Abstract: The characteristics of a power storage device are improved and the lifetime of the power storage device is prolonged. An electrode is manufactured through the following steps: a step of forming an electrode film; a step of forming a damage layer by ion doping on the electrode film; and a step of providing a damage region between the damage layer and a surface. Alkali ion insertion and extraction can be performed by dipping of an electrode, in which the damage layer and the damage region are formed, in a solution containing an alkali ion. A space in which the volume of the electrode is expanded can be secured by the formation of the damage layer and the damage region. Note that another lithium may be used instead of an alkali metal.

Abstract: A secondary battery in which graphite that is an active material can occlude and release lithium efficiently is provided. Further, a highly reliable secondary battery in which the amount of lithium inserted and extracted into/from graphite that is an active material is prevented from varying is provided. The secondary battery includes a negative electrode including a current collector and graphite provided over the current collector, and a positive electrode. The graphite includes a plurality of graphene layers. Surfaces of the plurality of graphene layers are provided substantially along the direction of an electric field generated between the positive electrode and the negative electrode.

Abstract: Disclosed is a power storage unit which can safely operate over a wide temperature range. The power storage unit includes: a power storage device; a heater for heating the power storage device; a temperature sensor for sensing the temperature of the power storage device; and a control circuit configured to inhibit charge of the power storage device when its temperature is lower than a first temperature or higher than a second temperature. The first temperature is exemplified by a temperature which allows the formation of a dendrite over a negative electrode of the power storage device, whereas the second temperature is exemplified by a temperature which causes decomposition of a passivating film formed over a surface of a negative electrode active material.

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. The power storage element further includes a positive electrode active material layer over the positive electrode current collector layer and a negative electrode active material layer over the negative electrode current collector layer. An electrolyte layer in contact with at least the positive electrode active material layer and the negative electrode active material layer is provided. The electrolyte layer may be a solid electrolyte layer.

Abstract: An electric double layer capacitor, a lithium ion capacitor, and a charging device including a solar cell and either of the capacitors are disclosed. The electric double layer capacitor includes a first and second light-transmitting substrates; a pair of current collectors provided perpendicular to the substrates; active material layers provided on facing planes of the current collectors; and an electrolyte in a region surrounded by the substrates and the facing active material layers. The lithium ion capacitor includes a first and second light-transmitting substrates; a positive and negative electrode active material layers provided perpendicular to the substrates; and an electrolyte in a region surrounded by the facing substrates and the positive and negative electrode active material layers.

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: A semiconductor substrate is irradiated with accelerated hydrogen ions, thereby forming a damaged region including a large amount of hydrogen. After a single crystal semiconductor substrate and a supporting substrate are bonded to each other, the semiconductor substrate is heated, so that the single crystal semiconductor substrate is separated in the damaged region. A single crystal semiconductor layer which is separated from the single crystal semiconductor substrate is irradiated with a laser beam. The single crystal semiconductor layer is melted by laser beam irradiation, whereby the single crystal semiconductor layer is recrystallized to recover its crystallinity and to planarized a surface of the single crystal semiconductor layer. After the laser beam irradiation, the single crystal semiconductor layer is heated at a temperature at which the single crystal semiconductor layer is not melted, so that the lifetime of the single crystal semiconductor layer is improved.

Abstract: To provide a high-performance semiconductor device using an SOI substrate in which a substrate having low heat resistance is used as a base substrate, to provide a high-performance semiconductor device without performing mechanical polishing, and to provide an electronic device using the semiconductor device, planarity of a semiconductor layer is improved and defects in the semiconductor layer are reduced by laser beam irradiation. Accordingly, a high-performance semiconductor device can be provided without performing mechanical polishing. In addition, a semiconductor device is manufactured using a region having the most excellent characteristics in a region irradiated with the laser beam. Specifically, instead of the semiconductor layer in a region which is irradiated with the edge portion of the laser beam, the semiconductor layer in a region which is irradiated with portions of the laser beam except the edge portion is used as a semiconductor element.

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: When the single crystal semiconductor layer is melted, the outward diffusion of oxygen is promoted. Specifically, an SOI substrate is formed in such a manner that an SOI structure having a bonding layer including oxygen provided over a base substrate and a single crystal semiconductor layer provided over the bonding layer including oxygen is formed, and part of the single crystal semiconductor layer is melted by irradiation with a laser beam in a state that the base substrate is heated at a temperature of higher than or equal to 500° C. and lower than a melting point of the base substrate.

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: A power storage device with high output is provided, in which the specific surface area is increased while keeping the easy-to-handle particle size of its active material. The power storage device includes a positive electrode including a positive electrode current collector and a positive electrode active material layer, a negative electrode including a negative electrode current collector and a negative electrode active material layer, and an electrolyte. The negative electrode active material layer includes a negative electrode active material which is a particle in which a plurality of slices of graphite is overlapped with each other with a gap therebetween. It is preferable that the grain diameter of the particle be 1?m to 50 ?m. Further, it is preferable that the electrolyte be in contact with the gap between the slices of graphite.

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: To provide a carbon-based negative electrode material which can be used with an electrolyte containing PC as a main ingredient, a carbon-based negative electrode material having a graphene layer structure is crystalline and has pores. That is, the crystal structure of the carbon-based negative electrode material is distorted more significantly than that of graphite. Accordingly, the carbon-based negative electrode material has a larger interlayer distance between graphenes than graphite. It has been shown that such a negative electrode material can be used for a secondary battery which contains an electrolyte containing PC as a main ingredient.

Abstract: Forming an insulating film on a surface of the single crystal semiconductor substrate, forming a fragile region in the single crystal semiconductor substrate by irradiating the single crystal semiconductor substrate with an ion beam through the insulating film, forming a bonding layer over the insulating film, bonding a supporting substrate to the single crystal semiconductor substrate by interposing the bonding layer between the supporting substrate and the single crystal semiconductor substrate, dividing the single crystal semiconductor substrate at the fragile region to separate the single crystal semiconductor substrate into a single crystal semiconductor layer attached to the supporting substrate, performing first dry etching treatment on a part of the fragile region remaining on the single crystal semiconductor layer, performing second dry etching treatment on a surface of the single crystal semiconductor layer subjected to the first etching treatment, and irradiating the single crystal semiconductor la

Abstract: To provide a semiconductor substrate in which a semiconductor element having favorable crystallinity and high performance can be formed. A single crystal semiconductor substrate having an embrittlement layer and a base substrate are bonded with an insulating layer interposed therebetween; the single crystal semiconductor substrate is separated along the embrittlement layer by heat treatment; a single crystal semiconductor layer is fixed to the base substrate; the single crystal semiconductor layer is irradiated with a laser beam; the single crystal semiconductor layer is in a partially melted state to be recrystallized; and crystal defects are repaired. In addition, the energy density of a laser beam with which the best crystallinity of the single crystal semiconductor layer is obtained is detected by a microwave photoconductivity decay method.

Abstract: It is an object of the present invention to align the plane orientations of crystal grains of a semiconductor film crystallized by irradiation with a linear laser beam with a width of less than or equal to 5 ?m. By performing irradiation with the linear laser beam condensed by an aspheric cylindrical lens or a gradient index lens to completely melt the semiconductor film and scanning the linear laser beam, the completely melted semiconductor film is made to grow laterally. Because the linear beam is very narrow, the width of the semiconductor which is in a liquid state is also narrow, so the occurrence of turbulent flow in the liquid semiconductor is suppressed. Therefore, growth directions of adjacent crystal grains do not become disordered due to turbulent flow and are unformalized, and thus the plane orientations of the laterally grown crystal grains can be aligned.

Abstract: To prevent, in the case of irradiating a single crystal semiconductor layer with a laser beam, an impurity element from being taken into the single crystal semiconductor layer at the time of laser irradiation.

Abstract: To increase the conductivity and electric capacity of an electrode which includes active material particles and the like and is used in a battery, a graphene net including 1 to 100 graphene sheets is used instead of a conventionally used conduction auxiliary agent add binder. The graphene net which has a two-dimensional expansion and a three-dimensional structure is more likely to touch active material particles or another conduction auxiliary agent, thereby increasing the conductivity and the bonding strength between active material particles. This graphene net is obtained by mixing graphene oxide and active material particles and then heating the mixture in a vacuum or a reducing atmosphere.

Abstract: A negative electrode and a power storage device are provided, which have one of an alloy-based particle and an alloy-based whisker and a carbon film including 1 to 50 graphene layers. A surface of the alloy-based particle or the alloy-based whisker is covered with the carbon film. In addition, a method of manufacturing a negative electrode and a method of manufacturing a power storage device are provided, which have the step of mixing an alloy-based particle or an alloy-based whisker with graphene oxide, and the step of heating the mixture in a vacuum or in a reducing atmosphere.