Abstract: To provide an active material from which a sufficient discharge capacity is obtained, an electrode containing the active material, a lithium secondary battery including the electrode, and a method for making an active material. A method for making an active material includes a temperature elevation step of heating a mixture containing a lithium source, a pentavalent vanadium source, a phosphoric acid source, water, and a reductant in a hermetically sealed container at a temperature elevation rate T1 from 25° C. to 110° C. and then at a temperature elevation rate T2 from 110° C. to a designated temperature of 200° C. or more, in which T1>T2; T1=0.5 to 10° C./min; and T2=0.1 to 2.2° C./min.

Abstract: The present invention provides a method of manufacturing an active material comprising both ?-LiVOPO4 and ?-LiVOPO4. The method of manufacturing an active material in accordance with the present invention comprises a hydrothermal synthesis step of heating a mixture containing a lithium source, a phosphate source, a vanadium source, and water and having a pH greater 7 but smaller than 12.7; and a firing step of firing the mixture after being heated under pressure in the hydrothermal synthesis step.

Abstract: The present invention provides a method of manufacturing an active material which can form an electrochemical device excellent in discharge capacity. The method of manufacturing an active material in accordance with the present invention comprises a hydrothermal synthesis step of heating a mixture including a lithium compound, a metal compound containing one species selected from the group consisting of Fe, Mn, Co, Ni, and V, a phosphorus compound, and water within a reactor while keeping an internal pressure of the reactor at 0.3 MPa or lower by ventilating the inside of the reactor to the outside, and closing the reactor at a time when the temperature of the mixture reaches 100 to 150° C.; and a firing step of firing the mixture after the hydrothermal synthesis step.

Abstract: The method of manufacturing an active material in accordance with the first aspect of the invention yields an active material containing LiVOPO4 capable of improving the cycle characteristic of a battery. Methods of manufacturing active materials in accordance with the second, third, and fourth aspects of the present invention yield active materials containing LiVOPO4 capable of improving the discharge capacity of a battery.

Abstract: The first aspect of the present invention provides a method of manufacturing an active material capable of improving the discharge capacity of a lithium-ion secondary battery. The method of manufacturing an active material in accordance with the first aspect of the present invention comprises the steps of heating a phosphate source, a vanadium source, and water so as to form an intermediate containing phosphorus and vanadium and having a specific surface area of at least 0.1 m2/g but less than 25 m2/g; and heating the intermediate, a water-soluble lithium salt, and water. The second aspect of the present invention provides a method of manufacturing an active material capable of improving the rate characteristic of a lithium-ion secondary battery.

Abstract: A method for manufacturing an active material comprising: a hydrothermal synthesis step of heating under pressure, a mixture containing a lithium source, a vanadium source, a phosphoric acid source, water and a water-soluble polymer having a weight average molecular weight of from 200 to 100,000, wherein the ratio of the total mole number of repeating units of the whole water-soluble polymer to the mole number of the vanadium atoms is from 0.02 to 1.0, to produce a precursor of LiVOPO4 having a ?-type crystal structure; and a firing step of heating the precursor of LiVOPO4 having a ?-type crystal structure to obtain LiVOPO4 having a ?-type crystal structure.

Abstract: An active material which can improve the discharge capacity of a lithium-ion secondary battery is provided. The active material of the present invention contains a rod-shaped particle group having a ?-type crystal structure of LiVOPO4. The particle group has an average minor axis length S of 1 to 5 ?m, an average major axis length L of 2 to 20 ?m, and L/S of 2 to 10.

Abstract: Methods of manufacturing an active material capable of improving the discharge capacity of a lithium-ion secondary battery are provided. The first method of manufacturing an active material comprises a hydrothermal synthesis step of heating a mixture containing a lithium source, a phosphate source, a vanadium source, water, and a reducing agent to 100 to 195° C. under pressure; and a heat treatment step of heating the mixture to 500 to 700° C. after the hydrothermal synthesis step. The hydrothermal synthesis step adjusts the ratio [P]/[V] of the number of moles of phosphorus [P] contained in the mixture before heating to the number of moles of vanadium [V] contained in the mixture before heating to 0.9 to 1.2. The second method of manufacturing an active material comprises a hydrothermal synthesis step of heating a mixture containing a lithium source, a phosphate source, a vanadium source, water, and a reducing agent to 200 to 300° C.

Abstract: The present invention provides an active material which can increase the discharge capacity of a lithium-ion secondary battery as compared with the case using conventional LiMnPO4 as a positive electrode active material. The active material in accordance with the present invention contains a crystallite of LiMnPO4, the crystallite having a size of 20 to 93 nm in a direction perpendicular to a (060) plane thereof.

Abstract: The first aspect of the invention provides a method of manufacturing an active material capable of selectively synthesizing ?-LiVOPO4. The method of manufacturing an active material in accordance with the first aspect comprises a hydrothermal synthesis step of heating a mixture containing a lithium source, a phosphate source, a vanadium source, and water and having a pH of 7 or less; and a firing step of firing the mixture after being heated under pressure in the hydrothermal synthesis step. The second aspect of the invention provides an active material capable of attaining a sufficient discharge capacity at a high discharge current density, an electrode containing the same, and a lithium-ion secondary battery containing the electrode.

Abstract: The present invention provides a method of manufacturing an active material comprising both ?-LiVOPO4 and ?-LiVOPO4. The method of manufacturing an active material in accordance with the present invention comprises a hydrothermal synthesis step of heating a mixture containing a lithium source, a phosphate source, a vanadium source, and water and having a pH greater 7 but smaller than 12.7; and a firing step of firing the mixture after being heated under pressure in the hydrothermal synthesis step.

Abstract: The present invention provides a method of manufacturing an active material which can form an electrochemical device excellent in discharge capacity. The method of manufacturing an active material in accordance with the present invention comprises a hydrothermal synthesis step of heating a mixture including a lithium compound, a metal compound containing one species selected from the group consisting of Fe, Mn, Co, Ni, and V, a phosphorus compound, and water within a reactor while keeping an internal pressure of the reactor at 0.3 MPa or lower by ventilating the inside of the reactor to the outside, and closing the reactor at a time when the temperature of the mixture reaches 100 to 150° C.; and a firing step of firing the mixture after the hydrothermal synthesis step.

Abstract: An active material contains a triclinic LiVOPO4 crystal particle, while the crystal particle has a spherical form and an average particle size of 20 to 200 nm.

Abstract: An active material capable of forming an electrochemical device excellent in its discharge capacity and rate characteristic is provided. The active material in accordance with a first aspect of the present invention comprises a compound particle containing a compound having a composition represented by the following chemical formula (1), a carbon layer covering the compound particle, and a carbon particle. The active material in accordance with a second aspect of the present invention comprises a carbon particle and a compound particle having an average primary particle size of 0.03 to 1.4 ?m, being carried by the carbon particle, and containing a compound represented by the following chemical formula (1): LiaMXO4??(1) where a satisfies 0.9?a?2, M denotes one species selected from the group consisting of Fe, Mn, Co, Ni, and VO, and X denotes one species selected from the group consisting of P, Si, S, V, and Ti.