Electrode assembly, battery cell, battery and power consuming device

Abstract

The electrode assembly includes a cathode plate, an anode plate, a separator for isolating the anode and cathode plates, and an electrolyte adsorption layer disposed along at least one surface of the cathode plate, the anode plate, and the separator, the electrolyte adsorption layer having ion exchange passages formed as through-holes extending along the thickness of the electrolyte adsorption layer. The electrolyte adsorption layer disposed on at least one surface of the cathode plate, the anode plate, and the separator can adsorb and retain electrolyte, which is advantageous for the storage and release of electrolyte and the conduction and diffusion of ions, thereby improving the cycle performance and service life of the battery.

Description

[Technical field]

[0001] The present application relates to the field of batteries, and in particular to electrode assemblies, battery cells, batteries and power consuming devices. [Background technology]

[0002] Rechargeable batteries, also known as secondary batteries, are batteries that can be used continuously after being discharged by activating the active material through charging. Rechargeable batteries are widely used in electronic devices, such as mobile phones, notebook computers, battery cars, electric cars, electric airplanes, electric steamships, electric car toys, electric steamship toys, electric airplane toys, and electric tools.

[0003] Rechargeable batteries may include nickel cadmium batteries, nickel hydrogen batteries, lithium ion batteries, secondary alkaline zinc manganese batteries, and the like.

[0004] Currently, the batteries most commonly used in automobiles are generally lithium-ion batteries. As a rechargeable battery, lithium-ion batteries have the advantages of small volume, high energy density, high power density, many cycles, and long storage time.

[0005] The rechargeable battery includes an electrode assembly and an electrolyte, the electrode assembly including a negative electrode plate, a positive electrode plate, and a separator between the negative electrode plate and the positive electrode plate, the negative electrode plate each having a negative electrode active material layer, for example, the negative electrode active material of the negative electrode active material layer can be lithium manganese oxide, lithium cobalt oxide, lithium iron phosphate, or lithium nickel cobalt manganese oxide, and the surface of the positive electrode plate each having a positive electrode active material layer, for example, the positive electrode active material of the positive electrode active material layer can be graphite or silicon.

[0006] In the electrode assembly, the electrolyte is constantly consumed during the cycle process, and after the electrolyte between the positive plates is consumed, the electrolyte remaining in the case cannot be replenished in a timely manner. This causes a problem of a shortage of electrolyte after a long period of charging and discharging, which reduces the cycle life of the battery cell and the battery.

[0007] Therefore, how to improve the cycle life of batteries has become a major issue in the industry. Summary of the Invention

[0008] Aspects of the present application provide electrode assemblies, battery cells, batteries and power consuming devices that overcome or at least partially solve the above problems.

[0009] According to a first aspect of the present application, there is provided an electrode assembly, which includes a cathode plate, an anode plate, a separator, and an electrolyte adsorption layer, the separator is used to separate the cathode plate and the anode plate, the electrolyte adsorption layer is configured to be disposed along at least one surface of the cathode plate, the anode plate, and the separator, and the electrolyte adsorption layer is provided with ion exchange passages, which are through-holes arranged along the thickness direction of the electrolyte adsorption layer.

[0010] By disposing an electrolyte adsorption layer on at least one surface of the cathode plate, anode plate and separator, the electrolyte adsorption layer can be used to replenish the electrolyte consumed during cycling by retaining and slowly releasing the electrolyte, which is favorable for ion conduction and diffusion, and further improves the performance of the battery cell. The electrolyte adsorption layer is provided with ion exchange passages, which are through-holes arranged along the thickness direction of the electrolyte adsorption layer, which are favorable for the release of the electrolyte and the conduction and diffusion of the ions, and are favorable for improving the cycle performance and service life of the battery.

[0011] In some embodiments, an electrolyte adsorption layer is applied to one or both surfaces of a cathode plate, and / or an electrolyte adsorption layer is applied to one or both surfaces of an anode plate, and / or an electrolyte adsorption layer is applied to one or both surfaces of a separator.

[0012] In this embodiment, the electrolyte adsorption layer is attached to one or both surfaces of the negative electrode plate, the positive electrode plate or the separator, thereby improving the storage and retention performance of the electrolyte at one or both sides of the negative electrode plate, the positive electrode plate or the separator, thereby replenishing the electrolyte consumed during the cycle process, and favoring the conduction and diffusion of ions, and further improving the performance of the battery cell.

[0013] In some embodiments, the cathode plate, the separator and the anode plate are wound to form a folded region, and at least a portion of the electrolyte-adsorbing layer is disposed on at least one surface of the anode plate, the cathode plate and the separator within the folded region.

[0014] In this embodiment, at least a part of the electrolyte adsorption layer is disposed in the folded region of at least one surface of the cathode plate, the anode plate, and the separator, so that the electrolyte adsorption layer can fill the gap between the cathode plate and the anode plate in the folded region, and can hold and slowly release the electrolyte in the folded region to replenish the electrolyte consumed during the cycle process, which is favorable for ion conduction and diffusion, and further improves the performance of the battery cell. In addition, by disposing the electrolyte adsorption layer in the folded region of the surface of the cathode plate and / or the anode plate, the electrolyte adsorption layer can reinforce the cathode active material layer on the cathode plate and / or the anode active material layer on the anode plate, and can reduce the occurrence of the situation in which the cathode active material layer on the cathode plate and / or the anode active material layer on the anode plate are broken due to bending, and further improves the performance of the battery cell.

[0015] In some embodiments, at least a portion of the electrolyte adsorption layer is provided at the first fold site and / or the second fold site of the cathode plate in the fold region, and / or at least a portion of the electrolyte adsorption layer is provided at the first fold site and / or the second fold site of the anode plate, and / or at least a portion of the electrolyte adsorption layer is provided at the fold site of the separator adjacent to the first fold site of the cathode plate and / or the fold site of the separator adjacent to the second fold site of the cathode plate, and / or at least a portion of the electrolyte adsorption layer is provided at the fold site of the separator adjacent to the first fold site of the anode plate and / or the fold site of the separator adjacent to the second fold site of the anode plate.

[0016] In this embodiment, at least a part of the electrolyte adsorption layer is provided at the first and second folding sites of at least one of the cathode plate, the anode plate, and the separator, so that the uniformity of the electrolyte at the first and second folding sites can be improved compared to the first and second folding sites where the gap between the cathode plate and the anode plate is large, thereby reducing the impact on the energy density of the battery cell and improving the performance of the battery cell. In addition, by providing the electrolyte adsorption layer at the first and second folding sites of the folding region of the surface of the cathode plate and / or the anode plate, the electrolyte adsorption layer reinforces the cathode active material layer on the first and second folding sites of the cathode plate and / or the anode active material layer on the first and second folding sites of the anode plate, reducing the occurrence of a situation in which the active material layer breaks due to folding, and further improving the performance of the battery cell.

[0017] In some embodiments, the folding region includes a first folding section covering a centerline of the folding region and a second folding section located on at least one side of the first folding section, the centerline of the folding region being parallel to the winding axis of the electrode assembly, wherein the porosity of the portion of the electrolyte adsorption layer located within the first folding section is different from the porosity of the portion of the electrolyte adsorption layer located within the second folding section, and wherein the porosity of the electrolyte adsorption layer is the ratio of the area of ​​the ion exchange passage to the area of ​​the electrolyte adsorption layer.

[0018] In this embodiment, by adjusting the porosity of the support layer surface located in the first folded section and the second folded section, the performance of electrolyte release and ion conduction and diffusion in the first folded section and the second folded section can be adjusted, which is beneficial to improving the cycle performance and service life of the battery.

[0019] In some embodiments, in the bent region, the ion exchange channels are distributed on the electrolyte adsorption layer in a bent or curved line along a direction parallel to the winding axis of the electrode assembly.

[0020] In this embodiment, the ion exchange channels are arranged in a bent or curved shape on the electrolyte adsorption layer, so that the ion exchange channels are distributed at various widths and heights of the electrolyte adsorption layer. This allows the electrolyte adsorption layer to realize electrolyte release and ion conduction and diffusion at various heights and widths, which is beneficial to improving the cycle performance and service life of the battery.

[0021] In some embodiments, the electrolyte adsorption layer includes an adsorption base, one side of which is attached to a corresponding cathode plate, anode plate or separator, and the adsorption base provides ion exchange passages.

[0022] In this embodiment, the adsorption base is used to store and retain the electrolyte on the surface of the cathode plate, anode plate or separator, thereby replenishing the electrolyte consumed during cycling, which is favorable for ion conduction and diffusion, and further improving the performance of the battery cell. The adsorption base has ion exchange channels arranged along its thickness direction, which is favorable for the release of the electrolyte and the conduction and diffusion of the ions, and is favorable for improving the cycle performance and service life of the battery.

[0023] In this embodiment, the material of the adsorption base layer includes acrylic acid-acrylic acid ester copolymer, butadiene-styrene copolymer, styrene-acrylic acid copolymer, styrene-acrylic acid ester 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, glycerin ester type epoxy resin, silicone type resin, polyurethane, styrene-isoprene-styrene copolymer, and one of the above modified materials.

[0024] In some embodiments, the electrolyte adsorption layer includes an adsorption base and a support layer, one side of the adsorption base is attached to a corresponding cathode plate, anode plate or separator, and the support layer is attached to the other side of the adsorption base, and the ion exchange passages penetrate the support layer and the adsorption base along the thickness direction.

[0025] In this embodiment, the electrolyte adsorption layer includes an adsorption base and a support layer, the adsorption base has a certain fluidity, and is easy to move and deform on the surface of the cathode plate, anode plate or separator, which will affect the uniformity of the distribution of the electrolyte adsorption layer, and a support layer is installed on the opposite side of the adsorption base attached to the cathode plate, anode plate or separator, and the support layer can move ions and inhibit the movement and deformation of the adsorption base, so that the adsorption base is uniformly held on the surface of the cathode plate, anode plate or separator, and the electrolyte is stably held on the surface of the cathode plate, anode plate or separator for a long time, which is favorable to improving the cycle performance and service life of the battery. The ion exchange passage penetrates the support layer and the adsorption base, and the support layer and the adsorption base can be penetrated through the ion exchange passage, which is favorable to the release of electrolyte and the conduction and diffusion of ions, which is favorable to improving the cycle performance and service life of the battery.

[0026] In some embodiments, the material of the adsorptive base layer comprises one of acrylic acid-acrylic acid ester copolymers, butadiene-styrene copolymers, styrene-acrylic acid copolymers, styrene-acrylic acid ester copolymers, ethylene-vinyl acetate copolymers, acrylic acid grafted polyethylene, maleic anhydride grafted polyethylene, acrylic acid grafted polypropylene, maleic anhydride grafted polypropylene, polyvinylidene fluoride, carboxymethyl cellulose, polyimides, polyetherimides, polyethylene terephthalate, styrene-isoprene-styrene copolymer rubber, ethylene-vinyl acetate copolymer bisphenol A type epoxy resins, ethylene-vinyl acetate copolymer bisphenol F type epoxy resins, glyceryl ether type epoxy resins, glycerin ester type epoxy resins, silicone type resins, polyurethanes, styrene-isoprene-styrene copolymers, and modifications of the above materials.

[0027] In some embodiments, the material of the support layer includes one of polyvinyl chloride, polyethylene, polypropylene, polyvinylidene fluoride, hexafluoropropylene-vinylidene fluoride copolymers, tetrafluoropropylene-vinylidene fluoride copolymers, trifluorochloropropylene-vinylidene fluoride copolymers, polyethylene terephthalate, polyimide, polyetherimide, polycarbonate, polystyrene, polyphenylene sulfide, polyvinylidene fluoride or copolymers thereof, polyarylate, fibers, nylon, nonwoven fabrics, and modifications of the above materials.

[0028] In some embodiments, the thickness of the support layer is ≦50 um, the porosity of the support layer is 0<≦50%, and / or the tensile modulus of the support layer is ≦100 MPa, where the porosity of the support layer is the ratio of the total area of ​​the ion exchange passages to the area of ​​the support layer.

[0029] In this embodiment, the thickness of the support layer is set to ≦50um, so that the gap between the cathode plate and the anode plate can be controlled within a reasonable range, which is favorable for the transmission of ions. The porosity of the support layer is set to 0<porosity of the support layer≦50%, so that the ions can be made to flow better, and the flow and deformation of the adsorption base can be suppressed, so that the adsorption base can be uniformly held on the surface of the cathode plate, the anode plate or the separator, and the electrolyte can be stably held on the surface of the cathode plate, the anode plate or the separator for a long time, which is favorable for improving the cycle performance and service life of the battery. The tensile modulus of the support layer is ≦100Mpa, so that the support layer has good holding performance for the adsorption base.

[0030] According to a second aspect of the present application, there is provided a battery cell, which includes a case, an electrolyte, a cover plate and at least one of the electrode assemblies according to the above embodiments, wherein the case has a chamber and an opening, the electrode assembly and the electrolyte are accommodated in the chamber, and the cover plate is used to close the opening of the case.

[0031] According to a third aspect of the present application, there is provided a battery, the battery comprising a housing and at least one battery cell according to the above embodiments, the battery cell being housed within the housing.

[0032] According to a fourth aspect of the present application, there is provided a power consuming device configured to receive power supplied from the battery of any of the above embodiments.

[0033] The above description is only an outline of the technical solutions of the embodiments of the present application, which can be implemented based on the contents of the specification in order to more clearly understand the technical means of the embodiments of the present application, and in order to make the above and other objectives, features and advantages of the embodiments of the present application more obvious and understandable, the following lists specific embodiments of the present application. [Brief description of the drawings]

[0034] In order to more clearly explain the technical solutions of the embodiments of the present application, the following will briefly describe the drawings necessary for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain other drawings based on these drawings without paying any creative labor. [Figure 1] FIG. 1 is a perspective structural schematic diagram of an electrode assembly according to an embodiment of the present application. [Diagram 2] 2 is a structural schematic diagram of a cross section perpendicular to the winding axis K of the electrode assembly of FIG. 1. [Diagram 3] 1 is a structural schematic diagram of a cross section perpendicular to the winding axis K of an electrode assembly having a flat shape according to another embodiment of the present application. FIG. [Figure 4] 13 is a structural schematic diagram of a cross section perpendicular to the winding axis K of an electrode assembly having another flat shape according to another embodiment of the present application. FIG. [Diagram 5] 13 is a structural schematic diagram of a cross section perpendicular to the winding axis K of an electrode assembly having another flat shape according to another embodiment of the present application. FIG. [Figure 6] FIG. 13 is a structural schematic diagram of a cross section perpendicular to the winding axis K of an electrode assembly having another flat shape according to another embodiment of the present application. [Figure 7] FIG. 13 is a structural schematic diagram of a cross section perpendicular to the winding axis K of an electrode assembly having another flat shape according to another embodiment of the present application. [Figure 8] FIG. 13 is a structural schematic diagram of a cross section perpendicular to the winding axis K of an electrode assembly having another flat shape according to another embodiment of the present application. [Figure 9] FIG. 2 is a structural schematic diagram of an anode plate according to another embodiment of the present application. [Figure 10] FIG. 2 is a structural schematic diagram of a cathode plate according to another embodiment of the present application. [Figure 11] 11 is a schematic diagram of a cross-sectional structure taken along the line AA in FIG. 10. [Figure 12] 11 is a schematic diagram of a cross-sectional structure taken along the line BB in FIG. 10. [Figure 13] 11 is a schematic cross-sectional view of another embodiment of the present application taken along the line BB in FIG. 10. FIG. [Figure 14] 11 is a schematic cross-sectional view of another embodiment of the present application taken along the line BB in FIG. 10. FIG. [Figure 15] 11 is a schematic cross-sectional view of another embodiment of the present application taken along the line BB in FIG. 10. FIG. [Figure 16] FIG. 2 is a schematic diagram of the local structure of a bending region of an electrode assembly according to an embodiment of the present application. [Figure 17] 1 is a structural schematic diagram of a cross section perpendicular to the winding axis K of an electrode assembly having a flat shape according to another embodiment of the present application. FIG. [Figure 18] FIG. 2 is a structural schematic diagram of a cathode plate according to another embodiment of the present application. [Figure 19] FIG. 13 is a structural schematic diagram of a cross section perpendicular to the winding axis K of an electrode assembly having another flat shape according to another embodiment of the present application. [Figure 20] FIG. 13 is a structural schematic diagram of a cross section perpendicular to the winding axis K of an electrode assembly having another flat shape according to another embodiment of the present application. [Figure 21] FIG. 13 is a structural schematic diagram of a cross section perpendicular to the winding axis K of an electrode assembly having another flat shape according to another embodiment of the present application. [Figure 22] FIG. 13 is a structural schematic diagram of a cross section perpendicular to the winding axis K of an electrode assembly having another flat shape according to another embodiment of the present application. [Figure 23] FIG. 13 is a structural schematic diagram of a cross section perpendicular to the winding axis K of an electrode assembly having another flat shape according to another embodiment of the present application. [Figure 24] FIG. 13 is a structural schematic diagram of a cross section perpendicular to the winding axis K of an electrode assembly having another flat shape according to another embodiment of the present application. [Diagram 25] FIG. 13 is a structural schematic diagram of a cross section perpendicular to the winding axis K of an electrode assembly having another flat shape according to another embodiment of the present application. [Figure 26] FIG. 13 is a structural schematic diagram of a cross section perpendicular to the winding axis K of an electrode assembly having another flat shape according to another embodiment of the present application. [Figure 27] FIG. 2 is a structural schematic diagram of a cathode plate according to another embodiment of the present application. [Figure 28] FIG. 2 is a structural schematic diagram of a cathode plate according to another embodiment of the present application. [Figure 29] FIG. 2 is a structural schematic diagram of a cathode plate according to another embodiment of the present application. [Diagram 30] FIG. 2 is a structural schematic diagram of a battery cell according to another embodiment of the present application. [Diagram 31] FIG. 2 is a structural schematic diagram of a battery module according to another embodiment of the present application. [Diagram 32] FIG. 2 is a structural schematic diagram of a battery according to another embodiment of the present application. [Diagram 33] 2 is a structural schematic diagram of a power consumption device according to another embodiment of the present application; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings of the embodiments of the present application. It is clear that the described embodiments are only some of the embodiments of the present application, and are not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the present application.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. The terms used in the specification of the application herein are only intended to describe specific embodiments and are not intended to limit the application. The terms "including", "having" and any variations thereof in the specification, claims and above description of the drawings of the application are intended to cover non-exclusive "including".

[0037] When referring to an "embodiment" in the present specification, it means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The phrases appearing in various places in the specification do not necessarily all refer to the same embodiment, nor are they mutually exclusive independent or alternative embodiments. Those skilled in the art can explicitly and implicitly understand that the embodiments described herein may be combined with other embodiments.

[0038] The term "and / or" in this text is merely a relational relationship that describes related objects, and indicates that three relations can exist, for example, A and / or B may represent three cases: A alone, A and B in combination, and B alone. Also, the character " / " in this text generally indicates that the related objects before and after are in an "or" relationship.

[0039] In the description of this application, it should be understood that the orientations or positional relationships indicated by terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are orientations or positional relationships shown in the drawings, and are merely for the convenience and simplification of the description of this application, and do not indicate or suggest that the indicated device or element has a specific orientation and must be configured and operated in a specific orientation, and therefore should not be understood as a limitation on this application. In addition, terms such as "first", "second" and the like in the specification and claims of this application or the above drawings are used to distinguish different objects, are not intended to describe a specific order, and may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0040] In the description of this application, it should be explained that unless otherwise clearly specified and limited, the terms "attached", "connected" and "connected" should be understood in a broad sense, for example, may be fixedly connected, detachably connected, or integrally connected, may be mechanically connected, may be electrically connected, may be directly connected, may be indirectly connected via an intermediate medium, or may communicate the insides of two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific situation.

[0041] In order to make the volume of the lithium ion battery smaller and the energy density higher, the negative electrode plate, the positive electrode plate and the separator in the electrode assembly of the lithium ion battery can be wound and then compressed. For example, as shown in Fig. 1, Fig. 1 is a perspective structural schematic diagram of an electrode assembly, which includes a positive electrode plate, a negative electrode plate and a separator, in which the positive electrode plate, the negative electrode plate and the separator are stacked and then wound around a winding axis K to form a wound structure, the separator is an insulating film, which is used to isolate the positive electrode plate and the negative electrode plate and prevent the positive electrode plate and the negative electrode plate from shorting, the wound structure of the electrode assembly is in the shape of a flat body, and the structural schematic diagram of the cross section perpendicular to the winding axis K of the electrode assembly is as shown in Fig. 2.

[0042] 1 and 2, the electrode assembly includes a straight region P and folded regions C located at both ends of the straight region P. The straight region P refers to a region having a parallel structure in the wound structure, that is, the positive electrode plate 101, the negative electrode plate 102 and the separator 103 in the straight region P are approximately parallel to each other, that is, the surfaces of the positive electrode plate 101, the negative electrode plate 102 and the separator 103 of each layer in the straight region P of the electrode assembly are all flat. The folding region C refers to a region having a folding structure in the winding structure, i.e., the anode plate 101, the cathode plate 102 and the separator 103 in the folding region C are all folded, i.e., the surfaces of the anode plate 101, the cathode plate 102 and the separator 103 of each layer in the folding region C of the electrode assembly are all curved, and the folding region C has a winding direction L, which may be understood as a direction along the surface of the electrode assembly in the folding region C toward the straight region, for example, the winding direction L is along the winding direction of the winding structure in the folding region C.

[0043] The surface of the positive electrode plate 101 has a positive electrode active material layer made of a positive electrode active material, and the surface of the negative electrode plate 102 has a negative electrode active material layer made of a negative electrode active material. For example, the negative electrode active material may be lithium manganese oxide, lithium cobalt oxide, lithium iron phosphate, or lithium nickel-cobalt-manganese oxide, and the positive electrode active material may be graphite or silicon.

[0044] The inventors have found in the course of research that the electrolyte is constantly consumed during the cycle process of the electrode assembly, and after the electrolyte between the negative and positive plates is consumed, the electrolyte remaining in the case cannot be replenished in a timely manner, which causes the problem of a short lifespan of the battery cell and the battery pack due to a shortage of electrolyte after a long period of charging and discharging.

[0045] In view of this, the present application provides an electrode assembly, which includes a cathode plate, an anode plate, and a separator, and the separator is used to separate the anode plate from the cathode plate, where the anode plate, the cathode plate, and the separator may be stacked and then wound around a winding axis to form a structure, for example a flat-body wound structure, or the anode plate, the cathode plate, and the separator may be stacked and then folded continuously in a Z-shape. The electrode assembly may be formed by winding, or may be formed by folding continuously in a Z-shape. The electrode assembly further includes an electrolyte adsorption layer configured to be disposed along at least one surface of the cathode plate, the anode plate, and the separator, and the electrolyte adsorption layer is provided with an ion exchange passage, which is a through hole disposed along the thickness direction of the electrolyte adsorption layer.

[0046] By disposing the electrolyte adsorption layer on at least one surface of the cathode plate, the anode plate and the separator, the electrolyte adsorption layer can fill the gap between the cathode plate and the anode plate to hold the electrolyte and slowly release it, thereby replenishing the electrolyte consumed during the cycle process, which is favorable for the conduction and diffusion of ions, and further improving the performance of the battery cell. The electrolyte adsorption layer is provided with ion exchange passages arranged along its thickness direction, which is favorable for the release of the electrolyte and the conduction and diffusion of ions, and is favorable for improving the cycle performance and service life of the battery cell. The ion exchange passages may be through holes arranged in the thickness direction of the electrolyte adsorption layer, and the through holes may be uniformly or non-uniformly distributed on the surface of the electrolyte adsorption layer, and the through holes may have the same or different cross-sectional areas and / or hole depths, and the through holes may be one or more. The electrolyte is accommodated in the ion exchange passages, and ions can penetrate the electrolyte adsorption layer through the ion exchange passages.

[0047] The separator 103 has electronic insulation properties and is used to isolate the adjacent cathode plate 102 and anode plate 101 and prevent the adjacent cathode plate 102 and anode plate 101 from shorting. The separator 103 has a large number of micropores that penetrate it, allowing the electrolyte and ions to pass through freely, and has a very high permeability to lithium ions, so the separator 103 basically cannot block the passage of lithium ions. For example, the separator 103 includes a separator base layer and a functional layer located on the surface of the separator base layer, the separator base layer includes at least one of polypropylene, polyethylene, ethylene-propylene copolymer, polybutylene terephthalate, etc., and the functional layer may be a mixture layer of ceramic oxide and adhesive.

[0048] In the electrode assembly according to the embodiment of the present application, an electrolyte adsorption layer is attached to one or two surfaces of a cathode plate 1, and / or an electrolyte adsorption layer 4 is attached to one or two surfaces of an anode plate 2, and / or an electrolyte adsorption layer 4 is attached to one or two surfaces of a separator 3.

[0049] 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 plate 1 .

[0050] 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 plate 1 .

[0051] As shown in FIG. 5, in another embodiment of the present application, an electrolyte adsorption layer 4 is attached to both the inner and outer surfaces of the cathode plate 1 .

[0052] In some embodiments not shown, an electrolyte adsorption layer may be attached to the inner and / or outer surface of the anode plate 2, and the installation method may refer to the method of installing an electrolyte adsorption layer on the surface of the cathode plate 1 in Figures 3 to 5.

[0053] 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 plate 1 and the inner and outer surfaces of the anode plate 2 .

[0054] Here, the electrolyte adsorption layer 4 is attached to one or two surfaces of the cathode plate 1 and / or to one or two surfaces of the anode plate 2, and the electrolyte adsorption layer 4 may be attached to any surface of the cathode plate 1 and / or the anode plate 2 and / or to one or two surfaces of the separator 3. Here, attachment refers to attachment, coating, or spraying, and attachment can reduce positional movement of the electrolyte adsorption layer 4 during use of the battery cell.

[0055] As shown in FIG. 7, in another embodiment of the present application, an electrolyte adsorption layer 4 may be attached to the inner surface of the separator 3 .

[0056] As shown in FIG. 8, in another embodiment of the present application, an electrolyte adsorption layer 4 may be attached to the outer surface of the separator 3 .

[0057] In some embodiments not shown, the electrolyte adsorption layer 4 may be attached to both the inner and outer surfaces of the separator 3. For a method of attaching the electrolyte adsorption layer 4 to the separator 3, reference may be made to the method of providing the electrolyte adsorption layer 4 on the surface of the cathode plate 1 and / or the anode plate 2 in Figs. 3 to 6.

[0058] By disposing the electrolyte adsorption layer 4 on the surface of the separator 3, the gap between the cathode plate and anode plate is filled to hold and store the electrolyte, which can replenish the electrolyte consumed during the cycle process, which is favorable for the conduction and diffusion of ions, and further improves the cycle performance and service life of the battery cell. The electrolyte adsorption layer 4 is provided with ion exchange passages arranged along the thickness direction of the electrolyte adsorption layer, which is favorable for the release of electrolyte and the conduction and diffusion of ions, and is favorable for improving the cycle performance and service life of the battery cell.

[0059] The structure of the anode plate 2 may be as shown in FIG. 9, which is a structural schematic diagram of an anode plate according to another embodiment of the present application, in which the anode plate 2 includes an anode body portion 21 and an anode tab portion 22 extending outward from the anode body portion 21 along the winding axis K, and at least a portion of an area along the winding axis K on the surface of the anode body portion 21 is an anode active material layer 211, which is used for applying an anode active material, and the anode active material may be graphite or silicon.

[0060] In another embodiment of the present application, not only is a positive electrode active material layer 211 provided on a portion of the surface of the positive electrode main body portion 21, but also the positive electrode active material layer 211 is provided on the surface of the positive electrode tab portion 22 and in a root region close to the positive electrode main body portion 21, i.e., a portion of the surface of the positive electrode tab portion 22 is the positive electrode active material layer 211.

[0061] In another embodiment of the present application, as shown in FIG. 9, the positive electrode active material layer 211 covers the entire surface of the positive electrode main body 21 along the winding axis K.

[0062] In another embodiment of the present application, the negative electrode active material may not cover the entire surface of the negative electrode plate 1, for example, as shown in FIG. 10, which is a structural schematic diagram of a negative electrode plate in another embodiment of the present application.

[0063] The negative electrode plate 1 includes a negative electrode body portion 11 and at least one negative electrode tab portion 12 extending outward from the negative electrode body portion 11 along the winding axis K. At least a portion of the surface area of ​​the negative electrode body portion 11 is a negative electrode active material layer 111. A negative electrode active material can be applied to the negative electrode active material layer 111. For example, the negative electrode active material may be a ternary material, lithium manganate or lithium iron phosphate.

[0064] In another embodiment of the present application, the surface of the cathode body portion 11 further includes a first insulating layer-coated region 112 adjacent to the cathode active material layer 111, the first insulating layer-coated region 112 is located on a side of the cathode active material layer 111 closer to the cathode tab portion 12, and the first insulating layer-coated region 112 is used for coating an insulating material and for insulating and isolating the cathode active material layer 111 and the cathode tab portion 12, as shown in FIG. 11, for example. FIG. 11 is a schematic cross-sectional structure diagram of the AA direction in FIG. 10, in which two surfaces of the current collector of the cathode plate 1 have cathode active material layers 111, and the cathode tab portion 12 is a part of the current collector of the cathode plate 1, and the material of the current collector may be aluminum.

[0065] For example, the cathode active material layer 111 and the first insulating layer coated region 112 are distributed on the surface of the cathode main body 11 at both ends along the width direction of the cathode main body 11 (i.e., the winding axis K), and the cathode tab portion 12 and the first insulating layer coated region 112 belong to the same end of the cathode main body 11.

[0066] In another embodiment of the present application, the negative electrode active material layer 111 and the first insulating layer coating region 112 are two approximately parallel regions on the surface of the negative electrode body portion 11, and are distributed in the form of two layers on the surface of the negative electrode body portion 11 along the winding axis K.

[0067] In another embodiment of the present application, the first insulating layer coated region 112 may be located in a portion where the cathode body portion 11 and the cathode tab portion 12 are connected to each other, for example, the first insulating layer coated region 112 is located on the surface of the cathode body portion 11 and in a portion where the cathode tab portion 12 and the cathode tab portion 12 are connected to each other, and is used to isolate the surface of the cathode tab portion 12 from the cathode active material layer 111. In another embodiment of the present application, not only is the first insulating layer coated region 112 provided on the surface of the cathode body portion 11, but a second insulating layer coated region is also provided in a root region of the cathode tab portion 12 close to the cathode body portion 11, and the second insulating layer coated region is used to apply an insulating material.

[0068] In another embodiment of the present application, an insulating material is applied to the surface of the first insulating layer application region 112, and the insulating material includes an inorganic filler and an adhesive. The inorganic filler includes one or more of boehmite, alumina, magnesium oxide, titanium dioxide, zirconium oxide, silica, silicon carbide, boron carbide, calcium carbonate, aluminum silicate, calcium silicate, potassium titanate, and barium sulfate. The adhesive includes one or more of polyvinylidene fluoride, polyacrylonitrile, polyacrylic acid, polyacrylic acid ester, polyacrylic acid-acrylic acid ester, polyacrylonitrile-acrylic acid, and polyacrylonitrile-acrylic acid ester.

[0069] In another embodiment of the present application, each cathode plate 1 may include one or more cathode tab portions 12, and when the cathode plate 1 includes two or more cathode tab portions 12, all of the cathode tab portions 12 are located on the same side along the winding axis K of the cathode plate 1.

[0070] 9 and 10, when the cathode plate 1 and the anode plate 2 are stacked on each other, both ends along the winding axis K of the anode active material layer 211 of the anode plate 2 extend beyond the corresponding ends of the cathode active material layer 111 of the adjacent cathode plate 1, thus providing the electrode assembly with good energy density. For example, the positive electrode active material layer 211 has two ends along the winding axis K which are a first end 23 and a second end 24, and the negative electrode active material layer 111 has two ends along the winding axis K which are a third end 13 and a fourth end 14, in which the first end 23 of the positive electrode active material layer 211 and the third end 13 of the negative electrode active material layer 111 are located on the same side of the electrode assembly along the winding axis K, and the first end 23 of the positive electrode active material layer 211 exceeds the third end 13 of the negative electrode active material layer 111 along the winding axis K, the second end 24 of the positive electrode active material layer 211 and the fourth end 14 of the negative electrode 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 positive electrode active material layer 211 exceeds the fourth end 14 of the negative electrode active material layer 111 along the winding axis K.

[0071] The extent to which both ends of the positive electrode active material layer 211 along the winding axis K extend beyond the corresponding ends of the negative electrode active material layer 111 may be the same or different, and the extent may be in the range of 0.2 mm to 5 mm, for example.

[0072] As shown in FIG. 12, FIG. 12 is a schematic diagram of a cross-sectional structure in the BB direction in FIG. 10. Referring to FIG. 10, the electrolyte adsorption layer 4 is attached on the surface of the cathode active material layer 111, that is, on the surface of the cathode active material layer. By disposing the electrolyte adsorption layer 4 on at least one surface of the cathode plate 1, the anode plate 2, and the separator 3, the electrolyte adsorption layer 4 on which the electrolyte is adsorbed can fill the gap between the cathode plate 1 and the anode plate 2 to hold the electrolyte and slowly release it, thereby replenishing the electrolyte consumed during the cycle process, which is favorable for the conduction and diffusion of ions, and further improving the cycle performance and service life of the battery cell. The electrolyte adsorption layer 4 is provided with an ion exchange passage 40 installed along the thickness direction of the electrolyte adsorption layer, which is favorable for the release of the electrolyte and the conduction and diffusion of ions, and is favorable for improving the cycle performance and service life of the battery cell.

[0073] In some embodiments, the electrolyte adsorption layer 4 may employ any material suitable for adsorbing and retaining the electrolyte and resistant to corrosion by the electrolyte.

[0074] As shown in FIG. 12, in some embodiments, the electrolyte adsorption layer 4 can include an adsorption base layer 41, one side of which is attached to a corresponding cathode plate or anode plate, and the adsorption base layer 41 is provided with ion exchange channels 40.

[0075] The material of the adsorption base layer 41 includes at least one of acrylic acid-acrylic acid ester copolymer, butadiene-styrene copolymer, styrene-acrylic acid copolymer, styrene-acrylic acid ester 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, glycerin ester type epoxy resin, silicone type resin, polyurethane, styrene-isoprene-styrene copolymer, and modified products of the above materials.

[0076] 10 and 12, the ion exchange passages 40 may be arranged in one or more in the adsorption base layer 41. For example, the ion exchange passages 40 may be arranged in an array in the adsorption base layer 41, and each ion exchange passage 40 has the same diameter. The ion exchange passages 40 may be installed in the adsorption base layer 41 along the thickness direction of the adsorption base layer 41, and the ion exchange passages 40 may be through holes or blind holes, which can store more electrolyte in the space in the ion exchange passages and improve the electrolyte release performance and ion conduction and diffusion performance of the adsorption base layer 41. Without being limited thereto, the ion exchange passages 40 may be arranged non-uniformly in the adsorption base layer 41, and / or the ion exchange passages 40 may have different diameters and / or depths. The ion exchange channels 40 penetrate the adsorption base layer 41 and can be in direct contact with the cathode active material layer or the anode active material layer, which is advantageous for ions to escape from the cathode active material layer through the electrolyte in the ion exchange channels 40 and enter the anode active material layer, thereby improving the permeability of ions. In addition, a large amount of electrolyte can be stored in the ion exchange channels 40 to improve the electrolyte release performance and ion conduction and diffusion performance. By adjusting the arrangement mode and diameter of the ion exchange channels 40, the release performance and ion conduction and diffusion performance of the adsorption base layer 41 can be adjusted.

[0077] In order to provide good electrolyte storage and retention performance and to save costs, the electrolyte adsorption layer 4 includes a fifth end (upper end) and a sixth end (lower end) along the winding direction L (i.e., the winding axis K), and the fifth end of the electrolyte adsorption layer 4 exceeds the negative electrode active material layer of the negative electrode plate 1, and / or the sixth end of the electrolyte adsorption layer 4 exceeds the negative electrode active material layer, i.e., the fifth end of the electrolyte adsorption layer 4 exceeds the third end (upper end) of the negative electrode active material layer 111 along the winding axis K, and / or the sixth end of the electrolyte adsorption layer 4 exceeds the fourth end (lower end) of the negative electrode active material layer 111 along the winding axis K, for example, the excess size range is 0.2 mm to 5 mm. In this way, as much electrolyte as possible can be retained in the negative electrode active material layer, and the electrolyte can be slowly released on the surface of the negative electrode active material layer, thereby increasing the cycle performance and life of the battery cell.

[0078] In some embodiments, when the electrolyte adsorption layer 4 is composed of the adsorption base 41, the porosity of the electrolyte adsorption layer 4 is the porosity of the adsorption base 41, and the porosity of the adsorption base is 0<porosity of the adsorption base≦50%, for example, the porosity of the adsorption base may be 0.05%, 0.08%, 0.1%, 0.5%, 1%, 2%, 5%, 10%, 15%, 30%, 40%, etc. By adjusting the porosity of the adsorption base, the release performance and the ion conduction and diffusion performance of the adsorption base 41 can be adjusted.

[0079] In another embodiment of the present application, as shown in Fig. 13, it is a schematic cross-sectional structure diagram in the direction BB in Fig. 10. The difference between the embodiment of Fig. 13 and the embodiment shown in Fig. 12 is that an electrolyte adsorption layer 4 is provided on both surfaces of the cathode active material layer 111 on both surfaces of the cathode plate 1. The specific structure, attachment method and position of the electrolyte adsorption layer 4 are as shown in Fig. 12. In some embodiments not shown, the electrolyte adsorption layer 4 may be attached to one or two surfaces of the anode plate 2 or the separator 3, The specific structure of the electrolyte adsorption layer 4 on the anode plate 2 or the separator 3 is the same as the specific structure of the electrolyte adsorption layer 4 on the cathode plate 1, and the attachment manner and position of the electrolyte adsorption layer 4 on the anode plate 2 or the separator 3 are the same as the attachment manner and position of the electrolyte adsorption layer 4 on the cathode plate 1. Specifically, the structure shown in FIG. 12 or 13 may be referred to.

[0080] As shown in FIG. 14, FIG. 14 is a structural schematic diagram of a cathode plate in another embodiment of the present application.

[0081] In this embodiment, the structure of the cathode plate 1 is the same as that in Fig. 13. The electrolyte adsorption layer 4 in this 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 opposite to the side of the adsorption base layer 41 attached to the electrode plate, and the other side of the adsorption base layer 41 is attached to the cathode plate 1 as shown in Fig. 14, and the ion exchange passages can penetrate the support layer and the adsorption base layer along the thickness direction.

[0082] In some embodiments, the ion exchange passage 40 penetrates the support layer 42 and the adsorption base layer 41, as shown in FIG. 14. Specifically, a first ion exchange passage 401 is provided in the adsorption base layer 41, and a second ion exchange passage 402 is provided in the support layer, and the first ion exchange passage 401 and the second ion exchange passage 402 communicate with each other to form the ion exchange passage 40. The adsorption base layer 41 has a certain fluidity and is easy to move and deform on the surface of the electrode plate, which will affect the uniformity of the distribution of the adsorption base layer 41. The support layer 42 is provided on the opposite side of the adsorption base layer 41 to the side attached to the cathode plate 1, the anode plate 2 or the separator 3, and the support layer 42 can allow the ions to flow and inhibit the flow and deformation of the adsorption base layer 41, so that the adsorption base layer 41 is uniformly held on the surface of the electrode plate, and the electrolyte is uniformly distributed. The ion exchange channels 40 penetrate the support layer and the adsorption base layer, making it possible to penetrate the support layer 42 and the adsorption base layer 41 through the ion exchange channels 40, which is favorable for the release of electrolyte and the conduction and diffusion of ions, and is favorable for improving the cycle performance and service life of the battery.

[0083] In some embodiments, the second ion exchange passages 402 may be arranged in one or more in the support layer 42. For example, the second ion exchange passages 402 may be arranged in an array in the support layer 42, and each second ion exchange passage 402 has the same diameter. The second ion exchange passages 402 may be installed in the support layer 42 along the thickness direction of the support layer 42, and the second ion exchange passages 402 are through holes, which can store a large amount of electrolyte in the space within the second ion exchange passages 402 to improve the electrolyte release performance, and improve the electrolyte release and ion conduction and diffusion performance of the support layer 42. Without being limited thereto, the second ion exchange passages 402 may be arranged non-uniformly in the support layer 42, and / or the second ion exchange passages 402 may have different diameters.

[0084] In some embodiments, the first ion exchange passage 401 may be arranged in one or more in the adsorption base layer 41, for example, the first ion exchange passage 401 may be arranged in an array in the adsorption base layer 41, and each first ion exchange passage 401 has the same diameter. The first ion exchange passage 401 may be installed in the adsorption base layer 41 along the thickness direction of the adsorption base layer 41, and the ion exchange passage 40 may be a through hole or a blind hole, which can store more electrolyte in the space in the first ion exchange passage 401 and improve the performance of electrolyte release and ion conduction and diffusion of the adsorption base layer 41. Optionally, the shape and installation position of the first ion exchange passage 401 correspond to the shape and installation position of the second ion exchange passage 402, and the second ion exchange passage 402 communicates with the first ion exchange passage 401.

[0085] In some embodiments, the material of the adsorptive base layer 41 includes at least one of acrylic acid-acrylic acid ester copolymer, butadiene-styrene copolymer, styrene-acrylic acid copolymer, styrene-acrylic acid ester 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, glycerin ester type epoxy resin, silicone type resin, polyurethane, styrene-isoprene-styrene copolymer, and modifications of the above materials.

[0086] In some embodiments, components of support layer 42 include at least one of polyvinyl chloride, polyethylene, polypropylene, polyvinylidene fluoride, hexafluoropropylene-vinylidene fluoride copolymers, tetrafluoropropylene-vinylidene fluoride copolymers, trifluorochloropropylene-vinylidene fluoride copolymers, polyethylene terephthalate, polyimide, polyetherimide, polycarbonate, polystyrene, polyphenylene sulfide, polyvinylidene fluoride or copolymers thereof, polyarylate, fibers, nylon, nonwoven fabrics, and modifications of the foregoing materials.

[0087] In some embodiments, the thickness of the support layer 42 is ≦50 um, the porosity of the support layer 42 is 0<≦50%, and / or the tensile modulus of the support layer 42 is ≦100 MPa, where 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, where the total area of ​​the ion exchange channels 40 is the sum of the areas of one or more ion exchange channels.

[0088] In this embodiment, the thickness of the support layer 42 is set 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 favorable for the transmission of ions. The porosity of the support layer 42 is set to 0<porosity of the support layer 42≦50%, for example, the porosity of the support layer 42 may be a value such as 0.05%, 0.08%, 0.1%, 0.5%, 1%, 2%, 5%, 10%, 15%, 30%, 40%, etc. 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. By controlling the porosity of the support layer 42, it is possible to improve the flow of ions while suppressing the flow and deformation of the adsorption base layer 41, so that the adsorption base layer 41 can be uniformly held on the surface of the cathode plate 1, the anode plate 2 or the separator 3, and the electrolyte can be stably held on the surface of the cathode plate 1, the anode plate 2 or the separator 3 for a long period of time, which is favorable for improving the cycle performance and service life of the battery. The tensile modulus of the support layer 42 is ≦100 MPa, so that the support layer 42 has good holding performance for the adsorption base layer 41.

[0089] 15 shows a schematic diagram of the structure of a cathode plate in 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 difference between the embodiment in FIG. 15 and the embodiment in FIG. 14 is that an adsorption base layer 41 and a support layer 42 are provided on both sides of the cathode plate 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 plate 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.

[0090] In some embodiments not shown, an adsorption base layer 41 and a support layer 42 may be attached to one or two surfaces of the anode plate 2 or the separator 3. The specific structure of the adsorption base layer 41 and the support layer 42 in the anode plate 2 or the separator 3 is the same as the specific structure of the adsorption base layer 41 and the support layer 42 in the cathode plate 1, and the attachment manner and position of the adsorption base layer 41 and the support layer 42 in the anode plate 2 or the separator 3 are the same as the attachment manner and position of the adsorption base layer 41 and the support layer 42 in the cathode plate 1. The structures of the embodiments in Figs. 10 to 15 may be referred to.

[0091] The above examples merely roughly describe the positional relationship between the electrolyte adsorption layer and each of the cathode plate, anode plate, and separator, and the structural features of the electrolyte adsorption layer. In order to clarify the positional relationship between the electrolyte adsorption layer and each of the cathode plate, anode plate, and separator, and the structural features of the electrolyte adsorption layer, several electrode assemblies having a wound structure will be described in detail below.

[0092] As shown in FIG. 16, in another embodiment of the present application, whether the electrode assembly is formed by winding or by continuously folding like a Z-shape, the electrode assembly includes a straight region and a folded region connecting both ends of the straight region. For the sake of simplicity, the electrode assembly of this embodiment is described using a flat-body wound structure as an example. For example, the structure of one of the folded regions C and the straight region P of the flat-body wound structure may be as shown in FIG. 16, which is a schematic diagram of the local structure of the folded region of the electrode assembly according to one embodiment of the present application. In the folded region C, the electrode assembly includes a cathode plate 1, an anode plate 2, and a separator 3 for isolating the cathode plate 1 and the anode plate 2. Here, the separator 3 may be independently located between the adjacent cathode plate 1 and anode plate 2, or may be coated on the surface of the cathode plate 1 or the anode plate 2. In another embodiment of the present application, one separator 3, one cathode plate 1, another separator 3 and one anode plate 2 may be stacked and then wound or folded, and at least one (e.g., two or more) cathode plate 1, at least one (e.g., two or more) anode plate 2 and at least two separators (e.g., four or more, the number of separators is twice the number of cathode plates or anode plates) may be stacked and then wound or folded, forming a folding area. In the case where the electrode assembly has multiple layers of cathode plates 1, multiple layers of anode plates 2, and multiple layers of separators 3 in the folding region C, the folding region C includes a structure in which the cathode plates 1, the separators 3, and the anode plates 2 are alternately distributed, and the electrolyte adsorption layer 4 is attached to one or two surfaces of the cathode plates 1, and / or to one or two surfaces of the anode plates 2, and / or to one or two surfaces of the separators 3. By installing in this manner, the electrolyte adsorption layer 4 is included between at least one adjacent cathode plate 1 and anode plate 2. The cathode plate 1 and anode plate 2 adjacent to the folding region C refer to one in which one cathode plate 1 and one anode plate 2 are adjacent to each other in the folding region C, and there is no other cathode plate 1 or other anode plate 2 between them.

[0093] When the electrode assembly has a wound structure, the width direction of the cathode plate 1 and the anode plate 2 is parallel to the winding axis K, and the width direction of the cathode plate 1 and the anode plate 2 is parallel to a direction perpendicular to the winding direction L. When the electrode assembly does not have a wound structure, the width direction of the cathode plate 1 and the anode plate 2 is parallel to a direction perpendicular to the winding direction L. In the following, for the sake of simplicity, in this embodiment, the width direction of the cathode plate 1 and the anode plate 2, the direction perpendicular to the winding direction L, and the winding axis K are collectively referred to as the winding axis K.

[0094] 16, in some embodiments, the cathode plate 1, the separator 3 and the anode plate 2 are wound to form a folded region C, and the electrolyte adsorption layer 4 is configured to be disposed along the folded region C on at least one surface of the cathode plate 1, the anode plate 2 and the separator 3. That is, the electrolyte adsorption layer 4 may be attached to a part of the surface of the cathode plate 1, the anode plate and / or the separator.

[0095] In this embodiment, there is a large gap between the cathode plate 1 and the anode plate 2 in the folding region C, and the electrolyte adsorption layer 4 is provided in the folding region C to achieve better electrolyte storage and slow release effects. In this embodiment, at least a part of the electrolyte adsorption layer 4 is provided in the folding region C of at least one surface of the cathode plate 1, the anode plate 2, and the separator 3, so that the electrolyte adsorption layer 4 adsorbing the electrolyte fills the gap between the cathode plate 1 and the anode plate 2 in the folding region C, and retains and slowly releases the electrolyte in the folding region C, thereby replenishing the electrolyte consumed during the cycle, which is favorable for the conduction and diffusion of ions, and further improving the performance of the battery cell. The electrolyte adsorption layer is provided with an ion exchange passage provided along the thickness direction, which is favorable for the release of the electrolyte and the conduction and diffusion of ions, and is favorable for improving the cycle performance and service life of the battery cell. Arranging at least a part of the electrolyte adsorption layer 4 in the folding region C of at least one of the surfaces of the cathode plate 1, the anode plate 2, and the separator 3 specifically means that the entire electrolyte adsorption layer 4 is located in the folding region C of at least one of the surfaces of the cathode plate 1, the anode plate 2, and the separator 3, or that a part of the electrolyte adsorption layer 4 is located in the folding region C of at least one of the surfaces of the cathode plate 1, the anode plate 2, and the separator 3, and a part is located in the straight region P outside the folding region C. By arranging the electrolyte adsorption layer in the folding region C of the surface of the cathode plate 1 and / or the anode plate 2, the electrolyte adsorption layer 4 reinforces the cathode active material layer on the cathode plate 1 and / or the anode active material layer on the anode plate 2, and reduces the occurrence of a situation in which the cathode active material layer on the cathode plate 1 and / or the anode active material layer on the anode plate 2 are broken by folding, and further improves the performance of the battery cell.

[0096] In another embodiment of the present application, both ends of the electrolyte adsorption layer 4 extending along the winding direction L are located in the folding region C, i.e., the entire electrolyte adsorption layer 4 is located in the folding region C. In this embodiment, the electrode assembly further includes a straight region P connected to the folding region C, and the winding direction L refers to a direction along the curved surface of the folding region C toward the straight region P, and the direction perpendicular to the winding direction L refers to a direction perpendicular to the winding direction L.

[0097] In another embodiment of the present application, one end of the electrolyte adsorption layer 4 extending along the winding direction L is located in the straight region P, and the other end is located in the bent region C.

[0098] In another embodiment of the present application, in order to improve the electrolyte storage and retention performance in the folding region C, the electrolyte adsorption layer 4 has as large an area as possible in the folding region C, for example, both ends of the electrolyte adsorption layer 4 extending along the winding direction L are located in the straight region P, that is, the electrolyte adsorption layer 4 extends into the straight region P in addition to the folding region C.

[0099] In another embodiment of the present application, both ends of the electrolyte adsorption layer 4 extending along the winding direction L are located at the boundary between the folded region C and the straight region P, or both ends of the electrolyte adsorption layer 4 extending along the winding direction L are close to the boundary between the folded region C and the straight region P.

[0100] As shown in Fig. 17, Fig. 17 is a structural schematic diagram of a cross section perpendicular to a winding axis K of an electrode assembly having a flat shape according to another embodiment of the present application. The electrode assembly includes an anode plate 91, a cathode plate 92, a separator 93, a first electrolyte adsorption layer 94, a second electrolyte adsorption layer 95 and a third electrolyte adsorption layer 96, where the separator 93 is located between the anode plate 91 and the cathode plate 92, and the separator 93 is two sheets, which are represented by two dotted lines wound in the cross-sectional view of the electrode assembly in Fig. 17, and the anode plate 91, the cathode plate 92 and the separator 93 are stacked and then wound around the winding axis to form a flat-shaped wound structure. As shown in FIG. 18, FIG. 18 is a schematic view of the structure of the cathode plate 92 in FIG. 17 after development, and shows the attachment position of the second electrolyte adsorption layer 95 on the cathode plate 92.

[0101] Regarding the relevant technical features of the anode plate 91, the cathode plate 92, the separator 93, and the electrolyte adsorption layers 94 to 96 of this embodiment, the explanation of the embodiment corresponding to the above-mentioned Figures 1 to 15 may be referred to, and the explanation will be omitted here.

[0102] In this embodiment, the wound structure of the electrode assembly includes a straight region 9A, and a first folding region 9B1 and a second folding region 9B2 located on either side of the straight region 9A, where the straight region 9A is divided by a straight line and a dashed line from the first folding region 9B1 and the second folding region 9B2, respectively.

[0103] The anode plates 91 and cathode plates 92 included in the first folding region 9B1 and the second folding region 9B2 of the electrode assembly are stacked alternately in sequence, with a separator 93 between adjacent anode plates 91 and cathode plates 92, where the innermost electrode plates in the first folding region 9B1 and the second folding region 9B2 are both anode plates 91, and an electrolyte adsorption layer is provided (e.g., attached) on the inner surface of at least the innermost cathode plate 92 in the first folding region 9B1 and the second folding region 9B2, for example, an electrolyte adsorption layer is provided (e.g., attached) on the inner surface of each layer of the cathode plate 92 in the first folding region 9B1 and the second folding region 9B2. In this embodiment, the inner surface of the cathode plate 92 refers to the surface facing the winding axis of the cathode plate 92 or the surface facing the inside of the winding structure.

[0104] For example, the first folding region 9B1 has multiple layers of plates, for example, three layers of plates, and the innermost layer (which may be called the first layer) and the outermost layer (which may be called the third layer) of the first folding region 9B1 are both anode plates 91, and the plate between the innermost layer plate and the outermost layer plate (which may be called the second layer plate) is a cathode plate 92, which is the innermost cathode plate of the first folding region 9B1, and a first electrolyte adsorption layer 94 is attached to the inner surface of the cathode plate 92 in the first folding region 9B1.

[0105] The second folded region 9B2 has multiple layers of electrode plates, for example five layers of electrode plates, and the anode plates 91 and cathode plates 92 in the second folded region 9B2 are stacked alternately in a direction from the inside to the outside of the wound structure, with the anode plate 91 being the innermost electrode plate in the second folded region 9B2, and an electrolyte adsorption layer being attached to the inner surface of each layer of cathode plates 92 in the second folded region 9B2.

[0106] For example, along the direction from the inside to the outside of the wound structure, the second folded region 9B2 sequentially includes a first layer, a second layer, a third layer, a fourth layer, and a fifth layer of electrode plates, the first layer, the third layer, and the fifth layer of electrode plates are anode plates 91, the second layer and the fourth layer of electrode plates are cathode plates 92, and an electrolyte adsorption layer is attached to the inner surface of each cathode plate 92 of each layer in the second folded region 9B2. For example, a second electrolyte adsorption layer 95 is attached to the inner surface of the second layer of electrode plates (which are cathode plates 92) in the second folded region 9B2. A third electrolyte adsorption layer 96 is attached to the inner surface of the fourth layer of electrode plates (which are cathode plates 92) in the second folded region 9B2.

[0107] In this embodiment, both ends along the winding direction L of the first electrolyte solution adsorption layer 94, the second electrolyte solution adsorption layer 95, and the third electrolyte solution adsorption layer 96 are each located at the boundary between the folded region and the straight region. For example, both ends along the winding direction of the first electrolyte solution adsorption layer 94 are each located at the boundary between the first folded region 9B1 and the straight region 9A, and both ends along the winding direction of the second electrolyte solution adsorption layer 95 and the third electrolyte solution adsorption layer 96 are each located at the boundary between the second folded region 9B2 and the straight region 9A.

[0108] In this embodiment, the functions, structures, distribution methods, and other related contents of the first electrolyte adsorption layer 94, the second electrolyte adsorption layer 95, and the third electrolyte adsorption layer 96 may all be referred to the related contents of the electrolyte adsorption layers described in the embodiments of Figures 1 to 15 above, and therefore a description thereof will be omitted here.

[0109] As shown in Fig. 19, Fig. 19 is a structural schematic diagram of a cross section perpendicular to a winding axis K of an electrode assembly having another flat shape according to another embodiment of the present application. 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, where 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 to form a flat-shaped wound structure.

[0110] Regarding the technical features related to the anode plate 1001, the cathode plate 1002, and the separator 1003 of this embodiment, the description of the embodiment corresponding to the above-mentioned FIGS. 1 to 15 may be referred to, and the description will be omitted here.

[0111] In this embodiment, the wound structure of the electrode assembly includes a straight region 10A, and a first folded region 10B1 and a second folded region 10B2 located on either side of the straight region 10A.

[0112] The electrode assembly of this embodiment is substantially similar to the electrode assembly described in the embodiment corresponding to FIGS. 17 and 18, and may have the following differences.

[0113] An electrolyte adsorption layer is provided (e.g., attached) on the outer surface of at least the innermost cathode plate 1002 in the first folding region 10B1 and the second folding region 10B2, for example, an electrolyte adsorption layer is provided (e.g., attached) on the outer surface of each layer of the cathode plate 1002 in the first folding region 10B1 and the second folding region 10B2. In this embodiment, the outer surface of the cathode plate 1002 refers to the surface facing away from the winding axis of the cathode plate 1002 or the surface facing away from the inside of the winding structure.

[0114] For example, a first electrolyte-adsorbing layer 1004 is attached to the outer surface of the cathode plate 1002 in the first folded region 10B1.

[0115] For example, the second electrolyte-adsorbing layer 1005 is attached to the outer surface of the second layer of plate (which is the cathode plate 1002) in the second folding region 10B2. The third electrolyte-adsorbing layer 1006 is attached to the outer surface of the fourth layer of plate (which is the cathode plate 1002) in the second folding region 10B2.

[0116] In this embodiment, both ends along the winding direction of the first electrolyte solution adsorption layer 1004 are located at the boundary between the first folded region 10B1 and the straight region 10A, and both ends along the winding direction of the second electrolyte solution adsorption layer 1005 and the third electrolyte solution adsorption layer 1006 are located at the boundary between the second folded region 10B2 and the straight region 10A.

[0117] In this embodiment, the functions, structures, distribution methods, and other related details of the first electrolyte adsorption layer 1004, the second electrolyte adsorption layer 1005, and the third electrolyte adsorption layer 1006 may refer to the related details of the electrolyte adsorption layers described in the embodiments of Figures 1 to 15 above, and therefore will not be described here.

[0118] As shown in Fig. 20, Fig. 20 is a structural schematic diagram of a cross section perpendicular to the winding axis K of another flat-shaped electrode assembly according to another embodiment of the present application. The electrode assembly includes an anode plate 1101, a cathode plate 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, where the separator 1103 is located between the anode plate 1101 and the cathode plate 1102, and the anode plate 1101, the cathode plate 1102 and the separator 1103 are stacked and then wound around the winding axis to form a flat-shaped wound structure.

[0119] Regarding the technical features related to the anode plate 1101, the cathode plate 1102, and the separator 1103 of this embodiment, the description of the embodiment corresponding to the above-mentioned FIGS. 1 to 15 may be referred to, and the description will be omitted here.

[0120] In this embodiment, the wound structure of the electrode assembly includes a straight region 11A, and a first folded region 11B1 and a second folded region 11B2 located on both sides of the straight region 11A.

[0121] The electrode assembly of this embodiment is substantially similar to the electrode assembly described in the embodiment corresponding to FIGS. 17 and 18, and may have the following differences.

[0122] An electrolyte adsorption layer is provided (e.g., attached) to the inner surface of at least the innermost anode plate 1101 in the first folding region 11B1 and the second folding region 11B2, for example, an electrolyte adsorption layer is provided on the inner surface of each of the anode plates 1101 in the first folding region 11B1 and the second folding region 11B2. In this embodiment, the inner surface of the anode plate 1101 refers to the surface facing the winding axis of the anode plate 1101 or the surface facing the inside of the winding structure.

[0123] For example, the first electrolyte adsorption layer 1104 is attached to the inner surface of the innermost electrode plate (which is the anode plate 1101) in the first folding region 11B1, and the second electrolyte adsorption layer 1105 is attached to the inner surface of the outermost electrode plate (which is the anode plate 1101).

[0124] For example, the third electrolyte adsorption layer 1106 is attached to the inner surface of the first layer of electrode plate (which is the anode plate 1101) in the second folding region 11B2. The fourth electrolyte adsorption layer 1107 is attached to the inner surface of the third layer of electrode plate (which is the anode plate 1101) in the second folding region 11B2. The fifth electrolyte adsorption layer 1108 is attached to the inner surface of the fifth layer of electrode plate (which is the anode plate 1101) in the second folding region 11B2.

[0125] In this embodiment, both ends along the winding direction of the first electrolyte solution adsorption layer 1104 and the second electrolyte solution adsorption layer 1105 are each located at the boundary between the first folded region 11B1 and the straight region 11A, and both ends along the winding direction of the third electrolyte solution adsorption layer 1106, the fourth electrolyte solution adsorption layer 1107, and the fifth electrolyte solution adsorption layer 1108 are each located at the boundary between the second folded region 11B2 and the straight region 11A.

[0126] In this embodiment, the functions, structures, distribution methods, and other related contents of the first electrolyte adsorption layer 1104, the second electrolyte adsorption layer 1105, the third electrolyte adsorption layer 1106, the fourth electrolyte adsorption layer 1107, and the fifth electrolyte adsorption layer 1108 may all be referred to the related contents of the electrolyte adsorption layers described in the embodiments of Figures 1 to 15 above, and therefore further description is omitted here.

[0127] As shown in Fig. 21, Fig. 21 is a structural schematic diagram of a cross section perpendicular to the winding axis K of another flat-shaped electrode assembly according to another embodiment of the present application. 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, where 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 then wound around the winding axis to form a flat-shaped wound structure.

[0128] Regarding the technical features related to the anode plate 1201, the cathode plate 1202, and the separator 1203 of this embodiment, the description of the embodiment corresponding to the above-mentioned FIGS. 1 to 15 may be referred to, and the description will be omitted here.

[0129] In this embodiment, the wound structure of the electrode assembly includes a straight region 12A, and a first folded region 12B1 and a second folded region 12B2 located on both sides of the straight region 12A.

[0130] The electrode assembly of this embodiment is substantially similar to the electrode assembly described in the embodiment corresponding to FIGS. 17 and 18, and may have the following differences.

[0131] An electrolyte adsorption layer is provided (e.g., attached) to the outer surface of at least the innermost anode plate 1201 in the first folding region 12B1 and the second folding region 12B2, for example, an electrolyte adsorption layer is provided on the outer surface of each of the anode plates 1201 in the first folding region 12B1 and the second folding region 12B2. In this embodiment, the outer surface of the anode plate 1201 refers to the surface facing away from the winding axis of the anode plate 1201 or the surface facing away from the inside of the winding structure.

[0132] For example, the first electrolyte adsorption layer 1204 is attached to the outer surface of the innermost electrode plate (which is the anode plate 1201) in the first folding region 12B1, and the second electrolyte adsorption layer 1205 is attached to the outer surface of the outermost electrode plate (which is the anode plate 1201).

[0133] For example, the third electrolyte-adsorbing layer 1206 is attached to the outer surface of the first layer of plate (which is the anode plate 1201) in the second folding region 12B2. The fourth electrolyte-adsorbing layer 1207 is attached to the outer surface of the third layer of plate (which is the anode plate 1201) in the second folding region 12B2. The fifth electrolyte-adsorbing layer 1208 is attached to the outer surface of the fifth layer of plate (which is the anode plate 1201) in the second folding region 12B2.

[0134] In this embodiment, both ends along the winding direction of the first electrolyte solution adsorption layer 1204 and the second electrolyte solution adsorption layer 1205 are each located at the boundary between the first folded region 12B1 and the straight region 12A, and both ends along the winding direction of the third electrolyte solution adsorption layer 1206, the fourth electrolyte solution adsorption layer 1207, and the fifth electrolyte solution adsorption layer 1208 are each located at the boundary between the second folded region 12B2 and the straight region 12A.

[0135] In this embodiment, the functions, structures, distribution methods, and other related contents of the first electrolyte adsorption layer 1204, the second electrolyte adsorption layer 1205, the third electrolyte adsorption layer 1206, the fourth electrolyte adsorption layer 1207, and the fifth electrolyte adsorption layer 1208 may all be referred to the related contents of the electrolyte adsorption layers described in the embodiments of Figures 1 to 15 above, and therefore further description is omitted here.

[0136] As shown in Fig. 22, Fig. 22 is a structural schematic diagram of a cross section perpendicular to a winding axis K of another flat-shaped electrode assembly according to another embodiment of the present application. The electrode assembly includes an anode plate 1301, a cathode plate 1302, a separator 1303, and a plurality of electrolyte adsorption layers 1304, where the separator 1303 is located between the anode plate 1301 and the cathode plate 1302, and the anode plate 1301, the cathode plate 1302, and the separator 1303 are stacked and then wound around the winding axis to form a flat-shaped wound structure.

[0137] Regarding the technical features related to the anode plate 1301, the cathode plate 1302, and the separator 1303 of this embodiment, the description of the embodiment corresponding to the above-mentioned FIGS. 1 to 15 may be referred to, and the description will be omitted here.

[0138] In this embodiment, the wound structure of the electrode assembly includes a straight region 13A, and a first folded region 13B1 and a second folded region 13B2 located on both sides of the straight region 13A.

[0139] The electrode assembly of this embodiment is substantially similar to the electrode assembly described in the embodiment corresponding to FIGS. 17 and 18, and may have the following differences.

[0140] An electrolyte adsorption layer 1304 is attached to the inner surface of at least the innermost separator 1303 in the first folding region 13B1 and the second folding region 13B2, for example, an electrolyte adsorption layer 1304 is attached to the inner surface of each separator 1303 in the first folding region 13B1 and the second folding region 13B2. In this embodiment, the inner surface of the separator 1303 refers to the surface facing the winding axis of the separator 1303 or the surface facing the inside of the winding structure.

[0141] In this embodiment, both ends of each electrolyte adsorption layer 1304 in the first bent region 13B1 along the winding direction are located at the boundary between the first bent region 13B1 and the straight region 13A, and both ends of each electrolyte adsorption layer 1304 in the second bent region 13B2 along the winding direction are located at the boundary between the second bent region 13B1 and the straight region 13A. 13B2 and straight area 13A It is located on the border with

[0142] In this embodiment, an electrolyte adsorption layer 1304 is attached to the inner surface of the separator 1303 adjacent to the cathode plate 1302 or the anode plate 1301 in the first folding region 13B1 and the second folding region 13B2, so that the electrolyte adsorption layer can replenish the electrolyte for the adjacent cathode plate 1302 or the anode plate 1301.

[0143] In this embodiment, the relevant contents such as the function, structure, and distribution method of each electrolyte adsorption layer 1304 may all be referred to the relevant contents of the electrolyte adsorption layer described in the embodiments of Figures 1 to 15 above, and therefore the description will be omitted here.

[0144] As shown in Fig. 23, Fig. 23 is a structural schematic diagram of a cross section perpendicular to a winding axis K of another flat-shaped electrode assembly according to another embodiment of the present application. The electrode assembly includes an anode plate 1401, a cathode plate 1402, a separator 1403, and a plurality of electrolyte adsorption layers 1404, where the separator 1403 is located between the anode plate 1401 and the cathode plate 1402, and the anode plate 1401, the cathode plate 1402, and the separator 1403 are stacked and then wound around the winding axis to form a flat-shaped wound structure.

[0145] Regarding the technical features related to the anode plate 1401, the cathode plate 1402, and the separator 1403 of this embodiment, the description of the embodiment corresponding to the above-mentioned FIGS. 1 to 15 may be referred to, and the description will be omitted here.

[0146] In this embodiment, the wound structure of the electrode assembly includes a straight region 14A, and a first folded region 14B1 and a second folded region 14B2 located on either side of the straight region 14A.

[0147] The electrode assembly of this embodiment is substantially similar to the electrode assembly described in the embodiment corresponding to FIG. 17, and the differences therebetween may be as follows.

[0148] An electrolyte adsorption layer 1404 is attached to the outer surface of at least the innermost separator 1403 in the first folding region 14B1 and the second folding region 14B2, for example, an electrolyte adsorption layer 1404 is attached to the outer surface of each separator 1403 in the first folding region 14B1 and the second folding region 14B2. In this embodiment, the outer surface of the separator 1403 refers to the surface facing away from the winding axis of the separator 1403 or the surface facing away from the inside of the winding structure.

[0149] In this embodiment, both ends along the winding direction of each electrolyte adsorption layer 1404 in the first folding region 14B1 are located at the boundary between the first folding region 14B1 and the straight region 14A, and both ends along the winding direction of each electrolyte adsorption layer 1404 in the second folding region 14B2 are located at the boundary between the second folding region 14B2 and the straight region 14A.

[0150] In this embodiment, an electrolyte adsorption layer 1404 is attached to the outer surface of the separator 1403 adjacent to the cathode plate 1402 or the anode plate 1401 in the first folding region 14B1 and the second folding region 14B2, so that the electrolyte adsorption layer can replenish electrolyte for the adjacent cathode plate 1402 or anode plate 1401.

[0151] In this embodiment, the relevant contents such as the function, structure, and distribution method of each electrolyte adsorption layer 1404 may all be referred to the relevant contents of the electrolyte adsorption layer described in the embodiments of Figures 1 to 15 above, and therefore the description will be omitted here.

[0152] In some embodiments not shown, at least a portion of the electrolyte-adsorbing layer may be applied to both the inner and outer surfaces of the separator adjacent the cathode or anode plate in the first and second folded regions, such that the electrolyte-adsorbing layer can replenish electrolyte for the adjacent cathode or anode plate.

[0153] In the above embodiments, the separator adjacent to the cathode plate or anode plate in the first folding region and the second folding region specifically refers to the separator located on the inside and / or outside of the anode plate, or the separator located on the inside and / or outside of the cathode plate in the first folding region and the second folding region.

[0154] In some embodiments not shown, at least a part of the electrolyte adsorption layer is attached to the inner surface and / or the outer surface of at least one of the separator folding parts adjacent to the first folding part and the second folding part of the cathode plate and the separator folding parts adjacent to the first folding part and the second folding part of the anode plate. Specifically, at least a part of the electrolyte adsorption layer may be provided on the separator on the inner and / or the outer side of the first folding part of the cathode plate and the separator on the inner and / or the outer side of the second folding part of the cathode plate, and the electrolyte adsorption layer may be provided on the inner and / or the outer surface of the separator. Alternatively, at least a part of the electrolyte adsorption layer may be provided on the separator on the inner and / or the outer side of the first folding part of the anode plate and the separator on the inner and / or the outer side of the second folding part of the anode plate, and the electrolyte adsorption layer may be provided on the inner and / or the outer surface of the separator.

[0155] By providing at least a part of the electrolyte adsorption layer on the separator in the first folding region and the second folding region, the uniformity of the electrolyte at the first and second folding regions can be improved, compared to the first and second folding regions where the gap between the cathode plate and the anode plate is large, thereby reducing the impact on the energy density of the battery cell and improving the performance of the battery cell. As shown in FIG. 24, FIG. 24 is a structural schematic diagram of a cross section perpendicular to the winding axis K of another flat-shaped electrode assembly according to another embodiment of the present application. The electrode assembly includes an anode plate 1501, a cathode plate 1502, a separator 1503, and a plurality of electrolyte adsorption layers 1504, where the separator 1503 is located between the anode plate 1501 and the cathode plate 1502, and the anode plate 1501, the cathode plate 1502, and the separator 1503 are stacked and then wound around the winding axis to form a flat-shaped wound structure.

[0156] Regarding the technical features related to the anode plate 1501, the cathode plate 1502, and the separator 1503 of this embodiment, the description of the embodiment corresponding to the above-mentioned FIGS. 1 to 15 may be referred to, and the description will be omitted here.

[0157] In this embodiment, the wound structure of the electrode assembly includes a straight region 15A, and a first folded region 15B1 and a second folded region 15B2 located on either side of the straight region 15A.

[0158] The electrode assembly of this embodiment is substantially similar to the electrode assembly described in the embodiment corresponding to FIGS. 17 and 18, and may have the following differences.

[0159] The anode plates 1501 and cathode plates 1502 included in the first folding region 15B1 and the second folding region 15B2 of the electrode assembly are stacked alternately in sequence, with a separator 1503 between any adjacent anode plates 1501 and cathode plates 1502 in the first folding region 15B1 and the second folding region 15B2, where the innermost electrode plates in the first folding region 15B1 and the second folding region 15B2 are both anode plates 1501, and the inner and outer surfaces of at least the innermost cathode plates 1502 in the first folding region 15B1 and the second folding region 15B2 are both provided with electrolyte adsorption layers 1504, for example, the inner and outer surfaces of the cathode plates 1502 in each layer in the first folding region 15B1 and the second folding region 15B2 are both provided with electrolyte adsorption layers 1504. In this embodiment, the inner surface of the cathode plate 1502 refers to the surface facing the winding axis of the cathode plate 1502 or the surface facing the inside of the winding structure, and the outer surface of the cathode plate 1502 refers to the surface facing away from the winding axis of the cathode plate 1502 or the surface facing away from the inside of the winding structure.

[0160] For example, the first folding region 15B1 has multiple layers of plates, for example, three layers of plates, and the innermost layer (which may be called the first layer) and outermost layer (which may be called the third layer) of the first folding region 15B1 are both anode plates 1501, and the plate between the innermost layer plate and the outermost layer plate of the first folding region 15B1 (which may be called the second layer plate) is a cathode plate 1502, and an electrolyte adsorption layer 1504 is provided (e.g., attached) on both the inner and outer surfaces of the cathode plate 1502 in the first folding region 15B1.

[0161] The second folded region 15B2 has multiple layers of electrode plates, for example five layers of electrode plates, and the anode plates 1501 and cathode plates 1502 in the second folded region 15B2 are stacked alternately in a direction from the inside to the outside of the wound structure, with the anode plate 1501 being the innermost electrode plate in the second folded region 15B2, and an electrolyte adsorption layer 1504 being provided (for example, attached) on both the inner and outer surfaces of the cathode plates 1502 in each layer in the second folded region 15B2.

[0162] For example, along the direction from the inside to the outside of the wound structure, the second folded region 15B2 includes first, second, third, fourth and fifth layers of plates in order, the first, third and fifth layers of plates are positive electrode plates 1501, the second and fourth layers of plates are negative electrode plates 1502, and an electrolyte adsorption layer 1504 is provided on both the inner and outer surfaces of the second and fourth layers of plates in the second folded region 15B2.

[0163] In this embodiment, both ends along the winding direction L of each electrolyte solution adsorption layer 1504 are located at the boundary between the folded region and the straight region. For example, both ends along the winding direction of each electrolyte solution adsorption layer 1504 in the first folded region 15B1 are located at the boundary between the first folded region 15B1 and the straight region 15A, and both ends along the winding direction of each electrolyte solution adsorption layer 1504 in the second folded region 15B2 are located at the boundary between the second folded region 15B2 and the straight region 15A.

[0164] In this embodiment, the relevant contents such as the function, structure, and distribution method of each electrolyte adsorption layer 1504 may be referred to the relevant contents of the electrolyte adsorption layer described in the embodiments of Figures 1 to 15 above, and therefore the description will be omitted here.

[0165] 25 shows a schematic cross-sectional structure diagram of an electrode assembly having a flat shape according to another embodiment of the present application, the cross-sectional structure being perpendicular to the winding axis K. The electrode assembly includes an anode plate 1601, a cathode plate 1602, a separator 1603, a first electrolyte adsorption layer 1604, a second electrolyte adsorption layer 1605 and a third electrolyte adsorption layer 1606, where the separator 1603 is located between the anode plate 1601 and the cathode plate 1602, and the anode plate 1601, the cathode plate 1602 and the separator 1603 are stacked and then wound around the winding axis to form a flat-shaped wound structure.

[0166] Regarding the technical features related to the anode plate 1601, the cathode plate 1602, and the separator 1603 of this embodiment, the description of the embodiment corresponding to the above-mentioned FIGS. 1 to 15 may be referred to, and the description will be omitted here.

[0167] The electrode assembly of this embodiment is substantially similar to the electrode assembly described in the embodiment corresponding to FIGS. 17 and 18, and may have the following differences.

[0168] In this embodiment, the winding structure of the electrode assembly includes a first straight region 16A1, a second straight region 16A2, a first folded region 16B1 and a second folded region 16B2, the first straight region 16A1 and the second straight region 16A2 are arranged opposite each other, the first folded region 16B1 and the second folded region 16B2 are arranged opposite each other, both ends of the first folded region 16B1 are respectively connected to the ends on the same side of the first straight region 16A1 and the second straight region 16A2, and both ends of the second folded region 16B2 are respectively connected to the ends on the same other side of the first straight region 16A1 and the second straight region 16A2.

[0169] The anode plates 1601 and cathode plates 1602 included in the first folding region 16B1 and the second folding region 16B2 of the electrode assembly are stacked alternately in sequence, with a separator 1603 between adjacent anode plates 1601 and cathode plates 1602, where the innermost electrode plates in the first folding region 16B1 and the second folding region 16B2 are both anode plates 1601, and an electrolyte adsorption layer is provided (e.g., attached) on the inner surface of at least the innermost cathode plate 1602 in the first folding region 16B1 and the second folding region 16B2, for example, an electrolyte adsorption layer is provided (e.g., attached) on the inner surface of each layer of cathode plates 1602 in the first folding region 16B1 and the second folding region 16B2. In this embodiment, the inner surface of the cathode plate 1602 refers to the surface of the cathode plate 1602 that faces the winding axis, or the surface that faces the interior of the winding structure.

[0170] For example, the first folded region 16B1 has multiple layers of plates, for example three layers of plates, in which the innermost layer (which may be called the first layer) and the outermost layer (which may be called the third layer) of the first folded region 16B1 are both anode plates 1601, the plate between the innermost layer plate and the outermost layer plate (which may be called the second layer plate) is a cathode plate 1602, and a first electrolyte adsorption layer 1604 is attached to the inner surface of the cathode plate 1602 in the first folded region 16B1.

[0171] For example, the second folded region 16B2 has multiple layers of electrode plates, for example five layers of electrode plates, and the anode plates 1601 and cathode plates 1602 in the second folded region 16B2 are stacked alternately in a direction from the inside to the outside of the wound structure, with the anode plate 1601 being the innermost electrode plate in the second folded region 16B2, and an electrolyte adsorption layer being attached to the inner surface of each layer of cathode plates 1602 in the second folded region 16B2.

[0172] For example, along the direction from the inside to the outside of the wound structure, the second folded region 16B2 sequentially includes a first layer, a second layer, a third layer, a fourth layer, and a fifth layer of electrode plates, the first layer, the third layer, and the fifth layer of electrode plates are anode plates 1601, and the second layer and the fourth layer of electrode plates are cathode plates 1602, and the second electrolyte adsorption layer 1605 is attached to the inner surface of the cathode plate 1602 among the innermost adjacent anode plate 1601 and cathode plate 1602 in the second folded region 16B2, i.e., the second electrolyte adsorption layer 1605 is attached to the inner surface of the second layer of electrode plates (which is the cathode plate 1602) in the second folded region 16B2. The third electrolyte adsorption layer 1606 is attached to the inner surface of the fourth layer of electrode plates (which is the cathode plate 1602) in the second folded region 16B2.

[0173] In this embodiment, the first electrolyte solution-adsorption layer 1604 includes a first end and a second end along the winding direction L, the first end of the first electrolyte solution-adsorption layer 1604 is located in the first bent region 16B1, and the second end of the first electrolyte solution-adsorption layer 1604 is located in the first straight region 16A1. The second electrolyte solution-adsorption layer 1605 includes a first end and a second end along the winding direction L, the first end of the second electrolyte solution-adsorption layer 1605 is located in the second bent region 16B2, and the second end of the second electrolyte solution-adsorption 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, and the first end of the third electrolyte-adsorption layer 1606 is located in the second bent region 16B2, and the second end of the third electrolyte-adsorption layer 1606 is located in the second straight region 16A2. In another embodiment of the present application, the first end of the third electrolyte-adsorption layer 1606 may be located in the second bent region 16B2, and the second end of the third electrolyte-adsorption layer 1606 may be located in the first straight region 16A1.

[0174] In this embodiment, the functions, structures, distribution methods, and other related contents of the first electrolyte adsorption layer 1604, the second electrolyte adsorption layer 1605, and the third electrolyte adsorption layer 1606 may all be referred to the related contents of the electrolyte adsorption layers described in the embodiments of Figures 1 to 15 above, and therefore will not be described here.

[0175] As shown in Fig. 26, Fig. 26 is a structural schematic diagram of a cross section perpendicular to a winding axis K of an electrode assembly having a flat shape according to another embodiment of the present application. The electrode assembly includes an anode plate 1701, a cathode plate 1702, a separator 1703, a first electrolyte adsorption layer 1704, a second electrolyte adsorption layer 1705 and a third electrolyte adsorption layer 1706, where the separator 1703 is located between the anode plate 1701 and the cathode plate 1702, and the anode plate 1701, the cathode plate 1702 and the separator 1703 are stacked and then wound around the winding axis to form a flat-shaped wound structure.

[0176] Regarding the technical features related to the anode plate 1701, the cathode plate 1702, and the separator 1703 of this embodiment, the description of the embodiment corresponding to the above-mentioned FIGS. 1 to 15 may be referred to, and the description will be omitted here.

[0177] The electrode assembly of this embodiment is substantially similar to the electrode assembly described in the embodiment corresponding to FIGS. 17 and 18, and may have the following differences.

[0178] In this embodiment, the winding structure of the electrode assembly includes a first straight region 17A1, a second straight region 17A2, a first folded region 17B1 and a second folded region 17B2, the first straight region 17A1 and the second straight region 17A2 are arranged opposite each other, the first folded region 17B1 and the second folded region 17B2 are arranged opposite each other, both ends of the first folded region 17B1 are respectively connected to the ends on the same side of the first straight region 17A1 and the second straight region 17A2, and both ends of the second folded region 17B2 are respectively connected to the ends on the same other side of the first straight region 17A1 and the second straight region 17A2.

[0179] The anode plates 1701 and cathode plates 1702 included in the first folding region 17B1 and the second folding region 17B2 of the electrode assembly are stacked alternately in sequence, with a separator 1703 between adjacent anode plates 1701 and cathode plates 1702, where the innermost electrode plates in the first folding region 17B1 and the second folding region 17B2 are both anode plates 1701, and an electrolyte adsorption layer is provided (e.g., attached) on the inner surface of at least the innermost cathode plate 1702 in the first folding region 17B1 and the second folding region 17B2, for example, an electrolyte adsorption layer is provided (e.g., attached) on the inner surface of each layer of cathode plates 1702 in the first folding region 17B1 and the second folding region 17B2. In this embodiment, the inner surface of the cathode plate 1702 refers to the surface facing the winding axis of the cathode plate 1702 or the surface facing the interior of the winding structure.

[0180] For example, the first folded region 17B1 has multiple layers of plates, for example, three layers of plates, in which the innermost layer (which may be called the first layer) and the outermost layer (which may be called the third layer) of the first folded region 17B1 are both anode plates 1701, the plate between the innermost layer plate and the outermost layer plate (which may be called the second layer plate) is a cathode plate 1702, and a first electrolyte adsorption layer 1704 is attached to the inner surface of the cathode plate 1702 in the first folded region 17B1.

[0181] The second folded region 17B2 has multiple layers of electrode plates, for example five layers of electrode plates, and the anode plates 1701 and cathode plates 1702 in the second folded region 17B2 are stacked alternately in a direction from the inside to the outside of the wound structure, with the anode plate 1701 being the innermost electrode plate in the second folded region 17B2, and an electrolyte adsorption layer being attached to the inner surface of each layer of cathode plates 1702 in the second folded region 17B2.

[0182] For example, along the direction from the inside to the outside of the wound structure, the second folded region 17B2 sequentially includes a first layer, a second layer, a third layer, a fourth layer, and a fifth layer of electrode plates, the first layer, the third layer, and the fifth layer of electrode plates are anode plates 1701, and the second layer and the fourth layer of electrode plates are cathode plates 1702, and the second electrolyte adsorption layer 1705 is attached to the inner surface of the cathode plate 1702 among the innermost adjacent anode plate 1701 and cathode plate 1702 in the second folded region 17B2, i.e., the second electrolyte adsorption layer 1705 is attached to the inner surface of the second layer of electrode plates (which is the cathode plate 1702) in the second folded region 17B2. The third electrolyte adsorption layer 1706 is attached to the inner surface of the fourth layer of electrode plates (which is the cathode plate 1702) in the second folded region 17B2.

[0183] In this embodiment, the first electrolyte solution adsorption 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 adsorption layer 1704 are located in the first bent region 17B1. The second electrolyte solution adsorption layer 1705 includes a first end and a second end along the winding direction L, and both the first end of the second electrolyte solution adsorption layer 1705 is located at the boundary between the second bent region 17B2 and the first straight region 17A1, and both the second end of the second electrolyte solution adsorption layer 1705 is located at the boundary between the second bent region 17B2 and the second straight region 17A2. The third electrolyte solution adsorption layer 1706 includes a first end and a second end along the winding direction L, and both the first end and the second end of the third electrolyte solution adsorption layer 1706 are located in the second bent region 17B2.

[0184] In this embodiment, in the second folding region 17B2, the curvature of the electrode plate of each layer is gradually decreased along the direction perpendicular to the winding axis K and from the inside to the outside of the electrode assembly, i.e., the degree of folding is gradually decreased. Thus, the circumferential angle that each electrolyte adsorption layer covers along the winding direction in the second folding region 17B2 can be gradually decreased along the direction perpendicular to the winding axis K and from the inside to the outside of the electrode assembly. For example, the third electrolyte adsorption The circumferential angle that layer 1706 covers along the winding direction in second folding region 17B2 is smaller than the circumferential angle that second electrolyte adsorption layer 1705 covers in second folding region 17B2; for example, the circumferential angle that third electrolyte adsorption layer 1706 covers along the winding direction in second folding region 17B2 is 90°, and the circumferential angle that second electrolyte adsorption layer 1705 covers along the winding direction in second folding region 17B2 is 180°.

[0185] In this embodiment, the functions, structures, distribution methods, and other related contents of the first electrolyte adsorption layer 1704, the second electrolyte adsorption layer 1705, and the third electrolyte adsorption layer 1706 may all be referred to the related contents of the electrolyte adsorption layers described in the embodiments of Figures 1 to 15 above, and therefore will not be described here.

[0186] In the embodiments of Figures 17 to 26, the electrolyte adsorption layer 4 may be provided at a folding site corresponding to a predetermined number of foldings of at least one of the cathode plate, the anode plate, and the separator in the first folding region and the second folding region. In some embodiments, at least a part of the electrolyte adsorption layer is provided at the first folding site and / or the second folding site of the cathode plate in the folding region, and / or at least a part of the electrolyte adsorption layer is provided at the first folding site and / or the second folding site of the anode plate, and / or at least a part of the electrolyte adsorption layer is provided at the folding site of the separator adjacent to the first folding site of the cathode plate and / or the folding site of the separator adjacent to the second folding site, and / or at least a part of the electrolyte adsorption layer is provided at the folding site of the separator adjacent to the first folding site of the anode plate and / or the folding site of the separator adjacent to the second folding site. The predetermined number of folding times mentioned in this embodiment means winding the cathode plate, the separator and the anode plate from the inside to the outside to form an electric current. veryIt refers to the number of times that the folding is arranged in the order of front and rear in the process of forming an assembly. Taking the embodiment of FIG. 17 as an example, for the cathode plate 92, the position of the second electrolyte adsorption layer 95 is the first folding of the cathode plate 92, the position of the first electrolyte adsorption layer 94 is the second folding of the cathode plate 92, and the position of the third electrolyte adsorption layer 96 is the third folding of the cathode plate 92, it is inferred in this manner. Note that, taking the embodiment of FIG. 20 as an example, the position of the third electrolyte adsorption layer 1106 is the first folding of the anode plate 1101, the position of the first electrolyte adsorption layer 1104 is the second folding of the anode plate 1101, and the position of the fourth electrolyte adsorption layer 1107 is the third folding of the anode plate 1101, it is inferred in this manner. The predetermined number of folds of the cathode plate and the anode plate is not limited to the first or second fold, and any range of folds may be selected as necessary. For example, the electrolyte adsorption layer 4 may be provided at a fold site where the cathode plate is folded 1 to 4 times, 1 to 6 times, 1 to 8 times, 3 to 4 times, 3 to 6 times, 3 to 8 times, or another range of folds in the fold region, and / or the electrolyte adsorption layer 4 may be provided at a fold site where the anode plate is folded 1 to 4 times, 1 to 6 times, 1 to 8 times, 3 to 4 times, 3 to 6 times, 3 to 8 times, or another range of folds in the fold region. Alternatively, the electrolyte adsorption layer 4 may be provided at a folding portion of the separator adjacent to a folding portion of the cathode plate folded 1-4 times, 1-6 times, 1-8 times, 3-4 times, 3-6 times, 3-8 times, or other times in the folding region, or at a folding portion of the separator adjacent to a folding portion of the anode plate folded 1-4 times, 1-6 times, 1-8 times, 3-4 times, 3-6 times, 3-8 times, or other times. In the above embodiment, the separator adjacent to the cathode plate or the anode plate in the first folding region and the second folding region specifically refers to the separator located on the inside and / or outside of the anode plate, or the separator located on the inside and / or outside of the cathode plate in the first folding region and the second folding region.

[0187] In this embodiment, an electrolyte adsorption layer is provided at the fold portion of at least one of the cathode plate, the anode plate, and the separator, where the gap between the cathode plate 1 and the anode plate 2 is large, for example, the fold portion includes the first fold and the second fold, and only the electrolyte at the first and second fold portions is controlled, so that the electrolyte storage and retention performance at the first and second fold portions of the cathode plate 1 or the anode plate 2 can be improved, the ion conduction and diffusion performance can be improved, and the cycle performance and service life of the battery cell can be improved. In addition, by disposing an electrolyte adsorption layer at the first and second fold portions of the fold region of the surface of the cathode plate and / or the anode plate, the electrolyte adsorption layer can reinforce the cathode active material layer on the first and second fold portions of the cathode plate and / or the anode active material layer on the first and second fold portions of the anode plate, reducing the occurrence of the situation where the active material layer breaks due to folding, and further improving the performance of the battery cell.

[0188] As shown in FIG. 27, FIG. 27 is a schematic view of a cathode plate 1702 according to another embodiment of the present application after being unfolded. Specifically, FIG. 27 is a schematic view of the cathode plate 1702 in FIG. 27 after being unfolded at a position where the second electrolyte adsorption layer 1705 is attached. Here, the first folding region 17B1 and the second folding region 17B2 have a center line M, which is parallel to the winding axis of the electrode assembly and extends along the length direction of the electrode assembly in FIG. 26. The center line M divides the first folding region 17B1 and the second folding region 17B2 into two parts, an upper part and an lower part, respectively, along the width direction of the electrode assembly.

[0189] For the second electrolyte adsorption layer 1705, it includes an intermediate adsorption layer 43 located in a first folded section 1708 and a side adsorption layer 44 located in a second folded section 1709, where the first folded section 1708 covers the center line M of the folded area, i.e. the entire first folded section 1708 is located in the center of the folded area. The second folded section 1709 is located on at least one side of the first folded section 1708, and optionally, one second folded section 1709 is provided on each side of the first folded section, as shown in FIG. 27. Here, the porosity of the intermediate adsorption layer 43 is larger than the porosity of the side adsorption layer 44, as shown in FIG. 27. The porosity of the electrolyte adsorption layer of different folded sections is the ratio of the sum of the areas of all the ion exchange passages 40 on the electrolyte adsorption layer in one section to the area of ​​the electrolyte adsorption layer in the region. The porosity of the electrolyte adsorption layer can be adjusted by changing the diameter of the ion exchange passage 40 on the electrolyte adsorption layer and the number of ion exchange passages per unit area. For example, the diameter of the ion exchange passage 40 located in the intermediate adsorption layer 43 and / or the number of ion exchange passages per unit area may be greater than the diameter of the ion exchange passage 40 in the side adsorption layer 44 and / or the number of ion exchange passages per unit area. The structure of the second electrolyte adsorption layer 1705 of this embodiment may be disposed on one or two surfaces of a folding portion folded a predetermined number of times on at least one of the cathode plate, the anode plate, and the separator. In some embodiments, the porosity of the intermediate adsorption layer 43 is 0<≦50%. The porosity of the intermediate adsorption 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 may not have ion exchange passages 40, and the porosity of the side adsorption layer 44 may be 0<50%. The porosity of the side adsorption layer 44 may be a value such as 0, 0.05%, 0.08%, 0.1%, 0.5%, 1%, 2%, 5%, 10%, 15%, 30%, 40%, or other value.

[0190] As shown in FIG. 28, the porosity of the intermediate adsorption layer 43 may be smaller than the porosity of the side adsorption layer 44. For example, the diameter of the ion exchange passages 40 located in the intermediate adsorption layer 43 and / or the number of ion exchange passages per unit area may be smaller than the diameter of the ion exchange passages 40 in the side adsorption layer 44 and / or the number of ion exchange passages per unit area. The structure of the second electrolyte adsorption layer 1705 in this embodiment may be disposed on one or two surfaces of a folded portion that is folded a predetermined number of times in at least one of the cathode plate, the anode plate, and the separator. In some embodiments, the porosity of the side adsorption layer 44 is 0<≦50%. The porosity of the side adsorption layer 44 The rate is , 0.05%, 0.08%, 0.1%, 0.5%, 1%, 2%, 5%, 10%, 15%, 30%, 40%, or other values. In some embodiments, the porosity of the intermediate adsorbent layer 43 may be 0, i.e., no ion exchange passages 40 are provided in the intermediate adsorbent layer 43, and the porosity of the intermediate adsorbent layer 43 may be 0<50%. The porosity of the intermediate adsorbent layer 43 may be 0, 0.05%, 0.08%, 0.1%, 0.5%, 1%, 2%, 5%, 10%, 15%, 30%, 40%, or other values.

[0191] 29, FIG. 29 is a schematic view of the cathode plate 1702 according to another embodiment of the present application after unfolding, specifically, the cathode plate 1702 in FIG. 26 after unfolding at the position where the second electrolyte adsorption layer 1705 is attached, in which the ion exchange channels 40 are distributed in a bent line or curved line on the second electrolyte adsorption layer 1705 along a direction parallel to the winding axis K of the electrode assembly in the bending region. By disposing the ion exchange channels 40 in a bent line or curved line on the second electrolyte adsorption layer 1705, the ion exchange channels 40 are distributed at various widths and heights of the second electrolyte adsorption layer 1705, and the second electrolyte adsorption layer 1705 can realize the release of electrolyte and the conduction and diffusion of ions at various heights and widths, which is favorable for improving the cycle performance and service life of the battery. In this embodiment, 0<porosity of second electrolyte adsorption layer 1705≦50%. The porosity of second electrolyte adsorption layer 1705 may be 0.05%, 0.08%, 0.1%, 0.5%, 1%, 2%, 5%, 10%, 15%, 30%, 40%, etc., or other values.

[0192] 27 to 29 merely roughly describe the positional relationship between the electrolyte adsorption layer and the cathode plate and the structural features of the electrolyte adsorption layer, and the electrolyte adsorption layers in Fig. 27 to 29 are not limited to being disposed at the first and second folding sites of the cathode plate, but may be disposed at other sites on the cathode plate, and on the anode plate and separator. The electrolyte adsorption layer structures in the examples in Fig. 27 to 29 can be applied to the electrolyte adsorption layer structures in any one of the examples in Fig. 3 to Fig. 8 and Fig. 11 to Fig. 26.

[0193] As shown in Fig. 30, Fig. 30 is a structural schematic diagram of a battery cell according to another embodiment of the present application. The battery cell includes an outer frame 181 and one or more electrode assemblies 182 housed in the outer frame 181, the outer frame 181 includes a case 1811 and a cover plate 1812, the case 1811 has an accommodation chamber, and the case 1811 has an opening, that is, the plane does not have a case wall, and the inside and outside of the case 1811 communicate with each other so that the electrode assembly 182 can be accommodated in the accommodation chamber of the case 1811, and the cover plate 1812 and the case 1811 are combined at the opening of the case 1811 to form a hollow chamber, and after the electrode assembly 182 is accommodated in the outer frame 181, the outer frame 181 is filled with an electrolyte and sealed.

[0194] The case 1811 is determined by the shape after one or more electrode assemblies 182 are combined, and may be, for example, a hollow rectangular parallelepiped, a hollow cube, or a hollow cylinder. For example, when the case 1811 is a hollow rectangular parallelepiped or a cube, one of the planes of the case 1811 is an open surface, i.e., the plane does not have a case wall and communicates between the inside and outside of the case 1811, and when the case 1811 is a hollow cylinder, one of the circular side surfaces of the case 1811 is an open surface, i.e., the circular side surface does not have a case wall and communicates between the inside and outside of the case 1811.

[0195] In another embodiment of the present application, the case 1811 may be made from a conductive metallic material or plastic, and optionally, the case 1811 is made from aluminum or an aluminum alloy.

[0196] The structure of the electrode assembly 182 may refer to the relevant contents of the electrode assembly described in the embodiment of FIGS. 1 to 27, and the description thereof will be omitted here.

[0197] As shown in Fig. 31, Fig. 31 is a structural schematic diagram of a battery module according to another embodiment of the present application. 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 series-parallel means that the connection includes both series connection and parallel connection, and the structure of the battery cells 191 may refer to the battery cells described in the embodiment corresponding to Fig. 30, and the description here will be omitted.

[0198] 32 is a structural schematic diagram of a battery according to another embodiment of the present application, in which the battery includes a housing, and the housing accommodates a plurality of battery cells. The structure of the battery cell may refer to the structure of the battery cell shown in FIG. 30. Specific ways of accommodating a plurality of battery cells in a housing include directly mounting the battery cells in the housing, or combining a plurality of battery cells into a battery module, and then mounting the battery module in the battery.

[0199] As shown in FIG. 32, in some embodiments, the battery includes a plurality of battery modules 19 and a housing, the housing includes a lower housing 20 and an upper housing 30, the plurality of battery modules 19 may be connected in series or in parallel or in series-parallel, the lower housing 20 has an accommodation chamber, and the lower housing 20 has an opening so that the connected plurality of battery modules 19 can be accommodated in the accommodation chamber of the lower housing 20, the upper housing 30 and the lower housing 20 are joined at the opening of the lower housing 20 to form a hollow chamber, and the upper housing 30 and the lower housing 20 are joined and then sealed.

[0200] In another embodiment of the present application, the battery may solely power a power consuming device, and the battery may be referred to as a battery pack, for example, as used to power an automobile.

[0201] In another embodiment of the present application, according to the power consumption demand of the power consumption device, the multiple batteries are connected together and then combined into a battery pack, which is used to power the power consumption device. In another embodiment of the present application, the battery pack may be housed and enclosed in a housing.

[0202] For ease of explanation, the following embodiments are described taking as an example that the power consuming device includes a battery.

[0203] An embodiment of the present application further provides a power consuming device, for example, the power consuming device may be a motor vehicle, for example, a new energy vehicle, and the power consuming device includes a battery as described in the above-mentioned embodiment, where the battery used in the power consuming device may be the same as the battery described in the embodiment corresponding to Figure 31, and the description will be omitted here.

[0204] For example, FIG. 33 shows a structural schematic diagram of a power consumption device according to another embodiment of the present application. The power consumption device may be a vehicle, the vehicle may be a fuel oil vehicle, a gas vehicle or a new energy vehicle, the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, a range extender vehicle, etc. The vehicle includes a battery 2101, a controller 2102 and a motor 2103. The battery 2101 is for supplying power to the controller 2102 and the motor 2103 as the operation power source and driving power source of the vehicle, for example, the battery 2101 is for meeting the operating power demand during starting, navigating and running of the vehicle. 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 the power of the battery 2101 and uses it as the driving power source of the vehicle, providing driving power to the vehicle instead of or partially replacing fuel oil or natural gas.

[0205] As will be understood by those skilled in the art, some embodiments herein include some features that are included in other embodiments but not other features, but it is meant that a combination of features of different embodiments falls within the scope of the present application and forms a different embodiment. For example, in the claims, any one of the embodiments to be protected can be used in any combination manner.

[0206] The above embodiments are only used to explain the technical solutions of the present application, and are not intended to limit the same. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art can still understand that the technical solutions described in the above embodiments can be modified or some of the technical features can be replaced with equivalents, and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. 1. An electrode assembly comprising: a cathode plate, an anode plate, a separator for isolating the cathode plate and the anode plate, and an electrolyte adsorption layer configured to be disposed along at least one surface of the cathode plate, the anode plate, and the separator, the electrolyte adsorption layer being provided with an ion exchange passage which is a through hole provided along a thickness direction of the electrolyte adsorption layer, the cathode plate, the separator and the anode plate are wound to form a folded region, and at least a portion of the electrolyte adsorption layer is disposed on at least one surface of the cathode plate, the anode plate and the separator in the folded region; The folding region includes a first folding section covering a centerline of the folding region and a second folding section located on at least one side of the first folding section, the centerline of the folding region being parallel to a winding axis of the electrode assembly; An electrode assembly, wherein the porosity of a portion of the electrolyte adsorption layer located within the first folded section is different from the porosity of a portion of the electrolyte adsorption layer located within the second folded section, and the porosity of the electrolyte adsorption layer is the ratio of the area of ​​the ion exchange passage to the area of ​​the electrolyte adsorption layer.

2. 2. The electrode assembly of claim 1, wherein the electrolyte adsorption layer is attached to one or two surfaces of the cathode plate, and / or the electrolyte adsorption layer is attached to one or two surfaces of the anode plate, and / or the electrolyte adsorption layer is attached to one or two surfaces of the separator.

3. 2. The electrode assembly according to claim 1, wherein at least a portion of the electrolyte adsorption layer is provided at a first folding site and / or a second folding site of the cathode plate in a folding region, and / or at least a portion of the electrolyte adsorption layer is provided at a first folding site and / or a second folding site of the anode plate, and / or at least a portion of the electrolyte adsorption layer is provided at a folding site of the separator adjacent to the first folding site of the cathode plate and / or at a folding site of the separator adjacent to the second folding site of the cathode plate, and / or at least a portion of the electrolyte adsorption layer is provided at a folding site of the separator adjacent to the first folding site of the anode plate and / or at a folding site of the separator adjacent to the second folding site of the anode plate.

4. 4. The electrode assembly according to claim 3, wherein in the bent region, the ion exchange passages are distributed on the electrolyte adsorption layer in a bent line or curved line along a direction parallel to a winding axis of the electrode assembly.

5. 5. The electrode assembly according to claim 1, wherein the electrolyte adsorption layer comprises an adsorption base layer, the ion exchange passages being provided in the adsorption base layer.

6. 6. The electrode assembly of claim 5, wherein the material of the adsorption base layer comprises one of acrylic acid-acrylic acid ester copolymer, butadiene-styrene copolymer, styrene-acrylic acid copolymer, styrene-acrylic acid ester 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, glycerin ester type epoxy resin, silicone type resin, polyurethane, styrene-isoprene-styrene copolymer, and modifications of the above materials.

7. 5. The electrode assembly according to claim 1, wherein the electrolyte adsorption layer includes an adsorption base layer and a support layer, one side of the adsorption base layer is attached to a corresponding cathode plate, anode plate or separator, the support layer is attached to the other side of the adsorption base layer, and the ion exchange passage penetrates the support layer and the adsorption base layer along the thickness direction.

8. 8. The electrode assembly of claim 7, wherein the material of the adsorption base layer comprises one of acrylic acid-acrylic acid ester copolymer, butadiene-styrene copolymer, styrene-acrylic acid copolymer, styrene-acrylic acid ester 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, glycerin ester type epoxy resin, silicone type resin, polyurethane, styrene-isoprene-styrene copolymer, and modifications of the above materials.

9. 9. The electrode assembly of claim 7 or 8, wherein the material of the support layer comprises one of polyvinyl chloride, polyethylene, polypropylene, polyvinylidene fluoride, hexafluoropropylene-vinylidene fluoride copolymer, tetrafluoropropylene-vinylidene fluoride copolymer, trifluorochloropropylene-vinylidene fluoride copolymer, polyethylene terephthalate, polyimide, polyetherimide, polycarbonate, polystyrene, polyphenylene sulfide, polyvinylidene fluoride or its copolymer, polyarylate, fiber, nylon, non-woven fabric, and modifications of the above materials.

10. 10. The electrode assembly of claim 7, wherein the thickness of the support layer is ≦50 um, the porosity of the support layer is 0<≦50%, and / or the tensile modulus of the support layer is ≦100 MPa, where the porosity of the support layer is the ratio of the total area of ​​the ion exchange passages to the area of ​​the support layer.

11. A battery cell comprising a case, an electrolyte, a cover plate and at least one electrode assembly according to any one of claims 1 to 10, the case has an accommodation chamber and an opening, the electrode assembly and the electrolyte are accommodated in the accommodation chamber, The cover plate is used to close an opening of the case.

12. 12. A battery comprising: a housing; and at least one battery cell according to claim 11, said battery cell contained within said housing.

13. 13. A power consuming device comprising a battery according to claim 12 and configured to receive power provided by the battery according to claim 12.

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