Abstract: A negative electrode active material with sufficiently high discharge capacity at a high rate, and a negative electrode and a lithium ion secondary battery using the negative electrode active material. A negative electrode active material according to the invention includes a negative electrode active material particle containing silicon and silicon oxide, wherein a surface layer part of the negative electrode active material particle is a layer with lower density than a core part of the negative electrode active material particle. With such a structure of the negative electrode active material, the sufficiently high discharge capacity at a high rate can be obtained.

Abstract: A negative electrode active material is provided for a lithium ion secondary battery having high initial charging/discharging efficiency. The negative electrode active material containing silicon and silicon oxide has two phases with different compositions therein. One of the two phases has a lower silicon element concentration than the other phase, and is a fibrous phase forming a network structure in a cross section of primary particle of the negative electrode active material. Use of the negative electrode active material enables a sufficient increase in initial charging/discharging efficiency.

Abstract: Provided are a negative electrode active material for a lithium ion secondary battery, which has sufficiently high discharge capacity at a high rate. The negative electrode active material containing silicon and silicon oxide includes primary particles having two phases of different compositions therein. One of the two phases has a higher silicon element concentration than the other phase, and is a fibrous phase forming a network structure in a cross section of the primary particle. Use of the negative electrode active material enables a sufficient increase in discharge capacity at a high rate.

Abstract: A positive electrode active material contains a compound represented by a chemical formula LiVOPO4. A crystal system of the compound is an orthorhombic system, and the amount of tetravalent V of the compound is 27.7 mass % or more and 28.2 mass % or less.

Abstract: A lithium ion secondary battery with a high electrode density and an excellent rate discharge characteristic. The positive electrode includes a positive electrode active material of a compound represented by Lia(NixCoyAl1-x-y)O2 (0.95?a?1.05, 0.5?x?0.9, 0.05?y?0.2), and carbon adhered to the surface of the material, in the Raman spectrum using a laser of 532 nm, the positive electrode includes a peak PA (D band) at 1200˜1450 cm?1, a peak PB (G band) at 1450˜1700 cm?1 and a peak PC at 400˜600 cm?1, and when the intensities are normalized by regarding the maximum intensity as 1 and the minimum intensity as 0 in the wavenumber domain of 200˜1800 cm?1, Raman intensity of the minimum (V band) between the two peaks of said peak PA and said peak PB is 0.6 or less, and Raman intensity of said peak PC is 0.1 or more and 0.5 or less.

Abstract: To provide an active material with high capacity, high initial charge-discharge efficiency, and high average discharge voltage. An active material according to the present invention includes a first active material and a second active material, wherein the ratio (?) of the second active material (B) to the total amount by mole of the first active material (A) and the second active material (B) satisfies 0.4 mol %???18 mol % [where ?=(B/(A+B))×100].

Abstract: A negative electrode active material is provided for a lithium ion secondary battery having high initial charging/discharging efficiency. The negative electrode active material containing silicon and silicon oxide has two phases with different compositions therein. One of the two phases has a lower silicon element concentration than the other phase, and is a fibrous phase forming a network structure in a cross section of primary particle of the negative electrode active material. Use of the negative electrode active material enables a sufficient increase in initial charging/discharging efficiency.

Abstract: Provided are a negative electrode active material for a lithium ion secondary battery, which has sufficiently high discharge capacity at a high rate. The negative electrode active material containing silicon and silicon oxide includes primary particles having two phases of different compositions therein. One of the two phases has a higher silicon element concentration than the other phase, and is a fibrous phase forming a network structure in a cross section of the primary particle. Use of the negative electrode active material enables a sufficient increase in discharge capacity at a high rate.

Abstract: A negative electrode active material with sufficiently high discharge capacity at a high rate, and a negative electrode and a lithium ion secondary battery using the negative electrode active material. A negative electrode active material according to the invention includes a negative electrode active material particle containing silicon and silicon oxide, wherein a surface layer part of the negative electrode active material particle is a layer with lower density than a core part of the negative electrode active material particle. With such a structure of the negative electrode active material, the sufficiently high discharge capacity at a high rate can be obtained.

Abstract: An active material having high capacity and excellent charging/discharging cycle durability at high potential is provided. The active material has a layered structure and is represented by the following composition formula (1): LiyNiaCobMncMdOxFz1Pz2??(1) wherein the element M is at least one element selected from the group consisting of Al, Si, Zr, Ti, Fe, Mg, Nb, Ba and V, and 1.9?(a+b+c+d+y)?2.1, 1.0?y?1.3, 0<a?0.3, 0?b?0.25, 0.3?c?0.7, 0?d?0.1, 0.07?z1?0.15, 0.01?z2?0.1, and 1.9?(x+z1)?2.1 are satisfied.

Abstract: A negative electrode active material mainly contains silicon and silicon oxide. In the negative electrode active material, an Ar-laser Raman spectrum thereof includes a peak A corresponding to 950±30 cm?1 and a peak B corresponding to 480±30 cm?1, and an intensity ratio of the peak B to the peak A (B/A) is in the range of 1 to 10.

Abstract: To provide an active material with high capacity, high initial charge-discharge efficiency, and high average discharge voltage. An active material according to the present invention includes a first active material and a second active material, wherein the ratio (?) of the second active material (B) to the total amount by mole of the first active material (A) and the second active material (B) satisfies 0.4 mol %???18 mol % [where ?=(B/(A+B))×100].

Abstract: A lithium ion secondary battery with a high electrode density and an excellent rate discharge characteristic. The positive electrode includes a positive electrode active material of a compound represented by Lia(NixCoyAl1?x?y)O2 (0.95:?a?1.05, 0.5?x?0.9, 0.05?y?0.2), and carbon adhered to the surface of the material, in the Raman spectrum using a laser of 532 nm, the positive electrode includes a peak PA (D band) at 1200˜1450 cm?1, a peak PB (G band) at 1450˜1700 cm?1 and a peak PC at 400˜600 cm?1, and when the intensities are normalized by regarding the maximum intensity as 1 and the minimum intensity as 0 in the wavenumber domain of 200˜1800 cm?1, Raman intensity of the minimum (V band) between the two peaks of said peak PA and said peak PB is 0.6 or less, and Raman intensity of said peak PC is 0.1 or more and 0.5 or less.

Abstract: A positive electrode active material contains a compound represented by a chemical formula LiVOPO4. A crystal system of the compound is an orthorhombic system, and the amount of tetravalent V of the compound is 27.7 mass % or more and 28.2 mass % or less.

Abstract: A negative electrode active material mainly contains silicon and silicon oxide. In the negative electrode active material, an Ar-laser Raman spectrum thereof includes a peak A corresponding to 950±30 cm?1 and a peak B corresponding to 480±30 cm?1, and an intensity ratio of the peak B to the peak A (B/A) is in the range of 1 to 10.

Abstract: An active material having high capacity and excellent charging/discharging cycle durability at high potential is provided. The active material has a layered structure and is represented by the following composition formula (1): LiyNiaCobMncMdOxFz1Pz2 ??(1) wherein the element M is at least one element selected from the group consisting of Al, Si, Zr, Ti, Fe, Mg, Nb, Ba and V, and 1.9?(a+b+c+d+y)?2.1, 1.0?y?1.3, 0<a?0.3, 0?b?0.25, 0.3?c?0.7, 0?d?0.1, 0.07?z1?0.15, 0.01?z2?0.1, and 1.9?(x+z1)?2.1 are satisfied.

Abstract: Active material is obtained by sintering a precursor, has a layered structure and is represented by the following formula (1). The temperature at which the precursor becomes a layered structure compound in its sintering in atmospheric air is 450° C. or less. Alternatively, the endothermic peak temperature of the precursor when its temperature is increased from 300° C. to 800° C. in its differential thermal analysis in the atmospheric air is 550° C. or less. LiyNiaCobMncMdOxFz??(1) In formula (1), the element M is at least one of Al, Si, Zr, Ti, Fe, Mg, Nb, Ba, and V and 1.9?(a+b+c+d+y)?2.1, 1.0?y?1.3, 0<a?0.3, 0?b?0.25, 0.3?c?0.7, 0?d?0.1, 1.9?(x+z)?2.0, and 0?z?0.15 are satisfied.

Abstract: A rewritable phase-change optical recording medium is provided, which includes a substrate, a first information layer, a spacer layer, a second information layer, and a cover layer. The second information layer includes a recording film containing Sb as a main component and V or V and In as second components. When an amorphous mark formed in the recording film is irradiated with a reproduction beam, crystallization of the amorphous mark occurs only in a central portion in the width direction of the amorphous mark. The width direction is orthogonal to the scanning direction of the laser beam. The recording film is formed of a material that exhibits a change in degree of modulation of 5% or less when recorded information is repeatedly reproduced. The change in degree of modulation is a change from when the number of times of reproduction is 100,000 to when it is 400,000.

Abstract: A surface acoustic wave element, a surface acoustic wave device, a duplexer, and a method of making a surface acoustic wave element which significantly restrain characteristics from deteriorating are provided. The surface acoustic wave element in accordance with the present invention comprises a piezoelectric substrate, and an IDT electrode formed on the piezoelectric substrate, whereas the piezoelectric substrate has a volume resistivity of not less than 3.6×1010 ?·cm and not more than 1.5×1014 ?·cm. This surface acoustic wave element comprises the piezoelectric substrate having a low volume resistivity, whereas the volume resistivity is reduced to 1.5×1014 ?·cm or less. Therefore, discharging is restrained from occurring between IDT electrodes, whereby characteristics are significantly kept from deteriorating. Also, since the volume resistivity of the piezoelectric substrate is not less than 3.6×1010 ?·cm, the IDT electrodes are significantly prevented from short-circuiting with each other.

Abstract: A rewritable phase-change optical recording medium is provided, which includes a substrate, a first information layer, a spacer layer, a second information layer, and a cover layer. The second information layer includes a recording film containing Sb as a main component and V or V and In as second components. When an amorphous mark formed in the recording film is irradiated with a reproduction beam, crystallization of the amorphous mark occurs only in a central portion in the width direction of the amorphous mark. The width direction is orthogonal to the scanning direction of the laser beam. The recording film is formed of a material that exhibits a change in degree of modulation of 5% or less when recorded information is repeatedly reproduced. The change in degree of modulation is a change from when the number of times of reproduction is 100,000 to when it is 400,000.