Abstract: Provided is a semiconductor device having favorable reliability.

Abstract: An electrode and a power storage device each of which achieves better charge-discharge cycle characteristics and is less likely to deteriorate owing to separation of an active material, or the like are manufactured. As the electrode for the power storage device, an electrode including a current collector and an active material layer that is over the current collector and includes a particle containing niobium oxide and a granular active material is used, whereby the charge-discharge cycle characteristics of the power storage device can be improved. Moreover, contact between the granular active material and the particle containing niobium oxide makes the granular active material physically fixed; accordingly, deterioration due to expansion and contraction of the active material which occur along with charge and discharge of the power storage device, such as powdering of the active material layer or its separation from the current collector, can be suppressed.

Abstract: A power storage system having excellent characteristics is provided. A power storage system having high safety is provided. A power storage system with little degradation is provided. A storage battery having excellent characteristics is provided.

Abstract: A charging control device using machine learning is provided. A high-security charging control device is provided. A charging control system with little deterioration is provided. A storage battery having excellent characteristics is provided. An approximate charging end time is calculated. A result obtained when it is different from the estimated charging end time is fed back and learned, and accordingly the charging end can be precisely estimated after the next time. That is, the portable information terminal makes a charging plan with the use of artificial intelligence and the secondary battery is charged based on information about the charging plan. The charging plan is made to reduce the retention time of the full charging (SOC 100%) and charging is executed. Charging history information is stored in the portable information terminal and made use of to make the next charging plan.

Abstract: A power storage device with high capacity or high energy density is provided. A highly reliable power storage device is provided. A long-life power storage device is provided. An electrode includes an active material, a first binder, and a second binder. The specific surface area of the active material is S [m2/g]. The weight of the active material, the weight of the first binder, and the weight of the second binder are a, b, and c, respectively. The solution of {(b+c)/(a+b+c)}×100÷S is 0.3 or more. The electrode includes a first film in contact with the active material. The first film preferably includes a region in contact with the active material. The first film preferably includes a region with a thickness of 2 nm or more and 20 nm or less. The first film contains a water-soluble polymer.

Abstract: Disclosed is a power storage element including a positive electrode current collector layer and a negative electrode current collector layer which are arranged on the same plane and can be formed through a simple process. The power storage element further includes a positive electrode active material layer on the positive electrode current collector layer; a negative electrode active material layer on the negative electrode current collector layer; and a solid electrolyte layer in contact with at least the positive electrode active material layer and the negative electrode active material layer. The positive electrode active material layer and the negative electrode active material layer are formed by oxidation treatment.

Abstract: To improve the reliability of a power storage device. A granular active material including carbon is used, and a net-like structure is formed on part of a surface of the granular active material. In the net-like structure, a carbon atom included in the granular active material is bonded to a silicon atom or a metal atom through an oxygen atom. Formation of the net-like structure suppresses reductive decomposition of an electrolyte solution, leading to a reduction in irreversible capacity. A power storage device using the above active material has high cycle performance and high reliability.

Abstract: Disclosed is a power storage element including a positive electrode current collector layer and a negative electrode current collector layer which are arranged on the same plane and can be formed through a simple process. The power storage element further includes a positive electrode active material layer on the positive electrode current collector layer; a negative electrode active material layer on the negative electrode current collector layer; and a solid electrolyte layer in contact with at least the positive electrode active material layer and the negative electrode active material layer. The positive electrode active material layer and the negative electrode active material layer are formed by oxidation treatment.

Abstract: To improve the long-term cycle performance of a lithium-ion battery or a lithium-ion capacitor by minimizing the decomposition reaction of an electrolytic solution and the like as a side reaction of charge and discharge in the repeated charge and discharge cycles of the lithium-ion battery or the lithium-ion capacitor. A current collector and an active material layer over the current collector are included in an electrode for a power storage device. The active material layer includes a plurality of active material particles and silicon oxide. The surface of one of the active material particles has a region that is in contact with one of the other active material particles. The surface of the active material particle except the region is partly or entirely covered with the silicon oxide.

Abstract: To improve the long-term cycle performance of a lithium-ion battery or a lithium-ion capacitor by minimizing the decomposition reaction of an electrolytic solution and the like as a side reaction of charge and discharge in the repeated charge and discharge cycles of the lithium-ion battery or the lithium-ion capacitor. A current collector and an active material layer over the current collector are included in an electrode for a power storage device. The active material layer includes a plurality of active material particles and silicon oxide. The surface of one of the active material particles has a region that is in contact with one of the other active material particles. The surface of the active material particle except the region is partly or entirely covered with the silicon oxide.

Abstract: An object is to suppress electrochemical decomposition of an electrolyte solution and the like at a negative electrode in a lithium ion battery or a lithium ion capacitor: thus, irreversible capacity is reduced, cycle performance is improved, or operating temperature range is extended. A negative electrode for a power storage device including a negative electrode current collector, a negative electrode active material layer which is over the negative electrode current collector and includes a plurality of particles of a negative electrode active material, and a film covering part of the negative electrode active material. The film has an insulating property and lithium ion conductivity.

Abstract: A semiconductor device in which a circuit and a battery are efficiently stored is provided. In the semiconductor device, a first transistor, a second transistor, and a secondary battery are provided over one substrate. A channel region of the second transistor includes an oxide semiconductor. The secondary battery includes a solid electrolyte, and can be fabricated by a semiconductor manufacturing process. The substrate may be a semiconductor substrate or a flexible substrate. The secondary battery has a function of being wirelessly charged.

Abstract: The cycle performance of a lithium-ion secondary battery or a lithium-ion capacitor can be obtained by minimizing the decomposition reaction of an electrolytic solution, etc. in the repeated charge and discharge cycles of the lithium-ion secondary battery or the lithium-ion capacitor. An electrode includes a current collector and an active material layer over the current collector. The active material layer includes active material particles, a conductive additive, a binder, and a film containing silicon oxide as its main component. The surface of one of the active material particles includes at least one of a region in contact with the surface of another active material particle, a region in contact with the conductive additive, and a region in contact with the binder. The surface of the active material particle except these regions is at least partly in contact with the film containing silicon oxide as its main component.

Abstract: A semiconductor device in which a circuit and a power storage element are efficiently placed is provided. The semiconductor device includes a first transistor, a second transistor, and an electric double-layer capacitor. The first transistor, the second transistor, and the electric double-layer capacitor are provided over one substrate. A band gap of a semiconductor constituting a channel region of the second transistor is wider than a band gap of a semiconductor constituting a channel region of the first transistor. The electric double-layer capacitor includes a solid electrolyte.

Abstract: A semiconductor device in which a circuit and a battery are efficiently stored is provided. In the semiconductor device, a first transistor, a second transistor, and a secondary battery are provided over one substrate. A channel region of the second transistor includes an oxide semiconductor. The secondary battery includes a solid electrolyte, and can be fabricated by a semiconductor manufacturing process. The substrate may be a semiconductor substrate or a flexible substrate. The secondary battery has a function of being wirelessly charged.

Abstract: A semiconductor device having high reliability is provided.

Abstract: An object is to suppress electrochemical decomposition of an electrolyte solution and the like at a negative electrode in a lithium ion battery or a lithium ion capacitor; thus, irreversible capacity is reduced, cycle performance is improved, or operating temperature range is extended. A negative electrode for a power storage device including a negative electrode current collector, a negative electrode active material layer which is over the negative electrode current collector and includes a plurality of particles of a negative electrode active material, and a film covering part of the negative electrode active material. The film has an insulating property and lithium ion conductivity.

Abstract: Provided is a method for manufacturing a power storage device in which a crystalline silicon layer including a whisker-like crystalline silicon region is formed as an active material layer over a current collector by a low-pressure CVD method in which heating is performed using a deposition gas containing silicon. The power storage device includes the current collector, a mixed layer formed over the current collector, and the crystalline silicon layer functioning as the active material layer formed over the mixed layer. The crystalline silicon layer includes a crystalline silicon region and a whisker-like crystalline silicon region including a plurality of protrusions which project over the crystalline silicon region. With the protrusions, the surface area of the crystalline silicon layer functioning as the active material layer can be increased.

Abstract: A semiconductor device in which a circuit and a power storage element are efficiently placed is provided. The semiconductor device includes a first transistor, a second transistor, and an electric double-layer capacitor. The first transistor, the second transistor, and the electric double-layer capacitor are provided over one substrate. A band gap of a semiconductor constituting a channel region of the second transistor is wider than a band gap of a semiconductor constituting a channel region of the first transistor. The electric double-layer capacitor includes a solid electrolyte.

Abstract: The present invention relates to a power storage system including a negative electrode which has a crystalline silicon film provided as a negative electrode active material on the surface of a current collector and contains a conductive oxide in a surface layer section of the crystalline silicon film. Alternatively, the present invention relates to a method for manufacturing a power storage system, which includes the step of forming an amorphous silicon film on a current collector, adding a catalytic element for promoting crystallization of the amorphous silicon, onto a surface of the amorphous silicon film, heating the amorphous silicon film with the catalytic element added to crystallize the amorphous silicon film and thereby form a crystalline silicon film, and using the crystalline silicon film as a negative electrode active material layer.