Negative plate, lithium ion battery and preparation method thereof

A lithium-ion battery and negative electrode technology, which is applied in the manufacture of electrolyte batteries, secondary batteries, battery electrodes, etc., can solve problems such as poor cycle performance, large volume change, and battery capacity drop

Active Publication Date: 2014-08-13
RESEARCH INSTITUTE OF TSINGHUA UNIVERSITY IN SHENZHEN
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Most of the traditional commercialized lithium-ion battery anode materials are graphite materials. However, due to the large volume change of the graphite electrode during charging and discharging, the battery capacity decreases and the cycle performance deteriorates.

Method used

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  • Negative plate, lithium ion battery and preparation method thereof
  • Negative plate, lithium ion battery and preparation method thereof
  • Negative plate, lithium ion battery and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0063] Such as figure 1 The preparation method of above-mentioned lithium ion battery shown, comprises the steps:

[0064] S10. According to the mass percentage, add 80%~94% of lithium titanate particles coated with carbon on the surface, 3%~10% of conductive agent and 3%~10% of binder into the solvent, and mix well to obtain the negative electrode Slurry, the negative electrode slurry is coated on the negative electrode current collector and dried to form a negative electrode coating to obtain a negative electrode sheet.

[0065] In the negative electrode slurry, the solute solid content is 30%~70%.

[0066] The negative electrode slurry is coated on both sides of the negative electrode current collector, and the negative electrode sheet is prepared by baking, rolling and slicing.

[0067] The solvent can be N-methylpyrrolidone (NMP), dimethylamide or dimethylacetamide.

[0068] The conductive agent is at least one of super conductive carbon black, conductive graphite and ...

Embodiment 1

[0096] Add 90% of lithium titanate coated with carbon on the surface, 3% of SP, 2% of KS-6 and 5% of PVDF into the stirring tank according to the mass percentage, vacuumize and stir, add an appropriate amount of NMP and continue stirring to obtain the negative electrode Slurry, the negative electrode slurry is coated on both sides of the 20μm thick porous corroded aluminum foil after corrosion treatment, and the surface density of the pole piece coating is 250g / m 2 , through baking, rolling and slicing to prepare the negative electrode sheet.

[0097] 94% LiMn by mass ratio 2 o 4 , 1.5% SP, 1.5% KS-6 and 3% PVDF were dissolved in NMP and stirred to make positive electrode slurry, and the positive electrode slurry was coated on both sides of the light aluminum foil with a surface density of 400g / m 2 , through baking, rolling and slicing to prepare the positive electrode sheet.

[0098] By controlling the surface density of the coating, the ratio of the capacity per unit area...

Embodiment 2

[0103] Different from Example 1, the positive electrode active material is LiMn 2 o 4 with LiCoO 2 Mixture (weight ratio: 8:2), the positive electrode coating is coated on both sides of the light aluminum foil, the surface density is 370g / m 2 .

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Abstract

The invention discloses a negative electrode sheet, comprising a negative electrode collector and a negative electrode coating coated on the negative electrode collector; the negative electrode coating includes a negative electrode active material, a conductive agent and a binder; the negative electrode active material It is a lithium titanate particle whose surface is coated with carbon, and the lithium titanate particle has a spinel structure. The negative electrode active material of this kind of negative plate adopts lithium titanate coated with carbon on the surface. The crystal form of spinel lithium titanate does not change during the lithium ion intercalation-extraction process, the lattice constant changes very little, and the volume change is less than 1%. . When the negative electrode sheet is applied to a lithium ion battery, compared with the traditional lithium ion battery using graphite material as the negative electrode active material, the battery cycle performance is better. The present invention also provides a lithium ion battery using the above-mentioned negative electrode sheet and a preparation method thereof.

Description

technical field [0001] The invention relates to the field of energy storage devices, in particular to a negative electrode sheet, a lithium ion battery using the negative electrode sheet and a preparation method thereof. Background technique [0002] Energy and the environment are two major issues facing mankind in the 21st century. In my country, with the acceleration of industrialization and urbanization, the economy's demand for oil continues to increase, and my country's oil supply is obviously insufficient, and its dependence on foreign countries continues to increase. At the same time, as more and more oil and coal are mined and burned, greenhouse gases such as carbon dioxide in the atmosphere will continue to increase, and China is facing increasing pressure to reduce carbon emissions. The development and utilization of new energy is a strategic measure for the country to build an energy-saving society and reduce dependence on traditional energy. It is an inevitable ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/131H01M4/70H01M10/0525H01M10/058
CPCY02E60/122Y02E60/10Y02P70/50
Inventor 姜冬冬杨红平罗旭芳李锐赵方辉袁美蓉王臣徐永进
Owner RESEARCH INSTITUTE OF TSINGHUA UNIVERSITY IN SHENZHEN
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