The present invention relates to a positive electrode active material and a lithium secondary battery comprising the same.

An electrode for a lithium-ion cell comprising a layered-spinel composite oxide material is disclosed. The layered-spinel can be a material of formula xLiMO.sub.2.(1x)Li.sub.yM.sub.zO.sub.4, wherein 0<x<1; LiMO.sub.2 is a lithium metal oxide having a layered structure in which M comprises one or more transition metals and optionally lithium, and has a combined average oxidation state of +3; and Li.sub.yM.sub.zO.sub.4 is a lithium metal oxide having a spinel structure, 1y1.33, 1.66z2, and M comprises one or more transition metals, and has a combined average metal oxidation state in the range of about +3.5 to about +4.

An electrical conductor including: a first conductive layer including a plurality of metal nanowires; and a second conductive layer disposed on a surface of the first conductive layer, wherein the second conductive layer includes a plurality of metal oxide nanosheets, wherein in the first conductive layer, a metal nanowire of the plurality of metal nanowires contacts at least two metal oxide nanosheets of the plurality of metal oxide nanosheets, and wherein the plurality of metal oxide nanosheets includes an electrical connection between contacting metal oxide nanosheets.

Disclosed is a cathode active material in which lithium cobalt oxide particles and manganese (Mn) or titanium (Ti)-containing lithium transition metal oxide particles co-exist and a method of preparing the same.

A negative electrode active material including lithium titanium oxide particles, wherein the lithium titanium oxide particles have a Na content of 50 ppm-300 ppm, a K content of 500 ppm-2400 ppm and a crystallite size of 100-200 nm, and a lithium secondary battery including the same.

A positive electrode active material includes: a particle including a lithium composite oxide; a first layer that is provided on a surface of the particle and includes a lithium composite oxide; and a second layer that is provided on a surface of the first layer. The lithium composite oxide included in the particle and the lithium composite oxide included in the first layer have the same composition or almost the same composition, the second layer includes an oxide or a fluoride, and the lithium composite oxide included in the first layer has lower crystallinity than the lithium composite oxide included in the particle.

A titanium oxide compound according to the present invention comprises bronze-type titanium oxide or titanium oxide mainly composed of bronze-type titanium oxide, and contains calcium and/or silicon. The titanium oxide compound contains 0.005 to 2.5 mass % inclusive of calcium or 0.15 to 0.55 mass % inclusive of silicon, or contains 0.005 to 1.2 mass % inclusive of calcium and 0.15 to 0.2 mass % inclusive of silicon, or contains 0.005 to 0.1 mass % inclusive of calcium and 0.15 to 0.5 mass % inclusive of silicon.

An electrode for a secondary battery comprises a current collector; and an active material-containing layer has active materials which comprise titanium-containing composite oxide having an orthorhombic crystal structure and represented by a general formula Li.sub.2+aM1.sub.2bTi.sub.6cM2.sub.dO.sub.14+;

wherein the active material-containing layer has intensity ratio Ia/Ib in an X-ray diffraction pattern of the active material-containing layer, the Ia and the Ib are obtained by powder X-ray diffraction method using Cu-K ray, the intensity ratio is within a range of 0.5Ia/Ib2, the Ia is the strongest intensity of a diffraction peak among diffraction peaks appearing within a range of 42244, and the Ib is the strongest intensity of a diffraction peak among diffraction peaks appearing within a range of 44<248.

(M1 is at least one selected from the group consisting of Sr, Ba, Ca, Mg, Na, Cs, Rb and K, M2 is at least one selected from the group consisting of Zr, Sn, V, Nb, Ta, Mo, W, Y, Fe, Co, Cr, Mn, Ni and Al a is within a range of 0a6 b is within a range of 0b<2 c is within a range of 0c<6 d is within a range of 0d<6 is within a range of 0.50.5.)

According to one embodiment, an active material is provided. The active material includes a composite of a phase of a titanium-including composite oxide and a phase of a titanium dioxide. The titanium-including composite oxide has crystal structures which belong to a space group Cmca, a space group Fmmm, or both the space group Cmca and the space group Fmmm.

According to one embodiment, a negative electrode active material includes particles and a carbon material. The particles is represented by Li.sub.2+aA.sub.dTi.sub.6bB.sub.bO.sub.14c, where A is at least one element selected from the group consisting of Na, K, Mg, Ca, Ba, and Sr; B is a metal element other than Ti; and a, b, c, and d respectively satisfy 0a5, 0b6, 0c0.6, and 0d3. The carbon material covers at least a part of surfaces of the particles.