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.

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.

The present invention generally relates to a method for preparing metal oxide nanosheets. In a preferred embodiment, graphene oxide (GO) or graphite oxide is employed as a template or structure directing agent for the formation of the metal oxide nanosheets, wherein the template is mixed with metal oxide precursor to form a metal oxide precursor-bonded template. Subsequently, the metal oxide precursor-bonded template is calcined to form the metal oxide nanosheets. The present invention also relates to a lithium-ion battery anode comprising the metal oxide nanosheets. In a further preferred embodiment, the battery anode may comprise a reduced template, which is reduced graphene oxide (rGO) or reduced graphite oxide.

The present invention generally relates to a method for preparing metal oxide nanosheets. In a preferred embodiment, graphene oxide (GO) or graphite oxide is employed as a template or structure directing agent for the formation of the metal oxide nanosheets, wherein the template is mixed with metal oxide precursor to form a metal oxide precursor-bonded template. Subsequently, the metal oxide precursor-bonded template is calcined to form the metal oxide nanosheets. The present invention also relates to a lithium-ion battery anode comprising the metal oxide nanosheets. In a further preferred embodiment, the battery anode may comprise a reduced template, which is reduced graphene oxide (rGO) or reduced graphite oxide.

The present invention concerns a material with a non-stoichiometric spinel-type crystalline structure based on cobalt oxide doped with alkaline elements, its production process for obtaining it by precipitation with controlled washing, and its particular use as a highly active catalyst in the N.sub.2O decomposition reaction. Therefore, we understand that the present invention is in the area of green industry aimed at reducing N.sub.2O emissions into the atmosphere.

The present invention provides a positive electrode active material precursor for a secondary battery which includes primary particles of Co.sub.3O.sub.4 or CoOOH, wherein the primary particle contains a doping element in an amount of 3,000 ppm or more, and has an average particle diameter (D.sub.50) of 15 μm or more, and a positive electrode active material for a secondary battery which includes particles of a lithium cobalt-based oxide, wherein the primary particle contains a doping element in an amount of 2,500 ppm or more, and has an average particle diameter (D.sub.50) of 15 μm or more.

The present invention provides a positive electrode active material precursor for a secondary battery which includes primary particles of Co.sub.3O.sub.4 or CoOOH, wherein the primary particle contains a doping element in an amount of 3,000 ppm or more, and has an average particle diameter (D.sub.50) of 15 μm or more, and a positive electrode active material for a secondary battery which includes particles of a lithium cobalt-based oxide, wherein the primary particle contains a doping element in an amount of 2,500 ppm or more, and has an average particle diameter (D.sub.50) of 15 μm or more.

A cobalt oxide for a lithium secondary battery, a method of preparing the cobalt oxide; a lithium cobalt oxide for a lithium secondary battery formed from the cobalt oxide; and a lithium secondary battery having a positive electrode including the lithium cobalt oxide, the cobalt oxide having a tap density of about 2.8 g/cc to about 3.0 g/cc, and an intensity ratio of about 0.8 to about 1.2 of a second peak at 2θ of about 31.3±1° to a first peak at 2θ of about 19±1° in X-ray diffraction spectra, as analyzed by X-ray diffraction.

A process for preparing a metal hydroxide comprising (i) at least one metal chosen from nickel and cobalt and optionally (ii) at least one metal chosen from manganese, lithium and aluminum. The process comprises: reacting a metal sulfate comprising (i) at least one metal chosen from nickel and cobalt and optionally (iii) at least one metal chosen from manganese and aluminum with sodium hydroxide and optionally a chelating agent in order to obtain a solid comprising the metal hydroxide and a liquid comprising sodium sulfate; separating the liquid and the solid from one another to obtain the metal hydroxide; submitting the liquid comprising sodium sulfate to an electromembrane process for converting the sodium sulfate into sodium hydroxide; and reusing the sodium hydroxide obtained by the electromembrane process for reacting with the metal sulfate.

A process for preparing a metal hydroxide comprising (i) at least one metal chosen from nickel and cobalt and optionally (ii) at least one metal chosen from manganese, lithium and aluminum. The process comprises: reacting a metal sulfate comprising (i) at least one metal chosen from nickel and cobalt and optionally (iii) at least one metal chosen from manganese and aluminum with sodium hydroxide and optionally a chelating agent in order to obtain a solid comprising the metal hydroxide and a liquid comprising sodium sulfate; separating the liquid and the solid from one another to obtain the metal hydroxide; submitting the liquid comprising sodium sulfate to an electromembrane process for converting the sodium sulfate into sodium hydroxide; and reusing the sodium hydroxide obtained by the electromembrane process for reacting with the metal sulfate.