CN121925755A

CN121925755A - Battery cell, battery device, electricity utilization device and energy storage device

Info

Publication number: CN121925755A
Application number: CN202480003250.2A
Authority: CN
Inventors: 谢呈斌; 周文林; 郭志君; 蔡润琛
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2024-07-31
Filing date: 2024-07-31
Publication date: 2026-04-24
Also published as: WO2026025385A1

Abstract

A battery cell (100), a battery device (400), an electrical device, and an energy storage device are disclosed. The battery cell (100) includes a housing (1), at least one electrode assembly (2), electrode terminals (3), and an electrical connector (4). A receiving cavity (1a) is formed inside the housing (1), and the housing (1) includes a first wall (11) with a mounting hole. At least one electrode assembly (2) is located within the receiving cavity (1a), and the electrode assembly (2) includes an electrode body (21) and a tab (22) connected to the electrode body (21). The electrode terminal (3) passes through the mounting hole. The electrical connector (4) connects the electrode terminal (3) and the tab (22). Among them, the tab (22) includes a welding part (21). When there are multiple tabs (22) with the same polarity, the welding parts (21) of each tab (22) with the same polarity overlap at least partially to form an overlapping part (2211). The overlapping part (2211) is welded to the electrical connector (4) to form a solder mark (5).

Description

Battery cell, battery device, electricity utilization device and energy storage device

Technical Field

The disclosure relates to the field of battery technology, and in particular relates to a battery cell, a battery device, an electricity utilization device and an energy storage device.

Background

New energy batteries are increasingly used in life and industry, for example, new energy automobiles equipped with battery devices have been widely used, and in addition, battery devices are increasingly used in the field of energy storage and the like.

With the continuous development of battery technology, how to reduce the size of the battery cell and improve the production efficiency of the battery cell is one of the subjects of research in the industry.

Disclosure of Invention

In order to solve the technical problems, the present disclosure provides a battery cell, a battery device, an electricity consumption device and an energy storage device, which have small size, low production cost and high production efficiency.

The technical scheme of the disclosure is as follows.

The first aspect of the disclosure provides a battery cell, which comprises a shell, at least one electrode assembly, an electrode terminal and an electric connecting piece, wherein a containing cavity is formed in the shell, the shell comprises a first wall, a mounting hole is formed in the first wall, the electrode assembly is located in the containing cavity and comprises an electrode main body and a tab connected with the electrode main body, the electrode terminal penetrates through the mounting hole, the electric connecting piece is connected with the electrode terminal and the tab, the tab comprises welding parts, the welding parts of the tab with the same polarity are at least partially overlapped to form an overlapped part, and the overlapped part and the electric connecting piece are welded to form a welding mark.

The tabs with the same polarity of the battery cells are at least partially overlapped to form the overlapped part, and the overlapped part is welded with the electric connecting piece, so that the connection between the tabs and the electric connecting piece can be realized by only one-time welding, the welding times can be reduced, the production efficiency is improved, and the production cost is reduced.

In addition, because only one welding mark is formed after the plurality of lugs with the same polarity are welded with the electric connecting piece, compared with the situation that a plurality of welding marks are formed by welding a plurality of lugs respectively, the space occupied by the welding marks can be saved, so that the size of the electric connecting piece can be reduced, the size of the battery monomer can be effectively reduced, the battery monomer can be better applied to a mounting environment with a limited space, and the energy density of the battery monomer cannot be influenced.

In some embodiments, the electrode body has a thickness in a first direction, and the overlap has a width greater than the width of the solder mark in the first direction.

Therefore, the welding marks can be completely positioned in the overlapping area of the electrode lugs, so that the connection area between the electrode lugs can be increased, the welding reliability can be improved, the possibility that the electrode lugs cannot be well welded or the welding failure and other adverse conditions occur is reduced, and the welding quality is improved.

In some embodiments, the weld is located in a central region of the overlap.

Thereby, the welding reliability between the tabs having the same polarity can be further improved, so that the tabs overlapping each other at the overlapping portion can be sufficiently welded. In addition, the welding marks are positioned in the central area of the overlapping part, so that the extending lengths of the lugs at two opposite sides along the first direction are the same, the possibility that one lug stretches too much is reduced, and the reliability of the battery cell is improved.

In some embodiments, the electrical connector comprises a tab connection part, an electrode terminal connection part and an intermediate connection part, wherein the tab connection part is connected with the electrode terminal, the electrode terminal connection part is connected with the electrode terminal, the intermediate connection part is connected with the tab connection part and the electrode terminal connection part, the electrode terminal connection part and the tab connection part extend along a second direction, the intermediate connection part extends along a third direction, the tab connection part is closer to the first wall than the electrode terminal connection part in the third direction, the welding part of the tab is welded with one side of the tab connection part, which is opposite to the first wall, and the first direction, the second direction and the third direction are perpendicular to each other.

Therefore, the tab connection part and the electrode terminal connection part have a certain height difference along the third direction, so that the overlapping part of the tab can be positioned in a space generated by the height difference between the tab connection part and the electrode terminal connection part, the overlapping part cannot occupy too much space in the accommodating cavity of the shell, and the tab can be overlapped and welded with the electric connector under the condition of not affecting the energy density of the battery unit.

In some embodiments, the battery cell further comprises an insulating part located on one side of the first wall facing the electrode assembly, each tab further comprises a bending part connected with the welding part, the bending part protrudes towards the side of the first wall in the third direction relative to the welding part, and the width of the tab connection part is smaller than the first size along the first direction, wherein the first size is the width of the insulating part along the first direction minus the width of the bending part of each tab connected with the tab connection part along the first direction.

Because the tab need buckle when being connected with tab connecting portion, consequently, when the size of tab connecting portion is less than first size for can have sufficient space to hold the kink of tab in the casing, thereby satisfy the technological requirement that the tab buckled, improve the connection reliability between tab and the electric connection piece.

In some embodiments, the first dimension is a width of the insulator in the first direction minus 6 millimeters.

Therefore, the requirements of most tab folding processes can be met, and a sufficient distance size can be reserved between the insulating piece and the tab connecting part to accommodate the bending part of most tabs.

In some embodiments, the tab connection portion has a width greater than a width of the solder print along the first direction.

Therefore, the tab connection part can have enough space for welding the overlapping part of the tab, so that the welding reliability of the tab and the electric connection piece is higher.

In some embodiments, in the third direction, a height of the intermediate connection portion is a distance dimension between the bottom end surface of the electrode terminal and the insulator minus a distance dimension between the tab connection portion and the insulator.

Therefore, the mounting precision of the electric connector can be guaranteed, meanwhile, the height difference along the third direction can be formed between the lug connection part and the electrode terminal connection part of the electric connector, the overlapping part of the lug can be located in the space formed by the height difference, the overlapping part cannot occupy too much space in the shell, the lug can be welded with the electric connector through one welding mark, the thickness of a battery monomer is reduced while the energy density of the battery monomer is not influenced, the welding times are reduced, and the production cost is reduced.

In some embodiments, at least one side of the tab connection part along the first direction has an accommodating space, and the bending part is accommodated in the accommodating space.

From this, can make full use of electric connector along the accommodation space of first direction side, reduce the space that the utmost point ear was taken up in direction of height (third direction) for the utmost point ear is not wholly located electric connector's below, thereby is favorable to improving the space utilization in the free casing of battery, reserves bigger space for the electrode main part, and then can be when not changing the free casing size of battery, suitably increase the volume of electrode main part, improve the free energy density of battery.

In some embodiments, the width of the bending portion is smaller than the distance between the insulating member and the tab connection portion along the first direction.

Therefore, the shape of the tab can be guaranteed to be good, and the bending part of the tab can be contained in the containing space, so that the space occupied by the tab in the containing cavity along the third direction is saved.

In some embodiments, the tab connection portion is flat, and/or the electrode terminal connection portion is flat.

Therefore, the electrode terminal and the electrode lug are more favorable for being connected with the electrode terminal connecting part and the electrode lug connecting part respectively, the connection reliability is improved, and the stability of the electric connecting piece is better.

In some embodiments, the electrode terminals include positive and negative electrode terminals, the electrical connection includes first and second electrical connections, the tab includes a plurality of positive tabs and a plurality of negative tabs, each positive tab is on the same side as the positive electrode terminal, and/or each negative tab is on the same side as the negative electrode terminal, each positive tab is connected to the positive electrode terminal by the first electrical connection, and each negative tab is connected to the negative electrode terminal by the second electrical connection.

Therefore, the positive electrode tab is at least partially overlapped to form an overlapped part, the overlapped part is welded with the first electric connecting piece, the negative electrode tab is at least partially overlapped to form an overlapped part, and the overlapped part is welded with the second electric connecting piece, so that the positive electrode tab and the negative electrode tab can be connected with the first electric connecting piece and the second electric connecting piece only by one-time welding, the welding times are reduced, the production efficiency is improved, and the production cost is reduced. Moreover, as the positive electrode tab and the negative electrode tab are welded with the first electric connecting piece and the second electric connecting piece, only one welding mark is formed respectively, the thickness dimension of the battery cell is reduced, and the battery cell can be better applied to a mounting environment with a limited space.

In addition, because the positive electrode tab and the positive electrode terminal are positioned at the same end, and/or the negative electrode tab and the negative electrode terminal are positioned at the same end, the connection of the tab and the electrode terminal is more convenient, the space in the shell of the battery cell can be saved, and the energy density of the battery cell can be improved.

In some embodiments, the electrode terminals include positive and negative electrode terminals, the electrical connection includes first and second electrical connections, the tab includes a plurality of positive tabs and a plurality of negative tabs, each positive tab is on a different side than the positive electrode terminal, and/or each negative tab is on a different side than the negative electrode terminal, each positive tab is connected to the positive electrode terminal by the first electrical connection, and each negative tab is connected to the negative electrode terminal by the second electrical connection.

In addition, the positive electrode tab and the positive electrode terminal are positioned on different sides, and/or the negative electrode tab and the negative electrode terminal are positioned on different sides, so that the flexibility of connection between the tab and the electrode terminal is improved, and the connection flexibility between the battery cells is improved when a plurality of battery cells are grouped.

In some embodiments, the electrode assemblies are plural in number, the plural electrode assemblies are arranged side by side in the first direction, and the welding portions of the tabs having the same polarity of each electrode assembly are connected by the same electrical connector.

Therefore, the assembly steps can be reduced, the assembly difficulty is reduced, and the production cost is reduced.

A second aspect of the present disclosure provides a battery device comprising a case and at least one battery cell according to the first aspect of the present disclosure, the battery cell being housed in the case.

The battery device provided by the disclosure, due to the inclusion of the thinner battery cell provided by the first aspect, can effectively reduce the size of the battery device, so that the battery device can be installed in a limited-size installation environment, and has low production cost and high production efficiency. In addition, under the condition that the size of the box body of the battery device is not changed, more battery monomers can be contained in the box body, and the energy density of the battery device is improved.

A third aspect of the present disclosure provides an electrical device comprising a battery cell according to the first aspect of the present disclosure or a battery device according to the second aspect of the present disclosure for providing electrical energy.

The power utilization device according to the embodiment of the disclosure, due to the inclusion of the smaller battery cell provided in the first aspect or the smaller battery device provided in the second aspect, enables more battery cells or battery devices to be disposed in the power utilization device, is beneficial to prolonging the power supply time of the battery cell or the battery device to the power utilization device, and can also provide good power supply for the power utilization device under the condition that the space of the power utilization device is limited.

A fourth aspect of the present disclosure provides an energy storage device comprising a battery cell according to the first aspect of the present disclosure or a battery device according to the second aspect of the present disclosure for providing electrical energy.

The energy storage device according to the embodiments of the present disclosure, due to the inclusion of the smaller-sized battery cell provided in the first aspect or the smaller-sized battery device provided in the second aspect, enables more battery cells or battery devices to be disposed in the energy storage device, is beneficial to prolonging the power supply time of the battery cells or battery devices to the energy storage device, and can also provide good power supply for the energy storage device under the condition that the space of the energy storage device is limited.

The beneficial effects of the embodiment of the disclosure are that:

Through this disclosure, can reduce the battery monomer along thickness direction's size to can reduce the welding number of times, reduction in production cost improves production efficiency.

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 disclosure. 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 provided in some embodiments of the present disclosure;

Fig. 2 is an exploded perspective view of a battery device provided in some embodiments of the present disclosure;

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

FIG. 4 is a schematic view of a partial planar structure of a positive plate, a negative plate, and a separator of an electrode body provided by some embodiments of the present disclosure;

Fig. 5 is a schematic plan view of a battery cell according to some embodiments of the present disclosure;

fig. 6 is an enlarged view of a portion a circled in fig. 5;

Fig. 7 is a schematic perspective view of an electrical connector provided in some embodiments of the present disclosure;

fig. 8 is a schematic cross-sectional view of a battery cell provided by some embodiments of the present disclosure;

fig. 9 is an enlarged view of the portion B circled in fig. 8;

FIG. 10 is a partial schematic view of a tab connected to an electrical connection according to some embodiments of the present disclosure, wherein one electrode body is shown;

FIG. 11 is a partial schematic view of tabs connected to electrical connectors according to some embodiments of the present disclosure, wherein two electrode bodies are shown;

FIG. 12 is a partial schematic view of tabs connected to electrical connectors according to some embodiments of the present disclosure, wherein four electrode bodies are shown;

Fig. 13 is a partial schematic cross-sectional view of another view of a battery cell provided by some embodiments of the present disclosure.

The reference numerals describe 1-case, 1 a-housing cavity, 11-first wall, 12-sealed pouch, 2-electrode assembly, 21-electrode body, 211-positive plate, 212-negative plate, 213-separator, 22-tab, 221-weld, 2211-overlap, 222-fold, 223-positive tab, 224-negative tab, 3-electrode terminal, 31-positive terminal, 32-negative terminal, 4-electrical connector, 41-tab connector, 42-electrode terminal connector, 43-intermediate connector, 44-first electrical connector, 45-second electrical connector, 5-weld, 6-insulator, 10-housing space, 100-battery cell, 200-controller, 300-motor, 400-battery device, 401-case, 401 a-cover, 401 b-base plate, 1000-vehicle.

Detailed Description

Embodiments of the technical scheme of the present disclosure 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 disclosure, and thus are merely examples, not to limit the scope of the present disclosure.

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 disclosure belongs, the terms used herein are for the purpose of describing particular embodiments only and are not intended to be limiting of the disclosure, and the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusions.

In the description of the embodiments of the present disclosure, the technical terms "first," "second," "third," etc. are used merely to distinguish between different objects and should not 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 disclosure, the meaning of "a 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 present disclosure. 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 disclosure, 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, and may indicate that a exists alone, while a and B exist together, and B exists alone. In this context, the character "/" generally indicates that the associated object is an "or" relationship.

In the description of the embodiments of the present disclosure, the orientation or positional relationship indicated by the technical terms "length", "width", "thickness", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "circumferential", etc. are orientation or positional relationship based on the drawings, merely for convenience of describing the embodiments of the present disclosure and simplifying the description, and do not indicate or imply that the apparatus or element in question must have a specific orientation, be configured, operated, or used in a specific orientation, and thus should not be construed as limiting the embodiments of the present disclosure.

In describing embodiments of the present disclosure, unless explicitly stated or 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, mechanically connected, electrically connected, directly connected, indirectly connected via an intervening medium, or interconnected between two elements. The specific meaning of the above terms in the embodiments of the present disclosure will be understood by those of ordinary skill in the art according to specific circumstances.

In the description of the embodiments of the present disclosure, unless explicitly specified and limited otherwise, the term "contact" is to be understood in a broad sense as either direct contact or contact across an intermediate layer, as either contact with substantially no interaction force between the two in contact or contact with interaction force between the two in contact.

The present disclosure is described in detail below.

At present, new energy batteries are increasingly widely applied to life and industry. The new energy 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 a plurality of fields such as aerospace. With the continuous expansion of the application field of the power battery, the market demand of the power battery is also continuously expanding.

In the production and manufacturing process of the battery cell, it is necessary to electrically connect the tab of the electrode assembly in the battery cell with the electrode terminal provided in the case through an electrical connector (e.g., a tab), so that an electric current can be led out from or into the electrode assembly.

In the related art, when the number of the tabs with the same polarity in the battery unit is multiple, each tab is welded with the electrical connector separately, so as to form multiple welding marks on the electrical connector. The size of the electrical connector may be limited by the size and number of the solder marks, that is, the width (the size along the first direction) of the electrical connector may be larger in order to meet the process requirements of the soldering, so that the thickness (the size along the first direction) of the battery cell may be larger.

With the advancement of technology, the devices gradually tend to be integrated and miniaturized, so that the application of the battery cells with smaller thickness is gradually increased, for example, in the case of very limited installation space, the battery cells with larger thickness obviously cannot be installed. In order to reduce the size of the battery cell, the number of electrode assemblies inside the battery cell or the size of the electrode body may be reduced, which tends to affect the energy density of the battery cell.

The present disclosure addresses the problems in the related art described above by providing a battery cell including a case, at least one electrode assembly, an electrode terminal, and an electrical connector. The housing is formed with a receiving chamber inside and includes a first wall formed with a mounting hole. At least one electrode assembly is positioned in the accommodating cavity, and the electrode assembly comprises an electrode main body and a tab connected with the electrode main body. The electrode terminal is arranged in the mounting hole in a penetrating manner. The electrical connection member connects the electrode terminal and the tab. The electrode lugs comprise welding parts, and when the number of the electrode lugs with the same polarity is a plurality of electrode lugs, the welding parts of the electrode lugs with the same polarity are at least partially overlapped to form an overlapped part, and the overlapped part and the electric connecting piece are welded to form a welding mark.

Because only one welding mark is formed after the welding of the plurality of lugs with the same polarity and the electric connecting piece, the welding mark forming device can save the space occupied by the welding marks relative to the situation that the plurality of lugs are respectively welded to form the welding marks, so that the size of the electric connecting piece can be reduced, the size of the battery monomer can be effectively reduced, the battery monomer can be better applied to a mounting environment with limited space, and the energy density of the battery monomer cannot be influenced.

In addition, the tabs with the same polarity of the battery cells are at least partially overlapped to form an overlapped part, and the overlapped part is welded with the electric connecting piece, so that the connection between the tabs and the electric connecting piece can be realized by only one-time welding, the welding times can be reduced, the production efficiency is improved, and the production cost is reduced.

The battery cell provided by the embodiment of the disclosure can be used for, but is not limited to, energy storage power supply systems, vehicles, ships or aircrafts and other electric devices, and energy storage devices such as energy storage containers and energy storage electric cabinets.

The embodiment of the disclosure provides an electricity utilization device comprising the battery cell for providing electric energy, wherein the electricity utilization device comprises, but is not limited to, a mobile phone, a flat plate, 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.

In the following embodiments, for convenience of explanation, the electric device according to an embodiment of the present disclosure will be described by taking the vehicle 1000 as an example. The following description refers to the accompanying drawings.

Fig. 1 is a schematic structural diagram of a vehicle 1000 provided in some embodiments of the present disclosure. 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. As shown in fig. 1, the battery cell 100 is provided inside the vehicle 1000, and the battery cell 100 may be provided at the bottom or the head or the tail of the vehicle 1000. The battery cell 100 may be used for power supply of the vehicle 1000, for example, the battery cell 100 may serve 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 cell 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 disclosure, the battery cell 100 may not only serve as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, providing driving power for the vehicle 1000 instead of or in part instead of fuel oil or natural gas.

Fig. 2 is an exploded perspective view of a battery device 400 according to an embodiment of the present disclosure. As shown in fig. 2, the battery device 400 includes a case 401 and at least one battery cell 100, the case 401 includes a cover 401a and a base 401b, and the cover 401a covers over the base 401b, thereby forming a receiving area of the battery cell 100 between the base 401b and the cover 401 a.

In the battery device 400, the plurality of battery cells 100 may be connected in series, parallel, or a series-parallel connection between the plurality of battery cells 100, where the series-parallel connection refers to both the series connection and the parallel connection of the plurality of battery cells 100. The plurality of battery cells 100 can be directly connected in series, in parallel or in series-parallel, and then the whole body formed by the plurality of battery cells 100 is placed in the accommodating space formed by the bottom plate 401b and the cover body 401 a. Of course, the battery unit 100 may be a battery module formed by connecting a plurality of battery units 100 in series or parallel or series-parallel connection, and a plurality of battery modules are connected in series or parallel or series-parallel connection to form a whole and are accommodated in an accommodating space formed by the bottom plate 401b and the cover 401 a. The battery device 400 may further include other structures, for example, the battery device 400 may further include a bus bar member for making electrical connection between the plurality of battery cells 100.

Some embodiments of the present disclosure are described in detail below with reference to fig. 3 to 13.

Fig. 3 is an exploded perspective view of a battery cell provided in some embodiments of the present disclosure. Fig. 4 is a schematic view of a partial planar structure of a positive electrode tab, a negative electrode tab, and a separator of an electrode body provided in some embodiments of the present disclosure. Fig. 5 is a schematic plan view of a battery cell according to some embodiments of the present disclosure. Fig. 6 is an enlarged view of the portion a circled in fig. 5. Fig. 7 is a schematic perspective view of an electrical connector according to some embodiments of the present disclosure. Fig. 8 is a schematic cross-sectional view of a battery cell provided by some embodiments of the present disclosure. Fig. 9 is an enlarged view of the portion B circled in fig. 8. Fig. 10 is a partial schematic view of a tab connected to an electrical connector according to some embodiments of the present disclosure, wherein one electrode body is shown. Fig. 11 is a partial schematic view of a tab and an electrical connector according to some embodiments of the present disclosure, wherein two electrode bodies are shown. Fig. 12 is a partial schematic view of tabs connected to electrical connectors according to some embodiments of the present disclosure, wherein four electrode bodies are shown. Fig. 13 is a partial schematic cross-sectional view of another view of a battery cell provided by some embodiments of the present disclosure.

In some embodiments of the present disclosure, the first direction, the second direction, and the third direction are set to be perpendicular to each other for convenience of explanation, but it should be understood by those skilled in the art that the embodiments of the present disclosure are not limited to the case where the three directions are perpendicular to each other. For convenience of explanation, as shown by the arrows in fig. 3 to 11, the direction of the arrow X is the first direction, the direction of the arrow Y is the second direction, and the direction of the arrow Z is the third direction. The direction of the arrow Z along the third direction is sometimes referred to as "upper" and the opposite direction is sometimes referred to as "lower".

A first aspect of the present disclosure provides a battery cell 100, the battery cell 100 including a case 1, at least one electrode assembly 2, an electrode terminal 3, and an electrical connector 4. The housing 1 is internally formed with a housing chamber 1a, and the housing 1 includes a first wall 11, the first wall 11 being formed with a mounting hole. At least one electrode assembly 2 is positioned in the receiving chamber 1a, and the electrode assembly 2 includes an electrode body 21 and a tab 22 connected to the electrode body 21. The electrode terminal 3 is penetrated through the mounting hole. The electrical connector 4 connects the electrode terminal 3 and the tab 22. The tab 22 includes a welding portion 221, and when the number of tabs 22 with the same polarity is plural, the welding portions 221 of the tabs 22 with the same polarity are at least partially overlapped to form an overlapped portion 2211, and the overlapped portion 2211 is welded with the electrical connector 4 to form one weld 5.

The battery cell 100 is a basic unit capable of performing mutual conversion between chemical energy and electric energy, and can be used to manufacture the battery device 400 for supplying power to an electric device or an energy storage device.

In the embodiment of the present disclosure, the battery cell 100 is a secondary battery cell, and the secondary battery cell refers to a battery cell that can be continuously used by activating an active material in a charging manner after discharging the battery cell.

The battery cell 100 may be a lithium ion battery cell, a sodium lithium ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium sulfur battery cell, a magnesium ion battery cell, a nickel hydrogen battery cell, a nickel cadmium battery cell, a lead storage battery cell, etc., which the embodiment of the disclosure is not limited to.

In the disclosed embodiment, the battery cell 100 is a square-case battery cell. In some other embodiments, the battery cell 100 may be a battery cell of other shapes, and the present disclosure is not particularly limited.

As shown in fig. 3, the battery cell 100 includes a case 1, the case 1 being an outer protective case of the battery cell 100, and a receiving chamber 1a for receiving an electrode assembly 2, an electrolyte, and the like is formed inside. The shell 1 can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), an aluminum-plastic film or the like.

In some embodiments, the housing 1 may be a sealed structure or a non-sealed structure. As an example, when the case 1 is a sealed structure, the case 1 functions to protect the electrode assembly 2 accommodated therein. A sealing pouch 12 may be further included between the case 1 and the electrode assembly 2, and the sealing pouch 12 is used to encapsulate the electrode assembly 2 and the electrolyte. Specifically, the sealed bag 12 may be a bag-like insulating member or an aluminum plastic film.

The electrode assembly 2 is a component in which electrochemical reactions occur in the battery cell 100, and the electrode assembly 2 includes an electrode body 21. As shown in fig. 4, the electrode body 21 includes a positive electrode tab 211, a negative electrode tab 212, and a separator 213, and the positive electrode tab 211, the negative electrode tab 212, and the separator 213 are generally stacked in the thickness direction (first direction) of the battery cell. During charge and discharge of the battery cell 100, active ions (e.g., lithium ions) are inserted and extracted back and forth between the positive electrode tab 211 and the negative electrode tab 212. The separator 213 is disposed between the positive electrode sheet 211 and the negative electrode sheet 212, and can prevent the positive and negative electrode sheets from being short-circuited, and can pass active ions.

In some embodiments, the positive electrode tab 211 may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

As an example, the positive electrode current collector has two surfaces opposing in its own thickness direction, and the positive electrode active material is provided on either or both of the two surfaces opposing the positive electrode current collector.

As an example, the positive electrode current collector may employ a metal foil or a composite current collector. For example, as the metal foil, silver-surface-treated aluminum or stainless steel, copper, nickel, titanium, or the like can be used. The composite current collector may include a polymeric material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel alloy, titanium alloy, silver alloy, etc.) on a polymer material substrate (e.g., a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

As an example, the positive electrode active material may include at least one of lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. The present disclosure is not limited to these materials, but other conventional materials that can be used as a battery positive electrode active material may be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of the lithium-containing phosphate may include, but are not limited to, at least one of lithium iron phosphate (e.g., liFePO4 (which may also be abbreviated as LFP)), a composite of lithium iron phosphate and carbon, lithium manganese phosphate (e.g., liMnPO 4), a composite of lithium manganese phosphate and carbon, lithium manganese phosphate, and a composite of lithium manganese phosphate and carbon.

In some embodiments, the positive electrode tab 211 may be made of a metal foam. The foam metal can be foam nickel, foam copper, foam aluminum, foam alloy or the like. When the metal foam is used as the positive electrode, the surface of the metal foam may not be provided with the positive electrode active material, but may be provided with the positive electrode active material. As an example, a lithium source material, which is lithium metal and/or a lithium-rich material, potassium metal or sodium metal, may also be filled and/or deposited within the foam metal.

In some embodiments, the negative electrode tab 212 may include a negative electrode current collector.

As an example, the negative electrode current collector may employ a metal foil, a foam metal, or a composite current collector. For example, as the metal foil, silver-surface-treated aluminum or stainless steel, copper, nickel, carbon, titanium, or the like can be used. The composite current collector may include a polymeric material base layer and a metal layer. The foam metal can be foam nickel, foam copper, foam aluminum, foam alloy or the like. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel alloy, titanium alloy, silver alloy, etc.) on a polymer material substrate (e.g., a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.). In some embodiments, the material of the positive electrode current collector may be aluminum and the material of the negative electrode current collector may be copper.

In some embodiments, the separator 213 is a separator film. The type of the separator is not particularly limited in the present disclosure, and any known porous separator having good chemical and mechanical stability may be used.

As an example, the main material of the separator may be at least one selected from glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic.

In some embodiments, separator 213 is a solid state electrolyte.

In some embodiments, the electrode body 21 is a coiled structure. The positive pole piece and the negative pole piece are wound into a winding structure.

In some embodiments, the electrode body 21 is a lamination stack.

As an example, a plurality of positive electrode sheets 211 and negative electrode sheets 212 may be provided, respectively, and a plurality of positive electrode sheets 211 and a plurality of negative electrode sheets 212 may be alternately stacked.

As an example, a plurality of positive electrode sheets 211 may be provided, and the negative electrode sheet 212 is folded to form a plurality of folded sections that are stacked, with one positive electrode sheet 211 sandwiched between adjacent folded sections.

As an example, the positive electrode tab 211 and the negative electrode tab 212 are each folded to form a plurality of folded sections arranged in a stacked manner.

As an example, the separator 213 may be provided in plurality, respectively, between any adjacent positive electrode tab 211 or negative electrode tab 212.

As an example, the separator 213 may be continuously provided between any adjacent positive electrode sheet 211 or negative electrode sheet 212 by folding or winding.

In some embodiments, the battery cell 100 further includes an electrolyte that serves to conduct ions between the positive and negative electrodes. The type of electrolyte is not particularly limited in the present disclosure, and may be selected according to the need. The electrolyte may be liquid, gel or solid.

In some embodiments, the electrode assembly 2 includes tabs 22, which tabs 22 may conduct current away from the electrode body 21 or may conduct current to the electrode body 21. Tab 22 includes a positive tab 223 and a negative tab 224.

The electrode terminal 3 is inserted through the mounting hole of the first wall 11 of the case 1, and is partially positioned in the receiving cavity 1a of the case 1. The electrode terminal 3 is used to be directly or indirectly electrically connected with the tab 22 of the electrode assembly 2 to output power to the electrode body 21 of the electrode assembly 2 or input power to the electrode body 21 of the electrode assembly 2.

The first wall 11 is a wall surface of the case 1 to which the electrode terminal 3 is attached. The first wall 11 encloses a housing chamber 1a for housing the electrode assembly 2 together with other wall surfaces of the case 1. In the embodiment of the present disclosure, the electrode terminal 3 is mounted on an end cap, i.e., the end cap is configured as the first wall 11 of the case 1. In some other embodiments, if the electrode terminal 3 is mounted on the other wall surface of the case 1, the wall surface on which the electrode terminal 3 is mounted is configured as the first wall 11.

For example, the number of the electrode terminals 3 may be only one, and the electrode terminal 3 is connected to one of the positive electrode tab 223 or the negative electrode tab 224, and the other one of the positive electrode tab 223 or the negative electrode tab 224 is connected to the case 1. The number of the electrode terminals 3 may be two, and the two electrode terminals 3 are connected to the positive electrode tab 223 and the negative electrode tab 224, respectively.

In the embodiment of the present disclosure, the electrode terminal 3 includes a positive electrode terminal 31 and a negative electrode terminal 32, the positive electrode terminal 31 is connected to the positive electrode tab 223, and the negative electrode terminal 32 is connected to the negative electrode tab 224. Accordingly, the case 1 is correspondingly formed with two mounting holes for mounting the positive electrode terminal 31 and the negative electrode terminal 32, respectively. It will be appreciated by those skilled in the art that in some other embodiments, the number of electrode terminals 3 may also be more (more than two). When the number of the electrode terminals 3 is plural, the plural electrode terminals 3 may be mounted on the same wall surface of the case 1 or may be mounted on different wall surfaces of the case 1. When a plurality of electrode terminals 3 are mounted on different wall surfaces of the case 1, respectively, the wall surface on which each electrode terminal 3 is mounted may be configured as the first wall 11.

The electrode terminal 3 may be, for example, a post, and the electrode terminal 3 may be made of a conductive material to realize a conductive function of the electrode terminal 3.

In the embodiment of the present disclosure, the electrode terminal 3 is electrically connected with the tab 22 of the electrode assembly 2 through the electrical connector 4. The electrical connection 4 may also be referred to as an adapter.

In the related art, when the tab is connected with the electric connector, each tab with the same polarity is welded separately with different positions of the electric connector, so that a plurality of welding marks are formed on the electric connector, and in order to ensure the stability and reliability of welding, a certain process space is reserved between the welding area (welding mark) and the edge of the electric connector and between the welding area and different welding areas, so that the electric connector needs to have a sufficient width (the dimension along the first direction), the width of the electric connector is larger, and the thickness (the dimension along the first direction) of the battery cell is larger.

In the embodiment of the present disclosure, as shown in fig. 3, 5, 6 and 11, the number of electrode assemblies 2 is two, and one positive tab 223 and one negative tab 224 are led out from each electrode body 21 of each electrode assembly 2, that is, the number of tabs 22 with the same polarity is two, the two tabs 22 with the same polarity are arranged at intervals along the first direction, and the welding portions 221 of the tabs 22 with the same polarity are at least partially overlapped to form the overlapped portion 2211. The overlapping refers to a position where projections of the welding portions 221 of the tab 22 overlap each other in a projection plane perpendicular to the third direction.

The welded portion 221 is a portion of the tab 22 for welding, and the welded portion 221 is substantially flat, which is advantageous in improving welding stability. It will be appreciated by those skilled in the art that the solder 221 need not be soldered to the electrical connector 4 in all areas, but rather at least a portion of the solder 221 may be soldered to the electrical connector 4 in areas.

Since the tab 22 is welded to the electrical connector 4 at the overlapping portion 2211, two tabs 22 having the same polarity can be simultaneously connected to the electrical connector 4 by only one welding, and only one weld mark 5 is formed after the welding is completed. Like this, the utmost point ear 22 that can reduce welds the quantity of seal 5 with electric connector 4 after carrying out the welding to practice thrift the space that seal 5 itself occupy on electric connector 4, and can practice thrift the required technology space when seal 5 welds on electric connector 4, thereby can suitably reduce the size of electric connector 4, and then can reduce the size of battery monomer 100, make battery monomer 100 can be better be applied to in the comparatively limited installation environment in space, and can not influence the energy density of battery monomer 100.

In addition, since the tab 22 and the electrical connector 4 can be connected by only one welding, the number of welding times can be reduced in the process of processing and manufacturing the battery cell 100, thereby being beneficial to improving the production efficiency and the production takt and reducing the production cost.

As shown in fig. 10, the number of electrode assemblies 2 in the case 1 may be only one, and one electrode assembly 2 leads out two tabs of the same polarity. As shown in fig. 12, the number of the electrode assemblies 2 in the case 1 may be four, one tab 22 is led out of each electrode assembly 2, and the tabs 22 of each adjacent two electrode assemblies 2 overlap each other to form one integral tab, at least part of the two integral tabs overlap to form an overlapping portion 2211, and welding is performed with the electrical connection member 4 at the overlapping portion 2211.

The embodiment of the present disclosure does not specifically limit the number of electrode assemblies 2 in the battery cell 100, and the number of electrode assemblies 2 may be one, two, or more (more than two). The number of tabs 22 led out from each electrode assembly 2 and the arrangement mode of the tabs 22 are not specifically limited in the embodiment of the present disclosure, and only one solder mark 5 is formed after each tab 22 with the same polarity is welded to the electrical connector 4, that is, each tab 22 with the same polarity can be connected to the electrical connector 4 only by one welding.

In the embodiment of the present disclosure, the overlapping portion 2211 of the tab 22 may be welded with the electrical connector 4 by means of ultrasonic welding. Ultrasonic welding is to transfer high-frequency vibration waves to the surfaces of objects to be welded, and under the condition of pressurization, the surfaces of the objects are rubbed with each other to form fusion between molecular layers. Ultrasonic welding is a quick, clean, and efficient assembly process.

Of course, it will be appreciated by those skilled in the art that in some other embodiments, the overlapping portion of the tab 22 may be welded to the electrical connector 4 by any other welding means.

In some embodiments of the present disclosure, the thickness direction of the electrode body 21 is a first direction. In the first direction, the width of the overlap 2211 is greater than the width of the solder marks 5.

In some embodiments, the thickness direction of the battery cell 100 may also be referred to as a first direction, the direction in which the large surface (the wall surface with the largest area) of the case 1 is opposite may also be referred to as a first direction, and the width direction of the electrical connector 4 may also be referred to as a first direction. The first direction may also be a direction in which the positive electrode tab 211, the negative electrode tab 212, and the separator 213 of the electrode body 21 are stacked, and it should be understood by those skilled in the art that when the electrode body 21 is a rolled structure, the electrode body 21 includes a curved section and a straight section, and in this case, the stacking direction of the positive electrode tab, the negative electrode tab, and the separator of the straight section is the first direction. In the specific example shown in fig. 4 to 6, the up-down direction in fig. 4 to 5 is the first direction of the embodiment of the present disclosure.

Since the width of the overlap portion 2211 is greater than the width of the solder mark 5 along the first direction, the solder mark 5 can be completely located in the overlap region of the tabs 22 with the same polarity, so that the connection area between the tabs 22 at the overlap portion 2211 is increased, good welding can be performed between the tabs 22 with the same polarity, the welding reliability is higher, the possibility of occurrence of defects such as welding failure or cold welding is reduced, and the welding quality is improved.

In some embodiments of the present disclosure, as shown in fig. 6, the solder marks 5 are located in a central region of the overlap 2211.

The central region means that the opposite sides of the solder mark 5 in the first direction are spaced apart from the opposite sides of the overlap portion 2211 in the first direction by substantially the same distance, and the opposite sides of the solder mark 5 in the second direction are spaced apart from the opposite sides of the overlap portion 2211 in the second direction by substantially the same distance, that is, the solder mark 5 is arranged substantially symmetrically along the central axis of the overlap portion 2211.

Thereby, the welding reliability between the tabs 22 having the same polarity can be further improved, so that the plurality of tabs 22 at the overlap portion 2211 can be sufficiently welded.

In addition, the solder marks 5 are located in the central area of the overlapping portion 2211, so that the protruding lengths of the tabs 22 on two opposite sides along the first direction are the same, the possibility that one tab 22 is stretched too much is reduced, and the reliability of the battery cell 100 is improved.

In some embodiments of the present disclosure, the electrical connector 4 includes a tab connection portion 41, an electrode terminal connection portion 42, and an intermediate connection portion 43. The tab connection portion 41 connects the tab 22, the electrode terminal connection portion 42 connects the electrode terminal 3, and the intermediate connection portion 43 connects the tab connection portion 41 and the electrode terminal connection portion 42. The electrode terminal connection part 42 and the tab connection part 41 extend in the second direction, the intermediate connection part 43 extends in the third direction, and the tab connection part 41 is closer to the first wall 11 than the electrode terminal connection part 42 in the third direction. The welding portion 221 of the tab 22 is welded to the tab connection portion 41 on the side facing away from the first wall 11. The first direction, the second direction, and the third direction are perpendicular to each other.

The extending direction of the tab connection portion 41 and the electrode terminal connection portion 42 is a second direction, which may also be referred to as the length direction of the electrical connector 4. The extending direction of the intermediate connection portion 43 is a third direction, which may also be referred to as a height direction. In the specific example shown in fig. 8 and 9, the left-right direction in fig. 8 and 9 is the second direction in which the present disclosure is implemented, and the up-down direction is the third direction in the embodiment of the present disclosure.

As shown in fig. 7 and 9, the electrical connector 4 includes a tab connection portion 41, an electrode terminal connection portion 42, and an intermediate connection portion 43. The tab connection portion 41 is a structure for connecting with the tab 22 in the electrical connector 4, and the electrode terminal connection portion 42 is a structure for connecting with the electrode terminal 3 in the electrical connector 4.

The electrode terminal 3 may be welded with the electrode terminal connecting part 42 by means of laser welding, for example.

The intermediate connection portion 43 is a member of the electrical connector 4 that connects the tab connection portion 41 and the electrode terminal connection portion 42, and the tab connection portion 41 and the electrode terminal connection portion 42 are located on opposite sides of the intermediate connection portion 43 in the second direction, respectively.

In some embodiments, the intermediate connection part 43 may be provided as a fusing part, i.e., such that the intermediate connection part 43 includes a thinned region and/or a fusing hole, etc., such that the intermediate connection part 43 is fused when the current exceeds a rated value, i.e., the current is excessively large, thereby disconnecting the tab connection part 41 from the electrode terminal connection part 42, thereby cutting off the electrical connection of the tab 22 and the electrode terminal 3, reducing the possibility of short-circuiting of the battery cell 100, and making the reliability of the battery cell 100 higher.

Illustratively, the electrical connector 4 may be formed as a unitary structure, for example, the plate-like member may be manufactured by stamping, bending, cutting, etc. to form the unitary electrical connector 4.

Also for example, the tab connection part 41, the electrode terminal connection part 42, and the intermediate connection part 43 of the electrical connector 4 may be separately formed in a split structure and then assembled by splicing.

After the tabs 22 with the same polarity are at least partially overlapped to form the overlapped portion 2211, the overlapped portion 2211 may have a larger size along the third direction, and thus may occupy a part of the space in the accommodating cavity 1 a. In the embodiment of the present disclosure, however, since the intermediate connection part 43 extends in the third direction, the tab connection part 41 and the electrode terminal connection part 42 have a certain height difference in the third direction, so that the overlap part 2211 of the tab 22 can be located in a space generated by the height difference between the tab connection part 41 and the electrode terminal connection part 42, so that the overlap part 2211 does not occupy too much space in the receiving cavity 1a of the case 1, and thus the tab 22 can be welded with the electrical connector 4 in an overlapping manner without affecting the energy density of the battery cell 100.

In some embodiments of the present disclosure, the battery cell 100 further includes an insulating member 6, and the insulating member 6 is located at a side of the first wall 11 facing the electrode assembly 2. Each tab 22 further includes a bending portion 222, where the bending portion 222 is connected to the welding portion 221, and the bending portion 222 protrudes toward the side of the first wall 11 with respect to the welding portion 221 in the third direction. In the first direction, the tab connection portion 41 has a width smaller than the first dimension. The first dimension is the width of the insulator 6 along the first direction minus the width of the bent portion 222 of each tab 22 connected to the tab connection portion 41 along the first direction.

The insulating member 6 is made of an insulating material and is located between the first wall 11 and the electrode assembly 2. The insulator 6 may be integrally preformed from plastic or assembled from plastic parts. When the case 1 is made of a metal material, the insulator 6 can electrically insulate the electrode assembly 2 from the first wall 11, reducing the possibility of short circuits caused by contact of the tab 22 with the first wall 11 made of a metal material. In addition, the insulating member 6 can also play a certain supporting role on the electrode assembly 2, and the possibility of the electrode assembly 2 moving inside the accommodating cavity 1a is reduced.

The insulator 6 may be a plastic frame, for example.

The tab 22 needs to be bent when connected to the tab connection portion 41, and one end of the bent portion 222 is connected to the welding portion 221 and the other end is connected to the electrode main body 21. The embodiment of the present disclosure does not specifically limit the bending shape of the bending portion 222, and the tab 22 may be bent according to actual situations.

As illustrated in fig. 11 and 13, the bending portion 222 of the tab 22 protrudes toward the side of the first wall 11 along the third direction relative to the welding portion 221, and when viewed along the second direction, the cross section of the bending portion 222 of the embodiment of the present disclosure is generally inverted U-shaped, and one side wall of the bending portion 222 is generally inclined, so that the inclined side wall is not easy to interfere with the insulator 6 (lower plastic) in the housing 1, and the space between the tab connection portion 41 and the inner wall of the housing 1 can be more fully utilized to accommodate the bending portion 222 of the tab 22.

In addition, compared with the mode that the tab 22 shown in fig. 12 is bent by 90 °, the structure of the tab 22 shown in fig. 11 and fig. 13 is more compact, and the dimension of the tab 22 along the third direction is smaller, so that the space occupied by the tab 22 is smaller, the space in the accommodating cavity 1a of the housing 1 is saved, the space in the accommodating cavity 1a for accommodating the electrode main body 21 is increased, and the energy density of the battery cell 100 is improved.

Also illustratively, as shown in FIG. 12, the fold 222 may be generally inverted L-shaped when viewed in the second direction.

In the embodiment of the present disclosure, when the width of the tab connection portion 41 is smaller than the first size, enough space can be provided in the housing 1 to accommodate the bent portion 222 of the tab 22, so as to meet the process requirement of bending the tab 22, and improve the connection reliability between the tab 22 and the electrical connection member 4.

In general, the process size required for bending a single tab 22 is 3mm, and therefore, in the case where the tab 22 is protruded from both opposite sides in the first direction, the process size required for bending the tab 22 is 6mm, that is, a space of at least 3mm is reserved between one side of the insulating member 6 and the edge of the tab connection portion 41 to accommodate the bent portion 222 of the tab 22, and then, in the case where the tab 22 is protruded from both sides, a space of at least 6mm is required in total.

In some embodiments of the present disclosure, the first dimension is the width of the insulator 6 in the first direction minus 6 millimeters.

As shown in fig. 6, the dimension of the insulator 6 in the first direction is V, and the dimension of the tab connection portion in the first direction is W, W < V-6, in millimeters (mm). Of course, it should be understood by those skilled in the art that when the electrode assembly 2 is drawn with the tab 22 only along one side of the first direction, W may be smaller than V-3.

Thus, the process requirement of folding most of the tabs 22 can be satisfied, so that the insulation member 6 and the tab connection portion 41 can have a sufficient distance dimension to accommodate most of the bent portions 222 of the tabs 22.

In some embodiments of the present disclosure, the tab connection portion 41 has a width greater than the width of the solder mark 5 in the first direction.

Thereby, the tab connection portion 41 can have a sufficient space for welding the overlapping portion 2211 of the tab, so that the welding reliability of the tab 22 and the electrical connector 4 is higher.

Specifically, a certain process gap is reserved when the tab 22 is welded with the electrical connector 4, so as to improve welding reliability or reduce the possibility of occurrence of defects such as welding failure caused by errors. Typically, the process gap to be met by one side of the solder mark 5 is 1.5mm, and the process gap to be met by both sides is 3mm.

As shown in fig. 6, the width of the solder mark 5 in the first direction is Z, then W > Z, and specifically, W > z+3, in millimeters (mm).

Therefore, the process requirement of welding the tab 22 and the tab connection part 41 can be met, so that the tab connection part 41 has enough space to facilitate welding of the overlapping part 2211 of the tab 22 and the tab connection part 41, and the welding reliability of welding the tab 22 and the electric connection piece 4 is improved.

In some embodiments of the present disclosure, the height of the intermediate connection part 43 is the distance dimension between the bottom end surface of the electrode terminal 3 and the insulator 6 minus the distance dimension between the tab connection part 41 and the insulator 6 in the third direction.

The bottom end surface of the electrode terminal 3 refers to an end surface of the electrode terminal 3 toward the electrode assembly 2 side in the third direction.

As shown in fig. 9, in the third direction, the dimension of the distance between the bottom end surface of the electrode terminal 3 and the insulator 6 is N, and the dimension of the distance M between the tab connection portion 41 and the insulator 6 is N-M, the dimension of the intermediate connection portion 43 in the third direction.

Certain gaps are reserved between the lug connection parts 41 and the insulating piece 6, so that certain error spaces can be reserved, and the installation of the electric connection piece 4 is facilitated.

In general, the distance dimension M between the tab connection portion 41 and the insulator 6 in the third direction is in the range of 0.1mm to 0.3 mm. Illustratively, M may be 0.1mm, 0.2mm, 0.3mm, or the like.

Thereby, it is possible to form a height difference in the third direction between the tab connection part 41 and the electrode terminal connection part 42 of the electrical connector 4 while ensuring the mounting accuracy of the electrical connector 4, so that the overlap part 2211 of the tab 22 can be located in a space formed by the height difference, so that the overlap part 2211 does not occupy too much space in the case 1, and so that the tab 22 can be welded with the electrical connector 4 by one welding mark 5, and the tab reduces the thickness of the battery cell 100 while not affecting the energy density of the battery cell 100, and reduces the number of welding times, and reduces the production cost.

In some embodiments of the present disclosure, at least one side of the tab connection portion 41 along the first direction has an accommodating space 10, and the bending portion 222 is accommodated in the accommodating space 10.

Therefore, the accommodating space 10 of the electric connector 4 along the side of the first direction can be fully utilized, the space occupied by the tab 22 in the height direction (third direction) is reduced, and the tab 22 is not wholly positioned below the electric connector 4, so that the space utilization rate in the shell 1 of the battery cell 100 is improved, a larger space is reserved for the electrode main body 21, the size of the shell 1 of the battery cell 100 is not changed, the volume of the electrode main body 21 is properly increased, and the energy density of the battery cell 100 is improved.

In the third direction, a space region between the inner wall surface of the first wall 11 on the side facing the accommodating chamber 1a and the surface of the tab connection portion 41 on the side facing away from the first wall 11, and a space region between the tab connection portion 41 and the inner wall surface of the case 1 in the first direction, both space regions together define the accommodating space 10 for accommodating the bent portion 222.

Illustratively, at least a portion of the tab connection portion 41 may be recessed in a first direction to form a recessed portion that defines at least a portion of the receiving space 10.

Also illustratively, in the first direction, a sufficient space may be reserved between the electrical connector 4 and the inner wall of the housing 1, thereby forming the accommodating space 10 accommodating the bent portion 222 of the tab 22.

The embodiment of the present disclosure does not specifically limit the formation manner of the accommodating space 10, as long as there is enough space to accommodate the tab 22.

In the third direction, the top surface of the bending portion 222 is substantially flush with the surface of the tab connection portion 41 facing the first wall 11 side, or may be slightly higher than the surface of the tab connection portion 41 facing the first wall 11 side, so that the region of the accommodating space 10 in the height direction can be fully utilized to accommodate the tab 22 more, thereby providing a larger space for the electrode main body 21 and increasing the energy density of the battery cell 100.

The top surface of the bent portion 222 refers to a surface of the bent portion 222 closest to the side of the first wall 11 in the first direction. Flush means that the top surface of the bending portion 222 is substantially in the same horizontal plane as the surface of the tab connection portion 41 facing the first wall 11.

Of course, it should be understood by those skilled in the art that in some other embodiments, for example, when the length of the tab 22 is shorter, the top surface of the bending portion 222 may be lower than the surface of the tab connection portion 41 facing the side of the first wall 11, and the user may set the configuration according to the actual situation.

In some embodiments of the present disclosure, the width of the bending portion 222 is smaller than the distance dimension between the insulating member 6 and the tab connection portion 41 in the first direction.

Therefore, the shape of the tab 22 can be ensured to be good, and the bending part 222 of the tab 22 can be accommodated in the accommodating space 10, so that the space occupied by the tab 22 in the accommodating cavity 1a along the third direction is saved, and the energy density of the battery cell 100 is improved. Moreover, the tab 22 is not easily contacted with the case 1, and the possibility of short circuit of the battery cell 100 is reduced.

In some embodiments of the present disclosure, the tab connection part 41 is flat and/or the electrode terminal connection part 42 is flat.

This is advantageous in that the electrode terminal 3 and the tab 22 are connected to the electrode terminal connecting portion 42 and the tab connecting portion 41, respectively, and the connection reliability is improved, so that the stability of the electrical connector 4 is improved.

Of course, those skilled in the art will appreciate that in some other embodiments, the tab connection portion 41 and the electrode terminal connection portion 42 may take any other suitable shape.

In some embodiments of the present disclosure, the electrode terminal 3 includes a positive electrode terminal 31 and a negative electrode terminal 32. The electrical connector 4 comprises a first electrical connector 44 and a second electrical connector 45. The tab 22 includes a plurality of positive tabs 223 and negative tabs 224, each positive tab 223 being on the same side as the positive terminal 31 and/or each negative tab 224 being on the same side as the negative terminal 32, each positive tab 223 being connected to the positive terminal 31 by a first electrical connection 44, each negative tab 224 being connected to the negative terminal 32 by a second electrical connection 45.

Therefore, the positive electrode tab 223 is at least partially overlapped to form the overlapped part 2211, and the overlapped part 2211 is welded with the first electrical connector 44, the negative electrode tab 224 is at least partially overlapped to form the overlapped part 2211, and the overlapped part 2211 is welded with the second electrical connector 45, so that the positive electrode tab 223 and the negative electrode tab 224 can be connected with the first electrical connector 44 and the second electrical connector 45 only by one-time welding, the welding times are reduced, the production efficiency is improved, and the production cost is reduced. Moreover, since the positive electrode tab 223 and the negative electrode tab 224 are welded with the first electrical connector 44 and the second electrical connector 45, only one welding mark 5 is formed, which is beneficial to reducing the thickness dimension of the battery cell 100, so that the battery cell 100 can be better applied to a mounting environment with a limited space.

In addition, since the positive electrode tab 223 and the positive electrode terminal 31 are located at the same side and/or the negative electrode tab 224 and the negative electrode terminal 32 are located at the same side, connection of the tab 22 and the electrode terminal 3 is more facilitated, and space in the battery cell case can be saved, which is advantageous for improving energy density of the battery cell.

Illustratively, the positive tab 223 is on the same side as the positive terminal 31 and the negative tab 224 is on the same side as the negative terminal 32.

Also illustratively, the positive tab 223 is on the same side as the positive terminal 31 and the negative tab 224 is on a different side than the negative terminal 32.

Further exemplary, the positive tab 223 is located on a different side from the positive terminal 31, and the negative tab 224 is located on the same side as the negative terminal 32.

It should be understood by those skilled in the art that when the tab 22 and the electrode terminal 3 are located on the same side, the tab connection portion 41 of the electrical connector 4 is generally in a flat plate shape extending in one direction, and the positive tab 223 and the negative tab 224 may be located on the same side of the electrode body 21 or may be located on different sides of the electrode body 21, respectively.

Illustratively, the positive tab 223 and the negative tab 224 are located on the same side of the electrode body 21, and the positive terminal 31 and the negative terminal 32 are located on the same side as the positive tab 223 and the negative tab 224.

Also illustratively, the positive tab 223 and the negative tab 224 are located on different sides of the electrode body 21, the positive terminal 31 is located on the same side as the positive tab 223, and the negative terminal 32 is located on the same side as the negative tab 224.

In some embodiments of the present disclosure, the electrode terminal 3 includes a positive electrode terminal 31 and a negative electrode terminal 32. The electrical connector 4 comprises a first electrical connector 44 and a second electrical connector 45. The tab 22 includes a plurality of positive tabs 223 and a plurality of negative tabs 224, each positive tab 223 being located on a different side from the positive terminal 31 and/or each negative tab 224 being located on a different side from the negative terminal 32, the positive tab 223 being connected to the positive terminal 31 by the first electrical connection 44 and the negative tab 224 being connected to the negative terminal 32 by the second electrical connection 45.

In addition, since the positive electrode tab 223 and the positive electrode terminal 31 are located at different sides and/or the negative electrode tab 224 and the negative electrode terminal 32 are located at different sides, it is advantageous to improve the flexibility of connection of the tab 22 and the electrode terminal 3 and to improve the flexibility of connection of the battery cells 100 to each other when a plurality of battery cells 100 are grouped.

Illustratively, the positive tab 223 is located on a different side than the positive terminal 31, and the negative tab 224 is located on a different side than the negative terminal 32.

It will be understood by those skilled in the art that when the tab 22 and the electrode terminal 3 are located at different sides, the tab connection portion 41 of the electrical connector 4 is generally in an "L" shape or an inverted "L" shape, that is, the tab connection portion 41 includes two sections extending in different directions, one of which is the same as the extending direction of the electrode terminal connection portion 42 and the other of which is perpendicular to the extending direction of the electrode terminal connection portion 42, so as to connect the electrode terminal 3 and the tab 22 located at different sides.

When the tab 22 and the electrode terminal 3 are located on different sides, the positive electrode tab 223 and the negative electrode tab 224 may be located on the same side of the electrode body 21, or may be located on different sides of the electrode body 21.

Illustratively, the positive electrode tab 223 and the negative electrode tab 224 are located on the same side of the electrode body 21, and the positive electrode terminal 31 and the negative electrode terminal 32 are located on different sides from the sides of the positive electrode tab 223 and the negative electrode tab 224, and in this case, the positive electrode terminal 31 and the negative electrode terminal 32 may be located on the same side or on different sides.

Further illustratively, the positive tab 223 and the negative tab 224 are located on different sides of the electrode body 21, and the positive terminal 31 and the negative terminal 32 are located on different sides of the positive tab 223 and the negative tab 224, respectively.

Further exemplary, the positive tab 223, the negative tab 224, the positive terminal 31, and the negative terminal 32 may be located at four different sides, respectively.

In some embodiments of the present disclosure, the number of electrode assemblies 2 is plural, the plurality of electrode assemblies 2 are arranged side by side in the first direction, and the welding portions 221 of the same-polarity tabs 22 of the respective electrode assemblies 2 are connected by the same electrical connector 4.

The plurality of electrode assemblies 2 can increase the energy density of the battery cell 100. And a plurality of electrode assemblies 2 are connected through the same electric connecting piece 4 to the electrode lugs 22 with the same polarity, so that the assembly steps of the battery cell 100 can be reduced, the assembly difficulty is reduced, and the production cost is reduced.

A second aspect of the present disclosure provides a battery device 400, where the battery device 400 includes a case 401 and at least one battery cell 100 according to the first aspect of the present disclosure, and the battery cell 100 is accommodated in the case 401.

The battery device 400 provided by the present disclosure, due to the inclusion of the thinner battery cell 100 provided by the first aspect, can effectively reduce the size of the battery device 400, so that the battery device 400 can be installed in a limited-size installation environment, and has low production cost and high production efficiency.

In addition, in the case where the size of the case 401 of the battery device 400 is not changed, more battery cells 100 can be accommodated in the case 401, which is advantageous in improving the energy density of the battery device 400.

A third aspect of the present disclosure provides an electrical device comprising the battery cell 100 of the first aspect of the present disclosure or the battery device 400 of the second aspect of the present disclosure for providing electrical energy.

The power consumption device according to the embodiments of the present disclosure, due to including the smaller-sized battery cell 100 provided in the first aspect or the smaller-sized battery device 400 provided in the second aspect, enables more battery cells 100 or battery devices 400 to be disposed in the power consumption device, is beneficial to prolonging the power supply time of the battery cells 100 or the battery devices 400 to the power consumption device, and can also provide good power supply for the power consumption device in the case of limited space of the power consumption device.

A fourth aspect of the present disclosure provides an energy storage device comprising a battery cell 100 according to the first aspect of the present disclosure or a battery device 400 according to the second aspect of the present disclosure for providing electrical energy.

The energy storage device according to the embodiments of the present disclosure, due to including the smaller-sized battery cell 100 provided in the first aspect or the smaller-sized battery device 400 provided in the second aspect, enables more battery cells 100 or battery devices 400 to be disposed in the energy storage device, is beneficial to prolonging the power supply time of the battery cells 100 or the battery devices 400 to the energy storage device, and can also provide good power supply for the energy storage device in the case of limited space of the energy storage device.

Specific examples of some embodiments of the present disclosure are described below with reference to the drawings.

As a specific example, the battery cell (battery cell 100) includes a switching piece (electrical connector 4), a bare cell (electrode body 21), and a tab 22, which is connected to the bare cell. The tabs with the same polarity are overlapped and then welded on the switching sheet through a welding mark 5.

The switching piece is set to a zigzag structure, and includes a first portion (electrode terminal connecting portion 42), a second portion (tab connecting portion 41) and a connecting portion (intermediate connecting portion 43), the first portion and the second portion are arranged at intervals in the Z direction (third direction), the first portion and the second portion are connected by the connecting portion, the first portion is welded with the electrode post (electrode terminal 3), the second portion is welded with the tab, and the second portion is closer to the lower plastic (insulating member 6) than the first portion.

The overlapped region (overlapped portion 2211) of the tab completely covers the weld, and the weld is symmetrical with the center line at the overlapped portion.

The dimension W of the switching sheet along the thickness direction (the first direction) of the battery cell meets the requirement of V-6mm > W > Z+3mm, wherein the width of plastic under the battery cell (the dimension along the first direction) is V, and the welding width (the dimension along the first direction) is Z.

The foregoing embodiments are merely for illustrating the technical solutions of the present disclosure, and not for limiting the same, and although the present disclosure has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions described in the foregoing embodiments may be modified or some or all of the technical features may be equivalently replaced, and these modifications or replacements do not depart from the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present disclosure, and should be covered in the scope of the present disclosure. In particular, the technical features mentioned in the respective embodiments may be combined in any manner as long as there is no structural conflict.

Industrial applicability

Through the present disclosure, a battery cell, a battery device, an electricity consumption device, and an energy storage device, which are small in size, low in production cost, and high in production efficiency, are provided.

Claims

A battery cell, wherein the battery cell comprises:

A housing having a receiving cavity formed therein, the housing including a first wall formed with a mounting hole;

At least one electrode assembly located in the receiving chamber, the electrode assembly including an electrode body and a tab connected with the electrode body;

An electrode terminal penetrating the mounting hole, and

An electrical connection member connecting the electrode terminal and the tab;

The electrode lugs comprise welding parts, and when the number of the electrode lugs with the same polarity is a plurality of electrode lugs, the welding parts of the electrode lugs with the same polarity are at least partially overlapped to form overlapped parts, and the overlapped parts and the electric connecting piece are welded to form a welding mark.
The battery cell according to claim 1, wherein,

The thickness direction of the electrode main body is a first direction;

and along the first direction, the width of the overlapped part is larger than the width of the welding mark.
The battery cell according to claim 1 or 2, wherein,

The solder marks are located in the central area of the overlapping portion.
The battery cell according to any one of claim 1 to 3, wherein,

The electric connector comprises a tab connecting part, an electrode terminal connecting part and an intermediate connecting part, wherein the tab connecting part is connected with the tab, the electrode terminal connecting part is connected with the electrode terminal, and the intermediate connecting part is connected with the tab connecting part and the electrode terminal connecting part;

The electrode terminal connecting portion and the tab connecting portion extend in a second direction, the intermediate connecting portion extends in a third direction, and the tab connecting portion is closer to the first wall than the electrode terminal connecting portion in the third direction;

The welding part of the tab is welded with one side of the tab connecting part, which is away from the first wall;

the first direction, the second direction, and the third direction are perpendicular to each other.
The battery cell according to claim 4, wherein,

The battery cell further includes an insulating member located at a side of the first wall facing the electrode assembly;

Each tab further comprises a bending part, the bending part is connected with the welding part, and the bending part protrudes towards the side where the first wall is located in the third direction relative to the welding part;

the width of the tab connection part is smaller than a first size along the first direction;

The first dimension is a width of the insulating member along the first direction minus a width of the bending portion of each tab connected with the tab connection portion along the first direction.
The battery cell according to claim 5, wherein,

The first dimension is the width of the insulator in the first direction minus 6 millimeters.
The battery cell according to claim 5 or 6, wherein,

And along the first direction, the width of the tab connection part is larger than the width of the welding mark.
The battery cell according to any one of claims 5 to 7, wherein,

And along the third direction, the height of the intermediate connection part is the distance between the bottom end surface of the electrode terminal and the insulating piece minus the distance between the tab connection part and the insulating piece.
The battery cell according to any one of claims 5 to 8, wherein,

At least one side of the tab connection part along the first direction is provided with an accommodating space

The bending part is accommodated in the accommodating space.
The battery cell according to claim 9, wherein,

And the width of the bending part is smaller than the distance between the insulating part and the tab connecting part along the first direction.
The battery cell according to any one of claims 1 to 10, wherein,

The tab connection part is flat and/or

The electrode terminal connection part is flat.
The battery cell according to any one of claims 1 to 11, wherein,

The electrode terminals include a positive electrode terminal and a negative electrode terminal;

the electrical connector comprises a first electrical connector and a second electrical connector;

the electrode lugs comprise a plurality of positive electrode lugs and a plurality of negative electrode lugs, the positive electrode lugs and the positive electrode terminals are located on the same side, and/or the negative electrode lugs and the negative electrode terminals are located on the same side, the positive electrode lugs are connected with the positive electrode terminals through the first electric connecting pieces, and the negative electrode lugs are connected with the negative electrode terminals through the second electric connecting pieces.
The battery cell according to any one of claims 1 to 11, wherein,

The electrode terminals include a positive electrode terminal and a negative electrode terminal;

the electrical connector comprises a first electrical connector and a second electrical connector;

The electrode lugs comprise a plurality of positive electrode lugs and a plurality of negative electrode lugs, each positive electrode lug and each positive electrode terminal are located on different sides, and/or each negative electrode lug and each negative electrode terminal are located on different sides, each positive electrode lug is connected with the positive electrode terminal through the first electric connecting piece, and each negative electrode lug is connected with the negative electrode terminal through the second electric connecting piece.
The battery cell according to any one of claims 1 to 13, wherein,

The electrode assemblies are arranged in parallel along the first direction, and the welding parts of the electrode lugs with the same polarity of the electrode assemblies are connected through the same electric connecting piece.
A battery device, wherein the battery device comprises:

Case body, and

At least one battery cell according to any one of claims 1 to 14, which is accommodated in the case.
An electrical device, wherein the electrical device comprises the battery cell of any one of claims 1 to 14 or the battery device of claim 15 for providing electrical energy.
An energy storage device, wherein the energy storage device comprises the battery cell of any one of claims 1 to 14 or the battery device of claim 15 for providing electrical energy.