Abstract: A positive electrode material includes: Li2Ni?M1?M2?Mn?O4-?; a layered structure including a Li layer and a Ni layer; and a chemical bond of M2-O. ? satisfies an equation of 0.50<??1.33. ? satisfies an equation of 0??<0.67. ? satisfies an equation of 0.33???1.1. ? satisfies an equation of 0??<1.00. ? satisfies an equation of 0???1.00. M1 represents at least one selected from Co and Ga.

Abstract: A positive electrode material includes: a composite oxide of solid solution including Li2SnO3 and Li2Ni?M1?M2?Mn84 O4-?. ? satisfies an equation of 0.50???1.35. ? satisfies an equation of 0 ??<1.0. ? satisfies an equation of 0???0.66. ? and ? satisfies an equation of 0.33??+??1.1. ? satisfies an equation of 0???0.66. ? satisfies an equation of 0???1.00. M1 represents at least one selected from Sn, Sb0.5Al0.5. M2 represents Sb.

Abstract: A positive electrode material includes: Li2Ni?M1?M2?Mn?O4-? that has a layered structure including a Li layer and a Ni layer, and in which a Ni—O bond length is shorter than that calculated from the Shannon's ionic radii. ? satisfies a relation of 0.50<??1.33, ? satisfies a relation of 0??<0.67, ? satisfies a relation of 0.33???1.1, ? satisfies a relation of 0???1.00, ? satisfies a relation of 0??1.00, M1 represents at least one selected from Co and Ga, M2 represents at least one selected from Ge, Sn and Sb. A positive electrode material may indicate a peak intensity ratio (I003/I104) of 0.

Abstract: A lithium-ion secondary battery includes: a first cathode active material having a polyanion structure which stores and releases a lithium ion; and a second cathode active material having a lithium diffusion coefficient different from a lithium diffusion coefficient of the first cathode active material. The second cathode active material has a layered rock salt-type structure. A discharge curve of the first cathode material and a discharge curve of the second cathode material intersect with each other at at least two points.

Abstract: A cathode active material for a nonaqueous electrolyte secondary battery includes a core part and a shell part arranged to a surface of the core part. The core part includes an inorganic oxide having a polyanion structure. The inorganic oxide is LixMnyM1-yXO4, in which M is at least one of Co, Ni, Fe, Cu, Cr, Mg, Ca, Zn, and Ti, X is at least one of P, As, Si, and Mo, and 0?x<1.0 and 0.5?y?1.0. The inorganic oxide has a maximum mass change ratio G1 in a temperature range from a room temperature to 250° C. when heated under inert atmosphere, and has a maximum mass change ratio G2 in a temperature range from 350° C. to 500° C. when heated under inert atmosphere. A difference between the maximum mass change ratio G2 and the maximum mass change ratio G1 is less than or equal to 5%.

Abstract: A positive electrode active material includes a conductive matrix and a lithium metal compound of a polyanion structure provided on the surface of the conductive matrix. The lithium metal compound is expressed as Li?M0?X?O4-?Z?, in which: M0 is one or more selected from Mn, Co, Ni, Fe, Cu, Cr, Mg, Ca, Zn, and Ti; X is one or more selected from P, As, Si, Mo, and Ge; Z is one or more selected from Al, Mg, Ca, Zn, and Ti, being optionally includable; ? satisfies 0???2.0; ? satisfies 0???1.5; ? satisfies 1???1.5; and ? satisfies 0???1.5.