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.

Disclosed are a positive active material for a rechargeable lithium battery, a method of manufacturing the same, and a rechargeable lithium battery including the same. More specifically, the positive active material for a rechargeable lithium battery is a compound having an orthorhombic layered structure represented by the following Chemical Formula 1 or a compound represented by the following Chemical Formula 2, a method for producing the same, and a rechargeable lithium battery including the same.
Li.sub.1+xM.sub.yO.sub.2+z[Chemical Formula 1]
{.sub.m(Li.sub.1+xM.sub.yO.sub.2+z)}.{.sub.1-m(LiMO.sub.2)}[Chemical Formula 2] Wherein, in the above Chemical Formula 1 or Chemical Formula 2, M is one or more elements selected from the group consisting of Mn, Co, Ni, Al, Ti, Mo, V, Cr, Fe, Cu, Zr, Nb, and Ga, 0.7x1.2, 0.8y1.2, 0.2z0.2, and 0<m1.

Provided are a method of manufacturing a cathode active material including a first step of preparing a metal glycolate solution, a second step of mixing lithium-containing transition metal oxide particles and the metal glycolate solution and stirring in a paste state, a third step of drying the paste-state mixture, and a fourth step of performing a heat treatment on the dried mixture, a cathode active material including a metal oxide layer which is manufactured by the above method, and a secondary battery composed of a cathode including the cathode active material.

Mixed-metal oxides and lithiated mixed-metal oxides are disclosed that involve compounds according to, respectively, Ni.sub.xMn.sub.yCo.sub.zMe.sub.O.sub. and Li.sub.1+Ni.sub.xMn.sub.yCo.sub.zMe.sub.O.sub.. In these compounds, Me is selected from B, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Fe, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Ru, Ag, In, and combinations thereof; 0x1; 0y1; 0z<1; x+y+z>0; 00.5; and x+y+>0. For the mixed-metal oxides, 15. For the lithiated mixed-metal oxides, 0.11.0 and 1.93. The mixed-metal oxides and the lithiated mixed-metal oxides include particles having an average density greater than or equal to 90% of an ideal crystalline density.

A positive-electrode material for a lithium ion secondary battery contains a lithium complex compound that is represented by the formula: Li.sub.1+aNi.sub.bMn.sub.cCo.sub.dTi.sub.eM.sub.fO.sub.2+, and has an atomic ratio Ti.sup.3+/Ti.sup.4+ between Ti.sup.3+ and Ti.sup.4+, as determined through X-ray photoelectron spectroscopy, of greater than or equal to 1.5 and less than or equal to 20. In the formula, M is at least one element selected from the group consisting of Mg, Al, Zr, Mo, and Nb, and a, b, c, d, e, f, and are numbers satisfying 0.1a0.2, 0.7<b0.9, 0c<0.3, 0d<0.3, 0<e0.25, 0f<0.3, b+c+d+e+f=1, and 0.20.2.

A compound represented by Li.sub.Co.sub.(1-x-2y)Me.sub.x(M1M2).sub.yO.sub., (Formula (I)) wherein Me, is one or more of Li, Mg, Al, Ca, Ti, Zr, V, Cr, Mn, Fe, Ni, Cu, Zn, Ru and Sn, and wherein 0x0.3, 0<y0.4, 0.951.4, and 1.902.10 is disclosed. Further, particles including such compounds are described.

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 electrode active material contains a lithium composite oxide and a covering material. The lithium composite oxide contains at least one element selected from the group consisting of fluorine, chlorine, nitrogen, and sulfur. The lithium composite oxide has a crystal structure that belongs to space group C2/m. The ratio I.sub.(003)/I.sub.(104) of a first integrated intensity I.sub.(003) of a first peak corresponding to a (003) plane to a second integrated intensity I.sub.(104) of a second peak corresponding to a (104) plane in an XRD pattern of the lithium composite oxide satisfies 0.05I.sub.(003)/I.sub.(104)0.90. The covering material has an electron conductivity of 10.sup.6 S/m or less.

A mixed conductor, a method of preparing the same, and a cathode, a lithium-air battery, and an electrochemical device each including the mixed conductor. The mixed conductor is represented by Formula 1 and having electronic conductivity and ionic conductivity:

Li.sub.xMO.sub.2-Formula 1

wherein, in Formula 1, M is a Group 4 element, a Group 5 element, a Group 6 element, a Group 7 element, a Group 8 element, a Group 10 element, a Group 11 element, a Group 12 element, or a combination thereof, and 0<x<1 and 01 are satisfied.

Provided is a precursor of a positive electrode active material containing, in a reduced amount, impurities which do not contribute to a charge/discharge reaction but rather corrode a firing furnace and peripheral equipment and thus having excellent battery characteristics and safety, and production method thereof. A method for producing a precursor of a positive electrode active material for nonaqueous electrolyte secondary batteries having a hollow structure or porous structure includes obtaining the precursor by washing nickel-manganese composite hydroxide particles having a particular composition ratio and a pore structure in which pores are present within the particles with an aqueous carbonate solution having a carbonate concentration of 0.1 mol/L or more.