CN218414694U

CN218414694U - Battery structure for improving lithium precipitation at edge of battery core

Info

Publication number: CN218414694U
Application number: CN202222289967.9U
Authority: CN
Inventors: 芮秉龙; 刘伟星; 郭李根
Original assignee: Huizhou Liwinon Energy Technology Co Ltd
Current assignee: Huizhou Liwinon Energy Technology Co Ltd
Priority date: 2022-08-30
Filing date: 2022-08-30
Publication date: 2023-01-31
Anticipated expiration: 2032-08-30

Abstract

The utility model belongs to the technical field of battery production and manufacture, in particular to a battery structure for improving lithium precipitation at the edge of a battery cell, which comprises a first pole piece and a second pole piece; in the width direction, the width of the first pole piece is equal to the width of the second pole piece; first pole piece includes first mass flow body, bottom and top layer, the bottom sets up the surface of first mass flow body, the top layer sets up the surface of bottom, the top layer is provided with the insulating layer respectively at width direction's both ends, the top layer with insulating layer width sum equals the width of bottom. The utility model discloses an optimize the pole piece structure, can improve electric core edge and analyse lithium, help improving the quality of battery.

Description

Battery structure for improving lithium precipitation at edge of battery core

Technical Field

The utility model belongs to the technical field of battery manufacturing, concretely relates to battery structure for improving lithium is separated out at electric core edge.

Background

The lithium ion battery as a novel secondary battery has the advantages of large energy density and power density, high working voltage, light weight, small volume, long cycle life, good safety, environmental protection and the like, and has wide application prospect in the aspects of portable electric appliances, electric tools, large-scale energy storage, electric traffic power supplies and the like.

For the safety performance of the battery core, the nitrile additive is mainly added into the electrolyte, but the cost is increased, and the performance of the original battery core is also greatly influenced.

In the existing structure, overhand refers to a part of an anode pole piece, which is beyond a positive anode pole piece in the length and width directions, and lithium is easy to separate from the edge of a battery cell due to the fact that the battery cell has overhand pole pieces in an overhand area are uneven, so that the quality of a battery is affected.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a: aiming at the defects of the prior art, the battery structure for improving the lithium separation at the edge of the battery core is provided, the lithium separation at the edge of the battery core can be improved by optimizing the pole piece structure, and the quality of the battery is improved.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a battery structure for improving lithium precipitation at the edge of a battery core comprises a first pole piece and a second pole piece; in the width direction, the width of the first pole piece is equal to the width of the second pole piece; first pole piece includes first mass flow body, bottom and top layer, the bottom sets up the surface of first mass flow body, the top layer sets up the surface of bottom, the top layer is provided with the insulating layer respectively at width direction's both ends, the top layer with insulating layer width sum equals the width of bottom.

Preferably, the insulating layer is disposed along an edge of the skin layer.

Preferably, the thickness of the surface layer is equal to the thickness of the insulating layer.

Preferably, the particle size of the insulating layer is less than 10 μm, the thickness of the insulating layer is 20-40 μm, and the width of the insulating layer is 0.1-3mm.

Preferably, the material of the insulating layer is ceramic or boehmite.

Preferably, the second pole piece includes a second current collector and a membrane layer disposed on a surface of the second current collector.

Preferably, the separator is located between the surface layer of the first pole piece and the membrane layer of the second pole piece.

Preferably, the width of the film layer is equal to the width of the base layer in the width direction.

Preferably, the width of the diaphragm is greater than the width of the first pole piece or the second pole piece.

Preferably, the first current collector is an aluminum foil, and the second current collector is a copper foil.

The beneficial effects of the utility model reside in that, the utility model discloses a first pole piece and the second pole piece that the width equals to at the width direction's of first pole piece both ends coating insulating layer, through the thickness of adjusting the insulating layer, make the thickness at pole piece edge unanimous with the thickness at pole piece center, improve the roughness on pole piece surface, avoid the pole piece edge to appear the problem of separating lithium, help improving the electric core heat abuse, the safety problem who falls. The utility model discloses an optimize the pole piece structure, can improve electric core edge and analyse lithium, help improving the quality of battery.

Drawings

Features, advantages and technical effects of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of the first pole piece of the present invention.

Fig. 2 is the structure schematic diagram of the winding core of the utility model.

Wherein the reference numerals are as follows:

1-a first pole piece; 11-a first current collector; 12-a bottom layer; 13-a surface layer; 14-an insulating layer;

2-a second pole piece; 21-a second current collector; 22-a membrane layer;

3-a separator;

y-width direction.

Detailed Description

As used in the specification and in the claims, certain terms are used to refer to particular components. As one skilled in the art will appreciate, manufacturers may refer to a component by different names. This specification and claims do not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. "substantially" means within an acceptable error range, and a person skilled in the art can solve the technical problem within a certain error range to substantially achieve the technical effect.

Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can include, for example, fixed connections, detachable connections, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

The present invention will be described in further detail with reference to fig. 1 to 2, but the present invention is not limited thereto.

Implementation mode one

Embodiment one will be described below with reference to fig. 1 to 2

The battery structure for improving the lithium precipitation at the edge of the battery cell comprises a first pole piece 1 and a second pole piece 2; in the width direction Y, the width of the first pole piece 1 is equal to the width of the second pole piece 2; the first pole piece 1 comprises a first current collector 11, a bottom layer 12 and a surface layer 13, wherein the bottom layer 12 is arranged on the surface of the first current collector 11, the surface layer 13 is arranged on the surface of the bottom layer 12, two ends of the surface layer 13 in the width direction Y are respectively provided with an insulating layer 14, and the sum of the widths of the surface layer 13 and the insulating layer 14 is equal to the width of the bottom layer 12.

Because in the existing structure, the battery core has overhang, and the pole piece in the overhang area is uneven, which causes the lithium to be easily separated from the edge of the battery core, and affects the quality of the battery, therefore, the first pole piece 1 and the second pole piece 2 with the same width are adopted, the insulating layer 14 is coated at the two ends of the first pole piece 1 in the width direction Y, and the thickness of the insulating layer 14 is adjusted, so that the thickness of the edge of the pole piece is consistent with the thickness of the center of the pole piece, thereby improving the flatness of the surface of the pole piece, avoiding the problem of lithium separation at the edge of the pole piece, and being beneficial to improving the safety problem of thermal abuse and falling of the battery core.

In this embodiment, the width of the bottom layer 12 is equal to the sum of the width of the surface layer 13 and the insulating layers 14 on both sides thereof, so as to ensure that the thickness of the edge of the pole piece is consistent with the thickness of the center of the pole piece, thereby avoiding the occurrence of lithium deposition at the edge of the pole piece.

In the basis the utility model discloses an in the battery structure for improving electric core edge lithium analysis, insulating layer 14 sets up along the edge of top layer 13, and in this embodiment, insulating layer 14 also can be understood as setting up along the edge of top layer 13, and through the thickness of adjusting insulating layer 14 promptly, the breach that the edge of filling top layer 13 and bottom 12 enclose, the thickness of top layer 13 and the thickness of insulating layer 14 equal for the thickness at pole piece edge is unanimous with the thickness at pole piece center.

In the battery structure for improving the cell edge lithium deposition according to the present invention, the particle size of the insulating layer 14 is less than 10 μm, the thickness of the insulating layer 14 is 20-40 μm, and the width of the insulating layer 14 is 0.1-3mm. The thickness and width of the insulating layer 14 are limited, and the insulating layer 14 is prevented from being too thick or too wide, so that the production cost of the pole piece is increased.

In the battery structure for improving cell edge lithium deposition according to the present invention, the second pole piece 2 includes the second current collector 21 and the membrane layer 22 disposed on the surface of the second current collector 21.

In a battery structure for improving cell edge lithium deposition according to the present invention, in the width direction Y, the width of the membrane layer 22 is equal to the width of the bottom layer 12, and in some embodiments, the width of the bottom layer 12 of the first pole piece 1 is equal to the width of the second pole piece 2.

According to the utility model discloses an in the battery structure for improving electric core edge and analyse lithium, still include diaphragm 3, diaphragm 3 is located between the top layer 13 of first pole piece 1 and the diaphragm layer 22 of second pole piece 2, plays the effect on the top layer 13 of interval first pole piece 1 and the diaphragm layer 22 of second pole piece 2, reduces the probability that first pole piece 1 and second pole piece 2 take place the short circuit. In the present embodiment, the membrane layer 22 includes, but is not limited to, one or more of graphite, soft carbon, hard carbon, carbon fiber, mesocarbon microbeads, silicon-based materials, tin-based materials, lithium titanate, or other metals capable of forming an alloy with lithium. Wherein, the graphite can be selected from one or more of artificial graphite, natural graphite and modified graphite; the silicon-based material can be one or more of simple substance silicon, silicon-oxygen compound, silicon-carbon compound and silicon alloy; the tin-based material can be one or more selected from simple substance tin, tin oxide compound and tin alloy. The anode current collector is generally a structure or part that collects current and may be any of a variety of materials known in the art as suitable for use as an anode current collector in a lithium ion battery.

Specifically, the battery cell may include at least two pole pieces stacked on each other and having opposite polarities, where the pole pieces having opposite polarities form a cathode piece of the battery and an anode piece of the battery, respectively. In order to avoid short circuit between the cathode sheet and the anode sheet, a diaphragm 3 is arranged between every two adjacent pole pieces, and the pole pieces with opposite polarities are electrically isolated by the diaphragm 3. The separator 3 may be any of various materials suitable for lithium ion battery separators in the art, and for example, may be a combination including, but not limited to, one or more of polyethylene, polypropylene, polyvinylidene fluoride, aramid, polyethylene terephthalate, polytetrafluoroethylene, polyacrylonitrile, polyimide, polyamide, polyester, natural fiber, and the like.

The at least two pole pieces may include a first pole piece 1 and a second pole piece 2, the polarities of the first pole piece 1 and the second pole piece 2 are opposite, and the first pole piece 1 and the second pole piece 2 are stacked on each other.

Specifically, the first pole piece 1 may be a cathode piece, and the second pole piece 2 may be an anode piece; alternatively, the first electrode sheet 1 may be an anode sheet, and the second electrode sheet 2 may be a cathode sheet, which is not limited herein.

In some examples, the cells may be wound cells. The first pole piece 1 and the second pole piece 2 are both one, and the first pole piece 1, the diaphragm 3 and the second pole piece 2 which are sequentially stacked are wound around the winding center to form a winding structure.

In other examples, the cells may be laminated cells. The first pole pieces 1 are multiple, the second pole pieces 2 are multiple, the multiple first pole pieces 1 and the multiple second pole pieces 2 are sequentially staggered and stacked in the same direction, and a diaphragm 3 is arranged between every two adjacent first pole pieces 1 and second pole pieces 2, so that the first pole pieces 1 and the second pole pieces 2 are electrically insulated.

The utility model discloses a theory of operation is:

adopt the first pole piece 1 and the second pole piece 2 that the width equals to at the both ends coating insulating layer 14 of the width direction Y of first pole piece 1, through the thickness of adjusting insulating layer 14, make the thickness at pole piece edge unanimous with the thickness at pole piece center, improve the roughness on pole piece surface, avoid the pole piece edge to appear the problem of analyzing lithium, help improving the safety problem that electric core heat abuse, fall.

Second embodiment

The difference from the first embodiment is that: the insulating layer 14 of the embodiment is made of AT9 ceramic, and after coating and rolling, the insulating layer is stripped according to the width of the anode to obtain a cathode sheet coated on both sides, wherein the cathode slurry is centered, the AT9 ceramic is uniform and has the same width, the cathode sheet and the anode sheet are aligned and wound on both sides during winding, and the width of the diaphragm 3 is greater than the width of the first pole piece 1 or the second pole piece 2.

Other structures are the same as those of the first embodiment, and are not described herein again.

Third embodiment

The difference from the first embodiment is that: the insulating layer 14 of the present embodiment is made of boehmite, and after coating and rolling, the cathode sheet coated on both sides is obtained by striping according to the width of the anode, such that the cathode slurry is centered, and the boehmite is uniformly and equally wide, and the cathode sheet and the anode sheet are wound in alignment on both sides during winding, wherein the first current collector 11 is an aluminum foil, and the second current collector 21 is a copper foil, including but not limited to a metal foil, and more specifically, including but not limited to an aluminum foil, a copper foil, and the like.

Other structures are the same as those in the first embodiment, and are not described again here.

Variations and modifications to the above-described embodiments may become apparent to those skilled in the art from the disclosure and teachings of the above description. Therefore, the present invention is not limited to the above-mentioned embodiments, and any obvious modifications, replacements or variations made by those skilled in the art on the basis of the present invention belong to the protection scope of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

1. A battery structure for improving lithium extraction at the edge of a battery cell, which is characterized by comprising a first pole piece (1) and a second pole piece (2);

in the width direction (Y), the width of the first pole piece (1) is equal to the width of the second pole piece (2);

first pole piece (1) includes first mass flow body (11), bottom (12) and top layer (13), bottom (12) set up the surface of first mass flow body (11), top layer (13) set up the surface of bottom (12), top layer (13) are provided with insulating layer (14) respectively at the both ends of width direction (Y), top layer (13) with insulating layer (14) width sum equals the width of bottom (12).

2. The battery structure of claim 1, wherein the cell edge comprises: the insulating layer (14) is arranged along the edge of the surface layer (13).

3. The battery structure of claim 1, wherein the cell edge comprises: the thickness of the surface layer (13) is equal to that of the insulating layer (14).

4. The battery structure of claim 1, wherein the cell edge comprises: the particle size of the insulating layer (14) is smaller than 10 mu m, the thickness of the insulating layer (14) is 20-40 mu m, and the width of the insulating layer (14) is 0.1-3mm.

5. The battery structure of claim 1, wherein: the material of the insulating layer (14) is ceramic or boehmite.

6. The battery structure of claim 1, wherein: the second pole piece (2) comprises a second current collector (21) and a membrane layer (22) arranged on the surface of the second current collector (21).

7. The battery structure of claim 6, wherein the cell edge comprises: the diaphragm is characterized by further comprising a diaphragm (3), wherein the diaphragm (3) is located between the surface layer (13) of the first pole piece (1) and the diaphragm layer (22) of the second pole piece (2).

8. The battery structure of claim 6, wherein: the width of the film layer (22) is equal to the width of the base layer (12) in the width direction (Y).

9. The battery structure of claim 7, wherein: the width of the diaphragm (3) is larger than the width of the first pole piece (1) or the second pole piece (2).

10. The battery structure of claim 7, wherein the cell edge comprises: the first current collector (11) is an aluminum foil, and the second current collector (21) is a copper foil.