Sumitomo Metal Mining Company, Ltd.

Toyota Jidosha Kabushiki Kaisha

Denso Corporation

Ryuichi Kuzuo

Katsuya Kase

Minoru Shiraoka

Yutaka Oyama

Syuhei Oda

Tomoyoshi Ueki

Hideo Sasaoka

Manabu Yamada

Satoru Suzuki

Takuichi Arai

Atsushi Kawamoto

Kenji Ohmori

Kazuhiro Ohkawa

Junya Tada

Syuuhei Oda

Koichi Yokoyama

Hiroko Sekiya

A method for producing coated nickel hydroxide powder for a positive electrode of an alkaline secondary battery wherein the pH of a suspension of a nickel hydroxide powder is kept at 8 to 11.5, and an aqueous cobalt salt solution and an aqueous alkali solution are supplied to the suspension to coat the surface of nickel hydroxide particles with cobalt hydroxide. Then, the pH of a slurry of the cobalt hydroxide-coated nickel hydroxide powder is adjusted to 12.5 to 13.0, and oxygen is supplied to the slurry so that the total amount of oxygen supplied per mole of cobalt in the coating is 30 l/mol or more to oxidize the cobalt hydroxide.

Coated nickel hydroxide powder for positive electrode active material for alkaline secondary battery, and production method therefor

A coated nickel hydroxide powder that has a cobalt compound coating having improved uniformity and adhesion properties on the surface of particles thereof and is therefore suitable for a positive electrode active material of an alkaline secondary battery is obtained by coating the surface of nickel hydroxide particles with a cobalt compound, and has a transmittance ratio of 30% or higher as determined by (A&#x2212;B)/(B&#x2212;B). The transmittance A (coated nickel hydroxide powder), the transmittance B(nickel hydroxide powder), or the transmittance B(nickel hydroxide powder and cobalt compound containing cobalt in an amount corresponding to the amount of cobalt contained in the coating) can be determined by measuring the transmittance of a tubular transparent cell after shaking the tightly-closed transparent cell containing each powder for a certain time and then taking the contents out of the transparent cell.

Coated nickel hydroxide powder for positive electrode active material of alkaline secondary battery, and evaluation method for coating adhesion properties of coated nickel hydroxide powder

Provided is a cathode active material for a non-aqueous electrolyte secondary battery capable of obtaining high initial discharge capacity and good output characteristics at low temperature. In order to achieve this, a cathode active material that is a lithium nickel composite oxide composed of secondary particles that are an aggregate of primary particles is expressed by the general expression: Li(NiCoAl)MO(where 0.98&#x2266;w&#x2266;1.10, 0.05&#x2266;x&#x2266;0.3, 0.01&#x2266;y&#x2266;0.1, 0&#x2266;z&#x2266;0.05, and M is at least one metal element selected from a group consisting of Mg, Fe, Cu, Zn and Ga), and where the crystallite diameter at (003) plane of that lithium nickel composite oxide that is found by X-ray diffraction and the Scherrer equation is within the range of 1200 &#x212b; to 1600 &#x212b; is used as the cathode material.

Positive electrode active material for non-aqueous electrolyte secondary battery and production method for same, precursor for positive electrode active material, and non-aqueous electrolyte secondary battery using positive electrode active material

A coated nickel hydroxide powder suitable as a cathode active material for alkaline secondary battery includes nickel hydroxide powder particles which have a coating layer thereon of preferably cobalt hydroxide or cobalt oxyhydroxide.

Coated nickel hydroxide powder as cathode active material for alkaline secondary battery and method for producing same

Disclosed is a nonaqueous secondary battery () comprising a positive electrode () having a positive current collector () made of a metal, and a positive electrode active material () composed of a lithium-metal complex oxide. The surface of the positive electrode active material () is coated with a lithium salt () having an average thickness of 20-50 nm.

Coated positive electrode active material, positive electrode for nonaqueous secondary battery, nonaqueous secondary battery, and their production methods

Provided is a cathode active material for a non-aqueous electrolyte secondary battery capable of obtaining high initial discharge capacity and good output characteristics at low temperature. In order to achieve this, a cathode active material that is a lithium nickel composite oxide composed of secondary particles that are an aggregate of primary particles is expressed by the general expression: Li(NiCoAl)MO(where 0.98&#x2266;w&#x2266;1.10, 0.05&#x2266;x&#x2266;0.3, 0.01&#x2266;y&#x2266;0.1, 0&#x2266;z&#x2266;0.05, and M is at least one metal element selected from a group consisting of Mg, Fe, Cu, Zn and Ga), and where the crystallite diameter at (003) plane of that lithium nickel composite oxide that is found by X-ray diffraction and the Scherrer equation is within the range of 1200 {acute over (&#x212b;)} to 1600 {acute over (&#x212b;)} is used as the cathode material.

A method for producing a coated nickel hydroxide powder suitable as a cathode active material for alkaline secondary battery includes the steps of: dispersing a nickel hydroxide powder in water to prepare a suspension, an aqueous alkali solution to the suspension with stirring to keep a pH of the suspension at 8 or higher as measured at 25&#xb0; C., and supplying an aqueous cobalt salt solution to the suspension to coat a surface of each particles of the nickel hydroxide powder with cobalt hydroxide crystallized out by neutralization.

Coated nickel hydroxide powder as cathode active material for alkaline secondary battery and method for producing the same

To provide a positive electrode active material for a non-aqueous electrolyte secondary battery, which if used as a positive electrode for a lithium ion secondary battery, the battery internal resistance can be reduced, giving a secondary battery superior in output characteristics and life property. After mixing raw material powders in specified quantities of each so as to become a lithium-metal complex oxide represented by LiNiMO(wherein M is at least one kind or more of metal elements selected from the group consisting of Co, Al, Mg, Mn, Ti, Fe, Cu, Zn, and Ga; and w and z respectively satisfy 0&#x3c;w&#x2266;0.25, and 1.0&#x2266;z&#x2266;1.1), baking is performed in two stages. At first the temperature is raised from room temperature to a first stage baking temperature (450 to 550&#xb0; C.) at a temperature rise rate of 0.5 and 15&#xb0; C./min, and held for 1 to 10 hours. Then the temperature is raised to a second stage baking temperature (650 to 800&#xb0; C.), and held for 0.6 to 30 hours.

Positive electrode active material for non-aqueous electrolyte secondary battery and manufacturing method thereof, and non-aqueous electrolyte secondary battery using same

Disclosed are magnetic discs having (A) a Cr-layer, as a lower layer, which has a composition comprising (1) substantially Cr or (2) 10% by weight or less of one or more selected from Cu, Nb, Ti, V, Zr, Mo, Zn, W and Ta, and a balance of being substantially Cr, and (B) a magnetic recording medium layer, as an upper layer, which has a composition comprising (1) substantially Co, (2) 30% by weight or less of Ni and a balance of being substantially Co, (3) 10% by weight or less of one or more selected from Y, La, Ce, Pr, Nd, Sm, Gd, Tb and Dy, and a balance of being substantially Co, (4) 30% by weight or less of Ni, 10% by weight or less of one or more selected from Y, La, Ce, Pr, Nd, Sm, Gd, Tb and Dy, and a balance of being substantially Co, (5) 10% by weight or less of one or more selected from Cu, Nb, Ti, V, Cr, Zr, Mo, Zn, W and Ta, and a balance of being substantially Co, (6) 30% by weight or less of Ni, 10% by weight or less of one or more selected from Cu, Nb, Ti, V, Cr, Zr, Mo, Zn, W and Ta, and a balance of being substantially Co, (7) 10% by weight or less of one or more selected from Y, La, Ce, Pr, Nd, Sm, Gd, Tb and Dy, 10% by weight or less of one or more selected from Cu, Nb, Ti, V, Cr, Zr, Mo, Zn, W and Ta, and a balance of being substantially Co, or (8) 30% by weight or less of Ni, 10% by weight or less of one or more selected from Y, La, Ce, Pr, Nd, Sm, Gd, Tb and Dy, 10% by weight or less of one or more selected from Cu, Nb, Ti, V, Cr, Zr, Mo, Zn, W and Ta, and a balance of being substantially Co, both as formed on a non-magnetic substrate, except those where the lower layer has the composition (1) and the upper layer has the composition (1) or (2) as well as those where the lower layer has the composition (1) and the upper layer has the composition (5) or (6) containing only one or more of Cr, Ta and/or W. The magnetic discs have noticeably improved magnetic characteristics and/or corrosion-resistance.

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Niihama, Japan

Ryuichi Kuzuo