Abstract: A system is provided with which data on the internal state of a storage battery such as SOC-OCV characteristics and FCC can be obtained with high accuracy and highly accurate estimation is possible even in the case of repeating charging and discharging for a long period. The storage battery management system includes a vehicle that includes a unit enabling data transmission and reception; the vehicle includes a storage battery, a balancing circuit electrically connected to the storage battery, and a vehicle control unit having a function of controlling the balancing circuit; the storage battery includes an assembled battery including a plurality of battery cells; the vehicle control unit has a function of selecting an estimated value that most closely shows a state of each of the battery cells included in the assembled battery; and the balancing circuit has a function of being controlled in accordance with the selected estimated value.

Abstract: A secondary battery management system for achieving a secondary battery capable of being used even at low temperatures. The secondary battery management system includes a secondary battery that is charged and discharged at higher than or equal to ?50° C. and lower than or equal to 0° C., a first circuit having a function of measuring a voltage of the secondary battery, a second circuit having a function of measuring a current of the secondary battery, and a control circuit to which information on voltage from the first circuit or information on current from the second circuit is input. The control circuit starts charging to the secondary battery. The control circuit performs arithmetic operation of data showing battery characteristics on the basis of a value input from the first circuit or the second circuit. The control circuit detects a local maximum value of the data. The control circuit stops the charging when detecting the local maximum value.

Abstract: A secondary battery includes a positive electrode active material layer including a primary particle containing lithium, nickel, cobalt, and manganese and a secondary particle formed by aggregation of the primary particles, and calcium is contained between adjacent primary particles of the secondary particle. With such a structure, calcium inhibits oxygen release from the primary particle in charging and discharging, whereby the reliability of the secondary battery is improved.

Abstract: A positive electrode active material that is unlikely to generate defects even when charging and discharging at a high voltage and/or at a high temperature is provided. A positive electrode active material in which crystal structures are unlikely to collapse even when charging and discharging are repeated is also provided. The positive electrode active material contains lithium, cobalt, oxygen, and an additive element. The positive electrode active material includes a surface portion, an inner portion. The positive electrode active material contains the additive element in the surface portion. The surface portion is a region extending from a surface of the positive electrode active material to a depth of 10 nm or less toward the inner portion, and the surface portion and the inner portion are topotaxy. A degree of diffusion of the additive element vary between crystal planes of the surface portion, and the additive element is at least one or two or more selected from nickel, aluminum, and magnesium.

Abstract: A semiconductor device with little variation in transistor characteristics is provided. First to third oxide films, a first conductive film, a first insulating film, and a second conductive film are sequentially formed. Shaping them into island-like shapes. An insulator is formed over the island-like shapes and an opening is formed in the insulator and a part of the island-like shapes. Another oxide film, a gate insulating film, and a gate electrode are formed in the opening in this order to form the transistor.

Abstract: A power storage system with a high energy density is provided. A power storage system with a high degree of safety is provided. A secondary battery with a high energy density is provided. A secondary battery with a high degree of safety is provided. A charging unit has a function of controlling start and stop of charge of a secondary battery and a function of controlling a charge current of the secondary battery. The secondary battery includes a positive electrode, the positive electrode includes a positive electrode active material particle, the positive electrode active material particle is lithium cobalt oxide to which magnesium is added. The charging unit has a function of controlling charge of the secondary battery by a first step of starting constant current charge of the secondary battery at a time t1; and a second step of stopping the charge at a time t2.

Abstract: A battery evaluation system that performs evaluation by easily linking a plurality of measurement methods relating to a secondary battery is provided. A charge and discharge device is configured to perform, in a first period, either or both of charge and discharge of a secondary battery. The first measurement device is configured to perform, in the first period, measurement of a spectrum a plurality of times. The arithmetic portion is configured to generate a first graph using the plurality of measured spectra. The arithmetic portion is configured to generate data of a second graph using a set of data including a voltage and the time of measurement of the voltage. A display portion is configured to display the first graph and the second graph at the same time. The battery evaluation system is configured to set a first area in one of the first graph and the second graph and to display a second area corresponding to the first area in the other of the first graph and the second graph.

Abstract: A transistor having a large S value or a semiconductor device performing calculation utilizing a transistor operation in a subthreshold region is provided. The transistor includes an oxide semiconductor layer including a channel formation region, a gate electrode including a region overlapping with the oxide semiconductor layer with an insulating layer therebetween, and a first conductive layer including a region overlapping with the oxide semiconductor layer with a ferroelectric layer therebetween. In particular, the ferroelectric layer includes a crystal having a crystal structure exhibiting ferroelectricity.

Abstract: A method for depositing a metal oxynitride film by epitaxial growth at a low temperature is provided. It is a method for manufacturing a metal oxynitride film, in which the metal oxynitride film is epitaxially grown on a single crystal substrate by a sputtering method using an oxide target with a gas containing a nitrogen gas introduced. The oxide target contains zinc, the substrate during the deposition of the metal oxynitride film is higher than or equal to 80° C. and lower than or equal to 400° C., and the flow rate of the nitrogen gas is greater than or equal to 50% and lower than or equal to 100% of the total flow rate of the gas.

Abstract: A semiconductor device that can be miniaturized or highly integrated is provided. A first conductor is formed over a substrate, a ferroelectric layer is formed over the first conductor, a second conductor is formed over the ferroelectric layer while substrate heating is performed, the ferroelectric layer includes hafnium oxide and zirconium oxide, and heat treatment at 500° C. or higher is not performed after the formation of the second conductor.

Abstract: A positive electrode active material having a crystal structure that is unlikely to be broken by repeated charging and discharging is provided. A positive electrode active material with high charge and discharge capacity is provided. A projection is provided on the surface of the positive electrode active material. The projection preferably contains zirconium and yttrium and is a rectangular solid. The projection preferably has a crystal structure that is tetragonal, cubic, or a mixture of two phases, tetragonal and cubic. In the positive electrode active material, the transition metal is one or two or more selected from cobalt, nickel, and manganese, and the additive elements are at least two or more selected from magnesium, fluorine, aluminum, zirconium, and yttrium.

Abstract: A method for depositing a metal oxynitride film by epitaxial growth at a low temperature is provided. It is a method for manufacturing a metal oxynitride film, in which the metal oxynitride film is epitaxially grown on a single crystal substrate by a sputtering method using an oxide target with a gas containing a nitrogen gas introduced. The oxide target contains zinc, the substrate during the deposition of the metal oxynitride film is higher than or equal to 80° C. and lower than or equal to 400° C., and the flow rate of the nitrogen gas is greater than or equal to 50% and lower than or equal to 100% of the total flow rate of the gas.

Abstract: A positive electrode for a secondary battery having excellent cycle performance is provided. The positive electrode for a secondary battery includes a positive electrode current collector layer, a base film, a positive electrode active material layer, and a cap layer; the base film contains titanium nitride; the positive electrode active material layer contains lithium cobalt oxide; and the cap layer contains titanium oxide. The use of titanium nitride for the base film can inhibit oxidation of the positive electrode current collector and diffusion of metal atoms while ensuring an adequate conductivity. The use of titanium oxide for the cap layer can inhibit a side reaction between the positive electrode active material layer and an electrolyte and collapse of a crystal structure of the electrode active material, improving the cycle performance.

Abstract: A negative electrode active material particle with little deterioration is provided. Alternatively, a novel negative electrode active material particle is provided. Alternatively, a power storage device with little deterioration is provided. Alternatively, a highly safe power storage device is provided. Alternatively, a novel power storage device is provided. The electrode includes an active material and a conductive additive; the active material contains a metal or a compound including one or more elements selected from silicon, tin, gallium, aluminum, germanium, lead, antimony, bismuth, silver, zinc, cadmium, and indium; the conductive additive contains a graphene compound; and the graphene compound contains fluorine.

Abstract: To provide a positive electrode active material film that does not have a (003) orientation and has a layered rock-salt crystal structure even though an inexpensive substrate such as a glass substrate is used, and a positive electrode including the positive electrode active material film. The positive electrode includes a substrate, a positive electrode current collector film, and the positive electrode active material film. The positive electrode current collector film has a stacked structure of a titanium film and a titanium nitride film. The titanium film has a crystal structure belonging to a space group P63/mmc and a (101) orientation, the titanium nitride film has a crystal structure belonging to a space group Fm-3m and a (311) orientation, and the positive electrode active material film has a layered rock-salt crystal structure and a (116) orientation.

Abstract: A power storage device or the like with low power consumption is provided. Alternatively, a power storage device or the like with high integration is provided. A first battery cell includes a first electrode over a first substrate, a positive electrode active material layer over the first electrode, an electrolyte layer over the positive electrode active material layer, a negative electrode active material layer over the electrolyte layer, and a second electrode over the negative electrode active material layer. The comparison circuit includes a first input terminal, a second input terminal, an output terminal, and a first transistor. The first transistor includes an oxide semiconductor over the first substrate, a first insulator over the oxide semiconductor, and a gate electrode over the first insulator. The first electrode is electrically connected to the gate of the first transistor and the first input terminal.

Abstract: A positive electrode active material having a crystal structure that is unlikely to be broken by repeated charging and discharging is provided. A positive electrode active material with high charge and discharge capacity is provided. A positive electrode active material including lithium, cobalt, nickel, magnesium, and oxygen, in which the a-axis lattice constant of an outermost surface layer of the positive electrode active material is larger than the a-axis lattice constant of an inner portion and in which the c-axis lattice constant of the outermost surface layer is larger than the c-axis lattice constant of the inner portion. A rate of change between the a-axis lattice constant of the outermost surface layer and the a-axis lattice constant of the inner portion is preferably larger than 0 and less than or equal to 0.

Abstract: A semiconductor device including an inorganic light-emitting element is provided. The semiconductor device includes the inorganic light-emitting element, a transistor, and a capacitor. The inorganic light-emitting element includes a first film and a second film. The first film contains indium, oxygen, and nitrogen, and the second film contains gallium and nitrogen. The first film has a wurtzite structure or a cubic crystal structure, and the second film has a wurtzite structure and grows on the first film. The first film functions as a cathode electrode of the inorganic light-emitting element. One electrode of the capacitor is formed above the second film included in the inorganic light-emitting element, and the transistor including a metal oxide in a semiconductor layer is formed above the other electrode of the capacitor. The one electrode of the capacitor has a function of reflecting light emitted from the inorganic light-emitting element.

Abstract: A positive electrode active material in which a discharge capacity decrease due to charge and discharge cycles is suppressed and a secondary battery including the positive electrode active material are provided. A positive electrode active material in which a change in a crystal structure, e.g., a shift in CoO2 layers is small between a discharged state and a high-voltage charged state is provided. For example, a positive electrode active material that has a layered rock-salt crystal structure belonging to the space group R-3m in a discharged state and a crystal structure belonging to the space group P2/m in a charged state where x in LixCoO2 is greater than 0.1 and less than or equal to 0.24 is provided. When the positive electrode active material is analyzed by powder X-ray diffraction, a diffraction pattern has at least diffraction peaks at 2? of 19.47±0.10° and 2? of 45.62±0.05°.

Abstract: A semiconductor device with little variation in transistor characteristics is provided. A first insulator to a third insulator are formed. A fourth insulator, a first oxide film, a second oxide film, a third oxide film, a first conductive film, a first insulating film, and a second conductive film are sequentially formed over the third insulator. Shaping them into island-like shapes to form a first oxide, a second oxide, a first oxide layer, a first conductive layer, a first insulating layer, and a second conductive layer. The second conductive layer is removed. A fifth insulator and a sixth insulator are formed over the fourth insulator, the first oxide, the second oxide, the first oxide layer, the first conductive layer, and the first insulating layer. An opening reaching the second oxide is formed to form a third oxide, a fourth oxide, a first conductor, a second conductor, a seventh insulator, and an eighth insulator. A fifth oxide, a ninth insulator, and a third conductor are formed in the opening.