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 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 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 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. In at least the first surface or the second surface, a first area rate is larger than a second area rate.

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 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 includes a wound electrode group and a lithium-ion conductive nonaqueous electrolyte. The wound electrode group includes a positive electrode, a negative electrode, and a separator between the positive electrode and the negative electrode. The negative electrode includes a negative electrode current collector. The negative electrode current collector includes: a layer having a first surface facing outward of the winding of the electrode group and a second surface facing inward of the winding of the electrode group; first protrusions protruding from the first surface; and second protrusions protruding from the second surface. Lithium metal is deposited on the first surface and the second surface by charging. A second average height of the second protrusions is higher than a first average height of the first protrusions.

Abstract: A lithium secondary battery includes a wound electrode group and a lithium-ion conductive nonaqueous electrolyte. The wound electrode group includes a positive electrode, a negative electrode, and a separator between the positive electrode and the negative electrode. The negative electrode includes a negative electrode current collector. The negative electrode current collector includes: a layer having a first surface facing outward of the winding of the electrode group and a second surface facing inward of the winding of the electrode group; first protrusions protruding from the first surface; and second protrusions protruding from the second surface. Lithium metal is deposited on the first surface and the second surface by charging. A first average height of the first protrusions is higher than a second average height of the second protrusions.

Abstract: Object: To provide a battery negative electrode material exhibiting both a merit of high specific capacity obtained by using Si, and a merit of high cycle durability obtained by using a non-graphitizable carbon material. Resolution Means: A negative electrode material (1) of a battery of the present invention includes silicon material areas (10) made of a silicon material, and a carbon material area (20) made of a carbon material. The carbon material area (20) is formed in a surrounding area of the silicon material area (10), separated by a cavity (30) at least at a portion. In addition, an (002) average interlayer spacing d002 of the carbon material area (20) determined by powder X-ray diffraction is from 0.365 nm to 0.390 nm.

Abstract: A negative electrode active material includes a plurality of layers and lithium located between the plurality of layers, each of the plurality of layers containing carbon and boron, and nitrogen or phosphorus, wherein a molar ratio of the boron to the carbon is more than 0.6.

Abstract: A negative electrode active material includes a layered compound that includes: a plurality of layers and calcium located between the plurality of layers; each of the plurality of layers containing carbon and boron and further containing nitrogen or phosphorus.

Abstract: A negative electrode active material contains a graphite material represented by a formula CaxByC1-y, where x and y satisfy 0<x<0.2 and 2x?y?0.5.