CN216793724U

CN216793724U - Pole piece and lithium ion battery

Info

Publication number: CN216793724U
Application number: CN202122904542.XU
Authority: CN
Inventors: 杨国强; 胡小勇; 王恒
Original assignee: Dongguan Weike Battery Co ltd
Current assignee: Dongguan Weike Battery Co ltd
Priority date: 2021-11-25
Filing date: 2021-11-25
Publication date: 2022-06-21
Anticipated expiration: 2031-11-25

Abstract

The utility model provides a pole piece and a lithium ion battery, wherein the pole piece comprises a current collector and a slurry coating, the surface of an active substance coated on the current collector forms the slurry coating, the part of the current collector, which is not coated with the active substance, forms a hollow foil area for welding a pole lug, and the hollow foil area forms an uneven concave-convex surface. The pole piece forms an uneven concave-convex surface on the hollow foil, electrolyte can be fully retained in the groove of the hollow foil through the arrangement of the concave-convex surface, the structure can improve the liquid retention capacity of the lithium ion battery by utilizing the thickness difference between the pole lug and the hollow foil, and simultaneously, the unevenness of a battery cell caused by the thickness difference between the pole lug and the hollow foil is optimized to a certain extent; and a method for improving the liquid retention amount by repeated charging and discharging is not adopted, so that the production cost is reduced.

Description

Pole piece and lithium ion battery

Technical Field

The utility model belongs to the technical field of lithium ion batteries, and particularly relates to a lithium ion battery.

Background

With the improvement and development of lithium ion battery products, the requirements of users on the service life of the battery are higher and higher. At present, the main factor limiting the service life of the soft package type lithium ion battery is the content of electrolyte in the battery, and the high liquid retention capacity has longer cycle service life.

In the prior art, the pole piece is made to fully absorb electrolyte through charging and discharging for many times after formation, but the improvement method has the following defects: 1. the improvement of the liquid absorption capacity of the pole piece is limited, especially in a high-voltage system, the gap of the pole piece is relatively small, and the absorption effect of the electrolyte in the charging and discharging process is poor. 2. The production cost is increased, the time cost is increased in the process of charging and discharging for many times, and the electric power cost is increased.

In view of this, it is necessary to provide a technical solution for solving the above technical problems, and the present invention provides a pole piece and a lithium ion battery.

SUMMERY OF THE UTILITY MODEL

One of the objects of the present invention is: to prior art's not enough, provide a pole piece, lithium ion battery, through setting up empty paper tinsel into unevenness's corrugated surface, electrolyte can remain in the recess of corrugated surface to can improve lithium ion battery's guarantor's liquid measure.

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

in a first aspect, the utility model provides a pole piece, which comprises a current collector and a slurry coating, wherein the slurry coating is formed on the surface of the current collector coated with an active substance, the part of the current collector, which is not coated with the active substance, forms a hollow foil for welding a pole lug, and the hollow foil is provided with an uneven concave-convex surface.

Preferably, the uneven surface is a stripe of irregular shape.

Preferably, the concave-convex surface is a tire mark.

Preferably, the relief surface is a raised pattern.

Preferably, the concave-convex surface is a sawtooth pattern.

Preferably, the roughness Ra of the concave-convex surface is 50 to 100.

Preferably, the thickness of the concave-convex surface is less than or equal to the thickness of the slurry coating.

Preferably, the thickness of the concave-convex surface is 0.1 to 0.15 mm.

Preferably, the pole piece is a positive pole piece or a negative pole piece.

In a second aspect, the present invention further provides a lithium ion battery, including a positive electrode plate, a negative electrode plate and a diaphragm, wherein the lithium ion battery is formed by winding the positive electrode plate, the negative electrode plate and the diaphragm, and at least one of the positive electrode plate or the negative electrode plate is the above-mentioned electrode plate.

Compared with the prior art, the beneficial effects of the utility model include but are not limited to:

the pole piece of the utility model forms the rugged concave-convex surface on the hollow foil, the electrolyte can be fully retained in the groove of the hollow foil by arranging the rugged concave-convex surface, the structure can improve the liquid retention of the lithium ion battery by utilizing the thickness difference between the pole lug and the hollow foil, and simultaneously, the unevenness of the battery cell caused by the thickness difference between the pole lug and the hollow foil is optimized to a certain extent; and a method for improving the liquid retention amount by charging and discharging for many times is not adopted, so that the production cost is reduced.

Drawings

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

Fig. 2 is a schematic structural diagram of a pole piece according to the present invention.

Fig. 3 is a third schematic structural diagram of a pole piece according to the present invention.

In fig. 1, 2, and 3: 100-pole piece 1-current collector; 2-slurry coating 3-void foil zone

Detailed Description

Embodiments of the present application will be described in detail below. The examples of the present application should not be construed as limiting the present application.

The present application is further illustrated with reference to specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the claims.

The utility model provides a pole piece 100, the pole piece 100 comprises a current collector 1 and a slurry coating 2, the surface of the current collector 1 coated with active substances forms the slurry coating 2, the part of the current collector 1 not coated with the active substances forms an empty foil area 3 for welding a pole ear, and the empty foil area 3 forms an uneven concave-convex surface 31. Thereby realize the thickness difference between utmost point ear and the empty paper tinsel through the setting of concave-convex surface 31, the recess department of the empty paper tinsel can be fully remain to electrolyte to play the effect that improves and protect the liquid measure. The shape of the concave-convex surface 31 on the empty foil region 3 can be formed by stamping or other means, and the specific way of forming the concave-convex surface 31 is not limited.

The uneven surface 31 is irregular stripes, the uneven surface 31 is tire marks, or the uneven surface 31 is wavy stripes, or the uneven surface 31 is sawtooth stripes, or the uneven surface 31 is annual ring stripes, or the uneven surface 31 is oblique stripes. Fig. 1, fig. 2 and fig. 3 are schematic structural diagrams of a pole piece 100 of the present invention, in fig. 1, the concavo-convex surface 31 is a tire print, in fig. 2, the concavo-convex surface 31 is a wave pattern, in fig. 3, the concavo-convex surface 31 is a diagonal stripe, and the drawings only illustrate a few figures, but are not limited to the figures, as long as the concavo-convex surface 31 with unevenness in the empty foil area 3 can be realized.

Furthermore, the roughness Ra of the concave-convex surface 31 is 50-100, and the roughness of the concave-convex surface 31 within a certain range can further improve the liquid retaining amount of the electrolyte.

Moreover, the thickness of unsmooth face 31 is less than the thickness of thick liquids coating 2, and the thickness scope of unsmooth face 31 is 0.1 ~ 0.15mm, because of empty foil district 3 need weld utmost point ear, and the thickness difference between thick liquids coating 2 and the unsmooth face 31 provides the space for utmost point ear is placed to avoid the unevenness of electric core.

Further, the pole piece 100 of the present invention may be a positive pole piece or a negative pole piece. Based on the structure of the pole piece 100, the utility model also provides a lithium ion battery, which comprises a battery cell and a shell, wherein the battery cell is arranged in the shell, the battery cell comprises a positive pole piece, a negative pole piece and a diaphragm, the lithium ion battery is formed by winding the positive pole piece, the negative pole piece and the diaphragm, and at least one of the positive pole piece or the negative pole piece is the pole piece 100. The hollow foil area 3 forming the uneven concave-convex surface 31 in the lithium ion battery is positioned on the outermost layer of the battery cell, so that the liquid retention amount is improved, and meanwhile, the floating liquid can be reduced.

The pole piece 100 of the utility model forms the rugged concave-convex surface 31 on the hollow foil, the electrolyte can be fully retained in the groove of the hollow foil by the arrangement of the concave-convex surface 31, the structure can improve the liquid retention of the lithium ion battery by using the thickness difference between the tab and the hollow foil, and simultaneously, the unevenness of the battery cell caused by the thickness difference between the tab and the hollow foil is optimized to a certain extent; and a method for improving the liquid retention amount by charging and discharging for many times is not adopted, so that the production cost is reduced; the pole piece structure can be suitable for batteries of various types and systems.

Variations and modifications to the above-described embodiments may also occur to those skilled in the art, which fall within the scope of the utility model as disclosed and taught herein. The present invention is illustrated by the above-mentioned examples, but the present invention is not limited to the above-mentioned detailed process equipment and process flow, i.e. it is not meant to imply that the present invention must rely on the above-mentioned detailed process equipment and process flow to be practiced. Therefore, the present invention is not limited to the above-mentioned embodiments, and any obvious improvement, replacement or modification made by those skilled in the art based on the present invention is within 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 is characterized by comprising a current collector and a slurry coating, wherein the surface of the current collector coated with active substances forms the slurry coating, the part of the current collector, which is not coated with the active substances, forms an empty foil area for welding a pole lug, and the empty foil area is provided with an uneven concave-convex surface.

2. The pole piece of claim 1 wherein the relief surface is a stripe of irregular shape.

3. The pole piece of claim 2 wherein the relief surface is a tire print.

4. The pole piece of claim 2, wherein the relief surface is a raised or indented or annual ring.

5. The pole piece of claim 2, wherein the relief surface is a diagonal stripe.

6. The pole piece of claim 2, wherein the roughness Ra of the concave-convex surface is 50-100.

7. The pole piece of claim 2 wherein the relief surface has a thickness less than the thickness of the slurry coating.

8. The pole piece of claim 7, wherein the thickness of the concave-convex surface is 0.1-0.15 mm.

9. The pole piece of claim 1, wherein the pole piece is a positive pole piece or a negative pole piece.

10. A lithium ion battery is characterized by comprising an electric core, wherein the electric core comprises a positive pole piece, a negative pole piece and a diaphragm, the electric core is formed by winding the positive pole piece, the negative pole piece and the diaphragm, and at least one of the positive pole piece or the negative pole piece is the pole piece of any one of claims 1 to 9.