The present invention relates to a lithium compound, a nickel-based cathode active material, a method for preparing lithium oxide, a method for preparing a nickel-based cathode active material, and a secondary battery using same. The lithium compound includes primary particles of Li.sub.2O having an average particle diameter (D50) of less than or equal to 5 μm; and secondary particles composed of the primary particles.

A negative electrode active material containing negative electrode active material particles. The negative electrode active material particles include silicon compound particles each containing an oxygen-containing silicon compound. The silicon compound particle contains at least one of Li.sub.2SiO.sub.3 and Li.sub.2Si.sub.2O.sub.5. The silicon compound particle has, in a Si K-edge spectrum obtained from a XANES spectrum: a peak P derived from the Li silicate and located near 1847 eV; and a peak Q gentler than the peak P and located near 1851 to 1852 eV. This provides a negative electrode active material that is capable of stabilizing a slurry when the negative electrode active material is used for a secondary battery, and capable of increasing the battery capacity by improving the initial efficiency.

Silicon-carbon composite materials and related processes are disclosed that overcome the challenges for providing amorphous nano-sized silicon entrained within porous carbon. Compared to other, inferior materials and processes described in the prior art, the materials and processes disclosed herein find superior utility in various applications, including energy storage devices such as lithium ion batteries.

The present invention relates to a method of preparing ultra-pure silicon carbide in which a super-porous spherical silica aerogel is used as a silica raw material. By preparing the silica aerogel particles using low-cost water glass, a reaction area with respect to a carbon raw material is increased to enable low-temperature synthesis of silicon carbide, the size and shape of silicon carbide powder may be uniformly controlled to prepare ultra-pure silicon carbide, and economic efficiency and productivity of the silicon carbide synthesis may be improved. Thus, it is expected that the silicon carbide powder prepared by the preparation method of the present invention may be provided as an optimized raw material for the preparation of silicon carbide sintered body and single crystal (ingot).

A porous carbon material wherein a particle diameter is 10 μm or more but 1 cm or less; wherein a bulk specific gravity is 0.20 g/cm.sup.3 or more; and wherein a mesopore volume is 0.10 cm.sup.3/g or more.

A dielectric substance includes a core-shell grain having a twin crystal structure. An interface of the twin crystal structure of the core-shell grain extends from a shell on one side, passes through a core, and extends to the shell on the other side.

According to one embodiment, a tungsten oxide powder is provided. The tungsten oxide has an average particle size along a major axis of 10 μm or less, an average aspect ratio of 10 or less, and 0 to 4 crystal defects per unit area of 9 nm.sup.2 on a surface or sectional surface in a direction of a minor axis of a primary particle.

A negative electrode active material including natural graphite, wherein a D.sub.90/D.sub.10, which is the ratio of D.sub.90 to D.sub.10, is 2.20 or less, a D.sub.50 is 6 μm to 11 μm, and a BET specific surface area is 2.2 m.sup.2/g or less.

A process is described for manufacturing white pigment containing products. The white pigment containing products are obtained from at least one white pigment and impurities containing material via froth flotation.

Zinc oxide particles are prepared as a dry powder through a vapor phase formed by a plasma process, or by introducing defects into stoichiometric zinc oxide particles in a liquid carrier through mechanical stress. The zinc oxide has an O:Zn ratio of at least 0.99, an average particle size of 10 to 300 nm, and a sufficient concentration of oxygen vacancies and zinc vacancies to give a dispersion of the particles in C12-C15 alkyl benzoate an orange to tan color corresponding to a ΔE value of at least 15 in a Dispersion Color Test. The particles contain no aggregates and have no detectable particles 500 nm or larger, on a number-weighted basis