A process for preparing a cathode material of the form Li.sub.aMn.sub.1-x-y-zFe.sub.xCo.sub.yNi.sub.zO.sub.2-dCl.sub.d is provided. In addition, a Li.sub.aMn.sub.1-x-y-zFe.sub.xCo.sub.yNi.sub.zO.sub.2-dCl.sub.d cathode material for electrochemical systems is provided. Furthermore, a lithium or lithium-ion rechargeable electrochemical cell is provided, incorporating the Li.sub.aMn.sub.1-x-y-zFe.sub.xCo.sub.yNi.sub.zO.sub.2-dCl.sub.d cathode material in a positive electrode.

An object of the present invention or a problem to be solved by the present invention is to provide, as a material for use as a positive electrode of a sodium secondary battery, a novel material that allows the resulting battery to have capacity characteristics superior to those of conventional batteries. The composite metal oxide of the present invention has a composition represented by the general formula Na.sub.xMe.sub.yO.sub.2, where Me is at least one selected from the group consisting of Fe, Mn, and Ni, x satisfies 0.8<x≦1.0, and y satisfies 0.95≦y<1.05, and consists of a P2 structure. The sodium secondary battery of the present invention includes: a positive electrode (13) containing the composite metal oxide of the present invention; a negative electrode (16) containing a material capable of absorbing and desorbing Na ions; and an electrolyte containing Na ions and anions.

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.

A cathode active material contains a compound having a crystal structure of space group FM-3M, represented by composition formula (1), and having a half-width in 2δ of 0.9° or more and 2.4° or less for a (200) diffraction peak in powder X-ray diffraction (XRD): Li.sub.xMe.sub.yO.sub.2. . . (1). In the formula, Me represents one or two or more elements selected from the group consisting of Mn, Nb, Ti, 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.

A composite cathode active material including: a first metal oxide having a layered crystal structure; and a second metal oxide having a perovskite crystal structure, wherein the second metal oxide includes a first metal and a second metal that are each 12-fold cubooctahedrally coordinated to oxygen. Also a cathode including the composite cathode material and a lithium battery containing the cathode.

A sodium manganese composite oxide represented by Formula 1:
Na.sub.xMa.sub.yMn.sub.zMb.sub.vO.sub.2+d  Formula 1
wherein, 0.2≦x≦1, 0<y≦0.2, 0<z≦1, 0≦v<1, 0<z+v≦1, −0.3≦d<1, Ma is an electrochemically inactive metal, and Mb is different from Ma and Mn, and is at least one transition metal selected from elements in Groups 4 to 12 of the periodic table of the elements.

To increase the amount of lithium ions that can be received in and released from a positive electrode active material to achieve high capacity and high energy density of a secondary battery. A lithium manganese oxide particle includes a first region and a second region. The valence number of manganese in the first region is lower than the valence number of manganese in the second region. The lithium manganese oxide has high structural stability and high capacity characteristics.

The present invention discloses a method for preparing lithium-rich manganese-based cathode material. The method comprises: dispersing α-MnO.sub.2 micron particles, a nickel salt and a lithium-containing compound in a solvent to obtain a mixture, then evaporating the mixture to remove the solvent, and calcining the solid product obtained from the evaporation; wherein the lithium-containing compound is a lithium salt and/or lithium hydroxide. The present invention also provides a lithium-rich manganese-based cathode material prepared by the above method. The present invention also provides a lithium-ion battery of which anode material contains the foregoing lithium-rich manganese-based anode material. The lithium-rich manganese-based cathode material provided by the present invention has high rate capability and prolonged cycle stability.