CN220439824U - Battery monomer, battery and electric equipment - Google Patents

Abstract

The utility model relates to the technical field of batteries and provides a battery cell, a battery and electric equipment, wherein the battery cell comprises an electrode assembly and a current collecting member, and the electrode assembly comprises an electrode main body and a lug arranged at the end part of the electrode main body; the current collecting member is arranged on the tab, and the outer edge part of the current collecting member is overlapped with the outer edge part of the tab so that the part of the tab is exposed to the outside. According to the battery cell provided by the utility model, the outline size of the current collecting member is smaller than that of the lug, so that the current collecting member cannot cover the lug completely, and then when the current collecting member is connected with the lug by laser welding, laser beams can be emitted from the side direction, namely, the current collecting member forms a small acute angle with the plane of the lug, so that the probability of diaphragm damage caused by the fact that the laser beams vertically enter the plane of the lug is reduced, and the yield of manufacturing the electrode assembly is improved.

Description

Battery monomer, battery and electric equipment

Technical Field

The utility model relates to the technical field of batteries, and particularly provides a battery monomer, a battery and electric equipment.

Background

With the development of new energy technology, batteries are increasingly used in mobile phones, notebooks, electric vehicles, and the like.

The battery cell serves as an energy storage element, and generally, an electrochemical reaction occurs between the electrode assembly and the electrolyte, thereby outputting electric energy. In the battery cell, the end cap and the electrode assembly may be electrically connected through the current collecting member. In general, the current collecting member is connected to the tab of the electrode assembly by welding, and the welding direction (the transmission direction of the welding laser) of the welding device is perpendicular or nearly perpendicular to the current collecting member, so that the welding process is difficult to avoid the separator of the electrode assembly, and the short circuit phenomenon of the electrode sheet of the electrode assembly is easy to occur.

Disclosure of Invention

The utility model provides a battery monomer, a battery and electric equipment, and aims to solve the problem that the existing battery monomer is easy to cause pole piece short circuit in the manufacturing process.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

in a first aspect, embodiments of the present application provide a battery cell, including:

an electrode assembly including an electrode body and a tab provided at an end of the electrode body;

and the current collecting member is arranged on the tab, and the outer edge part of the current collecting member is overlapped with the outer edge part of the tab so that the part of the tab is exposed to the outside.

The utility model has the beneficial effects that: according to the battery cell provided by the utility model, the outline size of the current collecting member is smaller than that of the electrode lug, and the current collecting member cannot completely cover the electrode lug, so that part of the electrode lug is exposed, and then when the current collecting member is connected with the electrode lug by laser welding, laser beams can be emitted from the side direction, namely, the laser beams form a small acute angle with the plane of the electrode lug, so that the probability of diaphragm damage caused by the fact that the laser beams vertically irradiate into the plane of the electrode lug is reduced, and the yield of manufacturing the electrode assembly is improved.

In some embodiments, at least a portion of the outer edge portion of the current collecting member is recessed inwardly to form a notched structure.

In some embodiments, the current collecting member includes a base body whose outer edge portion is recessed inward to form the notch structure, and the tab is able to pass through the notch structure to the outside.

In some embodiments, the current collecting member includes a base body and a laminated body that are laminated, the base body is disposed on the tab, and an outer edge portion of the base body and/or an outer edge portion of the laminated body is recessed inward to form the notch structure.

In some embodiments, the outline of the substrate is the same as the outline of the tab, and the substrate covers the tab, and the outer edge of the laminated body is recessed inwards to form the notch structure.

In some embodiments, the geometric center of the current collecting member is collinear with the winding center axis of the electrode body, and the notch structure is recessed inwardly to the geometric center of the current collecting member.

In some embodiments, a projection of one of the outer edge portions of the current collecting member onto the end portion of the electrode body is close to a winding center axis of the electrode body.

In some embodiments, a projection of an outer edge portion of the current collecting member on the tab coincides with a winding center axis of the electrode body.

In a second aspect, embodiments of the present application provide a battery, including the above-described battery cell.

In a third aspect, an embodiment of the present application provides an electric device, including the battery described above.

It will be appreciated that the advantages of the second and third aspects described above may be found in the relevant description of the first aspect described above and will not be described in detail here.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed in the embodiments or the description of the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic structural diagram of an electric device according to an embodiment of the present utility model;

fig. 2 is a schematic structural diagram of a battery according to an embodiment of the present utility model;

fig. 3 is a schematic structural diagram of a battery cell according to an embodiment of the present utility model;

fig. 4 is a schematic structural diagram of a tab and a current collecting member according to a first embodiment of the present utility model;

fig. 5 is a schematic structural diagram of a tab and a current collecting member according to a second embodiment of the present utility model;

fig. 6 is a schematic structural diagram of a tab and a current collecting member according to a third embodiment of the present utility model;

fig. 7 is a schematic structural diagram of a tab and a current collecting member according to a fourth embodiment of the present utility model;

fig. 8 is an exploded view of an electrode assembly according to a fifth embodiment of the present utility model;

fig. 9 is an exploded view of an electrode assembly according to a sixth embodiment of the present utility model.

Wherein, each reference sign in the figure:

10000. an electric device; 1000. a controller; 2000. a motor;

3000. a battery; 3001. a battery cell; 3002. a battery case; 30021. a first portion; 30022. a second portion;

10. an electrode assembly; 20. a housing; 30. an end cap;

11. an electrode main body; 12. a tab; 40. a current collecting member; 40a, a notch structure; 41. a base; 42. a laminate;

winding the central axis N.

Detailed Description

Embodiments of the present utility model are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present utility model and should not be construed as limiting the utility model.

In the description of the present utility model, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the present utility model and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present utility model.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present utility model, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the present utility model, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

The battery cell serves as an energy storage element, and generally, an electrochemical reaction occurs between the electrode assembly and the electrolyte, thereby outputting electric energy. In the battery cell, the end cap and the electrode assembly may be electrically connected through the current collecting plate. Typically, the current collecting plates are connected to the tabs of the electrode assembly by laser welding. Specifically, the laser welding beam is incident along the direction vertical to the lug or approximately vertical to the plane of the lug, so as to realize the connection of the current collecting disc and the lug. However, in order to improve the reliability of the welded connection of the two, the thickness of the current collecting disc is relatively thin, which also easily causes the problem that the current collector is welded through to damage the separator, and finally causes the electrode assembly to be shorted.

In view of this, the present application provides an electrode assembly, wherein, at least partial outer fringe portion of the current collecting member does not overlap with the outer fringe portion of the tab, that is, the outline size of the current collecting member is smaller than the outline size of the tab, so that the current collecting member cannot completely cover the tab, so that the tab is partially exposed to the outside, and then, when the current collecting member is connected with the tab by laser welding, the laser beam can be emitted from the side direction, that is, an acute angle is formed between the current collecting member and the plane of the tab, so as to reduce the probability of damage to the diaphragm caused by the laser beam vertically incident into the plane of the tab, and improve the yield of the manufactured electrode assembly.

The battery cell comprises an electrode assembly and electrolyte, wherein the electrode assembly consists of a positive plate, a negative plate and a separation membrane. The battery cell mainly relies on metal ions to move between the positive and negative electrode plates to operate. The positive plate comprises a positive electrode current collector and a positive electrode active material layer, wherein the positive electrode active material layer is coated on the surface of the positive electrode current collector, the current collector without the positive electrode active material layer protrudes out of the current collector coated with the positive electrode active material layer, and the current collector without the positive electrode active material layer is laminated to serve as a positive electrode lug. For convenience of description, the tab refers to the positive electrode tab and/or the negative electrode tab.

In the present application, the battery cell includes, but is not limited to, a lithium ion secondary battery cell, a lithium ion primary battery cell, a lithium sulfur battery cell, a sodium lithium ion battery cell, a sodium ion battery cell, a magnesium ion battery cell, or the like. The battery cells may be cylindrical, flat, rectangular, or otherwise shaped. The battery cells are generally classified into three types according to the packaging method: cylindrical battery cells, square battery cells and soft package battery cells.

The embodiment of the application provides a power consumption device 10000 which uses the battery cell 3001 as a power supply and can be applied to vehicles, mobile phones, portable equipment, notebook computers, ships, spacecrafts, electric tools and the like. The vehicle can be a fuel oil vehicle, a fuel gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure-powered vehicle, a hybrid power vehicle or a range-extended vehicle; spacecraft including airplanes, rockets, space shuttles, spacecraft, and the like; the electric toy includes fixed or mobile electric toys, such as a game machine, an electric car toy, an electric ship toy, an electric plane toy, and the like; power tools include metal cutting power tools, grinding power tools, power tools for assembly of power tools and iron, such as electric drills, power grinders, power wrenches, power screwdrivers, electric hammers, impact drills, concrete vibrators, electric planers, and the like.

The battery cell 3001 described in the embodiments of the present application is not limited to the above-described electric device 10000, but may be applied to all devices using the battery cell 3001, but for simplicity of description, the following embodiments are described by taking an electric automobile as an example.

For example, referring to fig. 1, a schematic structural diagram of a vehicle according to an embodiment of the present application is shown, where the vehicle may be a fuel-oil vehicle, a gas-fired vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid electric vehicle or an extended range vehicle. A battery 3000, a controller 1000, and a motor 2000 may be provided in the interior of the vehicle, and the controller 1000 is configured to control the battery 3000 to supply power to the motor 2000. For example, the battery 3000 may be provided at the bottom or the head or the tail of the vehicle. Battery 3000 may be used for power supply of a vehicle, for example, battery 3000 may be used as an operating power source for a vehicle, for circuitry of a vehicle, for example, for operating power requirements at start-up, navigation and run-time of a vehicle. In another embodiment of the present application, battery 3000 may be used not only as an operating power source for a vehicle, but also as a driving power source for a vehicle, instead of or in part instead of fuel oil or natural gas, to provide driving power for the vehicle.

References to battery 3000 in the embodiments of the present application refer to a single physical module that includes one or more battery cells 3001 to provide higher voltage and capacity. Referring to fig. 2, a battery 3000 may include a plurality of battery cells 3001. The number of the battery cells 3001 and the connection condition between the battery cells 3001 can be set according to the requirements to meet different power requirements. Specifically, the plurality of battery cells 3001 may be connected in series or parallel or in series-parallel, where series-parallel refers to a mixture of series and parallel connection, so that the battery 3000 has a larger capacity or power. Alternatively, the plurality of battery cells 3001 may be connected in series or parallel or series-parallel to form the battery 3000 module, and then the plurality of battery 3000 modules may be connected in series or parallel or series-parallel to form the battery 3000. That is, a plurality of battery cells may directly constitute the battery 3000, or may constitute a battery module first, and the battery module may constitute the battery 3000 again.

The battery 3000 further includes a battery case 3002, and an accommodating space is provided inside the battery case 3002, and a plurality of battery cells are accommodated in the accommodating space. As shown, the battery case 3002 may include two portions, referred to herein as a first portion 30021 and a second portion 30022, respectively, referring to the figures and drawings, which are the first portion 30021 of the battery case 3002. The first portion 30021 and the second portion 30022 may be connected by snap fit, adhesive, or the like to form a receiving space. The plurality of battery cells are connected in parallel or in series-parallel combination and then placed in a box formed by connecting the first portion 30021 and the second portion 30022. Wherein the shape of the first portion 30021 and the second portion 30022 may be determined according to a shape formed by combining a plurality of battery cells.

The battery case 3002 is used for protecting at least one battery cell, so as to reduce the influence of liquid or other foreign matters outside the battery 3000 on the charge or discharge of the at least one battery cell. The battery cells may be in a cylindrical shape, a flat shape, a rectangular shape, or other shapes, which are not limited in the embodiments of the present application. The packaging mode of the battery cell includes, but is not limited to, a cylindrical battery cell, a square battery cell, a soft package battery cell, and the like, which is not particularly limited in the embodiment of the present application.

In addition, the battery 3000 may further include other structures, which are not described in detail herein. For example, the battery 3000 may further include a bus member. The bus bar member is used to realize electrical connection between the plurality of battery cells, for example, parallel connection, serial connection or series-parallel connection between the plurality of battery cells. Specifically, the bus member may realize electrical connection between the battery cells by connecting electrode terminals of the battery cells. Further, the bus member may be fixedly connected with the electrode terminals of the battery cells by welding. Alternatively, the confluence part may include a conductive mechanism, and the electric power generated by the plurality of battery cells may be further drawn through the battery case 3002 by the conductive mechanism.

Each battery cell 3001 may be, but is not limited to, a lithium ion battery cell, a lithium sulfur battery cell, a sodium ion battery cell, or a magnesium ion battery cell. The battery cell 3001 may be in the shape of a cylinder, a flat body, a rectangular parallelepiped, or other shapes, etc.

Referring to fig. 3, fig. 3 is a schematic exploded view of a battery cell 3001 according to some embodiments of the present disclosure. The battery cell 3001 refers to the smallest unit constituting the battery 3000. As shown in fig. 3, the battery cell 3001 includes a case 20, an end cap 30, an electrode assembly 10, electrode terminals, and other functional components.

The end cap 30 refers to a member that is covered at the opening of the case 20 to isolate the inner environment of the battery cell 3001 from the outer environment. Without limitation, the shape of the end cap 30 may be adapted to the shape of the housing 20 to fit the housing 20. Optionally, the end cover 30 may be made of a material (such as an aluminum alloy) with a certain hardness and strength, so that the end cover 30 is not easy to deform when being extruded and collided, so that the battery cell 3001 can have a higher structural strength, and the safety performance can be improved. The end cap 30 may be provided with functional parts such as electrode terminals and the like. The electrode terminals may be used in connection with the electrode assembly 10 for outputting or inputting electric power of the battery cells. In some embodiments, a pressure relief mechanism may also be provided on the end cap 30 for relieving the internal pressure of the battery cell 3001 when the internal pressure or temperature reaches a threshold. The material of the end cap 30 may be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not particularly limited in the embodiments of the present application. In some embodiments, an insulating member may also be provided on the inside of the end cap 30, which may be used to isolate electrical connection components within the housing 20 from the end cap 30 to reduce the risk of short circuits. By way of example, the insulating member may be plastic, rubber, or the like.

The case 20 is an assembly for cooperating with the end cap 30 to form an internal environment of the battery cell 3001, wherein the formed internal environment may be used to house the electrode assembly 10, electrolyte, and other components. The case 20 and the end cap 30 may be separate components, and an opening may be provided in the case 20, and the interior of the battery cell may be formed by covering the opening with the end cap 30 at the opening. It is also possible to integrate the end cap 30 and the housing 20, but specifically, the end cap 30 and the housing 20 may form a common connection surface before other components are put into the housing, and when the interior of the housing 20 needs to be sealed, the end cap 30 is then covered with the housing 20. The housing 20 may be of various shapes and sizes, such as rectangular parallelepiped, cylindrical, hexagonal prism, etc. Specifically, the shape of the case 20 may be determined according to the specific shape and size of the electrode assembly. The material of the housing 20 may be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not particularly limited in the embodiments of the present application.

The electrode assembly 10 is a component in which electrochemical reactions occur in the battery cell 3001. One or more electrode assemblies 10 may be contained within the case 20. The electrode assembly 10 is mainly formed by winding or laminating a positive electrode tab and a negative electrode tab, and a separator is generally provided between the positive electrode tab and the negative electrode tab. The parts of the positive pole piece and the negative pole piece with active substances form an electrode main body of the electrode assembly, and the parts of the positive pole piece and the negative pole piece without active substances form electrode lugs respectively. The positive electrode tab and the negative electrode tab may be located at one end of the electrode body together or at two ends of the electrode body respectively. During charge and discharge of the battery, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tab is connected with the electrode terminal to form a current loop.

Referring to fig. 3 to 9 in combination, fig. 3 is an exploded view of a battery cell 3001 provided in some embodiments of the present application;

in a first aspect, embodiments of the present application provide a battery cell 3001 including an electrode assembly 10 and a current collecting member 40.

The electrode assembly 10 includes an electrode body 11 and a tab 12 provided at an end of the electrode body 11;

the current collecting member 40 is disposed on the tab 12 such that an outer edge portion of a portion of the current collecting member 40 coincides with an outer edge portion of the tab 12 to expose a portion of the tab 12 to the outside.

It is understood that the current collecting member 40 is a component for electrically connecting the end cap of the battery cell with the tab 12. The outline of the current collecting member 40 may be various, such as a circle, a rectangle, a triangle, an ellipse, an irregular shape, and the like. The shape of the current collecting member 40 may be adapted to the shape of the case of the battery cell. For example, the housing is a cylinder, the manifold member 40 is a circular structure, and the manifold member 40 may also be referred to as a manifold disk.

In the set position, the current collecting member 40 is connected to both the tab 12 of the electrode assembly 10 and the end cap of the electrode assembly 10. The tab 12 of the electrode assembly 10 connected to the current collecting member 40 may be a positive tab or a negative tab.

The outer edge of the current collecting member 40 means the edge of the current collecting member 40, and is also a portion constituting the outline of the current collecting member 40. The outer edge portion of the current collecting member 40 may be one or more, for example, the current collecting member 40 having a circular or oval shape has only one outer edge portion; the number of the outer edge portions of the triangular or rectangular current collecting member 40 is plural. Then, the overlapping of the outer edge of the current collecting member 40 and the outer edge of the tab 12 means that the current collecting member 40 does not completely cover the tab 12, so that the portion of the tab 12 is exposed to the outside, so as to satisfy the welding mode of the welding laser beam entering laterally.

As illustrated in fig. 5, the current collecting member 40 has a circular structure in which an outer edge portion of the current collecting member 40 is tangent to an outer edge portion of the tab 12, so that a part of the tab 12 may be exposed to the outside from an uncovered area of the current collecting member 40 to satisfy the lateral incidence of the welding laser beam.

As shown in fig. 6, for example, the current collecting member 40 has a structure in which an outer edge portion is in a wave state, one outer edge portion of the current collecting member 40 coincides with an outer edge portion of the tab 12, and similarly, a part of the tab 12 may be exposed to the outside from an uncovered area of the current collecting member 40 so as to satisfy the lateral incidence of the welding laser beam.

For example, as shown in fig. 7, the current collecting member 40 has a rectangular structure, the current collecting member 40 of the rectangular structure is provided at the middle of the tab 12 such that the portion of the outer edge portion of the current collecting member 40 overlapping the outer edge portion of the tab 12 is each vertex of the current collecting member 40, and then the tab 12 may be exposed to the outside from the area not covered by the current collecting member 40 to satisfy the side incidence of the welding laser beam.

According to the battery cell provided by the utility model, as the outer edge part of the current collecting member 40 and the outer edge part of the tab 12 are overlapped, the outline of the current collecting member 40 is smaller than that of the tab 12, so that the tab 12 is partially exposed, and thus, the current collecting member 40 cannot completely cover the tab 12, when the current collecting member 40 is connected with the tab 12 in a laser welding way, laser beams can enter from the side direction, namely, the incident direction of the laser beams forms a small acute angle with the plane of the tab 12, so that the probability of diaphragm damage caused by the perpendicular incidence of the laser beams into the plane of the tab 12 is reduced, and the yield of the manufactured electrode assembly 10 is improved; meanwhile, the whole material consumption of the incoming material collecting member 40 can be reduced, and the material consumption cost of the collecting member 40 can be reduced to a certain extent.

Referring to fig. 4, in some embodiments, at least a portion of the outer edge of the current collecting member 40 is recessed inward to form a notch structure 40a.

It is appreciated that the shape of the notch structure 40a includes, but is not limited to, semi-circular, rectangular, bar-shaped, etc.; the number of the notch structures 40a may be one or more, and the position where the notch structures 40a are provided may be any one of the outer edge portions of the current collecting member 40.

The tab 12 can be exposed to the outside through the notch structure 40a, and a laser beam can be laterally injected at the notch structure 40a during laser welding to reduce the probability of damage to the diaphragm.

Illustratively, as shown in fig. 4, the initial profile of the current collecting member 40 is circular, and after the notch structure 40a is formed at the outer edge portion thereof, the final profile of the current collecting member 40 is three-quarters of a circle. When the laser welding is performed, the welding track of the laser beam is along the outer edge of the notch structure 40a and the arc-shaped outer edge of the current collecting member 40, and when the arc-shaped outer edge of the current collecting member 40 coincides with the outer edge of the tab 12, the laser beam at the outer edge of the notch structure 40a can be injected laterally, that is, the incident direction of the laser beam forms a small acute angle with the plane of the tab 12.

Illustratively, the initial profile of the current collecting member 40 is circular, the number of notched structures 40a is two, and symmetrically disposed about the center point of the current collecting member 40. Similarly, when the laser welding is performed, the welding track of the laser beam is along the outer edge of each notch structure 40a and the arc-shaped outer edge of the current collecting member 40, and when the arc-shaped outer edge of the current collecting member 40 coincides with the outer edge of the tab 12, the laser beam at the outer edge of each notch structure 40a can be injected laterally, that is, the incident direction of the laser beam forms a small acute angle with the plane of the tab 12.

Referring to fig. 8, in some embodiments, the current collecting member 40 includes a base 41, and an outer edge portion of the base 41 is recessed inward to form a notch structure 40a, so that the tab 12 can penetrate through the notch structure 40a to the outside.

It is understood that such a current collecting member 40 has a single-layered sheet structure, and the notch structure 40a formed on the outer edge portion of the base 41 penetrates the base 41 in the thickness direction of the base 41, so that when the base 41 is placed on the tab 12, a part of the tab 12 can pass through the notch structure 40a to the outside.

The thickness of the single-layer current collecting member 40 with the substrate 41 is thinner, so that the welding device is suitable for a welding scene with lower light intensity of laser beams, and meanwhile, the thinner current collecting member 40 is more beneficial to realizing welding connection of the lugs 12, so that the probability of diaphragm damage is reduced.

Illustratively, as shown in fig. 8, the initial profile of the current collecting member 40 is circular, and after the notch structure 40a is formed at the outer edge portion thereof, the final profile of the current collecting member 40 is three-quarters of a circle.

Referring to fig. 9, in some embodiments, the current collecting member 40 includes a base 41 and a stacked body 42 stacked on each other, the base 41 is disposed on the tab 12, and an outer edge portion of the base 41 and/or an outer edge portion of the stacked body 42 is recessed inward to form a notch structure 40a.

It will be appreciated that such current collecting member 40 has a layered structure of two or more layers. For example, a single layer laminate 42 is provided on the base 41 to form a two-layer laminated structure, or a multi-layer laminate 42 is provided on the base 41 to form a multi-layer laminated structure. Here, the connection method of the base 41 and the laminate 42 includes, but is not limited to, integral molding, welding, insertion, screw connection, caulking, and the like, and the materials of the base 41 and the laminate 42 may be the same or different. For example, the material of the base 41 is the same as that of the tab 12, and the material of the laminate 42 is the same as that of the end cap of the battery cell, so that the same material can optimize the stability of the welded connection when the connection between the base 41 and the tab 12 and the connection between the end cap of the battery cell and the laminate 42 are achieved by welding.

And, the notch structure 40a may be selectively provided on the outer edge portion of the base 41; alternatively, the laminate 42 is provided on the outer edge portion thereof; alternatively, the notch structure 40a is formed by being recessed inward in the outer edge portions of the base 41 and the laminated body 42. When the notch structure 40a is formed on the substrate 41, the stacked body 42 should be offset from the notch structure 40a so that the notch structure 40a is exposed, thereby satisfying the welding requirement of the laser beam from the side. And when the notch structures 40a are formed on the substrate 41 and the laminated body 42, the projections of the notch structures 40a on the substrate 41 and the projections of the notch structures 40a on the laminated body 42 on the tab 12 should be overlapped, so that each notch structure 40a is in an exposed state, so as to meet the welding requirement of the laser beam from side to side.

So set up, the cross-section that overflows of this kind of multilayer structure's mass flow component 40 is bigger, and the overflow performance is higher, simultaneously, through setting up breach structure 40a in order to satisfy the welding requirement that laser beam side direction penetrated into, reduces the probability that the diaphragm was damaged.

Referring to fig. 9, in a specific embodiment, the outline of the base 41 is the same as the outline of the tab 12, and the base 41 covers the tab 12, and the outer edge of the laminated body 42 is recessed inward to form a notch structure 40a.

It is understood that the current collecting member 40 has a double-layer structure, the outline of the base 41 is the same as that of the tab 12, and the tab 12 is covered, for example, when the tab 12 has a circular structure, the base 41 has a circular structure. The outline of the laminate 42 may be the same as that of the base 41, or the outline of the base 41 may be different. For example, the base 41 has a circular configuration, and the initial contour of the laminate 42 may have a circular configuration.

And, when the notch structure 40a is formed in the laminate 42, the outer edge portion formed by the notch structure 40a is distant from the outer edge portion of the tab 12, that is, the outer edge portion of the laminate 42 of the current collecting member 40 where the notch structure 40a is located is not overlapped with the outer edge portion of the tab 12. Thus, the base 41 is disposed at a position on the tab 12, and alternatively, the outer edge portion of the base 41 may be selected to completely overlap, i.e., completely cover, the outer edge portion of the tab 12.

As shown in fig. 9, the base 41 of the current collecting member 40 has a circular outer shape, the initial outer shape of the laminated body 42 is circular in accordance with the outer shape of the tab 12, and after the notch structure 40a is formed in the outer edge portion thereof, the final outer shape of the laminated body 42 is three-quarters circular.

Referring to fig. 8, in some embodiments, the geometric center of the current collecting member 40 is collinear with the winding center axis N of the electrode body 11, and the notch structure 40a is recessed inward to the geometric center of the current collecting member 40.

It will be appreciated that when the manifold member 40 is of a regular geometry, such as circular, square, oval, the geometric center of such manifold member 40 is the center of the circle, the intersection of the diagonals of the square, and the center of the oval. When the manifold member 40 is irregularly geometrically shaped, the geometric center of the manifold member 40 is the geometric center of gravity.

The electrode body 11 is wound with the electrode sheet and then placed in the case of the battery cell, and then the winding center axis N of the electrode body 11 is collinear or substantially collinear with the center axis of the case.

The notch structure 40a is recessed inward to the geometric center of the current collecting member 40, that is, to the winding center axis N of the electrode body 11, so that the outer edge portion of the notch structure 40a is close to the winding center axis N of the electrode body 11, and when the laser welding connection is performed, the welding track extends along the outer edge portion of the notch structure 40a, and also extends from the inner ring to the outer ring of the electrode body 11.

Cell polarization refers to the phenomenon that when a cell passes a current, the potential deviates from the equilibrium potential. When the welding track of the current collecting member 40 and the tab 12 are overlapped or basically overlapped with the winding track of the single-layer or multi-layer wound pole piece of the electrode main body 11, the battery cell can generate a battery polarization phenomenon, and the method for improving the battery polarization phenomenon is to extend the welding track of the current collecting member 40 and the tab 12 from the inner ring to the outer ring of the electrode main body 11 so as to meet the requirement that the current collecting member 40 can be connected with the winding heat of each layer and increase the overcurrent area.

Here, the notch structure 40a may be recessed inward to the geometric center of the current collecting member 40 such that the outer edge portion where the notch structure 40a is located is close to but does not intersect the winding center axis N of the electrode body 11, or such that the outer edge portion where the notch structure 40a is located intersects the winding center axis N of the electrode body 11.

As illustrated in fig. 4, the initial outline of the current collecting member 40 is circular, the outline of the tab 12 is also circular, the final outline of the current collecting member 40 is three-quarters circular after the notched structure 40a is formed at the outer edge of the current collecting member 40, and the projection of the outer edge of the notched structure 40a on the tab 12 extends from the inner ring to the outer ring of the electrode body 11.

Referring to fig. 9, in some embodiments, a projection of one outer edge portion of the current collecting member 40 on the end portion of the electrode body 11 is close to the winding center axis N of the electrode body 11.

It will be understood that the end of the electrode body 11 refers to the end of the pole piece that forms a columnar structure or a similar columnar structure after winding, typically, the tab 12 and the current collecting member 40 are disposed on the end of the electrode body 11, and the tab 12 needs to completely cover the end of the electrode body 11 in the assembly process, so that the winding center axis N of the electrode body 11 coincides with the center line of the tab 12, the projection of the outer edge of the current collecting member 40 on the end of the electrode body 11 is close to the winding center axis N of the electrode body 11, that is, the projection of the outer edge of the current collecting member 40 on the end of the electrode body 11 is also located at the center line of the tab 12, and then the welding track of the current collecting member 40 and the tab 12 is also the inner ring of the electrode body 11 extending to the outer ring, which can also improve the battery polarization phenomenon.

Here, the current collecting member 40 may have only one outer edge portion according to the outer contour of the current collecting member 40, for example, the current collecting member 40 has a circular structure, an oval structure; alternatively, the current collecting member 40 may be formed of a plurality of outer edge portions, for example, a triangular structure or a rectangular structure of the current collecting member 40.

Illustratively, the current collecting member 40 has a circular structure, and the arc-shaped outer edge portion of the current collecting member 40 is located at the winding center axis N of the electrode body 11, i.e., the arc-shaped outer edge portion of the current collecting member 40 is close to the projection on the tab 12, even intersecting the winding center axis N of the electrode body 11.

Illustratively, as shown, the current collecting member 40 has a triangular structure, and one of the outer edge portions of the current collecting member 40 is located at the winding center axis N of the electrode body 11, i.e., one of the outer edge portions of the current collecting member 40 is close to the projection on the tab 12, even intersecting the winding center axis N of the electrode body 11.

Referring to fig. 9, in a specific embodiment, the projection of the outer edge portion of the current collecting member 40 on the tab 12 coincides with the winding center axis N of the electrode body 11.

It can be understood that, the projection of the outer edge of the current collecting member 40 on the tab 12 coincides with the winding central axis N of the electrode body 11, so that the welding track of the current collecting member 40 and the tab 12 extends from the innermost ring to the outer ring of the electrode body 11, thereby maximally realizing the electrical connection between the electrode sheets of each layer of the electrode body 11 and the current collecting member 40, and greatly improving the polarization phenomenon of the battery.

Referring to fig. 4 and 8, the present application provides a specific embodiment, a battery cell including an electrode assembly 10 and a current collecting member 40. The electrode assembly 10 includes an electrode body 11 and a tab 12 provided at an end of the electrode body 11; the current collecting member 40 is disposed on the tab 12, and an outer edge portion of the current collecting member 40 is recessed inward to form a notch structure 40a. The electrode body 11 is wound to form a cylindrical structure, the tab 12 at the end of the electrode body 11 is in a circular structure, the current collecting member 40 comprises a base 41, the base 41 is also in a circular structure in an initial state, and after the notch structure 40a is formed, the current collecting member 40 forms a three-quarter circular structure, so that the tab 12 can be exposed to the outside through the notch structure 40a, and then, in a welding process, the welding requirement of side injection of a welding beam is met.

And, the projection of the outer edge of the notch structure 40a on the tab 12 intersects with the winding central axis N of the electrode body 11, so that the welding track between the current collecting member 40 and the tab 12 is from the winding central axis N of the electrode body 11 to the outer ring, effectively improving the problem of battery polarization.

Referring to fig. 9, another embodiment is provided, which is different from the above embodiment in that the current collecting member 40 includes a base 41 and a laminated body 42 laminated on the base 41, the base 41 is disposed on the tab 12 and completely covers the tab 12, the outline of the laminated body 42 is smaller than that of the base 41, the outer edge of the laminated body 42 is recessed inwards to form a notch structure 40a, and similarly, after the notch structure 40a is formed, the laminated body 42 forms a three-quarter circular structure.

In a second aspect, embodiments of the present application provide a battery, including the above-described battery cell.

In a third aspect, an embodiment of the present application provides an electric device, including the battery described above.

It will be appreciated that the advantages of the second and third aspects described above may be found in the relevant description of the first aspect described above and will not be described in detail here.

The foregoing description of the preferred embodiments of the utility model is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the utility model.

Claims (10)

1. A battery cell, comprising:

an electrode assembly including an electrode body and a tab provided at an end of the electrode body;

and the current collecting member is arranged on the tab, and the outer edge part of the current collecting member part coincides with the outer edge part of the tab so that the part of the tab is exposed to the outside.

2. The battery cell of claim 1, wherein: at least part of the outer edge part of the current collecting member is inwards recessed to form a notch structure.

3. The battery cell of claim 2, wherein: the current collecting member comprises a base body, wherein the outer edge part of the base body is inwards recessed to form the notch structure, and the tab can penetrate through the notch structure to the outside.

4. The battery cell of claim 2, wherein: the current collecting member comprises a substrate and a lamination body which are arranged in a lamination manner, wherein the substrate is arranged on the tab, and the outer edge part of the substrate and/or the outer edge part of the lamination body is inwards recessed to form the notch structure.

5. The battery cell of claim 4, wherein: the appearance profile of the base body is the same as that of the tab, the base body covers the tab, and the outer edge part of the laminated body is inwards recessed to form the notch structure.

6. The battery cell according to any one of claims 2 to 5, wherein: the geometric center of the current collecting member is collinear with the winding center axis of the electrode body, and the notch structure is recessed inward to the geometric center of the current collecting member.

7. The battery cell according to any one of claims 1 to 5, wherein: a projection of one outer edge portion of the current collecting member on the end portion of the electrode body is close to a winding center axis of the electrode body.

8. The battery cell of claim 7, wherein: the projection of the outer edge of the current collecting member on the tab coincides with the winding center axis of the electrode body.

9. A battery, characterized in that: comprising a battery cell according to any one of claims 1 to 8.

10. An electrical consumer, characterized in that: comprising a battery according to claim 9.