Abstract: In a nonaqueous electrolyte secondary battery containing SiOX as a negative electrode active material, initial charge/discharge efficiency and cycle characteristics are increased. A negative electrode active material for nonaqueous electrolyte secondary batteries is provided. The negative electrode active material contains particles comprising of SiOx (0.8?X?1.2). The particles have cracks therein. SiOX preferably contains a lithium silicate phase, a Si-M compound, or an oxide of M (M is at least one selected from the group consisting of Al, Ti, Fe, and Ni). The cracks preferably extend radially from inner portions of the particles.

Abstract: A negative-electrode active material for a non-aqueous electrolyte secondary battery containing a silicon material, wherein the negative-electrode active material can constitute a non-aqueous electrolyte secondary battery having high charge capacity, high initial charge/discharge efficiency, and good cycle characteristics. A negative-electrode active material particle according to an embodiment includes a lithium silicate phase represented by Li2zSiO(2+z) {0<z<2} and particles dispersed in the lithium silicate phase. Each of the particles includes a silicon core particle and a surface layer formed of an iron alloy containing Si (FeSi alloy). In an XRD pattern of the negative-electrode active material particle obtained by XRD measurement, a diffraction peak of the FeSi alloy at 2?=approximately 45 degrees has a half-width of 0.40 degrees or more, and a diffraction peak of a Si (111) plane at 2?=approximately 28 degrees has a half-width of 0.40 degrees or more.

Abstract: The initial charge/discharge efficiency and cycle characteristics of a non-aqueous electrolyte secondary battery that contains a silicon material as a negative-electrode active material are improved. A negative-electrode active material particle (10) according to an embodiment includes a lithium silicate phase (11) represented by Li2zSiO(2+z) {0<z<2} and silicon particles (12) dispersed in the lithium silicate phase (11). A lithium silicate constituting the lithium silicate phase has a crystallite size of 40 nm or less. The crystallite size is calculated using the Scherrer equation from the half-width of a diffraction peak of a (111) plane of the lithium silicate in an XRD pattern obtained by XRD measurement of the negative-electrode active material particle 10.

Abstract: There is provided a negative electrode active material for a nonaqueous electrolyte secondary battery, the negative electrode active material including a base particle containing Si and SiO2, a mixed phase coating that covers a surface of the base particle and contains SiO2 and carbon, and a carbon coating that covers a surface of the mixed phase coating. The base particle is preferably formed of SiOX (0.5?X?1.5). The mixed phase coating preferably contains carbon dispersed in a phase formed of SiO2. The cycle characteristics of a nonaqueous electrolyte secondary battery including negative electrode active material particles containing Si and SiO2 are improved.

Abstract: A negative-electrode active material for a non-aqueous electrolyte secondary battery containing a silicon material, wherein the negative-electrode active material can constitute a non-aqueous electrolyte secondary battery having high charge capacity, high initial charge/discharge efficiency, and good cycle characteristics. A negative-electrode active material particle according to an embodiment includes a lithium silicate phase represented by Li2zSiO(2+z) {0<z<2} and particles dispersed in the lithium silicate phase. Each of the particles includes a silicon core particle and a surface layer formed of an iron alloy containing Si (FeSi alloy). In an XRD pattern of the negative-electrode active material particle obtained by XRD measurement, a diffraction peak of the FeSi alloy at 2?=approximately 45 degrees has a half-width of 0.40 degrees or more, and a diffraction peak of a Si (111) plane at 2?=approximately 28 degrees has a half-width of 0.40 degrees or more.

Abstract: Negative electrode active material particles each include a composite particle containing silicon particles and a lithium silicate phase represented by LixSiOy (0<x?4, and 0<y?4); and a surface layer provided on the surface of the composite particle, and the surface layer contains a silane coupling agent.

Abstract: There is provided a negative electrode active material for a nonaqueous electrolyte secondary battery, the negative electrode active material including a base particle containing Si and SiO2, a mixed phase coating that covers a surface of the base particle and contains SiO2 and carbon, and a carbon coating that covers a surface of the mixed phase coating. The base particle is preferably formed of SiOX (0.5?X?1.5). The mixed phase coating preferably contains carbon dispersed in a phase formed of SiO2. The cycle characteristics of a nonaqueous electrolyte secondary battery including negative electrode active material particles containing Si and SiO2 are improved.

Abstract: The initial charge/discharge efficiency and cycle characteristics of a non-aqueous electrolyte secondary battery that contains a silicon material as a negative-electrode active material are improved. A negative-electrode active material particle (10) according to an embodiment includes a lithium silicate phase (11) represented by Li2zSiO(2+z) {0<z<2} and silicon particles (12) dispersed in the lithium silicate phase (11). A lithium silicate constituting the lithium silicate phase has a crystallite size of 40 nm or less. The crystallite size is calculated using the Scherrer equation from the half-width of a diffraction peak of a (111) plane of the lithium silicate in an XRD pattern obtained by XRD measurement of the negative-electrode active material particle 10.

Abstract: The cycle characteristics of a nonaqueous electrolyte secondary battery including negative electrode active material particles containing Si and SiO2 are improved. There is provided a negative electrode active material for a nonaqueous electrolyte secondary battery, the negative electrode active material including a base particle containing Si and SiO2, a mixed phase coating that covers a surface of the base particle and contains SiO2 and carbon, and a carbon coating that covers a surface of the mixed phase coating. The base particle is preferably formed of SiOX (0.5?X?1.5). The mixed phase coating preferably contains carbon dispersed in a phase formed of SiO2.

Abstract: In a nonaqueous electrolyte secondary battery in which SiOx is used as a negative electrode active material, initial charge/discharge efficiency and cycle characteristics are improved. Provided is a negative electrode active material, containing particles made of SiOx (0.5?X?1.5), for nonaqueous electrolyte secondary batteries. In the negative electrode active material, amorphous carbon is stuck on carbon coatings. The particles made of SiOx preferably have a size of 1 ?m to 15 ?m. Particles of amorphous carbon preferably have a size of 0.01 ?m to 1 ?m. One hundred percent of the surface of SiOx is preferably covered by the carbon coatings.

Abstract: In a nonaqueous electrolyte secondary battery containing SiOX as a negative electrode active material, initial charge/discharge efficiency and cycle characteristics are increased. A negative electrode active material for nonaqueous electrolyte secondary batteries is provided. The negative electrode active material contains particles comprising of SiOx (0.8?X?1.2). The particles have cracks therein. SiOX preferably contains a lithium silicate phase, a Si-M compound, or an oxide of M (M is at least one selected from the group consisting of Al, Ti, Fe, and Ni). The cracks preferably extend radially from inner portions of the particles.

Abstract: In a nonaqueous electrolyte secondary battery using SiOx (0<x<2) as a negative electrode active material, cycle characteristics are improved. There is provided a nonaqueous electrolyte secondary battery including a negative electrode active material which contains a substance represented by SiOx (0<x<2). In this nonaqueous electrolyte secondary battery, when the value of x in the above general formula is represented by xs at a surface of the substance and is represented by xb at a central portion thereof, xb<xs holds, and when a depth of the substance from the topmost surface thereof at which x=(xs+xb)/2 holds is represented by za (?m), and when the average particle diameter of the substance is represented by R (?m), 0.05<za and 0.025?za/R?0.4 hold.

Abstract: In nonaqueous electrolyte secondary batteries that use silicon or silicon oxide as a negative electrode active material, the initial charge-discharge efficiency and the cycle characteristics are improved. A negative electrode active material particle (13a) is a particulate negative electrode active material used for nonaqueous electrolyte secondary batteries, and includes a base particle (14) composed of silicon or silicon oxide and a conductive coating layer (15) that coats at least part of a surface of the base particle (14). A pore (16) is formed in the particle. The pore (16) preferably includes an interfacial pore (16z) formed between the base particle (14) and the coating layer (15).