A positive electrode active material includes a lithium composite oxide and a zirconium oxide coating layer and a lithium zirconium oxide coating layer that are in a form of sequential layers on the lithium composite oxide.

A particulate precursor compound for manufacturing a lithium transition metal (M)-oxide powder usable as an active positive electrode material in lithium-ion batteries, wherein (M) is Ni.sub.xMn.sub.yCo.sub.zA.sub.v, A being a dopant, wherein 0.33x0.60, 0.20y0.33, and 0.20z0.33, v0.05, and x+y+z+v=1, the precursor having a specific surface area PBET in m.sup.2/g, a tapped density PTD in g/cm.sup.3, a median particle size PD50 in m, and wherein (I).

To provide a carbonate compound and a cathode active material, whereby a lithium ion secondary battery having excellent cycle characteristics can be obtained. A process for producing a carbonate compound, which comprises mixing a sulfate (A) comprising a sulfate comprising a sulfate of Mn and a sulfate of Ni, or a sulfate comprising a sulfate of Mn, a sulfate of Ni and a sulfate of Co, and a carbonate (B) which is at least one carbonate selected from the group consisting of sodium carbonate and potassium carbonate, in the form of aqueous solutions and controlling the proportion of Mn to the total of Ni, Co and Mn contained in the sulfate (A) to be higher than 65 mol % at the initiation of the mixing, to precipitate a carbonate compound having a proportion of Mn of from 33.3 to 65 mol %, a proportion of Ni of from 17.5 to 50 mol % and a proportion of Co of from 0 to 33.3 mol % to the total of Ni, Co and Mn in the total average composition. A process for producing a cathode active material, which comprises mixing the carbonate compound obtained by the above process and lithium carbonate, followed by firing at from 500 to 1,000 C.

[Summary] A positive electrode active material is provided to contain: a solid solution lithium-containing transition metal oxide (A) represented by Li.sub.1.5[Ni.sub.aCo.sub.bMn.sub.c[Li].sub.d]O.sub.3 (where a, b, c and d satisfy the relations of a+b+c+d=1.5, 0.1<d0.4, 1.1a+b+c<1.4, 0.2a0.7 and 0<b/a<1); and a lithium-containing transition metal oxide (B) represented by LiM.sub.XMn.sub.2XO.sub.4 (where M represents Cr or Al, and x satisfies the relation of 0x<2).

A composite positive active material includes a lithium nickel cobalt aluminum composite oxide. A full width at half maximum (FWHM) of a peak of a (104) plane of the lithium nickel cobalt aluminum composite oxide is 0.15 or less and an FWHM of a peak of a (108) plane of the lithium nickel cobalt aluminum composite oxide is 0.15 or less, the peaks being obtained by X-ray diffraction analysis using a CuK X-ray. A method of preparing the composite positive active material, and a lithium secondary battery including a positive electrode including the composite positive active material are disclosed.

The present invention relates to a process for preparing transition metal hydroxides with a mean particle diameter in the range from 6 to 12 m (D50), which comprises combining, in a stirred vessel, at least one solution of at least one transition metal salt with at least one solution of at least one alkali metal hydroxide to prepare an aqueous suspension of transition metal hydroxide, and, in at least one further compartment, continuously introducing a mechanical power in the range from 50 to 10 000 W/l in a proportion of the suspension in each case, based on the proportion of the suspension, and then recycling the proportion into the stirred vessel.

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.

Layered double hydroxides having a high surface area (at least 125 m.sup.2/g) and the formula (I)

[M.sup.z+.sub.1-xM.sup.y+.sub.x(OH).sub.2].sup.a+(X.sup.n-).sub.a/n.sup.+bH.sub.2O.c(AMO-solvent)(I)

wherein M and M are different and each is a charged metal cation (and must be present), z=1 or 2; y=3 or 4, 0<x<0.9, b is 0 to 10, c=0 to 10, X is an anion, n is the charge on the anion, and a=z(1x)+xy2; AMO-solvent is aqueous miscible organic solvent, may be prepared by a method which comprises a) precipitating a layered double hydroxide having the formula

[M.sup.z+.sub.1-xM.sup.y+.sub.x(OH).sub.2].sup.a+(X.sup.n-).sub.a/n.sup.+bH.sub.2O wherein M, M, z, y, x, a, b and X are as defined above from a solution containing the cations of the metals M and M and the anion X.sup.n-; b) ageing the layered double hydroxide precipitate obtained in step a) in the original solution; c) collecting, then washing the layered double hydroxide precipitate; d) dispersing the wet layered double hydroxide in an AMO solvent so as to produce a slurry of the layered double hydroxide in the solvent; e) maintaining the dispersion obtained in step d); and f) recovering and drying the layered double hydroxide.

The high surface area products have low particle size and are particularly suitable for use as catalysts, catalyst supports, sorbents and coatings.

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.

Embodiments disclosed herein relate to using cobalt (Co) to fine tune the magnetic properties, such as permeability and magnetic loss, of nickel-zinc ferrites to improve the material performance in electronic applications. The method comprises replacing nickel (Ni) with sufficient Co.sup.+2 such that the relaxation peak associated with the Co.sup.+2 substitution and the relaxation peak associated with the nickel to zinc (Ni/Zn) ratio are into near coincidence. When the relaxation peaks overlap, the material permeability can be substantially maximized and magnetic loss substantially minimized. The resulting materials are useful and provide superior performance particularly for devices operating at the 13.56 MHz ISM band.