A power storage device with high capacity is provided. A power storage device with high energy density is provided. A highly reliable power storage device is provided. A long-life power storage device is provided. An electrode with high capacity is provided. An electrode with high energy density is provided. A highly reliable electrode is provided. Such a power storage device includes a first electrode and a second electrode. The first electrode includes a first current collector and a first active material layer. The first active material layer includes active material particles, spaces provided on the periphery of the active material particles, graphene, and a binder. The active material particles are silicon. The active material particles and the spaces are surrounded by the graphene and the binder.

Provided is a metal sheet having a carbon material capable of stably exhibiting excellent characteristics when used for an electrode of an electricity storage device. A metal sheet having a carbon material includes a porous metal sheet provided with a transition metal present on a surface and a carbon material of at least one of a carbon fiber and a carbon particle, the carbon material being formed from the porous metal sheet, the carbon material being disposed in a pore of the porous metal sheet.

A power storage device with high capacity is provided. A power storage device with high energy density is provided. A highly reliable power storage device is provided. A long-life power storage device is provided. An electrode with high capacity is provided. An electrode with high energy density is provided. A highly reliable electrode is provided. Such a power storage device includes a first electrode and a second electrode. The first electrode includes a first current collector and a first active material layer. The first active material layer includes active material particles, spaces provided on the periphery of the active material particles, graphene, and a binder. The active material particles are silicon. The active material particles and the spaces are surrounded by the graphene and the binder.

A power storage device with high capacity is provided. A power storage device with high energy density is provided. A highly reliable power storage device is provided. A long-life power storage device is provided. An electrode with high capacity is provided. An electrode with high energy density is provided. A highly reliable electrode is provided. Such a power storage device includes a first electrode and a second electrode. The first electrode includes a first current collector and a first active material layer. The first active material layer includes active material particles, spaces provided on the periphery of the active material particles, graphene, and a binder. The active material particles are silicon. The active material particles and the spaces are surrounded by the graphene and the binder.

A bipolar capacitor-assisted solid-state battery is disclosed that includes a plurality of electrochemical battery unit cells, each of which includes a negative electrode, a positive electrode, and a lithium ion-conductive electrolyte-containing separator disposed between the negative electrode and the positive electrode. The lithium ion-conductive electrolyte-containing separator of each electrochemical battery unit cell comprises a solid-state electrolyte material, and, additionally, at least one negative electrode of the electrochemical battery unit cells or at least one positive electrode of the electrochemical battery unit cells includes a capacitor material. The bipolar capacitor-assisted solid-state battery further includes a bipolar current collector disposed between a negative electrode of one electrochemical battery unit cell and a positive electrode of an adjacent electrochemical battery unit cell. A method for manufacturing the disclosed bipolar capacitor-assisted solid-state battery is also disclosed.

A method for manufacturing an electrochemical device includes the following steps: a step of preparing a positive electrode, the positive electrode including a first current collector and a positive electrode layer containing a conductive polymer; a step of preparing a negative electrode, the negative electrode including a second current collector and a negative electrode layer; and a step of sealing the positive electrode, the negative electrode, and an electrolytic solution in an exterior body. The step of preparing the positive electrode includes a step of holding the positive electrode in depressurized atmosphere and then introducing gas containing CO.sub.2 as a primary component into the depressurized atmosphere.

A method for manufacturing an electrochemical device includes the following steps: a step of preparing a positive electrode, the positive electrode including a first current collector and a positive electrode layer containing a conductive polymer; a step of preparing a negative electrode, the negative electrode including a second current collector and a negative electrode layer; and a step of sealing the positive electrode, the negative electrode, and an electrolytic solution in an exterior body. The step of preparing the positive electrode includes a step of holding the positive electrode in depressurized atmosphere and then introducing gas containing CO.sub.2 as a primary component into the depressurized atmosphere.

The present invention relates to a current collector comprising: a substrate, the substrate being made of a first material, the first material comprising a polymer, and a grid in contact with the substrate, the grid being made of a second material, the second material comprising metal particles.

The present invention relates to a current collector comprising: a substrate, the substrate being made of a first material, the first material comprising a polymer, and a grid in contact with the substrate, the grid being made of a second material, the second material comprising metal particles.

A power storage device having flexibility is provided. A power storage device of which the capacity is not likely to deteriorate even when being curved is provided. A power storage device includes a first electrode, a second electrode, and an electrolytic solution. The first electrode and the second electrode overlap with each other. The first electrode includes a first current collector and a first active material layer. The first current collector has a first surface and a second surface. The first active material layer is provided on the first surface. The first current collector has a first bent portion with the second surface inside. The second surface includes a first region and a second region. The first region overlaps with the second region. The first region is connected to the second region at a portion different from the first bent portion.