Abstract: A positive electrode active material according to the present disclosure includes: a lithium composite oxide which includes Mn and at least one selected from the group consisting of F, Cl, and N, and S. The lithium composite oxide has a crystalline structure which belongs to the space group Fd-3m, and a relationship 1.40?intensity ratio IMn1/IMn2?1.90 is satisfied. The intensity ratio IMn1/IMn2 is a ratio of an intensity IMn1 to an intensity IMn2. The intensity IMn1 and the intensity IMn2 are intensities of a first proximity peak and a second proximity peak, respectively, of the Mn in a radial distribution function of the Mn included in the lithium composite oxide.

Abstract: A positive electrode active material for a secondary battery includes a lithium metal composite oxide having a crystal structure based on a rock salt structure belonging to a space group Fm-3m, wherein the lithium metal composite oxide includes Cu and a transition metal element M1 other than Li and Cu. The lithium metal composite oxide is preferably represented by a composition formula LiaMnbCucA2dO2-eFe (where A2 is at least one element excluding Li, Mn, Cu, O, and F, and 0<a?1.35, 0.4?b?0.9, 0<c?0.2, 0?d?0.2, 0?e?0.66, 1.75?a+b+c+d?2 are satisfied).

Abstract: A positive electrode active material for a secondary battery including: a lithium metal composite oxide having a crystal structure based on a rock salt structure belonging to a space group Fm-3m. The lithium metal composite oxide contains an element A1 of at least one selected from the group consisting of Ca, Al, and Si, and in the lithium metal composite oxide, a total of Ca, Al, and Si contents relative to a total of the lithimn metal composite oxide is 10 to 1000 ppm by mass.

Abstract: A positive electrode active material for a secondary battery includes a lithium metal composite oxide having a crystal structure based on a rock salt structure belonging to a space group Fm-3m, wherein the lithium metal composite oxide includes Ti and a metal element M1 other than Li and Ti. The metal element M1 preferably further includes at least one selected from the group consisting of Fe, Ge, Si, and Ga.

Abstract: A positive electrode active material for a secondary battery has a lithium metal composite oxide having a crystal structure based on a rock salt structure belonging to a space group Fm-3m, and the crystal structure has a vacancy to which no lithium or metal atom is disposed. For the lithium metal composite oxide, for example, a composite oxide represented by a composition formula LiaMnbMcO2-dFd (where M is at least one metal element excluding Li and Mn, 0<a?1.4, 0.4?b?0.95, 0?c?0.2, 0?d?0.66, and 1.75?a+b+c<2 are satisfied) can be used.

Abstract: This positive electrode active material for a non-aqueous electrolyte secondary battery contains a lithium-transition metal composite oxide that has a rock salt-related structure and is represented by the compositional formula LiaMnbMcO2-xFx (in the formula: M is at least one metal element excluding Li and Mn; 2.000<a+b+c?2.195; 1.0<a?1.4; 0.4?b?0.9; 0?c?0.2; and 0.2?x?0.6). The metal element M preferably is at least one selected from Ni, Sn, Mo, Ti, W, Zn, and Al.

Abstract: A positive-electrode active material contains a lithium composite oxide containing manganese. The crystal structure of the lithium composite oxide belongs to a space group Fd-3m. The integrated intensity ratio I(111)/I(400) of a first peak I(111) on the (111) plane to a second peak I(400) on the (400) plane in an XRD pattern of the lithium composite oxide satisfies 0.05?I(111)/I(400)?0.90.

Abstract: This positive electrode active substance for a non-aqueous electrolyte secondary battery contains a lithium-transition metal composite oxide which has a crystal structure belonging to the space group Fm-3m and is represented by the compositional formula LixMnyMaObFc (in the formula: M is at least one type of metal element excluding Mn; x+y+a=b+c=2; 1<x?1.35; 0.4?y?0.9; 0?a?0.2; and 1.3?b?1.8). In addition, the lattice constant a of the lithium-transition metal composite oxide is 4.09-4.16.

Abstract: This positive electrode active material for a non-aqueous electrolyte secondary battery contains a lithium-transition metal composite compound. The lithium-transition metal composite compound is represented by general formula LixMnyNizMe?OaFb (in the formula, 1?x?1.2, 0.4?y?0.8; 0?z?0.4, x+y+z=2, 0<?<0.05, 1.8?a?2, and 1.8?a±b?2.2 are satisfied, and Me represents at least two kinds of elements selected from metal elements other than Li, Mn, and Ni) and Me includes at least one kind of element having an ion radius of 0.6 ? or more.

Abstract: A positive-electrode active material contains a lithium composite oxide containing at least one selected from the group consisting of F, Cl, N, and S. The crystal structure of the lithium composite oxide belongs to a space group C2/m. An XRD pattern of the lithium composite oxide comprises a first peak within the first range of 44 degrees to 46 degrees of a diffraction angle 2? and a second peak within the second range of 18 degrees to 20 degrees of the diffraction angle 2?. The ratio of the second integrated intensity of the second peak to the first integrated intensity of the first peak is within a range of 0.05 to 0.90.

Abstract: A positive-electrode active material contains a lithium composite oxide, wherein the lithium composite oxide is a multiphase mixture including a first phase, of which a crystal structure belongs to a space group Fm-3m, and a second phase, of which a crystal structure belongs to a space group Fd-3m; and in an XRD pattern of the lithium composite oxide, the integrated intensity ratio I(18°-20°)/I(43°-46°) of a first maximum peak I(18°-20°) within a first range of 18 degrees to 20 degrees at a diffraction angle 2? to a second maximum peak I(43°-46°) within a second range of 43 degrees to 46 degrees at the diffraction angle 2? satisfies 0.05?I(18°-20°)/I(43°-46°)?0.90.

Abstract: A positive electrode active material includes a lithium composite oxide containing: at least one element selected from the group consisting of fluorine, chlorine, nitrogen, sulfur, bromine, and iodine; and a covering material that covers a surface of the lithium composite oxide. The lithium composite oxide has a crystal structure that belongs to a space group R-3 m. The ratio I(003)/I(104) of a first integrated intensity I(003) of a first peak corresponding to a (003) plane to a second integrated intensity I(104) of a second peak corresponding to a (104) plane in an XRD pattern of the lithium composite oxide satisfies 0.62?I(003)/I(104) ?0.90. The covering material has an electron conductivity of 106S/m or less.

Abstract: A positive electrode active material according to the present disclosure includes: a lithium composite oxide which includes Mn and at least one selected from the group consisting of F, Cl, and N, and S. The lithium composite oxide has a crystalline structure which belongs to the space group Fd-3m, and a relationship 1.40?intensity ratio IMn1/IMn2?1.90 is satisfied. The intensity ratio IMn1/IMn2 is a ratio of an intensity IMn1 to an intensity IMn2. The intensity IMn1 and the intensity IMn2 are intensities of a first proximity peak and a second proximity peak, respectively, of the Mn in a radial distribution function of the Mn included in the lithium composite oxide.

Abstract: A positive electrode active material includes a lithium composite oxide and a covering material that covers a surface of the lithium composite oxide. The covering material has an electron conductivity of 106 S/m or less. The lithium composite oxide is a multiphase mixture including a first phase having a first crystal structure that belongs to a space group Fm-3m and a second phase having a second crystal structure that belongs to a space group other than a space group Fm-3m. The ratio I(18°-20°)/I(43°-46°) of a first integrated intensity I(18°-20°) of a first maximum peak present at a first diffraction angle 2? of 18° or more and 20° or less to a second integrated intensity I(43°-46°) of a second maximum peak present at a second diffraction angle 2? of 43° or more and 46° or less in an XRD pattern of the lithium composite oxide satisfies 0.05?I(18°-20°)/I(45°-46°)?0.90.

Abstract: A positive electrode active material according to the present disclosure includes: a lithium composite oxide which contains Mn and at least one selected from the group consisting of F, Cl, and N, and S. The lithium composite oxide has a crystalline structure which belongs to a layered structure, and a relationship 0.95?intensity ratio IMn1/IMn2?1.75 is satisfied. The intensity ratio IMn1/IMn2 is a ratio of an intensity IMn1 to an intensity IMn2. The intensity IMn1 is an intensity of a first proximity peak of the Mn in a radial distribution function of the Mn contained in the lithium composite oxide. The intensity IMn2 is an intensity of a second proximity peak of the Mn in the radial distribution function of the Mn contained in the lithium composite oxide.

Abstract: A positive electrode active material includes a lithium composite oxide and a covering material that covers a surface of the lithium composite oxide. The covering material has an electron conductivity of 106 S/m or less. The lithium composite oxide is a multiphase mixture including a first phase having a first crystal structure that belongs to a space group Fm-3m and a second phase having a second crystal structure that belongs to a space group other than a space group Fm-3m. The ratio I(18°-20°)/I(43°-46°) of a first integrated intensity I(18°-20°) of a first maximum peak present at a first diffraction angle 2? of 18° or more and 20° or less to a second integrated intensity I(43°-46°) of a second maximum peak present at a second diffraction angle 2? of 43° or more and 46° or less in an XRD pattern of the lithium composite oxide satisfies 0.05?I(18°-20°)/I(43°-46°)?0.90.

Abstract: A positive-electrode active material contains a compound represented by the following composition formula (1): LixMeyO?X???(1) where Me denotes one or more elements selected from the group consisting of Mn, Ni, Co, Fe, Al, Sn, Cu, Nb, Mo, Bi, Ti, V, Cr, Y, Zr, Zn, Na, K, Ca, Mg, Pt, Au, Ag, Ru, Ta, W, La, Ce, Pr, Sm, Eu, Dy, and Er, X denotes two or more elements selected from the group consisting of F, Cl, Br, I, N, and S, and x, y, ?, and ? satisfy 0.75?x?2.25, 0.75?y?1.50, 1??<3, and 0<??2, respectively. A crystal structure of the compound belongs to a space group Fm-3m.

Abstract: A positive electrode active material comprising: a compound which has a crystal structure belonging to space group Fm-3m and which is represented by the following composition formula: LixMeyO?X?. In the formula, the Me represents one or more elements selected from the group consisting of Mn, Ni, Co, Fe, Al, Sn, Cu, Nb, Mo, Bi, Ti, V, Cr, Y, Zr, Zn, Na, K, Ca, Mg, Pt, Au, Ag, Ru, Ta, W, La, Ce, Pr, Sm, Eu, Dy, and Er. The X represents one element selected from the group consisting of Cl, Br, I, N, and S. The following conditions are satisfied: 0.5?x?1.5; 0.5?y?1.0; 1??<2; and 0<??1.

Abstract: A positive-electrode active material contains a lithium composite oxide containing manganese. The crystal structure of the lithium composite oxide belongs to a space group Fd-3m. The integrated intensity ratio I(111)/I(400) of a first peak I(111) on the (111) plane to a second peak I(400) on the (400) plane in an XRD pattern of the lithium composite oxide satisfies 0.05?I(111)/I(400)?0.90.

Abstract: A positive electrode active material for a battery, the positive electrode active material comprising a compound having a crystal structure of space group Fm-3m and represented by composition formula (1): LixMe1?Me2?O2 . . . (1). In the formula, Me1 represents one or more elements selected from the group consisting of Mn, Ni, Co, Fe, Al, Sn, Cu, Nb, Mo, Bi, Ti, V, Cr, Y, Zr, Zn, Na, K, Ca, Mg, Pt, Au, Ag, Ru, Ta, W, La, Ce, Pr, Sm, Eu, Dy, and Er, Me2 represents one or more elements selected from the group consisting of B, Si, and P, and the following conditions are met: 0<?; 0<?; ?+?=y; 0.5?x/y?3.0; and 1.5?x+y?2.3.