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Composite material for lithium ion battery cathode and preparation method thereof as well as cathode and battery

A technology for lithium-ion batteries and composite materials, which is applied to composite materials for negative electrodes of lithium-ion batteries and its preparation, as well as in the field of negative electrodes and batteries. It can solve the problems of unsatisfactory improvement in the performance of graphite negative electrode materials, and achieve improved rate discharge performance and reduced metal content. Effect

Inactive Publication Date: 2009-05-27
海宁市盐官工业投资有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to overcome the problem that graphite surface modification is not ideal for improving the performance of graphite negative electrode materials in the prior art, and to provide a lithium-ion battery that significantly improves the rate discharge performance, initial discharge efficiency, reversible capacity and cycle performance of the battery. Negative electrode material and preparation method thereof

Method used

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  • Composite material for lithium ion battery cathode and preparation method thereof as well as cathode and battery
  • Composite material for lithium ion battery cathode and preparation method thereof as well as cathode and battery
  • Composite material for lithium ion battery cathode and preparation method thereof as well as cathode and battery

Examples

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preparation example Construction

[0049] The preparation method of the negative electrode provided by the present invention comprises mixing the lithium ion battery negative electrode active material provided by the present invention, a binder and a solvent, coating and / or filling on the conductive substrate, drying, calendering or not calendering, The negative electrode can be obtained.

[0050] Described solvent can be selected from N-methylpyrrolidone (NMP), dimethylformamide (DMF), diethylformamide (DEF), dimethylsulfoxide (DMSO), tetrahydrofuran (THF) and water and One or more of alcohols. The amount of the solvent can make the paste have viscosity and fluidity, and can be coated on the conductive substrate. Generally, based on the weight of the negative electrode active material, the content of the solvent is 50-150% by weight, preferably 70-120% by weight.

[0051] The drying and calendering methods and conditions are well known to those skilled in the art. For example, the drying temperature is gene...

Embodiment 1

[0064] This example illustrates the preparation method of the active material for lithium ion battery negative electrode provided by the present invention.

[0065] With 2 kilograms of median particle diameter D50 be 18 microns, crystallite layer spacing d002 correction value is 0.3365 nanometers of graphite, 54.2 grams of copper chloride (molecular formula: CuCl 2 2H 2 O), be dissolved in 2.5 kilograms of deionized water, stir for 20 minutes, then add 28 grams of sodium hydroxide, stir and leave standstill for 30 minutes. The suspension was vacuum filtered, and the filter cake was washed with deionized water more than twice, each time with 2 kg of water. Then the above product was dried at 100°C, and then stored in an oven at 300°C for 2 hours at a high temperature, and the product was stored under argon protection at 450°C for 3 hours to obtain the negative electrode material A1 with a coating percentage of 1%.

Embodiment 2

[0067] This example illustrates the preparation method of the active material for lithium ion battery negative electrode provided by the present invention.

[0068] According to the same method as in Example 1, the negative electrode material A2 that the coating percentage is 2% is obtained, the difference is that the metal salt added is 160 grams of copper sulfate pentahydrate, and the corresponding reaction reagent is 94 grams of sodium oxalate, placed in Store at high temperature in an oven at 380°C for 2 hours, and store the product under argon protection at 450°C for 3 hours.

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Abstract

The invention relates to a composite material for a cathode of a lithium ion battery, a preparation method thereof, and the cathode and the battery which contains the cathode material. The composite material comprises graphite and metals, wherein the metals coat on the surface of the graphite; the metals are copper and / or nickel; and the content of the metals is 0.1 to 5 weight percent on the basis of the weight of the graphite. The method for preparing the composite material comprises the following steps: making a mixture of an aqueous solution of metallic salts and the graphite contact a precipitant of the metallic salts, transforming deposits of the metallic salts coating on the surface of the graphite into metal oxide, and reducing the metal oxide into the metals. The preparation method is characterized in that the metallic salts are water-soluble cupric salts and / or water-soluble nickel salts, and the content of the metals in the prepared composite material accounts for 0.1 to 5 weight percent of that of the graphite due to the amount of the graphite and salts of water-soluble metals. Because the content of the metals in the composite material for the cathode is reduced, the rate discharge performance, the initial discharge efficiency, the reversible capacity and the cycling performance of the battery can be obviously improved.

Description

technical field [0001] The invention relates to a composite material for negative electrodes of lithium ion batteries and a preparation method thereof, as well as negative electrodes and batteries containing the negative electrode materials. technical background [0002] Lithium-ion secondary batteries are widely used due to their high specific energy, high operating voltage, wide operating temperature range, low self-discharge rate, long cycle life, no pollution, light weight and good safety performance. Carbon materials are currently the most commonly used negative electrode active materials for lithium-ion batteries, and the technology is relatively mature. Among them, graphite has high crystallinity and a good layered structure, which is a good charge and discharge platform. [0003] At present, some people have modified the surface of graphite by coating copper or nickel on the surface. As pointed out in the article "Research Progress of Natural Graphite and Its Surfa...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/36B22F1/02H01M4/02H01M10/40
CPCY02E60/122Y02E60/10
Inventor 姜俊刚李科张建飞刘卫平
Owner 海宁市盐官工业投资有限公司