JP2019145521A - Electronic apparatus - Google Patents

Abstract

To provide a flexible secondary battery having a new structure.SOLUTION: A resin 130 is sandwiched in a sealing region, and therefore, the thickness of an electrode portion and the thickness of a sealing region of an exterior body 107 are brought close to each other, and wrinkles generated in the exterior body 107 are suppressed.SELECTED DRAWING: Figure 1

Description

The present invention relates to an object, a method, or a manufacturing method. Or this invention relates to a process, a machine, a manufacture, or a composition (composition of matter). In particular, one embodiment of the present invention relates to a semiconductor device, a display device, a light-emitting device, a power storage device, an imaging device, a driving method thereof, or a manufacturing method thereof. In particular, one embodiment of the present invention relates to a secondary battery and a method for manufacturing the secondary battery.

Lithium-ion secondary batteries are small, lightweight, and have a high energy density. They are used in a wide range of electronic devices, including mobile information terminals such as smartphones and tablet terminals, mobile devices such as notebook PCs and portable game machines. Widely used.

A lithium ion secondary battery generally has an electrode part in which electrodes (a positive electrode and a negative electrode) are wound or stacked, and an exterior body that covers the electrode part.

In addition to iron and aluminum cans, a metal foil laminate film in which a plastic film is laminated on a metal foil is widely used for an exterior body of a lithium ion secondary battery. The metal foil laminate film can be sealed by thermocompression bonding, and has advantages such as a high degree of freedom in shape, light weight, and flexibility.

For example, Patent Document 1 discloses a secondary battery that uses a metal foil laminate film for an exterior body and further uses a reinforcing resin to supplement the strength of the sealing region of the exterior body.

On the other hand, wearable devices have been actively developed among mobile devices in recent years. It is preferable that the wearable device has a shape along the curved surface of the body from the property of being worn. Therefore, the secondary battery mounted on the wearable device is also required to have a shape along the curved surface of the body, like the display and other cases.

For example, Patent Document 2 and Patent Document 3 disclose a secondary battery having a curved shape.

JP 2011-181310 A US Patent Application Publication No. 2013/0108907 JP 2012-151110 A

Although the metal foil laminate film has the advantages as described above, when it is used for a curved secondary battery or an outer package of a flexible secondary battery, there is a problem in strength.

Specifically, in a curved secondary battery or a flexible secondary battery using a metal foil laminate film as an exterior body, a sealing region of the exterior body, such as an area 250 shown in FIG.
It was found that stress was applied in the vicinity thereof and wrinkles were likely to occur.

Wrinkles of the exterior body caused by excessive stress may lead to serious defects such as cracks and breakage of the exterior body.

Therefore, according to one embodiment of the present invention, a secondary battery having a novel structure and a method for manufacturing the secondary battery are provided. Specifically, a secondary battery having a novel structure with flexibility and a method for manufacturing the secondary battery are provided.

One of the reasons that stress is applied to the sealing region of the exterior body and the vicinity thereof is that there is a large difference between the thickness of the electrode portion and the thickness of the sealing region.

Therefore, in order to solve the above problems, in one embodiment of the present invention, wrinkles generated in the exterior body are suppressed by bringing the thickness of the electrode portion close to the thickness of the sealing region of the exterior body.

One embodiment of the present invention is a secondary battery including an electrode portion including a positive electrode, a negative electrode, and a separator, and an exterior body covering the electrode portion, the secondary battery having flexibility, The exterior body has a sealing region, and the secondary battery has a resin sandwiched between the exterior bodies in the sealing region, and a part of the resin is in contact with the outer surface of the exterior body. Next battery.

Further, in the above, the thickness T ₁ of the portion sandwiched between the resin sheaths is 0 of the thickness T ₂ of the electrode portion.
. It is preferably 8 times or more and 1.2 times or less.

Moreover, in the above, it is preferable that an exterior body has an unevenness | corrugation.

In the above, it is preferable to use polypropylene as the resin.

In the above, it is preferable that the friction coefficient μ _{1 of the} resin located outside the sealing region of the exterior body is smaller than the friction coefficient μ _{2 of} the exterior body.

A secondary battery having a novel structure and a method for manufacturing the secondary battery can be provided. Specifically, a secondary battery having a novel structure having flexibility and a method for manufacturing the secondary battery can be provided. More specifically, by making the thickness of the electrode portion close to the thickness of the sealing region of the exterior body, a secondary battery in which wrinkles generated in the exterior body are suppressed can be provided.

The top view and sectional drawing explaining the example of a structure of a secondary battery. The perspective view explaining the example of a structure of a secondary battery. Sectional drawing explaining the example of a structure of a secondary battery. Sectional drawing explaining the example of a structure of a secondary battery. The top view explaining the example of a structure of a secondary battery. 8A and 8B illustrate an example of a method for manufacturing a secondary battery. 8A and 8B illustrate an example of a method for manufacturing a secondary battery. 8A and 8B illustrate an example of a method for manufacturing a secondary battery. 8A and 8B illustrate an example of a method for manufacturing a secondary battery. 8A and 8B illustrate an example of a method for manufacturing a secondary battery. Sectional drawing explaining the positive electrode active material which can be used for a secondary battery. Sectional drawing explaining the conductive support agent etc. which can be used for a secondary battery. Sectional drawing explaining the example of a structure of a secondary battery. Sectional drawing explaining the example of a structure of a secondary battery. The top view and sectional drawing explaining the example of a structure of a secondary battery. The perspective view explaining the example of a structure of a secondary battery, a top view, and sectional drawing. The top view and sectional drawing explaining the example of a structure of a secondary battery. The top view, sectional drawing, and perspective view explaining the example of a structure of a secondary battery. 8A and 8B illustrate an example of a method for manufacturing a secondary battery. The top view and sectional drawing explaining the example of a structure of a secondary battery. 8A and 8B illustrate an example of a method for manufacturing a secondary battery. The block diagram explaining the battery control unit of an electrical storage apparatus. The conceptual diagram explaining the battery control unit of an electrical storage apparatus. The circuit diagram explaining the battery control unit of an electrical storage apparatus. The circuit diagram explaining the battery control unit of an electrical storage apparatus. The conceptual diagram explaining the battery control unit of an electrical storage apparatus. The block diagram explaining the battery control unit of an electrical storage apparatus. The flowchart explaining the battery control unit of an electrical storage apparatus. FIG. 10 illustrates an example of an electronic device. FIG. 10 illustrates an example of an electronic device. FIG. 10 illustrates an example of an electronic device. FIG. 10 illustrates an example of an electronic device. 10A and 10B each illustrate an example of an electronic device. 10A and 10B each illustrate an example of an electronic device. The top view explaining the prior art example of a secondary battery. Sectional drawing explaining conventional examples, such as a conductive support agent.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be easily understood by those skilled in the art that modes and details can be variously changed. In addition, the present invention is not construed as being limited to the description of the embodiments below.

“Electrically connected” includes a case of being connected via “something having an electric action”. Here, the “having some electric action” is not particularly limited as long as it can exchange electric signals between the connection targets.

The position, size, range, and the like of each component illustrated in the drawings and the like may not represent the actual position, size, range, or the like for easy understanding. Therefore, the disclosed invention is not necessarily limited to the position, size, range, or the like disclosed in the drawings and the like.

Ordinal numbers such as “first”, “second”, and “third” are used to avoid confusion between components.

Note that the terms “film” and “layer” can be interchanged with each other depending on the case or circumstances. For example, the term “conductive layer” may be changed to the term “conductive film”. Alternatively, for example, the term “insulating film” may be changed to the term “insulating layer” in some cases.

(Embodiment 1)
In this embodiment, an example of a structure of a secondary battery according to one embodiment of the present invention will be described with reference to FIGS.

[1. Typical configuration]
1A, 1B, 1C, and 2 show an example of a typical configuration of the secondary battery 100. FIG. FIG. 1A is a top view of the secondary battery. FIG. 1B is a cross-sectional view taken along one-dot broken line A1-A2 in FIG. FIG. 1C is a cross-sectional view taken along one-dot broken line B1-B2 in FIG. FIG. 2 is a perspective view of the secondary battery 100. As shown in FIG.
It can be flexible or curved in at least one axial direction.

In addition, in this specification etc., when a certain thing has a curvature, a certain thing will bend,
In other words, it has a concave surface, has a convex surface, warps, deforms, and the like. Moreover, it is not restricted to having these characteristics in the whole itself, What is necessary is just to have these characteristics in at least one part.

1 and 2 includes a plurality of positive electrodes 111, a positive electrode lead 121 electrically connected to the plurality of positive electrodes 111, a plurality of negative electrodes 115, and a negative electrode electrically connected to the plurality of negative electrodes 115. A lead 125 is provided. Each positive electrode 111 is covered with a separator 103. In this specification and the like, the plurality of positive electrodes 111, the plurality of negative electrodes 115, and the plurality of separators 103 are collectively referred to as an electrode portion. Further, as shown in FIG. 1 (B) and (C), it will be referred to thickness of the electrode portion and the T _2.

The secondary battery 100 includes an exterior body 107 that covers the electrode portion. Further, the secondary battery 100 has an electrolytic solution 104 in a region covered with the exterior body 107.

Further, the secondary battery 100 has a resin 130. In the sealing region, the resin 130 is positioned between the outer casing 107 above the electrode section and the outer casing 107 below the electrode section, and the upper casing 107 above the electrode section and the lower section of the electrode section. It has the function of keeping the space | interval of the exterior body 107 of. Part of the resin 130 is provided in contact with the outer surface of the exterior body 107.

In this specification and the like, the sealing region is a region that is provided at an end portion of the secondary battery 100 and has a function of bonding the exterior body 107 above the electrode portion and the exterior body 107 below the electrode portion. Say. Further, the thickness of the portion of the resin 130 sandwiched between the exterior bodies 107 is referred to as T _{1 as} shown in FIGS. When the exterior body 107 is deformed or has a concave portion or a convex portion due to embossing or the like, the thickness of the thickest portion of the portion sandwiched between the exterior bodies 107 of the resin 130 is referred to as T _1. I will do it. The exterior body 107 has an inner surface, an outer surface,
In addition, a surface having a side surface, part of which is in contact with the electrolyte, is referred to as an inner surface, a surface not in contact with the inner surface is referred to as an outer surface, and a surface sandwiched between the inner surface and the outer surface is referred to as a side surface.

The thickness T ₁ of the portion of the resin 130 sandwiched between the exterior bodies 107 is preferably 0.7 times or more and 1.3 times or less, and 0.8 times or more and 1.2 times the thickness T ₂ of the electrode part. It is more preferable that the ratio is not more than twice. By making the thickness of the electrode portion close to the thickness of the sealing region of the exterior body as described above, wrinkles generated in the exterior body 107 when the secondary battery 100 is curved can be suppressed.

By suppressing wrinkles generated in the exterior body 107, the exterior body 107 can be prevented from cracking, breaking, and the like, and the secondary battery 100 with high reliability can be obtained.

Further, it is preferable that the friction coefficient μ ₁ of the resin 130 is smaller than the friction coefficient μ ₂ of the exterior body 107. In particular, it is preferable that the friction coefficient μ ₁ of the resin 130 located outside the sealing region of the exterior body 107 is smaller than the friction coefficient μ _{2 of} the exterior body 107.

In the secondary battery 100 of one embodiment of the present invention, the resin 130 is provided on the outermost side of the secondary battery 100. In addition, as illustrated in FIGS. 1B and 1C, the resin 130 may be provided in the thickest portion of the secondary battery 100. Therefore, when the secondary battery 100 is bent, a main portion that comes into contact with surrounding members or the like may be the resin 130.

Therefore, by making the friction coefficient of the resin 130 smaller than the friction coefficient of the exterior body 107,
Friction with surrounding members and the like when the secondary battery 100 is bent can be reduced. Therefore, the secondary battery 100 that is more easily bent can be obtained.

Incidentally, the friction coefficient mu ₂ of the friction coefficient mu ₁ and the package body 107 of the resin 130 is intended to refer to static friction coefficient. The static friction coefficient can be measured by a method based on, for example, JIS K 7125 or ISO8295.

Further, the positive electrode lead 121 and the negative electrode lead 125 have a sealing layer 120. Resin 130
The sealing layer 120 may partially overlap.

1 includes three positive electrodes 111 each having a positive electrode active material layer 102 formed on one surface of a positive electrode current collector 101 and a negative electrode active material layer 106 formed on one surface of a negative electrode current collector 105. In addition, three negative electrodes 115 are provided. These electrodes are arranged so that the positive electrode active material layer 102 and the negative electrode active material layer 106 face each other with the separator 103 interposed therebetween. In addition, the surfaces of the negative electrode 115 on which the negative electrode active material layer 106 is not formed are arranged so as to contact each other.

With such an arrangement, a contact surface between metals, that is, the surfaces of the negative electrode 115 that do not have the negative electrode active material layer 106 can be formed. Compared with the contact surface between the active material layer and the separator 103, the metal-to-metal contact surface can reduce the friction coefficient.

Therefore, when the positive electrode 111 and the negative electrode 115 are bent, the negative electrode active material layer 10 of the negative electrode 115 is
By sliding the surfaces not having 6, the stress caused by the difference between the inner diameter and the outer diameter of the curve can be released. Therefore, deterioration of the positive electrode 111 and the negative electrode 115 can be suppressed. Further, the secondary battery 100 with high reliability can be obtained.

Note that the secondary battery 100 in which one or two positive electrodes 111 and 115 are stacked may be used. By reducing the number of stacked layers, the secondary battery 100 can be made thinner and more easily bent. Further, four or more of the positive electrode 111 and the negative electrode 115 may be stacked. By increasing the number of stacked layers, the capacity of the secondary battery 100 can be increased.

In the secondary battery 100 in FIG. 1, the example in which the separator 103 covers the positive electrode 111 is described; however, one embodiment of the present invention is not limited thereto. The separator 103 may cover the negative electrode 115. Further, the separator 103 only needs to be provided between the positive electrode active material layer 102 and the negative electrode active material layer 106, and thus the separator 103 may not cover the positive electrode 111 or the negative electrode 115.

In general, a secondary battery sometimes swells because a gas generated by decomposition of an electrolytic solution or the like accumulates in a region covered with an exterior body during repeated charge / discharge cycles. In the secondary battery 100 of one embodiment of the present invention, since the space between the upper exterior body and the lower exterior body of the electrode is maintained by the resin 130, even when the secondary battery swells, the influence is reduced. be able to.

[2. Sealing Modification 1]
FIG. 3A shows a secondary battery 100a as a modification of the secondary battery 100 shown in FIGS.
Indicates. FIG. 3A is a cross-sectional view of the secondary battery 100a, and FIG.
It is sectional drawing equivalent to B).

A secondary battery 100a shown in FIG. 3A is different from the secondary battery 100 shown in FIGS. As shown in FIG. 3A, the resin 130 may partially have a curved surface. Since the resin 130 has a curved surface, it is possible to further reduce friction with surrounding members and the like when the secondary battery 100a is bent.

[3. Sealing modification 2]
FIG. 3B shows a secondary battery 100b as a modification of the secondary battery 100 shown in FIGS.
Indicates. FIG. 3B is a cross-sectional view of the secondary battery 100b, and FIG.
It is sectional drawing equivalent to B).

A secondary battery 100b illustrated in FIG. 3B is different from the secondary battery 100 illustrated in FIGS. The secondary battery 100b in FIG. 3B includes the exterior body 107 on the side surface of the electrode portion in addition to the exterior body 107 above the electrode portion and the exterior body 107 below the electrode portion. The exterior body 107 on the upper side of the electrode part and the exterior body 107 on the side surface of the electrode part are bonded in the region 107b. Further, the exterior body 107 on the lower side of the electrode portion and the exterior body 107 on the side surface of the electrode portion are bonded in the region 107c. By having the exterior body 107 on the side surface of the electrode part, it is possible to further suppress the entry of substances such as water, which can be a cause of deterioration of the secondary battery, into the electrode part, and the electrolyte 104 may leak to the outside. Can be further reduced.

[4. Sealing modification 3]
FIG. 3C shows a secondary battery 100c as a modification of the secondary battery 100 shown in FIGS.
Indicates. FIG. 3C is a cross-sectional view of the secondary battery 100c, and FIG.
It is sectional drawing equivalent to B).

A secondary battery 100c shown in FIG. 3C is different from the secondary battery 100 shown in FIGS. The secondary battery 100c in FIG. 3C includes two kinds of resins, a resin 130a and a resin 130b, which are different materials. Here, the resin in the region sandwiched between the exterior bodies 107 is the resin 130a, and the resin in the region not sandwiched between the exterior bodies 107 is the resin 130a.
Let b.

By using two types of resins of different materials, for example, a material suitable for adhesion to the resin 130a or a material suitable for maintaining the interval between the exterior bodies 107 is used, and deterioration of the secondary battery including water is used for the resin 130b. It is possible to use different materials depending on the location, such as using a material that does not easily transmit a substance that can be a factor. Therefore, the secondary battery 100c is more reliable and less likely to deteriorate.

Note that although an example in which resins of two different materials are used is described in FIG. 3C, one embodiment of the present invention is not limited thereto. You may use resin of 3 or more types of different materials. Moreover, you may have the area | region where several resin was mixed.

[5. Sealing modification 4]
FIG. 4A shows a secondary battery 100d as a modification of the secondary battery 100 shown in FIGS.
Indicates. 4A is a cross-sectional view of the secondary battery 100d, and FIG.
It is sectional drawing equivalent to B).

A secondary battery 100d illustrated in FIG. 4A is different from the secondary battery 100 illustrated in FIGS. In the secondary battery 100d illustrated in FIG. 4A, a part of the exterior body 107 is deformed toward the electrode portion.

[6. Sealing modification 5]
FIG. 4B shows a secondary battery 100e as a modification of the secondary battery 100 shown in FIGS.
Indicates. 4B is a cross-sectional view of the secondary battery 100e, and FIG.
It is sectional drawing equivalent to B).

A secondary battery 100e illustrated in FIG. 4B is different from the secondary battery 100 illustrated in FIGS. In the secondary battery 100e illustrated in FIG. 4B, part of the exterior body 107 is deformed toward the side opposite to the electrode portion.

[7. Modification 6 of sealing]
FIG. 4C shows a secondary battery 100c as a modification of the secondary battery 100 shown in FIGS.
1 is shown. 4C is a cross-sectional view of the secondary battery 100c1, and is a cross-sectional view of the secondary battery 100 corresponding to FIG. 1B.

A secondary battery 100c1 illustrated in FIG. 4C is different from the secondary battery 100 illustrated in FIGS. 1 and 2 in the configuration of the resin 130. A secondary battery 100c1 illustrated in FIG. 4C includes three kinds of resins of different materials: a resin 130a, a resin 130b, and a resin 130c. For the resin 130a and the resin 130b, the description of FIG. 3C can be referred to.

As the resin 130c, an inorganic material such as silica used as a glass frit, glass fiber, spacer, or gap material can be used. When the resin 130 includes an inorganic material, the secondary battery 100c1 with higher reliability can be obtained.

[8. Sealing Variation 7]
FIG. 5A shows a secondary battery 100f as a modification of the secondary battery 100 shown in FIGS.
Indicates. FIG. 5A is a cross-sectional view of the secondary battery 100f, and FIG.
It is sectional drawing equivalent to B).

The secondary battery 100f shown in FIG. 5A is different from the secondary battery 100 shown in FIGS. 1 and 2 in the position where the resin 130 is provided. In the secondary battery 100f shown in FIG.
Among the seven sides, the resin 130 is provided on two sides parallel to the curve axis. Also, the outer package 10
Of the seven sides, the side perpendicular to the curve axis is sealed by directly bonding the exterior bodies 107 together.

Even with such a configuration, the thickness of the electrode portion can be made closer to the thickness of the sealing region of the exterior body. Therefore, wrinkles generated in the exterior body 107 when the secondary battery 100 is bent can be suppressed.

[9. Sealing modification 8]
FIG. 5B shows a secondary battery 100g as a modification of the secondary battery 100 shown in FIGS.
Indicates. FIG. 5B is a cross-sectional view of the secondary battery 100g, and FIG.
It is sectional drawing equivalent to B).

The secondary battery 100g shown in FIG. 5B is different from the secondary battery 100 shown in FIGS. 1 and 2 in the position where the resin 130 is provided. In the secondary battery 100f shown in FIG.
Among the seven sides, the resin 130 is provided on the side perpendicular to the curve axis. The exterior body 107
Of these sides, two sides parallel to the axis of curvature are sealed by directly bonding the exterior bodies 107 together.

Note that one embodiment of the present invention is described in this embodiment. Alternatively, in another embodiment, one embodiment of the present invention will be described. Note that one embodiment of the present invention is not limited thereto. For example, although a curved secondary battery including a resin is shown as one embodiment of the present invention, one embodiment of the present invention is not limited thereto. Depending on circumstances or circumstances, in one embodiment of the present invention, the power storage device may be deformed at any time, such as by bending or stretching, or may be fixed in a certain shape. Alternatively, for example, depending on circumstances or conditions, in one embodiment of the present invention, the power storage device may be left uncurved. For example, as an embodiment of the present invention, an example in which the present invention is applied to a lithium ion secondary battery has been described. However, one embodiment of the present invention is not limited thereto. In some cases or depending on the situation, one embodiment of the present invention includes various secondary batteries, lead storage batteries, lithium ion polymer secondary batteries, nickel / hydrogen storage batteries, nickel / cadmium storage batteries, nickel / iron storage batteries, nickel・ Zinc storage battery, silver oxide ・
The present invention may be applied to a zinc storage battery, a solid battery, an air battery, a zinc air battery, a primary battery, a capacitor, an electric double layer capacitor, an ultra capacitor, a super capacitor, a lithium ion capacitor, or the like. Alternatively, for example, depending on circumstances or circumstances, one embodiment of the present invention may not be applied to a lithium ion secondary battery.

This embodiment can be implemented in appropriate combination with any of the other embodiments. Further, the modification example of the present embodiment can be implemented in combination with other modification examples as appropriate.

(Embodiment 2)
In this embodiment, a secondary battery according to one embodiment of the present invention, particularly FIG.
An example of a method for manufacturing the secondary battery 100c illustrated in FIG.

[1. Prepare positive electrode and cover with separator]
First, the positive electrode active material layer 102 is formed over the positive electrode current collector 101 and processed into the shape of the positive electrode 111. Next, the positive electrode 111 is sandwiched between the bent separators 103 (FIG. 6A).

Then, the outer peripheral portion of the separator 103 outside the positive electrode 111 is bonded to form a bag-like separator 103 (FIG. 6B). Adhesion of the outer peripheral portion of the separator 103 may be performed using an adhesive or the like, or may be performed by ultrasonic welding or fusion by heating.

In this embodiment, polypropylene is used as the separator 103, and the separator 103 is used.
The outer peripheral part of is bonded by heating. FIG. 6B shows an adhesive portion as a region 103a.
In this way, the positive electrode 111 can be covered with the separator 103. Separator 103
May be formed so as to cover the positive electrode active material layer 102, and it is not necessary to cover the entire positive electrode 111.

Note that in FIG. 6A, the separator 103 is bent; however, one embodiment of the present invention is not limited to this. For example, the positive electrode 111 may be sandwiched between two separators. In that case, the region 103a may be formed so as to surround most of the four sides.

In addition, the outer peripheral portion of the separator 103 may be bonded intermittently, or may be bonded as dots at regular intervals as shown in FIG.

Alternatively, adhesion may be performed only on one side of the outer peripheral portion. Or only on the two sides of the outer periphery,
Joining may be performed. Or you may join to 4 sides of an outer peripheral part. As a result, 4
The sides can be made uniform.

[2. Prepare negative electrode]
Next, the negative electrode active material layer 106 is formed over the negative electrode current collector 105 and processed into the shape of the negative electrode 115 (FIG. 6C).

[3. Stack positive and negative electrodes]
Next, the positive electrode 111 and the negative electrode 115 are stacked (FIG. 7A). In this embodiment mode, three positive electrodes 111 each having a positive electrode active material layer 102 formed on one surface and three negative electrodes 115 each having a negative electrode active material layer 106 formed on one surface are stacked. These are arranged so that the positive electrode active material layer 102 and the negative electrode active material layer 106 face each other with the separator 103 interposed therebetween. In addition, the surfaces of the negative electrode 115 on which the negative electrode active material layer 106 is not formed are arranged so as to contact each other.

[4. Connect the positive and negative leads]
Next, the positive electrode tabs of the plurality of positive electrode current collectors 101 and the positive electrode lead 121 having the sealing layer 120 are electrically connected by applying ultrasonic waves while applying pressure (ultrasonic welding).

The lead electrode is likely to be cracked or cut due to the stress generated by applying a force from the outside after the power storage unit is manufactured. Therefore, when the positive electrode lead 121 is ultrasonically welded, it may be sandwiched between bonding dies having protrusions, and a curved portion may be formed separately from the connection region on the positive electrode tab. By providing the curved portion, it is possible to relieve stress generated by applying a force from the outside after the secondary battery 100 is manufactured. Therefore, the reliability of the secondary battery 100 can be improved.

Moreover, it is not limited to forming a curved part in a positive electrode tab, The material of a positive electrode electrical power collector is stainless steel,
It may be configured such that titanium or the like has strength and the thickness of the positive electrode current collector is 10 μm or less so that stress generated by external force applied from the outside after manufacturing the secondary battery can be easily relaxed.

Of course, it goes without saying that the stress concentration of the positive electrode tab may be reduced by combining a plurality of these.

Similarly to the positive electrode current collector 101, the negative electrode tabs of the plurality of negative electrode current collectors 105, and the sealing layer 120
Are electrically connected by ultrasonic welding (FIG. 7B). At this time, similarly to the positive electrode tab, a configuration may be adopted in which stress is easily relieved, for example, a curved portion is provided in the negative electrode tab, or the current collector material is made strong.

[5. Place resin and electrode part on film for exterior body]
Next, the film 107a used for the exterior body is prepared, and the resin 130a is disposed over the film 107a (FIG. 8A).

Next, an electrode part (a plurality of positive electrodes 111) to which the positive electrode lead 121 and the negative electrode lead 125 are connected.
And a plurality of negative electrodes 115) are arranged on the film 107a (FIG. 8B).

[6. Adhere one side of the exterior body]
Next, the film 107a is bent, and the resin 130a and the electrode portion are sandwiched between the bent film 107a. Then, one side of the film 107a (region 107d in FIG. 8C)
, The film 107a on the upper side of the electrode part, the resin 130a, and the film 107a on the lower side of the electrode part are bonded (FIG. 8C). Adhesion can be performed by, for example, heat welding.

[7. Bond the other side of the exterior body]
Next, on the other side of the film 107a (region 107d in FIG. 9A), the film 107a on the upper side of the electrode part, the resin 130a, the film 107a on the lower side of the electrode part,
Are bonded (FIG. 9A).

[8. Inject electrolyte]
Next, the electrolytic solution 104 is injected into a region covered with the film 107a from a portion where the film 107a is not bonded (FIG. 9B).

[9. Seal]
Then, while vacuuming, the remaining side of the film 107a is heated and pressed (see FIG. 9).
The region 107d) in (C) is bonded to form the sealed exterior body 107 with the film 107a (FIG. 9C). These operations are performed in an environment that excludes oxygen and water by using a glove box. The evacuation may be performed using a degassing sealer, an injection sealer, or the like.
Moreover, heating and pressurization can be performed by sandwiching between two heatable bars of the sealer. For example, the degree of vacuum is 60 kPa, heating is 190 ° C., and pressure is 0.
. It can be 3 seconds at 1 MPa. At this time, the positive electrode and the negative electrode may be pressurized from above the film 107a. By pressurization, bubbles mixed during the electrolyte injection can be excluded from between the positive electrode and the negative electrode.

[10. Provide resin]
Next, the resin 130 b is provided in a region not sandwiched between the exterior bodies 107. Through the above steps, the secondary battery 100 can be manufactured (FIG. 10).

In addition, it is preferable to charge / discharge aging in the process before providing said resin 130b. Furthermore, it is more preferable to remove the gas generated by the decomposition of the electrolytic solution during aging and then reseal, and then provide the resin 130b.

In this specification and the like, aging refers to a process performed to detect an initial failure of a secondary battery and to form a stable film on the negative electrode active material by initial charge / discharge. Specifically, it is a process involving charging and discharging for one cycle or more that is held in a charged state for a long time at a temperature close to the upper limit of the battery operating temperature range. Furthermore, you may include the process of extracting the gas generated in the area | region covered with the exterior body.

By forming a stable film on the negative electrode active material in the initial charge and discharge, in the subsequent charge and discharge,
Consumption of carrier ions resulting from the formation of a further film can be suppressed. Therefore, by performing aging, the performance of the secondary battery can be further stabilized and defective cells can be selected.

This embodiment can be implemented in appropriate combination with any of the other embodiments.

(Embodiment 3)
In this embodiment, materials that can be used for the secondary battery according to one embodiment of the present invention will be described in detail with reference to FIGS.

[1. Positive electrode]
The positive electrode 111 includes a positive electrode current collector 101 and a positive electrode active material layer 10 formed on the positive electrode current collector 101.
2 or the like.

The positive electrode current collector 101 can be formed using a material that has high conductivity and does not elute at the potential of the positive electrode, such as metals such as stainless steel, gold, platinum, aluminum, and titanium, and alloys thereof. Alternatively, an aluminum alloy to which an element that improves heat resistance, such as silicon, titanium, neodymium, scandium, or molybdenum, is added can be used. Alternatively, a metal element that forms silicide by reacting with silicon may be used. Examples of metal elements that react with silicon to form silicide include zirconium, titanium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, cobalt, nickel, and the like. Positive electrode current collector 10
As for 1, shape, such as foil shape, plate shape (sheet shape), net shape, punching metal shape, expanded metal shape, can be used suitably. The positive electrode current collector 101 may have a thickness of 5 μm to 30 μm. Further, an undercoat layer may be provided on the surface of the positive electrode current collector 101 using graphite or the like.

In addition to the positive electrode active material, the positive electrode active material layer 102 includes a binder (binder) for increasing the adhesion of the positive electrode active material, a conductive auxiliary agent for increasing the conductivity of the positive electrode active material layer 102, and the like. Also good.

Examples of the positive electrode active material used for the positive electrode active material layer 102 include a composite oxide having an olivine crystal structure, a layered rock salt crystal structure, or a spinel crystal structure. As the positive electrode active material, for example, LiFeO ₂ , LiCoO ₂ , LiNiO ₂ , LiMn ₂ O ₄ , V ₂ O ₅ , C
Compounds such as r ₂ O ₅ and MnO ₂ are used.

Particularly, LiCoO ₂ has the capacity is large, it is stable in the atmosphere as compared to LiNiO _2, because there are advantages such that it is thermally stable than LiNiO _2, preferred.

In addition, a small amount of lithium nickelate (LiNiO ₂ or LiNi _1-x MO ₂ (M = Co) is added to the lithium-containing material having a spinel-type crystal structure containing manganese such as LiMn ₂ O _4.
, Al, etc.) are preferable because the characteristics of the secondary battery using the same can be improved.

Further, as the positive electrode active material, _a lithium manganese composite oxide that can be represented by _a composition formula Li _a Mn _{b McO d} can be used. Here, the element M is preferably a metal element selected from lithium and manganese, or silicon or phosphorus, and more preferably nickel. Further, when measuring the whole particles of the lithium manganese composite oxide, it is necessary to satisfy 0 <a/(b+c)<2, c> 0, and 0.26 ≦ (b + c) / d <0.5 during discharge. preferable. In addition, the whole metal of lithium manganese composite oxide, silicon,
The composition of phosphorus or the like can be measured using, for example, ICP-MS (inductively coupled plasma mass spectrometer). The composition of oxygen in the entire lithium manganese composite oxide particles is, for example, ED
It is possible to measure using X (energy dispersive X-ray analysis). ICP-
It can obtain | require by using together with MS analysis and using valence evaluation of molten gas analysis and XAFS (X-ray absorption fine structure) analysis. Note that the lithium manganese composite oxide means an oxide containing at least lithium and manganese, such as chromium, cobalt, aluminum, nickel,
It may contain at least one element selected from the group consisting of iron, magnesium, molybdenum, zinc, indium, gallium, copper, titanium, niobium, silicon, and phosphorus.

In order to develop a high capacity, it is preferable to use a lithium manganese composite oxide having regions having different crystal structures, crystal orientations, or oxygen contents in the surface layer portion and the central portion. In order to obtain such a lithium manganese composite oxide, the composition formula is Li _a Mn _b Ni _c O _d (1.6.
≦ a ≦ 1.848, 0.19 ≦ c / b ≦ 0.935, 2.5 ≦ d ≦ 3) are preferable. Furthermore, it is particularly preferable to use a lithium manganese composite oxide represented by a composition formula of Li _1.68 Mn _0.8062 Ni _0.318 O ₃ . In this specification and the like, the lithium manganese composite oxide represented by the composition formula of Li _1.68 Mn _0.8062 Ni _0.318 O ₃ refers to the ratio (molar ratio) of the amount of raw material to Li ₂ CO _3. : MnCO ₃ :
A lithium manganese composite oxide formed by setting NiO = 0.84: 0.8062: 0.318. Therefore, the lithium manganese composite oxide has a composition formula of Li _1.68 M.
n _0.8062 Ni _0.318 O ₃ but may deviate from this composition.

FIG. 11 shows an example of a cross-sectional view of lithium manganese composite oxide particles having regions having different crystal structures, crystal orientations, or oxygen contents.

As shown in FIG. 11A, a lithium manganese composite oxide having regions having different crystal structures, crystal orientations, or oxygen contents includes a first region 331, a second region 332, and a third region 333. It is preferable to have. The second region is in contact with at least a part of the outside of the first region. Here, “outside” means closer to the surface of the particle. Moreover, it is preferable that a 3rd area | region has an area | region which corresponds to the surface of the particle | grains which have lithium manganese complex oxide.

In addition, as illustrated in FIG. 11B, the first region 331 may include a region that is not covered with the second region 332. In addition, the second region 332 may have a region that is not covered by the third region 333. Further, for example, a region where the third region 333 is in contact with the first region 331 may be included. In addition, the first region 331 may have a region that is not covered by either the second region 332 or the third region 333.

The second region preferably has a composition different from that of the first region.

For example, the composition of the first region and the second region is measured separately, the first region has lithium, manganese, element M and oxygen, and the second region has lithium, manganese, element M and oxygen. And the atomic ratio of lithium, manganese, element M, and oxygen in the first region is a1: b1: c
The case where the atomic ratio of lithium, manganese, element M, and oxygen in the second region is expressed as a2: b2: c2: d2 is described as 1: d1. In addition, each composition of a 1st area | region and a 2nd area | region can be measured by EDX (energy dispersive X-ray analysis) using TEM (transmission electron microscope), for example. In measurement using EDX, it may be difficult to measure the composition of lithium. Therefore, hereinafter, the difference in composition between the first region and the second region will be described for elements other than lithium. Here, d1 / (b1 + c1) is preferably 2.2 or more, more preferably 2.3 or more, and further preferably 2.35 or more and 3 or less. D2 / (b2 + c2) is preferably less than 2.2, more preferably less than 2.1, and even more preferably 1.1 or more and 1.9 or less. Even in this case, the composition of the entire lithium manganese composite oxide particle including the first region and the second region preferably satisfies the above-described 0.26 ≦ (b + c) / d <0.5.

Further, the manganese included in the second region may have a valence different from that of the manganese included in the first region. The element M included in the second region may have a valence different from that of the element M included in the first region.

More specifically, the first region 331 is preferably a lithium manganese composite oxide having a layered rock salt type crystal structure. The second region 332 is preferably a lithium manganese composite oxide having a spinel crystal structure.

Here, when there is a spatial distribution in the composition of each region and the valence of the element, for example, the composition and valence are evaluated for a plurality of locations, the average value is calculated, the composition of the region, It may be a valence.

Further, a transition layer may be provided between the second region and the first region. Here, the transition layer is, for example, a region where the composition changes continuously or stepwise. Alternatively, the transition layer is a region where the crystal structure changes continuously or stepwise. Alternatively, the transition layer is a region where the lattice constant of the crystal changes continuously or stepwise. Alternatively, a mixed layer may be provided between the second region and the first region. Here, the mixed layer refers to a case where two or more crystals having different crystal orientations are mixed, for example. Alternatively, the mixed layer refers to a case where two or more crystals having different crystal structures are mixed, for example. Alternatively, the mixed layer refers to a case where two or more crystals having different compositions are mixed, for example.

Carbon or a metal compound can be used for the third region. Here, examples of the metal include cobalt, aluminum, nickel, iron, manganese, titanium, zinc, and lithium. As an example of the metal compound, the third region may include an oxide with these metals, a fluoride, or the like.

Among the above, the third region particularly preferably has carbon. Since carbon has high conductivity, for example, the resistance of the electrode can be lowered by using particles coated with carbon for the electrode of the storage battery. In addition, since the third region has carbon, the second region in contact with the third region can be oxidized. The third region may include graphene, may include graphene oxide, or may include reduced graphene oxide. Graphene and reduced graphene oxide have excellent electrical properties of having high conductivity, and excellent physical properties of high flexibility and mechanical strength. Further, the lithium manganese composite oxide particles can be efficiently coated.

When the third region has carbon such as graphene, the cycle characteristics of the secondary battery using the lithium manganese composite oxide as the positive electrode material can be improved.

The thickness of the layer containing carbon is preferably 0.4 nm or more and 40 nm or less.

The lithium manganese composite oxide has, for example, an average primary particle size of 5 nm or more and 5
It is preferably 0 μm or less, and more preferably 100 nm or more and 500 nm or less. It is preferable specific surface area is less than ^{5 m} 2 / g or more ^{15 m} 2 / g. Moreover, it is preferable that the average particle diameter of a secondary particle is 5 micrometers or more and 50 micrometers or less. The average particle diameter can be measured by observation with an SEM (scanning electron microscope) or TEM, a particle size distribution meter using a laser diffraction / scattering method, or the like. The specific surface area can be measured by a gas adsorption method.

Alternatively, as a positive electrode active material, a composite material (general formula LiMPO ₄ (M is Fe (II), Mn
(II), one or more of Co (II), Ni (II))). General formula Li
Representative examples of _{MPO 4, LiFePO 4, LiNiPO 4} , LiCoPO 4, LiM
_{nPO 4, LiFe a Ni b PO} 4, LiFe a Co b PO 4, LiFe a Mn b PO 4
, LiNi _a Co _b PO ₄ , LiNi _a Mn _b PO ₄ (a + b is 1 or less, 0 <a <1, 0
<B <1), LiFe _c Ni _d Co _e PO ₄ , LiFe _c Ni _d M _e PO ₄ , LiNi
_c Co _d Mn _e PO ₄ (c + d + e is 1 or less, 0 <c <1, 0 <d <1, 0 <e <1),
LiFe _f Ni _g Co _h Mn _i PO ₄ (f + g + h + i is 1 or less, 0 <f <1, 0 <g <
Lithium compounds such as 1, 0 <h <1, 0 <i <1) can be used as the material.

In particular, LiFePO ₄ is preferable because it satisfies the requirements for the positive electrode active material in a balanced manner, such as safety, stability, high capacity density, and the presence of lithium ions extracted during initial oxidation (charging).

Or the general formula Li _(2-j) MSiO ₄ (M is Fe (II), Mn (II), Co (
II), one or more of Ni (II), 0 ≦ j ≦ 2) and the like can be used. Representative examples of the general formula Li _(2-j) MSiO ₄ include Li _(2-j) FeSiO ₄ , Li _{(2
-J) NiSiO 4, Li (2} -j) CoSiO 4, Li (2-j) MnSiO 4, Li
_{(2-j) Fe k Ni} l SiO 4, Li (2-j) Fe k Co l SiO 4, Li (2-j
_{) Fe k Mn l SiO 4,} Li (2-j) Ni k Co l SiO 4, Li (2-j) Ni k
Mn _l SiO ₄ (k + _l is 1 or less, 0 <k <1,0 <l <1), Li (2-j) Fe m N
_{i n Co q SiO 4, Li} (2-j) Fe m Ni n Mn q SiO 4, Li (2-j) Ni
_{m Co n Mn q SiO 4 (} m + n + q is 1 or less, 0 <m <1,0 <n <1,0 <q <1)
_{, Li (2-j) Fe} r Ni s Co t Mn u SiO 4 (r + s + t + u ≦ 1, 0 <r
Lithium compounds such as <1, 0 <s <1, 0 <t <1, 0 <u <1) can be used as the material.

Further, as the positive electrode active material, A _x M ₂ (XO ₄ ) ₃ (A = Li, Na, Mg, M = Fe, M
n, Ti, V, Nb, X = S, P, Mo, W, As, Si) may be used. NASICON type compounds include Fe ₂ (MnO ₄ ) ₃ , F
e ₂ (SO ₄ ) ₃ , Li ₃ Fe ₂ (PO ₄ ) _{3 and the} like. Further, as a positive electrode active material, Li
₂ MPO ₄ F, Li ₂ MP ₂ O ₇ , compounds represented by the general formula of Li ₅ MO ₄ (M = Fe, Mn), perovskite fluorides such as NaFeF ₃ and FeF ₃ , TiS ₂ , MoS _{2 and the} like Metal chalcogenides (sulfides, selenides, tellurides), oxides having a reverse spinel crystal structure such as LiMVO ₄ , vanadium oxides (V ₂ O ₅ , V ₆ O ₁₃ , LiV ₃
O ₈ etc.), manganese oxides, organic sulfur compounds and the like can be used.

In addition, when carrier ions are alkali metal ions other than lithium ions or alkaline earth metal ions, as the positive electrode active material, instead of lithium, an alkali metal (for example, sodium or potassium), an alkaline earth metal (for example, , Calcium, strontium, barium, beryllium, magnesium, etc.) may be used. For example, NaFeO ₂ or Na _{2
/ 3} [Fe _1/2 Mn _1/2 ] O ₂ or other sodium-containing layered oxide can be used as the positive electrode active material.

Note that although not illustrated, a conductive material such as a carbon layer may be provided on the surface of the positive electrode active material layer 102. By providing a conductive material such as a carbon layer, the conductivity of the electrode can be improved.
For example, the coating of the carbon layer on the positive electrode active material layer 102 can be formed by mixing carbohydrates such as glucose at the time of firing the positive electrode active material.

The average primary particle diameter of the granular positive electrode active material layer 102 may be 50 nm or more and 100 μm or less.

As the conductive assistant, for example, a carbon material, a metal material, or a conductive ceramic material can be used. Moreover, you may use a fibrous material as a conductive support agent. The content of the conductive additive relative to the total amount of the active material layer is preferably 1 wt% or more and 10 wt% or less, and preferably 1 wt% or more and 5 wt%.
% Or less is more preferable.

The conductive assistant can form an electrically conductive network in the electrode. The conductive auxiliary agent can maintain the electric conduction path between the active materials. By adding a conductive additive in the active material layer, an active material layer having high electrical conductivity can be realized.

As the conductive assistant, for example, artificial graphite such as natural graphite or mesocarbon microbeads, carbon fiber, or the like can be used. As the carbon fibers, for example, carbon fibers such as mesophase pitch-based carbon fibers and isotropic pitch-based carbon fibers can be used. Moreover, carbon nanofiber, a carbon nanotube, etc. can be used as carbon fiber. Carbon nanotubes can be produced by, for example, a vapor phase growth method. In addition, as the conductive auxiliary agent, for example, carbon materials such as carbon black (acetylene black (AB), etc.), graphite (graphite) particles, graphene, fullerene can be used. Further, for example, metal powder such as copper, nickel, aluminum, silver, gold, metal fiber, conductive ceramic material, or the like can be used.

Flaky graphene has excellent electrical properties such as high electrical conductivity, and excellent physical properties such as flexibility and mechanical strength. Therefore, by using graphene as a conductive additive, the contact point and the contact area between the active materials can be increased.

Note that in this specification, graphene includes single-layer graphene or multilayer graphene of two to 100 layers. Single-layer graphene refers to a sheet of one atomic layer of carbon molecules having a π bond. The graphene oxide refers to a compound obtained by oxidizing the graphene. Note that in the case of reducing graphene oxide to form graphene, all oxygen contained in the graphene oxide is not desorbed and part of oxygen remains in the graphene. When oxygen is contained in graphene, the oxygen ratio is 2 atto of graphene as a whole when measured by XPS.
not less than 11% and not more than 11%, preferably not less than 3% and not more than 10
c% or less.

Graphene enables surface contact with low contact resistance, and is extremely conductive even if it is thin, and a conductive path can be efficiently formed in an active material layer even with a small amount.

When an active material having a small average particle diameter, for example, an active material having a size of 1 μm or less is used, the specific surface area of the active material is large, and more conductive paths are required to connect the active materials. In such a case, it is particularly preferable to use graphene that has very high conductivity and can efficiently form a conductive path even in a small amount.

Below, the cross-sectional structural example in the case of using a graphene as a conductive support agent for a positive electrode active material layer is demonstrated. Note that graphene may be used for the negative electrode active material layer as a conductive additive.

FIG. 12A is a longitudinal sectional view of the positive electrode active material layer 102 and the positive electrode current collector 101. The positive electrode active material layer 102 includes a granular positive electrode active material 322, graphene 321 as a conductive additive, and a binder (also referred to as a binder, not shown).

In the longitudinal section of the positive electrode active material layer 102, as shown in FIG.
2, the sheet-like graphene 321 covers the positive electrode active material to such an extent that the sheet-like graphene 321 is in surface contact. In FIG. 12A, the graphene 321 is schematically represented by a thick line, but is actually a thin film having a thickness of a single layer or multiple layers of carbon molecules. Multiple graphene 32
Since 1 is formed so as to cover or cover a plurality of granular positive electrode active materials 322, or to stick on the surface of the plurality of granular positive electrode active materials 322, they are in surface contact with each other. Further, the graphenes 321 are in surface contact with each other, so that a plurality of graphenes 321 form a three-dimensional electrical conduction network.

This is because graphene oxide having extremely high dispersibility in a polar solvent is used for forming the graphene 321. In order to volatilize and remove the solvent from the dispersion medium containing the uniformly dispersed graphene oxide and reduce the graphene oxide to graphene, the graphene 321 remaining in the positive electrode active material layer 102 partially overlaps and is in surface contact with each other. An electric conduction path is formed by covering the positive electrode active material. Note that the reduction of graphene oxide may be performed by, for example, heat treatment or may be performed using a reducing agent.

Therefore, unlike the granular conductive auxiliary agent such as acetylene black that makes point contact with the active material, the graphene 321 enables surface contact with low contact resistance, and thus without increasing the amount of the conductive auxiliary agent. The electrical conductivity between the positive electrode active material 322 and the graphene 321 can be improved. Therefore, the ratio of the positive electrode active material 322 in the positive electrode active material layer 102 can be increased. Thereby, the discharge capacity of the power storage device can be increased.

Further, when graphene is bonded to each other, network graphene (hereinafter referred to as graphene net) can be formed. When the active material is covered with graphene net, the graphene net can also function as a binder for bonding particles. Therefore, since the amount of the binder can be reduced or not used, the ratio of the active material to the electrode volume and the electrode weight can be improved. That is, the capacity of the power storage device can be increased.

Such a configuration in which graphene is used as a conductive additive for the positive electrode active material layer or the negative electrode active material layer as described above is particularly effective in a secondary battery having curvature or flexibility.

FIG. 36A shows a longitudinal sectional view of the positive electrode active material layer 102 and the positive electrode current collector 101 in the case where a particulate conductive auxiliary agent 323 such as acetylene black is used as a conductive auxiliary agent as a conventional example. . The positive electrode active materials 322 form an electric conduction network by contact with the particulate conductive additive 323.

FIG. 36B illustrates the case where the positive electrode active material layer 102 and the positive electrode current collector 101 in FIG. 36A are curved. As shown in FIG. 36B, when a particulate conductive auxiliary agent 323 is used as the conductive auxiliary agent,
As the positive electrode active material layer 102 is curved, the distance between the positive electrode active materials 322 changes, and there is a possibility that a part of the electrical conduction network between the positive electrode active materials 322 is cut off.

On the other hand, FIG. 12B illustrates the case where the positive electrode active material layer 102 and the positive electrode current collector 101 in FIG. 12A using graphene as a conductive additive are curved. Since graphene is a flexible sheet, as the positive electrode active material layer 102 is curved as shown in FIG.
Even if the distance between the 22 is changed, the electric conduction network can be maintained.

The electrode used for the secondary battery of one embodiment of the present invention can be manufactured by various methods. For example,
When an active material layer is formed on a current collector using a coating method, a paste is prepared by mixing an active material, a binder, a conductive additive, and a dispersion medium (also referred to as a solvent), and the paste is formed on the current collector. Is applied to vaporize the dispersion medium. Thereafter, if necessary, pressing may be performed by a compression method such as a roll press method or a flat plate press method, and consolidation may be performed.

As the dispersion medium, for example, water or an organic solvent having polarity such as N-methylpyrrolidone (NMP) or dimethylformamide can be used. From the viewpoint of safety and cost, it is preferable to use water.

For example, the binder preferably contains a water-soluble polymer. For example, polysaccharides can be used as the water-soluble polymer. As the polysaccharide, cellulose derivatives such as carboxymethyl cellulose (CMC), methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, regenerated cellulose, starch, and the like can be used.

The binder is preferably a rubber material such as styrene-butadiene rubber (SBR), styrene / isoprene / styrene rubber, acrylonitrile / butadiene rubber, butadiene rubber, fluororubber, ethylene / propylene / diene copolymer. These rubber materials are more preferably used in combination with the water-soluble polymer described above.

Alternatively, as a binder, polystyrene, polymethyl acrylate, polymethyl methacrylate (PMMA), sodium polyacrylate, polyvinyl alcohol (PVA), polyethylene oxide (PEO), polypropylene oxide, polyimide, polyvinyl chloride,
Materials such as polytetrafluoroethylene, polyethylene, polypropylene, isobutylene, polyethylene terephthalate, nylon, polyvinylidene fluoride (PVdF), polyacrylonitrile (PAN), polyvinyl chloride, ethylene propylene diene polymer, polyvinyl acetate, polymethyl methacrylate, nitrocellulose Is preferably used.

You may use a binder in combination of 2 or more types among the above.

The content of the binder with respect to the total amount of the positive electrode active material layer 102 is preferably 1 wt% or more and 10 wt% or less, more preferably 2 wt% or more and 8 wt% or less, and further preferably 3 wt% or more and 5 wt% or less. In addition, the content of the conductive additive with respect to the total amount of the positive electrode active material layer 102 is preferably 1 wt% or more and 10 wt% or less, and more preferably 1 wt% or more and 5 wt% or less.

When the positive electrode active material layer 102 is formed using a coating method, a positive electrode active material, a binder, and a conductive additive are mixed to prepare a positive electrode paste (slurry), which is applied onto the positive electrode current collector 101 and dried. Just do it.

[2. Negative electrode]
The negative electrode 115 includes a negative electrode current collector 105 and a negative electrode active material layer 10 formed on the negative electrode current collector 105.
6 or the like.

For the negative electrode current collector 105, a material that has high conductivity and does not alloy with carrier ions such as lithium, such as metals such as stainless steel, gold, platinum, iron, copper, and titanium, and alloys thereof can be used. Alternatively, an aluminum alloy to which an element that improves heat resistance, such as silicon, titanium, neodymium, scandium, or molybdenum, is added can be used. Negative electrode current collector 10
5 can use shapes, such as foil shape, plate shape (sheet shape), net shape, punching metal shape, and expanded metal shape, as appropriate. The negative electrode current collector 105 may have a thickness of 5 μm to 30 μm. Further, an undercoat layer may be provided on the surface of the negative electrode current collector 105 using graphite or the like.

Note that it is preferable that the material of the negative electrode current collector be strong, such as stainless steel or titanium, because the negative electrode current collector can withstand deformation due to expansion of the negative electrode active material layer. This is particularly suitable when a material having a large volume change accompanying charge / discharge, such as a material containing silicon, is used as the negative electrode active material.

In addition to the negative electrode active material, the negative electrode active material layer 106 includes a binder (binder) for increasing the adhesion of the negative electrode active material, a conductive auxiliary agent for increasing the conductivity of the negative electrode active material layer 106, and the like. Also good. The binder and the conductive auxiliary material used for the positive electrode active material layer can be referred to for the binder and the conductive auxiliary material used for the negative electrode active material layer.

As the negative electrode active material, a material capable of dissolving and precipitating lithium or reversibly reacting with lithium ions can be used, and lithium metal, a carbon-based material, an alloy-based material, and the like can be used.

Lithium metal has a low redox potential (−3.045 V with respect to a standard hydrogen electrode) and a large specific capacity per weight and volume (3860 mAh / g and 2062 mAh / cm ³ , respectively).
Therefore, it is preferable.

Examples of the carbon-based material include graphite, graphitizable carbon (soft carbon), non-graphitizable carbon (hard carbon), carbon nanotube, graphene, and carbon black.

Examples of graphite include artificial graphite such as mesocarbon microbeads (MCMB), coke-based artificial graphite, and pitch-based artificial graphite, and natural graphite such as spheroidized natural graphite.

Graphite exhibits a potential as low as that of lithium metal (0.1 to 0.3 V vs. Li / Li ⁺ ) when lithium ions are inserted into the graphite (when a lithium-graphite intercalation compound is formed). Thereby, a lithium ion secondary battery can show a high operating voltage. Further, graphite is preferable because it has advantages such as relatively high capacity per unit volume, small volume expansion, low cost, and high safety compared to lithium metal.

In addition to the carbon material described above, an alloy-based material capable of performing a charge / discharge reaction by alloying with a carrier ion or a dealloying reaction can be used as the negative electrode active material. When the carrier ions are lithium ions, examples of alloy materials include Mg, Ca, Al, Si, Ge
A material containing at least one of Sn, Pb, As, Sb, Bi, Ag, Au, Zn, Cd, Hg, In, and the like can be used. Such an element has a large capacity with respect to carbon. In particular, silicon has a theoretical capacity of 4200 mAh / g. For this reason, it is preferable to use silicon for the negative electrode active material. Examples of alloy materials using such elements include Mg ₂ Si, Mg ₂ Ge, Mg ₂ Sn, SnS ₂ , V ₂ Sn ₃ , FeSn ₂ ,
CoSn ₂ , Ni ₃ Sn ₂ , Cu ₆ Sn ₅ , Ag ₃ Sn, Ag ₃ Sb, Ni ₂ MnSb,
Examples include CeSb ₃ , LaSn ₃ , La ₃ Co ₂ Sn ₇ , CoSb ₃ , InSb, SbSn, and the like.

Further, as the negative electrode active material, SiO, SnO, SnO _2, titanium dioxide _(TiO 2), lithium titanium oxide _{(Li 4 Ti 5 O 12)} , lithium - graphite intercalation _{compounds, (Li x C} 6)
Niobium pentoxide (Nb ₂ O ₅ ), tungsten oxide (WO ₂ ), molybdenum oxide (MoO
₂ ) etc. can be used.

Note that SiO refers to silicon oxide powder and can also be expressed as SiO _y (2>y> 0). SiO may contain a silicon-rich part. For example, SiO is Si ₂ O.
₃ , a material containing one or more selected from Si ₃ O ₄ or Si ₂ O, and a mixture of Si powder and silicon dioxide SiO ₂ . In addition, SiO may contain other elements (carbon, nitrogen, iron, aluminum, copper, titanium, calcium, manganese, etc.). That is, it refers to a material containing a plurality of materials selected from single crystal Si, amorphous Si, polycrystalline Si, Si ₂ O ₃ , Si ₃ O ₄ , Si ₂ O, and SiO ₂ , and SiO is a colored material. Si not SiO
If it is O _x (X is 2 or more), it is colorless and transparent or white and can be distinguished. However, when a secondary battery is manufactured using SiO as a material of the secondary battery, and SiO is oxidized by repeating charge and discharge, it may be transformed into SiO ₂ .

Further, as the anode active material, a double nitride of lithium and a transition metal, Li ₃ with N-type structure _{Li 3-x M x N (} M = Co, Ni, Cu) can be used. For example, Li _2.6
Co _0.4 N ₃ shows a large charge / discharge capacity (900 mAh / g, 1890 mAh / cm ³ ) and is preferable.

When lithium and transition metal double nitride is used, the negative electrode active material contains lithium ions.
The positive electrode active material is preferably combined with materials such as V ₂ O ₅ and Cr ₃ O ₈ that do not contain lithium ions. Even when a material containing lithium ions is used for the positive electrode active material, lithium and transition metal double nitride can be used as the negative electrode active material by previously desorbing lithium ions contained in the positive electrode active material. .

A material that causes a conversion reaction can also be used as the negative electrode active material. For example, a transition metal oxide that does not undergo an alloying reaction with lithium, such as cobalt oxide (CoO), nickel oxide (NiO), or iron oxide (FeO), may be used as the negative electrode active material. Further, materials that cause a conversion reaction include Fe ₂ O ₃ , CuO, Cu ₂ O, RuO ₂ , Cr ₂ O.
₃ oxides, sulfides such as CoS _0.89 , NiS, CuS, Zn ₃ N ₂ , Cu ₃ N, G
nitrides such as e ₃ N ₄ , phosphides such as NiP ₂ , FeP ₂ , and CoP ₃ , FeF ₃ , BiF ₃
Also occurs with fluorides such as Note that since the potential of the fluoride is high, it may be used as a positive electrode active material.

In the case where the negative electrode active material layer 106 is formed using a coating method, a negative electrode paste (slurry) is prepared by mixing the negative electrode active material and a binder, and applied to the negative electrode current collector 105 and dried. Good.

Further, graphene may be formed on the surface of the negative electrode active material layer 106. For example, when the negative electrode active material is silicon, the volume change due to the insertion and extraction of carrier ions in the charge / discharge cycle is large, so that the adhesion between the negative electrode current collector 105 and the negative electrode active material layer 106 decreases, and the charge / discharge cycle is reduced. Battery characteristics deteriorate due to discharge. Therefore, when graphene is formed on the surface of the negative electrode active material layer 106 containing silicon, the adhesion between the negative electrode current collector 105 and the negative electrode active material layer 106 is reduced even if the volume of silicon is changed in a charge / discharge cycle. This is preferable because it can be suppressed and deterioration of battery characteristics is reduced.

Further, a film such as an oxide may be formed on the surface of the negative electrode active material layer 106. The film formed by the decomposition of the electrolytic solution during charging cannot release the amount of charge consumed during the formation, and forms an irreversible capacity. On the other hand, by providing a film of oxide or the like on the surface of the negative electrode active material layer 106 in advance, generation of irreversible capacity can be suppressed or prevented.

As a film covering such a negative electrode active material layer 106, niobium, titanium, vanadium, tantalum, tungsten, zirconium, molybdenum, hafnium, chromium, aluminum, or an oxide film of any one of these elements, or any of these elements An oxide film containing one and lithium can be used. Such a film is a sufficiently dense film as compared with a film formed on the surface of the negative electrode by a conventional decomposition product of the electrolytic solution.

For example, niobium oxide (Nb ₂ O ₅ ) has a low electrical conductivity of 10 ⁻⁹ S / cm and high insulation properties. For this reason, the niobium oxide film inhibits the electrochemical decomposition reaction between the negative electrode active material and the electrolytic solution. On the other hand, the lithium diffusion coefficient of niobium oxide is 10 ⁻⁹ cm ² / sec and has high lithium ion conductivity. For this reason, it is possible to permeate | transmit lithium ion. Further, silicon oxide or aluminum oxide may be used.

For example, a sol-gel method can be used to form a film that covers the negative electrode active material layer 106. The sol-gel method is a method of forming a thin film by baking a solution made of a metal alkoxide, a metal salt, or the like to a gel that has lost fluidity due to a hydrolysis reaction or a polycondensation reaction. Since the sol-gel method is a method of forming a thin film from a liquid phase, raw materials can be homogeneously mixed at a molecular level. For this reason, the active material can be easily dispersed in the gel by adding a negative electrode active material such as graphite to the raw material of the metal oxide film at the solvent stage. In this manner, a film can be formed on the surface of the negative electrode active material layer 106. By using the coating film, it is possible to prevent a reduction in the capacity of the power storage unit.

[3. Separator]
As a material for forming the separator 103, cellulose or polypropylene (PP)
Porous insulators such as polyethylene (PE), polybutene, nylon, polyester, polysulfone, polyacrylonitrile, polyvinylidene fluoride, and tetrafluoroethylene can be used. Moreover, you may use the nonwoven fabrics, such as glass fiber, and the diaphragm which compounded glass fiber and polymer fiber. Moreover, in order to improve heat resistance, you may use the separator which performed ceramic application | coating or aramid coating to the polyester nonwoven fabric.

[4. Electrolyte]
As a solvent of the electrolytic solution 104 used for the secondary battery 100, an aprotic organic solvent is preferable. For example, ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate, chloroethylene carbonate, vinylene carbonate, γ-butyrolactone, γ-valerolactone, dimethyl carbonate (DMC), diethyl carbonate (D
EC), ethyl methyl carbonate (EMC), methyl formate, methyl acetate, methyl butyrate,
1,3-dioxane, 1,4-dioxane, dimethoxyethane (DME), dimethyl sulfoxide, diethyl ether, methyl diglyme, acetonitrile, benzonitrile, tetrahydrofuran, sulfolane, sultone, etc., or two of these The above can be used in any combination and ratio.

Moreover, the safety | security with respect to a liquid-leakage property increases by using the polymeric material gelatinized as a solvent of electrolyte solution. Further, the secondary battery can be made thinner and lighter. Typical examples of the polymer material to be gelated include silicone gel, acrylic gel, acrylonitrile gel, polyethylene oxide, polypropylene oxide, and fluorine-based polymer.

In addition, by using one or more ionic liquids (room temperature molten salts) that are flame retardant and volatile as the electrolyte solvent, the internal temperature increases due to internal short circuit or overcharge of the battery. Also,
The secondary battery can be prevented from rupturing or igniting.

As the electrolytes dissolved in the above solvent, when using a lithium carrier ion, e.g. _{LiPF 6, LiClO 4, LiAsF 6} , LiBF 4, LiAlCl 4, Li
SCN, LiBr, LiI, Li ₂ SO ₄ , Li ₂ B ₁₀ C ₁₁ , Li ₂ B ₁₂ C _11
2 , LiCF ₃ SO ₃ , LiC ₄ F ₉ SO ₃ , LiC (CF ₃ SO ₂ ) ₃ , LiC (C _{2
F 5 SO 2) 3, LiN} (CF 3 SO 2) 2, LiN (C 4 F 9 SO 2) (CF 3 SO 2
), LiN (C ₂ F ₅ SO ₂ ) ₂ or the like, or two or more of them can be used in any combination and ratio.

In addition, as the electrolytic solution used for the secondary battery, a highly purified electrolytic solution having a small content of elements other than the constituent elements of the granular dust and the electrolytic solution (hereinafter also simply referred to as “impurities”) is used. preferable. Specifically, the weight ratio of impurities to the electrolytic solution is 1% or less, preferably 0.1% or less,
More preferably, it is preferable to set it as 0.01% or less. Moreover, you may add additives, such as vinylene carbonate, to electrolyte solution.

[5. Exterior body]
Although there are various structures for the secondary battery, in this embodiment mode, a film is used to form the exterior body 107. Among these, a metal foil laminated film obtained by laminating a plastic film on a metal foil is preferable because it can be sealed by thermocompression bonding, has a high degree of freedom in shape, is lightweight, and has flexibility. . Aluminum, stainless steel, tin, nickel steel, etc. can be used as a material for the metal foil of the metal foil laminate film. As the plastic film laminated on the metal foil, polyethylene terephthalate, nylon, polyethylene or the like can be used.

Note that in this specification and the like, the term “laminate” refers to a processing method in which thin materials such as a metal foil and a plastic film are attached and laminated.

The film used for the exterior body 107 is selected from a hybrid material film including an organic material (organic resin, fiber, etc.) and an inorganic material (ceramic, etc.) and a carbon-containing film (carbon film, graphite film, etc.) in a metal foil. A single layer film or a laminate of a plurality of these laminated films may be used.

Moreover, it is preferable that the exterior body 107 is formed with a concave portion, a convex portion, or a concave portion and a convex portion by embossing or the like.

A film having a metal foil is easy to emboss, and when the embossing is performed to form a concave portion or a convex portion, the surface area of the exterior body 107 that comes into contact with the outside air is increased.

Further, when the shape of the secondary battery 100 is changed by applying a force from the outside, among the exterior bodies 107 of the secondary battery 100, the inner exterior body 107 near the bending center is subjected to compressive stress, and from the bending center. A tensile stress is applied to the outer outer casing 107. These stresses may cause the exterior body to be distorted, and a part of the exterior body 107 may be deformed or partially destroyed.

By forming a concave portion or a convex portion on the exterior body 107 by embossing or the like, the creepage distance of the exterior body 107 can be increased, and the compressive stress and tensile stress per unit length can be reduced. Therefore, the reliability of the secondary battery 100 can be improved.

The strain is a measure of deformation indicating the displacement of the material point in the object with respect to the reference (initial state) length of the object. It can also be said that by forming a concave portion or a convex portion in the exterior body 107, the influence of strain generated by applying force from the outside of the secondary battery can be suppressed within an allowable range.

[6. resin]
As the resin 130 used in the secondary battery 100, it is preferable to use a resin having adhesiveness, heat-fusibility, elasticity, or permeation resistance, and a resin that does not generate decomposition products upon contact with the electrolytic solution. Is preferred. For example, polypropylene, polyethylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyethylene terephthalate, polyurethane, epoxy resin, phenol resin, melamine resin, acrylic resin, polyimide, polyamide, rubber, silicone resin, or the like can be used.

Note that in the case where the resin 130 is made of two or more kinds of materials, it is preferable to use a material having adhesiveness or heat-sealability or a material having elasticity for the resin 130a provided in the region sandwiched between the exterior bodies. By using a material having adhesiveness or heat-sealing property, adhesion between the exterior body 107 and the resin 130a can be strengthened. In addition, by using an elastic material,
A secondary battery having excellent flexibility can be obtained.

Examples of the adhesive material include an epoxy resin and an acrylic resin. Examples of the material having heat-fusibility include polypropylene and polyethylene. Examples of the elastic material include rubber and silicone resin.

For the resin 130b provided in a region not sandwiched between the outer casings 107, it is preferable to use a material that is resistant to permeation with respect to substances that can cause deterioration of the secondary battery such as water. Note that a part of the resin 130 b is provided in contact with the outer surface of the exterior body 107.

Examples of the material having resistance to permeation of water include polyethylene, polypropylene, a silicon oxide deposited film, and an aluminum oxide deposited film.

Furthermore, it is preferable that the resin 130b provided in the region not sandwiched between the exterior bodies 107 includes a desiccant. For example, silica gel can be used as the desiccant. By including the desiccant in the resin 130b, it is possible to further suppress water from entering the electrode portion of the secondary battery.

This embodiment can be implemented in appropriate combination with any of the other embodiments.

(Embodiment 4)
In this embodiment, examples of other structures of the secondary battery according to one embodiment of the present invention will be described with reference to FIGS.

[1. Modification Example 1 of Electrode Section]
FIG. 13A illustrates an example of stacking of the positive electrode 111 and the negative electrode 115, which is different from those in FIGS.
In FIG. 13A, a positive electrode 111a having a positive electrode active material layer 102 on both surfaces of a positive electrode current collector 101.
And four negative electrodes 115 each having the negative electrode active material layer 106 are stacked on one surface of the negative electrode current collector 105. Even with the structure as shown in FIG. 13A, a contact surface of metals, that is, surfaces of the negative electrode 115 which do not have a negative electrode active material can be formed.

[2. Modification Example 2 of Electrode Section]
FIG. 13B illustrates an example of stacking of the positive electrode 111 and the negative electrode 115, which is different from those in FIGS.
In FIG. 13B, a positive electrode 111a having a positive electrode active material layer 102 on both surfaces of the positive electrode current collector 101.
Two negative electrodes 115 each having a negative electrode active material layer 106 on one side of the negative electrode current collector 105, and one negative electrode 115 a having a negative electrode active material layer on both sides of the negative electrode current collector 105. FIG.
By providing the active material layer on both sides of the current collector as in B), the capacity per unit volume of the secondary battery 100 can be increased.

[3. Modification 3 of electrode part]
FIG. 13C illustrates an example of stacking of the positive electrode 111 and the negative electrode 115, which is different from those in FIGS.
In FIG. 13C, an electrolytic solution having a polymer is used as the electrolytic solution 104, and a pair of positive electrodes 11 is used.
1, a negative electrode 115, and a separator 103 are bonded together with an electrolytic solution 104. With such a configuration, when the secondary battery 100 is curved, the positive electrode 111 and the negative electrode 1 in which a battery reaction is performed.
Slip between 15 can be suppressed.

In addition, a large number of metal contact surfaces, that is, the surfaces of the positive electrode 111 that do not have the positive electrode active material and the surfaces of the negative electrode 115 that do not have the negative electrode active material can be formed. Therefore, the secondary battery 10
When 0 is curved, these contact surfaces slip, so that stress generated by the difference between the inner diameter and the outer diameter of the curve can be released.

Therefore, the deterioration of the secondary battery 100 can be further suppressed. Further, the secondary battery 100 with higher reliability can be obtained.

As the polymer of the electrolytic solution 104 in the example of FIG. 13C, for example, a polyethylene oxide-based, polyacrylonitrile-based, polyvinylidene fluoride-based, polyacrylate-based, or polymethacrylate-based polymer can be used. In addition, it is preferable to use a polymer that can gel the electrolytic solution 104 at room temperature (for example, 25 ° C.). In this specification and the like, for example, a polyvinylidene fluoride-based polymer means a polymer containing polyvinylidene fluoride (PVDF), and includes a poly (vinylidene fluoride-hexafluoropropylene) copolymer and the like.

The polymer can be qualitatively analyzed by using FT-IR (Fourier transform infrared spectrophotometer) or the like. For example, a polyvinylidene fluoride-based polymer has absorption showing a C—F bond in a spectrum obtained by FT-IR. In addition, the polyacrylonitrile-based polymer has absorption showing a C≡N bond in the spectrum obtained by FT-IR.

Note that description of FIG. 1 can be referred to except for a method of stacking the positive electrode 111 and the negative electrode 115.

[4. Modification 4 of electrode part]
FIG. 14 shows an example of a secondary battery 100h having a positive electrode 111 and a negative electrode 115 having lengths different from those in FIG. 14A is a flat state, and FIG. 14B is a curved secondary battery 100.
It is sectional drawing of h.

As shown in FIG. 14A, the positive electrode 111 and the negative electrode 115 of the secondary battery 100h shown in FIG. 14 are curved with the inner diameter side electrode bent from the outer diameter side electrode when the secondary battery 100h is bent. The direction is shortened.

With such a structure, as illustrated in FIG. 14B, when the secondary battery 100h is curved with a certain curvature, the ends of the positive electrode 111 and the negative electrode 115 can be aligned. That is, all the regions of the positive electrode active material layer 102 included in the positive electrode 111 can be disposed to face the negative electrode active material layer 106 included in the negative electrode 115. Therefore, the positive electrode active material included in the positive electrode 111 can be contributed to the battery reaction without waste. Therefore, the capacity per volume of the secondary battery 100h can be increased. This configuration is particularly effective when the curvature of the secondary battery 100 is fixed when the secondary battery 100h is used.

Note that the description of FIG. 1 can be referred to in addition to the lengths of the plurality of positive electrodes 111 and the plurality of negative electrodes 115.

[5. Modification 1 of exterior body]
15A and 15B, the secondary battery 10 having an exterior body 107e having a shape different from that in FIG.
0i is indicated. FIG. 15A is a top view of the secondary battery 100i. FIG. 15B is the same as FIG.
It is sectional drawing in the dashed-dotted line C1-C2 of (A).

The exterior body 107e included in the secondary battery 100i has a concave portion and a convex portion by embossing. By using the exterior body 107e having unevenness, the stress of the exterior body 107e when the shape of the secondary battery 100i is changed can be relieved. Therefore, the highly reliable secondary battery 100i can be obtained.

[6. Modification 2 of exterior body]
FIG. 15C illustrates a secondary battery 100j having an exterior body 107f having a shape different from those in FIGS. 15A and 15B. 15C is a cross-sectional view of the secondary battery 100j, and the secondary battery 100i
FIG. 16 is a cross-sectional view corresponding to FIG.

The secondary battery 100j includes two exterior bodies, exterior bodies 107e and 107, each having a different pitch of unevenness.
f. When the secondary battery 100j is bent, the outer battery body 107e having a wide uneven pitch is provided on the outer cover body on the inner diameter side from the electrode portion, and the uneven pitch is narrower on the outer cover body on the outer diameter side than the electrode section. An exterior body 107 is included.

By using the exterior bodies 107e and 107f having different concave and convex pitches on the inner diameter side and the outer diameter side of the curve, the stress applied to the exterior body can be further relaxed. Therefore, the secondary battery 100j with higher reliability can be obtained.

[5. Modification 1 of lead position etc.]
FIG. 16 shows a secondary battery 100k having a configuration different from that shown in FIG. FIG. 16A shows a secondary battery 100.
FIG. 16B is a top view of the secondary battery 100k when k is curved. FIG.
FIG. 16C is a cross-sectional view taken along dashed line D1-D2 in FIG.

In the secondary battery 100k shown in FIG. 16, the positions of the positive electrode lead 121 and the negative electrode lead 125 are
This is different from the secondary battery 100 of FIG. Moreover, the positive electrode 111, the separator 103, and the negative electrode 11
5 and the shape of the exterior body 107 are also different from those of the secondary battery 100 of FIG.

In the secondary battery 100k shown in FIG. 16, the positive electrode lead 121 and the negative electrode lead 125 are drawn out from opposite sides of the exterior body 107, respectively. Further, the line connecting the positive electrode lead 121 and the negative electrode lead 125 is not parallel to the curve axis of the secondary battery 100k. With such a configuration, the positive electrode lead 121 and the negative electrode lead 125 are electrically connected.
The tab portion of the positive electrode 111 and the tab portion of the negative electrode 115 can be provided at a place where the influence of bending is relatively small. The tab of the positive electrode 111 and the tab of the negative electrode 115 are thinly elongated, and are thinner than the electrode portion on which the active material is formed, and tend to be weak against bending. Positive electrode 11
By providing the tab of 1 and the tab of the negative electrode 115 at a place where the influence of bending is small, the secondary battery 100k with higher reliability can be obtained.

Position of positive electrode lead 121 and negative electrode lead 125 of secondary battery 100k, and positive electrode 11
1, description of FIG. 1 can be referred to for configurations other than the shapes of the negative electrode 115, the separator 103, and the exterior body 107.

[6. Modification Example 2 of Lead Position, etc.]
FIG. 17A shows a secondary battery 100m having a structure different from that in FIG. FIG. 17A is a top view of the secondary battery 100m.

A secondary battery 100m illustrated in FIG. 17A is different from the secondary battery 100k in FIG. 16 in the shapes of the positive electrode 111, the separator 103, the negative electrode 115, and the outer package 107. The positive electrode 111, the negative electrode 115, the separator 103, and the exterior body 107 of the secondary battery 100m illustrated in FIG.
Is longer in the direction connecting the tab portion of the positive electrode 111 and the tab portion of the negative electrode 115 than in the direction of the axis of curvature. Even in the secondary battery 100m having such a structure, the tab of the positive electrode 111 and the negative electrode 1
Fifteen tabs can be provided at locations where the influence of bending is relatively small.

Position of positive electrode lead 121 and negative electrode lead 125 of secondary battery 100m, and positive electrode 11
1, description of FIG. 1 can be referred to for configurations other than the shapes of the negative electrode 115, the separator 103, and the exterior body 107.

[7. Modification Example 3 of Lead Position, etc.]
FIG. 17B1 and FIG. 17B2 show a secondary battery 100n different from FIG. FIG.
7 (B1) is a top view of the secondary battery 100n. FIG. 17B2 is a cross-sectional view taken along one-dot dashed line E1-E2 in FIG.

The secondary battery 100n in FIGS. 17B1 and 17B2 includes a positive electrode 111, a negative electrode 115,
The separator 103 and the exterior body 107 have a plurality of holes 221. Since the secondary battery 100n illustrated in FIGS. 17B1 and 17B2 has the hole 221, the secondary battery 100n can also be disposed in a band portion of an electronic device that requires a hole, for example, a wristwatch type device. Therefore, the capacity of the secondary battery 100n can be increased.

Position of positive electrode lead 121 and negative electrode lead 125 of secondary battery 100n, and positive electrode 11
1, description of FIG. 1 can be referred to for configurations other than the shapes of the negative electrode 115, the separator 103, and the exterior body 107.

[8. Modification 1 of separator shape, etc.]
FIG. 18 shows a secondary battery 100p different from FIG. FIG. 18A is a top view of the secondary battery 100p. 18B is a cross-sectional view taken along dashed-dotted line F1-F2 in FIG. FIG. 18C illustrates the positive electrode 111, the negative electrode 115, and the separator 103 of the secondary battery 100p.
It is the perspective view which extracted and showed.

The secondary battery 100p shown in FIG. 18 is different from the secondary battery 100 in FIG. 1 in the positions of the positive electrode lead 121 and the negative electrode lead 125 and the shapes of the positive electrode 111, the negative electrode 115, the separator 103, and the outer package 107.

Here, part of a method for manufacturing the secondary battery 100p illustrated in FIG. 18 will be described with reference to FIGS.

First, the negative electrode 115 is placed over the separator 103 (FIG. 19A). At this time, negative electrode 1
The negative electrode active material layer included in 15 is disposed so as to overlap with the separator 103.

Next, the separator 103 is bent, and the separator 103 is overlaid on the negative electrode 113. Next, the positive electrode 111 is stacked over the separator 103 (FIG. 19B). At this time, the positive electrode 11
1 is arranged so that the positive electrode active material layer 102 included in 1 overlaps with the separator 103 and the negative electrode active material layer 106. When an electrode having an active material layer formed on one side of the current collector is used, the positive electrode active material layer 102 of the positive electrode 111 and the negative electrode active material layer 106 of the negative electrode 115 are separated from each other by the separator 1.
03 so as to face each other.

When a material that can be thermally welded, such as polypropylene, is used for the separator 103, the electrode is displaced during the manufacturing process by thermally welding the region where the separators 103 overlap each other and then stacking the next electrode. Can be suppressed. Specifically, the region where the separators 103 are not overlapped with each other, for example, the region 10 in FIG.
It is preferable to heat weld the region indicated by 3a.

By repeating this step, the positive electrode 111 and the negative electrode 115 can be stacked with the separator 103 interposed therebetween as shown in FIG.

Note that a plurality of negative electrodes 115 and a plurality of positive electrodes 111 may be alternately sandwiched between separators 103 that are repeatedly bent in advance.

Next, as illustrated in FIG. 19C, the plurality of positive electrodes 111 and the plurality of negative electrodes 115 are covered with a separator 103.

Further, as shown in FIG. 19D, a plurality of positive electrodes 111 and a plurality of negative electrodes 1 are formed by heat welding a region where the separators 103 overlap each other, for example, a region 103b shown in FIG. 19D.
15 is covered with a separator 103 and bound.

Note that the plurality of positive electrodes 111, the plurality of negative electrodes 115, and the separator 103 may be bound using a binding material.

In order to stack the positive electrode 111 and the negative electrode 115 in such a process, the separator 103 is
One separator 103 has a region sandwiched between a plurality of positive electrodes 111 and a plurality of negative electrodes 115, and a region disposed so as to cover the plurality of positive electrodes 111 and the plurality of negative electrodes 115.

In other words, the separator 103 included in the secondary battery 100p in FIG. 15 is one separator that is partially folded. In the folded region of the separator 103, a plurality of positive electrodes 1
11 and a plurality of negative electrodes 115 are sandwiched.

The configuration of the secondary battery 100p other than the shapes of the positive electrode 111, the negative electrode 115, the separator 103, and the outer package 107 and the position shapes of the positive electrode lead 121 and the negative electrode lead 125 can be referred to the description of FIG.

[9. Modification 2 of separator shape, etc.]
FIG. 20 shows a secondary battery 100q different from FIG. FIG. 20A is a top view of the secondary battery 100q. 20B1 is a cross-sectional view of the first electrode assembly 140, and FIG. 20B2 is a cross-sectional view of the second electrode assembly 141. 20C is a cross-sectional view taken along dashed-dotted line G1-G2 in FIG. In FIG. 20C, the first electrode assembly 14 is shown for clarity.
0, the electrode assembly 141 and the separator 103 are extracted and shown.

The secondary battery 100q shown in FIG. 20 includes an arrangement of the positive electrode 111 and the negative electrode 115, and the separator 1
The arrangement of 03 is different from the secondary battery 100h of FIG.

As shown in FIG. 20C, the secondary battery 100q includes a plurality of first electrode assemblies 140 and a plurality of electrode assemblies 141.

As shown in FIG. 20B 1, in the first electrode assembly 140, the positive electrode 111 a having the positive electrode active material layer 102 on both surfaces of the positive electrode current collector 101, the separator 103, and the negative electrode active material on both surfaces of the negative electrode current collector 105. A negative electrode 115 a having a material layer 106, a separator 103, and a positive electrode 111 a having a positive electrode active material layer 102 are stacked in this order on both surfaces of the positive electrode current collector 101. In addition, FIG.
As shown in B2), in the second electrode assembly 141, the negative electrode 115a having the negative electrode active material layer 106 on both surfaces of the negative electrode current collector 105, the separator 103, and the positive electrode active material layer 102 on both surfaces of the positive electrode current collector 101 are shown. A negative electrode 115 a having a negative electrode active material layer 106 is laminated in this order on both surfaces of a positive electrode 111 a having a separator 103, a separator 103, and a negative electrode current collector 105.

Further, as shown in FIG. 20C, the plurality of first electrode assemblies 140 and the plurality of electrode assemblies 141 are covered with a rolled separator 103.

Here, part of a method for manufacturing the secondary battery 100q illustrated in FIG. 20 will be described with reference to FIGS.

First, the first electrode assembly 140 is placed over the separator 103 (FIG. 21A).

Next, the separator 103 is bent, and the separator 103 is overlaid on the first electrode assembly 140. Next, two sets of second electrode assemblies 141 are stacked above and below the first electrode assembly 140 with the separator 103 interposed therebetween (FIG. 21B).

Next, the separator 103 is wound so as to cover the two sets of second electrode assemblies 141. Further, two sets of first electrodes are arranged above and below the two sets of second electrode assemblies 141 via separators 103.
The electrode assemblies 140 are stacked (FIG. 21C).

Next, the separator 103 is wound so as to cover the two sets of first electrode assemblies 140 (FIG. 21D).

In order to stack the plurality of first electrode assemblies 140 and the plurality of electrode assemblies 141 in such a process, these electrode assemblies are disposed between the separators 103 wound in a spiral shape.

In addition, it is preferable that the positive electrode 111a of the electrode assembly 140 disposed on the outermost side is not provided with the positive electrode active material layer 102 on the outer side.

20B1 and 20B2 illustrate the structure in which the electrode assembly includes three electrodes and two separators, one embodiment of the present invention is not limited thereto. 4 or more electrodes, 3 separators
It is good also as a structure which has more than one sheet. By increasing the number of electrodes, the capacity of the secondary battery 100q can be further improved. Alternatively, the structure may include two electrodes and one separator. When there are few electrodes, it can be set as the secondary battery 100q which is easier to curve. In addition, FIG.
C), the secondary battery 100i includes three sets of the first electrode assemblies 140 and the second electrode assemblies 141.
However, one embodiment of the present invention is not limited to this. Furthermore, it is good also as a structure which has many electrode assemblies. By increasing the number of electrode assemblies, the capacity of the secondary battery 100q can be further improved. Moreover, it is good also as a structure which has fewer electrode assemblies. When there are few electrode assemblies, it can be set as the secondary battery 100q which is easy to curve.

The description about FIG. 18 can be referred to in addition to the arrangement of the positive electrode 111 and the negative electrode 115 and the arrangement of the separator 103 in the secondary battery 100q.

This embodiment can be implemented in appropriate combination with any of the other embodiments. Further, the modification example of the present embodiment can be implemented in combination with other modification examples as appropriate.

(Embodiment 5)
A battery control unit (BMU) that can be used in combination with the secondary battery described in the above embodiment and a transistor suitable for a circuit included in the battery control unit are described with reference to FIGS. To explain. In this embodiment, a battery control unit of a power storage device having battery cells connected in series will be described.

When charging / discharging is repeated for a plurality of battery cells connected in series, the capacity (output voltage) varies depending on variations in characteristics between the battery cells. In battery cells connected in series, the capacity at the time of overall discharge depends on the battery cells having a small capacity. If the capacity varies, the capacity at the time of discharge decreases. In addition, if charging is performed with reference to a battery cell having a small capacity, there is a risk of insufficient charging. Moreover, if charging is performed with reference to a battery cell having a large capacity, there is a risk of overcharging.

Therefore, the battery control unit of the power storage device having the battery cells connected in series has a function of aligning the variation in capacity between the battery cells that causes insufficient charging or overcharging. The circuit configuration for aligning the variation in capacity between battery cells includes a resistance method, a capacitor method, or an inductor method, but here is an example of a circuit configuration that can use a transistor with a small off-current to equalize the variation in capacity. Will be described.

As the transistor with low off-state current, a transistor including an oxide semiconductor (OS transistor) in a channel formation region is preferable. By using an OS transistor with a small off-state current in the circuit configuration of the battery control unit of the power storage device, the amount of charge leaking from the battery can be reduced, and a decrease in capacity over time can be suppressed.

An oxide semiconductor used for the channel formation region is an In-M-Zn oxide (M represents Ga, Sn,
Y, Zr, La, Ce, or Nd) is used. In the target used for forming the oxide semiconductor film, the atomic ratio of metal elements is In: M: Zn = x ₁ : y ₁ : z _1
, X ₁ / y ₁ is 1/3 or more and 6 or less, further 1 or more and 6 or less, and z ₁ / y ₁ is 1
/ 3 or more and 6 or less, more preferably 1 or more and 6 or less. Note that when z ₁ / y ₁ is greater than or equal to 1 and less than or equal to 6, a CAAC-OS film can be easily formed as the oxide semiconductor film.

Here, the CAAC-OS film is described.

The CAAC-OS film is one of oxide semiconductor films having a plurality of c-axis aligned crystal parts.

Transmission Electron Microscope (TEM: Transmission Electron Micro)
Scope), a composite analysis image of a bright field image and a diffraction pattern of the CAAC-OS film (
Also called a high-resolution TEM image. ) Can be observed to confirm a plurality of crystal parts.
On the other hand, a clear boundary between crystal parts, that is, a crystal grain boundary (also referred to as a grain boundary) cannot be confirmed even by a high-resolution TEM image. Therefore, it can be said that the CAAC-OS film is unlikely to decrease in electron mobility due to crystal grain boundaries.

When a high-resolution TEM image of the cross section of the CAAC-OS film is observed from a direction substantially parallel to the sample surface,
It can be confirmed that metal atoms are arranged in layers in the crystal part. Each layer of metal atoms
The shape reflects a surface (also referred to as a formation surface) on which the CAAC-OS film is formed or the unevenness of the upper surface, and is arranged in parallel with the formation surface or the upper surface of the CAAC-OS film.

On the other hand, when a high-resolution TEM image of a plane of the CAAC-OS film is observed from a direction substantially perpendicular to the sample surface, it can be confirmed that metal atoms are arranged in a triangular shape or a hexagonal shape in a crystal part. However, there is no regularity in the arrangement of metal atoms between different crystal parts.

When structural analysis is performed on a CAAC-OS film using an X-ray diffraction (XRD) apparatus, for example, in the analysis of a CAAC-OS film having an InGaZnO ₄ crystal by an out-of-plane method, A peak may appear when the diffraction angle (2θ) is around 31 °. Since this peak is attributed to the (009) plane of the InGaZnO ₄ crystal, the crystal of the CAAC-OS film has c-axis orientation, and the c-axis is oriented in a direction substantially perpendicular to the formation surface or the top surface. Can be confirmed.

Note that when the CAAC-OS film including an InGaZnO ₄ crystal is analyzed by an out-of-plane method, a peak may also appear when 2θ is around 36 ° in addition to the peak where 2θ is around 31 °. A peak at 2θ of around 36 ° indicates that a crystal having no c-axis alignment is included in part of the CAAC-OS film. The CAAC-OS film preferably has a peak at 2θ of around 31 ° and no peak at 2θ of around 36 °.

The CAAC-OS film is an oxide semiconductor film with a low impurity concentration. Impurities include hydrogen, carbon,
It is an element other than the main component of the oxide semiconductor film, such as silicon or a transition metal element. In particular, an element such as silicon, which has a stronger bonding force with oxygen than the metal element included in the oxide semiconductor film, disturbs the atomic arrangement of the oxide semiconductor film by depriving the oxide semiconductor film of oxygen, and has crystallinity. It becomes a factor to reduce. In addition, heavy metals such as iron and nickel, argon, carbon dioxide, and the like have large atomic radii (or molecular radii). Therefore, if they are contained inside an oxide semiconductor film, the atomic arrangement of the oxide semiconductor film is disturbed, resulting in crystallinity. It becomes a factor to reduce. Note that the impurity contained in the oxide semiconductor film might serve as a carrier trap or a carrier generation source.

The CAAC-OS film is an oxide semiconductor film with a low density of defect states. For example, oxygen vacancies in the oxide semiconductor film can serve as carrier traps or can generate carriers by capturing hydrogen.

A low impurity concentration and a low density of defect states (small number of oxygen vacancies) is called high purity intrinsic or substantially high purity intrinsic. A highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor film has few carrier generation sources, and thus can have a low carrier density. Therefore,
A transistor including the oxide semiconductor film includes an electric characteristic in which the threshold voltage is negative (
Also called normally-on. ). A highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor film has few carrier traps. Therefore, a transistor including the oxide semiconductor film has a small change in electrical characteristics and has high reliability. Note that the charge trapped in the carrier trap of the oxide semiconductor film takes a long time to be released, and may behave as if it were a fixed charge. Therefore, a transistor including an oxide semiconductor film with a high impurity concentration and a high density of defect states may have unstable electrical characteristics.

In addition, a transistor including a CAAC-OS film has little variation in electrical characteristics due to irradiation with visible light or ultraviolet light.

Note that an OS transistor has a larger band gap than a transistor having silicon in a channel formation region (Si transistor), and thus dielectric breakdown is less likely to occur when a high voltage is applied. When battery cells are connected in series, a voltage of several hundred volts is generated. The circuit configuration of the battery control unit of the power storage device applied to such a battery cell includes the OS described above.
A transistor is suitable.

FIG. 22 illustrates an example of a block diagram of a power storage device. The power storage device BT00 shown in FIG. 22 includes a terminal pair BT01, a terminal pair BT02, a switching control circuit BT03, and a switching circuit BT0.
4, a switching circuit BT05, a transformation control circuit BT06, a transformation circuit BT07, and a battery unit BT08 including a plurality of battery cells BT09 connected in series.

22 includes a terminal pair BT01, a terminal pair BT02, a switching control circuit BT03, a switching circuit BT04, a switching circuit BT05, a transformation control circuit BT06, and a transformation circuit BT07. The part can be called a battery control unit.

The switching control circuit BT03 controls operations of the switching circuit BT04 and the switching circuit BT05. Specifically, the switching control circuit BT03 determines the battery cell (discharge battery cell group) to be discharged and the battery cell (charge battery cell group) to be charged based on the voltage measured for each battery cell BT09.

Further, the switching control circuit BT03 outputs a control signal S1 and a control signal S2 based on the determined discharge battery cell group and charge battery cell group. The control signal S1 is output to the switching circuit BT04. This control signal S1 is a signal for controlling the switching circuit BT04 so as to connect the terminal pair BT01 and the discharge battery cell group. The control signal S2 is output to the switching circuit BT05. This control signal S2 is a signal for controlling the switching circuit BT05 so as to connect the terminal pair BT02 and the rechargeable battery cell group.

In addition, the switching control circuit BT03 is based on the configuration of the switching circuit BT04, the switching circuit BT05, and the transformer circuit BT07 so that terminals of the same polarity are connected between the terminal pair BT02 and the rechargeable battery cell group. A control signal S1 and a control signal S2 are generated.

Details of the operation of the switching control circuit BT03 will be described.

First, the switching control circuit BT03 measures the voltage for each of the plurality of battery cells BT09. Then, the switching control circuit BT03, for example, sets the battery cell BT09 having a voltage equal to or higher than a predetermined threshold to a high voltage battery cell (high voltage cell), and sets the battery cell BT09 having a voltage lower than the predetermined threshold to a low voltage battery cell (constant voltage). Voltage cell).

Various methods can be used for determining the high voltage cell and the low voltage cell. For example, the switching control circuit BT03 uses each battery cell BT0 based on the voltage of the battery cell BT09 having the highest voltage or the lowest voltage among the plurality of battery cells BT09.
It may be determined whether 9 is a high voltage cell or a low voltage cell. In this case, the switching control circuit BT03
Can determine whether each battery cell BT09 is a high voltage cell or a low voltage cell by determining whether or not the voltage of each battery cell BT09 is equal to or higher than a predetermined ratio with respect to a reference voltage. Then, the switching control circuit BT03 determines the discharge battery cell group and the charge battery cell group based on the determination result.

In the plurality of battery cells BT09, a high voltage cell and a low voltage cell can be mixed in various states. For example, the switching control circuit BT03 has a mixture of high voltage cells and low voltage cells.
The portion where the highest number of high voltage cells are connected in series is the discharge battery cell group. In addition, the switching control circuit BT03 sets a portion where the most low voltage cells are continuously connected in series as a rechargeable battery cell group. Further, the switching control circuit BT03 may preferentially select the battery cell BT09 close to overcharge or overdischarge as the discharge battery cell group or the charge battery cell group.

Here, an operation example of the switching control circuit BT03 in the present embodiment will be described with reference to FIG. FIG. 23 is a diagram for explaining an operation example of the switching control circuit BT03. In addition,
For convenience of explanation, FIG. 23 illustrates an example in which four battery cells BT09 are connected in series.

First, in the example of FIG. 23A, when the voltages of the battery cells a to d are the voltages Va to Vd, a case where Va = Vb = Vc> Vd is shown. That is, three continuous high voltage cells a to c and one low voltage cell d are connected in series. In this case, the switching control circuit BT03 determines three consecutive high voltage cells a to c as a discharge battery cell group. Further, the switching control circuit BT03 determines the low voltage cell D as a rechargeable battery cell group.

Next, the example of FIG. 23B shows a case where Vc >> Vb = Vc >> Vd. That is, two continuous low voltage cells a and b, one high voltage cell c, and one low voltage cell d near overdischarge are connected in series. In this case, the switching control circuit BT03
The high voltage cell c is determined as a discharge battery cell group. In addition, since the low voltage cell d is close to overdischarge, the switching control circuit BT03 preferentially determines the low voltage cell d as a charging battery cell group instead of the two consecutive low voltage cells a and b.

Finally, the example of FIG. 23C shows a case where Va> Vb = Vc = Vd. That is, one high voltage cell a and three consecutive low voltage cells b to d are connected in series. In this case, the switching control circuit BT03 determines the high voltage cell a as a discharge battery cell group. In addition, the switching control circuit BT03 determines three consecutive low voltage cells b to d as a rechargeable battery cell group.

The switching control circuit BT03 is a control signal in which information indicating the discharge battery cell group to which the switching circuit BT04 is connected is set based on the results determined as in the examples of FIGS. 23 (A) to (C). The control signal S2 in which information indicating S1 and the rechargeable battery cell group to which the switching circuit BT05 is connected is set is output to the switching circuit BT04 and the switching circuit BT05.

The above has described the details of the operation of the switching control circuit BT03.

The switching circuit BT04 sets the connection destination of the terminal pair BT01 to the discharge battery cell group determined by the switching control circuit BT03 according to the control signal S1 output from the switching control circuit BT03.

The terminal pair BT01 is composed of a pair of terminals A1 and A2. Switching circuit BT04
Is connected to one of the terminals A1 and A2 with the positive terminal of the battery cell BT09 located on the most upstream side (high potential side) in the discharge battery cell group, and the other in the discharge battery cell group. The connection destination of the terminal pair BT01 is set by connecting to the negative electrode terminal of the battery cell BT09 located on the most downstream side (low potential side). Note that the switching circuit BT04 can recognize the position of the discharge battery cell group using the information set in the control signal S1.

The switching circuit BT05 sets the connection destination of the terminal pair BT02 to the rechargeable battery cell group determined by the switching control circuit BT03 according to the control signal S2 output from the switching control circuit BT03.

The terminal pair BT02 is configured by a pair of terminals B1 and B2. Switching circuit BT05
Is connected to one of the terminals B1 and B2 with the positive terminal of the battery cell BT09 located at the most upstream (high potential side) in the rechargeable battery cell group, and the other is connected to the rechargeable battery cell group. The connection destination of the terminal pair BT02 is set by connecting to the negative electrode terminal of the battery cell BT09 located on the most downstream (low potential side). Note that the switching circuit BT05 can recognize the position of the rechargeable battery cell group using the information set in the control signal S2.

24 and 2 are circuit diagrams showing configuration examples of the switching circuit BT04 and the switching circuit BT05.
As shown in FIG.

In FIG. 24, the switching circuit BT04 includes a plurality of transistors BT10 and buses BT11 and BT12. The bus BT11 is connected to the terminal A1. Bus BT1
2 is connected to the terminal A2. One of the sources or drains of the plurality of transistors BT10 is connected to the buses BT11 and BT12 alternately every other one. The other of the sources or drains of the plurality of transistors BT10 is connected between two adjacent battery cells BT09.

Note that, among the plurality of transistors BT10, the other of the source and the drain of the transistor BT10 located at the uppermost stream is connected to the positive terminal of the battery cell BT09 located at the uppermost stream of the battery unit BT08. In addition, among the plurality of transistors BT10, the other of the source and the drain of the transistor BT10 located on the most downstream side is connected to the negative electrode terminal of the battery cell BT09 located on the most downstream side of the battery unit BT08.

The switching circuit BT04 is connected to one of the plurality of transistors BT10 connected to the bus BT11 and the bus B in response to a control signal S1 applied to the gates of the plurality of transistors BT10.
The discharge battery cell group and the terminal pair BT01 are connected by bringing one of the plurality of transistors BT10 connected to T12 into a conductive state. Thereby, the positive electrode terminal of battery cell BT09 located most upstream in the discharge battery cell group is the terminal A1 or A of the terminal pair.
2 is connected. Moreover, the negative electrode terminal of battery cell BT09 located in the most downstream in the discharge battery cell group is connected to either the terminal A1 or A2 of the terminal pair, that is, the terminal not connected to the positive electrode terminal.

An OS transistor is preferably used as the transistor BT10. Since the OS transistor has a small off-state current, it is possible to reduce the amount of charge leaked from a battery cell that does not belong to the discharge battery cell group, and to suppress a decrease in capacity over time. In addition, the OS transistor is unlikely to break down when a high voltage is applied. Therefore, even if the output voltage of the discharge battery cell group is large, the battery cell BT09 connected to the transistor BT10 to be turned off and the terminal pair BT01 can be insulated.

In FIG. 24, the switching circuit BT05 includes a plurality of transistors BT13, a current control switch BT14, a bus BT15, and a bus BT16. Bus BT15 and BT
16 is arranged between the plurality of transistors BT13 and the current control switch BT14. One of the sources or drains of the plurality of transistors BT13 is alternately connected to the buses BT15 and BT16 alternately. The other of the sources or drains of the plurality of transistors BT13 is connected between two adjacent battery cells BT09.

Note that, among the plurality of transistors BT13, the other of the source and the drain of the transistor BT13 located at the uppermost stream is connected to the positive terminal of the battery cell BT09 located at the uppermost stream of the battery unit BT08. In addition, among the plurality of transistors BT13, the other of the source and the drain of the transistor BT13 located on the most downstream side is connected to the negative terminal of the battery cell BT09 located on the most downstream side of the battery unit BT08.

As the transistor BT13, an OS transistor is preferably used similarly to the transistor BT10. Since the OS transistor has a small off-state current, it is possible to reduce the amount of charge leaked from a battery cell that does not belong to the rechargeable battery cell group, and to suppress a decrease in capacity over time. In addition, the OS transistor is unlikely to break down when a high voltage is applied. for that reason,
Transistor BT which is in a non-conductive state even when the voltage for charging the rechargeable battery cell group is large
The battery cell BT09 to which the terminal 13 is connected and the terminal pair BT02 can be insulated.

The current control switch BT14 has a switch pair BT17 and a switch pair BT18. One end of the switch pair BT17 is connected to the terminal B1. The other end of the switch pair BT17 is branched by two switches. One switch is connected to the bus BT15 and the other switch is connected to the bus BT16. One end of the switch pair BT18 is connected to the terminal B2. The other end of the switch pair BT18 is branched by two switches. One switch is connected to the bus BT15 and the other switch is connected to the bus BT16.

The switches of the switch pair BT17 and the switch pair BT18 are transistors BT10.
Similarly to the transistor BT13, an OS transistor is preferably used.

The switching circuit BT05 connects the charging battery cell group and the terminal pair BT02 by controlling the combination of the on / off state of the transistor BT13 and the current control switch BT14 according to the control signal S2.

For example, the switching circuit BT05 includes the rechargeable battery cell group and the terminal pair BT0 as follows.
2 is connected.

The switching circuit BT05 brings the transistor BT13 connected to the positive terminal of the battery cell BT09 located most upstream in the charging battery cell group into a conductive state in response to the control signal S2 applied to the gates of the plurality of transistors BT10. . The changeover circuit BT05 is connected to the negative terminal of the battery cell BT09 located most downstream in the charging battery cell group according to the control signal S2 given to the gates of the plurality of transistors BT10.
1 is turned on.

The polarity of the voltage applied to the terminal pair BT02 can vary depending on the configuration of the discharge battery cell group connected to the terminal pair BT01 and the transformer circuit BT07. Moreover, in order to flow an electric current in the direction which charges a rechargeable battery cell group, it is necessary to connect terminals of the same polarity between the terminal pair BT02 and the rechargeable battery cell group. Therefore, the current control switch 152 switches the switch pair BT17 and the switch pair BT1 according to the polarity of the voltage applied to the terminal pair BT02 by the control signal S2.
It is controlled to switch each of the eight connection destinations.

As an example, a description will be given of a state where a voltage is applied to the terminal pair BT02 so that the terminal B1 is a positive electrode and the terminal B2 is a negative electrode. At this time, the battery cell BT09 on the most downstream side of the battery unit BT08
Is a charging battery cell group, the switch pair BT17 is controlled to be connected to the positive terminal of the battery cell BT09 by the control signal S2. That is, the switch connected to the bus BT16 of the switch pair BT17 is turned on, and the bus BT1 of the switch pair BT17 is turned on.
The switch connected to 5 is turned off. On the other hand, the switch pair BT18 controls the control signal S2.
Is controlled so as to be connected to the negative terminal of the battery cell BT09. That is, the switch connected to the bus BT15 of the switch pair BT18 is turned on, and the switch pair B
The switch connected to the bus BT16 of T18 is turned off. In this way, terminals having the same polarity are connected between the terminal pair BT02 and the rechargeable battery cell group. And the direction of the electric current which flows from terminal pair BT02 is controlled so that it may become a direction which charges a charging battery cell group.

The current control switch 152 is not the switching circuit BT05 but the switching circuit BT0.
4 may be included. In this case, the polarity of the voltage applied to the terminal pair BT02 is controlled by controlling the polarity of the voltage applied to the terminal pair BT01 in accordance with the current control switch BT14 and the control signal S1. The current control switch BT14 controls the direction of current flowing from the terminal pair BT02 to the rechargeable battery cell group.

FIG. 25 is a circuit diagram showing a configuration example of the switching circuit BT04 and the switching circuit BT05, which is different from FIG.

In FIG. 25, the switching circuit BT04 includes a plurality of transistor pairs BT21 and a bus BT24.
And a bus BT25. The bus BT24 is connected to the terminal A1. The bus BT25 is connected to the terminal A2. One ends of the plurality of transistor pairs BT21 are branched by a transistor BT22 and a transistor BT23, respectively. One of the source and the drain of the transistor BT22 is connected to the bus BT24. One of the source and the drain of the transistor BT23 is connected to the bus BT25. Also,
The other ends of the plurality of transistor pairs are connected between two adjacent battery cells BT09. Of the plurality of transistor pairs BT21, the other end of the transistor pair BT21 located at the most upstream is connected to the positive terminal of the battery cell BT09 located at the most upstream of the battery unit BT08. Moreover, the other end of the transistor pair BT21 located on the most downstream side of the plurality of transistor pairs BT21 is connected to the negative electrode terminal of the battery cell BT09 located on the most downstream side of the battery unit BT08.

The switching circuit BT04 switches the connection destination of the transistor pair BT21 to either the terminal A1 or the terminal A2 by switching the conduction / non-conduction state of the transistor BT22 and the transistor BT23 according to the control signal S1. Specifically, transistor B
If T22 is conductive, the transistor BT23 is nonconductive and the connection destination is the terminal A1. On the other hand, if the transistor BT23 is conductive, the transistor BT22
Becomes non-conductive, and the connection destination is the terminal A2. Which of the transistors BT22 and BT23 is turned on is determined by the control signal S1.

Two transistor pairs BT21 are used to connect the terminal pair BT01 and the discharge battery cell group. Specifically, the connection destination of the two transistor pairs BT21 is determined based on the control signal S1, whereby the discharge battery cell group and the terminal pair BT01 are connected. 2
The connection destinations of the two transistor pairs BT21 are controlled by the control signal S1 so that one is the terminal A1 and the other is the terminal A2.

The switching circuit BT05 includes a plurality of transistor pairs BT31, a bus BT34, and a bus BT.
35. The bus BT34 is connected to the terminal B1. In addition, bus BT35
It is connected to the terminal B2. One ends of the plurality of transistor pairs BT31 are branched by a transistor BT32 and a transistor BT33, respectively. One end branched by the transistor BT32 is connected to the bus BT34. One end branched by the transistor BT33 is connected to the bus BT35. Also, a plurality of transistor pairs BT31
The other end of each is connected between two adjacent battery cells BT09. Note that, among the plurality of changeover switch pairs 154, the other end of the changeover switch pair 154 located on the uppermost stream is connected to the positive terminal of the battery cell BT09 located on the uppermost stream of the battery unit BT08.
In addition, among the plurality of transistor pairs BT31, the transistor pair BT31 located on the most downstream side
Is connected to the negative terminal of the battery cell BT09 located on the most downstream side of the battery unit BT08.

The switching circuit BT05 switches the connection destination of the transistor pair BT31 to either the terminal B1 or the terminal B2 by switching the conduction / non-conduction state of the transistor BT32 and the transistor BT33 according to the control signal S2. Specifically, transistor B
If T32 is conductive, the transistor BT33 is nonconductive and the connection destination is the terminal B1. On the other hand, if the transistor BT33 is conductive, the transistor BT32
Becomes non-conductive, and the connection destination is the terminal B2. Which of the transistor BT32 and the transistor BT33 becomes conductive is determined by the control signal S2.

Two transistor pairs BT31 are used to connect the terminal pair BT02 and the rechargeable battery cell group. Specifically, the connection destination of the two transistor pairs BT31 is determined based on the control signal S2, whereby the rechargeable battery cell group and the terminal pair BT02 are connected. 2
The connection destinations of the two transistor pairs BT31 are controlled by the control signal S2 so that one is the terminal B1 and the other is the terminal B2.

The connection destination of each of the two transistor pairs BT31 is determined by the polarity of the voltage applied to the terminal pair BT02. Specifically, when a voltage is applied to the terminal pair BT02 such that the terminal B1 is a positive electrode and the terminal B2 is a negative electrode, the upstream transistor pair BT31 is in a conductive state and the transistor BT33 is in a nonconductive state. It is controlled by the control signal S2 so as to be in a state. On the other hand, the downstream transistor pair BT31 is controlled by the control signal S2 so that the transistor BT33 is conductive and the transistor BT32 is nonconductive. Further, when a voltage is applied to the terminal pair BT02 so that the terminal B1 is a negative electrode and the terminal B2 is a positive electrode, the upstream transistor pair BT31 has the transistor BT33 in a conductive state and the transistor BT32 in a nonconductive state. It is controlled by the control signal S2. On the other hand, the transistor pair BT31 on the downstream side controls the control signal S2 so that the transistor BT32 is conductive and the transistor BT33 is nonconductive.
Controlled by. In this way, terminals having the same polarity are connected between the terminal pair BT02 and the rechargeable battery cell group. And the direction of the electric current which flows from terminal pair BT02 is controlled so that it may become a direction which charges a charging battery cell group.

The transformation control circuit BT06 controls the operation of the transformation circuit BT07. The transformation control circuit BT06 generates a transformation signal S3 for controlling the operation of the transformation circuit BT07 based on the number of battery cells BT09 included in the discharge battery cell group and the number of battery cells BT09 included in the charge battery cell group. And output to the transformer circuit BT07.

When the number of battery cells BT09 included in the discharge battery cell group is greater than the number of battery cells BT09 included in the charge battery cell group, an excessively large charge voltage is applied to the charge battery cell group. Need to prevent. Therefore, the transformation control circuit BT06 outputs a transformation signal S3 that controls the transformation circuit BT07 so as to step down the discharge voltage (Vdis) within a range in which the rechargeable battery cell group can be charged.

Further, when the number of battery cells BT09 included in the discharge battery cell group is equal to or less than the number of battery cells BT09 included in the charge battery cell group, a charging voltage necessary for charging the charge battery cell group is ensured. There is a need. For this reason, the transformation control circuit BT06 boosts the discharge voltage (Vdis) within a range in which an excessive charging voltage is not applied to the rechargeable battery cell group.
A transformation signal S3 for controlling 07 is output.

In addition, the voltage value used as the excessive charging voltage can be determined in view of the product specifications of the battery cell BT09 used in the battery unit BT08. The voltage stepped up and stepped down by the transformer circuit BT07 is applied to the terminal pair BT02 as a charging voltage (Vcha).

Here, an operation example of the transformation control circuit BT06 in the present embodiment is shown in FIGS. 26 (A) to (C).
Will be described. FIGS. 26A to 26C are conceptual diagrams for explaining an operation example of the transformation control circuit BT06 corresponding to the discharge battery cell group and the charge battery cell group described in FIGS. 23A to 23C. FIG. 26A to 26C illustrate the battery control unit BT41. As described above, the battery control unit BT41 includes the terminal pair BT01 and the terminal pair B.
T02, switching control circuit BT03, switching circuit BT04, switching circuit BT0
5, a transformation control circuit BT06, and a transformation circuit BT07.

In the example shown in FIG. 26A, as described in FIG. 23A, three continuous high voltage cells a to c and one low voltage cell d are connected in series. In this case, FIG.
), The switching control circuit BT03 determines the high voltage cells a to c as the discharge battery cell group and the low voltage cell d as the charge battery cell group. Then, the transformation control circuit BT06 uses the discharge voltage (Vdi) based on the ratio of the number of battery cells BT09 included in the charge electric cell group with respect to the number of battery cells BT09 included in the discharge battery cell group.
The step-up / step-down ratio N of s is calculated.

When the number of battery cells BT09 included in the discharge battery cell group is greater than the number of battery cells BT09 included in the charge battery cell group, the discharge battery is applied as it is to the terminal pair BT02 without being transformed. An excessive voltage may be applied to the battery cell BT09 included in the cell group via the terminal pair BT02. Therefore, in the case as shown in FIG. 26A, it is necessary to lower the charging voltage (Vcha) applied to the terminal pair BT02 below the discharging voltage. Furthermore, in order to charge the charging battery cell group, the charging voltage needs to be larger than the total voltage of the battery cells BT09 included in the charging battery cell group. Therefore, transformer control circuit B
T06 sets the step-up / step-down ratio N to be larger than the ratio of the number of battery cells BT09 included in the charging electric cell group when the number of battery cells BT09 included in the discharge battery cell group is used as a reference.

The transformation control circuit BT06 sets the step-up / step-down ratio N to 1 to the ratio of the number of battery cells BT09 included in the charging electric cell group when the number of battery cells BT09 included in the discharge battery cell group is used as a reference. It is preferable to increase it by about 10%. At this time, the charging voltage is larger than the voltage of the charging battery cell group, but the charging voltage is actually equal to the voltage of the charging battery cell group. However, in order to make the voltage of the charging battery cell group equal to the charging voltage in accordance with the step-up / down ratio N, the transformation control circuit BT06 passes a current for charging the charging battery cell group. This current is applied to the transformation control circuit BT0.
The value set to 6.

In the example shown in FIG. 26A, the number of battery cells BT09 included in the discharge battery cell group is three.
Since the number of battery cells BT09 included in the charged battery cell group is one, the transformation control circuit BT06 calculates a value slightly larger than 1/3 as the step-up / step-down ratio N. Then, the transformation control circuit BT06 steps down the discharge voltage according to the step-up / step-down ratio N, and outputs a transformation signal S3 that converts it to a charging voltage to the transformation circuit BT07. Then, the transformer circuit BT07 applies the charging voltage transformed according to the transformation signal S3 to the terminal pair BT02. Then, the battery cell BT09 included in the charging battery cell group is charged by the charging voltage applied to the terminal pair BT02.

Also, in the example shown in FIG. 26B and FIG. 26B, the step-up / step-down ratio N is calculated as in FIG. In the examples shown in FIGS. 26B and 26C, the number of battery cells BT09 included in the discharge battery cell group is equal to or less than the number of battery cells BT09 included in the charge battery cell group. N is 1 or more. Therefore, in this case, the transformation control circuit BT06 outputs a transformation signal S3 that boosts the discharge voltage and converts it to a received voltage.

Transformer circuit BT07 converts the discharge voltage applied to terminal pair BT01 into a charge voltage based on transform signal S3. Then, the transformer circuit BT07 sends the converted charging voltage to the terminal pair BT0.
2 is applied. Here, the transformer circuit BT07 electrically insulates between the terminal pair BT01 and the terminal pair BT02. Thereby, the transformer circuit BT07 has the absolute voltage of the negative terminal of the battery cell BT09 located most downstream in the discharge battery cell group and the negative terminal of the battery cell BT09 located most downstream in the charge battery cell group. Prevents short circuit due to difference from absolute voltage. Furthermore, as described above, the transformer circuit BT07 converts the discharge voltage, which is the total voltage of the discharge battery cell group, into a charge voltage based on the transform signal S3.

Further, the transformer circuit BT07 is, for example, an insulation type DC (Direct Current) -DC.
A converter or the like can be used. In this case, the transformation control circuit BT06 is an insulation type DC-
By outputting a signal for controlling the on / off ratio (duty ratio) of the DC converter as the transformation signal S3, the charging voltage converted by the transformation circuit BT07 is controlled.

Insulated DC-DC converters include flyback, forward, RCC (
Although there are a Ringing Choke Converter) method, a push-pull method, a half-bridge method, a full-bridge method, and the like, an appropriate method is selected according to the target output voltage.

FIG. 27 shows the configuration of a transformer circuit BT07 using an insulated DC-DC converter. Insulation type D
The C-DC converter BT51 includes a switch unit BT52 and a transformer unit BT53.
The switch unit BT52 is a switch for switching on / off the operation of the isolated DC-DC converter. For example, a MOSFET (Metal-Oxide-Semiconductor)
Tor field-effect transistor), a bipolar transistor, or the like. Further, the switch unit BT52 periodically switches between the on state and the off state of the isolated DC-DC converter BT51 based on the transform signal S3 that is output from the transform control circuit BT06 and controls the on / off ratio. Note that the switch unit BT52 can take various configurations depending on the method of the insulation type DC-DC converter used. The transformer unit BT53 converts the discharge voltage applied from the terminal pair BT01 into a charge voltage. In detail,
The transformer unit BT53 operates in conjunction with the on / off state of the switch unit BT52, and converts the discharge voltage into a charge voltage according to the on / off ratio. This charging voltage is applied to the switch unit BT5.
In the two switching cycles, the longer the on-time is, the larger the time is. On the other hand, the charging voltage becomes smaller as the time in which the switch is turned on is shorter in the switching cycle of the switch unit BT52. In the case of using an insulated DC-DC converter, the terminal pair BT01 and the terminal pair BT02 can be insulated from each other inside the transformer unit BT53.

A processing flow of the power storage device BT00 in the present embodiment will be described with reference to FIG. FIG.
These are flowcharts which show the flow of a process of electrical storage apparatus BT00.

First, the power storage device BT00 acquires a voltage measured for each of the plurality of battery cells BT09 (step S001). Then, the power storage device BT00 determines whether or not a start condition for the operation of aligning the voltages of the plurality of battery cells BT09 is satisfied (step S002). The start condition can be, for example, whether or not the difference between the maximum value and the minimum value of the voltage measured for each of the plurality of battery cells BT09 is equal to or greater than a predetermined threshold. If this start condition is not satisfied (step S0
02: NO), because the voltage of each battery cell BT09 is in a balanced state, the power storage device BT00 does not perform the subsequent processing. On the other hand, if the start condition is satisfied (step S
002: YES), the power storage device BT00 executes a process of aligning the voltages of the battery cells BT09. In this process, the power storage device BT00 determines whether each battery cell BT09 is a high voltage cell or a low voltage cell based on the measured voltage for each cell (step S003). Then, the power storage device BT00 determines a discharge battery cell group and a charge battery cell group based on the determination result (step S004). Further, power storage device BT00 has a control signal S1 for setting the determined discharge battery cell group as a connection destination of terminal pair BT01, and a control signal S2 for setting the determined charge battery cell group as a connection destination of terminal pair BT02. Generate (step S005). The power storage device BT00 outputs the generated control signal S1 and control signal S2 to the switching circuit BT04 and the switching circuit BT05, respectively. The terminal pair BT01 and the discharge battery cell group are connected by the switching circuit BT04, and the terminal pair BT02 is connected by the switching circuit BT05.
Are connected to the discharge battery cell group (step S006). The power storage device BT00 generates the transformation signal S3 based on the number of battery cells BT09 included in the discharge battery cell group and the number of battery cells BT09 included in the charge battery cell group (step S007). And
Based on the transformation signal S3, the power storage device BT00 converts the discharge voltage applied to the terminal pair BT01 into a charging voltage and applies it to the terminal pair BT02 (step S008). Thereby, the electric charge of the discharge battery cell group is moved to the charge battery cell group.

Also, in the flowchart of FIG. 28, a plurality of steps are described in order, but the execution order of each step is not limited to the description order.

As described above, according to the present embodiment, when the charge is transferred from the discharge battery cell group to the charge battery cell group,
Unlike the capacitor method, there is no need for a configuration in which charges from the discharge battery cell group are temporarily accumulated and then discharged to the charge battery cell group. Thereby, the charge transfer efficiency per unit time can be improved. In addition, the discharge battery cell group and the charge battery cell group are individually switched by the switching circuit BT04 and the switching circuit BT05.

Further, the transformer circuit BT07 converts the discharge voltage applied to the terminal pair BT01 based on the number of battery cells BT09 included in the discharge battery cell group and the number of battery cells BT09 group included in the charge battery cell group. And applied to the terminal pair BT02. Thereby, no matter how the discharge-side and charge-side battery cells BT09 are selected, the movement of charges can be realized without any problem.

Furthermore, by using OS transistors for the transistors BT10 and BT13, the amount of charge leaked from the battery cell BT09 that does not belong to the charge battery cell group and the discharge battery cell group can be reduced. Thereby, battery cell BT09 which does not contribute to charge and discharge
The decrease in capacity can be suppressed. In addition, the OS transistor has less variation in characteristics with respect to heat than the Si transistor. Thereby, even if the temperature of battery cell BT09 rises, normal operation | movement, such as switching of the conduction | electrical_connection state and non-conduction state according to control signal S1, S2, can be performed.

(Embodiment 6)
In this embodiment, an example in which the secondary battery described in Embodiment 1 is mounted on an electronic device will be described.

An example in which a flexible secondary battery is mounted on an armband type electronic device is shown in FIG. An armband device 7300 illustrated in FIG. 29 can be attached to the arm 7301 and includes a display portion having a curved surface and a secondary battery that can be bent.

Note that in the display portion, a display element, a display device that includes a display element, a light-emitting element, and a light-emitting device that includes a light-emitting element can have various modes or have various elements. . A display element, a display device, a light emitting element, or a light emitting device includes, for example, an EL (electroluminescence) element (an EL element including an organic substance and an inorganic substance, an organic EL element, an inorganic EL element), an LED (white LED, red LED, green LED, Blue LEDs, etc.), transistors (transistors that emit light according to current), electron-emitting devices, liquid crystal devices, electronic ink,
Electrophoretic element, grating light valve (GLV), plasma display (PDP)
), Display element using MEMS (micro electro mechanical system), digital micromirror device (DMD), DMS (digital micro shutter),
MIRASOL (registered trademark), IMOD (interference modulation) element, shutter type MEMS display element, optical interference type MEMS display element, electrowetting element, piezoelectric ceramic display, or display element using carbon nanotubes, And at least one of them. In addition to these, a display element, a display device, a light-emitting element, or a light-emitting device may include a display medium in which contrast, luminance, reflectance, transmittance, and the like change due to electric or magnetic action. An example of a display device using an EL element is an EL display. As an example of a display device using an electron-emitting device, a field emission display (FED) or an SED type flat display (SED: Surface-conduction Electron-emitter)
Display). As an example of a display device using a liquid crystal element, there is a liquid crystal display (a transmissive liquid crystal display, a transflective liquid crystal display, a reflective liquid crystal display, a direct view liquid crystal display, a projection liquid crystal display) and the like. An example of a display device using electronic ink, electronic powder fluid (registered trademark), or an electrophoretic element is electronic paper. Note that in the case of realizing a transflective liquid crystal display or a reflective liquid crystal display, part or all of the pixel electrode may have a function as a reflective electrode. For example, part or all of the pixel electrode may have aluminum, silver, or the like. Further, in that case, a memory circuit such as an SRAM can be provided under the reflective electrode. Thereby, power consumption can be further reduced. In addition, when using LED, you may arrange | position graphene or graphite under the electrode and nitride semiconductor of LED. Graphene or graphite may be a multilayer film in which a plurality of layers are stacked. Thus, by providing graphene or graphite, a nitride semiconductor, for example,
An n-type GaN semiconductor layer having a crystal or the like can be easily formed. Furthermore, a p-type GaN semiconductor layer having a crystal or the like can be provided thereon to form an LED. Note that an AlN layer may be provided between graphene or graphite and an n-type GaN semiconductor layer having a crystal. Note that the GaN semiconductor layer of the LED may be formed by MOCVD.
However, by providing graphene, the GaN semiconductor layer of the LED can be formed by a sputtering method.

Furthermore, the armband device 7300 preferably has one or more functional elements. For example, as a sensor, force, displacement, position, velocity, acceleration, angular velocity, number of rotations, distance, light, liquid, magnetism, temperature, chemical substance Those having a function of measuring sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared can be used. Moreover, you may have functional elements, such as a touch panel, an antenna, an electric power generation element, and a speaker.

For example, if the armband type device 7300 is worn on the user's arm at night and the display unit emits light, a traffic safety effect can be obtained. In addition, soldiers and security guards have armband type devices on the upper arm.
While wearing 300, it is possible to confirm the display displayed on the display section of the new device of the upper arm by receiving the instructions of the superior in real time while making a forward movement. Military personnel and security guards carry helmets on their heads and have weapons and tools in their hands, making them difficult to use with radios, mobile phones, and devices worn on the head. It is useful for military personnel and guards to wear a new device on the upper arm and to operate the armband type device 7300 by voice input to a voice input unit such as a microphone even when both hands are blocked.

Also, the armband device 7300 can be usefully used in the sports field. For example, in the case of a marathon or the like, the athlete checks the time with a wristwatch, but it is difficult to check the time unless the arm swings once. If you stop swinging your arms, the rhythm will be disturbed, which may interfere with the competition. The armband device 7300 can be attached to the upper arm to display the time without stopping the swinging of the arm, and also displays other information (such as the course's own position information and own health status) on the display. Can be made. In addition, the player can operate the new device by voice input without using both hands, ask the coach by the communication function, and the player can confirm the instruction by voice output and display by the voice output unit such as a speaker It is useful to have also.

Further, even in a construction site or the like, an operator wearing a helmet can easily acquire communication and other person's position information so that the armband type device 7300 can be worn on the arm and operated. it can.

FIG. 30 shows an example in which a flexible secondary battery is mounted on another electronic device. As an electronic device to which a secondary battery having a flexible shape is applied, for example, a television device (also referred to as a television or a television receiver), a monitor for a computer, a digital camera,
Examples thereof include a large-sized game machine such as a digital video camera, a digital photo frame, a mobile phone (also referred to as a mobile phone or a mobile phone device), a portable game machine, a portable information terminal, a sound reproducing device, and a pachinko machine.

In addition, a secondary battery having a flexible shape can be incorporated along an inner wall or an outer wall of a house or a building, or along a curved surface of an automobile interior or exterior.

FIG. 30A illustrates an example of a mobile phone. A mobile phone 7400 includes a housing 7401.
In addition to the display portion 7402 incorporated in the mobile phone, an operation button 7403, an external connection port 7404, a speaker 7405, a microphone 7406, and the like are provided. Note that the mobile phone 7400 includes a secondary battery 7407.

FIG. 30B illustrates a state where the mobile phone 7400 is bent. Mobile phone 740
When 0 is deformed by an external force to bend the whole, the secondary battery 7407 provided in the inside is also bent. At that time, the state of the bent secondary battery 7407 is shown in FIG.
). The secondary battery 7407 is a thin secondary battery. The secondary battery 7407 is fixed in a bent state. Note that the secondary battery 7407 includes a lead electrode 7408 electrically connected to the current collector 7409. For example, the current collector 7409 is a copper foil, and part of the current collector 7409 is alloyed with gallium to improve adhesion with the active material layer in contact with the current collector 7409. Thereby, the secondary battery 7407 is highly reliable in a bent state.

FIG. 30D illustrates an example of a bangle display device. The portable display device 7100
A housing 7101, a display portion 7102, operation buttons 7103, and a secondary battery 7104 are provided.
FIG. 30E shows the state of the secondary battery 7104 bent. When the secondary battery 7104 is bent and attached to the user's arm, the casing is deformed and the curvature of a part or all of the secondary battery 7104 changes. Note that the curvature at a given point of the curve expressed by the value of the radius of the corresponding circle is the curvature radius, and the reciprocal of the curvature radius is called the curvature. Specifically, a part or all of the main surface of the housing or the secondary battery 7104 changes within a radius of curvature of 40 mm or more and 150 mm or less. The curvature radius on the main surface of the secondary battery 7104 is 40 mm or more and 150.
If it is the range below mm, high reliability can be maintained.

In addition, the bendable secondary battery can be mounted efficiently in various electronic devices. For example, a stove 7500 illustrated in FIG.
The module 7511 includes a secondary battery 7501, a motor, a fan, a blower opening 7511a, and a thermoelectric generator. In the stove 7510, fuel is supplied from the opening 7512a and ignited, and then the motor and fan of the module 7511 are rotated using the power of the secondary battery 7501 so that the outside air can be sent from the blower opening 7511a to the inside of the stove 7510. . Thus, in order to take in outside air efficiently, it can be set as the stove with a strong thermal power. Furthermore, cooking can be performed in the upper grill 7513 using the thermal energy obtained for the combustion of the fuel. Further, the thermal energy can be converted into electric power by the thermoelectric generator of the module 7511 and the secondary battery 7501 can be charged. Further, the secondary battery 750
1 can be output from the external terminal 7511b.

This embodiment can be implemented in appropriate combination with any of the other embodiments.

(Embodiment 7)
In this embodiment, another example of an electronic device in which the secondary battery described in Embodiment 1 can be mounted is described.

FIG. 31A and FIG. 31B illustrate an example of a tablet terminal that can be folded. A tablet terminal 9600 illustrated in FIGS. 31A and 31B includes a housing 9630a, a housing 9630b, a movable portion 9640 that connects the housing 9630a and the housing 9630b, and a display portion 96.
31a and a display portion 9631 having a display portion 9631b, a display mode switch 962
6, power switch 9627, power saving mode switch 9625, fastener 9629,
An operation switch 9628. FIG. 31A shows a state where the tablet terminal 9600 is opened, and FIG. 31B shows a state where the tablet terminal 9600 is closed.

In addition, the tablet terminal 9600 includes a secondary battery 9635 inside the housing 9630a and the housing 9630b. The secondary battery 9635 is provided across the housing 9630 a and the housing 9630 b through the movable portion 9640.

Part of the display portion 9631 a can be a touch panel region 9632 a and data can be input when a displayed operation key 9638 is touched. The display portion 963
In 1a, as an example, a configuration in which half of the area has a display-only function and a configuration in which the other half has a touch panel function is shown, but the configuration is not limited thereto. Display unit 963
All the regions 1a may have a touch panel function. For example, the display unit 96
The entire surface of 31a can be displayed as a keyboard button and used as a touch panel, and the display portion 9631b can be used as a display screen.

Further, in the display portion 9631b, as in the display portion 9631a, part of the display portion 9631b can be a touch panel region 9632b. Further, a keyboard button can be displayed on the display portion 9631b by touching a position where the keyboard display switching button 9539 on the touch panel is displayed with a finger or a stylus.

Touch input can be performed simultaneously on the touch panel region 9632a and the touch panel region 9632b.

A display mode switching switch 9626 can switch a display direction such as a vertical display or a horizontal display, and can select a monochrome display or a color display. The power saving mode change-over switch 9625 can optimize the display luminance in accordance with the amount of external light in use detected by an optical sensor incorporated in the tablet terminal 9600. The tablet terminal may include not only an optical sensor but also other detection devices such as a gyroscope, an acceleration sensor, and other sensors that detect inclination.

FIG. 31A illustrates an example in which the display areas of the display portion 9631b and the display portion 9631a are the same, but there is no particular limitation, and one size may differ from the other size, and the display quality may also be different. May be different. For example, one display panel may be capable of displaying images with higher definition than the other.

FIG. 31B illustrates a closed state, in which a tablet terminal includes a housing 9630, a solar cell 96, and the like.
33, a charge / discharge control circuit 9634 including a DCDC converter 9636 is provided. Further, as the secondary battery 9635, the secondary battery of one embodiment of the present invention is used.

Note that since the tablet terminal 9600 can be folded in two, the housing 9630a and the housing 9630b can be folded so as to overlap when not in use. By folding
Since the display portion 9631a and the display portion 9631b can be protected, durability of the tablet terminal 9600 can be improved. Further, a secondary battery 9635 using the secondary battery of one embodiment of the present invention.
Has flexibility and its charge / discharge capacity is unlikely to decrease even when bending and stretching are repeated. Therefore, a tablet terminal with excellent reliability can be provided.

In addition, the tablet terminal shown in FIGS. 31A and 31B has a function for displaying various information (still images, moving images, text images, etc.), a calendar, a date, or a time. A function for displaying on the display unit, a touch input function for performing touch input operation or editing of information displayed on the display unit, a function for controlling processing by various software (programs), and the like can be provided.

The solar cell 9633 mounted on the surface of the tablet terminal allows power to be supplied to the touch panel,
It can be supplied to a display unit, a video signal processing unit, or the like. Note that the solar battery 9633 can be provided on one or two surfaces of the housing 9630, and the secondary battery 9635 can be charged efficiently. Note that as the secondary battery 9635, when the secondary battery of one embodiment of the present invention is used, a reduction in discharge capacity due to repetition of charge and discharge can be suppressed; thus, a tablet terminal that can be used for a long time is used. be able to.

Further, the structure and operation of the charge / discharge control circuit 9634 illustrated in FIG.
C) will be described with reference to a block diagram. FIG. 31C illustrates a solar battery 9633 and a secondary battery 96.
35, DCDC converter 9636, converter 9637, switches SW1 to SW3,
The display portion 9631 shows a secondary battery 9635, a DCDC converter 9636,
The converter 9637 and the switches SW1 to SW3 are portions corresponding to the charge / discharge control circuit 9634 illustrated in FIG.

First, an example of operation in the case where power is generated by the solar battery 9633 using external light is described.
The DCDC is used so that the power generated by the solar battery becomes a voltage for charging the secondary battery 9635.
The converter 9636 performs step-up or step-down. When power from the solar battery 9633 is used for the operation of the display portion 9631, the switch SW1 is turned on and the converter 963 is turned on.
7, the voltage required for the display portion 9631 is increased or decreased. In addition, the display portion 963
When the display at 1 is not performed, SW1 is turned off, SW2 is turned on, and the secondary battery 9635 is turned on.
The configuration may be such that charging is performed.

Note that the solar battery 9633 is described as an example of the power generation unit, but is not particularly limited, and the secondary battery 9635 is charged by another power generation unit such as a piezoelectric element (piezo element) or a thermoelectric conversion element (Peltier element). It may be a configuration. For example, a non-contact power transmission module that wirelessly (contactlessly) transmits and receives power for charging and other charging means may be combined.

Further, the secondary battery described in Embodiment 1 can be mounted on a wearable device as shown in FIG.

For example, it can be mounted on an eyeglass-type device 400 as shown in FIG. The eyeglass-type device 400 includes a frame 400a and a display unit 400b. By mounting the secondary battery on the temple portion of the curved frame 400a, the eyeglass-type device 400 having a good weight balance and a long continuous use time can be obtained.

Further, it can be mounted on the headset type device 401. The headset type device 401 includes at least a microphone section 401a, a flexible pipe 401b, and an earphone section 401c. A secondary battery can be provided in the flexible pipe 401b or the earphone unit 401c.

It can also be mounted on a device 402 that can be directly attached to the body. Device 40
The secondary battery 402b can be provided in the two thin housings 402a.

Moreover, it can mount in the device 403 which can be attached to clothes. A secondary battery 403 b can be provided in a thin housing 403 a of the device 403.

Further, it can be mounted on a wristwatch type device 405. The wristwatch type device 405 includes a display portion 405a and a belt portion 405b, and the display portion 405a or the belt portion 405b includes
A secondary battery can be provided.

Further, it can be mounted on the belt type device 406. The belt-type device 406 includes a belt portion 406a and a wireless power feeding / receiving portion 406b, and a secondary battery can be mounted inside the belt portion 406a.

In addition, the secondary battery described in Embodiment 1 can be mounted on the bracelet device 407 as illustrated in FIG. The bracelet type device 407 includes two curved secondary batteries 407b in a case 407a. Further, a curved display portion 40 is provided on the surface of the case 407a.
7c is provided. For a display portion that can be used for the display portion 407c, FIG.
The description about the display part can be taken into consideration. The bracelet type device 407 is connected to the connecting portion 40.
7d and a hinge part 407e, and the hinge part 407e can be moved to the connecting part 407d as a center. In addition, charging or the like can be performed through an external terminal provided in the connection portion 407d.

In addition, the secondary battery described in Embodiment 1 can be mounted on the wearable device 410 as illustrated in FIG. The wearable device 410 includes a curved secondary battery 412 and a sensor unit 413 in a main body 411. Wearable device 410
Has a display portion 415 and a band portion 414 and can be worn on the wrist, for example. For the display portion that can be used for the display portion 415, the description of the display portion in FIG. 29 can be referred to.

FIG. 33 shows an example of another electronic device. In FIG. 33, a display device 8000 is an example of an electronic device using the secondary battery 8004 according to one embodiment of the present invention. Specifically, the display device 800
0 corresponds to a display device for receiving TV broadcasts, and includes a housing 8001, a display portion 8002, a speaker portion 8003, a secondary battery 8004, and the like. A secondary battery 8004 according to one embodiment of the present invention is provided in the housing 8001. The display device 8000 can receive power from a commercial power supply. Alternatively, the display device 8000 can use power stored in the secondary battery 8004. Thus, the display device 8000 can be used when the secondary battery 8004 according to one embodiment of the present invention is used as an uninterruptible power supply even when power cannot be supplied from a commercial power supply due to a power failure or the like.

The display portion 8002 includes a liquid crystal display device, a light-emitting device including a light-emitting element such as an organic EL element in each pixel, an electrophoretic display device, and a DMD (Digital Micromirror Device).
ce), PDP (Plasma Display Panel), FED (Field)
A semiconductor display device such as an Emission Display) can be used.

The display device includes all information display devices such as a personal computer and an advertisement display in addition to a TV broadcast reception.

In FIG. 33, a stationary lighting device 8100 includes a secondary battery 81 according to one embodiment of the present invention.
3 is an example of an electronic device using 03. Specifically, the lighting device 8100 includes a housing 8101, a light source 8102, a secondary battery 8103, and the like. In FIG. 33, the secondary battery 8103 has a housing 81.
Although the case where 01 and the light source 8102 are provided inside the ceiling 8104 is illustrated, the secondary battery 8103 may be provided inside the housing 8101. The lighting device 8100 can receive power from a commercial power supply. Alternatively, the lighting device 8100 can use power stored in the secondary battery 8103. Thus, the lighting device 8100 can be used by using the secondary battery 8103 according to one embodiment of the present invention as an uninterruptible power supply even when power cannot be supplied from a commercial power supply due to a power failure or the like.

Note that FIG. 33 illustrates the installation type lighting device 8100 provided on the ceiling 8104; however, the secondary battery according to one embodiment of the present invention is not the ceiling 8104, for example, the side wall 8105 and the floor 8
106, a window-type lighting device provided in a window 8107, or the like, or a desktop-type lighting device.

The light source 8102 can be an artificial light source that artificially obtains light using electric power. Specifically, discharge lamps such as incandescent bulbs and fluorescent lamps, and light emitting elements such as LEDs and organic EL elements are examples of the artificial light source.

In FIG. 33, an air conditioner having an indoor unit 8200 and an outdoor unit 8204 includes:
FIG. 6 is an example of an electronic device using the secondary battery 8203 according to one embodiment of the present invention. Specifically, the indoor unit 8200 includes a housing 8201, an air outlet 8202, a secondary battery 8203, and the like. Although FIG. 33 illustrates the case where the secondary battery 8203 is provided in the indoor unit 8200, the secondary battery 8203 may be provided in the outdoor unit 8204. Alternatively, the secondary battery 8203 may be provided in both the indoor unit 8200 and the outdoor unit 8204. The air conditioner can receive power from a commercial power supply. Alternatively, the air conditioner can use power stored in the secondary battery 8203. In particular, the secondary battery 82 is provided in both the indoor unit 8200 and the outdoor unit 8204.
When 03 is provided, the air conditioner can be used by using the secondary battery 8203 according to one embodiment of the present invention as an uninterruptible power supply even when power cannot be supplied from a commercial power supply due to a power failure or the like. It becomes.

Note that FIG. 33 illustrates a separate type air conditioner including an indoor unit and an outdoor unit. However, an integrated air conditioner having the functions of the indoor unit and the outdoor unit in one housing is illustrated. The secondary battery according to one embodiment of the present invention can also be used.

In FIG 33, an electric refrigerator-freezer 8300 is an example of an electronic device including the secondary battery 8304 according to one embodiment of the present invention. Specifically, the electric refrigerator-freezer 8300 includes a housing 8301, a refrigerator door 8302, a refrigerator door 8303, a secondary battery 8304, and the like. In FIG. 33, the secondary battery 8304 is provided inside the housing 8301. Electric refrigerator-freezer 8300
Electric power can be supplied from a commercial power supply, or electric power stored in the secondary battery 8304 can be used. Therefore, the electric refrigerator-freezer 8300 can be used by using the secondary battery 8304 according to one embodiment of the present invention as an uninterruptible power supply even when electric power cannot be supplied from the commercial power supply due to a power failure or the like.

This embodiment can be implemented in appropriate combination with any of the other embodiments.

(Embodiment 8)
In this embodiment, an example in which the secondary battery described in Embodiment 1 is mounted on a vehicle is shown.

When a secondary battery is mounted on a vehicle, a hybrid vehicle (HEV), an electric vehicle (EV),
Alternatively, a next-generation clean energy vehicle such as a plug-in hybrid vehicle (PHEV) can be realized.

FIG. 34 illustrates a vehicle using one embodiment of the present invention. Car 8 shown in FIG.
Reference numeral 400 denotes an electric vehicle using an electric motor as a power source for traveling. Or
This is a hybrid vehicle in which an electric motor and an engine can be appropriately selected and used as a power source for traveling. By using one embodiment of the present invention, a vehicle having a long cruising distance can be realized. The automobile 8400 includes a secondary battery. The secondary battery can not only drive an electric motor but also supply power to a light-emitting device such as a headlight 8401 and a room light (not shown).

The secondary battery can supply power to a display device such as a speedometer or a tachometer included in the automobile 8400. The secondary battery can supply power to a semiconductor device such as a navigation system included in the automobile 8400.

A car 8500 illustrated in FIG. 34B can charge a secondary battery included in the car 8500 by receiving power from an external charging facility by a plug-in method, a non-contact power feeding method, or the like. FIG. 34B illustrates a state in which the power storage device mounted on the automobile 8500 is charged through the cable 8022 from the ground-installed charging device 8021. When charging, the charging method, connector standard, and the like may be appropriately performed by a predetermined method such as CHAdeMO (registered trademark) or a combo. The charging device 8021 may be a charging station provided in a commercial facility,
It may also be a household power source. For example, a secondary battery mounted on an automobile 8500 can be charged by an external power supply by plug-in technology. Charging is ACDC
AC power can be converted into DC power through a converter such as a converter.

In addition, although not shown, the power receiving device can be mounted on the vehicle, and electric power can be supplied from the ground power transmitting device in a contactless manner and charged. In the case of this non-contact power supply method, charging can be performed not only when the vehicle is stopped but also during traveling by incorporating a power transmission device on a road or an outer wall. In addition, this non-contact power feeding method may be used to transmit and receive power between vehicles. Furthermore, a solar battery may be provided in the exterior part of the vehicle, and the secondary battery may be charged when the vehicle is stopped or traveling. An electromagnetic induction method or a magnetic field resonance method can be used for such non-contact power supply.

Moreover, the secondary battery mounted in the vehicle can also be used as a power supply source other than the vehicle. In this case, it is possible to avoid using a commercial power source at the peak of power demand.

This embodiment can be implemented in appropriate combination with any of the other embodiments.

100 Secondary battery 100a Secondary battery 100b Secondary battery 100c Secondary battery 100c1 Secondary battery 100d Secondary battery 100e Secondary battery 100f Secondary battery 100g Secondary battery 100h Secondary battery 100i Secondary battery 100j Secondary battery 100k Secondary battery 100m Secondary battery 100n Secondary battery 100p Secondary battery 100q Secondary battery 101 Positive electrode current collector 102 Positive electrode active material layer 103 Separator 103a Region 103b Region 104 Electrolytic solution 105 Negative electrode current collector 106 Negative electrode active material layer 107 Exterior body 107a film 107b region 107c region 107d region 107e exterior body 107f exterior body 111 positive electrode 111a positive electrode 113 negative electrode 115 negative electrode 115a negative electrode 120 sealing layer 121 positive electrode lead 125 negative electrode lead 130 resin 130a resin 130b resin 130c resin 140 Assembly 141 Electrode assembly 151 Switch 152 Current control switch 154 Switch pair 221 Hole 250 Region 321 Graphene 322 Positive electrode active material 323 Conductive aid 331 Region 332 Region 333 Region 400 Eyeglass-type device 400a Frame 400b Display unit 401 Headset device 401a Microphone unit 401b Flexible pipe 401c Earphone unit 402 Device 402a Case 402b Secondary battery 403 Device 403a Case 403b Secondary battery 405 Wristwatch type device 405a Display unit 405b Belt unit 406 Belt type device 406a Belt unit 406b Wireless power feeding / receiving unit 407 Type device 407a case 407b secondary battery 407c display unit 407d connection unit 407e hinge unit 410 wearable device 411 412 Secondary battery 413 Sensor unit 414 Band unit 415 Display unit 7100 Portable display device 7101 Case 7102 Display unit 7103 Operation button 7104 Secondary battery 7300 Armband device 7301 Arm 7400 Mobile phone 7401 Case 7402 Display unit 7403 Operation button 7404 External Connection port 7405 Speaker 7406 Microphone 7407 Secondary battery 7408 Lead electrode 7409 Current collector 7500 Stove 7501 Secondary battery 7510 Stove 7511 Module 7511a Air outlet 7511b External terminal 7512 Main body 7512a Opening 7513 Grill 8000 Display device 8001 Housing 8002 Display unit 8003 Speaker unit 8004 Secondary battery 8021 Charging device 8022 Cable 8100 Lighting device 8101 Case 8102 Light source 8103 Secondary battery 81 4 Ceiling 8105 Side wall 8106 Floor 8107 Window 8200 Indoor unit 8201 Case 8202 Air outlet 8203 Secondary battery 8204 Outdoor unit 8300 Electric refrigerator / freezer 8301 Case 8302 Refrigeration room door 8303 Freezer compartment door 8304 Secondary battery 8400 Car 8401 Headlight 8500 Car 9600 Tablet type terminal 9625 Switch 9626 Switch 9627 Power switch 9628 Operation switch 9629 Tool 9630 Case 9630a Case 9630b Case 9631 Display unit 9631a Display unit 9631b Display unit 9632a Region 9632b Region 9633 Solar cell 9634 Charge / discharge control circuit 9635 Two Secondary battery 9636 DCDC converter 9637 Converter 9638 Operation key 9539 Button 9640 Movable part BT00 Power storage device BT01 Terminal pair BT 02 Terminal pair BT03 Control circuit BT04 Circuit BT05 Circuit BT06 Transformer control circuit BT07 Transformer circuit BT08 Battery part BT09 Battery cell BT10 Transistor BT11 Bus BT12 Bus BT13 Transistor BT14 Current control switch BT15 Bus BT16 Bus BT17 Switch pair BT22 Transistor pair BT21 Transistor pair BT23 Transistor BT24 Bus BT25 Bus BT31 Transistor pair BT33 Transistor BT33 Transistor BT34 Bus BT35 Bus BT41 Battery control unit BT51 Insulation type DC-DC converter BT52 Switch part BT53 Transformer part S1 Control signal S2 Control signal S3 Transform signal SW1 Switch SW3 Switch 12 BT
16 BT

Claims (3)

A curved secondary battery, and a curved display portion;
The secondary battery includes an electrode part having a positive electrode, a negative electrode, and a separator, and an exterior body covering the electrode part,
The exterior body has a sealing region,
The secondary battery has a resin sandwiched between the exterior bodies in the sealing region,
A part of the resin is in contact with the outer surface of the exterior body,
Than said friction coefficient mu ₂ of the exterior body, the outer body the sealing area of friction coefficient mu ₁ is small electronic apparatus of the resin located outside of. In claim 1,
A thickness T ₁ of a portion of the resin sandwiched between the exterior bodies is 0.8 to 1.2 times the thickness T ₂ of the electrode portion. In claim 1 or claim 2,
The exterior body is an electronic device having irregularities.

Images