2601.

Among the technical scheme of this application embodiment, can increase body 2601 roughness through setting up a plurality of archs 2602, improve the high anti-problem of laser when laser welding, improve welding efficiency and welded intensity to through setting up a plurality of archs 2602, the part increases the thickness of mass flow component 26, reduces the fenestrate possibility of welding, improves the welding goodness.

In some embodiments of the present application, please refer to fig. 4 and fig. 5 in combination, the body 2601 includes: a base portion 2603 and a terminal connecting portion 2604. The terminal connecting portion 2604 protrudes from the base portion 2603 in the thickness direction of the base portion 2603. And the terminal connecting portion 2604 has a first surface 2605 and a second surface 2606 disposed opposite to each other. The first surface 2605 is farther from the base portion 2603 than the second surface 2606, wherein the first surface 2605 is for connecting the electrode terminal 25 and the plurality of protrusions 2602 are provided on the second surface 2606.

In the above-described embodiment, the terminal connecting portion 2604 is provided to protrude toward the electrode terminal 25, thereby improving the welding stability between the current collecting member 26 and the electrode terminal 25. To facilitate connection with electrical equipment or connection wires, the electrode terminals 25 are generally disposed to protrude from the surface of the end cap assembly 21. Therefore, providing the terminal connection portion 2604 on the body 2601 can match the shape of the electrode terminal 25, facilitate the connection between the current collecting member 26 and the electrode terminal 25, and ensure the stability of the connection and the stability of the electrical conduction. While the current collecting member 26 is at least partially received in the mounting hole of the electrode terminal 25, it is possible to improve space utilization inside the battery cell, thereby improving energy density.

In some embodiments of the present application, the first surface 2605 may also be provided with a plurality of protrusions 2602, and the plurality of protrusions 2602 protrude from the first surface 2605 upwards along the thickness direction of the body 2601, so as to increase the roughness of the first surface 2605 for enhancing the connection strength of the welding with the electrode assembly 2301.

In some embodiments of the present application, the second surface 2606 is configured to be distant from the base portion 2603 in a direction in which the terminal connecting portion 2604 protrudes and form a concave portion, and the second surface 2606 is a bottom surface of the concave portion. The concave part provides a containing space for the plurality of protrusions 2602, further reduces the occupation of the internal space of the battery cell 20, improves the energy density of the battery, provides an operating space for welding, and avoids the influence of laser energy on other components in the battery cell 20 during laser welding.

In some embodiments of the present application, a protruding dimension of the plurality of protrusions 2602 with respect to the second surface 2606 in a thickness direction of the body 2601 is smaller than a depth of the recess.

The structure can meet the requirements of reducing laser high-reflection and improving welding goodness, and meanwhile, the manufacturability of the plurality of protrusions 2602 at the processing position of the current collecting member 26 is increased, and the production cost is reduced. And the protruding dimension is smaller than the depth of the recess, so that interference between the protrusion 2602 and other structures in the battery cell 100 can be avoided, and the safety of the battery is ensured.

In some embodiments of the present application, the plurality of protrusions 2602 are equal in protrusion size. The above structure can ensure that the end surfaces of the plurality of protrusions 2602 facing away from the second surface 2606 are located in the same plane. The energy distribution of all parts of the welding area is balanced during laser welding, and the connection reliability of the welding part is improved.

In some embodiments of the present application, as shown in FIG. 6, a reflection reducing region 2607 is disposed on the second surface 2606, the plurality of protrusions 2602 are uniformly distributed on the reflection reducing region 2607, an area A of the reflection reducing region 2607 and an area B of the second surface 2606 satisfy a relationship, A ≧ 70% B. The relieved region 2607 serves to reduce the area of the smooth region on the second surface 2606. The area of the reflection reduction region 2607 satisfies the above requirements, and the connection reliability of the current collecting member 26 and the electrode terminal 25 can be ensured.

In some embodiments of the present application, the recess may be circular in shape, and the relief region 2607 may be correspondingly configured as a circle or a donut. Also, the center of the subtractive region 2607 coincides with the center point of the second surface, i.e., the subtractive region 2607 is generally disposed in the middle region of the second surface 2606. The welding region of the electrode terminal 25 and the current collecting member 26 is generally in the middle region of the second surface 2606, and the arrangement of the reflection reduction region 2607 therein can ensure the roughness of the welding region as much as possible and improve the connection strength of the welding region.

When the current collecting member 26 and the electrode terminal 25 are laser-welded, laser light acts on the reflection reduction region 2607, and the plurality of protrusions 2602 of the reflection reduction region 2607 can reduce the reflectivity of the laser light, so that the energy of the laser light can be effectively absorbed and converted into heat, thereby achieving welding. Therefore, the above-described structure can further improve the connection reliability of the current collecting member 26 and the electrode terminal 25.

In some embodiments of the present application, the orthographic projection of the protrusion 2602 on the bottom surface of the recess has the shape: square or oval. The protrusions 2602 shown in fig. 7 are square protrusions 2602, and a plurality of the protrusions 2602 are distributed in an array on the second surface 2606. The square or oval protrusions 2602 facilitate production and manufacture and ensure production efficiency.

In some embodiments of the present application, the shape of the orthographic projection of the protrusion 2602 on the second surface 2606 may also be: circular, oval, racetrack, triangular or circular, etc. The structure can be designed according to the use requirement, and the technical effects of improving the roughness of the second surface 2606 to reduce the laser reflection of the welding surface and improve the production yield can be achieved.

In some embodiments of the present application, the plurality of protrusions 2602 have a protrusion height H in the thickness direction of the base 2603, where H satisfies 0.03mm ≦ H ≦ 0.5 mm. The height of the protrusion 2602 is set too low to significantly change the roughness of the second surface 2606, so that the effect of effectively reducing the height of the weld is not achieved. The protrusions 2602 are set too high and may interfere with other structures and cause material waste. Setting up reasonable arch 2602 height can be under the circumstances of guaranteeing welding strength, control material and manufacturing cost, prevent to interfere with other parts simultaneously.

In some embodiments of the present application, as shown in FIG. 7, the shortest distance between the boundaries of two adjacent protrusions 2602 is L, and L is greater than or equal to 0.5mm and less than or equal to 2 mm.

The too large distance between the boundaries of two adjacent protrusions 2602 can cause the light reflection phenomenon in the region between the boundaries; too small a distance between the boundaries of two adjacent protrusions 2602 may result in a waste of material. Therefore, the spacing distance of the protrusions 2602 is set in the range of 0.5mm to 2mm, the laser reflection of the welding surface can be reduced, and the production yield is improved.

In some embodiments of the present application, the area of the orthographic projection of each protrusion 2602 on the first surface 2605 is S, 0.09mm ≦ S ≦ 1 mm.

If the area of each projection 2602 is designed to be too small, the roughness of the welded region cannot be effectively improved, and the current collecting member is not effectively reinforced, and a hole may be formed during welding; the area of each protrusion 2602 is designed to be too large, which results in waste of material and increases the production cost. According to the technical scheme, the reasonable range of the protruding area of the protrusion 2602 is set, so that the production cost is controlled within the reasonable range while the perforation phenomenon is avoided during welding.

In some embodiments of the present application, optionally, the height H of each protrusion 2602 is 0.05mm, the shortest distance between the boundaries of two protrusions 2602 is 0.5mm, the protrusions are rectangular, and the area S of each protrusion 2602 is 0.25 mm.

In some embodiments of the present application, optionally, the height H of each protrusion 2602 is 0.03mm, the shortest distance between the boundaries of two protrusions 2602 is 0.5mm, the protrusions are rectangular, and the area S of each protrusion 2602 is 0.09 mm.

In some embodiments of the present application, optionally, the height H of the protrusion 2602 is 0.5mm, the shortest distance between the boundaries of two protrusions 2602 is 2mm, the protrusions are rectangular, and the area S of each protrusion 2602 is 1 mm.

In some embodiments of the present application, a plurality of protrusions 2602 are integrally formed with body 2601. The body 2601 and the protrusions 2602 are usually made of the same material, and the protrusions 2602 can be formed on the body 2601 by stamping the substrate to form the terminal connecting portion 2604 and the plurality of protrusions 2602, or melting the material and injecting the melted material into a mold for cooling and forming, and forming corresponding holes and grooves on the mold. With the above configuration, the projection 2602 can be provided on the body 2601 at the time of manufacturing the current collecting member 26, thereby improving the production efficiency.

Embodiments of the present application also provide a battery cell 20, which includes: a case 22, electrode terminals 25, an electrode assembly 2301, and a current collecting member 26. The case 22 is provided with a receiving cavity, the electrode terminal 25 is provided at the case 22, the electrode assembly 2301 is received in the receiving cavity, and the electrode assembly 2301 includes a main body portion and tabs drawn from the main body portion. A current collecting member 26, the current collecting member 26 being disposed between the electrode terminal 25 and the body portion of the electrode assembly 2301, the current collecting member 26 for electrically connecting the electrode terminal 25 and the tab, and a plurality of protrusions 2602 for increasing surface roughness of the body of the current collecting member 26.

The current collecting member 26 has the technical characteristics of any one of the above embodiments, so that the battery cell 20 in the present application can also ensure the connection strength between the current collecting member 26 and the electrode terminal 25 and the stability of current transmission.

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; such modifications and substitutions do not depart from the spirit and scope of the present disclosure, and the present disclosure should be construed as being covered by the claims and the specification. 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

1. A current collecting member for electrically connecting an electrode assembly of a battery cell and an electrode terminal, the current collecting member comprising:

a body;

a plurality of protrusions for increasing surface roughness of the body, the plurality of protrusions protruding from the body in a thickness direction of the body such that a thickness of the current collecting member at the protrusions is greater than a thickness of the body;

wherein the body comprises:

a base;

and a terminal connection part protruding from the base part in a thickness direction of the base part, the terminal connection part having a first surface and a second surface opposite to each other, the first surface being farther from the base part than the second surface, the first surface being connected to the electrode terminal, the plurality of protrusions being provided on the second surface.

2. The current collecting member according to claim 1, wherein the second surface is configured to be distant from the base in a direction in which the terminal connecting portion protrudes and to form a recess, the second surface being a bottom surface of the recess.

3. A current collecting member according to claim 2, wherein a protruding dimension of the plurality of protrusions with respect to the second surface in a thickness direction of the body is smaller than a depth of the recess.

4. The current collecting member of claim 3, wherein the protrusion sizes of the plurality of protrusions are equal.

5. The current collecting member according to claim 4, wherein a reflection reducing region is provided on the second surface, the plurality of protrusions are uniformly distributed in the reflection reducing region, an area A of the reflection reducing region and an area B of the second surface satisfy a relationship, and A is greater than or equal to 70% B.

6. The current collecting member according to claim 5, wherein an orthographic projection of the protrusion on the bottom surface of the recess has a shape of: square or oval.

7. The current collecting member according to claim 3, wherein a protrusion height of the plurality of protrusions in a thickness direction of the base is H, 0.03mm ≦ H ≦ 0.5 mm.

8. The current collecting member according to claim 5, wherein the shortest distance between the boundaries of two adjacent protrusions is L, and L is greater than or equal to 0.5mm and less than or equal to 2 mm.

9. The current collecting member according to claim 5, wherein an area of a forward projection of each said protrusion on the first surface is S, 0.09mm ≦ S ≦ 1 mm.

10. The current collecting member of any one of claims 1 to 9, wherein the plurality of projections are integrally formed with the body.

11. A battery cell, comprising:

a housing provided with an accommodating chamber;

an electrode terminal provided in the case;

an electrode assembly accommodated in the accommodation chamber, the electrode assembly including a main body portion and a tab drawn out from the main body portion;

the current collecting member according to any one of claims 1 to 10, which is provided between the electrode terminal and the main body portion of the electrode assembly, for electrically connecting the electrode terminal and the tab, and a plurality of protrusions for increasing surface roughness of a body of the current collecting member.

12. A battery comprising the battery cell of claim 11.

13. An electrical device comprising a battery as claimed in claim 12 for providing electrical energy.