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Different-orientation spherical natural graphite negative electrode material and preparation method thereof

A technology of natural graphite and negative electrode material, applied in the field of electrochemical power supply, can solve the problems of accelerated capacity decay, exfoliation of graphite layers, etc., and achieve the effects of inhibiting exfoliation of layers, easy operation and low preparation cost

Active Publication Date: 2010-08-11
CHINA THREE GORGES UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

When lithium ions are deeply intercalated between graphite layers or fast intercalation / deintercalation occurs, the graphite flakes will be exfoliated due to stress concentration or rapid stress unloading, thereby accelerating capacity fading. Therefore, spherical natural graphite with this structure is not suitable as a power lithium ion. Use of battery negative electrode materials

Method used

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  • Different-orientation spherical natural graphite negative electrode material and preparation method thereof
  • Different-orientation spherical natural graphite negative electrode material and preparation method thereof
  • Different-orientation spherical natural graphite negative electrode material and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026]Embodiment 1. with natural flake graphite micropowder, purity >=99%, mixes with deionized water, adds deflocculating agent and regulates solid content to 30~50% by mass percentage, then adds the PVA of natural flake graphite micropowder weight 5% and The mixture of CMC is used as a binder, and after adding a small amount of defoamer, it is stirred in a mixer for 2 to 5 hours. The obtained slurry is atomized, dried and granulated on a spray dryer, and the obtained powder is placed in a rotary kiln for heat treatment in a nitrogen atmosphere. The temperature is controlled at 600-1000°C for 2-5 hours, and the rotation speed is 3-5 rpm. The obtained powder material is the hetero-orientation spherical natural graphite negative electrode material. The obtained hetero-orientation spherical natural graphite negative electrode material was used to prepare electrodes for electrochemical tests. The electrode preparation method, battery assembly and test conditions are the same as ...

Embodiment 2

[0027] Embodiment 2. with natural flake graphite micropowder, purity >=99%, mix with deionized water, add deflocculating agent and regulate solid content to 30~50% by mass percentage, then add the PVA of natural flake graphite micropowder weight 10% and The mixture of CMC is used as a binder, and then the binder and a small amount of defoamer are added and stirred in a mixer for 2 to 5 hours. The obtained slurry is atomized, dried and granulated on a spray dryer, and the obtained powder is placed in a rotary kiln for heat treatment in a nitrogen atmosphere at a temperature of 600-1000°C for 2-5 hours and a rotary kiln speed of 3-5 rpm , the obtained powder material is the different orientation spherical natural graphite negative electrode material. The obtained hetero-orientation spherical natural graphite negative electrode material was used to prepare electrodes for electrochemical tests. The electrode preparation method, battery assembly and test conditions are the same as...

Embodiment 3

[0028] Embodiment 3. with natural flake graphite powder, purity ≥ 99%, mix with dehydrated alcohol and add deflocculant to regulate solid content to 30~50% by mass percentage, then add the polyvinyl alcohol of natural flake graphite powder quality 5% Butyral PVB is used as a binder, and it is stirred in a mixer for 2 to 5 hours. The obtained slurry is atomized, dried and granulated on a spray dryer, and the obtained powder is placed in a rotary kiln for heat treatment in a nitrogen atmosphere. The temperature is controlled at 600-1000°C for 2-5 hours, and the rotation speed is 3-5 rpm. The obtained powder material is the hetero-orientation spherical natural graphite negative electrode material. The obtained hetero-orientation spherical natural graphite negative electrode material was used to prepare electrodes for electrochemical tests. The electrode preparation method, battery assembly and test conditions are the same as in Comparative Example 1. The first lithium intercala...

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Abstract

The invention relates to a different-orientation spherical natural graphite negative electrode material and a preparation method thereof. The method comprises the following steps: mixing natural crystalline flake graphite micro powder and dispersion medium; adding deflocculants for regulating the solid content; then, placing materials and bonding agents into a pulp mixing machine to be stirred; carrying out atomization, drying and granulation on the pulp on a spraying drying machine to obtain powdery materials; carrying out heat treatment on the powdery materials in nitrogen gas atmosphere through a revolving furnace; and cooling the obtained powder to obtain the different orientation spherical natural graphite negative electrode material. The graphite negative electrode material consists of a plurality of layered graphite crystalline flakes, and the layered graphite crystalline flakes are glued and have different orientations. The graphite negative electrode material prepared by the method of the invention has the obvious characteristics that the specific capacity of the material is high, the circulation stability is high, the micro spheres formed by the graphite flakes of the graphite with different orientations can effectively inhabit the layer flake peeling caused by deep lithium insertion, the graphite flake adhesion and the carbon coverage can be realized at the same time, the powder agglomeration can be avoided through dynamic sintering, and the invention is favorable for obtaining the spherical natural graphite micro powder with uniform granularity.

Description

technical field [0001] The invention relates to a kind of different-orientation spherical natural graphite negative electrode material of a lithium secondary battery and a preparation technology thereof, belonging to the technical field of electrochemical power sources. Background technique [0002] The development of lithium-ion batteries depends largely on the development and application of high-performance positive and negative electrode materials. At present, practical lithium-ion batteries mainly use artificial graphite (such as mesocarbon microspheres MCMB and CMS) as negative electrode materials and transition metal oxides (such as LiCoO 2 ) are cathode materials, and the preparation costs of these materials are very high. Just LiCoO 2 However, due to the limited reserves of transition metals and the toxicity of cobalt, its application range is gradually shrinking, and the lower cost lithium iron phosphate (LiFePO 4 ) Cathode materials are increasingly favored by v...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/133H01M4/1393
CPCY02E60/122Y02E60/10
Inventor 杨学林李云峰张鹏昌张露露
Owner CHINA THREE GORGES UNIV
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