CN219591599U

CN219591599U - Battery monomer, battery and power consumption device

Info

Publication number: CN219591599U
Application number: CN202320166943.6U
Authority: CN
Inventors: 苏华圣; 邢承友; 李全坤; 徐春光; 王鹏; 金海族
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2023-02-01
Filing date: 2023-02-01
Publication date: 2023-08-25
Anticipated expiration: 2033-02-01

Abstract

The application discloses a battery monomer, a battery and an electricity utilization device. The battery cell includes a case, an electrode assembly, an electrode terminal, and a current collecting member. The case is for accommodating the electrode assembly. The electrode assembly includes a tab. The electrode terminal is disposed in the case. The current collecting member includes a tab connection portion and a terminal connection portion. The tab connection part is used for connecting the tab. The terminal connection part is used for connecting the electrode terminals. The terminal connecting parts comprise a plurality of layers of sub-terminal connecting parts which are arranged in a stacked mode, each layer of sub-terminal connecting part comprises sub-riveting parts, and any two adjacent sub-riveting parts are riveted and fixed. The terminal connecting part of the current collecting member is designed into the laminated multi-layer sub-terminal connecting part, deformation can be more tolerated between layers during bending, the bending capacity of the multi-layer sub-terminal connecting part is stronger, the overall thickness of the multi-layer sub-terminal connecting part can be made thicker under the condition of the same bending capacity, the overcurrent area is increased, the internal resistance is reduced, and the temperature rise is reduced, so that the safety of the battery is improved.

Description

Battery monomer, battery and power consumption device

Technical Field

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

Background

Energy conservation and emission reduction are key to sustainable development of the automobile industry, and electric vehicles become an important component of sustainable development of the automobile industry due to the energy conservation and environmental protection advantages of the electric vehicles. For electric vehicles, battery technology is an important factor in the development of the electric vehicles.

The current collecting member is a part of the battery for connecting the electrode terminal and the tab of the electrode assembly, and in order to reduce the height space occupied by the current collecting member in the battery, the terminal connecting portion of the current collecting member is generally designed to be bendable, however, the terminal connecting portion of the current collecting member is mostly of a single-layer integrated structure, the bending capability is limited, the thickness of the terminal connecting portion cannot be made too thick for convenient bending, the overcurrent area of the current collecting member is small, the internal resistance is large, the temperature rise is large, and the safety of the battery is further reduced.

Disclosure of Invention

In view of the above, the present utility model provides a battery cell, a battery and an electric device, which can alleviate the problems of small overcurrent area, large internal resistance, large temperature rise of a current collecting member and further reduce the safety of the battery.

In a first aspect, the present utility model provides a battery cell. The battery cell includes an electrode assembly, a case, an electrode terminal, and a current collecting member. The electrode assembly includes a tab. The case is for accommodating the electrode assembly. The electrode terminals are disposed on the housing. The current collecting member includes a tab connection portion for connecting the tab and a terminal connection portion for connecting the electrode terminal and the tab connection portion. The terminal connecting parts comprise a plurality of layers of sub-terminal connecting parts which are arranged in a stacked mode, each layer of sub-terminal connecting part comprises sub-riveting parts, and any two adjacent sub-riveting parts are riveted and fixed.

In the technical scheme of the embodiment of the application, the terminal connecting part of the current collecting member is designed into the laminated multi-layer sub-terminal connecting part, and compared with the current collecting member with a single-layer integrated structure, the bonding force between the multi-layer sub-terminal connecting parts is smaller, and deformation can be more tolerated between the layers during bending, so that the bending capability of the multi-layer sub-terminal connecting part is stronger, and under the condition of the same bending capability, the overall thickness of the multi-layer sub-terminal connecting part (namely the thickness of the terminal connecting part) can be made thicker, the overcurrent area is increased, the internal resistance is reduced, and the temperature rise is reduced, thereby improving the safety of the battery. In addition, the multi-layer sub-terminal connecting part is bent to a greater extent, so that the height space occupied by the current collecting member can be reduced, the energy density of the battery cell is improved, and the energy density of the battery is further improved. Meanwhile, any two adjacent layers of sub-terminal connecting parts are riveted and fixed by utilizing the adjacent two sub-riveting parts to realize riveting connection, compared with the terminal connecting parts formed by connecting all layers of sub-terminal connecting parts by adopting a welding process, the positioning precision of the terminal connecting parts during connection is improved, the welding process is not needed, and the production efficiency of the current collecting component is improved.

In some embodiments, any two adjacent sub-rivets are welded together. Namely, the riveting positions of the sub-terminal connecting parts of each layer are welded and reinforced, so that the connection strength between the sub-terminal connecting parts of each layer is improved; on the other hand, the overcurrent area of the current collecting component is increased, the internal resistance is reduced, the temperature rise is reduced, and the safety performance of the battery monomer is improved.

In some embodiments, the terminal connection parts are provided with a fixing structure in which all the sub-caulking parts are sequentially stacked and fitted to each other.

Compared with the mode that after the sub-terminal connecting parts of a plurality of single layers are punched and cut, the sub-terminal connecting parts of the single layers are stacked and welded to form the terminal connecting parts, the sub-riveting parts of the sub-terminal connecting parts of the adjacent layers are stacked to form a fixed structure, positioning is accurate, alignment is easy, a welding process is not needed, and meanwhile, the production efficiency of the current collecting member is improved. Compared with the terminal connecting part which is obtained by winding materials into a plurality of layers and then cutting, the riveting of the sub-riveting parts of the sub-terminal connecting parts of the adjacent layers can reduce burrs.

In some embodiments, the fixing structure is disposed at an end region of the terminal connection part near the electrode terminal. In this way, the sub-terminal connection parts of the respective layers can be riveted to form the terminal connection part of the integrated structure.

In some embodiments, the fixing structure is disposed at an end region of the terminal connection portion near the tab connection portion. In this way, after the terminal connecting parts of the integrated structure are riveted on the sub-terminal connecting parts of each layer, the terminal connecting parts of the integrated structure can be conveniently riveted with the tab connecting parts.

In some embodiments, the fixing structure is disposed at an end region of the terminal connection part near the electrode terminal, and at an end region of the terminal connection part near the tab connection part. Thus, on one hand, each layer of sub-terminal connection part can be riveted to form a terminal connection part with an integrated structure; on the other hand, after the terminal connecting parts of the integrated structure are riveted on the sub-terminal connecting parts of each layer, the terminal connecting parts of the integrated structure can be conveniently riveted with the tab connecting parts; in still another aspect, the opposite ends of the terminal connection part are provided with fixing structures, so that the binding force of the two ends of the terminal connection part of the integrated structure is relatively uniform, and the whole combination is firmer.

In certain embodiments, the number of fixation structures is one or more. When the number of the fixing structures is one, the positioning precision of the sub-terminal connecting parts of any adjacent layers during riveting is ensured. When the quantity of fixed knot constructs is a plurality of, a plurality of fixed knot constructs not only can guarantee the positioning accuracy when the sub-terminal connecting portion of arbitrary adjacent layer rivets, can also promote the joint strength between the sub-terminal connecting portion, is difficult to break away from each other to the job stabilization nature of mass flow component has been promoted.

In certain embodiments, the cross-sectional shape of the fixation structure includes any one of square, rectangular, and circular. The cross section shape of the fixing structure is not limited, and can be any one of square, rectangle and round, so that the design difficulty of the terminal connecting part is reduced, and the manufacture of the current collecting member is simplified.

In some embodiments, the terminal connection part has a first main surface and a second main surface which are oppositely arranged in the thickness direction of the terminal connection part after being unfolded, the fixing structure is formed with a concave part on one side of the first main surface, and the fixing structure is formed with a first convex part on the second main surface. The fixed knot constructs including first convex part and concave part, can avoid the staggered floor when piling up when riveting formation terminal connecting portion, and the location is accurate, and aligns easily, need not welding process simultaneously, has promoted the production efficiency of mass flow component. In addition, the fixing structure includes the first convex portion and the concave portion, and burrs can be reduced.

In some embodiments, the tab connection portion is disposed on a side of the terminal connection portion near the second main surface, and the tab connection portion is provided with a first accommodating portion, and the first protrusion is accommodated in the first accommodating portion. The first protruding portion is accommodated in the first accommodating portion, and can play a role in positioning when the terminal connecting portion is connected with the tab connecting portion.

In some embodiments, the terminal connection portion is fixedly connected to the tab connection portion through the first protrusion. The first convex part is fixedly connected to the first accommodating part, so that the terminal connecting part is fixedly connected to the lug connecting part through the first convex part, and compared with the terminal connecting part which is connected to the lug connecting part by adopting a welding process, the positioning precision of the terminal connecting part and the lug connecting part is improved, the welding process is not needed, and the production efficiency of the current collecting member is improved.

In some embodiments, each of the sub-caulking portions has a sub-protrusion and a sub-recess, each of the sub-protrusions protruding in a direction of the second main surface, each of the sub-recesses being recessed from the first main surface in a direction of the second main surface, the sub-protrusion of one of the adjacent two sub-caulking portions accommodating and being fixedly connected to the sub-recess of the other sub-caulking portion.

Compared with the mode that after the sub-terminal connecting parts of a plurality of single layers are punched and cut, the sub-terminal connecting parts of the single layers are stacked and welded to form the terminal connecting parts, the staggered layers during stacking can be avoided through riveting between the sub-protrusions and the sub-concave parts of the sub-terminal connecting parts of adjacent layers, positioning is accurate, alignment is easy, a welding process is not needed, and meanwhile, the production efficiency of the current collecting component is improved. Compared with the terminal connecting part which is obtained by cutting after the material is rolled into a plurality of layers, burrs can be reduced by riveting the sub-protrusions and the sub-recesses of the sub-terminal connecting parts of the adjacent layers.

In some embodiments, the terminal connection part is provided with a second accommodating part, and the tab connection part is provided with a second protruding part, and the second protruding part is accommodated in the second accommodating part. The second convex part is accommodated in the second accommodating part, so that the positioning precision of the terminal connecting part and the tab connecting part can be improved.

In some embodiments, the tab connection portion is fixedly connected to the terminal connection portion through the second protrusion. The second convex part is fixedly connected to the second accommodating part, so that the lug connection part is fixedly connected to the terminal connection part through the second convex part, and compared with the lug connection part which is connected to the terminal connection part by adopting a welding process, the positioning precision of the lug connection part and the terminal connection part is improved, the welding process is not needed, and the production efficiency of the current collecting member is improved.

In some embodiments, the terminal connection and the tab connection are at least partially welded. Namely, the welding reinforcement is carried out between the terminal connecting part and the tab connecting part, so that on one hand, the overcurrent area of the current collecting member is increased, the internal resistance is reduced, the temperature rise is reduced, and the safety performance of the battery cell is improved; on the other hand, the connection between the terminal connection part and the tab connection part is firmer, the terminal connection part and the tab connection part are not easy to separate, and the working stability of the current collecting member is improved.

In some embodiments, the solder marks formed between the terminal connection portions and the tab connection portions are located in areas other than the fixing structure. The welding marks formed between the terminal connecting parts and the tab connecting parts are positioned in the area outside the fixed structure, so that on one hand, the overcurrent area of the current collecting member is increased, the internal resistance is reduced, the temperature rise is reduced, and the safety performance of the battery cell is improved; on the other hand, the terminal connecting part and the lug connecting part are firmly connected without damaging riveting, and are not easy to separate, so that the working stability of the current collecting member is improved.

In some embodiments, the terminal connection part is disposed between the tab connection part and the electrode terminal in a bent manner. The terminal connecting part is arranged between the lug connecting part and the electrode terminal in a bending way, so that the height space occupied by the current collecting component in the battery cell can be reduced, on one hand, the structure of the battery cell is more compact, and on the other hand, more space can be vacated for the electrode assembly under the same height of the battery cell, thereby increasing the energy density of the battery cell.

In a second aspect, the present application provides a battery comprising a battery cell according to any one of the embodiments described above.

In the technical scheme of the embodiment of the application, the battery uses the battery monomer in the embodiment of the first aspect, and in the battery monomer, the bending capability of the multi-layer sub-terminal connecting part of the current collecting member is stronger, and the battery is not easy to break, so that the working stability of the battery is ensured; meanwhile, under the condition of the same bending capability, the overall thickness of the multi-layer sub-terminal connecting part can be made thicker, the overcurrent area is increased, the internal resistance is reduced, and the temperature rise is reduced, so that the safety of the battery is improved. In addition, the multi-layer sub-terminal connecting part is bent to a greater extent, so that the height space occupied by the current collecting member can be reduced, the energy density of the battery cell is improved, and the energy density of the battery is further improved.

In a third aspect, the present disclosure provides an electrical device, including a battery according to any one of the embodiments, the battery being configured to provide electrical energy.

In the technical scheme of the embodiment of the application, the battery in the embodiment of the second aspect is used in the electric device, and in the battery cell of the battery, the bending capability of the multi-layer sub-terminal connecting part of the current collecting member is stronger and is not easy to break, so that the working stability of the electric device is ensured; meanwhile, under the condition of the same bending capability, the overall thickness of the multi-layer sub-terminal connecting part can be made thicker, the overcurrent area is increased, the internal resistance is reduced, and the temperature rise is reduced, so that the safety of the battery is improved. In addition, the multilayer sub-terminal connecting portion is bent to a greater extent, so that the height space occupied by the current collecting member can be reduced, the energy density of the battery unit is improved, the energy density of the battery is improved, and the endurance time of the power utilization device is further improved.

The foregoing description is only an overview of the present application, and is intended to provide a better understanding of the technical means of the present application, as it is embodied in accordance with the present application, and is intended to provide a better understanding of the above and other objects, features and advantages of the present application, as it is embodied in the following specific examples.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the application. Also, like reference numerals are used to designate like parts throughout the accompanying drawings. In the drawings:

FIG. 1 is a schematic illustration of a vehicle according to some embodiments of the application;

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

fig. 3 is a schematic perspective view of a battery cell according to some embodiments of the present application;

FIG. 4 is a schematic perspective view of a top cap assembly according to some embodiments of the present application;

FIG. 5 is a schematic view of an exploded construction of a header assembly according to some embodiments of the present application;

FIG. 6 is a schematic plan view of a top cap assembly according to some embodiments of the present application;

FIG. 7 is a schematic cross-sectional view of the cap assembly shown in FIG. 6 taken along line VII-VII;

FIG. 8 is a schematic cross-sectional view of the cap assembly shown in FIG. 6 taken along line VIII-VIII;

fig. 9 is a schematic perspective view of a current collecting member according to some embodiments of the present application;

fig. 10 is an exploded view of a current collecting member according to some embodiments of the present application;

fig. 11 is a schematic perspective view of a terminal connection portion in a current collecting member according to some embodiments of the present application;

fig. 12 is a schematic plan view of a current collecting member according to some embodiments of the present application;

fig. 13 is a schematic cross-sectional view of the current collecting member shown in fig. 12 taken along line XIII-XIII;

fig. 14 is a schematic plan view of a current collecting member according to some embodiments of the present application;

fig. 15 is a schematic cross-sectional view of the current collecting member shown in fig. 14 taken along line XV-XV;

fig. 16 is a schematic perspective view of a current collecting member according to some embodiments of the present application.

Reference numerals in the specific embodiments are as follows:

a vehicle 1000;

battery 100, controller 200, motor 300;

a case 10, a first portion 11, a second portion 12;

the battery cell 20, the top cap assembly 21, the current collecting member 211, the tab connection portion 2111, the connection region 21111, the welding region 21113, the terminal connection portion 2113, the first connection section 21131, the second connection section 21133, the bent section 21135, the fixing structure 2115, the sub-rivet 21151, the first receiving portion 2117, the second receiving portion 2118, the sub-receiving portion 21181, the second protrusion 2119, the sub-terminal connection portion 21137, the top cap sheet 212, the first insulating member 213, the second insulating member 214, the connecting member 215, the electrode terminal 216, the sealing member 217; a housing 23; and an electrode assembly 25.

Detailed Description

Embodiments of the technical scheme of the present application will be described in detail below with reference to the accompanying drawings. The following examples are only for more clearly illustrating the technical aspects of the present application, and thus are merely examples, and are not intended to limit the scope of the present application.

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

In the description of embodiments of the present application, the technical terms "first," "second," and the like are used merely to distinguish between different objects and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated, a particular order or a primary or secondary relationship. In the description of the embodiments of the present application, the meaning of "plurality" is two or more unless explicitly defined otherwise.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases 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. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

In the description of the embodiments of the present application, the term "and/or" is merely an association relationship describing an association object, and indicates that three relationships may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

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

In the description of the embodiments of the present application, the orientation or positional relationship indicated by the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationship shown in the drawings, and are merely for convenience of description and simplification of the description, and do not indicate or imply that the apparatus or element referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the embodiments of the present application.

In the description of the embodiments of the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured" and the like should be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally formed; or may 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 embodiments of the present application will be understood by those of ordinary skill in the art according to specific circumstances.

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

The inventors noted that the current common battery is to knead the tab of the electrode assembly, weld the current collecting member with the tab, and then bend the current collecting member and electrically connect the current collecting member with the electrode terminal, thereby realizing current conduction. This places high demands on the current collecting member's ability to flow through. However, the terminal connection portion of the current collecting member cannot be made too thick for convenience of bending and process welding (welding of the current collecting member and the tab of the electrode assembly), so that the overcurrent area S of the terminal connection portion is small, and the terminal connection portion length L is also relatively long because of the three-fold terminal connection portion being required for the bending process, and as is known from the resistance calculation formula r=ρ×l/S, the internal resistance of the terminal connection portion becomes relatively large, and both the overcurrent and internal resistance requirements cannot meet the requirements of the power battery.

In order to alleviate the problems of the current collecting member that the overcurrent area is small, the internal resistance is large, the temperature rise is also large, and the safety of the battery is further reduced, the inventors have studied and found that the terminal connection portion of the current collecting member may be designed as a laminated multi-layered sub-terminal connection portion. Compared with the current collecting member with a single-layer integrated structure, the binding force between the multi-layer sub-terminal connecting parts is smaller, and deformation can be more tolerated between the layers during bending, so that the bending capacity of the terminal connecting parts with the multi-layer structure is stronger, the overall thickness of the terminal connecting parts with the multi-layer structure can be made thicker under the condition of the same bending capacity, the overcurrent area of the current collecting member is larger, the internal resistance is smaller, and the temperature rise is reduced, so that the safety of the battery can be improved.

Based on the above considerations, in order to design the terminal connection portion of the current collecting member as a laminated multi-layered sub-terminal connection portion, the inventors have also found that: the terminal connecting part of the multilayer structure obtained by cutting the material after stacking a plurality of layers can generate a large number of edge burrs, and after the sub-terminal connecting parts of a plurality of single layers are punched, the terminal connecting parts of the multilayer structure obtained by welding the plurality of single-layer sub-terminal connecting parts are stacked together, so that the terminal connecting parts of the multilayer structure can not be aligned, the efficiency is low during welding, and the mass production can not be realized by the two manufacturing modes. The inventor has conducted intensive studies to design a current collecting member for a battery cell, wherein the terminal connecting part of the current collecting member is designed into a plurality of layers of laminated sub-terminal connecting parts, and any two adjacent layers of sub-terminal connecting parts are riveted.

The battery cell disclosed by the embodiment of the application can be used for an electric device using a battery as a power supply or various energy storage systems using the battery as an energy storage element. The electric device may 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. Among them, the electric toy may include fixed or mobile electric toys, such as game machines, electric car toys, electric ship toys, electric plane toys, and the like, and the spacecraft may include planes, rockets, space planes, and spacecraft, and the like.

For convenience of description, the following embodiment will take an electric device according to an embodiment of the present application as an example of the vehicle 1000.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a vehicle 1000 according to some embodiments of the application. The vehicle 1000 may be a fuel oil vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or a range-extended vehicle. The battery 100 is provided in the interior of the vehicle 1000, and the battery 100 may be provided at the bottom, the head, or the tail of the vehicle 1000. The battery 100 may be used for power supply of the vehicle 1000, for example, the battery 100 may be used as an operating power source of the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, the controller 200 being configured to control the battery 100 to power the motor 300, for example, for operating power requirements during start-up, navigation, and travel of the vehicle 1000.

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

Referring to fig. 2, fig. 2 is an exploded view of a battery 100 according to some embodiments of the present application. 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 an accommodating space for the battery cell 20, and the case 10 may have various structures. In some embodiments, the case 10 may include a first portion 11 and a second portion 12, the first portion 11 and the second portion 12 being overlapped with each other, the first portion 11 and the second portion 12 together defining an accommodating space for accommodating the battery cell 20. The second portion 12 may be a hollow structure with one end opened, the first portion 11 may be a plate-shaped structure, and the first portion 11 covers the opening side of the second portion 12, so that the first portion 11 and the second portion 12 together define a containing space; the first portion 11 and the second portion 12 may be hollow structures each having an opening at one side, and the opening side of the first portion 11 is engaged with the opening side of the second portion 12. Of course, the case 10 formed by the first portion 11 and the second portion 12 may be of various shapes, such as a cylinder, a rectangular parallelepiped, or the like.

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

Wherein each battery cell 20 may be a secondary battery or a primary battery; but not limited to, lithium sulfur batteries, sodium ion batteries, or magnesium ion batteries. The battery cell 20 may be in the shape of a cylinder, a flat body, a rectangular parallelepiped, or other shapes, etc. The battery cell 20 refers to the smallest unit constituting the battery 100. In the present application, the battery cell 20 is exemplified by a cylindrical battery.

Referring to fig. 3, a battery cell 20 according to some embodiments of the application is shown. The battery cell 20 includes a case 23, an electrode assembly 25, an electrode terminal 216, and a current collecting member 211. The case 23 serves to accommodate the electrode assembly 25. The electrode assembly 25 includes a tab 251. The electrode terminal 216 is provided to the case 23. Referring to fig. 9 and 10, the current collecting member 211 includes tab connection portions 2111 and terminal connection portions 2113. The tab connection portion 2111 is used for connecting the tab 251. The terminal connection portion 2113 is for connecting the electrode terminal 216 and the tab connection portion 2111. Referring to fig. 13, the terminal connection portion 2113 includes a plurality of sub-terminal connection portions 21137 stacked, each of the sub-terminal connection portions 21137 includes a sub-caulking portion 21151, and any adjacent two of the sub-caulking portions 21151 are caulking-fixed.

The case 23 may have a cylindrical structure, and a receiving chamber for receiving the electrode assembly 25 and the electrolyte is formed inside the case 23. The both ends of the case 23 are provided with openings so that the electrode assembly 25 can be placed in the receiving chamber of the case 23 through the openings. The housing 23 may be made of a metal material, such as aluminum or an aluminum alloy, or an insulating material, such as plastic, rubber, or the like.

The electrode assembly 25 includes a pole piece unit and a tab 251 extending from at least one end surface. Specifically, along the height direction (H) of the battery cell 20, the pole piece unit has two end faces disposed opposite to each other, and in the battery cell 20, the two end faces of the pole piece unit extend out of the tab 251 respectively, which are a positive electrode tab and a negative electrode tab respectively. The pole piece unit comprises a negative pole piece, a positive pole piece and an isolating film, wherein the isolating film is positioned between the adjacent negative pole piece and positive pole piece and is used for isolating the negative pole piece and the positive pole piece.

In one possible design, the negative electrode sheet, separator and positive electrode sheet are sequentially laminated and wound to form a pole piece unit of the electrode assembly 25, i.e., the pole piece unit is a wound structure. Meanwhile, the electrode plate units are provided with gaps after being formed, electrolyte can enter the electrode plate units through the gaps, and the negative electrode plate and the positive electrode plate are infiltrated.

The negative electrode sheet includes a negative electrode current collector (e.g., copper foil) and a negative electrode active material layer (e.g., carbon or silicon) coated on a surface of the negative electrode current collector, and the positive electrode sheet includes a positive electrode current collector (e.g., aluminum foil) and a positive electrode active material layer (e.g., ternary material, lithium iron phosphate or lithium cobalt oxide) coated on a surface of the positive electrode current collector. The negative electrode lug is connected with the negative electrode plate and extends out of the electrode plate unit, the negative electrode lug can be directly cut by the negative electrode current collector, the positive electrode lug is connected with the positive electrode plate and extends out of the electrode plate unit, and the positive electrode lug can be directly cut by the positive electrode current collector.

Electrode terminals 216 are functional components that can be used to conduct current in electrode assembly 25 out of battery 100 to output or input electrical energy to battery cell 20. The electrode terminals 216 include a positive electrode terminal and a negative electrode terminal, which are respectively located at both ends of the pole piece unit. One end of each electrode terminal 216 protrudes into the inside of the battery cell 20, and the end surface of the other end is exposed to the outside of the battery cell 20 and may be connected with an external electrical connector.

The current collecting member 211 is a member for covering the opening of the battery cell 20, connecting the tab 251 of the electrode assembly 25 in the opening, and connecting the electrode terminal 216 of the battery cell 20. The current collecting member 211 needs to be made of a conductive metal material to ensure a good conductor between the tab 251 and the electrode terminal 216 after being connected to the tab 251 and the electrode terminal 216. The current collecting member 211 used in the embodiment of the present application may be applied to the cylindrical battery cell 20, and may also be applied to battery cells 20 of other shapes, such as a rectangular parallelepiped shape.

Referring to fig. 3, 9 and 10, the tab connection portion 2111 is a portion of the current collecting member 211 covered on the opening of the case 23 of the battery cell 20, and the tab connection portion 2111 may be provided in a shape adapted to the shape of the opening of the case 23 of the battery cell 20, for example, an approximately circular shape. Meanwhile, the tab connection portion 2111 is also used for welding with the tab 251 of the electrode assembly 25. The welding region 21113 of the tab connection portion 2111 is a region for welding the tab 251 of the electrode assembly 25, and an appropriate area and position may be set according to the need of welding the tab 251. The connection region 21111 of the tab connection portion 2111 is a region for connecting the terminal connection portion 2113, and the connection region 21111 of the tab connection portion 2111 is disposed at a position which does not affect the welding of the tab 251 and the tab connection portion 2111, that is, the connection region 21111 of the tab connection portion 2111 is disposed at a region where the tab connection portion 2111 remains after the welding region 21113 is removed. The connection region 21111 may be a partial region occupying the tab connection portion 2111 after the welding region 21113 is removed, for example, a left side region or a right side region occupying the tab connection portion 2111 after the welding region 21113 is removed. Of course, the connection region 21111 may also occupy the entire area of the tab connection portion 2111 after the weld region 21113 is removed, for example, the left and right side areas of the tab connection portion 2111 after the weld region 21113 is removed. In addition, the current collecting member 211 provided in the embodiment of the present application does not limit the shapes of the welding region 21113 and the connection region 21111 of the tab connection portion 2111.

With continued reference to fig. 5, 9 and 10, the terminal connection portion 2113 is a part of the current collecting member 211 for connecting the electrode terminal 216. The terminal connection portion 2113 is connected to the connection region 21111 to ensure that the current collecting member 211 is used as a component that conducts current. The material of the terminal connection portion 2113 and the material of the tab connection portion 2111 may be made of the same conductive metal material or may be made of different conductive metal materials, so long as it is ensured that the current collecting member 211 can serve as a good conductor between the tab 251 and the electrode terminal 216 after being connected to the tab 251 and the electrode terminal 216, respectively. The length of the terminal connection portion 2113 is longer than the length of the tab connection portion 2111. Specifically, referring to fig. 8, the terminal connection portion 2113 includes a first connection section 21131, a second connection section 21133, and a bent section 21135 between the first connection section 21131 and the second connection section 21133. The first connection section 21131 and the second connection section 21133 are respectively located at opposite ends of the expanded terminal connection portion 2113 in the longitudinal direction thereof, the first connection section 21131 being for connection with the electrode terminal 216, and the second connection section 21133 being for connection with the tab connection portion 2111 and being located at the connection region 21111. The bending section 21135 is a region of the terminal connection portion 2113 for connecting between the first connection section 21131 and the second connection section 21133, and has a better bending property. The bending section 21135 may be bent at a position connected to the first connection section 21131, and the bending section 21135 may be bent at a position connected to the second connection section 21133, so that the bent current collecting member 211 takes a Z shape.

The terminal connection portion 2113 includes a plurality of sub-terminal connection portions 21137 which are stacked, wherein each sub-terminal connection portion 21137 is identical and can be easily mass-molded by the same process. The sub-terminal connection portions 21137 of the plurality of layers are stacked on top of each other and the plurality of layers are secured together using a bonding process to form a terminal connection portion 2113 of unitary construction. Specifically, referring to fig. 13, each of the sub-terminal connection portions 21137 includes a sub-rivet 21151, and any two adjacent sub-rivets 21151 are rivet-fixed.

Riveting is a process or method of joining two parts to be joined together by punching holes in them, then placing rivets in them and riveting them with a rivet gun. In the present application, any two adjacent layers of sub-terminal connection parts 21137 are connected by riveting, and the sub-terminal connection parts 21137 of each layer are connected by directly riveting any two adjacent layers of sub-terminal connection parts 21137 without using rivets.

In the technical solution of the embodiment of the present application, the terminal connection portion 2113 of the current collecting member 211 is designed into a laminated multi-layer sub-terminal connection portion 21137, and compared with a current collecting member with a single-layer integrated structure, the multi-layer sub-terminal connection portion 21137 has smaller bonding force, and is more tolerant to deformation between layers during bending, so that the bending capability of the multi-layer sub-terminal connection portion 21137 is stronger, and under the condition of the same bending capability, the overall thickness of the multi-layer sub-terminal connection portion 21137 (i.e., the thickness of the terminal connection portion 2113) can be made thicker, the overcurrent area is increased, the internal resistance is reduced, and the temperature rise is reduced, thereby improving the safety of the battery 100 (shown in fig. 2). In addition, the multi-layered sub-terminal connection part 21137 is bent to a greater extent to reduce the height space occupied by the current collecting member 211, thereby improving the energy density of the battery cell 20 and thus the energy density of the battery 100. Meanwhile, the two adjacent sub-terminal connecting parts 21137 are riveted and fixed by the two adjacent sub-riveting parts 21151 to realize riveting connection, so that compared with the case that the sub-terminal connecting parts of all the layers are connected by adopting a welding process, the positioning precision of the terminal connecting parts 2113 during connection is improved, the welding process is not needed, and the production efficiency of the current collecting member 211 is improved.

Optionally, referring to fig. 3, according to some embodiments of the present application, the battery cell 20 further includes a top cap assembly 21. The electrode assembly 25 is housed in the case 23. The opposite ends of the electrode assembly 25 are provided with a positive electrode tab and a negative electrode tab, respectively. The top cap assembly 21 is covered on the openings at both ends of the case 23, and both the positive electrode tab and the negative electrode tab are connected to the tab connection portion 2111 (shown in fig. 9) of the current collecting member 211 in the top cap assembly 21.

The cap assembly 21 is a member that is covered on an opening of the case 23 of the battery cell 20 to provide a closed space for the electrode assembly 25, electrolyte, etc. located inside the case 23, and the electric power of the electrode assembly 25 is drawn to the outside through the electrode terminal 216 of the cap assembly 21.

The opposite ends of the battery cell 20 are provided with the top cap assembly 21, the bending capability of the multi-layered sub-terminal connection part 21137 is stronger, and the overall thickness of the multi-layered sub-terminal connection part 21137 can be made thicker under the same bending capability, so that the overcurrent area of the current collecting member 211 is increased, the internal resistance is reduced, and the temperature rise is reduced, thereby improving the safety of the battery 100 (shown in fig. 2). In addition, the multi-layer sub-terminal connection portion 21137 is bent to a greater extent, so that the height space occupied by the current collecting member 211 in the top cover assembly 21 at both ends can be reduced, and more space can be made at both ends for the positive and negative electrode plates respectively under the same height of the battery cell 20, thereby further increasing the energy density of the battery cell 20.

Optionally, referring to fig. 4 and 5, the cap assembly 21 includes a current collecting member 211, a cap sheet 212, a first insulating member 213, a second insulating member 214, a connecting member 215, and an electrode terminal 216 according to some embodiments of the present application. In particular, referring to fig. 5-8, the top cover sheet 212 includes opposite first and second sides. The first insulator 213 is mounted to a first side of the top cover sheet 212. A second insulator 214 is mounted to a second side of the top cover sheet 212. The connection element 215 is mounted to the side of the first insulating element 213 facing away from the top cover sheet 212. The current collecting member 211 is mounted to a side of the second insulator 214 facing away from the top cover sheet 212. The electrode terminal 216 is penetrated through the first connection section 21131 of the current collecting member 211, the second insulator 214, the top cap sheet 212, the first insulator 213 and the connector 215, and opposite ends of the electrode terminal 216 are connected to the connector 215 and the first connection section 21131 of the current collecting member 211, respectively.

Referring to fig. 3 and 4 together, the top cover 212 is a part that covers the opening of the housing 23 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the cover sheet 212 may be adapted to the shape of the opening of the housing 23 to fit the housing 23. Alternatively, the top cover sheet 212 may be made of a material (such as an aluminum alloy) with a certain hardness and strength, so that the top cover sheet 212 is not easy to deform when being extruded and collided, so that the battery cell 20 can have a higher structural strength, and the safety performance can be improved. The first side of the top sheet 212 is the side facing away from the interior of the housing 23 and the second side of the top sheet 212 is the side facing towards the interior of the housing 23.

Referring to fig. 5, the connection member 215 is a member of the cap plate 212 for riveting one end of the electrode terminal 216, and the connection member 215 may be made of aluminum. The first insulating member 213 and the second insulating member 214 are members provided on the cover sheet 212 to perform an electric insulating function, and the first insulating member 213 and the second insulating member 214 are each made of an insulating material such as plastic, rubber, or the like. The first insulating member 213 is located on a first side of the top cover sheet 212 for carrying the connecting member 215 and electrically insulating the connecting member 215 from the top cover sheet 212. A second insulator 214 is located on the second side of the top cover sheet 212 for receiving the current collecting member 211 and electrically insulating the current collecting member 211 from the top cover sheet 212. The provision of the first insulating member 213 and the second insulating member 214 can reduce the risk of short circuits.

Referring to fig. 7 and 8, opposite ends of the electrode terminal 216 are connected to the connection member 215 and the first connection section 21131 of the current collecting member 211, respectively, and the second connection section 21133 of the current collecting member 211 is connected to the tab 251 of the electrode assembly 25 through the tab connection portion 2111 to guide current of the electrode assembly 25 to the connection member 215 on the first side sequentially through the tab 251, the current collecting member 211, and the electrode terminal 216. The first insulating member 213 and the second insulating member 214 are disposed on opposite sides of the top cover sheet 212, so that the top cover sheet 212 is insulated, and the risk of short circuit is reduced.

Optionally, referring to fig. 5 and 7, according to some embodiments of the present application, the top cap assembly 21 further includes a sealing member 217, wherein the sealing member 217 is sleeved on the electrode terminal 216 and is located between the top cover sheet 212 and the electrode terminal 216, for sealing a gap between the top cover sheet 212 and the electrode terminal 216.

The seal 217 is a functional member for sealing against leakage of the electrolyte in the battery 100. The material of the seal 217 may be an elastic material such as rubber, plastic, or the like. The shape of the sealing member 217 may be circular, square, or the like, and it is only necessary to match the shape of the outer circumferential wall of the electrode terminal 216, and a gap between the top cap sheet 212 and the electrode terminal 216 may be provided. The sealing member 217 is positioned between the electrode terminal 216 and the cap plate 212 to fill the gap, and leakage of electrolyte inside the battery cell 20 can be prevented.

Optionally, referring to fig. 13, any two adjacent sub-rivets 21151 are welded together according to some embodiments of the application. Namely, the caulking position of each layer of sub-terminal connection parts 21137 is reinforced by welding, so that the connection strength between each layer of sub-terminal connection parts 21137 is improved; on the other hand, the overcurrent area of the current collecting member 211 is increased, the internal resistance is reduced, the temperature rise is reduced, and the safety performance of the battery cell 20 is improved.

Optionally, referring to fig. 10 to 13, according to some embodiments of the present application, the terminal connection portion 2113 is provided with a fixing structure 2115, and in the fixing structure 2115, all the sub-rivet portions 21151 are sequentially stacked and mated with each other. That is, a plurality of sub-caulking portions 21151 are laminated to form one fixing structure 2115.

The fixing structure 2115 is a structure for performing a positioning and fixing function when two members to be connected are connected to each other, and the sub-caulking portion 21151 is a structure for performing a positioning and fixing function when two members to be connected are connected to each other. The plurality of sub-caulking portions 21151 are mutually engaged to position and fixedly connect two members to be connected, that is, to position and fixedly connect adjacent two sub-terminal connecting portions 21137.

Compared with the mode of forming the terminal connection part by laminating and welding the plurality of single-layer sub-terminal connection parts after punching and cutting the plurality of single-layer sub-terminal connection parts, the fixing structure 2115 is formed by laminating the sub-riveting parts 21151 of the sub-terminal connection parts 21137 of the adjacent layers, positioning is accurate, alignment is easy, and meanwhile, a welding process is not needed, so that the production efficiency of the current collecting member 211 is improved. The caulking of the sub-caulking portions 21151 of the sub-terminal connection portions 21137 of the adjacent layers can reduce burrs as compared to the terminal connection portions obtained by cutting after the material is rolled into a plurality of layers.

Optionally, referring to fig. 5, 13 and 15, a fixing structure 2115 is provided at an end region of the terminal connection portion 2113 near the electrode terminal 216 according to some embodiments of the present application. That is, the fixing structure 2115 is provided at the first connection section 21131 of the terminal connection portion 2113. In this way, each layer of sub-terminal connection portions 21137 can be riveted to form the integrally constructed terminal connection portion 2113.

Optionally, referring to fig. 5 and 13, a fixing structure 2115 is provided at an end region of the terminal connection portion 2113 near the tab connection portion 2111 according to some embodiments of the present application. That is, the fixing structure 2115 is provided at the second connection section 21133 of the terminal connection portion 2113. In this way, after the sub-terminal connection portions 21137 are crimped to form the integrally configured terminal connection portions 2113, the integrally configured terminal connection portions 2113 can be easily crimped to the tab connection portions 2111.

In accordance with some embodiments of the present application, optionally, referring to fig. 5 and 13, a fixing structure 2115 is provided at an end region of the terminal connection portion 2113 near the electrode terminal 216, and at an end region of the terminal connection portion 2113 near the tab connection portion 2111. That is, the first connection section 21131 of the terminal connection portion 2113 is provided with the fixing structure 2115, and the second connection section 21133 of the terminal connection portion 2113 is also provided with the fixing structure 2115. In this manner, on the one hand, each layer of sub-terminal connection portions 21137 can be riveted to form the integrally structured terminal connection portion 2113; on the other hand, after the sub-terminal connection portions 21137 of the respective layers are crimped to form the integrally structured terminal connection portions 2113, the integrally structured terminal connection portions 2113 can be easily crimped to the tab connection portions 2111; in still another aspect, the opposite ends of the terminal connection portion 2113 are provided with the fixing structures 2115, so that the coupling force of the two ends of the terminal connection portion 2113 of the integral structure is relatively uniform and the integral coupling is stronger.

Optionally, referring to fig. 11, 15 and 16, the number of fixation structures 2115 is one or more, according to some embodiments of the present application.

Referring to fig. 14 and 15, when the number of fixing structures 2115 is one, the fixing structures 2115 may be disposed at the first connection section 21131 (as shown in fig. 15) of the terminal connection portion 2113, may be disposed at the second connection section 21133 of the terminal connection portion 2113, and may be disposed at the bending section 21135 of the terminal connection portion 2113, which is not limited herein. The positioning accuracy at the time of caulking the sub-terminal connection parts 21137 of any adjacent layer can be ensured regardless of where the one fixing structure 2115 is provided at the terminal connection part 2113.

Referring to fig. 11 and 16, when the number of the fixing structures 2115 is plural, the plural fixing structures 2115 may be disposed at the first connection section 21131 of the terminal connection portion 2113, at the second connection section 21133 of the terminal connection portion 2113, or at the bending section 21135 of the terminal connection portion 2113. Alternatively, a part of the plurality of fixing structures 2115 is provided at the first connection section 21131 of the terminal connection portion 2113, and the remaining part is provided at the second connection section 21133 of the terminal connection portion 2113, as shown in fig. 11 and 16; alternatively, a part of the plurality of fixing structures 2115 is provided at the first connection section 21131 of the terminal connection portion 2113, and the remaining part is provided at the bending section 21135 of the terminal connection portion 2113; alternatively, a part of the plurality of fixing structures 2115 is provided at the second connection section 21133 of the terminal connection portion 2113, and the remaining part is provided at the bending section 21135 of the terminal connection portion 2113; still alternatively, a part of the plurality of fixing structures 2115 is provided at the first connection section 21131 of the terminal connection portion 2113, another part is provided at the second connection section 21133 of the terminal connection portion 2113, and another part is provided at the bent section 21135 of the terminal connection portion 2113. Regardless of where the plurality of fixing structures 2115 are provided at the terminal connection portions 2113, not only can the positioning accuracy of the sub-terminal connection portions 21137 of any adjacent layer be ensured at the time of caulking, but also the connection strength between the sub-terminal connection portions 21137 can be improved, and the connection strength between the sub-terminal connection portions is not easily separated from each other, thereby improving the working stability of the current collecting member 211.

Optionally, referring to fig. 11, a cross-sectional shape of the fixation structure 2115 includes any one of square, rectangular, and circular, according to some embodiments of the present application.

Referring to fig. 11, 13 and 15, the cross section of the fixing structure 2115 is the cross section of the sub-rivet 21151, that is, the plane of the sub-rivet 21151 cut parallel to the plane of the upper surface of the sub-terminal connection portion 21137. The cross-sectional shape of the fixing structure 2115 is not limited, and may be any one of square, rectangular, circular, and other polygonal shapes, thereby reducing the difficulty in designing the terminal connection portion 2113 and simplifying the fabrication of the current collecting member 211.

Optionally, referring to fig. 11 and 16, the number of fixing structures 2115 is plural, and a part of the plurality of fixing structures 2115 is disposed at the first connection section 21131 of the terminal connection portion 2113, and the other part is disposed at the second connection section 21133 of the terminal connection portion 2113, and the cross-sectional shapes of the plurality of fixing structures 2115 may be the same or different.

Referring to fig. 11 to 13, in one example, the cross-sectional shapes of the plurality of fixing structures 2115 are the same. Specifically, the cross-sectional shape of the fixing structure 2115 on the first connection section 21131 of the terminal connection portion 2113 is rectangular, and the cross-sectional shape of the fixing structure 2115 on the second connection section 21133 of the terminal connection portion 2113 is also rectangular. The plurality of fixing structures 2115 are designed to have the same cross-sectional shape, and the process of manufacturing the terminal connection portion 2113 can be simplified.

Referring to fig. 16, in another example, the plurality of fixation structures 2115 have at least partially different cross-sectional shapes. Specifically, the cross-sectional shape of the fixing structure 2115 on the first connection section 21131 of the terminal connection portion 2113 is rectangular, and the cross-sectional shape of the fixing structure 2115 on the second connection section 21133 of the terminal connection portion 2113 is partially rectangular, and the other is circular. The cross-sectional shapes of the fixing structures 2115 are designed to be different, so that the fixing structures can be positioned more easily during riveting, riveting dislocation is avoided, and a foolproof effect is achieved.

Optionally, referring to fig. 13 and 15, the terminal connection portion 2113 has a first main surface 21138 and a second main surface 21139 opposite to each other in a thickness direction thereof after being unfolded according to some embodiments of the present application. The fixing structure 2115 has a recess formed on one side of the first main surface 21138, and the fixing structure 2115 has a first protrusion formed on the second main surface 21139.

The first main surface 21138 is a partial region of the terminal connection portion 2113 which is left after the surface facing the tab connection portion 2111 is removed from the recess, and the second main surface 21139 is a partial region of the terminal connection portion 2113 which is left after the surface facing the tab connection portion 2111 is removed from the first protrusion.

In one example, the first protrusion is a structure in which the terminal connection portion 2113 of the flat sheet structure is stamped to be convex with respect to the second main surface 21139, and correspondingly, the recess is a space structure in which the terminal connection portion 2113 of the flat sheet structure is stamped to be concave with respect to the first main surface 21138, as shown in fig. 13 and 15. In another example, the recess is a space structure of a flat sheet-like structure in which the terminal connection portion 2113 is stamped and recessed relative to the first main surface 21138, and the first protrusion is not protruding relative to the second main surface 21139, but is flush with the second main surface 21139, the first protrusion being defined only relative to the recess.

The fixing structure 2115 includes a first protrusion and a recess, which can prevent the staggered layers when stacked when the terminal connection portion 2113 is formed by caulking, is positioned accurately, and is easily aligned, and simultaneously, a welding process is not required, thereby improving the production efficiency of the current collecting member 211. In addition, the fixing structure 2113 includes a first convex portion and a concave portion, and burrs can also be reduced.

In accordance with some embodiments of the present application, optionally, referring to fig. 12 and 13, a tab connection portion 2111 is provided at a side of the terminal connection portion 2113 near the second main surface 21139, the tab connection portion 2111 is provided with a first receiving portion 2117, and the first protrusion of the fixing structure 2115 is received in the first receiving portion 2117. The first protrusion of the fixing structure 2115 is accommodated in the first accommodating portion 2117, and functions as a positioning function when the terminal connection portion 2113 is connected to the tab connection portion 2111.

The first receiving portion 2117 may be a through hole or a groove. The arrangement positions of the first accommodation portions 2117 correspond to the arrangement positions of the fixing structures 2115 on the second connection section 21133, and the number of the first accommodation portions 2117 corresponds to the number of the fixing structures 2115 on the second connection section 21133. Specifically, when the number of the fixing structures 2115 on the second connection section 21133 is one, then the number of the first accommodation portions 2117 is also one; when the number of the fixing structures 2115 on the second connection section 21133 is plural, then the number of the first accommodation portions 2117 is plural.

Further, the cross-sectional shape of the fixing structure 2115 is not limited, and may be any of square, rectangular, and circular. Accordingly, the cross-sectional shape of the first accommodation portion 2117 is not limited, and may be any one of a square, a rectangle, and a circle, as long as the cross-sectional shape of the fixing structure 2115 matches the cross-sectional shape of the corresponding first accommodation portion 2117. Thus, the difficulty in designing the tab connection portion 2111 is reduced, and the fabrication of the current collecting member 211 is further simplified.

Optionally, referring to fig. 12 and 13, the terminal connection portion 2113 is fixedly connected to the tab connection portion 2111 through a first protrusion, according to some embodiments of the present application.

At this time, the first accommodation portion 2117 is also a structure for performing positioning and fixing functions when two members to be connected are connected to each other. The fixing structure 2115 and the first receiving portion 2117 cooperate with each other to position and/or fixedly connect two members to be connected, i.e., the tab connection portion 2111 and the terminal connection portion 2113. When the first protrusion of the fixing structure 2115 is fixedly connected (riveted) to the first receiving portion 2117, it is possible to connect the terminal connection portion 2113 to the tab connection portion 2111 by riveting, and compared with the terminal connection portion 2113 connected to the tab connection portion 2111 by a welding process, the positioning accuracy of the connection between the terminal connection portion 2113 and the tab connection portion 2111 is improved, and the welding process is not required, so that the production efficiency of the current collecting member 211 is improved.

Meanwhile, the number of the first accommodating parts 2117 can be larger than the number of the fixing structures 2115 on the second connecting section 21133, on one hand, when one of the first accommodating parts 2117 is damaged, the fixing structures 2115 can be riveted with more than one of the first accommodating parts 2117; on the other hand, in the case where the mounting of other parts in the battery cell 20 needs to be considered, it may be necessary to perform the offset mounting of the terminal connection portion 2113 and the tab connection portion 2111 in the width direction, and then the fixing structure 2115 is riveted with the other first receiving portions 2117 that are more than necessary to enable the offset mounting of the terminal connection portion 2113 and the tab connection portion 2111 in the width direction, thereby facilitating the mounting of other parts in the battery cell 20.

Optionally, referring to fig. 13, in some embodiments, each sub-rivet 21151 has a sub-protrusion and a sub-recess, each sub-protrusion protruding toward the second main surface 21139, each sub-recess being recessed from the first main surface 21138 toward the second main surface 21139, the sub-protrusion of one sub-rivet 21151 of two adjacent sub-rivets 21151 being received in and fixedly connected to the sub-recess of the other sub-rivet 21151.

The sub-protrusion and sub-recess riveting of the sub-terminal connection portions 21137 of the adjacent layers may be achieved by a stamping process, for example, the second-layer sub-terminal connection portion 21137 is stacked on the first-layer sub-terminal connection portion 21137 and is aligned with the region where the fixing structure 2115 is to be formed for stamping, so that the second-layer sub-terminal connection portion 21137 is riveted with the first-layer sub-terminal connection portion 21137, and the sub-protrusion and the sub-recess are formed on both the first-layer sub-terminal connection portion 21137 and the second-layer sub-terminal connection portion 21137; then, the third-layer sub-terminal connection part 21137 is stacked on the second-layer sub-terminal connection part 21137 and is punched in alignment with the sub-recess of the second-layer sub-terminal connection part 21137, so that the third-layer sub-terminal connection part 21137 is riveted with the second-layer sub-terminal connection part 21137, and sub-protrusions and sub-recesses are formed on the third-layer sub-terminal connection part 21137; next, the fourth-layer sub-terminal connection part 21137 is stacked on the third-layer sub-terminal connection part 21137 and is punched in alignment with the sub-recess of the third-layer sub-terminal connection part 21137, so that the fourth-layer sub-terminal connection part 21137 is riveted with the third-layer sub-terminal connection part 21137, and sub-protrusions and sub-recesses are formed on the fourth-layer sub-terminal connection part 21137; the sub-terminal connection portions 21137 of the respective layers are thus stacked and caulking-connected to the terminal connection portions 2113 of the single-piece structure.

Compared with the mode that after the sub-terminal connection parts of a plurality of single layers are punched and cut first, the sub-terminal connection parts of the single layers are stacked and welded to form the terminal connection parts, the sub-protrusions and the sub-concave parts of the sub-terminal connection parts 21137 of the adjacent layers are riveted, so that staggered layers during stacking can be avoided, positioning is accurate, alignment is easy, a welding process is not needed, and meanwhile, the production efficiency of the current collecting member 211 is improved. The sub-protrusions and sub-recesses of the sub-terminal connection portions 21137 of adjacent layers can reduce burrs as compared to a terminal connection portion having a multi-layered structure obtained by cutting after rolling the material into a plurality of layers.

According to some embodiments of the present application, alternatively, referring to fig. 12 to 15, the riveting between the sub-terminal connection parts 21137 of the adjacent layers and the riveting between the sub-protrusions of the sub-terminal connection part 21137 of the outermost layer and the receiving part 2117 may be performed in a progressive die.

The continuous die means that a press adopts a strip-shaped stamping raw material in one stamping stroke, a plurality of cold stamping dies for stamping procedures are simultaneously completed at a plurality of different stations on a pair of dies, and each time the dies are stamped, the material strip moves once at fixed intervals until the product is completed. Specifically, it is assumed that the terminal connection portion 2113 includes three layers of sub-terminal connection portions 21137, and there are two stations on the mold, one for each current collecting member 211. In the case of performing the caulking between the sub-protrusion of the sub-terminal connection portion 21137 of the outermost layer and the receiving portion 2117 of the tab connection portion 2111 and then performing the caulking between the sub-protrusion of the sub-terminal connection portion 21137 of the adjacent layer and the sub-recess, the following steps are simultaneously performed at two stations: the material strips corresponding to the two stations are punched for the first time by the die, the material strips are blanked simultaneously, the sub-terminal connecting portion 21137 is used as a first layer (outermost layer) sub-terminal connecting portion 21137, the first layer sub-terminal connecting portion 21137 is punched, the sub-protrusions on the first layer sub-terminal connecting portion 21137 are riveted with the accommodating portions 2117 (grooves or through holes) which are arranged in advance on the connecting regions 21111 of the tab connecting portions 2111 in the die, and sub-concave portions are formed on the first main surface 21138 side of the first layer sub-terminal connecting portion 21137; then, the material tape is moved at a certain distance until the material tape is located in the area corresponding to the two stations, the material tape is punched for the second time by the die, and the material tape is blanked at the same time, at this time, the sub-terminal connecting portion 21137 is used as a second-layer sub-terminal connecting portion 21137, the second-layer sub-terminal connecting portion 21137 is punched, so that the sub-protrusions on the second-layer sub-terminal connecting portion 21137 are punched from the sub-recesses on the first-layer sub-terminal connecting portion 21137 into the first-layer sub-terminal connecting portion 21137 to form riveting, and the sub-recesses are formed on the first main surface 21138 side of the second-layer sub-terminal connecting portion 21137; finally, the tape is moved at a fixed distance again until the tape is again provided in the region corresponding to the two stations, the tape is punched out of the mold for the third time, and the tape is simultaneously blanked, at this time, the sub-terminal connecting portion 21137 serves as a third-layer sub-terminal connecting portion 21137, the third-layer sub-terminal connecting portion 21137 is punched, the sub-protrusions thereon are punched from the sub-recesses on the second-layer sub-terminal connecting portion 21137 into the second-layer sub-terminal connecting portion 21137 to form riveting, and the sub-recesses are formed on the first main surface 21138 side of the third-layer sub-terminal connecting portion 21137, so that the connection between the respective terminal connecting portions 2113 and the tab connecting portions 2111 of the two current collecting members 211 on the two stations and the riveting between the sub-terminal connecting portions 21137 of the adjacent layers can be simultaneously achieved.

Riveting between the sub-terminal connection parts 21137 of the adjacent layers and riveting of the sub-terminal connection part 21137 of the outermost layer and the tab connection part 2111 are performed in a progressive die, which can automatically realize overlapped riveting, improve the positioning accuracy of the current collecting member 211, and simultaneously can realize mass production and improve the production efficiency of the current collecting member 211.

In accordance with some embodiments of the present application, optionally, referring to fig. 12 to 15, the sub-protrusions of the sub-terminal connection portions 21137 of the adjacent layers are interference-fitted with the sub-recesses, and the sub-protrusions of the sub-terminal connection portions 21137 of the outermost layers are interference-fitted with the accommodation portions 2117.

The riveting of the sub-protrusions of the outer-layer sub-terminal connection parts 21137 and the accommodating parts 2117 can be realized through a stamping process, after stamping, the sub-protrusions of the outer-layer sub-terminal connection parts 21137 are in interference fit with the accommodating parts 2117, the interference fit enables the connection between the terminal connection parts 2113 and the tab connection parts 2111 to be firmer, the terminal connection parts 2113 and the tab connection parts 2111 are not easy to separate, and the working stability of the current collecting member 211 is improved. Riveting between the sub-protrusions and the sub-recesses of the sub-terminal connection portions 21137 of the adjacent layers can also be achieved through a stamping process, and after stamping, the sub-protrusions and the sub-recesses of the sub-terminal connection portions 21137 of the adjacent layers are in interference fit, so that connection between the multi-layer sub-terminal connection portions 21137 is firmer.

In accordance with some embodiments of the present application, as shown in fig. 14 and 15, optionally, a second receiving portion 2118 is provided on the terminal connecting portion, a second protrusion 2119 is provided on the tab connecting portion, and the second protrusion 2119 is received in the second receiving portion 2118.

In the case where the fixing structure 2115 is provided in the end region (first connection section 21131) of the terminal connection portion 2113 adjacent to the electrode terminal 216, the second receiving portion 2118 may be further provided in the end region (second connection section 21133) of the terminal connection portion 2113 adjacent to the tab connection portion 2111, and at this time, the second protrusion 2119 is received in the cavity 2118, so that the positioning accuracy when the terminal connection portion 2113 and the tab connection portion 2111 are connected can be improved.

Specifically, in one example, each of the sub-terminal connection portions 21137 is provided with a sub-receiving portion 21181, and a plurality of sub-receiving portions 21181 are aligned and communicate and together form a second receiving portion 2118, and the second protrusions 2119 can be received in the second receiving portion 2118. The second receiving portion 2118 may be a through hole penetrating the first main surface 21138 and the second main surface 21139, or may be a groove penetrating the second main surface 21139, but not penetrating the first main surface 21138. The second protrusions 2119 are received in the second receiving portions 2118, which improves positioning accuracy when the terminal connection portions 2113 are connected to the tab connection portions 2111, and further improves production efficiency of the current collecting member 211. In another example, some of the sub-terminal connection portions 21137 are provided with sub-receiving portions 21181, and these sub-receiving portions 21181 are aligned and connected to form the second receiving portion 2118 together, while other terminal connection portions 21137 may not be provided with sub-receiving portions 21181, and at this time, the second receiving portion 2118 is a groove penetrating the second main surface 21139 and not penetrating the first main surface 21138, and similarly, the second protrusion 2119 may be received in the second receiving portion 2118 which is the groove.

Optionally, referring to fig. 14 and 15, the tab connection portion 2111 is fixedly connected to the terminal connection portion 2113 by a second protrusion 2119, according to some embodiments of the present application.

Specifically, in one example, each of the sub-terminal connection portions 21137 is provided with a sub-receiving portion 21181, and the plurality of sub-receiving portions 21181 are aligned and communicated to form a second receiving portion 2118 together, and the second protrusions 2119 can be interference fit (fixedly connected) in the second receiving portion 2118 through a riveting process. The second receiving portion 2118 may be a through hole penetrating the first main surface 21138 and the second main surface 21139, or may be a groove penetrating the second main surface 21139, but not penetrating the first main surface 21138. The second protrusions 2119 are directly riveted with the second receiving portions 2118, so that positioning accuracy of the terminal connection portions 2113 and the tab connection portions 2111 is improved, a welding process is saved, and production efficiency of the current collecting member 211 is improved. In another example, some of the sub-terminal connection portions 21137 are provided with sub-receiving portions 21181, which sub-receiving portions 21181 are aligned and connected to form the second receiving portion 2118 together, while other of the terminal connection portions 21137 are not provided with sub-receiving portions 21181, and at this time, the second receiving portion 2118 is a groove penetrating the second main surface 21139 and not penetrating the first main surface 21138, and similarly, the second protrusion 2119 may be directly riveted with the second receiving portion 2118.

Optionally, referring to fig. 10, the terminal connection portion 2113 and the tab connection portion 2111 are at least partially welded according to some embodiments of the application.

The second connection section 21133 is welded to the connection region 21111 of the tab connection 2111. In one example, the solder marks formed between the terminal connection portions 2113 and the tab connection portions 2111 are located in areas other than the fixing structures 2115. The second connection section 21133 is welded at a region outside the fixing structure 2115 on the connection region 21111, namely, a non-riveted position between the terminal connection portion 2113 and the tab connection portion 2111 is welded and reinforced, so that on one hand, the overcurrent area of the current collecting member 211 is increased, the internal resistance is reduced, the temperature rise is reduced, and the safety performance of the battery cell 20 (shown in fig. 3) is improved; on the other hand, the connection between the terminal connection portion 2113 and the tab connection portion 2111 is firmer, and the terminal connection portion 2113 and the tab connection portion 2111 are not easily separated, thereby improving the working stability of the current collecting member 211.

In another example, the solder marks formed between the terminal connection portion 2113 and the tab connection portion 2111 may also be located in the area of the fixing structure 2115. The second connection section 21133 is welded on the connection region 21111 in the region where the fixing structure 2115 is located, that is, in the riveting position between the terminal connection portion 2113 and the tab connection portion 2111, the welding reinforcement is performed, on the one hand, the overcurrent area of the current collecting member 211 is increased, the internal resistance is reduced, the temperature rise is reduced, and the safety performance of the battery cell 20 (shown in fig. 3) is improved; on the other hand, the connection between the terminal connection portion 2113 and the tab connection portion 2111 is firmer, and the terminal connection portion 2113 and the tab connection portion 2111 are not easily separated, thereby improving the working stability of the current collecting member 211.

Optionally, referring to fig. 10, the second connection section 21133 is welded to the connection region 21111 of the tab connection portion 2111 by at least one of ultrasonic welding, molecular diffusion welding, and laser welding, according to some embodiments of the present application.

The ultrasonic welding is to convert current into high-frequency electric energy through an ultrasonic generator, then convert the high-frequency electric energy into mechanical motion through a transducer, finally transmit the mechanical motion to a welding head through an amplitude transformer, transmit the received vibration energy to the interface of the second connecting section 21133 and the tab connecting part 2111, convert the vibration energy into heat energy through a friction mode, gather the heat energy at the interface of the second connecting section 21133 and the tab connecting part 2111 to enable the interface to be melted rapidly, and enable the interface of the second connecting section 21133 and the tab connecting part 2111 to be integrated after a certain pressure is applied. By ultrasonic welding, the tab connection portion 2111 and the terminal connection portion 2113 can be compacted by applying pressure, cold welding is prevented, firmness of the tab connection portion 2111 and the terminal connection portion 2113 after welding is ensured, and meanwhile, metal bonding between the tab connection portion 2111 and the terminal connection portion 2113 can be achieved in a short time and at a low temperature by ultrasonic welding.

The molecular diffusion welding is a welding method in which the tab connection portion 2111 and the terminal connection portion 2113 are bonded by diffusing molecules at their interfaces at a predetermined temperature and a predetermined pressure at a high temperature. By using molecular diffusion welding, if the connection region 21111 of the tab connection portion 2111 and the second connection section 21133 of the terminal connection portion 2113 are made of the same material, there is no heat affected zone at the welded portion, and thus there is no residual stress and no melting defect. In addition, the molecular diffusion welding has low welding temperature, little damage to the tab connection portion 2111 and the terminal connection portion 2113, high welding accuracy, and little deformation.

The laser welding is a method of welding by using a focused laser beam as an energy source to bombard heat generated at the interface between the tab connection portion 2111 and the terminal connection portion 2113. By adopting the laser welding, the welding speed of the laser welding is high, the welding depth is large, and the deformation of the welding part between the tab connection part 2111 and the terminal connection part 2113 is small while the firmness after the welding of the tab connection part 2111 and the terminal connection part 2113 is ensured.

Optionally, referring to fig. 3, 8 and 10, the terminal connection portion 2113 is disposed between the tab connection portion 2111 and the electrode terminal 216 in a bending manner according to some embodiments of the present application. The terminal connection portion 2113 is disposed between the tab connection portion 2111 and the electrode terminal 216 in a bent manner, so that a height space occupied by the current collecting member 211 in the battery cell 20 can be reduced, on the one hand, the structure of the battery cell 20 is made more compact, and on the other hand, more space can be made for the electrode sheet in the electrode assembly 25 at the same height of the battery cell 20, thereby increasing the energy density of the battery cell 20.

In a second aspect, referring to fig. 2, the present application further provides a battery 100, including the battery cell 20 according to any of the above embodiments.

In the technical solution of the embodiment of the present application, please combine fig. 3 and 10, the battery 100 uses the battery cell 20 in the embodiment of the first aspect, and in the top cover assembly 21 of the battery cell 20, the bending capability of the multi-layer sub-terminal connection portion 21137 of the current collecting member 211 is stronger, and is not easy to break, thereby ensuring the working stability of the battery 100; meanwhile, under the same bending capability, the overall thickness of the multi-layered sub-terminal connection part 21137 can be made thicker, so that the overcurrent area of the current collecting member 211 is increased, the internal resistance is reduced, and the temperature rise is reduced, thereby improving the safety of the battery 100. In addition, the multi-layered sub-terminal connection part 21137 is bent to a greater extent to reduce the height space occupied by the current collecting member 211, thereby improving the energy density of the battery cell 20 and thus the energy density of the battery 100.

In a third aspect, referring to fig. 1, the present application further provides an electric device, where the electric device includes the battery 100 according to any one of the above embodiments, and the battery 100 is used to provide electric energy.

In the technical solution of the embodiment of the present application, please combine fig. 3 and fig. 10, the battery 100 in the embodiment of the second aspect is used in the electric device, and in the battery unit 20 of the battery 100, the bending capability of the multi-layer sub-terminal connection portion 21137 of the current collecting member 211 in the top cover assembly 21 is stronger, and is not easy to break, so that the working stability of the electric device is ensured; meanwhile, under the same bending capability, the overall thickness of the multi-layered sub-terminal connection part 21137 may be made thicker such that the overcurrent area of the current collecting member 211 is increased, the internal resistance is reduced, and the temperature rise is reduced, thereby improving the safety of the battery 100. In addition, the multi-layer sub-terminal connection portion 21137 is bent to a greater extent, so that the height space occupied by the current collecting member 211 can be reduced, and the energy density of the battery cell 20 is improved, thereby improving the energy density of the battery 100 and further improving the endurance time of the electric device.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the application, and are intended to be included within the scope of the appended claims and description. In particular, the technical features mentioned in the respective embodiments may be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, comprising:

an electrode assembly including a tab;

a case for accommodating the electrode assembly;

an electrode terminal provided to the case; and

The current collecting component comprises a tab connecting part and a terminal connecting part, wherein the tab connecting part is used for connecting the tab, the terminal connecting part is used for connecting the electrode terminal, the terminal connecting part comprises a plurality of layers of sub-terminal connecting parts which are arranged in a stacked mode, each layer of sub-terminal connecting parts comprise sub-riveting parts, and any two adjacent sub-riveting parts are fixedly riveted.

2. The battery cell of claim 1, wherein any adjacent two of the sub-rivet portions are welded together.

3. The battery cell according to claim 1 or 2, wherein the terminal connection part is provided with a fixing structure in which all the sub-rivet fixing structures are sequentially stacked and fitted to each other.

4. The battery cell according to claim 3, wherein the fixing structure is provided at an end region of the terminal connection part near the electrode terminal and/or at an end region of the terminal connection part near the tab connection part.

5. A battery cell according to claim 3, wherein the number of the fixing structures is one or more.

6. The battery cell according to claim 3, wherein the terminal connection portion has a first main surface and a second main surface which are disposed opposite to each other in a thickness direction thereof after being developed, the fixing structure is formed with a concave portion on one side of the first main surface, and the fixing structure is formed with a first convex portion on the second main surface.

7. The battery cell according to claim 6, wherein the tab connection portion is provided at a side of the terminal connection portion near the second main surface, the tab connection portion is provided with a first receiving portion, and the first protrusion is received in the first receiving portion.

8. The battery cell as defined in claim 7, wherein the terminal connection portion is fixedly connected to the tab connection portion through the first protrusion.

9. The battery cell according to claim 7, wherein each of the sub-caulking portions has a sub-protrusion and a sub-recess, each of the sub-protrusions protruding in a direction toward the second main surface, each of the sub-recesses being recessed from the first main surface toward the second main surface, the sub-protrusion of one of the adjacent two sub-caulking portions being received in and fixedly connected to the sub-recess of the other sub-caulking portion.

10. The battery cell according to claim 1, wherein the terminal connection portion is provided with a second receiving portion, the tab connection portion is provided with a second protruding portion, and the second protruding portion is received in the second receiving portion.

11. The battery cell as defined in claim 10, wherein the tab connection portion is fixedly connected to the terminal connection portion through the second protrusion.

12. The battery cell of claim 1, wherein the terminal connection portion and the tab connection portion are at least partially welded.

13. The battery cell as recited in claim 12, wherein the terminal connection portion is provided with a fixing structure, and a weld formed between the terminal connection portion and the tab connection portion is located in an area other than the fixing structure.

14. The battery cell according to claim 1, wherein the terminal connection portion is provided between the tab connection portion and the electrode terminal in a bent manner.

15. A battery comprising a cell according to any one of claims 1-14.

16. An electrical device comprising the battery of claim 15 for providing electrical energy.