METHOD OF PRODUCING HIGH PURITY SiOx NANOPARTICLES WITH EXCELLENT VOLATILITY AND APPARATUS FOR PRODUCING THE SAME

Abstract

The present disclosure provides a method of producing high purity SiOx nanoparticles with excellent volatility and an apparatus for producing the same, which enables mass production of SiOx nanoparticles by melting silicon through induction heating and injecting gas to a surface of the molten silicon. The apparatus includes a vacuum chamber, a graphite crucible into which raw silicon is charged, the graphite crucible being mounted inside the vacuum chamber, an induction melting part which forms molten silicon by induction heating of the silicon material received in the graphite crucible, a gas injector which injects a gas into the graphite crucible to be brought into direct contact with a surface of the molten silicon, and a collector disposed above the graphite crucible and collecting SiOx vapor produced by reaction between the molten silicon and the injected gas.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application claims the benefit under 35 U.S.A. §119 of Korean Patent Application No. 10-2011-0030414, filed on Apr. 1, 2011 in the Korean Intellectual Property Office, the entirety of which is incorporated herein by reference.BACKGROUND[0002]1. Technical Field[0003]The present invention relates to a technique for producing high purity SiOx nanoparticles and, more particularly, to a method of producing high purity SiOx nanoparticles with excellent volatility and an apparatus for producing the same, which enables mass production of SiOx nanoparticles by melting a silicon raw material through induction heating and injecting gas to a surface of the molten silicon.[0004]2. Description of the Related Art[0005]Generally, a carbon electrode is used as an anode for lithium ion batteries. Carbon electrodes are advantageous in terms of high charge and discharge efficiency. However, the carbon electrode has limitation in application to an anode f...

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Benefits of technology

[0008]One aspect of the present invention is to provide an apparatus for producing SiOx nanoparticles, which melts raw silicon by electromagnetic induction heating using an induction coil and injects various gases onto a surface of molten silicon, thereby enabling mass production of SiOx nanoparticles.

[0012]According to embodiments of the invention, the apparatus may produce high purity SiOx nanoparticles having a particle size of about 50 nm or less at low cost in a short time through application of both electromagnetic induction melting and rapid cooling.

[0013]In addition, since the SiOx nanoparticles produced by the method according to embodiments of the invention have a high battery capacity of about 1500 mAh / g and may have a particle size of about 50 nm or less, it is expected that the SiOx nanoparticles will increase charge and discharge efficiency to three times or more that of carbon electrodes.

[0014]Further, when the SiOx nanoparticles produced by the method according to the embodiments are applied to an anode material for lithium ion batteries, the anode does not suffer from volume expansion and is thus prevented from cracking or short circuit.

[0015]Further, when the SiOx nanoparticles produced by the method according to the embodiments are subjected to carbon coating simultaneously with manufacture of SiOx particles, application of the carbon coated SiOx-C particles to an anode material for lithium ion batteries may improve charge and discharge efficiency of the lithium ion batteries based on improvement in electrical conductivity by carbon coating.

Problems solved by technology

However, the carbon electrode has limitation in application to an anode for next generation lithium ion batteries on account of a low theoretical capacity of 375 mAh / g.

Such high volume expansion induces cracking or short circuit of the anode of the lithium ion battery made of silicon.

On the other hand, although silicon Si is known as undergoing reduction in stress caused by volume expansion when the particle size of silicon varies from a micrometer scale (μm) to a nanoscale (nm), nanoscale silicon particles also provide a problem of cracking or short circuit of the anode due to volume expansion.

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