Abstract: To provide a cathode active material for a lithium ion secondary battery excellent in the cycle characteristics and rate characteristics even when charging is conducted at a high voltage. A cathode active material for a lithium ion secondary battery, which comprises particles (III) having a covering layer comprising a metal oxide (I) containing at least one metal element selected from the group consisting of elements in Groups 3 and 13 of the periodic table and lanthanoid elements, and a compound (II) containing Li and P, on the surface of a lithium-containing composite oxide comprising lithium and a transition metal element, wherein the atomic ratio of said P to said metal element (P/metal element) contained within 5 nm of the surface layer of the particles (III) is from 0.03 to 0.45.

Abstract: To provide a cathode active material for a lithium ion secondary battery excellent in the cycle characteristics and rate characteristics even when charging is conducted at a high voltage. A cathode active material for a lithium ion secondary battery, which comprises particles (III) having a covering layer comprising a metal oxide (I) containing at least one metal element selected from the group consisting of elements in Groups 3 and 13 of the periodic table and lanthanoid elements, and a compound (II) containing Li and P, on the surface of a lithium-containing composite oxide comprising lithium and a transition metal element, wherein the atomic ratio of said P to said metal element (P/metal element) contained within 5 nm of the surface layer of the particles (III) is from 0.03 to 0.45.

Abstract: To provide a cathode active material for a lithium ion secondary battery excellent in the cycle characteristics and rate characteristics even when charging is conducted at a high voltage. A cathode active material for a lithium ion secondary battery, which comprises particles (III) having a covering layer comprising a metal oxide (I) containing at least one metal element selected from the group consisting of elements in Groups 3 and 13 of the periodic table and lanthanoid elements, and a compound (II) containing Li and P, on the surface of a lithium-containing composite oxide comprising lithium and a transition metal element, wherein the atomic ratio of said P to said metal element (P/metal element) contained within 5 nm of the surface layer of the particles (III) is from 0.03 to 0.45.

Abstract: To provide a cathode active material for a lithium ion secondary battery excellent in the cycle characteristics and rate characteristics even when charging is conducted at a high voltage. A cathode active material for a lithium ion secondary battery, which comprises particles (III) having a covering layer comprising a metal oxide (I) containing at least one metal element selected from the group consisting of Al, Y, Ga, In, La, Pr, Nd, Gd, Dy, Er and Yb, and a compound (II) containing Li and at least one non-metal element selected from the group consisting of S and B, on the surface of a lithium-containing composite oxide, wherein the atomic ratio (the non-metal element/the metal element) contained within 5 nm of the surface layer of the particles (III) is within a specific range.

Abstract: To provide a cathode active material for a lithium ion secondary battery, and its production process. A lithium-containing composite oxide containing a transition metal element and a composition (1) are contacted to obtain particles (I) having a compound containing a metal element (M) attached, which are mixed with a compound which generates HF by heating, and the mixture is heated to obtain particles (III) having a covering layer (II) containing the metal element (M) and fluorine element formed on the surface of the lithium-containing composite oxide. Composition (1): a composition having a compound containing no Li element and containing at least one metal element (M) selected from Mg, Ca, Sr, Ba, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Ni, Pb, Cu, Zn, Al, In, Sn, Sb, Bi, La, Ce, Pr, Nd, Gd, Dy, Er and Yb dissolved or dispersed in a solvent.

Abstract: To provide a process for producing a cathode active material for a lithium ion secondary battery, a cathode for a lithium ion secondary battery, and a lithium ion secondary battery. A production process which comprises contacting a lithium-containing composite oxide containing Li element and a transition metal element with a composition (1) {an aqueous solution containing cation M having at least one metal element (m)} and a composition (2) {an aqueous solution containing anion N having at least one element (n) selected from the group consisting of S, P, F and B, forming a hardly soluble salt when reacted with the cation M}, wherein the total amount A (mL/100 g) of the composition (1) and the composition (2) contacted per 100 g of the lithium-containing composite oxide is in a ratio of 0.1<A/B<5 based on the oil absorption B (mL/100 g) of the lithium-containing composite oxide.

Abstract: Disclosed is an optical member in the form of a film or a thin plate. The optical member contains near infrared absorbing particles comprising crystallites of an oxide containing at least Cu and P and having a number average aggregated particle size of at least 20 nm and at most 200 nm. Further, a near infrared cut filter, a solid-state imaging element, a lens for an imaging device and an imaging/display device are disclosed. They comprise a near infrared absorbing layer containing near infrared absorbing particles comprising crystallites of an oxide containing at least Cu and P and having a number average aggregated particle size of at least 20 nm and at most 200 nm.

Abstract: To provide a cathode active material for a lithium ion secondary battery excellent in the cycle characteristics and rate characteristics even when charging is conducted at a high voltage. A cathode active material for a lithium ion secondary battery, which comprises particles (III) having a covering layer comprising a metal oxide (I) containing at least one metal element selected from the group consisting of elements in Groups 3 and 13 of the periodic table and lanthanoid elements, and a compound (II) containing Li and P, on the surface of a lithium-containing composite oxide comprising lithium and a transition metal element, wherein the atomic ratio of said P to said metal element (P/metal element) contained within 5 nm of the surface layer of the particles (III) is from 0.03 to 0.45.

Abstract: To provide a cathode active material for a lithium ion secondary battery excellent in the cycle characteristics and rate characteristics even when charging is conducted at a high voltage. A cathode active material for a lithium ion secondary battery, which comprises particles (III) having a covering layer comprising a metal oxide (I) containing at least one metal element selected from the group consisting of Al, Y, Ga, In, La, Pr, Nd, Gd, Dy, Er and Yb, and a compound (II) containing Li and at least one non-metal element selected from the group consisting of S and B, on the surface of a lithium-containing composite oxide, wherein the atomic ratio (the non-metal element/the metal element) contained within 5 nm of the surface layer of the particles (III) is within a specific range.

Abstract: To provide a cathode active material for a lithium ion secondary battery, and its production process. A lithium-containing composite oxide containing a transition metal element and a composition (1) are contacted to obtain particles (I) having a compound containing a metal element (M) attached, which are mixed with a compound which generates HF by heating, and the mixture is heated to obtain particles (III) having a covering layer (II) containing the metal element (M) and fluorine element formed on the surface of the lithium-containing composite oxide. Composition (1): a composition having a compound containing no Li element and containing at least one metal element (M) selected from Mg, Ca, Sr, Ba, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Ni, Pb, Cu, Zn, Al, In, Sn, Sb, Bi, La, Ce, Pr, Nd, Gd, Dy, Er and Yb dissolved or dispersed in a solvent.

Abstract: To provide a process for producing a cathode active material for a lithium ion secondary battery, a cathode for a lithium ion secondary battery, and a lithium ion secondary battery. A production process which comprises contacting a lithium-containing composite oxide containing Li element and a transition metal element with a composition (1) {an aqueous solution containing cation M having at least one metal element (m)} and a composition (2) {an aqueous solution containing anion N having at least one element (n) selected from the group consisting of S, P, F and B, forming a hardly soluble salt when reacted with the cation M}, wherein the total amount A (mL/100 g) of the composition (1) and the composition (2) contacted per 100 g of the lithium-containing composite oxide is in a ratio of 0.1<A/B<5 based on the oil absorption B (mL/100 g) of the lithium-containing composite oxide.

Abstract: The present invention provides a method for producing a cathode active material for a lithium ion secondary battery excellent in the discharge capacity and the cycle characteristics and having high durability, and methods for producing a lithium ion secondary battery and a cathode for a lithium ion secondary battery. A lithium-containing composite oxide comprising Li element and at least one transition metal element selected from the group consisting of Ni, Co and Mn (provided that the molar amount of the Li element is more than 1.2 times the total molar amount of said transition metal element) and a composition (1) {a composition having a compound (1) containing no Li element and comprising Mn element as an essential component, dissolved or dispersed in a solvent} are contacted, followed by heating to produce a cathode active material for a lithium ion secondary battery.

Abstract: The present invention provides a cathode active material for a lithium ion secondary battery excellent in the cycle characteristics and rate characteristics even when charged at a high voltage, a cathode, a lithium ion secondary battery and a method for producing a cathode active material for a lithium ion secondary battery. The cathode active material comprises particles (II) having an oxide (I) of at least one metal element selected from Zr, Ti and Al locally distributed at the surface of a lithium-containing composite oxide comprising Li element and at least one transition metal element selected from the group consisting of Ni, Co and Mn (provided that the molar amount of the Li element is more than 1.2 times the total molar amount of said transition metal element).

Abstract: Disclosed is an optical member in the form of a film or a thin plate. The optical member contains near infrared absorbing particles comprising crystallites of an oxide containing at least Cu and P and having a number average aggregated particle size of at least 20 nm and at most 200 nm. Further, a near infrared cut filter, a solid-state imaging element, a lens for an imaging device and an imaging/display device are disclosed. They comprise a near infrared absorbing layer containing near infrared absorbing particles comprising crystallites of an oxide containing at least Cu and P and having a number average aggregated particle size of at least 20 nm and at most 200 nm.