Abstract: A negative electrode active material includes a compound represented by a composition formula of MgxMe1-xO1-xH2x, where Me is at least one selected from the group consisting of Mn, Fe, Co, Ni, and Cu, and 0.5?x?0.9.

Abstract: A lithium secondary battery comprises an electrode group and a nonaqueous electrolyte having lithium-ion conductivity. A negative electrode current collector has a first surface facing outward of winding of the electrode group and a second surface facing inward of the winding of the electrode group. At least the first surface or the second surface includes a first region and a second region that is closer to an innermost circumference of the winding of the electrode group than the first region. Protrusions include outer-circumference-side protrusions disposed on the first region and inner-circumference-side protrusions disposed on the second region. In at least the first surface or the second surface, a first area rate is smaller than a second area rate.

Abstract: A lithium secondary battery includes a positive electrode, a negative electrode, a separator, and a nonaqueous electrolyte having lithium-ion conductivity. A negative electrode current collector includes a layer having a first surface and a second surface opposite to the first surface, first protrusions protruding from the first surface, and second protrusions protruding from the second surface. The first and second surfaces are surfaces on which lithium metal is deposited during charge. When viewed in a direction of a normal to the first surface, a total area of overlap between the first protrusions and the second protrusions is ½ or less of a total area of the first protrusions.

Abstract: A lithium secondary battery includes a positive electrode, negative electrode, a separator, and a nonaqueous electrolyte having lithium-ion conductivity. The positive electrode contains a positive electrode active material containing lithium. The negative electrode faces the positive electrode. The separator is disposed between the positive and negative electrodes. The negative electrode includes a negative electrode current collector. The negative electrode current collector includes a layer having a first surface, and protrusions protruding from the first surface. The first surface is a surface on which lithium metal is deposited during charge. The protrusions do not divide the first surface into parts.

Abstract: A lithium secondary battery comprises an electrode group and a nonaqueous electrolyte having lithium-ion conductivity. A negative electrode current collector has a first surface facing outward of winding of the electrode group and a second surface facing inward of the winding of the electrode group. At least the first surface or the second surface includes a first region and a second region that is closer to an innermost circumference of the winding of the electrode group than the first region. Protrusions include outer-circumference-side protrusions disposed on the first region and inner-circumference-side protrusions disposed on the second region. A first average height of the outer-circumference-side protrusions is larger than a second average height of the inner-circumference-side protrusions.

Abstract: A lithium secondary battery includes a positive electrode, a negative electrode, a separator, and a nonaqueous electrolyte having lithium-ion conductivity. The positive electrode contains a positive electrode active material containing lithium. The negative electrode faces the positive electrode. The separator is disposed between the positive and negative electrodes. The negative electrode includes a negative electrode current collector. The negative electrode current collector includes a layer and protrusions. The layer has a first surface on which lithium metal is deposited during charge. The protrusions protrude from the first surface. At least one of the protrusions includes a conductive material and an insulative material.

Abstract: A lithium secondary battery comprises an electrode group and a nonaqueous electrolyte having lithium-ion conductivity. A negative electrode current collector has a first surface facing outward of winding of the electrode group and a second surface facing inward of the winding of the electrode group. At least the first surface or the second surface includes a first region and a second region that is closer to an innermost circumference of the winding of the electrode group than the first region. Protrusions include outer-circumference-side protrusions disposed on the first region and inner-circumference-side protrusions disposed on the second region. A first average height of the outer-circumference-side protrusions is smaller than a second average height of the inner-circumference-side protrusions.

Abstract: A lithium secondary battery includes an electrode group and a nonaqueous electrolyte having lithium ion conductivity. A negative electrode includes a negative electrode current collector. The negative electrode current collector has a first surface facing an outward direction of winding of the electrode group and a second surface facing an inward direction of the winding of the electrode group. Lithium metal is deposited on the first surface and the second surface by charge. The negative electrode further includes first protrusions protruding from the first surface and second protrusions protruding from the second surface. A ratio A1X/A1 is less than a ratio A2X/A2. A1X is a sum of projected areas of the first protrusions on the first surface. A1 is an area of the first surface. A2X is a sum of projected areas of the second protrusions on the second surface. A2 is an area of the second surface.

Abstract: A lithium secondary battery includes an electrode group and a nonaqueous electrolyte having lithium ion conductivity. A negative electrode includes a negative electrode current collector. The negative electrode current collector has a first surface facing an outward direction of winding of the electrode group and a second surface facing an inward direction of the winding of the electrode group. Lithium metal is deposited on the first surface and the second surface by charge. The negative electrode further includes first protrusions protruding from the first surface and second protrusions protruding from the second surface. A ratio A1X/A1 is greater than a ratio A2X/A2. A1X is a sum of projected areas of the first protrusions on the first surface. A1 is an area of the first surface. A2X is a sum of projected areas of the second protrusions on the second surface. A2 is an area of the second surface.

Abstract: A lithium secondary battery comprises an electrode group and a nonaqueous electrolyte having lithium-ion conductivity. A negative electrode current collector has a first surface facing outward of winding of the electrode group and a second surface facing inward of the winding of the electrode group. At least the first surface or the second surface includes a first region and a second region that is closer to an innermost circumference of the winding of the electrode group than the first region. Protrusions include outer-circumference-side protrusions disposed on the first region and inner-circumference-side protrusions disposed on the second region. In at least the first surface or the second surface, a first area rate is larger than a second area rate.

Abstract: A positive-electrode active material contains a compound that has a crystal structure belonging to the space group FM3-M and that is represented by the composition formula (1): LixMeyO?F???(1) wherein Me denotes one or two or more elements selected from the group consisting of B, Ce, Si, Zr, Nb, Pr, Ti, W, Ge, Mo, Sn, and solid solutions thereof, and the following conditions are satisfied. 1.8?x?2.2 0.8?y?1.3 1.2???2.5 0.5???1.

Abstract: An active material for a fluoride ion secondary battery includes a composite fluoride which contains: an alkali metal or NH4; a transition metal; and fluorine.

Abstract: An active material for a fluoride ion secondary battery includes a metal composite fluoride. The metal composite fluoride contains at least one metal selected from the group consisting of an alkali metal, an alkaline earth metal, scandium, yttrium, and a lanthanoid; a first transition metal; a second transition metal different from the first transition metal; and fluorine.

Abstract: A nonaqueous electrolyte liquid for an alkaline earth metal secondary battery includes: a nonaqueous solvent: an alkaline earth metal cation; an organic molecule coordinated to the alkaline earth metal cation; and an anion. The organic molecule is a carbonic acid ester, a carboxylic acid ester, a phosphoric acid ester, or a sulfonic acid ester.

Abstract: A positive electrode material includes an active material represented by Li2Mn(1?2x)NixMoxO3 (where 0<x<0.4).

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 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-3m. The ratio |(003)/|(104) of a first integrated intensity ||(003) of a first peak corresponding to a (003) plane to a second integrated intensity ||(104) of a second peak corresponding to a (104) plane in an XRD pattern of the lithium composite oxide satisfies 0.62?|(003)/|(104)?0.90.

Abstract: A positive-electrode active material contains a compound represented by the following composition formula (1): LixMeyAzO?F???(1) where Me denotes one or more elements selected from the group consisting of Mn, Co, Ni, Fe, Al, Cu, Nb, Mo, Ti, Cr, Zr, Zn, Na, K, Ca, Mg, Pt, Au, Ru, and W, A denotes one or more elements selected from the group consisting of B, Si, and P, and the following conditions: 1.3?x?2.1, 0.8?y?1.3, 0<z?0.2, 1.8???2.9, and 0.1???1.2 are satisfied. A crystal structure of the compound belongs to a space group Fm-3m.

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 cathode active material contains a compound represented by composition formula (1): LixNay{Li?Na?Mn(1?????z)Az}O2. In the formula, A represents at least one selected from the group consisting of Co, Ni, Fe, and Al, and the following conditions are met: 0.75?x?1.0, 0<y?0.01, 0.75<x+y?1, 0.16???0.3, 0<??0.01, 0.2??+??0.3, and 0?z?0.15.