A positive active material for a rechargeable lithium battery includes a core including an overlithiated oxide represented by Chemical Formula 1, a first coating layer on the core and including a compound having a spinel structure, and a second coating layer on the first coating layer and including a compound represented by Chemical Formula 2. The compound having a spinel structure shows a peak between about 2.6 V and about 2.7 V in a graph of differential capacity dQ/dV vs. voltage, where the voltage is between about 4.7 V and about 2.5 V. In Chemical Formula 1, 0<x<1, 0<a<1, 0<b<1, 0<c<1, and a+b+c=1. In Chemical Formula 2, 0d<1 and 0<e1.
xLi.sub.2MnO.sub.3.(1x)LiNi.sub.aCo.sub.bMn.sub.cO.sub.2,Chemical Formula 1
Li.sub.dTi.sub.eO.sub.2.Chemical Formula 2

Compounds that can be used as cathode active materials for lithium ion batteries are described. In some embodiments, the cathode active material includes the compound Li.sub.xNi.sub.aM.sub.bN.sub.cO.sub.2 where M is selected from Mn, Ti, Zr, Ge, Sn, Te and a combination thereof; N is selected from Mg, Be, Ca, Sr, Ba, Fe, Ni, Cu, Zn, and a combination thereof; 0.9<x<1.1; 0.7<a<1; 0<b<0.3; 0<c<0.3; and a+b+c=1. Other cathode active materials, precursors, and methods of manufacture are presented.

The disclosed embodiments relate to the manufacture of a precursor co-precipitate material for a cathode active material composition. During manufacture of the precursor co-precipitate material, an aqueous solution containing at least one of a manganese sulfate and a cobalt sulfate is formed. Next, a NH.sub.4OH solution is added to the aqueous solution to form a particulate solution comprising irregular secondary particles of the precursor co-precipitate material. A constant pH in the range of 10-12 is also maintained in the particulate solution by adding a basic solution to the particulate solution.

Disclosed herein is a method for making a particulate (oxy)hydroxide of TM, where TM is a combination of nickel and at least one metal selected from Co and Mn, the process including: (a) providing an aqueous solution () containing water-soluble salts of Ni and of at least one transition metal selected from Co and Mn, (b) combining a solution () and a solution () and, if applicable, a solution () at a pH value in a range of from 12.0 to 13.0 determined at 23 C. in a continuous stirred tank reactor, thereby creating a slurry of solid particles of a hydroxide containing nickel, and (c) transferring slurry from step (b) into a batch-wise operated stirred tank reactor where a solution () and a solution () and optionally a solution () are combined with the slurry at a pH value in a range of from 11.0 to 12.0 determined at 23 C.

According to the present disclosure, a method for manufacturing a positive electrode active material that can contribute to improvement of battery performance. The manufacture method disclosed herein includes: a preparation step S10 of preparing a starting raw material containing at least a transition metal element; a formulation step S20 of formulating a transition metal solution by dissolving, in an extractant, the transition metal element in the starting raw material; a precursor production step S30 of crystallizing a positive electrode active material precursor by adding an alkali solution to the transition metal solution; and an active material production step S40 of producing a positive electrode active material by heating the positive electrode active material precursor together with a lithium compound. In the manufacture method disclosed herein is characterized in that a sulfate ion concentration of the transition metal solution is 0.9 mol/L or lower during the precursor production step.

Provided is a positive electrode active material that is capable of improving output characteristics when used as positive electrode material for a non-aqueous electrolyte secondary battery. A lithium mixture that is obtained by adding and mixing a lithium compound to a transition metal composite hydroxide that was obtained from a crystallization reaction undergoes calcination in an atmosphere having an oxygen concentration of 4% by volume or greater. In this calcination process, carbon dioxide gas concentration in the atmosphere while the temperature is maintained at a calcination temperature is kept at 10% by volume or less, and preferably kept at 0.01% by volume to 10% by volume. As a result, positive electrode active material is obtained that includes a lithium transition metal composite oxide that is composed of secondary particles that are formed from aggregates of plural primary particles, and that has a carbon content of 0.010% by mass to 0.100% by mass.

Ferrite films, antennas including ferrite films, and methods of making thereof are provided. The methods can include tape casting of a slurry to produce a green film, wherein the slurry includes a ferrite powder, a dispersant, and a binder in a suitable solvent; and densifying the green film to produce the ferrite film having a thickness of 50 m to 5 mm. The methods can be used to make large area films, for example the films can have a lateral area of about 1000 cm.sup.2 to 3000 cm.sup.2. VHF/UHF antennas are including the ferrite films are also provided.

Provided are uniquely structured electrochemically active particles characterized by a first electrochemically active material and a second electrochemically active material disposed about the first material whereby at least the second material includes a modifier present as a continuous transition concentration gradient from the first material into the second material whereby the concentration is lower in the first material than the second material. Also provided are processes of producing the particle and electrochemical cells incorporating the particles as a positive electrode material in a cathode.

A positive active material includes an overlithiated lithium transition metal oxide including: a metal cation and a Li.sub.2MO.sub.3 phase, wherein M is at least one metal selected from a Period 4 transition metal having an average oxidation number of +4 and a Period 5 transition metal having an average oxidation number of +4, and wherein an amount of the Li.sub.2MO.sub.3 phase is less than or equal to about 20 mole percent, based on 1 mole of the overlithiated lithium transition metal oxide.

An object of the present invention is to provide a ferrite material that is excellent in temperature characteristic and DC superimposition characteristic. The present invention relates to NiZnCu-based ferrite particles comprising 70 to 95% by weight of an NiZnCu ferrite having a specific composition, 1 to 20% by weight of nickel oxide, 0 to 20% by weight of zinc oxide and 1 to 10% by weight of copper oxide, and a ferrite sintered ceramics obtained by sintering the ferrite particles.