Provided are a positive electrode active material for nonagueous secondary batteries, the material having a narrow particle-size distribution and a monodisperse property and being capable of increasing a battery capacity; an industrial production method thereof; and a nonaqueous secondary battery using the positive electrode active material and having excellent electrical characteristics. The positive electrode active material is represented by a general formula: Li.sub.1+uNi.sub.xCo.sub.yMn.sub.zM.sub.tO.sub.2+ (wherein, 0.05u0.95, x+y+z+t=1, 0x0.5, 0y0.5, 0.5z<0.8, 0t0.1, and M is an additive element and at least one element selected from Mg, Ca, Al, Ti, V, Cr, Zr, Nb, Mo, and W), has an average particle diameter of 3 to 12 um, and has [(d.sub.90d.sub.10)/average particle diameter], an index indicating a scale of particle-size distribution, of 0.60 or less.

Electrode materials for electrochemical cells and batteries and methods of producing such materials are disclosed herein. The electrode materials comprise an active lithium metal oxide material prepared by: (a) contacting the lithium metal oxide material with an aqueous acidic solution containing one or more metal cations; and (b) heating the so-contacted lithium metal oxide from step (a) to dryness at a temperature below 200 C. The metal cations in the aqueous acidic solution comprise one or more metal cations selected from the group consisting of an alkaline earth metal ion, a transition metal ion, and a main group metal ion.

Electrode materials for electrochemical cells and batteries and methods of producing such materials are disclosed herein. A method of preparing an active lithium metal oxide material suitable for use in an electrode for a lithium electrochemical cell comprises the steps of: (a) contacting the lithium metal oxide material with an aqueous acidic solution containing one or more metal cations; and (b) heating the so-contacted lithium metal oxide from step (a) to dryness at a temperature below 200 C. The metal cations in the aqueous acidic solution comprise one or more metal cations selected from the group consisting of an alkaline earth metal ion, a transition metal ion, and a main group metal ion.

Provided herein is a method for preparing a ternary cathode material for lithium-ion battery by a static mixer, wherein the cathode material comprises a lithium multi-metal composite oxide represented by xLi.sub.2MnO.sub.3. (1-x) LiNi.sub.aMn.sub.bCo.sub.cAl .sub.(1-a-b-e)O.sub.2, where 0a<1, 0b<1, 0c<1, a+b+c1, and 0x<1. The cathode material disclosed herein exhibits a high initial specific capacity, possesses good safety characteristics and shows excellent capacity retention.

Provided is a positive electrode for a lithium ion battery, the electrode comprising a nano-crystalline layered-layered composite structure of a material having the general formula xLi.sub.2MO.sub.3(1x)LiMO.sub.2 in which 0<x<1, where M is one or more ion with an average oxidation state of three and with at least one ion being Mn or Ni, and where M is one or more ions with an average oxidation state of four. Another aspect provides a positive electrode for a lithium ion battery, the electrode comprising a nano-crystalline layered-spinel composite structure of a material having the general formula xLi.sub.2MnO.sub.3. (1x)LiMn.sub.2yM.sub.yO.sub.4 in which 0.5<x<1.0, 0y<1, and where M is one or more metal cations. Also provided is the positive electrode which comprises a nano-coating of inert oxide, inert phosphate or inert fluoride on the nano-crystalline composite structure. Additional aspects provide a lithium ion battery comprising a negative electrode, an electrolyte and the positive electrode, as well as methods of preparing the positive electrode composite structure and the nano-coating of inert oxide, inert phosphate or inert fluoride.

A positive active material for a rechargeable lithium battery includes a lithium nickel-based composite oxide including a secondary particle in which a plurality of plate-shaped primary particles are agglomerated; and a lithium manganese composite oxide having at least two crystal lattice structures, wherein the secondary particle has a regular array structure in which (003) planes of the primary particles are oriented in a vertical direction with respect to the surface of the secondary particle.

A method of forming a high energy density composite cathode material is disclosed. The method includes providing a lithium-rich manganese layered oxide (LRMO), coating the LRMO with a TiO.sub.2 precursor, and ball-milling the TiO.sub.2 coated LRMO with LiH to form a Li.sub.xTiO.sub.2 coated LRMO composite, wherein x is less than or equal to 1 and greater than zero.

A mixed ionic and electronic conductor represented by Formula 1:

T.sub.xVa.sub.yA.sub.1-x-yM.sub.zO.sub.3-,

wherein T includes at least one monovalent cation, A includes at least one of a monovalent cation, a divalent cation, and a trivalent cation, M includes at least one of a trivalent cation, a tetravalent cation, and a pentavalent cation, M is an element other than Ti and Zr, Va is a vacancy, is an oxygen vacancy, 0<x, y0.25, 0<z<1, and 01.

A perovskite material represented by Formula 1:

Li.sub.xA.sub.yM.sub.zO.sub.3-Formula 1 wherein in Formula 1, 0<x1, 0<y1, 0<x+y<1, 0<z1.5, 01, A is H, Na, K, Rb, Cs, Ca, Sr, Ba, Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, or a combination thereof, and M is Ni, Pd, Pb, Fe, Ir, Co, Rh, Mn, Cr, Ru, Re, Sn, V, Ge, W, Zr, Mo, Hf, U, Nb, Th, Ta, Bi, Li, H, Na, K, Rb, Cs, Ca, Sr, Ba, Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Mg, Al, Si, Sc, Zn, Ga, Ag, Cd, In, Sb, Pt, Au, or a combination thereof.

Acoustically active articles having a composition including a nano-structured metal oxide are provided. The nano-structured metal oxide has the formula M1xM2yOz, where M1 is selected from the group consisting of alkali metals, alkaline earth metals, and combinations thereof, M2 is a transition metal or post-transition metal, and M2 has an atomic number no greater than 78. The articles can lower a resonant frequency of a cavity by no less than 50 Hz when the cavity is filled with the article and the resonant frequency is in a range from about 50 Hz to about 1500 Hz.