Ngk Insulators, Inc.

Panasonic Corporation

Nobuyuki Kobayashi

Tsutomu Nanataki

Yukinobu Yura

Shohei Yokoyama

Ryuta Sugiura

Kei Sato

Jun Yoshikawa

Shigeki Okada

Shuichi Ozawa

Akira Urakawa

Iwao Ohwada

Masaya Ugaji

Natsumi Shimogawa

Kaoru Nagata

Nobuo Takahashi

Hirofumi Yamaguchi

Katsuhiro Imai

Koichi Kondo

Yuki Bessho

Kazuyuki Mizuno

Kazuyuki Kaigawa

Masahiro Murasato

Haruo Otsuka

Kazuki Maeda

Yuki Fujita

Kouichi Kondou

Koichi Yoshino

Provided is a lithium secondary battery including: a positive electrode plate which is a lithium complex oxide sintered plate; a negative electrode layer; a separator; an electrolytic solution; and a pair of exterior films having outer peripheral edges sealed with each other to form an internal space that accommodates the battery elements, wherein the portions of the negative electrode layer and the separator corresponding to the outer extension of the battery is deviated toward the positive electrode plate side from the portions of the negative electrode layer and the separator corresponding to the body of the battery.

Lithium rechargeable battery and card with built-in battery

Disclosed is a lithium complex oxide sintered plate for use in a positive electrode of a lithium secondary battery. The lithium complex oxide sintered plate has a structure in which a plurality of primary grains having a layered rock-salt structure are bonded, and has a porosity of 3 to 30%, a mean pore diameter of 15 &#x3bc;m or less, an open pore rate of 70% or more, a thickness of 40 to 200 &#x3bc;m, a primary grain diameter of 20 &#x3bc;m or less, the primary grain diameter being a mean diameter of the primary grains, and a pore diameter distribution in which the number of peaks is one and volume-based D10, D50 and D90 pore diameters satisfy expressions: D50/D10&#x2265;2.5, D90/D50&#x2265;2.5 and D90/D10&#x2265;8.0.

Lithium complex oxide sintered body plate

Provided is a lithium titanate sintered plate for use in a negative electrode of a lithium secondary battery. The lithium titanate sintered plate has a structure in which a plurality of primary grains are bonded, and has: a thickness of 10 to 290 &#x3bc;m; a primary grain diameter of 0.70 &#x3bc;m or less, the primary grain diameter being a mean grain diameter of the primary grains; a porosity of 21 to 45%; an open pore rate of 60% or more; a mean pore aspect ratio of 1.15 or more; a ratio of 30% or more of pores having an aspect ratio of 1.30 or more to all the pores; and a mean pore diameter of 0.70 &#x3bc;m or less, wherein volume-based D10 and D90 pore diameters satisfy the relationship: 4.0&#x2264;D90/D10&#x2264;50.

Lithium titanate sintered plate

Disclosed is a lithium complex oxide sintered plate for use in a positive electrode of a lithium secondary battery. The lithium complex oxide sintered plate has a structure where a plurality of primary grains having a layered rock-salt structure are bonded, and has a porosity of 3 to 30%, a mean pore diameter of 15 &#x3bc;m or less, an open pore rate of 70% or more, and a thickness of 40 to 200 &#x3bc;m. The primary grains have a primary grain diameter of 20 &#x3bc;m or less, the primary grain diameter being a mean diameter of the primary grains, and a pore diameter distribution includes a first peak corresponding to a pore diameter of more than 0 &#x3bc;m to 1.2 &#x3bc;m or less and a second peak corresponding to a pore diameter which is larger than the pore diameter corresponding to the first peak and is 20 &#x3bc;m or less.

Provided is a method for manufacturing a lithium cobaltate oriented sintered plate, comprising (a) providing a green sheet comprising CoOparticles, (b) firing the green sheet to form a CoOoriented sintered plate, and (c) firing the sintered plate in the presence of a lithium source to introduce lithium and thereby form the lithium cobaltate oriented sintered plate composed of LiCoO, the method further comprising (d1) attaching a Mg-containing compound to the CoOoriented sintered plate before the step (c) or (d2) attaching the Mg-containing compound to the lithium cobaltate oriented sintered plate after the step (c) to fire the sintered plate. According to the present invention, a lithium cobaltate oriented sintered plate can be manufactured in which grain boundaries in the plate thickness direction are significantly reduced and with which enhanced battery performance can be achieved when used as a positive electrode active material in lithium secondary batteries.

Method for manufacturing lithium cobaltate oriented sintered plate

There is provided a positive electrode active material capable of achieving a high volume energy density and yet superior rate characteristics when configured as a positive electrode for lithium secondary batteries. This positive electrode active material comprises a plurality of secondary particles each comprising primary particles composed of a lithium-nickel based complex oxide having a layered rock-salt structure. The plurality of secondary particles have a volume-based average particle diameter D50 of 5 to 100 &#x3bc;m, and at least part of the plurality of secondary particles are coarse secondary particles having a particle diameter of 9 &#x3bc;m or greater. The coarse secondary particles have a voidage of 5 to 25%, and the ratio of through holes among all voids in the coarse secondary particles is 70% or greater.

Positive electrode active material for lithium secondary battery and positive electrode including same

A crystal production method according to the present invention includes a film formation and crystallization step of spraying a raw material powder containing a raw material component to form a film containing the raw material component on a seed substrate containing a single crystal at a predetermined single crystallization temperature at which single crystallization of the raw material component occurs, and crystallizing the film containing the raw material while maintaining the single crystallization temperature. In the film formation and crystallization step, preferably, the single crystallization temperature is 900&#xb0; C. or higher. Furthermore, in the film formation and crystallization step, preferably, the raw material powder and the seed substrate are each a nitride or an oxide.

Method for forming a single crystal by spraying the raw material onto a seed substrate

An object of the present invention is to provide a lithium secondary battery cathode which can more improve characteristics of the battery. The cathode of the present invention includes an electroconductive cathode current collector, a plurality of plate-like particle formed of a cathode active material, and a binder containing microparticles formed of the cathode active material and being smaller than the plate-like particles. The plate-like particles are formed so as to have an aspect ratio of 4 to 50. The plate-like particles are arranged such that the particles cover the surface of the cathode current collector surface at a percent area of 85 to 98%. The binder is disposed so as to intervene between two adjacent plate-like particles.

Lithium secondary battery cathode

To provide a lithium secondary battery which has high capacity while maintaining excellent cycle characteristic. The lithium secondary battery cathode of the present invention includes a cathode collector formed of a conductive substance, and a cathode active material layer formed of a sintered lithium composite oxide sheet. The cathode active material layer is bonded to the cathode collector by the mediation of a conductive bonding layer. A characteristic feature of the present invention resides in that the cathode active material layer has a thickness of 30 &#x3bc;m or more, a mean pore size of 0.1 to 5 &#x3bc;m, and a voidage of 3% or more and less than 15%.

Lithium secondary battery and cathode of the lithium secondary battery with conductive bonding layer

To provide a lithium secondary battery which has high capacity while maintaining excellent cycle characteristic. The lithium secondary battery cathode of the present invention includes a cathode collector formed of a conductive substance, and a cathode active material layer formed of a sintered lithium composite oxide sheet. The cathode active material layer is bonded to the cathode collector by the mediation of a conductive bonding layer. A characteristic feature of the present invention resides in that the cathode active material layer has a thickness of 30 &#x3bc;m or more, a voidage of 3 to 30%, and an open pore ratio of 70% or higher.

Lithium secondary battery and cathode of the lithium secondary battery

To provide a lithium secondary battery which has high capacity while maintaining excellent charge-discharge characteristic, and to provide a cathode of the lithium secondary battery and a plate-like particle for cathode active material to be contained in the cathode. The plate-like particle of cathode active material for a lithium secondary battery of the present invention has a layered rock salt structure, a thickness of 5 &#x3bc;m or more and less than 30 &#x3bc;m, 2 or less of [003]/[104] which is a ratio of intensity of X-ray diffraction by the (003) plane to intensity of X-ray diffraction by the (104) plane, a voidage of 3% or more and less than 30%, and an open pore ratio of 70% or higher.

Plate-like particle of cathode active material for lithium secondary battery, cathode of the lithium secondary battery and lithium secondary battery

The present invention provides a positive electrode active material for lithium secondary batteries, comprising domain-oriented agglomerated particles, wherein each of the domain-oriented agglomerated particles comprises a plurality of individually oriented secondary particles such that adjacent secondary particles thereof have mutually different orientation directions, and wherein each of the individually oriented secondary particles is composed of a plurality of primary particles which are composed of a lithium complex oxide with a layered rock-salt structure and are oriented such that the (003) planes of the primary particles do not intersect each other at least in one axial direction. According to the present invention, a positive electrode active material can be provided that is capable of achieving not only high initial output performance but also a high output performance retention rate when charging and discharging are performed repeatedly.

Positive electrode active material for lithium secondary battery

To provide a lithium secondary battery which has high capacity while maintaining excellent charge-discharge characteristic, and to provide a cathode of the lithium secondary battery and a plate-like particle for cathode active material to be contained in the cathode. The plate-like particle of cathode active material for a lithium secondary battery of the present invention has a layered rock salt structure, a thickness of 5 &#x3bc;m or more and less than 30 &#x3bc;m, 2 or less of [003]/[104] which is a ratio of intensity of X-ray diffraction by the (003) plane to intensity of X-ray diffraction by the (104) plane, a mean pore size of 0.1 to 5 &#x3bc;m, and a voidage of 3% or more and less than 15%.

An object of the present invention is to provide a lithium secondary battery which has improved capacity, durability, and rate characteristic as compared with conventional lithium secondary batteries. A plate-like particle or a film for a lithium secondary battery cathode active material has a layered rock salt structure. The (003) plane is oriented in a direction intersecting the direction of the plate surface of the particle or film.

Plate-like particle for cathode active material for lithium secondary battery, cathode active material film for lithium secondary battery, methods for manufacturing the particle and film, method for manufacturing cathode active material for lithium secondary battery, and lithium secondary battery

The present invention provides a cathode active material for a lithium secondary battery containing therein an open pore having a protrusion which is formed so as to extend from the inner surface of the open pore toward the center of the open pore. Specifically, the protrusion is formed so as to extend toward the center of a virtual circle formed by approximating the shape of a cross section of the open pore to a circular shape. The protrusion is formed of the same material as the remaining portion of the cathode active material.

Growing community of inventors

Nagoya, Japan

Nobuyuki Kobayashi