CN221282308U

CN221282308U - Battery monomer, battery and power consumption device

Info

Publication number: CN221282308U
Application number: CN202322518806.7U
Authority: CN
Inventors: 吴凯; 许宝云
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2023-09-15
Filing date: 2023-09-15
Publication date: 2024-07-05
Anticipated expiration: 2033-09-15

Abstract

The application relates to the technical field of batteries and discloses a battery cell, a battery and an electric device, wherein the battery cell comprises a positive pole piece, a negative pole piece and a separation film, and the negative pole piece and the positive pole piece are arranged in a lamination way; the barrier film is arranged between the positive pole piece and the negative pole piece, the projection of the positive pole piece to the barrier film is a first projection, the projection of the negative pole piece to the barrier film is a second projection, the first projection does not exceed the circumferential edge of the barrier film, the second projection does not exceed the circumferential edge of the barrier film, the size of the barrier film is larger than that of the positive pole piece at least in the first direction, the size of the barrier film is larger than that of the negative pole piece, and the stacking direction of the positive pole piece, the barrier film and the negative pole piece is perpendicular to the first direction. The application reduces the possibility of short circuit between the pole pieces and the pole lugs, and improves the quality of the battery monomer.

Description

Battery monomer, battery and power consumption device

Technical Field

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

Background

This section provides merely background information related to the application, which is not necessarily prior art.

The battery is used as an energy supply device and is widely applied to various industries. When a short circuit occurs in the battery, the use of the battery is not only affected, but also there is a risk of thermal runaway of the battery. It is an important research direction of the battery if the possibility of short circuit of the battery cell is reduced to improve the quality of the battery cell.

Disclosure of utility model

In view of the above, the present application provides a battery cell, a battery and an electric device, so as to reduce the possibility of short circuit of the battery cell and improve the quality of the battery cell.

The first aspect of the application provides a battery cell, which comprises a positive pole piece, a negative pole piece and a separation film; the negative pole piece and the positive pole piece are arranged in a lamination way; the separator is arranged between the positive pole piece and the negative pole piece in a stacked manner, the projection of the positive pole piece to the separator is a first projection, the projection of the negative pole piece to the separator is a second projection, the first projection does not exceed the circumferential edge of the separator, the second projection does not exceed the circumferential edge of the separator, and at least in the first direction, the size of the separator is larger than that of the positive pole piece and larger than that of the negative pole piece; wherein, the first direction is perpendicular to the lamination direction between the positive electrode sheet, the separator and the negative electrode sheet.

According to the technical scheme provided by the embodiment of the application, the possibility of short circuit between the pole pieces and the pole lugs is reduced, and the quality of the battery monomer is improved. Specifically, the first projection formed by the positive pole piece and the second projection formed by the negative pole piece do not exceed the circumferential edge of the isolating film, so that the positive pole piece and the negative pole piece can be isolated by the isolating film, and the possibility of lap-joint short circuit of the positive pole piece and the negative pole piece is reduced. Because at least in the first direction, the size of the isolation film is greater than the size of the positive pole piece, and the size of the isolation film is greater than the size of the negative pole piece, the isolation film is provided with a part exceeding the positive pole piece and the negative pole piece, and thus, when the negative pole piece and the positive pole piece are connected with the tab, the tab can be arranged at one end of the negative pole piece and the positive pole piece along the first direction, and the part of the isolation film exceeding the positive pole piece and the negative pole piece can support the tab, so that the possibility of turning over the tab is reduced, and the possibility of short circuit of battery cells caused by contact of the tab and the pole piece with opposite polarity is reduced, and the possibility of tab missing welding is reduced.

In some embodiments of the present application, in the first direction, the size of the negative electrode tab is a first size, in the first direction, the size of the separator is a second size, the second size is larger than the first size, and a difference of the second size minus the first size is a first difference H1, where the first difference H1 satisfies the following relationship: h1 Not less than 6+ (CW-10)/10; the positive electrode plate comprises a positive electrode active material layer, CW is a value corresponding to the weight of the positive electrode active material in the unit area of the positive electrode active material layer, the unit of CW is mg/cm ², and the unit of the value of the first difference H1 is millimeter. The battery monomer of this embodiment can be the battery monomer of no negative pole design, sets for first difference H1 to be greater than or equal to 6+ (CW-10)/10, and the barrier film exceeds the length of negative pole piece longer, under the marginal deposition metal ion of negative pole piece formed metal attachment's circumstances, because the barrier film's isolation effect, can reduce the metal attachment at negative pole piece marginal and the overlap joint of anodal pole piece and cause the possibility of short circuit, can improve the battery monomer simultaneously and satisfy the possibility of cycle number demand, has improved the quality of battery monomer.

In some embodiments of the application, the first difference H1 is 6 mm or greater. The first difference H1 is set to be not less than 6 mm, so that the possibility of short circuit caused by overlapping of the metal attachment on the edge of the negative electrode plate and the positive electrode plate can be reduced, the possibility that the battery cell meets the cycle number requirement can be improved, and the quality of the battery cell is improved.

In some embodiments of the present application, the value range of the first difference H1 is greater than or equal to 6mm and less than or equal to 14 mm.

In some embodiments of the application, the separator extends beyond the negative electrode tab at both ends of the first direction, and the difference between the dimension of the separator extending beyond the negative electrode tab at one end of the first direction and the dimension of the separator extending beyond the negative electrode tab 0 at the other end of the first direction is no more than 1 mm. The two ends of the isolating film in the first direction exceed the negative electrode plate, and based on the limitation of corresponding dimensions, the isolating film can play a good isolating role on the negative electrode plate and the positive electrode plate at the two ends, the possibility of short circuit caused by overlapping of metal attachments on the edge of the negative electrode plate and the positive electrode plate is reduced, meanwhile, the possibility that the battery cell meets the cycle times requirement can be improved, and the quality of the battery cell is improved.

In some embodiments of the application, the projection of the positive pole piece onto the negative pole piece is a third projection, the third projection not exceeding the circumferential edge of the negative pole piece. The third projection does not exceed the circumferential edge of the negative electrode plate, so that the area of the negative electrode plate is not smaller than that of the positive electrode plate, the negative electrode plate has larger metal ion deposition area, the possibility of short circuit caused by overlapping of the metal attachments formed by metal ions on the edge of the negative electrode plate and the positive electrode plate is reduced, the possibility that the battery cell meets the cycle number requirement can be improved, and the quality of the battery cell is improved.

In some embodiments of the application, the size of the negative electrode tab in the first direction is a first size, and the size of the positive electrode tab in the first direction is a third size, the first size being greater than the third size. The size of the positive electrode plate is smaller than that of the negative electrode plate in the first direction, so that the negative electrode plate has larger metal ion deposition area, the possibility of short circuit caused by overlapping of a metal attachment formed by metal ions on the edge of the negative electrode plate and the positive electrode plate is reduced, the possibility that the battery meets the cycle number requirement can be improved, and the quality of the battery monomer is improved.

In some embodiments of the present application, the difference of the first dimension minus the third dimension is a third difference H3, the third difference H3 satisfying the following relationship: h3 Not less than 3+ (CW-10)/10; the positive electrode plate comprises a positive electrode active material layer, CW is a value corresponding to the weight of the positive electrode active material in the unit area of the positive electrode active material layer, the unit of CW is mg/cm ², and the unit of the value of the third difference H3 is millimeter. The third difference H3 is set to be H3 which is more than or equal to 3+ (CW-10)/10, the length of the negative electrode plate exceeding the positive electrode plate is longer, the deposition area of the negative electrode plate is larger, the possibility of short circuit caused by overlapping of metal ions at the edge of the negative electrode plate and the positive electrode plate can be reduced, meanwhile, the possibility that the battery cell meets the requirement of the cycle times can be improved, and the quality of the battery cell is improved.

In some embodiments of the application, the third difference H3 is 3 millimeters or greater. The third difference H3 is set to be not less than 3 mm, so that the possibility of short circuit caused by overlapping of metal ions at the edge of the negative electrode plate and the positive electrode plate can be reduced, the possibility that the battery cell meets the cycle number requirement can be improved, and the quality of the battery cell is improved.

In some embodiments of the present application, the third difference H3 has a value range greater than or equal to 3mm and less than or equal to 6 mm.

In some embodiments of the application, at both ends of the first direction, the negative electrode tab exceeds the positive electrode tab, and a difference between a dimension of the negative electrode tab exceeding the positive electrode tab at one end of the first direction and a dimension of the negative electrode tab exceeding the positive electrode tab at the other end of the first direction is no more than 1 millimeter. The two ends of the negative electrode plate in the first direction exceed the positive electrode plate, and the metal attachments at the edges of the two ends of the negative electrode plate can be reduced to cause short circuit with the positive electrode plate based on the limitation of corresponding dimensions, meanwhile, the possibility that the battery cell meets the cycle times is improved, and the quality of the battery cell is improved.

In some embodiments of the present application, an end of the positive electrode tab in the first direction is provided with an insulating layer, and in the first direction, the insulating layer covers and exceeds an edge of the negative electrode tab. Through the isolation effect of the insulating layer, the possibility of short circuit caused by overlap joint of metal attachments formed by metal ions at the edge of the negative electrode plate and the positive electrode plate can be reduced, meanwhile, the possibility that the battery cell meets the cycle number requirement can be improved, and the quality of the battery cell is improved.

In some embodiments of the present application, the battery cell further includes a positive electrode tab, the positive electrode tab is disposed at one end of the positive electrode tab along the first direction, and the isolation film covers a portion of the positive electrode tab; and/or, the battery cell further comprises a negative electrode tab, the negative electrode tab is arranged at one end of the negative electrode pole piece along the first direction, and the isolating film covers part of the negative electrode tab along the first direction. Through setting up anodal utmost point ear and negative pole utmost point ear in the tip of battery monomer along first direction, the part that the barrier film surpassed anodal pole piece and negative pole piece can support the part that anodal utmost point ear and negative pole utmost point ear are in between end cover and the pole piece, has reduced the possibility that the utmost point ear was turned over. Meanwhile, as the lug is supported by the isolating film, when the battery vibrates, the influence of the vibration on the lug is reduced, the problem that the lug is torn is solved, and the installation stability of the lug is improved.

In some embodiments of the application, the battery cell is an alkali metal battery and the negative electrode tab includes a negative electrode current collector coated with a conductive layer.

In some embodiments of the application, the active ion of the alkali metal cell is sodium ion.

A second aspect of the application proposes a battery comprising a battery cell according to the application or according to any embodiment of the application.

A third aspect of the application proposes an electrical consumer and any embodiment of the application proposes a battery for providing electrical energy to the electrical consumer.

The foregoing description is only an overview of the present application, and is intended to be implemented in accordance with the teachings of the present application in order that the same may be more clearly understood and to make the same and other objects, features and advantages of the present application more readily apparent.

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 figures. In the drawings:

FIG. 1 schematically illustrates a schematic structural view of a vehicle provided by some embodiments of the present application;

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

Fig. 3 schematically illustrates a split schematic of a battery cell according to some embodiments of the application;

fig. 4 schematically shows a cross-sectional view of a battery cell;

Fig. 5 schematically shows a cross-sectional view of a battery cell;

Fig. 6 schematically illustrates a schematic view of some battery cells of an embodiment of the present application;

fig. 7 schematically illustrates a schematic view of a battery cell according to some embodiments of the application;

fig. 8 schematically illustrates a cross-sectional view of a stacked arrangement of positive electrode tabs, negative electrode tabs, and separator films according to some embodiments of the application.

Reference numerals in the specific embodiments are as follows:

1000. A vehicle; 100. a battery; 200. a controller; 300. a motor; 10. a case; 11. a first portion; 12. a second portion; 20. a battery cell; 21. an end cap; 211. a negative electrode terminal; 212. a positive electrode terminal; 213. a pressure release mechanism; 22. a housing; 23. an electrode assembly; 231. a negative electrode tab; 232. a positive electrode tab;

400. a positive electrode sheet; 410. a positive electrode current collector; 420. a positive electrode active material layer; 430. an insulating layer;

500. a negative electrode plate; 510. a negative electrode current collector; 520. a conductive layer;

600. A separation film;

L1, a first dimension; l2, second dimension; l3, third dimension; l4, fourth dimension; x, a first direction; y, stacking direction.

Detailed Description

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

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

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

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

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

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

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

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

Rechargeable batteries, which may be referred to as secondary batteries or power batteries, are currently in relatively wide use, including lithium sulfur batteries, sodium lithium ion batteries, magnesium ion batteries, sodium ion batteries, and the like.

Rechargeable batteries typically include one or more battery cells, which typically include a housing and an electrode assembly disposed within the housing and an electrolyte, the electrode assembly being in the electrolyte and typically including a positive electrode tab, a negative electrode tab, and a separator disposed between the negative and positive electrode tabs. The positive electrode plate generally comprises a positive electrode current collector and a positive electrode active substance coated on the positive electrode current collector, metal ions (cations) in the positive electrode active substance are escaped into electrolyte in the charging process of the battery cell, pass through the isolating membrane and reach the negative electrode plate, and the metal ions can be deposited on the negative electrode plate and reduced into metal. The negative electrode plate can be of a design without a negative electrode, and a negative electrode active material can be coated on a negative electrode current collector so as to embed metal ions. In the mode of non-negative electrode design, the negative electrode current collector is not coated with negative electrode active material, a conductive layer can be coated on the negative electrode current collector, the current collector is assisted to deposit metal ions, and the battery cell is also called a battery cell of non-negative electrode design.

In a cell of a non-negative design, metal ions deposit on the negative electrode sheet during charging of the cell, causing the volume of the negative electrode sheet to expand, thereby causing the electrolyte to be squeezed out of the interior of the electrode assembly. In order to meet the storage requirement of the electrolyte, a large space needs to be reserved between the case and the electrode assembly. The larger reserved space is easy to cause the electrode assembly to shake, and the length of the electrode lug needed by the electrode assembly is generally longer, so that the problem that the electrode lug turns over and is in leakage welding or lap-joint short circuit between the electrode lug and the electrode plate is caused easily when the electrode lug and the electrode terminal or the switching piece of the end cover are assembled.

Meanwhile, it was found in the study that there is a possibility that the negative electrode overlaps the positive electrode to cause risk in the electrode assembly of such a non-negative electrode design. This is because, in the process of charging the battery cell, when metal ions are deposited on the negative electrode plate, part of the metal ions are deposited on the edge of the negative electrode plate to form metal attachments, and when the metal attachments at the edge are excessively deposited, the situation that the negative electrode and the positive electrode are overlapped may occur, so that the short circuit of the battery cell is caused.

In order to alleviate the problems, the application provides a battery cell, which comprises a positive pole piece, a negative pole piece and a separation film, wherein the negative pole piece and the positive pole piece are laminated; the barrier film lamination sets up between positive pole piece and negative pole piece, and the projection of positive pole piece to the barrier film is first projection, and the projection of negative pole piece to the barrier film is the second projection, and first projection does not surpass the circumference edge of barrier film, and the second projection does not surpass the circumference edge of barrier film, and at least in first direction, and the size of barrier film is greater than the size of positive pole piece and is greater than the size of negative pole piece, and first direction perpendicular to laminating direction between positive pole piece, barrier film and the negative pole piece.

According to the battery cell, the first projection formed by the positive electrode plate and the second projection formed by the negative electrode plate do not exceed the peripheral edge of the isolating film, so that the positive electrode plate and the negative electrode plate can be isolated by the isolating film, and the possibility of lap-joint short circuit of the positive electrode plate and the negative electrode plate is reduced. And, because at least in first direction, the size of barrier film is greater than the size of anodal pole piece, and the size of barrier film is greater than the size of negative pole piece for the barrier film has the part that surpasss anodal pole piece and negative pole piece, negative pole piece and anodal pole piece like this can set up the tab on the one end of negative pole piece and anodal pole piece along first direction when connecting the tab, and the barrier film surpasses the part of anodal pole piece and negative pole piece like this and can support the tab, has reduced the possibility that the tab turns over, thereby reduced the tab and the pole piece contact that the polarity is opposite and lead to the battery cell short circuit, and reduced the possibility that the tab leaks and welds. Meanwhile, the isolating film has a part exceeding the negative electrode plate, so that under the condition that metal ions are deposited on the edge of the negative electrode plate to form metal attachments, the possibility of short circuit caused by overlapping of the negative electrode and the positive electrode can be reduced due to the isolating effect of the isolating film.

Some embodiments of the application disclose a battery cell that may be used in, but is not limited to, electrical devices such as vehicles, boats, or aircraft. A power supply system having the battery cell, the battery, and the like disclosed in the present application constituting the power utilization device may be used.

Some embodiments of the present application provide an electrical device using a battery as a power source, which may be, but is not limited to, a cell phone, a tablet, a notebook computer, an electrical toy, an electrical tool, a battery car, an electrical car, a ship, a spacecraft, etc. Among them, the electric toy may include fixed or mobile electric toys, such as game machines, electric car toys, electric ship toys, electric plane toys, and the like, and the spacecraft may include planes, rockets, space planes, and spacecraft, and the like.

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

Referring to fig. 1, fig. 1 schematically illustrates a schematic structural diagram of a vehicle 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. The battery 100 is provided in the interior of 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.

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

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

Wherein each battery cell 20 may be a secondary battery or a primary battery; but not limited to, lithium sulfur batteries, sodium ion batteries, or magnesium ion batteries. The battery cell 20 may be in the shape of a cylinder, a flat body, a rectangular parallelepiped, or other shapes, etc.

Referring to fig. 3, fig. 3 schematically illustrates a cross-sectional view of a battery cell according to some embodiments of the application. The battery cell 20 refers to the smallest unit constituting the battery. As shown in fig. 3, the battery cell 20 includes an end cap 21, a case 22, an electrode assembly 23, and other functional components.

The end cap 21 refers to a member that is covered at the opening of the case 22 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 21 may be adapted to the shape of the housing 22 to fit the housing 22. Optionally, the end cover 21 may be made of a material (such as an aluminum alloy) with a certain hardness and strength, so that the end cover 21 is not easy to deform when being extruded and collided, so that the battery cell 20 can have higher structural strength, and the safety performance can be improved. The end cap 21 may be provided with functional components such as electrode terminals (which may include a positive electrode terminal 212 and a negative electrode terminal 211) and the like. The electrode terminals may be used to be electrically connected with the electrode assembly 23 for outputting or inputting electric power of the battery cell 20. In some embodiments, the end cap 21 may also be provided with a pressure relief mechanism 213 for relieving the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. The material of the end cap 21 may be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and some embodiments of the present application are not limited thereto. In some embodiments, insulation may also be provided on the inside of the end cap 21, which may be used to isolate electrical connection components within the housing 22 from the end cap 21 to reduce the risk of short circuits. By way of example, the insulation may be plastic, rubber, or the like.

The case 22 is an assembly for cooperating with the end cap 21 to form an internal environment of the battery cell 20, wherein the formed internal environment may be used to accommodate the electrode assembly 23, the electrolyte, and other components. The case 22 and the end cap 21 may be separate members, and an opening may be provided in the case 22, and the interior of the battery cell 20 may be formed by covering the opening with the end cap 21 at the opening. It is also possible to integrate the end cap 21 and the housing 22, but specifically, the end cap 21 and the housing 22 may form a common connection surface before other components are put into the housing, and when it is necessary to encapsulate the inside of the housing 22, the end cap 21 is then put into place with the housing 22. The housing 22 may be of various shapes and sizes, such as rectangular parallelepiped, cylindrical, hexagonal prism, etc. Specifically, the shape of the case 22 may be determined according to the specific shape and size of the electrode assembly 23. The material of the housing 22 may be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and some embodiments of the present application are not limited thereto.

The electrode assembly 23 is a component in which electrochemical reactions occur in the battery cell 20. One or more electrode assemblies 23 may be contained within the housing 22. The electrode assembly 23 is mainly formed by winding or stacking a pole piece structure in which the positive pole piece 400 and the negative pole piece 500 are integrated, and a separator 600 is generally provided between the positive pole piece 400 and the negative pole piece 500 of the adjacent pole piece structure. Specifically, in some embodiments, as shown in fig. 4, fig. 4 schematically illustrates a cross-sectional view of an electrode assembly 23, and the electrode assembly 23 may be formed by sequentially stacking an entire negative electrode tab 500, an entire separator 600, and an entire positive electrode tab 400 and then winding them; in other embodiments, as shown in fig. 5, fig. 5 schematically shows a cross-sectional view of an electrode assembly 23, and the electrode assembly 23 may be formed by sequentially stacking a plurality of positive electrode tabs 400, a separator 600, and a plurality of negative electrode tabs 500 in such a manner that the separator 600 is disposed between the positive electrode tabs 400 and the negative electrode tabs 500.

The positive electrode tab 400 includes a positive electrode current collector 410 and a positive electrode active material layer 420, and the positive electrode active material layer 420 is coated on the surface of the positive electrode current collector 410. For example, in the lithium ion battery 100, the material of the positive electrode current collector 410 may be an aluminum foil sheet, and the active material of the positive electrode active material layer 420 may be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, or the like. In the sodium ion battery 100, the material of the positive electrode current collector 410 may be an aluminum foil sheet, and the active material of the positive electrode active material layer 420 includes, but is not limited to, at least one of sodium transition metal oxide, polyanion compound, and prussian blue compound.

The negative electrode tab 500 includes a negative electrode current collector 510. The material of the negative electrode current collector 510 may be copper. The negative electrode current collector 510 may be provided with no active material, and in order to enhance the deposition ability of metal ions to the negative electrode current collector 510, a primer material layer may be coated on the negative electrode current collector 510 to form a primer material layer, and the primer material layer may have conductivity, and may also be referred to as a conductive layer, and the primer material layer may increase the specific surface area of the negative electrode current collector 510, thereby increasing the deposition ability of metal ions to the negative electrode current collector. The primer material may be one formed of SP (conductive carbon) and a high binding binder. In some technologies, a negative electrode active material layer may be disposed on the negative electrode current collector 510, and the negative electrode active material layer may be carbon (for example, graphite) or silicon, etc. coated on the surface of the negative electrode current collector 510. In the following embodiments of the present application, unless otherwise specified, negative electrode current collector 510 is described as an example without providing a negative electrode active material layer.

The material of the separator 600 may be PP (polypropylene) or PE (polyethylene).

The positive pole piece can also be connected with a positive pole lug, the positive pole lug is not coated with an active substance layer, the positive pole piece is also connected with a negative pole lug, and the negative pole lug is also not coated with an active substance layer. The positive electrode tab 232 and the negative electrode tab 231 may be located at one end of the electrode assembly 23 together or at both ends of the electrode assembly 23 respectively. During charge and discharge of the battery 100, the positive electrode active material layer 420 reacts with the electrolyte, the positive electrode tab 232 is connected to the positive electrode terminal 212, and the negative electrode tab 231 is connected to the negative electrode terminal 211 to form a current loop.

According to some embodiments of the present application, as shown in fig. 6, 7 and 8, fig. 6 schematically illustrates a schematic view of some battery cells according to some embodiments of the present application, fig. 7 schematically illustrates a schematic view of some battery cells according to some embodiments of the present application, and fig. 8 schematically illustrates a schematic cross-sectional view of a stacked arrangement of a positive electrode tab, a negative electrode tab and a separator according to some embodiments of the present application; the present embodiment proposes a battery cell 20 including a positive electrode tab 400, a negative electrode tab 500, and a separator 600. The negative electrode sheet 500 and the positive electrode sheet 400 are stacked; the isolation film 600 is stacked between the positive electrode sheet 400 and the negative electrode sheet 500, the projection of the positive electrode sheet 400 to the isolation film 600 is a first projection, the projection of the negative electrode sheet 500 to the isolation film 600 is a second projection, the first projection does not exceed the circumferential edge of the isolation film 600, the second projection does not exceed the circumferential edge of the isolation film 600, and at least in the first direction X, the size of the isolation film 600 is larger than the size of the positive electrode sheet 400 and larger than the size of the negative electrode sheet 500, and the first direction X is perpendicular to the stacking direction Y among the positive electrode sheet 400, the isolation film 600 and the negative electrode sheet 500.

In fig. 6 to 7, for ease of understanding, the components such as the case of the battery cell 20 are omitted, and only a partial schematic view of the battery cell 20, specifically, a schematic view of the corresponding portion of the electrode assembly 23 is shown.

The positive electrode sheet 400 and the separator 600, and the separator 600 and the negative electrode sheet 500 are generally adhered to each other, in other words, the positive electrode sheet 400, the separator 600, and the negative electrode sheet 500 are all disposed in parallel at corresponding positions. The direction in which the positive electrode tab 400, the separator 600, and the negative electrode tab 500 are sequentially stacked forms a stacking direction Y between the positive electrode tab 400, the negative electrode tab 500, and the separator 600. The form in which the positive electrode sheet 400, the separator 600 and the negative electrode sheet 500 are sequentially stacked includes the form in which the positive electrode sheet 400, the separator 600 and the negative electrode sheet 500 are stacked to form the electrode assembly 23, as shown in fig. 5; also included are separator 600, positive electrode sheet 400 and negative electrode sheet 500, which are stacked in sequence and wound to form the form of electrode assembly 23, as shown in fig. 4. In the case where the separator 600, the positive electrode sheet 400, and the negative electrode sheet 500 are wound to form the electrode assembly 23, the lamination direction Y between the positive electrode sheet 400, the negative electrode sheet 500, and the separator 600 is the radial direction of the wound electrode assembly, that is, the lamination direction is the direction in which the large faces of the positive electrode sheet 400, the negative electrode sheet 500, and the separator 600 are disposed in this order, and referring to fig. 4, the lamination direction is an arbitrary direction within the paper surface, and the first direction X is a direction perpendicular to the paper surface. As shown in fig. 5, in the case where the plurality of positive electrode tabs 400 and the plurality of negative electrode tabs 500 are stacked to form the battery cell 20, the stacking direction Y between the positive electrode tabs 400, the negative electrode tabs 500, and the separator 600 is the up-down direction in fig. 5, and the first direction X may be the left-right direction or the direction perpendicular to the paper surface.

The positive electrode sheet 400 is understood as a portion of the positive electrode current collector 410 coated with the positive electrode active material layer 420, that is, the positive electrode current collector 410 corresponding to the positive electrode active material layer 420 is the positive electrode sheet 400 defined in this embodiment, and the region of the positive electrode current collector 410 not coated with the active material is the positive electrode tab 232. In some cases, the positive electrode current collector 410 also needs to serve as a carrier for the insulating layer 430, in which case, a part of the position of the positive electrode current collector 410 is coated with the positive electrode active material layer 420 and forms the positive electrode tab 400, the positive electrode current collector 410 also has a part of the position not having the positive electrode active material attached thereto, which is used as a coating region of the insulating layer 430, and these positions of the positive electrode current collector 410, which are used to coat the insulating layer 430, are understood as a part of the positive electrode tab 232 in this embodiment. Referring to fig. 6 to 8, the positive electrode active material layer 420 corresponds to the positive electrode tab 400, the positive electrode collector 410 protruding from the positive electrode tab 400 and covered by the insulating layer 430, and the protruding portion protruding from the insulating layer 430 form the positive electrode tab 232. More specifically, as shown in fig. 8, the boundary between the insulating layer 430 and the positive electrode active material layer 420 is a boundary, the positive electrode tab 400 refers to a portion formed by the positive electrode current collector 410 on the left side of the boundary and the positive electrode active material layer 420 coated thereon, and the positive electrode tab 232 is a portion of the positive electrode current collector 410 on the right side of the boundary, wherein the positive electrode current collector 410 attached by the insulating layer 430 is also understood as a portion of the positive electrode tab 232.

The first projection is a projection of the positive electrode tab 400, and since the positive electrode active material layer 420 forming the positive electrode tab 400 coincides with the positive electrode tab 400, the size of the positive electrode tab 400 can be understood with reference to the positive electrode active material layer 420. Specifically, the first projection is understood to be an orthographic projection of the positive electrode active material layer 420 on the separator 600 along the lamination direction Y between the positive electrode sheet 400, the negative electrode sheet 500 and the separator 600, and since the positive electrode sheet 400 and the separator 600 are generally disposed in a bonded manner, the surface of the positive electrode sheet 400 to which the separator 600 is connected coincides with the first projection, more specifically, the shape, size, extending direction, etc. of the positive electrode sheet 400 and the first projection are the same. The first projection does not exceed the circumferential edge of the separator 600, and it is understood that the size of the positive electrode tab 400 is equal to or smaller than the size of the separator 600 in any direction of the plane in which the separator 600 is located. The size of the separator 600 is larger than the size of the positive electrode tab 400 at least in the first direction X, and it is understood that the size of the separator 600 along this direction is larger than the size of the positive electrode tab 400 along this direction at least in one direction perpendicular to the stacking direction Y between the positive electrode tab 400, the negative electrode tab 500, and the separator 600, so that the separator 600 has a portion protruding beyond the edge of the positive electrode tab 400. Specifically, along the first direction X, one end of the separator 600 may protrude out of the positive electrode sheet 400, that is, one end of the separator 600 is aligned with one end of the positive electrode sheet 400, and the other end of the separator 600 is located outside the other end of the positive electrode sheet 400; along the first direction X, the separator 600 may also have both ends protruding from the positive electrode sheet 400, that is, as shown in fig. 6, both ends of the separator 600 are located outside the ends corresponding to the positive electrode sheet 400.

The negative electrode tab 500 includes a negative electrode current collector 510, and a negative electrode active material layer may be disposed on the negative electrode current collector 510 to form a battery cell 20 having a negative electrode; the negative electrode current collector 510 may be provided with a conductive layer 520 to form the battery cell 20 without a negative electrode. The negative electrode tab of this embodiment is a portion of the negative electrode current collector coated with a negative electrode active material or a conductive layer. Specifically, in the case of the negative electrode arrangement, the negative electrode tab 500 according to the present embodiment may be understood as a portion of the negative electrode current collector 510 coated with the negative electrode active material layer, that is, the negative electrode current collector 510 corresponding to the negative electrode active material layer is the negative electrode tab 500 defined in the present embodiment, and the region of the negative electrode current collector 510 that is not coated is the negative electrode tab 231. In the case of no negative electrode design, the negative electrode tab 500 described in this embodiment may be understood as a portion of the negative electrode current collector 510 coated with the conductive layer 520, that is, the negative electrode current collector 510 corresponding to the conductive layer 520 is the negative electrode tab 500 defined in this embodiment, and the region of the negative electrode current collector 510 not coated with the conductive layer or the active material is the negative electrode tab 231. Referring to fig. 6 to 8, in this embodiment, the non-negative electrode design is taken as an example, and the conductive layer 520 is the same or substantially the same as the width (the width is the dimension in the left-right direction in fig. 6 and 7) of the corresponding negative electrode current collector 510, and is matched with the corresponding negative electrode current collector to form a negative electrode tab 500, and the protruding portion protruding from the negative electrode tab 500 forms a negative electrode tab 231. More specifically, as shown in fig. 8, with the edge of the negative conductive layer 520 as a boundary, the negative electrode tab 500 refers to a portion of the negative electrode current collector 510 on the left side of the boundary, and the conductive layer 520 coated thereon together form a portion, and the negative electrode tab 231 is a portion of the negative electrode current collector 510 on the right side of the boundary.

The second projection is a projection of the negative electrode tab 500, and since the conductive layer 520 or the negative electrode active material layer forming the negative electrode tab 500 is the same or substantially the same size as the negative electrode current collector 510, the size of the negative electrode tab 500 can be understood with reference to the conductive layer 520 or the negative electrode active material layer. Specifically, the second projection is understood as an orthographic projection of the negative electrode sheet 500 on the separator 600 along the lamination direction Y between the positive electrode sheet 400, the negative electrode sheet 500 and the separator 600, and since the negative electrode sheet 500 and the separator 600 are generally disposed in a bonded manner, the surface of the negative electrode sheet 500 connected to the separator 600 coincides with the second projection, more specifically, the shape, the size, the extending direction, etc. of the negative electrode sheet 500 and the second projection are the same. The second projection does not exceed the circumferential edge of the separator 600, which is understood to mean that the size of the negative electrode tab 500 is equal to or smaller than the size of the separator 600 in any direction of the plane in which the separator 600 lies. The size of the separator 600 is larger than the size of the negative electrode tab 500 at least in the first direction X, and it is understood that the size of the separator 600 along this direction is larger than the size of the negative electrode tab 500 along this direction at least in one direction of the plane in which the separator 600 is located, so that the separator 600 has a portion protruding beyond the edge of the negative electrode tab 500. Specifically, along the first direction X, one end of the separator 600 may protrude out of the negative electrode tab 500, that is, one end of the separator 600 is aligned with one end of the negative electrode tab 500, and the other end of the separator 600 is located outside the other end of the negative electrode tab 500; along the first direction X, the separator 600 may also have both ends protruding from the negative electrode tab 500, that is, as shown in fig. 6, both ends of the separator 600 are located outside the ends corresponding to the negative electrode tab 500.

The first projection formed by the positive electrode plate 400 and the second projection formed by the negative electrode plate 500 of the battery cell 20 in this embodiment do not exceed the circumferential edge of the isolating film 600, so that the positive electrode plate 400 and the negative electrode plate 500 can be isolated by the isolating film 600, and the possibility of overlap short circuit between the positive electrode plate 400 and the negative electrode plate 500 is reduced. In addition, at least in the first direction X, the size of the isolating film 600 is greater than the size of the positive electrode plate 400, and the size of the isolating film 600 is greater than the size of the negative electrode plate 500, so that the isolating film 600 has a portion exceeding the positive electrode plate 400 and the negative electrode plate 500, and thus, when the negative electrode plate 500 and the positive electrode plate 400 are connected with the tab, the tab can be arranged at one end of the negative electrode plate 500 and the positive electrode plate 400 along the first direction X, and thus, the portion of the isolating film 600 exceeding the positive electrode plate 400 and the negative electrode plate 500 can support the tab, the possibility of turning over the tab is reduced, and the possibility of short circuit of the battery 100 caused by contact between the tab and the electrode plate with opposite polarity is reduced, and the possibility of tab missing welding is reduced.

The battery cell 20 of this embodiment may be of a non-negative electrode design, the negative electrode current collector 510 may be coated with a conductive layer 520, that is, a primer material, as a deposition carrier for metal ions (for example, sodium ions in the sodium ion battery 100 or lithium ions in the lithium ion battery 100, in this embodiment, the sodium ion battery 100 is taken as an example), and the conductive layer 520 may be coated with a primer material on the negative electrode current collector 510 to increase the specific surface area of the negative electrode current collector 510, so as to improve the deposition capability of the metal ions on the negative electrode current collector 510. Unlike the negative electrode tab 500 having a negative electrode active material layer, in the negative electrode-free battery cell 20, metal ions may be preferentially deposited on a negative electrode active material (e.g., graphite), and in the negative electrode-free battery cell 20, a portion of the metal ions may be deposited on the edge of the negative electrode tab 500 (i.e., the negative electrode current collector 510) and form a metal attachment on the edge, increasing the risk of the negative electrode tab (sodium metal) overlapping the positive electrode tab 400 or the positive electrode tab 232.

In the battery cell 20 of this embodiment, since the isolating film 600 has a portion beyond the negative electrode plate 500, in the case that the metal attachment is deposited on the edge of the negative electrode plate 500, the possibility of short circuit caused by overlapping between the metal attachment on the edge of the negative electrode plate 500 and the positive electrode plate 400 or the positive electrode tab 232 can also be reduced due to the isolating effect of the isolating film 600.

As the number of charge and discharge cycles of the battery 100 increases, the amount of metal adherent deposited at the edges of the negative electrode tab 500 increases, and accordingly, the risk of the battery 100 overlapping the positive electrode tab 400 or the positive electrode tab 232 due to the metal adherent deposited on the negative electrode tab 500 increases. In this embodiment, the separator 600 has a portion beyond the negative electrode plate 500, so as to increase the number of charge and discharge cycles of the battery cell 20, thereby increasing the possibility that the battery cell 20 meets the cycle number requirement, and improving the quality of the battery cell 20.

In addition, in the battery cell 20 without the negative electrode design, the metal attachment formed by the metal ions is deposited on the negative electrode current collector 510 during the charging process, the volume of the battery cell 20 is expanded, the electrolyte is easy to extrude from the inside of the pole piece, a larger residual space is needed to be used as a space for extruding the electrolyte, the connection distance between the tab and the end cover 21 is longer, and when the tab of the battery cell 20 without the negative electrode design is assembled with the end cover or the adapter piece, the tab turnover and other problems are more easy to occur compared with the battery cell 20 provided with the negative electrode active material layer. In which the battery cell 20 is generally disposed in the case 22, the residual space is understood to be a space in the case 22 where the battery cell 20 and the electrolyte are not disposed, that is, a space remaining after the case 22 is disposed with the battery cell 20 and the electrolyte.

The isolating film 600 of the battery cell 20 of this embodiment may have a portion that exceeds the positive electrode plate 400 and the negative electrode plate 500 at the end where the positive electrode plate 400 and the negative electrode plate 500 are disposed, so that the portion of the isolating film 600 that exceeds the positive electrode plate 400 and the negative electrode plate 500 may support the portion of the tab between the end cover 21 and the electrode plate, thereby reducing the possibility of turning over the tab. Meanwhile, since the tab is supported by the separator 600, the influence of vibration to which the tab is subjected is reduced when the battery 100 vibrates, the problem that the tab is easily broken at the junction with the end cover 21 (electrode terminal of the end cover 21) or the pole piece is alleviated, and the mounting stability of the tab is improved.

According to some embodiments of the present application, optionally, as shown in fig. 6, in the first direction X, the size of the negative electrode tab 500 is a first size L1, in the first direction X, the size of the separator 600 is a second size L2, the second size L2 is greater than the first size L1, the difference of the second size L2 minus the first size L1 is a first difference H1, and the first difference H1 satisfies the following relationship: h1 Not less than 6+ (CW-10)/10; the positive electrode sheet 400 includes a positive electrode active material layer 420, CW is a value corresponding to the weight of the positive electrode active material in a unit area of the positive electrode active material layer 420, CW is a unit of mg/cm ² (milligrams per cubic centimeter), and the first difference H1 is a unit of millimeter.

The first dimension L1 may be the maximum distance between two opposite sides of the negative electrode tab 500 in the first direction X, as shown in fig. 6, the opposite sides of the negative electrode tab 500 in the first direction X are generally parallel, so that the distances of the opposite sides of the negative electrode tab 500 in the first direction X are the same.

The second dimension L2 may be the maximum distance between the opposite sides of the barrier film 600 in the first direction X, as shown in fig. 6, the opposite sides of the barrier film 600 in the first direction X are generally parallel, so the distance between the opposite sides of the barrier film 600 in the first direction X is the same.

The first difference H1 is the dimension of the separator 600 beyond the negative electrode tab 500 in the first direction X. The separator 600 may extend beyond the negative electrode tab 500 at both ends of the first direction X, and accordingly, the first difference H1 is the sum of the dimensions of the separator 600 extending beyond the negative electrode tab 500 at both ends of the first direction X.

CW can be simply considered as the areal density of the positive electrode active material layer 420, and specifically, the weight per unit area of the positive electrode active material. In order to correspond to the unit (millimeter) of the current first difference H1, CW is a weight value in milligrams per square centimeter of the positive electrode active material layer 420. CW is calculated only from the value, and the value of the first difference H1 in mm is finally obtained. The unit area or per square centimeter is generally calculated as the area of the large surface of the positive electrode active material layer 420, regardless of the thickness of the positive electrode active material layer 420, so that CW is positively correlated with the thickness of the positive electrode active material layer 420, i.e., the larger the thickness of the positive electrode active material layer 420, the larger the CW is in general.

CW may be obtained by weighing and calculating. Specifically, a certain area of the positive electrode current collector 410 is taken first, the weight of the positive electrode current collector 410 is weighed, and then a certain area of the positive electrode sheet 400 coated with the positive electrode active material layer 420 is taken, and the weight of the positive electrode sheet 400 is weighed. The weight of the positive electrode collector 410 per unit area and the weight of the positive electrode tab 400 per unit area can be converted from the two weights, the weight of the positive electrode active material per unit area can be obtained by subtracting the weight of the positive electrode collector 410 per unit area from the weight of the positive electrode tab 400 per unit area, and the value corresponding to the weight of the positive electrode active material per unit area is taken as CW.

In the case where the positive electrode active material layer 420 is formed on both sides of the positive electrode current collector 410 by coating the positive electrode active material on both sides, the weight of the positive electrode current collector 410 per unit area is calculated by calculating the area of both sides of the positive electrode current collector 410. Similarly, the weight of the positive electrode sheet 400 per unit area is calculated as the area of both sides. That is, CW is a value of the weight of the positive electrode active material on one surface of the positive electrode current collector 410.

The value CW corresponding to the weight of the positive electrode active material in the unit area of the positive electrode active material layer 420 may be set to be greater than 0mg/cm ² and less than or equal to 30mg/cm ², so that the internal resistance of the battery cell 20 may be reasonable and the processing may be convenient. The larger the weight of the positive electrode active material in the unit area of the positive electrode active material layer 420 (that is, the larger the CW), the larger the amount of metal ions that the negative electrode tab 500 needs to carry, so that the problem of positive and negative electrode overlap short-circuiting is more likely to occur.

In this embodiment, the battery cell 20 may be a battery cell 20 without a negative electrode design, the first difference H1 is set to be greater than or equal to 6+ (CW-10)/10, the length of the isolating film 600 exceeding the negative electrode plate 500 is longer, and under the condition that metal ions are deposited at the edge of the negative electrode plate 500, the possibility of short circuit caused by overlapping of the metal ions at the edge of the negative electrode plate 500 and the positive electrode plate 400 can be reduced due to the isolating effect of the isolating film 600, and meanwhile, the possibility that the battery cell 2 meets the cycle number requirement can be improved, and the quality of the battery cell 2 is improved. And, establish the positive correlation with the first difference by weight (i.e., CW) of the positive electrode active material in the unit area, the more suitable first difference can be reasonably selected according to the weight of the positive electrode active material in the unit area, and the more reasonable length of the separator 600 beyond the negative electrode plate 500 can be selected.

It should be noted that, the maximum value of the second dimension L2 is limited by the residual space of the battery cell 20, and generally, the maximum value of the second dimension L2 of the separator 600 is smaller than the dimension of the housing 22 along the first direction X, so that the battery cell 20 can be mounted in the housing 22; meanwhile, the maximum value of the second dimension L2 should be designed such that the separator 600 does not affect the welding of the positive and negative electrode tabs 232 and 231 with the end caps or the tabs. The weight of the positive electrode active material in the unit area of the positive electrode active material layer 420 and the first size L1 may be set according to the electricity demand of the battery cell 20, etc. Specifically, according to the electric quantity requirement of the battery cell 20, the residual space of the battery cell 20 can be calculated, and the distance between the negative electrode tab 500 and the casing 22 can be calculated through the residual space, so that the maximum value of the second dimension L2, i.e., the first difference H1, can be determined according to the distance.

According to some embodiments of the application, optionally, the first difference H1 is greater than or equal to 6 millimeters.

The first difference H1 may be set to be greater than or equal to 6 mm in the case where the weight of the positive electrode active material per unit area of the positive electrode active material layer 420 is any value. For example, in the case where the weight of the positive electrode active material per unit area of the positive electrode active material layer 420 cannot be known, the first difference H1 may be set to 6 mm or more when the first difference H1 is designed.

When the value CW corresponding to the weight of the positive electrode active material per unit area of the positive electrode active material layer 420 is 10mg/cm ² or less, the first difference H1 may be not less than 6mm, and specifically may be 6 mm. In the case where the value CW corresponding to the weight of the positive electrode active material in the unit area of the positive electrode active material layer 420 is greater than 10mg/cm ², the first difference value H1 is not less than 6+ (CW-10)/10, such that the first difference value H1 is generally greater than 6 millimeters, the corresponding first difference value H1 may be set according to the value CW corresponding to the weight of the positive electrode active material in the unit area of the positive electrode active material layer 420.

The first difference H1 may specifically be 6 mm, 6.1 mm, 6.2 mm, 6.5 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, etc.

The battery cell 20 of this embodiment may be a battery cell 20 without a negative electrode design, and the first difference H1 is set to be not less than 6 mm, so that the possibility of short circuit caused by overlapping of the metal attachment on the edge of the negative electrode plate 500 and the positive electrode plate 400 can be reduced, and meanwhile, the possibility that the battery cell 20 meets the cycle number requirement can be improved, and the quality of the battery cell 20 is improved.

According to some embodiments of the application, optionally, the first difference H1 has a value range greater than or equal to 6mm and less than or equal to 14 mm.

The first difference H1 may be accurate to a position after the decimal point, and the actual error may be in the range of 0.1mm in the actual design.

In this embodiment, the upper limit of the first difference H1 is set to 14 mm, so that the cycle times requirement of most of the battery cells 20 can be met, and the spacer film 600 is not too long, which is beneficial to the reasonable design of the battery cells 20.

According to some embodiments of the application, optionally, at both ends of the first direction X, the separator exceeds the negative electrode tab, and a difference between a dimension of the separator 600 exceeding the negative electrode tab 500 at one end of the first direction X and a dimension of the separator 600 exceeding the negative electrode tab 500 at the other end of the first direction X is not more than 1mm.

That is, the projections (i.e., the second projections) of the negative electrode tab 500 to the separator 600 are all located inside the two ends of the separator 600 in the first direction X, so that the two ends of the separator 600 in the first direction X exceed the negative electrode tab 500, and the dimension difference between the two exceeding ends is not more than 1 millimeter. Specifically, the difference may be 0 mm, that is, the separator is the same in size beyond the negative electrode sheet at both ends in the first direction; the difference may also be 0.5mm, for example, the separator 600 has a dimension exceeding the negative electrode tab 500 by 3 mm at one end in the first direction X, and the separator 600 has a dimension exceeding the negative electrode tab 500 by 3.5 mm at the other end in the first direction X.

According to the embodiment, the two ends of the isolating film 600 in the first direction X exceed the negative electrode plate 500, and based on the limitation of corresponding dimensions, the isolating film 600 can well isolate the negative electrode plate 500 from the positive electrode plate 400 at the two ends, so that the possibility of short circuit caused by overlapping of metal attachments at the edge of the negative electrode plate 500 and the positive electrode plate 400 is reduced, the possibility of meeting cycle times requirements of the battery cell 20 is improved, and the quality of the battery cell 20 is improved.

Optionally, as shown in fig. 6-8, the projection of the positive pole piece 400 to the negative pole piece 500 is a third projection, which does not exceed the circumferential edge of the negative pole piece 500, according to some embodiments of the present application.

The third projection is a positive projection of the positive electrode sheet 400 to the negative electrode sheet 500, and the third projection does not exceed the circumferential edge of the negative electrode sheet 500, which is understood to mean that the size of the positive electrode sheet 400 is less than or equal to the negative electrode sheet 500.

According to the embodiment, the third projection does not exceed the circumferential edge of the negative electrode plate 500, so that the area of the negative electrode plate 500 is not smaller than that of the positive electrode plate 400, the negative electrode plate 500 has larger metal ion deposition area, the possibility of short circuit caused by overlapping of metal attachments on the edge of the negative electrode plate 500 and the positive electrode plate 400 is reduced, the possibility that the battery cell 20 meets the cycle number requirement can be improved, and the quality of the battery cell 20 is improved.

According to some embodiments of the present application, optionally, as shown in fig. 6 to 8, in the first direction X, the size of the negative electrode tab 500 is a first size L1, and in the first direction X, the size of the positive electrode tab 400 is a third size L3, and the first size L1 is greater than the third size L3.

The third dimension L3 may be the maximum distance between the opposite sides of the positive electrode tab 400 in the first direction X, as shown in fig. 6, the opposite sides of the positive electrode tab 400 in the first direction X are generally parallel, so the distance between the opposite sides of the positive electrode tab 400 in the first direction X is the same.

Along the first direction X, the negative electrode tab 500 may have one end protruding the positive electrode tab 400, that is, one end of the negative electrode tab 500 is aligned with one end of the positive electrode tab 400, and the other end of the negative electrode tab 500 is located outside the other end of the positive electrode tab 400; along the first direction X, the negative electrode tab 500 may also have both ends protruding from the positive electrode active material layer 420, that is, both ends of the negative electrode tab 500 are located outside the corresponding ends of the positive electrode tab 400, as shown in fig. 6 to 8.

In this embodiment, the size of the positive electrode plate 400 is smaller than the size of the negative electrode plate 500 in the first direction X, so that the negative electrode plate 500 has a larger deposition area of metal attachments, the possibility of short circuit caused by overlapping of metal ions at the edge of the negative electrode plate 500 and the positive electrode plate 400 is reduced, the possibility that the battery cell 20 meets the cycle number requirement is improved, and the quality of the battery cell 20 is improved.

According to some embodiments of the application, optionally, the difference of the first dimension L1 minus the third dimension L3 is a third difference H3, and the third difference H3 satisfies the following relationship: h3 Not less than 3+ (CW-10)/10; the positive electrode sheet 400 includes a positive electrode active material layer 420, CW is a value corresponding to the weight of the positive electrode active material in a unit area of the positive electrode active material layer 420, CW is a unit of mg/cm ², and the third difference H3 is a unit of millimeter.

The third difference H3 is the dimension of the negative electrode tab 500 in the first direction X beyond the positive electrode tab 400. The negative electrode tab 500 may extend beyond the positive electrode tab 400 at both ends of the first direction X, and correspondingly, the third difference H3 is the sum of the dimensions of the separator 600 extending beyond the positive electrode tab 400 along both ends of the first direction X.

The battery cell 20 of this embodiment may be a battery cell 20 without a negative electrode design, where the third difference H3 is set to be greater than or equal to H3+ (CW-10)/10, the length of the negative electrode plate 500 exceeding the positive electrode active material layer 420 is longer, the deposition area of the negative electrode plate 500 may be larger, the possibility of short circuit caused by overlapping of the metal attachment on the edge of the negative electrode plate 500 and the positive electrode plate 400 may be reduced, and meanwhile, the possibility that the battery cell 20 satisfies the cycle number requirement may be improved, and the quality of the battery cell 20 is improved. And, establish the positive correlation with the third difference value H3 by the weight of the positive electrode active material in the unit area (CW), can rationally select the more suitable third difference value H3 according to the weight of the positive electrode active material in the unit area, and the length of the negative electrode pole piece 500 exceeding the positive electrode piece 400 is more rationally selected.

According to some embodiments of the application, optionally, the third difference H3 is 3 mm or more.

The third difference H3 may be set to be 3 mm or more in the case where the weight of the positive electrode active material per unit area of the positive electrode active material layer 420 is any value. For example, in the case where the weight of the positive electrode active material per unit area of the positive electrode active material layer 420 cannot be known, the third difference H3 may be set to 3 mm or more when the third difference H3 is designed.

When the value CW corresponding to the weight of the positive electrode active material per unit area of the positive electrode active material layer 420 is 10mg/cm ² or less, the third difference H3 may be not less than 3 mm, and specifically may be 3 mm. In the case where the value CW corresponding to the weight of the positive electrode active material per unit area of the positive electrode active material layer 420 is greater than mg/cm ², the third difference H3 is greater than or equal to 3+ (CW-10)/10 such that the third difference H3 is generally greater than 3 millimeters, the corresponding third difference H3 may be set according to the value CW corresponding to the weight of the positive electrode active material per unit area of the positive electrode active material layer 420.

The third difference H3 may be 3 mm, 3.1 mm, 3.2 mm, 3.5 mm, 4 mm, 5mm, 6 mm.

The battery cell 20 of this embodiment may be a battery cell 20 without a negative electrode design, and the third difference H3 is set to be not less than 3 mm, so that the possibility of short circuit caused by overlapping of metal ions at the edge of the negative electrode plate 500 and the positive electrode plate 400 can be reduced, and meanwhile, the possibility that the battery cell 20 meets the cycle number requirement can be improved, and the quality of the battery cell 20 is improved.

According to some embodiments of the application, optionally, the third difference H3 has a value range greater than or equal to 3 mm and less than or equal to 6 mm.

The third difference H3 may be accurate to a position after the decimal point, and the actual error may be in the range of 0.1mm in the actual design.

In this embodiment, the upper limit of the third difference H3 is set to 6 mm, which can meet the cycle number requirement of most battery cells 20, and the length between the negative electrode pole piece 500 and the positive electrode pole piece 400 is not too long, which is beneficial to the reasonable design of the battery cells 20.

Optionally, according to some embodiments of the present application, at both ends of the first direction X, the negative electrode tab 500 exceeds the positive electrode tab 400, and a difference between a dimension of the negative electrode tab 500 exceeding the positive electrode tab 400 at one end of the first direction X and a dimension of the negative electrode tab 500 exceeding the positive electrode tab 400 at the other end of the first direction X is not more than 1 mm.

That is, the projections (i.e., the third projections) of the positive electrode tab 400 to the negative electrode tab 500 are all located inside the two ends of the negative electrode tab 500 in the first direction X, so that the two ends of the negative electrode tab 500 in the first direction X exceed the positive electrode tab 400, and the dimension difference between the two exceeding ends is not more than 1 millimeter. Specifically, the difference may be 0 mm, that is, the dimensions of the negative electrode tab 500 exceeding the positive electrode tab 400 at both ends in the first direction are the same; the difference may also be 0.5 mm, for example, the negative electrode tab 500 has a dimension exceeding the positive electrode tab 400 by 1.5 mm at one end in the first direction X, and the negative electrode tab 500 has a dimension exceeding the positive electrode tab 400 by 2 mm at the other end in the first direction X.

Through the negative pole piece 500 both ends in the first direction X surpass positive pole piece 400 to based on the restriction of corresponding size, can reduce the metal attachment of negative pole piece 500 both ends edge and positive pole piece 400 overlap joint and cause the possibility of short circuit, can improve the possibility that battery cell 20 satisfies cycle number demand simultaneously, improved the quality of battery cell 20.

According to some embodiments of the present application, optionally, as shown in fig. 7 and 8, an end of the positive electrode tab 400 in the first direction X is provided with an insulating layer 430, and the insulating layer 430 covers an edge of the negative electrode tab 500 and exceeds the edge of the negative electrode tab 500 in the first direction X.

The insulating layer 430 covers the edge of the negative electrode tab 500 and exceeds the edge of the negative electrode tab 500, which means that the end of the negative electrode tab 500 corresponding to the insulating layer 430 is covered by the insulating layer 430, and the insulating layer 430 exceeds the edge of the end of the insulating layer 430, in other words, the projection of the end of the negative electrode tab 500 corresponding to the insulating layer 430 is located in the insulating layer 430.

The insulating layer 430 is a layer formed of an insulating material, and specifically, the insulating layer 430 may be formed by coating an insulating material on a portion of the positive electrode collector 410 where the positive electrode tab 400 is not formed, that is, a portion of the positive electrode collector 410 where the positive electrode active material layer 420 is not coated. The insulating layer 430 may cover a portion of the positive electrode tab 232, and the insulating layer 430 may perform an insulating function and may also support the positive electrode tab 232.

The dimension of the insulating layer 430 along the first direction X is defined as a fourth dimension L4, and a sum of the fourth dimension L4 and the third dimension L3 is greater than the first dimension L1. The fourth dimension L4 is the maximum distance between the opposite sides of the insulating layer 430 along the first direction X. The insulating layer 430 is generally associated with the position of the positive electrode tab 232, that is, the insulating layer 430 is generally disposed at the end of the positive electrode current collector 410 connected to the positive electrode tab 232.

In general, in the first direction X, the third dimension L3 of the positive electrode sheet 400 is smaller than the first dimension L1 of the negative electrode sheet 500, and the sum of the fourth dimension L4 and the third dimension L3 is larger than the first dimension L1, which is equivalent to increasing the dimension of the insulating layer 430 in the first direction X, and the isolation effect of the insulating layer 430 can reduce the possibility of short circuit caused by overlapping between the metal attachment on the edge of the negative electrode sheet 500 and the positive electrode sheet 400, and can improve the possibility that the battery cell 20 meets the cycle number requirement, thereby improving the quality of the battery cell 20.

In the case where the insulating layer 430 is provided, the projection of the insulating layer 430 onto the insulating film 600 may not exceed the insulating film 600, that is, the insulating layer 430 may not exceed the circumferential edge of the insulating film 600. The maximum size of the insulating layer 430 may refer to the maximum size of the separation film 600, i.e., as shown in fig. 7 and 8, the insulating layer 430 may be disposed close to the edge of the separation film 600, but generally slightly lower than the edge of the separation film 600.

According to some embodiments of the present application, optionally, the battery cell 20 further includes a positive electrode tab 232, the positive electrode tab 232 is disposed at one end of the positive electrode tab 400 along the first direction X, and the isolating film 600 covers a portion of the positive electrode tab 232; and/or, the battery cell 20 further includes a negative electrode tab 231, the negative electrode tab 231 is disposed at one end of the negative electrode tab 500 along the first direction X, and the isolating film 600 covers a portion of the negative electrode tab 231.

As shown in fig. 6 to 8, the positive electrode tab 232 and the negative electrode tab 231 may be located at the same end of the battery cell 20 in the first direction X. In other embodiments, the positive tab 232 and the negative tab 231 may also be located at different ends of the battery cell 20 along the first direction X.

Through setting up anodal utmost point ear 232 and negative pole utmost point ear 231 in battery cell 20 along the both ends of first direction X, the part that barrier film 600 surpassed anodal pole piece 400 and negative pole piece 500 can support the part that anodal utmost point ear 232 and negative pole utmost point ear 231 are in between end cover 21 and the pole piece, has reduced the possibility that the utmost point ear turns over. Meanwhile, since the tab is supported by the separator 600, the influence of vibration to which the tab is subjected is reduced when the battery 100 vibrates, the problem that the tab is easily broken at the junction with the end cover 21 (electrode terminal of the end cover 21) or the pole piece is alleviated, and the mounting stability of the tab is improved.

According to some embodiments of the present application, optionally, the battery cell 20 is an alkali metal battery, and the negative electrode tab 500 includes a negative electrode current collector 510, and the negative electrode current collector 510 is coated with a conductive layer 520.

The negative electrode current collector 510 is coated with a conductive layer 520, which is understood to mean that the battery cell 20 is of a non-negative electrode design.

According to some embodiments of the application, the active ion of the alkali metal cell is sodium ion.

According to some embodiments of the present application, a battery 100 is provided, and the battery 100 includes a battery cell 20 according to the present application or any embodiment of the present application.

According to some embodiments of the present application, an electrical device is provided, and a battery 100 provided in an embodiment of the present application, the battery 100 is used for providing electrical energy for the electrical device.

The powered device may be any of the devices or systems described above that employ battery 100.

According to some embodiments of the present application, optionally, as shown in fig. 6 to 8, the present embodiment proposes a battery cell 20 including a positive electrode tab 400, a negative electrode tab 500, and a separator 600. The negative electrode sheet 500 and the positive electrode sheet 400 are stacked; the isolation film 600 is disposed between the positive electrode sheet 400 and the negative electrode sheet 500, the projection of the positive electrode sheet 400 to the isolation film 600 is a first projection, the projection of the negative electrode sheet 500 to the isolation film 600 is a second projection, the first projection does not exceed the circumferential edge of the isolation film 600, the second projection does not exceed the circumferential edge of the isolation film 600, and at least in the first direction X, the size of the isolation film 600 is larger than the size of the positive electrode sheet 400, and the size of the isolation film 600 is larger than the size of the negative electrode sheet 500, and the first direction X is perpendicular to the lamination direction Y between the positive electrode sheet 400, the negative electrode sheet 500 and the isolation film 600. The battery cell 20 further includes a positive electrode tab 232 and a negative electrode tab 231, wherein the positive electrode tab 232 is disposed at one end of the positive electrode tab 400 along the first direction X, and the negative electrode tab 231 is disposed at an end of the negative electrode tab 500 along the first direction X. The negative electrode tab 500 includes a negative electrode current collector 510, and a conductive layer 520 is coated on the negative electrode current collector 510; the positive electrode sheet 400 includes a positive electrode current collector 410, a positive electrode active material layer 420 is disposed on the positive electrode current collector 410, an insulating layer 430 is disposed at an end of the positive electrode sheet 400 along the first direction X, and a sodium ion active material is coated in the positive electrode active material layer 420.

The size of the negative electrode tab 500 in the first direction X is the first size L1, and the size of the separator 600 in the first direction X is the second size L2. In the first direction X, the size of the positive electrode tab 400 is the third size L3, and in the first direction X, the size of the insulating layer 430 is the fourth size L4. The difference of the second dimension L2 minus the first dimension L1 is a first difference H1, and the first difference H1 satisfies the following relationship: h1 Not less than 6+ (CW-10)/10; and, the first difference H1 is not less than 6 mm. The difference of the first dimension L1 minus the third dimension L3 is a third difference H3, and the third difference H3 satisfies the following relationship: h3 Not less than 3+ (CW-10)/10, and the third difference H3 is not less than 3 mm. The sum of the fourth dimension L4 and the third dimension L3 is greater than the first dimension L1. Where CW is a value corresponding to the weight of the positive electrode active material in a unit area of the positive electrode active material layer 420, and CW is a value in mg/cm ² (milligrams per cubic centimeter) H1 in millimeters.

Specifically, in the case where CW is 10mg/cm ² or less, the first difference H1 may be 6 mm, the third difference H3 may be 3mm, and the second difference H2 may be 9 mm. In the case of CW of 15mg/cm ², the first difference H1 may be 6.5 mm, the third difference H3 may be 3.5 mm and the second difference H2 may be 10 mm. In the case of CW 20mg/cm ², the first difference H1 may be 7 mm, the third difference H3 may be 4 mm, and the second difference H2 may be 11 mm.

At both ends of the first direction X, the separator 600 extends beyond the negative electrode tab 500, and the size of the separator 600 extending beyond the negative electrode tab 500 at one end of the first direction X is equal to the size of the separator 600 extending beyond the negative electrode tab 500 at the other end of the first direction X. At both ends of the first direction X, the negative electrode tab 500 extends beyond the positive electrode tab 400, and the dimension of the negative electrode tab 500 exceeding the positive electrode tab 400 at one end of the first direction X is equal to the dimension of the negative electrode tab 500 exceeding the positive electrode tab 400 at the other end of the first direction X.

In the case of satisfying the requirements of most batteries 100, CW is generally 30mg/cm ² or less, the maximum value of the first difference H1 is not more than 14 mm, and the third difference H3 is not more than 6 mm.

The difference between the second dimension L2 and the third dimension L3 is a second difference H2, where the second difference H2 is a dimension of the separator 600 exceeding the positive electrode active material layer 420 in the first direction X, and the second difference H2 is equal to a sum of the first difference H1 and the third difference H3. Specifically, the second difference H2 satisfies the following relationship: h2 More than or equal to 9+ (CW-10)/5. Where CW is a value corresponding to the weight of the positive electrode active material in each square centimeter of the positive electrode active material layer 420, and the second difference H2 is in millimeters. The second difference H2 may not exceed 20 mm.

The separator 600 may extend beyond the positive electrode tab 400 at both ends of the first direction X, and correspondingly, the second difference H2 is the sum of the dimensions of the separator 600 extending beyond the positive electrode tab 400 along both ends of the first direction X. The foregoing description of various embodiments is intended to highlight differences between the various embodiments, which may be the same or similar to each other by reference, and is not repeated herein for the sake of brevity.

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

Claims

1. A battery cell, comprising:

A positive electrode sheet;

The negative pole piece is laminated with the positive pole piece;

The separator is arranged between the positive pole piece and the negative pole piece in a stacked manner, the projection of the positive pole piece to the separator is a first projection, the projection of the negative pole piece to the separator is a second projection, the first projection does not exceed the circumferential edge of the separator, the second projection does not exceed the circumferential edge of the separator, and at least in the first direction, the size of the separator is larger than that of the positive pole piece and larger than that of the negative pole piece;

Wherein, the first direction is perpendicular to the lamination direction between the positive electrode sheet, the separator and the negative electrode sheet.

2. The battery cell according to claim 1, wherein in the first direction, the size of the negative electrode tab is a first size, and in the first direction, the size of the separator is a second size, the second size is larger than the first size, a difference of the second size minus the first size is a first difference H1, and the first difference H1 satisfies the following relationship:

H1≥6+(CW-10)/10；

The positive electrode plate comprises a positive electrode active material layer, CW is a value corresponding to the weight of the positive electrode active material in the unit area of the positive electrode active material layer, the unit of CW is mg/cm ², and the unit of the value of the first difference H1 is millimeter.

3. The battery cell of claim 2, wherein the first difference H1 is 6 millimeters or greater.

4. The battery cell of claim 3, wherein the first difference H1 has a value in a range of 6 mm or more and 14 mm or less.

5. The battery cell of any one of claims 2-4, wherein the separator extends beyond the negative electrode tab at both ends in the first direction, and wherein a difference between a dimension of the separator extending beyond the negative electrode tab at one end in the first direction and a dimension of the separator extending beyond the negative electrode tab at the other end in the first direction is no more than 1 millimeter.

6. The battery cell of any one of claims 1-4, wherein the projection of the positive electrode tab onto the negative electrode tab is a third projection, the third projection not exceeding a circumferential edge of the negative electrode tab.

7. The battery cell of claim 6, wherein in the first direction the negative electrode tab is a first dimension and in the first direction the positive electrode tab is a third dimension, the first dimension being greater than the third dimension.

8. The battery cell of claim 7, wherein the difference of the first dimension minus the third dimension is a third difference H3, the third difference H3 satisfying the relationship:

H3≥3+(CW-10)/10；

The positive electrode plate comprises a positive electrode active material layer, CW is a value corresponding to the weight of the positive electrode active material in the unit area of the positive electrode active material layer, the unit of CW is mg/cm ², and the unit of the value of the third difference H3 is millimeter.

9. The battery cell of claim 8, wherein the third difference H3 is 3 millimeters or greater.

10. The battery cell of claim 9, wherein the third difference H3 has a value in a range of 3 mm or more and 6 mm or less.

11. The battery cell of claim 8, wherein the negative electrode tab extends beyond the positive electrode tab at both ends in the first direction, and wherein a difference between a dimension of the negative electrode tab exceeding the positive electrode tab at one end in the first direction and a dimension of the negative electrode tab exceeding the positive electrode tab at the other end in the first direction is no more than 1 millimeter.

12. The battery cell according to any one of claims 1-4, wherein an end of the positive electrode tab in the first direction is provided with an insulating layer, the insulating layer covering and exceeding an edge of the negative electrode tab in the first direction.

13. The battery cell of any one of claims 1-4, further comprising a positive electrode tab disposed at one end of the positive electrode tab in the first direction, the separator covering a portion of the positive electrode tab;

And/or, the battery cell further comprises a negative electrode tab, the negative electrode tab is arranged at one end of the negative electrode pole piece along the first direction, and the isolating film covers part of the negative electrode tab along the first direction.

14. The battery cell of any one of claims 1-4, wherein the battery cell is an alkali metal battery and the negative electrode tab comprises a negative electrode current collector coated with a conductive layer.

15. The battery cell of claim 14, wherein the active ion of the alkali metal cell is sodium ion.

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

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