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.

A positive electrode active material has a small difference in a crystal structure between the charged state and the discharged state. For example, the crystal structure and volume of the positive electrode active material, which has a layered rock-salt crystal structure in the discharged state and a pseudo-spinel crystal structure in the charged state at a high voltage of approximately 4.6 V, are less likely to be changed by charging and discharging as compared with those of a known positive electrode active material. In order to form the positive electrode active material having the pseudo-spinel crystal structure in the charged state, it is preferable that a halogen source such as a fluorine and a magnesium source be mixed with particles of a composite oxide containing lithium, a transition metal, and oxygen, which is synthesized in advance, and then the mixture be heated at an appropriate temperature for an appropriate time.

Provided is a method for inhibiting extractant degradation in the DSX process through the metal extraction control, the method comprising steps of: (a) adding limestone to a copper solvent extraction-raffinate to precipitate iron (Fe) and aluminum (Al) as a slurry, recovering a clarifying liquid; and (b) adding sulfuric acid to the recovered clarifying liquid to adjust the pH thereof.

There is provided a Co-based 5-V spinel-type lithium manganese-containing complex oxide not only having an operating potential of 4.5 V or higher but also being capable of extending its capacity region of a 5.5 to 5.5 V region and being capable of enhancing its energy density as well. There is proposed a spinel-type lithium cobalt manganese-containing complex oxide having a crystal structure classified as a space group Fd-3m and being represented by the general formula [Li.sub.x(Co.sub.yMn.sub.3−x−y)O.sub.4−δ] (wherein 0.90≦x≦1.15 and 0.75≦y≦1.25), wherein the oxide has a crystallite size measured by a Rietveld method using the fundamental method of 100 nm to 200 nm, an interatomic distance of Li—O of 1.80 Å to 2.00 Å, and a strain of 0.20 to 0.50.

An e-type iron-based oxide magnetic particle powder has narrow particle size distribution and has a low content of fine particles which do not contribute to magnetic recording characteristics. As a result, a narrow coercive force distribution is achieved and the powder is suitable for increasing recording density of a magnetic recording medium. The powder containing substituting metal elements can be obtained by: adding an alkali to an aqueous solution containing trivalent iron ions and ions of the metals for partially substituting Fe sites to neutralize the aqueous solution to a pH of 1.5 to 2.5; then adding a hydroxycarboxylic acid; further adding the alkali to neutralize the aqueous solution to a pH of 8.0 to 9.0; washing with water a precipitation of an iron oxyhydroxide containing the substituting metal elements produced; and coating the iron oxyhydroxide containing the substituting metal elements with a silicon oxide and heating the resultant.

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.

Radiofrequency and other electronic devices can be formed from textured hexaferrite materials, such as Z-phase barium cobalt ferrite Ba.sub.3Co.sub.2Fe.sub.24O.sub.41 (Co.sub.2Z) having enhanced resonant frequency. The textured hexaferrite material can be formed by sintering fine grain hexaferrite powder at a lower temperature than conventional firing temperatures to inhibit reduction of iron. The textured hexaferrite material can be used in radiofrequency devices such as circulators or telecommunications systems.

Lithium metal oxides may be regenerated under ambient conditions from materials recovered from partially or fully depleted lithium-ion batteries. Recovered lithium and metal materials may be reduced to nanoparticles and recombined to produce regenerated lithium metal oxides. The regenerated lithium metal oxides may be used to produce rechargeable lithium ion batteries.

This disclosure relates to photocatalytic polyoxometalate compositions of tungstovanadates and uses as water oxidation catalysts. In certain embodiments, the disclosure relates to compositions comprising water, a complex of a tetra-metal oxide cluster and VW.sub.9O.sub.34 ligands, and a photosensitizer. Typically, the metal oxide cluster is Co. In certain embodiments, the disclosure relates to electrodes and other devices comprising water oxidation catalysts disclosed herein and uses in generating fuels and electrical power from solar energy.

A negative electrode active material according to one embodiment includes a titanium oxide compound having a crystal structure of monoclinic system titanium dioxide. The titanium oxide compound is modified by at least one kind of ion selected from the group consisting of an alkali metal cation, an alkali earth metal cation, a transition metal cation, a sulfide ion, a sulfuric acid ion and a chloride ion.