CN212485369U

CN212485369U - Flexible negative electrode of lithium ion battery and lithium ion battery

Info

Publication number: CN212485369U
Application number: CN202021147205.XU
Authority: CN
Inventors: 欧云; 成娟娟; 周梦成; 张羽佳
Original assignee: Hunan University of Science and Technology
Current assignee: Hunan University of Science and Technology
Priority date: 2020-06-19
Filing date: 2020-06-19
Publication date: 2021-02-05
Anticipated expiration: 2030-06-19

Abstract

The utility model discloses a lithium ion battery's flexible negative pole and lithium ion battery, flexible negative pole include that carbon is conductive film and flexible conductive substrate, and carbon is conductive film and prepares on flexible conductive substrate, and carbon is conductive film's thickness is 10nm ~ 1 mu m, and carbon is conductive film and is pure carbon film, and carbon is conductive film and includes conductive carbon black, graphite class, carbon nanotube, C60. The carbon-based conductive film prepared on the flexible conductive substrate is suitable for lithium ion batteries in various forms, has universal applicability and high electrochemical stability, so that the safety of the battery is obviously improved; greatly reducing the quality of the battery and simultaneously enabling the lithium battery to be more portable.

Description

Flexible negative electrode of lithium ion battery and lithium ion battery

Technical Field

The utility model relates to a lithium ion battery's flexible negative pole and lithium ion battery belongs to the high specific energy secondary battery technical field that can fill and discharge.

Background

Lithium ion batteries have been developed for over 50 years as one of the most important energy storage systems of the current generation, asking this year for the nobel prize in chemistry. Originally, accidents such as explosion often occur, and the like are well applied to various electronic devices, and the traditional lithium ion battery enters the life of everyone. With the rapid development of economy in China, the demand for new battery materials is increasing, and in addition to the strong demands of mobile phones, notebook computers, tablet computers, electronic watches and various intelligent portable electronic devices on new, efficient and environment-friendly batteries, new battery materials are emerging continuously in the world. The lithium ion battery is a future development direction, which is closer to safety and stability, and is light and portable, and the electrode material is a key core material in the lithium ion battery, so that the electrode material is required to have the characteristics of safety and stability, light and portable property, low cost, high applicability and the like.

The negative electrode material of the lithium ion battery which is already marketed at present comprises tin-based materials, lithium titanate, carbon nano materials, graphene materials and other products, but the negative electrode material is unstable in chemical property, has some potential safety hazards, is easy to explode, causes personnel and property loss, is low in energy density, is not light and portable, is not beneficial to being used on wearable or portable electronic equipment, is relatively complex in production process, improves the cost, reduces the repeatability, is low in applicability, and is generally suitable for being used in solid button type lithium ion batteries. The carbon-based conductive material has the characteristics of good conductivity, chemical stability, small density, low price and the like, can be quickly and effectively deposited on the flexible conductive substrate by adopting a physical method to obtain the ultrathin carbon-based negative electrode film material, and is a good electrode material of the lithium ion battery. However, the lithium ion battery made of the existing carbon material has small capacity and more internal defects, and is not beneficial to the industrial production.

SUMMERY OF THE UTILITY MODEL

The utility model aims at solving foretell technical current situation, and provide a stable and light flexible negative pole and lithium ion battery that the controllability is strong, be fit for flexible mass flow body, low-cost low energy consumption.

The utility model discloses technical scheme as follows:

a flexible negative electrode of a lithium ion battery comprises a carbon conductive film and a flexible conductive substrate, wherein the carbon conductive film is prepared on the flexible conductive substrate, the thickness of the carbon conductive film is 10 nm-1 mu m, and the carbon conductive film is a pure carbon film.

In one embodiment, the carbon-based conductive film is made of one of conductive carbon black, graphite, carbon nanotubes, and C60.

In one embodiment, the flexible conductive substrate is made of copper foil, aluminum foil, flexible conductive glass, PET or PEN.

In one embodiment, the carbon-based conductive film is prepared by a carbon-based negative electrode material on a flexible conductive substrate by a spin coating method, a blade coating method or a vacuum evaporation method.

A lithium ion battery is a solid button lithium ion battery assembled in the order of metal lithium, electrolyte, diaphragm, electrolyte and carbon-based conductive film electrode, or a flexible lithium ion battery assembled in the order of lithium foil, electrolyte, diaphragm, electrolyte and carbon-based conductive film electrode, or an ultrathin lithium ion battery assembled in the order of lithium foil, lithium phosphorus oxynitride electrolyte and carbon-based conductive film electrode, wherein the carbon-based conductive film electrode is the flexible negative electrode.

Compared with the prior art, the utility model, following advantage and outstanding effect have: the utility model discloses a method of physical method prepares carbon system negative pole material on flexible conductive substrate, as lithium ion battery's negative pole. The utility model can be used for lithium ion batteries with various forms, has universal applicability and high electrochemical stability, thereby obviously improving the safety of the battery; the quality of the battery is greatly reduced, the lithium battery is more portable, the carbon-based negative electrode material has high ion mobility, and the charging and discharging speed of the battery is improved. The utility model discloses an active material of flexible negative pole is pure carbon film, and electric conductive property is excellent and more stable for the negative electrode material structure of traditional coating method preparation. Furthermore, the utility model discloses the flexible carbon base negative pole of preparation can obtain the active material of nanometer level, can reserve more spaces in the battery system, does benefit to the increase of the anodal active material of restriction battery energy density, can promote the development of battery design.

Drawings

Fig. 1 is a schematic structural diagram of the flexible negative electrode provided by the present invention.

Fig. 2 is a schematic diagram of a structural principle of a solid button lithium ion battery provided by the present invention.

Fig. 3 is a first charge-discharge curve diagram of the solid button lithium ion battery obtained in example 1 at a magnification of 0.1C.

Fig. 4 is a cycle performance curve diagram of the solid button lithium ion battery obtained in example 1 at a magnification of 0.1C.

Fig. 5 is a cycle performance curve diagram of the solid button lithium ion battery obtained in example 2 at a magnification of 0.1C.

Fig. 6 is a cycle performance curve diagram of the solid button lithium ion battery obtained in example 3 at a magnification of 0.1C.

Wherein: 1-a negative electrode casing; 2-foamed nickel; 3-metallic lithium; 4-a separator; 5-carbon-based negative electrode material; 6-current collector; 7-Positive electrode case

Detailed Description

The present invention will be further described with reference to several specific examples, but the scope of the present invention is not limited to the following examples.

Examples 1 to 3 are all solid button lithium ion batteries assembled in the order of metallic lithium, electrolyte, separator, electrolyte, carbon-based conductive thin film electrode. As shown in fig. 1 and 2, the lithium ion battery includes a negative electrode can 1 and a positive electrode can 7, the negative electrode can 1 and the positive electrode can 7 form a button-shaped receiving space, and the nickel foam 2, the metallic lithium 3, the separator 4, the carbon-based negative electrode material 5, and the current collector 6 are sequentially received in the receiving space.

The carbon-based negative electrode material 5 may be one of conductive carbon black, graphite, carbon nanotube, and C60. The carbon-based negative electrode material 5 is prepared on a flexible conductive substrate to form a carbon-based conductive film with the thickness of 10 nm-1 μm.

The current collector 6 can be a flexible conductive substrate made of copper foil, aluminum foil, flexible conductive glass, PET or PEN.

Of course, the lithium ion battery may be a flexible lithium ion battery assembled in the order of lithium foil, electrolyte, separator, electrolyte, and carbon-based conductive thin film electrode, or an ultra-thin lithium ion battery assembled in the order of lithium foil, lithium phosphorus oxynitride electrolyte (LiPON), and carbon-based conductive thin film electrode.

Example 1: the solid button lithium ion battery assembled with the metal lithium/electrolyte/diaphragm/electrolyte/carbon conductive film electrode has the test temperature of 30 ℃. The carbon-based conductive film is made of C60 material, and is deposited on the flexible conductive copper foil by a vacuum evaporation method (the temperature is 420 ℃, and the evaporation time is 40 minutes) to be used as a negative electrode material of the solid button lithium ion battery. The first charge-discharge curve of the prepared solid button lithium ion battery is shown in figure 3 under the circulation of 0.1C, and the first discharge specific capacity is 580mAh g^-1The discharge voltage platform is 1.0V; the cycle performance at 0.1C rate is shown in FIG. 4, and the specific discharge capacity is 202mAh g after 200 cycles^-1。

Example 2: the solid button lithium ion battery assembled with the metal lithium/electrolyte/diaphragm/electrolyte/carbon conductive film electrode has the test temperature of 30 ℃. The carbon-based conductive film is made of C60 material, and is deposited on the flexible conductive copper foil by a spin coating method (spin coating is carried out in a dynamic glue dripping mode for 60 seconds at a low speed according to 500 revolutions per minute, the speed at a high speed is 10000 revolutions per minute, and the time of the high speed spin coating is 30 seconds) to be used as a negative electrode material of the solid button lithium ion battery. The prepared solid button lithium ion battery has the cycle performance under the multiplying power of 0.1C as shown in figure 5, and the discharge specific capacity is 175mAh g after 200 cycles^-1。

Example 3: the solid button lithium ion battery assembled with the metal lithium/electrolyte/diaphragm/electrolyte/carbon conductive film electrode has the test temperature of 30 ℃. The carbon-based conductive film is prepared by compounding carbon fiber and C60 in a mass ratio of 1:1, and is deposited on the flexible conductive copper foil by a spin coating method (a dynamic glue dripping mode is adopted for spin coating, the low-speed section is spin-coated for 60 seconds at a speed of 500 revolutions per minute, the high-speed section is at a speed of 10000 revolutions per minute, and the high-speed spin coating time is at 30 seconds) to serve as a negative electrode material of the solid button lithium ion battery. The prepared solid button lithium ion battery has the cycle performance under the multiplying power of 0.1C as shown in figure 6, and the specific discharge capacity is 214mAh g after 148 cycles^-1。

Claims

1. The flexible negative electrode of the lithium ion battery is characterized by comprising a carbon conductive film and a flexible conductive substrate, wherein the carbon conductive film is prepared on the flexible conductive substrate, the thickness of the carbon conductive film is 10 nm-1 mu m, and the carbon conductive film is a pure carbon film.

2. The flexible negative electrode of claim 1, wherein the carbon-based conductive film is made of one of conductive carbon black, graphite, carbon nanotubes, and C60.

3. The flexible negative electrode of claim 1, wherein the flexible conductive substrate is made of copper foil, aluminum foil, flexible conductive glass, PET or PEN.

4. The flexible negative electrode of claim 1, wherein the carbon-based conductive film is prepared from a carbon-based negative electrode material on a flexible conductive substrate by spin coating, knife coating, or vacuum evaporation.

5. A lithium ion battery is a solid button lithium ion battery assembled in the order of metallic lithium, electrolyte, diaphragm, electrolyte and carbon-based conductive film electrode, or a flexible lithium ion battery assembled in the order of lithium foil, electrolyte, diaphragm, electrolyte and carbon-based conductive film electrode, or an ultrathin lithium ion battery assembled in the order of lithium foil, lithium phosphorus oxynitride electrolyte and carbon-based conductive film electrode, wherein the carbon-based conductive film electrode is the flexible negative electrode of any one of claims 1 to 4.