Power storage device

Abstract

To provide a power storage device that can be bent repeatedly, a power storage device with high reliability, a power storage device with a long life, an electronic appliance that can be bent repeatedly, or an electronic appliance with flexibility.SOLUTION: A power storage device includes a positive electrode, a negative electrode, and an exterior package covering the positive electrode and the negative electrode. The exterior package includes a metal layer and a resin layer. The metal layer is thinner in a part of an outer edge part of the exterior package than in the other parts than the outer edge part. The exterior package includes a plurality of slits in the outer edge part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an article, a method, or a manufacturing method. The invention relates to the manufacture or composition of matter. One embodiment of the present invention is a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, or any of these devices. In particular, the present invention relates to a driving method thereof, a manufacturing method thereof, or an evaluation method thereof. The present invention relates to a power storage device, a manufacturing method thereof, and an evaluation method thereof.

[0002] In this specification, the term "power storage device" refers to elements and devices in general that have a power storage function. That is why. [Background technology]

[0003] In recent years, secondary batteries such as lithium-ion secondary batteries, lithium-ion capacitors, air batteries, etc. In particular, the development of high-power, high-energy-density lithium-ion batteries is being actively pursued. Sodium-ion secondary batteries are used in mobile phones, smartphones, and laptops. Electronic devices such as mobile information terminals, portable music players, digital cameras, or medical devices , hybrid vehicle (HEV), electric vehicle (EV), or plug-in hybrid vehicle (P With the development of the semiconductor industry, next-generation clean energy vehicles such as hybrid electric vehicles (HEVs) are rapidly becoming Demand is expanding, and it has become an essential source of rechargeable energy in today's information society. Patent Document 1 shows an example of mounting a power storage device on an electronic device.

[0004] In recent years, electronic devices that are worn on the human body have been proposed, and wearable displays have become available. To improve convenience, such electronic devices are often worn on the human body. It is required that the desorption can be repeated. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2015-38868 Summary of the Invention [Problem to be solved by the invention]

[0006] When impurities get into the inside of the electricity storage device, the characteristics of the electricity storage device deteriorate. For example, impurities such as water may get mixed into the non-aqueous electrolyte, reducing the discharge capacity. The airtightness of the device's exterior is low, so atmospheric components get mixed into the area surrounded by the exterior, As a result, impurities may be mixed into the power storage device.

[0007] In addition, the power storage device mounted on the electronic device worn on the human body is When the battery is repeatedly attached and detached, the battery itself may be repeatedly bent. When bending, deterioration of the exterior occurs, and impurities such as moisture enter the area surrounded by the exterior. Knowing the concentration of moisture, etc., in the area surrounded by the exterior body is important for improving the reliability of the energy storage device. This is important for improving reliability.

[0008] An object of one embodiment of the present invention is to provide a power storage device that can be repeatedly bent. Another object of one embodiment of the present invention is to provide a highly reliable power storage device. Another object of one embodiment of the present invention is to provide a power storage device with a long lifetime. Another object of one embodiment of the present invention is to provide an electronic device that can be repeatedly bent. Another object of one embodiment of the present invention is to provide a flexible electronic device. It shall be one of the following.

[0009] Another object of one embodiment of the present invention is to provide a flexible film. Alternatively, one aspect of the present invention is to provide a film that can be repeatedly bent. This is one of the topics.

[0010] Another object of one embodiment of the present invention is to provide a power storage device with a novel structure. Another embodiment of the present invention is a novel power storage device, an electronic device equipped with the novel power storage device, or the like. One of our goals is to provide

[0011] The description of these problems does not preclude the existence of other problems. One embodiment does not necessarily have to solve all of these problems. The subject matter will be self-evident from the description, drawings, claims, etc. It is possible to extract other issues from the drawings, claims, etc. [Means for solving the problem]

[0012] One aspect of the present invention is a battery comprising a positive electrode, a negative electrode, and an exterior body that encases the positive electrode and the negative electrode, wherein the exterior body The metal layer has an outer periphery and a resin layer. The metal layer has an outer periphery and a resin layer. The exterior body is thinner than parts other than the edge, and has a plurality of slits on the outer edge.

[0013] In addition, the power storage device of one embodiment of the present invention is preferably sealed with an outer casing at the outer edge. It's nice.

[0014] Alternatively, one embodiment of the present invention is a battery including a positive electrode, a negative electrode, and an exterior body that encases the positive electrode and the negative electrode, The outer casing has a first region and a second region, and the second region is at least a portion of the outer periphery of the outer casing. The exterior body has a metal layer and a resin layer, and the metal layer in the first region is in contact with a part of the second the exterior body is thicker than the metal layer in the first region, and the exterior body has a plurality of slits in the second region. In the above configuration, the second region has a strip shape, and the major axes of the plurality of slits are Preferably, the second electrode is substantially perpendicular to the long axis of the belt-like shape. The region has a band-like shape, and the angle formed by the major axis of the plurality of slits and the major axis of the band-like shape is is preferably 45° or more and less than 90°.

[0015] In the power storage device of one embodiment of the present invention, the distance between adjacent slits is 2 mm or more and 3 mm or less. It is preferable that the length is m or less.

[0016] Alternatively, one embodiment of the present invention is a battery including a positive electrode, a negative electrode, and an exterior body that encases the positive electrode and the negative electrode, The exterior body has a first region and a second region, and the second region is at least part of the outer edge of the exterior body. the exterior body has a metal layer, and the metal layer is in contact with at least a part of the first region and the second region. The exterior body is thicker than the first slit and is closer to the center of the electricity storage device than the first slit. and a second slit, and the angle formed by the long axis of the first slit and the long axis of the band-like shape is is a°, the angle between the long axis of the second slit and the long axis of the strip shape is b°, and a is , b is a larger storage device.

[0017] Alternatively, one embodiment of the present invention is a battery including a positive electrode, a negative electrode, and an exterior body that encases the positive electrode and the negative electrode, The exterior body has a metal layer and a resin layer, and the metal layer is The outer casing is thinner than a part other than the edge portion, and the first slit and the power storage device are closer to each other than the first slit. a second slit near the center of the device, and a long axis of the first slit and a long axis of the band-shaped The angle between the axis and the second slit is a°, and the angle between the long axis of the second slit and the long axis of the strip shape is a°. b°, and a is a storage device smaller than b.

[0018] Alternatively, one embodiment of the present invention is a battery including a positive electrode, a negative electrode, and an exterior body that encases the positive electrode and the negative electrode, The exterior body has a metal layer, and the metal layer is thinner at a part of the outer edge of the exterior body than at the other part. The exterior body is an electricity storage device having two or more holes in the outer edge portion. Preferably, the two or more holes are arranged linearly. are preferably 0.1 mm or more and 3 mm or less.

[0019] The power storage device of one embodiment of the present invention preferably can be repeatedly bent.

[0020] Another embodiment of the present invention is a power storage device including any one of the above power storage devices, a transistor, and In the above structure, the transistor is an oxide semiconductor. It is preferable to have a conductor.

[0021] Another embodiment of the present invention is an electronic device including any one of the above power storage devices. be.

[0022] Another embodiment of the present invention is a display device including any one of the above power storage devices and a display portion. It is an electronic device. [Effects of the Invention]

[0023] According to one embodiment of the present invention, a power storage device that can be repeatedly bent can be provided. According to one embodiment of the present invention, a highly reliable power storage device can be provided. According to one embodiment of the present invention, a power storage device with a long lifetime can be provided. According to this aspect, an electronic device that can be repeatedly bent can be provided. According to one embodiment, a flexible electronic device can be provided.

[0024] According to one embodiment of the present invention, a flexible film can be provided. According to one aspect of the present invention, a film that can be repeatedly bent can be provided. .

[0025] According to one embodiment of the present invention, a power storage device with a novel structure can be provided. According to one embodiment of the present invention, a novel power storage device, an electronic device equipped with the novel power storage device, and the like are provided. It is possible.

[0026] The description of these effects does not preclude the existence of other effects. An embodiment does not necessarily have to have all of these effects. The above will be made clear from the description, drawings, claims, etc. It is possible to extract other effects from the descriptions in the aspects and claims. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 2 illustrates a top surface of a power storage device. [Figure 2] FIG. 2 illustrates a top surface of a power storage device. [Figure 3] FIG. 2 illustrates a top surface of a power storage device. [Figure 4]FIG. 2 is a cross-sectional view of a power storage device. [Figure 5] FIG. 2 illustrates a top surface of a power storage device. [Figure 6] FIG. 2 illustrates a top surface of a power storage device. [Figure 7] FIG. 2 illustrates a top surface of a power storage device. [Figure 8] 2A and 2B are diagrams illustrating a top surface and a cross section of a power storage device. [Figure 9] FIG. 10 is a diagram illustrating the radius of curvature of a surface. [Figure 10] FIG. 2 is a diagram illustrating the radius of curvature of a film. [Figure 11] 1A to 1C illustrate a method for manufacturing a power storage device. [Figure 12] 1A to 1C illustrate a method for manufacturing a power storage device. [Figure 13] 1A to 1C illustrate a method for manufacturing a power storage device. [Figure 14] FIG. 2 is a cross-sectional view of a power storage device. [Figure 15] FIG. 2 is a cross-sectional view of a power storage device. [Figure 16] FIG. 2 is a cross-sectional view of a power storage device. [Figure 17] FIG. 2 is a diagram illustrating a cross section of a film. [Figure 18] FIG. 2 is a diagram illustrating a cross section of a film. [Figure 19] FIG. 2 is a diagram illustrating a cross section of a film. [Figure 20] FIG. [Figure 21] FIG. [Figure 22] FIG. [Figure 23] FIG. [Figure 24] 1A and 1B are diagrams illustrating examples of an electronic device, a band, and a power storage device. [Figure 25] FIG. 1 illustrates an example of a power storage device. [Figure 26] FIG. 1 illustrates an example of a power storage device. [Figure 27] FIG. 1 illustrates an example of a power storage device. [Figure 28] 1A to 1C illustrate an example of a method for manufacturing a power storage device. [Figure 29] FIG. 2 is a diagram illustrating a cross section of a particle. [Figure 30] FIG. 2 is a diagram illustrating a cross section of an electrode. [Figure 31] 1A and 1B are diagrams illustrating examples of electronic devices. [Figure 32] 1A and 1B are diagrams illustrating examples of electronic devices. [Figure 33] 1A and 1B are diagrams illustrating examples of electronic devices. [Figure 34] 1A and 1B are diagrams illustrating examples of electronic devices. [Figure 35] 1A and 1B are diagrams illustrating examples of electronic devices. [Figure 36] FIG. 1 is a block diagram illustrating one embodiment of the present invention. [Figure 37] FIG. 1 is a conceptual diagram illustrating one embodiment of the present invention. [Figure 38] FIG. 1 is a circuit diagram illustrating one embodiment of the present invention. [Figure 39] FIG. 1 is a circuit diagram illustrating one embodiment of the present invention. [Figure 40] FIG. 1 is a conceptual diagram illustrating one embodiment of the present invention. [Figure 41] FIG. 1 is a block diagram illustrating one embodiment of the present invention. [Figure 42] 1 is a flowchart illustrating one embodiment of the present invention. [Figure 43] Photo of a storage device. [Figure 44] Photo of a storage device. [Figure 45] FIG. 10 is a graph showing the amount of moisture in a power storage device. DETAILED DESCRIPTION OF THE INVENTION

[0028] The embodiments of the present invention will be described in detail below with reference to the drawings. The present invention is not limited to these descriptions, and various modifications in form and details are possible by those skilled in the art. Therefore, the present invention should not be construed as being limited to the description of the following embodiments. It is not something that is done.

[0029] In each figure described in this specification, the size and dimensions of each element such as a film, layer, substrate, and region are The thicknesses and the like may be exaggerated for clarity of explanation. The components are not limited to their size, nor are they limited to the relative sizes of each other. stomach.

[0030] In this specification, ordinal numbers such as first, second, etc. are used for convenience. It does not indicate the order of processes or the order of lamination. "The" can be replaced with "the second" or "the third" as appropriate. Ordinal numbers described in the specification etc. and ordinal numbers used to identify one aspect of the present invention may not match.

[0031] In the configuration of the present invention described in this specification, etc., The same reference numerals are used for the same parts in different drawings, and repeated explanations will be omitted. In addition, when referring to parts with similar functions, the hatch pattern is the same and a special symbol is attached. This may not be the case.

[0032] In this specification, both the positive electrode and the negative electrode for the electricity storage device are collectively referred to as electrodes. In this case, the electrode refers to at least one of the positive electrode and the negative electrode. do.

[0033] Here, the charging and discharging rates of the storage device will be explained. For example, When charging a secondary battery of [Ah] at a constant current, a charge rate of 1C means that charging will be completed in 1 hour. The current value is I [A], and a charging rate of 0.2C is I / 5 [A] (i.e., 5 hours Similarly, a discharge rate of 1C is the current value at which the battery will be discharged in 1 hour. The discharge rate of 0.2C is I / 5[A] (i.e. (i.e., the current value at which discharge is completed in 5 hours).

[0034] (Embodiment 1) In this embodiment, a power storage device of one embodiment of the present invention and an exterior body of the power storage device will be described. Reveal.

[0035] An example of the power storage device is a secondary battery that uses an electrochemical reaction, such as a lithium ion battery. Examples of the electricity storage device include an electric double layer capacitor and a redox capacitor. Examples include electrochemical capacitors, air batteries, and fuel cells.

[0036] The power storage device of one embodiment of the present invention is preferably capable of repeatedly charging and discharging.

[0037] When charging and discharging the power storage device, the electrolyte may decompose at the reaction potential of the electrodes. The decomposition reaction of the electrolyte is often an irreversible reaction. The charge / discharge efficiency may decrease, resulting in a decrease in the discharge capacity of the power storage device. It goes down.

[0038] In addition, the discharge capacity may gradually decrease with repeated charging and discharging due to the decomposition reaction of the electrolyte. There is a match.

[0039] By using a non-aqueous electrolyte as the electrolyte of the electricity storage device, the range of potential at which the electricity storage device operates can be expanded. For example, it may be possible to increase the potential range of the electrolyte. Decomposition can be suppressed, and the discharge capacity of the electricity storage device can be increased. An exterior body according to one embodiment of the present invention will be described below.

[0040] When impurities enter the area surrounded by the exterior body of the power storage device, This can cause a decrease in performance. For example, impurities such as water can get mixed into the non-aqueous electrolyte, reducing the discharge capacity. For example, if the airtightness of the exterior of the electricity storage device is low, components in the atmosphere may penetrate into the exterior. As a result, impurities are mixed into the power storage device.

[0041] Here, in the electricity storage device, the concentration of moisture in the area surrounded by the exterior body is The amount of electrolyte contained in the area surrounded by the exterior body is preferably 300 ppm or less by weight. Preferably, 100 ppm or less is more preferable, 50 ppm or less is even more preferable, and 20 ppm or less is even more preferable. m or less is more preferable.

[0042] In the electricity storage device, the amount of moisture in the area surrounded by the exterior body is measured by, for example, Karl Fischer's method. It can be measured using a char moisture meter or the like.

[0043] The exterior body is preferably made of a material with low impurity permeability. In particular, a material with low moisture permeability is preferred. It is preferable that the material contains a material, for example, a metal.

[0044] The exterior of the power storage device of one embodiment of the present invention may be a film (referred to as a sheet or foil). In some cases, it is preferable to use

[0045] The outer casing of one embodiment of the present invention is made of aluminum, copper, tin, niobium, titanium, nickel, manganese, or the like. At least one selected from metals such as iron, molybdenum, tungsten, tantalum, and chromium It is preferable that the metal has at least one of these metals. In addition, an alloy of these metals may be used. For example, The outer casing may have a metal layer containing these metals or alloys. Here, aluminum, copper, tin, niobium, titanium, etc. have a small Young's modulus, Aluminum is also inexpensive and easy to process. It is particularly preferable as the metal contained in the housing.

[0046] Here, the thickness of the metal layer is, for example, 5 μm or more and 200 μm or less, or 10 μm or more and 100 μm or less. μm or less, or 15 μm to 50 μm.

[0047] Alternatively, the exterior body of one aspect of the present invention may have a carbon sheet. For example, a film containing graphite, carbon fiber, activated carbon, graphene, a graphene compound, etc. Examples include:

[0048] The exterior body of one aspect of the present invention preferably contains a resin. Examples of resins include polyethylene, polypropylene, and polycarbonate. Polyamides, ionomers, polyamides, etc. can be used.

[0049] In addition, to prevent a short circuit between the electrodes of the storage device and the exterior body, the electrical conductivity of the surface of the exterior body is Therefore, it is preferable that the exterior body has a resin layer or the like on the surface. For example, a film having a metal layer and a resin layer on both sides can be used as the exterior body. Cut.

[0050] For example, the outer casing of one aspect of the present invention is a film having the metal or the alloy. At least one of the front and rear surfaces may have a resin layer.

[0051] For example, metal films (aluminum, stainless steel, copper, etc.) and organic materials are used as exterior materials. Plastic films made of organic materials (resins, fibers, etc.) and inorganic materials (ceramics, etc.) Hybrid material films containing carbon-containing inorganic films (carbon films, graphite films, etc.) graphite film, etc.) or a laminate consisting of multiple of these Use film.

[0052] When using a metal film, it is necessary to apply a polypropylene film to the inner surface to insulate the surface. Materials such as propylene, polyethylene, polycarbonate, ionomer, polyamide, etc. The outer surface is covered with an insulating synthetic resin layer such as polyamide resin or polyester resin. Alternatively, the resin layer may be polyethylene terephthalate. A metal film may be coated with a laminated film of two or more layers. For example, the inner surface is covered with a material such as polypropylene, and the outer surface is covered with a polyamide resin and a polyamide resin. It may be coated with a film laminated with ethylene terephthalate (PET) resin or the like. For example, the thickness of the resin layer is 10 μm to 200 μm, or 15 μm to 100 μm. be.

[0053] The power storage device of one embodiment of the present invention is susceptible to deformation due to deformation of a device in which the power storage device is mounted. can be done.

[0054] The power storage device of one embodiment of the present invention can be bent. It can be installed in deforming devices, such as electronic devices such as wearable devices. When wearing or while wearing a wearable device, deformation may occur, causing This can improve the fit of the wearable device.

[0055] Electronic devices such as wearable devices are repeatedly attached to and detached from the human body. Therefore, it is preferable that the power storage device of one embodiment of the present invention can be repeatedly bent. It is preferable that:

[0056] Bending the power storage device causes the exterior body to deform. This may cause cracks or thinning of the exterior. This phenomenon may cause the exterior body to become more permeable to impurities. Therefore, impurities in the air, such as moisture, can easily get into the area surrounded by the exterior body. become.

[0057] When the power storage device of one embodiment of the present invention is repeatedly bent, the exterior body of the power storage device may be impurities. It is possible to suppress an increase in the permeability of materials.

[0058] Here, repeatedly bending refers to repeatedly bending the wire between a large radius of curvature and a small radius of curvature. When bending the energy storage device, the smaller the radius of curvature, the greater the deformation of the exterior body. Cracks and other damage are more likely to occur.

[0059] When bending the electricity storage device, deformation may become large in localized areas of the exterior body. In areas where deformation is large, the exterior may be more susceptible to cracks.

[0060] <Electricity storage device> FIG. 8 is a diagram illustrating a specific configuration of a power storage device. As an example of the device 500, a thin storage battery is shown.

[0061] As shown in FIG. 8A, the power storage device 500 includes a positive electrode 503, a negative electrode 506, a separator 507, and a 507, and an outer casing 509. The power storage device 500 has a positive electrode lead 510 and a negative electrode lead The positive electrode lead 510 is welded to the positive electrode 503, and the negative electrode lead 511 is It is welded to the negative electrode 506 .

[0062] The exterior body 509 has a region 509a and a region 509b. The region 509b is, for example, This is the area where the outer periphery of the exterior body 509 is joined by thermocompression bonding. Region 509b is called the sealed portion. The sealing portion, i.e., region 509b, corresponds to the outer edge of the exterior body, for example. In the example shown in (A), the exterior body 509 has sealing regions on three sides. ), the region 509b is located on three sides of the exterior body 509. In the top view of the body, region 509b is adjacent to the outside of region 509a. The positive electrode lead 510 and the negative electrode lead 511 are connected to the same side of the outer casing 509 and the outer casing 50 It is taken out of the 9.

[0063] The sealing structure of the energy storage device is made by folding a rectangular film in the middle and sealing the two edges. The structure is such that the film is layered and fixed on three sides with an adhesive layer to seal it, or two films are layered and the film The four end faces are fixed and sealed with an adhesive layer.

[0064] The adhesive layer can be made of thermoplastic film material, heat-curing adhesive, anaerobic adhesive, or UV-curing adhesive. Photo-curing adhesives such as adhesives and reaction-curing adhesives can be used. The materials used include epoxy resin, acrylic resin, silicone resin, and phenolic resin. It is possible.

[0065] The exterior body preferably has a metal layer and a resin layer. The resin layer in the region 509b is The metal layer in the region 509b has a thinner portion than the resin layer in the region 509a. It is preferable to have a thinner portion than the metal layer.

[0066] An example of a cross-sectional view between the dashed dotted line A1-A2 in FIG. 8(A) is shown in FIG. 8(B), and the cross-sectional view between the dashed dotted line B An example of a cross section between 1-B2 is shown in FIG. 8(C). 5 shows a cross-sectional structure of a power storage device 500 fabricated using three pairs of a positive electrode 503 and a negative electrode 506.

[0067] As shown in FIGS. 8A to 8C, the power storage device 500 includes a positive electrode 503, a negative electrode 506, a The separator 507 is a positive electrode The exterior body 509 is filled with an electrolyte 508. .

[0068] In the power storage device 500, the positive electrode 503 and the negative electrode 506 are located inside the exterior body 509. The positive electrode 503 and the negative electrode 506 are preferably wrapped in an outer casing 509. The housing 509 is preferably bag-shaped.

[0069] The positive electrode 503 includes a positive electrode active material layer 502 and a positive electrode current collector 501. The negative electrode includes an active material layer 505 and a negative electrode current collector 504. The active material layer is formed on one or both sides of the current collector. The separator 507 is disposed between the positive electrode current collector 501 and the negative electrode current collector 504. do.

[0070] A battery cell may have one or more positive electrodes and one or more negative electrodes. For example, a battery cell may have Alternatively, a laminated structure consisting of a plurality of positive electrodes and a plurality of negative electrodes may be used. The number of pairs of the positive electrode active material layer and the negative electrode active material layer facing each other is five. The number of pairs is not limited to five, and may be more or less. In addition, when the number of active material layers is small, the storage battery can have a larger capacity. This allows the storage battery to be thin and highly flexible.

[0071] FIG. 1A is a top view of a power storage device of one embodiment of the present invention. 8A, the difference between the 00 and the 509b is that the 00 has a slit 261 in the region 509b. In the power storage device of one embodiment of the present invention, the region 509b has a plurality of slits. It is preferable that:

[0072] The slit 261 may be, for example, a notch, a cut, or a gap (in English, for example). For example, cut or rift.

[0073] The slit 261 has, for example, a linear shape. The linear shape may be, for example, a straight line. Alternatively, it may be a curved line. It may also be a combination of a straight line and a curved line. , spiral, arc, etc.

[0074] In FIG. 1(A), the region 509b has a band-shaped In FIG. 1(A), the major axis of each of the plurality of slits 261 is perpendicular to the major axis of the band. The long axis of each of the plurality of slits 261 and the long axis of the band are perpendicular to each other. For example, the long axis of each of the plurality of slits 261 and the long axis of the band may be The angle may be equal to or greater than 45° and less than 90°.

[0075] In each of the plurality of slits 261, the distance between adjacent slits is, for example, 2 m. It is fine if it is more than m and less than 3 cm.

[0076] FIG. 1B is an enlarged view of the area surrounded by the dashed line in FIG. 1A. 9b has a plurality of linear slits 261.

[0077] 1(C)(D), 2(A), 2(B), 2(C) and 2(D) show the expansion of the region 509b. A large diagram is shown.

[0078] As shown in FIGS. 1C and 1D, the major axes of the plurality of slits 261 are For example, when the power storage device 500 is bent, the direction of curvature may be different in the region having a different curvature. In this case, the direction of the slit 261 may be changed.

[0079] As shown in FIG. 1C, among the plurality of slits 261, the first slit and the second slit Consider slits 261a and 261b as slits. The long axis direction of the region 509b is indicated by a direction 263. The angle between the major axes is a°, and the angle between the major axis of the slit 261b and the major axis of the region 509b is b°. ° (a° and b° are both acute angles). In Figure 1(C), a is greater than b. In addition, in FIG. 1(D), adjacent slits are aligned along the dashed line A1-A2 shown in FIG. 1(A). It is roughly symmetrical with respect to parallel lines.

[0080] As shown in FIG. 2(A), the slit 261 may have a wedge shape. Alternatively, as shown in FIG. 2(B), the end of the slit 261 may have an arcuate shape. In addition, as shown in FIG. 2(C), the end of the exterior body 509 may have a wave-shaped shape. The end of the exterior body 509 may have a shape such as a curve, a wavy line, an arc, or a shape with multiple inflection points. It's okay to have one.

[0081] Also, Fig. 2(D) shows an example of a curved slit. Slit 261 shown in Fig. 2(D) has an arc-shaped end.

[0082] The power storage device 500 shown in FIG. 3A includes an outer casing 509. The outer casing 509 includes a region 5 In FIG. 3A, the region 509a and the region 509b The boundary between the region 509a and the region 509b has a wave shape. The area 509a and the area 509b may be a wavy line, an arc, or a shape having multiple inflection points. By forming the boundary of 509b in the above-described shape, when the power storage device 500 is bent, In some cases, the stress on the exterior body 509 due to the deformation of the device 500 can be alleviated. 3(A) is an enlarged view of the area surrounded by the dashed line. The width of the region 509b in the vicinity of the region where the slits 261 are adjacent is width b1, and the width of the region between the adjacent slits 261 is width b2. The width of the region 509b is defined as width b2. In FIG. 3A, width b1 is larger than width b2. stomach.

[0083] In the enlarged view of the region 509b shown in FIG. 3(C), the boundary between the region 509a and the region 509b is wavy. The case where the end of the outer casing 509 has a wave-shaped shape is combined with the case where the end of the outer casing 509 has a wave-shaped shape. Here, in FIG. 3(C), the wave at the boundary between the region 509a and the region 509b is The peaks and valleys of the waves at the end of the exterior body 509 are roughly Here is a matching example:

[0084] The center of gravity of the power storage device may be referred to as the center of the power storage device. The center of the power storage device may be referred to as the center of the power storage device.

[0085] Here, the power storage device of one embodiment of the present invention can be repeatedly bent, for example. 4B show the structure of the power storage device 500 of one embodiment of the present invention, which is shown along the dashed-dotted line A1-A2 1 and 2, a simplified cross section corresponding to the dashed line B1-B2 is shown. 9 has a region 509 a and a region 509 b, and the laminate 541 is wrapped in an exterior body 509 . The laminate 541 has a positive electrode 503 , a negative electrode 506 , and a separator 507 .

[0086] An example of bending the power storage device 500 will be described. A cross section of the device 500 after bending is shown in FIG. 4(C).

[0087] The power storage device 500 of one embodiment of the present invention includes a plurality of slits 261 in the region 509b. As a result, cracks and the like occurring in exterior body 509 can be suppressed.

[0088] Alternatively, for example, a plurality of slits 261 may be arranged radially.

[0089] 5(A) and (B) are top views of the power storage device 500. In this figure, the slits 261 above the dashed line A1-A2 are They are arranged approximately symmetrically with respect to the dashed dotted line A1-A2.

[0090] Alternatively, the region 509b may be formed by two or more holes (e.g., dotted holes, or The spotted holes may be arranged in a line, for example. stomach.

[0091] The major diameter of each of the plurality of holes is, for example, 0.1 mm or more and 3 mm or less. The diameter of each of the dot-like holes may be different. It can also refer to a wide area.

[0092] The power storage device 500 shown in FIG. 6A includes an outer casing 509. The outer casing 509 includes a region 5 6B shows the area surrounded by the dashed line in FIG. As shown in FIG. 6B, the power storage device 500 has a hole in the region 509b. The holes 262 have a dot-like shape and the holes 262 are arranged in a line. Here, the shape of the holes as viewed from above may be a circle, an ellipse, a rectangle, a rhombus, a polygon, or the like.

[0093] As shown in FIG. 7, a positive electrode lead 510 and a negative electrode lead 511 are disposed on opposite sides of an outer casing 509. The electrodes may be taken out of the exterior body 509 from the sides.

[0094] The solvent of the electrolytic solution 508 is preferably an aprotic organic solvent, for example, ethylene carbonate. Carbonate (EC), Propylene Carbonate (PC), Butylene Carbonate, Chloride Ethylene carbonate, vinylene carbonate, gamma-butyrolactone, gamma-valerolactone Dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl Carbonate (EMC), methyl formate, methyl acetate, methyl butyrate, 1,3-dioxane, 1,4-dioxane, dimethoxyethane (DME), dimethyl sulfoxide, diethyl ethane ether, methyl diglyme, acetonitrile, benzonitrile, tetrahydrofuran, One of these, rholan, sultone, etc., or any combination and ratio of two or more of these It can be used at a rate.

[0095] In addition, by using a polymer material that gels as a solvent for the electrolyte, it is possible to prevent leakage, etc. Safety is improved. In addition, it is possible to make the secondary battery thinner and lighter. Representative examples of such materials include silicone gel, acrylic gel, acrylonitrile gel, and poly Ethylene oxide gel, polypropylene oxide gel, fluorine polymer gel etc.

[0096] In addition, a flame-retardant and non-volatile ionic liquid (room-temperature molten salt) is used as the solvent for the electrolyte. By using one or more, the internal temperature of the storage device can be prevented from rising due to an internal short circuit or overcharging. Even if the battery is damaged, it can prevent the battery from exploding or catching fire. The electrolyte solution is made of tetravalent cations and anions. ammonium cations, tertiary sulfonium cations, and quaternary phosphonium cations Aliphatic onium cations such as imidazolium cations and pyridinium cations The following aromatic cations are also used as anions in electrolytes: monovalent amide-based Anions, monovalent methide anions, fluorosulfonate anions, perfluoroalkanes perfluoroalkyl borate anion, tetrafluoroborate anion, perfluoroalkyl bo ... phosphate anion, hexafluorophosphate anion, or perfluoroalkyl phosphate hydrate anions, etc.

[0097] In addition, the supporting electrolyte dissolved in the above solvent uses lithium ions as a carrier. For example, LiPF6, LiClO4, LiAsF6, LiBF4, LiAlCl4 , LiSCN, LiBr, LiI, Li2SO4, Li2B 10 Cl 10 , Li2B 12 Cl 12 , LiCF3SO3, LiC4F9SO3, LiC(CF3SO2)3, LiC (C2F5SO2)3, LiN(CF3SO2)2, LiN(C4F9SO2)(CF3 SO2), LiN(C2F5SO2)2, or any combination of these lithium salts The above can be used in any combination and ratio.

[0098] In addition, the electrolyte used in the electricity storage device is free from granular waste and elements other than the constituent elements of the electrolyte (hereinafter referred to as It is preferable to use a highly purified electrolyte solution with a low content of impurities. Specifically, the weight ratio of impurities to the electrolyte is 1% or less, preferably 0.1% or less. More preferably, it is set to 0.01% or less.

[0099] In addition, the electrolyte contains vinylene carbonate, propane sultone (PS), and tert-butyl Addition of benzene (TBB), fluoroethylene carbonate (FEC), LiBOB, etc. The concentration of the additive may be, for example, 0.1% by weight or more relative to the total solvent. The upper limit should be 5% by weight or less.

[0100] Alternatively, a polymer gel electrolyte may be used in which a polymer is swollen with an electrolytic solution.

[0101] Examples of polymers include polyalkylene oxides such as polyethylene oxide (PEO). Polymers with side structures, PVDF, polyacrylonitrile, etc., and their For example, a copolymer containing PVDF and hexafluoropropylene ( PVDF-HFP, a copolymer of PVDF and HFP, can be used. The polymer may have a porous shape.

[0102] In addition, instead of the electrolytic solution, a solid electrolyte containing an inorganic material such as a sulfide or oxide, It is possible to use a solid electrolyte containing a polymer material such as PEO (polyethylene oxide). When a solid electrolyte is used, there is no need to install a separator or spacer. Since the entire battery can be solidified, there is no risk of leakage, dramatically improving safety.

[0103] The separator 507 may be made of, for example, paper, nonwoven fabric, glass fiber, ceramics, or Nylon (polyamide), Vinylon (polyvinyl alcohol fiber), polyester, It is recommended to use synthetic fibers such as acrylic, polyolefin, and polyurethane. This can be done.

[0104] The positive electrode 503 and the negative electrode 506 will be described in detail in the following embodiment.

[0105] In the above configuration, the exterior body 509 of the storage battery has a minimum curvature radius of, for example, 3 mm or more. 0 mm or less, more preferably 3 mm to 10 mm. The film that forms the exterior of the storage battery is made up of one or two sheets, and the storage battery has a laminated structure. In the case of a battery, the cross-sectional structure of the curved battery is sandwiched between two curves of the film that is the exterior body. The resulting structure is

[0106] The radius of curvature of a surface will be explained with reference to FIG. 9. In FIG. 9(A), a curved surface 1700 is On the cut plane 1701, a part of the curve 1702 included in the surface 1700 is cut into an arc of a circle. By approximation, the radius of the circle is taken as the radius of curvature 1703 and the center of the circle is taken as the center of curvature 1704 . 9B shows a top view of the curved surface 1700. FIG. 9C shows the curved surface 1700 on the plane 1701. When cutting a curved surface with a plane, the angle of the plane relative to the curved surface and the cutting position are important. The radius of curvature of the curve that appears in the cross section will differ depending on the position. The smaller radius of curvature is taken as the radius of curvature of the surface.

[0107] The secondary battery is curved, sandwiching electrodes, electrolyte, etc., 1805 between two films as the exterior body. In this case, the radius of curvature 1802 of the film 1801 on the side closer to the center of curvature 1800 of the secondary battery is smaller than the radius of curvature 1804 of the film 1803 on the side farther from the center of curvature 1800 ( When a secondary battery is bent to make its cross section arc-shaped, the center of curvature is 180°. The surface of the film is subjected to compressive stress, and the surface of the film far from the center of curvature 180° is subjected to tension. By providing a slit in the sealing part of the exterior body, this Even if compressive or tensile stress is applied, the effects of strain are kept within the allowable range. Therefore, the secondary battery can be prevented from being damaged by the smallest curvature radius of the exterior body on the side closer to the center of curvature. The diameter is, for example, 3 mm or more and 30 mm or less, more preferably 3 mm or more and 10 mm or less. It can be transformed as follows.

[0108] The cross-sectional shape of the secondary battery is not limited to a simple arc shape, and may be a shape having a partial arc. For example, the shape shown in FIG. 10(C), a wave shape (FIG. 10(D)), an S-shape, etc. When the curved surface of the secondary battery has a shape with multiple centers of curvature, Among the radii of curvature at each of the centers of curvature, the surface with the smallest radius of curvature is 2 The smallest radius of curvature of the outer casing closest to the center of curvature of one outer casing is, for example, 3 mm or more and 30 mm More preferably, the deformation can be made to be 3 mm or more and 10 mm or less.

[0109] <Production method> The separator 507 is processed into a bag shape and encases either the positive electrode 503 or the negative electrode 506. For example, as shown in FIG. 11(A), the positive electrode 503 is sandwiched between the electrodes. The separator 507 is folded in half so that the sealing portion 5 is located outside the area overlapping with the positive electrode 503. By sealing with 14, the positive electrode 503 can be reliably supported within the separator 507. Then, as shown in FIG. 11(B), the positive electrode 503 and the negative electrode 504 wrapped in the separator 507 are The electrodes 506 are alternately stacked and arranged in an exterior body 509, thereby forming a thin storage battery. It is preferable to form the power storage device 500 having such a structure.

[0110] FIG. 12 shows an example in which a current collector is welded to a lead electrode. The positive electrode 503 wrapped in the separator 507 and the negative electrode 506 are stacked alternately. The positive electrode current collector of the negative electrode 506 is connected to the positive electrode lead 510. An example in which the positive electrode current collector 501 is welded to the positive electrode lead 510 is shown below. 12(B), the positive electrode current collector 501 is welded in a welding region 512 by ultrasonic welding or the like. The positive electrode current collector 501 is welded to the electrode lead 510. The positive electrode current collector 501 has a curved portion 5 shown in FIG. By providing the electrode 13, stress generated when external force is applied after the production of the power storage device 500 can be reduced. This can mitigate the risk of electric shock and improve the reliability of the electricity storage device 500. The area where welding is performed on the body or negative electrode current collector is sometimes called a tab area.

[0111] FIG. 13A is a perspective view illustrating a method for manufacturing a power storage device 500, and FIG. 13B is a perspective view illustrating a method for manufacturing a power storage device 500. 13A and 13B are top views illustrating a method for manufacturing the battery device 500. As shown in FIG. 13A, the positive electrode lead a positive electrode to which a lead 510 is welded, and a negative electrode to which a lead 511 is welded and which is wrapped around the negative electrode. The stacked laminate 541 is wrapped in an exterior body 509. As shown in FIG. 13(B), The power storage device 500 includes a sealing portion 509i, a sealing portion 509j, and a sealing portion 509k. During the manufacturing process, for example, the sealing portion 509k is sealed, then the sealing portion 509i is sealed, and the sealing portion Before sealing the area that will become 509j, an electrolyte is injected from the area, and then the sealing portion 509j The three sealing portions 509i to 509k are combined to form a region It's called 509b.

[0112] Next, a slit or a hole is made in the region 509b. For example, the slit or the like is made by cutting the outer surface with a blade. The area 509b of the housing 509 may be cut off. Alternatively, the area 509b may be processed by a laser or the like. Alternatively, slits or the like may be provided.

[0113] <Example of a slit> 43 and 44 show an example in which an exterior body 509 of a power storage device 500 has a slit in the sealing portion. It should be noted that exterior body 509 has an uneven surface (also called embossing).

[0114] FIG. 43(A) is a photograph of the power storage device 500 observed from above, and FIG. 43(B) is a photograph of the power storage device 500 observed from above. 44 is a photograph of the power storage device 500 observed from the side. The exterior body is 60mm wide and 75mm long, and the width of the sealing parts on the left and right sides is 5mm to 6mm. The width of the sealing part on the top edge where the lead electrodes are taken out was between 5 mm and 5.5 mm. A slit was made in the sealing area of ​​the exterior body using scissors. The slit was made approximately along the edge of the exterior body. The holes were provided approximately vertically, at intervals of about 3 mm, and at a length of about 2 mm from the end.

[0115] <Example of lamination> Next, various examples of lamination of a positive electrode, a negative electrode, and a separator are shown.

[0116] FIG. 14A shows an example in which six layers of positive electrodes 111 and six layers of negative electrodes 115 are stacked. The electrode 111 has a positive electrode current collector 121 on one side of which a positive electrode active material layer 122 is provided. The negative electrode 115 has a negative electrode current collector 125 on one surface of which a negative electrode active material layer 126 is provided.

[0117] In the configuration shown in FIG. 14(A), the positive electrode 111 is a planar structure that does not have a positive electrode active material layer 122. The positive electrode 115 is placed on the negative electrode 115 so that the surfaces thereof not having the negative electrode active material layer 126 are in contact with each other. By stacking the positive electrode 111 and the negative electrode 115 in this order, the positive electrode active material of the positive electrode 111 can be The surfaces of the negative electrodes 115 that do not have the negative electrode active material layer 122 are called the surfaces of the negative electrodes 115 that do not have the negative electrode active material layer 126. The metal-to-metal contact surface is formed by the active material and the separator. The coefficient of friction can be reduced compared to the contact surface of the other surface.

[0118] Therefore, when the power storage device is bent, the surface of the positive electrode 111 that does not have the positive electrode active material layer 122 is flush with the surface of the positive electrode 111. The surfaces of the negative electrodes 115 that do not have the negative electrode active material layer 126 slide against each other, so that the inner and outer diameters of the curve Here, the inner radius of the curve is, for example, the radius of the storage device 5 When bending the battery pack 500, the battery pack 500 is positioned inside the bending portion of the exterior body 509 of the battery pack 500. Therefore, deterioration of the power storage device 500 can be suppressed. Moreover, the power storage device 500 can be made highly reliable.

[0119] FIG. 14(B) shows an example of lamination of a positive electrode 111 and a negative electrode 115, which is different from that shown in FIG. 14(A). In the configuration shown in FIG. 14(B), a positive electrode active material layer 122 is provided on both sides of a positive electrode current collector 121. 14(B) differs from the configuration shown in FIG. 14(A) in that the positive electrode current collector By providing the positive electrode active material layers 122 on both sides of the positive electrode active material layer 121, The capacity can be increased.

[0120] FIG. 14(C) shows an example of lamination of the positive electrode 111 and the negative electrode 115, which is different from that shown in FIG. 14(B). In the configuration shown in FIG. 14(C), a negative electrode active material layer 126 is provided on both sides of a negative electrode current collector 125. 14(C) differs from the configuration shown in FIG. 14(B) in that the negative electrode current collector By providing the negative electrode active material layers 126 on both sides of the negative electrode active material layer 125, The capacity can be further increased.

[0121] In the configuration shown in FIG. 14, the separator 123 encases the positive electrode 111 in a bag-like shape. However, the present invention is not limited to this. 15(A) shows an example in which the separator 123 has a different structure from that shown in FIG. A sheet-like separator 123 is provided between each of the active material layer 122 and the negative electrode active material layer 126. The configuration shown in FIG. 15(A) differs from the configuration shown in FIG. 14(A) in that Six layers of positive electrodes 111 and six layers of negative electrodes 115 are stacked, and six layers of separators 123 are provided. .

[0122] FIG. 15(B) shows an example in which a separator 123 different from that in FIG. 15(A) is provided. In the configuration shown in FIG. 15(B), one separator 123 separates the positive electrode active material layer 122 and the negative electrode active material layer 123. The point where the layer 126 is folded back multiple times so as to be sandwiched between the layers 126 is shown in FIG. The structure shown in FIG. 15(B) is different from the structure shown in FIG. 15(A). It can also be said that the structure is such that the layers are connected by extending the connector 123. In the configuration, six layers of positive electrodes 111 and six layers of negative electrodes 115 are stacked. The separator 123 may be folded five times or more. The electrode 111 is not only sandwiched between the porous layer 126 but also extends to form a plurality of positive electrodes 111 and negative electrodes 112. 15 may be bound together.

[0123] Alternatively, the positive electrode, the negative electrode, and the separator may be stacked as shown in Figure 16(A). FIG. 16(A) is a cross-sectional view of the first electrode assembly 130, and FIG. 16(B) is a cross-sectional view of the second electrode assembly 131. 16(C) is a cross-sectional view taken along dashed line A1-A2 shown in the top view of FIG. 1(A) and the like. In FIG. 16(C), for clarity, the first electrode assembly 130 and the second electrode assembly The body 131 and the separator 123 are selectively shown.

[0124] As shown in FIG. 16(C), the power storage device 500 includes a plurality of first electrode assemblies 130 and It has a plurality of second electrode assemblies 131.

[0125] As shown in FIG. 16(A), in the first electrode assembly 130, the positive electrode current collector 121 has a A positive electrode 111a having a positive electrode active material layer 122, a separator 123, and both surfaces of a negative electrode current collector 125 The negative electrode 115a has a negative electrode active material layer 126 thereon, the separator 123, and the positive electrode current collector 121. The positive electrode 111a having the positive electrode active material layer 122 on the surface is laminated in this order. As shown in B), in the second electrode assembly 131, a negative electrode active material is applied to both sides of the negative electrode current collector 125. The negative electrode 115a having the layer 126, the separator 123, and the positive electrode current collector 121 are provided on both sides with the positive electrode active material. The cathode 111a has a porous layer 122, a separator 123, and a negative electrode active material on both sides of the negative electrode current collector 125. The negative electrode 115a having the material layer 126 is laminated in this order.

[0126] Furthermore, as shown in FIG. 16(C), a plurality of first electrode assemblies 130 and a plurality of second The electrode assembly 131 is covered with a wound separator 123 .

[0127] <Unevenness of the exterior body> Here, the exterior body may have irregularities. For example, protrusions may be provided on the film. Examples of providing convex portions on a film include embossing the film and forming the film into a bellows shape. , etc.

[0128] Metal films are easy to emboss. This increases the surface area of ​​the exterior body exposed to the outside air, for example, the ratio of the surface area to the area seen from above. The embossing process creates a shape on the surface (or back) of the film. The formed convex portion forms a closed space with a variable volume, with the film as part of the wall of the sealing structure. This closed space can be said to be formed by the convex parts of the film forming a bellows structure. In addition to embossing, which is a type of press processing, Any method that can form the above structure is acceptable.

[0129] Next, the cross-sectional shape of the convex portion will be described with reference to FIGS.

[0130] As shown in FIG. 17, in the film 10, a convex portion 10a having a peak in a first direction and The protrusions 10b having peaks in the first direction and the second direction are alternately arranged. The first direction is one surface side, and the second direction is the other surface side. The part may refer to the maximum point when the first direction is the positive direction. The peak of the direction may refer to the maximum point when the second direction is the positive direction.

[0131] The cross-sectional shape of the protrusions 10a and 10b may be a hollow semicircular shape, a hollow semi-elliptical shape, a hollow polygonal shape, Alternatively, it can be hollow and irregular. In the case of a hollow polygonal shape, it has more corners than a hexagon. By having this, it is possible to reduce the concentration of stress at the corners, which is preferable.

[0132] FIG. 17 shows the depth 351 of the protrusions 10a, the pitch 352 of the protrusions 10a, and the depth 353 of the protrusions 10b. 353, the distance between the convex portions 10a and 10b 354, the thickness of the film 10 355, The bottom thickness 356 of the portion 10a is shown. Also, the height 357 is the maximum height of the surface of the film. The difference between the height and the minimum height.

[0133] Next, various examples of the film 10 having the protrusions 10a are shown in FIGS. 18(A) to 18(F).

[0134] Also, various examples of the film 10 having the convex portions 10a and the convex portions 10b are shown in FIG. Shown in (D).

[0135] Next, the top surface shape of the convex portion will be described with reference to FIGS.

[0136] The film shown in FIG. 20(A) has convex portions 10a having peaks arranged regularly on one side. Here, the dashed line e1 indicating the direction in which the protrusions 10a are arranged is aligned with respect to the side of the film. It is slanted.

[0137] The film shown in FIG. 20(B) has convex portions 10a having peaks arranged regularly on one side. Here, the broken line e1 indicating the direction in which the protrusions 10a are arranged is aligned with respect to the long side of the film. are parallel.

[0138] The film shown in FIG. 21(A) has a convex portion 10a having a top on one side and a convex portion 10b on the other side. The protrusions 10b having a top are regularly arranged. The dashed line e1 indicating the direction in which the projections 10b are aligned and the dashed line e2 indicating the direction in which the projections 10b are aligned are oblique to the side of the film. and the dashed lines e1 and e2 intersect.

[0139] The film shown in FIG. 21(B) has a convex portion 10a having a top on one side and a convex portion 10b on the other side. The protrusions 10b having a top are regularly arranged. The broken line e1 indicating the direction in which the protrusions 10b are arranged and the broken line e2 indicating the direction in which the protrusions 10b are arranged are aligned with respect to the long side of the film. They are parallel.

[0140] The film shown in FIG. 21(C) has a protrusion 10a having a top on one side and a The protrusions 10b having a top are regularly arranged. The broken line e1 indicating the direction in which the protrusions 10b are arranged and the broken line e2 indicating the direction in which the protrusions 10b are arranged are aligned with respect to the short side of the film. They are parallel.

[0141] The film shown in FIG. 21(D) has a convex portion 10a having a top on one side and a convex portion 10b on the other side. The protrusions 10b each having a peak are irregularly arranged.

[0142] Although the top surface shape of each of the protrusions shown in FIGS. 20 and 21 is circular, it is possible to For example, it may be polygonal or irregular.

[0143] 21, a film having a convex portion 10a having a top on one side and a convex portion 10b on the other side is also used. The convex portions 10b having their apexes on the other surface side may have the same upper surface shape. As shown in FIG. 2(A), a protrusion 10a having a top on one side and a protrusion 10b having a top on the other side are provided. The upper surface shapes of the adjacent protrusions 10b may be different from each other.

[0144] In the film shown in FIG. 22(A), the upper surface shape of the protrusion 10a is linear, and the protrusion 1 The upper surface shape of the protrusion 10a is a circle. The upper surface shape of the protrusion 10a may be a straight line, a curved line, a wavy line, or the like. The upper surface shape of the protrusion 10b may be polygonal, zigzag, or irregular. may be.

[0145] Alternatively, as shown in FIG. 22(B), the upper surface shape of the protrusions 10a and 10b may be a cross shape. That's fine.

[0146] By having the upper surface shape as shown in Figs. 20 to 22, it is possible to bend in at least two directions. Stress can be relieved.

[0147] 23 shows an example in which the upper surface shape of the convex portion is linear. As a cross section taken along the dashed line e3 shown in Figures 23(A) to 23(D), 7 to 19 can be applied.

[0148] The film shown in FIG. 23(A) has linear protrusions 10a arranged on one surface. Here, the broken line e1 indicating the direction of the linear protrusion 10a is aligned with the side of the film. The film shown in FIG. 23(B) has a linear shape with a peak on one side. The protrusions 10a and linear protrusions 10b having a peak on the other surface side are arranged alternately. Here, a broken line e1 indicates the direction of the linear protrusion 10a, and a broken line e2 indicates the direction of the linear protrusion 10b. Line e2 is parallel to the edge of the film.

[0149] The film shown in FIG. 23(C) has linear protrusions 10a arranged on one surface. Here, the broken line e1 indicating the direction of the linear protrusion 10a is aligned with the side of the film. The film shown in FIG. 23(D) has a linear shape with a peak on one side. The protrusions 10a and linear protrusions 10b having a peak on the other surface side are arranged alternately. Here, a broken line e1 indicates the direction of the linear protrusion 10a, and a broken line e2 indicates the direction of the linear protrusion 10b. Line e2 is oblique to the edge of the film.

[0150] The exterior body of one embodiment of the present invention has a plurality of protrusions, and the depth of the protrusions is preferably 1 mm or less. , more preferably 0.15 mm or more and less than 0.8 mm, and further preferably 0.3 mm or more and It is less than 0.7mm.

[0151] The density of the protrusions per area is, for example, 0.02 pieces / mm 2 More than 2 pieces / mm 2 The following is preferred Preferably, 0.05 pieces / mm 2 More than 1 piece / mm 2Less than 0.1 pieces / mm is more preferable. 2 Below Upper 0.5 pieces / mm 2 The following is even more preferred:

[0152] This embodiment mode can be implemented in appropriate combination with other embodiment modes.

[0153] (Embodiment 2) In this embodiment, electronic devices of one embodiment of the present invention will be described with reference to FIGS. 24 to 28. Reveal.

[0154] <Smartwatch configuration example> FIG. 24A shows a perspective view of a wristwatch-type mobile information terminal (also called a smart watch) 700. The mobile information terminal 700 includes a housing 701, a display panel 702, a clasp 703, a band The keyboard 705 has keyboards 705A and 705B, and operation buttons 711 and 712.

[0155] A display panel 702 mounted on a housing 701 that also serves as a bezel has a rectangular display area. The display area is a curved surface. The display panel 702 is flexible. It is preferable that the display area be non-rectangular.

[0156] The band 705A and the band 705B are connected to the housing 701. The clasp 703 is The band 705A and the housing 701 are connected via a pin, for example. The band 705B and the housing 701, as well as the band 70 The same applies to the connection between 5A and clasp 703.

[0157] 24B and 24C are perspective views of the band 705A and the power storage device 750, respectively. The band 705A includes a power storage device 750. The power storage device 750 may include, for example, The power storage device 750 can be used in the band 70. 5A, and a positive electrode lead 751 and a negative electrode lead 752 are each partially buried. The positive electrode lead 751 and the negative electrode lead 752 protrude from the lead 705A (see FIG. 24(B)). The cover 752 is electrically connected to the display panel 702. The surface of the power storage device 750 is The pins are covered with a body 753 (see FIG. 24(C)). Specifically, the positive electrode lead 751 and the display panel 702, and the negative electrode lead The band 705A and the display panel 702 are connected to each other. The bands 705A and 705B may be electrically connected via pins. In addition, the configuration of the connection portion of the housing 701 can be simplified.

[0158] The power storage device 750 is flexible.

[0159] The band 705A can be manufactured by being integrally formed with the power storage device 750. For example, The electricity storage device 750 is set in a mold corresponding to the outer shape of the band 705A, and the material of the band 705A is The material is poured into a mold and hardened to produce the band 705A shown in FIG. 24(B). Cut.

[0160] When rubber material is used as the material for the band 705A, the rubber is hardened by heat treatment. For example, if fluororubber is used as the rubber material, heat treatment at 170°C for 10 minutes will When silicone rubber is used as the rubber material, it is cured at 150°C for 10 minutes. The power storage device of one embodiment of the present invention has high heat resistance, so the rubber material This can suppress damage during heat treatment associated with integral formation with the battery and deterioration of charge / discharge characteristics.

[0161] The materials used for the band 705A include fluororubber, silicone rubber, and fluorosilicone. Examples include urethane rubber and urethane rubber.

[0162] The power supply to the power storage device 750, including the aging, is performed by the integrated type with the band 705A. In other words, the power storage device 500 described in the first embodiment is It is preferable to perform a heat treatment before energizing the power supply device 500. The heat treatment is performed at a temperature of 150° C. or higher. At 190°C or less, the vulcanization time for the above rubber material is appropriate, for example, at 170°C. It is preferable to perform the heating process for 10 minutes. Deterioration of charge / discharge characteristics can be suppressed.

[0163] Note that the portable information terminal 700 shown in FIG. 24(A) can have various functions. For example, functions to display various information (still images, videos, text images, etc.) in the display area, Touch panel function, calendar, date or time display function, various software ( It has the function of controlling processing by using a program, wireless communication function, and various functions using wireless communication function. Functions for connecting to computer networks, transmitting various data using wireless communication functions, The function is to receive, read out the program or data recorded on the recording medium and display it in the display area. It may have the function of displaying the information in a specific area, etc.

[0164] In addition, a speaker, a sensor (force, displacement, position, velocity, acceleration, angular velocity) Degrees, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, electricity Includes functions to measure pressure, power, radiation, flow rate, humidity, gradient, vibration, odor or infrared. The portable information terminal 700 may have a light-emitting element, a microphone, etc. The display panel 702 can be manufactured by using the above.

[0165] Although FIG. 24 shows an example in which the power storage device 750 is included in the band 705A, 750 may be included in band 705B. Band 705B may be included in band 705A. The same materials as those mentioned above can be used.

[0166] The rubber material used for the band 705A is preferably highly resistant to chemicals. It is preferable that the material has low reactivity with the electrolyte contained in the electrical device 750 .

[0167] Even if the band 705A has excellent chemical resistance, cracks and peeling may occur in the band 705A. In this case, if the user of the portable information terminal 700 comes into contact with the electrolyte leaking from the power storage device 750, If the portable information terminal 700 has a function for detecting electrolyte leakage, When a solution leak is detected, the user can stop operating the mobile information terminal 700 and remove it. Therefore, the portable information terminal 700 can be made highly secure.

[0168] <Configuration example of power storage device> Next, a flexible power storage device will be described with reference to FIGS. The power storage device of one embodiment of the present invention may have a curved shape. It is flexible and can be used in both a curved and an uncurved state. Good too.

[0169] FIG. 25(A) shows a perspective view of the secondary battery 200, and FIG. 25(B) shows a top view of the secondary battery 200. The figure is shown.

[0170] FIG. 26(A) shows a cross-sectional view taken along the dashed line C1-C2 in FIG. 25(B). 25B shows a cross-sectional view taken along the dashed line C3-C4 in FIG. 25B. In A) and B), some components are selectively shown to make the diagram clearer.

[0171] The secondary battery 200 includes a positive electrode 211, a negative electrode 215, and a separator 203. The battery 200 further includes a positive electrode lead 221, a negative electrode lead 225, and an outer casing 207. .

[0172] The positive electrode 211 and the negative electrode 215 each have a current collector and an active material layer. The negative electrode 215 and the positive electrode 216 are disposed with the separator 203 interposed between them so that the active material layers face each other. are.

[0173] The electrodes (positive electrode 211 and negative electrode 215) of the secondary battery 200 are located on the inner diameter side of the curve. It is preferable that the one positioned on the outer diameter side is longer in the axial direction of the curve than the one positioned on the outer diameter side. With this configuration, when the secondary battery 200 is bent at a certain curvature, the positive electrode 211 and In other words, the positive electrode active material layer of the positive electrode 211 can be aligned with the negative electrode 215. All of these regions can be disposed facing the negative electrode active material layer of the negative electrode 215. Therefore, the positive electrode active material contained in the positive electrode 211 can be made to contribute to the battery reaction without waste. Therefore, the capacity per unit volume of the secondary battery 200 can be increased. This is particularly effective when the curvature of the secondary battery 200 is fixed when the secondary battery 200 is used. .

[0174] The positive electrode lead 221 is electrically connected to the plurality of positive electrodes 211. The positive electrode lead 221 and the negative electrode lead 22 are electrically connected to the plurality of negative electrodes 215. 5 each have a sealing layer 220.

[0175] The exterior body 207 includes a plurality of positive electrodes 211, a plurality of negative electrodes 215, and a plurality of separators 203. The secondary battery 200 has an electrolyte (not shown) in the area covered by the exterior body 207. The secondary battery 200 is sealed by bonding three sides of the exterior body 207.

[0176] 26(A) and (B), a plurality of strip-shaped separators 203 are used to separate a positive electrode 211 and a negative electrode 215, one separator 203 is disposed between each of the electrodes 215. The shape is not limited to this. One sheet of separator is folded zigzag (into an accordion shape). , or wound so that the separator is located between the positive and negative electrodes. That's fine.

[0177] For example, a method for manufacturing a secondary battery 200 is shown in FIGS. FIG. 27 shows a cross section taken along the dashed line C1-C2 in FIG. 25(B) when the ion implantation device is used.

[0178] First, the negative electrode 215 is placed on the separator 203 (FIG. 28(A)). The negative electrode active material layer of the electrode 215 is disposed so as to overlap the separator 203 .

[0179] Next, the separator 203 is folded and placed on top of the negative electrode 215. Then, the positive electrode 211 is placed on the separator 203 (FIG. 28(B)). The positive electrode active material layer of the separator 203 is disposed so as to overlap with the negative electrode active material layer. When an electrode having an active material layer formed on one side of a current collector is used, the positive electrode 211 The positive electrode active material layer of the negative electrode 215 and the negative electrode active material layer of the negative electrode 215 are arranged opposite each other with the separator 203 interposed therebetween. Place it in.

[0180] When the separator 203 is made of a material that can be heat-sealed, such as polypropylene, The overlapping area of ​​the electrodes 203 is thermally welded together, and then the next electrode is placed on top of it. Specifically, the electrode overlapping with the negative electrode 215 or the positive electrode 211 can be prevented from shifting during the process. In the region where the separators 203 are not overlapped, for example, the region 20 in FIG. It is preferable to heat weld the area indicated by 3a.

[0181] By repeating this process, the separator 203 is sandwiched between the positive and negative electrodes as shown in FIG. 28(C). The electrode 211 and the negative electrode 215 can be stacked.

[0182] The separator 203 is repeatedly folded in advance, and a plurality of negative electrodes 215 and a plurality of negative electrodes 215 are attached to the separator 203. The positive electrodes 211 may be arranged so as to be sandwiched alternately.

[0183] Next, as shown in FIG. 28(C), a plurality of positive electrodes 211 and a plurality of negative electrodes are separated by a separator 203. Covers pole 215.

[0184] Furthermore, as shown in FIG. 28(D), in the region where the separators 203 overlap each other, for example, For example, by thermally welding the region 203b shown in FIG. 28(D), a plurality of positive electrodes 211 and a plurality of negative electrodes 215 is covered with a separator 203 and bound together.

[0185] The plurality of positive electrodes 211, the plurality of negative electrodes 215, and the separator 203 are bound together using a binding material. May be tied up.

[0186] In this process, the positive electrode 211 and the negative electrode 215 are stacked, and the separator 203 is In one separator 203, the area sandwiched between a plurality of positive electrodes 211 and a plurality of negative electrodes 215 and a region disposed so as to cover the plurality of positive electrodes 211 and the plurality of negative electrodes 215. .

[0187] In other words, the separator 203 of the secondary battery 200 shown in FIGS. 27 and 28(D) is , is a single separator that is partially folded. A plurality of positive electrodes 211 and a plurality of negative electrodes 215 are sandwiched between the positive electrodes 211 and the negative electrodes 215.

[0188] This embodiment mode can be implemented in appropriate combination with other embodiment modes.

[0189] (Embodiment 3) In this embodiment, a positive electrode and a negative electrode included in a power storage device of one embodiment of the present invention will be described. do.

[0190] The positive electrode of one embodiment of the present invention preferably contains a positive electrode active material. The positive electrode of one embodiment of the present invention may contain a binder. good.

[0191] The negative electrode of one embodiment of the present invention preferably contains a negative electrode active material. The negative electrode of one embodiment of the present invention may contain a binder. good.

[0192] <Negative electrode active material> As the negative electrode active material, for example, a carbon-based material or an alloy-based material can be used.

[0193] Carbon materials include graphite, easily graphitizable carbon (soft carbon), and non-graphitizable carbon (hard carbon). carbon nanotubes, graphene, carbon black, etc. stomach.

[0194] Examples of graphite include artificial graphite and natural graphite. Examples include carbon microbeads (MCMB), coke-based artificial graphite, and pitch-based artificial graphite. Here, spherical graphite having a spherical shape can be used as the artificial graphite. For example, the MCMB may have a spherical shape, which is preferable. It is relatively easy to reduce the product, which is sometimes preferable. , flake graphite, and spherical natural graphite.

[0195] Graphite is formed when lithium ions are inserted into graphite (when lithium-graphite intercalation compounds are formed) It shows a low potential similar to that of lithium metal (0.1V to 0.3V vs. Li / L i + This allows the lithium-ion secondary battery to exhibit a high operating voltage. In addition, graphite has a relatively high capacity per unit volume, a relatively small volume expansion, and is inexpensive. It is preferable because it has advantages such as higher safety compared to lithium metal.

[0196] As a negative electrode active material, it can carry out charge-discharge reactions by alloying and dealloying reactions with lithium. Any element can be used, such as silicon, tin, gallium, aluminum, Germanium, lead, antimony, bismuth, silver, zinc, cadmium, indium, etc. Materials containing at least one of these elements can be used. These elements have a higher capacity than carbon. Silicon has a particularly high theoretical capacity of 4200mAh / g. Silicon is preferably used, and compounds containing these elements may also be used. For example, SiO, Mg2Si, Mg2Ge, SnO, SnO2, Mg2Sn, SnS2, V2Sn3, FeSn2, CoSn2, Ni3Sn2, Cu6Sn5, Ag3Sn, Ag 3Sb, Ni2MnSb, CeSb3, LaSn3, La3Co2Sn7, CoSb3, Examples include InSb and SbSn. Here, charging and discharging occurs through alloying and dealloying reactions with lithium. Elements that can undergo a reaction and compounds containing such elements are sometimes called alloy materials. be.

[0197] In this specification and the like, SiO refers to, for example, silicon monoxide. Alternatively, SiO refers to, for example, It can also be expressed as SiOx, where x preferably has a value close to 1. For example, x is preferably 0.2 or more and 1.5 or less, and more preferably 0.3 or more and 1.2 or less.

[0198] Further, the negative electrode active material of one embodiment of the present invention may contain silicon, lithium, and oxygen. For example, silicon and lithium silicon oxide positioned outside the silicon may be used. It may have.

[0199] In addition, titanium dioxide (TiO2) and lithium titanium oxide (Li4 Ti5O 12 ), lithium-graphite intercalation compound (Li x C6), niobium pentoxide (Nb2O5 ), tungsten oxide (WO2), molybdenum oxide (MoO2), etc. can be done.

[0200] In addition, the negative electrode active material is a composite nitride of lithium and transition metals, which has a Li3N structure. つLi 3-x M xN (M=Co, Ni, Cu) can be used. For example, Li 2. 6Co 0.4 N3 has a large charge / discharge capacity (900mAh / g, 1890mAh / cm 3 )of This is preferable.

[0201] When a composite nitride of lithium and transition metals is used, lithium ions are included in the negative electrode active material, As a positive electrode active material, materials that do not contain lithium ions, such as V2O5 and Cr3O8, are used. In addition, when a material containing lithium ions is used as the positive electrode active material, However, by first removing the lithium ions contained in the positive electrode active material, As the lithium-transition metal nitride, a complex nitride of lithium and a transition metal can be used.

[0202] In addition, a material that undergoes a conversion reaction can also be used as the negative electrode active material. For example, lithium oxides such as cobalt oxide (CoO), nickel oxide (NiO), and iron oxide (FeO) A transition metal oxide that does not form an alloy with aluminum may be used as the negative electrode active material. Further materials that can produce this include Fe2O3, CuO, Cu2O, RuO2, and Cr2O3 oxides such as CoS 0.89 , NiS, CuS and other sulfides, Zn3N2, Cu3N, Ge Nitrides such as 3N4, phosphides such as NiP2, FeP2, CoP3, FeF3, BiF3, etc. There is also fluoride.

[0203] The lower the reaction potential of the negative electrode active material, the higher the voltage of the power storage device can be, which is preferable. On the other hand, when the potential is low, the power to reduce the electrolyte is also strong, so for example, The range of potentials within which the electrolyte does not undergo electrolysis is called the potential window. The negative electrode is essentially a cathode whose electrode potential is equal to that of the electrolyte. It must be within the potential window, but for example, lithium ion secondary batteries and lithium ion capacitors The potential of most of the active materials used in the negative electrode of a battery exceeds the potential window of almost all electrolytes. In particular, materials with low reaction potential, such as graphite and silicon, have the advantage of being able to increase the voltage of the storage device. However, there is a problem in that the electrolyte is more susceptible to reductive decomposition.

[0204] <Cathode active material> As the positive electrode active material, for example, an olivine type crystal structure, a layered rock salt type crystal structure, or a spin A composite oxide having a flannel-type crystal structure can be used.

[0205] Positive electrode active materials include LiFeO2, LiCoO2, LiNiO2, LiMn2O4, and V 2O5, Cr2O5, MnO2, etc. can be used. In particular, LiCoO2 , large capacity, more stable in air than LiNiO2, All of these materials are preferred because they are thermally stable. The lithium-containing material has a spinel-type crystal structure containing nickel and a small amount of lithium nickel oxide. (LiNiO2 and LiNi 1-x M x When O2 (M=Co, Al, etc.) is mixed, This is preferable because it can improve the characteristics of the secondary battery using it.

[0206] For example, the average particle size of the primary particles of the positive electrode active material is 5 nm or more and 50 μm or less. It is preferable that the specific surface area is 100 nm or more and 500 nm or less, and more preferable that the specific surface area is 5 m 2 / g or more 15m 2 The average particle size of the secondary particles is preferably The average particle size is preferably 5 μm or more and 50 μm or less. Observation using a microscope or TEM, or particle size distribution analyzer using laser diffraction and scattering methods, etc. The specific surface area can be measured by a gas adsorption method.

[0207] In addition, the positive electrode active material is a compound having the composition formula Li a Mn b M c O d Lithium ma The element M can be any element other than lithium or manganese. It is preferable to use a metal element selected from the group consisting of silicon and phosphorus, and nickel is preferred. Furthermore, when measuring the entire particle of the lithium manganese composite oxide, When powered on <a / (b+c)<2、かつc>, 0 0 and 0.26≦(b+c) / d<0.5 In order to realize high capacity, it is preferable to have a crystal structure between the surface layer and the center. The lithium manganese composite oxide has regions with different crystal orientations or oxygen contents. In order to obtain such a lithium manganese composite oxide, it is preferable that, for example, 1.6≦ It is preferable that a≦1.848, 0.19≦c / b≦0.935, and 2.5≦d≦3. Furthermore, Li 1.68 Mn 0.8062 Ni 0.318 The formula is O3 It is particularly preferable to use lithium manganese composite oxide. 1. 68 Mn 0.8062 Ni 0.318 Lithium manganese composite with the formula O3 The oxide is the ratio (molar ratio) of the amount of raw materials, Li2CO3:MnCO3:NiO=0 ​Lithium manganese composite oxide formed by 0.84:0.8062:0.318 Therefore, the lithium manganese composite oxide has the composition formula Li 1.68 Mn 0.80 62 Ni 0.318 It is expressed as O3, but the composition may deviate from this.

[0208] The composition of metals, silicon, phosphorus, etc. of the entire lithium manganese composite oxide particle is, for example, For example, it can be measured using an ICP-MS (inductively coupled plasma mass spectrometer). The oxygen composition of the entire particle of lithium manganese composite oxide can be measured by, for example, EDX (energy dispersion It can also be measured using ICP-MS analysis. This can be determined by using valence evaluation from melt gas analysis and XAFS (X-ray absorption fine structure) analysis. The lithium manganese composite oxide is a compound oxide containing at least lithium and manganese. It refers to oxides containing chromium, cobalt, aluminum, nickel, iron, magnesium, Molybdenum, zinc, indium, gallium, copper, titanium, niobium, silicon, and phosphorus It may contain at least one element selected from the group consisting of:

[0209] Lithium manganese composite oxide having regions with different crystal structures, crystal orientations or oxygen contents An example of a cross section of a particle is shown in Figure 29.

[0210] As shown in FIG. 29(A), the crystal structure, crystal orientation, or oxygen content of the region is different. The lithium manganese composite oxide has a region 331, a region 332, and a region 333. The region 332 is preferably in contact with at least a part of the outside of the region 331. The side indicates that it is closer to the surface of the particle. It is preferred to have a region of the particle that coincides with the surface with the oxide.

[0211] As shown in FIG. 29(B), the region 331 has an area that is not covered by the region 332. Also, the region 332 may have an area that is not covered by the region 333. For example, the area 331 may be adjacent to the area 333. 32 and region 333.

[0212] Region 332 preferably has a different composition than region 331 .

[0213] For example, the composition of region 331 and region 332 are measured separately, and region 331 contains lithium and manganese. region 332 contains lithium, manganese, element M, and oxygen; The atomic ratio of lithium, manganese, element M, and oxygen in region 331 is a1:b1: The atomic ratio of lithium, manganese, element M, and oxygen in region 332 is expressed as c1:d1. The case where area 331 and area 3 are expressed as a2:b2:c2:d2 will be explained. The composition of each of the 32 samples can be determined by, for example, EDX (Energy Dispersion X-ray Diffraction) using a TEM (Transmission Electron Microscope). In EDX measurements, the lithium composition can be measured. Therefore, in the following, we will focus on the difference in composition between region 331 and region 332. Here, d1 / (b1+c1) is 2.2 or more. is preferable, and is more preferable to be 2.3 or more, and is further preferable to be 2.35 or more and 3 or less. It is more preferable that d2 / (b2+c2) is less than 2.2, and more preferably 2.1. It is more preferable that the ratio is less than 1.1, and even more preferable that the ratio is 1.1 or more and 1.9 or less. Even in this case, the entire lithium manganese composite oxide particle including the regions 331 and 332 The composition preferably satisfies the above-mentioned condition 0.26≦(b+c) / d<0.5.

[0214] Furthermore, the manganese in region 332 has a different valence than the manganese in region 331. The element M contained in the region 332 may have a different valence from the element M contained in the region 331. It may have a number.

[0215] More specifically, the region 331 is a lithium manganese composite having a layered rock salt type crystal structure. The region 332 is preferably a lithium oxide having a spinel-type crystal structure. Preferably, the oxide is a manganese-manganese composite oxide.

[0216] Here, if there is a spatial distribution in the composition of each region or the valence of elements, for example, The composition and valence of each region are evaluated, and the average value is calculated. good.

[0217] A transition layer may be provided between the region 332 and the region 331. Here, the transition layer is For example, the transition layer is a region where the composition changes continuously or stepwise. A transition layer is a region where the structure changes continuously or stepwise. The constants change continuously or stepwise. A mixed layer may be provided between the two layers. Here, the mixed layer is, for example, a layer having two or more different crystal orientations. The mixed layer refers to a mixture of the above crystals. Alternatively, the mixed layer may be a mixture of crystals with different crystal structures, e.g. This refers to a mixture of two or more crystals. Alternatively, a mixed layer may be a mixture of crystals with different compositions, e.g. This refers to the case where two or more crystals are mixed together.

[0218] The region 333 can be made of carbon or a metal compound. For example, cobalt, aluminum, nickel, iron, manganese, titanium, zinc, lithium, etc. Examples of metal compounds include oxides and fluorides of these metals. can be.

[0219] Of the above, it is particularly preferable that the region 333 contains carbon. Carbon has high electrical conductivity. Therefore, by using carbon-coated particles in the electrodes of a power storage device, it is possible to, for example, reduce the resistance of the electrodes. Furthermore, the region 333 preferably contains a graphene compound. By using a graphene compound in region 333, particles of lithium manganese composite oxide The graphene compound will be described later. More specifically, 33 may include, for example, graphene or graphene oxide. In addition, graphene obtained by reducing graphene oxide may be used as the graphene. Graphene has excellent electrical properties, such as high conductivity, and high flexibility. and has excellent physical properties such as high mechanical strength. By using laphene to perform reduction, the region 332 in contact with the region 333 may be oxidized. be.

[0220] The region 333 has a graphene compound, and thus the lithium manganese composite oxide can be used as a positive electrode. The cycle characteristics of a secondary battery using the material can be improved.

[0221] The thickness of the carbon-containing layer is preferably 0.4 nm or more and 40 nm or less.

[0222] In addition, the lithium manganese composite oxide has, for example, an average particle size of primary particles of 5 nm or more. It is preferably 50 μm or less, and more preferably 100 nm or more and 500 nm or less. It is also preferable that the specific surface area is 5m 2 / g or more 15m 2 / g or less. The average particle size of the secondary particles is preferably 5 μm or more and 50 μm or less.

[0223] Alternatively, a composite material (general formula LiMPO4 (M is Fe(II), M One or more of Ni(II), Co(II), Ni(II) can be used. Representative examples of iMPO4 include LiFePO4, LiNiPO4, LiCoPO4, and Li MnPO4, LiFe a Ni b PO4, LiFe a Co b PO4, LiFe a Mn b PO 4. LiNi a Co b PO4, LiNi a Mn b PO4(a+b is less than 1, 0 <a<1、 0 <b<1)、LiFe c Ni d Co e PO4, LiFe c Ni d Mn e PO4, LiN i c Co d Mn e PO4(c+d+e is less than 1, 0 <c<1、0<d<1、0<e<1) , LiFe f Ni g Co h Mn iPO4 (where f + g + h + i is 1 or less, 0 < f < 1, 0 < g <1, 0 < h < 1, 0 < i < 1), etc., lithium compounds can be used.

[0224] In particular, LiFePO4 satisfies well the requirements for a cathode active material, such as safety, stability, high capacity density, and the presence of lithium ions that can be extracted during initial oxidation (charging), so it is preferable.

[0225] Alternatively, as the cathode active material, a composite material represented by the general formula Li (2-j) MSiO4 (M is one or more of Fe(II), Mn(II), Co(II), Ni(II), 0 ≤ j ≤ 2), etc., can be used. As representative examples of the general formula Li (2-j) MSiO4, there are Li (2-j) F eSiO4, Li (2-j) NiSiO4, Li (2-j) CoSiO4, Li (2-j ) MnSiO4, Li (2-j) Fe k Ni l SiO4, Li (2-j) Fe k Co l S iO4, Li (2-j) Fe k Mn l SiO4, Li (2-j) Ni k Co l SiO4, Li (2-j) Ni k Mn l SiO4 (where k + l is 1 or less, 0 < k < 1, 0 < l < 1), L i (2-j) Fe m Ni n Co q SiO4, Li (2-j) Fe m Ni n Mn q SiO4 , Li​(2-j) Ni m Co n Mn q SiO4 (where 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 SiO4 (r + s + t + u is 1 or less, 0 < r < 1, 0 < s < 1, 0 < t < 1, 0 < u < 1), etc. lithium compounds can be used as materials.

[0226] Also, as the positive electrode active material, A x M2(XO4)3 (A = Li, Na, Mg, M = Fe, Mn, Ti, V, Nb, X = S, P, Mo, W, As, Si) represented by the general formula of NASICON type compounds can be used. NASICON type compounds include Fe2(MnO4)3, Fe2(SO4)3, Li3Fe2(PO4)3, etc. Also, as the positive electrode active material, L i2MPO4F, Li2MP2O7, Li5MO4 (M = Fe, Mn) represented by the general formula of compounds, perovskite type fluorides such as NaFeF3, FeF3, metal chalcogenides (sulfides, selenides, tellurides) such as TiS2, MoS2 etc., oxides having an inverse spinel type crystal structure such as LiMVO4, vanadium oxide systems (V2O5, V6O ., LiV 13 3O8, etc.), manganese oxides, organic sulfur compounds, etc. can be used as materials. When the carrier ion is an alkali metal ion other than lithium ion or an alkaline earth

[0227] metal ion, as the positive electrode active material, instead of lithium, an alkali metal (e.g., sodium or potassium, etc.), an alkaline earth metal (e.g., calcium, strontium, barium etc.) can be used. For example, NaFeO2 or Na 2 / 3 [Fe 1 / 2 Mn 1 / 2 ]O2 as the positive electrode active material. It can be used as such.

[0228] Furthermore, a combination of two or more of the above materials may be used as the positive electrode active material. For example, A solid solution of a combination of the above materials can be used as the positive electrode active material. iCo 1 / 3 Mn 1 / 3 Ni 1 / 3 A solid solution of O2 and Li2MnO3 is used as the positive electrode active material. You can be there.

[0229] Although not shown, a conductive material such as a carbon layer may be provided on the surface of the positive electrode active material. By providing a conductive material such as a base layer, the conductivity of the electrode can be improved. The carbon layer is coated on the positive electrode active material by mixing carbohydrates such as glucose during the firing of the positive electrode active material. It can be formed by

[0230] The average particle size of the primary particles of the granular positive electrode active material is 50 nm or more and 100 μm or less. It would be good to do so.

[0231] <Binder> As binders, styrene-butadiene rubber (SBR), styrene-isoprene-styrene Acrylonitrile butadiene rubber, butadiene rubber, ethylene propylene It is preferable to use a diene-based rubber material such as a diene copolymer. Fluorine rubber can be used.

[0232] As the binder, it is preferable to use, for example, a water-soluble polymer. As the molecule, for example, polysaccharides can be used. cellulose (CMC), methyl cellulose, ethyl cellulose, hydroxypropyl cellulose Cellulose derivatives such as cellulose, diacetyl cellulose, and regenerated cellulose, as well as starch These water-soluble polymers can be used in combination with the rubber materials described above. It is even better if there is one.

[0233] Alternatively, the binder may be polystyrene, polymethyl acrylate, or polymethyl methacrylate. Polymethyl methacrylate (PMMA), sodium polyacrylate, polyvinyl Polyvinyl alcohol (PVA), polyethylene oxide (PEO), polypropylene oxide, Polyimide, polyvinyl chloride, polytetrafluoroethylene, polyethylene, polypropylene Polyethylene, polyisobutylene, polyethylene terephthalate, nylon, polyvinylidene fluoride Polyvinyl fluoride (PVdF), polyacrylonitrile (PAN), ethylene propylene diene polymer It is preferable to use materials such as polyvinyl acetate and nitrocellulose.

[0234] Two or more of the above binders may be used in combination.

[0235] The content of the binder relative to the total amount of the active material layer is preferably 1 wt % or more and 10 wt % or less, More preferably, the content is 2 wt% or more and 8 wt% or less, and even more preferably, 3 wt% or more and 5 wt% or less. 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. It is preferable that the content be 1 wt % or more and 5 wt % or less.

[0236] <Conductive additive>

[0237] As the conductive additive, for example, a carbon material, a metal material, or a conductive ceramic material is used. In addition, a fibrous material may be used as the conductive additive. The content of the conductive additive is preferably 1 wt% or more and 10 wt% or less, and more preferably 1 wt% or more and 5 wt% or less. It is more preferable that the content is t% or less.

[0238] The conductive additive can form an electrically conductive network in the electrode. This allows the positive electrode active material layer to maintain an electrical conduction path between the positive electrode active materials. By adding an auxiliary agent, an active material layer having high electrical conductivity can be realized.

[0239] Examples of the conductive additive include natural graphite, artificial graphite such as mesocarbon microbeads, and carbon. Examples of carbon fibers include mesophase pitch carbon fibers. Carbon fibers such as carbon fibers, isotropic pitch-based carbon fibers, etc. can be used. Carbon nanofibers, carbon nanotubes, etc. can be used. The nanotubes can be produced by, for example, a vapor phase growth method. For example, carbon black (acetylene black (AB) etc.), graphite particles Carbon materials such as silicon, graphene, and fullerene can be used. Metal powders and fibers such as nickel, aluminum, silver, and gold, as well as conductive ceramic materials can be used.

[0240] A graphene compound may be used as the conductive additive.

[0241] Graphene compounds have excellent electrical properties, such as high conductivity, as well as high flexibility and In some cases, the graphene has excellent physical properties, such as high mechanical strength. Graphene compounds have a planar shape. Graphene compounds enable surface contact with low contact resistance. In addition, even if the material is thin, it can have very high conductivity, and a small amount can be used efficiently in the active material layer. Therefore, graphene compounds are used as conductive additives. This is preferable because it is possible to increase the contact area between the active material and the conductive additive. In addition, it is preferable because it may be possible to reduce electrical resistance. For example, it is particularly preferred to use graphene or multigraphene or RGO.

[0242] When using an active material with a small particle size, for example, an active material with a particle size of 1 μm or less, the specific surface area of ​​the active material In such cases, the active material is required to have a small number of conductive paths. The use of a graphene compound that can efficiently form a conductive path even in a small amount is particularly advantageous. Preferred.

[0243] As an example, the following describes a case where a graphene compound is used as a conductive additive in an active material layer. An example of the surface configuration will be described.

[0244] 30(A) shows a vertical cross-sectional view of the active material layer 102. The active material layer 102 is made of granular active material. 103, a graphene compound 321 as a conductive additive, and a binder 104. So, if graphene or multi-graphene is used as the graphene compound 321, Here, the graphene compound 321 preferably has a sheet shape. The graphene compound 321 may be a multi-graphene or / and a plurality of graphenes. The sheets may be partially overlapped to form a sheet.

[0245] In the vertical cross section of the active material layer 102, as shown in FIG. 30(A), In the portion, the sheet-like graphene compound 321 is dispersed almost uniformly. In this example, the graphene compound 321 is shown as a schematic diagram with a thick line, but in reality it is a single layer of carbon molecules. The graphene compounds 321 are formed of a plurality of granular active materials. The active material 103 is wrapped around, covered with, or stretched on the surface of a plurality of particles of the active material 103. Since they are formed to adhere to each other, they are in surface contact with each other.

[0246] Here, a plurality of graphene compounds are bonded to each other to form a mesh-like graphene compound. forming a graphene compound net or graphene net. When the active material is covered with a graphene net, the graphene net can Therefore, the amount of binder can be reduced. Since it can be used or not, the active material in the electrode volume and electrode weight can be reduced. The ratio of the power consumption to the quality of the battery can be improved. In other words, the capacity of the battery can be increased. do.

[0247] Here, graphene oxide is used as the graphene compound 321, and is mixed with an active material to form an active material. After forming the layer that will become the graphene layer 102, it is preferable to reduce the layer. By using graphene oxide, which has extremely high dispersibility in polar solvents, The compound 321 can be dispersed approximately uniformly inside the active material layer 102. The solvent is evaporated from the dispersion medium containing the graphene oxide dispersed in the solution, and the graphene oxide is reduced. Therefore, the graphene compound 321 remaining on the active material layer 102 partially overlaps with each other. By dispersing the particles so that they come into surface contact with each other, a three-dimensional conductive path can be formed. The reduction of graphene oxide may be carried out by, for example, heat treatment or by using a reducing agent. You may go.

[0248] Therefore, unlike granular conductive additives such as acetylene black, which come into point contact with the active material, Since the phenyl compound 321 enables surface contact with low contact resistance, it is not necessary to use a conventional conductive additive. Improves electrical conductivity between the granular active material 103 and the graphene compound 321 with a smaller amount than that Therefore, the ratio of the active material 103 in the active material layer 102 can be increased. This makes it possible to increase the discharge capacity of the power storage device.

[0249] FIG. 30(B) shows an enlarged view of the area surrounded by the dashed line in FIG. 30(A). The graphene compound 321 may be present in a layer form on the surface of the active material 103. It is preferable that the binder 104 has a region in contact with the surface of the active material 10. 3 and the graphene compound 321. An adhesive 104 is provided, and further, a graphene compound 321 is provided on the binder 104.

[0250] <Current collector> The current collector is made of metals such as stainless steel, gold, platinum, aluminum, titanium, and alloys of these metals. Highly conductive materials such as gold can be used. It is preferable that the current collector does not dissolve at the potential of the positive electrode. It is preferable that the alloy does not form with carrier ions such as silicon, titanium, neodymium, etc. Aluminum with added elements that improve heat resistance, such as aluminum, scandium, and molybdenum Alloys can be used. Metal elements that react with silicon to form silicides can also be used. The metal element that reacts with silicon to form silicide is zirconium. Cr, titanium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten The current collectors are available in foil, plate (sheet), mesh, and plate shapes. The current collector may be in the form of a punched metal, an expanded metal, or the like. It is preferable to use a material having a thickness of 5 μm or more and 30 μm or less.

[0251] This embodiment mode can be implemented in appropriate combination with other embodiment modes.

[0252] (Fourth embodiment) In this embodiment, an example of use of a power storage device of one embodiment of the present invention will be described with reference to FIGS. 31 to 35. and explain.

[0253] The power storage device of one embodiment of the present invention can be used in electronic devices and lighting devices, for example. The power storage device of one embodiment of the present invention has excellent charge and discharge characteristics. It can be used for a long time on a single charge, and the decrease in capacity due to charge / discharge cycles is suppressed. Because the battery life is limited, the usable time is unlikely to decrease even if the battery is repeatedly charged. The power storage device of one embodiment exhibits excellent charge / discharge characteristics over a wide temperature range, including a high-temperature environment, Its high long-term reliability and safety make it possible to improve the safety and reliability of electronic devices and lighting equipment. Cut.

[0254] Examples of electronic devices include television sets (also known as televisions or television receivers). (hereinafter referred to as "computer monitors"), digital cameras, digital video cameras, digital photo frames, mobile phones (also called mobile phones or mobile phone devices), portable game consoles, Examples include portable information terminals, audio playback devices, and large game machines such as pachinko machines.

[0255] Since the power storage device of one embodiment of the present invention has flexibility, the power storage device itself or the power storage Installing electronic equipment or lighting equipment using the device on the interior or exterior walls of a house or building, or on an automatic It can also be incorporated into the curved interior or exterior of a vehicle.

[0256] FIG. 31A shows an example of a mobile phone. The mobile phone 7400 includes a housing 740 1, in addition to a display unit 7402, operation buttons 7403, an external connection port 7404, The mobile phone 7400 is equipped with a speaker 7405, a microphone 7406, and the like. It has an electrical device 7407.

[0257] FIG. 31(B) shows the mobile phone 7400 in a bent state. When the 00 is deformed by an external force and the whole is curved, the storage battery installed inside The power storage device 7407 is a thin storage battery. The power storage device 7407 in a curved state is fixed as shown in FIG. .

[0258] FIG. 31(D) shows an example of a bangle-type display device. The portable display device 7100 is , a housing 7101, a display portion 7102, operation buttons 7103, and a power storage device 7104. FIG. 31E shows the bent state of the power storage device 7104.

[0259] FIG. 31(F) shows an example of a wristwatch-type portable information terminal. Portable information terminal 7200 The watch includes a housing 7201, a display unit 7202, a band 7203, a buckle 7204, and an operation button 7 205, an input / output terminal 7206, etc.

[0260] The portable information terminal 7200 is capable of performing functions such as mobile phone calls, e-mails, document browsing and creation, music playback, internet connection, and so on. It can run various applications such as internet communication and computer games. Cut.

[0261] The display surface of the display unit 7202 is curved, and the display is performed along the curved display surface. The display portion 7202 is provided with a touch sensor, and the screen can be touched with a finger or a stylus. For example, the icon 7 displayed on the display unit 7202 can be operated by touching the You can launch the application by touching 207.

[0262] The operation button 7205 is used to set the time, turn the power on and off, and turn wireless communication on and off. It has various functions such as auto-start, silent mode activation and deactivation, power saving mode activation and deactivation, etc. For example, an operating system built into the mobile information terminal 7200 can be The system also allows the functions of the operation buttons 7205 to be freely set.

[0263] In addition, the mobile information terminal 7200 is capable of performing standardized short-range wireless communication. For example, by communicating with a wireless headset, hands-free You can also make calls.

[0264] The portable information terminal 7200 also has an input / output terminal 7206, and can be connected to other information terminals via a connector. Data can be exchanged directly through the input / output terminal 7206. The charging operation can be performed by wireless power supply without going through the input / output terminal 7206. You may go.

[0265] The display portion 7202 of the portable information terminal 7200 includes the power storage device of one embodiment of the present invention. For example, the power storage device 7104 in FIG. 31E may be curved and placed inside the housing 7201. The flexible member 7204 may be incorporated in the band 7203 in a flexible state or may be incorporated inside the band 7203 in a flexible state.

[0266] FIG. 32(A) shows an example of a wrist-worn activity meter. The activity meter 7250 is The housing 7251 includes a body 7251, a band 7203, a buckle 7204, and the like. It is equipped with a wireless communication device, a pulse sensor, an acceleration sensor, a temperature sensor, etc. Activity meter 7250 The device uses a pulse sensor and an acceleration sensor to acquire information such as the wearer's pulse rate and activity level, and The activity meter has a function to transmit the information to an external mobile information terminal via a wired communication device. The 7250 has the function of measuring the wearer's calorie consumption and calorie intake, as well as the function of counting steps. The activity meter 7250 may have a function to measure a sleep state. The information acquired by the above function may be displayed.

[0267] The activity meter 7250 includes the power storage device of one embodiment of the present invention. The power storage device 7104 shown in FIG. 7 is placed in a curved state inside the housing 7251 or in a band 720. It can be incorporated into the interior of 3 in a bendable state.

[0268] FIG. 32B shows an example of a wristband-type display device. The display device 7300 has a display unit 7304 and includes the power storage device of one embodiment of the present invention. The display portion 7304 may be provided with a touch sensor, and may function as a portable information terminal. It is also possible to do so.

[0269] The display surface of the display unit 7304 is curved, and images are displayed along the curved display surface. The display device 7300 can also communicate with the display device 7300 by short-distance wireless communication according to a communication standard. You can change the situation.

[0270] The display device 7300 is also equipped with an input / output terminal, and can be directly connected to other information terminals via a connector. It is possible to exchange data and also charge via the input / output terminal. The charging operation may be performed by wireless power supply without using the input / output terminals.

[0271] FIG. 32C shows an example of a glasses-type display device. The frame 7351 has a frame 7352 and the like. A projection unit (not shown) that contacts the frame 7352 and projects an image or video onto the lens 7351. The display device 7350 displays an image 7351A on the entire lens 7351 so that the wearer can view the image. Or, the lens 7351 has a function of displaying the image 7351B in a direction that allows the image 7351B to be seen. It has the function of displaying the information in a direction that can be seen by the wearer.

[0272] The display device 7350 includes the power storage device of one embodiment of the present invention. The figure shows an enlarged view of the tip 7355 of the arm 7352. The tip 7355 is made of fluorine rubber and silicone. The tip portion 7355 can be formed of a rubber material such as corn rubber. The device 7360 is implanted, and a positive lead 7361 and a negative lead 7362 are attached to the distal end 73 55. The positive electrode lead 7361 and the negative electrode lead 7362 are protruding from the frame 73 52 and is electrically connected to the wiring connected to the projection unit, etc. The power storage device 355 is manufactured together with the power storage device 7360 by integral formation as described in Embodiment 2. It is possible.

[0273] The tip portion 7355 and the power storage device 7360 are flexible. It can be worn to fit snugly to the user's head shape.

[0274] Figures 33(A) and 33(B) show an example of a foldable tablet terminal. 96), the tablet terminal 9600 shown in (B) has a pair of housings 9630 and a pair of housings 963 0, a movable part 9640, a display part 9631a, a display part 9631b, a display mode switching Switch 9626, power switch 9627, power saving mode switch 9625, The tablet terminal 9629 has a fastener 9629 and an operation switch 9628. 33(A) shows the tablet terminal 600 in an open state, and FIG. 33(B) shows the tablet terminal 9600 in a closed state. It shows.

[0275] The tablet terminal 9600 also includes a power storage unit 9635 inside the housing 9630 . The power storage unit 9635 passes through the movable portion 9640 and moves from one housing 9630 to the other housing 9630. It is set up over a distance of .

[0276] A part of the display portion 9631a can be used as a touch panel area 9632a. By touching the operation keys 9638, data can be input. In 31a, for example, half of the area has a display function only, and the other half Although the display area 9 has a touch panel function, it is not limited to this configuration. The entire area of ​​631a may have a touch panel function. The entire surface of the display 9631a is used as a touch panel by displaying keyboard buttons. can be used as a display screen.

[0277] In addition, in the display unit 9631b, as in the display unit 9631a, The area can be used as a touch panel area 9632b. Touch the area where the display switch button 9639 is displayed with your finger or a stylus. This allows keyboard buttons to be displayed on the display portion 9631b.

[0278] In addition, the touch panel area 9632a and the touch panel area 9632b are simultaneously You can also use touch input.

[0279] A display mode changeover switch 9626 changes the display orientation, such as portrait or landscape. You can switch between black and white and color display. The switch 9625 is a device that detects the use of a light sensor built into the tablet terminal 9600. The display brightness can be optimized according to the amount of external light at the time. In addition to optical sensors, other sensors such as gyros and acceleration sensors that detect tilt are also used. An ejection device may be built in.

[0280] FIG. 33A shows an example in which the display areas of the display portions 9631a and 9631b are the same. However, there is no particular limitation, and the size of one display part and the size of the other display part may be different. The display quality may be different, for example, one may display a higher resolution image than the other. The display panel may also be a display panel that can display images.

[0281] FIG. 33(B) shows the tablet terminal in a closed state, and the tablet terminal includes a housing 9630 and a solar cell 9631. 633, and a charge / discharge control circuit 9634 including a DC / DC converter 9636. The power storage device of one embodiment of the present invention is used as the power supply 9635.

[0282] Since the tablet terminal 9600 can be folded in half, when not in use, the tablet terminal 9600 can be folded in half. It can be folded so that the 0 overlaps. By folding, the display part 9631 a. Since the display part 9631b can be protected, the durability of the tablet terminal 9600 can be improved. Furthermore, the power storage unit 9635 using the power storage device of one embodiment of the present invention has flexibility. The charge / discharge capacity is not easily reduced even after repeated bending and stretching. Therefore, it is a highly reliable tablet. We can provide a portable terminal.

[0283] In addition, the tablet devices shown in Figures 33(A) and 33(B) can display various information (status, Functions that display still images, videos, text images, etc. on the display, calendar, date, time, etc. The function to display information on the display unit, and the function to input or edit the information displayed on the display unit. It has input functions, functions to control processing using various software (programs), etc. It is possible.

[0284] The solar cell 9633 attached to the surface of the tablet terminal supplies power to the touch panel. The solar cell 9633 can be supplied to a display unit, a video signal processor, or the like. The power storage unit 9635 can be efficiently charged by providing the power storage unit 9635 on one or both sides of the housing 9630. The power storage unit 9635 is preferably a lithium ion battery. The use of silicon batteries has the advantage of enabling miniaturization.

[0285] The configuration and operation of the charge / discharge control circuit 9634 shown in FIG. A block diagram is shown in FIG. 33(C). 5, DC-DC converter 9636, converter 9637, switches SW1 to SW3, table The display unit 9631 is shown, and the storage battery 9635, the DC-DC converter 9636, 33B. This corresponds to 34.

[0286] First, an example of operation when power is generated by the solar cell 9633 using external light will be described. The power generated by the solar cell is converted into a voltage to charge the storage battery 9635. The voltage is increased or decreased by a C converter 9636. When power is being used from the battery 9633, the switch SW1 is turned on and the converter 96 37 increases or decreases the voltage to the voltage required for the display unit 9631. When not displaying 31, turn switch SW1 off and switch SW2 on. The power storage unit 9635 may be charged using the power storage unit 9635 .

[0287] The solar cell 9633 is shown as an example of a power generating means, but is not particularly limited thereto. , by other power generation means such as piezoelectric elements and thermoelectric conversion elements (Peltier elements) For example, the power storage unit 9635 may be configured to be charged. A wireless power transmission module that charges by transmitting power, or a configuration that combines other charging methods It may also be possible to use the following.

[0288] Another example of electronic equipment is shown in FIG. 34. In FIG. 34, a display device 8000 is a display device according to the present invention. 8 is an example of an electronic device including a power storage device 8004 of one embodiment. 8000 corresponds to a display device for receiving TV broadcasts, and includes a housing 8001, a display unit 8002, a speaker, and The power storage device 8004 of one embodiment of the present invention includes: The display device 8000 is provided inside a housing 8001. The display device 8000 is supplied with power from a commercial power source. The power can be received or stored in the power storage device 8004 can be used. Therefore, even when power cannot be supplied from a commercial power source due to a power outage or the like, the present invention can be used. The display device 8000 can be used by using the power storage device 8004 as an uninterruptible power supply. become.

[0289] The display unit 8002 is a display device having a light emitting element such as a liquid crystal display device or an organic EL element in each pixel. Optical devices, electrophoretic displays, DMD (Digital Micromirror Devices) ice), PDP (Plasma Display Panel), FED (Field A semiconductor display device such as a reflective LED (emission display) can be used.

[0290] In addition to TV broadcast reception, display devices are also used for personal computers and advertising displays. This includes all display devices for displaying information, such as:

[0291] In FIG. 34, a stationary lighting device 8100 includes a power storage device 8 according to one embodiment of the present invention. 8103. Specifically, the lighting device 8100 includes a housing 8101, The light source 8102, the power storage device 8103, and the like are included. In FIG. 101 and a light source 8102 are installed inside a ceiling 8104. Although shown in the figure, the power storage device 8103 may be provided inside the housing 8101. The device 8100 can receive power from a commercial power source or can store power in a power storage device 8103. The stored power can also be used. Therefore, in the event of a power outage, the power supply from the commercial power source can be reduced. Even when power cannot be received, the power storage device 8103 of one embodiment of the present invention can be used as an uninterruptible power supply. This allows the lighting device 8100 to be used.

[0292] In addition, FIG. 34 illustrates a lighting device 8100 of a fixed type provided on a ceiling 8104. However, in the power storage device of one embodiment of the present invention, the side wall 8105, the floor 8106, and the like are not included in the ceiling 8104. It can be used for a fixed lighting device provided in a window 8107 or a desk. It can also be used in upper lighting devices.

[0293] The light source 8102 can be an artificial light source that artificially obtains light using electricity. Specifically, this applies to incandescent lamps, discharge lamps such as fluorescent lamps, and light-emitting devices such as LEDs and organic EL elements. An example of the artificial light source is a light element.

[0294] In FIG. 34, an air conditioner having an indoor unit 8200 and an outdoor unit 8204 is 8 is an example of an electronic device including a power storage device 8203 of one embodiment of the present invention. The indoor unit 8200 includes a housing 8201, an air outlet 8202, a power storage device 8203, and the like. In the example shown, the power storage device 8203 is provided in the indoor unit 8200. The electric device 8203 may be provided in the outdoor unit 8204. The power storage device 8203 may be provided in both the outdoor units 8204. The power supply can be supplied from a commercial power source or stored in the power storage device 8203. In particular, both the indoor unit 8200 and the outdoor unit 8204 are provided with a power storage device 8 If 203 is installed, when power cannot be supplied from the commercial power source due to a power outage, etc. However, by using the power storage device 8203 of one embodiment of the present invention as an uninterruptible power supply, Conditioner can be used.

[0295] In addition, Figure 34 shows a separate type air conditioner consisting of an indoor unit and an outdoor unit. However, it is an integrated air conditioner that has the functions of both an indoor unit and an outdoor unit in a single housing. The power storage device according to one embodiment of the present invention can also be used for the conditioner.

[0296] In FIG. 34, an electric refrigerator-freezer 8300 includes a power storage device 8304 according to one embodiment of the present invention. Specifically, an electric refrigerator-freezer 8300 includes a housing 8301, The refrigerator door 8302, the freezer door 8303, the power storage device 8304, and the like are included. A power storage device 8304 is provided inside the housing 8301. The power supply can be supplied from a commercial power source, or the power stored in the power storage device 8304 can be used. Therefore, when power cannot be supplied from the commercial power source due to a power outage, etc. Even in this case, by using the power storage device 8304 of one embodiment of the present invention as an uninterruptible power supply, 8300 refrigerators and freezers will be available for use.

[0297] In addition, electronic devices such as microwave ovens and electric rice cookers generate high voltage for a short period of time. Therefore, it is used as an auxiliary power source to supplement the power that cannot be supplied by commercial power. By using a power storage device according to one embodiment of the present invention, fluctuations in commercial power supply can be reduced when an electronic device is used. This can prevent the car from falling.

[0298] In addition, during times when electronic devices are not in use, the total amount of power that can be supplied by commercial power suppliers is also During the time period when the ratio of the amount of electricity actually used (called the electricity usage rate) is low, By storing power in the electrical equipment, it is possible to prevent the power usage rate from increasing outside the above time periods. For example, in the case of the electric refrigerator-freezer 8300, when the temperature is low, the refrigerator compartment door 83 02, during the night when the freezer door 8303 is not opened or closed, power is supplied to the power storage device 8304. Then, as the temperature rises, the refrigerator door 8302 and the freezer door 8303 open and close. By using the power storage device 8304 as an auxiliary power source during the daytime, The rate can be kept low.

[0299] The power storage device of one embodiment of the present invention can also be mounted on a vehicle.

[0300] When a power storage device is installed in a vehicle, it becomes a hybrid vehicle (HEV), an electric vehicle (EV), or It will be possible to realize next-generation clean energy vehicles such as plug-in hybrid vehicles (PHEVs). do.

[0301] 35A and 35B illustrate examples of vehicles using the power storage device of one embodiment of the present invention. The automobile 8400 shown in (A) is an electric automobile that uses an electric motor as a power source for running. Alternatively, an electric motor and an engine can be selected as the power source for driving. By using one embodiment of the present invention, a cruising range can be increased. The automobile 8400 also has a power storage device. The device not only drives the electric motor but also the headlights 8401 and the interior lights (see illustration) It can supply power to light-emitting devices such as LEDs (without LEDs).

[0302] In addition, the power storage device may be used for displaying the speedometer, tachometer, etc. of the automobile 8400. The power storage device can supply power to the navigation system of the automobile 8400. The power supply can be used to power semiconductor devices such as gating systems.

[0303] The automobile 8500 shown in FIG. 35B is a power storage device that is plugged in. It can be charged by receiving power from an external charging facility using a method such as contactless power supply. FIG. 35(B) shows a diagram of a charging device 8021 mounted on a ground and a charging device 8022 mounted on a vehicle 8500. The power storage device 8024 is shown being charged via a cable 8022. For charging methods and connector specifications, please refer to the specifications of CHAdeMO (registered trademark) and Combo. The charging device 8021 may be a charging station installed in a commercial facility. For example, plug-in technology can be used to The power storage device 8024 mounted on the automobile 8500 can be charged by the power supply. Charging is performed by converting AC power to DC power via a converter such as an AC / DC converter. It is possible to do so.

[0304] Although not shown, a power receiving device is mounted on the vehicle, and power is supplied contactlessly from a power transmitting device on the ground. In this case, the power transmission device is installed on the road or on the exterior wall. By incorporating this, charging can be done not only when the vehicle is stopped but also while the vehicle is moving. The vehicle may transmit and receive power between them by using the power transmission method. A solar cell may be provided to charge the power storage device while the vehicle is stopped or running. The power can be supplied by an electromagnetic induction method or a magnetic resonance method.

[0305] According to one embodiment of the present invention, the cycle characteristics of a power storage device can be improved, and the reliability can be improved. Furthermore, according to one embodiment of the present invention, the characteristics of the power storage device can be improved, Therefore, the size and weight of the power storage device itself can be reduced. This contributes to reducing the vehicle's weight, thereby improving the vehicle's cruising range. The onboard power storage device can also be used as a power supply source for vehicles. This can avoid using commercial power during peak hours.

[0306] This embodiment mode can be combined with other embodiment modes as appropriate.

[0307] (Embodiment 5) Batteries that can be used in combination with battery cells containing the materials described in the above embodiments A control unit (Battery Management Unit: BMU) and the battery See Figures 36 to 42 for transistors suitable for the circuits that make up the pond control unit. In this embodiment, the power supply of a power storage device having battery cells connected in series will be described. The pond control unit will now be described.

[0308] When multiple battery cells connected in series are repeatedly charged and discharged, In this case, the capacity (output voltage) of each battery cell differs due to variations in charge / discharge characteristics. When multiple battery cells are connected in series, the total discharge capacity is proportional to the capacity of the battery cell with the smallest capacity. If there is a difference in the capacity of each battery cell, the overall capacity during discharge will be smaller. However, if charging is performed based on the voltage of a battery cell with a small capacity, there is a risk of the battery being insufficiently charged. Furthermore, if charging is performed based on the voltage of a battery cell with a large capacity, there is a risk of overcharging.

[0309] Therefore, the battery control unit of the power storage device having battery cells connected in series It has the function of equalizing the capacity variations between battery cells, which can cause short circuits and overcharging. The circuit configuration to equalize the capacitance variation between the capacitors can be a resistor type, a capacitor type, or an inverter type. There are other methods such as inductor type, but here we use a transistor with a small off-current to reduce capacitance variations. An example of a circuit configuration that can align the above will be described below.

[0310] As a transistor with a low off-state current, a transistor having an oxide semiconductor in a channel formation region is An OS transistor with a small off-state current is preferred. By using it in the circuit configuration of the device's battery control unit, the amount of charge leaking from the battery is reduced, It is possible to suppress the decrease in capacity over time.

[0311] The oxide semiconductor used in the channel formation region is In-M-Zn oxide (M is Ga, Sn , Y, Zr, La, Ce, or Nd) is used. In the target, the atomic ratio of the metal elements is In:M:Zn=x1:y1:z1. and 、 x1 / y1 is 1 / 3 or more and 6 or less, and further 1 or more and 6 or less, and z1 / y1 is It is preferable that z1 / y1 is 1 / 3 or more and 6 or less, and more preferably 1 or more and 6 or less. When the content is 6 or less, a CAAC-OS film is easily formed as the oxide semiconductor film. .

[0312] Here, the CAAC-OS film will be described.

[0313] The CAAC-OS film is one of the oxide semiconductor films that has multiple crystal parts aligned along the c-axis. .

[0314] Transmission Electron Microscope (TEM) A combined analysis image of the bright-field image and diffraction pattern of the CAAC-OS film was obtained using a microscope. (also called high-resolution TEM images) On the other hand, high-resolution TEM images also clearly show the boundaries between crystals, i.e., grain boundaries. Therefore, the CAAC-OS film is It can be said that the decrease in electron mobility caused by the grain boundaries is unlikely to occur.

[0315] When a high-resolution TEM image of the cross section of the CAAC-OS film was observed from a direction approximately parallel to the sample surface, It can be seen that the metal atoms are arranged in layers in the crystal part. The CAAC-OS film is formed on a surface (also called a surface on which the film is formed) or on the upper surface. The CAAC-OS film has a shape similar to that of the crystalline silicon film, and is arranged parallel to the surface on which the CAAC-OS film is formed or the upper surface thereof.

[0316] On the other hand, a high-resolution TEM image of the plane of the CAAC-OS film was observed from a direction almost perpendicular to the sample surface. They then confirmed that the metal atoms in the crystals were arranged in triangular or hexagonal shapes. However, there is no regularity in the arrangement of metal atoms between different crystal parts.

[0317] X-ray diffraction (XRD) of the CAAC-OS film When structural analysis is performed using this device, for example, CAAC-OS with InGaZnO4 crystals can be seen. In the out-of-plane analysis of the film, the diffraction angle (2θ) peaks around 31°. This peak is attributed to the (009) plane of the InGaZnO4 crystal. Therefore, the crystals of the CAAC-OS film have a c-axis orientation, and the c-axis faces the surface on which the film is formed or the upper surface. It can be seen that it is oriented in a substantially vertical direction.

[0318] In addition, the out-of-plane structure of the CAAC-OS film with InGaZnO4 crystals In the analysis by the NMR method, in addition to the peak at 2θ near 31°, a peak also appeared at 2θ near 36°. The peak at 2θ around 36° is due to the presence of c-axis orientation in part of the CAAC-OS film. The CAAC-OS film contains crystals that do not have crystalline structure. It is preferable that the peak is exhibited at 2θ of about 36° and that the peak is not exhibited at 2θ of about 36°.

[0319] The CAAC-OS film is an oxide semiconductor film with a low concentration of impurities. The oxide semiconductor film is made of an element other than the main component, such as silicon or a transition metal element. The elements such as ZnO, which have stronger bonding strength with oxygen than the metal elements constituting the oxide semiconductor film, By removing oxygen from the oxide semiconductor film, the atomic arrangement of the oxide semiconductor film is disrupted, and the crystallinity is reduced. In addition, heavy metals such as iron and nickel, argon, and carbon dioxide are Because the diameter (or molecular radius) is large, when the molecule is contained inside the oxide semiconductor film, The impurities contained in the oxide semiconductor film are likely to disturb the atomic arrangement of the oxide semiconductor film, which may result in a decrease in crystallinity. The pure material may act as a carrier trap or a carrier generation source.

[0320] The CAAC-OS film is an oxide semiconductor film with a low density of defect states. Oxygen vacancies in semiconductor films can act as carrier traps and trap hydrogen. This can become a carrier generation source.

[0321] The low impurity concentration and low defect level density (low oxygen vacancies) are called high-purity intrinsic or The term "high-purity intrinsic" refers to a substantially high-purity intrinsic oxide semiconductor. The film has a small number of carrier generation sources, so the carrier density can be reduced. The transistor including the oxide semiconductor film has electrical characteristics in which the threshold voltage is negative. (also called normally-on) is rare. An oxide semiconductor film with intrinsic purity has few carrier traps. Transistors using conductor films have little fluctuation in electrical characteristics and are highly reliable. Note that it takes time for the charges trapped in the carrier traps in the oxide semiconductor film to be released. The time it takes for the impurity concentration to reach the target is long, and it may behave as if it were a fixed charge. A transistor using an oxide semiconductor film with a high density of defect states has unstable electrical characteristics. This may be the case.

[0322] In addition, the electrical characteristics of transistors using CAAC-OS films are improved by irradiation with visible light or ultraviolet light. There is little gender variation.

[0323] Note that an OS transistor is a transistor having silicon in a channel formation region (Si Since the band gap is larger than that of semiconductors (transistors), dielectric breakdown occurs less when 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 applied to such a battery cell in the power storage device includes the following: It is suitable to use the OS transistor described above.

[0324] An example of a block diagram of a power storage device is shown in Fig. 36. The power storage device BT00 shown in Fig. 36 includes: A terminal pair BT01, a terminal pair BT02, a switching control circuit BT03, and a switching circuit BT 04, a switching circuit BT05, a transformer control circuit BT06, and a transformer circuit BT07, and a battery unit BT08 including a plurality of battery cells BT09 connected to the battery unit BT08.

[0325] In addition, in the power storage device BT00 of FIG. 36, the terminal pair BT01 and the terminal pair BT02 are A switching control circuit BT03, a switching circuit BT04, a switching circuit BT05, and a transformer control circuit The part consisting of the control circuit BT06 and the transformer circuit BT07 is called the battery control unit. You can do it.

[0326] The switching control circuit BT03 controls the operation of the switching circuits BT04 and BT05. Specifically, the switching control circuit BT03 controls the voltage measured for each battery cell BT09. Based on the voltage, the battery cells to be discharged (discharge battery cell group) and the battery cells to be charged (charge Determine the battery cell group.

[0327] Furthermore, the switching control circuit BT03 controls the determined discharge battery cell group and charge battery cell group. The control signal S1 and the control signal S2 are output based on the group of rules. This control signal S1 is output to the circuit BT04. The control signal S2 is a signal that controls the switching circuit BT04 to connect the This control signal S2 is output to the switching circuit BT05. This signal controls the switching circuit BT05 so as to connect the BT05 to the group of conductors.

[0328] The switching control circuit BT03 includes a switching circuit BT04, a switching circuit BT05, And considering the configuration of the transformer circuit BT07, between the terminal pair BT01 and the discharge battery cell group, or Between the terminal pair BT02 and the charging battery cell group, the control is performed so that terminals of the same polarity are connected. The control signal S1 and the control signal S2 are generated.

[0329] The operation of the switching control circuit BT03 will now be described in detail.

[0330] First, the switching control circuit BT03 measures the voltage of each of the multiple battery cells BT09. Then, the switching control circuit BT03 selects, for example, the battery cell BT09 having a voltage equal to or higher than a predetermined threshold. A high-voltage battery cell (high-voltage cell), a battery cell with a voltage below a predetermined threshold BT09 is considered a low-voltage It is determined to be a battery cell (low voltage cell).

[0331] It should be noted that various methods can be used to determine whether a cell is a high-voltage cell or a low-voltage cell. For example, the switching control circuit BT03 selects the most The voltage of each battery cell BT09 is used as the reference voltage. 09 may determine whether it is a high-voltage cell or a low-voltage cell. In this case, the switching control circuit BT0 3 determines whether the voltage of each battery cell BT09 is equal to or greater than a predetermined ratio of the reference voltage. By doing so, it is possible to determine whether each battery cell BT09 is a high-voltage cell or a low-voltage cell. Then, based on the result of this determination, the switching control circuit BT03 switches between the discharge battery cell group and the charge battery cell group. The battery cell group is determined.

[0332] In addition, among the multiple battery cells BT09, high voltage cells and low voltage cells are mixed in various states. For example, the switching control circuit BT03 can The part with the largest number of high-voltage cells connected in series is the discharge battery cell group. The switching control circuit BT03 charges the part with the most low-voltage cells connected in series. The switching control circuit BT03 detects whether a battery is close to being overcharged or overdischarged. The cell BT09 is preferentially selected as a discharge battery cell group or a charge battery cell group. Good too.

[0333] An example of the operation of the switching control circuit BT03 in this embodiment will now be described with reference to FIG. FIG. 37 is a diagram for explaining an example of the operation of the switching control circuit BT03. For convenience of explanation, FIG. 37 shows an example in which four battery cells BT09 are connected in series. explain.

[0334] First, in the example of FIG. 37(A), the voltages of battery cells a to d are voltages Va to Vd. This shows the case where the relationship Va=Vb=Vc>Vd is satisfied. In other words, three consecutive high The high-voltage cells a to c and one low-voltage cell d are connected in series. The control circuit BT03 determines three consecutive high-voltage cells a to c as a discharge battery cell group. The switching control circuit BT03 also determines the low voltage cell d as the charging battery cell group. do.

[0335] Next, the example in Figure 37(B) shows a case where the relationship is Vc>Va=Vb>>Vd. That is, two consecutive low voltage cells a and b, one high voltage cell c, and one over-discharged cell The nearby low-voltage cell d is connected in series. In this case, the switching control circuit BT03 , the high-voltage cell c is determined as the discharge battery cell group. Since the low voltage cell d is close to over-discharge, it is not the two consecutive low voltage cells a and b that are the low voltage cells. The voltage cell d is determined as the charging battery cell group with priority.

[0336] Finally, the example in Figure 37(C) shows a case where the relationship Va>Vb=Vc=Vd holds. 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 selects the high voltage cell a as the discharge battery cell group. The switching control circuit BT03 also determines whether three consecutive low-voltage cells b to d are charged. The battery cell group is determined as follows:

[0337] The switching control circuit BT03 determines the results as shown in the examples of FIGS. 37(A) to 37(C). Based on the result, information indicating the discharge battery cell group to which the switching circuit BT04 is connected is set. The control signal S1 and information indicating the charging battery cell group to which the switching circuit BT05 is connected are The set control signal S2 is sent to the switching circuit BT04 and the switching circuit BT05. Output each one.

[0338] The above is a detailed explanation of the operation of the switching control circuit BT03.

[0339] The switching circuit BT04 responds to the control signal S1 output from the switching control circuit BT03. Therefore, the connection destination of the terminal pair BT01 is determined by the switching control circuit BT03. Set to a group of cells.

[0340] The terminal pair BT01 is composed of a pair of terminals F1 and F2. 4, either one of the terminals F1 and F2 is connected to the most upstream (highest) of the discharge battery cell group. The positive terminal of the battery cell BT09 located on the positive side of the discharge battery cell group is connected to the positive terminal of the battery cell BT09 located on the positive side of the discharge battery cell group. By connecting it to the negative terminal of the battery cell BT09 located at the most downstream (low potential side), The connection destination of the child pair BT01 is set. The switching circuit BT04 is set to the control signal S1. The position of the discharged battery cell group can be recognized using the obtained information.

[0341] The switching circuit BT05 responds to the control signal S2 output from the switching control circuit BT03. Therefore, the connection destination of the terminal pair BT02 is changed to the rechargeable battery determined by the switching control circuit BT03. Set to a group of cells.

[0342] The terminal pair BT02 is composed of a pair of terminals G1 and G2. 5, either one of the terminals G1 and G2 is connected to the most upstream (highest) of the charging battery cell group. The positive terminal of the battery cell BT09 located on the positive side of the battery cell group is connected to the positive terminal of the battery cell BT09 located on the positive side of the battery group. By connecting it to the negative terminal of the battery cell BT09 located at the most downstream (low potential side), The connection destination of the slave pair BT02 is set. The switching circuit BT05 is set to the control signal S2. The position of the rechargeable battery cell group can be recognized using the obtained information.

[0343] 38 and 39 are circuit diagrams showing examples of the configuration of the switching circuits BT04 and BT05. Shown in 39.

[0344] In FIG. 38, the switching circuit BT04 includes a plurality of transistors BT10 and a bus BT11. The bus BT11 is connected to the terminal F1. 12 is connected to the terminal F2. The sources or drains of the plurality of transistors BT10 One of the two is alternately connected to the bus BT11 and the other to the bus BT12. In addition, the other of the sources or drains of the plurality of transistors BT10 is connected to two adjacent It is connected between the battery cell BT09.

[0345] Among the multiple transistors BT10, the transistor BT10 located at the most upstream The other of the source and drain is connected to the positive terminal of the battery cell BT09 located at the most upstream of the battery module BT08. The most downstream of the plurality of transistors BT10 is connected to the terminals. The other of the source and drain of the transistor BT10 is located at the most downstream of the battery section BT08. The negative terminal of the battery cell BT09 is connected to the negative terminal of the battery cell BT09.

[0346] The switching circuit BT04 supplies a control signal S1 to the gates of the plurality of transistors BT10. In response to the bus BT11, one of the plurality of transistors BT10 is connected to the bus BT11. One of the plurality of transistors BT10 connected to BT12 is in a conductive state. By doing so, the discharge battery cell group and the terminal pair BT01 are connected. The positive terminal of the battery cell BT09, which is located most upstream in the cell group, is connected to the terminal F1 of the terminal pair or F2. Also, the battery located most downstream in the discharge battery cell group. The negative terminal of cell BT09 is connected to the other of the terminals F1 and F2 of the terminal pair, i.e., the positive terminal The terminal that is not connected to the other terminal is connected to the other terminal.

[0347] It is preferable to use an OS transistor for the transistor BT10. Since the off-state current of the discharged battery cell is small, the amount of charge leaking from the battery cells that do not belong to the discharged battery cell group is small. This reduces the capacitance loss over time. Dielectric breakdown is unlikely to occur when high voltage is applied. Therefore, the output voltage of the discharge battery cell group is large. Even if the voltage is high, the transistor BT10 is in a non-conducting state. The pair BT01 can be insulated.

[0348] In addition, in FIG. 38, the switching circuit BT05 includes a plurality of transistors BT13 and a current control The buses BT15 and BT16 are connected to the control switch BT14 and the bus BT15. T16 is disposed between the plurality of transistors BT13 and the current control switch BT14. The sources or drains of the plurality of transistors BT13 are alternately connected. The plurality of transistors BT13 are connected to buses BT15 and BT16. The other of the source and drain of each battery cell is connected between two adjacent battery cells BT09. It is being done.

[0349] Among the plurality of transistors BT13, the transistor BT13 located at the most upstream The other of the source and drain is connected to the positive terminal of the battery cell BT09 located at the most upstream of the battery module BT08. The most downstream of the plurality of transistors BT13 is connected to the terminals. The other of the source and drain of the transistor BT13 is located at the most downstream of the battery section BT08. The negative terminal of the battery cell BT09 is connected to the negative terminal of the battery cell BT09.

[0350] The transistor BT13 is an OS transistor, similar to the transistor BT10. Since the OS transistor has a small off-state current, it is preferable that the OS transistor does not belong to the rechargeable battery cell group. This reduces the amount of charge leaking from the battery cells and prevents the capacity from decreasing over time. In addition, OS transistors are less likely to experience dielectric breakdown when high voltages are applied. , transistor B, which is in a non-conducting state even if the voltage for charging the charging battery cell group is large. The battery cell BT09 connected to T13 can be insulated from the terminal pair BT02. .

[0351] The current control switch BT14 includes a switch pair BT17 and a switch pair BT18. One end of the switch pair BT17 is connected to the terminal G1. The other end is branched by two switches, one of which is connected to bus BT15 and the other The switch pair BT18 is connected to the bus BT16. One end of the switch pair BT18 is connected to the terminal G2. The other end of the switch pair BT18 is branched into two switches. One switch is connected to bus BT15 and the other switch is connected to bus BT16. do.

[0352] The switches included in the switch pair BT17 and the switch pair BT18 are transistors BT1 Similarly to transistors BT10 and BT13, it is preferable to use OS transistors.

[0353] The switching circuit BT05 switches the transistor BT13 and the current control By controlling the combination of on / off states of the control switch BT14, the charging battery cell Connect the group to terminal pair BT02.

[0354] As an example, the switching circuit BT05 connects the charging battery cell group and the terminal pair BT Connect to 02.

[0355] The switching circuit BT05 supplies a control signal S2 to the gates of the plurality of transistors BT13. Depending on the charging status, the positive terminal of the battery cell BT09 located most upstream in the charging battery cell group is connected. The switching circuit BT05 turns on the transistor BT13. In response to a control signal S2 applied to the gate of a number of transistors BT13, The transistor BT1 connected to the negative terminal of the battery cell BT09 located most downstream 3 is put into a conductive state.

[0356] The polarity of the voltage applied to terminal pair BT02 is the same as that of the discharge battery cell connected to terminal pair BT01. The number of cells may vary depending on the configuration of the battery cell group and the transformer circuit BT07. To allow current to flow in the same direction, the terminals of the same polarity must be connected between the terminal pair BT02 and the charging battery cells. Therefore, the current control switch BT14 is controlled by the control signal S2. , switch pair BT17 and switch pair B depending on the polarity of the voltage applied to terminal pair BT02. It is controlled to switch the connection destination of T18 respectively.

[0357] For example, a voltage is applied to the terminal pair BT02 such that terminal G1 is positive and terminal G2 is negative. In this case, the most downstream battery cell BT0 of the battery module BT08 If 9 is a charging battery cell group, the switch pair BT17 is connected to the battery by the control signal S2. The switch pair BT17 is controlled to be connected to the positive terminal of the cell BT09. The switch connected to the bus BT16 is turned on, and the bus BT On the other hand, the switch pair BT18 is in the OFF state when the control signal S 2, the negative terminal of the battery cell BT09 is controlled to be connected to the negative terminal of the battery cell BT09. The switch connected to the bus BT15 of the switch pair BT18 is turned on, and The switch connected to the bus BT16 of BT18 is turned off. Between the pair BT02 and the charging battery cell group, terminals with the same polarity are connected. The direction of the current flowing from the terminal pair BT02 is controlled so that it is in the direction that charges the battery cell group. To be controlled.

[0358] In addition, the current control switch BT14 is connected to the switching circuit B instead of the switching circuit BT05. It may be included in T04.

[0359] FIG. 39 shows a configuration of the switching circuit BT04 and the switching circuit BT05, which is different from that shown in FIG. FIG.

[0360] In FIG. 39, the switching circuit BT04 includes a plurality of transistor pairs BT21 and a bus BT2 The bus BT24 is connected to the terminal F1. The transistor pair BT25 is connected to the terminal F2. Each of them is branched by a transistor BT22 and a transistor BT23. One of the source and drain of the transistor BT22 is connected to the bus BT24. One of the source and drain of the transistor BT23 is connected to the bus BT25. , the other ends of the plurality of transistor pairs BT21 are connected to the two adjacent battery cells BT09. Among the multiple transistor pairs BT21, the transistor located at the most upstream position is The other end of the transistor pair BT21 is connected to the battery cell BT09 located at the most upstream of the battery section BT08. The positive terminal of the transistor pair BT21 is connected to the most downstream terminal of the transistor pair BT21. The other end of the transistor pair BT21 is connected to the battery cell BT08 located at the most downstream side. It is connected to the negative terminal of 09.

[0361] The switching circuit BT04 switches the transistors BT22 and BT23 in response to the control signal S1. By switching the conductive / non-conductive state of the transistor pair BT23, the The connection destination is switched to either terminal F1 or terminal F2. If BT22 is conductive, transistor BT23 is non-conductive and is connected to On the other hand, if the transistor BT23 is in a conducting state, the transistor BT2 Transistor BT22 and transistor BT23 are in a non-conductive state and are connected to terminal F2. Which of the resistors BT23 is in a conductive state is determined by a control signal S1.

[0362] To connect the terminal pair BT01 to the discharge battery cell group, two transistor pairs BT21 are used. Specifically, the connection of the two transistor pairs BT21 is controlled based on the control signal S1. By determining the destinations, the discharge battery cell group and terminal pair BT01 are connected. The two transistor pairs BT21 are connected to terminal F1 and terminal F2. The control signal S1 controls the child F2.

[0363] The switching circuit BT05 includes a plurality of transistor pairs BT31, a bus BT34, and a bus B The bus BT34 is connected to the terminal G1. The bus BT35 is , and the terminal G2. One end of each of the plurality of transistor pairs BT31 is connected to the transistor The output is branched by transistor BT32 and transistor BT33. One end of the branched signal is connected to a bus BT34. One end of the branched transistors is connected to a bus BT35. The other end of each of the terminals BT09 is connected between two adjacent battery cells BT09. Among the several transistor pairs BT31, the other end of the transistor pair BT31 located at the most upstream position is The positive terminal of the battery cell BT09 located at the most upstream position of the battery unit BT08 is connected to the positive terminal of the battery cell BT09. In addition, among the plurality of transistor pairs BT31, the transistor pair BT31 located at the most downstream position The other end is connected to the negative terminal of the battery cell BT09 located at the most downstream side of the battery unit BT08. do.

[0364] The switching circuit BT05 switches the transistors BT32 and BT33 in response to the control signal S2. By switching the conductive / non-conductive state of the transistor pair BT33, the The connection destination is switched to either terminal G1 or terminal G2. If BT32 is conductive, transistor BT33 is non-conductive and is connected to Conversely, if the transistor BT33 is in a conductive state, the transistor BT3 Transistor BT32 and transistor BT33 are in a non-conductive state and are connected to terminal G2. Which of the resistors BT33 is in a conductive state is determined by a control signal S2.

[0365] To connect the terminal pair BT02 to the charging battery cells, two transistor pairs BT31 are used. Specifically, the connection of the two transistor pairs BT31 is controlled based on the control signal S2. By determining the destinations, the charging battery cell group and terminal pair BT02 are connected. The two transistor pairs BT31 are connected to terminal G1 and terminal G2. It is controlled by the control signal S2 to become the child G2.

[0366] The two transistor pairs BT31 are connected to the terminal pair BT02. Specifically, terminal G1 is the positive terminal and terminal G2 is the negative terminal. When a voltage such as this is applied to the terminal pair BT02, the upstream transistor pair BT31 When the transistor BT32 is turned on, the transistor BT33 is turned off. On the other hand, the downstream transistor pair BT31 is controlled by the control signal S2 as follows: The transistor BT33 is controlled to be in a conductive state and the transistor BT32 is controlled to be in a non-conductive state. The terminal G1 is controlled by the control signal S2. The terminal G1 is negative and the terminal G2 is positive. When voltage is applied to terminal pair BT02, the upstream transistor pair BT31 so that the transistor BT33 is in a conducting state and the transistor BT32 is in a non-conducting state. On the other hand, the downstream transistor pair BT31 is controlled by the control signal S2. The control signal S is set to ON so that the transistor BT32 is in a conducting state and the transistor BT33 is in a non-conducting state. In this way, the same voltage is applied between the terminal pair BT02 and the charging battery cell group. The terminals with the same polarity are connected together. The direction of the current flowing from the terminal pair BT02 is as follows: The charge is controlled so as to charge the battery cell group.

[0367] The transformer control circuit BT06 controls the operation of the transformer circuit BT07. is 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. A transformer signal S3 for controlling the operation of the transformer circuit BT07 is generated based on the number of the buffer cells BT09. and outputs it to the transformer circuit BT07.

[0368] The number of battery cells BT09 included in the discharge battery cell group is the same as the number of battery cells BT09 included in the charge battery cell group. If the number of battery cells is greater than the number of BT09, an excessively large charging voltage will be applied to the charging battery cell group. Therefore, the voltage transformer control circuit BT06 controls the charging voltage The transformer circuit BT07 is designed to lower the discharge voltage (Vdis) to a level that allows the battery cell group to be charged. The transformer outputs a transform signal S3 that controls the

[0369] In addition, the number of battery cells BT09 included in the discharge battery cell group is If the number of battery cells BT09 is less than the number of battery cells BT09, the charging capacity required to charge the charging battery cell group is Therefore, the voltage transformer control circuit BT06 controls the charging battery cell group to Transformer circuit B is used to boost the discharge voltage (Vdis) within a range where excessive charging voltage is not applied. It outputs a transformer signal S3 that controls T07.

[0370] The voltage value that constitutes the excessive charging voltage is the voltage of the battery cell BT09 used in the battery module BT08. The voltage can be determined in consideration of the product specifications, etc. The voltage thus generated is applied to the terminal pair BT02 as the charging voltage (Vcha).

[0371] Here, an example of the operation of the transformer control circuit BT06 in this embodiment is shown in FIGS. 40(A) to (C) are the same as those in the radiation diagrams described in FIGS. 37(A) to (C). An example of the operation of the voltage transformer control circuit BT06 corresponding to the power battery cell group and the charge battery cell group will be explained. 40(A) to 40(C) are conceptual diagrams for illustrating the battery control unit BT41. As described above, the battery control unit BT41 has the terminal pair BT01 and the terminal pair BT02. BT02, a switching control circuit BT03, a switching circuit BT04, and a switching circuit BT 05, a voltage transformation control circuit BT06, and a voltage transformation circuit BT07.

[0372] In the example shown in FIG. 40(A), three consecutive high voltages are generated as explained in FIG. 37(A). In this case, the high-voltage cells a to c and one low-voltage cell d are connected in series. As explained using A), the switching control circuit BT03 discharges the high voltage cells a to c. The low-voltage cell d is determined as the battery cell group, and the low-voltage cell d is determined as the charging battery cell group. The control circuit BT06 determines the number of battery cells BT09 included in the discharge battery cell group as a reference. Based on the ratio of the number of battery cells BT09 included in the charging battery cell group, the discharge voltage (Vd Calculate the conversion ratio N from the current (V is ) to the charging voltage (V cha ).

[0373] The number of battery cells BT09 included in the discharge battery cell group is the same as the number of battery cells BT09 included in the charge battery cell group. If the number of battery cells is greater than BT09, the discharge voltage is directly transferred to the terminal pair BT02 without being transformed. If the voltage is applied as is, the battery cell BT09 included in the charging battery cell group will be charged via the terminal pair BT02. Therefore, in the case shown in Figure 40(A), Now, let's make the charging voltage (Vcha) applied to the terminal pair BT02 lower than the discharging voltage. Furthermore, in order to charge the battery cell group, the charging voltage must be The voltage must be greater than the total voltage of the battery cells BT09 included in the transformer control circuit. BT06 is the number of charge cells when the number of battery cells BT09 included in the discharge battery cell group is used as the standard. The conversion ratio N is set to be larger than the ratio of the number of battery cells BT09 included in the battery cell group.

[0374] The transformer control circuit BT06 determines the number of battery cells BT09 included in the discharge battery cell group as a standard. When the conversion ratio N is It is preferable to make it 1 to 10% larger. At this time, the charging voltage is higher than the voltage of the charging battery cell group. However, in reality, the charging voltage is equal to the voltage of the battery cell group. The voltage control circuit BT06 is configured to equalize the voltage of the charging battery cell group with the charging voltage according to the conversion ratio N. This current flows through the transformer control circuit BT06 to charge the battery cell group. The value set in

[0375] In the example shown in FIG. 40(A), the number of battery cells BT09 included in the discharge battery cell group is Since there is only one battery cell BT09 in the charging battery cell group, the voltage control circuit The circuit BT06 calculates a value slightly larger than 1 / 3 as the conversion ratio N. The circuit BT06 converts the discharge voltage into a charging voltage by converting the voltage into a charging voltage according to the conversion ratio N. 3 to the transformer circuit BT07. Then, the transformer circuit BT07 outputs The transformed charging voltage is applied to the terminal pair BT02. The battery cell BT09 included in the charging battery cell group is charged by the charging voltage.

[0376] In addition, in the examples shown in FIG. 40(B) and FIG. 40(C), as in FIG. 40(A), the conversion ratio In the examples shown in FIG. 40(B) and FIG. 40(C), the number of cells included in the discharge battery cell group is calculated. The number of battery cells BT09 included in the charging battery cell group is less than or equal to the number of battery cells BT09 included in the charging battery cell group. Therefore, the conversion ratio N is equal to or greater than 1. In this case, the transformer control circuit BT06 is configured as follows: It outputs a voltage transformation signal S3 that boosts the discharge voltage and converts it into a charge voltage.

[0377] The transformer circuit BT07 generates a discharge voltage applied to the terminal pair BT01 based on the transformer signal S3. The transformer circuit BT07 converts the converted charging voltage into a terminal pair BT 02. Here, the transformer circuit BT07 is connected between the terminal pair BT01 and the terminal pair BT02. This allows the transformer circuit BT07 to be electrically isolated from the most discharged battery cells. The absolute voltage of the negative terminal of the downstream battery cell BT09 and the lowest voltage of the charging battery cell group This prevents a short circuit due to the difference in absolute voltage between the negative terminal of the battery cell BT09 located downstream. Furthermore, as described above, the transformer circuit BT07 converts the voltage of the discharge battery cell group based on the transformer signal S3. The total voltage, the discharge voltage, is converted into a charge voltage.

[0378] The transformer circuit BT07 is, for example, an isolated DC (Direct Current)-D In this case, the transformer control circuit BT06 is an isolated DC -The signal that controls the on / off ratio (duty ratio) of the DC converter is the transformer signal S3. By outputting this signal, the charging voltage converted by the transformer circuit BT07 is controlled.

[0379] There are three types of isolated DC-DC converters: flyback, forward, and RCC. (Ring Choke Converter) method, push-pull method, half There are bridge and full bridge types, but depending on the size of the desired output voltage, An appropriate method is selected depending on the situation.

[0380] The configuration of the transformer circuit BT07 using an isolated DC-DC converter is shown in Figure 41. The DC-DC converter BT51 has a switch unit BT52 and a transformer unit BT53. The switch BT52 switches the operation of the isolated DC-DC converter on and off. A switch, such as a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistors and bipolar transistors The switch unit BT52 is realized by using a transformer or the like. The isolated DC-DC converter is driven based on the transformer signal S3 that controls the on / off ratio. The switch unit BT51 periodically switches between the on state and the off state. Various configurations are possible depending on the type of isolated DC-DC converter used. The unit BT53 converts the discharge voltage applied from the terminal pair BT01 into a charge voltage. The transformer unit BT53 operates in conjunction with the on / off state of the switch unit BT52. The discharge voltage is converted into a charge voltage according to the on / off ratio. This charge voltage is In the switching period of 52, the longer the ON time, the larger the capacitance. The time during which the voltage is in the ON state is short in the switching period of the switch unit BT52. When using an isolated DC-DC converter, the transformer BT53 Within this, the terminal pair BT01 and the terminal pair BT02 can be insulated from each other.

[0381] The processing flow of power storage device BT00 in this embodiment will be described with reference to FIG. 2 is a flowchart showing the flow of processing by the power storage device BT00.

[0382] First, the power storage device BT00 acquires the voltage measured for each of the plurality of battery cells BT09 ( Step S101). Then, the power storage device BT00 aligns the voltages of the plurality of battery cells BT09. It is determined whether the start condition for the operation is satisfied (step S102). For example, the difference between the maximum and minimum voltages measured for each of the plurality of battery cells BT09 is If this start condition is not met (step S 102:NO), the voltage of each battery cell BT09 is balanced, so the storage On the other hand, if the start condition is met (step S102: YES), the power storage device BT00 executes a process for aligning the voltages of the battery cells BT09. In this process, power storage device BT00 performs the following on the basis of the measured voltage of each cell: It is determined whether each battery cell BT09 is a high-voltage cell or a low-voltage cell (step S103). Then, the power storage device BT00 determines the discharge battery cell group and the charge battery cell group based on the determination result. Furthermore, the power storage device BT00 determines the discharge battery cell group to be discharged (step S104). A control signal S1 sets the terminal pair BT01 to the terminal pair BT02, and a control signal S2 sets the terminal pair BT01 to the terminal pair BT02. A control signal S2 is generated to set the connection destination of the child pair BT02 (step S105). The device BT00 transmits the generated control signals S1 and S2 to the switching circuits BT04 and BT05. Then, the switching circuit BT04 outputs the signal to the terminals The terminal pair BT01 is connected to the discharge battery cell group, and the terminal pair BT0 2 and the discharge battery cell group are connected (step S106). The number of battery cells BT09 included in the discharge battery cell group and the number of battery cells included in the charge battery cell group are Based on the number of the BT09, a transformed signal S3 is generated (step S107). Based on the transformation signal S3, the power storage device BT00 changes the discharge voltage applied to the terminal pair BT01. is converted into a charging voltage and applied to the terminal pair BT02 (step S108). The charge of the battery cells is transferred to the battery cells.

[0383] In addition, in the flowchart of FIG. 42, multiple steps are listed in order, but each step The order in which the steps are performed is not limited to the order in which they are listed.

[0384] As described above, according to this embodiment, when transferring charges from the discharge battery cell group to the charge battery cell group, Like the capacitor method, the charge from the discharged battery cells is first stored and then transferred to the charging battery cells. This eliminates the need for a structure that emits charge to a group of electrons. In addition, the switching circuit BT04 and the switching circuit BT05 Therefore, among the discharge battery cell group and the charge battery cell group, the battery cells connected to the transformer circuit are individually can be switched to.

[0385] Furthermore, the number of battery cells BT09 included in the discharge battery cell group is and the number of battery cells BT09 included in the charging battery cell group. The applied discharge voltage is converted into a charge voltage and applied to the terminal pair BT02. Regardless of the selection of the battery cell BT09 on the supply and charging sides, the charge transfer can be performed without any problems. It can be realized.

[0386] Furthermore, OS transistors are used for the transistors BT10 and BT13. As a result, leakage from the battery cell BT09 that does not belong to the charging battery cell group or the discharging battery cell group occurs. This reduces the amount of charge in the battery cell BT0 that does not contribute to charging or discharging. The decrease in capacitance of the OS transistor can be suppressed. This causes the temperature of the battery cell BT09 to rise. However, normal operation, such as switching between conductive and non-conductive states according to the control signals S1 and S2, is possible. It can be made to work.

[0387] This embodiment mode can be implemented in appropriate combination with other embodiment modes. [Example]

[0388] In this example, the amount of moisture in the exterior of the power storage device is measured when the power storage device is repeatedly bent. The results are presented.

[0389] As a power storage device, the thin storage battery described in Embodiment 1 was manufactured. A sheet with a resin layer of 80 μm on one side of the rubber layer and a resin layer of approximately 30 μm on the other side was used. The sheet was prepared under the conditions that it was not embossed, and Two conditions were used: one with embossing and the other without. The width of the exterior body as seen from above is 60 mm. The width of the left and right sealing parts was set between 5mm and 6mm as the first condition. The first condition was about 3 mm (W width), and the second condition was about 3 mm (N width). The width of the edge seal was between 5 mm and 5.5 mm.

[0390] The positive electrode was made by forming a positive electrode active material layer of 80 μm thick on one side of a 20 μm thick aluminum current collector. The electrode was made of a 18 μm thick copper current collector with a 82 μm thick layer of negative electrode active material formed on one side. The positive electrode active material was lithium cobalt oxide, and the negative electrode active material was Graphite was used in each case.

[0391] A stack was prepared by alternately stacking positive electrodes, separators, and negative electrodes. The positive electrode active material layer and the negative electrode active material layer were configured to face each other in six layers.

[0392] Next, the tab area of ​​the stacked positive electrode is connected to the positive electrode lead, and the tab area of ​​the stacked negative electrode is connected to the negative electrode lead. Next, the positive electrode, separator, and negative electrode were alternately stacked. The laminate was sandwiched between films that served as exterior bodies, and two sides were sealed by heat. The card was removed from the same side of the outer casing.

[0393] Next, 1800 μL of PC was injected, and then the remaining side was sealed.

[0394] Next, a slit was provided in the sealing area of ​​the exterior body in the same manner as in the examples shown in FIGS. 43 and 44. The slits were made using scissors. The slits were approximately perpendicular to the sides of the exterior body and were approximately 3 m long. The wires were spaced at intervals of 1 m and approximately 2 mm long from the end.

[0395] The energy storage device was manufactured by the above steps. Table 1 shows whether the sheets used as the outer packaging were embossed or not.

[0396] [Table 1]

[0397] In this embodiment, a supporting electrolyte such as a lithium salt is not added, and the device functions as a power storage device. However, if you inject an electrolyte into the battery instead of using a PC, it can be used as a power storage device to charge and discharge electricity. do.

[0398] Next, a bending test of the energy storage device was carried out. The test equipment for bending the device was designed to be stretched in the depth direction. The center of the energy storage device is directly above the support. The test device has an arm that extends in the left and right directions. The tip of the arm is held The arm is mechanically connected to the plate. By moving the tip of the arm up and down, the The bending test of the energy storage device is carried out by placing the energy storage device between two holding plates. Therefore, by moving the tip of the arm up and down, the cylindrical support The energy storage device can be bent along the support body. By bending the battery pack, the battery pack can be bent with a radius of curvature of 40 mm. By sandwiching the storage device between two holding plates, unnecessary forces other than bending are prevented from entering the storage device. In addition, bending force is applied uniformly to the entire energy storage device. It can be done.

[0399] The bending test conditions are bending with a radius of curvature of 40 mm or more and 150 mm or less, and bending once for 10 seconds. The bending was performed at intervals of 10,000 seconds.

[0400] First, a bending test was carried out on the electricity storage devices A1, A2, A3, C1, and C2. The tab area of ​​the positive electrode 503, the tab area of ​​the negative electrode 506, the positive electrode lead 510, and the negative electrode lead 5 The area including 11, for example, the area 522 in FIG. 1(A), is not moved, and the upper surface of FIG. The area below the area 522, for example, the area 521, has a curvature radius of 40 mm or more and 150 mm or less. Repeated bending at the same diameter.

[0401] Next, regarding the power storage devices A4, A5, A6, B1, B2, B3, C3, C4, and C5, A bending test was conducted. Here, the energy storage device was sandwiched between metal plates, and the entire area was bent by 40 m. The wire was repeatedly bent with a radius of curvature of 100 mm or more and 150 mm or less.

[0402] Next, a storage test was carried out on the energy storage device that had undergone the bending test. The mixture was placed in a container containing water and kept at 120°C for 24 hours.

[0403] Next, one side of the storage device that had undergone the storage test was cut and opened, and 1800 μL of PC was injected. After that, the added solvent was spread over the entire area surrounded by the exterior body, and then the exterior body was The solvent in the area surrounded by was squeezed out and collected.

[0404] Next, coulometric titration Karl Fischer moisture meter MKC-610-DT (Kyoto Electronics Manufacturing Co., Ltd.) The water content of the recovered solvent was measured using the method described above.

[0405] FIG. 45(A) shows the results for the power storage devices A1, A2, A3, C1, and C2. The moisture content was higher than 500 ppm in C1 and C2, and higher than 900 ppm in the storage device C1. Repeated bending can cause cracks in the exterior of the energy storage device, reducing its airtightness. On the other hand, in the electricity storage devices A1 to A3, the amount of moisture was 50 It was less than 0 ppm, and in A3 it was about 300 ppm.

[0406] FIG. 45(B) shows the results of the power storage devices A4, A5, A6, B1, B2, C3, C4, and C5. The results are shown in Table 1. Compared with the power storage devices C3 to C5 that do not have slits, the power storage devices C3 to C5 that have slits It was suggested that the amount of moisture that penetrated was reduced in the energy storage devices A4 to A6. It was suggested that the penetration of moisture can be suppressed even in this case. [Explanation of symbols]

[0407] 10 Film 10a Convex part 10b Convex part 102 Active material layer 103 Active material 104 Binder 111 Positive electrode 111a positive electrode 115 Negative electrode 115a negative electrode 121 Positive electrode current collector 122 Cathode active material layer 123 Separator 125 Negative electrode current collector 126 Negative electrode active material layer 130 Electrode assembly 131 Electrode assembly 200 Secondary battery 203 Separator 203a area 203b area 207 Exterior body 211 Positive electrode 215 negative electrode 220 Sealing layer 221 Positive lead 225 Negative lead 250 Secondary battery 261 Slit 261a Slit 261b Slit 262 holes 321 Graphene Compounds 331 areas 332 areas 333 areas 352 pitches 354 distance 500 Electricity storage device 501 Positive electrode current collector 502 Positive electrode active material layer 503 Positive electrode 504 Negative electrode current collector 505 Negative electrode active material layer 506 negative electrode 507 Separator 508 Electrolyte 509 Exterior body 509a area 509b area 509i Sealing part 509j Sealing part 509k Sealing part 510 Positive lead 511 Negative lead 512 Welding Area 513 Curved section 514 Sealing part 521 areas 522 areas 541 Laminate 700 Mobile Information Terminals 701 Case 702 Display Panel 703 Clasp 705A band 705B band 711 Operation button 712 Operation Button 750 Energy Storage Device 751 Positive lead 752 Negative lead 753 Exterior body 1700 curved surface 1701 Plane 1702 Curve 1703 Radius of curvature 1704 Center of curvature 1800 Center of curvature 1801 Film 1802 radius of curvature 1803 Film 1804 radius of curvature 7100 Portable display devices 7101 Housing 7102 Display section 7103 Operation button 7104 Energy storage devices 7200 Personal Digital Assistant 7201 Case 7202 Display section 7203 Band 7204 Buckle 7205 Operation button 7206 Input / output terminal 7207 Icon 7250 Activity meter 7251 Case 7300 display device 7304 Display section 7350 Display device 7351 Lens 7351A Images 7351B Images 7352 Frame 7355 Tip 7360 Energy storage devices 7361 Positive lead 7362 Negative lead 7400 mobile phone 7401 Housing 7402 Display section 7403 Operation button 7404 External connection port 7405 Speaker 7406 Microphone 7407 Electricity storage devices 8000 display device 8001 Case 8002 Display section 8003 Speaker section 8004 Electricity storage devices 8021 Charging device 8022 cable 8024 Electricity storage device 8100 Lighting equipment 8101 Housing 8102 Light source 8103 Energy storage devices 8104 Ceiling 8105 Side wall 8106 beds 8107 Window 8200 indoor unit 8201 Housing 8202 Ventilation outlet 8203 Energy storage devices 8204 Outdoor unit 8300 Electric refrigerator-freezer 8301 Housing 8302 Refrigerator door 8303 Freezer door 8304 Energy storage devices 8400 Automobiles 8401 Headlight 8500 cars 9600 tablet device 9625 Switch 9626 Switch 9627 Power Switch 9628 Operation Switch 9629 Fasteners 9630 chassis 9631 Display section 9631a Display section 9631b Display section 9632a area 9632b area 9633 Solar Cells 9634 Charge / Discharge Control Circuit 9635 Electricity storage unit 9636 DC / DC Converter 9637 Converter 9638 Operation key 9639 Button 9640 Moving parts

Claims

1. a positive electrode, a negative electrode, and an exterior body that encases the positive electrode and the negative electrode; the exterior body has a first region and a second region that is in contact with the outside of the first region, the second region is a sealing portion to which the outer periphery of the exterior body is joined, the boundary between the first region and the second region has a wavy line shape with a peak on the first region side, the exterior body has a slit in the second region, the slit is provided at a position facing the peak, The slit has a wedge shape.

2. a positive electrode, a negative electrode, and an exterior body that encases the positive electrode and the negative electrode; the exterior body has a first region and a second region that is in contact with the outside of the first region, the second region is a sealing portion to which the outer periphery of the exterior body is joined, the boundary between the first region and the second region has a wavy line shape with a peak on the first region side, the exterior body has a slit in the second region, The slit is provided at a position opposite to the peak.

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