A kind of preparation method of graphite material for lithium ion battery

A technology for lithium-ion batteries and graphite materials, which is applied in the field of preparation of graphite materials for lithium-ion batteries, can solve the problems of reducing battery safety performance and energy reduction, and achieve high production efficiency, short heating time, and good sealing of the furnace body Effect

Active Publication Date: 2016-01-20
刘铁建
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Among them, in order to reduce the thickness of the negative electrode sheet, it can be realized by reducing the amount of active material, binder, etc., and by increasing the compaction density of the negative electrode; but the former will also lead to a decrease in energy while reducing the thickness, so , it is not beneficial to increase the volume energy density of the battery; and the latter has a limited increase in the volume energy density of the battery, because the graphite negative electrode has the problem of rebound, the greater the compaction density, the greater the rebound of the battery during the cycle large, which greatly reduces the safety performance of the battery

Method used

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  • A kind of preparation method of graphite material for lithium ion battery

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Effect test

Embodiment 1

[0030] The preparation method of a kind of lithium-ion battery graphite material that present embodiment provides, comprises the following steps:

[0031] Step 1: Add coconut shell charcoal into a high-temperature carbonization furnace with a pressure of 0.5 MPa under an argon gas atmosphere, heat to 1000°C and keep at this temperature for 5 hours to carbonize coconut shell charcoal, and at the same time vacuumize the carbonization furnace The vacuum inside is -20KPa, after cooling, the coconut shell charcoal after carbonization is obtained;

[0032] Step 2: Add the carbonized coconut shell carbon obtained in Step 1 into the graphitization furnace under an argon atmosphere, and then inject coal tar pitch, which has a dynamic viscosity of 90 Pa·s at 60°C, and stir thoroughly , and vacuumize at the same time, so that the vacuum degree in the graphitization furnace is -10KPa, and then graphitize at 2600°C. The duration of graphitization is 5h, and graphite is obtained after cooli...

Embodiment 2

[0035] The preparation method of a kind of lithium-ion battery graphite material that present embodiment provides, comprises the following steps:

[0036] Step 1: In a nitrogen gas atmosphere, add fruit shell charcoal to a high-temperature carbonization furnace with a pressure of 0.8 MPa, heat to 1100°C and continue at this temperature for 10 hours to carbonize the shell charcoal, and at the same time vacuumize the carbonization furnace. The vacuum degree is -30KPa, after cooling, obtain the shell charcoal after carbonization;

[0037] Step 2: Add the carbonized coconut shell charcoal obtained in Step 1 into the graphitization furnace under a nitrogen gas atmosphere, and then inject petroleum pitch, which has a dynamic viscosity of 70 Pa·s at 60°C. Vacuumize the graphitization furnace so that the vacuum degree in the graphitization furnace is -1KPa, and then graphitize at 2500°C. The duration of graphitization is 10h, and graphite is obtained after cooling.

[0038] Wherein, ...

Embodiment 3

[0040]The preparation method of a kind of lithium-ion battery graphite material that present embodiment provides, comprises the following steps:

[0041] Step 1: Add wood charcoal into a high-temperature carbonization furnace with a pressure of 1 MPa in a nitrogen gas atmosphere, heat to 1000°C and keep at this temperature for 15 hours to carbonize the wood charcoal, and at the same time vacuumize the carbonization furnace. It is -1KPa, after cooling, the charcoal after carbonization is obtained;

[0042] Step 2: Add the carbonized wood charcoal obtained in Step 1 into the graphitization furnace under a nitrogen gas atmosphere, and then inject natural pitch whose dynamic viscosity at 60°C is 60 Pa·s. Vacuum, make the vacuum degree in the graphitization furnace be -80KPa, then graphitize at 2700°C, the duration of graphitization is 1h, and obtain graphite after cooling.

[0043] Wherein, the mass ratio of wood charcoal and natural asphalt is 10:1.

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Abstract

The invention belongs to the technical field of lithium ion batteries, and in particular relates to a preparation method of a graphite material of a lithium ion battery. The preparation method comprises the following steps: in an inert gas atmosphere, adding activated carbon into a high-temperature carbonization furnace, heating to 900 to 1,100 DEG C to carbonize the activated carbon, simultaneously vacuumizing, and cooling to obtain the carbonized activated carbon; in the inert gas atmosphere, adding the carbonized activated carbon obtained in the step one into a graphitization furnace, injecting asphalt, fully stirring, vacuumizing, graphitizing at the temperature of 2,500 to 2,700 DEG C, and cooling to obtain the graphite. Compared with the prior art, the preparation method has the advantages that the activated carbon is carbonized in a high-temperature and high-pressure kettle first, then the asphalt is injected into the high-temperature and high-pressure kettle, the liquid asphalt can fill holes in the carbonized activated carbon, the graphite with high true density can be obtained by subsequent high-temperature high-pressure graphitizing treatment, and the volume per gram of the graphite and the first discharge efficiency of the lithium ion battery using the graphite are improved.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, in particular to a preparation method of graphite materials for lithium ion batteries. Background technique [0002] In graphite crystals, carbon atoms in the same layer are sp2 hybridized to form covalent bonds, and each carbon atom is connected to three other atoms by three covalent bonds. Six carbon atoms form a hexagonal ring on the same plane, extending into a sheet structure. The distance between layers of graphite is relatively large, generally 340pm, and the bonding force between carbon atoms on the same layer is very strong. Strong, extremely difficult to destroy. Due to the above structural characteristics of graphite, it has high temperature resistance, electrical and thermal conductivity, lubricity and chemical stability, etc., so it is widely used as refractory materials (such as graphite crucible), conductive materials (such as carbon rods, graphite gaskets, etc.), W...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/583
CPCH01M4/587H01M10/0525Y02E60/10
Inventor 刘铁建
Owner 刘铁建
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