Disclosed are a silicon-carbon composite material for a secondary lithium battery and a preparation method therefor. The silicon-carbon composite material for a secondary lithium battery comprises a core containing a silicon-based material, a first coating layer, and a second coating layer. The first coating layer is an electrically conductive layer, the second coating layer is an ion-conducting layer, and the first coating layer and the second coating layer are not limited to a certain order. In the silicon-carbon composite material provided by the present disclosure, the coating layer is a composite material, which combines the electroconductive (or ion-conducting) capability of a matrix material, and the reinforcing and toughening properties of a reinforcing phase, such that the material has a strong anti-expansion capability. In the secondary battery, the coating layer is less prone to breaking, which results in less fresh surface and so reduces the consumption of an electrolyte and improves the cycle performance of the battery. Additionally, the preparation method of the present disclosure is simple and easy to implement, and is suitable for large-scale industrial production.

A Si-containing film forming composition comprising a catalyst and/or a polysilane and a N—H free, C-free, and Si-rich perhydropolysilazane having a molecular weight ranging from approximately 332 dalton to approximately 100,000 dalton and comprising N—H free repeating units having the formula [—N(SiH3)x(SiH2-)y], wherein x=0, 1, or 2 and y=0, 1, or 2 with x+y=2; and x=0, 1 or 2 and y=1, 2, or 3 with x+y=3. Also disclosed are synthesis methods and applications for using the same.

The present invention relates to a method for preparing a spherical silica powder filler, comprising the following steps: performing hydrolytic condensation on an organic silicon compound to obtain polysiloxane precipitate, wherein the organic silicon compound comprises silane having the chemical formula of (R.sub.1).sub.a(R.sub.2).sub.b(R.sub.3).sub.cSi(X).sub.d, wherein R.sub.1, R.sub.2, and R.sub.3 are independently selected C1-18 hydrocarbyl groups or hydrogen atoms; X is a hydrolysable functional group; a, b, and c are 0, 1, 2, or 3; d is 1, 2, 3, or 4; and a+b+c+d=4; smashing and drying the polysiloxane precipitate to obtain siloxane angular powder; and melting and spherifying the siloxane angular powder into the spherical silica powder filler. The present invention also provides a spherical silica powder filler obtained by the method and an application thereof. The present invention takes the organic silicon compound as the starting material, and the resulting spherical silica powder filler does not contain radioactive elements such as uranium and thorium, and therefore, the requirement of low radioactivity is satisfied.

Provided are a composition for depositing a silicon-containing thin film containing a bis(aminosilyl)alkylamine compound and a method for manufacturing a silicon-containing thin film using the same, and more particularly, a composition for depositing a silicon-containing thin film, containing the bis(aminosilyl)alkylamine compound capable of being usefully used as a precursor of the silicon-containing thin film, and a method for manufacturing a silicon-containing thin film using the same.

Provided are a composition for depositing a silicon-containing thin film containing a bis(aminosilyl)alkylamine compound and a method for manufacturing a silicon-containing thin film using the same, and more particularly, a composition for depositing a silicon-containing thin film, containing the bis(aminosilyl)alkylamine compound capable of being usefully used as a precursor of the silicon-containing thin film, and a method for manufacturing a silicon-containing thin film using the same.

Instabilities in the pyrogenic production of fumed silica caused by use of silanes having low ignition temperatures are caused by mixing the silanes, at a temperature above their dew point(s) with fuel gas in the absence of the use of a dynamic or static mixer, and then combining the resultant mixed stream with an oxygen containing gas and igniting. Self-ignition of the silanes and also the deposition of flammable or pyrophoric substances are avoided.

Provided are a composition for depositing a silicon-containing thin film containing a bis(aminosilyl)alkylamine compound and a method for manufacturing a silicon-containing thin film using the same, and more particularly, a composition for depositing a silicon-containing thin film, containing the bis(aminosilyl)alkylamine compound capable of being usefully used as a precursor of the silicon-containing thin film, and a method for manufacturing a silicon-containing thin film using the same.

A process for the production of nanoparticles from a liquid mixture comprising at least one precursor and at least one solvent in a reactor with continuous through-flow comprises the steps of feeding at least one oxygen-containing gas inflow stream having a temperature into the at least one reactor, adding at least one fuel having a temperature to the oxygen-containing gas inflow stream, wherein the fuel and the oxygen-containing gas inflow stream form a homogeneous ignitable mixture having a temperature, wherein the temperature of the homogeneous ignitable mixture is above the autoignition temperature of the homogeneous ignitable mixture, introducing at least one precursor-solvent mixture into the homogeneous ignitable mixture; autoignition of the ignitable mixture of oxygen-containing gas and fuel after an ignition delay time to form a stabilized flame and reacting the precursor-solvent mixture in the stabilized flame to form nanoparticles from the metal salt precursor, removing the formed nanoparticles.

A technique for obtaining anhydrous hydrogen fluoride (AHF) from an aqueous solution of hexafluorosilicic acid (HSA). A method for obtaining hydrogen fluoride from an aqueous solution of hexafluorosilicic acid can include mixing a solution of hexafluorosilicic acid with a sulfuric acid solution, desorbing the hydrogen fluoride from the resultant solution of sulfuric acid, treating it with sulfuric acid and condensing the anhydrous hydrogen fluoride from unabsorbed gasses. The generated gaseous products are then burned in a fire of hydrogen-containing fuel and an oxygen-containing oxidant, yielding a solid silicon dioxide. The remaining products are cooled and yield condensed anhydrous hydrogen fluoride.

instabilities in the pyrogenic production of fumed silica caused by use of Mimes having low ignition temperatures are caused by mixing the silanes, at a temperature above their dew point(s) with fuel gas in the absence of the use of a dynamic or static mixer, and then combining the resultant mixed stream with an oxygen containing gas and igniting. Self-ignition of the silanes and also the deposition of flammable or pyrophoric substances are avoided.