Toda Kogyo Corporation

Denka Company Limited

Teruaki Santoki

Kazuhiko Kikuya

Osamu Sasaki

Hideaki Sadamura

Jun Koujima

Takanori Doi

Akihisa Kajiyama

Kousaku Tamari

Masaaki Maekawa

Kazutoshi Ishizaki

Hiroshi Yamamoto

Kenichi Nakata

Takahiko Sugihara

Takashi Kawasaki

Hiroshi Yokota

Kazutoshi Matsumoto

Akira Yoda

Yasuo Kakihara

Ryuta Masaki

Setsuo Yamamoto

Mitsuru Matsuura

Manabu Yamamoto

Yuji Mishima

Daisuke Morita

Taiki Imahashi

Daisuke Nishikawa

Satoshi Nakamura

Tsuyoshi Wakiyama

Masaki Nishimura

Takamitsu Harada

Taro Inada

An object of the present invention is to provide a positive electrode mixture capable of conducting stable charging and discharging with a less amount of gasses generated which has an operating voltage or an initial crystal phase transition voltage of not less than 4.5 V on the basis of lithium. The present invention relates to a positive electrode mixture comprising carbon black having a bulk density of not more than 0.1 g/cm, a crystallite size of 10 to 40 &#x212b;, an iodine adsorption of 1 to 150 mg/g, a volatile content of not more than 0.1% and a metal impurity content of not more than 20 ppm, and a positive electrode active substance having an operating voltage or an initial crystal phase transition voltage of not less than 4.5 V on the basis of lithium.

Positive electrode mixture and non-aqueous electrolyte secondary battery

The present invention relates to Li-Ni composite oxide particles that exhibit a high initial discharge capacity and are excellent in thermal stability when used as a positive electrode active substance for non-aqueous electrolyte secondary batteries, and a process for producing the Li-Nicomposite oxide particles. The Li-Ni composite oxide particles of the present invention have a composition of LiNiCoM1M2Owherein x, y, a and b represent 1.00&#x2266;x&#x2266;1.10; 0&#x3c;y&#x2266;0.25; 0&#x3c;a&#x2266;0.25; and 0&#x2266;b&#x2266;0.10, respectively; M1 is at least one element selected from the group consisting of Al and Mn; and M2 is at least one element selected from the group consisting of Zr and Mg, in which a product of a metal occupancy (%) of lithium sites of the Li-Ni composite oxide as determined by Rietveld analysis of X-ray diffraction thereof and a crystallite size (nm) of the Li-Ni composite oxide as determined by the Rietveld analysis is not less than 700 and not more than 1400.

Li-Ni composite oxide particles and process for producing the same, and non-aqueous electrolyte secondary battery

Positive electrode active substance particles including a compound having at least a crystal system belonging to a space group of R&#x2212;3m and a crystal system belonging to a space group of C2/m, and boron. The compound is a composite oxide comprising at least Li, Mn, and Co and/or Ni; a relative intensity ratio [(a)/(b)] of a maximum diffraction peak intensity (a) observed at 2&#x3b8;=20.8&#xb1;1&#xb0; in a powder X-ray diffraction pattern of the positive electrode active substance as measured using a Cu-Ku ray to a maximum diffraction peak intensity (b) observed at 2&#x3b8;=18.6&#xb1;1&#xb0; in the powder X-ray diffraction pattern, is 0.02 to 0.5; a content of Mn in the positive electrode active substance particles such that a molar ratio of Mn/(Ni+Co+Mn) is not less than 0.55; and the positive electrode active substance particles include boron in an amount of 0.001 to 3% by weight.

Positive electrode active substance particles and process for producing the same, and non-aqueous electrolyte secondary battery

Li&#x2014;Ni composite oxide particles for a non-aqueous electrolyte secondary battery with a large charge/discharge capacity and excellent thermal stability in a charged condition. The Li&#x2014;Ni composite oxide secondary particles form core particles having a composition LiNiCoMnMOin which 0.9&#x2266;x1&#x2266;1.3; 0.1&#x2266;y1&#x2266;0.3; 0.0&#x2266;z1&#x2266;0.3; 0&#x2266;w1&#x2266;0.1; and M is Al or Fe. The Li&#x2014;Ni composite oxide has a composition LiNiCoMnMOin which 0.9&#x2266;x2&#x2266;1+z2; 0&#x2266;y2&#x2266;0.33; 0&#x2266;z2&#x2266;0.5; 0&#x2266;w2&#x2266;0.1; and M is Al, Fe, Mg, Zr or Ti and is coated or present on a surface of the secondary particles.

Li-Ni composite oxide particles for non-aqueous electrolyte secondary battery, process for producing the same, and non-aqueous electrolyte secondary battery

The present invention relates to Li&#x2014;Ni-based composite oxide particles comprising Mn, and Co and/or Al, wherein Co and Al are uniformly dispersed within the particles, and Mn is present with a gradient of its concentration in a radial direction of the respective particles such that a concentration of Mn on a surface of the respective particles is higher than that at a central portion thereof. The Li&#x2014;Ni-based composite oxide particles can be produced by allowing an oxide and a hydroxide comprising Mn to mechanically adhere to Li&#x2014;Ni-based oxide comprising Co and/or Al; and then heat-treating the obtained material at a temperature of not lower than 400&#xb0; C. and not higher than 1,000&#xb0; C. The Li&#x2014;Ni-based composite oxide particles of the present invention are improved in thermal stability and alkalinity.

Li&#x2014;Ni-based composite oxide particles for non-aqueous electrolyte secondary battery, process for producing the same, and non-aqueous electrolyte secondary battery

The present invention relates to Li&#x2014;Ni composite oxide particles for a non-aqueous electrolyte secondary cell which have a large charge/discharge capacity, an excellent packing density and excellent storage performance. The Li&#x2014;Ni composite oxide particles for a non-aqueous electrolyte secondary cell which have a composition represented by the formula:LiNiCoAl0in which 0.9&#x3c;x&#x3c;1.3; 0.1&#x3c;y&#x3c;0.3; and 0&#x3c;z&#x3c;0.3, wherein the composite oxide particles have a rate of change in specific surface area of not more than 10% as measured between before and after applying a pressure of 1 t/cmthereto, and a sulfate ion content of not more than 1.0%, can be produced by mixing Ni&#x2014;Co hydroxide particles having a sulfate ion content of not more than 1.0% whose surface is coated with an Al compound having a primary particle diameter of not more than 1 &#x3bc;m, with a lithium compound; and calcining the resulting mixture.

Li-Ni composite oxide particles for non-aqueous electrolyte secondary cell, process for producing the same, and non-aqueous electrolyte secondary cell

A perpendicular magnetic recording medium, comprises a substrate; a soft-magnetic layer formed on the substrate; an NaCl-type oxide layer for orientation control formed on the soft-magnetic layer, having a thickness of from more than 0 to less than 10 nm; and a magnetic recording layer formed on the NaCl-type oxide layer for orientation control, comprising a maghemite thin film. Such a perpendicular magnetic recording medium is capable of showing excellent magnetic properties, a high recording resolution and improved surface properties.

Perpendicular magnetic recording medium

A magnetic recording medium exhibiting a high coercive force and excellent squareness having a substrate, an underlayer formed on the substrate, and a spinel-type iron oxide thin film with maghemite as a main component formed on the underlayer. The spinel-type iron oxide thin film has a thickness (t) of 5 to 50 nm, is constituted by grains having an average grain size (D) of 5 to 30 nm, standard deviation of sizes of grain of not more than 4 nm and a ratio (D/t) of the average grain size (D) to the thickness (t) of less than 1.0, exhibits a coercive force of not less than 159 kA/m (2,000 Oe) and a coercive squareness ratio S* of not less than 0.5:1 in a longitudinal recording medium or a squareness ratio not less than 0.75:1 in a perpendicular recording medium.

Magnetic recording medium and process for producing the same

A magnetic recording medium including a substrate and formed on the substrate a maghemite thin film having a surface roughness represented by a center line mean roughness Ra of 0.1 to 1.0 nm, and a coercive force squareness S* value of not less than 0.50. This magnetic recording medium exhibits excellent magnetic properties, especially, coercive force squareness S* value and a more enhanced surface smoothness.

A magnetic recording medium, comprises a substrate; and a Co-containing spinel-type iron oxide thin film formed on the substrate, having a Co content of 1 to 20 mol % based on Fe, a coercive force value of not less than 159 kA/m (2,000 Oe), a thickness of 5 to 200 nm, a center line average height Ra of 0.1 to 0.8 nm and a maximum height (Rmax) of not more than 10 nm. The magnetic recording medium is capable of exhibiting a relatively high coercive force, especially a coercive force of not less than 159 kA/m (2,000 Oe) despite as small a film thickness as not more than 200 nm, and an excellent surface smoothness.

Growing community of inventors

Fukuoka-ken, Japan

Teruaki Santoki