Process for the preparation of siox having a nanoscale filament structure and use thereof as anode material in lithium-ion batteries

Abstract

A process for the preparation of nanofilament particles of SiOx in which x is between 0.8 and 1.2, the process including: a step of a fusion reaction between silica (SiO2) and silicon (Si), at a temperature of at least about 1410° C., to produce gaseous silicon monoxide (SiO); and a step of condensation of the gaseous SiO to produce the SiOx nanofilament particles. The process may also include using carbon.

1 - 34 . (canceled) 
     
     
         35 . A process for the preparation of nanofilament particles of SiO x  in which x is between 0.8 and 1.2, the process comprising:
 a step comprising a fusion reaction between silica (SiO 2 ) and liquid silicon (Si), at a temperature of at least about 1410° C., to produce gaseous silicon monoxide (SiO); and   a step comprising condensation of the gaseous SiO to produce the SiO x  nanofilament particles, wherein the condensation step is performed in a low temperature area of a furnace, the gaseous SiO being moved to the low temperature area by a vector gas.   
     
     
         36 . The process according to  claim 35 , wherein the SiO 2  is in solid form. 
     
     
         37 . The process according to  claim 35 , wherein the fusion step is performed in an induction furnace, an electric arc furnace or a submerged arc furnace. 
     
     
         38 . The process according to  claim 35 , wherein the vector gas is selected from the group consisting of inert gas, oxidant gas, reduction gas, volatile hydrocarbon and combinations thereof. 
     
     
         39 . The process according to  claim 35 , wherein the fusion step is performed under vacuum. 
     
     
         40 . The process according to  claim 35 , wherein the fusion step is performed under inert atmosphere which is of Ar, He or N 2 . 
     
     
         41 . The process according to  claim 35 , wherein the temperature at the fusion step is between about 1450 and about 1700° C. 
     
     
         42 . The process according to  claim 35 , wherein the furnace is an induction furnace, and the agitation stems from a magnetic field produced by the furnace. 
     
     
         43 . The process according to  claim 35 , wherein x is about 1. 
     
     
         44 . The process according to  claim 35 , wherein the SiO 2  is in a form which is quartz, quartzite or a combination thereof. 
     
     
         45 . The process according to  claim 35 , wherein the SiO x  particles are in spherical agglomerates consisting of nanofilaments, each agglomerate having a diameter of about 2 to 10 μm. 
     
     
         46 . The process according to  claim 45 , wherein the nanofilaments each have a diameter of about 50 nm, and the spherical agglomerates are linked together by spheres each having a diameter of about 100 to 150 nm. 
     
     
         47 . The process according to  claim 35 , wherein the nanofilament SiO x  particles obtained comprise at least one of: amorphous SiO 2 , crystalline Si and SiC. 
     
     
         48 . Nanofilament particles of SiO x  obtained by the process as defined in  claim 35 . 
     
     
         49 . A method comprising fabricating an anode with nanofilament particles of SiO x  obtained by the process as defined in  claim 35 . 
     
     
         50 . A material comprising nanofilament particles of SiO x  in which x is between 0.8 and 1.2 obtained by a process comprising:
 a step comprising a fusion reaction between silica (SiO 2 ), liquid silicon (Si), and, at a temperature of at least about 1410° C., to produce gaseous silicon monoxide (SiO); and   a step comprising condensation of the gaseous SiO to produce the SiO x  nanofilament particles, wherein the condensation step is performed in a low temperature area of a furnace, the gaseous SiO being moved to the low temperature area by a vector gas.   
     
     
         51 . An anode comprising the material as defined in  claim 50 . 
     
     
         52 . A battery comprising the anode as defined in  claim 51 .