Abstract: An object is to reduce variation in shape of crystals that are to be formed. Solutions containing respective raw materials are made in an environment where an oxygen concentration is lower than that in air, the solutions containing the respective raw materials are mixed in an environment where an oxygen concentration is lower than that in air to form a mixture solution, and with use of the mixture solution, a composite oxide is formed by a hydrothermal method.

Abstract: Occlusion and release of lithium ion are likely to one-dimensionally occur in the b-axis direction of a crystal in a lithium-containing composite oxide having an olivine structure. Thus, a positive electrode in which the b-axes of lithium-containing composite oxide single crystals are oriented vertically to a surface of a positive electrode current collector is provided. The lithium-containing composite oxide particles are mixed with graphene oxide and then pressure is applied thereto, whereby the rectangular parallelepiped or substantially rectangular parallelepiped particles are likely to slip. In addition, in the case where the rectangular parallelepiped or substantially rectangular parallelepiped particles whose length in the b-axis direction is shorter than those in the a-axis direction and the c-axis direction are used, when pressure is applied in one direction, the b-axes can be oriented in the one direction.

Abstract: [Object] Provided is a means for improving cycle characteristics by suppressing electrode deterioration resulting from non-uniformity of voltage across an electrode plane in a high-capacity and large-area non-aqueous electrolyte secondary battery that includes lithium nickel-based composite oxide as a positive electrode active substance.

Abstract: Occlusion and release of lithium ion are likely to one-dimensionally occur in the b-axis direction of a crystal in a lithium-containing composite oxide having an olivine structure. Thus, a positive electrode in which the b-axes of lithium-containing composite oxide single crystals are oriented vertically to a surface of a positive electrode current collector is provided. The lithium-containing composite oxide particles are mixed with graphene oxide and then pressure is applied thereto, whereby the rectangular parallelepiped or substantially rectangular parallelepiped particles are likely to slip. In addition, in the case where the rectangular parallelepiped or substantially rectangular parallelepiped particles whose length in the b-axis direction is shorter than those in the a-axis direction and the c-axis direction are used, when pressure is applied in one direction, the b-axes can be oriented in the one direction.

Abstract: An object is to reduce variation in shape of crystals that are to be formed. Solutions containing respective raw materials are made in an environment where an oxygen concentration is lower than that in air, the solutions containing the respective raw materials are mixed in an environment where an oxygen concentration is lower than that in air to form a mixture solution, and with use of the mixture solution, a composite oxide is formed by a hydrothermal method.

Abstract: [Object] Provided is a means for improving cycle characteristics by suppressing electrode deterioration resulting from non-uniformity of voltage across an electrode plane in a high-capacity and large-area non-aqueous electrolyte secondary battery that includes lithium nickel-based composite oxide as a positive electrode active substance.

Abstract: An object is to reduce variation in shape of crystals that are to be manufactured. Raw materials are each weighed, solutions containing the respective raw materials are formed in an environment where an oxygen concentration is lower than that in air, the solutions containing the respective raw materials are mixed in an environment where an oxygen concentration is lower than that in air to form a mixture solution, and with use of the mixture solution, a composite oxide is formed by a hydrothermal method.

Abstract: A positive-electrode active material with improved electrical conductivity, and a power storage device using the material are provided. A positive-electrode active material with large capacity, and a power storage device using the material are provided. A core including lithium metal oxide is used as a core of a main material of the positive-electrode active material, and one to ten pieces of graphene is used as a covering layer for the core. A hole is provided for graphene, whereby transmission of a lithium ion is facilitated, resulting in improvement of use efficiency of current.

Abstract: The formation method of graphene includes the steps of forming a layer including graphene oxide over a first conductive layer; and supplying a potential at which the reduction reaction of the graphene oxide occurs to the first conductive layer in an electrolyte where the first conductive layer as a working electrode and a second conductive layer with a as a counter electrode are immersed. A manufacturing method of a power storage device including at least a positive electrode, a negative electrode, an electrolyte, and a separator includes a step of forming graphene for an active material layer of one of or both the positive electrode and the negative electrode by the formation method.

Abstract: The formation method of graphene includes the steps of forming a layer including graphene oxide over a first conductive layer; and supplying a potential at which the reduction reaction of the graphene oxide occurs to the first conductive layer in an electrolyte where the first conductive layer as a working electrode and a second conductive layer with a as a counter electrode are immersed. A manufacturing method of a power storage device including at least a positive electrode, a negative electrode, an electrolyte, and a separator includes a step of forming graphene for an active material layer of one of or both the positive electrode and the negative electrode by the formation method.

Abstract: The power extraction efficiency of a nonaqueous electrolyte secondary battery such as a lithium ion battery is improved. A material having magnetic susceptibility anisotropy such as an olivine type oxide including a transition metal element is used for active material particles. The active material particles and an electrolyte solution are mixed to form a slurry. The slurry is applied to a current collector, and then the current collector is left in a magnetic field. Thus, the active material particles are oriented. With the use of active material particles oriented in such a manner, the power extraction efficiency can be improved.

Abstract: At least one of an aqueous solution A containing lithium, an aqueous solution B containing iron, manganese, cobalt, or nickel, and an aqueous solution C containing a phosphoric acid includes graphene oxide. The aqueous solution A is dripped into the aqueous solution C, so that a mixed solution E including a precipitate D is prepared. The mixed solution E is dripped into the aqueous solution B, so that a mixed solution G including a precipitate F is prepared. The mixed solution G is subjected to heat treatment in a pressurized atmosphere, so that a mixed solution H is prepared, and the mixed solution H is then filtered. Thus, particles of a compound containing lithium and oxygen which have a small size are obtained.

Abstract: At least one of an aqueous solution A containing lithium, an aqueous solution B containing iron, manganese, cobalt, or nickel, and an aqueous solution C containing a phosphoric acid includes graphene oxide. The aqueous solution A is dripped into the aqueous solution C, so that a mixed solution E including a precipitate D is prepared. The mixed solution E is dripped into the aqueous solution B, so that a mixed solution G including a precipitate F is prepared. The mixed solution G is subjected to heat treatment in a pressurized atmosphere, so that a mixed solution H is prepared, and the mixed solution H is then filtered. Thus, particles of a compound containing lithium and oxygen which have a small size are obtained.

Abstract: At least one of an aqueous solution A containing lithium, an aqueous solution B containing iron, manganese, cobalt, or nickel, and an aqueous solution C containing a phosphoric acid includes graphene oxide. The aqueous solution A is dripped into the aqueous solution C, so that a mixed solution E including a precipitate D is prepared. The mixed solution E is dripped into the aqueous solution B, so that a mixed solution G including a precipitate F is prepared. The mixed solution G is subjected to heat treatment in a pressurized atmosphere, so that a mixed solution H is prepared, and the mixed solution H is then filtered. Thus, particles of a compound containing lithium and oxygen which have a small size are obtained.

Abstract: The formation method of graphene includes the steps of forming a layer including graphene oxide over a first conductive layer; and supplying a potential at which the reduction reaction of the graphene oxide occurs to the first conductive layer in an electrolyte where the first conductive layer as a working electrode and a second conductive layer with a as a counter electrode are immersed. A manufacturing method of a power storage device including at least a positive electrode, a negative electrode, an electrolyte, and a separator includes a step of forming graphene for an active material layer of one of or both the positive electrode and the negative electrode by the formation method.

Abstract: The present invention relates to a solar power generation device which includes an electric double-layer capacitor and a solar cell. The electric double-layer capacitor includes a pair of current collectors formed using a light-transmitting conductive material; active materials which are dispersed on the pair of current collectors; a light-transmitting electrolyte layer which is provided between the pair of current collectors; and a terminal portion which is electrically connected to the current collector. The solar cell includes, over a light-transmitting substrate, a first light-transmitting conductive film; a photoelectric conversion layer which is provided in contact with the first light-transmitting conductive film; and a second light-transmitting conductive film which is provided in contact with the photoelectric conversion layer.

Abstract: Highly-pure graphite oxide, graphene oxide, or graphene is mass-produced. Graphite is oxidized by an oxidizer, so that a graphite oxide solution is obtained, and electrodialysis is performed on the graphite oxide solution to remove aqueous ions, whereby the purity of graphite oxide is increased. Graphene oxide manufactured using the graphite oxide is mixed with powder, and the mixture is reduced, whereby graphene exhibiting conductive properties is yielded and the powder can be bonded. Such graphene can be used instead of a conduction auxiliary agent or a binder of a variety of batteries.

Abstract: At least one of an aqueous solution A containing lithium, an aqueous solution B containing iron, manganese, cobalt, or nickel, and an aqueous solution C containing a phosphoric acid includes graphene oxide. The aqueous solution A is dripped into the aqueous solution C, so that a mixed solution E including a precipitate D is prepared. The mixed solution E is dripped into the aqueous solution B, so that a mixed solution G including a precipitate F is prepared. The mixed solution G is subjected to heat treatment in a pressurized atmosphere, so that a mixed solution H is prepared, and the mixed solution H is then filtered. Thus, particles of a compound containing lithium and oxygen which have a small size are obtained.

Abstract: Occlusion and release of lithium ion are likely to one-dimensionally occur in the b-axis direction of a crystal in a lithium-containing composite oxide having an olivine structure. Thus, a positive electrode in which the b-axes of lithium-containing composite oxide single crystals are oriented vertically to a surface of a positive electrode current collector is provided. The lithium-containing composite oxide particles are mixed with graphene oxide and then pressure is applied thereto, whereby the rectangular parallelepiped or substantially rectangular parallelepiped particles are likely to slip. In addition, in the case where the rectangular parallelepiped or substantially rectangular parallelepiped particles whose length in the b-axis direction is shorter than those in the a-axis direction and the c-axis direction are used, when pressure is applied in one direction, the b-axes can be oriented in the one direction.

Abstract: An object is to reduce variation in shape of crystals that are to be manufactured. Raw materials are each weighed, solutions containing the respective raw materials are formed in an environment where an oxygen concentration is lower than that in air, the solutions containing the respective raw materials are mixed in an environment where an oxygen concentration is lower than that in air to form a mixture solution, and with use of the mixture solution, a composite oxide is formed by a hydrothermal method.