Sumitomo Metal Mining Company, Ltd.

Toyota Jidosha Kabushiki Kaisha

Tetsutaro Hayashi

Willy Shun Kai Bong

Yuji Yamamoto

Yoshinari Makimura

Momoko Procter

Satoshi Kanada

Ryuta Sugiura

Taira Aida

Toshihiro Kato

Kensaku Mori

Masanori Takagi

Rei Kokado

Shinsuke Suganuma

Hiroyuki Toya

Daisuke Horikawa

Hideyuki Saka

Shuhei Oda

To provide a positive electrode active material capable of further reducing positive electrode resistance and exhibiting better output characteristics. A positive electrode active material includes a coating layer formed of a metal composite oxide of Li and one or more metal elements selected from Al, Ti, Zr, Nb, Mo, and W on at least a part of a surface of lithium transition metal-containing composite oxide particles, and has d50 of 3.0 to 7.0 μm, a BET specific surface area of 2.0 to 5.0 m/g, a tap density of 1.0 to 2.0 g/cm, and an oil absorption amount of 30 to 60 ml/100 g, in which the amount of metal elements other than Li contained in the coating layer is 0.1 to 1.5 atom % with respect to the total number of atoms of Ni, Mn, and Co contained in the composite oxide particles.

Positive electrode active material for lithium ion secondary battery and lithium ion secondary battery

A positive electrode active material is constituted by lithium transition metal-containing composite oxide particles having a layered rock salt type crystal structure and are composed of secondary particles each formed of an aggregation of primary particles. The secondary particles have a d50 of 3.0 to 7.0 μm, a BET specific surface area of 1.8 to 5.5 m/g, a pore peak diameter of 0.01 to 0.30 μm, and a log differential pore volume [dV/d(log D)] of 0.2 to 0.6 ml/g within a range of the pore peak diameter. In each of a plurality of primary particles having a primary particle size of 0.1 to 1.0 μm, a coefficient of variation of the concentration of an additive element M is 1.5 or less.

A positive electrode active material includes lithium transition metal-containing composite oxide particles containing an additive element M1 and includes a coating layer formed of a metal composite oxide of Li and a metal element M2 on a part of a surface of the particles. The particles have a d50 of 3.0 to 7.0 μm, a BET specific surface area of 2.0 to 5.0 m/g, a tap density of 1.0 to 2.0 g/cm, and an oil absorption amount of 30 to 60 ml/100 g. For each of a plurality of primary particles having a primary particle size within a range of 0.1 to 1.0 μm among the primary particles, a coefficient of variation of the concentration of M1 is 1.5 or less, and the amount of M2 is 0.1 to 1.5 atom % with respect to the total number of atoms of Ni, Mn, and Co contained in the composite oxide particles.

To provide a cathode active material capable of reducing cathode resistance of a secondary battery by enhancing electron conductivity thereof without reducing discharge capacity of the secondary battery. Lanthanum compound particles each having a perovskite-type structure are dispersed on surfaces of secondary particles of a lithium transition metal-containing composite oxide and/or in gaps or grain boundaries between primary particles thereof. The lanthanum compound particles have a cross-sectional average particle size of 0.70 μm or less. The number of lanthanum compound particles present per unit area of the cross sections of the secondary particles is 0.03 particles/μmto 0.10 particles/μm, and the number of lanthanum compound particles present per unit area of the surfaces of the secondary particles is 0.01 particles/μmto 0.25 particles/μm. The content of lanthanum with respect to the entire cathode active material is within a range of 0.1% by mass to 5% by mass.

Cathode active material for lithium ion secondary battery and lithium ion secondary battery

The present disclosure can bring excellent output characteristics to a nonaqueous electrolyte secondary battery that uses a cathode active material containing tungsten while desired durability is secured. The battery of the present disclosure includes a cathode, an anode, and a nonaqueous electrolyte. The cathode includes a cathode active material layer that contains a granular cathode active material. The cathode active material includes a core part that contains a lithium-transition metal composite oxide of a layered structure; a tungsten-concentrated layer that is formed over a surface of the core part and has a higher tungsten concentration than in the core part; and a lithium-tungsten compound particle that adheres to at least part of a surface of the tungsten-concentrated layer and contains tungsten and lithium. In the battery of the present disclosure, the tungsten-concentrated layer has an amorphous structure. This can bring excellent output characteristics while desired durability is secured.

Nonaqueous electrolyte secondary battery

A non-aqueous electrolyte secondary battery that has a low initial resistance and an increase in resistance after charging and discharging is suppressed. The secondary battery includes a positive electrode, a negative electrode, and a non-aqueous electrolyte. The positive electrode includes a positive electrode active substance layer, which contains a lithium composite oxide having a layered structure. The lithium composite oxide is a porous particle. A surface of the porous particle includes a layer having a rock salt type structure. A thickness of the layer is not less than 5 nm and not more than 80 nm. A void ratio of the porous particle is not less than 15% and not more than 48%. The porous particle contains two or more voids having diameters that are at least 10% of the particle diameter of the porous particle. The surface of the porous particle includes a coating of lithium tungstate.

Non-aqueous electrolyte secondary battery including a positive electrode active substance containing a lithium composite oxide porous particle and a rock salt layer

A non-aqueous electrolyte secondary battery is obtained using a lithium composite oxide having a layered structure in a positive electrode active substance. An increase in resistance following repeated charging and discharging is suppressed. The battery includes a positive electrode provided with a positive electrode active substance layer, a negative electrode and a non-aqueous electrolyte. The positive electrode active substance layer contains a porous particle lithium composite oxide having a layered structure. The average void ratio of the porous particle is not less than 12% but not more than 50%, and it contains two or more voids having diameters that are at least 8% of its particle diameter. The surface of the porous particle is provided with a coating of lithium tungstate. The coverage ratio of the surface of the porous particle by the lithium tungstate is not less than 10% but not more than 65%.

Non-aqueous electrolyte secondary battery including a positive electrode active substance containing a lithium composite oxide porous particle having voids

A non-aqueous electrolyte secondary battery which is obtained using a lithium composite oxide having a layered structure and coated with a tungsten-containing compound in a positive electrode active substance, and which has a low initial resistance, and in which an increase in resistance following repeated charging and discharging is suppressed. The non-aqueous electrolyte secondary battery includes a positive electrode, a negative electrode and a non-aqueous electrolyte. The positive electrode includes a positive electrode active substance layer containing a lithium composite oxide having a layered structure. The lithium composite oxide includes a porous particle having a void ratio of not less than 20% but not more than 50%. The porous particle contains two or more voids having diameters that are at least 10% of the particle diameter of the porous particle. The surface of the porous particle is provided with a coating containing tungsten oxide and lithium tungstate.

Nonaqueous electrolyte secondary battery including a positive electrode active substance containing a lithium composite oxide porous particle having voids

Provided is a nonaqueous electrolyte secondary battery with a positive electrode active material that contains an excess of Li and has a layered structure, the nonaqueous electrolyte secondary battery having a high output and enabling prevention of gelation of the positive electrode active material layer-forming paste during production. The herein disclosed nonaqueous electrolyte secondary battery includes a positive electrode, a negative electrode, and a nonaqueous electrolyte. The positive electrode includes a positive electrode active material layer. The positive electrode active material layer contains a lithium composite oxide having a layered structure as a positive electrode active material. The compositional ratio of the lithium atom to the metal atom other than a lithium atom contained in the lithium composite oxide is greater than 1. The lithium composite oxide is in the form of porous particles. Each of the porous particles has at least two voids each of which has the percentage of a void area with respect to the area occupied by each of the particles in a cross-sectional view thereof of at least 1%. Each of the porous particles is provided with a coating of lithium tungstate on a surface thereof.

The cathode active material is capable of reducing cathode resistance of a secondary battery by enhancing electron conductivity thereof without reducing discharge capacity of the secondary battery. The method for manufacturing a cathode active material includes: mixing transition metal-containing composite compound particles containing lanthanum with a lithium compound to obtain a lithium mixture; calcinating the lithium mixture at a temperature equal to or lower than the melting point of the lithium compound; and then subjecting the lithium mixture to main firing at a firing temperature within a range of 725&#xb0; C. to 1000&#xb0; C. Lithium carbonate is preferably used as the lithium compound, and in this case, the calcination temperature is within a range of 600&#xb0; C. to 723&#xb0; C. It is preferable to obtain the transition metal-containing composite compound particles containing lanthanum by a coprecipitation method and to uniformly disperse a lanthanum element in the particles.

Method for manufacturing cathode active material for lithium ion secondary battery

Provided is a positive electrode material that allows reducing battery resistance. The positive electrode material disclosed herein has particles of a positive electrode active material, each having a void communicating between the surface and at least the interior; and an electronic conductor present on the surface of the particles of the positive electrode active material. The positive electrode active material has a layered rock salt structure, and has a composition represented by Formula (I) below. The electronic conductor has a composition represented by Formula (II) below,LiNiMnCoMO&#x2003;&#x2003;(I)LaMaCoMbO&#x2003;&#x2003;(II)

Positive electrode material

A positive electrode for a lithium ion secondary battery includes a positive electrode composite material layer. The positive electrode composite material layer includes composite particles and electron conductive particles. The composite particles include positive electrode active material particles and a coating film. The coating film is formed on the surface of the positive electrode active material particles. The coating film contains a first electron conductive oxide. The electron conductive particles are dispersed in the positive electrode composite material layer. The electron conductive particles contain a second electron conductive oxide. Each of the first electron conductive oxide and the second electron conductive oxide has a perovskite structure.

Positive electrode for lithium ion secondary battery and manufacturing method thereof

A positive electrode active material includes secondary particles. The secondary particles include a plurality of primary particles. The primary particles include a lithium-containing composite metal oxide. Inside the secondary particles, an electron conducting oxide is disposed at at least a part of a grain boundary between the primary particles. The electron conducting oxide has a perovskite structure.

Positive electrode active material, lithium ion secondary battery, and method of producing positive electrode active material

A positive electrode active material for lithium secondary batteries disclosed herein comprises a lithium transition metal oxide of a layered structure, represented by formula LiNiCoMnCaMO(where &#x2212;0.05&#x2264;&#x3b1;&#x2264;0.2, x+y+z+&#x3b2;+&#x3b3;&#x2245;1, 0.3&#x2264;x&#x2264;&#x2264;0.7, 0.1&#x2264;y&#x2264;0.4, 0.1&#x2264;z&#x2264;0.4, 0.0002&#x2264;&#x3b2;&#x2264;0.0025, 0.0002&#x2264;&#x3b2;+&#x3b3;&#x2264;0.02, and in a case where &#x3b3;&#x3e;0, M is absent or represents one, two or more elements selected from the group consisting of Na, Mg, Al, Ti, V, Cr, Zr, Nb, Mo, Hf, Ta and W). The tap density of the positive electrode active material ranges from 1.8 to 2.5 g/cm.

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Niihama, Japan

Tetsutaro Hayashi