Method for preparing silicon-carbon composite anode and lithium ion battery

A negative electrode, silicon-carbon composite technology, applied in battery electrodes, secondary batteries, circuits, etc., can solve volume expansion and other problems, achieve the effects of increasing energy density, avoiding capacity loss, and easy processing

Active Publication Date: 2015-06-03
江苏中兴派能电池有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to provide a silicon-carbon composite negative electrode, a preparation method of the electrode and a lithium-ion battery using the negative electrode. The problem of volume expansion, improve the cycle performance of silicon materials in the process of use

Method used

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  • Method for preparing silicon-carbon composite anode and lithium ion battery
  • Method for preparing silicon-carbon composite anode and lithium ion battery
  • Method for preparing silicon-carbon composite anode and lithium ion battery

Examples

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preparation example Construction

[0030] The preparation process of the silicon-carbon composite negative electrode of the present invention is as follows:

[0031] Thoroughly mix and disperse the silicon source and the carbon source, add a binder and a solvent to prepare a negative electrode slurry with a solid content of 10%-80%, and the solvent is deionized water or NMP solution; wherein,

[0032] The silicon source is elemental silicon, the particle size distribution of the elemental silicon is 100nm-80um, the purity of the elemental silicon is above 99.9%, and the silicon source accounts for 10%-80% of the total mass of the silicon-carbon negative electrode;

[0033] The carbon source includes a carbon negative electrode material and a conductive agent, the carbon negative electrode material is one or more of carbon fiber, graphite and mesocarbon microspheres, and the conductive agent is a carbon black conductive agent, graphite conductive agent and graphite One or more of alkenes, the carbon negative ele...

Embodiment 1

[0064] (1) Preparation of negative electrode

[0065] 1200g of elemental silicon powder (accounting for 60% of the total mass of silicon-carbon negative electrode, particle size distribution of 500nm-15um, and a purity of 99.999%), 760g of carbon source (accounting for 38% of the total mass of silicon-carbon negative electrode) and 40g of PVDF (accounting for 2% of the total mass of the silicon-carbon negative electrode, Solvay PVDF5130) was prepared into a slurry with a solid content of 60%, and the balance was NMP solvent, wherein the carbon source was 532g of carbon fiber (accounting for 26.6% of the total mass of the silicon-carbon negative electrode, Qingdao Taineng Co., Ltd.), 152g of Super P (accounting for 7.6% of the total mass of the silicon carbon negative electrode, Temegao Graphite Co., Ltd.) and 76g of carbon nanotubes (accounting for 3.8% of the total mass of the silicon carbon negative electrode, Beijing Tiannai Technology Co., Ltd.) mixture;

[0066] The prep...

Embodiment 2

[0077] The silicon carbon negative electrode was prepared according to the same method as in Example 1.

[0078] The difference is that 1600g of silicon silicon powder, 380g of carbon source and 20g of PVDF were prepared into a slurry with a solid content of 60%, wherein the carbon source was a mixture of 323g of carbon fiber and 57g of carbon nanotube.

[0079] Battery assembly was carried out with reference to the battery assembly of Example 1, and a button-type lithium-ion battery C-2 and a stacked-type lithium-ion battery F-2 were produced. Wherein the weight of the negative electrode active material in the laminated battery is 1.8g, and the weight of the positive electrode active material is 16.27g.

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Abstract

The invention discloses a silicon-carbon composite anode comprising a silicon source and a carbon source, wherein silicon source is monatomic silicon, the particle size distribution is 100 nm to 80 microns, and the mass of the silicon source accounts for 10-80% of the total mass of the silicon-carbon composite anode; the carbon source comprises a carbon anode material and a conductive agent, the carbon anode material is one or more of carbon fiber, graphite and mesocarbon microbead, and the mass of the carbon anode material accounts for 10-90% of the total mass of the carbon source. According to the silicon-carbon composite anode disclosed by the invention, one-step coating forming, hot pressing flaking, carbonization treatment and high-temperature calcination are carried out on anode slurry prepared by mixing the silicon source with the carbon source, so as to guarantee that the silicon material is effectively dispersed in a carbon skeleton, the prepared silicon-carbon anode can effectively relieve the volume expansion of the silicon material in charging and discharging processes in a circulation process and guarantee excellent cycle performance of the battery; the silicon-carbon composite anode is prepared by one-step coating forming, and no current collector is needed, so that the production process is simplified and the battery is guaranteed to have high energy density; meanwhile, the invention further provides a lithium ion battery containing the silicon-carbon composite anode.

Description

technical field [0001] The invention relates to a battery negative electrode, a preparation method thereof, and a battery using the negative electrode. Specifically, the invention relates to a silicon-carbon composite negative electrode of a lithium-ion secondary battery, a preparation method thereof, and a silicon-carbon composite negative electrode using the silicon-carbon composite negative electrode. lithium-ion secondary battery. Background technique [0002] Due to its small size and high energy density, lithium-ion secondary batteries are widely used as mainstream power sources in electronic products such as mobile communication equipment, digital cameras, and notebook computers. At present, the capacity of the secondary battery of the traditional lithium cobalt oxide / graphite system is close to its theoretical maximum capacity, and it is difficult to increase its volumetric energy density by increasing the dressing density, thinning the thickness of the current colle...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/36H01M10/0525
CPCY02E60/10
Inventor 鲍添增朱广焱
Owner 江苏中兴派能电池有限公司
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