Long-life modified natural graphite cathode material as well as preparation method and use thereof

A technology of natural graphite and negative electrode material, applied in chemical instruments and methods, battery electrodes, inorganic chemistry, etc., can solve problems such as poor cycle performance and poor safety, and achieve improved cycle life, high spheroidization, and good electrochemical performance. Effect

Active Publication Date: 2018-03-20
GUANGDONG DONGDAO NEW ENERGY +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method is mainly aimed at the bottleneck problems such as poor cycle performance and poor safety when the carbon coating layer falls off when the natural graphite is used as the negative electrode, resulting in poor cycle performance and poor safety. The modified natural graphite with long life can be prepared by the method of the present invention. Ink anode material

Method used

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  • Long-life modified natural graphite cathode material as well as preparation method and use thereof
  • Long-life modified natural graphite cathode material as well as preparation method and use thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0054] (1) the spherical natural graphite with an average particle diameter of 8 μm and the coal tar pitch (0.5% quinoline insoluble matter content) with an average particle diameter of 15 μm are mixed uniformly by mass ratio 100:40, and sealed in the aluminum skin;

[0055] (2) Place the aluminum skin of step (1) in a hot isostatic press, raise the temperature to 300°C at 100MPa, keep the temperature and hold the pressure for 1 hour, turn off the power and cool to room temperature with the furnace;

[0056] (3) the material that step (2) obtains is broken into 3mm coarse powder in Raymond machine;

[0057] (4) Put the material obtained in step (3) into kerosene at 60°C, stir at a speed of 300r / min for 3 hours, filter, wash the filtrate once again, and dry at 160°C under vacuum;

[0058] (5) Under the protection of nitrogen, the material obtained in step (4) is first heated to 900° C. at a heating rate of 3° C. / min, and kept for 30 minutes; then heated to 1300° C. at a heating...

Embodiment 2

[0061] (1) The spherical natural graphite with an average particle diameter of 12 μm and the impregnated asphalt (0.6% quinoline insoluble matter content) with an average particle diameter of 20 μm are mixed uniformly by mass ratio 100:35, and sealed in a rubber bag;

[0062] (2) Place the rubber bag of step (1) in a hot isostatic press, raise the temperature to 350°C at 120MPa, keep the temperature and hold the pressure for 2 hours, then turn off the power and cool to room temperature with the furnace;

[0063] (3) the material obtained in step (2) is broken into 2mm coarse powder in a turbine pulverizer;

[0064] (4) Put the material obtained in step (3) into washing oil at 100°C, stir at a speed of 400r / min for 2 hours, filter, wash the filtrate once again, and dry at 200°C under vacuum;

[0065] (5) Under the protection of nitrogen, the material obtained in step (4) is first heated to 900° C. at a heating rate of 5° C. / min, and kept for 40 minutes; then heated to 1300° C. ...

Embodiment 3

[0067] (1) The spherical natural graphite with an average particle diameter of 18 μm and the impregnated pitch (0.4% quinoline insoluble matter content) with an average particle diameter of 20 μm are mixed uniformly by mass ratio 100:40, and sealed in the aluminum skin;

[0068] (2) Place the aluminum skin of step (1) in a hot isostatic press, raise the temperature to 320°C at 80MPa, keep the temperature and hold the pressure for 3 hours, turn off the power and cool to room temperature with the furnace;

[0069] (3) the material obtained in step (2) is broken into 1mm coarse powder in the Raymond machine;

[0070] (4) Put the material obtained in step (3) into xylene at 120° C., stir at a speed of 500 r / min for 2 hours, filter, rewash the filtrate twice, and dry at 200° C. under vacuum;

[0071] (5) Under the protection of nitrogen, the material obtained in step (4) is first heated to 900° C. at a heating rate of 4° C. / min, and kept for 50 minutes; then heated to 1300° C. at a...

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Abstract

The invention discloses a long-life modified natural graphite cathode material as well as a preparation method and use thereof. According to the preparation method, natural graphite powder and asphaltare dipped by virtue of a hot isostatic pressure machine, so that holes in graphite particles can be completely filled with asphalt at high temperature and high pressure conditions; and meanwhile, anasphalt coating layer is formed on the surface of the natural graphite powder, and graphitization is carried out so as to obtain the modified natural graphite cathode material with a core-shell structure, wherein synthetic graphite is embedded into the inside and surface of the natural graphite in situ, the filling rate of the synthetic graphite in the holes of the natural graphite is more than or equal to 94%, the surfaces of the particles are smooth, and the spheroidization degrees of the particles are high. According to the preparation method, the primary coulombic efficiency of the modified natural graphite cathode material is more than or equal to 96%, and the capacity retention ratio of the material after being circulated at a room temperature 1C for 1500 cycles is more than or equal to 80%, so that the prepared material is high in primary coulombic efficiency, long in service life and can be used for replacing synthetic graphite for producing powder battery cathode materials, and the cost is greatly lowered. The preparation method is simple in preparation process and low in cost and has relatively high practicability.

Description

technical field [0001] The invention relates to the technical field of carbon negative electrode materials for lithium ion batteries, in particular to a long-life modified natural graphite negative electrode material for lithium ion power batteries and its preparation method and application. Background technique [0002] Lithium-ion batteries have a series of advantages such as high specific capacity, high working voltage, good safety, and no memory effect, and are widely used in 3C products, power devices, and energy storage equipment. With the popularity of new energy vehicles, its application scope has been expanded to electric vehicles, automobiles and other fields. In recent years, with the continuous improvement of electronic products, vehicle-mounted and energy storage equipment for miniaturization, light weight, multi-function, and long-term driving, the requirements for high energy density, high rate performance, and long cycle life of lithium-ion batteries constan...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B32/205H01M4/587H01M10/0525
CPCC01P2004/03C01P2004/32C01P2004/61H01M4/587H01M10/0525Y02E60/10
Inventor 吴其修叶振坤叶雨佐史有利
Owner GUANGDONG DONGDAO NEW ENERGY
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