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.

1 . An apparatus for producing SiOx nanoparticles comprising:
 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.   
     
     
         2 . The apparatus of  claim 1 , wherein the graphite crucible has a cylindrical structure open at an upper side thereof and is provided with a plurality of slits formed by cutting part of a wall of the graphite crucible. 
     
     
         3 . The apparatus of  claim 1 , wherein the induction melting part comprises a refractory crucible enclosing the graphite crucible and an induction coil wound around an outer periphery of the graphite crucible. 
     
     
         4 . The apparatus of  claim 3 , wherein the induction coil is embedded in a wall of the refractory crucible. 
     
     
         5 . The apparatus of  claim 3 , wherein AC current having a frequency of 10 kHz or less is applied to the induction coil. 
     
     
         6 . The apparatus of  claim 1 , wherein the gas injector comprises a gas supply tube to which gas is supplied from outside, and an injection nozzle coupled to one end of the gas supply tube and disposed inside the graphite crucible. 
     
     
         7 . The apparatus of  claim 1 , wherein the injection gas is selected from Ar, H 2 , O 2 , H 2 O, and a mixture thereof. 
     
     
         8 . The apparatus of  claim 1 , wherein the collector further comprises a coating gas injection nozzle to perform carbon coating of the SiOx particles. 
     
     
         9 . A method of producing SiOx nanoparticles, comprising:
 charging raw silicon into a graphite crucible;   performing induction heating of the raw silicon in the graphite crucible to form molten silicon;   injecting a gas into the graphite crucible such that the gas is brought into direct contact with a surface of the molten silicon; and   collecting SiOx particles by cooling and condensing SiOx vapor produced by reaction between the molten silicon and the injected gas.   
     
     
         10 . The method of  claim 9 , wherein the injection gas is selected from Ar, H 2 , O 2 , H 2 O, and a mixture thereof. 
     
     
         11 . The method of  claim 9 , wherein the induction heating is performed by applying AC current having a frequency of 10 kHz or less to the induction coil. 
     
     
         12 . The method of  claim 9 , wherein the collecting of the SiOx particles comprises ejecting a coating gas onto the SiOx particles. 
     
     
         13 . The method of  claim 12 , wherein the coating gas is selected from CH 4 , C 2 H 6 , C 3 H 8 , C 4 H 10 , C 5 H 12 , C 6 H 14 , and a mixture thereof. 
     
     
         14 . SiOx nanoparticles for an anode material of a lithium ion battery produced by the method according to  claim 9 . 
     
     
         15 . The SiOx nanoparticles of  claim 14 , wherein the nanoparticles have a particle size of 10˜50 nm.