CN218586015U

CN218586015U - Pole piece structure for improving cycle lithium analysis and lithium ion battery

Info

Publication number: CN218586015U
Application number: CN202222066336.0U
Authority: CN
Inventors: 丁华健; 李思; 汪勇; 胡本安; 安建; 于子龙; 陈杰
Original assignee: Huizhou Liwinon Energy Technology Co Ltd
Current assignee: Huizhou Liwinon Energy Technology Co Ltd
Priority date: 2022-08-08
Filing date: 2022-08-08
Publication date: 2023-03-07
Anticipated expiration: 2032-08-08

Abstract

The utility model belongs to the technical field of battery production and manufacture, in particular to a pole piece structure for improving cycle lithium precipitation, which comprises a pole piece body, wherein the pole piece body comprises a current collector and an active substance layer coated on the surface of the current collector; the surface of the pole piece body is coated with an adhesive layer which is used for being adhered with a pole piece or an isolating membrane of a battery. The utility model discloses an optimize the structure of pole piece, can solve the problem that the distance increases between the pole piece that electrolyte infiltration leads to.

Description

Pole piece structure for improving cycle lithium analysis and lithium ion battery

Technical Field

The utility model belongs to the technical field of battery production manufacturing, concretely relates to a pole piece structure and lithium ion battery for improving circulation and analyzing lithium.

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.

The lithium ion battery generally comprises a positive electrode, a negative electrode, a separation film, an electrolyte and an aluminum plastic film. With the increasing demand of the industry on the quick charge performance of the lithium ion battery, however, the quick charge is restricted by the lithium separation of the negative electrode, the capacity loss caused by the lithium separation is almost irreversible, and the lithium separation causes the capacity reduction of the lithium ion battery and the safety performance of the battery core to be reduced along with the lapse of time.

In the process of infiltrating the battery cell with the electrolyte, the battery cell is infiltrated by the outer layer like the inner layer, so that the adhesiveness between the outer layer anode plate/isolating membrane/cathode plate is poor, the head and the tail are more obvious, the transmission distance of lithium ions is gradually increased in the circulation process of the battery cell, the lithium ions can not be normally embedded, the black spots on the head and the tail of the outer layer are abnormally separated out, the separated lithium is gradually diffused from outside to inside in the later circulation process, the expansion of the capacity and the circulation thickness of the battery cell can also fail, and the safety performance can also be reduced.

SUMMERY OF THE UTILITY MODEL

One of the purposes of the utility model lies in: aiming at the defects of the prior art, the pole piece structure for improving the cycle lithium separation is provided, and the problem of the distance increase between the pole pieces caused by the immersion of the electrolyte can be solved by optimizing the structure of the pole piece.

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

a pole piece structure for improving cycle lithium separation comprises a pole piece body, wherein the pole piece body comprises a current collector and an active substance layer coated on the surface of the current collector; the surface of the pole piece body is coated with an adhesive layer which is used for being adhered with a pole piece or an isolating membrane of a battery.

Preferably, the adhesive layer is disposed along a length direction or a width direction of the pole piece body.

Preferably, the bonding layer is located on one surface or two surfaces of the pole piece body in the thickness direction.

Preferably, the adhesive layer is formed on the surface of the pole piece body by spraying or roll coating.

Preferably, the thickness of the bonding layer is 0-0.01mm.

Preferably, the material of the bonding layer is PVDF, a blending modified material of PVDF or PMMA, and the blending material is SiO2, tiO2, al2O3, ceO2, mgO, znO or NiO.

A second object of the present invention is to provide a lithium ion battery, including first pole piece, second pole piece and barrier film, the barrier film is set up first pole piece with between the second pole piece, first pole piece and/or the second pole piece adopts foretell improvement circulation to analyse the pole piece structure of lithium.

Preferably, the surfaces of the first pole piece, the second pole piece and the isolating membrane are all provided with adhesive layers.

Preferably, the first pole piece, the second pole piece and the isolation film form a winding core.

Preferably, the winding core further comprises a shell, and the winding core is accommodated in the shell.

The beneficial effects of the utility model reside in that, the utility model discloses a recoating the adhesive linkage that has the adhesion on the surface of pole piece body for the surface of pole piece body has the adhesion, help strengthening the bonding strength between pole piece body and the barrier film, keep the distance between the pole piece, it is poor to alleviate the pole piece adhesion that electrolyte infiltration caused, it is big to lead to the ion transmission distance, produce and separate out the lithium problem, compare current structure, electrolyte infiltration electric core in-process, the distance between the pole piece does not change, lithium ion can normally imbed, help reducing electric core and take place to separate out the lithium probability.

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 a first embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a second embodiment of the present invention.

Fig. 3 is a schematic cross-sectional view of the first pole piece, the second pole piece and the isolation film of the present invention.

Wherein the reference numerals are as follows:

1-pole piece body; 11-a first pole piece; 12-a second pole piece;

2-an adhesive layer;

3-an isolating membrane;

x-length direction; h-thickness 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. The description 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 of ordinary skill in the art.

The present invention will be described in further detail with reference to fig. 1 to 3, but the present invention is not limited thereto.

Implementation mode one

The following describes embodiment one with reference to fig. 1

The pole piece structure for improving the cycle lithium separation comprises a pole piece body 1, wherein the pole piece body 1 comprises a current collector and an active substance layer coated on the surface of the current collector; the surface of the pole piece body 1 is coated with an adhesive layer 2 which is used for being adhered with a pole piece or an isolating membrane of a battery.

In the process of infiltrating the battery cell with the electrolyte, the outer layer is infiltrated like the inner layer, so that the adhesiveness between the outer anode plate/isolating membrane/cathode plate is poor, the head and the tail are more obvious, the transmission distance of lithium ions is gradually increased in the cycle process of the battery cell, the lithium ions can not be normally embedded, and the abnormal lithium precipitation of black spots at the head and the tail of the outer layer is caused.

According to the utility model discloses an in the pole piece structure for improving circulation and analyse lithium, adhesive linkage 2 sets up along pole piece body 1's length direction X or width direction. In the present embodiment, the adhesive layer 2 is continuously sprayed in the length direction X or the width direction, and the adhesive layer 2 may cover the whole pole piece body 1 or partially cover the pole piece body 1, and may be adjusted according to the actual battery structure.

According to the utility model discloses an in the pole piece structure for improving circulation and analyzing lithium, adhesive linkage 2 is located the two sides of the thickness direction H of pole piece body 1, and in some embodiments, the two sides that are located the pole piece body 1 in roll core intermediate level all have adhesive linkage 2, nevertheless the utility model discloses not taking this as the limit, can adjusting in the position of rolling up the core according to pole piece body 1, the one side that is located the outmost pole piece body 1 of roll core has adhesive linkage 2, helps reducing the cost of battery.

The utility model discloses a theory of operation is:

through the adhesive linkage 2 that has the adhesion of coating again on the surface at pole piece body 1 for the surface of pole piece body 1 has the adhesion, help strengthening the bonding strength between pole piece body 1 and barrier film 3, keep the distance between the pole piece, it is poor to alleviate the pole piece adhesion that electrolyte infiltration caused, it is big to lead to ion transmission distance, produce and analyse the lithium problem, compare current structure, electrolyte infiltration electric core in-process, the distance between the pole piece does not change, lithium ion can normally imbed, help reducing electric core and take place to analyse the lithium probability.

Second embodiment

The difference from the first embodiment is that: the adhesive layer 2 of this embodiment is located the one side of the thickness direction H of pole piece body 1, and is concrete, and the one side that is located the outermost pole piece body 1 of book core has adhesive layer 2, can adjust at the position of rolling up the core according to pole piece body 1, and the two sides that are located the pole piece body 1 in roll core intermediate level all have adhesive layer 2 promptly to match different bonding demands, adhesive layer 2 passes through spraying or roller coat and forms on the surface of pole piece body 1. In the present embodiment, the adhesive is sprayed on the surface of the pole piece body 1 during or after the pole piece body 1 is coated or dried, or the adhesive may be roll-coated on the surface of the pole piece body 1 after the pole piece body 1 is coated and dried.

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 thickness of the adhesive layer 2 of the present embodiment is 0 to 0.01mm, which prevents the increase of the production cost of the battery due to the excessive thickness of the adhesive layer 2, and the material of the adhesive layer 2 is PVDF (polyvinylidene fluoride), a blend modified material of PVDF (polyvinylidene fluoride), or PMMA (polymethyl methacrylate), and the blend material includes, but is not limited to, siO2, tiO2, al2O3, ceO2, mgO, znO, niO, and the like.

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

Lithium ion battery

The utility model discloses a pole piece structure for improving circulation and analyzing lithium of embodiment one ~ three.

The lithium ion battery comprises a first pole piece 11, a second pole piece 12 and a separation film 3, wherein the separation film 3 is arranged between the first pole piece 11 and the second pole piece 12, and the first pole piece 11 and/or the second pole piece 12 adopt the pole piece structure for improving cycle lithium analysis.

Specifically, the battery core comprises at least two pole pieces which are mutually overlapped and have opposite polarities, and the pole pieces with the opposite polarities respectively form a positive pole piece of the battery and a negative pole piece of the battery. In order to avoid short circuit between the positive pole piece and the negative pole piece, an isolating film 3 is arranged between every two adjacent pole pieces, and the pole pieces with opposite polarities are electrically isolated through the isolating film 3. At least one of the pole pieces may have the pole piece structure in the above embodiment, and in another embodiment, the adhesive layers 2 are disposed on the surfaces of the first pole piece 11, the second pole piece 12, and the isolation film 3, which is helpful for improving the adhesion between the pole pieces and the isolation film 3.

The first pole piece 11 and the second pole piece 12 have opposite polarities, and the first pole piece 11 and the second pole piece 12 are stacked on each other.

Specifically, the first pole piece 11 may be a positive pole piece, and the second pole piece 12 may be a negative pole piece by adopting the positive pole piece structures of the above embodiments 1 to 8; alternatively, the first pole piece 11 may be a negative pole piece, and the second pole piece 12 may be a positive pole piece, which is not limited herein.

In some examples, the cells may be wound cells. The first pole piece 11 and the second pole piece 12 are both one, the first pole piece 11, the isolation film 3 and the second pole piece 12 which are sequentially stacked are wound around the winding center to form a winding structure, and the first pole piece 11, the second pole piece 12 and the isolation film 3 form a winding core.

In other examples, the cells may be laminated cells. The first pole pieces 11 are multiple, the second pole pieces 12 are multiple, the multiple first pole pieces 11 and the multiple second pole pieces 12 are sequentially stacked in a staggered manner along the same direction, and the isolating film 3 is arranged between every two adjacent first pole pieces 11 and second pole pieces 12, so that the first pole pieces 11 and the second pole pieces 12 are electrically insulated.

In some examples, the battery further comprises a casing, wherein the winding core is accommodated in the casing, the casing plays a role of protecting the battery cell, and the casing comprises but is not limited to an aluminum casing or a packaging bag and can be matched according to an actual battery structure.

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. The pole piece structure for improving the cycle lithium deposition is characterized by comprising a pole piece body (1), wherein the pole piece body (1) comprises a current collector and an active substance layer coated on the surface of the current collector;

the surface of the pole piece body (1) is coated with an adhesive layer (2) which is used for being adhered with a pole piece or an isolating membrane (3) of a battery.

2. A pole piece structure for improving lithium cycling analysis according to claim 1, wherein: the bonding layer (2) is arranged along the length direction (X) or the width direction of the pole piece body (1).

3. A pole piece structure for improving lithium cycling analysis according to claim 1, wherein: the bonding layer (2) is positioned on one surface or two surfaces of the pole piece body (1) in the thickness direction (H).

4. A pole piece structure for improving lithium cycling analysis according to claim 1, wherein: the adhesive layer (2) is formed on the surface of the pole piece body (1) through spraying or roll coating.

5. A pole piece structure for improving lithium cycling analysis according to claim 1, wherein: the thickness of the bonding layer (2) is 0-0.01mm.

6. A lithium ion battery, characterized by: the lithium ion battery comprises a first pole piece (11), a second pole piece (12) and a separation film (3), wherein the separation film (3) is arranged between the first pole piece (11) and the second pole piece (12), and the first pole piece (11) and/or the second pole piece (12) adopt the pole piece structure for improving cycle lithium extraction of any one of claims 1 to 5.

7. The lithium ion battery of claim 6, wherein: the surfaces of the first pole piece (11), the second pole piece (12) and the isolating membrane (3) are all provided with adhesive layers (2).

8. The lithium ion battery of claim 6, wherein: the first pole piece (11), the second pole piece (12) and the isolating film (3) form a winding core.

9. The lithium ion battery of claim 8, wherein: the winding core is accommodated in the shell.