Sanyo Electric Co., Ltd.

Panasonic Intellectual Property Management Co., Ltd.

Daizo Jito

Takeshi Ogasawara

Akihiro Kawakita

Shin Fujitani

Masahisa Fujimoto

Maruo Kamino

Hisaki Tarui

Noriyuki Tamura

Ryuji Ohshita

Hiromasa Yagi

Katsunobu Sayama

Kei Kobayashi

Masaki Hirase

Shiori Nakamizo

Atsushi Fukui

Hiroshi Minami

Yasuyuki Kusumoto

Yoichi Domoto

Yoshio Kato

Shigeki Matsuta

Tomohiro Harada

Nobuhiro Sakitani

Noriko Fukamichi

An object of the present invention is to provide a nonaqueous electrolyte secondary battery that can attain a smaller increase in direct current resistance after charge discharge cycles. An aspect of the invention resides in a nonaqueous electrolyte secondary battery wherein a positive electrode active material includes a secondary particle formed by aggregation of primary particles of a lithium transition metal oxide, and a secondary particle formed by aggregation of primary particles of a rare earth compound. On a surface of the secondary particle of the lithium transition metal oxide, the secondary particle of the rare earth compound is attached to a recess formed between adjacent primary particles of the lithium transition metal oxide in such a manner that the secondary particle of the rare earth compound is attached to each of the primary particles forming the recess. The lithium transition metal oxide includes magnesium dissolved therein.

Nonaqueous electrolyte secondary batteries

There is provided a positive electrode active material for a nonaqueous electrolyte secondary battery capable of suppressing a decrease in the capacity retention ratio after high-temperature cycles. There is provided a positive electrode active material for a nonaqueous electrolyte secondary battery that includes a secondary particle formed by aggregation of primary particles formed of a lithium transition metal oxide. A rare-earth compound secondary particle formed by aggregation of particles formed of a rare-earth compound adheres to a recess formed between primary particles adjacent to each other on a surface of the secondary particle, and the rare-earth compound secondary particle adheres to both the primary particles adjacent to each other in the recess. The lithium transition metal oxide contains tungsten dissolved therein.

Positive electrode active material for nonaqueous electrolyte secondary battery

A positive electrode active material for nonaqueous electrolyte secondary batteries is provided with which increased DCR after cycling can be controlled. A positive electrode active material according to an aspect of the present invention is secondary particles of a lithium transition metal oxide formed through the aggregation of primary particles of the oxide, the lithium transition metal oxide containing at least Ni. Secondary particles of a rare earth compound formed through the aggregation of particles of the rare earth compound are adhering to depressions each created between adjacent two of the primary particles on the surfaces of the secondary particles. The secondary particles of the rare earth compound are adhering to both of the two adjacent primary particles at the depressions.

There is provided a positive electrode active material for a nonaqueous electrolyte secondary battery capable of suppressing an increase in DCR during cycles. There is provided a positive electrode active material for a nonaqueous electrolyte secondary battery that includes a secondary particle formed by aggregation of primary particles formed of a lithium transition metal oxide. A rare-earth compound secondary particle formed by aggregation of particles formed of a rare-earth compound adheres to a recess formed between primary particles adjacent to each other on a surface of the secondary particle, and the rare-earth compound secondary particle adheres to both the primary particles adjacent to each other in the recess. A tungsten-containing compound adheres to an interface of primary particles inside the secondary particle formed of the lithium transition metal oxide.

A positive electrode active material for a nonaqueous electrolyte secondary battery which includes a secondary particle of a lithium transition metal oxide, the secondary particle being formed by coagulation of primary particles of the lithium transition metal oxide; secondary particles of a rare earth compound, the secondary particles each being formed by coagulation of primary particles of the rare earth compound; and particles of an alkali-metal fluoride. The secondary particles of the rare earth compound are each deposited on a groove between a pair of adjacent primary particles which is formed in a surface of the secondary particle of the lithium transition metal oxide so as to come into contact with both of the pair of adjacent primary particles in the groove. The particles of the alkali-metal fluoride are deposited on the surface of the secondary particle of the lithium transition metal oxide.

Positive electrode active material for nonaqueous electrolyte secondary batteries, and nonaqueous electrolyte secondary battery

It is an object of the present invention to provide a positive electrode for nonaqueous electrolyte secondary batteries that can suppress decreases in the discharge capacity and discharge voltage even when continuous charging is performed at high temperature and that can also suppress decreases in the discharge voltage and energy density even in the charge and discharge after the continuous charging, and to provide a nonaqueous electrolyte secondary battery that uses the positive electrode. The positive electrode includes a positive electrode active material composed of a mixture containing lithium cobalt oxidehaving a surface to which an erbium compoundis partly adhered and lithium nickel cobalt manganese oxide and a binder. The content of the lithium nickel cobalt manganese oxide is 1% by mass or more and 50% by mass or less relative to the total amount of the positive electrode active material.

Positive electrode for nonaqueous electrolyte secondary battery and nonaqueous electrolyte secondary battery using the positive electrode

A lithium secondary battery has a positive electrode () containing a positive electrode active material having particles of lithium cobalt oxide, a negative electrode () containing a negative electrode active material having silicon particles, a separator interposed between the positive electrode () and the negative electrode (), and a non-aqueous electrolyte. Particles of erbium hydroxide or erbium oxyhydroxide are adhered to a surface of the lithium cobalt oxide particles in a dispersed form.

Lithium secondary battery having positive electrode active material including lithium transition metal composite oxide with particles of rare earth compound adhered thereto

A rechargeable lithium battery including a negative electrode made by depositing a noncrystalline thin film composed entirely or mainly of silicon on a current collector, a positive electrode and a nonaqueous electrolyte, characterized in that said nonaqueous electrolyte contains carbon dioxide dissolved therein.

Lithium secondary battery and method for producing same

A lithium secondary battery is provided with a positive electrode, a negative electrode (), a separator interposed between the positive and negative electrodes, and an electrode assembly having the negative electrode (), the positive electrode, and the separator. The negative electrode () has a negative electrode current collector () and negative electrode active material layers (), () formed on respective surfaces of the negative electrode current collector (). The negative electrode active material layers are composed of an alloy containing silicon, which intercalates and deintercalates lithium, and iron, which does not intercalate or deintercalate lithium. At least a portion of the electrode assembly has a curved portion in which the negative electrode active material layer () disposed inward relative to the negative electrode current collector contains a higher concentration of the iron than the negative electrode active material layer () disposed outward relative to the negative electrode current collector.

Lithium secondary battery

A method of manufacturing an electrode for a lithium secondary battery in which a thin film of active material is deposited on a current collector is provided that eliminates adverse effects on the battery caused by protrusions adhered on an electrode surface. The method of manufacturing an electrode for lithium secondary batteries includes depositing a thin film of active material on a current collector using thin-film deposition equipment as shown in FIG., and performing a compression process after depositing the thin film, whereby the heights of protrusions formed on the electrode surface are reduced.

Method of manufacturing electrode for lithium secondary batteries

A method of manufacturing an electrode for a secondary cell capable of readily forming an active material layer only on a necessary portion of a collector by a method supplying raw material from a gas phase is obtained. This method of manufacturing an electrode for a secondary cell comprises steps of forming a mask layer containing a material reduced in adhesion to a collector due to a high temperature for forming an active material layer on a prescribed region of the collector, forming the active material layer on the collector and on the mask layer by a method supplying raw material from a gas phase and removing the mask layer and part of the active material layer formed on the mask layer. Thus, the mask layer is readily separated from the collector after the active material layer is formed by the method supplying raw material from a gas phase. Consequently, the mask layer and part of the active material layer formed on the mask layer are so readily removed that the active material layer is readily located only on a necessary portion of the collector.

Method of manufacturing electrode for secondary cell

An electrode having a current collector and, formed thereon, a thin film comprising an active material, characterized in that a thin alloy film (such as Sn&#x2014;Co) comprising a metal which can form an alloy with lithium (such as Sn) and a metal which can not form an alloy with lithium (such as Co) is formed on a current collector such as a copper foil. It is preferred that the above metal which can form an alloy with lithium and the above metal which can not form an alloy with lithium can not form an intermetallic compound with each other.

Electrode for rechargeable lithium battery and rechargeable lithium battery

A lithium secondary battery-use electrode and a lithium secondary battery, which are high in discharge capacity and excellent in cycle characteristics, characterized in that a layer consisting of a metal alloying with Li is provided on a substrate consisting of a metal not alloying with Li, and a layer having these metals mixed therein is formed between the above layer and the substrate.

A method of manufacturing a lithium secondary cell capable of preventing an active material layer from oxidation and moisture absorption is obtained. This method of manufacturing a lithium secondary cell comprises steps of forming an active material layer on a collector by a method supplying raw material through discharge into a vapor phase and holding the collector formed with the active material layer at least under an inert atmosphere or under a vacuum atmosphere up to preparation of the cell. Thus, the collector formed with the active material layer is prevented from exposure to the atmosphere, whereby the active material layer is prevented from oxidation and moisture absorption. Consequently, a lithium secondary cell having excellent characteristics can be prepared.

Method of and apparatus for manufacturing lithium secondary cell

A lithium secondary battery comprises a negative electrode containing lithium metal or a material previously storing lithium as an active material, a positive electrode containing a positive active material, and an electrolyte containing a non-aqueous electrolyte solution. The positive active material is a thin film formed by depositing on a substrate from vapor phase or liquid phase and including an oxide containing at least iron as a main constituent by a sputtering method, a reactive deposition method, a vacuum deposition method, a chemical vapor deposition method, a spraying method, a plating method, or a method in combination of these methods.

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Kobe, Japan

Daizo Jito