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Silicon-based composite negative electrode material for lithium ion battery, preparation method thereof, and lithium ion battery negative electrode containing the material

A technology for lithium ion batteries and negative electrode materials, applied in battery electrodes, secondary batteries, circuits, etc., can solve the problems of poor batch stability, low yield and high cost, and achieve good structural stability and electrochemical stability. Effect

Active Publication Date: 2020-05-26
GENERAL RESEARCH INSTITUTE FOR NONFERROUS METALS BEIJNG +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The traditional nano-silicon preparation methods mainly include chemical vapor deposition, physical evaporation, solution method and laser ablation method, etc., but these methods are high in cost, low in yield and poor in batch stability

Method used

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  • Silicon-based composite negative electrode material for lithium ion battery, preparation method thereof, and lithium ion battery negative electrode containing the material
  • Silicon-based composite negative electrode material for lithium ion battery, preparation method thereof, and lithium ion battery negative electrode containing the material
  • Silicon-based composite negative electrode material for lithium ion battery, preparation method thereof, and lithium ion battery negative electrode containing the material

Examples

Experimental program
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Effect test

Embodiment 1

[0046] Take 50g of micron silicon powder with a median particle size of 3μm and a silicon content of more than 99%, add it to 950g of ethanol, ultrasonically disperse it for 30 minutes, pour it into the cavity of an ultrafine ball mill, and add 0.5wt% lignin with the quality of silicon powder sodium sulfonate. Zirconia balls with a diameter of 0.3 mm were used as the ball milling medium, and the ball-to-material ratio (mass ratio) was 14:1, and ball milled at a speed of 1800 rpm for 10 hours to obtain a nano-silicon dispersion.

[0047] Add 12.6g of phenolic resin and 226g of flaky conductive graphite KS-6 to the nano-silicon dispersion, and ball mill at 1000rpm for 1 hour to obtain a uniform mixed slurry. The mixed slurry was spray-dried to obtain granular powder, which was placed in a tube-type vacuum furnace and calcined at 600° C. for 1 h under an argon atmosphere to obtain an intermediate product.

[0048] Take 15g of the intermediate product, put it into 14g of medium-t...

Embodiment 2

[0055] Take 50g of micron silicon powder with a median particle size of 3μm and a silicon content greater than 99%, add it to 950g of ethanol, and after ultrasonic dispersion for 30min, pour it into the cavity of an ultrafine ball mill, and add 0.5wt% silicon powder mass of twelve Sodium Alkyl Sulfonate. Using zirconia balls with a diameter of 0.3mm as the ball milling medium, the ball-to-material ratio (mass ratio) is 14:1, ball milled at a speed of 1800rpm for 10 hours, and then the ball mill liquid was centrifuged at a speed of 11000rpm to remove large particles to obtain nano Nano-silicon dispersion liquid with silicon particle size less than 100nm.

[0056] Add 6.3g of phenolic resin and 113g of flaky conductive graphite KS-6 to the nano-silicon dispersion, and ball mill at 1000rpm for 1 hour to obtain a uniform mixed slurry. The mixed slurry was spray-dried to obtain granular powder, which was placed in a tube-type vacuum furnace and calcined at 600° C. for 1 h under an...

Embodiment 3

[0068] Take 50g of micron silicon powder with a median particle size of 3μm and a silicon content of more than 99%, add it to 950g of ethanol, ultrasonically disperse it for 30 minutes, pour it into the cavity of an ultrafine ball mill, and add 0.5wt% lignin with the quality of silicon powder sodium sulfonate. Using zirconia balls with a diameter of 0.3mm as the ball milling medium, the ball-to-material ratio (mass ratio) is 14:1, ball milled at a speed of 1800rpm for 10 hours, and then the ball mill liquid was centrifuged at a speed of 11000rpm to remove large particles to obtain nano Silicon dispersion.

[0069] Add 133g of glucose and 302g of flaky conductive graphite KS-6 to the nano-silicon dispersion, and ball mill at 1000rpm for 1 hour to obtain a uniform mixed slurry. The mixed slurry was spray-dried to obtain granular powder, which was placed in a tube-type vacuum furnace and calcined at 600° C. for 1 h under an argon atmosphere to obtain an intermediate product.

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Abstract

The present invention discloses a silicon composite negative electrode material for a lithium ion battery, a preparation method thereof, and a lithium ion battery negative electrode comprising same. The silicon composite negative electrode material uses graphite as a base material and an active material, and uses nano silicon as the active material. The nano silicon is uniformed distributed on the surface of the graphite. The nano silicon is tightly combined with the surface of the graphite through a carbon-containing conductor. A core shell structure negative electrode material formed by an amorphous carbon shell layer wraps at the outer most layer of surface of the graphite or carbon-containing conductor or nano silicon. The preparation method comprises the following steps of preparing nano silicon; preparing graphite or carbon-containing conductor precursor or nano silicon paste; spray drying, and cracking at high temperature so as to obtain graphite or carbon-containing conductor or nano silicon composite power; performing carbon source organic precursor liquid phase wrapping so as to prepare a silicon composite negative electrode material precursor; and carbonizing, breaking and screening the silicon composite negative electrode material precursor so as to obtain the negative electrode material. The negative electrode material has uniform particle size, and has good structure stability and electrochemical stability and high electrochemical activity.

Description

technical field [0001] The invention relates to a silicon-based composite negative electrode material for a lithium ion battery, a preparation method thereof and a lithium ion battery negative electrode containing the material. Background technique [0002] Lithium-ion batteries have been widely used in portable electronic devices, large-scale energy storage power stations and electric vehicles because of their advantages such as high working voltage, long cycle life, no memory effect, small self-discharge effect, and environmental friendliness. At present, graphite-based anode materials are mainly used as anode materials for commercialized lithium-ion batteries, but their theoretical specific capacity is only 372mAh / g, which cannot meet the requirements for the development of lithium-ion batteries with higher specific energy and high power density in the future. Therefore, finding high-capacity anode materials to replace carbon has become an important development direction....

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/36H01M4/38H01M4/587H01M4/62H01M10/0525
CPCH01M4/366H01M4/386H01M4/587H01M4/621H01M4/624H01M4/625H01M10/0525Y02E60/10
Inventor 李进卢世刚王建涛杨娟玉
Owner GENERAL RESEARCH INSTITUTE FOR NONFERROUS METALS BEIJNG