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:
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:
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:
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:
An energy storage device having high capacity per weight or volume and a positive electrode active material for the energy storage device are manufactured. A surface of a main material included in the positive electrode active material for the energy storage device is coated with two-dimensional carbon. The main material included in the positive electrode active material is coated with a highly conductive material which has a structure expanding two-dimensionally and whose thickness is ignorable, whereby the amount of carbon coating can be reduced and an energy storage device having capacity close to theoretical capacity can be obtained even when a conduction auxiliary agent is not used or the amount of the conduction auxiliary agent is extremely small. Accordingly, the amount of carbon coating in a positive electrode and the volume of the conduction auxiliary agent can be reduced; consequently, the volume of the positive electrode can be reduced.
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 positive electrode active material layer includes a plurality of particles of a positive electrode active material and a reaction mixture where reduced graphene oxide is bonded to a polymer having a functional group as a side chain. The reduced graphene oxide has a sheet-like shape and high conductivity and thus functions as a conductive additive by being in contact with the plurality of particles of the positive electrode active material. The reaction mixture serves as an excellent binder since the reduced graphene oxide is bonded to the polymer. Therefore, even a small amount of the reaction mixture where the reduced graphene oxide is eovalently bonded to the polymer excellently serves as a conductive additive and a binder.
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:
Graphene is formed with a practically uniform thickness on an uneven object. The object is immersed in a graphene oxide solution, and then taken out of the solution and dried; alternatively, the object and an electrode are immersed therein and voltage is applied between the electrode and the object used as an anode. Graphene oxide is negatively charged, and thus is drawn to and deposited on a surface of the object, with a practically uniform thickness. After that, the object is heated in vacuum or a reducing atmosphere, so that the graphene oxide is reduced to be graphene. In this manner, a graphene layer with a practically uniform thickness can be formed even on a surface of the uneven object.