Contamination of fluidized bed-produced polycrystalline granules by phosphorus is reduced by employing as seals and/or packings, graphite containing <500 ppmw of phosphorus.

The invention provides a nano-silicon agglomerate composite negative electrode material of pine needle and branch-shaped three-dimensional network structure and a method for preparing the same. The nano-silicon agglomerate composite negative electrode material comprises nano-sized core particles, a nano-silicon agglomerate of pine needle and branch-shaped three-dimensional network structure growing around the nano-sized core particles, and a composite coating layer over the nano-silicon agglomerate of needles and branch-shaped three-dimensional network structure. With measurements, it is shown that the nano-silicon agglomerate composite negative electrode material, when being applied in lithium ion battery, has excellent battery charge-discharge cycle performances and rate capability, and it has an initial discharge capacity per gram of more than 2600 mAh/g, and an initial coulombic efficiency of no less than 85%.

The invention provides a nano-silicon agglomerate composite negative electrode material of pine needle and branch-shaped three-dimensional network structure and a method for preparing the same. The nano-silicon agglomerate composite negative electrode material comprises nano-sized core particles, a nano-silicon agglomerate of pine needle and branch-shaped three-dimensional network structure growing around the nano-sized core particles, and a composite coating layer over the nano-silicon agglomerate of needles and branch-shaped three-dimensional network structure. With measurements, it is shown that the nano-silicon agglomerate composite negative electrode material, when being applied in lithium ion battery, has excellent battery charge-discharge cycle performances and rate capability, and it has an initial discharge capacity per gram of more than 2600 mAh/g, and an initial coulombic efficiency of no less than 85%.

Example systems are described for producing solar grade silicon from a silicon-generating reaction and recycled silicon particles. In one example, a system for manufacturing high purity solid silicon includes a reactor and a cooling chamber. The reactor includes one or more outlets and a reactor chamber. The one or more outlets are configured to receive a silicon tetrahalide, a reducing agent, and recycled silicon particles. The reactor chamber is configured to react the silicon tetrahalide and the reducing agent to produce fresh silicon, a halide salt, and reaction heat. The reactor chamber heats the recycled silicon particles, the fresh silicon, and the halide salt using at least a portion of the reaction heat to form molten silicon and molten halide salt. The molten silicon includes melted fresh silicon and melted recycled silicon particles. The cooling chamber is configured to cool the molten silicon to form the solid silicon.

A method for preparing a reaction product including an aryl-functional silane includes sequential steps (1) and (2). Step (1) is contacting, under silicon deposition conditions, (A) an ingredient including (I) a halosilane such as silicon tetrahalide and optionally (II) hydrogen (H.sub.2); and (B) a metal combination comprising copper (Cu) and at least one other metal, where the at least one other metal is selected from the group consisting of gold (Au), cobalt (Co), chromium (Cr), iron (Fe), magnesium (Mg), manganese (Mn), nickel (Ni), palladium (Pd), and silver (Ag); thereby forming a silicon alloy catalyst comprising Si, Cu and the at least one other metal. Step (2) is contacting the silicon alloy catalyst and (C) a reactant including an aryl halide under silicon etching conditions.

An apparatus and a process for the production of high purity silicon from silica containing material such as quartz or quartzite, using a vacuum electric arc furnace, are disclosed.

An apparatus and a process for the production of high purity silicon from silica containing material such as quartz or quartzite, using a vacuum electric arc furnace, are disclosed.

The method for producing silicon metal and porous carbon from rice hulls is provided. The method comprises a first step S1 of producing a rice hull charcoal M2 containing SiO.sub.2 and C by heat treatment of rice hulls M1; a second step S4 of exposing the rice hull charcoal M4 to at least any one of heated first inert gas G2 or reducing gas to produce SiC; a third step S5 of exposing SiC to a heating atmosphere containing Cl.sub.2 gas to produce SiCl.sub.4 and porous carbon P1; a fourth step S7 of reacting SiCl.sub.4 and Zn to produce silicon metal P2 and ZnCl.sub.2; and a fifth step S9 of electrolyzing ZnCl.sub.2 to produce Zn and Cl.sub.2 gas. The Cl.sub.2 gas in the fifth step S9 is used in the third step S5, and Zn in the fifth step S9 is used in the fourth step S7.

The method for producing silicon metal and porous carbon from rice hulls is provided. The method comprises a first step S1 of producing a rice hull charcoal M2 containing SiO.sub.2 and C by heat treatment of rice hulls M1; a second step S4 of exposing the rice hull charcoal M4 to at least any one of heated first inert gas G2 or reducing gas to produce SiC; a third step S5 of exposing SiC to a heating atmosphere containing Cl.sub.2 gas to produce SiCl.sub.4 and porous carbon P1; a fourth step S7 of reacting SiCl.sub.4 and Zn to produce silicon metal P2 and ZnCl.sub.2; and a fifth step S9 of electrolyzing ZnCl.sub.2 to produce Zn and Cl.sub.2 gas. The Cl.sub.2 gas in the fifth step S9 is used in the third step S5, and Zn in the fifth step S9 is used in the fourth step S7.

We provide a mesoporous silicon material (PSi) prepared via a template-free and HF-free process. The production process is facile and scalable, and it may be conducted under mild reaction conditions. The silicon may be produced directly by the reduction of a silicon-halogenide precursor (for example, SiCl.sub.4) with an alkaline alloy (for example, NaK alloy). The resulting Si-salt matrix is then annealed for the pore formation and crystallite growth. Final product is obtained by removal of the salt by-products with water.