Abstract: To provide graphene oxide that has high dispersibility and is easily reduced. To provide graphene with high electron conductivity. To provide a storage battery electrode including an active material layer with high electric conductivity and a manufacturing method thereof. To provide a storage battery with increased discharge capacity. A method for manufacturing a storage battery electrode that is to be provided includes a step of dispersing graphene oxide into a solution containing alcohol or acid, a step of heating the graphene oxide dispersed into the solution, and a step or reducing the graphene oxide.

Abstract: To provide graphene oxide that has high dispersibility and is easily reduced. To provide graphene with high electron conductivity. To provide a storage battery electrode including an active material layer with high electric conductivity and a manufacturing method thereof. To provide a storage battery with increased discharge capacity. A method for manufacturing a storage battery electrode that is to be provided includes a step of dispersing graphene oxide into a solution containing alcohol or acid, a step of heating the graphene oxide dispersed into the solution, and a step or reducing the graphene oxide.

Abstract: A power storage device having high capacitance is provided. A power storage device with excellent cycle characteristics is provided. A power storage device with high charge and discharge efficiency is provided. A power storage device including a negative electrode with low resistance is provided. A negative electrode for the power storage device includes a current collector and an active material layer including a plurality of active material particles over the current collector. The active material particle is silicon, and the size of the silicon particle is greater than or equal to 0.001 ?m and less than or equal to 7 ?m.

Abstract: To provide graphene oxide that has high dispersibility and is easily reduced. To provide graphene with high electron conductivity. To provide a storage battery electrode including an active material layer with high electric conductivity and a manufacturing method thereof. To provide a storage battery with increased discharge capacity. A method for manufacturing a storage battery electrode that is to be provided includes a step of dispersing graphene oxide into a solution containing alcohol or acid, a step of heating the graphene oxide dispersed into the solution, and a step or reducing the graphene oxide.

Abstract: To increase the amount of lithium ions that can be received in and released from a positive electrode active material to achieve high capacity and high energy density of a secondary battery. A lithium manganese oxide particle includes a first region and a second region. The valence number of manganese in the first region is lower than the valence number of manganese in the second region. The lithium manganese oxide has high structural stability and high capacity characteristics.

Abstract: A novel multilayer film, a multilayer film suitable for an exterior material for a secondary battery, or a multilayer film that can be favorably used for a secondary battery suitable for a portable information terminal is provided. At least a metal layer and a resin layer are stacked as the multilayer film. A resin that constitutes the resin layer preferably has a durometer hardness of A90 or less, preferably A60 or less. Further, it is preferable that the resin be a material that does not break even when it is stretched to 150% of its original length, more preferably to 200% of its original length, in one direction. The thickness of the resin layer is preferably greater than or equal to 100 ?m and less than or equal to 5 mm, more preferably greater than or equal to 500 ?m and less than or equal to 3 mm.