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: Silicon oxide which is an oxide containing at least silicon, in which part of silicon is replaced by boron, aluminum, or gallium, is provided.

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: A power storage device with high capacity is provided. Alternatively, a power storage device with excellent cycle characteristics is provided. Alternatively, a power storage device with high charge and discharge efficiency is provided. Alternatively, a power storage device with a long lifetime is provided. A negative electrode active material is provided over a negative electrode current collector, and the negative electrode active material layer is formed in such a manner that first layers and second layers are alternately stacked. The first layer includes at least an element selected from Si, Mg, Ca, Ga, Al, Ge, Sn, Pb, Sb, Bi, Ag, Zn, Cd, As, Hg, and In. The second layer includes oxygen and the same element as the one included in the first layer.

Abstract: Although a material containing silicon attracts attention as a high-capacity negative electrode active material, it has a problem of having a large irreversible capacity at the initial charge and discharge cycle. As a negative electrode active material, a particle which is a mixture of silicon, lithium metasilicate, and lithium oxide is used. Because lithium metasilicate and lithium oxide are already contained in the particle of the negative electrode active material, a compound containing lithium and oxygen (lithium orthosilicate and lithium metasilicate), which is a cause of the irreversible capacity at the initial charge, is not generated any more. This enables a negative electrode active material with a small irreversible capacity.

Abstract: Irreversible capacity which causes a decrease in the charge and discharge capacity of a power storage device is reduced, and electrochemical decomposition of an electrolyte solution and the like on a surface of an electrode is inhibited. Further, the cycle characteristics of the power storage device is improved by reducing or inhibiting a decomposition reaction of the electrolyte solution and the like occurring as a side reaction in repeated charging and discharging of the power storage device. A power storage device electrode includes a current collector and an active material layer that is over the current collector and includes a binder and an active material. A coating film is provided on at least part of a surface of the active material. The coating film is spongy.

Abstract: A control method of a media conveyance device enables accurately detecting media slack by a detection mechanism with multiple emitters and multiple photodetectors disposed opposite the emitters. A printer (media conveyance device) has a controller that controls a delivery mechanism, a conveyance mechanism that conveys media, a delivery mechanism, and a conveyance mechanism, and controls conveying roll paper; a first detector including a first emitter and first photodetector; and a second detector including a second emitter and second photodetector. When driving the conveyance mechanism, the controller selectively controls the first emitter and first photodetector to emit, and drives a spindle based on signal output from the first detector when first emitter emits, and signal output from the second detector when second emitter emits.

Abstract: As an electrode for a power storage device, an electrode including a current collector, a first active material layer over the current collector, and a second active material layer that is over the first active material layer and includes a particle containing niobium oxide and a granular active material is used, whereby the charge-discharge cycle characteristics and rate 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 or its separation from the current collector, can be suppressed.

Abstract: A printer can suppress paper lifting away from the platen surface even when conveying strong paper (regardless of paper strength) (a printer that can suppress paper uplift from the platen and is not easily affected by the type of paper). A printer 40 in which the platen surface 42a is on the inkjet head 21 side of a plane C through position A where paper 11 is held by a conveyance roller 36, and position B where the paper is held by a discharge roller, has: on the printhead 21 side of the plane C between the platen 42 and conveyance roller 36, at least one entry angle control unit 44 that contacts the paper 11 conveyed toward the platen surface 42a, and controls the entry angle of the paper 11 to the platen surface 42a; and on the printhead 21 side of the plane C between the platen 42 and the discharge roller 37, at least one exit angle control unit 46 that contacts the paper 11 conveyed in the direction away from the platen surface 42a, and controls the exit angle of the paper 11 from the platen surface 42a.

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 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 decomposition reaction of an electrolyte solution and the like caused as a side reaction of charge and discharge is minimized in repeated charge and discharge of a lithium ion battery or a lithium ion capacitor, and thus the lithium ion battery or the lithium ion capacitor can have long-term cycle performance. A negative electrode for a power storage device includes a negative electrode current collector and a negative electrode active material layer which includes a plurality of particles of a negative electrode active material. Each of the particles of the negative electrode active material has an inorganic compound film containing a first inorganic compound on part of its surface. The negative electrode active material layer has a film in contact with an exposed part of the negative electrode active material and part of the inorganic compound film. The film contains an organic compound and a second inorganic compound.

Abstract: A lithium ion secondary battery includes a positive electrode, a negative electrode, and an electrolyte provided between the positive electrode and the negative electrode. The positive electrode includes a positive electrode current collector and a positive electrode active material layer over the positive electrode current collector. The positive electrode active material layer includes a plurality of lithium-containing, composite oxides each of which is expressed by LiMPO4 (M is one or more of Fe (II), Mn (II), Co (II), and Ni (II)) that is a general formula. The lithium-containing composite oxide is a flat single crystal particle in which the length in the b-axis direction is shorter than each of the lengths in the a-axis direction and the c-axis direction. The lithium-containing composite oxide is provided over the positive electrode current collector so that the b-axis of the single crystal particle intersects with the surface of the positive electrode current collector.

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: A storage battery includes positive and negative electrodes and an electrolytic solution. The negative electrode includes a first element and carbon. The first element is any of silicon, tin, gallium, aluminum, germanium, lead, antimony, bismuth, silver, zinc, cadmium, and indium. The negative electrode includes an active material and a first layer in contact with a surface of the active material. The first layer has a thickness of 10 nm to 1000 nm inclusive. The electrolytic solution contains first and second cations. The first cation is one or more of a lithium ion, a sodium ion, a calcium ion, and a magnesium ion. The second cation is an imidazolium cation or a tertiary sulfonium cation.

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: A control method of a media conveyance device enables accurately detecting media slack by a detection mechanism with multiple emitters and multiple photodetectors disposed opposite the emitters. A printer (media conveyance device) has a controller that controls a delivery mechanism, a conveyance mechanism that conveys media, a delivery mechanism, and a conveyance mechanism, and controls conveying roll paper; a first detector including a first emitter and first photodetector; and a second detector including a second emitter and second photodetector. When driving the conveyance mechanism, the controller selectively controls the first emitter and first photodetector to emit, and drives a spindle based on signal output from the first detector when first emitter emits, and signal output from the second detector when second emitter emits.

Abstract: A decomposition reaction of an electrolyte solution and the like caused as a side reaction of charge and discharge is minimized in repeated charge and discharge of a lithium ion battery or a lithium ion capacitor, and thus the lithium ion battery or the lithium ion capacitor can have long-term cycle performance. A negative electrode for a power storage device includes a negative electrode current collector and a negative electrode active material layer which includes a plurality of particles of a negative electrode active material. Each of the particles of the negative electrode active material has an inorganic compound film containing a first inorganic compound on part of its surface. The negative electrode active material layer has a film in contact with an exposed part of the negative electrode active material and part of the inorganic compound film. The film contains an organic compound and a second inorganic compound.

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 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 a power storage device includes a number of composites in particulate forms. The composites include a negative electrode active material, a first functional material, and a compound. The compound includes a constituent element of the negative electrode active material and a constituent element of the first functional material. The negative electrode active material includes a region in contact with at least one of the first functional material or the compound.