The present invention relates to Li-Ni composite oxide particles that exhibit a high initial discharge capacity and are excellent in thermal stability when used as a positive electrode active substance for non-aqueous electrolyte secondary batteries, and a process for producing the Li-Nicomposite oxide particles. The Li-Ni composite oxide particles of the present invention have a composition of Li.sub.xNi.sub.1yabCo.sub.yM1.sub.aM2.sub.bO.sub.2 wherein x, y, a and b represent 1.00x1.10; 0<y0.25; 0<a0.25; and 0b0.10, respectively; M1 is at least one element selected from the group consisting of Al and Mn; and M2 is at least one element selected from the group consisting of Zr and Mg, in which a product of a metal occupancy (%) of lithium sites of the Li-Ni composite oxide as determined by Rietveld analysis of X-ray diffraction thereof and a crystallite size (nm) of the Li-Ni composite oxide as determined by the Rietveld analysis is not less than 700 and not more than 1400.

Provided is a positive electrode active material that can be used to fabricate a nonaqueous electrolyte secondary battery having excellent output characteristics not only in an environment at normal temperature but also in all temperature environments from extremely low to high temperatures.

A positive electrode active material for nonaqueous electrolyte secondary batteries, the positive electrode active material includes a boron compound and lithium-nickel-cobalt-manganese composite oxide of general formula (1) having a layered hexagonal crystal structure. The lithium-nickel-cobalt-manganese composite oxide includes secondary particles composed of agglomerated primary particles. The boron compound is present on at least part of the surface of the primary particles, and contains lithium.

Li.sub.1+sNi.sub.xCo.sub.yMn.sub.zMo.sub.tM.sub.wO.sub.2 (1)

A composite positive active material includes: a composite including a first metal oxide represented by Formula 1 and having a layered structure, and a second metal oxide having at least one crystal structure selected from a layer structure, a perovskite structure, a rock salt structure, and a spinel structure, wherein a content of the second metal oxide is greater than 0 and equal to or less than 0.2 moles, per mole of the composite,

LiNi.sub.xM.sup.1.sub.1-xO.sub.2-eM.sup.2.sub.eFormula 1

wherein, in Formula 1, M.sup.1 is at least one element selected from Group 4 to Group 14 of the Periodic Table of the Elements; M.sup.a is at least one element selected from F, S, Cl, and Br; 0.7x<1; and 0e<1. Also, a positive electrode including the composite positive active material, and a lithium battery including the positive electrode.

Provided is a cathode active material for a non-aqueous electrolyte secondary battery that has a uniform particle size and high packing density, and that is capable of increased battery capacity and improved coulomb efficiency. When producing a nickel composite hydroxide that is a precursor to the cathode active material by supplying an aqueous solution that includes at least a nickel salt, a neutralizing agent and a complexing agent into a reaction vessel while stirring and performing a crystallization reaction, a nickel composite hydroxide slurry is obtained while controlling the ratio of the average particle size per volume of secondary particles of nickel composite hydroxide that is generated inside the reaction vessel with respect to the average particle size per volume of secondary particles of nickel composite hydroxide that is finally obtained so as to be 0.2 to 0.6, after which, while keeping the amount of slurry constant and continuously removing only the liquid component, the crystallization reaction is continued until the average particle size per volume of secondary particles of the nickel composite hydroxide becomes 8.0 m to 50.0 m.

A composite precursor represented by Formula 1, a composite prepared therefrom represented by Formula 2, a method of preparing a composite precursor and a composite, a positive electrode for lithium secondary battery including the same, and a lithium secondary battery employing the same.
aMn.sub.3O.sub.4-bM(OH).sub.2Formula 1
wherein in Formula 1, 0<a0.8, 0.2b<1
and M is at least one metal selected from the group consisting of titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron, (Fe), cobalt (Co), nickel (Ni), copper (Cu), aluminum (Al), magnesium (Mg), zirconium (Zr), and boron (B)
aLi.sub.2MnO.sub.3-bLi.sub.yMO.sub.2Formula 2
wherein in Formula 2, 0a0.6, 0.4b1
1.0y1.05,
and M is at least one metal selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Al, Mg, Zr, and B.

Disclosed are a positive electrode active material, a method of preparing the same, and a positive electrode and a rechargeable lithium battery including the same, the positive electrode active material including core particles including a layered lithium nickel-manganese-based composite oxide, a first coating layer on a surface of the core particles and containing Al, and a second coating layer on the first coating layer and containing Co.

A positive electrode active material precursor includes Ni and Mn and secondary particles formed by the aggregation of a plurality of primary particles. The secondary particles have a ratio of a core area to a total area of the particles ranging from 28.7% to 34.1%, and a porosity ranging from 11.3% to 11.7%. Also provided is a method for preparing the positive electrode active material precursor. Additionally, a positive electrode active material including a reaction product of the positive electrode active material precursor and a lithium raw material is provided. Also provided is a method for preparing a positive electrode active material using the positive electrode active material precursor.

Processes and systems for isolating manganese (Mn), cobalt (Co), nickel (Ni) as a purified co-precipitated product or alternatively independent products, from a lithium-ion battery waste stream like black mass are provided. The process may include processing black mass in an extraction process that comprises mixing the black mass with a source of iron (III) ions and a source of iron (II) ions in an aqueous liquid to extract Mn, Ni, and Co and the at least one impurity element to form a stream, then filtering solids including the graphite and iron hydroxide from the stream that then comprises Mn, Ni, and Co and at least one impurity element. The stream may be further purified by removing the at least one impurity element and Mn, Ni, and Co can be separated from the stream to form one or more recovered products comprising one or more of Mn, Ni, and C0.

The invention relates to a method for preparing transitional-metal particles (cathode particle precursor) under a co-precipitation reaction. In this method, by feeding different types of anion compositions and/or cation compositions, and adjusting the pH to match with the species, precipitated particles are deposited to form a slurry, colleting the slurry, treating with water, and drying to get a cathode particle precursor. Mixing the cathode particle precursor with a lithium source and calcining to yield core-shell structured cathode active particles. Such cathode active particle can be used to prepare cathode of lithium-ion battery.

A method of preparing a positive electrode active material precursor for a secondary battery includes preparing a positive electrode active material precursor by a co-precipitation reaction while adding a transition metal-containing solution containing transition metal cations, a basic solution, and an ammonium solution to a batch-type reactor, wherein a molar ratio of ammonium ions contained in the ammonium solution to the transition metal cations contained in the transition metal-containing solution added to the batch-type reactor is 0.5 or less, and a pH in the batch-type reactor is maintained at 11.2 or less.