A composite positive active material for a lithium secondary battery including a lithium cobalt-based oxide; a method of preparing the same; and a lithium secondary battery including a positive electrode for a lithium secondary battery including the composite positive active material are provided. The composite positive active material for a lithium secondary battery includes the lithium cobalt-based oxide, a particle coating part in a form of islands on one surface of the lithium cobalt-based oxide, the particle coating part including a first coating layer containing lithium titanium-based oxide, and a surface coating part in an internal region of another surface of the lithium cobalt-based oxide.

A negative active material includes a carbon material. The carbon material satisfies the following relationship: 6<Gr/K<16, Gr is a graphitization degree of the carbon material, measured by means of X-ray diffraction; and K is a ratio Id/Ig of a peak intensity Id of the carbon material at a wavenumber of 1250 cm.sup.−1 to 1650 cm.sup.−1 to a peak intensity Ig of the carbon material at a wavenumber of 1500 cm.sup.−1 to 1650 cm.sup.−1, and is measured by using Raman spectroscopy, and K is 0.06 to 0.15. The negative active material according to this application can significantly improve an energy density, cycle performance, and rate performance of the electrochemical device.

Supplemental lithium can be used to stabilize lithium ion batteries with lithium rich metal oxides as the positive electrode active material. Dramatic improvements in the specific capacity at long cycling have been obtained. The supplemental lithium can be provided with the negative electrode, or alternatively as a sacrificial material that is subsequently driven into the negative electrode active material. The supplemental lithium can be provided to the negative electrode active material prior to assembly of the battery using electrochemical deposition. The positive electrode active materials can comprise a layered-layered structure comprising manganese as well as nickel and/or cobalt.

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+α, 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 α are numbers satisfying −0.1≦a≦0.2, 0.7<b≦0.9, 0≦c<0.3, 0≦d<0.3, 0<e≦0.25, 0≦f<0.3, b+c+d+e+f=1, and −0.2≦α≦0.2.

The present invention relates to an anode active material for lithium secondary battery and a lithium secondary battery including the same, and more specifically it relates to an anode active material for lithium secondary battery in which the a lithium ion diffusion path in the primary particles is formed to exhibit specific directivity, and a lithium secondary battery including the same. The cathode active material for lithium secondary battery of the present invention has a lithium ion diffusion path exhibiting specific directivity in the primary particles and the secondary particles, thus not only the conduction velocity of the lithium ion is fast and the lithium ion conductivity is high but also the cycle characteristics are improved as the crystal structure hardly collapses despite repeated charging and discharging.

A pulverulent cathode material contains at least one mixed oxide containing the metal components Li, at least one further metal component selected from the group consisting of Mn, Ni and Co. The pulverulent cathode material is produced by a process in which an ammonia-containing aerosol containing metal compound of the metal components is converted in a high-temperature zone of a reaction space and then the solids are removed.

A lithium secondary battery is produced by employing a charging method where a positive electrode upon charging has a maximum achieved potential of 4.3 V (vs. Li/Li.sup.+) or lower. The lithium secondary battery contains an active material including a solid solution of a lithium transition metal composite oxide having an α-NaFeO.sub.2-type crystal structure. The solid solution has a diffraction peak observed near 20 to 30° in X-ray diffractometry using CuKα radiation for a monoclinic Li[Li.sub.1/3Mn.sub.2/3]O.sub.2-type before charge-discharge. The lithium secondary battery is charged to reach at least a region with substantially flat fluctuation of potential appearing in a positive electrode potential region exceeding 4.3 V (vs. Li/Li.sup.+) and 4.8 V (vs. Li/Li.sup.+) or lower. A dischargeable electric quantity in a potential region of 4.3 V (vs. Li/Li.sup.+) or lower is 177 mAh/g or higher.

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-δ  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 0≤δ≤1 are satisfied.

The present invention generally relates to P2-type layered materials for electrochemical devices such as Na-ion batteries with high rate performance, and methods of making or using such materials. In some embodiments, the P2-type layered material has the chemical formula Na.sub.X(Mn.sub.QFe.sub.RCo.sub.T)O.sub.2. The P2-type layered material may be synthesized, for example, by a solid state reaction. In some cases, the P2-type layered material may be used as an electrode in an electrochemical device. The electrochemical device may have higher initial discharge capacities at various charge/discharge rates in galvanostatic testing compared with the initial discharge capacities of other P2-type layered materials.

The present invention provides a method of producing a lithium mixed metal oxide, a lithium mixed metal oxide and a nonaqueous electrolyte secondary battery. The method includes a step of calcining a mixture of one or more compounds of M wherein M is one or more elements selected from the group consisting of nickel, cobalt and manganese, and a lithium compound, in the presence of one or more inactive fluxes selected from the group consisting of a fluoride of A, a chloride of A, a carbonate of A, a sulfate of A, a nitrate of A, a phosphate of A, a hydroxide of A, a molybdate of A and a tungstate of A, wherein A is one or more elements selected from the group consisting of Na, K, Rb, Cs, Ca, Mg, Sr and Ba. The lithium mixed metal oxide contains nickel, cobalt and manganese, has a BET specific surface area of from 3 m.sup.2/g to 15 m.sup.2/g, and has an average particle diameter within a range of 0.1 μm or more to less than 1 μm, the diameter determined by a laser diffraction scattering method.