The cathode active material is capable of reducing cathode resistance of a secondary battery by enhancing electron conductivity thereof without reducing discharge capacity of the secondary battery. The method for manufacturing a cathode active material includes: mixing transition metal-containing composite compound particles containing lanthanum with a lithium compound to obtain a lithium mixture; calcinating the lithium mixture at a temperature equal to or lower than the melting point of the lithium compound; and then subjecting the lithium mixture to main firing at a firing temperature within a range of 725° C. to 1000° C. Lithium carbonate is preferably used as the lithium compound, and in this case, the calcination temperature is within a range of 600° C. to 723° C. It is preferable to obtain the transition metal-containing composite compound particles containing lanthanum by a coprecipitation method and to uniformly disperse a lanthanum element in the particles.

Provided are a barium titanate powder having spherical shape fine particles which have an average particle diameter (D.sub.50) in a range of about 140-270 nm, a tetragonal structure having a markedly improved tetragonality (c/a) in a range of 1.007-1.01 in contrast to the conventional composition, and at the same time, a markedly improved crystallinity in a range of 93-96%, thereby showing improved dielectric properties, and a manufacturing method thereof.

A paramagnetic garnet-type transparent ceramic is a sintered body of complex oxide represented by the following formula (1), comprising SiO.sub.2 as a sintering aid in an amount of more than 0% by weight to 0.1% by weight or less, and has a linear transmittance of 83.5% or more at the wavelength of 1,064 nm for an optical path length of 25 mm:
(Tb.sub.1-x-yY.sub.xSc.sub.y).sub.3(Al.sub.1-zSc.sub.z).sub.5O.sub.12  (1)
wherein 0.05≤x<0.45, 0<y<0.1, 0.5<1−x−y<0.95, and 0.004<z<0.2.

A hydrotalcite is represented by formula (1):
(M.sup.2+).sub.1-X(M.sup.3+).sub.X(OH).sub.2(A.sup.n−).sub.X/n.Math.mH.sub.2O  (1), wherein M.sup.2+ indicates a divalent metal, M.sup.3+ indicates a trivalent metal, A.sup.n− indicates an n-valent anion, n indicates an integer of 1 to 6, 0.17≤x≤0.36, and 0≤m≤10. The hydrotalcite has (A) a lattice strain in the <003> direction is 3×10.sup.−3 or less as measured using an X-ray diffraction method; (B) primary particles with an average width between 5 nm and 200 nm inclusive per a SEM method; and (C) a degree of monodispersity of 50% or greater (degree of monodispersity (%)=(average width of primary particles as measured using the SEM method/average width of secondary particles as measured using a dynamic light scattering method)×100). A resin containing the hydrotalcite, a suspension containing the hydrotalcite and a method for producing the hydrotalcite are disclosed.

The present invention provides an alumina particle containing molybdenum (Mo) and an inorganic coating part provided on the surface of the alumina particle.

A modified boron nitride nanotube (BNNT) comprising pendant hydroxyl (OH) and amino (NH.sub.2) functional groups covalently bonded to a surface of the BNNT. Aqueous and organic solutions of these modified BNNTs are disclosed, along with methods of producing the same. The modified BNNTs and their solutions can be used to coat substrates and to make nanocomposites.

The present invention features a new way of doping layered cathode materials in lithium ion batteries. Using a .sup.“high entropy” doping strategy, more than four impurity elements can be introduced to the host materials. The present invention applies this high entropy doping strategy to a high nickel content layered oxide material and a lithium-manganese rich material. This new high entropy doping strategy allows the layered oxide materials used in the positive electrode of lithium ion battery to achieve high energy density, long life cycle and reduced reliance on the expensive and toxic cobalt, all of which are desired attributes for improving the performance of lithium ion batteries and reducing their cost.

Disclosed herein are processes for purifying as-synthesized boron nitride nanotube (BNNT) material to remove impurities of boron, amorphous boron nitride (a-BN), hexagonal boron nitride (h-BN) nanocages, h-BN nanosheets, and carbon-containing compounds. The processes include heating the BNNT materials at different temperatures in the presence of inert gas and a hydrogen feedstock or in the presence of oxygen.

A method of manufacturing a cerium dioxide powder is provided. The method includes mixing a cerium salt, an amine and solvent to form a mixed solution, in which the amine includes a secondary amine, a tertiary amine or a combination thereof, and the tertiary amine is selected from the group consisting of hexamethylenetetramine, triethylenediamine and a combination thereof. A solvothermal reaction of the mixed solution is performed to form the cerium dioxide powder. The cerium dioxide powder manufactured by the method is also provided herein.

Provided is a novel solid electrolyte material of high density and high ionic conductivity, and an all-solid-state lithium ion secondary battery that utilizes the solid electrolyte material. The solid electrolyte material has a chemical composition represented by Li.sub.7-3xGa.sub.xLa.sub.3Zr.sub.2O.sub.12 (0.08≤x<0.5), has a relative density of 99% or higher, belongs to space group I-43d, in the cubic system, and has a garnet-type structure. The lithium ion conductivity of the solid electrolyte material is 2.0×10.sup.−3 S/cm or higher. The solid electrolyte material has a lattice constant a such that 1.29 nm≤a≤1.30 nm, and lithium ions occupy the 12a site, the 12b site and two types of 48e site, and gallium occupies the 12a site and the 12b site, in the crystal structure. The all-solid-state lithium ion secondary battery has a positive electrode, a negative electrode, and a solid electrolyte. The solid electrolyte is made up of the solid electrolyte material of the present invention.