CN220914303U

CN220914303U - Battery cell

Info

Publication number: CN220914303U
Application number: CN202322496793.8U
Authority: CN
Inventors: 黄佳琴; 孙田成; 刘平; 李翔宇; 尹小强
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2023-09-13
Filing date: 2023-09-13
Publication date: 2024-05-07
Anticipated expiration: 2033-09-13

Abstract

The utility model discloses a battery which is characterized by comprising a positive plate, a negative plate and a diaphragm, wherein a die cutting surface of the positive plate with paint is provided with a sealing glue, and the sealing glue is used for preventing ions from precipitating. According to the battery provided by the utility model, the die cutting surface of the positive plate with the coating is provided with the sealing glue, and the sealing glue is used for preventing ions from separating out, so that the ions at the die cutting surface of the battery are prevented from separating out, and the electrical property, the service life and the safety of the battery are improved.

Description

Battery cell

Technical Field

The utility model relates to the technical field of batteries, in particular to a battery.

Background

In recent years, batteries have been widely used in the fields of smart phones, tablet computers, smart wear, electric tools, electric automobiles, and the like. With the wide application of batteries, consumers have raised higher demands on battery performance, service life and safety.

However, ion precipitation is easy to occur at the die-cut surface of the battery, so that the battery performance is reduced, the cycle life is greatly shortened, the quick charge capacity of the battery is limited, and disastrous consequences such as combustion, explosion and the like can be possibly caused.

Disclosure of utility model

In the summary, a series of concepts in a simplified form are introduced, which will be further described in detail in the detailed description. The summary of the utility model is not intended to define the key features and essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

The utility model provides a battery, which comprises a positive plate, a negative plate and a diaphragm, wherein a sealing glue is arranged at the die cutting surface of the positive plate with paint, and the sealing glue is used for preventing ions from precipitating.

Illustratively, the die cut surface of the positive electrode sheet is a cut surface formed by die cutting by a die cutter, the die cut surface being located at an edge of the positive electrode sheet.

Illustratively, the sealant is formed at the die cut face by post-heating solidification.

Illustratively, the heating temperature to form the encapsulant includes a range of 120 ℃ to 200 ℃.

Illustratively, the positive electrode sheet further comprises a tab with a coating, and a seal is arranged at the edge of the tab and used for preventing ions from precipitating.

Illustratively, the encapsulant has a thickness in the range of less than 1mm.

Illustratively, the positive electrode sheet includes a positive electrode current collector and a coating of a positive electrode current collector surface, the coating including a positive electrode active material.

Illustratively, the battery comprises a laminated battery or a wound battery.

Illustratively, the ions include lithium ions.

Illustratively, the ions include sodium ions.

According to the battery provided by the utility model, the die cutting surface of the positive plate with the coating is provided with the sealing glue, and the sealing glue is used for preventing ions from separating out, so that the ions at the die cutting surface of the battery are prevented from separating out, and the electrical property, the service life and the safety of the battery are improved.

Drawings

The following drawings are included to provide an understanding of the utility model and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the utility model and their description to explain the principles of the utility model.

In the accompanying drawings:

Fig. 1 is a top view of a positive electrode tab of a battery according to an embodiment of the present utility model;

Fig. 2 is a cross-sectional view of a positive electrode tab A-A of the battery of fig. 1 according to an embodiment of the present utility model.

Detailed Description

In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present utility model. It will be apparent, however, to one skilled in the art that the utility model may be practiced without one or more of these details. In other instances, well-known features have not been described in detail in order to avoid obscuring the utility model.

In order that the utility model may be fully understood, a detailed description will be given in the following description to illustrate the battery of the utility model. It will be apparent that the utility model is not limited to the specific details of those skilled in the art of batteries. Preferred embodiments of the present utility model are described in detail below, however, the present utility model may have other embodiments in addition to these detailed descriptions.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the present utility model. As used herein, the singular is intended to include the plural unless the context clearly indicates otherwise. Furthermore, it will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Exemplary embodiments according to the present utility model will now be described in more detail with reference to the accompanying drawings. These exemplary embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. It should be appreciated that these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of these exemplary embodiments to those skilled in the art. In the drawings, thicknesses of layers and regions are exaggerated for clarity, and the same reference numerals are used to denote the same elements, so that descriptions thereof will be omitted.

Aiming at the problem that ion precipitation is easy to occur at the die-cut surface of a battery, the utility model provides a battery, which comprises a positive plate 100, a negative plate and a diaphragm, wherein as shown in fig. 1, a sealing adhesive 140 is arranged at the die-cut surface of the positive plate 100 with paint, and the sealing adhesive 140 is used for preventing ion precipitation.

In one embodiment, the battery comprises a laminated battery or a wound battery.

In one embodiment, as shown in fig. 2, the positive electrode tab 100 includes a positive electrode current collector 110 and a coating 120 on a surface of the positive electrode current collector, the coating 120 including a positive electrode active material.

In one embodiment, taking a lithium ion battery as an example, the positive electrode sheet 100 of the lithium ion battery is generally prepared by uniformly mixing a positive electrode active material (such as lithium cobaltate, lithium manganate, lithium iron phosphate, etc.) with a conductive agent (such as acetylene black, conductive graphite, furnace black, etc.), a binder (such as polyvinylidene fluoride, sodium carboxymethyl cellulose, and styrene-butadiene rubber), etc., stirring to form a paste, uniformly coating both side surfaces of a positive electrode current collector (such as aluminum foil) with a paste, drying under a nitrogen flow to remove an organic dispersant, pressing with a roll press, and cutting into a positive electrode sheet with a specified size according to design requirements.

In one embodiment, as shown in fig. 1 and 2, the positive electrode tab 100 further includes a tab 130 with a coating, wherein the tab 130 includes a region with a coating and a region without a coating.

In one embodiment, the active material of the negative electrode sheet of the lithium ion battery mainly comprises graphite or lithium titanate, the negative electrode current collector may use copper foil, and the preparation process of the negative electrode sheet is approximately the same as that of the positive electrode sheet, and will not be described herein.

In one embodiment, a separator is disposed between the positive and negative electrode sheets for isolating the positive and negative electrodes and preventing electrons in the battery from freely passing therethrough, and allowing ions in the electrolyte to freely pass between the positive and negative electrodes. The battery can limit the rise of current under the condition of overcharge or temperature rise by isolating the anode and the cathode, so that the explosion caused by short circuit of the battery is prevented, the battery has the function of micropore self-closing protection, and plays a role in protecting the safety of battery users and equipment. Separator is generally made of PE (polyethylene) or PP (polypropylene).

In one embodiment, when the positive plate is die cut by a die cutter, a die cut surface is formed at the edge of the positive plate, as shown in FIG. 2, at which time a die cutter is utilized to form the encapsulant 140 at the die cut surface with the coating. Specifically, the die cutting machine has the function of precisely identifying the die cutting surface, and when the area with the coating is die-cut, the edge sealing treatment of the die cutting surface is completed by controlling the die cutting process so as to form a sealing adhesive 140 at the die cutting surface with the coating; when the area without the coating is die-cut, the edge sealing treatment is not performed. In addition, the edge sealing treatment of the tab 130 with the paint is also completed by controlling the die cutting process.

For the lithium ion battery, through preventing the lithium ion of the die cutting face of the positive plate with the coating from taking off and inserting, the lithium ion of the die cutting face of the positive plate with the coating can not migrate to the negative electrode in the charging process, and then the problem of lithium precipitation at the corresponding position of the negative electrode is solved. Since the die cutting surface without the coating has no lithium ion deintercalation, the edge sealing treatment is only needed to be carried out on the die cutting surface with the coating and the tab with the coating.

In one embodiment, the encapsulant 140 has high stability and is resistant to electrolyte corrosion, and polyurethane, methacrylic acid, etc. may be used, which is solid at normal temperature, and is a liquid that melts to a certain temperature to become flowable and has a certain viscosity.

In one embodiment, after the positive plate is die-cut by the die-cutting machine, the sealing glue is heated to 120-200 ℃ to form a liquid with certain viscosity, the heated sealing glue passes through the glue holes of the die-cutting knife edge, and the die-cutting face of the strip material is heat-sealed during die-cutting identification, so that the heated liquid is solidified at the die-cutting face with the coating and the tab with the coating to form the sealing glue 140, and the thickness of the sealing glue 140 is generally less than 1mm, preferably 0.1mm.

By forming a seal at the die cut face of the coated positive electrode tab and at the edge of the tab, ion precipitation, including but not limited to lithium or sodium ions, can be prevented.

The present utility model has been illustrated by the above-described embodiments, but it should be understood that the above-described embodiments are for purposes of illustration and description only and are not intended to limit the utility model to the embodiments described. In addition, it will be understood by those skilled in the art that the present utility model is not limited to the embodiments described above, and that many variations and modifications are possible in light of the teachings of the utility model, which variations and modifications are within the scope of the utility model as claimed. The scope of the utility model is defined by the appended claims and equivalents thereof.

Claims

1. The battery is characterized by comprising a positive plate, a negative plate and a diaphragm, wherein a sealing glue is arranged at the die cutting surface of the positive plate with the coating, and the sealing glue is used for preventing ions from precipitating.

2. The battery of claim 1 wherein the die cut surface of the positive electrode sheet is a cut surface formed by die cutting by a die cutter, the die cut surface being located at an edge of the positive electrode sheet.

3. The battery of claim 1, wherein the encapsulant is formed at the die cut surface by solidification after heating.

4. The battery of claim 3 wherein the heating temperature to form the encapsulant comprises 120 ℃ to 200 ℃.

5. The battery of claim 1, wherein the positive electrode tab further comprises a tab with a coating, and wherein the tab has a seal at an edge thereof, the seal being configured to prevent ion precipitation.

6. The battery of claim 1, wherein the encapsulant has a thickness in the range of less than 1mm.

7. The battery of claim 1, wherein the positive electrode tab comprises a positive electrode current collector and a coating of a surface of the positive electrode current collector, the coating comprising a positive electrode active material.

8. The battery of claim 1, wherein the battery comprises a laminated battery or a wound battery.

9. The battery of claim 1, wherein the ions comprise lithium ions.

10. The battery of claim 1, wherein the ions comprise sodium ions.