Osaka Titanium Technologies Co., Ltd.

Shingo Kizaki

Yusuke Kashitani

Kohki Takeshita

Shinji Shimosaki

Hideaki Kanno

Takehisa Fujita

Kouji Yasuda

Kazuo Nishioka

[Problem to be solved] To produce an SiO powder having a rounded spherical particulate shape and a small particle diameter; and further having a low degree of impurity contamination, efficiently and economically. [Solution] A mixture of Si and SiOas an SiO gas generation raw materialis loaded into a crucible. The mixture in the crucibleis heated under a reduced pressure so as to generate SiO gas. The generated SiO gas is accumulated on a deposition baserotating on the crucible. When SiO depositaccumulated on the deposition baseis scraped off with a blade, a tip of the bladeis separated from a surface of the deposition base, and in a state in which a portion of the SiO depositaccumulated on the deposition baseis left on the deposition base, the remaining SiO depositis scraped off by the bladeand collected as an SiO powder

SiO powder production method and spherical particulate SiO powder

There is produced a Li-containing silicon oxide powder containing a crystallized lithium silicate that is mostly water-insoluble LiSiOand containing little crystalline Si. This object is attained through the mixing of a lower silicon oxide powder represented by a compositional formula SiO(0.5&#x3c;x&#x3c;1.5) with a powdered lithium source that involves grinding of the powdered lithium source; controlling a median diameter D1 of the lower silicon oxide powder and a median diameter D2 of the powdered lithium source so as to fulfill 0.05&#x2264;D2/D1&#x2264;2; and calcining the mixed powder at 300&#xb0; C. or higher and 800&#xb0; C. or lower.

Li-containing silicon oxide powder and production method thereof

This invention provides a powder for a negative electrode of a lithium ion secondary battery, which is a powder that includes a silicon oxide powder containing Li. When a molar ratio between Li, Si and O is taken as y:1:x, the average composition of the powder overall satisfies the relation 0.5&#x3c;x&#x3c;1.5 and the relation 0.1&#x3c;y/x&#x3c;0.8. The volume median diameter of the powder for a negative electrode is within a range from 0.5 to 30 &#x3bc;m. When X-ray diffraction measurement of the powder is performed using a Cu Kray, a relation P2/P1&#x2264;1.0 and a relation P3/P1&#x2264;1.0 are satisfied, where P1 represents a height of a peak attributed to LiSiO, P2 represents a height of a peak attributed to crystalline Si, and P3 represents a height of a peak attributed to LiSiO.

Powder for negative electrode of lithium ion secondary battery, and method for producing such powder

A silicon oxide for use as a negative electrode active material of a lithium-ion secondary battery is characterized by: a g-value measured by an ESR spectrometer is in the range of not less than 2.0020 to not more than 2.0050; and given that A, B, and C are the area intensities of peaks near 420 cm, 490 cmand 520 cmrespectively in a Raman spectrum measured by a Raman spectroscopy, A/B is not less than 0.5 and C/B is not more than 2. The lithium-ion secondary battery has excellent cycle characteristic and initial efficiency in addition to high capacity. The silicon oxide preferably has a spin density in the range of not less than 1&#xd7;10spins/g to not more than 5&#xd7;10spins/g. A negative electrode material for the lithium-ion secondary battery contains not less than 20% by mass of this silicon oxide as a negative electrode active material.

Silicon oxide and negative electrode material for lithium-ion secondary battery

A negative electrode material powder for a lithium ion secondary battery having a conductive carbon film on the surface of a lower-silicon-oxide powder; wherein a specific surface area in BET measurement ranges from more than 0.3 m/g to 40 m/g, and no SiC peak appears at 2&#x3b8;=35.6&#xb0;&#xb1;0.01&#xb0; or the half-value width of the appeared peak is 2&#xb0; or more in XRD measurement using CuKrays. The proportion of said carbon film preferably ranges from 0.2% to 2.5% by mass. Said powder preferably has 100000 &#x3a9;cm or less of specific resistance. In XRD, P2/P1&#x3c;0.01 is preferably satisfied between the highest value P1 of halo of SiOand a value P2 of the strongest linear peak of Si (111) above the halo. Accordingly, said powder can be used in the secondary battery with a large discharge capacity and a preferable cycle characteristics for practical use.

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

A silicon oxide in the form of powder is represented by SiO, wherein, when the silicon oxide is measured by use of an X-ray diffractometer comprising a sealed tube light source as a light source and a high speed detector as a detector, a halo is detected at 20&#xb0;&#x2266;2&#x3b8;&#x2266;40&#xb0;, and a peak is detected at the highest quartz line position therein. The height P1 of the halo and the height P2 of the peak at the highest quartz line position satisfy P2/P1&#x2266;0.05. This silicon oxide is used as the negative electrode active material, whereby a lithium-ion secondary battery having stable initial efficiency and cycle characteristic can be obtained. The x of the SiOis preferably 0.7&#x3c;x&#x3c;1.5. A negative electrode material for lithium-ion secondary battery contains not less than 20 mass % of this silicon oxide as a negative electrode active material.

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Amagasaki, Japan

Shingo Kizaki