Abstract: The present invention provides a negative electrode active material for a non-aqueous electrolyte secondary battery, including negative electrode active material particles containing a silicon compound expressed by SiO where 0.55?x?1.6, the negative electrode active material particles at least partially coated with a carbon coating, the carbon coating exhibiting a peak at 2?=25.5° having a half width of 1.5° to 4.5° in an X-ray diffraction spectrum measured after separating the carbon coating from the negative electrode active material particles, the carbon coating exhibiting scattering peaks at 1330 cm?1 and 1580 cm?1 in Raman spectrum obtained by Raman spectrometry measured after separating the carbon coating from the negative electrode active material particles, wherein a ratio of an intensity of the scattering peak at 1330 cm?1 to that at 1580 cm?1 satisfies 0.7<I1330/I1580<2.0.

Abstract: A negative electrode active material including: a particle of negative electrode active material containing silicon-based material of SiOx (0.5?x?1.6); wherein the intensity A of a peak in a Si-region given in the chemical shift region of from ?50 to ?95 ppm and the intensity B of a peak in a SiO2-region given in the chemical shift region of from ?96 to ?150 ppm in a 29Si-MAS-NMR spectrum of the silicon-based material satisfy a relationship that A/B?0.8. This provides a negative electrode active material which can increase a battery capacity, and can improve cycle characteristics and initial charge/discharge characteristics when used as a negative electrode active material for a lithium ion secondary battery.

Abstract: A silicon-containing material capable of being doped with lithium and de-doped, wherein when three-electrode cell produced by using working electrode including silicon-containing material as active material, reference electrode made of metallic lithium, counter electrode made of metallic lithium, and electrolyte having lithium ionic conductivity is charged and discharged to measure relationship between charging or discharging capacity and potential of working electrode on basis of reference electrode, ratio of first capacity to second capacity is 38% or more while current flows in direction in which lithium of silicon-containing material is de-doped in discharge, where first capacity is discharging capacity with respect to potential range from potential in fully charged state to 400 mV, and second capacity is discharging capacity with respect to potential range from a potential in fully charged state to 2000 mV.

Abstract: The invention provides a rotary tubular furnace including a rotatable furnace tube having an inlet end through which silicon compound particles (SiOx where 0.5?x<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?B/A<1, and a distance C between the heat portion and the outlet end and the overall length A satisfy 0.04?C/A?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.

Abstract: A negative electrode active material for use in a non-aqueous electrolyte secondary battery. The negative electrode active material is composed of a mixture of a silicon-contained material and a carbon material and capable of being doped with lithium and de-doped. Silicon contained in the silicon-contained material has a crystallite size of 10 nm or less. This crystallite size is calculated by a Scherrer method from a half width of a diffraction peak attributable to Si (220) in X-ray diffraction. This negative electrode active material can maintain a high usage rate of the silicon-contained material at the time of charging and discharging in a non-aqueous electrolyte secondary battery that uses the mixture of the silicon-contained material and the carbon material as the negative electrode active material.

Abstract: A silicon-contained material capable of being doped with lithium and de-doped, wherein when a three-electrode cell produced by using a working electrode including the silicon-contained material as an active material, a reference electrode made of metallic lithium, a counter electrode made of metallic lithium, and an electrolyte having lithium ionic conductivity is charged and discharged to graph a relationship between a derivative of a charging or discharging capacity with respect to an electric potential of the working electrode on the basis of the reference electrode and the electric potential, a ratio B/A is 2 or less while current flows in a direction in which the lithium of the silicon-contained material is de-doped in the discharge, A being the derivative maximum value with respect to a potential range from 260 to 320 mV, and B is the derivative maximum value with respect to a potential range from 420 to 520 mV.

Abstract: The present invention relates to a negative electrode material for nonaqueous electrolyte secondary batteries, which is composed of a silicon composite body that has a structure wherein microcrystals or fine particles of silicon are dispersed in a substance having a composition different from that of the microcrystals or fine particles, said silicon composite body having a crystallite size of the microcrystals or fine particles of 8.0 nm or less as calculated using Scherrer's equation on the basis of the half width of the diffraction peak belonging to Si(220) in an X-ray diffraction. The present invention is able to provide a negative electrode material for nonaqueous electrolyte secondary batteries, which has excellent coulombic efficiency, and a nonaqueous electrolyte secondary battery.

Abstract: The present invention provides a negative electrode material for a non-aqueous electrolyte secondary battery, comprising negative electrode active material particles containing a silicon compound expressed by SiOx at least partially coated with a carbon coating where 0.5?x?1.6. The negative electrode active material particles have a negative zeta potential and exhibiting fragments of CyHz compound in an outermost surface layer of the silicon compound when subjected to TOF-SIMS. This negative electrode material can increase the battery capacity and improve the cycle performance and battery initial efficiency. The invention also provides a negative electrode active material layer, a negative electrode, and a non-aqueous electrolyte secondary battery using this material, and a method of producing this material.

Abstract: The present invention provides a negative electrode for a non-aqueous electrolyte secondary battery, the negative electrode comprising a negative electrode active material layer containing: negative electrode active materials including carbon active material and silicon active material composed of SiOx at least partially coated with lithium carbonate where 0.5?x?1.6; and binders including carboxymethyl cellulose or metal salt thereof, polyacrylic acid or metal salt thereof, and styrene-butadiene rubber or polyvinylidene fluoride, and a non-aqueous electrolyte secondary battery including this negative electrode. The negative electrode can increase the battery capacity and improve the cycle performance and first charge and discharge efficiency.