A positive electrode for a rechargeable battery, comprising a lithium metal oxide powder having a layered crystal structure and having the formula Li.sub.xTm.sub.yHm.sub.zO.sub.6, with 3x4.8, 0.60y2.0, 0.60z2.0, and x+y+z=6, wherein Tm is one or more transition metals of the group consisting of Mn, Fe, Co, Ni, and Cr; wherein Hm is one or more metals of the group consisting of Zr, Nb, Mo and W. The lithium metal oxide powder may comprise dopants and have the formula Li.sub.xTm.sub.yHm.sub.zM.sub.mO.sub.6 A, wherein A is either one or more elements of the group consisting of F, S or N; and M is either one or more metal of the group consisting of Ca, Sr, Y, La, Ce and Zr, with either >0 or m>0, 0.05, m0.05 and x+y+z+m=6.

A method of producing an oxide of manganese including reacting, in a first aqueous solution, a manganese salt and an alkali agent to form manganese hydroxide; separating the manganese hydroxide from the first solution; mixing the manganese hydroxide into an aqueous medium to form a manganese hydroxide suspension; mixing the manganese hydroxide suspension with alkali metal hydroxide to form a second aqueous solution; and oxidizing the manganese hydroxide in the second aqueous solution to form an oxide of manganese. The dried oxide of manganese includes birnessite, a maximum of 20% hausmannite, and a maximum of 10% feitknechtite, may further include a maximum of 400 ppm of anions, may have a specific surface area of at least 25 m2/g, and may have an average oxidation state of greater than 3.5.

Provided is a cerium-zirconium-based composite oxide having an excellent OSC, high catalytic activity, and excellent heat resistance, and also provided is a method for producing the same. The cerium-zirconium-based composite oxide comprises cerium, zirconium, and a third element other than these elements. The third element is (a) a transition metal element or (b) at least one or more elements selected from the group consisting of rare earth elements and alkaline earth metal elements. After a heat treatment at 1,000 C. to 1,100 C. for 3 hours, (1) the composite oxide has a crystal structure containing a pyrochlore phase, (2) a value of {I111/(I111+I222)}100 is 1 or more, and (3) the composite oxide has an oxygen storage capacity at 600 C. of 0.05 mmol/g or more, and an oxygen storage capacity at 750 C. of 0.3 mmol/g or more.

Nanowires useful as heterogeneous catalysts are provided. The nanowire catalysts are useful in a variety of catalytic reactions, for example, the oxidative coupling of methane to C2 hydrocarbons. Related methods for use and manufacture of the same are also disclosed.

Embodiments of the present disclosure are directed to hydrogen-selective oxygen carrier materials and methods of using hydrogen-selective oxygen carrier materials. The hydrogen-selective oxygen carrier material may comprise a core material, which includes a redox-active transition metal oxide; a shell material, which includes one or more alkali transition metal oxides; and a support material. The shell material may be in direct contact with at least a majority of an outer surface of the core material. At least a portion of the core material may be in direct contact with the support material. The hydrogen-selective oxygen carrier material may be selective to combust hydrogen in an environment that includes hydrogen and hydrocarbons.

Provided are polycrystalline lithium manganese oxide particles represented by Chemical Formula 1 and a method of preparing the same:
Li.sub.(1+x)Mn.sub.(2-x-y-f)Al.sub.yM.sub.fO.sub.(4-z)<Chemical Formula 1> where M is sodium (Na), or two or more mixed elements including Na, 0x0.2, 0<y0.2, 0<f0.2, and 0z0.2. According to an embodiment of the present invention, limitations, such as the Jahn-Teller distortion and the dissolution of Mn.sup.2+, may be addressed by structurally stabilizing the polycrystalline lithium manganese oxide particles. Thus, life characteristics and charge and discharge capacity characteristics of a secondary battery may be improved.

Embodiments related to electroactive compounds, their methods of manufacture, and use are described. In one embodiment, an electroactive compound may include Na(Fe.sub.aX.sub.1-a)O.sub.2. X includes at least one of Ti, V, Cr, Mn, Co, Ni, and a is greater than 0 and less than or equal to 0.4. In another embodiment, an electroactive compound may include Na(Mn.sub.wFe.sub.xCo.sub.yNi.sub.z)O.sub.2, where w, x, y, and z are greater than 0. Further, a sum of w, x, y, and z is equal to 1 in some cases.

Disclosed is a method for preparing a precursor of lithium composite transition metal oxide for lithium secondary batteries, using a reactor having a closed structure including an outer stationary cylinder; an inner rotary cylinder on the same axis; and a rotation reaction area disposed between them, wherein ring-shaped vortex pairs that are uniformly arranged in a rotation axis direction and rotate in opposite directions are formed in the rotation reaction area. According to the method of the invention, raw materials comprising an aqueous solution of two or more transition metal salts, an aqueous solution of a complex forming additive, and a basic aqueous solution for maintaining pH are fed through an inlet into the rotation reaction area where a coprecipitation reaction is performed under a non-nitrogen atmosphere to form lithium composite transition metal oxide particles which are then discharged through a reactor outlet.

The cathode active material for a nonaqueous electrolyte secondary battery according to an aspect of the present disclosure mainly comprises a compound represented by a composition formula: Li.sub.xNa.sub.y(Li.sub.Na.sub.Mn.sub.1)O.sub.2, where x, y, , and satisfy 0.75x1.0, 0<y0.01, 0.75<x+y1, 0.160.3, 00.01, and 0.2+0.3.

Aluminum dry-coated and heat treated cathode material precursors. A particulate precursor compound for manufacturing an aluminum coatedlithium transition metal (M)-oxide powder usable as an active positive electrode material in lithium-ion batteries includes a transition metal (M)-oxide core and a non-amorphous aluminum oxide coating layercovering the core. By providing a heat treatment process for mixed metal precursors that may be combined with an aluminum dry-coating process, novel aluminum containing precursors that may be used to form high quality nickel based cathode materials are obtained. The aluminum dry-coated and heat treated precursors include particles have, compared to prior art precursors, relatively low impurity levels of carbonate and/or sulfide, and can be produced at lower cost.