Shin-etsu Chemical Co., Ltd.

Sanyo Electric Co., Ltd.

Koichiro Watanabe

Susumu Ueno

Yoshiharu Konya

Tetsuo Nakanishi

Hirofumi Fukuoka

Hiroki Yoshikawa

Takakazu Hirose

Hiromichi Kamo

Masahiro Furuya

Kohta Takahashi

Atsushi Fukui

Meguru Kashida

Maruo Kamino

Mikio Aramata

Satoru Miyawaki

Kazuyuki Taniguchi

Taizo Sunano

Yasuo Takano

The present invention provides a negative electrode material for a lithium-ion secondary battery, the negative electrode material comprising silicon active material particles containing silicon and nitrogen, the silicon active material particles being capable of occluding and emitting lithium ions, wherein an amount of the nitrogen contained in each silicon active material particle is in the range from 100 ppm to 50,000 ppm, a negative electrode and lithium-ion secondary battery using the material, and a method of producing the material. The negative electrode material is suitable for a lithium-ion secondary battery negative electrode that has high first charge and discharge efficiency and excellent cycle performance and makes the best use of high battery capacity and low volume expansion rate of a silicon material such as a silicon oxide material.

Negative electrode material for lithium-ion secondary battery, negative electrode for lithium-ion secondary battery, lithium-ion secondary battery, and method of producing negative electrode material for lithium-ion secondary battery

A negative electrode active material for a non-aqueous electrolyte secondary battery, including negative electrode active material particles containing a silicon compound (SiOwhere 0.5&#x2264;x&#x2264;1.6), the negative electrode active material particles being coated with a carbon coating composed of a substance at least partially containing carbon, the carbon coating having a density ranging from 1.2 g/cmto 1.9 g/cm, the negative electrode active material particles having a characteristic of type II or type III adsorption-desorption isotherm in the IUPAC classification, as obtained by adsorption-desorption isotherm measurement with nitrogen gas. This negative electrode active material can increase the battery capacity and improve the cycle performance and battery initial efficiency.

Negative electrode active material for non-aqueous electrolyte secondary battery, negative electrode for non-aqueous electrolyte secondary battery, non-aqueous electrolyte secondary battery, and method of producing negative electrode material for non-aqueous electrolyte secondary battery

Provided is a negative electrode material that is suitable for use in a negative electrode of a lithium ion secondary battery having high capacity and excellent cycle characteristics. Also provided are a negative electrode and a lithium ion secondary battery using the same. The negative electrode material for lithium ion secondary battery comprises a particle that contains silicon and is capable of storing and releasing a lithium ion and that is characterized, in a volume-based distribution as measured with a laser diffraction particle size distribution meter, by (mode diameter&#x2014;D)/D=0.13 or greater and (D&#x2014;mode diameter)/D=0.28 or less, where the mode diameter is the most frequent value in the distribution, Dis the diameter at 50% accumulation and Dis the diameter at 90% accumulation.

Negative electrode material for lithium ion secondary battery, negative electrode, and lithium ion secondary battery

The invention provides a rotary tubular furnace including a rotatable furnace tube having an inlet end through which silicon compound particles (SiOwhere 0.5&#x2264;x&#x3c;1.6) are put therein and an outlet end through which the particles coated with carbon are taken out therefrom; and a heating chamber having a heater to heat the furnace tube, wherein the furnace tube is composed of a heat portion inside the heating chamber and a non-heat portion outside the heating chamber, a length B of the heat portion and an overall length A of the furnace tube satisfy 0.4&#x2264;B/A&#x3c;1, and a distance C between the heat portion and the outlet end and the overall length A satisfy 0.04&#x2264;C/A&#x2264;0.35. This furnace can inhibit clogging of the furnace tube and mass-produce a negative electrode active material for a non-aqueous electrolyte secondary battery having a high capacity with inhibited variations in the amount of carbon coating and crystallinity.

Rotary tubular furnace, method of producing negative electrode active material for non-aqueous electrolyte secondary battery, negative electrode active material for non-aqueous electrolyte secondary battery, and non-aqueous electrolyte secondary battery

A method of producing a negative electrode material for use in a non-aqueous electrolyte secondary battery, including: making base powder containing silicon; measuring a volume average particle diameter of this powder by particle size distribution with laser diffractometry; randomly sampling 5000 particles or more from the powder and measuring their roundness; selecting the powder if the volume average particle diameter ranges from 0.5 to 20 &#x3bc;m, the roundness of the sampled particles is 0.93 or more on average, and a ratio of the number of particles having a roundness of 0.85 or less is 5% or less; and coating the selected powder with carbon. A negative electrode material useful for a non-aqueous electrolyte secondary battery that has excellent cycle performance and makes the best use of advantages of a silicon-contained material, a method of producing this negative electrode material, and a lithium-ion secondary battery.

Negative electrode material for use in non-aqueous electrolyte secondary battery, method of producing the same, and lithium-ion secondary battery

Silicon oxide particles each comprising an inner portion having an iron content of 10-1,000 ppm and an outer portion having an iron content of up to 30 ppm are suitable as negative electrode active material in nonaqueous electrolyte secondary batteries. Using a negative electrode comprising the silicon oxide particles as active material, a lithium ion secondary battery or electrochemical capacitor having a high capacity and improved cycle performance can be constructed.

Silicon oxide particles, making method, lithium ion secondary battery, and electrochemical capacitor

The present invention is a negative electrode material for non-aqueous electrolyte secondary batteries, comprising at least: particles wherein silicon nanoparticles are dispersed in silicon oxide (silicon oxide particles); and a metal oxide coating formed on a surface of the silicon oxide particles. As a result, there is provided a negative electrode material for non-aqueous electrolyte secondary batteries that enables the production of a negative electrode suitable for lithium-ion secondary batteries and the like that provides improved safety and cycle performance over conventional negative electrode materials.

Negative electrode material for non-aqueous electrolyte secondary batteries, manufacturing method therefor, and lithium-ion secondary batteries

A Si&#x2014;O&#x2014;Al composite comprising silicon, silicon oxide, and aluminum oxide exhibits a powder XRD spectrum in which the intensity of a signal of silicon at 28.3&#xb0; is 1-9 times the intensity of a signal near 21&#xb0;. A negative electrode material comprising the Si&#x2014;O&#x2014;Al composite is used to construct a non-aqueous electrolyte secondary battery which is improved in 1st cycle charge/discharge efficiency and cycle performance while maintaining the high battery capacity and low volume expansion upon charging of silicon oxide.

Non-aqueous electrolyte secondary battery, negative electrode, negative electrode material, and preparation of Si&#x2014;O&#x2014;Al composite

This invention provides a negative electrode material for a rechargeable battery with a nonaqueous electrolyte, characterized in that the negative electrode material contains polycrystalline silicon particles as an active material, the particle diameter of crystallites of the polycrystalline silicon is not less than 20 nm and not more than 100 nm in terms of a crystallite size determined by the Scherrer method from the full width at half maximum of a diffraction line attributable to Si (111) around 2&#x3b8;=28.4&#xb0; in an x-ray diffraction pattern analysis, and the true specific gravity of the silicon particles is 2.300 to 2.320.

Negative electrode material for nonaqueous electrolyte secondary battery

A negative electrode material comprising an active material and 1-20 wt % of a polyimide resin binder is suitable for use in non-aqueous electrolyte secondary batteries. The active material comprises silicon oxide particles and 1-50 wt % of silicon particles. The negative electrode exhibits improved cycle performance while maintaining the high battery capacity and low volume expansion of silicon oxide. The non-aqueous electrolyte secondary battery has a high initial efficiency and maintains improved performance and efficiency over repeated charge/discharge cycles by virtue of mitigated volumetric changes during charge/discharge cycles.

Non-aqueous electrolyte secondary battery, negative electrode material, and making method

A silicon-silicon oxide-lithium composite comprises a silicon-silicon oxide composite having such a structure that silicon grains having a size of 0.5-50 nm are dispersed in silicon oxide, the silicon-silicon oxide composite being doped with lithium. Using the silicon-silicon oxide-lithium composite as a negative electrode material, a lithium ion secondary cell having a high initial efficiency and improved cycle performance can be constructed.

Silicon-silicon oxide-lithium composite, making method, and non-aqueous electrolyte secondary cell negative electrode material

By using a halogen-free siloxane and an organometallic compound containing at least one metal other than silicon as feed stocks, and simultaneously atomizing and burning them in a flame, spherical particles of silica-containing compound oxide are prepared which are substantially halogen-free, consist of 0.5-99% by weight of metal oxides and the balance of silica, and have a particle size of 10 nm to 3 &#x3bc;m. The particles are useful as a filler in epoxy resin base semiconductor sealants, a refractive index modifier or the like.

Spherical particles of silica-containing compound oxide and method of production

A hydrophobic silica fine powder is prepared by premixing a hydrophilic silica fine powder with a dimer diol siloxane or cyclic siloxane as a hydrophobizing agent, mixing them in a ball mill for achieving dispersion and for achieving cleavage or disintegration and consolidation, and thereafter heating at 100-300&#xb0; C. in an ammonia or amine-containing atmosphere. The powder has an aerated bulk density of 100-300 g/l, a specific surface area of 40-300 m/g, a primary particle diameter of 10-120 nm, and a degree of hydrophobization of 40-80 as measured by methanol titration and is less bulky, easy to handle and disperse and stable in a kneaded mixture.

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Annaka, Japan

Koichiro Watanabe