The present invention provides a silicon-silicon composite oxide-carbon composite, a method for preparing same, and a negative electrode active material for a lithium secondary battery, comprising same. More particularly, the silicon-silicon composite oxide-carbon composite of the present invention has a core-shell structure wherein the core comprises silicon, a silicon oxide compound, and magnesium silicate, and the shell comprises a carbon layer. In addition, by having a specific range of span values through the adjustment of particle size distribution of the composite, when used as a negative electrode active material of a secondary battery, the composite can improve not only the capacity of the secondary battery but also the cycle characteristics and initial efficiency thereof.

Silicon particles with a reduced and/or delayed propensity to generate hydrogen gas by reaction with water in aqueous inks for preparing lithium ion battery anodes are prepared by milling silicon, preferably in an oxidative atmosphere, followed by heat treating at an elevated temperature in vacuum or an inert atmosphere.

Silicon particles with a reduced and/or delayed propensity to generate hydrogen gas by reaction with water in aqueous inks for preparing lithium ion battery anodes are prepared by milling silicon, preferably in an oxidative atmosphere, followed by heat treating at an elevated temperature in vacuum or an inert atmosphere.

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.

Provided are semiconductor particles including a Group 12-16 semiconductor including a Group 12 element and a Group 16 element, a Group 13-15 semiconductor including a Group 13 element and a Group 15 element, or a Group 14 semiconductor including a Group 14 element, the semiconductor particles having a plasma frequency of 1.7×10.sup.14 rad/s to 4.7×10.sup.14 rad/s and a maximum length of 1 nm to 2,000 nm; and a dispersion, a film, an optical filter, a building member, or a radiant cooling device, in all of which the semiconductor particles are used.

Provided are semiconductor particles including a Group 12-16 semiconductor including a Group 12 element and a Group 16 element, a Group 13-15 semiconductor including a Group 13 element and a Group 15 element, or a Group 14 semiconductor including a Group 14 element, the semiconductor particles having a plasma frequency of 1.7×10.sup.14 rad/s to 4.7×10.sup.14 rad/s and a maximum length of 1 nm to 2,000 nm; and a dispersion, a film, an optical filter, a building member, or a radiant cooling device, in all of which the semiconductor particles are used.

A preparation method of a composite anode material of micrometer-sized carbon-coated silicon and carbon includes: subjecting micrometer-sized silicon particles to a chemical vapor deposition reaction under a gas atmosphere containing carbon to obtain carbon-coated first micrometer-sized silicon particles; dispersing the carbon-coated first micrometer-sized silicon particles in a first mixed solvent to obtain a dispersed solution; adding alkali into the dispersed solution and heating the dispersed solution to obtain carbon-coated second micrometer-sized silicon particles; dispersing the carbon-coated second micrometer-sized silicon particles and graphene oxide in a second mixed solvent that are subjected to a hydrothermal reaction to obtain a composite hydrogel of reduced graphene oxide, silicon, and carbon; and heating the hydrogel to obtain the composite anode material.

A production method is provided in which submicronic particles containing silicon are incorporated into a matrix, wherein, during the incorporation of the particles, the particles are in a compacted state with a bulk density of more than 0.10 grams per cubic centimeter, and the compacted particles have a specific surface area at least 70% of that of the particles considered separately without contact between each other.

A production method is provided in which submicronic particles containing silicon are incorporated into a matrix, wherein, during the incorporation of the particles, the particles are in a compacted state with a bulk density of more than 0.10 grams per cubic centimeter, and the compacted particles have a specific surface area at least 70% of that of the particles considered separately without contact between each other.