Provided is a positive electrode active material for a non-aqueous electrolyte secondary battery, the active material including a lithium-transition metal composite oxide containing lithium, nickel, cobalt, and manganese, having a layered structure, having a ratio D.sub.50/D.sub.SEM of from 1 to 4, and having a ratio of a number of moles of nickel to a total number of moles of metals other than lithium of greater than 0.8 and less than 1, a ratio of a number of moles of cobalt to the total number of moles of metals other than lithium of less than 0.2, a ratio of a number of moles of manganese to the total number of moles of metals other than lithium of less than 0.2, and a ratio of the number of moles of manganese to a sum of the number of moles of cobalt and the number of moles of manganese of less than 0.58.

Process for making a manganese composite (oxy)hydroxide with a mean particle diameter D50 in the range from 2 to 16 μm comprising the step(s) of combining (a) an aqueous solution containing salts of nickel and of manganese, and, optionally, at least one of Al, Mg, or transition metals other than nickel and manganese wherein at least 50 mole-% of the metal is manganese, (b) with an aqueous solution of an alkali metal hydroxide and (c) an organic acid or its alkali or ammonium salt wherein said organic acid bears at least two functional groups per molecule and at least one of the functional groups is a carboxylate group.

A positive electrode active material that has high capacity and excellent charge and discharge cycle performance for a secondary battery is provided. The positive electrode active material includes a group of particles including a first group of particles and a second group of particles. The group of particles includes lithium, cobalt, nickel, aluminum, magnesium, oxygen, and fluorine. When the number of cobalt atoms included in the group of particles is taken as 100, the number of nickel atoms is greater than or equal to 0.05 and less than or equal to 2, the number of aluminum atoms is greater than or equal to 0.05 and less than or equal to 2, and the number of magnesium atoms is greater than or equal to 0.1 and less than or equal to 6. When particle size distribution in the group of particles is measured by a laser diffraction and scattering method, the first group of particles has a first peak and the second group of particles has a second peak; the first peak has a local maximum value at longer than or equal to 2 μm and shorter than or equal to 4 μm, and the second peak has a local maximum value at longer than or equal to 9 μm and shorter than or equal to 25 μm.

A raw material solution containing trivalent iron ions, or trivalent iron ions and ions of a metal element that partially substitutes Fe sites, and an alkaline aqueous solution for neutralizing the raw material solution are added to a reaction system to adjust the pH of the reaction system from 1.0 to 3.0 or lower. Hydroxycarboxylic acid is added to the obtained reaction solution and the pH of the reaction system is then neutralized from 7.0 to 10.0 or lower. The obtained precipitate of a substituent metal element-containing iron oxyhydroxide is coated with silicon oxide, followed by heating so as to form particles of ε-iron oxide in which Fe sites are partially substituted by other metal elements, and then, a slurry containing the particles is classified. The iron-based oxide magnetic powder has a particle shape close to a perfect sphere and is suitable for use in a magnetic recording medium.

A grain-oriented M-type hexagonal ferrite has the formula MeFe.sub.12O.sub.19, and a dopant effective to provide planar magnetic anisotropy and magnetization in a c-plane, or a cone anisotropy, in the hexagonal crystallographic structure wherein Me is Sr.sup.+, Ba.sup.2+ or Pb.sup.2+, and wherein greater than 30%, preferably greater than 80%, of c-axes of the ferrite grains are aligned perpendicular to the c-plane.

A method of preparing a positive electrode active material for a secondary battery includes preparing a positive electrode active material precursor including nickel (Ni), cobalt (Co), and at least one selected from the group consisting of manganese (Mn) and aluminum (Al); and forming a lithium composite transition metal oxide by mixing the positive electrode active material precursor and a lithium source and performing calcination, wherein the positive electrode active material precursor includes nickel (Ni) in an amount of 60 mol % or more out of the entire metal element, and a molar ratio (Li/M) of lithium (Li) of the lithium source to the entire metal element (M) of the positive electrode active material precursor is greater than 1.1.

Cathode active material in particulate form with a mean particle diameter in the range from 2 to 16 .Math.m (D50), wherein the cathode active material has the composition Li.sub.1+xTM.sub.1-xO.sub.2 wherein x is in the range of from 0.1 to 0.2 and TM is a combination of elements according to general formula (I), (Ni.sub.aCo.sub.bMn.sub.c).sub.1-d-eM.sup.1.sub.dM.sup.2.sub.e where the variables are each defined as follows: a is in the range from 0.20 to 0.40, b is in the range of from zero to 0.15, c is in the range of from 0.50 to 0.75, d is in the range of from zero to 0.015, and e is in the range of from zero to 0.02, M.sup.1 is selected from Al, Ti, Zr, Mo, W, Fe, Nb, and Mg, M.sup.2 is selected from B and K, with a + b + c = 1.0 wherein said composite oxide has a specific surface (BET) in the range from 0.5 m.sup.2/gto 10 m.sup.2/gand a pressed density of at least 2.9 g/cm.sup.3, and wherein said cathode active material has an average primary particle diameter in the range of from 200 to 3,000 nm.

Process for making a partially coated electrode active material wherein said process comprises the following steps: (a) Providing an electrode active material according to general formula Li.sub.1+xTM.sub.1-xO.sub.2, wherein TM is Ni and, optionally, at least one of Co and Mn, and, optionally, at least one element selected from Al, Mg, and Ba, transition metals other than Ni, Co, and Mn, and x is in the range of from zero to 0.2, wherein at least 50 mole-% of the transition metal of TM is Ni, (b) treating said electrode active material with an aqueous medium, (c) partially removing water by solid-liquid separation method, (d) treating the solid residue with an aqueous formulation of at least one heteropolyacid or its respective ammonium or lithium salt, (e) treating the residue thermally.

The present disclosure relates to a positive active material including a lithium transition metal oxide substituted with Na, W, Mg, Ti, and S, a method of preparing the same, and a lithium secondary battery having a positive electrode including the positive active material.

A cerium-zirconium-aluminum-based composite material, a cGPF catalyst and a preparation method thereof are provided. The cerium-zirconium-aluminum-based composite material adopts a stepwise precipitation method, firstly preparing an aluminum-based pre-treated material, then coprecipitating the aluminum-based pre-treated material with zirconium and cerium sol, and finally roasting at high temperature to obtain the cerium-zirconium-aluminum-based composite material. The cerium-zirconium-aluminum-based composite material has better compactness and higher density, and when it is used in cGPF catalyst, it occupies a smaller volume of pores on the catalyst carrier, such that cGPF catalyst has lower back pressure and better ash accumulation resistance, which is beneficial to large-scale application of cGPF catalyst.