Modified lithium ion battery graphite negative material and preparation method thereof

A technology of lithium ion battery and graphite negative electrode, which is applied in the field of electrochemical materials and new energy, can solve the problems of difficulty in uniformly covering graphite negative electrode material, easy agglomeration, and high activity of nano-scale silicon powder, and achieves easy realization and simple process. , the effect of wide application prospects

Active Publication Date: 2014-07-16
HEFEI GUOXUAN HIGH TECH POWER ENERGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, nano-scale silicon powder is very active, easy to agglomerate, and it is difficult to evenly cover the surface of graphite negative electrode materials.

Method used

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  • Modified lithium ion battery graphite negative material and preparation method thereof
  • Modified lithium ion battery graphite negative material and preparation method thereof
  • Modified lithium ion battery graphite negative material and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] 1) Weigh butyl titanate, silicon powder and graphite according to the molar ratio Ti:Si:C=3:0.8:500. The ball milling mixing treatment was carried out under the protection of nitrogen with the absolute ethanol solution of CMC with a mass percent content of 0.5% as the dispersant. The obtained mixed slurry was vacuum-dried at 80° C. to obtain a dried material.

[0026] 2) Under the protection of a nitrogen-hydrogen mixed atmosphere with a hydrogen volume percentage of 1%, the obtained dry material is heated to 1550°C for 2 hours, and then cooled to 1200°C for 5 hours, the heating rate is 2°C / min, and sintered The material is naturally cooled to room temperature with the furnace, that is, a similar figure 1 curve, figure 2 with 3 The surface shown in the map has a titanium silicon carbon coated layer of graphite material.

Embodiment 2

[0028] 1) Weigh butyl titanate, silicon powder and graphite according to the molar ratio Ti:Si:C=3:1.2:800. Using 2.0% by mass of CMC in absolute ethanol as a dispersant, ultrasonic mixing was performed under the protection of argon. The obtained mixed slurry was vacuum-dried at 100° C. to obtain a dried material.

[0029] 2) The obtained dry material is heated to 1550°C for 2 hours under the protection of an argon-hydrogen mixed atmosphere with a hydrogen volume percentage of 2.5%, and then cooled to 1350°C for 5 hours at a heating rate of 5°C / min. The material is naturally cooled to room temperature with the furnace, and the following figure 1 curve, figure 2 with 3 The surface shown in the map has a titanium silicon carbon coated layer of graphite material.

Embodiment 3

[0031] 1) Weigh titanium tetrachloride, elemental silicon powder and graphite according to the molar ratio Ti:Si:C=3:1.5:2000. Ball milling and mixing treatment was carried out under the protection of argon with 2.0% PEG in absolute ethanol as the dispersant. The obtained mixed slurry was vacuum-dried at 120° C. to obtain a dried material.

[0032] 2) The obtained dried material is heated to 1550°C for 2 hours under the protection of an argon-hydrogen mixed atmosphere with a hydrogen volume percentage of 3.5%, and then cooled to 1250°C for 5 hours at a heating rate of 8°C / min, and sintered The material is naturally cooled to room temperature with the furnace, that is, a similar figure 1 curve, figure 2 with 3 The surface shown in the map has a titanium silicon carbon coated layer of graphite material.

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PUM

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Abstract

The invention discloses a modified lithium ion battery graphite negative material and a preparation method thereof, and belongs to the fields of an electrochemical material and a new energy source. The surface of the modified lithium ion battery graphite negative material is coated with a Ti2SiC2 conductive network. The method comprises the following steps: weighing a titanium source, a silicon source and graphite; adding a dispersing agent and carrying out ball-milling or ultrasonic mixing treatment under the protection of inert gas, and then drying; and sintering the dry material under the protection of a mixed atmosphere of hydrogen and inert gas. The modified lithium ion battery graphite negative material is smooth in surface, uniform in surface property, and high in electronic conductivity. by a surface cladding layer, direct contact of a graphite negative electrode and electrolyte is effectively weakened and the corrosion of the electrolyte is alleviated; the titanium, silicon and carbon surface cladding layer is good in chemical stability and conductivity, a stable crystal structure can be effectively kept in the repeated charge and discharge processes, the electrical conductivity is obviously improved, and the first coulombic efficiency, the rate capability and the cycle performance are obviously improved.

Description

technical field [0001] The invention belongs to the field of electrochemical materials and new energy sources, and in particular relates to a lithium ion battery negative electrode material, in particular to a modified lithium ion battery graphite negative electrode material and a preparation method thereof. Background technique [0002] In recent years, with the rapid development of new energy vehicles, lithium-ion batteries with high power, high capacity and long cycle life have become a hot spot in the development of countries all over the world. As one of the four main materials of lithium-ion batteries, graphite anode materials are currently commercially used on a large scale. [0003] Graphite negative electrodes mainly include natural graphite and artificial graphite. Natural graphite has an ideal layered structure and high lithium intercalation ability, but its structure is unstable, and it is easy to cause co-intercalation of solvent molecules, causing the layers t...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/587H01M4/62
CPCH01M4/366H01M4/587H01M4/624H01M10/0525Y02E60/10
Inventor 杨茂萍
Owner HEFEI GUOXUAN HIGH TECH POWER ENERGY
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