Abstract:
In the case where a film, which has lower strength than a metal can, is used as an exterior body of a secondary battery, a current collector provided in a region surrounded by the exterior body, an active material layer provided on a surface of the current collector, or the like might be damaged when force is externally applied to the secondary battery. A secondary battery that is durable even when force is externally applied thereto is provided. A region that is easily partly bent and a region that is not easily partly bent owing to a protective material provided in the region are intentionally formed to obtain the durable secondary battery.
Abstract:
Deterioration of a power storage device is reduced. Switches that control the connections of a plurality of power storage devices separately are provided. The switches are controlled with a plurality of control signals, so as to switch between charge and discharge of each of the power storage devices or between serial connection and parallel connection of the plurality of power storage devices. Further, a semiconductor circuit having a function of carrying out arithmetic is provided for the power storage devices, so that a control system of the power storage devices or a power storage system is constructed.
Abstract:
A battery capable of changing its form safely is provided. A bendable battery having a larger thickness is provided. A battery with increased capacity is provided. For an exterior body of the battery, a film in the shape of a periodic wave in one direction is used. A space is provided in an area surrounded by the exterior body and between an end portion of the electrode stack that is not fixed and an interior wall of the exterior body. Furthermore, the phases of waves of a pair of portions of the exterior body between which the electrode stack is located are different from each other. In particular, the phases are different from each other by 180 degrees so that wave crest lines overlap with each other and wave trough lines overlap with each other.
Abstract:
In the case where a secondary battery is repetitively curved, portions which tend to cause deterioration such as crack or breakage are, for example, a positive electrode tab and a negative electrode tab. This is because these portions are narrow projected portions, and tend to have low mechanical strength against repetitive curving in some cases. In view of the above, the positive electrode tab and the negative electrode tab are provided in portions relatively less affected by curving. More specifically, secondary battery includes a positive electrode, a positive electrode lead electrically connected to the positive electrode, a negative electrode, a negative electrode lead electrically connected to the negative electrode, a separator, and an exterior body wrapping the positive electrode, the negative electrode, and the separator. The positive electrode, the separator, the negative electrode, and the exterior body can be curved in a first direction. The positive electrode lead and the negative electrode lead are drawn from opposite sides of the exterior body.
Abstract:
In the case where a film, which has lower strength than a metal can, is used as an exterior body of a secondary battery, a current collector provided in a region surrounded by the exterior body, an active material layer provided on a surface of the current collector, or the like might be damaged when force is externally applied to the secondary battery. A secondary battery that is durable even when force is externally applied thereto is provided. A region that is easily partly bent and a region that is not easily partly bent owing to a protective material provided in the region are intentionally formed to obtain the durable secondary battery.
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:
A secondary battery with an exterior body having a novel sealing structure, and a structure of a sealing portion that relaxes a stress of deformation are provided. The secondary battery includes a positive electrode, a negative electrode, an electrolyte solution, and an exterior body enclosing at least part of the positive electrode, at least part of the negative electrode, and the electrolyte solution. The exterior body includes a first region having a shape with a curve, a shape with a wavy line, a shape with an arc, or a shape with a plurality of inflection points, and a second region having the same shape as the first region. The first region is in contact with the second region. Alternatively, the first region has a shape without a straight line. The secondary battery may be flexible, and the exterior body in a region having flexibility may include the first region.
Abstract:
An exterior body of a secondary battery includes an insertion portion for insertion of a third electrode including metal lithium. An injection and expelling portion through which an electrolyte solution can be replaced is further provided. Specifically, a nonaqueous secondary battery includes a positive electrode, a negative electrode, an electrolyte solution, a separator, and an exterior body covering the positive electrode, the negative electrode, and the electrolyte solution. The exterior body includes a positive electrode terminal to which the positive electrode is electrically connected, a negative electrode terminal to which the negative electrode is electrically connected, and an insertion portion for insertion of a third electrode including metal lithium.
Abstract:
The adhesion between metal foil serving as a current collector and a negative electrode active material is increased to enable long-term reliability. An electrode active material layer (including a negative electrode active material or a positive electrode active material) is formed over a base, a metal film is formed over the electrode active material layer by sputtering, and then the base and the electrode active material layer are separated at the interface therebetween; thus, an electrode is formed. The electrode active material particles in contact with the metal film are bonded by being covered with the metal film formed by the sputtering. The electrode active material is used for at least one of a pair of electrodes (a negative electrode or a positive electrode) in a lithium-ion secondary battery.
Abstract:
The adhesion between metal foil serving as a current collector and a negative electrode active material is increased to enable long-term reliability. An electrode active material layer (including a negative electrode active material or a positive electrode active material) is formed over a base, a metal film is formed over the electrode active material layer by sputtering, and then the base and the electrode active material layer are separated at the interface therebetween; thus, an electrode is formed. The electrode active material particles in contact with the metal film are bonded by being covered with the metal film formed by the sputtering. The electrode active material is used for at least one of a pair of electrodes (a negative electrode or a positive electrode) in a lithium-ion secondary battery.