An object is to reduce variation in shape of crystals that are to be formed. Solutions containing respective raw materials are made in an environment where an oxygen concentration is lower than that in air, the solutions containing the respective raw materials are mixed in an environment where an oxygen concentration is lower than that in air to form a mixture solution, and with use of the mixture solution, a composite oxide is formed by a hydrothermal method.

Provided are magnetic particles (cobalt ferrite) having a micrometer-order average particle diameter and similar particle diameters. A cobalt ferrite precursor is heated in the presence of a sulfite, thereby obtaining intended cobalt ferrite magnetic particles.

A positive electrode active material includes powder of composite particles including a lithium transition metal composite oxide having a lamellar rock-salt structure and a spinel phase. The spinel phase includes an oxide including lithium and at least a first element X1 selected from the group consisting of magnesium, aluminum, titanium, manganese, yttrium, zirconium, molybdenum, and tungsten, and the lithium transition metal composite oxide includes nickel or cobalt and the first element X1.

A positive electrode active material includes powder of composite particles including a lithium transition metal composite oxide having a lamellar rock-salt structure and a spinel phase. The spinel phase includes an oxide including lithium and at least a first element X1 selected from the group consisting of magnesium, aluminum, titanium, manganese, yttrium, zirconium, molybdenum, and tungsten, and the lithium transition metal composite oxide includes nickel or cobalt and the first element X1.

The present invention relates to a process for preparing a cobalt-containing Fischer-Tropsch synthesis catalyst with good physical properties and high cobalt loading. In one aspect, the present invention provides a process for preparing a supported cobalt-containing Fischer-Tropsch synthesis catalyst, said process comprising the steps of: (a) impregnating a support material with cobalt haydroxide nitrate, or a hydrate thereof, of formula (I) below to form an impregnated support material, [Co(OH).sub.x(NO.sub.3).sub.(2-x).yH.sub.2O] (I) where: 0<x<2 0≤y≤6 (b) drying and calcining the impregnated support material.

The present invention relates to a lithium secondary battery. The lithium secondary battery includes a positive electrode including a positive active material; a negative electrode including a negative active material; and an electrolyte including a non-aqueous organic solvent, a lithium salt, and an additive including a compound represented by Chemical Formula 1. The negative active material includes Si at about 0.1 wt % to about 32 wt % in amount based on a total weight of the negative active material. ##STR00001## wherein, in Chemical Formula 1, A is a substituted or unsubstituted aliphatic chain or (—C.sub.2H.sub.4—O—C.sub.2H.sub.4-)n, and n is an integer from 1 to 10.

A method for forming a positive electrode active material of a lithium ion secondary battery is provided. In the method for forming a positive electrode active material, a first container that includes a mixture of lithium oxide, fluoride, and a magnesium compound and fluoride that is outside the first container are provided in a heating furnace, and the heating furnace is heated at a temperature higher than or equal to a temperature at which the fluoride is volatilized or sublimated. It is further preferable that the fluoride be lithium fluoride and the magnesium compound be magnesium fluoride.

A method of preparing a positive electrode active material includes mixing a lithium raw material and a nickel-containing transition metal hydroxide precursor containing nickel in an amount of 65 mol % or more based on a total number of moles of transition metals and performing a first heat treatment to prepare a nickel-containing lithium transition metal oxide. The method also includes mixing a boron and carbon-containing raw material and a cobalt-containing raw material with the nickel-containing lithium transition metal oxide to form a mixture, and performing a second heat treatment on the mixture to form a coating material including B and Co on a surface of the lithium transition metal oxide. A positive electrode active material prepared by the preparation method is formed, and a positive electrode for a lithium secondary battery and a lithium secondary battery which include the positive electrode active material.

The present invention relates to a positive electrode additive for a lithium secondary battery, a manufacturing method thereof, a positive electrode for a lithium secondary battery including the same, and a lithium secondary battery including the same.

The positive electrode additive for a lithium secondary battery according to an exemplary embodiment of the present invention is represented by Chemical Formula 1 below.

Li.sub.6xCo.sub.1-yM.sub.yO.sub.4  [Chemical Formula 1] (In the Chemical Formula 1, 0.9≤x≤1.1, 0<y≤0.1, My=B.sub.aW.sub.b, 0≤a≤0.1, 0≤b≤0.1, and, a and b are not simultaneously 0.)

Another positive electrode additive for a lithium secondary battery according to an exemplary embodiment of the present invention includes a core represented by Chemical Formula 2 below; and a coating layer comprising at least one of boron (B) and tungsten (W).

Li.sub.6xCoO.sub.4  [Chemical Formula 2] (In the Chemical Formula 2, 0.9≤x≤1.1.)

Various lithium cobalt oxides materials having a chemical formula of Li.sub.x Co.sub.y O.sub.z, and method and apparatus of producing the various lithium cobalt oxides materials are provided. The method includes adjusting a molar ratio M.sub.LiSalt:M.sub.CoSalt of a lithium-containing salt, and a cobalt-containing salt within a liquid mixture to be equivalent to a ratio of x:y, drying a mist of the liquid mixture in the presence of a gas to form a gas-solid mixture, separating the gas-solid mixture into one or more solid particles of an oxide material, and annealing the solid particles of the oxide material in the presence of another gas flow to obtain crystalized particles of the lithium cobalt oxide material. The process system has a mist generator, a drying chamber, one or more gas-solid separator, and one or more reactors.