Graphite composite material as well as preparation method and application thereof

A composite material, graphite technology, applied in the direction of active material electrodes, electrical components, battery electrodes, etc., can solve problems such as the inability to meet fast charging performance

Active Publication Date: 2020-09-18
BTR NEW MATERIAL GRP CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

It solves the problem that the graphite anode material in the prior art cannot meet the fast charging performance and improve the capacity and cycle performance at the same time

Method used

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  • Graphite composite material as well as preparation method and application thereof
  • Graphite composite material as well as preparation method and application thereof
  • Graphite composite material as well as preparation method and application thereof

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preparation example Construction

[0087] In a second aspect, the present invention provides a method for preparing a graphite composite material as described in the first aspect, said method comprising the steps of:

[0088] Carrying out the first oxidation treatment on the graphite-based carbon material raw material to form a cross-linked structure carbon layer on the surface, and carbonize to obtain primary particles;

[0089] mixing the primary granules with a binder for granulation to obtain secondary granules; and

[0090] Coating pitch on the surface of the secondary particles, performing a second oxidation treatment, forming a cross-linked carbon layer on the surface, graphitizing, and obtaining a graphite composite material with a second hard carbon coating layer.

[0091] The present invention oxidizes the graphite carbon material raw material, and then carbonizes it, so that a hard carbon coating layer is formed on the surface of the graphite carbon material raw material particle surface. At the same...

Embodiment 1

[0137] A preparation method of graphite composite material:

[0138] (1) Use a crusher to roughly crush oil-based needle-shaped green coke raw materials to obtain crushed materials with a particle size of less than 5 mm, and then use a mechanical mill to crush until the particle size is: D10 is 5 μm, D50 is 9 μm, D90 is 17 μm, and Dmax is 25 μm of fine powder;

[0139] (2) The pulverized fine powder is subjected to low-temperature oxidation in the oxidation rotary furnace. The low-temperature oxidation condition is: the heating rate is 2°C / min, the temperature is raised to 300°C, and then kept for 1 hour, and then the material is cooled and discharged. The air flow rate in the whole process is 60L / h; after the low temperature oxidation, send the oxidized fine powder into the kiln at 1150℃ for carbonization for 16h, N 2 The flow rate is 60m 3 / h;

[0140] (3) Mix the needle-shaped raw coke micro-powder after carbonization in step (2) with polystyrene resin at a mass ratio of...

Embodiment 2

[0145] (1) Use a crusher to roughly crush oil-based needle-shaped green coke raw materials to obtain crushed materials with a particle size of less than 5 mm, and then use a mechanical mill to crush until the particle size is: D10 is 4.5 μm, D50 is 8 μm, D90 is 16 μm, and Dmax is 25μm fine powder;

[0146] (2) The pulverized micropowder is subjected to low-temperature oxidation in an oxidation rotary furnace. The low-temperature oxidation condition is: the heating rate is 2°C / min, the temperature is raised to 300°C, and then kept for 1.5h, and then cooled and discharged. The whole process The air ventilation rate is 60L / h; after the low-temperature oxidation is completed, the oxidized fine powder is sent to a kiln at 1150°C for carbonization for 16 hours, N 2 The flow rate is 60m 3 / h;

[0147] (3) Mix the needle-shaped green coke powder after carbonization in step (2) with polystyrene resin at a mass ratio of 90:10 for 30 minutes, and then put it into a heating reactor for ...

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Abstract

The invention relates to a graphite composite material as well as a preparation method and application thereof. The graphite composite material is of a core-shell structure and comprises a secondary particle inner core and a second hard carbon coating layer on the surface of the secondary particle, wherein the secondary particles comprise a plurality of primary particles, and each primary particlecomprises a first hard carbon coating layer. In the graphite composite material provided by the invention, the hard carbon coating layer formed on the surface layer of the primary particle is tightlybonded with the inner core of the particle, no gap exists between the coating layer and the inner core, and the thickness consistency of the coating layer is high; the hard carbon coating layer of the secondary particle shell is beneficial to stabilizing the primary particle accumulation structure, and is beneficial to the long cycle performance of the material; the first hard carbon coating layer formed on the surface layer of the primary particle and the second hard carbon coating layer formed on the surface layer of the secondary particle can accelerate the desolvation process of lithium ions, so that lithium ions can be inserted into graphite more quickly; and according to the graphite composite material, the capacity can be ensured, and meanwhile, the quick charge and cycle performance can be greatly improved.

Description

technical field [0001] The invention belongs to the technical field of battery materials, and in particular relates to a graphite composite material, its preparation method and application. Background technique [0002] Graphite anode material has the characteristics of high energy density, good cycle performance, mature preparation technology, and low manufacturing cost. It is the mainstream commercial anode material for lithium-ion batteries; In order to meet the higher requirements, it is generally hoped to improve the fast charging ability at room temperature and low temperature, so that the graphite anode material must be specially designed and processed to meet the fast charging requirements. [0003] Existing technology: 1. A layer of hard carbon or soft carbon is coated on the graphite surface. Although the surface coating can reduce the interface impedance and improve the fast charging performance, due to the long diffusion path of the primary particle structure, it...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/36H01M4/583H01M4/133H01M10/05
CPCH01M4/366H01M4/583H01M4/133H01M10/05H01M2004/027Y02E60/10
Inventor 夏路徐晓东王为张梦任建国
Owner BTR NEW MATERIAL GRP CO LTD
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