A nickel-based hydroxide powder is provided which has an average crystallite size, as determined by Scherrer fitting of the (00I) reflections of an XRD powder diffraction pattern of the nickel-based hydroxide powder, of at most 10 nm, together with a process for producing nickel-based hydroxide powders. The nickel-based hydroxide powders find utility as precursors for the formation of lithium transition metal oxide active electrode materials.

Disclosed are novel precursor particles for preparing a cathode active material including transition metal precursor particles containing one or more transition metals, and one or more of an alkali metal and an alkaline earth metal, wherein the alkali metal and the alkaline earth metal are contained in one or more of inner and outer parts of the transition metal precursor particles, and a novel precursor powder including the novel precursor particles.

The present disclosure relates to the technical field of lithium ion battery, and discloses a Lithium-Manganese-rich material and a preparation method and a use thereof.

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.

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 positive-electrode active material for a lithium-ion secondary battery, wherein an average pore size of the positive-electrode active material is 0.2 μm to 1.0 μm when a pore size is measured in a range of 0.0036 μm to 400 μm.

A method for relithiating cathode material from spent lithium-based batteries, the method comprising: (i) mixing delithiated cathode material and a lithium salt with an ionic liquid in which the lithium salt is at least partially soluble to form an initial mixture; (ii) heating the initial mixture to a temperature of 100° C. to 300° C. to result in relithiation of the delithiated cathode material; and (iii) separating the ionic liquid from the relithiated cathode material; wherein, in embodiments, the cathode material is a lithium metal oxide, wherein the metal is selected from the group consisting of Ni, Co, Fe, Mn, Al, Zr, Ti, Nb, and combinations thereof, or wherein the cathode material has the formula LiNi.sub.xMn.sub.yCo.sub.zO.sub.2, wherein x>0, y>0, z>0, and x+y+z=1; wherein, in some embodiments, the ionic liquid has a nitrogen-containing cationic portion, such as an imidazolium ionic liquid.

The present invention relates to a lithium metal complex oxide and a preparation method thereof, and more particularly, to a lithium metal complex oxide mixed with a metal compound for a lithium reaction, stirred and heat-treated to allow residual lithium and a metal compound for reducing lithium (or a metal compound for lithium reduction) to react with each other on a surface to form a product, which is included in the lithium metal complex oxide, in which the content of Ni.sup.3+ is higher than the content of Ni.sup.2+ and a ratio of Ni.sup.3+/Ni.sup.2+ is 1.5 or greater so that life characteristics and capacity characteristics are improved, while residual lithium is reduced, and a preparation method thereof.

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.