Secondary batteries

Abstract

To provide a rechargeable battery suitable for personal digital assistants or wearable devices. , novel electronic devices having various external shapes, and secondary shapes suitable for those shapes We provide batteries. [Solution] The film has recesses or protrusions that relieve the stress generated when an external force is applied. The secondary battery is sealed using a film. The film is press-formed, for example, E The embossing process creates a pattern composed of recessed or raised areas.

Description

Technical Field

[0001] The present invention relates to an article, a method, or a manufacturing method. Alternatively, the present invention relates to a process, a machine, a manufacture, or a composition of matter. Or, one aspect of the present invention relates to a semiconductor device, a display device, a light-emitting device, a power storage device, an imaging device, a driving method thereof, or a manufacturing method thereof. In particular, it relates to electronic devices. In addition, in this specification, an electronic device generally refers to all devices having a secondary battery, and an electro-optical device having a secondary battery, an information terminal device having a secondary battery, a vehicle having a secondary battery, etc. are all electronic devices.

[0002] Note that in this specification, an electronic device refers to all devices having a secondary battery, and an electro-optical device having a secondary battery, an information terminal device having a secondary battery, a vehicle having a secondary battery, etc. are all electronic devices.

Background Art

[0003] In recent years, portable information terminals typified by smartphones have been actively developed. Users expect that a portable information terminal, which is a type of electronic device, is lightweight and small-sized.

[0004] Regardless of location, and without restricting the freedom of both hands, Patent Document 1 discloses an example of a wearable device through which information can be obtained visually. Patent Document 1 discloses a goggle-type display device capable of communication and including a CPU. The device of Patent Document 1 is also included in a type of electronic device. ]

[0005] Wearable devices and portable information terminals often mount a secondary battery capable of repeated charging or discharging. Wearable devices and portable information terminals are required to be lightweight and small-sized, and therefore, the capacity of the secondary battery is small, and the operation of wearable devices and portable information terminals [[ID=I3]] There is a problem with the limited production time. Two components to be installed in wearable devices and personal digital assistants. The next battery needs to be lightweight, compact, and capable of long operating times. Yes, they are.

[0006] Examples of rechargeable batteries include nickel-metal hydride batteries and lithium-ion rechargeable batteries. Among them, lithium-ion secondary batteries are being actively developed because they offer high capacity and can be made smaller. It is happening.

[0007] In lithium-ion secondary batteries, the electrodes that function as the positive or negative electrode are lithium Umium metals, carbon-based materials, alloy materials, etc., are used. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2005-157317 [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] One of our objectives is to provide a rechargeable battery suitable for mobile information terminals.

[0010] Alternatively, one of the objectives is to provide a rechargeable battery suitable for wearable devices.

[0011] Alternatively, an electronic device having a structure with various external shapes, and two shapes suitable for that shape. Providing the next generation of batteries is also one of the challenges. Alternatively, novel electronic devices, novel secondary batteries, Furthermore, one of the challenges is to provide novel energy storage devices.

[0012] Furthermore, the description of these problems does not preclude the existence of other problems. One approach does not necessarily need to solve all of these problems. The title will become clear from the description in the specification, drawings, claims, etc. It is possible to extract other issues from the descriptions in the drawings, claims, etc. [Means for solving the problem]

[0013] When designing electronic devices with complex external shapes, the enclosure is designed with a complex external shape, and the inside of that enclosure... Electronic components (power supplies, wiring, transistors, resistors, capacitors, etc.) are placed in the space. If the electronic device is large and heavy, then the inside of the casing is relatively large. Due to the large volume of space, electronic components can be arranged relatively freely.

[0014] When electronic devices with complex external shapes are small and require weight reduction, the casing is The internal space volume is small, and the electronic components and their sizes must be selected and arranged to fit that volume. In this case, the smaller the size of the electronic component, the more expensive it becomes, and the higher the manufacturing cost. It happens.

[0015] Furthermore, in the case of secondary batteries, the capacity increases as the volume or weight of the secondary battery increases. There is a tendency for this to be the case, and when built into small electronic devices, there are limitations on the size and placement of secondary batteries. .

[0016] Furthermore, vehicles with secondary batteries, such as electric vehicles and hybrid vehicles, require a single charge. The longer the driving range, the more the volume and weight of the secondary battery increases. Mau.

[0017] Therefore, a rechargeable battery whose shape can be changed is used in an electronic device, and the casing of that electronic device To efficiently arrange secondary batteries and other electronic components within the internal space of the body.

[0018] When an external force is applied to change the shape of a secondary battery, the casing of the secondary battery is affected. When an external force is applied to an object such as a lumber, stress is placed on the object, causing partial deformation or partial fracture. There is a risk of this happening.

[0019] The secondary battery has a structure that relieves strain caused by stress. Strain refers to the stress on an object. A measure of deformation that shows the displacement of a point of material within an object relative to a reference (initial) length. The degree of deformation caused by applying force from outside the pond, i.e., the effect of strain, must be kept within acceptable limits. We provide a secondary battery.

[0020] One embodiment of the invention disclosed herein relates to the stress on a film caused by an applied external force. This is a secondary battery sealed using a film having recesses or protrusions that mitigate stress.

[0021] Another embodiment of the configuration of the invention disclosed herein is a surface in which a portion of the surface is formed by a recess or a protrusion. This is a secondary battery sealed using a film having a pattern.

[0022] Another embodiment of the configuration of the invention disclosed herein is a surface formed by recesses or protrusions on a portion of the surface. The first film having a pattern is different from the first film formed by recesses or protrusions. A secondary battery sealed by laminating a second film having a pattern on part of its surface. That is the case.

[0023] (1) Another embodiment of the configuration of the invention disclosed herein has a film, the film being recessed A region having a pattern formed by parts or protrusions, and a region having a pattern formed by recesses or protrusions The region having no pattern has a portion having a first film thickness and a portion having a second film thickness. This is a secondary battery sealed using a film formed in a specific area.

[0024] (2) Another embodiment of the configuration of the invention disclosed herein has a film, the film being recessed A region having a pattern formed by parts or protrusions, and a region having a pattern formed by recesses or protrusions The region having no pattern and the region having a pattern consists of a portion having a first film thickness and a portion having a second film thickness. The portion formed in minutes and having a first film thickness has recesses or protrusions having a first pitch The portion having the second film thickness is a film having recesses or protrusions having a second pitch. This is a rechargeable battery sealed using [a specific method / technology]. Here, "pitch" refers to the bottom or protrusion of adjacent recesses. This refers to the distance between the vertices of a part when viewed from above.

[0025] (3) Another embodiment of the configuration of the invention disclosed herein is, in (1) or (2), a recess Or, regions having a pattern formed by convex parts and regions without a pattern formed by concave or convex parts This is a secondary battery with a boundary between its regions.

[0026] (4) Another embodiment of the configuration of the invention disclosed herein has a film, the film having a recess Alternatively, it has a first pattern formed by protrusions, and the film has a portion having a first film thickness and a second The film has a portion having a thickness of 2, and the film has a second pattern formed by recesses or protrusions. The film has a portion having a third film thickness and a portion having a fourth film thickness, and the first The pattern is formed by a portion having a first film thickness and a portion having a second film thickness, and the second pattern is formed by a third A secondary electric device sealed with a film formed with a portion having a thickness of one and a portion having a fourth thickness. It is a pond.

[0027] (5) Another embodiment of the configuration of the invention disclosed herein has a film, the film having a recess or It has a first pattern formed by convex portions, and the film has a portion having a first film thickness and a portion having a second film thickness The film has a portion having a second pattern formed by recesses or protrusions, and the film has a portion having a second pattern formed by recesses or protrusions. The film has a portion having a third film thickness and a portion having a fourth film thickness, and a portion having a first film thickness The part has a recess or protrusion having a first pitch, and the part having a third film thickness has a second pitch This is a secondary battery sealed with a film having recesses or protrusions.

[0028] (6) Another embodiment of the configuration of the invention disclosed herein is, in (4) or (5), a recess to A boundary between the first pattern formed by the convex portion and the second pattern formed by the concave or convex portion. It is a secondary battery that has [a certain feature].

[0029] (7) Another embodiment of the configuration of the invention disclosed herein is a first film and a second film and The first film has regions having patterns formed by recesses or protrusions, and the second The film has areas without patterns formed by recesses or protrusions, and areas with patterns. The region is formed by a portion having a first film thickness and a portion having a second film thickness, and the first film and This is a rechargeable battery sealed with a second film.

[0030] (8) Another embodiment of the configuration of the invention disclosed herein is a first film and a second film and The first film has regions having patterns formed by recesses or protrusions, and the second The film has areas without patterns formed by recesses or protrusions, and areas with patterns. The region is formed by a portion having a first film thickness and a portion having a second film thickness, and the portion having the first film thickness The portion having a first pitch is a recess or protrusion, and the portion having a second film thickness is the It has a recess or protrusion with a pitch of 2, and seals using a first film and a second film. It is a rechargeable battery that has been shut down.

[0031] (9) Another embodiment of the configuration of the invention disclosed herein is, in (7) or (8), the first Between the film and the second film, there is at least a positive electrode active material layer, a negative electrode active material layer, and an electrolyte. It is a secondary battery that includes [a specific component / feature].

[0032] (10) Another embodiment of the configuration of the invention disclosed herein is, in (2) or (8), the first This is a secondary battery with a different pitch for the first and second stages.

[0033] (11) Another embodiment of the configuration of the invention disclosed herein is, in (2) or (8), the first The depth of the recess having a pitch or the height of the protrusion, and the depth of the second recess having a pitch or This is a secondary battery in which the height of the protrusion is less than half the thickness of the secondary battery.

[0034] (12) Another embodiment of the configuration of the invention disclosed herein is a first film and a second film and The first film has a first pattern formed by recesses or protrusions, and the first film The film has a portion having a first film thickness and a portion having a second film thickness, and the second film extends to the recess. The second film has a second pattern formed by convex portions, and the second film has a portion having a third film thickness and the The first pattern has a portion having a thickness of 4, and the first pattern has a portion having a thickness of 1 and a portion having a thickness of 2. The second pattern is formed by a portion having a third thickness and a portion having a fourth thickness. This is a rechargeable battery that has been constructed and sealed with a first film and a second film.

[0035] (13) Another embodiment of the configuration of the invention disclosed herein is a first film and a second film and The first film has a first pattern formed by recesses or protrusions, and the first film The film has a portion having a first film thickness and a portion having a second film thickness, and the second film extends to the recess. The second film has a second pattern formed by convex portions, and the second film has a portion having a third film thickness and the It has a portion having a film thickness of 4, and the portion having a first film thickness has a recess having a first pitch or It has a convex portion, and the portion having a third film thickness has a concave or convex portion having a second pitch, This is a rechargeable battery sealed with a first film and a second film.

[0036] (14) Another embodiment of the configuration of the invention disclosed herein is, in (12) or (13), the Between film 1 and film 2, there is at least a positive electrode active material layer, a negative electrode active material layer, and It is a secondary battery that contains a dissolving agent.

[0037] (15) Another embodiment of the configuration of the invention disclosed herein is, in (5) or (13), a recess Alternatively, the first pattern formed by the protrusions consists of a portion having a first film thickness and a portion having a second film thickness. The second pattern, formed by recesses or protrusions, has a third thickness and a fourth This is a secondary battery formed by a portion having a film thickness.

[0038] (16) Another embodiment of the configuration of the invention disclosed herein is, in (5) or (13), the first The depth of a recess or the height of a protrusion having a pitch of a second pitch or This is a secondary battery in which the height of the protrusion is less than half the thickness of the secondary battery.

[0039] In the above configuration, the film pattern is a visible geometric pattern, consisting of two diagonal lines. It is a geometric pattern where lines intersect. When it is a geometric pattern where two diagonal lines intersect, Even without it, stress from bending in two directions can be relieved. Also, the arrangement of recesses and protrusions is regular. The arrangement of recesses and protrusions may be irregular, not just the precisely arranged patterns. When positioned, it relieves stress on two-dimensional bending, three-dimensional irregular bending, or torsion. It can be combined. Also, the film has multiple areas with different patterns depending on the location. This is also a good idea. For example, you could have two different patterns on one film by having different patterns on the edges and the center. A pattern of the same kind may be provided, and more than three types of patterns may be provided. Also, the bendable part The film may have recesses or protrusions only in certain areas, and the other parts may have flat surfaces. Furthermore, the shape of the recesses and protrusions is not particularly limited.

[0040] The recesses or protrusions in the film are formed by press processing (e.g., embossing). This can be done. Recesses or protrusions formed on the surface (or back) of the film by embossing. This forms a closed space with a variable volume, where the film is part of the wall of the sealing structure. The enclosed space is formed by a bellows made of a film having a pattern formed by recesses or protrusions. It can also be considered a bellows structure. The sealing structure using film provides waterproofing and dustproofing. It has an effect. In addition, not only embossing, which is a type of press processing, but also lifting of a part of the film. Techniques that can create carvings (reliefs) are also acceptable. Furthermore, combinations of these techniques, such as embossing, are also possible. Pressing and other pressing processes may be performed on a single film. The embossing process can be applied to a single sheet of film.

[0041] While there are various structural designs for secondary batteries, this design uses a film as the outer casing. The film must be water-resistant and gas-resistant. Furthermore, the film used for the exterior is metal-filled. Lum (aluminum, stainless steel, nickel steel, gold, silver, copper, titanium, nichrome, iron, tin) tantalum, niobium, molybdenum, zirconium, zinc, and other metals or alloys that make up metal foil. ), plastic films made from organic materials, organic materials (organic resins, fibers, etc.) and inorganic materials Hybrid material films containing materials (such as ceramics), carbon-containing inorganic films (car Single-layer films or multiple films selected from (such as bon film and graphite film) A laminated film consisting of the above is used. The metal film is easy to emboss, When processing is performed to form recesses or protrusions, the surface area of ​​the film exposed to the outside air increases. It has excellent heat dissipation properties.

[0042] Furthermore, the sealing structure of the secondary battery is made by folding a single rectangular film in the middle and then folding the two ends... The structure involves overlapping two films and fixing the three sides with an adhesive layer to seal them, or overlapping two films and the film The structure is designed to close off the four edges by fixing them with an adhesive layer.

[0043] The adhesive layer can be a thermoplastic film material, a thermosetting adhesive, or an anaerobic adhesive, or an UV-curing adhesive. Photocuring adhesives such as chemical-curing adhesives and reaction-curing adhesives can be used. The adhesive materials include epoxy resin, acrylic resin, silicone resin, and phenolic resin. You can use it.

[0044] When bonding the adhesive layer and the film and fixing them to form a sealing structure, pressure is applied, and the part that is pressed The size of the recesses or protrusions is made different at the edges of the film and in the center of the film. If the depth of the recess or the height of the protrusion at the edge of the film is reduced compared to the center of the film, The effects of strain can be kept within acceptable limits.

[0045] A recess or protrusion is provided in the center, and a recess or protrusion is provided at the edge of the film, which is the part to be pressed. If this is not provided, even if there is volume expansion inside the secondary battery in the central part, the secondary battery will be large. It can expand considerably. Therefore, it has the effect of preventing the secondary battery from rupturing. On the other hand, at the end Because there are no recesses or protrusions, the ends offer greater flexibility and stress relief compared to the central part. The effect will decrease. Therefore, providing recesses or protrusions at the edges of the film will reduce strain. This helps to keep the impact within an acceptable range.

[0046] Furthermore, there are several ways to interpret what it means to give electronic devices a complex external shape. This involves giving the external appearance of electronic devices a complex shape, such as a curved shape, and then fixing it in place. To secure it, the secondary battery will need to be bent once and then fixed in that bent position. In addition, there are electronic devices with complex external shapes that do not deform even when force is applied from the outside, and those that do not deform even when force is applied. They can be divided into those that change. In addition, electronic devices with a simple external shape can be externally... It is a method of deforming by applying force. When deforming electronic equipment by applying force, the force It is desirable that the secondary battery can also deform each time a load is applied.

[0047] Another embodiment of the configuration of the invention disclosed herein is a housing having a curved surface in part, and a housing having a curved surface The rechargeable battery has a casing which has a mold formed on a part of its surface with recesses or protrusions. It is an electronic device that is a film with a specific appearance.

[0048] Another embodiment of the configuration of the invention disclosed herein is a housing and two parts in contact with a part of the housing. The secondary battery has a secondary battery, and the casing of the secondary battery has a pattern formed on part of its surface by recesses or protrusions. It is a film that causes deformation, and it is an electronic device in which a part of the casing deforms.

[0049] In the above configuration, the casing of the secondary battery has a radius of curvature of 10 mm or more and a radius of curvature of 150 mm or less. Preferably, it can be deformed within a range of a radius of curvature of 30 mm or more and a radius of curvature of 150 mm or less. The film that forms the outer casing of the secondary battery is composed of one or two layers. In the case of a battery, if the cross-sectional shape of the battery is curved to be an arc, the electrodes and electrolyte etc. The structure is sandwiched between two curved surfaces of the film.

[0050] Here, we will explain the radius of curvature of the surface of the exterior using Figure 1. Figure 1(A) shows In the plane 1701 obtained by cutting the curved surface 1700, the curve 1 included in the curved surface 1700 Approximate a portion of 702 as an arc of a circle, set the radius of that circle to a radius of curvature of 1703, and curve the center of the circle. The ratio center is set to 1704. Figure 1(B) shows a top view of the curved surface 1700. Figure 1(C) shows a plane The cross-sectional view shows the curved surface 1700 cut by 1701. When cutting a curved surface with a plane, the curved surface is Depending on the angle of the plane and the position of the cut, the radius of curvature of the curve that appears in the cross-section will differ. However, in this specification, the smallest radius of curvature is defined as the radius of curvature of the surface.

[0051] A secondary battery, which uses two films as an outer casing to sandwich electrodes and electrolyte 1805, is curved. In that case, the radius of curvature of film 1801 on the side closer to the center of curvature 1800 of the secondary battery is 180. 2 is smaller than the radius of curvature 1804 of film 1803 on the side farther from the center of curvature 1800. (Figure 2(A)). If the secondary battery is curved to make the cross-section arc-shaped, then the distance from the center of curvature 1800 is Tensile stress is applied to the surface of the film (Figure 2(B)). Recesses or When a pattern is formed by convex parts, even if tensile stress is applied in this way, the strain The effects of curvature can be kept within an acceptable range. Therefore, secondary batteries are positioned close to the center of curvature. The outer casing on the left side deforms within a range where the radius of curvature is 10 mm or more, preferably 30 mm or more. It is possible.

[0052] Furthermore, the cross-sectional shape of a secondary battery is not limited to a simple arc shape, but can be as shown in Figure 2(C). The part can also be made into a shape that has an arc.

[0053] When viewed from the cross-section of a bent secondary battery, the outer surface is stretched and the inner surface is compressed. In other words, the outside stretches and the inside contracts.

[0054] By forming an optimal pattern on the exterior film with recesses or protrusions, secondary electricity When the pond is bent, wrinkles and cracks form in the film, causing it to deteriorate and break, and the electrolyte leaks out. The risk of this happening will decrease.

[0055] Like watches, a part of the device comes into contact with a part of the user's body (such as the wrist or arm). In other words, by having the user wear the device, the user can experience something that is lighter than its actual weight. It can give a feeling. An electronic device with an external shape that has a curved surface that conforms to a part of the user's body. By using flexible rechargeable batteries, the rechargeable batteries can be fixed into a shape suitable for electronic devices. It can be installed.

[0056] Furthermore, if the user moves the part of their body to which the electronic device is attached, the curved surface conforms to that part of the body. Even if they do use it, they may feel uncomfortable, perceive the electronic device as a nuisance, and it could cause stress. Yes. Therefore, the configuration is such that at least a part of the electronic device deforms in accordance with the body's movements. This makes it possible to create electronic devices that the user does not feel any discomfort with, and prevents deformation of electronic devices. A flexible secondary battery can also be installed in that section.

[0057] Or, not limited to cases where the external shape of the electronic device is curved or complex, simple It may also be an electronic device in terms of its external shape. For example, the internal odor of an electronic device with a simple external shape. The number and size of components that can be built into an electronic device are determined by the volume of space formed by the electronic device's casing. This is often the deciding factor. A flexible secondary battery is placed in the gap between components other than the secondary battery. This allows for effective use of the space formed by the casing of electronic devices, and also enables miniaturization. can.

[0058] Wearable devices include wearable cameras, wearable microphones, and wearables. Wearable input devices such as rubble sensors, wearable displays, and wearables Wearable output devices such as speakerphones, and wearable devices that combine these functions. This includes input / output terminals. Furthermore, wearable devices are those that control each device and perform data calculations. This includes processing equipment, typically including wearable computers with CPUs. A wearable device is a device that stores, transmits, and receives data. On paper, this also includes mobile information terminals and memory devices. [Effects of the Invention]

[0059] This enables the realization of a secondary battery with a novel structure, or a novel energy storage device.

[0060] Because the shape of the secondary battery can be freely designed, for example, a secondary battery with a curved surface can be used. This increases the overall flexibility of the device, enabling the creation of devices with a wide variety of designs. This is possible. Furthermore, it allows for the creation of unnecessary space within a device with a curved surface. By placing the secondary battery inside the curved surface of the device, along the curved surface of the device, air inside the device can be airborne. The space can be used effectively.

[0061] Therefore, it is possible to realize electronic devices with novel structures.

[0062] Furthermore, the description of these effects does not preclude the existence of other effects. One embodiment does not necessarily have to possess all of these effects. Furthermore, other effects may be considered. This will become clear from the description in the specification, drawings, claims, etc., and the specification, drawings It is possible to extract effects other than those mentioned above from the descriptions in the surfaces, claims, etc. [Brief explanation of the drawing]

[0063] [Figure 1]This is a diagram illustrating the radius of curvature of a surface. [Figure 2] This is a diagram illustrating the center of curvature. [Figure 3] This is a top view showing one aspect of the present invention. [Figure 4] This is a top view showing one aspect of the present invention. [Figure 5] This is an explanatory diagram of an embossing process showing one embodiment of the present invention. [Figure 6] These are a top view, a cross-sectional view, and a schematic diagram illustrating one aspect of the present invention. [Figure 7] These are a top view and a cross-sectional view showing one aspect of the present invention. [Figure 8] This is a cross-sectional view of a secondary battery showing one aspect of the present invention. [Figure 9] This is a cross-sectional view of a secondary battery showing one aspect of the present invention. [Figure 10] This is a top view showing one aspect of the present invention. [Figure 11] This is a top view showing one aspect of the present invention. [Figure 12] These are perspective views and cross-sectional views illustrating one aspect of the present invention. [Figure 13] These are perspective views and cross-sectional views illustrating one aspect of the present invention. [Figure 14] This is a diagram illustrating an electronic device that has a flexible rechargeable battery. [Figure 15] This is a diagram illustrating electronic devices. [Figure 16] This is a diagram illustrating a vehicle equipped with a secondary battery. [Figure 17] This is a cross-sectional view and photograph illustrating Example 1. [Figure 18] This graph shows the frictional force data for Example 1. [Figure 19] This is a diagram of Example 2. [Figure 20] This is a diagram of Example 2. [Figure 21] This is a photograph showing Example 2. [Figure 22] This is a diagram of Example 3. [Figure 23]This figure shows Examples 3 and 4. [Figure 24] This graph shows the data from the load test in Example 3. [Figure 25] This graph shows the data from the load test in Example 4. [Modes for carrying out the invention]

[0064] The embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention This is not limited to the description below, and its form and details can be changed in various ways, as is the case for those skilled in the art. This will be easily understood. Furthermore, the present invention shall be interpreted as being limited to the contents of the embodiments described below. It is not something that should be done.

[0065] "Electrically connected" means connected via "something that has some kind of electrical effect". This includes connections. Here, "something that has some kind of electrical effect" refers to electrical signals between connected objects. There are no particular restrictions as long as it allows for the transfer of numbers.

[0066] The location, size, and scope of each component shown in the drawings, etc., are for the purpose of facilitating understanding. The position, size, and range of the edges may not be shown. Therefore, the disclosed invention is not necessarily However, this is not limited to the location, size, and scope disclosed in drawings, etc.

[0067] Ordinal numbers such as "1st," "2nd," and "3rd" are added to avoid confusion of constituent elements. That is the case.

[0068] Furthermore, the words "membrane" and "layer" can be used interchangeably depending on the context or situation. Accordingly, they can be interchanged. For example, the term "conductive layer" can be replaced with "conductive layer". In some cases, the term can be changed to "film." Or, for example, "insulating film." In some cases, it may be possible to change the term to "insulating layer."

[0069] (Embodiment 1) In this embodiment, as shown in Figures 3 to 9, the film is embossed to create a pattern. This example shows how to fabricate a lithium-ion secondary battery using a film.

[0070] First, prepare a sheet made of a flexible substrate. The sheet will be a laminate and a metal film. Use a product that has an adhesive layer (also called a heat seal layer) on one or both sides. The adhesive layer uses a heat-sealable resin film containing polypropylene or polyethylene. In this embodiment, the sheet has a nylon resin on the surface of an aluminum foil, and The gold foil has an acid-resistant polypropylene film on the back and a laminate of polypropylene films. Use the attached sheet. Cut this sheet to prepare the film 10 shown in Figure 3(A).

[0071] Then, a portion of this film 10 (film 10a) is embossed, and the film No embossing is applied to 10b. The resulting product is shown in Figure 3(B). This is film 11. As shown in Figure 3(B), the surface of film 11a has irregularities. This creates a visible pattern, but does not create any irregularities on the surface of the film 11b. Furthermore, between the film 11a with uneven surfaces and the film 11b without uneven surfaces, It has a boundary. In Figure 3(B), the embossed portion of the film 11 is Film 11a is defined as the part that has not been embossed, and film 11b is defined as the part that has not been embossed. The embossing of film 11a may form the same uneven surface over the entire surface, or it may form the same uneven surface over the entire surface of film 11a. In some places, two or more different types of bumps and ridges may be formed. The combination has boundaries between its different contours.

[0072] Furthermore, the entire surface of film 10 in Figure 3(A) is embossed, and a film like the one in Figure 4(A) is produced. Film 22 may be manufactured. Note that the embossing of film 22 is to create the same uneven surface. Alternatively, two or more different types of bumps and ridges may be formed depending on the location of the film 22. When forming two or more different types of bumps and depressions, there must be a boundary between those different bumps and depressions.

[0073] Note that this example shows how to emboss the sheet after cutting it, but the order is not particularly limited. The process is not fixed, and the sheet is embossed before cutting, then cut, as shown in Figure 3(B). The state shown is also acceptable. Alternatively, the sheet may be folded and heat-sealed before being cut. stomach.

[0074] The following is an explanation of embossing, a type of press work.

[0075] Figure 5 is a cross-sectional view showing an example of embossing. Embossing is a process that involves pressing. It is a type of process in which an embossed roll with a textured surface is pressed onto a film, and the embossed roll This refers to the process of creating a textured surface on a film that corresponds to the unevenness of the surface. This is a roll with a pattern engraved on its surface.

[0076] Figure 5(A) shows an example of embossing on one side of a film.

[0077] Figure 5(A) shows an embossing roll 53 in contact with one side of the film and a roll in contact with the other side. The film 50 is sandwiched between the roll 54 and the film 50 in the direction of film travel 60 This shows the film being sent out. A pattern is formed on the film surface by pressure or heat. The pattern may be formed on the film surface by both pressure and heat.

[0078] Figure 5(A) shows what is also called single-sided embossing, with embossing roll 53 and roll 54 (metal). Processing can be done using a combination of rolls or elastic rolls (such as rubber rolls). .

[0079] Furthermore, Figure 5(B) shows that between the embossing roll 53 and the roll 54, one side is embossed once. This shows the processed film 51 being sandwiched and being fed out in the direction of travel 60. The embossing roll 53 rotates in contact with the unembossed side of the film 51. Therefore, film 51 is embossed on both sides. As in this example, one film It is also possible to emboss the lume multiple times.

[0080] Furthermore, Figure 5(C) shows an enlarged view of the cross-section of the film 52 which has been embossed on both sides. H1 indicates the film thickness in the recessed or convex parts of the film. Also, H2 This refers to the thickness of the film at the boundary between a recess and the adjacent protrusion, or between a protrusion and the adjacent protrusion. This shows the film thickness at the boundary of the recess. The film thickness is not uniform, and H2 is H Less than 1.

[0081] Figure 5(D) shows another example of embossing applied to both sides of the film.

[0082] Figure 5(D) shows the embossing roll 53 in contact with one side of the film and the other side The film 50 is sandwiched between the embossing roll 55 and the film 50 as the film progresses This indicates that it is being sent out in direction 60.

[0083] Figure 5(D) is also called double-sided embossing, where a recessed area and a raised area, and a raised area and a recessed area, are paired together. The processing can be done by combining the embossing roll 53 and the embossing roll 55. In addition, embossing raises a portion of the surface of film 50, and embossing indents the surface. The continuous bumps and ridges create a pattern on the surface of the film 50.

[0084] Figure 5(E) shows an embossed roll 53 with a different pitch of protrusions than one of the embossing rolls 53 in Figure 5(D). Roll 56 is being used. Here, the pitch of the protrusions or the pitch of the embossing is adjacent to This refers to the distance between the vertices of matching protrusions. For example, the distance P in Figure 5(E) is the distance between the vertices of the protrusions. This is called the pitch of the embossing or embossing. Figure 5(E) shows the embossing roll 53 and the embossing roller. The image shows the film 50 sandwiched between the 56s and being fed out in the direction of travel 60. Protrusion By changing the pitch, it is possible to apply embossing with different pitches to both sides of the film. Cut.

[0085] Figure 5(F) shows the embossing roll 57 in contact with one side of the film and the other side The film 50 is sandwiched between the embossing roll 58 and the film 50 as the film progresses This indicates that it is being sent out in direction 60.

[0086] Figure 5(F) shows an embossing roll, also known as tip-to-tip double-sided embossing. This is a combination of 57 and embossed roll 58, which has the same pattern as embossed roll 57. The phases of the convex and concave parts of the embossing roll are aligned, and there is a difference between the front and back of the film 50. It is possible to form a pattern with almost no particles. Also, unlike Figure 5(F), the same envelope It is also possible to perform embossing without aligning the phases of the convex and concave parts of the boss roll.

[0087] Furthermore, the use of embossing rolls is not limited to embossing plates; embossing plates may also be used. Furthermore, it is not limited to embossing; if you create a raised (relief) pattern on a part of the film, good.

[0088] In this embodiment, a pattern is created by providing bumps and ridges on both sides of a portion of the film 10 (film 10a). A film 11 is made by forming a shape, and the film 11 is folded in the middle and the two ends overlap. The structure will be sealed on three sides with an adhesive layer.

[0089] Next, fold the film 11 along the dotted line shown in Figure 3(B) to obtain the state shown in Figure 6(A). Let's assume that.

[0090] Furthermore, as shown in Figure 6(B), the positive electrode active material layer 18 constituting the secondary battery has a shape formed on a part of its surface. The positive electrode current collector 12, separator 13, and negative electrode active material layer 19 are formed on a portion of the surface. Prepare a stack of negative electrode current collectors 14. Also, the positive electrode current collector 12 and the negative electrode current collector 14, etc. The current collectors include stainless steel, gold, platinum, zinc, iron, nickel, copper, aluminum, and Metals such as tan, tantalum, and their alloys, which have high conductivity and can hold lithium ions, etc. Materials that do not alloy with carrier ions can be used. Also, silicon, titanium, and neo- Aluminum with added elements that improve heat resistance, such as zinc, scandium, and molybdenum. A metal alloy can be used. Additionally, a metal element that reacts with silicon to form a silicide can be used. It may be formed by zirconium. Metal elements that react with silicon to form silicides include zirconium. Titanium, Titanium, Hafnium, Vanadium, Niobium, Tantalum, Chromium, Molybdenum, These include sten, cobalt, nickel, etc. Also, current collectors come in foil, plate (sheet) form, Shapes such as mesh, cylindrical, coil, perforated metal, and expanded metal are used as appropriate. It is possible to use a current collector with a thickness of 5 μm to 40 μm. Here, to simplify the explanation, we will describe the positive electrode current collector 12 on which the positive electrode active material layer 18 is formed, One combination of stacking a parator 13 and a negative electrode current collector 14 on which a negative electrode active material layer 19 is formed. An example of housing it in an outer casing was shown, but in order to increase the capacity of the secondary battery, the combination Multiple units can be stacked and stored in the outer casing.

[0091] Then, two lead electrodes 16 having a sealing layer 15 as shown in Figure 6(C) are prepared. Terminal 16, also known as the lead terminal, pulls either the positive or negative electrode of the secondary battery to the outside of the outer film. It is provided for outputting. As for the leads, the positive lead uses aluminum, and the negative lead uses Nickel-plated copper is used.

[0092] Then, the positive lead and the protruding part of the positive electrode current collector 12 are electrically connected by ultrasonic welding or the like. To be continued. Also, the negative electrode lead and the protruding part of the negative electrode current collector 14 are connected by ultrasonic welding or the like to provide electrical protection. Connect to it.

[0093] Then, in order to leave one side open for the electrolyte solution, heat-press the two sides of the film 11. Then seal it (hereafter, the shape of the film in this state will also be called a bag shape). During heat sealing, The sealing layer 15 provided on the lead electrode also melts, fixing the gap between the lead electrode and the film 11. Then, under reduced pressure or in an inert gas atmosphere, the film 11 forms a bag-like structure into which a desired amount of electrolyte is poured. It is then dripped onto the inside. And finally, the periphery of film 11 that was left unheated. The material is sealed by applying heat pressure.

[0094] In this way, the secondary battery 40 shown in Figure 6(D) can be manufactured.

[0095] The casing of the resulting secondary battery 40 has a pattern with irregularities on the surface of the film 10. Furthermore, the area between the dotted line and the end in Figure 6(D) is the thermocompression area 17, and that part It also has a pattern with irregularities on its surface. The irregularities in the heat-sealed area 17 are smaller compared to the central part. However, it can alleviate the stress applied when the secondary battery is bent.

[0096] Furthermore, an example of a cross-section obtained by cutting along the dashed line AB in Figure 6(D) is shown in Figure 6(E).

[0097] As shown in Figure 6(E), the unevenness of the film 11a is such that it overlaps with the positive electrode current collector 12, The thermocompression bonding region 17 differs. As shown in Figure 6(E), the positive electrode current collector 12 and the positive electrode active material are different. Layer 18, separator 13, negative electrode active material layer 19, and negative electrode current collector 14 are stacked in that order. It is sandwiched between folded films 11 and further sealed at the ends with an adhesive layer 30, The remaining space inside the bent film 11 contains an electrolyte solution 20.

[0098] Similarly, to form a pattern on both sides of the entire surface of film 10, film 22 is created The secondary battery 40 shown in Figure 7(B) may be fabricated by using the film 22 shown in Figure 4(A). Figure 7(A) shows the paper folded along the dotted line.

[0099] Cut along the dashed line E-F in the secondary battery 40 shown in Fig. 7(B) fabricated using the film 22 An example of the cross-section is shown in Fig. 7(C).

[0100] As shown in Fig. 7(C), the concavities and convexities of the film 22 are different in the region overlapping with the positive electrode current collector 12 and the thermal compression bonding region 17. As shown in Fig. 7(C), the positive electrode current collector 12, the positive electrode active material layer 18, the separator 13, the negative electrode active material layer 19, and the negative electrode current collector 14 are laminated in this order and are sandwiched between the folded film 22, and further sealed with the adhesive layer 30 at the ends. The other space inside the folded film 22 contains the electrolyte solution 20.

[0101] Examples of the positive electrode active material used for the positive electrode active material layer 18 include composite oxides having an olivine-type crystal structure, a layered rock salt-type crystal structure, or a spinel-type crystal structure. As the positive electrode active material , for example, compounds such as LiFeO2, LiCoO2, LiNiO2, LiMn2O4, V2O5, Cr 2O5, and MnO2 are used.

[0102] Alternatively, a composite material (general formula LiMPO4 (M is one or more of Fe(II), Mn(II), Co( II), Ni(II))) can be used. Representative examples of the general formula LiMPO4 include LiFePO4, LiNiPO4, LiCoPO4, LiMnPO4, LiF e a Ni b PO4, LiFe a Co b PO4, LiFe a Mn b PO4, LiNi a Co b PO4, LiNi a Mn b PO4 (a + b is 1 or less, 0 < a < 1, 0 < b < 1), Li Fec Ni d Co e PO4, LiFe c Ni d Mn e PO4, LiNi c Co d Mn e P O4 (where c + d + e is less than or equal to 1, 0 < c < 1, 0 < d < 1, 0 < e < 1), LiFe f Ni g Co h Mn i PO4 (where f + g + h + i is less than or equal to 1, 0 < f < 1, 0 < g < 1, 0 < h < 1, 0 < i < 1), etc., lithium compounds can be used as materials.

[0103] Or, a composite material such as the general formula Li (2-j) MSiO4 (M is one or more of Fe(II), Mn(II), Co (II), Ni(II), 0 ≤ j ≤ 2) can be used. The general formula Li (2-j) MSiO4 representative examples include Li (2-j) FeSiO4, Li ( 2-j) NiSiO4, Li (2-j) CoSiO4, Li (2-j) MnSiO4, L​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​ Ni n Co q SiO4, Li (2-j) Fe m Ni n Mn q SiO4, Li (2-j) N i 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 (where 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 for this purpose.

[0104] In addition, as the positive electrode active material, A x M2(XO4)3 (A = Li, Na, Mg, M = Fe, Mn, Ti, V, Nb, Al, X = S, P, Mo, W, As, Si, x ≧ 2) represented by the general formula can be used. Examples of the NASICON type compound include Fe2( MnO4)3, Fe2(SO4)3, Li3Fe2(PO4)3, etc. Also, as the positive electrode active material, compounds represented by the general formula of Li2MPO4F, Li2MP2O7, Li5MO4 (M = Fe, Mn), perovskite type fluorides such as NaFeF3, FeF3, metal chalcogenides (sulfides, selenides, tellurides) such as Ti S2, MoS2, oxides having an inverse spinel type crystal structure such as LiMV O4, vanadium oxides (V2O5, V6 O 13 , LiV3O8, etc.), manganese oxides, organic sulfur, etc. can be used as materials.

[0105] Note that the carrier ions are alkali metal ions other than lithium ions, and alkaline earth In the case of metal ions, instead of lithium, alkali metals (for example, na) can be used as the positive electrode active material. (e.g., thorium and potassium), alkaline earth metals (e.g., calcium, strontium, ba (e.g., lium, beryllium, or magnesium) may also be used.

[0106] The separator 13 can be cellulose (paper) or polypropylene with voids. Insulators such as polyethylene can be used.

[0107] The electrolyte is an electrolyte that allows carrier ions to move, and the carrier ions are Materials containing lithium ions are used. Typical examples of electrolytes include LiPF6 and LiC lO4, LiAsF6, LiBF4, LiCF3SO3, Li(CF3SO2)2N, L There are lithium salts such as i(C2F5SO2)2N. These electrolytes are used individually. It is also acceptable to use two or more types in any combination and ratio.

[0108] Furthermore, a material that allows carrier ions to move is used as the solvent for the electrolyte. As the medium, an aprotic organic solvent is preferred. Typical examples of aprotic organic solvents are ethylene carbonate (EC), propylene carbonate, dimethyl carbonate, di Ethyl carbonate (DEC), γ-butyrolactone, acetonitrile, dimethoxyethanol These include tetrahydrofuran, and one or more of these can be used. By using a polymer material that gels as the solvent for the electrolyte, safety against leakage, etc. This increases the likelihood of battery thinning and weight reduction. Examples include silicone gel, acrylic gel, acrylonitrile gel, polyethylene Examples include phosphate gels, polypropylene oxide gels, and fluorine polymer gels. Furthermore, one ionic liquid (a room-temperature molten salt) that is flame-retardant and non-volatile is used as the solvent for the electrolyte. Alternatively, by using multiple units, even if the internal temperature rises due to an internal short circuit or overcharging of the battery... This can prevent the battery from rupturing or catching fire. Note that ionic liquids are salts in a fluid state. It has high ion mobility (conductivity). Also, ionic liquids have high cation mobility (conductivity). Includes. As an ionic liquid, it contains ethylmethylimidazolium (EMI) cation. Liquid, or N-methyl-N-propylpiperidinium (PP 13 ) containing cations Examples include on-liquids.

[0109] In addition, instead of an electrolyte, a solid electrolyte containing inorganic materials such as sulfide-based or oxide-based materials may be used. Solid electrolytes containing polymer materials such as PEO (polyethylene oxide) can be used. It is possible. When using a solid electrolyte, the installation of separators and spacers becomes unnecessary. Also, Because the entire battery can be made solid, the risk of leakage is eliminated, dramatically improving safety.

[0110] Furthermore, the negative electrode active material of the negative electrode active material layer 19 may be lithium dissolved or deposited, or lithium Materials capable of ion insertion and removal can be used, including lithium metals, carbon-based materials, and alloys. System materials, etc., can be used.

[0111] Lithium metal has a low oxidation-reduction potential (-3.045V compared to a standard hydrogen electrode) and is heavy And they have a high specific capacity per unit volume (3860mAh / g and 2062mAh / cm³, respectively). 3) Therefore, it is preferable.

[0112] Examples of carbon-based materials include graphite, easily graphitizable carbon (soft carbon), and poorly graphitizable carbon (hard carbon). Carbon fiber, carbon nanotubes, graphene, fullerene, carbon black, etc. There is.

[0113] Graphite includes mesocarbon microbeads (MCMB), coke-based artificial graphite, and pip There are artificial graphites such as cyanide-based artificial graphite and natural graphites such as spheroidized natural graphite.

[0114] Graphite is formed when lithium ions are inserted into graphite (during the formation of lithium-graphite intercalation compounds). It exhibits a potential as low as lithium metal (0.1V to 0.3V vs. Li / L). i+). This allows lithium-ion secondary batteries to exhibit a high operating voltage. Furthermore, graphite has a relatively high volume per unit volume, low volume expansion, and is inexpensive. It is preferable because it has advantages such as higher safety compared to um metals.

[0115] As a negative electrode active material, the charge-discharge reaction is carried out by alloying and dealloying reactions with lithium. Possible alloy materials or oxides can also be used. The carrier ion is lithium ion. In that case, alloy materials include, for example, Al, Si, Ge, Sn, Pb, Sb, and Bi. Examples include materials containing at least one of Ag, Au, Zn, Cd, In, Ga, etc. These elements have a larger capacity than carbon, and silicon in particular has a theoretical capacity of 4200 mA. The h / g is dramatically high. For this reason, it is preferable to use silicon as the negative electrode active material. Examples of alloy materials using such elements include Mg2Si, Mg2Ge, and Mg2Sn , SnS2, V2Sn3, FeSn2, CoSn2, Ni3Sn2, Cu6Sn5, Ag 3Sn, Ag3Sb, Ni2MnSb, CeSb3, LaSn3, La3Co2Sn7, There are CoSb3, InSb, SbSn, etc. Note that SiO refers to a powder of silicon oxide containing a silicon-rich part, and can also be expressed as SiO (2>y>0). For example, S y iO includes a material containing one or more selected from Si2O3, Si3O4, or Si2O, or a mixture of Si powder and silicon dioxide SiO2. Also, SiO may contain other elements (carbon, nitrogen, iron, aluminum, copper, titanium, calcium, manganese, etc.). That is, SiO refers to a material containing a plurality selected from single crystal Si, amorphous Si, polycrystalline Si, Si2O3, Si3O 4, Si2O, SiO2. Also, SiO is a colored material. SiO that is not SiO is colorless and transparent or white, and can be distinguished. However, after manufacturing a secondary battery using SiO as a negative electrode active material and repeatedly charging and discharging, if SiO is oxidized, it may be transformed into SiO2. x

[0116] Also, as the negative electrode active material, oxides such as SiO, SnO, SnO2, titanium dioxide (TiO2), lithium titanium oxide (Li4Ti5O 12 ), lithium-graphite intercalation compound (Li x C6) , niobium pentoxide (Nb2O5), tungsten oxide (WO2), molybdenum oxide (MoO 2), etc. can be used.

[0117] Also, as the negative electrode active material, Li M (3-x) N (M = Co, Ni, Cu) which is a complex nitride of lithium and transition metals and has a Li3N-type structure can be used. For example, Li x ​ 2.6 Co 0.4 The N3 has a large charge / discharge capacity (900mAh / g, 1890mAh / cm²). 3 ) indicates a preference.

[0118] When using a lithium-transition metal binitride, lithium ions are included in the negative electrode active material. In combination with materials such as V2O5 and Cr3O8 that do not contain lithium ions as the positive electrode active material. It is preferable that this be done. Furthermore, when using a material containing lithium ions as the positive electrode active material, Also, by pre-desorbing the lithium ions contained in the positive electrode active material, the negative electrode active material A lithium-transition metal composite can be used as the composite material.

[0119] Furthermore, materials that undergo a conversion reaction can also be used as the negative electrode active material. For example For example, lithium, such as cobalt oxide (CoO), nickel oxide (NiO), and iron oxide (FeO). Transition metal oxides that do not undergo alloying reactions with chromium may be used as the negative electrode active material. The materials that can react are also Fe2O3, CuO, Cu2O, RuO2, and Cr2 Oxides such as O3, CoS 0.89 , sulfides such as NiS and CuS, Zn3N2, Cu3N, Nitrides such as Ge3N4, phosphides such as NiP2, FeP2, CoP3, FeF3, BiF This also occurs with fluorides of grade 3. Furthermore, because the potential of the above fluorides is high, they are not used as positive electrode active materials. It's okay to be there.

[0120] Furthermore, in addition to the negative electrode active material mentioned above, the negative electrode active material layer 19 also contains, in order to improve the adhesion of the active material Even if it has a binder, a conductive additive to enhance the conductivity of the negative electrode active material layer 19, good.

[0121] The configuration of the secondary battery is, for example, that the thickness of the separator 13 is approximately 15 μm or more and approximately 30 μm or less. The positive electrode current collector 12 is approximately 10 μm or more and approximately 40 μm or less, and the positive electrode active material layer 18 is approximately 50 μm or more. 100 μm or less, negative electrode active material layer 19 is approximately 50 μm or more and approximately 100 μm or less, negative electrode current collector 14 The thickness is approximately 5 μm to approximately 40 μm. The thickness of film 11 is approximately 0.113 mm. Furthermore, the embossing depth on film 11 is approximately 500 μm. If the embossing depth is 2mm or more, the overall thickness of the secondary battery becomes too thick.

[0122] A higher battery capacity per unit volume is preferable. The larger the volume of the battery portion relative to the entire secondary battery, the larger the result. Furthermore, as the overall thickness of the secondary battery increases, the proportion of the battery per unit volume decreases. The battery capacity will also be smaller.

[0123] The battery portion preferably accounts for 50% or more of the total volume of the secondary battery. (Figure 8) (A) shows the C-D cross-section of the secondary battery in Figure 6(D). Also, Figure 9(A) is Figure 7( Figure B) shows a cross-sectional view of the secondary battery along the line G-H. Figures 8(A) and 9(A) show the inside of the battery. Structure 70, embossed film 71 covering the top surface of the battery, embossed film covering the bottom surface of the battery The diagram shows the unprocessed film 72 and the embossed film 72. To ensure cleanliness, a positive electrode current collector with a positive electrode active material layer, a separator, and a negative electrode active material layer are formed. The laminated structure of the negative electrode current collector and other components, along with the electrolyte, are collectively shown as the internal structure of the battery, 70. T is the thickness of the internal structure of the battery, and t1 is the embossed film covering the top surface of the battery. The sum of the depth of the emboss of the film 71 and the film thickness, and t2 is the embossing that covers the lower surface of the battery It shows the film thickness of the film 72 where the film is not embossed and the sum of the depth of the emboss of the embossed film 72 and the film thickness. At this time, the thickness of the entire secondary battery is T+ t1+t2. Therefore, in order to make the ratio of the volume of the internal structure 70 part of the battery in the entire secondary battery 50% or more, it is necessary to set T>t1+t2.

[0124] In FIGS. 6(E) and 7(C), although the adhesive layer 30 is only partially shown , a layer made of polypropylene is provided on the surface of the film where the film is bonded,

[0125] and only the thermocompression-bonded part becomes the adhesive layer 30. Also, FIGS. 6(E) and 7(C) show an example in which the lower side of the film 11b or the film 22 is fixed and pressure-bonded. In this case, since the upper side is bent greatly and a step is formed , when a plurality of, for example, eight or more combinations of the above laminates are provided between the bent film 11 or the film 22, the step becomes large, and there is a risk that too much stress is applied to the upper side of the film 11a or the film 22. Also, for that reason, there is also a risk that the displacement between the end of the upper film and the end of the lower film becomes large. In that case, in order to prevent displacement at the end, a step may also be provided on the lower film, and pressure-bonding may be performed at the center so that the stress is equalized.

[0126]

[0127] Also, when a large displacement occurs, there is a region where a part of the end of one film does not overlap with the other film . This region may be cut off to align the ends of the upper film and the lower film to correct the displacement.​​

[0127] Here, we will use Figure 6(F) to explain the current flow during the charging of a secondary battery. Carrier ions When a lithium-ion secondary battery is considered as a closed circuit, the movement of lithium ions and current The flow will be in the same direction. Note that in lithium-ion secondary batteries, the anode flows during charging and discharging. The anode and cathode are swapped, and the oxidation and reduction reactions are reversed. Therefore, the electrode with a high reaction potential is called the positive electrode, and the electrode with a low reaction potential is called the negative electrode. In this specification, whether charging or discharging, a reverse pulse current is applied. Whether it is a positive or negative terminal, or when charging current is flowing, the positive terminal is the "positive terminal" or "+ terminal (positive terminal)". The negative electrode will be called the "negative electrode" or "- electrode (minus electrode)". Oxidation reaction Using the terms anode and cathode, which are related to reduction reactions, charging The timing of discharge and the time of discharge are reversed, which can cause confusion. Therefore, the anode The terms (anode) and (cathode) will not be used in this specification. When using the terms anode and cathode, it refers to whether the device is charging or discharging. Clearly indicate which terminal it corresponds to, and also indicate whether it is the positive or negative terminal. Let's do it this way.

[0128] The charger is connected to the two terminals shown in Figure 6(F), and the secondary battery 40 is charged. As the battery 40 charges, the potential difference between the electrodes increases. In Figure 6(F), the secondary battery 40 Electrons flow from the external terminal toward the positive electrode current collector 12, and within the secondary battery 40, the positive electrode Current flows from the current collector 12 to the negative electrode current collector 14, and from the negative electrode to the external terminal of the secondary battery 40. The direction in which the current flows is considered the positive direction. In other words, the direction in which the charging current flows is considered the positive direction of the current. I am worried.

[0129] In this embodiment, a rectangular film is folded in the middle and the two ends are overlapped and sealed. While examples of such structures have been shown, the shape of the film is not limited to rectangles. Triangles, squares, and five-sided films are also possible. It can be any symmetrical shape other than a rectangle, such as a polygon (e.g., a square), a circle, or a star.

[0130] In this embodiment, an example of a small battery used in a portable information terminal is shown, but it is not particularly limited. Furthermore, it can be applied to large batteries installed in vehicles and other similar devices.

[0131] In this embodiment, an example of its application to a lithium-ion secondary battery was shown, but One aspect of the invention is not limited thereto. Various secondary batteries, for example, lead-acid batteries, lithium batteries, etc. Onpolymer secondary batteries, nickel-metal hydride batteries, nickel-cadmium batteries, nickel • Iron batteries, nickel-zinc batteries, silver oxide-zinc batteries, solid-state batteries, air batteries, etc. It can also be applied to various energy storage devices, for example Furthermore, it can also be applied to primary batteries, capacitors, lithium-ion capacitors, and the like. Furthermore, solar cells, light sensors, touch sensors, display devices, FPC (flexible printed circuit boards) (substrate), optical film (polarizing plate, phase difference plate, prism sheet, light reflection sheet, light diffusion sheet) It can also be applied to things like (e.g., tents).

[0132] (Embodiment 2) In this embodiment, as shown in Figure 3(C), two films 11a and 11b are prepared. Using Figures 6 and 8, we will show an example of how to create a secondary battery by bonding two films together. As shown in Figure 4(B), two films 23 and 24 are made, and the two films Figures 7 and 9 illustrate an example of fabricating a secondary battery by bonding films together.

[0133] Flexible rechargeable batteries are not meant to be used as standalone batteries, but rather attached to electronic devices or other electronic equipment. Therefore, in many cases, once the shape of the rechargeable battery to be installed in an electronic device is determined, the two There is no need to change the shape of the next battery.

[0134] For example, if you attach a rechargeable battery that is curved in one direction at a certain angle to an electronic device, many In that case, the shape of the secondary battery is determined by curving it in one direction at that angle. Therefore, there is no need to reverse the curve. Nor is there any need to curve it in the opposite direction.

[0135] Therefore, when considering bending a secondary battery, the reaction when bending it in only one direction is important. You just need to consider the force.

[0136] Figure 8(B) shows the secondary battery shown in Figure 6(D) made using the film shown in Figure 6(A), in one direction. This shows a cross-sectional view of a CD when it is curved. However, to simplify the diagram, the positive electrode active material layer is shown. Laminated structures such as a positive electrode current collector, a separator, and a negative electrode current collector with a negative electrode active material layer formed thereon The structure and electrolyte are collectively shown as the internal structure of the battery, 70.

[0137] When the secondary battery is curved as shown in Figure 8(B), the film 7 covers the bottom surface of the secondary battery. Compressive stress is applied to part 2, and tensile stress is applied to the film 71 covering the top surface of the secondary battery. As shown in Figure 8(B), a pattern is formed on the surface of the film 71 by recesses or protrusions. Thus, even if tensile stress is applied to film 71, the effects of strain are not permitted. It can be kept within the capacity range. Therefore, the curve of the outer casing of the secondary battery is closer to the center of curvature. It can be deformed within a range where the radius of deformation is 10 mm or more, preferably 30 mm or more.

[0138] Figure 9(B) shows the secondary battery shown in Figure 7(B) made using the film shown in Figure 7(A), in one direction. The diagram shows a cross-sectional view of the GH (Gross Electron) layer when curved. However, to simplify the diagram, the positive electrode active material layer is shown. Laminated structures such as a positive electrode current collector, a separator, and a negative electrode current collector with a negative electrode active material layer formed thereon The structure and electrolyte are collectively shown as the internal structure of the battery, 70.

[0139] In Figure 8(B), only the film 71 covering the top surface of the secondary battery has recesses or protrusions formed on its surface. Although examples of films having a pattern have been described, the present invention is not limited to these examples. Not only 71, but also the film 72 on the bottom surface of the secondary battery, which is subjected to compressive stress as shown in Figure 9(B) Furthermore, embossing may be applied. Both film 71 and film 72 are recessed. Alternatively, by having a pattern formed by convex parts, the effects of strain can be further suppressed. Furthermore, the film 72 on the lower surface of the secondary battery, which is subjected to compressive stress, has two diagonal directions. It can be a geometric pattern with intersecting lines, or the vertical stripe pattern 1301 shown in Figure 10(A) or Figure 10 (B) may be a horizontal stripe pattern 1302.

[0140] The film 71 covering the top surface of the secondary battery is subjected to tensile stress, causing the film to stretch more. It is desirable to apply an embossed finish. An embossed finish with a narrower pitch is preferable. This increases the surface area of ​​the film, making it easier to stretch when the film is bent. Therefore, when bending with a smaller radius of curvature, as shown in Figures 8(C) and 9(C)... The pitch of the embossing on the film covering the top surface, as shown in Figures 8(A) and 9(A) It would be better to narrow the pitch of the embossing on the film.

[0141] Furthermore, in Figure 9, two films with optimized embossing depth and pitch are prepared and sealed. By stopping this process, the secondary battery was completed, but it is optimal for relieving tensile stress on a single film. Even when performing both standardized embossing and embossing optimized for compressive stress relief Good. In that case, an envelope optimized for tensile stress relief is applied to half of the area of ​​one film. Boss machining is performed, and embossing optimized for compressive stress relief is applied to half of the area. Furthermore, there are areas where embossing optimized for tensile stress relief and areas where compressive stress relief is performed. The film is folded using the boundary of the area where the optimized embossing has been applied as a crease. Simply align the edges of the film and seal it.

[0142] Figure 8(D) shows the area of ​​film 72 enclosed by the dotted lines shown in Figures 8(A) and 9(A). This is an enlarged view. The film covering the bottom surface of the secondary battery consists of multiple layers, as shown in Figure 8(D). Laminated films can be used. For example, film 72a can be made of polypropylene, f The layers consist of aluminum for film 72b and nylon for film 72c. It is possible.

[0143] Film 11a with optimized embossing depth and pitch, and film without embossing. Using film 11b, or films 23 and 24 with optimized embossing depth and pitch. After that, similar to Embodiment 1, the positive electrode current collector 12, separator 13, and negative The stacked combination of the electrode current collector 14 is placed between two films. The surface of the positive electrode current collector 12 A positive electrode active material layer 18 is formed in part, and a negative electrode active material layer 1 is formed on part of the surface of the negative electrode current collector 14. 9 is formed. Next, the lead electrode 16 is subjected to ultrasonic waves against the protrusion of the positive electrode current collector 12. The lead electrode 16 is electrically connected by welding or other means, and is ultrasonically connected to the protrusion of the negative electrode current collector 14. Electrical connections are made by wave welding, etc. Then, one side is left open to hold the electrolyte. The film is sealed by heat-sealing three sides to form a bag shape. If the inside is under reduced pressure... Alternatively, the desired amount of electrolyte is added dropwise under an inert gas atmosphere. The secondary battery is completed by sealing one side of the film using heat compression.

[0144] Furthermore, in this embodiment, a secondary battery is attached to an electronic device and curved in one direction. I have described the case where the battery is used without being returned to its original state, but what about a rechargeable battery that has been bent in one direction? You can repeatedly bend and straighten it, but not to the point where it returns to its original state.

[0145] (Embodiment 3) In this embodiment, the folded film 11 has a laminated structure that is partially different from that of Embodiment 1. Examples of storing multiple sets are shown in Figures 11 to 13.

[0146] This embodiment uses the embossed film 11a shown in Embodiment 2 and embossed Film 11b without embossing, and films 23 and 2 with embossing. It can also be used as a combination of stacked items to be stored between the 4.

[0147] Figure 11(A) shows the positive electrode current collector 12, Figure 11(B) shows the separator 13, and Figure 11(C) shows the negative electrode Figure 11(D) shows the current collector 14, the sealing layer 15 and lead electrode 16, and Figure 11(E) shows the film. The top views of each of the 11 are shown.

[0148] In Figure 11, the respective dimensions are approximately equal, and the region 21 enclosed by the dashed line in Figure 11(E) The dimensions are almost identical to those of the separator in Figure 11(B). Also, the dotted line in Figure 11(E) and The area between the edges becomes the thermocompression bonding area 17.

[0149] Figure 12(A) shows an example in which positive electrode active material layers 18 are provided on both sides of the positive electrode current collector 12. To explain in more detail, the negative electrode current collector 14, negative electrode active material layer 19, separator 13, positive electrode active material layer 1 8. Positive electrode current collector 12, positive electrode active material layer 18, separator 13, negative electrode active material layer 19, negative electrode current collector The components are arranged in the order of body 14. This is a cross-sectional view of the layered structure when cut by plane 80. This is shown in Figure 12(B).

[0150] Note that Figure 12(A) shows an example where two separators are used, but 1 The separator is folded and two ends are sealed to form a bag, and the positive electrode current collector 12 is housed in between. It is also possible to have a structure that allows for this. The positive electrode current collector 12 housed in a bag-shaped separator has two sides A positive electrode active material layer 18 is formed thereon.

[0151] Furthermore, it is also possible to provide a negative electrode active material layer 19 on both sides of the negative electrode current collector 14. Figure 12 (C) is between two negative electrode current collectors 14, each having a negative electrode active material layer 19 on only one side. Three negative electrode current collectors 14, each having a negative electrode active material layer 19 on one side, and positive electrode active material layers 18 on both sides. The secondary battery consists of four positive electrode current collectors 12 and eight separators 13 sandwiched between them. An example is shown. In this case as well, instead of using eight separators, four bag-shaped separators are used. That's fine.

[0152] The capacity of the secondary battery can be increased by increasing the number of layers. Also, the positive electrode current collector 12 A positive electrode active material layer 18 is provided on both sides, and a negative electrode active material layer 19 is provided on both sides of the negative electrode current collector 14. This allows for a reduction in the thickness of the rechargeable battery.

[0153] Figure 13(A) shows a positive electrode current collector 12 with a positive electrode active material layer 18 on only one side, and a negative electrode current collector 14 This diagram shows a secondary battery formed by providing a negative electrode active material layer 19 on only one side. A detailed explanation follows. Then, a negative electrode active material layer 19 is provided on one side of the negative electrode current collector 14, and in contact with the negative electrode active material layer 19 The separator 13 is stacked in such a way. The separator on the side not in contact with the negative electrode active material layer 19 The surface of -13 is the positive electrode active material layer 18 of the positive electrode current collector 12, which has a positive electrode active material layer 18 formed on one side. 8 is in contact. On the surface of the positive electrode current collector 12, there is yet another positive electrode active material layer 18 on one side. The positive electrode current collector 12 formed on the positive electrode active material layer 18 is in contact with it. The surfaces that do not have a bond are arranged facing each other. And then, separator 1 3 is formed, and the negative electrode active material layer 19 is formed on one side of the negative electrode current collector 14. The layers are stacked so that they are in contact with the separator. The stacked structure in Figure 13(A) is cut by the plane 90. Figure 13(B) shows a cross-sectional view of the material after it has been cut.

[0154] Figure 13(A) shows two separators being used, but one separator can be folded and both sides Two positive electrode current collectors 12 are formed by sealing the ends to create a bag shape, with a positive electrode active material layer 18 placed on one side between them. You can put one sheet in between.

[0155] Figure 13(C) shows a diagram of multiple layers of the layered structure shown in Figure 13(A) stacked together. Then, the surfaces of the negative electrode current collector 14 that do not have the negative electrode active material layer 19 formed on them, and the positive electrode current collector 1 The two positive electrode active material layers 18 are positioned facing each other, with the sides that do not have the positive electrode active material layer 18 facing each other. Figure 1 In 3(C), there are 12 positive electrode current collectors 12, 12 negative electrode current collectors 14, and 12 separators 1 This shows how the 3s are stacked.

[0156] A positive electrode active material layer 18 is provided on only one side of the positive electrode current collector 12, and a negative electrode active material layer 18 is provided on only one side of the negative electrode current collector 14. The structure in which an electrode active material layer 19 is provided and laminated is such that the positive electrode active material layer 18 is placed on both sides of the positive electrode current collector 12. Compared to a structure in which negative electrode active material layers 19 are provided on both sides of the negative electrode current collector 14, the number of current collectors Because the number of components increases, the thickness of the secondary battery becomes larger. However, the positive electrode current collector 12 On the side where the positive electrode active material layer 18 is not formed, the positive electrode active material layer 18 of another positive electrode current collector 12 It faces an unformed surface, and the metal surfaces are in contact with each other. Similarly, the negative electrode current collector The side of 14 where the negative electrode active material layer 19 is not formed is the negative electrode active material layer 1 of another negative electrode current collector 14. 9 is facing a surface where it is not formed, and the metal surfaces are in contact with each other. Because they are in contact, frictional force is not as strong, making the metal surfaces more prone to sliding against each other. Therefore, when bending a rechargeable battery, the metal inside the battery slips, causing the battery to bend. It's getting cheaper.

[0157] Furthermore, the protruding portion of the positive electrode current collector 12 and the protruding portion of the negative electrode current collector 14 are also called tab portions. When bending a secondary battery, the tab portions of the positive electrode current collector 12 and the negative electrode current collector 14 are easily cut. This has a long, slender shape with a protruding tab, and stress is easily applied to the base of the tab. be.

[0158] A positive electrode active material layer 18 is provided on only one side of the positive electrode current collector 12, and a negative electrode active material layer 18 is provided on only one side of the negative electrode current collector 14. The structure in which an electrode active material layer 19 is provided and stacked has surfaces where the positive electrode current collectors 12 are in contact with each other and negative electrode current collectors The bodies 14 have surfaces that come into contact with each other. The surfaces that come into contact with each other have low frictional resistance and do not deform the battery. This makes it easier to release the stress caused by the difference in radius of curvature that occurs when this is done. Also, the positive electrode current collector 12 A positive electrode active material layer 18 is provided on only one side, and a negative electrode active material layer 19 is provided on only one side of the negative electrode current collector 14. The layered structure increases the total thickness of the tab section, so the positive electrode active material is attached to both sides of the positive electrode current collector 12. Compared to a structure in which layer 18 is provided and negative electrode active material layers 19 are provided on both sides of the negative electrode current collector 14, the stress distribution is This design prevents the wires from breaking at the tab portion.

[0159] When stacking them in this manner and fixing all of the positive electrode current collectors 12 to make electrical connections, the connections are made all at once. Ultrasonic welding is performed to enable this. Furthermore, in addition to the positive electrode current collector 12, the lead electrode is also superimposed. Ultrasonic welding allows for efficient electrical connections.

[0160] By overlapping the tab portion with the tab portion of another positive electrode current collector and applying pressure while applying ultrasonic waves, Ultrasonic welding can be performed.

[0161] (Embodiment 4) In this embodiment, using Figures 14 to 16, we will describe either Embodiment 1 or 2. An example of an electronic device incorporating a lithium-ion secondary battery obtained using this method is shown. Form 3 can also be combined with this.

[0162] A secondary battery obtained using any one of Embodiments 1 to 3 has a thin and flexible casing. It is a film that is attached to a support structure having a curved surface, and the radius of curvature of the support structure is large It can be deformed into a flexible shape that conforms to the curved surface of the large region.

[0163] As an electronic device that applies a power storage device with a flexible shape, for example, a head mouse Display devices such as projector displays and goggle-type displays (television or television). (Also called a computer receiver), personal computers such as desktop and notebook computers, computer Monitors for use with data, digital cameras, digital video cameras, digital photo frames Electronic organizers, e-readers, electronic translators, toys, microphones and other voice input devices, electrical Shavers, electric toothbrushes, high-frequency heating devices such as microwave ovens, electric rice cookers, electric washing machines, Vacuum cleaners, water heaters, fans, hair dryers, humidifiers, dehumidifiers, air conditioners, etc. Harness equipment, dishwasher, dish dryer, clothes dryer, futon dryer, electric refrigerator, electric freezer Electric refrigerators and freezers, DNA storage freezers, flashlights, power tools, smoke detectors, gas alarms Alarm systems such as security alarm systems, industrial robots, hearing aids, cardiac pacemakers, X-ray imaging equipment. Health and medical equipment such as radiation detectors, electric massagers and dialysis machines, and mobile phones ( Mobile phones (also called mobile phone devices), portable game consoles, personal digital assistants, lighting devices, heads Phones, stereos, remote controllers, clocks (desk clocks, wall clocks, etc.), cordless batteries Portable or stationary devices such as cordless phones, transceivers, pedometers, calculators, and digital audio players. Examples include sound reproduction devices and large game machines such as pachinko machines.

[0164] Furthermore, energy storage devices with flexible shapes can be installed in the interior or exterior walls of houses and buildings, or in automated systems. It can also be integrated to conform to the curved surfaces of the car's interior or exterior.

[0165] Figure 14(A) shows an example of a mobile phone. The mobile phone 7400 has a housing 740 In addition to the display unit 7402 incorporated into 1, there are also operation buttons 7403, an external connection port 7404, It is equipped with speaker 7405, microphone 7406, etc. Note that the mobile phone 7400 is a storage It has an electrical device 7407.

[0166] Figure 14(B) shows the mobile phone 7400 in a curved state. When 00 is deformed by an external force and the whole thing is bent, the power storage device located inside it The 7407 is also bent. Figure 14 shows the state of the bent energy storage device 7407 at that time. As shown in C). The energy storage device 7407 is a laminated battery (layered battery, film outer casing). It is also called a battery. The energy storage device 7407 is fixed in a bent position. The energy storage device 7407 has lead electrodes 7408 that are electrically connected to the current collector 7409. Yes. For example, the film on the exterior of the energy storage device 7407 is embossed, and Device 7407 has a highly reliable configuration even when bent. Furthermore, mobile phones The 7400 has a slot for inserting a SIM card and USB devices such as USB memory sticks. A connector section for connecting parts may be provided.

[0167] Figure 14(D) shows an example of a bendable mobile phone, which can be worn around the forearm. By bending it into shape, it can be made into a bangle-shaped mobile phone as shown in Figure 14(E). The unit 7100 consists of the housing 7101, the display unit 7102, the operation buttons 7103, and the energy storage device 71 It is equipped with 04. Figure 14(F) also shows the state of the bendable energy storage device 7104. When the power storage device 7104 is bent and attached to the user's arm, the housing deforms and the power storage device The curvature of part or all of position 7104 changes. Specifically, the radius of curvature changes by 10 mm or more. If part or all of the main surface of the housing or energy storage device 7104 changes within a range of 50 mm or less The energy storage device 7104 is electrically connected to the current collector 7106 and the lead electrode 7105. It has, for example, a plurality of irregularities are formed on the surface of the film of the outer casing of the energy storage device 7104. The press processing is performed, and the energy storage device 7104 is bent many times, changing its curvature. It is configured to maintain high reliability. Furthermore, the 7100 mobile phone uses a SIM card. Slots for inserting cards, and connectors for connecting USB devices such as USB memory sticks. A section such as a tab may be provided. Also, when the central part of the mobile phone shown in Figure 14(D) is folded... It can also be shaped as shown in Figure 14(G). Furthermore, the central part of the mobile phone can be further... By folding it so that the ends of the mobile phone overlap as shown in Figure 14(H), it can be made smaller. It can be made small enough to fit in the user's pocket, etc. Thus, the portable cell phone shown in Figure 14(D) The story is about a device that can change into multiple shapes, and to achieve this, there are a few things needed. However, it is desirable that the housing 7101, the display unit 7102, and the energy storage device 7104 have flexibility. It seems so.

[0168] Furthermore, Figure 15(A) shows an example of a vacuum cleaner. By equipping the vacuum cleaner with a secondary battery... It can be made cordless, and the inside of the vacuum cleaner has a dust collection space for sucking up and storing dirt. Therefore, the smaller the space occupied by the energy storage device 7604, the better. It is a molded structure, and a bendable energy storage device 7604 is positioned between the outer surface and the dust collection space. It is useful to do so.

[0169] The vacuum cleaner 7600 is equipped with an operation button 7603 and a power storage device 7604. Also, Figure 1 Figure 5(B) shows a bendable energy storage device 7604. The energy storage device 7604 is an outer casing. The film has been embossed, and the reliability of the energy storage device 7604 when it is bent is It has a high configuration. The energy storage device 7604 has lead electrodes 760 that are electrically connected to the negative electrode. It has 1 and a lead electrode 7602 that is electrically connected to the positive electrode.

[0170] In addition, the energy storage device 7604 has two lead electrodes exposed on one of the short sides of its outer casing. As an example, Figure 15(C) shows a bendable energy storage device 7605. 05 is a configuration in which the current collector or lead electrode is exposed on each of the two short sides of the outer casing. It is complete. If the film of the outer casing of the energy storage device 7605 is also embossed, it will bend. It is capable and highly reliable.

[0171] The thin energy storage device 7604 is a secondary battery with a laminate structure as shown in Embodiments 1 to 3. It can be manufactured using the manufacturing method.

[0172] The slim energy storage device 7604 has a laminated structure and is bent and fixed in place. The vacuum cleaner 7600 has a display unit 7606 that displays the remaining power of the slim power storage device 7604. It has a display unit 7606 in which the display surface is curved to match the shape of the outer surface of the vacuum cleaner. Yes. Also, the vacuum cleaner has a connection cord for plugging into an outlet and a thin power storage device 7 Once the 604 has enough power charged, you can also use the vacuum cleaner by unplugging the cord. Furthermore, the slim 7604 energy storage device can be charged wirelessly without using a connecting cord. You may go.

[0173] Furthermore, if a flexible energy storage device is installed in a vehicle, hybrid electric vehicles (HEVs) Next-generation clean energy vehicles such as electric vehicles (EVs) or plug-in hybrid vehicles (PHEVs) This makes it possible to realize energy-powered vehicles. It also includes agricultural machinery and motorized bicycles, including electric-assist bicycles. Cars, motorcycles, electric wheelchairs, electric carts, small or large vessels, submarines, fixed-wing aircraft and rotary-wing aircraft. For mobile vehicles such as aircraft, rockets, satellites, space probes, planetary probes, and spacecraft. It can also be equipped with a flexible energy storage device.

[0174] Figure 16 illustrates a vehicle using one aspect of the present invention. The automobile shown in Figure 16(A) The 8100 is an electric vehicle that uses an electric motor as its power source for propulsion. It is possible to appropriately select and use an electric motor and an engine as the power source for propulsion. It is a hybrid vehicle. When a laminated secondary battery is installed in the vehicle, multiple A battery module, which integrates laminated secondary batteries, is installed in one or more locations. To place. By using one aspect of the present invention, the energy storage device itself can be made smaller and lighter, for example. For example, by installing a curved energy storage device on the inside of the tire, it is possible to realize a vehicle with a long driving range. This is possible. In addition, energy storage devices of various shapes can be placed in the gaps of the vehicle, It can secure space for passengers and other passengers inside the vehicle. In addition, the 8100 vehicle has an energy storage device. The energy storage device not only drives the electric motor, but also the headlights 8101 and the room light. It can supply power to light-emitting devices such as LEDs (not shown).

[0175] Furthermore, the energy storage device is used in the speedometer, tachometer, and other displays of the automobile 8100. It can supply power to the display device. In addition, the energy storage device is the navigation system of the automobile 8100. It can supply power to semiconductor devices such as gated systems.

[0176] The automobile 8200 shown in Figure 16(B) plugs into the energy storage device of the automobile 8200. It can be charged by receiving power from an external charging facility using methods such as contactless power supply. It can be done. Figure 16(B) shows the ground-mounted charging device 8021 being mounted on the automobile 8200. This shows the state in which the energy storage device is being charged via cable 8022. During charging, Charging methods and connector specifications are as specified by CHAdeMO® or Combo. It is fine to proceed as appropriate. The charging device 8021 may be a charging station installed in a commercial facility. It could also be a household power supply. For example, external power supply via plug-in technology. This allows the battery storage device installed in the 8200 vehicle to be charged. Charging is performed by AC / DC. This can be done by converting AC power to DC power via a conversion device such as a converter.

[0177] Although not shown in the diagram, a power receiving device is mounted on the vehicle, and power is supplied wirelessly from a ground-based power transmission device. It can also be charged by supplying power. In this contactless power supply method, the power transmission equipment is installed on the road or exterior wall. By incorporating this, charging can be performed not only when the vehicle is stopped but also while it is in motion. The electric system may be used to transmit and receive power between two vehicles. Furthermore, the vehicles Solar panels may be installed on the exterior to charge the energy storage device when the vehicle is stopped or in motion. For contactless power supply, electromagnetic induction or magnetic resonance methods can be used.

[0178] According to one aspect of the present invention, the degree of freedom in the installation location of the energy storage device is increased, and the vehicle design of the car becomes more efficient. This can be done well. Furthermore, according to one aspect of the present invention, the characteristics of the energy storage device can be improved. This makes it possible to make the energy storage device itself smaller and lighter. If this can be achieved, it will contribute to reducing the vehicle's weight, thus improving its driving range. Also, The battery storage device installed in the vehicle can also be used as a power source other than the vehicle itself. In this case, This allows us to avoid using commercial power sources during peak electricity demand.

[0179] This embodiment can be freely combined with any one of embodiments 1 to 3.

[0180] Furthermore, the content described in one embodiment (even a part of it) may be subject to change in implementation. Other content (even partial content) described in form, and / or one or more other facts The content described in the form of implementation (even if only a part of it) may be applied, combined, or replaced. It is possible to perform tasks such as drawing.

[0181] Furthermore, the content described in each embodiment refers to the use of various figures in each embodiment. This refers to the content described or the content described using the text included in the specification.

[0182] Note that a diagram (even a part of it) described in one embodiment may be a part of that diagram. , other figures (even partial ones) described in the embodiment, and / or one or more In the diagram (or even just a part of it) described in another embodiment of the number, by combining them... This allows for the creation of even more diagrams.

[0183] Furthermore, any content not specified in the drawings or text within the specification will be excluded. This can constitute one embodiment of the invention that specifies that, or, for a certain value, an upper limit When a numerical range is specified, such as a value and a lower limit, you can arbitrarily narrow that range. Or, by excluding one point within that scope, one aspect of the invention that excludes part of that scope is defined. This can be determined. For example, the prior art falls within the technical scope of one aspect of the present invention. It is possible to specify that it does not fall under this category.

[0184] A concrete example is a circuit diagram that uses transistors 1 through 5 in a certain circuit. Let's assume that it is described. In that case, the circuit does not have a sixth transistor. It is possible to define the following as an invention. Or, the circuit does not have a capacitive element. It is possible to define that the circuit takes a certain connection structure. The invention can be defined as not having a sixth transistor like the one present. Alternatively, the circuit does not have capacitive elements that have a certain connection structure. The invention can be defined as follows: For example, the gate is in contact with the gate of the third transistor. It is possible to define the invention as not having a sixth transistor that is subsequently connected. Alternatively, for example, a capacitive element in which the first electrode is connected to the gate of the third transistor It is possible to define the invention as not possessing such a feature.

[0185] Another concrete example is, for a certain value, for example, "a certain voltage is between 3V and 10V." Let's say it is stated that "it is preferable that there is a certain voltage." In that case, for example, if a certain voltage is -2 It is possible to define one aspect of the invention as "except when V is greater than or equal to 1V." For example, one aspect of the invention can be defined as "except when a certain voltage is 13V or higher." It is possible. Furthermore, for example, the invention could be defined as having a voltage of 5V or more and 8V or less. This is also possible. Furthermore, for example, the invention could be defined as having a voltage of approximately 9V. That is the case. However, for example, the voltage is between 3V and 10V, but is 9V. It is also possible to define the invention in this way. Furthermore, for a certain value, it is stated that "it is within this range." If it was stated that "it is preferable" or "it is preferable to satisfy these conditions", However, certain values ​​are not limited to those listed. In other words, "preferred" or "suitable" Even if it is stated otherwise, it is not necessarily limited to those statements.

[0186] Another concrete example would be, for a certain value, for example, "It is preferable that a certain voltage is 10V." Let's assume it is stated as "suitable". In that case, for example, if a certain voltage is between -2V and 1V It is possible to define one aspect of the invention as, except in the case below. Or, for example, a It is possible to define one aspect of the invention as "except when the voltage is 13V or higher."

[0187] Another concrete example is describing the properties of a certain substance, for instance, "A certain film is an insulating film." Let's assume it is stated as follows. In that case, except, for example, if the insulating film is an organic insulating film. It is possible to define one aspect of the invention as follows: or, for example, the insulating film is inorganic It is possible to define one aspect of the invention as "except when it is an insulating film." Or, for example, It is possible to define one aspect of the invention as, except when the film is a conductive film. Alternatively, one aspect of the invention may be defined as, for example, except when the film is a semiconductor film. It is possible.

[0188] Another concrete example is a layered structure, for example, "a certain film between film A and film B." It is stated that "a film is provided." In that case, for example, if the film is made up of four or more layers The invention can be defined as "except in the case of a multilayer film." Or, for example, film A and It is possible to define the invention as "except in cases where a conductive film is provided between that film and the other film." ru.

[0189] In this specification, active elements (transistors, diodes, etc.) and passive elements are used. For all terminals of components such as capacitive and resistive elements, specify their connection destinations. Even without this, a person skilled in the art may be able to constitute one aspect of the invention. Even without specifying the destination, one aspect of the invention can be said to be clear. And the destination of the connection is specified. If the content described herein is included, then one aspect of the invention that does not specify the connection destination is considered to be in accordance with the present invention. In some cases, it may be possible to determine that this information is described in the detailed documentation. This is especially true when there are multiple connection points for the terminal. In cases where such a scenario is possible, it is not necessary to limit the connection destination of that terminal to a specific location. Therefore, active elements (transistors, diodes, etc.), passive elements (capacitive elements, resistive elements) By specifying the connection destination for only some of the terminals that such as (etc.) have, the invention It may be possible to constitute one aspect of this.

[0190] Furthermore, in this specification, etc., if a certain circuit is specified, then at least the connection destination is identified. If you are a professional, you may be able to identify the invention. Or, regarding a certain circuit, Even without specifying the function, a person skilled in the art may be able to identify the invention. In other words, if the function is specified, then one aspect of the invention can be said to be clear. In some cases, it may be possible to determine that one aspect of the invention described herein is included in this specification. Therefore, for a given circuit, even without specifying its function, if the connection destination is specified, one can identify the invention. This is disclosed as an embodiment and can constitute one aspect of the invention. In a given circuit, even without specifying the connection destination, if the function is specified, it can be considered one aspect of the invention. This is disclosed and can constitute one aspect of the invention.

[0191] In this specification, etc., the figures or text described in a particular embodiment may differ from the actual figures or text. Therefore, it is possible to take a part of it and constitute one aspect of the invention. If a diagram or text describing a particular part is included, then a portion of that diagram or text may be taken. The content disclosed is also disclosed as one aspect of the invention and constitutes one aspect of the invention. It is possible to do so. And it can be said that one aspect of the invention is clear. Therefore, for example, active elements (transistors, diodes, etc.), wiring, passive elements (capacitive elements) (e.g., resistive elements), conductive layer, insulating layer, semiconductor layer, organic material, inorganic material, component, device, operation In drawings or documents describing one or more methods, manufacturing methods, etc., a part thereof It is possible to extract N items and constitute one aspect of the invention. For example, N items (N From a circuit diagram that has circuit elements (transistors, capacitive elements, etc.) of integers, M pieces (M is an integer and M < N) Circuit elements (transistors, capacitive elements, etc.) can be extracted to form one aspect of the invention. As another example, from a cross-sectional view composed of N (N is an integer) layers, M (M is an integer and M < N) layers can be extracted to form one aspect of the invention. As yet another example, from a flowchart composed of N (N is an integer) elements, M (M is an integer and M < N) elements can be extracted to form one aspect of the invention. As yet another example, from a sentence described as "A has B, C, D, E, or F", some of the elements can be arbitrarily extracted to form one aspect of the invention such as "A has B and E", "A has E and F", "A has C, E, and F", or "A has B, C, D, and E".

[0192] In this specification and the like, when at least one specific example is described in a figure or sentence described in a certain embodiment, those skilled in the art can easily derive the superordinate concept of that specific example. Therefore, when at least one specific example is described in a figure or sentence described in a certain embodiment, the superordinate concept of that specific example is also disclosed as one aspect of the invention and can form one aspect of the invention. And it can be said that that aspect of the invention is clear.

[0193] In this specification and the like, at least the content described in the figure (even a part of the figure) is disclosed as one aspect of the invention and can form one aspect of the invention. Therefore, for a certain content, if it is described in a figure, it can be described using a sentence.​​​​​​​​​ Even if it is not disclosed, the content is disclosed as one aspect of the invention, and one aspect of the invention It is possible to construct it. Similarly, a diagram showing a part of the figure is also one embodiment of the invention. This is disclosed as such, and it can constitute one aspect of the invention. One aspect of the invention can be said to be clear. [Examples]

[0194] In this embodiment, using Figures 17 and 18, an electrode with an active material layer on both sides of the current collector and This section explains the results of a comparison of frictional force between an electrode with an active material layer on one side of a current collector and an electrode with an active material layer on one side. ru.

[0195] First, in order to conduct an experiment comparing frictional forces, multiple electrodes were prepared on a glass plate and stacked, and the voltage between them was measured. The comparison was made by removing the poles.

[0196] The actual configuration of a secondary battery is such that a negative electrode active material layer is provided on the surface of a region enclosed by an outer casing. A first current collector, a second current collector having a positive electrode active material layer on its surface, and a negative electrode active material layer on its surface The third current collector is positioned so that it partially overlaps with the first current collector and the second current collector. A separator is placed between the two current collectors. Additionally, a separator is placed between the second and third current collectors.

[0197] In this example, the experiment was conducted using the same laminate structure as described above, which is used in secondary batteries.

[0198] The first, second, and third current collectors are placed on a glass plate, and 42 g / cm³ is applied to them. 2 The load In addition, a current collector with a positive electrode active material layer on its surface is subjected to a load measuring instrument (Aiko) in the horizontal direction. The maximum value was measured by pulling it with an engineering-grade RX-2.

[0199] Figure 17(A) shows a schematic cross-sectional view of a sample with a single-sided coating condition for the negative electrode. On the glass plate 101, there is a negative electrode active material layer 102a, a negative electrode current collector 103a, and a negative electrode current collector 1 03b, negative electrode active material layer 102b, separator 104, positive electrode active material layer 105a, positive electrode current collector 106, positive electrode active material layer 105b, separator 104, negative electrode active material layer 107a, negative electrode current collector The layers were stacked in the following order: 108a, negative electrode current collector 108b, and negative electrode active material layer 107b. Then the load With 109 still in place, the positive electrode (positive electrode active material layer 105a, positive electrode current collector 1) was grasped with clip 120. 06. The positive electrode active material layer 105b) was pulled horizontally 110 degrees and the frictional force was measured.

[0200] Figure 17(B) shows a schematic cross-sectional view of a sample with negative electrode double-sided coating conditions. On a glass plate 101, a negative electrode active material layer 102a, a negative electrode current collector 103, and a negative electrode active material layer 1 02b, Separator 104, Positive electrode active material layer 105a, Positive electrode current collector 106, Positive electrode active material layer 1 05b, Separator 104, Negative electrode active material layer 107a, Negative electrode current collector 108, Negative electrode active material layer 1 The layers were stacked in the order of 07b, and then the clip 120 was used to grip the load 109. The electrodes (positive electrode active material layer 105a, positive electrode current collector 106, positive electrode active material layer 105b) are positioned horizontally 11 The object was pulled to zero, and the frictional force was measured.

[0201] In both conditions shown in Figure 17(A) and (B), the positive electrode was coated on both sides. Therefore, The positive electrode consisted of a positive electrode active material layer 105a, a positive electrode current collector 106, and a positive electrode active material layer 105b.

[0202] Figure 17(C) also shows a photograph of the friction force comparison experiment.

[0203] Furthermore, in both conditions shown in Figure 17(A) and Figure 17(B), the laminate is in a dry state. We also compared the results under two conditions: one where the laminate was wet with electrolyte, and another where it was wet. Measurements were taken three times under each condition. The results are shown in Figure 18.

[0204] From the results shown in Figure 18, if the internal structure of the secondary battery is as shown in Figure 17(A), then in a dry state and The secondary battery became easier to bend in both wet and wet conditions. This is because the metal surface is the same Because the metals are in contact, frictional force is not greatly exerted, and the contacting surfaces of the metals slide against each other. This was because it made it easier to bend. Therefore, by coating only one side, the secondary battery became easier to bend. It became clear that... [Examples]

[0205] In this embodiment, using Figures 19 to 21, a thin secondary battery is used with the apparatus shown in Figure 21. After repeatedly performing bending actions, a water barrier performance evaluation test was conducted on the casing of the secondary battery. I will now explain the results of an experiment to determine whether bending causes damage.

[0206] Whether the exterior is damaged can be determined not only by visual inspection, but also by using a Karl Fischer moisture meter. The amount of moisture inside the secondary battery is measured, and if the amount of moisture exceeds 100 ppm, the sample is... The water barrier properties were deemed unacceptable. The exterior was severely damaged by bending, resulting in cracks and other issues. When this occurs, moisture penetrates through that area, increasing the internal moisture content.

[0207] Karl Fischer moisture meters are devices that use coulometric titration (MKC, manufactured by Kyoto Electronics Manufacturing Co., Ltd.). (-610-DT) was used.

[0208] First, twelve types of samples were prepared. The shapes of the samples are as shown in Figures 19 and 20. The sample lengths and widths were varied. Furthermore, the number of layers, i.e., the thickness of the sample, was also varied. In addition to varying the curvature, we also applied different conditions to the bending radius, resulting in a total of 12 different samples. That's what I decided.

[0209] As a sample, a film embossed according to Embodiments 1 to 3 is used as an outer casing. Samples were prepared using the same procedure as for secondary batteries. However, the secondary battery was enclosed in its outer casing. Instead of the electrolyte placed in the region, propylene carbonate is used, and propylene carbonate The amount of moisture inside was detected. Therefore, the sample shown in this embodiment does not function as a secondary battery. Therefore, although it cannot be charged or discharged, it can be used as a secondary battery by replacing the electrolyte with propylene carbonate. Since it can be charged and discharged when manufactured in this way, the design capacity in that case is calculated in Table 1.

[0210] [Table 1]

[0211] Furthermore, the number of stacked current collectors placed in the area surrounded by the outer casing in a single sample is shown in Table 2. The samples were prepared as shown, and the total thickness of each sample is indicated.

[0212] [Table 2]

[0213] Three of each of the 12 types of samples prepared were subjected to 10,000 bending cycles using a bending test machine. Afterward, it is kept in a container (constant temperature bath) with a pressure adjustment mechanism at 120°C for 24 hours with water, Table 1 shows the results of measuring the amount of moisture contained inside the sample using a Karl Fischer moisture meter. Conditions where the moisture content exceeded 100 ppm in even one of the three conditions were marked as NG.

[0214] Figures 21(A) and 21(B) show the process of bending a sample using a bending test machine. This is a photographic diagram showing the child. The bending test machine can set the radius of curvature, and in this embodiment, the minimum bending curvature The results of testing with radii set to 30mm, 40mm, 60mm, and 100mm are shown in Table 1. I showed it.

[0215] From the results shown in Table 1, when the cell length is 75 mm or less, and the cell thickness is 3.4 mm or less... In the case below, even after 10,000 bending and stretching cycles, the outer casing sustains minimal damage and retains its water barrier properties. It became clear that it remained that way.

[0216] Figure 21(C) shows a photograph of the external appearance of the bending test machine 1100. The manufactured lithium-ion secondary battery 1200 was placed there. Since 1200 is sandwiched between the two retaining plates 1101, in Figure 21(C) it is lithium The ion secondary battery 1200 is shown with a dashed line. Also, the bending test machine 1100 shows the lithium in the center. A cylindrical support with a radius of curvature of 40 mm extends in the depth direction directly beneath the 1200 ion secondary battery. (Not shown) It also has an arm 1102 extending in the left-right direction. It has the tip of the arm 1102 which is mechanically connected to the retaining plate 1101. By moving the tip of part 1102 up and down, the holding plate 1101 is bent along the support. It can be stretched. The bending test of the lithium-ion secondary battery 1200 is performed by lithium-ion The procedure was performed with the ON secondary battery 1200 sandwiched between two retaining plates 1101. Therefore, Arm 1 By moving the tip of 102 up and down, lithium ions are released along the cylindrical support. The secondary battery 1200 can be bent and straightened. Specifically, the tip of the arm 1102 By lowering the portion, the lithium-ion secondary battery 1200 can be bent with a radius of curvature of 40 mm. It is possible to bend and straighten the lithium-ion secondary battery 1200. By performing the operation with the battery 1200 sandwiched between two holding plates 1101, other than bending and straightening can be achieved. This prevents unwanted force from being applied to the lithium-ion secondary battery 1200. The force applied during bending and straightening can be uniformly distributed throughout the entire 1200 lithium-ion secondary battery. [Examples]

[0217] In this embodiment, as shown in Figures 22 to 23, an electrode is constructed in which an active material layer is provided on one side of the current collector. Regarding the secondary battery manufactured and the secondary battery made with electrodes having active material layers on both sides of the current collector, I will now explain the results of the measurement of the load required for bending.

[0218] First, a sample of a secondary battery made with an electrode having an active material layer on only one side of the current collector, and We prepared a sample of a secondary battery made with electrodes that have active material layers on both sides of the electrode body.

[0219] A more specific configuration of the secondary battery is that, under single-sided coating conditions, the negative electrode active material layer 1 is applied to only one side. Between two negative electrode current collectors 1902, each equipped with 903, a positive electrode active material layer 1905 is provided on only one side. It consists of six positive electrode current collectors 1904 and four negative electrodes with a negative electrode active material layer 1903 on only one side. The current collector 1902 was sandwiched between six separators 1906.

[0220] Under double-sided coating conditions, two negative electrode current collectors are provided with a negative electrode active material layer 1903 on only one side. Between 1902, there are three positive electrode current collectors 1904, each having a positive electrode active material layer 1905 on both sides, and both Two negative electrode current collectors 1902, each having a negative electrode active material layer 1903 on its surface, and six separators 19 The structure was designed with 06 in between.

[0221] Figure 22(A) shows a schematic cross-sectional view of a sample under single-sided coating conditions. As shown below, negative electrode current collector 1902, negative electrode active material layer 1903, separator 1906, positive Electrode active material layer 1905, cathode current collector 1904, cathode current collector 1904, cathode active material layer 1905 , separator 1906, negative electrode active material layer 1903, negative electrode current collector 1902, negative electrode current collector 190 2. Negative electrode active material layer 1903, separator 1906, positive electrode active material layer 1905, positive electrode current collector 1 904, positive electrode current collector 1904, positive electrode active material layer 1905, separator 1906, negative electrode active material Layer 1903, negative electrode current collector 1902, negative electrode current collector 1902, negative electrode active material layer 1903, separate 1906, positive electrode active material layer 1905, positive electrode current collector 1904, positive electrode current collector 1904, positive electrode The active material layer 1905, separator 1906, negative electrode active material layer 1903, and negative electrode current collector 1902 The batteries were stacked in sequence to form a secondary battery with a thickness of approximately 2 mm.

[0222] Figure 22(B) shows a schematic cross-sectional view of a sample with double-sided coating conditions. As shown below, negative electrode current collector 1902, negative electrode active material layer 1903, separator 1906, positive Electrode active material layer 1905, positive electrode current collector 1904, positive electrode active material layer 1905, separator 1906 , negative electrode active material layer 1903, negative electrode current collector 1902, negative electrode active material layer 1903, separator 19 06, Positive electrode active material layer 1905, Positive electrode current collector 1904, Positive electrode active material layer 1905, Separator 1906, negative electrode active material layer 1903, negative electrode current collector 1902, negative electrode active material layer 1903, separate 1906, positive electrode active material layer 1905, positive electrode current collector 1904, positive electrode active material layer 1905, The palator 1906, the negative electrode active material layer 1903, and the negative electrode current collector 1902 are stacked in that order, and the thickness A rechargeable battery approximately 2 mm in size was used.

[0223] Next, the sample is placed between the curved jig 1400 and tested on the testing machine 1410 (EZ Gra Using a PH (manufactured by Shimadzu Corporation), a load was applied, and the radius of curvature was measured from an uncurved state to approximately 40m. Move jig 1401 in the direction of jig 1402 so that the displacement is 6 mm / min up to m. Furthermore, the sample was curved in a direction parallel to the lead electrode extraction direction.

[0224] Figures 23(A) and 23(B) show schematic diagrams of the jig 1400 and testing machine 1410 having curved surfaces. A diagram is shown. A jig 1400 having a curved surface, in contact with the inner diameter of the curve of sample 1420. Part 1401 has a convex section with a radius of curvature of 40 mm, and the jig 1402 that contacts the outer diameter has a radius of curvature of 42 mm. It has a recess of m.

[0225] In Figures 23(A) and 23(B), X1 is the upper edge of jig 1401 and the upper edge of jig 1402. This refers to the distance at the furthest point, and in Figure 23(B), X2 is the upper edge of jig 1401 relative to jig 140 This refers to the distance when the top edge of 2 is closest to the edge. Also, ΔX in Figure 23(B) is the distance between X1 and X2. This represents the difference in distance, which is the actual travel distance of jig 1401.

[0226] The cell curvature was specifically performed as follows: First, the inner diameter of the curve of the sample is tangent to the inner diameter of the curve. The jig 1401 and the jig 1402 that contacts the outer diameter were connected to the testing machine 1410. Sample 1420 was placed on jig 1402 which is in contact with the outer diameter. Then, the arrow in Figure 23(A) In the direction of the mark (compression direction), the sample 14 is sandwiched between the jig 1400 using the testing machine 1410. A load was applied to 20. In this way, the sample was transformed into a radius of curvature as shown in Figure 23(B). The load required to bend it to 40mm was measured.

[0227] Samples prepared under single-sided coating conditions and samples prepared under double-sided coating conditions were compared with a radius of curvature of 4. Figure 24 shows the results of measuring the load required to bend the material to 0 mm. The solid line represents one side. The sample shown is prepared under the coating conditions; the dashed line indicates the result of the sample prepared under double-sided coating conditions. The displacement shown on the horizontal axis represents the distance traveled by jig 1401 as it contacts the inner diameter of the curve of jig 1400. This refers to ΔX shown in Figure 23(B). The displacement is when the spacing of the jig 1400 is 40 mm. 0mm when the sample is not curved, and when the contact area between the sample and the jig 1400 is at its maximum. The measurement will be 40 mm when it is finished. Also, displacement can be rephrased as displacement amount, distance traveled, etc. That's good too.

[0228] As shown in Figure 24, for each sample, the amount of curvature required after a certain displacement The graph shows a rapid increase in load. This is because the thin tab portions of the positive and negative electrodes were thin at the beginning. This is because the first part curved, followed by the thicker part containing the active material layer.

[0229] As shown in Figure 24, the results indicate that a secondary electric current was fabricated using an electrode with an active material layer on only one side of the current collector. Comparing a pond with a secondary battery made with electrodes that have active material layers on both sides of the current collector, one side coated Under these conditions, the secondary battery could be bent with less load than under double-sided coating conditions. Why? Therefore, when metal surfaces are in contact with each other, frictional force does not act greatly, and the metals are in contact. This was because the surfaces that were touching each other were slippery. Therefore, by coating only one side, secondary batteries It became clear that it becomes easier to bend. [Examples]

[0230] In this example, the load required for bending was measured for thin secondary batteries of different thicknesses. Let's explain the results.

[0231] First, we prepared two samples each of three types of samples: A, B, and C. Sample A Sample A has 2 layers (1.5 mm thick), Sample B has 6 layers (2.5 mm thick), Sample C The number of layers was set to 10 (thickness 3.4 mm). Here, for example, the number of layers of 2 refers to the positive electrode and the negative electrode. This refers to having two of each item.

[0232] Samples A, B, and C differ from those in Example 2 in only the number of layers; the sample length is 75 mm and the sample width is 75 mm. The samples were prepared in the same way as the 60mm samples. The conditions for samples A, B, and C are shown in Table 3.

[0233] [Table 3]

[0234] Next, samples A, B, and C were placed in a curved jig 1400 and tested using the testing machine 141. Using 0 (EZ Graph, manufactured by Shimadzu Corporation), a load is applied, starting from a non-curved state. Jig 1401 is set to jig 1402 so that the displacement is 6 mm / min up to a radius of curvature of approximately 40 mm. It was moved in that direction. Also, the cell was curved in a direction parallel to the direction in which the lead electrodes were pulled out.

[0235] The load was measured using the same testing machine and fixture as in Example 3.

[0236] The load required to bend samples A, B, and C to a radius of curvature of 40 mm was measured. The results are shown in Figure 25(A). The solid line represents sample A (2 layers, 1.5 mm thickness), and the dashed line represents Sample B (6 layers, 2.5 mm thickness), the dotted line is Sample C (10 layers, 3.4 mm thickness) This is the result for mm. Also, in Figure 25(A), to make the figure clearer, samples A, B, and C are shown. Each example was shown for one sample.

[0237] As shown in Figure 25(A), for all samples, after a certain displacement, the curvature is necessary. The graph showed a sudden increase in load. This is because the tab portions of the positive and negative electrodes were used earlier. This is because the thinner section curved first, followed by the thicker section containing the active material layer.

[0238] The load value required to bend the thick portion containing the active material layer is shown in Figure 25(A) The points where the slopes of curves A, B, and C become sharply larger were selected. The thick portion containing the active material layer was then analyzed. The slope of the curve corresponding to the load value required to create the curve is determined to be 6 N / mm or greater. Figure 25(B) shows the points where the slope is 6 N / mm or greater in samples A, B, and C. The graph shows the sample thickness on the horizontal axis.

[0239] As is clear from Figure 25(B), the thicker the sample, the more the sample is curved. The load required to bend it, more specifically, the load needed to curve the thicker portion of the sample containing the active material layer. It became clear that the required load would increase. [Explanation of Symbols]

[0240] 10 films 10a film 10b film 11 Film 11a film 11b Film 12 Positive electrode current collector 13 Separator 14 Negative electrode current collector 15. Sealing layer 16 Lead electrodes 17 Thermocompression bonding area 18 Cathode active material layer 19 Negative electrode active material layer 20 Electrolyte 21 areas 22 film 23 Film 24 film 30 Adhesive layer 40 Secondary battery 50 film 51 film 52 film 53 Embossing Roll 54 rolls 55 Embossing Roll 56 Embossing Roll 57 Embossing Roll 58 Embossing Roll 60 Direction of travel 70 Structure 71 Film 72 film 72a film 72b film 72c film 80 planes 90 plane 101 Glass plate 102a Negative active material layer 102b Negative electrode active material layer 103 Negative electrode current collector 103a Negative electrode current collector 103b Negative electrode current collector 104 Separator 105a Cathode active material layer 105b Positive electrode active material layer 106 Positive electrode current collector 107a Negative electrode active material layer 107b Negative electrode active material layer 108 Negative electrode current collector 108a Negative electrode current collector 108b Negative electrode current collector 109 Load 110 Horizontal 120 clips 1100 Testing Machine 1101 Holding plate 1102 Arm 1200 Lithium-ion rechargeable batteries 1301 Vertical stripe pattern 1302 Horizontal stripe pattern 1400 jigs 1401 Jig 1402 Jig 1410 Testing machine 1420 samples 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 1805 Electrodes and electrolytes 1901 Exterior 1902 Negative electrode current collector 1903 Negative active material layer 1904 Positive electrode current collector 1905 Cathode active material layer 1906 Separator 7100 Mobile Phone 7101 enclosure 7102 Display section 7103 Operation Buttons 7104 Energy storage device 7105 Lead Electrode 7106 Current collector 7400 mobile phones 7401 enclosure 7402 Display section 7403 Operation Buttons 7404 External connection port 7405 Speaker 7406 Microphone 7407 Energy storage device 7408 Lead Electrode 7409 Current collector 7600 Vacuum cleaner 7601 Lead Electrode 7602 Lead Electrode 7603 Operation Buttons 7604 Energy storage device 7605 Energy Storage Device 7606 Display section 8021 Charging device 8022 Cable 8100 Automobile 8101 Headlight 8200 automobiles

Claims

1. A secondary battery having a curved surface, The aforementioned secondary battery is Exterior body and The first negative electrode active material layer, A first negative electrode current collector having the first negative electrode active material layer provided on one side, A second negative electrode current collector having a region in contact with the first negative electrode current collector, The second negative electrode current collector has a second negative electrode active material layer provided on one side thereof, A secondary battery in which the first negative electrode active material layer, the first negative electrode current collector, the second negative electrode current collector, and the second negative electrode active material layer are housed in a region surrounded by the outer casing.

2. A secondary battery having a curved surface, The aforementioned secondary battery is Exterior body and The first positive electrode active material layer, A first positive electrode current collector having the first positive electrode active material layer provided on one side, A second positive electrode current collector having a region in contact with the first positive electrode current collector, The second positive electrode current collector has a second positive electrode active material layer provided on one side thereof, A secondary battery in which the first positive electrode active material layer, the first positive electrode current collector, the second positive electrode current collector, and the second positive electrode active material layer are housed in a region surrounded by the aforementioned outer casing.

Images