Abstract: A lithium-manganese composite oxide containing a lithium-iron-manganese composite oxide represented by the composition formula. Li1+x?w(FeyNizMn1?y?z)1?xO2??, where 0<x<?, 0?w<0.8, 0<y<1, 0<z<0.5, y+z<1, and 0??<0.5, in which at least in a state of charge of a lithium ion battery using the lithium-manganese composite oxide as a positive-electrode active material, at least some of iron atoms are pentavalent.

Abstract: A lithium-manganese composite oxide represented by formula (1): Li1+x[(FeyNi1?y)zMn1?z]1?xO2 (1) wherein x, y, and z satisfy the following: 0<x??, 0?y<1.0, and 0<z?0.6, and wherein the content ratio of Li to the total content of Fe, Ni, and Mn (Li/(Fe+Ni+Mn)) is 1.55 or less on a molar ratio basis, the lithium-manganese composite oxide containing a crystalline phase having a layered rock-salt structure. This composite oxide is a novel material made from less resource-constrained and cheaper elements, and exhibits a high specific capacity, excellent charge-and-discharge cycle characteristics, and a high discharge capacity at a high current density (excellent rate characteristics), when used in the positive electrode material for lithium-ion secondary batteries.

Abstract: A lithium-manganese composite oxide containing a lithium-iron-manganese composite oxide represented by the composition formula. Li1+x?w(FeyNizMn1?y?z)1?xO2??, where 0<x<1/3, 0?w<0.8, 0<y<1, 0<z<0.5, y+z<1, and 0??<0.5, in which at least in a state of charge of a lithium ion battery using the lithium-manganese composite oxide as a positive-electrode active material, at least some of iron atoms are pentavalent.

Abstract: There is provided a lithium-iron-manganese-based composite oxide capable of providing a lithium-ion secondary battery which has a high capacity retention rate in charge/discharge cycles and in which the generation of a gas caused by charge/discharge cycles is suppressed. A lithium-iron-manganese-based composite oxide having a layered rock-salt structure, wherein at least a part of the surface of a lithium-iron-manganese-based composite oxide represented by the following formula is coated with an oxide of at least one metal selected from the group consisting of La, Pr, Nd, Sm and Eu: LixM1(y-p)MnpM2(z-q)FeqO(2-?) wherein 1.05?x?1.32, 0.33?y?0.63, 0.06?z?0.50, 0<p?0.63, 0.06?q?0.50, 0???0.80, y?p, and z?q; M1 is at least one element selected from Ti and Zr; and M2 is at least one element selected from the group consisting of Co, Ni and Mn.

Abstract: A lithium-manganese composite oxide containing a lithium-iron-manganese composite oxide represented by the composition formula: Li1+x?w(FeyNizMn1?y?z)1?xO2??, where 0<x<?, 0?w<0.8, 0<y<1, 0<z<0.5, y+z<1, and 0??<0.5, in which at least in a state of charge of a lithium ion battery using the lithium-manganese composite oxide as a positive-electrode active material, at least some of iron atoms are pentavalent.

Abstract: A lithium-manganese composite oxide represented by formula (1): Li1+x[(FeyNi1?y)zMn1?z]1?xO2 (1) wherein x, y, and z satisfy the following: 0<x??, 0?y<1.0, and 0<z?0.6, and wherein the content ratio of Li to the total content of Fe, Ni, and Mn (Li/(Fe+Ni+Mn)) is 1.55 or less on a molar ratio basis, the lithium-manganese composite oxide containing a crystalline phase having a layered rock-salt structure. This composite oxide is a novel material made from less resource-constrained and cheaper elements, and exhibits a high specific capacity, excellent charge-and-discharge cycle characteristics, and a high discharge capacity at a high current density (excellent rate characteristics), when used in the positive electrode material for lithium-ion secondary batteries.

Abstract: There is provided a lithium-iron-manganese-based composite oxide capable of providing a lithium-ion secondary battery which has a high capacity retention rate in charge/discharge cycles and in which the generation of a gas caused by charge/discharge cycles is reduced. A lithium-iron-manganese-based composite oxide having a layered rock-salt structure, wherein at least a part of the surface of a lithium-iron-manganese-based composite oxide represented by the following formula (1) is coated with an inorganic material: LixM1(y-p)MnpM2(z-p)FeqO(2-?) (1) (wherein 1.05?x?1.32, 0.33?y?0.63, 0.06?z?0.50, 0<p?0.63, 0.06?q?0.50, 0???0.80, y?p, and z?q; M1 is at least one element selected from Ti and Zr; and M2 is at least one element selected from the group consisting of Co, Ni and Mn).

Abstract: There is provided a lithium-iron-manganese-based composite oxide capable of providing a lithium-ion secondary battery which has a high capacity retention rate in charge/discharge cycles and in which the generation of a gas caused by charge/discharge cycles is suppressed. A lithium-iron-manganese-based composite oxide having a layered rock-salt structure, wherein at least a part of the surface of a lithium-iron-manganese-based composite oxide represented by the following formula is coated with an oxide of at least one metal selected from the group consisting of La, Pr, Nd, Sm and Eu: LixM1(y-p)MnpM2(z-q)FeqO(2-?) wherein 1.05?x?1.32, 0.33?y?0.63, 0.06?z?0.50, 0<p?0.63, 0.06?q?0.50, 0???0.80, y?p, and z?q; M1 is at least one element selected from Ti and Zr; and M2 is at least one element selected from the group consisting of Co, Ni and Mn.

Abstract: There is provided a lithium-iron-manganese-based composite oxide capable of providing a lithium-ion secondary battery which has a high capacity retention rate in charge/discharge cycles and in which the generation of a gas caused by charge/discharge cycles is reduced. A lithium-iron-manganese-based composite oxide having a layered rock-salt structure, wherein at least a part of the surface of a lithium-iron-manganese-based composite oxide represented by the following formula (1) is coated with an inorganic material: LixM1(y-p)MnpM2(z-p)FeqO(2-?) (1) (wherein 1.05?x?1.32, 0.33?y?0.63, 0.06?z?0.50, 0<p?0.63, 0.06?q?0.50, 0???0.80, y?p, and z?q; M1 is at least one element selected from Ti and Zr; and M2 is at least one element selected from the group consisting of Co, Ni and Mn).