CN222927735U

CN222927735U - Battery monomer, battery, power utilization device and energy storage device

Info

Publication number: CN222927735U
Application number: CN202421483290.5U
Authority: CN
Inventors: 谢勇锋; 程启; 周健; 周文林; 李全坤
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2024-06-26
Filing date: 2024-06-26
Publication date: 2025-05-30
Anticipated expiration: 2034-06-26
Also published as: WO2026000623A1

Abstract

The present application discloses a battery cell, a battery, an electric device and an energy storage device. The battery cell comprises: a housing having a storage space; an electrode terminal arranged in the housing; at least one electrode assembly arranged in the storage space, the electrode assembly comprising a main body and a pole ear arranged in the main body, the pole ear comprising a plurality of pole ear sheets, and the pole ear is directly connected to the electrode terminal. The present application can reduce the impedance of the battery cell during charging and discharging, thereby reducing the temperature rise.

Description

Battery monomer, battery, power utilization device and energy storage device

Technical Field

The application relates to the technical field of batteries, in particular to a battery cell, a battery, 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 having a battery mounted therein have been widely used, and in addition, batteries are increasingly used in the field of energy storage and the like.

In a new energy vehicle that carries a battery, the battery may be used to fully or partially power. In the energy storage field, the battery may be mounted in an energy storage case or directly on the user side. Along with the continuous expansion of the application field of the power battery, not only is higher requirement on the performance of the battery, but also higher requirement on the reliability and the light weight of the battery.

Disclosure of utility model

In order to solve the technical problems, the application provides a battery cell, a battery, an electric device and an energy storage device which are high in reliability and light in weight.

The application is realized by the following technical scheme.

The first aspect of the application provides a battery cell, which comprises a shell, an electrode terminal and at least one electrode assembly, wherein the shell is provided with an accommodating space, the electrode terminal is arranged in the shell, the electrode assembly is arranged in the accommodating space and comprises a main body part and a tab arranged in the main body part, the tab comprises a plurality of tab pieces, and the tab pieces are directly connected with the electrode terminal.

The electrode lug comprises a plurality of electrode lugs, the electrode lug is directly connected with the electrode terminal, overcurrent capacity can be improved to meet high-rate charge and discharge requirements, meanwhile, the overcurrent capacity can be shortened, impedance in the process of charging and discharging of the battery monomer is reduced, and accordingly temperature rise is reduced, adverse effects of high temperature on battery performance can be relieved even in a use scene of high-rate charge and discharge of the battery monomer, the risk of thermal runaway of the battery monomer is reduced, and accordingly reliability of the battery monomer is improved.

In some embodiments, the tab has a connection portion and a folded portion, the connection portion is connected between the main body portion and the folded portion, the folded portion is formed by stacking and connecting a plurality of tab pieces together, and the folded portion is directly connected with the electrode terminal.

The folded part is formed by laminating and connecting the plurality of tab sheets, so that when the folded part is directly connected with the electrode terminal, the connection effect of the switching sheet and the electrode terminal can be achieved, namely, the impedance caused by the conventional use of the switching sheet is reduced on the premise of not reducing the connection effect of the tab sheets and the electrode terminal.

In some embodiments, a first welding connection part is formed at the gathering part, the plurality of tabs are connected into a whole through the first welding connection part, the gathering part and the electrode terminal are connected with each other through a second welding connection part, and in the same projection plane perpendicular to the thickness direction of the gathering part, the projection of the second welding connection part and the first welding connection part has an overlapping part.

The plurality of tab is connected as an organic wholely through first welded connection portion and makes to be located and connects between the plurality of tab of drawing in portion more compactly to the projection of second welded connection portion and first welded connection portion has the portion that overlaps, makes to draw in portion and electrode terminal connection through second welded connection portion connection more reliable, reduces the rosin joint risk, thereby promotes the overcurrent capacity when high multiplying power charge and discharge, and can also reduce the temperature rise.

In some embodiments, the projection of the second welded connection does not exceed the projection of the first welded connection in the same plane of projection perpendicular to the thickness direction of the gather.

Therefore, all the second welding connection parts are positioned in the first welding connection part area, and the connection reliability between the furling part and the electrode terminal is further improved.

In some embodiments, the projected area of the second welded connection is 30% to 100% of the projected area of the first welded connection.

The proper welding area between the furling part and the electrode terminal can meet the overcurrent requirement and play the role of overcurrent protection.

In some embodiments, the gathering portion is configured as a plate-like structure.

The internal structure of the furling part of the plate-shaped structure is more compact, so that the effect of connecting the transfer piece with the electrode terminal in the past can be more similar when the furling part is directly connected with the electrode terminal, thereby further improving the overcurrent performance and the connection reliability.

In some embodiments, the gathering portion is ultrasonically welded by a plurality of the tabs.

The plurality of tab pieces are closely attached and compacted together by high-frequency vibration of the ultrasonic welding head, so that the folded part has a compact structure like a plate. Thus, even if the folded portion and the electrode terminal are laser welded, reliable connection can be achieved.

In some embodiments, the furled portion is laser welded to the electrode terminal.

Because the folding part is connected together through a plurality of tab stacks and forms compact structure, from this, also can realize reliable connection through the switching piece like before through laser welding, reduce the rosin joint risk, promote the connection reliability to can also promote machining efficiency.

In some embodiments, an end of the connecting portion connected to the gathering portion is located at a thickness direction center of the main body portion.

Therefore, the middle structure of the tab enables the passing flow paths of the tabs to be approximately the same, the passing flow is more uniform, and the temperature rise of the battery monomer under high-rate charge and discharge can be reduced, so that the cycle life of the battery monomer can be obviously improved. In addition, the middle structure of the lug is convenient to weld with the electrode terminal.

In some embodiments, the electrode terminal comprises a positive electrode terminal and a negative electrode terminal, the tab comprises a positive electrode tab and a negative electrode tab, the positive electrode tab and the negative electrode tab are respectively arranged at the same end of the main body part, the positive electrode tab is directly connected with the positive electrode terminal, and the negative electrode tab is directly connected with the negative electrode terminal.

The positive electrode tab and the negative electrode tab are respectively and directly connected with the positive electrode terminal and the negative electrode terminal, so that the internal impedance of the battery can be reduced, the charge and discharge temperature rise of the battery can be reduced, and the reliability of the battery can be improved.

In some embodiments, two electrode assemblies are provided, the two electrode assemblies are connected with the same polarity of the electrode lugs, and the electrode lugs of each electrode assembly are directly connected with the electrode terminals through the respective furling parts.

The two electrode assemblies are respectively and directly connected with the electrode terminals through the respective furling parts, so that the internal impedance of the battery can be reduced, the charge and discharge temperature rise of the battery can be reduced, and the reliability of the battery can be improved while the capacity of the battery is improved.

In some embodiments, two of the electrode assemblies are disposed opposite each other in a thickness direction of the main body portion.

The two electrode assemblies which are oppositely arranged reduce the occupation of the shell space, and are beneficial to improving the volume energy density of the battery.

A second aspect of the application provides a battery comprising a case, and at least one battery cell provided in the first aspect, wherein the battery cell is arranged in the case.

A third aspect of the present application provides an electrical device comprising the battery cell provided in the first aspect or the battery provided in the second aspect, the battery being capable of providing electrical energy to the electrical device.

A fourth aspect of the application provides an energy storage device comprising a battery cell as provided in the first aspect or a battery as provided in the second aspect, the battery being capable of storing electrical energy and of providing electrical energy.

The utility model has the following effects:

according to the embodiment of the application, the reliability and the weight of the battery monomer and even the battery can be improved.

Drawings

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

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

fig. 2 is an exploded perspective view of a battery provided in some embodiments of the application;

Fig. 3 is an exploded perspective view of a battery cell according to some embodiments of the present application;

FIG. 4 is a schematic illustration of an electrode assembly and end cap joined together according to some embodiments of the present application;

FIG. 5 is an exploded view of an electrode assembly and an end cap according to some embodiments of the present application;

Fig. 6 is an enlarged schematic view of a portion of the structure of the electrode assembly of fig. 5;

Fig. 7 is an enlarged schematic view of a portion of the structure of an electrode assembly according to other embodiments of the present application;

FIG. 8 is a schematic illustration of the structure of an end cap provided in some embodiments of the application;

FIG. 9 is a top view of an end cap provided in some embodiments of the application;

FIG. 10 is an enlarged schematic view in partial cross-section of an end cap provided in accordance with some embodiments of the application;

Fig. 11 is a schematic cross-sectional view of a pressing member for pressing a tab to an electrode terminal according to some embodiments of the present application.

Reference numerals illustrate:

1000-vehicle;

100-battery, 200-controller, 300-motor;

1-a battery;

2-box, 3-lower box, 4-upper box;

10-housing, 11-shell, 12-first housing wall;

22-electrode terminal, 22 a-positive electrode terminal, 22 b-negative electrode terminal, 221-first connecting portion, 221 a-connecting surface, 222-second connecting portion, 231-positioning portion, 231 a-first surface, 231 b-second surface, 2211-terminal plate, 2221-terminal plate, 23-insulator, 233-protrusion portion, 234-explosion-proof valve escape hole, 235-injection escape hole;

30-electrode assembly, 31-main body part, 32-tab, 32 a-tab, 32 c-positive tab, 32 d-negative tab, 321-connecting part, 322-gathering part, 322 b-second welding connecting part, 322 c-first welding connecting part;

O-center, X-layer thickness direction, Y-thickness direction, Z-length direction, S-pressing piece.

Detailed Description

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

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

In the description of embodiments of the present application, 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 application, the meaning of "plurality" is two or more unless explicitly defined otherwise.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

In the description of the embodiment of the present application, the term "and/or" is merely an association relationship describing the 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 application, 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, and are merely for convenience of describing the embodiments of the present application and for simplifying the description, and are not intended to indicate or imply that the apparatus or element in question must have a specific orientation, be constructed, operated, or used in a specific orientation, and thus should not be construed as limiting the embodiments of the present application.

In describing embodiments of the present application, unless explicitly stated or limited otherwise, the terms "mounted," "connected," "secured" and other terms such as "fixed" are to be construed broadly as referring to either a fixed connection, a removable connection, or an integral body, a mechanical connection, an electrical connection, a direct connection, an indirect connection via an intermediary, a communication between two elements, or an interaction between two elements. The specific meaning of the above terms in the embodiments of the present application will be understood by those of ordinary skill in the art according to specific circumstances.

In the description of the embodiments of the present application, 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.

In the embodiment of the application, the battery cell may be a secondary battery, and the secondary battery refers to a battery which can be continuously used by activating the active material in a charging manner after the battery cell discharges.

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

The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During charge and discharge of the battery, active ions (e.g., lithium ions) are inserted and extracted back and forth between the positive electrode and the negative electrode. The separator is arranged between the positive electrode and the negative electrode, can play a role in preventing the positive electrode and the negative electrode from being short-circuited, and can enable active ions to pass through.

In some embodiments, the positive electrode may be a positive electrode sheet, which 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, aluminum, nickel, carbon electrode, carbon, 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. However, the present application is not limited to these materials, and 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 (such as LiFePO ₄ (which may also be referred to simply as LFP)), a composite of lithium iron phosphate and carbon, lithium manganese phosphate (such as 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 may be a metal foam. The foam metal can be foam nickel, foam copper, foam aluminum, foam alloy, foam carbon 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 may be a negative electrode tab, which 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, aluminum, nickel, carbon electrode, carbon, nickel, 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, foam carbon 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 electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

In some embodiments, the separator is a separator film. The type of the separator is not particularly limited, and any known porous separator having good chemical stability and mechanical stability can 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, the separator is a solid state electrolyte. The solid electrolyte is arranged between the anode and the cathode and plays roles in transmitting ions and isolating the anode and the cathode.

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

In some embodiments, the electrode assembly is a rolled structure. The positive plate and the negative plate are wound into a winding structure.

In some embodiments, the electrode assembly is a lamination stack.

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

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

As an example, the positive and negative electrode sheets are each folded to form a plurality of folded sections in a stacked arrangement.

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

As an example, the separator may be continuously provided, being disposed between any adjacent positive or negative electrode sheets by folding or winding.

In some embodiments, the electrode assembly may have a cylindrical shape, a flat shape, a polygonal column shape, or the like.

In some embodiments, the electrode assembly is provided with tabs that can conduct current away from the electrode assembly. The tab includes a positive tab and a negative tab.

In some embodiments, the battery cell may include a housing. The case is used to encapsulate the electrode assembly, the electrolyte, and the like. The shell 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.

As an example, the battery cell may be a cylindrical battery, a prismatic battery, a pouch battery, or a battery of other shape, the prismatic battery including a square-case battery, a blade-shaped battery, a polygonal-prismatic battery, such as a hexagonal-prismatic battery, etc., and the present application is not particularly limited.

In some embodiments, the housing includes an end cap and a case, the case being provided with an opening, the end cap closing the opening to form a closed space for accommodating the electrode assembly, electrolyte, and the like. The housing may be provided with one or more openings. One or more end caps may also be provided.

In some embodiments, a pressure relief mechanism is provided on the housing. The pressure release mechanism is used for releasing the internal pressure of the battery.

In some embodiments, the battery referred to herein may be a battery module comprising a single physical module of one or more battery cells to provide higher voltage and capacity. When a plurality of battery cells are provided, the plurality of battery cells are connected in series, in parallel or in series-parallel through the converging component. The plurality of battery cells are arranged and fixed to form a battery module.

In some embodiments, the battery of the present application may also be a battery pack, which includes a case and at least one battery cell or battery module, which is accommodated in the case.

In some embodiments, the tank may be part of the chassis structure of the vehicle. For example, a portion of the tank may become at least a portion of the floor of the vehicle, or a portion of the tank may become at least a portion of the cross member and the side member of the vehicle.

The present application will be 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. Along with the continuous expansion of the application field of the power battery, not only is higher requirement on the performance of the battery, but also higher requirement on the reliability and the light weight of the battery.

The battery cell can generate heat in the charge and discharge process, and the larger the internal impedance of the battery cell is, the more obvious the heat is. In general, the tabs of the battery cells are connected with the electrode terminals through the switching pieces, and the switching pieces generate larger impedance in the charging and discharging processes of the battery cells, so that the battery cells are seriously heated. In addition, for the battery cell having high-rate charge and discharge performance, since the current flowing through the switching piece is larger, heat generation is more remarkable, which may adversely affect the cycle life of the battery cell, and even risk of thermal runaway may occur, resulting in poor reliability of the battery cell and thus the battery.

In view of the above, the present application provides a battery including a case having an accommodating space, an electrode terminal provided to the case, and at least one electrode assembly provided in the accommodating space, the electrode assembly including a body part and a tab provided to the body part, the tab including a plurality of tab pieces, the tab being directly connected to the electrode terminal.

The battery cell comprises a plurality of electrode lugs, wherein the electrode lugs are directly connected with electrode terminals, overcurrent capacity can be improved to meet high-rate charge and discharge requirements, meanwhile, the overcurrent capacity can be shortened, impedance in the process of charging and discharging of the battery cell is reduced, and accordingly temperature rise is reduced.

The embodiment of the application also provides a battery, which comprises at least one battery cell. The battery may be used in, but is not limited to, energy storage power systems, vehicles, boats or aircraft, and other electrical devices.

The battery provided by the embodiment of the application can be a battery pack. The battery pack can also be used in, but not limited to, energy storage power systems, vehicles, boats or aircraft, and other electrical devices. The use of a battery pack can provide a higher total energy.

The embodiment of the application provides an electric device comprising the battery cell or the battery for providing electric energy, wherein the electric device can be, but is not limited to, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, a battery car, an electric automobile, a ship, a spacecraft and the like. 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 application 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 according to some embodiments of the present application. The vehicle 1000 may be a fuel oil vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or a range-extended vehicle. As shown in fig. 1, the battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom or the head or the tail of the vehicle 1000. The battery 100 may be used for power supply of the vehicle 1000, for example, the battery 100 may be used as an operating power source of the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, the controller 200 being configured to control the battery 100 to power the motor 300, for example, for operating power requirements during start-up, navigation, and travel of the vehicle 1000.

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

Fig. 2 is an exploded perspective view of a battery according to some embodiments of the present application. As shown in fig. 2, the battery 100 includes a case 2, and the case 2 includes a lower case 3 and an upper case 4, and the lower case 3 and the upper case 4 are covered together to form an accommodating space for accommodating the battery cell 1.

In the battery 100, the number of the battery cells 1 may be plural, and the plurality of battery cells 1 may be connected in series, parallel, or series-parallel, where series-parallel refers to both of the plurality of battery cells 1 being connected in series and parallel. The battery units 1 can be directly connected in series or in parallel, and then the whole formed by the battery units 1 is placed in the accommodating space formed by covering the lower case 3 and the upper case 4, and of course, the battery 100 can also be in a form of a battery module formed by connecting the battery units 1 in series or in parallel, and then the battery modules are connected in series or in parallel to form a whole and are accommodated in the accommodating space formed by covering the lower case 3 and the upper case 4. The battery 100 may further include other structures, for example, the battery 100 may further include a bus member for making electrical connection between the plurality of battery cells 1.

Some embodiments of the present application are described in detail below with reference to fig. 3 to 11.

Fig. 3 is an exploded perspective view of a battery cell according to some embodiments of the present application, fig. 4 is a schematic view of a structure in which an electrode assembly according to some embodiments of the present application is coupled to an end cap, and fig. 5 is an exploded perspective view of an electrode assembly according to some embodiments of the present application, wherein a positional relationship between the electrode assembly 30 and the end cap shown in fig. 4 can be regarded as a view angle in which the electrode assembly 30 of fig. 3, in which two sides face each other, is flattened in an end-to-end state in a direction away from each other, and in which tabs of the electrode assembly 30 are flattened from a bent state of fig. 3 to a straight state, and also can be regarded as a view angle in a process of coupling the tabs 32 with the electrode terminals 22 during a battery manufacturing process.

Fig. 6 is an enlarged schematic view of a portion of the electrode assembly shown in fig. 5, and fig. 7 is an enlarged schematic view of a portion of the electrode assembly according to other embodiments of the present application, wherein the tab 32 of the electrode assembly 30 shown in fig. 6 and fig. 7 is a view in an unbent state, and the view in a bent state of the tab 32 can be referred to the electrode assembly 30 shown in fig. 3.

Fig. 8 is a schematic structural view of an end cap according to some embodiments of the present application, in which two electrode terminals 22 are respectively disposed with pressing members S, fig. 9 is a top view of an end cap according to some embodiments of the present application, in which one of the two electrode terminals 22 is disposed with the pressing member S and the other is not disposed with the pressing member S, fig. 10 is an enlarged partial cross-sectional view of an end cap according to some embodiments of the present application, in which the electrode terminal 22 is not disposed with the pressing member S, and fig. 11 is a schematic cross-sectional view of an electrode tab pressed and fixed on an electrode terminal by the pressing member according to some embodiments of the present application.

In the embodiment of the application, an arrow Z in the definition graphic is denoted as a first direction Z, an arrow Y is denoted as a second direction Y, an arrow X is denoted as a third direction X, and the first direction Z, the second direction Y and the third direction X are perpendicular to each other.

In some embodiments, arrow X may also be represented as a lamination direction X of the plurality of tabs 32a, a thickness direction X of the end cap, arrow Y may also be represented as a width direction Y of the end cap, arrow Z may also be represented as a length direction Z of the body portion 31, and a length direction Z of the end cap. In addition, as will be understood by those skilled in the art, the main body 31 in fig. 4 to 7 is a flattened view of the main body 31 in fig. 3, and thus, the thickness direction of the main body 31 in fig. 4 to 7 is the same as the thickness direction of the folded portion 322, and the thickness direction of the main body 31 in fig. 3 is perpendicular to the thickness direction of the folded portion 322.

The embodiment of the application provides a battery cell 1, and referring to fig. 3 to 7, the battery cell 1 includes a case 10, an electrode terminal 22, and at least one electrode assembly 30. The case 10 has a receiving space a, the electrode terminal 22 is provided in the case 10, at least one electrode assembly 30 is provided in the receiving space a, the electrode assembly 30 includes a body portion 31 and a tab 32 provided in the body portion 31, the tab 32 includes a plurality of tabs 32a, and the tab 32 is directly connected to the electrode terminal 22.

The case 10 has a receiving space a for receiving the electrode assembly 30, and in addition, the receiving space a may receive an electrolyte and other components.

For example, referring to fig. 3, the case 10 has a plurality of case walls enclosing the receiving space a, the plurality of case walls including the first case wall 12 therein, the first case wall 12 may be an end cap of the battery cell 1, the remaining case walls of the plurality of case walls enclose a case 11 having an opening through which the electrode assembly 30 is received in the receiving space a, and the opening is closed by the first case wall 12 to form the receiving space a in which the electrode assembly 30 is received. The electrode terminal 22 may be disposed on the first case wall 12.

The shape of the first housing wall 12 may be adapted to the shape of the opening of the housing 11. The material of the first housing wall 12 may be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application is not limited thereto. For example, the first housing wall 12 may be made of a material having a certain hardness and strength (such as an aluminum alloy), so that the first housing wall 12 is not easily deformed when being impacted by extrusion, and the battery cell 1 can have a higher structural strength.

In some embodiments, insulation may also be provided between the first housing wall 12 and the opening of the housing 11 to reduce the risk of short circuits and to provide a sealing effect. In some embodiments, the first housing wall 12 may further comprise a pressure relief mechanism for relieving the internal pressure of the battery cell 1 when the internal pressure reaches a threshold value.

The case 10 may have various shapes, such as a rectangular parallelepiped shape, a cylindrical shape, a hexagonal prism shape, etc., and an appropriate case 10 may be determined according to the specific shape of the electrode assembly 30. The material of the housing 10 may be a metal material or a non-metal material, for example, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, aluminum plastic, etc., which is not particularly limited in the embodiment of the present application.

The electrode terminal 22 is electrically connected to the electrode assembly 30 for outputting or inputting electric power. When the battery cells 1 are plural, the electrode terminals 22 of the respective battery cells 1 may also be connected by a bus member, thereby connecting the plural battery cells in series and/or in parallel.

The number of the electrode assemblies 30 may be one, two or more. Each electrode assembly 30 includes a main body 31 and a tab 32 provided to the main body 31. Illustratively, the body portion 31 includes a positive pole piece, a negative pole piece, and a separator interposed between the positive pole piece and the negative pole piece. In one example, the positive electrode sheet, the separator, and the negative electrode sheet may be wound at least two times to form a wound structure, and in another example, the positive electrode sheet, the separator, and the negative electrode sheet may be stacked to form a laminated structure.

The tab 32 includes a plurality of tabs 32a (shown in fig. 6 and 7), each tab 32a is connected to the main body 31, and each tab 32a may be integrally formed with the main body 31.

The tab 32 can conduct current from the main body 31. The plurality of tab pieces 32a can improve the overcurrent capability and can be more suitable for the high-rate charge and discharge requirements.

The tab 32 includes a plurality of tabs 32a, and the tab 32 is directly connected with the electrode terminal 22, so that the overcurrent capacity can be improved to meet the high-rate charge and discharge requirements, and meanwhile, the overcurrent path can be shortened, the impedance of the battery cell 1 in the charge and discharge process can be reduced, and thus the temperature rise can be reduced, even if the battery cell 1 is in a use scene of high-rate charge and discharge, the adverse effect of high temperature on the battery performance can be relieved, the risk of thermal runaway of the battery cell 1 is reduced, and the reliability of the battery cell 1 and even the battery 100 is improved, and in addition, the conventional adapter sheet is omitted, so that the battery cell 1 and even the battery 100 are lighter.

In some embodiments, the tab 32 has a connection portion 321 and a folded portion 322, the connection portion 321 is connected between the main body portion 31 and the folded portion 322, the folded portion 322 is formed by stacking and connecting a plurality of tab pieces 32a together, and the folded portion 322 is directly connected to the electrode terminal 22.

The stacked and connected together of the folded portion 322 by the plurality of tabs 32a means that the plurality of tabs 32a are stacked in the thickness direction thereof and the tabs 32a are gathered together so that the folded portion 322 is formed as a relatively compact integral structure.

After the electrode assembly 30 is wound to form a winding structure, the tabs 32a may be loose, gaps between the tabs 32a in the stacking direction (the third direction X in fig. 6) are large, and the loose tabs 32a are easily connected with the electrode terminals 22, so that the loose tabs are not firmly connected, for example, a risk of cold welding exists in a welding process, resulting in poor overcurrent capability, and cannot meet the high-rate charge-discharge requirement.

In this case, the plurality of loose tabs 32a are stacked together at the same position to form the compact folded portion 322, and the compact folded portion 322 is directly connected (for example, laser welded) to the electrode terminal 22, thereby enabling reliable connection. As an example, the tightly packed folded portion 322 may have a plate-like structure similar to that of the conventional tab, so that the same connection effect of the tab and the electrode terminal 22 can be achieved basically when the folded portion 322 is directly connected (e.g., laser welded) to the electrode terminal 22.

The folded part is connected together in a stacked manner through the plurality of tab pieces 32a to form a compact integrated structure, so that the folded part 322 is more firmly connected with the electrode terminal 22 directly, the virtual connection risk is reduced, and the overcurrent capacity of the tab pieces 32 is improved. That is, even if the conventional transfer sheet is omitted, the overcurrent capacity of the tab 32 can be improved to meet the high-rate charge and discharge requirements without reducing the connection effect of the tab 32 and the electrode terminal 22, and the impedance in the charge and discharge process of the battery cell 1 can be reduced, so that the temperature rise is reduced, the adverse effects of the high temperature of the battery cell 1 on the performance and the cycle life are relieved, and the thermal runaway risk of the battery cell 1 can be reduced, so that the reliability of the battery cell 1 and even the battery 100 is improved.

In some embodiments, a first welding connection portion 322c is formed at the folded portion 322, the plurality of tabs 32a are integrally connected by the first welding connection portion 322c, the folded portion 322 and the electrode terminal 22 are connected to each other by a second welding connection portion 322b, and the projection of the second welding connection portion 322b and the first welding connection portion 322c has an overlapping portion in the same projection plane perpendicular to the thickness direction X of the folded portion 322.

In the same projection plane perpendicular to the thickness direction X of the folded portion 322, the projection of the second welding connection portion 322b and the first welding connection portion 322c has an overlapping portion, which can be understood as that the folded portion 322, the plurality of tab pieces 32a are connected together by welding to form the first welding connection portion 322c having a certain area, and the folded portion 322 and the electrode terminal 22 are connected together by welding to form the second welding connection portion 322b in the area of the first welding connection portion 322 c.

For example, first, the plurality of tab pieces 32a located at the folded portion 322 may be ultrasonically pre-welded to form a first welding connection portion 322c (ultrasonic welding) at the folded portion 322, the first welding connection portion 322c tightly connecting the plurality of tab pieces 32a located at the folded portion 322 together to form an integrated structure, and then the folded portion 322 and the electrode terminal 22 may be connected by laser welding in the region of the first welding connection portion 322c to form a second welding connection portion 322b (laser welding) between the folded portion 322 and the electrode terminal 22 such that the second welding connection portion 322b at least partially coincides with the first welding connection portion 322 c.

Therefore, the plurality of tabs 32a are integrally connected through the first welding connection portion 322c, so that the connection between the plurality of tabs 32a located at the gathering portion is more compact, and the projection of the second welding connection portion 322b and the projection of the first welding connection portion 322c are provided with overlapped portions, so that the gathering portion 322 connected through the second welding connection portion 322b and the electrode terminal 22 are connected more reliably, the risk of cold joint is reduced, the overcurrent capacity during high-rate charge and discharge is improved, and the temperature rise is also reduced.

In some embodiments, the projection of the second welded connection 322b does not exceed the projection of the first welded connection 322c in the same plane of projection perpendicular to the thickness direction X of the gather 322.

Accordingly, all of the second welding connection portions 322b are located in the region of the first welding connection portions 322c, and the connection reliability between the gathered portions 322 and the electrode terminals 22 is further improved.

In some embodiments, the projected area of the second welded connection 322b accounts for 30% to 100% of the projected area of the first welded connection 322 c. Illustratively, the projected area of the second weld connection 322b accounts for 30%, 35%, 40%, 45%, 50%, 55%, 60%, 70%, 80%, 90%, 100% of the projected area of the first weld connection 322 c.

The welding area between the folded portion 322 and the electrode terminal 22 is in a proper range, so that the overcurrent requirement can be met, and the overcurrent protection function can be achieved.

In some embodiments, the gathering portion 322 is configured as a plate-like structure.

The plate-like structure may be rectangular, square, oval or other shape.

The internal structure of the folded portion 322 of the plate-shaped structure is more compact, so that the effect of connecting the conventional adapter piece with the electrode terminal 22 can be more similar when the folded portion 322 is directly connected with the electrode terminal 22, thereby further improving the overcurrent capacity and the connection reliability.

In some embodiments, the folded portion 322 has a portion overlapping with the electrode terminal 22 along the layer thickness direction X of the folded portion 322.

The folded portion 322 and the electrode terminal 22 are stacked on each other along the layer thickness direction X of the folded portion 322, and the folded portion 322 may be entirely overlapped with the electrode terminal 22 or partially overlapped with the electrode terminal 22.

This can further shorten the flow passage of the tab 32, reduce the impedance, further reduce the battery temperature, and improve the battery performance and reliability.

In some embodiments, the end of the connecting portion 321 to which the gathering portion 322 is connected is located on one side of the thickness direction center O of the main body portion 31 (shown in fig. 7) or at the thickness direction center O of the main body portion 31 (shown in fig. 6).

Referring to fig. 7, the plurality of tabs 32a are each gathered together toward one side of the center O in the thickness direction of the main body portion 31 so as to deviate from the gathered portion 322 of the center O.

The plurality of tab pieces 32a form a central furling part 322, which is beneficial to reducing the internal resistance of the battery cell 1, reducing the temperature rise of the battery cell 1 during high-rate discharge and improving the performance and reliability of the battery.

Referring to fig. 6, the end of the connecting portion 321 to which the gathered portion 322 is connected is located substantially at the thickness direction center O of the main body portion 31.

The plurality of tabs 32a are each gathered together toward the center O in the thickness direction (X direction in fig. 6, Y direction in fig. 3) of the main body portion 31 to form a centrally disposed gathered portion 322. The end of the connecting portion 321 to which the gathered portion 322 is connected is located substantially at the thickness direction center O of the main body portion 31, and is understood in a broad sense as being within an allowable manufacturing error or measurement error range.

Therefore, the folded part 322 of the tab 32 is arranged in the middle, so that the flowing paths of the tabs 32a are approximately the same, the flowing is more uniform, the temperature rise of the battery cell 1 under high-rate charge and discharge can be reduced, and the cycle life of the battery cell 1 can be obviously improved. In addition, the centrally disposed structure of the tab 32 facilitates welding with the electrode terminal 22.

In some embodiments, referring to fig. 4 and 5, the electrode terminal 22 includes a positive electrode terminal 22a and a negative electrode terminal 22b, the tab 32 includes a positive electrode tab 32c and a negative electrode tab 32d, the positive electrode tab 32c and the negative electrode tab 32d are respectively disposed at the same end of the main body 31, the positive electrode tab 32c is directly connected to the positive electrode terminal 22a, and the negative electrode tab 32d is directly connected to the negative electrode terminal 22 b.

The positive and negative terminals 22a, 22b are spaced apart along the length Z of the end cap. The positive electrode tab 32c and the negative electrode tab 32d are led out from the same end of the main body 31 and are arranged at intervals along the longitudinal direction Z of the electrode assembly 30. The positive electrode tab 32c includes a plurality of positive electrode tabs stacked and connected together to form a positive electrode gathering portion directly connected to the positive electrode terminal 22a, and the negative electrode tab 32d includes a plurality of negative electrode tabs stacked and connected together to form a negative electrode gathering portion directly connected to the negative electrode terminal 22 b.

The positive electrode tab 32c and the negative electrode tab 32d are respectively and directly connected with the positive electrode terminal 22a and the negative electrode terminal 22b, so that the internal impedance of the battery can be reduced, the charge and discharge temperature rise of the battery can be reduced, and the reliability of the battery can be improved. In addition, the positive electrode tab 32c and the negative electrode tab 32d are disposed at the same end of the main body 31, which is helpful for improving the space utilization of the housing, thereby improving the volumetric energy density of the battery cell 1.

In some embodiments, the electrode assemblies 30 are provided in at least two, at least two electrode assemblies 30 are connected with the same polarity of the tab, and the tab 32 of each electrode assembly 30 is directly connected with the electrode terminal 22 through the respective folded portion 322.

At least two electrode assemblies 30 are respectively connected with the electrode terminals 22 through respective furling parts 322, so that the internal impedance of the battery cell 1 can be reduced, the charge and discharge temperature rise of the battery can be reduced, the reliability of the battery can be improved, the capacity of the battery can be improved, and the high-rate discharge requirement can be met.

In some embodiments, referring to fig. 8 to 11, the electrode terminal 22 penetrates the first case wall 12 and has a first connection part 221 located in the receiving space a (shown in fig. 3), the first connection part 221 has a connection surface 221a adjacent to the electrode assembly 30 in a thickness direction X (a third direction X in fig. 8) of the first case wall 12, the connection surface 221a is connected to the tab 32, and the insulating member 23 includes a positioning part 231, the positioning part 231 is disposed around an outer circumference of the first connection part 221, the positioning part 231 has a first surface 231a adjacent to one side of the electrode assembly 30 in the first case wall thickness direction X, and the first surface 231a is at least flush with a portion of the connection surface 221a adjacent to the positioning part 231.

The electrode terminal 22 is provided to the first case wall 12 for connection with the tab 32, thereby outputting and inputting electric power. When the battery cells 1 are plural, the electrode terminals 22 of the respective battery cells 1 may also be connected by a bus member, thereby connecting the plurality of battery cells 1 in series and/or in parallel. The electrode terminal 22 may be made of various materials, for example, conductive metals such as copper, iron, aluminum, stainless steel, aluminum alloy, and the like. The electrode terminal 22 is sometimes present in the form of a post, for example.

The electrode terminal 22 penetrates the first case wall 12 and has a first connection part 221 located in the receiving space a, and it may be that the electrode terminal 22 has the first connection part 221 protruding at least partially to one side in the first case wall thickness direction X (third direction X), that is, the first connection part 221 has a height H ₁ exceeding the first case wall 12 in the first case wall thickness direction X. Referring to fig. 11, the height H ₁ is a distance between a face (connection face 221 a) of the first connection part 221 on the side remote from the first case wall 12 and a face of the first case wall 12 on the side remote from the electrode assembly 30 along the first case wall thickness direction X. As an example, referring to fig. 3 and 11, along the first housing wall thickness direction X, a portion of the first connection portion 221 protrudes from the first housing wall 12 in the accommodation space a, and another portion extends to the outside of the housing 10 through the first housing wall 12 and is connected with the second connection portion 222, and the second connection portion 222 may be used to connect external bus members.

The first connection part 221 has a connection surface 221a adjacent to the electrode assembly 30 side along the first case wall thickness direction X, and the first connection part 221 is connected to the tab 32 through the connection surface 221 a. The connection surface 221a may be directly connected to the tab 32. The connection mode can be welding, bonding and the like. The shape of the connection surface 221a may be square, circular, oval, or other shapes.

The insulator 23 serves to isolate the electrode terminal 22 from the first case wall 12 to reduce the risk of short circuits. The material of the insulating member 23 may be plastic, rubber, or other material having insulating properties.

The insulating member 23 includes a positioning portion 231, where the positioning portion 231 is disposed around the outer periphery of the first connecting portion 221, and may be along the first housing wall thickness direction X, where the positioning portion 231 protrudes from the first housing wall 12 located on the same side as the first connecting portion 221, and the positioning portion 231 may completely or partially surround the first connecting portion 221 to perform positioning and insulating functions on the first connecting portion 221. Illustratively, the positioning portion 231 has a closed ring shape surrounding the outer periphery of the first connecting portion 221.

The positioning portion 231 has a first face 231a adjacent to the electrode assembly 30 side along the first case wall thickness direction X, and the first face 231a is flush with at least a portion of the connection face 221a adjacent to the positioning portion 231. The first surface 231a being flush with at least a portion of the connection surface 221a near the positioning portion 231 may be understood as being slightly lower or slightly higher or flush with the connection surface 221a along the first housing wall thickness direction X, and a height difference between the two may be within a range allowed by a machining error. The first surface 231a may be flush with a portion of the connection surface 221a near the positioning portion 231, or the first surface 231a may be flush with the connection surface 221a as a whole. Illustratively, the connection face 221a may be generally planar with the first face 231a being flush with the planar face.

The first face 231a may be understood as having a prescribed extension dimension along the first direction Z (first case wall length direction) and/or the second direction Y (first case wall width direction), so that the first face 231a can provide sufficient support space for the pressing piece S to support the pressing piece S when the pressing piece S presses the tab 32 against the electrode terminal 22. As for the extension dimension, the range may be determined based on the size of the pressing piece so that the supporting space formed by the first face 231a can reach the extent of supporting the pressing piece S. The first face 231a supports the pressing piece S, it is understood that the pressing piece S may be entirely supported by the first face 231a, i.e., the pressing piece S is entirely located on the first face 231a, or a portion of the pressing piece S is supported by the first face 231a, i.e., a portion of the pressing piece S is located on the first face 231a, for example, see fig. 11, and a portion of the pressing piece S is supported by the first face 231a and another portion is supported by the connection face 221a of the first connection part 221, i.e., the first face 231a of the positioning part 231 and the connection face 221a of the first connection part 221 together support the pressing piece S. Of course, the pressing pieces S may be supported entirely by the first surface 231 a.

As an example, referring to fig. 9, 10 and 11, in the step of directly welding the tab 32 and the electrode terminal 22, the pressing piece S presses the tab 32 against the connection surface 221a by the pressing piece S so that the tab 32 is positioned between the connection surface 221a and the pressing piece S, and the pressing piece S surrounds the welding region of the tab 32 and the connection surface 221a, for example, the center of the pressing piece S may be substantially overlapped with the center of the first connection portion 221, and the pressing piece S is supported together by the first surface 231a of the positioning portion 231 and the connection surface 221a of the first connection portion 221, whereby the tab 32 is pressed against the connection surface 221a more closely, and then the bonding head is inserted into the annular space of the pressing piece S to perform the welding operation of the tab 32 and the connection surface 221a, thereby firmly welding the connection surface 221a and the tab 32 together. The pressing piece S can also reduce splashing of particles in the welding process, and reduce the short circuit risk of the battery cell 1.

Through the locating part having the first face 231a and the first face 231a flush with the connection face 221a of the first connection part 221, in the process of connecting the tab 32 with the electrode terminal 22, the first face 231a can provide a supporting space for the pressing member S, thereby reducing the gap between the tab 32 and the electrode terminal 22, further ensuring that the tab is more firmly connected with the electrode terminal, improving connection reliability, simultaneously not only not increasing the weight of the battery cell 1 excessively, but also not increasing the cost excessively, thereby being beneficial to the weight reduction and cost control of the battery. If the volume of the electrode terminal 22 is increased to provide a supporting space for the pressing member, the weight of the battery cell 1 is greatly increased, which is disadvantageous in light weight of the battery cell 1 and high in cost.

In some embodiments, referring to fig. 9, 10 and 11, the pressing member S has a pressing surface S1, the pressing surface S1 is used to press the tab 32 against the connection surface 221a, the dimension of the connection surface 221a along the first housing wall length direction Z is D ₁, the dimension of the first surface 231a along the first housing wall length direction Z is D ₂, the dimension of the pressing surface S1 along the first housing wall length direction Z is D ₃, the dimension of the connection surface 221a along the first housing wall width direction Y is W ₁, the dimension of the first surface 231a along the first housing wall width direction Y is W ₂, and the dimension of the pressing surface S1 along the first housing wall width direction Y is W ₃, wherein D ₁+2D₂≥D₃,W₁+2W₂≥W₃.

D ₃ may be a distance between two opposite outer edges of the pressing piece S along the first housing wall length direction Z, and W ₃ may be a distance between two opposite outer edges of the pressing piece S along the first housing wall width direction Y. The dimension D ₂ of the positioning portion 231 along the first housing wall length direction Z and the dimension W ₂ along the first housing wall width direction Y can be adaptively adjusted according to the size of the pressing piece S.

In the step of connecting the tab 32 to the electrode terminal 22, the tab 32 is pressed against the connection surface 221a of the first connection part 221 by the pressing member S, and at least a portion of the pressing member S is supported by the first surface 231a of the positioning part 231 due to D ₁+2D₂≥D₃,W₁+2W₂≥W₃, whereby the tab 32 is pressed against the connection surface 221a of the first connection part 221 more closely, and the connection reliability is improved.

In some embodiments, the absolute value of the difference in height of the first face 231a and the connecting face 221a along the thickness direction X of the first housing wall is in the range of 0mm to 0.3 mm.

The first surface 231a may be slightly lower or slightly higher or flush with the connection surface 221a, so that the difference in height therebetween may be within the allowable tolerance of processing.

By controlling the height difference between the first surface 231a and the connection surface 221a within a proper error range, the tab 32 can be smoothly cut into the connection surface 221a by the pressing member S, and the connection reliability can be improved.

In some embodiments, the thickness of the first face 231a along the length direction Z of the first housing wall and/or the width direction Y of the first housing wall is 1mm or more and 3mm or less.

In the prior art, the thickness of the positioning portion 231 is generally less than 1mm, and only the positioning function of the first connecting portion 221 is performed. The positioning portion 231 of the embodiment of the application not only plays a role in positioning the first connection portion 221, but also has a function of supporting the pressing piece S, so that the pressing piece S can press the tab 32 on the first connection portion 221 more closely, subsequent welding is facilitated, the risk of cold joint is reduced, and the connection reliability is improved.

In some embodiments, the electrode terminal 22 further includes a second connection part 222 located outside the case 10 along the first case wall thickness direction X, and the second connection part 222 is connected with the first connection part 221. The second connection portion 222 may be riveted with the first connection portion 221 or both may be formed as a unitary structure.

The second connecting portion 222 may be used to connect an external bus member, through which a plurality of battery cells 1 may be connected together to form a battery module, thereby improving the capacity of the battery and meeting the high-power electricity demand.

In some embodiments, the electrode terminal 22 includes a terminal plate 2221 and a terminal plate 2211 connected to each other, the first connection part 221 includes the terminal plate 2211, and the terminal plate 2211 includes the connection surface 221a. The terminal plate 2221 and the terminal plate 2211 may be riveted or integrally constructed.

The terminal plate 2211 has a disk shape, for example, a disk shape or an oval shape, and may be made of a metal capable of conducting electricity, such as copper, iron, aluminum, stainless steel, or an aluminum alloy.

The terminal plate 2211 includes a connection surface 221a, where the connection surface 221a is substantially planar, so that the connection surface 221a is tightly attached to the tab 32, facilitating subsequent connection, and improving connection reliability.

In some embodiments, the second connection portion 222 includes a terminal plate 2221.

The terminal plate 2221 has a plate shape and has a flat surface that can be used for connection with the bus member. The shape of the terminal plate 2221 may be circular, square, or other shapes. The material of the terminal plate 2221 may be the same as or different from that of the terminal plate 2211.

The second connection portion 222 includes the terminal plate 2221, so that the connection surface 221a is more tightly attached to the bus member, facilitating subsequent connection, and improving connection reliability.

In some embodiments, the positioning portion 231 has a second surface 231b, and the second surface 231b is disposed around the outer circumference of the first connection portion 221 and contacts the outer circumference of the first connection portion 221.

The shape of the positioning portion 231 may be adapted to the shape of the first connection portion 221. Because the positioning portion 231 is flush with the first connecting portion 221 along the thickness direction of the first housing wall 12, the positioning portion 231 more firmly encloses the first connecting portion 221 therein, so as to improve positioning stability, reduce the risk of shaking during connection (e.g. welding) of the tab 32 and the first connecting portion 221, and facilitate connection reliability.

In some embodiments, the insulator 23 further includes a portion 232 (shown in fig. 10) located between the first connection 221 and the first housing wall 12 along the first housing wall thickness direction X.

The portion 232 between the first connection 221 and the first housing wall 12 serves to isolate the first connection 221 from the first housing wall 12, reducing the risk of short circuits. It will be appreciated that the portion 232 between the first connection 221 and the first housing wall 12 has a through hole for the first connection 221 to pass through.

In some embodiments, the insulating member 23 further includes a protrusion 233 protruding toward one side of the electrode assembly 30 along the first case wall thickness direction X.

The protrusion 233 may be used to abut against the body portion 31 of the electrode assembly 30, reducing the risk of shaking of the electrode assembly 30.

Illustratively, the first housing wall 12 (e.g., end cap) is further provided with an explosion-proof valve and a liquid injection hole, and the insulating member 23 includes an insulating body provided with an explosion-proof valve escape hole 234 corresponding to the explosion-proof valve and a liquid injection escape hole 235 corresponding to the liquid injection hole.

Next, a specific example of an embodiment of the present application will be described with reference to fig. 3 to 11.

The battery cell 1 of the embodiment of the present application includes a case 10, an electrode terminal 22, and an electrode assembly 30.

The case 10 includes a plurality of case walls including a first case wall 12 therein, the remaining case walls enclosing a case 11 having an opening, the first case wall 12 may be an end cap of the battery cell 1, and the first case wall 12 closes the opening such that the case 11 and the first case wall 12 form an accommodating space a for accommodating the electrode assembly 30.

Referring to fig. 8 to 11, the electrode terminal 22 is disposed on the first case wall 12 with an insulating member 23 interposed between the first case wall 12 and the case 11, the electrode terminal 22 includes a first connection portion 221 penetrating through the first case wall 12 and protruding from a side of the first case wall 12 near the electrode assembly 30 (shown in fig. 3) in a thickness direction X thereof, and a second connection portion 222 protruding from a side of the first case wall 12 distant from the electrode assembly 30 in the thickness direction X thereof, and the second connection portion 222 is riveted with the first connection portion 221.

The insulating member 23 includes a positioning portion 231 protruding from the first case wall 12 toward the electrode assembly 30 (shown in fig. 1) side in the thickness direction X thereof, and the positioning portion 231 is provided around the outer periphery of the first connection portion 221, and functions to position the first connection portion 221. The positioning part 231 has a first face 231a adjacent to the electrode assembly 30 along the first case wall thickness direction X, and the first connection part 221 has a connection face 221a adjacent to the electrode assembly 30 along the first case wall thickness direction X, the first face 231a being flush with the connection face 221 a. Specifically, the first connecting portion 221 protrudes from the first housing wall 12 by a height H ₁, and the positioning portion 231 protrudes from the first housing wall 12 by a height H ₂,H₁ to a height H ₂, which is in a range of 0mm to 0.3 mm. The first connection part 221 is directly welded to the tab 32 of the electrode assembly 30 through the connection surface 221a, and in the step of connecting the tab 32 to the first connection part 221, the first surface 231a is used to support the pressing piece S so that the pressing piece S presses the tab 32 against the connection surface 221a of the first connection part 221.

Referring to fig. 3 to 5, each electrode assembly 30 includes a main body portion 31 and two tabs 32 provided to the main body portion 31 and respectively led out from the same end of the main body portion 31, each tab 32 includes a plurality of tabs 32a, the tab 32 has a connection portion 321 and a folded portion 322, the connection portion 321 is connected between the main body portion 31 and the folded portion 322, the folded portion 322 is connected together by ultrasonic welding via the plurality of tabs 32a to form a compact and integral plate-like structure, an ultrasonic welding mark is formed on the folded portion 322, the folded portion 322 has an overlapping portion with the electrode terminal 22 along a layer thickness direction X of the folded portion 322, the folded portion 322 is directly connected with a connection surface 221a of the electrode terminal 22 by laser welding, and a laser welding mark (a second welding connection portion 322b shown in fig. 4) is formed on the folded portion 322, wherein the laser welding mark coincides with the ultrasonic welding mark, the folded portion 322 is folded relative to the connection portion 321, and the main body portions 31 of the two electrode assemblies 30 are arranged to be folded along the layer thickness direction Y (shown in fig. 3).

The electrode assembly 30 is formed by stacking a plurality of tabs 32a of each electrode assembly 30 together toward the same position by an ultrasonic welding apparatus to form a tab 32 having a folded portion 322 and a connection portion 321, forming the folded portion 322 into a compact integral plate-like structure, and forming ultrasonic welding marks on the folded portion 322, then stacking the compact folded portion 322 of the electrode assembly 30 on the connection surface 221a of the first connection portion 221 of each electrode terminal 22 in the layer thickness direction X, then pressing the folded portion 322 on the connection surface 221a by an annular pressing piece S, and the pressing piece S is supported together by the connection surface 221a and the first surface 231a to attach the folded portion 322 to the connection surface 221a, and then laser welding the folded portion 322 and the connection surface 221a at the ultrasonic welding position of the folded portion 322 by a welding head extending into the pressing piece S to complete the welding operation of the tab 32 of the electrode assembly 30 and the electrode terminal 22. Thereafter, the pressing piece S is removed, the two main body portions 31 are respectively rotated 90 degrees toward each other so as to be disposed face-to-face in the thickness direction (shown in fig. 3), thereby bending the folded portion 322 with respect to the connecting portion 321, and then the two electrode assemblies 30 are put into the case 10 with the first case wall 12 closing the opening of the case 10.

The present application also provides a battery 100 comprising a case 2 and at least one of the above-mentioned battery cells 1.

Referring to fig. 2, the case 2 includes a lower case 3 and an upper case 4, and the lower case 3 and the upper case 4 are covered with each other, thereby forming an accommodating space of the battery cell 1.

The present application also provides an electric device comprising the above-mentioned battery cell 1 or battery 100 for supplying electric energy.

The present application also provides an energy storage device comprising the above-mentioned battery cell 1 or battery 100 for providing electric energy, the battery cell 1 being capable of storing electric energy and being capable of providing electric energy.

The energy storage device may be an energy storage tank or an energy storage cabinet. The energy storage cabinet comprises a plurality of battery bins for accommodating the battery cells 1. In addition, the energy storage cabinet can further comprise a thermal management component, a power supply control component and the like.

The foregoing embodiments are merely for illustrating the technical solution of the present application, and not for limiting the same, and although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solution described in the foregoing embodiments may be modified or some or all of the technical features may be equivalently replaced, and the modification or replacement does not deviate the essence of the corresponding technical solution from the scope of the technical solution of the embodiments of the present application, and is intended to be covered in the scope of the present application. In particular, the technical features mentioned in the respective embodiments may be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the present application.

Claims

1. A battery cell, comprising:

A housing having a receiving space;

An electrode terminal, disposed on the housing;

At least one electrode assembly is disposed in the accommodating space, wherein the electrode assembly comprises a main body and a pole ear disposed on the main body, wherein the pole ear comprises a plurality of pole ear sheets, and the pole ear is directly connected to the electrode terminal.

2. The battery cell according to claim 1, characterized in that:

The electrode tab has a connecting portion and a gathering portion, wherein the connecting portion is connected between the main body portion and the gathering portion, the gathering portion is formed by stacking and connecting a plurality of the electrode tab sheets, and the gathering portion is directly connected to the electrode terminal.

3. The battery cell according to claim 2, characterized in that:

A first welding connection portion is formed on the gathered portion, and a plurality of the pole tabs are connected as one body through the first welding connection portion.

The gathered portion and the electrode terminal are connected to each other via a second welding connection portion, and in the same projection plane perpendicular to the thickness direction of the gathered portion, projections of the second welding connection portion and the first welding connection portion have an overlapping portion.

4. The battery cell according to claim 3, characterized in that:

In the same projection plane perpendicular to the thickness direction of the gathered portion, the projection of the second welding connection portion does not exceed the projection of the first welding connection portion.

5. The battery cell according to claim 4, characterized in that:

The projection of the second weld connection has an area of 30% to 100% of the projection of the first weld connection.

6. The battery cell according to any one of claims 2 to 5, characterized in that:

The gathered portion is configured as a plate-shaped structure.

7. The battery cell according to any one of claims 2 to 5, characterized in that:

One end of the connecting portion connected to the gathering portion is located at the center of the main body in the thickness direction.

8. The battery cell according to any one of claims 2 to 5, characterized in that:

The electrode terminal includes a positive terminal and a negative terminal;

The tabs include a positive tab and a negative tab, the positive tab and the negative tab are respectively arranged at the same end of the main body, the positive tab is directly connected to the positive terminal, and the negative tab is directly connected to the negative terminal.

9. The battery cell according to claim 8, characterized in that:

Two electrode assemblies are provided, and the electrode tabs of the two electrode assemblies with the same polarity are electrically connected, and the electrode tabs of each electrode assembly are directly connected to the same electrode terminal through their respective retracted parts.

10. The battery cell according to claim 9, characterized in that:

The two electrode assemblies are arranged opposite to each other along the thickness direction of the main body.

11. A battery, comprising:

Box;

At least one battery cell according to any one of claims 1 to 10, wherein the battery cell is disposed in the casing.

12. An electrical device, characterized in that the electrical device comprises the battery cell according to any one of claims 1 to 10 or the battery according to claim 11, and the battery can provide electrical energy for the electrical device.

13. An energy storage device, characterized in that it comprises the battery cell according to any one of claims 1 to 10 or the battery according to claim 11, wherein the battery can store electrical energy and provide electrical energy.