Abstract: A method for producing a negative electrode active material for a lithium ion secondary battery, comprising a step of charging either silicon and copper (II) oxide or silicon and copper metal in a pulverization device, pulverizing either the silicon and copper (II) oxide or silicon and copper metal, and simultaneously mixing either silicon and copper (II) oxide or silicon and copper metal thus pulverized. A negative electrode active material for a lithium ion secondary battery is produced by the method.

Abstract: A negative electrode active material for a lithium ion secondary battery, comprising silicon, copper and oxygen as major constitutional elements, the negative electrode active material for a lithium ion secondary battery, containing fine particles of silicon having an average crystallite diameter (Dx) measured by an X-ray diffractometry of 50 nm or less, and having elemental ratios, expressed by molar ratios, Cu/(Si+Cu+O) and O/(Si+Cu+O) of from 0.02 to 0.30, wherein the negative electrode active material contains an intermetallic compound of silicon and copper.

Abstract: A method for producing a negative electrode active material for a lithium ion secondary battery, comprising a step of charging either silicon and copper (II) oxide or silicon and copper metal in a pulverization device, pulverizing either the silicon and copper (II) oxide or silicon and copper metal, and simultaneously mixing either silicon and copper (II) oxide or silicon and copper metal thus pulverized. A negative electrode active material for a lithium ion secondary battery is produced by the method.

Abstract: A negative electrode active material for a lithium ion secondary battery, comprising silicon, copper and oxygen as major constitutional elements, the negative electrode active material for a lithium ion secondary battery, containing fine particles of silicon having an average crystallite diameter (Dx) measured by an X-ray diffractometry of 50 nm or less, and having elemental ratios, expressed by molar ratios, Cu/(Si+Cu+O) and O/(Si+Cu+O) of from 0.02 to 0.30, wherein the negative electrode active material contains an intermetallic compound of silicon and copper.

Abstract: In the case where a silicon substance having a high theoretical capacity as a negative electrode active material for a lithium ion secondary battery is used as a negative electrode active material, such a negative electrode active material is provided that has a high initial battery capacity and suffers less deterioration in performance even when many cycles of charge and discharge are repeated. A lithium ion secondary battery using the negative electrode active material is provided. Silicon and copper (II) oxide, or silicon, metallic copper and water are pulverized and simultaneously mixed in a pulverization device, thereby providing a negative electrode active material that has good cycle characteristics and a large battery capacity.

Abstract: A field electron emission film that is capable of being operated with low electric power and enhancing the uniformity in luminance within the light emission surface contains from 60 to 99.9% by mass of tin-doped indium oxide and from 0.1 to 20% by mass of carbon nanotubes. The film has a structure wherein grooves having a width in a range of from 0.1 to 50 mm are formed in a total extension of 2 mm or more per 1 mm2 on a surface of the film, and carbon nanotubes are exposed on a wall surface of the grooves. After forming an ITO film containing carbon nanotubes on a substrate, grooves are formed on a surface of the ITO film, and the end portions of the carbon nanotubes exposed to the wall surface of the grooves are designated as an emitter.

Abstract: [Problem] In the case where a silicon substance having a high theoretical capacity as a negative electrode active material for a lithium ion secondary battery is used as a negative electrode active material, such a negative electrode active material is provided that has a high initial battery capacity and suffers less deterioration in performance even when many cycles of charge and discharge are repeated. A lithium ion secondary battery using the negative electrode active material is provided. [Solution] Silicon and copper (II) oxide, or silicon, metallic copper and water are pulverized and simultaneously mixed in a pulverization device, thereby providing a negative electrode active material that has good cycle characteristics and a large battery capacity.

Abstract: A field electron emission film that is capable of being operated with low electric power and enhancing the uniformity in luminance within the light emission surface contains from 60 to 99.9% by mass of tin-doped indium oxide and from 0.1 to 20% by mass of carbon nanotubes. The film has a structure wherein grooves having a width in a range of from 0.1 to 50 mm are formed in a total extension of 2 mm or more per 1 mm2 on a surface of the film, and carbon nanotubes are exposed on a wall surface of the grooves. After forming an ITO film containing carbon nanotubes on a substrate, grooves are formed on a surface of the ITO film, and the end portions of the carbon nanotubes exposed to the wall surface of the grooves are designated as an emitter.

Abstract: A lithium ion secondary battery is provided with a positive electrode, a negative electrode containing an active material, and an electrolytic solution, wherein the active material includes a core portion capable of occluding and releasing lithium ions, an amorphous or low-crystalline coating portion disposed on at least a part of the surface of the core portion, and a fibrous carbon portion disposed on at least a part of the surface of the coating portion, and the coating portion contains Si and O as constituent elements, while the atomic ratio y (O/Si) of O relative to Si satisfies 0.5?y?1.8.

Abstract: A secondary battery capable of obtaining superior battery characteristics is provided. The secondary battery of the present technology includes a cathode, an anode including an active material, and an electrolytic solution. The active material includes a core section and covering section, the core section being capable of inserting and extracting lithium ions, and the covering section being provided in at least part of a surface of the core section and being a low-crystalline or a noncrystalline. The core section includes Si and O as constituent elements, and an atom ratio x (O/Si) of O with respect to Si satisfies O?x<0.5. The covering section includes Si and O as constituent elements, and an atom ratio y (O/Si) of O with respect to Si satisfies 0.5?y?1.8. The covering section has voids, and a carbon-containing material is provided in at least part of the voids.

Abstract: A lithium ion secondary battery is provided with a positive electrode, a negative electrode containing an active material, and an electrolytic solution, wherein the active material includes a core portion capable of occluding and releasing lithium ions, an amorphous or low-crystalline coating portion disposed on at least a part of the surface of the core portion, and a fibrous carbon portion disposed on at least a part of the surface of the coating portion, and the coating portion contains Si and O as constituent elements, while the atomic ratio y (O/Si) of O relative to Si satisfies 0.5?y?1.8.

Abstract: A single crystal silicon wafer is sliced off so as to have a slant surface that is inclined from plane (001) such that the normal of the slant surface is inclined by 0.01.degree. to 0.2.degree. from direction [001] toward direction [110]. After being cleaned, the silicon wafer is heat-treated at 600-1,300.degree. C. for not less than 1 minute in an ultrapure argon or hydrogen atmosphere containing nitrogen at not more than 0.1 ppm, to thereby cause the slant surface to have a stepped crystal surface structure. The stepped crystal surface structure is constituted of step walls Sa and Sb when it has been formed by a heat treatment in an argon atmosphere, and substantially all of its step walls are of a type Sb when it has been formed by a heat treatment in a hydrogen atmosphere.

Abstract: A silicon wafer is mirror-polished until obtaining surface roughness Ra of 0.70-1.00 nm, Rq of 0.80-1.10 nm, or Rt of 4.50-7.00 nm. The resulting wafer is heat-treated at a temperature not lower than 1,200.degree. C. for 30 minutes to 4 hours in a hydrogen gas atmosphere. According to another aspect, a silicon wafer is mirror-polished until obtaining surface roughness values Ra' of 0.08-0.70 nm, rms of 0.10-0.90 nm, and P-V of 0.80-5.80 nm in a square area of 90 .mu.m by 90 .mu.m, and surface roughness values Ra' of 0.13-0.40 nm, rms of 0.18-0.50 nm, and P-V of 1.30-2.50 nm in a square area of 500 nm by 500 nm. The resulting wafer is heat-treated at 1,100.degree.-1,300.degree. C. for 30 minutes to 4 hours in a hydrogen gas atmosphere.