A method of preparing a positive active material for a lithium secondary battery represented by the following Chemical Formula 1 (Li.sub.wNi.sub.xCo.sub.yMn.sub.1-x-y-zM.sub.zO.sub.2) includes: (a) preparing a metal salt aqueous solution including a lithium raw material, a manganese raw material, a nickel raw material, and a cobalt raw material; (b) wet-pulverizing the metal salt aqueous solution using beads having a particle diameter of 0.05 to 0.30 mm at 2000 to 6000 rpm for 2 to 12 hours to prepare a slurry; (c) adding a carbon source to the slurry; (d) spray-drying the slurry of the step (c) to prepare a mixed powder; and (e) heat-treating the mixed powder.

According to one embodiment, a positive electrode active material for a non-aqueous electrolyte secondary battery contains a lithium/transition metal composite oxide that contains 80 mol % or more, relative to the total mol number of metal elements other than Li, of Ni and at least one kind of metal element selected from among Co, Mn, Al, W, Mg, Mo, Nb, Ti, Si and Zr. When a filtrate of a suspension, said suspension being prepared by adding 250 mg of the positive electrode active material to 10 mL of a 17.5 mass % aqueous solution of hydrochloric acid, dissolving by heating at 90° C. for 2 hours and then diluting to 50 mL, is analyzed by inductively coupled plasma mass spectrometry, the elution amount of S in the filtrate is 0.002 mmol or greater.

The present technology relates to electrode materials comprising an electrochemically active material, wherein the electrochemically active material comprises a P2-type or a O3-type layered sodium metal oxide. The electrochemically active material is of formula Na.sub.xMO.sub.2, wherein 0.5≤x≤1.0 and M is selected from Co, Mn, Fe, Ni, Ti, Cr, V, Cu, Sb and their combinations. Also described are electrodes, electrochemical cells and batteries comprising the electrode materials.

A process for preparing a metal oxide-containing powder that comprises conducting spray pyrolysis that comprises aerosolizing a slurry that comprises solidphase particles in a liquid that comprises at least one precursor compound, which comprises one or more metallic elements of at least one metal oxide, to form droplets of said slurry, and calcining the droplets to at least partially decompose the at least one precursor compound and form the metal oxide-containing powder having a non-hollow morphology.

A cathode active material contains a compound having a crystal structure of space group FM-3M and represented by composition formula (1): Li.sub.xMe.sub.yO.sub.2 . . . (1). In the formula, Me represents any of the following: Mn; Mn and one or two or more elements selected from the group consisting of Co, Fe, Sn, Cu, Mo, Bi, V, and Cr; Ni, Mn, and one or two or more elements selected from the group consisting of Co, Fe, Sn, Cu, Mo, Bi, V, and Cr; and one or two or more elements selected from the group consisting of Ni, Co, Fe, Sn, Cu, Mo, Bi, V, and Cr. In addition to this, the following conditions are met: 0.5≦x/y≦3.0; and 1.5≦x+y≦2.3.

Supplemental lithium can be used to stabilize lithium ion batteries with lithium rich metal oxides as the positive electrode active material. Dramatic improvements in the specific capacity at long cycling have been obtained. The supplemental lithium can be provided with the negative electrode, or alternatively as a sacrificial material that is subsequently driven into the negative electrode active material. The supplemental lithium can be provided to the negative electrode active material prior to assembly of the battery using electrochemical deposition. The positive electrode active materials can comprise a layered-layered structure comprising manganese as well as nickel and/or cobalt.

A positive electrode active material, which has high capacity and excellent charge and discharge cycle performance, for a lithium-ion secondary battery is provided. The positive electrode active material contains lithium, cobalt, an element X, and fluorine, and includes a region represented by a layered rock-salt structure. The space group of the region is represented by R-3m. The element X is one or more selected from elements that have a property in which ΔE3 obtained by subtracting, from the stabilization energy in the case of substitution of the element at a lithium position in lithium cobalt oxide, the stabilization energy before the substitution is smaller than ΔE4 obtained by subtracting, from the stabilization energy in the case of substitution of the element at a cobalt position in lithium cobalt oxide, the stabilization energy before the substitution. ΔE3 and ΔE4 are calculated by the first-principles calculation.

A positive electrode active material for non-aqueous electrolyte secondary batteries that can achieve a high output characteristic and a high battery capacity when used in a positive electrode of a battery and that can achieve a high electrode density, and a non-aqueous electrolyte secondary battery that uses such a positive electrode active material and can achieve a high capacity and a high output. A lithium-manganese-cobalt composite oxide includes plate-shaped secondary particles each obtained by aggregation of a plurality of plate-shaped primary particles caused by overlapping of plate surfaces of the plate-shaped primary particles, wherein a shape of the primary particles is any one of a spherical, elliptical, oval, or a planar projected shape of a block-shaped object, and the secondary particles have an aspect ratio of 3 to 20 and a volume-average particle size (Mv) of 4 μm to 20 μm as measured by a laser diffraction scattering process.

Cathode active materials are provided. The cathode active material can include a plurality of cathode active compound particles. A coating is disposed over each of the cathode active compound particles. The coating can include at least one of ZrO.sub.2, La.sub.2O.sub.3, a mixture of Al.sub.2O.sub.3 and ZrO.sub.2 or a mixture of Al.sub.2O.sub.3 and La.sub.2O.sub.3. The battery cells that include the cathode active material are also provided.

Provided is a precursor of a positive electrode active material containing, in a reduced amount, impurities which do not contribute to a charge/discharge reaction but rather corrode a firing furnace and peripheral equipment and thus having excellent battery characteristics and safety, and production method thereof. A method for producing a precursor of a positive electrode active material for nonaqueous electrolyte secondary batteries having a hollow structure or porous structure includes obtaining the precursor by washing nickel-manganese composite hydroxide particles having a particular composition ratio and a pore structure in which pores are present within the particles with an aqueous carbonate solution having a carbonate concentration of 0.1 mol/L or more.