Kabushiki Kaisha Toyota Chuo Kenkyusho

Toyota Jidosha Kabushiki Kaisha

Yoshio Ukyo

Shigetaka Wada

Toshio Kandori

Akihiko Suda

Hideo Sobukawa

Tsuyoshi Sasaki

Hideyuki Nakano

Mareo Kimura

Masayuki Fukui

Tetsuro Kobayashi

Masao Kohzaki

Yuichi Itou

Youji Takeuchi

Hiroki Kondo

Yoshiaki Kikuchi

Motoyoshi Okumura

Masahiro Sugiura

Tadashi Suzuki

Kazumasa Takatori

Hiroshi Hirayama

Chikaaki Okuda

Yasuo Ikeda

Yasuhito Kondo

Hidehito Matsuo

Osamu Hiruta

Yoji Takeuchi

Takahiko Honma

Yoriko Matsuoka

The present invention provides a water based lithium secondary battery that can inhibit deteriorations in capacity owing to charge-and-discharge operations and maintain a high capacity even after it is charged and discharged repeatedly. The water based lithium secondary battery includes a positive electrode, a negative electrode, a separatorsandwiched between these, and an aqueous electrolyte solution obtained by dissolving an electrolyte made of a lithium salt in a water based solvent. As the water based solvent, a pH buffer solution is employed. The buffer solution is obtained by dissolving an acid and its conjugate base's salt, a base and its conjugate acid's salt, a salt made from a weak acid and a strong base, a salt made from a weak base and a strong acid, or a salt made from a weak acid and a weak base in water.

Water based lithium secondary battery

A battery characteristic detecting method according to the invention includes a first step in which constant current discharge from a battery is performed at a predetermined current value, and a voltage during constant current discharge is measured; a second step in which overpotential for mass transfer control in the battery or resistance for the mass transfer control in the battery is calculated based on the voltage measured in the first step; and a third step in which a determination that a characteristic change has occurred in the battery is made, when the overpotential for the mass transfer control in the battery or the resistance for the mass transfer control in the battery calculated in the second step is larger than a predetermined threshold value.

Method and device for monitoring deterioration of battery

There is provided a secondary cell having a positive electrode and a negative electrode which is made of solid active materials and an electrolyte layer which has been intervened between the positive electrode and the negative electrode. At least one of solid active materials for constituting the positive electrode and the negative electrode is composed of a mixed oxygen ion and electron conductor capable of inserting and eliminating oxygen ion or absorbing and releasing oxygen.

Secondary cell

The present invention provides a secondary battery which is less expensive, whose safety is extremely high, which is of large capacity as well as good cyclic characteristic, and which uses an aqueous solution for the electrolytic solution. A lithium secondary battery according to the present invention is constituted by including a positive electrode, formed by binding a positive-electrode raw-material mixture including a positive electrode active material, a negative electrode, formed by binding a negative-electrode raw-material mixture including a negative electrode active material, and an electrolytic solution, comprising an aqueous solution in which a lithium salt is dissolved, said positive electrode active material including at least one of a layered structure lithium-manganese composite oxide whose basic composition is LiMnOand an olivine structure lithium-iron composite phosphorus oxide whose basic composition is LiFePO. The present lithium secondary battery can be used in the fields of communication appliances and information-related appliances, and as an electric source for electric automobiles and the like.

Lithium secondary battery

A carbon-containing lithium-iron composite phosphorus oxide for a lithium secondary battery positive electrode active material, includes particles being composed of a lithium-iron composite phosphorus oxide having an olivine structure whose basic composition is LiFePO, and being composited with carbonaceous fine particles. A process for producing the same includes the steps of mixing a lithium compound making a lithium source, an iron compound making an iron source, a phosphorus-containing ammonium salt making a phosphorus source and carbonaceous fine particles, thereby preparing a mixture, and calcicing the mixture at a temperature of from 600&#xb0; C. or more to 750&#xb0; C. or less.

Carbon-containing lithium-iron composite phosphorus oxide for lithium secondary battery positive electrode active material and process for producing the same

Lithium manganese composite oxide for lithium secondary battery cathode active material, manufacturing method thereof, and lithium secondary battery using the composite oxide as cathode active material

A solid solution particle of oxides contains a solid solution of oxides in which one oxide is dissolved into the other oxide, and in which the degree of dissolution of one oxide into the other oxide is not less 50%, and in which an average diameter of crystallite is not more than 100 nm. The solid solution particle of oxides has small average diameter of a crystallite and large specific surface area, and it improves capacities such as an oxygen storage ability due to high degree of dissolution. A catalyst for purifying exhaust gases has excellent purifying performance by employing the solid solution comprising ceria and zirconia which has large OSC and high oxygen adsorption and discharge speed.

Solid solution particle of oxides, a process for producing the same and

A catalyst for purifying exhaust gases includes a porous support; a cerium oxide or a solid solution of a cerium oxide and a zirconium oxide in a state of mutual solid solution, loaded on the porous support; and a noble metal element loaded on the porous support. The cerium oxide or the solid solution has an average particle diameter of from 5 to 100 nm. The cerium oxide is present in the solid solution in an amount of from 0.2 to 4.0 by molar ratio with respect to the zirconium oxide therein. The catalyst can be prepared by: coating and calcinating on a support substrate a slurry of a cerium oxide sol, a cerium oxide sol and a zirconium oxide sol, on a solid solution powder of a cerium oxide and a zirconium oxide in a state of mutual solid solution; and loading a noble metal element thereon. The cerium oxide or its solid solution has a surface area large enough to effect an oxygen storage function, and has an average particle diameter large enough to prevent the same from entering deeply into fine pores of a porous support, thereby providing a catalyst fully exhibiting both of the oxygen storage capability and the catalytic activity.

Catalyst for purifying exhaust gases and process for producing the same

A method for producing a catalyst having high catalytic activity even at high temperatures of 1200.degree. C. or higher. Fine alumina particles, of which 50% by weight or more have a particle size of 100 nm or less, are mixed with a catalytic component and a substance of inhibiting the sintering of fine alumina particles to form a slurry mixture. This slurry is dried and then calcined to obtain a porous catalyst. The fine alumina particles in the porous catalyst have a large specific surface area even at high temperatures and therefore the porous catalyst maintains its high catalytic activity even at high temperatures of 1200.degree. C. or higher.

Method for producing catalyst

A silicon nitride sintered body includes silicon nitride as a principal component, silicon carbide dispersed therein and at least one of boron and boron compounds in an amount of from 0.005 to 0.5% by weight in terms of the weight of boron with respect to the total weight of the sintered body. The addition of boron or boron compounds improves the high-temperature characteristics such as creep resistance of the sintered body.

Silicon nitride sintered body

A sintered body of silicon nitride composed of .alpha.'-Si.sub.3 N.sub.4 and .beta.'-Si.sub.3 N.sub.4, the former being represented by the formula Y.sub.x (Si,Al).sub.12 (O,N).sub.16 (where the value of x, which denotes the amount of occluded Y, is in the range of 0&lt;x&lt;0.3), with the value of x for .alpha.'-Si.sub.3 N.sub.4 in the outer part of the sintered body being greater than for .alpha.'-Si.sub.3 N.sub.4 in the inner part of the sintered body. The sintered body will find use as high-temperature structural material owing to its high strength and high toughness.

Sintered body of silicon nitride

A sintered body composed of .alpha.'-silicon nitride and .beta.'-silicon nitride, and having a surface portion which contains a greater proportion of .alpha.'-silicon nitride than its inner portion does. It has high strength and excellent wear resistance. It is produced by preparing a molded body from a sintering material, disposing about the molded body a sintering material which can form a sintered product containing a greater proportion of .alpha.'-silicon nitride than the sintered product of the molded body will, and sintering the molded body and the material disposed about it.

Sintered body of silicon nitride and a process for making the same

A silicon nitride sintered body composed of .alpha.'-silicon nitride and .beta.'-silicon nitride, which are present in the ratio of 0.05-0.50 to 0.50-0.95 in terms of the peak strength ratio of X-ray diffraction, and have very small crystal grain size and specific compositions. The sintered body has high strength and high toughness and is superior in oxidation resistance.

Growing community of inventors

Seto, Japan

Yoshio Ukyo