Toray Industries, Inc.

Manabu Kawasaki

Eiichiro Tamaki

Koki Miyazono

Yoshihide Hirai

Koichiro Manabe

Toshihisa Nonaka

Zhijun Chen

Peiyu Sun

Yuka Yamashiki

Zhenqi Wu

Gangqiao Liu

Takashi Konishi

Hanxiao Yang

Yoshitake Hara

An object of the present invention is to improve the electron conductivity and ion conductivity of the surface of a positive electrode active material to provide a lithium ion battery having high capacity and high output. The present invention relates to a positive electrode for a lithium ion secondary battery, including a mixture layer containing a positive electrode active material for a lithium ion secondary battery and graphene, wherein the mixture layer has a percentage of abundance of silicon composing a siloxane bond in total elements of 0.4 atomic % or more as measured by X-ray photoelectron spectroscopy.

Positive electrode for lithium ion secondary battery, graphene/positive electrode active material composite particles, manufacturing methods for same, and positive electrode paste for lithium ion secondary battery

A graphene/organic solvent dispersion liquid is in a stably dispersed state and also unlikely to cause electrolysis of water. A graphene/organic solvent dispersion liquid is also provided including graphene dispersed in an organic solvent and having a value of (W2&#x2212;W1)/G in the range of 0.005 or more and 0.05 or less, wherein W1 and W2 are the water fractions measured at 130&#xb0; C. and 250&#xb0; C., respectively, by the Karl Fischer's method and G is the solid fraction of the graphene.

Graphene/organic solvent dispersion and method for producing same, and method for producing lithium-ion battery electrode

The purpose of the present invention is to provide a graphene dispersion which has high dispersibility and which is capable of exhibiting high electrical conductivity and ionic conductivity when used as a raw material for producing an electrode material. The present invention provides a graphene dispersion including a graphene, an amine compound having a molecular weight of 150 or less, and an organic solvent, wherein the mass ratio of an amine compound to the graphene is 0.005 or more and 0.30 or less.

Graphene dispersion, method for producing electrode paste, and method for producing electrode

The purpose of the present invention is to provide a graphene which has high dispersibility, high electrical conductivity and oxidation resistance namely a graphene which has high electrochemical stability. In order to achieve the above-described purpose, a surface-treated graphene according to the present invention is obtained by having a compound represented by general formula (1) or a neutralized salt thereof adhere to a graphene. In general formula (1), A represents a benzene-based aromatic group with a condensation number of 1-4, which has no phenolic hydroxy group; Rrepresents a direct bond, a divalent hydrocarbon group having 1-12 carbon atoms, or a divalent organic group having 1-12 carbon atoms, which has a structure selected from the group consisting of an ether bond, an ester bond, an alcohol structure and a carbonyl structure; each of Rand Rindependently represents a hydrogen atom, a hydrocarbon group having 1-12 carbon atoms, or an organic group having 1-12 carbon atoms, which has a structure selected from the group consisting of an ether bond, an ester bond, an alcohol structure and a carbonyl structure; and n represents an integer of 1-6. 

Surface-treated graphene, surface-treated graphene/organic solvent dispersion liquid, surface-treated graphene/electrode active material composite particles and electrode paste

A graphene material has a specific form that has a high dispersibility and can maintain a high electric conductivity and ion conductivity when used as material for electrode manufacturing. A graphene dispersion liquid is provided including graphene dispersed in an organic solvent and meeting both 0.5 &#x3bc;m&#x2264;S&#x2264;15 &#x3bc;m and 1.0&#x2264;D/S&#x2264;3.0 wherein D is the median diameter (&#x3bc;m) of the graphene measured by the laser diffraction/scattering type particle size distribution measurement method and S is the average size (&#x3bc;m) in the planar direction of the graphene calculated from the arithmetic mean of the longest diameter and shortest diameter of the graphene observed by a laser microscope.

Graphene dispersion, process for producing same, process for producing particles of graphene/active material composite, and process for producing electrode paste

A graphene material in a specific form is provided that has a high dispersibility and can maintain a high electric conductivity and ion conductivity when used as material for electrode manufacturing. A graphene dispersion liquid is provided including graphene dispersed in a solvent having a N-methyl pyrolidone content of 50 mass % or more and, when diluted with N-methylpyrolidone to a graphene weight fraction of 0.000013, giving a diluted solution having a weight-based absorptivity coefficient, which is calculated by Equation (1) given below, of 25,000 cm&#x2212;1 or more and 200,000 cm&#x2212;1 or less at a wavelength of 270 nm:weight-based absorptivity coefficient (cm)=absorbance/{0.000013&#xd7;cell's optical path length (cm)}.&#x2003;&#x2003;(1)

A paste composition containing an inorganic filler, a resin and a solvent, wherein the paste composition is characterized in that it contains one or more solvents of which the boiling point is 160&#xb0; C. or higher and an inorganic filler of which the mean particle diameter is 5 &#x3bc;m or smaller, and the total content of the solvent is 25 wt % or less based on the total amount of the paste composition, and a dielectric composition containing an inorganic filler and resin, wherein the inorganic filler includes inorganic fillers of at least two kinds of mean particle diameter, and the greatest mean particle diameter of said mean particle diameters is 0.1-5 &#x3bc;m and is 3 times or more the minimum mean particle diameter.

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Otsu, Japan

Manabu Kawasaki