Nec Energy Devices, Ltd.

Envision Aesc Energy Devices Ltd.

Showa Denko K.k.

Yasutaka Kono

Shinako Kaneko

Hitoshi Ishikawa

Takayuki Suzuki

Hiroo Takahashi

Jiro Iriyama

Takehiro Noguchi

Koji Utsugi

Hideaki Sasaki

Tatsuji Numata

Ryuichi Kasahara

Tetsuya Kajita

Yoko Hashizume

Yuka Chikugo

Mitsuru Hanasaki

Kouzou Takeda

Kou Ishiguchi

Kazunari Fukase

Tomoyuki Ohta

Ippei Waki

Koh Ishiguchi

Jiro Uchida

Hiroshi Kobayashi

Yoko Hasizume

A graphite-based negative electrode active material including a first graphite particle being spheroidized and a second graphite particle having a roundness lower than the roundness of the first graphite particle, wherein the content of the second graphite particle based on the sum of the first graphite particle and the second graphite particle is in the range of 1 to 30% by mass, the ratio of a median particle diameter (D) to a particle diameter at 5 cumulative % (D), D/D, in a cumulative distribution of the first graphite particle is smaller than the ratio of a median particle diameter (D) to a particle diameter at 5 cumulative % (D), D/D, in a cumulative distribution of the second graphite particle, and the tap density in saturation of the particle mixture of the first graphite particle and the second graphite particle is higher than both the tap density in saturation of the first graphite particle and the tap density in saturation of the second graphite particle.

Graphite-based negative electrode active material, negative electrode, and lithium ion secondary battery

A polymer gel electrolyte containing at least a lithium salt and an aprotic solvent, in which an amorphous polymer layer is formed on the surface of an electrode active material.

Polymer gel electrolyte, lithium ion battery and method for producing same

A lithium ion secondary battery electrode according to the present invention includes (A) a non-fluorinated polymer; (B) an active material; (C) a thickener; and (D) a conductive auxiliary agent. An elution ratio of (A) the non-fluorinated polymer in an electrolytic solution solvent at 60&#xb0; C. is equal to or less than 1.0 mass %, and a swelling ratio of (A) the non-fluorinated polymer in the electrolytic solution solvent at 60&#xb0; C. is equal to or more than 10 mass % and equal to or less than 50 mass %.

Lithium ion secondary battery electrode, method of manufacturing the same, and lithium ion secondary battery

There is provided a lithium ion battery which maintains the flame retardancy of an electrolyte over a long period of time, has high energy density, and has improved charge/discharge cycle characteristics, high temperature storage characteristics, and rate characteristics. The lithium ion battery according to the present exemplary embodiment is a lithium ion battery comprising an electrolyte containing at least an ionic liquid and a lithium salt, a positive electrode, and a negative electrode, wherein the negative electrode includes a negative electrode active material which is a carbon material treated with a surface treatment agent.

Lithium ion battery

An object of the present invention is to provide a gel electrolyte for a lithium ion secondary battery having flame retardancy over a long period and a good capacity maintenance rate. The gel electrolyte for a lithium ion secondary battery according to the exemplary embodiment contains a lithium salt, a copolymer of at least one first monomer selected from compounds represented by chemical formulae (1) and (2) and a second monomer represented by chemical formula (4), at least one oxo-acid ester derivative of phosphorus selected from compounds represented by chemical formulae (5) to (7), and at least one disulfonate ester selected from a cyclic-chain type disulfonate ester represented by chemical formula (8) and a linear-chain type disulfonate ester represented by chemical formula (9).

Gel electrolyte for lithium ion secondary battery, and lithium ion secondary battery

An object of the present invention is to provide: a binder for a lithium ion secondary battery electrode, which is water-dispersible type and has favorable adhesion between active materials and between the active material and current collectors, along with charge-discharge high-temperature cycle characteristics; a slurry using the binder; an electrode using the slurry; and a lithium ion secondary battery using the electrode. The present invention relates to a binder composition for a lithium ion secondary battery electrode, which is obtained by emulsion polymerization of an ethylenically unsaturated monomer in the presence of a surfactant, the ethylenically unsaturated monomer containing, as essential constituents, 15 to 70 mass % of styrene with respect to the total mass of ethylenically unsaturated monomers, an ethylenically unsaturated carboxylic acid ester, an ethylenically unsaturated carboxylic acid and an internal cross-linking agent.

Binder for lithium ion secondary battery electrode, slurry obtained using the binder for electrode, electrode obtained using the slurry, and lithium ion secondary battery using the electrode

A non-aqueous electrolyte can suppress decomposition of a solvent, improve the cycle life of a secondary battery, suppress the rise of resistance of a secondary battery and improve the capacity maintenance ratio of a secondary battery. A non-aqueous electrolyte secondary battery formed by using such a non-aqueous electrolyte includes a non-aqueous electrolyte containing an aprotic solvent and a disulfonic acid ester as expressed by chemical formula 1 shown below, a positive electrode and a negative electrode: 

Non-aqueous electrolyte and non-aqueous electrolyte secondary battery using the same

There are provided a nonaqueous-type electrolyte solution having high flame retardancy and a good capacity retention rate, and a device comprising the nonaqueous-type electrolyte solution. The nonaqueous-type electrolyte solution is used in a device comprising a positive electrode, a negative electrode and the nonaqueous-type electrolyte solution, and contains a lithium salt and a compound having a phosphazene structure, and further contains 0.05% by mass or more and 12.0% by mass or less of at least one disulfonate ester selected from a cyclic disulfonate ester and a chain disulfonate ester based on the total of the nonaqueous-type electrolyte solution.

Nonaqueous-type electrolyte solution, and device comprising the same

Growing community of inventors

Kanagawa, Japan

Yasutaka Kono