A reactor for nanoparticle production comprising a main chamber including a first nozzle to which raw material gas is supplied, a lens housing connected to the main chamber in a fluidly movable manner and including a second nozzle for supplying flushing gas to the lens housing, a lens mounted on the lens housing, a light source for irradiating a laser, which passes through the lens to reach the raw material gas in the main chamber, and a hood for discharging nanoparticles generated in the main chamber. A cross-sectional area of at least a part of the lens housing decreases along a direction facing the main chamber.

A reactor for nanoparticle production comprising a main chamber including a first nozzle to which raw material gas is supplied, a lens housing connected to the main chamber in a fluidly movable manner and including a second nozzle for supplying flushing gas to the lens housing, a lens mounted on the lens housing, a light source for irradiating a laser, which passes through the lens to reach the raw material gas in the main chamber, and a hood for discharging nanoparticles generated in the main chamber. A cross-sectional area of at least a part of the lens housing decreases along a direction facing the main chamber.

A submicron sized Si based powder having an average primary particle size between 20 nm and 200 nm, wherein the powder has a surface layer comprising SiO.sub.x, with 0<x<2, the surface layer having an average thickness between 0.5 nm and 10 nm, and wherein the powder has a total oxygen content equal or less than 3% by weight at room temperature. The method for making the powder comprises a step where a Si precursor is vaporized in a gas stream at high temperature, after which the gas stream is quenched to obtain Si particles, and the Si particles are quenched at low temperature in an oxygen containing gas.

A submicron sized Si based powder having an average primary particle size between 20 nm and 200 nm, wherein the powder has a surface layer comprising SiO.sub.x, with 0<x<2, the surface layer having an average thickness between 0.5 nm and 10 nm, and wherein the powder has a total oxygen content equal or less than 3% by weight at room temperature. The method for making the powder comprises a step where a Si precursor is vaporized in a gas stream at high temperature, after which the gas stream is quenched to obtain Si particles, and the Si particles are quenched at low temperature in an oxygen containing gas.

The present invention provides a nanoparticle synthesis device capable of improving productivity of nanoparticles by increasing the size of a reaction region of laser pyrolysis of a source gas.

The present invention provides a nanoparticle synthesis device capable of improving productivity of nanoparticles by increasing the size of a reaction region of laser pyrolysis of a source gas.

An object of the present invention is to provide carbon-coated Si—C composite particles capable of maintaining a high Si utilization rate and suppressing deterioration of initial coulombic efficiency due to oxidation over time of a lithium-ion secondary battery.

The carbon-coated Si—C composite particles of the present invention includes Si—C composite particles containing a carbon material and silicon; and a carbonaceous layer present on surfaces of the Si—C composite particles, wherein the carbon coverage thereof is 70% or more, wherein the BET specific surface area is 200 m.sup.2/g or less; wherein R value (I.sub.D/I.sub.G) is 0.30 or more and 1.10 or less and I.sub.Si/I.sub.G is 0.15 or less, when the peak attributed to Si is present at 450 to 495 cm.sup.−1 and the intensity of the peak is defined as I.sub.Si, in Raman spectrum of the carbon-coated Si—C composite particles: and wherein the full width at half maximum of the peak of a 111 plane of Si is 3.00 deg. or more, and (peak intensity of a 111 plane of SiC)/(peak intensity of the 111 plane of Si) is 0.01 or less, in the XRD pattern measured by powder XRD using a Cu-Kα ray of the carbon-coated Si—C composite particles.

An object of the present invention is to provide carbon-coated Si—C composite particles capable of maintaining a high Si utilization rate and suppressing deterioration of initial coulombic efficiency due to oxidation over time of a lithium-ion secondary battery.

The carbon-coated Si—C composite particles of the present invention includes Si—C composite particles containing a carbon material and silicon; and a carbonaceous layer present on surfaces of the Si—C composite particles, wherein the carbon coverage thereof is 70% or more, wherein the BET specific surface area is 200 m.sup.2/g or less; wherein R value (I.sub.D/I.sub.G) is 0.30 or more and 1.10 or less and I.sub.Si/I.sub.G is 0.15 or less, when the peak attributed to Si is present at 450 to 495 cm.sup.−1 and the intensity of the peak is defined as I.sub.Si, in Raman spectrum of the carbon-coated Si—C composite particles: and wherein the full width at half maximum of the peak of a 111 plane of Si is 3.00 deg. or more, and (peak intensity of a 111 plane of SiC)/(peak intensity of the 111 plane of Si) is 0.01 or less, in the XRD pattern measured by powder XRD using a Cu-Kα ray of the carbon-coated Si—C composite particles.

An apparatus that forms liquid silicon includes a. a device by which a gas can be brought to a high-temperature state in which it is at least partially present as plasma, b. a reaction space and a feed conduit for the high-temperature gas opening into the reaction space, c. a nozzle having a nozzle channel that opens directly into the reaction space and through which a gaseous or particulate silicon-containing starting material can be fed into the reaction space, and d. a device adapted to introduce an inert gas into the reaction space such that it protects the exit opening of the nozzle channel against thermal stress resulting from the high-temperature gas.

Methods for producing nanostructures from copper-based catalysts on porous substrates, particularly silicon nanowires on carbon-based substrates for use as battery active materials, are provided. Related compositions are also described. In addition, novel methods for production of copper-based catalyst particles are provided. Methods for producing nanostructures from catalyst particles that comprise a gold shell and a core that does not include gold are also provided.