Abstract: A silicon-silicon oxide-lithium composite comprises a silicon-silicon oxide composite having such a structure that silicon grains having a size of 0.5-50 nm are dispersed in silicon oxide, the silicon-silicon oxide composite being doped with lithium. Using the silicon-silicon oxide-lithium composite as a negative electrode material, a lithium ion secondary cell having a high initial efficiency and improved cycle performance can be constructed.

Abstract: A conductive silicon composite in which particles of the structure that silicon crystallites are dispersed in silicon dioxide are coated on their surfaces with carbon affords satisfactory cycle performance when used as the negative electrode material in a non-aqueous electrolyte secondary cell.

Abstract: A metallic silicon powder is prepared by effecting chemical reduction on silica stone, metallurgical refinement, and metallurgical and/or chemical purification to reduce the content of impurities. The powder is best suited as a negative electrode material for non-aqueous electrolyte secondary cells, affording better cycle performance.

Abstract: A Si—C—O composite powder is obtained by curing a reactive silane or siloxane having crosslinkable groups through heat curing or catalytic reaction into a crosslinked product and sintering the crosslinked product in an inert gas stream at a temperature of 700-1,400° C. into an inorganic state. It exhibits satisfactory cycle performance when used as the negative electrode material for non-aqueous electrolyte secondary cells.

Abstract: A silicon composite comprises silicon particles whose surface is at least partially coated with a silicon carbide layer. It is prepared by subjecting a silicon powder to thermal CVD with an organic hydrocarbon gas and/or vapor at 900-1,400° C., and heating the powder for removing an excess free carbon layer from the surface through oxidative decomposition.

Abstract: Silicon composite particles are prepared by sintering primary fine particles of silicon, silicon alloy or silicon oxide together with an organosilicon compound. Sintering of the organosilicon compound results in a silicon-base inorganic compound which serves as a binder. Each particle has the structure that silicon or silicon alloy fine particles are dispersed in the silicon-base inorganic compound binder, and voids are present within the particle.

Abstract: A lithium ion secondary cell having a high capacity, improved first charge/discharge efficiency and improved cycle performance is obtainable using as the negative electrode material a lithium-containing silicon oxide powder having the formula: SiLixOy wherein x and y are 0<x<1.0 and 0<y<1.5, with the lithium being fused and partially crystallized.

Abstract: A metallic silicon-containing composite in which metallic silicon nuclei are coated with an inert material which does not contribute to adsorption and desorption of lithium ions is a useful negative electrode material for lithium ion secondary batteries. Using the composite as a negative electrode active material, a lithium ion secondary battery having a high capacity and excellent cycle performance can be fabricated.

Abstract: A silicon oxide powder can be continuously prepared by feeding a raw material powder mixture containing silicon dioxide powder into a reaction chamber (2) at a temperature of 1,100-1,600° C., to produce a silicon oxide gas, transferring the silicon oxide gas to a deposition chamber (11) through a transfer conduit (10) maintained at a temperature of from higher than 1,000° C. to 1,300° C., causing silicon oxide to deposit on a substrate (13) which is disposed and cooled in the deposition chamber, scraping the silicon oxide deposit, and recovering the deposit in a recovery chamber (18). The method and apparatus is capable of continuous and stable production of amorphous silicon oxide powder of high purity.

Abstract: A C/Si/O composite material having improved oxidation resistance is prepared by impregnating graphite with a crosslinkable silane or siloxane, causing the silane or siloxane to crosslink within the graphite, and heating at 300-1,200° C. in a non-oxidizing gas. The C/Si/O composite material can be efficiently prepared through simple steps, on an industrial scale and at a low cost and will find use as a high-temperature structural material by virtue of oxidation resistance.

Abstract: A silicon oxide powder can be continuously prepared by feeding a raw material powder mixture containing silicon dioxide powder into a reaction chamber (2) at a temperature of 1,100-1,600° C., to produce a silicon oxide gas, transferring the silicon oxide gas to a deposition chamber (11) through a transfer conduit (10) maintained at a temperature of from higher than 1,000° C. to 1,300° C., causing silicon oxide to deposit on a substrate (13) which is disposed and cooled in the deposition chamber, scraping the silicon oxide deposit, and recovering the deposit in a recovery chamber (18). The method and apparatus is capable of continuous and stable production of amorphous silicon oxide powder of high purity.

Abstract: A silicon oxide powder represented by the formula: SiOx wherein 1.05≦x≦1.5 and having a BET specific surface area of 5-300 m2/g is useful as a negative electrode material to construct a lithium ion secondary cell having a high capacity and improved cycle performance.

Abstract: A non-aqueous electrolyte secondary battery negative electrode material is provided wherein a negative electrode active material containing a lithium ion-occluding and releasing material which has been treated with an organosilicon base surface treating agent is surface coated with a conductive coating. Using the negative electrode material, a lithium ion secondary battery having a high capacity and improved cycle performance is obtainable.

Abstract: A fine &bgr;-silicon carbide powder is prepared by impregnating graphite with an organosilicon compound selected from crosslinkable silanes and siloxanes, causing the organosilicon compound to crosslink within the graphite, and heating at 1,300° C. or higher in an inert gas stream for reaction. Using only low-temperature heat treatment in air and high-temperature heat treatment in inert gas, the invention enables industrial, economical manufacture of fine silicon carbide powder in a stable manner.

Abstract: Silicon oxide containing active silicon represented by the general formula: SiOx wherein x is from 0.8 to 1.9, when analyzed by solid state NMR (29Si DD/MAS) with a sufficient relaxation time set, exhibits a spectrum having two separate peaks, a broad peak (A1) centered at −70 ppm and a broad peak (A2) centered at −110 ppm, the area ratio A1/A2 being in the range of 0.1≦A1/A2≦1.0.

Abstract: A conductive silicon composite in which particles of the structure that silicon crystallites are dispersed in silicon dioxide are coated on their surfaces with carbon affords satisfactory cycle performance when used as the negative electrode material in a non-aqueous electrolyte secondary cell.

Abstract: A conductive silicon oxide powder in which particles of silicon oxide having the formula: SiOx wherein 1≦x<1.6 are covered on their surfaces with a conductive carbon coating by chemical vapor deposition treatment is useful as a negative electrode active material to construct a lithium ion secondary cell having a high capacity and improved cycle performance.

Abstract: A C/Si/O composite material having improved oxidation resistance is prepared by impregnating graphite with a crosslinkable silane or siloxane, causing the silane or siloxane to crosslink within the graphite, and heating at 300-1,200° C. in a non-oxidizing gas. The C/Si/O composite material can be efficiently prepared through simple steps, on an industrial scale and at a low cost and will find use as a high-temperature structural material by virtue of oxidation resistance.

Abstract: A fine &bgr;-silicon carbide powder is prepared by impregnating graphite with an organosilicon compound selected from crosslinkable silanes and siloxanes, causing the organosilicon compound to crosslink within the graphite, and heating at 1,300° C. or higher in an inert gas stream for reaction. Using only low-temperature heat treatment in air and high-temperature heat treatment in inert gas, the invention enables industrial, economical manufacture of fine silicon carbide powder in a stable manner.

Abstract: A lithium ion secondary cell having a high capacity, improved first charge/discharge efficiency and improved cycle performance is obtainable using as the negative electrode material a lithium-containing silicon oxide powder having the formula: SiLixOy wherein x and y are 0<x<1.0 and 0<y<1.5, with the lithium being fused and partially crystallized.