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 hydrogenation catalyst contains a hydrogenation catalyst carrier and an active hydrogenation component. The active hydrogenation component includescompriscs a Group VIB metal sulfide and a Group VIII metal compound, and the molar proportion of a substance of the Group VIII metal compound that interacts with the Group VIB metal sulfide to the total amount of the Group VIII metal compound is 60-100%. The hydrogenation catalyst has a higher active metal sulfurizing degree and a higher number of type II active centers, and can be applied to the hydrogenation treatment process of oil products such as distillate oils and residual oils

A layered double hydroxide is represented by the following formula (I): Ni.sup.2+.sub.1−(x+y+z)Fe.sup.3+.sub.xV.sup.3+.sub.yCo.sup.3+.sub.z(OH).sub.2A.sup.n−.sub.(x+y+z)/n.Math.mH.sub.2O . . . (I). In one embodiment, in the formula (I), (x+y+z) is from 0.2 to 0.5, “x” represents more than 0 and 0.3 or less, “y” represents from 0.04 to 0.49, and “z” represents more than 0 and 0.2 or less.

Provided is a battery including: a positive electrode containing a positive electrode active material; a negative electrode; and an electrolyte solution containing a nonaqueous solvent. The positive electrode active material contains a compound represented by composition formula (1) below and having a crystal structure belonging to space group FM3-M: Li.sub.xMe.sub.yO.sub.αF.sub.β. (1) Here, Me is one or two or more elements selected from the group consisting of Mn, Co, Ni, Fe, Al, B, Ce, Si, Zr, Nb, Pr, Ti, W, Ge, Mo, Sn, Bi, Cu, Mg, Ca, Ba, Sr, Y, Zn, Ga, Er, La, Sm, Yb, V, and C. x, y, α, and β satisfy the following conditions: 1.7≤x≤2.2, 0.8≤y≤1.3, 1≤α≤2.5, and 0.5≤β≤2, respectively. The nonaqueous solvent includes at least one solvent selected from hydrofluoroethers, phosphazenes, phosphates, and perfluoropolyethers.

A lithium transition metal oxide which is capable of minimizing a side reaction with an electrolyte, thereby suppressing the generation of gas during charging and discharging of a lithium secondary battery is provided. The lithium transition metal oxide is a lithium cobalt oxide which contains a hetero-element, wherein the hetero-element includes a 4th period transition metal; and at least one selected from the group consisting of a group 2 element, a group 13 element, a group 14 element, a 5th period transition metal, and a 6th period transition metal. The lithium transition metal oxide has a cumulative 50% particle diameter (D50) of 10.0 μm to 25.0 μm and a ratio (D.sub.max/D.sub.min) of a maximum particle diameter (D.sub.max) to a minimum particle diameter (D.sub.min) of 10.0 to 60.0 when measured by laser diffraction scattering particle size distribution.

A cathode active material for lithium secondary batteries, a method of preparing the same, a cathode including the same, and a lithium secondary battery including the cathode are provided. The cathode active material includes nickel-based lithium metal oxide secondary particles each including a plurality of large primary particles, the nickel-based lithium metal oxide secondary particles having a hollow structure having pores therein, each of the plurality of large primary particles having a size of about 2 μm to about 6 μm, and each of the nickel-based lithium metal oxide secondary particles having a size of about 10 μm to about 18 μm; and a cobalt compound-containing coating layer on surfaces of the nickel-based lithium metal oxide secondary particles.

A positive-electrode active material containing a compound that has a crystal structure belonging to the space group FM-3M and is represented by the composition formula (1):
Li.sub.xMe.sub.yO.sub.αF.sub.β  (1) wherein Me denotes one or two or more elements selected from the group consisting of Mn, Co, Ni, Fe, and Al, and the following conditions are satisfied. 1.3≤x≤2.2, 0.8≤y≤1.3, 1≤α≤2.93, 0.07≤β≤2.

A lithium transition metal oxide, which is a lithium cobalt oxide containing a hetero-element, is capable of minimizing a side reaction with an electrolyte, thereby suppressing the generation of gas during charging and discharging of a lithium secondary battery is provided. The hetero-element includes a 4th period transition metal; and at least one selected from the group consisting of a group 2 element, a group 13 element, a group 14 element, a 5th period transition metal, and a 6th period transition metal. A positive electrode additive for a lithium secondary battery, and a lithium secondary battery are also provided.

A process for synthesizing a material, includes: (a) providing a plurality of powders including at least one lithiated powder including lithium, at least one TM powder including, for more than 95.0% of its mass, a transition metal chosen from titanium; cobalt, manganese, nickel, niobium, tin, iron and mixtures thereof, and at least one chalcogen powder including, for more than 95.0% of its mass, a chalcogen element chosen from sulfur, selenium, tellurium and mixtures thereof, (b) preparing a particulate mixture by mixing all the powders of the plurality or by mixing one of the powders of the plurality with a milled material obtained by; milling a particulate assembly formed by mixing at least two of the other powders of the plurality, and (c) milling the particulate fixture to form the material.