Sumitomo Chemical Company, Limited

Asahi Glass Company, Limited

Kentaro Tsunozaki

Takeshi Kawasato

Haisheng Zeng

Toshio Suzuki

Yasuyuki Takimoto

Tegi Ri

Tomohiro Sakai

Yasuhide Kawaguchi

Michinori Suehara

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.

Cathode active material for lithium ion secondary battery, and process for its production

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.

Cathode active material for lithium ion secondary battery

To provide a cathode active material having excellent cycle characteristics and a small decrease in the discharge voltage, and a process for its production. A process for producing a cathode active material, which comprises a step of mixing at least one sulfate (A) selected from the group consisting of a sulfate of Ni, a sulfate of Co and a sulfate of Mn with at least one carbonate (B) selected from the group consisting of sodium carbonate and potassium carbonate in an aqueous solution state to obtain a coprecipitated compound, a step of mixing the coprecipitated compound with an aqueous phosphate solution, a step of volatilizing a water content from the mixture of the coprecipitated compound and the aqueous phosphate solution to obtain a precursor compound, and a step of mixing the precursor compound with lithium carbonate and firing the mixture at from 500 to 1000&#xb0; C.; and a cathode active material obtainable by the production process, which comprises Li, at least one transition metal element (X) selected from the group consisting of Ni, Co and Mn, and P, wherein the average coefficient of variation (CV value) of the calculated peak intensity ratio (Ip/Ix) of P to the transition metal element (X) is from 0 to 20% as determined by a method for measuring coefficient of variation.

Cathode active material and process for its production

To provide a process for producing a cathode active material for a lithium ion secondary battery which can improve the initial charge and discharge efficiency (initial efficiency) and the cycle retention of a lithium ion secondary battery. A process for producing a cathode active material for a lithium ion secondary battery, which comprises a step (I) of bringing a lithium-containing composite oxide (I) containing Li element and a transition metal element into contact with a washing liquid and then separating it from the washing liquid to obtain a lithium-containing composite oxide (II), a step (II) of bringing the lithium-containing composite oxide (II) into contact with a composition (1) consisting of an aqueous solution containing an anion (A) preferably containing F and a composition (2) consisting of an aqueous solution containing a cation (M) preferably containing Al or Zr, and a step (III) of heating the lithium-containing composite oxide (II) after the step (II), in this order.

Process for producing cathode active material for lithium ion secondary battery

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.

Process for producing cathode active material for lithium ion secondary battery, cathode for lithium ion secondary battery, and lithium ion secondary battery

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&#x3c;A/B&#x3c;5 based on the oil absorption B (mL/100 g) of the lithium-containing composite oxide.

To provide a photocurable composition from which a cured product excellent in mold release characteristics and mechanical strength can be obtained, and a method for producing a molded product excellent in durability, with a fine pattern having a reverse pattern of a mold precisely transferred on its surface. A photocurable compositioncomprising from 15 to 60 mass % of a compound (A) which is an aromatic compound having at least two rings or an alicyclic compound having at least two rings and which has two (meth)acryloyloxy groups, from 5 to 40 mass % of a compound (B) having a fluorine atom and having at least one carbon-carbon unsaturated double bond (excluding the compound (A)), from 10 to 55 mass % of a compound (C) having one (meth)acryloyloxy group (excluding the compound (B)) and from 1 to 12 mass % of a photopolymerization initiator (D) (provided that (A)+(B)+(C)+(D)=100 mass %) is used.

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Tokyo, Japan

Kentaro Tsunozaki