CN214477598U

CN214477598U - Electrode assembly, battery cell, battery and electric device

Info

Publication number: CN214477598U
Application number: CN202121682336.2U
Authority: CN
Inventors: 曾毓群; 张盛武; 唐鸣浩; 林文法; 刘会会; 叶杰
Original assignee: Jiangsu Contemporary Amperex Technology Ltd
Current assignee: Jiangsu Contemporary Amperex Technology Ltd
Priority date: 2021-07-23
Filing date: 2021-07-23
Publication date: 2021-10-22
Anticipated expiration: 2031-07-23

Abstract

The application provides an electrode subassembly, battery monomer, battery and power consumption device. The electrode assembly includes: the separator is used for separating the cathode pole piece and the anode pole piece; an electrolyte adsorption layer configured to be laid along a surface of at least one of the cathode pole piece, the anode pole piece, and the separator; and an ion exchange channel is arranged on the electrolyte adsorption layer and is a through hole arranged along the thickness direction of the electrolyte adsorption layer. According to the technical scheme, the electrolyte adsorption layer is arranged on at least one surface of the cathode pole piece, the anode pole piece and the separator, so that the electrolyte can be adsorbed and maintained, the storage, release and ion conduction and diffusion of the electrolyte are facilitated, the cycle performance of the battery is improved, and the service life of the battery is prolonged.

Description

Electrode assembly, battery cell, battery and electric device

Technical Field

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

Background

A rechargeable battery, which may be referred to as a secondary battery, refers to a battery that can be continuously used by activating an active material by means of charging after the battery is discharged. Rechargeable batteries are widely used in electronic devices such as mobile phones, notebook computers, battery cars, electric automobiles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and electric tools, etc.

The rechargeable battery may include a cadmium nickel battery, a hydrogen nickel battery, a lithium ion battery, a secondary alkaline zinc manganese battery, and the like.

At present, a battery used by an automobile mostly is a lithium ion battery, and the lithium ion battery as a rechargeable battery has the advantages of small volume, high energy density, high power density, multiple recycling times, long storage time and the like.

The rechargeable battery includes an electrode assembly including a cathode sheet, an anode sheet, and a separator between the cathode sheet and the anode sheet, and an electrolyte. The cathode pole pieces are provided with cathode active material layers, for example, the cathode active material of the cathode active material layers can be lithium manganate, lithium cobaltate, lithium iron phosphate or lithium nickel cobalt manganese; the anode active material layer is formed on the surface of the anode pole piece, and the anode active material of the anode active material layer can be graphite or silicon.

For an electrode assembly, electrolyte can be continuously consumed in the circulating process, and after the electrolyte between anode plates is consumed, the electrolyte dissociated in a shell can not be timely supplemented in place, so that the problems that after long-term charging and discharging use, the electrolyte is insufficient, the battery monomer and the circulating service life of the battery are attenuated can be caused.

Therefore, how to increase the cycle life of the battery becomes a difficult problem for the industry.

Disclosure of Invention

Aspects of the present application provide an electrode assembly, a battery cell, a battery, and a power using device that overcome or at least partially solve the above problems.

A first aspect of the present application provides an electrode assembly, including: the cathode pole piece, the anode pole piece, the separator and the electrolyte adsorption layer. The separator is used for separating the cathode pole piece and the anode pole piece; the electrolyte adsorption layer is configured to be arranged along the surface of at least one of the cathode pole piece, the anode pole piece and the separator; the electrolyte adsorption layer is provided with an ion exchange channel, and the ion exchange channel is a through hole arranged along the thickness direction of the electrolyte adsorption layer.

The electrolyte adsorption layer is arranged on the surface of at least one of the cathode pole piece, the anode pole piece and the separator, and can be used for keeping and slowly releasing electrolyte so as to supplement the electrolyte consumed in the circulating process, thus being beneficial to the conduction and diffusion of ions and further improving the performance of the single battery; be equipped with the ion exchange passageway on electrolyte adsorbed layer, the ion exchange passageway is for following the through-hole that the thickness direction of electrolyte adsorbed layer set up is favorable to electrolyte release and ionic conduction and diffusion, is favorable to improving the cyclicity ability and the life of battery.

In some embodiments, an electrolyte adsorption layer is attached to one surface or both surfaces of the cathode electrode sheet, and/or an electrolyte adsorption layer is attached to one surface or both surfaces of the anode electrode sheet, and/or an electrolyte adsorption layer is attached to one surface or both surfaces of the separator.

In the embodiment, the electrolyte adsorption layer is attached to one surface or two surfaces of the cathode pole piece, the anode pole piece or the separator, so that the storage performance and the retention performance of the electrolyte at one side or two sides of the cathode pole piece, the anode pole piece or the separator can be improved, the electrolyte consumed in the circulation process is supplemented, the conduction and the diffusion of ions are facilitated, and the performance of the battery monomer is improved.

In some embodiments, the cathode pole piece, the separator, and the anode pole piece are wound to form a bent region, and at least a portion of the electrolyte solution adsorption layer is disposed on a surface of at least one of the cathode pole piece, the anode pole piece, and the separator in the bent region.

In the embodiment, at least one part of the electrolyte adsorption layer is arranged in the bending area on the surface of at least one of the cathode pole piece, the anode pole piece and the separator, the electrolyte adsorption layer adsorbed with the electrolyte can fill the gap between the cathode pole piece and the anode pole piece in the bending area, and the electrolyte can be kept and slowly released in the bending area to supplement the electrolyte consumed in the circulation process, so that the conduction and the diffusion of ions are facilitated, and the performance of the battery monomer is improved. In addition, an electrolyte adsorption layer is arranged in a bending area on the surface of the cathode pole piece and/or the anode pole piece, and the electrolyte adsorption layer can also strengthen a cathode active material layer on the cathode pole piece and/or an anode active material layer on the anode pole piece, so that the situation that the cathode active material layer on the cathode pole piece and/or the anode active material layer on the anode pole piece is broken due to bending is reduced, and the performance of the battery cell is improved.

In some embodiments, at least a portion of the electrolyte solution adsorption layer is disposed at the first bending portion and/or the second bending portion of the cathode plate in the bending region, and/or at least a portion of the electrolyte solution adsorption layer is disposed at the first bending portion and/or the second bending portion of the anode plate, and/or at least a portion of the electrolyte solution adsorption layer is disposed at the bending portion of the separator adjacent to the first bending portion and/or the second bending portion of the cathode plate, and/or at least a portion of the electrolyte solution adsorption layer is disposed at the bending portion of the separator adjacent to the first bending portion and/or the second bending portion of the anode plate.

In this embodiment, at least one part of the electrolyte adsorption layer is disposed at the first bending portion and the second bending portion of at least one of the cathode plate, the anode plate and the separator, so that the uniformity of the electrolyte at the first bending portion and the second bending portion can be improved for the first bending portion and the second bending portion with a large gap between the cathode plate and the anode plate, and the performance of the battery cell can be improved while the influence on the energy density of the battery cell is reduced. In addition, lay the electrolyte adsorbed layer in the regional first and second time of buckling of the surface of cathode pole piece and/or anode pole piece, the electrolyte adsorbed layer can also be to the first and second time of the cathode pole piece on the position of buckling the negative pole active material layer and/or the first and second time of the position of buckling the positive pole piece on the positive pole active material layer strengthen, reduce the active material layer and take place because of the cracked condition of buckling, and then improve the free performance of battery.

In some embodiments, the bending region includes a first bending section covering a center line of the bending region and a second bending section positioned at least one side of the first bending section, the center line of the bending region being parallel to a winding axis of the electrode assembly; the porosity of the part of the electrolyte adsorption layer in the first bending subarea is different from the porosity of the part of the electrolyte adsorption layer in the second bending subarea, wherein the porosity of the electrolyte adsorption layer is the ratio of the area of the ion exchange channel to the area of the electrolyte adsorption layer.

In the embodiment, the porosity of the surface of the support layer in the first bending subarea and the second bending subarea is adjusted, so that the electrolyte release, ion conduction and diffusion performance of the first bending subarea and the second bending subarea can be adjusted, and the cycle performance and the service life of the battery can be improved.

In some embodiments, the ion exchange channels are arranged in a zigzag or curved line on the electrolyte adsorption layer in the bending region along a direction parallel to the winding axis of the electrode assembly.

In the embodiment, the ion exchange channels are arranged on the electrolyte adsorption layer in a broken line or a curve, so that the ion exchange channels are distributed at different widths and height positions of the electrolyte adsorption layer, the electrolyte adsorption layer can realize electrolyte release and ion conduction and diffusion at different heights and width positions, and the improvement of the cycle performance and the service life of the battery are facilitated.

In some embodiments, the electrolyte adsorption layer comprises an adsorption base layer, one side of the adsorption base layer is attached to a corresponding cathode pole piece, anode pole piece or separator, and the adsorption base layer is provided with an ion exchange channel.

In the embodiment, the adsorption base layer is used for storing and maintaining the electrolyte on the surfaces of the cathode pole piece, the anode pole piece or the separator so as to supplement the electrolyte consumed in the circulating process, thereby being beneficial to the conduction and the diffusion of ions and further improving the performance of the battery monomer; the ion exchange channel arranged along the thickness direction of the adsorption base layer is beneficial to electrolyte release and ion conduction and diffusion, and is beneficial to improving the cycle performance and the service life of the battery.

In this embodiment, the material of the adsorption base layer is one of acrylic acid-acrylate copolymer, butadiene-styrene copolymer, styrene-acrylic acid copolymer, styrene-acrylate copolymer, ethylene-vinyl acetate copolymer, acrylic acid grafted polyethylene, maleic anhydride grafted polyethylene, acrylic acid grafted polypropylene, maleic anhydride grafted polypropylene, polyvinylidene fluoride, carboxymethyl cellulose, polyimide, polyetherimide, polyethylene terephthalate, styrene-isoprene-styrene copolymer rubber, ethylene-vinyl acetate copolymer bisphenol a type epoxy resin, ethylene-vinyl acetate copolymer bisphenol F type epoxy resin, glyceryl ether type epoxy resin, glyceryl ester type epoxy resin, silicone type resin, polyurethane, and styrene-isoprene-styrene copolymer.

In some embodiments, the electrolyte adsorption layer includes an adsorption base layer attached at one side thereof to a corresponding cathode pole piece, anode pole piece or separator, and a support layer attached at the other side thereof; the ion exchange channels penetrate through the supporting layer and the adsorption base layer along the thickness direction.

In this embodiment, the electrolyte adsorption layer includes adsorption base layer and supporting layer, the adsorption base layer has certain mobility, take place to remove and warp easily at the surface of cathode pole piece, anode pole piece or separator, and then influence the homogeneity that the electrolyte adsorption layer distributes, set up the supporting layer at the adsorption base layer with the cathode pole piece, the opposite side of anode pole piece or separator attached side, the supporting layer can be when making the ion flow, restrain the flow and the deformation of adsorption base layer, with the even maintenance of adsorption base layer at the surface of cathode pole piece, anode pole piece or separator, and then make the electrolyte can be long-term and stable keep at the surface of cathode pole piece, anode pole piece or separator, be favorable to improving the cyclicity ability and the life of battery. The ion exchange channel penetrates through the supporting layer and the adsorption base layer, so that the ion exchange channel can penetrate through the supporting layer and the adsorption base layer, electrolyte release and ion conduction and diffusion are facilitated, and the cycle performance and the service life of the battery are improved.

In some embodiments, the material of the adsorption base layer is one of acrylic acid-acrylate copolymer, butadiene-styrene copolymer, styrene-acrylic acid copolymer, styrene-acrylate copolymer, ethylene-vinyl acetate copolymer, acrylic acid grafted polyethylene, maleic anhydride grafted polyethylene, acrylic acid grafted polypropylene, maleic anhydride grafted polypropylene, polyvinylidene fluoride, carboxymethyl cellulose, polyimide, polyetherimide, polyethylene terephthalate, styrene-isoprene-styrene copolymer rubber, ethylene-vinyl acetate copolymer bisphenol a type epoxy resin, ethylene-vinyl acetate copolymer bisphenol F type epoxy resin, glyceryl ether type epoxy resin, glyceryl ester type epoxy resin, silicone type resin, polyurethane, styrene-isoprene-styrene copolymer.

In some embodiments, the material of the support layer is one of polyvinyl chloride, polyethylene, polypropylene, polyvinylidene fluoride, hexafluoropropylene-vinylidene fluoride copolymer, tetrafluoropropene-vinylidene fluoride copolymer, chlorotrifluoroethylene-vinylidene fluoride copolymer, polyethylene terephthalate, polyimide, polyetherimide, polycarbonate, polystyrene, polyphenylene sulfide, polyvinylidene fluoride or a copolymer thereof, polyarylate, fiber, nylon, or nonwoven fabric.

In some embodiments, the support layer has a thickness of 50um or less, 0< the porosity of the support layer of 50% or less, and/or the tensile modulus of the support layer of 100MPa or less, wherein the porosity of the support layer is the ratio of the total area of the ion exchange channels to the area of the support layer.

In the embodiment, the thickness of the supporting layer is set to be less than or equal to 50um, so that the gap between the cathode pole piece and the anode pole piece can be controlled within a reasonable range, and the transmission of ions is facilitated. The porosity of the supporting layer is set to be 0< the porosity of the supporting layer is less than or equal to 50%, so that the flow and deformation of the adsorption base layer can be better inhibited while ions flow, the adsorption base layer is uniformly maintained on the surface of the cathode pole piece, the anode pole piece or the separator, and then the electrolyte can be stably maintained on the surface of the cathode pole piece, the anode pole piece or the separator for a long time, and the improvement of the cycle performance and the service life of the battery are facilitated. The tensile modulus of the supporting layer is less than or equal to 100Mpa, so that the supporting layer has better holding performance on the adsorption base layer.

A second aspect of the present application provides a battery cell, including: the electrode assembly comprises a shell, electrolyte, a cover plate and at least one electrode assembly of the embodiment, wherein the shell is provided with a containing cavity and an opening, and the electrode assembly and the electrolyte are contained in the containing cavity; the cover plate is used for closing the opening of the shell.

A third aspect of the present application provides a battery, which includes a case and at least one of the battery cells of the above embodiments, wherein the battery cell is accommodated in the case.

A fourth aspect of the present application provides an electric device configured to receive electric power supplied from the battery of the above-described embodiment.

The foregoing description is only an overview of the technical solutions of the embodiments of the present application, and the embodiments of the present application can be implemented according to the content of the description in order to make the technical means of the embodiments of the present application more clearly understood, and the detailed description of the present application is provided below in order to make the foregoing and other objects, features, and advantages of the embodiments of the present application more clearly understandable.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

Fig. 1 is a schematic perspective view of an electrode assembly according to an embodiment of the present disclosure;

FIG. 2 is a structural schematic diagram of a cross-section of the electrode assembly of FIG. 1 taken perpendicular to the winding axis K;

fig. 3 is a structural view of a cross-section of a flat-shaped electrode assembly perpendicular to a winding axis K according to another embodiment of the present application;

fig. 4 is a structural view of a cross section of another flat-shaped electrode assembly perpendicular to a winding axis K according to another embodiment of the present application;

fig. 5 is a structural view of a cross section of another flat-shaped electrode assembly perpendicular to a winding axis K according to another embodiment of the present application;

fig. 6 is a structural view of a cross section perpendicular to a winding axis K of another flat-body-shaped electrode assembly according to another embodiment of the present application;

fig. 7 is a structural view of a cross section perpendicular to a winding axis K of another flat-body-shaped electrode assembly according to another embodiment of the present application;

fig. 8 is a structural view of a cross section perpendicular to a winding axis K of another flat-body-shaped electrode assembly according to another embodiment of the present application;

FIG. 9 is a schematic structural diagram of an anode sheet according to another embodiment of the present disclosure;

FIG. 10 is a schematic view of a cathode plate according to another embodiment of the present application;

FIG. 11 isbase:Sub>A schematic cross-sectional view taken along line A-A of FIG. 10;

FIG. 12 is a schematic cross-sectional view taken along line B-B of FIG. 10;

FIG. 13 is a schematic cross-sectional view taken along line B-B of FIG. 10 in another embodiment of the present application;

FIG. 14 is a schematic cross-sectional view taken along line B-B of FIG. 10 in another embodiment of the present application;

FIG. 15 is a schematic cross-sectional view taken along line B-B of FIG. 10 in accordance with another embodiment of the present application;

FIG. 16 is a partial schematic view of an electrode assembly in accordance with one embodiment of the present application at a bend region thereof;

fig. 17 is a structural view of a cross section of a flat-shaped electrode assembly perpendicular to a winding axis K according to another embodiment of the present application;

FIG. 18 is a schematic view of a cathode plate according to another embodiment of the present application;

fig. 19 is a structural view of a cross section perpendicular to a winding axis K of another flat-body-shaped electrode assembly according to another embodiment of the present application;

fig. 20 is a structural view of a cross section perpendicular to a winding axis K of another flat-body-shaped electrode assembly according to another embodiment of the present application;

fig. 21 is a structural view of a cross section of another flat-shaped electrode assembly perpendicular to a winding axis K according to another embodiment of the present application;

fig. 22 is a structural view of a cross section perpendicular to a winding axis K of another flat-body-shaped electrode assembly according to another embodiment of the present application;

fig. 23 is a structural view of a cross section perpendicular to a winding axis K of an electrode assembly in another flat body shape according to another embodiment of the present application;

fig. 24 is a structural view of a cross section perpendicular to a winding axis K of another flat-shaped electrode assembly according to another embodiment of the present application;

fig. 25 is a structural view of a cross section of another flat-shaped electrode assembly perpendicular to a winding axis K according to another embodiment of the present application;

fig. 26 is a structural view of a cross section perpendicular to a winding axis K of an electrode assembly in another flat body shape according to another embodiment of the present application;

FIG. 27 is a schematic view of a cathode plate according to another embodiment of the present application;

FIG. 28 is a schematic view of a cathode plate according to another embodiment of the present application;

FIG. 29 is a schematic view of a cathode plate according to another embodiment of the present application;

fig. 30 is a schematic structural diagram of a battery cell according to another embodiment of the present application;

fig. 31 is a schematic structural view of a battery module according to another embodiment of the present application;

fig. 32 is a schematic structural view of a battery according to another embodiment of the present application;

fig. 33 is a schematic structural diagram of an electric device according to another embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection 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 in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "including" and "having," and any variations thereof in the description and claims of this application and the description of the figures above, are intended to cover a non-exclusive inclusion.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase 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. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein may be combined with other embodiments.

The term "and/or" herein is merely an association relationship describing an associated object, and means that there may be three relationships, for example, a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

In the description of the present application, it is to be understood that the terms "central," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present application and to simplify the description, but are not intended to indicate or imply that the device or element so referred to must have a particular orientation, be constructed and operated in a particular orientation, and are not to be construed as limiting the present application. Furthermore, the terms "first," "second," and the like in the description and claims of this application or in the foregoing drawings are used for distinguishing between different objects and not necessarily for describing a particular sequential order, either explicitly or implicitly, including one or more of the features. In the description of the present application, "a plurality" means two or more unless otherwise specified.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

In order to make the lithium ion battery smaller in size and higher in energy density, a cathode pole piece, an anode pole piece, and a separator in an electrode assembly of the lithium ion battery may be wound and then compacted. For example, as shown in fig. 1, there is a perspective view illustrating an electrode assembly including an anode sheet, a cathode sheet and a separator, wherein the anode sheet, the cathode sheet and the separator are stacked and then wound around a winding axis K to form a wound structure, the separator is an insulating film for separating the anode sheet and the cathode sheet and preventing the anode sheet and the cathode sheet from being short-circuited, the wound structure of the electrode assembly has a flat shape, and a structural view of the electrode assembly along a cross section perpendicular to the winding axis K may be as shown in fig. 2.

Referring to fig. 1 and 2, the electrode assembly includes a flat region P and bent regions C at both ends of the flat region P. The flat region P refers to a region having a parallel structure in the wound structure, i.e., the anode sheet 101, the cathode sheet 102 and the separator 103 in the flat region P are substantially parallel to each other, i.e., the surface of the electrode assembly in each layer of the anode sheet 101, the cathode sheet 102 and the separator 103 in the flat region P is a plane. The bending region C refers to a region of the winding structure having a bending structure, that is, the anode sheet 101, the cathode sheet 102 and the separator 103 in the bending region C are all bent, that is, the surface of each layer of the anode sheet 101, the cathode sheet 102 and the separator 103 of the electrode assembly in the bending region C is a curved surface, and the bending region C has a winding direction L, which may be understood as a direction pointing to a straight region along the surface of the electrode assembly in the bending region C, for example, the winding direction L is along the winding direction of the winding structure in the bending region C.

The surface of the anode plate 101 has an anode active material layer composed of an anode active material, and the surface of the cathode plate 102 has a cathode active material layer composed of a cathode active material, for example, the cathode active material may be lithium manganate, lithium cobaltate, lithium iron phosphate, or lithium nickel cobalt manganate, and the anode active material may be graphite or silicon.

The inventor finds that electrolyte is continuously consumed by the electrode assembly in the circulating process, and the electrolyte between the cathode and anode sheets can not be timely supplemented in place after being consumed, so that the problem that the service lives of a battery monomer and a battery pack are too early due to insufficient electrolyte after long-term charging and discharging is caused.

In view of the above, the present application is directed to an electrode assembly including a cathode plate, an anode plate, and a separator for separating the cathode plate from the anode plate, wherein the anode plate, the cathode plate, and the separator may be stacked and then wound around a winding axis to form a wound structure, for example, a wound structure of a flat body, and the anode plate, the cathode plate, and the separator may be stacked and then continuously folded in a zigzag shape. The electrode assembly may be formed by winding, or may be continuously folded in a zigzag shape. The electrode assembly further includes an electrolyte adsorption layer configured to be disposed along a surface of at least one of the cathode pole piece, the anode pole piece, and the separator; and the electrolyte adsorption layer is provided with an ion exchange channel, and the ion exchange channel is a through hole arranged along the thickness direction of the electrolyte adsorption layer.

The electrolyte adsorption layer is arranged on the surface of at least one of the cathode pole piece, the anode pole piece and the separator, and can fill the gap between the cathode pole piece and the anode pole piece, so that the electrolyte is kept and slowly released, the electrolyte consumed in the circulation process is supplemented, the conduction and the diffusion of ions are facilitated, and the performance of the battery monomer is improved; the ion exchange channel arranged along the thickness direction of the electrolyte adsorption layer is beneficial to electrolyte release and ion conduction and diffusion, and is beneficial to improving the cycle performance and the service life of the battery monomer. The ion exchange channels can be through holes arranged in the thickness direction of the electrolyte adsorption layer, the through holes can be uniformly or non-uniformly distributed on the surface of the electrolyte adsorption layer, the through holes can have the same or different cross-sectional areas and/or hole depths, and the number of the through holes can be one or more. The ion exchange channel is internally provided with electrolyte, and ions can pass through the electrolyte adsorption layer through the ion exchange channel.

The separator 103 has an electrical insulating property, and is used to separate the adjacent cathode electrode tab 102 and anode electrode tab 101, and prevent the adjacent cathode electrode tab 102 and anode electrode tab 101 from short-circuiting. The separator 103 has a large number of pores penetrating therethrough, and is capable of allowing the electrolyte and ions to pass freely therethrough, and has good permeability to lithium ions, so that the separator 103 cannot substantially block the passage of lithium ions. For example, the separator 103 includes a separator base layer including at least one of polypropylene, polyethylene, ethylene-propylene copolymer, polybutylene terephthalate, and the like, and a functional layer on a surface of the separator base layer, and the functional layer may be a mixture layer of a ceramic oxide and a binder.

The electrode assembly of the embodiment of the present application has an electrolyte adsorption layer attached to one surface or both surfaces of the cathode sheet 1, and/or an electrolyte adsorption layer 4 attached to one surface or both surfaces of the anode sheet 2, and/or an electrolyte adsorption layer 4 attached to one surface or both surfaces of the separator 3.

As shown in fig. 3, in another embodiment of the present application, an electrolyte adsorption layer 4 is attached to the inner surface of the cathode tab 1.

As shown in fig. 4, in another embodiment of the present application, an electrolyte adsorption layer 4 is attached to the outer surface of the cathode tab 1.

As shown in fig. 5, in another embodiment of the present application, an electrolyte adsorption layer 4 is attached to both the inner surface and the outer surface of the cathode sheet 1.

In some embodiments not shown in the figures, an electrolyte adsorption layer can also be attached to the inner surface and/or the outer surface of the anode plate 2, and the electrolyte adsorption layer can be arranged on the surface of the cathode plate 1 in a manner as shown in fig. 3 to 5.

As shown in fig. 6, in another embodiment of the present application, an electrolyte adsorption layer 4 is attached to the inner and outer surfaces of the cathode sheet 1, and the inner and outer surfaces of the anode sheet 2.

Wherein, the electrolyte adsorption layer 4 is attached on one surface or two surfaces of the cathode pole piece 1, and/or, is attached on one surface or two surfaces of the anode pole piece 2, also can be the electrolyte adsorption layer 4 is attached on any surface of the cathode pole piece 1 and/or the anode pole piece 2, and/or, is attached on one surface or two surfaces of the separator 3. Wherein, the attachment refers to adhesion or coating or spraying, and through the attachment, the position movement of the electrolyte absorption layer 4 in the use process of the battery cell can be reduced.

As shown in fig. 7, in another embodiment of the present application, an electrolyte solution adsorption layer 4 may be attached to the inner surface of the separator 3.

As shown in fig. 8, in another embodiment of the present application, an electrolyte solution adsorption layer 4 may be attached to the outer surface of the separator 3.

In some embodiments not shown in the drawings, an electrolyte solution adsorption layer 4 may also be attached to both the inner surface and the outer surface of the separator 3. The manner of attaching the electrolyte adsorption layer 4 on the separator 3 can refer to the manner of providing the electrolyte adsorption layer 4 on the surface of the cathode sheet 1 and/or the anode sheet 2 in fig. 3 to 6.

The surface of the separator 3 is provided with the electrolyte adsorption layer 4 which can also fill the gap between the cathode pole piece and the anode pole piece, maintain and store the electrolyte so as to supplement the electrolyte consumed in the circulation process, facilitate the conduction and diffusion of ions and further improve the circulation performance and the service life of the battery monomer; the ion exchange channel arranged along the thickness direction of the electrolyte adsorption layer is arranged on the electrolyte adsorption layer 4, so that electrolyte release and ion conduction and diffusion are facilitated, and the cycle performance and the service life of the battery monomer are improved.

The structure of the anode sheet 2 can be as shown in fig. 9, which is a schematic structural diagram of an anode sheet according to another embodiment of the present disclosure, the anode sheet 2 includes an anode main body portion 21 and an anode tab portion 22 extending outward from the anode main body portion 21 along a winding axis K, at least a partial region on a surface of the anode main body portion 21 along the winding axis K is an anode active material layer 211, the anode active material layer 211 is used for coating an anode active material, and the anode active material can be graphite or silicon.

In another embodiment of the present application, not only the partial region of the surface of the anode body portion 21 is provided with the anode active material layer 211, but also the root region of the surface of the anode lug portion 22 close to the anode body portion 21 is provided with the anode active material layer 211, that is, the partial region of the anode lug portion 22 is the anode active material layer 211.

In another embodiment of the present application, as shown in fig. 9, the anode active material layer 211 covers the entire surface of the anode main body portion 21 along the winding axis K.

In another embodiment of the present application, the cathode active material may not cover the whole surface of the cathode sheet 1, for example, as shown in fig. 10, which is a schematic structural diagram of a cathode sheet in another embodiment of the present application.

The cathode sheet 1 includes a cathode body 11 and at least one cathode tab portion 12 extending outward of the cathode body 11 along a winding axis K, at least a partial region of a surface of the cathode body 11 is a cathode active material layer 111, and the cathode active material layer 111 may be coated with a cathode active material, for example, the cathode active material may be a ternary material, lithium manganate, or lithium iron phosphate.

In another embodiment of the present application, the surface of the cathode main body portion 11 further includesbase:Sub>A first insulating layer coating region 112 adjacent to the cathode active material layer 111, the first insulating layer coating region 112 is located on one side of the cathode active material layer 111 adjacent to the cathode ear portion 12, the first insulating layer coating region 112 is used for coating an insulating material for insulating and separating the cathode active material layer 111 and the cathode ear portion 12, for example, as shown in fig. 11, which isbase:Sub>A schematic cross-sectional structure inbase:Sub>A-base:Sub>A direction in fig. 10, two surfaces ofbase:Sub>A current collector of the cathode pole piece 1 are provided with the cathode active material layer 111, and the cathode ear portion 12 isbase:Sub>A part of the current collector of the cathode pole piece 1, wherein the material of the current collector may be aluminum.

For example, the cathode active material layer 111 and the first insulating layer coating region 112 are distributed at both ends in the width direction of the cathode main body portion 11 (i.e., the winding axis K) on the surface of the cathode main body portion 11, and the cathode tab portion 12 and the first insulating layer coating region 112 belong to the same end of the cathode main body portion 11.

In another embodiment of the present application, the cathode active material layer 111 and the first insulating layer-coated region 112 are two substantially parallel regions on the surface of the cathode main body portion 11, and are distributed in two layers on the surface of the cathode main body portion 11 along the winding axis K.

In another embodiment of the present application, the first insulating layer coating region 112 may be located at a portion where the cathode main body portion 11 and the cathode tab portion 12 are connected to each other, for example, the portion where the first insulating layer coating region 112 is located on the surface of the cathode main body portion 11 and connected to the cathode tab portion 12, for separating the surface of the cathode tab portion 12 and the cathode active material layer 111. In another embodiment of the present application, not only the first insulating layer coating region 112 is provided on the surface of the cathode main body portion 11, but also a second insulating layer coating region for coating an insulating substance is provided in the root region of the cathode lug portion 12 near the cathode main body portion 11.

In another embodiment of the present application, the surface of the first insulation layer-coating region 112 is coated with an insulation substance including an inorganic filler and a binder. The inorganic filler comprises one or more of boehmite, alumina, magnesia, titanium dioxide, zirconia, silicon dioxide, silicon carbide, boron carbide, calcium carbonate, aluminum silicate, calcium silicate, potassium titanate and barium sulfate. The binder comprises one or more of polyvinylidene fluoride, polyacrylonitrile, polyacrylic acid, polyacrylate, polyacrylic acid-acrylate, polyacrylonitrile-acrylic acid and polyacrylonitrile-acrylate.

In another embodiment of the present application, each cathode sheet 1 may include one or two or more cathode ear portions 12, and when the cathode sheet 1 includes two or more cathode ear portions 12, all the cathode ear portions 12 are located on the same side of the cathode sheet 1 along the winding axis K.

Referring to fig. 9 and 10, when the cathode sheet 1 and the anode sheet 2 are stacked on each other, both ends of the anode active material layer 211 of the anode sheet 2 along the winding axis K are protruded beyond the corresponding ends of the cathode active material layers 111 of the adjacent cathode sheets 1, so that the electrode assembly can have a better energy density. For example, the two ends of the anode active material layer 211 along the winding axis K are the first end 23 and the second end 24, respectively, and the two ends of the cathode active material layer 111 along the winding axis K are the third end 13 and the fourth end 14, respectively, wherein the first end 23 of the anode active material layer 211 and the third end 13 of the cathode active material layer 111 are located on the same side of the electrode assembly along the winding axis K, the first end 23 of the anode active material layer 211 exceeds the third end 13 of the cathode active material layer 111 along the winding axis K, the second end 24 of the anode active material layer 211 and the fourth end 14 of the cathode active material layer 111 are located on the other side of the electrode assembly along the winding axis K, and the second end 24 of the anode active material layer 211 exceeds the fourth end 14 of the cathode active material layer 111 along the winding axis K.

The dimensions of both ends of the anode active material layer 211 along the winding axis K beyond the corresponding ends of the cathode active material layer 111 may be the same or different, for example, the range of the exceeding dimensions is 0.2 mm to 5 mm.

As shown in fig. 12, which is a schematic cross-sectional structure in the direction B-B in fig. 10, in conjunction with fig. 10, the electrolyte solution adsorption layer 4 is attached on the surface of the cathode active material layer 111, i.e., on the surface of the cathode active material layer. The electrolyte adsorption layer 4 is arranged on the surface of at least one of the cathode pole piece 1, the anode pole piece 2 and the separator 3, the electrolyte adsorption layer 4 adsorbing the electrolyte can fill the gap between the cathode pole piece 1 and the anode pole piece 2, and can keep and slowly release the electrolyte so as to supplement the electrolyte consumed in the circulation process, thus being beneficial to the conduction and diffusion of ions and further improving the circulation performance and service life of the battery monomer; the ion exchange channel 40 arranged along the thickness direction of the electrolyte adsorption layer is arranged on the electrolyte adsorption layer 4, so that electrolyte release and ion conduction and diffusion are facilitated, and the cycle performance and the service life of the battery monomer are improved.

In some embodiments, the electrolyte solution adsorption layer 4 may be made of any material suitable for adsorbing and holding an electrolyte solution and resistant to corrosion by the electrolyte solution.

As shown in fig. 12, in some embodiments, the electrolyte adsorption layer 4 may include an adsorption base layer 41, one side of the adsorption base layer 41 is attached to a corresponding cathode or anode pole piece, and the adsorption base layer 41 is provided with an ion exchange channel 40.

The material of the adsorption base layer 41 is at least one of acrylic acid-acrylate copolymer, butadiene-styrene copolymer, styrene-acrylic acid copolymer, styrene-acrylate copolymer, ethylene-vinyl acetate copolymer, acrylic acid grafted polyethylene, maleic anhydride grafted polyethylene, acrylic acid grafted polypropylene, maleic anhydride grafted polypropylene, polyvinylidene fluoride, carboxymethyl cellulose, polyimide, polyetherimide, polyethylene terephthalate, styrene-isoprene-styrene copolymer rubber, ethylene-vinyl acetate copolymer bisphenol a type epoxy resin, ethylene-vinyl acetate copolymer bisphenol F type epoxy resin, glyceryl ether type epoxy resin, glyceryl ester type epoxy resin, silicone type resin, polyurethane, and styrene-isoprene-styrene copolymer.

As shown in fig. 10 and 12 in conjunction, one or more ion exchange channels 40 may be disposed on an adsorption substrate 41, for example, the ion exchange channels 40 may be arranged in an array on the adsorption substrate 41, each ion exchange channel 40 having the same diameter. The ion exchange channels 40 can be arranged in the adsorption base layer 41 along the thickness direction of the adsorption base layer 41, the ion exchange channels 40 can be through holes or blind holes, and the space in the ion exchange channels can store more electrolyte, so that the electrolyte release performance and the ion conduction and diffusion performance of the adsorption base layer 41 are improved. Without limitation, the ion exchange channels 40 may also be non-uniformly arranged on the adsorbent bed 41, and/or the ion exchange channels 40 may have different diameters and/or depths. The ion exchange channel 40 may penetrate the adsorption base layer 41 and directly contact with the cathode active material layer or the anode active material layer, which is beneficial for ions to be separated from the cathode active material layer through the electrolyte in the ion exchange channel 40 and to be embedded into the anode active material layer, so as to improve the ion permeability, and in addition, more electrolyte may be stored in the ion exchange channel 40 and the release performance, ion conduction and diffusion performance of the electrolyte may be improved, and the release performance, ion conduction and diffusion performance of the adsorption base layer 41 may be adjusted by adjusting the arrangement mode and diameter of the ion exchange channel 40.

In order to provide better electrolyte storage and retention performance and save cost, the electrolyte absorption layer 4 includes a fifth end (upper end) and a sixth end (lower end) in the direction perpendicular to the winding direction L (i.e. the winding axis K), the fifth end of the electrolyte absorption layer 4 exceeds the cathode active material layer of the cathode sheet 1 and/or the sixth end of the electrolyte absorption layer 4 exceeds the cathode active material layer, i.e. the fifth end of the electrolyte absorption layer 4 exceeds the third end (upper end) of the cathode active material layer 111 in the winding axis K, and/or the sixth end of the electrolyte absorption layer 4 exceeds the fourth end (lower end) of the cathode active material layer 111 in the winding axis K, for example, the exceeding size range is 0.2 mm to 5 mm. Therefore, the electrolyte can be kept in the cathode active material layer as much as possible, the electrolyte is slowly released on the surface of the cathode active material layer, and the cycle performance and the service life of the battery monomer are enhanced.

In some embodiments, when the electrolyte adsorption layer 4 is composed of the adsorption base layer 41, the porosity of the electrolyte adsorption layer 4 is the porosity of the adsorption base layer 41, and the porosity of the adsorption base layer is 0< the porosity of the adsorption base layer ≦ 50%, for example, the porosity of the adsorption base layer may be 0.05%, 0.08%, 0.1%, 0.5%, 1%, 2%, 5%, 10%, 15%, 30%, 40%, or the like. By adjusting the porosity of the adsorption base layer, the release properties and ion conduction and diffusion properties of the adsorption base layer 41 can be adjusted.

In another embodiment of the present application, as shown in fig. 13, a schematic cross-sectional structure in a direction B-B in fig. 10 is shown. The embodiment of fig. 13 differs from the embodiment shown in fig. 12 in that the electrolyte solution adsorption layers 4 are provided on the surfaces of the cathode active material layers 111 on both surfaces of the cathode sheet 1. The specific structure and attachment manner and position of the electrolyte solution adsorption layer 4 are the same as those in fig. 12. In some embodiments not shown in the drawings, the electrolyte absorption layer 4 may also be attached to one or both surfaces of the anode sheet 2 or the separator 3, and the specific structure and attachment manner and position of the electrolyte absorption layer 4 are the same as those of the cathode sheet 1, and reference may be made to the structure in fig. 12 or 13.

Fig. 14 is a schematic structural diagram of a cathode plate according to another embodiment of the present application.

In this embodiment, the structure of the cathode sheet 1 is the same as that in fig. 13. The electrolyte adsorption layer 4 of the present embodiment includes an adsorption base layer 41 and a support layer 42, the support layer 42 is attached to the other side of the adsorption base layer 41, which is the opposite side of the adsorption base layer 41 from the side to which the electrode sheet is attached, as shown in fig. 14, the other side of the adsorption base layer 41 is attached to the cathode electrode sheet 1, and ion exchange channels may penetrate through the support layer and the adsorption base layer in the thickness direction.

In some embodiments, the ion exchange channels 40 extend through the support layer 42 and the adsorption base layer 41, as shown in fig. 14. Specifically, a first ion exchange channel 401 is disposed on the adsorption substrate 41, a second ion exchange channel 402 is disposed on the support layer, and the first ion exchange channel 401 and the second ion exchange channel 402 are communicated to form the ion exchange channel 40. Because the adsorption base layer 41 has certain fluidity, the adsorption base layer is easy to move and deform on the surface of the pole piece, and further the uniformity of the distribution of the adsorption base layer 41 is influenced, the support layer 42 is arranged on the opposite side of the adsorption base layer 41 to the side attached to the cathode pole piece 1, the anode pole piece 2 or the separator 3, and the support layer 42 can inhibit the flow and deformation of the adsorption base layer 41 while enabling ions to flow, so that the adsorption base layer 41 is uniformly maintained on the surface of the pole piece, and further the electrolyte is uniformly distributed. The ion exchange channels 40 penetrate through the support layer and the adsorption base layer, so that the ion exchange channels 40 penetrate through the support layer 42 and the adsorption base layer 41, electrolyte release and ion conduction and diffusion are facilitated, and the cycle performance and the service life of the battery are improved.

In some embodiments, one or more of the second ion exchange channels 402 may be disposed on the support layer 42, for example, the second ion exchange channels 402 may be arranged in an array on the support layer 42, each second ion exchange channel 402 having the same diameter. The second ion exchange channels 402 may be disposed in the support layer 42 along the thickness direction of the support layer 42, the second ion exchange channels 402 are through holes, and the space inside the second ion exchange channels 402 may store more electrolyte and improve the release performance of the electrolyte, and improve the electrolyte release and ion conduction and diffusion performance of the support layer 42. Without limitation, the second ion exchange channels 402 may also be non-uniformly arranged on the support layer 42, and/or the second ion exchange channels 402 may have different diameters.

In some embodiments, the first ion exchange channels 401 may be arranged in one or more rows on the adsorption substrate 41, for example, the first ion exchange channels 401 may be arrayed on the adsorption substrate 41, each first ion exchange channel 401 having the same diameter. The first ion exchange channels 401 can be arranged in the adsorption base layer 41 along the thickness direction of the adsorption base layer 41, the ion exchange channels 40 can be through holes or blind holes, and the space in the first ion exchange channels 401 can store more electrolyte, so that the electrolyte release and ion conduction and diffusion performance of the adsorption base layer 41 are improved. Alternatively, the shape and arrangement position of the first ion exchange passage 401 correspond to the shape and arrangement position of the second ion exchange passage 402, and the second ion exchange passage 402 communicates with the first ion exchange passage 401.

In some embodiments, the material of the adsorption base layer 41 is at least one of acrylic acid-acrylate copolymer, butadiene-styrene copolymer, styrene-acrylic acid copolymer, styrene-acrylate copolymer, ethylene-vinyl acetate copolymer, acrylic acid grafted polyethylene, maleic anhydride grafted polyethylene, acrylic acid grafted polypropylene, maleic anhydride grafted polypropylene, polyvinylidene fluoride, carboxymethyl cellulose, polyimide, polyetherimide, polyethylene terephthalate, styrene-isoprene-styrene copolymer rubber, ethylene-vinyl acetate copolymer bisphenol a type epoxy resin, ethylene-vinyl acetate copolymer bisphenol F type epoxy resin, glyceryl ether type epoxy resin, glyceryl ester type epoxy resin, silicone type resin, polyurethane, styrene-isoprene-styrene copolymer.

In some embodiments, the support layer 42 is at least one of polyvinyl chloride, polyethylene, polypropylene, polyvinylidene fluoride, hexafluoropropylene-vinylidene fluoride copolymer, tetrafluoropropene-vinylidene fluoride copolymer, chlorotrifluoropropene-vinylidene fluoride copolymer, polyethylene terephthalate, polyimide, polyetherimide, polycarbonate, polystyrene, polyphenylene sulfide, polyvinylidene fluoride or copolymers thereof, polyarylate, fiber, nylon, or nonwoven fabric.

In some embodiments, the support layer 42 has a thickness of 50um,0< the porosity of the support layer 42 of 50%, and/or the tensile modulus of the support layer 42 of 100MPa, wherein the porosity of the support layer 42 is the ratio of the total area of the ion exchange channels 40 to the area of the support layer. Wherein the total area of the ion exchange channels 40 is the sum of the areas of one or more ion exchange channels.

In this embodiment, the thickness of the supporting layer 42 is set to be less than or equal to 50um, so that the gap between the cathode plate 1 and the anode plate 2 can be controlled within a reasonable range, which is beneficial to the transmission of ions. The porosity of the support layer 42 is set to 0< the porosity of the support layer 42 ≦ 50%, for example, the porosity of the support layer 42 may be 0.05%, 0.08%, 0.1%, 0.5%, 1%, 2%, 5%, 10%, 15%, 30%, 40%, or the like. When the electrolyte adsorption layer 4 is composed of the adsorption base layer 41 and the support layer 42, the porosity of the support layer 42 may be approximately equal to the porosity of the electrolyte adsorption layer. Through controlling the porosity of the supporting layer 42, the flow and deformation of the adsorption base layer 41 can be suppressed while the ions can flow better, the adsorption base layer 41 is uniformly maintained on the surface of the cathode plate 1, the anode plate 2 or the separator 3, and then the electrolyte can be stably maintained on the surface of the cathode plate 1, the anode plate 2 or the separator 3 for a long time, which is beneficial to improving the cycle performance and prolonging the service life of the battery. The tensile modulus of the support layer 42 is less than or equal to 100Mpa, so that the support layer 42 has better holding performance on the adsorption base layer 41.

Fig. 15 is a schematic structural diagram of a cathode plate according to another embodiment of the present application. In this embodiment, the structure of the cathode plate 1 is the same as that in fig. 11. The embodiment of fig. 15 differs from the embodiment of fig. 14 in that an adsorption base layer 41 and a support layer 42 are provided on both sides of the cathode pole piece 1. One side of the adsorption base layer 41 is attached to the surface of the cathode active material layer 111 on both sides of the cathode electrode sheet 1, i.e., the surface of the cathode active material layer, and the support layer 42 is attached to the other side of the adsorption base layer 41.

In some embodiments not shown in the figures, the adsorption base layer 41 and the support layer 42 can also be attached to one or two surfaces of the anode sheet 2 or the separator 3, and the specific structure of the adsorption base layer 41 and the support layer 42 and the attachment manner and position on the anode sheet 2 or the separator 3 are the same as the attachment manner on the cathode sheet, and reference can be made to the structure of the embodiment of fig. 10 to 15.

The above embodiments only roughly describe the positional relationship of the electrolyte adsorption layer with the cathode pole piece, the anode pole piece and the separator, respectively, and the structural features of the electrolyte adsorption layer, and in order to make the positional relationship of the electrolyte adsorption layer with the cathode pole piece, the anode pole piece and the separator, respectively, and the structure of the electrolyte adsorption layer clearer, the following detailed description is made of several electrode assemblies having a winding structure, respectively.

As shown in fig. 16, in another embodiment of the present application, the electrode assembly, whether formed by winding or formed by continuously folding in a zigzag shape, includes a straight region and a bent region connecting both ends of the straight region, and for simplicity of description, the electrode assembly of the present embodiment is described by taking a flat body winding structure as an example, for example, one of the bent regions C and the straight region P of the flat body winding structure may be as shown in fig. 16, which is a partial structural schematic diagram of an electrode assembly of an embodiment of the present application in the bent region thereof, and the electrode assembly includes a cathode pole piece 1, an anode pole piece 2 and a separator 3 for separating the cathode pole piece 1 from the anode pole piece 2 in the bent region C thereof, wherein the separator 3 may be independent between the adjacent cathode pole piece 1 and anode pole piece 2, or may be coated on the surface of the cathode pole piece 1 or the anode pole piece 2. In another embodiment of the present application, the separator 3, the cathode sheet 1, the separator 3, and the anode sheet 2 may be stacked and then wound or folded, or at least one (e.g., two or more) cathode sheet 1 and at least one (e.g., two or more) anode sheet 2 and at least two separators (e.g., four or more, the number of the separators is 2 times of the number of the cathode sheet or the anode sheet) may be stacked and then wound or folded, and a bending region C is formed, and when the electrode assembly has the plurality of cathode sheets 1, the plurality of anode sheets 2, and the plurality of separators 3 in the bending region C, the bending region C includes a structure in which the cathode sheets 1, the separators 3, and the anode sheets 2 are alternately distributed, and the electrolyte adsorption layer 4 is attached to one surface or both surfaces of the cathode sheet 1, and/or both surfaces of the anode sheet 2, and/or one surface or both surfaces of the separator 3. By the arrangement, an electrolyte adsorption layer 4 is included between at least one adjacent layer of the cathode pole piece 1 and the anode pole piece 2. The cathode pole piece 1 and the anode pole piece 2 adjacent to each other in the bending region C mean that one layer of the cathode pole piece 1 and one layer of the anode pole piece 2 are adjacent to each other in the bending region C, and the other layer of the cathode pole piece 1 or the other layer of the anode pole piece 2 is not included between the two layers.

When the electrode assembly has a winding structure, the width directions of the cathode and

anode sheets

1 and 2 are parallel to the winding axis K, and the width directions of the cathode and

anode sheets

1 and 2 are parallel to a direction perpendicular to the winding direction L; when the electrode assembly does not have a winding structure, the width directions of the cathode and

anode electrode tabs

1 and 2 are parallel to a direction perpendicular to the winding direction L, and for the sake of simplicity of the subsequent description, the width directions of the cathode and

anode electrode tabs

1 and 2, the direction perpendicular to the winding direction L, and the winding axis K are collectively referred to as a winding axis K in this embodiment.

As shown in fig. 16, in some embodiments, the cathode sheet 1, the separator 3, and the anode sheet 2 are wound to form a bent region C, and the electrolyte solution adsorption layer 4 is configured to run along the bent region C of the surface of at least one of the cathode sheet 1, the anode sheet 2, and the separator 3. That is, the electrolyte solution adsorption layer 4 may be attached on a part of the surface of the cathode sheet 1, the anode sheet and/or the separator.

In this embodiment, in the bending region C, a larger gap is formed between the cathode plate 1 and the anode plate 2, and the electrolyte adsorption layer 4 is disposed in the bending region C, so that better electrolyte storage and slow release effects can be achieved. In the embodiment, at least one part of the electrolyte adsorption layer 4 is distributed in the bending area C on the surface of at least one of the cathode pole piece 1, the anode pole piece 2 and the separator 3, the electrolyte adsorption layer 4 adsorbed with the electrolyte can fill the gap between the cathode pole piece 1 and the anode pole piece 2 in the bending area C, and the electrolyte is kept and slowly released in the bending area C to supplement the electrolyte consumed in the circulation process, so that the conduction and the diffusion of ions are facilitated, and the performance of a battery monomer is improved; the electrolyte adsorption layer is provided with the ion exchange channel arranged along the thickness direction, so that the electrolyte is favorable for electrolyte release and ion conduction and diffusion, the cycle performance of the battery monomer is favorably improved, and the service life of the battery monomer is prolonged. At least one part of the electrolyte adsorption layer 4 is arranged in the bent area C of the surface of at least one of the cathode pole piece 1, the anode pole piece 2 and the separator 3, specifically, the whole electrolyte adsorption layer 4 is positioned in the bent area C of the surface of at least one of the cathode pole piece 1, the anode pole piece 2 and the separator 3, or one part of the electrolyte adsorption layer 4 is positioned in the bent area C of the surface of at least one of the cathode pole piece 1, the anode pole piece 2 and the separator 3, and one part is positioned in the straight area P outside the area. In addition, an electrolyte adsorption layer is arranged in a bending area C on the surface of the cathode pole piece 1 and/or the anode pole piece 2, and the electrolyte adsorption layer 4 can also strengthen a cathode active material layer on the cathode pole piece 1 and/or an anode active material layer on the anode pole piece 2, so that the situation that the cathode active material layer on the cathode pole piece 1 and/or the anode active material layer on the anode pole piece 2 are broken due to bending is reduced, and the performance of the battery monomer is improved.

In another embodiment of the present application, both ends of the electrolyte solution adsorbing layer 4 extending along the winding direction L are located in the bending region C, that is, all of the electrolyte solution adsorbing layer 4 is located in the bending region C. In this embodiment, the electrode assembly further includes a straight region P connected to the bent region C, the winding direction L is a direction along the curved surface of the bent region C and directed toward the straight region P, and the direction perpendicular to the winding direction L is a direction perpendicular to the winding direction L.

In another embodiment of the present application, one end of the electrolyte solution adsorption layer 4 extending in the winding direction L is located in the straight region P, and the other end is located in the bent region C.

In another embodiment of the present application, in order to improve the storage and retention performance of the electrolyte in the bending region C, the electrolyte adsorption layer 4 has a larger area in the bending region C as much as possible, for example, both ends of the electrolyte adsorption layer 4 extending in the winding direction L are located in the straight region P, that is, the electrolyte adsorption layer 4 extends to the straight region P in addition to the bending region C.

In another embodiment of the present application, two ends of the electrolyte solution adsorbing layer 4 extending along the winding direction L are located at a boundary between the bending region C and the straight region P, or two ends of the electrolyte solution adsorbing layer 4 extending along the winding direction L are close to a boundary between the bending region C and the straight region P.

As shown in fig. 17, which is a schematic structural view of a cross section perpendicular to a winding axis K of a flat electrode assembly according to another embodiment of the present disclosure, the electrode assembly includes an anode sheet 91, a cathode sheet 92, a separator 93, a first electrolyte adsorption layer 94, a second electrolyte adsorption layer 95, and a third electrolyte adsorption layer 96, wherein the separator 93 is located between the anode sheet 91 and the cathode sheet 92, the separator 93 is two sheets, and the two dotted lines of winding are used to indicate in the cross section of the electrode assembly of fig. 17, and the anode sheet 91, the cathode sheet 92, and the separator 93 are stacked and then wound around the winding axis to form a flat winding structure. Fig. 18 is a schematic view showing the cathode sheet 92 of fig. 17 after being unfolded, showing the attachment position of the second electrolyte absorption layer 95 to the cathode sheet 92.

The relevant technical features of the anode plate 91, the cathode plate 92, the separator 93 and the electrolyte absorption layers 94 to 96 of this embodiment can refer to the description of the embodiment corresponding to fig. 1 to 15, and are not repeated herein.

In this embodiment, the winding structure of the electrode assembly includes a straight region 9A and first and second bending regions 9B1 and 9B2 located at both sides of the straight region 9A, wherein the straight region 9A and the first and second bending regions 9B1 and 9B2 are divided by a straight dotted line, respectively.

The electrode assembly includes anode pole pieces 91 and cathode pole pieces 92 in the first bending region 9B1 and the second bending region 9B2, which are alternately laminated in sequence, and a separator 93 is disposed between the adjacent anode pole pieces 91 and cathode pole pieces 92, wherein the innermost pole pieces of the first bending region 9B1 and the second bending region 9B2 are both the anode pole pieces 91, and the inner side surface of at least the innermost cathode pole piece 92 of the first bending region 9B1 and the second bending region 9B2 is provided with (e.g., attached to) an electrolyte absorption layer, e.g., the inner side surface of each cathode pole piece 92 of the first bending region 9B1 and the second bending region 9B2 is provided with (e.g., attached to) an electrolyte absorption layer. In this embodiment, the inner surface of the cathode sheet 92 refers to the surface of the cathode sheet 92 facing the winding axis or the surface facing the inside of the winding structure.

For example, the first bending region 9B1 has a plurality of electrode sheets, such as three electrode sheets, the electrode sheets of the innermost layer (also referred to as the first layer) and the outermost layer (also referred to as the third layer) of the first bending region 9B1 are both the anode electrode sheet 91, the electrode sheet between the innermost electrode sheet and the outermost electrode sheet (also referred to as the second electrode sheet) is the cathode electrode sheet 92, the cathode electrode sheet 92 is the cathode electrode sheet of the innermost side of the first bending region 9B1, and the first electrolyte solution adsorption layer 94 is attached to the inner side surface of the cathode electrode sheet 92 of the first bending region 9B 1.

The second bending region 9B2 has a plurality of layers of pole pieces, for example, five layers of pole pieces, and the anode pole pieces 91 and the cathode pole pieces 92 of the second bending region 9B2 are sequentially and alternately stacked in the direction from inside to outside of the winding structure, the innermost pole piece of the second bending region 9B2 is the anode pole piece 91, and the inner side surface of each layer of cathode pole piece 92 of the second bending region 9B2 is attached with an electrolyte adsorption layer.

For example, in the direction from the inside to the outside of the winding structure, the second bending region 9B2 includes first, second, third, fourth, and fifth electrode sheets in sequence, the first, third, and fifth electrode sheets are anode electrode sheets 91, the second and fourth electrode sheets are cathode electrode sheets 92, and an electrolyte adsorption layer is attached to the inner side surface of each cathode electrode sheet 92 of the second bending region 9B 2. For example, the second electrolyte solution adsorption layer 95 is attached to the inner side surface of the second layer pole piece (which is the cathode pole piece 92) of the second bend region 9B 2. The third electrolyte solution adsorption layer 96 is attached to the inner side surface of the fourth layer pole piece (which is the cathode pole piece 92) of the second bend region 9B 2.

In this embodiment, the two ends of the first electrolyte absorption layer 94, the second electrolyte absorption layer 95 and the third electrolyte absorption layer 96 along the winding direction L are respectively located at the junction of the bending region and the straight region, for example, the two ends of the first electrolyte absorption layer 94 along the winding direction are respectively located at the junction of the first bending region 9B1 and the straight region 9A, and the two ends of the second electrolyte absorption layer 95 and the third electrolyte absorption layer 96 along the winding direction are respectively located at the junction of the second bending region 9B2 and the straight region 9A.

In this embodiment, the functions, structures, distribution manners, and other relevant contents of the first electrolyte absorption layer 94, the second electrolyte absorption layer 95, and the third electrolyte absorption layer 96 can all refer to the relevant contents of the electrolyte absorption layers described in the embodiments of fig. 1 to 15, and are not repeated herein.

As shown in fig. 19, which is a schematic structural view of a cross section perpendicular to a winding axis K of another flat-shaped electrode assembly according to another embodiment of the present disclosure, the electrode assembly includes an anode plate 1001, a cathode plate 1002, a separator 1003, a first electrolyte adsorption layer 1004, a second electrolyte adsorption layer 1005, and a third electrolyte adsorption layer 1006, wherein the separator 1003 is located between the anode plate 1001 and the cathode plate 1002, and the anode plate 1001, the cathode plate 1002, and the separator 1003 are stacked and then wound around the winding axis into a flat-shaped winding structure.

The related technical features of the anode plate 1001, the cathode plate 1002 and the separator 1003 of this embodiment can refer to the description of the embodiment corresponding to fig. 1 to 15, and are not repeated herein.

In the present embodiment, the winding structure of the electrode assembly includes a straight region 10A and first and second bending regions 10B1 and 10B2 located at both sides of the straight region 10A.

The electrode assembly of the present embodiment is substantially similar to the electrode assembly described in the corresponding embodiment of fig. 17 and 18, and its differences may be as follows.

At least the outer side surface of the innermost cathode electrode sheet 1002 of the first bent region 10B1 and the second bent region 10B2 is provided with (e.g., attached with) an electrolyte absorption layer, for example, the outer side surface of each cathode electrode sheet 1002 of the first bent region 10B1 and the second bent region 10B2 is provided with (e.g., attached with) an electrolyte absorption layer. In this embodiment, the outer surface of the cathode sheet 1002 refers to the surface of the cathode sheet 1002 facing away from the winding axis, or the surface facing away from the inside of the winding structure.

For example, the first electrolyte solution adsorption layer 1004 is attached to the outer side surface of the cathode tab 1002 of the first bent region 10B 1.

For example, the second electrolyte solution adsorption layer 1005 is attached to the outer side surface of the second layer pole piece (which is the cathode pole piece 1002) of the second folded region 10B2. The third electrolyte solution adsorption layer 1006 is attached to the outer side surface of the fourth layer pole piece (which is the cathode pole piece 1002) of the second bending region 10B2.

In this embodiment, two ends of the first electrolyte absorption layer 1004 along the winding direction are respectively located at a junction of the first bending region 10B1 and the straight region 10A, and two ends of the second electrolyte absorption layer 1005 and the third electrolyte absorption layer 1006 along the winding direction are respectively located at a junction of the second bending region 10B2 and the straight region 10A.

In this embodiment, the functions, structures, distribution manners, and other relevant contents of the first electrolyte absorption layer 1004, the second electrolyte absorption layer 1005, and the third electrolyte absorption layer 1006 may also refer to the relevant contents of the electrolyte absorption layers described in the embodiments of fig. 1 to 15, and are not described again here.

As shown in fig. 20, which is a schematic structural view of a cross section perpendicular to a winding axis K of another flat-body-shaped electrode assembly according to another embodiment of the present disclosure, the electrode assembly includes an anode pole piece 1101, a cathode pole piece 1102, a separator 1103, a first electrolyte adsorption layer 1104, a second electrolyte adsorption layer 1105, a third electrolyte adsorption layer 1106, a fourth electrolyte adsorption layer 1107, and a fifth electrolyte adsorption layer 1108, wherein the separator 1103 is located between the anode pole piece 1101 and the cathode pole piece 1102, and the anode pole piece 1101, the cathode pole piece 1102, and the separator 1103 are stacked and then wound around the winding axis to form a flat-body-shaped winding structure.

For the relevant technical features of the anode sheet 1101, the cathode sheet 1102 and the separator 1103 of this embodiment, reference may be made to the description of the embodiments corresponding to fig. 1 to 15, which is not repeated herein.

In the present embodiment, the winding structure of the electrode assembly includes a straight region 11A and first and second bending regions 11B1 and 11B2 located at both sides of the straight region 11A.

At least the inside surface of the innermost anode pole piece 1101 of the first bent region 11B1 and the second bent region 11B2 is provided with (e.g., attached with) an electrolyte adsorption layer, for example, the inside surface of each anode pole piece 1101 of the first bent region 11B1 and the second bent region 11B2 is provided with an electrolyte adsorption layer. In this embodiment, the inner surface of the anode sheet 1101 refers to the surface of the anode sheet 1101 facing the winding axis or the surface facing the inside of the winding structure.

For example, the first electrolyte solution adsorption layer 1104 is attached to the inner side surface of the innermost pole piece (which is the anode pole piece 1101) of the first bending region 11B1, and the second electrolyte solution adsorption layer 1105 is attached to the inner side surface of the outermost pole piece (which is the anode pole piece 1101).

For example, the third electrolyte solution adsorption layer 1106 is attached to the inner side surface of the first layer pole piece (which is the anode pole piece 1101) of the second bend region 11B2. The fourth electrolyte solution adsorption layer 1107 is attached to the inner side surface of the third layer pole piece (which is the anode pole piece 1101) of the second bend region 11B2. The fifth electrolyte solution adsorption layer 1108 is attached to the inner side surface of the fifth layer pole piece (which is the anode pole piece 1101) of the second bending region 11B2.

In this embodiment, two ends of the first electrolyte absorption layer 1104 and the second electrolyte absorption layer 1105 in the winding direction are located at a boundary between the first bending area 11B1 and the straight area 11A, and two ends of the third electrolyte absorption layer 1106, the fourth electrolyte absorption layer 1107 and the fifth electrolyte absorption layer 1108 in the winding direction are located at a boundary between the second bending area 11B2 and the straight area 11A.

In this embodiment, the functions, structures, distribution manners, and the like of the first electrolyte absorption layer 1104, the second electrolyte absorption layer 1105, the third electrolyte absorption layer 1106, the fourth electrolyte absorption layer 1107, and the fifth electrolyte absorption layer 1108 can all refer to the electrolyte absorption layers described in the embodiments of fig. 1 to 15, and are not repeated herein.

As shown in fig. 21, which is a schematic structural view of a cross section perpendicular to a winding axis K of another flat-body-shaped electrode assembly according to another embodiment of the present disclosure, the electrode assembly includes an anode plate 1201, a cathode plate 1202, a separator 1203, a first electrolyte adsorption layer 1204, a second electrolyte adsorption layer 1205, a third electrolyte adsorption layer 1206, a fourth electrolyte adsorption layer 1207, and a fifth electrolyte adsorption layer 1208, wherein the separator 1203 is located between the anode plate 1201 and the cathode plate 1202, and the anode plate 1201, the cathode plate 1202, and the separator 1203 are stacked and wound around the winding axis into a flat-body-shaped winding structure.

For the technical features related to the anode plate 1201, the cathode plate 1202 and the separator 1203 of this embodiment, reference may be made to the description of the embodiments corresponding to fig. 1 to 15, and no further description is given here.

In the present embodiment, the winding structure of the electrode assembly includes a straight region 12A and first and second bending regions 12B1 and 12B2 located at both sides of the straight region 12A.

At least the outer side surface of the innermost anode sheet 1201 of the first and second bent regions 12B1 and 12B2 is provided with (e.g., attached with) an electrolyte adsorption layer, for example, the outer side surface of each anode sheet 1201 of the first and second bent regions 12B1 and 12B2 is provided with an electrolyte adsorption layer. In this embodiment, the outer surface of the anode sheet 1201 refers to the surface of the anode sheet 1201 facing away from the winding axis or the surface facing away from the inside of the winding structure.

For example, a first electrolyte solution adsorption layer 1204 is attached to the outer side surface of the innermost pole piece (which is the anode pole piece 1201) of the first bending region 12B1, and a second electrolyte solution adsorption layer 1205 is attached to the outer side surface of the outermost pole piece (which is the anode pole piece 1201).

For example, the third electrolyte solution adsorption layer 1206 is attached to the outer side surface of the first layer pole piece (which is the anode pole piece 1201) of the second folded region 12B2. A fourth electrolyte solution adsorption layer 1207 is attached to the outer side surface of the third layer pole piece (which is the anode pole piece 1201) of the second bend region 12B2. The fifth electrolyte solution adsorption layer 1208 is attached to the outer side surface of the fifth layer pole piece (which is the anode pole piece 1201) of the second bent region 12B2.

In this embodiment, the two ends of the first electrolyte solution adsorbing layer 1204 and the second electrolyte solution adsorbing layer 1205 along the winding direction are located at the junction of the first bending region 12B1 and the straight region 12A, and the two ends of the third electrolyte solution adsorbing layer 1206, the fourth electrolyte solution adsorbing layer 1207 and the fifth electrolyte solution adsorbing layer 1208 along the winding direction are located at the junction of the second bending region 12B2 and the straight region 12A.

In this embodiment, the functions, structures, distribution manners, and the like of the first electrolyte absorption layer 1204, the second electrolyte absorption layer 1205, the third electrolyte absorption layer 1206, the fourth electrolyte absorption layer 1207, and the fifth electrolyte absorption layer 1208 can refer to the contents of the electrolyte absorption layers described in the embodiments of fig. 1 to 15, and are not repeated herein.

As shown in fig. 22, which is a schematic structural view of a cross section perpendicular to a winding axis K of another flat-body-shaped electrode assembly according to another embodiment of the present disclosure, the electrode assembly includes an anode pole piece 1301, a cathode pole piece 1302, a separator 1303 and a plurality of electrolyte absorption layers 1304, wherein the separator 1303 is located between the anode pole piece 1301 and the cathode pole piece 1302, and the anode pole piece 1301, the cathode pole piece 1302 and the separator 1303 are stacked and then wound around the winding axis into a flat-body-shaped winding structure.

The related technical features of the anode plate 1301, the cathode plate 1302 and the separator 1303 of this embodiment can refer to the description of the embodiment corresponding to fig. 1 to 15, and are not repeated herein.

In the present embodiment, the winding structure of the electrode assembly includes a straight region 13A and first and second bending regions 13B1 and 13B2 located at both sides of the straight region 13A.

At least the inner side surface of the innermost separator 1303 of the first bending region 13B1 and the second bending region 13B2 is attached with an electrolyte absorption layer 1304, for example, the inner side surface of each layer of separator 1303 of the first bending region 13B1 and the second bending region 13B2 is attached with an electrolyte absorption layer 1304. In the present embodiment, the inner side surface of the spacer 1303 means a surface of the spacer 1303 facing the winding axis or a surface facing the inside of the winding structure.

In this embodiment, two ends of each electrolyte absorption layer 1304 of the first bending region 13B1 along the winding direction are respectively located at a boundary between the first bending region 13B1 and the straight region 13A, and two ends of each electrolyte absorption layer 1304 of the second bending region 13B2 along the winding direction are respectively located at a boundary between the second bending region 12B2 and the straight region 12A.

In this embodiment, an electrolyte adsorption layer 1304 is attached to the inner side surfaces of the separators 1303, adjacent to the cathode pole piece 1302 or the anode pole piece 1301, of the first bending region 13B1 and the second bending region 13B2, so that the electrolyte adsorption layer can supplement the electrolyte to the adjacent cathode pole piece 1302 or anode pole piece 1301.

In this embodiment, the relevant contents of the function, structure, distribution mode, and the like of each electrolyte absorption layer 1304 can refer to the relevant contents of the electrolyte absorption layers described in the embodiments of fig. 1 to 15, and are not described herein again.

As shown in fig. 23, which is a schematic structural view of a cross section perpendicular to a winding axis K of another flat-body-shaped electrode assembly according to another embodiment of the present application, the electrode assembly includes an anode pole piece 1401, a cathode pole piece 1402, a separator 1403, and a plurality of electrolyte adsorbing layers 1404, wherein the separator 1403 is located between the anode pole piece 1401 and the cathode pole piece 1402, and the anode pole piece 1401, the cathode pole piece 1402, and the separator 1403 are stacked and wound around the winding axis into a flat-body-shaped winding structure.

For the technical features related to the anode plate 1401, the cathode plate 1402 and the separator 1403 of this embodiment, reference may be made to the description of the embodiments corresponding to fig. 1 to 15, and details are not repeated here.

In the present embodiment, the winding structure of the electrode assembly includes a straight region 14A and first and second bent regions 14B1 and 14B2 located at both sides of the straight region 14A.

The electrode assembly of the present embodiment is substantially similar to the electrode assembly described in the corresponding embodiment of fig. 17, and its differences may be as follows.

An electrolyte adsorption layer 1404 is attached to an outer side surface of at least the innermost separator 1403 of the first and second bending regions 14B1 and 14B2, for example, the electrolyte adsorption layer 1404 is attached to an outer side surface of each of the separators 1403 of the first and second bending regions 14B1 and 14B2. In this embodiment, the outer surface of the partition 1403 refers to the surface of the partition 1403 facing away from the winding axis or the surface facing away from the inside of the wound structure.

In this embodiment, two ends of each electrolyte absorption layer 1404 of the first bending region 14B1 along the winding direction are respectively located at a boundary between the first bending region 14B1 and the straight region 14A, and two ends of each electrolyte absorption layer 1404 of the second bending region 14B2 along the winding direction are respectively located at a boundary between the second bending region 14B2 and the straight region 14A.

In this embodiment, an electrolyte adsorption layer 1404 is attached to the outer surface of the separator 1403 adjacent to the cathode sheet 1402 or the anode sheet 1401 of the first bent region 14B1 and the second bent region 14B2, so that the electrolyte adsorption layer can replenish the adjacent cathode sheet 1402 or anode sheet 1401 with electrolyte.

In this embodiment, the function, structure, distribution and other relevant contents of each electrolyte absorption layer 1404 can refer to the relevant contents of the electrolyte absorption layers described in the embodiments of fig. 1 to 15, and are not repeated herein.

In some embodiments not shown in the figures, at least a part of an electrolyte solution adsorption layer may be further attached to both the inside surface and the outside surface of the separator adjacent to the cathode or anode pole piece in the first and second bending regions, so that the electrolyte solution adsorption layer may replenish the adjacent cathode or anode pole piece with an electrolyte solution.

In the above embodiments, the spacers adjacent to the cathode or anode pole piece in the first and second bending regions specifically refer to the spacers located inside and/or outside the anode pole piece or the spacers located inside and/or outside the cathode pole piece in the first and second bending regions.

In some embodiments not shown in the figures, at least a portion of the electrolyte solution adsorption layer is attached to the inner side surface and/or the outer side surface of at least one of the bent portion of the separator adjacent to the first bent portion and the second bent portion of the cathode sheet, and the bent portion of the separator adjacent to the first bent portion and the second bent portion of the anode sheet. Specifically, at least a part of the electrolyte solution adsorption layer may be disposed on the separator inside and/or outside the first-time bent portion of the cathode sheet and the separator inside and/or outside the second-time bent portion of the cathode sheet, and the electrolyte solution adsorption layer may be disposed on the inside surface and/or the outside surface of the separator. Or at least one part of the electrolyte adsorption layer can be arranged on the separator on the inner side and/or the outer side of the first bending part and the separator on the inner side and/or the outer side of the second bending part of the anode pole piece, and the electrolyte adsorption layer can be arranged on the inner side surface and/or the outer side surface of the separator.

At least one part of the electrolyte adsorption layer is arranged on the partition piece of the first bending area and the second bending area, so that the electrolyte uniformity of the first bending area and the second bending area is improved for the first bending area and the second bending area with larger gaps between the cathode pole piece and the anode pole piece, and the performance of the battery is improved while the influence on the energy density of the battery is reduced. As shown in fig. 24, which is a schematic structural view of a cross section perpendicular to a winding axis K of another flat-body-shaped electrode assembly according to another embodiment of the present application, the electrode assembly includes an anode pole piece 1501, a cathode pole piece 1502, a separator 1503, and a plurality of electrolyte absorption layers 1504, wherein the separator 1503 is located between the anode pole piece 1501 and the cathode pole piece 1502, and the anode pole piece 1501, the cathode pole piece 1502, and the separator 1503 are stacked and wound into a flat-body-shaped winding structure around the winding axis.

The features of the anode plate 1501, the cathode plate 1502 and the separator 1503 in this embodiment can be referred to the description of the embodiment corresponding to fig. 1 to 15, and are not repeated herein.

In the present embodiment, the winding structure of the electrode assembly includes a straight region 15A and first and second bending regions 15B1 and 15B2 located at both sides of the straight region 15A.

The electrode assembly of the present embodiment is substantially similar to the electrode assembly described in the corresponding embodiment of fig. 17 and 18, and the differences may be as follows.

The anode pole pieces 1501 and the cathode pole pieces 1502 included in the first bending region 15B1 and the second bending region 15B2 of the electrode assembly are sequentially and alternately stacked, a separator 1503 is arranged between any adjacent anode pole piece 1501 and cathode pole piece 1502 in the first bending region 15B1 and the second bending region 15B2, wherein the innermost pole pieces of the first bending region 15B1 and the second bending region 15B2 are both anode pole pieces 1501, and at least the inner side surface and the outer side surface of the innermost cathode pole piece 1502 in the first bending region 15B1 and the second bending region 15B2 are both provided with electrolyte absorption layers 1504, for example, the inner side surface and the outer side surface of each layer of cathode pole piece 1502 in the first bending region 15B1 and the second bending region 15B2 are both provided with electrolyte absorption layers 1504. In this embodiment, the inside surface of the cathode sheet 1502 refers to the surface of the cathode sheet 1502 facing the winding axis or the surface facing the inside of the winding structure, and the outside surface of the cathode sheet 1502 refers to the surface of the cathode sheet 1502 facing away from the winding axis or the surface facing away from the inside of the winding structure.

For example, the first bending region 15B1 has a plurality of layers of pole pieces, such as three layers of pole pieces, the pole pieces of the innermost layer (also referred to as the first layer) and the outermost layer (also referred to as the third layer) of the first bending region 15B1 are both the anode pole piece 1501, the pole piece (also referred to as the second layer) between the pole piece of the innermost layer and the outermost layer of the first bending region 15B1 is the cathode pole piece 1502, and both the inside surface and the outside surface of the cathode pole piece 1502 of the first bending region 15B1 are provided with (e.g., attached to) the electrolyte solution adsorption layer 1504.

The second bending region 15B2 has a plurality of layers of pole pieces, for example, five layers of pole pieces, and in the direction from inside to outside along the winding structure, the anode pole piece 1501 and the cathode pole piece 1502 of the second bending region 15B2 are alternately laminated in sequence, the innermost pole piece of the second bending region 15B2 is the anode pole piece 1501, and the inside surface and the outside surface of each layer of cathode pole piece 1502 of the second bending region 15B2 are provided with (for example, attached to) the electrolyte solution adsorption layer 1504.

For example, in the direction from inside to outside of the winding structure, the second bending region 15B2 sequentially includes first, second, third, fourth, and fifth electrode sheets, the first, third, and fifth electrode sheets are anode electrode sheets 1501, the second and fourth electrode sheets are cathode electrode sheets 1502, and electrolyte adsorption layers 1504 are disposed on the inner side surfaces and the outer side surfaces of the second and fourth electrode sheets of the second bending region 15B2.

In this embodiment, two ends of each electrolyte absorption layer 1504 along the winding direction L are respectively located at the junction between the bent region and the straight region, for example, two ends of each electrolyte absorption layer 1504 along the winding direction of the first bent region 15B1 are respectively located at the junction between the first bent region 15B1 and the straight region 15A, and two ends of each electrolyte absorption layer 1504 along the winding direction of the second bent region 15B2 are respectively located at the junction between the second bent region 15B2 and the straight region 15A.

In this embodiment, the functions, structures, distribution manners, and other relevant contents of each electrolyte absorption layer 1504 can refer to the electrolyte absorption layers described in the embodiments of fig. 1 to 15, and are not repeated herein.

As shown in fig. 25, which is a schematic structural view of a cross section perpendicular to a winding axis K of a flat-body-shaped electrode assembly according to another embodiment of the present application, the electrode assembly includes an anode pole piece 1601, a cathode pole piece 1602, a separator 1603, a first electrolyte absorption layer 1604, a second electrolyte absorption layer 1605, and a third electrolyte absorption layer 1606, wherein the separator 1603 is located between the anode pole piece 1601 and the cathode pole piece 1602, and the anode pole piece 1601, the cathode pole piece 1602, and the separator 1603 are stacked and wound around the winding axis into a flat-body-shaped winding structure.

The related technical features of the anode plate 1601, the cathode plate 1602 and the separator 1603 of this embodiment can refer to the description of the embodiment corresponding to fig. 1 to 15, and are not repeated herein.

In this embodiment, the winding structure of the electrode assembly includes a first flat region 16A1, a second flat region 16A2, a first bent region 16B1, and a second bent region 16B2, the first flat region 16A1 and the second flat region 16A2 are disposed opposite to each other, the first bent region 16B1 and the second bent region 16B2 are disposed opposite to each other, two ends of the first bent region 16B1 are respectively connected to the same side ends of the first flat region 16A1 and the second flat region 16A2, and two ends of the second bent region 16B2 are respectively connected to the other same side ends of the first flat region 16A1 and the second flat region 16A2.

The electrode assembly includes anode pole pieces 1601 and cathode pole pieces 1602 alternately laminated in sequence in the first bending region 16B1 and the second bending region 16B2, and a separator 1603 is provided between the adjacent anode pole pieces 1601 and cathode pole pieces 1602, wherein the innermost pole pieces of the first bending region 16B1 and the second bending region 16B2 are both the anode pole pieces 1601, and the inner side surfaces of at least the innermost cathode pole pieces 1602 of the first bending region 16B1 and the second bending region 16B2 are provided with (e.g., attached to) an electrolyte absorption layer, for example, the inner side surfaces of each of the cathode pole pieces 1602 of the first bending region 16B1 and the second bending region 16B2 are provided with (e.g., attached to) an electrolyte absorption layer. In this embodiment, the inside surface of the cathode plate 1602 refers to the surface of the cathode plate 1602 facing the winding axis or the surface facing the inside of the winding structure.

For example, the first bending region 16B1 has a plurality of layers of pole pieces, such as three layers of pole pieces, the pole pieces of the innermost layer (also referred to as the first layer) and the outermost layer (also referred to as the third layer) of the first bending region 16B1 are both the anode pole piece 1601, the pole piece between the innermost layer of the pole piece and the outermost layer of the pole piece (also referred to as the second layer of the pole piece) is the cathode pole piece 1602, and the first electrolyte solution adsorbing layer 1604 is attached to the inner side surface of the cathode pole piece 1602 of the first bending region 16B 1.

For example, the second bending region 16B2 has a plurality of layers of pole pieces, for example, five layers of pole pieces, and the anode pole pieces 1601 and the cathode pole pieces 1602 of the second bending region 16B2 are alternately laminated in sequence along the direction from the inside to the outside of the winding structure, the innermost pole piece of the second bending region 16B2 is the anode pole piece 1601, and the inner side surface of each layer of the cathode pole piece 1602 of the second bending region 16B2 is attached with an electrolyte solution adsorption layer.

For example, in the direction from inside to outside of the winding structure, the second bending region 16B2 includes first, second, third, fourth, and fifth electrode sheets in sequence, the first, third, and fifth electrode sheets are the anode electrode sheets 1601, the second and fourth electrode sheets are the cathode electrode sheets 1602, and the second electrolyte adsorption layer 1605 is attached to the inside surface of the cathode electrode sheet 1602 in the innermost adjacent anode electrode sheet 1601 and cathode electrode sheet 1602 of the second bending region 16B2, that is, the second electrolyte adsorption layer 1605 is attached to the inside surface of the second electrode sheet (which is the cathode electrode sheet 1602) of the second bending region 16B 2. The third electrolyte solution adsorption layer 1606 is attached to the inner side surface of the fourth layer pole piece (which is the cathode pole piece 1602) of the second bend region 16B 2.

In this embodiment, the first electrolyte solution adsorbing layer 1604 includes a first end and a second end along the winding direction L, the first end of the first electrolyte solution adsorbing layer 1604 is located in the first bending region 16B1, and the second end of the first electrolyte solution adsorbing layer 1604 is located in the first flat region 16A1. The second electrolyte solution absorbing layer 1605 includes a first end and a second end along the winding direction L, the first end of the second electrolyte solution absorbing layer 1605 is located in the second bending region 16B2, and the second end of the second electrolyte solution absorbing layer 1605 is located in the second straight region 16A2. The third electrolyte adsorption layer 1606 includes a first end and a second end along the winding direction L, the first end of the third electrolyte adsorption layer 1606 is located in the second bending region 16B2, and the second end of the third electrolyte adsorption layer 1606 is located in the second flat region 16A2. In another embodiment of the present application, a first end of the third electrolyte solution adsorption layer 1606 is located in the second bending region 16B2, and a second end of the third electrolyte solution adsorption layer 1606 may be located in the first flat region 16A1.

In this embodiment, the functions, structures, distribution manners, and the like of the first electrolyte absorption layer 1604, the second electrolyte absorption layer 1605, and the third electrolyte absorption layer 1606 may refer to the electrolyte absorption layers described in the embodiments of fig. 1 to 15, and are not described herein again.

As shown in fig. 26, which is a schematic structural view of a cross section perpendicular to a winding axis K of a flat electrode assembly according to another embodiment of the present disclosure, the electrode assembly includes an anode pole piece 1701, a cathode pole piece 1702, a separator 1703, a first electrolyte absorption layer 1704, a second electrolyte absorption layer 1705, and a third electrolyte absorption layer 1706, wherein the separator 1703 is located between the anode pole piece 1701 and the cathode pole piece 1702, and the anode pole piece 1701, the cathode pole piece 1702, and the separator 1703 are stacked and then wound into a flat winding structure around the winding axis.

The features of the anode plate 1701, the cathode plate 1702 and the separator 1703 of the present embodiment can be referred to the description of the corresponding embodiments of fig. 1 to 15, and are not repeated herein.

In this embodiment, the winding structure of the electrode assembly includes a first straight region 17A1, a second straight region 17A2, a first bent region 17B1, and a second bent region 17B2, the first straight region 17A1 and the second straight region 17A2 are disposed opposite to each other, the first bent region 17B1 and the second bent region 17B2 are disposed opposite to each other, two ends of the first bent region 17B1 are respectively connected to the same side ends of the first straight region 17A1 and the second straight region 17A2, and two ends of the second bent region 17B2 are respectively connected to the other same side ends of the first straight region 17A1 and the second straight region 17 A2.

The electrode assembly is formed by alternately laminating anode pole pieces 1701 and cathode pole pieces 1702 of the electrode assembly in sequence in a first bending region 17B1 and a second bending region 17B2, and a separator 1703 is arranged between the adjacent anode pole pieces 1701 and cathode pole pieces 1702, wherein the innermost pole pieces of the first bending region 17B1 and the second bending region 17B2 are both the anode pole pieces 1701, and the inner side surfaces of at least the innermost cathode pole pieces 1702 of the first bending region 17B1 and the second bending region 17B2 are provided with (e.g., attached to) an electrolyte absorption layer, for example, the inner side surfaces of each of the cathode pole pieces 1702 of the first bending region 17B1 and the second bending region 17B2 are provided with (e.g., attached to) an electrolyte absorption layer. In this embodiment, the inner surface of the cathode sheet 1702 refers to the surface of the cathode sheet 1702 facing the winding axis or the surface facing the inside of the winding structure.

For example, the first bending region 17B1 has a plurality of layers of pole pieces, for example, three layers of pole pieces, the pole pieces of the innermost layer (may also be referred to as a first layer) and the outermost layer (may also be referred to as a third layer) of the first bending region 17B1 are both the anode pole piece 1701, the pole piece between the innermost layer of the pole piece and the outermost layer of the pole piece (may also be referred to as a second layer of the pole piece) is the cathode pole piece 1702, and the first electrolyte adsorbing layer 1704 is attached to the inner side surface of the cathode pole piece 1702 of the first bending region 17B1.

The second bending region 17B2 has a plurality of layers of pole pieces, for example, five layers of pole pieces, and the anode pole pieces 1701 and the cathode pole pieces 1702 of the second bending region 17B2 are sequentially and alternately laminated in the direction from the inside to the outside of the winding structure, the pole piece at the innermost layer of the second bending region 17B2 is the anode pole piece 1701, and the inside surface of each layer of cathode pole piece 1702 of the second bending region 17B2 is attached with an electrolyte adsorption layer.

For example, in the direction from the inside to the outside of the wound structure, the second bending region 17B2 includes first, second, third, fourth, and fifth electrode sheets in order, the first, third, and fifth electrode sheets are anode electrode sheets 1701, the second and fourth electrode sheets are cathode electrode sheets 1702, and the second electrolyte adsorption layer 1705 is attached to the inside surface of the cathode electrode sheet 1702 of the innermost adjacent anode electrode sheet 1701 and cathode electrode sheet 1702 of the second bending region 17B2, that is, the second electrolyte adsorption layer 1705 is attached to the inside surface of the second electrode sheet (which is the cathode electrode sheet 1702) of the second bending region 17B2. The third electrolyte absorption layer 1706 is attached to the inner side surface of the fourth layer pole piece (which is the cathode pole piece 1702) of the second bending region 17B2.

In this embodiment, the first electrolyte solution adsorbing layer 1704 includes a first end and a second end along the winding direction L, and both the first end and the second end of the first electrolyte solution adsorbing layer 1704 are located in the first bending region 17B1. The second electrolyte absorption layer 1705 includes a first end and a second end along the winding direction L, the first end of the second electrolyte absorption layer 1705 is located at a boundary between the second bending region 17B2 and the first flat region 17A1, and the second end of the second electrolyte absorption layer 1705 is located at a boundary between the second bending region 17B2 and the second flat region 17 A2. The third electrolyte absorption layer 1706 includes a first end and a second end along the winding direction L, and the first end and the second end of the third electrolyte absorption layer 1706 are both located in the second bending region 17B2.

In this embodiment, in the second bending region 17B2, along the direction perpendicular to the winding axis K and from the inside to the outside of the electrode assembly, the curvature of each layer of electrode sheet decreases sequentially, that is, the bending degree decreases sequentially, and along the direction perpendicular to the winding axis K and from the inside to the outside of the electrode assembly, the circumferential angle covered by each electrolyte solution adsorption layer in the winding direction in the second bending region 17B2 may decrease sequentially, for example, the circumferential angle covered by the third electrolyte solution adsorption layer 1706 in the winding direction in the second bending region 17B2 may be smaller than the circumferential angle covered by the second electrolyte solution adsorption layer 1705 in the second bending region 17B2, for example, the circumferential angle covered by the third electrolyte solution adsorption layer 1706 in the winding direction in the second bending region 17B2 is 90 °, and the circumferential angle covered by the second electrolyte solution adsorption layer 1705 in the winding direction in the second bending region 17B2 is 180 °.

In this embodiment, the functions, structures, distribution manners, and the like of the first electrolyte absorption layer 1704, the second electrolyte absorption layer 1705, and the third electrolyte absorption layer 1706 can refer to the electrolyte absorption layers described in the embodiments of fig. 1 to 15, and are not described herein again.

In addition, in the embodiment of fig. 17 to 26, the electrolyte solution adsorption layer 4 may be disposed at a bent portion of at least one of the cathode sheet, the anode sheet, and the separator corresponding to a predetermined number of bends in the first and second bent regions. In some embodiments, at least a portion of the electrolyte solution adsorption layer is disposed at the first bending portion and/or the second bending portion of the cathode plate in the bending region, and/or at least a portion of the electrolyte solution adsorption layer is disposed at the first bending portion and/or the second bending portion of the anode plate, and/or at least a portion of the electrolyte solution adsorption layer is disposed at the bending portion of the separator adjacent to the first bending portion and/or the second bending portion of the cathode plate, and/or at least a portion of the electrolyte solution adsorption layer is disposed at the bending portion of the separator adjacent to the first bending portion and/or the second bending portion of the anode plate. The predetermined bending in this embodiment refers to the number of times that the cathode plate, the separator, and the anode plate are arranged in the sequence of bending when the cathode plate, the separator, and the anode plate are wound from inside to outside to form the motor assembly. Taking the embodiment of fig. 17 as an example, for the cathode sheet 92, the second electrolyte absorption layer 95 is located at the first bending of the cathode sheet 92, the first electrolyte absorption layer 94 is located at the second bending of the cathode sheet 92, the third electrolyte absorption layer 96 is located at the third bending of the cathode sheet 92, and so on. In addition, taking the embodiment of fig. 20 as an example, the third electrolyte absorption layer 1106 is located at the first bending of the anode sheet 1101, the first electrolyte absorption layer 1104 is located at the second bending of the anode sheet 1101, the fourth electrolyte absorption layer 1107 is located at the third bending of the anode sheet 1101, and so on. The predetermined bending times of the cathode plate and the anode plate are not limited to the first bending time and the second bending time, and any bending time range can be selected according to the needs, for example, the electrolyte adsorption layer 4 can be arranged at the bending position of the cathode plate bent for 1-4 times, 1-6 times, 1-8 times, or 3-4 times, 3-6 times, 3-8 times, or other bending times, and/or the electrolyte adsorption layer 4 is arranged at the bending position of the anode plate bent for 1-4 times, 1-6 times, 1-8 times, 3-4 times, 3-6 times, 3-8 times, or other bending times, and/or the electrolyte adsorption layer 4 is arranged at the bending position of the separator adjacent to the bending position of the cathode plate for 1-4 times, 1-6 times, 1-8 times, 3-4 times, 3-6 times, 3-8 times, or other bending times, or the bending position of the separator adjacent to the bending position of the anode plate for 1-4 times, 1-6 times, 1-8 times, 3-8 times, or other bending times, or other times of the separator adjacent to the bending position of the anode plate. In the above embodiments, the spacers adjacent to the cathode or anode pole piece in the first and second bending regions specifically refer to the spacers located inside and/or outside the anode pole piece or the spacers located inside and/or outside the cathode pole piece in the first and second bending regions.

In this embodiment, an electrolyte adsorption layer is disposed at a bending portion of a predetermined bending of at least one of the cathode plate, the anode plate, and the separator, and the predetermined bending portion with a large gap between the cathode plate 1 and the anode plate 2, for example, the predetermined bending includes a first bending and a second bending, and only the electrolytes at the first and second bending portions are regulated, so as to improve the electrolyte storage and retention performance at the first and second bending portions of the cathode plate 1 or the anode plate 2, improve the ionic conduction and diffusion performance, and improve the cycle performance and the service life of the battery cell. In addition, lay the electrolyte adsorbed layer in the regional first and second time of buckling of the surface of cathode pole piece and/or anode pole piece, the electrolyte adsorbed layer can also be to the first and second time of the cathode pole piece on the position of buckling the negative pole active material layer and/or the first and second time of the position of buckling the positive pole piece on the positive pole active material layer strengthen, reduce the active material layer and take place because of the cracked condition of buckling, and then improve the free performance of battery.

As shown in fig. 27, which is a schematic view of the cathode electrode piece 1702 of another embodiment of the present application after being unfolded, specifically, a schematic view of the cathode electrode piece 1702 in fig. 27 after being unfolded at a position where a second electrolyte absorption layer 1705 is attached to the cathode electrode piece 1702, wherein the first bending region 17B1 and the second bending region 17B2 have a central line M, the central line M is parallel to a winding axis of the electrode assembly and extends along a length direction of the electrode assembly in fig. 26, and the central line M divides the first bending region 17B1 and the second bending region 17B2 into an upper portion and a lower portion along a width direction of the electrode assembly.

For the second electrolyte solution adsorption layer 1705, it includes the middle adsorption layer 43 at the first bending subarea 1708, and the side adsorption layer 44 at the second bending subarea 1709, wherein the first bending subarea 1708 covers the middle line M of the bending area, i.e. the first bending subarea 1708 is located in the middle of the bending area as a whole; the second bending sub-area 1709 is located on at least one side of the first bending sub-area 1708, and as shown in fig. 27, optionally, one second bending sub-area 1709 is respectively provided on both sides of the first bending sub-area. As shown in fig. 27, wherein the porosity of the middle absorbent layer 43 is greater than the porosity of the side absorbent layers 44. The porosity of the electrolyte adsorption layer in the different bending sections is the ratio of the sum of the areas of all the ion exchange channels 40 on the electrolyte adsorption layer in one section to the area of the electrolyte adsorption layer in that region. The porosity of the electrolyte adsorption layer can be adjusted by changing the diameter of the ion exchange channels 40 on the electrolyte adsorption layer and the number of ion exchange channels per unit area. For example, the diameter of the ion exchange channels 40 and/or the number of ion exchange channels per unit area located in the middle adsorbent layer 43 may be greater than the diameter of the ion exchange channels 40 and/or the number of ion exchange channels per unit area in the side adsorbent layers 44. The structure of the second electrolyte solution adsorption layer 1705 of this embodiment may be disposed on one surface or both surfaces of the bending portion of the predetermined secondary bending of at least one of the cathode electrode sheet, the anode electrode sheet, and the separator. In some embodiments, 0< the porosity of the middle adsorbent layer 43 ≦ 50%. The porosity of the middle absorbent layer 43 may be 0.05%, 0.08%, 0.1%, 0.5%, 1%, 2%, 5%, 10%, 15%, 30%, 40%, etc., or other values. In some embodiments, the porosity of the side adsorption layer 44 may be 0, i.e., the side adsorption layer 44 is not provided with ion exchange channels 40, or 0< the porosity of the side adsorption layer 44 ≦ 50%. The side absorbent layer 44 porosity can be 0, 0.05%, 0.08%, 0.1%, 0.5%, 1%, 2%, 5%, 10%, 15%, 30%, 40%, etc. or other values.

As shown in fig. 28, the porosity of the middle absorbent layer 43 may also be smaller than the porosity of the side absorbent layers 44. For example, the diameter of the ion exchange channels 40 and/or the number of ion exchange channels per unit area located in the middle adsorbent layer 43 may be smaller than the diameter of the ion exchange channels 40 and/or the number of ion exchange channels per unit area in the side adsorbent layers 44. The structure of the second electrolyte solution adsorption layer 1705 of this embodiment may be disposed on one surface or both surfaces of the bending portion of the predetermined secondary bending of at least one of the cathode electrode sheet, the anode electrode sheet, and the separator. In some embodiments, 0< the porosity of the side adsorption layer 44 ≦ 50%. The side absorbent layer 44 may have a porosity of 0.05%, 0.08%, 0.1%, 0.5%, 1%, 2%, 5%, 10%, 15%, 30%, 40%, etc. or other values. In some embodiments, the porosity of the middle adsorbent layer 43 may be 0, i.e., no ion exchange channels 40 are provided on the middle adsorbent layer 43; the porosity of the middle adsorption layer 43 can be more than 0 and less than or equal to 50 percent. The porosity of the middle absorbent layer 43 may be 0, 0.05%, 0.08%, 0.1%, 0.5%, 1%, 2%, 5%, 10%, 15%, 30%, 40%, etc., or other values.

As shown in fig. 29, a schematic view of the cathode electrode piece 1702 of another embodiment of the present application after being unfolded, specifically a schematic view of the cathode electrode piece 1702 in fig. 26 after being unfolded with the second electrolyte absorption layer 1705 attached thereto, in the bending region, along the direction parallel to the winding axis K of the electrode assembly, the ion exchange channel 40 is distributed in a zigzag line or a curve on the second electrolyte absorption layer 1705. The ion exchange channels 40 are arranged on the second electrolyte adsorption layer 1705 to form a broken line or a curve, so that the ion exchange channels 40 are distributed at different widths and height positions of the second electrolyte adsorption layer 1705, the second electrolyte adsorption layer 1705 can realize electrolyte release and ion conduction and diffusion at different heights and width positions, and the improvement of the cycle performance and the service life of the battery are facilitated. In this embodiment, 0< the porosity of the second electrolyte adsorption layer 1705 is 50% or less. The porosity of the second electrolyte solution adsorption layer 1705 may be 0.05%, 0.08%, 0.1%, 0.5%, 1%, 2%, 5%, 10%, 15%, 30%, 40%, or the like, or other values.

The embodiment of fig. 27 to 29 only describes the positional relationship between the electrolyte absorption layer and the cathode pole piece and the structural features of the electrolyte absorption layer in a general way, and the electrolyte absorption layer of fig. 27 to 29 is not limited to be provided at the first and second bending portions of the cathode pole piece, and may be provided at other portions of the cathode pole piece, as well as on the anode pole piece and the separator. The structure of the electrolyte absorption layer of the embodiment of fig. 27 to 29 can be applied to the electrolyte absorption layer structure of any one of the embodiments of fig. 3 to 8 and 11 to 26.

Fig. 30 is a schematic structural diagram of a battery cell according to another embodiment of the present disclosure. The battery cell includes a case 181 and one or more electrode assemblies 182 accommodated in the case 181, the case 181 includes a case 1811 and a cover 1812, the case 1811 has an accommodating cavity, and the case 1811 has an opening, i.e., the plane does not have a case wall so that the inside and the outside of the case 1811 are communicated, so that the electrode assembly 182 can be accommodated in the accommodating cavity of the case 1811, the cover 1812 and the case 1811 are combined with the opening of the case 1811 to form a hollow cavity, and after the electrode assembly 182 is accommodated in the case 181, the case 181 is filled with an electrolyte and sealed.

The case 1811 is determined according to the shape of the one or more electrode assemblies 182 after being combined, and for example, the case 1811 may be a hollow rectangular parallelepiped or a hollow cube or a hollow cylinder. For example, when the housing 1811 is a hollow rectangular parallelepiped or cube, one of the planes of the housing 1811 is an open surface, i.e., the plane has no housing wall so that the housing 1811 communicates inside and outside; when the housing 1811 is a hollow cylinder, one of the circular side surfaces of the housing 1811 is an open surface, i.e., the circular side surface has no housing wall so that the housing 1811 communicates inside and outside.

In another embodiment of the present application, the housing 1811 may be made of a material of conductive metal or plastic, and optionally, the housing 1811 is made of aluminum or aluminum alloy.

The structure of the electrode assembly 182 can refer to the related contents of the electrode assembly described in the foregoing embodiments of fig. 1 to 27, and will not be described herein again.

As shown in fig. 31, which is a schematic structural diagram of a battery module according to another embodiment of the present disclosure, the battery module 19 includes a plurality of battery cells 191 connected to each other, where the plurality of battery cells 191 may be connected in series or in parallel or in series-parallel, where the series-parallel connection refers to connection including both series connection and parallel connection, and the structure of the battery cell 191 may refer to the battery cells described in the embodiment corresponding to fig. 30, and is not repeated herein.

Fig. 32 is a schematic structural diagram of a battery according to another embodiment of the present application, where the battery includes a case, and a plurality of battery cells are accommodated in the case. The structure of the battery cell may refer to the structure of the battery cell shown in fig. 30. The specific manner of accommodating the plurality of battery cells in the case may include: the battery monomer is directly arranged in the box body, or a plurality of battery monomers form a battery module, and then the battery module is arranged in the battery.

As shown in fig. 32, in some embodiments, the battery includes a plurality of battery modules 19 and a case including a lower case 20 and an upper case 30, the plurality of battery modules 19 may be connected in series or in parallel or in series, the lower case 20 has a receiving cavity, and the lower case 20 has an opening, so that the plurality of connected battery modules 19 may be received in the receiving cavity of the lower case 20, the upper case 30 and the lower case 20 are combined at the opening of the lower case 20 to form a hollow cavity, and the upper case 30 and the lower case 20 are combined and then sealed.

In another embodiment of the present application, the battery, which may be referred to as a battery pack, for example, for powering an automobile, may individually power the powered device.

In another embodiment of the present application, according to the power demand of the power-consuming device, a plurality of batteries are connected to each other and then combined into a battery pack for supplying power to the power-consuming device. In another embodiment of the present application, the battery pack may also be housed in a case and packaged.

For the sake of brevity, the following embodiments are described taking the example in which the electric device includes a battery.

An embodiment of the present application further provides an electric device, for example, the electric device may be an automobile, for example, a new energy vehicle, and the electric device includes the battery described in the foregoing embodiment, where the battery used in the electric device may be the battery described in the embodiment corresponding to fig. 31, and details thereof are not repeated here.

For example, as shown in fig. 33, which is a schematic structural diagram of an electric device according to another embodiment of the present application, the electric device may be an automobile, the automobile may be a fuel automobile, a gas automobile or a new energy automobile, and the new energy automobile may be a pure electric automobile, a hybrid electric automobile or a range-extended automobile. The car includes a battery 2101, a controller 2102, and a motor 2103. The battery 2101 is used to supply power to the controller 2102 and the motor 2103 as an operation power source and a driving power source of the automobile, and the battery 2101 is used for power demand for work at the start, navigation, and operation of the automobile, for example. For example, the battery 2101 supplies power to the controller 2102, the controller 2102 controls the battery 2101 to supply power to the motor 2103, and the motor 2103 receives and uses the power of the battery 2101 as a driving power source of an automobile, instead of or in part instead of fuel or natural gas, to provide driving power for the automobile.

Those skilled in the art will appreciate that although some embodiments herein include some features included in other embodiments, not others, combinations of features of different embodiments are meant to be within the scope of the application and form different embodiments. For example, in the claims, any of the claimed embodiments may be used in any combination.

The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.

Claims

1. An electrode assembly, comprising:

the separator is used for separating the cathode pole piece and the anode pole piece;

an electrolyte adsorption layer configured to be laid along a surface of at least one of the cathode pole piece, the anode pole piece, and the separator; the electrolyte adsorption layer is provided with an ion exchange channel, and the ion exchange channel is a through hole arranged along the thickness direction of the electrolyte adsorption layer.

2. The electrode assembly according to claim 1, wherein the electrolyte adsorption layer is attached to one surface or both surfaces of the cathode sheet, and/or,

the electrolyte adsorption layer is attached to one surface or two surfaces of the anode pole piece, and/or,

the electrolyte adsorption layer is attached to one surface or both surfaces of the separator.

3. The electrode assembly according to claim 2, wherein the cathode sheet, the separator, and the anode sheet are wound to form a bent region, and at least a portion of the electrolyte solution adsorption layer is disposed on a surface of at least one of the cathode sheet, the anode sheet, and the separator in the bent region.

4. The electrode assembly according to claim 3, wherein at least a portion of the electrolyte solution adsorption layer is disposed at a first and/or second bending portion of the cathode sheet in a bending region, and/or wherein at least a portion of the electrolyte solution adsorption layer is disposed at a first and/or second bending portion of the anode sheet, and/or wherein at least a portion of the electrolyte solution adsorption layer is disposed at a bending portion of the separator adjacent to the first and/or second bending portion of the cathode sheet, and/or wherein at least a portion of the electrolyte solution adsorption layer is disposed at a bending portion of the separator adjacent to the first and/or second bending portion of the anode sheet.

5. The electrode assembly according to claim 4, wherein the bending region includes a first bending section covering a center line of the bending region and a second bending section located at least one side of the first bending section, the center line of the bending region being parallel to a winding axis of the electrode assembly; wherein,

the porosity of the part of the electrolyte adsorption layer in the first bending subarea is different from the porosity of the part of the electrolyte adsorption layer in the second bending subarea, wherein the porosity of the electrolyte adsorption layer is the ratio of the area of the ion exchange channel to the area of the electrolyte adsorption layer.

6. The electrode assembly according to claim 4, wherein the ion exchange channels are arranged in a zigzag or curved line on the electrolyte solution adsorption layer in the bending region in a direction parallel to a winding axis of the electrode assembly.

7. The electrode assembly of any of claims 1-6, wherein the electrolyte adsorption layer comprises an adsorption base layer having the ion exchange channels disposed thereon.

8. The electrode assembly of claim 7, wherein the material of the adsorption base layer is one of acrylic acid-acrylate copolymer, butadiene-styrene copolymer, styrene-acrylic acid copolymer, styrene-acrylate copolymer, ethylene-vinyl acetate copolymer, acrylic acid grafted polyethylene, maleic anhydride grafted polyethylene, acrylic acid grafted polypropylene, maleic anhydride grafted polypropylene, polyvinylidene fluoride, carboxymethyl cellulose, polyimide, polyetherimide, polyethylene terephthalate, styrene-isoprene-styrene copolymer rubber, ethylene-vinyl acetate copolymer bisphenol A type epoxy resin, ethylene-vinyl acetate copolymer bisphenol F type epoxy resin, glyceryl ether type epoxy resin, glyceryl ester type epoxy resin, silicone type resin, polyurethane, styrene-isoprene-styrene copolymer.

9. The electrode assembly of any one of claims 1-6, wherein the electrolyte adsorption layer comprises an adsorption base layer attached at one side thereof to a corresponding cathode pole piece, anode pole piece or separator, and a support layer attached at the other side thereof, and the ion exchange channels penetrate the support layer and the adsorption base layer in the thickness direction.

10. The electrode assembly of claim 9, wherein the material of the adsorption base layer is one of acrylic acid-acrylate copolymer, butadiene-styrene copolymer, styrene-acrylic acid copolymer, styrene-acrylate copolymer, ethylene-vinyl acetate copolymer, acrylic acid grafted polyethylene, maleic anhydride grafted polyethylene, acrylic acid grafted polypropylene, maleic anhydride grafted polypropylene, polyvinylidene fluoride, carboxymethyl cellulose, polyimide, polyetherimide, polyethylene terephthalate, styrene-isoprene-styrene copolymer rubber, ethylene-vinyl acetate copolymer bisphenol a type epoxy resin, ethylene-vinyl acetate copolymer bisphenol F type epoxy resin, glyceryl ether type epoxy resin, glyceryl ester type epoxy resin, silicone type resin, polyurethane, styrene-isoprene-styrene copolymer.

11. The electrode assembly of claim 9, wherein the material of the support layer is one of polyvinyl chloride, polyethylene, polypropylene, polyvinylidene fluoride, hexafluoropropylene-vinylidene fluoride copolymer, tetrafluoropropene-vinylidene fluoride copolymer, chlorotrifluoropropene-vinylidene fluoride copolymer, polyethylene terephthalate, polyimide, polyetherimide, polycarbonate, polystyrene, polyphenylene sulfide, polyvinylidene fluoride or copolymers thereof, polyarylate, fiber, nylon, and nonwoven fabric.

12. The electrode assembly of claim 9, wherein the support layer has a thickness of 50um,0< the porosity of the support layer of 50% or less, and/or the tensile modulus of the support layer of 100Mpa or less, wherein the porosity of the support layer is the ratio of the total area of the ion exchange channels to the area of the support layer.

13. A battery cell, comprising: a case, an electrolyte, a cap plate, and at least one electrode assembly according to any one of claims 1 to 12,

the case has a receiving cavity in which the electrode assembly and the electrolyte are received and an opening;

the cover plate is used for closing the opening of the shell.

14. A battery comprising a case and at least one cell as recited in claim 13, said cell being received in said case.

15. An electrical device, wherein the electrical device is configured to receive power provided from the battery of claim 14.