摘要:
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.
摘要:
A secondary battery to be provided includes an electrode including silicon or a silicon compound, and the electrode includes, for example, a current collector formed using metal and a silicon film as an active material provided over the current collector. The hydrogen concentration in the silicon film of the electrode may be higher than or equal to 1.0×1018 cm−3 and lower than or equal to 1.0×1021 cm−3. Such a silicon film is formed over a current collector by a plasma CVD method or the like for example, and hydrogen is contained as little as possible in the silicon film, which is preferable. In order to contain hydrogen as little as possible in the silicon film, the silicon film may be formed over the current collector under a high temperature environment.
摘要:
An object is to provide a secondary battery having excellent charge-discharge cycle characteristics. A secondary battery including an electrode containing silicon or a silicon compound is provided, in which the electrode is provided with a layer containing silicon or a silicon compound over a layer of a metal material; a mixed layer of the metal material and the silicon is provided between the metal material layer and the layer containing silicon or a silicon compound; the metal material has higher oxygen affinity than that of ions which give and receive electric charges in the secondary battery; and an oxide of the metal material does not have an insulating property. The ions which give and receive electric charges are alkali metal ions or alkaline earth metal ions.
摘要:
A power storage device which can have an improved performance such as higher discharge capacity and in which deterioration due to peeling of an active material layer or the like is difficult to occur, and a method for manufacturing the power storage device are provided. The power storage device includes a current collector, a mixed layer formed over the current collector, and a crystalline silicon layer which is formed over the mixed layer and functions as an active material layer. The crystalline silicon layer includes a crystalline silicon region and a whisker-like crystalline silicon region including a plurality of protrusions projecting over the crystalline silicon region. The whisker-like crystalline silicon region includes a protrusion having a bending or branching portion.
摘要:
An energy storage device is provided in which a discharge capacity can be high and/or in which degradation of an electrode due to repetitive charge and discharge can be reduced. An electrode of the energy storage device which includes a crystalline silicon layer serving as an active material layer is provided. The crystalline silicon layer includes a crystalline silicon region and a whisker-like crystalline silicon region having a plurality of protrusions projected upward from the crystalline silicon region. The protrusions include a first protrusion and a second protrusion; the second protrusion has a larger length along the axis and a sharper tip than the first protrusion.
摘要:
An object is to improve characteristics of a power storage device by devising the shape of an active material layer. The characteristics of the power storage device can be improved by providing a power storage device including a first electrode, a second electrode, and an electrolyte provided between the first electrode and the second electrode. The second electrode includes an active material layer. The active material layer includes a plurality of projecting portions containing an active material and a plurality of particles containing an active material, which are arranged over the plurality of projecting portions or in a space between the plurality of projecting portions.
摘要:
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.
摘要:
An object of the present invention is to provide a method for manufacturing an SOI substrate provided with a semiconductor layer which can be used practically even where a substrate having a low upper temperature limit such as a glass substrate is used. The manufacturing method compromises the steps of preparing a semiconductor substrate provided with a bonding layer formed on a surface thereof and a separation layer formed at a predetermined depth from the surface thereof, bonding the bonding layer to the base substrate having a distortion point of 700° C. or lower so that the semiconductor substrate and the base substrate face each other, and separating a part of the semiconductor substrate at the separation layer by heat treatment in order to form a single-crystal semiconductor layer over the base substrate. In the manufacturing method, a substrate which shrinks isotropically at least by the heat treatment is used as the base substrate.
摘要:
An object of one embodiment of the present invention is to provide a technique for manufacturing a dense crystalline semiconductor film (e.g., a microcrystalline semiconductor film) without a cavity between crystal grains. A plasma region is formed between a first electrode and a second electrode by supplying high-frequency power of 60 MHz or less to the first electrode under a condition where a pressure of a reactive gas in a reaction chamber of a plasma CVD apparatus is set to 450 Pa to 13332 Pa, and a distance between the first electrode and the second electrode of the plasma CVD apparatus is set to 1 mm to 20 mm; crystalline deposition precursors are formed in a gas phase including the plasma region; a crystal nucleus of 5 nm to 15 nm is formed by depositing the deposition precursors; and a microcrystalline semiconductor film is formed by growing a crystal from the crystal nucleus.
摘要:
A power storage device which has improved performance such as higher discharge capacity and in which deterioration due to peeling or the like of an active material layer is less likely to be caused is provided. In an electrode for the power storage device, phosphorus-doped amorphous silicon is used for the active material layer over a current collector as a material that can be alloyed with lithium, and niobium oxide is deposited over the active material layer as a layer containing niobium. Accordingly, the capacity of the power storage device can be increased and the cycle characteristics and the charge-discharge efficiency can be improved.