Bands and watches

Abstract

To provide a battery that can be safely transformed, a battery that can be bent and made thick, and a battery with increased capacity.SOLUTION: A wavy film that continues periodically in one direction is used for an exterior of a battery. Moreover, a space is provided inside an exterior body between the unfixed end of an electrode stack and the inner wall of the exterior body. Further, the waves in the pair of portions of the exterior body sandwiching the electrode stack are formed to be out of phase. In particular, they are formed with a phase shift of 180 degrees such that the ridge lines overlap and the valley lines overlap.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] One aspect of the present invention relates to a battery. One aspect of the present invention relates to a bendable battery. One aspect of the present invention relates to an exterior body for a battery.

[0002] Note that one embodiment of the present invention is not limited to the above technical fields. The technical field of one embodiment of the present invention is a semiconductor device, a display device, a light-emitting device, a power storage device, a storage device, and a , electronic device, lighting device, input device, input / output device, driving method thereof, or manufacturing method thereof The law can be cited as one example. [Background technology]

[0003] In recent years, mobile information terminals such as smartphones have been actively developed. Users expect portable information terminals, which are a type of electronic device, to be lightweight and small. In addition, development of wearable devices that are attached to the user is also underway.

[0004] Equipment such as wearable devices and mobile information terminals are capable of repeated charging and discharging. They often have secondary batteries installed. In addition, such devices are required to be lightweight and compact. However, the capacity of the secondary battery is small, and the operating time is limited. As a secondary battery to be installed in such equipment, it is lightweight, small, and can be used for a long time. It is required that.

[0005] Patent Document 1 describes a highly flexible device that uses a thin, flexible film-like material as an exterior body. A battery is disclosed. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2012 / 140709 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when a flexible battery is manufactured using the technology disclosed in Patent Document 1, Unless the battery is thin (for example, less than 400 μm), the exterior body will not be damaged when the battery is bent. On the other hand, there is a risk that such a thin battery will not provide sufficient capacity. There is a problem.

[0008] An object of one embodiment of the present invention is to provide a battery that can be safely deformed. Another object of the present invention is to provide a battery that can be bent and has a large thickness. Another object of the present invention is to provide a battery with an increased capacity. Another object of the present invention is to provide a battery having high reliability. One of the challenges we face is to

[0009] The description of these problems does not preclude the existence of other problems. It is not necessary to solve all of these problems. It is possible to extract issues other than those mentioned above. [Means for solving the problem]

[0010] One aspect of the present invention is a battery having a laminate and an exterior body. The exterior body is folded in two so as to sandwich the laminate. The pair of first portions includes a first portion, a second portion, a pair of third portions, and a fourth portion. a portion that overlaps with one another and is surrounded by a second portion, a third portion, and a fourth portion, The second portion is located between the pair of first portions, and includes a portion overlapping the laminate. The pair of third portions are positioned opposite to each other so as to sandwich the first portion. The fourth portion is a strip-shaped portion extending in a direction intersecting with the first portion. The outer casing is a band-shaped part located on the opposite side of the second part with the third part in between. The laminate and the second portion are joined together inside the exterior body. Instead, there is a space between the laminate and the second portion.

[0011] In addition, in a plan view of the exterior body, the length of the third portion in the extending direction is longer than the lengths of the first portion and the second portion. It is preferable that the length of the second portion is longer than the length in a direction parallel to the first and fourth portions.

[0012] The first portion has a wave shape in which a plurality of parallel ridges and valleys are alternately arranged. Preferably, the third portion is flat.

[0013] In addition, the closer the first portion is to the second portion, the longer the wave period and the smaller the amplitude. It is preferred to have a region.

[0014] The exterior body has a pair of first portions, and a ridge line of one of the first portions and a ridge line of the other first portion. It is preferable that the pair of first portions have a region where the valley line does not coincide with the pair of first portions. It is preferable that the ridges of the two grooves have an overlapping area and the valleys of the two grooves have an overlapping area.

[0015] Also, the second portion preferably does not have a corrugated shape.

[0016] In addition, a valley line located closest to the second portion of the first portion is provided between the second portion and the valley line. It is preferable that the ridge is located.

[0017] In addition, when the battery is not bent, the second portion of the laminate inside the exterior body The distance between the edge of the laminate and the inner surface of the exterior body is π×t or less, assuming that the thickness of the laminate is 2t. It is preferable that the above.

[0018] Further, one aspect of the present invention is a method for manufacturing a laminated laminated film on an inside of an exterior body, the method comprising the following steps 1 to 3: The first step is to fabricate a battery having parallel ridges and a plurality of A film processed into a wavy shape with alternating valleys and multiple ridges at equal intervals. The second step is to prepare an exterior body of the above-mentioned. The third step is to bend the laminate 180 degrees in a direction perpendicular to the stacking direction. The other part of the exterior body is located outside the layer and extends in a direction perpendicular to the ridge line and valley line. In the third step, the exterior body is flattened. The folded portion of the exterior body is joined as shown in FIG. 1 and overlaps with the laminate of the exterior body. The exterior body is joined so that the spacing between the multiple ridge lines becomes wider as the ridge lines are closer to the outer periphery.

[0019] In addition, after the first step and before the second step, the ridges and valleys of the exterior body are aligned with the flat surfaces. The fourth step is to process the exterior body so that the strip-shaped portion extending in the longitudinal direction is flat. At this time, in the second step, the flattened portion of the exterior body is preferably It is preferable to fold the part.

[0020] In the second step, the ridges and valleys of the folded exterior body do not overlap. In particular, in the second step, The exterior body is folded over so that the ridges of the overlapping exterior body overlap each other and the valleys of the overlapping exterior body overlap each other. Folding is preferred. Effect of the Invention

[0021] According to one aspect of the present invention, a battery that can be safely deformed can be provided. It is possible to provide a battery that can be made thicker and has a higher capacity. It is possible to provide a battery having high reliability or at low cost. A battery can be manufactured.

[0022] Note that one embodiment of the present invention does not necessarily have all of these effects. Other effects can be extracted from the detailed description, drawings, claims, etc. [Brief description of the drawings]

[0023] [Figure 1] 3 illustrates an example of a battery configuration according to an embodiment. [Diagram 2] 1A to 1C are diagrams illustrating an example of a configuration when a battery is bent according to an embodiment; [Diagram 3] 1A to 1C are diagrams illustrating a method for manufacturing a battery according to an embodiment; [Figure 4] 1A to 1C are diagrams illustrating a method for manufacturing a battery according to an embodiment; [Diagram 5] 1A to 1C are diagrams illustrating a method for manufacturing a battery according to an embodiment; [Figure 6] 1A to 1C are diagrams illustrating a method for manufacturing a battery according to an embodiment; [Figure 7] 3 illustrates an example of a battery configuration according to an embodiment. [Figure 8] 1A to 1C are diagrams illustrating a method for processing a film according to an embodiment. [Figure 9] 1A to 1C are diagrams illustrating a method for processing a film according to an embodiment. [Figure 10] 1A to 1C are diagrams illustrating a method for manufacturing a battery according to an embodiment; [Figure 11] 3 illustrates an example of a battery configuration according to an embodiment. [Figure 12] 3 illustrates an example of a battery configuration according to an embodiment. [Figure 13] 3 illustrates an example of a battery configuration according to an embodiment. [Figure 14] 3 illustrates an example of a battery configuration according to an embodiment. [Figure 15] 3 illustrates an example of a battery configuration according to an embodiment. [Figure 16] 1 is an electronic device according to an embodiment. [Figure 17] 1 is an electronic device according to an embodiment. [Figure 18] A vehicle according to an embodiment. [Figure 19] 3 is a photograph showing the appearance of the battery according to Example 1. [Figure 20] 4 is an X-ray image of a battery according to Example 1. [Figure 21] 4 is an X-ray image of a battery according to Example 1. [Figure 22] 4 is an X-ray CT image of a battery according to Example 1. [Figure 23] 4 shows the results of a tensile test on the film according to Example 2. [Figure 24] 11 is a measurement result of the amount of water penetration according to Example 3. [Diagram 25] FIG. 13 is a diagram for explaining a measurement method according to the fourth embodiment. [Figure 26] 13 is a measurement result of the force required to bend the battery according to Example 4. [Figure 27] 13A to 13C are diagrams for explaining a method for producing a band according to the fifth embodiment. [Figure 28] 13 is a photograph of a band incorporating a battery according to Example 5. [Figure 29] 13 is a photograph of a band incorporating a battery according to Example 5. [Diagram 30] 11 is an X-ray image of a battery according to Example 6. [Diagram 31]11 is a photograph showing the appearance of a battery according to Example 6. [Diagram 32] 13 is a measurement result of the amount of water penetration according to Example 6. [Diagram 33] FIG. 13 is a diagram for explaining a calculation model according to the seventh embodiment. [Diagram 34] FIG. 23 is a diagram for explaining calculation results according to the seventh embodiment. [Diagram 35] FIG. 23 is a diagram for explaining calculation results according to the seventh embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The embodiment will be described in detail with reference to the drawings. However, the present invention is not limited to the following description. The present invention is not limited to the above embodiment, and various changes and modifications may be made in the form and details without departing from the spirit and scope of the present invention. It will be easily understood by those skilled in the art that the present invention can be realized by the following embodiments. The present disclosure should not be construed as being limited to the contents of the preceding paragraph.

[0025] In the configuration of the invention described below, the same parts or parts having similar functions are The same reference numerals are used in common between different drawings, and the repeated explanations are omitted. When referring to a function, the same hatch pattern may be used and no particular symbol may be added.

[0026] In each figure described in this specification, the size, layer thickness, or area of ​​each component is indicated by The figures may be exaggerated for clarity and are not necessarily limited to scale. stomach.

[0027] In this specification, ordinal numbers such as "first" and "second" are used to avoid confusion of components. The numbers are added for the purpose of convenience and are not intended to be limiting.

[0028] (Embodiment 1) In this embodiment, a configuration example and a manufacturing method example of a battery according to one embodiment of the present invention will be described. .

[0029] One aspect of the present invention is a bendable battery. By making the exterior body corrugated, the exterior body can be folded and folded. The stress caused by the wave is relieved by deformation that changes the wave period and amplitude, causing the exterior body to break. This can prevent the following from happening:

[0030] In the electrode stack of the battery according to one embodiment of the present invention, a portion to which a tab or the like is connected is fixed, and The battery is characterized in that the electrodes are misaligned relative to each other in other areas. When the electrode stack is pressed against the fixed point, the electrode stack is deformed so that each part is displaced relative to the other. can be done.

[0031] In one aspect of the present invention, a non-fixed end portion of the electrode laminate is disposed inside the exterior body, and This space prevents the electrode stack from shifting when the battery is bent. This can prevent a part of the electrode laminate from coming into contact with the inner wall of the exterior body. One aspect of the present invention is to prevent the electrode stack from being deformed due to deformation of the electrode stack, no matter how thick the electrode stack is. This can prevent the exterior from being damaged by contact with the battery. If the thickness of the pond is greater than 400 μm, or is 500 μm or more, or is 1 mm or more, Even if the material is not subjected to bending or stretching, it can be safely deformed repeatedly. It can also be applied to extremely thin batteries of less than 400 μm.

[0032] There is no limit to the thickness of the battery, but the required capacity of the electronic device in which the battery is installed and the shape of the device The thickness may be selected according to the application, such as the shape of the material, etc. For example, the thickness may be set to 10 mm or less, preferably 5 mm or less. m or less, more preferably 4 mm or less, and even more preferably 3 mm or less.

[0033] In order to form a larger space between the inner wall of the exterior body, the outer wall sandwiching the electrode laminate is It is preferable that the waves of the pair of portions of the housing are out of phase with each other. Of a pair of exterior body parts located on either side of each other, the ridge line of one part and the valley line of the other part It is preferable that the electrodes are formed so as to be offset from each other so as not to overlap each other. In the portion of the pair of exterior bodies sandwiching the laminate, the ridge lines overlap each other and the valley lines overlap each other. When the phases are shifted by 180 degrees, the distance between the electrode laminate and the exterior body is the shortest. This is preferable because it allows the formation of a long space. If the valleys of the parts are formed so that they overlap and are in phase, the shape of the space that is formed The shape of the electrode laminate becomes irregular, and the distance between the electrode laminate and the exterior body becomes the smallest. Therefore, this is not desirable.

[0034] In one embodiment of the present invention, for example, a film is folded in half in a direction parallel to the ridges and valleys of the waves. The electrode laminate is sandwiched between two pieces of paper and pressure is applied so that at least two sides perpendicular to the folded portion are flat. The film can be made by bonding it while applying heat. The film is folded so that the waves on the opposing films are at least slightly out of phase with each other. It is particularly preferable to fold the film so that the waves are out of phase with each other by 180 degrees. stomach.

[0035] Here, the phase of the waves of a pair of parts of the exterior body facing each other with the electrode laminate in between changes from before bonding to after bonding. Even in that case, there may be a misalignment after joining. In addition, the area adjacent to the bent portion may have a portion where the phases of the waves of the pair of portions do not match. preferable.

[0036] As a result of the joining, the two sides sandwiching the electrode laminate become longer than their natural lengths before joining. In the part overlapping with the electrode laminate, a force is generated that pulls it in a direction perpendicular to the ridges and valleys of the waves. On the other hand, the portion overlapping with the electrode laminate is provided with a tensile strength so as to maintain the wave shape. The force acting in the opposite direction to the bending force is generated. The force acting in the opposite direction to the bending force is weaker as the bending part approaches. The closer to the bent part, the more the waves of the exterior body are stretched. The outer casing is deformed so that the wave period becomes larger and the wave amplitude becomes smaller as the wave velocity increases. This mechanism ensures that the joint is sufficiently flat, and the bent part and A space can be formed between the electrode stack.

[0037] In order to form a sufficient space between the inner wall of the exterior body and the electrode laminate, The shape of the film waves is important. The smaller the period of the film waves, the larger the amplitude. For example, if the natural length of the wavy film is 1 When the film is stretched, the length is 1.02 times or more, preferably 1.05 times. More preferably, 1.1 times or more and 2 times or less of film should be used for the exterior. The wave shape may be various shapes such as a sine curve, a triangular wave shape, a circular arc shape, a rectangular shape, etc. Any shape can be used, and it is sufficient that the convex portions and concave portions are repeated in at least one direction. If the wave amplitude is large, the battery volume may become large, so make the wave period shorter. It is preferable to increase the ratio of the length of the stretched film to the natural length of the film. I wish.

[0038] In order to form a sufficient space, the bonding conditions are also important. The joint may not be flat but may become wavy, and there may be a risk that a sufficient space is not formed. The batteries are joined in a phase-shifted state, so if the joint is insufficient, the joint may break when the battery is deformed. However, with a well-optimized joining method, this can be prevented. The preferable conditions for bonding depend on the film material and the bonding agent used. For example, when polypropylene is used as the heat-sealing layer, In this case, a pressure sufficient to flatten the wavy embossed shape can be applied at a temperature above the melting point of polypropylene. In addition, the joint (top seal) in the direction parallel to the wavy embossing shape is more likely to be in the wavy embossing direction than in the wavy embossing direction. High pressure is applied to the joint (side seal) perpendicular to the embossed shape. is preferred.

[0039] According to one embodiment of the present invention, the shape of the secondary battery can be freely designed. By using secondary batteries, the freedom of electronic devices as a whole increases, allowing for a variety of designs. In addition, a secondary battery is attached along the inner surface of an electronic device having a curved surface. By installing this, the space inside the electronic device can be effectively utilized without creating any wasted space. It can be used.

[0040] Furthermore, according to one embodiment of the present invention, the capacity of the secondary battery can be increased, This makes it possible to extend the usable time of electronic devices and reduce the frequency of charging.

[0041] Therefore, electronic devices with novel structures can be realized.

[0042] More specific configuration examples and manufacturing method examples will be described below with reference to the drawings.

[0043] [Configuration example] FIG. 1(A) is a plan view of a battery 10 exemplified below. FIG. 1(B) is a plan view of a battery 10 exemplified below. 1(C), (D), and (E) are views from the direction indicated by the arrow in Fig. 1. 1(A) , sectional outlines taken along the cutting lines A1-A2, B1-B2, and C1-C2 in FIG. FIG.

[0044] The battery 10 includes an exterior body 11, a laminate 12 housed inside the exterior body 11, and a The electrode 13a and the electrode 13b are electrically connected to the external circuit board 11 and extend outside the external circuit board 11. In addition to the laminate 12, an electrolyte is enclosed inside the exterior body 11.

[0045] The exterior body 11 has a film-like shape and is folded in two so as to sandwich the laminated body 12. The exterior body 11 includes a pair of portions 31 that sandwich the laminate 12, a folded portion 32, and a pair of joints. The pair of joints 33 are arranged in a direction substantially perpendicular to the bent portion 32. The joint 34 is a strip-shaped portion that extends from the upper surface of the plate 31 and is provided so as to sandwich the portion 31 therebetween. The portion 31 is a strip-shaped portion located on the opposite side of the folded portion 32. It can also be said that the area is surrounded by a pair of joints 33 and 34. ) shows an example in which the joint 34 holds a part of the electrode 13a and a part of the electrode 13b.

[0046] At least the surface of the portion 31 of the exterior body 11 has irregularities in the direction in which the pair of joints 33 extend. In other words, the portion 31 has a repeating wavy shape where the ridges 21 and valleys 22 intersect. In FIG. 1(A) and other figures, the ridge line 21 connecting the tops of the convex portions is A valley line 22 connecting the bottoms of the valleys is shown by a dashed line.

[0047] In addition, in a plan view, the length of the joint 33 in the extending direction is longer than the length of the joint 34 of the exterior body 11. 31 and the folded portion 32, and is longer than the length of the joint portion 33 in a direction parallel to the extending direction. As shown in FIG. 1A, with respect to a line connecting the ends of a pair of joints 33 on the side of the bent portion 32 The portion of the bent portion 32 closest to the joint 34 is positioned toward the joint 34 by a distance L1. It is placed.

[0048] The laminate 12 has a configuration in which at least positive electrodes and negative electrodes are alternately laminated. The laminated body can also be called an electrode laminate. Here, the greater the number of layers in the laminate 12, the greater the capacity of the battery 10. The laminate 12 will be described in detail later.

[0049] Here, the thickness of the laminate 12 is, for example, 200 μm or more and 9 mm or less, preferably 400 μm or less. Preferably, the thickness is 500 μm or more and 3 mm or less, and more preferably, 500 μm or more and 2 mm or less. Typically, it is about 1.5 mm.

[0050] As shown in FIGS. 1(A), (C), and (D), inside the exterior body 11, The end closest to the bent portion 32 and the inner surface of the exterior body 11 located at the bent portion 32 There is a space 25 (also called a gap or void) between the two. The length in the direction parallel to the stretching direction is defined as distance d0. The distance between the end of the bent portion 32 and the inner surface of the exterior body 11 located at the bent portion 32 This can also be rephrased as "separation."

[0051] The laminate 12 includes electrodes 13a (and Therefore, the laminate 12 and the exterior body 11 are joined at the joint It can be said that the relative positions of the electrodes 13a and 13b are fixed by the electrode 34. The electrode 13b is joined to one of the plurality of positive electrodes and the plurality of negative electrodes. It is being done.

[0052] As shown in FIGS. 1(A), (C), and (D), the portion 31 of the exterior body 11 is folded. The closer to the portion 32, the larger the wave period becomes and the smaller the wave amplitude becomes. By producing the battery 10 in such a form, the exterior body 11 A space 25 can be formed inside the

[0053] As shown in Figs. 1C and 1D, the pair of portions 31 sandwiching the laminate 12 are It is most preferable that the laminate 12 is opposed to each other so that the phases are shifted by 180 degrees. The exterior body 11 is folded so that the ridge lines 21 overlap each other and the valley lines 22 overlap each other. It is preferable that the space 25 is bent. This allows the space 25 to have a good shape. can.

[0054] [About the space] Next, the shape of the battery 10 having the space 25 formed therein when it is bent will be described.

[0055] FIG. 2(A) is a schematic cross-sectional view showing a part of the configuration of the battery 10 in a simplified manner.

[0056] Here, a pair of parts 31 of the exterior body 11 are distinguished and are referred to as part 31a and part 3 Similarly, the ridges of the respective portions are indicated as ridges 21a, ridges 21b, and so on. b, the valley lines are distinguished and denoted as valley line 22a and valley line 22b.

[0057] In FIG. 2A, the laminate 12 has a configuration in which five electrodes 43 are laminated. 3 corresponds to the electrode 41 or the electrode 42 in FIG. 1(A). In addition, the multiple electrodes 43 are The relative positions are fixed at the end on the joint 34 side. 11, the relative position is fixed at a joint 34.

[0058] Inside the exterior body 11, a space 25 is provided near the bent portion 32. Here, when the exterior body 11 is not bent, the end of the electrode 43 on the side of the bent portion 32 and the exterior body The distance between the inner wall of 11 is set to d0.

[0059] The neutral plane of the battery 10 is defined as a neutral plane C. Here, the neutral plane C is a plane that the laminate 12 has. It is assumed that the neutral plane coincides with that of the centrally located electrode 43 among the five electrodes 43.

[0060] FIG. 2(B) is a schematic cross-sectional view of the battery 10 when bent into an arc shape around point O. Then, the battery 10 is bent so that the portion 31a is on the outside and the portion 31b is on the inside.

[0061] As shown in FIG. 2B, the outer portion 31a has a small wave amplitude and a small wave That is, the edge 21a of the outer portion 31a is deformed so that the period becomes larger. The distance between the adjacent grooves 22a and the distance between the adjacent valley lines 22a are increased. , the amplitude of the wave becomes large and the period of the wave becomes small. The distance between the ridge lines 21b and the distance between the valley lines 22b of the bent portion 31b are The gap between the parts 31a and 31b is narrowed. The stress applied to the battery 10 is relieved, and the battery 10 can be bent without damaging the exterior body 11. do.

[0062] As shown in FIG. 2B, the electrodes 43 are stacked so that they are offset relative to each other. As a result, the stress applied to the laminate 12 is relieved, and the laminate 12 is prevented from being damaged. In FIG. 2B, the individual electrodes 43 themselves can be bent without bending the battery 10. is shown as not stretched by bending. The thickness of the electrode 43 is By making the thickness of the electrodes 43 sufficiently small, the stress applied to each electrode 43 itself can be reduced. Cut.

[0063] Among the electrodes 43 of the laminate 12, the electrodes 43 located outside the neutral plane C are The end portion is shifted toward the joint portion 34 side.

[0064] On the other hand, the end of the electrode 43 located inside the neutral plane C is shifted toward the bent portion 32. Here, the end of the innermost electrode 43 on the side of the bent portion 32 and the inner surface of the exterior body 11 are The distance to the wall is reduced from d0 to d1. The relative shift between the innermost electrode 43 and the innermost electrode 43 is defined as distance d2. will be equal to the distance d0 minus the distance d2.

[0065] Here, if the distance d0 before bending is smaller than the distance d2 after bending, In this case, the electrode 43 located inside the neutral plane C of the laminate 12 is in contact with the inner wall of the exterior body 11. Therefore, the necessary distance d0 will be considered below.

[0066] In the following, we will explain using Figure 2(C). Figure 2(C) shows a curve corresponding to the mid-plane C. The curve corresponding to the innermost surface of the laminate 12 is shown by a dashed line as curve B, and the curve corresponding to the innermost surface of the laminate 12 is shown by a solid line as curve B. .

[0067] Curve C is a circular arc with radius r0, and curve B is a circular arc with radius r1. Radius r0 and radius r1 The difference between these is defined as t. Here, t is equal to 1 / 2 the thickness of the laminate 12. The arc lengths of curves C and B are equal. The central angle of curve C is θ, and the center of curve B is The central angle is θ+Δθ.

[0068] From the above relationship, the distance d2, which is the deviation of curve B from the end of curve C, is calculated as follows: It looks like this:

[0069]

number

[0070] That is, the distance d2 can be estimated by the thickness of the laminate 12 and the bending angle. It is shown that this does not depend on the length of the body 12 or the radius of curvature of the bend.

[0071] As described above, by making the distance d0 of the space 25 larger than or equal to the distance d2, the battery 10 It is possible to prevent the laminate 12 and the exterior body 11 from coming into contact with each other when the laminate 12 is bent. When the battery 10 having the laminate 12 with a thickness of 2t is bent for use, the maximum angle is defined as an angle θ Then, the distance d0 between the laminate 12 and the inner wall of the exterior body 11 in the space 25 is t×θ or less. The above value should be used.

[0072] For example, if the battery is bent by 30 degrees, the distance d0 of the space 25 must be πt / 6 or more. Similarly, if the cable is bent by 60 degrees, d0 should be πt / 3 or more. When bending it 90 degrees, d0 should be πt / 2 or more. When bending it 180 degrees, In this case, d0 should be set to πt or more.

[0073] For example, if the battery 10 is not used for purposes such as winding, the battery 10 is not intended to be used in a manner that is not intended. The maximum bending angle that can be used is 180 degrees. If the distance d0 is set to a length equal to or greater than πt, and preferably greater than πt, then all functions can be used. For example, when the battery 10 is folded in two, The battery 10 can be bent into a square or U-shape and incorporated into various electronic devices.

[0074] For example, when the battery 10 is wound in a cylindrical shape, it is possible to bend it 360 degrees. In order to deal with this, the distance d0 of the space 25 should be set to 2πt or more. In this case, the distance d0 of the space 25 should be set to an appropriate value accordingly. When the battery 10 is bent into a bellows shape, the direction and angle of the bent portion of the battery 10 and the bending The distance d0 of the space 25 can be set to an appropriate value depending on the number of parts.

[0075] This concludes the explanation of space 25.

[0076] [Example of manufacturing method] An example of a method for producing the battery 10 will be described below.

[0077] First, a flexible film that will become the exterior body 11 is prepared.

[0078] It is preferable to use a material with high water resistance and gas resistance for the film. The film used should be a laminated film made of a metal film and an insulating film. The metal film is preferably aluminum, stainless steel, nickel steel, gold, silver, Copper, titanium, chromium, iron, tin, tantalum, niobium, molybdenum, zirconium, zinc, etc. The insulating film may be a metal or alloy that can be used as a metal foil. Plastic films made of organic materials, organic materials (such as organic resins and fibers) and inorganic materials ( Hybrid material films containing inorganic materials (carbon, ceramic, etc.), carbon-containing inorganic films (carbon A single-layer film selected from the group consisting of a graphite film, a graphite film, and a combination of these. The metal film can be easily embossed, and Embossing to form protrusions increases the surface area of ​​the film exposed to the outside air. , and has excellent heat dissipation effect.

[0079] Next, the flexible film is embossed to create a wavy shape. An exterior body 11 having the above structure is formed.

[0080] The convex and concave portions of the film can be formed by pressing (e.g., embossing). The projections and recesses formed in the film by embossing serve to form a sealing structure. The film forms a variable volume closed space. It can be said that it is formed as a bellows structure. Also, a sealing structure using a film The structure is waterproof and dustproof. In addition, the embossing process, which is a type of press processing, It is also possible to use a method that can form a relief on a part of the film. Combination, for example embossing and other pressing processes, can be performed on one film. Also, multiple embossing processes may be performed on one film.

[0081] The convex portions of the film may be hollow semicircular, hollow semielliptical, hollow polygonal, or hollow indefinite. In the case of a hollow polygonal shape, it is possible to make the shape by having more angles than a triangle. , it is possible and preferable to reduce the concentration of stress at the corners.

[0082] An example of a schematic perspective view of the exterior body 11 thus formed is shown in FIG. 11 is a wavy surface of the battery 10 having a plurality of ridges 21 and valleys 22 arranged alternately. Here, adjacent ridges 21 and adjacent valleys 22 are arranged at equal intervals. It is preferable that

[0083] Next, a part of the exterior body 11 is folded so as to sandwich the laminated body 12 prepared in advance. At this time, the electrode 13 (electrode 13a or electrode 13b) connected to the laminate 12 is bent (FIG. 3(B)). It is preferable to adjust the length of the exterior body 11 so that the electrode 13b is exposed to the outside. The portion of the exterior body 11 that protrudes outward from the laminate 12 is connected to the rear joint 33 and the rear joint 34. Therefore, the width of the protruding portion is set to a sufficient length in consideration of the thickness of the laminate 12. do.

[0084] In FIG. 3B, a pair of portions 31 sandwiching the laminate 12 have waves with a phase difference of 180 degrees. In this example, the pair of portions 31 are arranged so as to be offset from each other. 2 shows a state in which the exterior body 11 is bent so that the grooves 21 and the valley lines 22 overlap each other. .

[0085] Here, the position of the bent portion 32 of the exterior body 11 and the shape of the bent portion 32 will be described. FIG. 4(A) is a schematic cross-sectional view of the exterior body 11. E) are the bending positions when the points P1 to P4 shown in FIG. 4(A) shows the cross-sectional shape of the bent portion 32. In the following, the direction shown by the arrow in FIG. In order to explain the case where the exterior body 11 is folded, the lower surface is placed on the outer surface of the battery 10. Therefore, in FIG. 4(A), the part protruding upward is called a valley line 22, and the part protruding downward is called a valley line 23. The portion is shown as edge 21.

[0086] In FIG. 4(B) to (E), the area surrounded by the bent portion 32 is hatched. Here, two positions where the periodicity of the wave of the exterior body 11 is broken are set as boundaries, and these The area sandwiched between the bent portions 32 is referred to as the bent portion 32. The shape of the bend 32 is exaggerated in the drawing, so its circumference may not be drawn correctly. do.

[0087] Point P1 is a point that coincides with valley line 22. As shown in FIG. 4(B), bending at point P1 In this way, the bent portion 32 can be formed into a substantially arc-shaped shape. This allows the opposing waves to be shifted 180 degrees out of phase.

[0088] Also, point P2 coincides with the ridge line 21. As shown in FIG. 4(C), the curve at point P2 When the bent portion 32 is bent, the bent portion 32 can be formed in a substantially arc shape. By raising the wave, the phase of the opposing waves can be shifted by 180 degrees.

[0089] Point P3 is between the ridge line 21 and the valley line 22 and is closer to the ridge line 21 than the midpoint between them. As shown in FIG. 4(D), the bending point is bent by being shifted from the ridge line 21 or the valley line 22. The shape of the bent portion 32 is not symmetrical but is distorted. The curve is made so that the ridges, valleys, and ridges and valleys of the opposing waves do not coincide with each other. It can be done.

[0090] Point P4 is a point that coincides with the midpoint between ridge line 21 and valley line 22. As shown in FIG. When bent at point P4, the shape of bent portion 32 becomes extremely irregular. The bent portion 32 is likely to have a shape that protrudes upward or downward. On the opposite side to the portion, it is difficult to keep a large distance between the laminate 12 and the inner wall of the exterior body 11. become.

[0091] Here, a common feature of Figs. 4(B), (C), and (D) is that the portion 31 A ridge line 21 is provided between the valley line 22 closest to the bent portion 32 and the bent portion 32. In particular, in FIG. 4B, the boundary of the bent portion 32 is aligned with the ridge line 21 of the wave. In this way, the ridges 21 of the two waves or their vicinity are the boundaries. As a result, the exterior body 11 is bent, and a wide area in the thickness direction is formed on the inside of the bent portion 32 and its vicinity. As described above, when the battery 10 is folded, the most space of the laminate can be secured. It is important to separate the electrodes located on the outside from the inner wall of the exterior body 11. By adopting such a shape, the distance can be made wider.

[0092] On the other hand, in FIG. 4(E), the valley line 2 closest to the bent portion 32 of the portion 31 on the lower surface side is There is no ridge line 21 between the bent portion 32 and the bent portion 32. In the vicinity of the insulating layer, a wide space in the thickness direction is unlikely to be formed.

[0093] Here, the portion of the exterior body 11 that becomes the bent portion 32 has a flat shape without a corrugated shape. For example, as shown in FIG. 5(A), a mold 51 having a flat surface is used. The outer casing is then pressed or pressed while being heated. A portion of the body 11 may be flattened.

[0094] A schematic cross-sectional view of exterior body 11 that has been partially flattened in this manner is shown in FIG. A part of exterior body 11 is flattened so as to connect ridge lines 21 to each other.

[0095] In FIG. 5(C), exterior body 11 is bent at point P5 in the center of the formed flat portion. As shown in FIG. 5(C), the flattened exterior body 11 is By forming the bent portion 32, a larger space can be formed than that shown in FIG. 4(B).

[0096] In addition, FIG. 5(D) and FIG. 5(E) show the results when the area is flattened over a wider area than that shown in FIG. 5(C). 5B, the edges 21 of the exterior body 11 are connected to each other. In this manner, the exterior body 11 is flattened over an area wider than the thickness of the laminate 12. By flattening the surface, a large space that is uniform in the thickness direction can be formed.

[0097] The above is an explanation of the relationship between the position of the bent portion and the shape of the bent portion.

[0098] As described above, after folding the exterior body 11 and sandwiching the laminated body 12, the exterior body 11 is joined. The portions that will become part 33 are joined by applying heat and pressure.

[0099] As shown in FIG. 6(A), the crimping is performed by clamping the exterior body 11 between a pair of dies 53 and 54 having flat surfaces. The mold 53 and the mold 54 are pressed together in a direction perpendicular to their surfaces. As a result, as shown in FIG. 6(B), the portion of the exterior body 11 that will become the joint portion 33 is flat. At this time, the mold 53 and the mold 54 are fixed so that they do not come closer than a certain point. It is preferable to provide a clearance. This ensures that the thickness of the joint is not thinner than a certain amount. This causes the conductive material (such as aluminum foil) in the film to become exposed, resulting in the breakdown of insulation. This can avoid problems such as the battery being damaged or degraded.

[0100] In order to make the joint 33 sufficiently flat, the pressure to form the later joint 34 is lower than that required for the pressure to form the joint 33. It is preferable to perform the bonding under the condition of the highest pressure possible. The pressure varies depending on the material and thickness of the exterior body. For example, when using a film with a thickness of about 110 μm, the pressure during compression is 100 kPa. Pa / cm 2 More than 1000kPa / cm 2 The range is as follows, typically 600kPa / c m 2 The temperature can be set to about the melting point of the material used for the fusion layer. For example, when polypropylene is used, it is preferable to set the angle to about 175 degrees.

[0101] In addition, the thickness of the joint 33 after the crimping is larger than the thickness of two of the exterior bodies 11 before the crimping. For example, the laminated film including the fusion layer in the exterior body is preferably formed so as to be thinner than the laminated film. When a film is used, the thickness of the fusion layer at the joint 33 after crimping is With respect to the thickness of the two fusion layers in the non-adhesive portions (such as the portion 31 of the battery 10 and the bent portion 32), 30% or more and 95% or less, preferably 50% or more and 90% or less, more preferably 60% or more and 80% or less. It is preferable that the ratio is 0% or less.

[0102] By forming the joint 33 under the above-mentioned conditions, the battery 10 can be folded repeatedly. Even if it is bent or deformed, the seal is not broken and it can be sealed inside the exterior body 11. This also makes it possible to prevent leakage of electrolyte and the like, thereby making the battery 10 extremely reliable and safe. In particular, as shown in FIG. 6A, the phase of the waves in the opposing parts of the exterior body 11 is 1. The joint 33 does not create a gap even if the battery 10 is deformed, even if the battery 10 is misaligned by 80 degrees. can be formed.

[0103] In FIG. 6(C), the force acting on each part of the exterior body 11 during bonding is shown diagrammatically by arrows. Here, the arrow is shown to be longer as the force increases.

[0104] A part of the exterior body 11, which was wavy before bonding, becomes flat by bonding, and The portion 3 of the exterior body 11 stretches in the stretching direction (indicated by the thick arrow). A pulling force is generated on the bent portion 32 side of the wire 1. The closer to the joint portion 33, the stronger this pulling force is. The distance from the joint 33 becomes smaller.

[0105] On the other hand, since the portion 31 has a corrugated shape, a resistance force is generated in the opposite direction to the above-mentioned force. The resistance increases as the distance from the bent portion 32 increases. The smaller it becomes.

[0106] As a result of the two types of forces as described above being applied to the portion 31 and the bent portion 32, the As shown in FIG. 1, the wave period of the portion 31 becomes continuous as it approaches the bent portion 32. The amount of stretch is greater closer to the joint 33. Since the distance from the bent portion 32 to the portion 31 becomes smaller, the central portion of the bent portion 32 is recessed toward the portion 31. become.

[0107] 6(E) and 6(F) are schematic cross-sectional views before and after forming the joint 33, respectively. As shown in FIG. 6(E), when the laminate 12 is in contact with the inner wall of the exterior body 11 before bonding, Even if the joint 33 is formed, the portion 31 of the exterior body 11 is stretched, so that the joint 33 may be formed as shown in FIG. The space 25 can be formed as shown in FIG.

[0108] In this manner, the flat joint portion 33 is formed, and the folded portion 32 and the laminate A space 25 can be formed between the first and second electrodes 12 .

[0109] Next, an electrolyte is introduced from the portion that will become the joint 34. The electrolyte is introduced under reduced pressure or in a vacuum. A desired amount of electrolyte is dropped onto the inside of the bag-shaped exterior body 11 in an active gas atmosphere.

[0110] Then, the portion to be the joint 34 is joined in the same manner as above. When the joint 34 is formed, the electrodes 13a and 13b are connected to the exterior body 11. An insulating sealing layer may be disposed between the electrodes 13a and 13b. The sealing layer melts during compression bonding to protect the electrodes 13a and 13b from damage. The electrode 13b and the film-like exterior body 11 are fixed to each other.

[0111] In this manner, the battery 10 shown in FIG. 1(A) etc. can be fabricated.

[0112] The above is a description of an example of a method for producing a battery.

[0113] [Battery shape] As described above, the space 25 is formed as a result of a part of the exterior body 11 expanding during the formation of the joint 33. That is, the distance d between the laminate 12 and the exterior body 11 in the space 25 is The distance d0 varies depending on the amount of elongation at the joint 33 of the exterior body 11. Therefore, as the film used for the exterior body 11, the film length with respect to the natural length of the wavy film is It is preferable to use a film which, when stretched, has a length ratio within the above range.

[0114] In addition, the greater the distance between the portion 31 and the joint 33, the smaller the amount of elongation. On the other hand, the greater the elongation of the joint 33, the greater the distance d0 becomes. Since the force acting on the joint 33 is large, the distance d0 can be increased even at a position far from the joint 33. Here, the amount of elongation of the joint 33 is different depending on the stretching direction of the joint 33 when the same film is used. It increases in proportion to the length of the direction.

[0115] FIG. 7 shows a schematic top view of the battery 10, which has a different aspect ratio from that of FIG. The length of the joint 33 in the extension direction is X, the distance between a pair of joints 33 (i.e., the width of the portion 31) is ) is Y1, the ratio of X to Y1 (i.e., the value of X / Y1) is 1 or more. For example, it is preferable to set the ratio of X to Y1 (X / Y1) to 1.2 or more. , 1.5 or more, 1.7 or more, 2 or more, or 3 or more. can be as large as you like, but considering productivity, it should be less than 100, or even less than 50. It is preferable to set the temperature at about 100° C.

[0116] In addition, if the width of the battery 10 including the joint portion 33 is Y2, the ratio of X to Y2 (X / Y 2) is, for example, 4 / 3 or 16 / 9, the ratio of the battery 10 to the electronic device This is preferable because it makes it easier to design the battery 10 and increases the versatility of the battery 10. When incorporating into a long and thin object such as a door, the ratio of X to Y2 (X / Y2) should be 1.5. It can be 1 or more, or 2 or more, or 3 or more, etc.

[0117] This concludes the explanation of the shape of the battery.

[0118] [About film processing methods] Next, a method for processing a film that can be used for exterior body 11 will be described.

[0119] First, a sheet made of a flexible substrate is prepared. The sheet is a laminate, and a metal film is The heat seal layer is provided on one or both sides of the heat seal layer. The heat-sealable resin film containing polypropylene, polyethylene, etc. is used. In the form of a sheet, a nylon resin is provided on the surface of an aluminum foil, A metal sheet with an acid-resistant polypropylene film on the back and a laminated polypropylene film on the back. This sheet is cut to prepare a film of the desired size.

[0120] Then, this film is embossed. As a result, the film has a concave and convex shape. The film has a plurality of concave and convex portions, so that the film can be visually recognized. It has a wavy pattern. In this example, the sheet is cut and then embossed. However, there is no particular restriction on the order in which the sheets are embossed before cutting, and then cut. Alternatively, the sheet may be folded and thermocompressed, and then cut.

[0121] The embossing process, which is a type of press working, will be described below.

[0122] Fig. 8 is a cross-sectional view showing an example of embossing. Note that embossing is a process in which depressions are formed on the surface. An embossing roll with projections is pressed against the film, creating projections and recesses that correspond to the projections and recesses of the embossing roll. The term "embossing roll" refers to the process of forming a pattern on a film. It is a chopped roll.

[0123] FIG. 8 shows an example of embossing on both sides of the film. The present invention relates to a method for forming a film having a protrusion having a protrusion portion.

[0124] FIG. 8 shows an embossing roll 55 in contact with one side of the film and an engraving roll 56 in contact with the other side. The film 50 is sandwiched between the embossing roll 56 and the film 50 in the film travel direction 6 The film is being fed to the printer at 0. The film is then patterned on the surface by pressure or heat. It is also possible to form a pattern on the film surface by using both pressure and heat.

[0125] Embossing rolls are available in a variety of materials, including metal rolls, ceramic rolls, plastic rolls, and rubber rolls. rolls, organic resin rolls, wood rolls, etc. can be used as appropriate.

[0126] FIG. 8 shows an embossing roll 56 which is a male embossing roll and an embossing roll 55 which is a female embossing roll. The embossing is performed using a male embossing roll 56 having a plurality of convex portions 56a. The protrusions correspond to the protrusions to be formed on the film to be processed. 55 has a plurality of protrusions 55a. The adjacent protrusions 55a form an embossed lower portion of the male pattern. The projections 56a on the guide 56 form recesses that fit into the projections formed on the film.

[0127] The embossing process makes a part of the film 50 raised, and the hollowing process makes a part of the film 50 recessed. By continuously pressing, it is possible to continuously form convex portions and flat portions. The film 50 can be patterned.

[0128] Next, a method for forming a film having a plurality of convex portions by a method different from that shown in FIG. FIG. 9 shows an example of embossing on one side of a film. This is a method for forming a film having protrusions with peaks on both sides.

[0129] FIG. 9(A) shows an embossing roll 55 in contact with one side of the film and a The film 50 is sandwiched between the roll 57 and the film 50, and is fed in the film travel direction 60. The roll 57 may be fixed and not rotated. In this case, the embossing roll 55 is provided on only one side of the film, so the film has multiple A protrusion is provided, but the protrusion does not have a space. That is, the protrusion protrudes from one surface and is recessed from the other surface. It is flat at

[0130] Next, as shown in FIG. 9(B), a frame having a convex portion formed on one side by embossing is formed. A part of the film 61 is removed. In this case, the protruding portion is in contact with the flat surface, i.e., the roll 57. The film is then partially removed from the surface that has been exposed to the laser. Thermal removal by irradiation of light, chemical removal by dripping etching solution, physical removal by tool There are also other options.

[0131] As a result, as shown in FIG. 9(C), a space 64 can be formed in the protrusion 63. In addition, a film 62 having protrusions 63 can be formed.

[0132] In the method for producing the film shown in each diagram of FIG. 9, a metal film is used as the film 50. Next, after the steps shown in FIG. 9(A) to FIG. 9(C), It is preferred that the film be provided with a heat seal layer on one or both sides.

[0133] As described above, by performing processing using an embossing roll, the processing device can be made smaller. In addition, since the film can be processed without being cut, it is suitable for mass production. In addition, the processing is not limited to the processing using an embossing roll, but may be, for example, a pair of embossing rolls having uneven surfaces. The film may be textured by pressing an embossing plate against the film. In this case, one of the embossing plates may be flat, and processing may be performed in a plurality of steps.

[0134] [Example of how to make a secondary battery] An example of a method for producing the battery 10, particularly a secondary battery, will be described below. Note that explanations of points that overlap with those described above may be omitted.

[0135] Here, a corrugated film-like exterior body 11 is folded in the center and two ends are overlapped. A method is used in which three sides are sealed with an adhesive layer.

[0136] The exterior body 11 including the corrugated film is bent into the state shown in FIG. 10(A). .

[0137] As shown in FIG. 10B, a positive electrode collector 72 and a separator 73 constitute a secondary battery. The positive electrode current collector 72 is laminated with the negative electrode current collector 74. A positive electrode active material layer is formed on a part of the surface of the negative electrode current collector 74. The positive electrode current collector 72 and the negative electrode current collector 74 are formed on a part of the surface. , stainless steel, gold, platinum, zinc, iron, nickel, copper, aluminum, titanium, tantalum, etc. Metals and their alloys, which have high electrical conductivity and combine with carrier ions such as lithium ions, Materials that do not oxidize can be used. In addition, silicon, titanium, neodymium, scandium Use aluminum alloys containing elements such as aluminum and molybdenum that improve heat resistance. Alternatively, the insulating layer may be formed of a metal element that reacts with silicon to form a silicide. Metal elements that react with silicon to form silicides include zirconium, titanium, Hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, The current collectors are available in foil, plate (sheet), mesh, cylinder, and copper. The shape of the sheet may be a roll, a punched metal, an expanded metal, or the like. It is recommended to use a current collector with a thickness of 5 μm to 40 μm. In order to simplify the process, the positive electrode current collector 72 on which the positive electrode active material layer is formed, the separator 73, the negative electrode active An example in which a combination of laminations of negative electrode current collectors 74 on which material layers are formed is combined and housed in an exterior body However, in order to increase the capacity of the secondary battery, multiple combinations are stacked and housed in an exterior body. do.

[0138] Then, two lead electrodes 76 having a sealing layer 75 shown in FIG. The electrodes 76 are also called lead terminals or tabs, and are used to connect the positive or negative electrodes of the secondary battery to the outside of the exterior film. The lead electrode 76 is provided to lead out to the side. For example, the positive lead is made of aluminum. The negative electrode lead is made of nickel-plated copper.

[0139] Then, the positive electrode lead and the protruding portion of the positive electrode current collector 72 are electrically connected by ultrasonic welding or the like. In addition, the negative electrode lead and the protruding portion of the negative electrode current collector 74 are electrically connected by ultrasonic welding or the like. Connect to.

[0140] In order to leave one side for inserting the electrolyte, the two sides of the film-like exterior body 11 are Then, the above-mentioned method is used to perform thermocompression bonding to form the joint 33. A desired amount of electrolyte is placed inside the bag-shaped film-like exterior body 11 in an inert gas atmosphere. Finally, the edge of the film that was left unbonded is heat-bonded. During the thermocompression bonding, the sealing layer 75 provided on the lead electrode is also melted, The lead electrodes and the film-like exterior body 11 are fixed together.

[0141] In this manner, the secondary battery 10 shown in FIG. 10(D) can be fabricated.

[0142] The film-like exterior body 11 which is the exterior body of the obtained secondary battery 10 has a wavy pattern. In addition, the area between the dotted line and the end in FIG. 10(D) is a joint 33 or a joint Part 34 is machined flat.

[0143] FIG. 10E shows an example of a cross section taken along the dashed line D1-D2 in FIG. 10D. vinegar.

[0144] As shown in FIG. 10(E), a positive electrode current collector 72, a positive electrode active material layer 78, a separator 73, a negative The electrode active material layer 79 and the negative electrode current collector 74 are laminated in this order, and then the laminate is wrapped in a folded film-like exterior. The end of the electrode is sealed by a joint 34. The remaining space is filled with The film-shaped exterior body 11 has an electrolyte 77 filled therein. can be.

[0145] The positive electrode active material used in the positive electrode active material layer 78 may have an olivine type crystal structure or a layered rock salt type There are composite oxides having a crystalline structure or a spinel-type crystalline structure. , such as LiFeO2, LiCoO2, LiNiO2, LiMn2O4, V2O5, Cr Compounds such as 2O5 and MnO2 are used.

[0146] Or, a composite material (general formula LiMPO4 (where M is Fe(II), Mn(II), Co( One or more of Ni(II) and Ni(II) can be used. Representative examples of the general formula LiMPO4 Examples include LiFePO4, LiNiPO4, LiCoPO4, LiMnPO4, and LiF e a Ni b PO4, LiFe a Co b PO4, LiFea Mn b PO4, LiNi a Co b PO4, LiNi a Mn b PO4 (a + b is less than or equal to 1, 0 < a < 1, 0 < b < 1), Li Fe c Ni d Co e PO4, LiFe c Ni d Mn e PO4, LiNi c Co d Mn e P O4 (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 (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.

[0147] 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. One 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 i (2-j) Fe k Ni l SiO4, Li (2-j) Fe k Co l SiO4, Li (2- j) Fe k Mn l SiO4, Li (2-j) Nik Co l SiO4, Li (2-j) Ni k Mn l SiO4 (k + l is 1 or less, 0 < k < 1, 0 < l < 1), Li (2-j) Fe m 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 (m + n + q is 1 or less, 0 < m < 1, 0 < n < 1, 0 < q < 1 ), Li (2-j) Fe r Ni s Co t Mn u SiO4 (r + s + t + u is 1 or less, 0 < r < 1, 0 < s < 1, 0 < t < 1, 0 < u < 1), etc. Lithium compounds can be used as materials .

[0148] 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) represented by the general formula NASICON-type compounds can be used. NASICON-type compounds include Fe2(MnO4 )3, Fe2(SO4)3, Li3Fe2(PO4)3, etc. Also, as the positive electrode active material , compounds represented by the general formula Li2MPO4F, Li2MP2O7, Li5MO4 (M = Fe, Mn), perovskite-type fluorides such as NaFeF3, FeF3, metal chalcogenides (sulfides, selenides, tellurides) such as TiS2, M oS2, and LiMVO4, etc. ​Oxides with an inverse spinel crystal structure, vanadium oxides (V2O5, V6O 13 , Materials such as LiV3O8, manganese oxides, and organic sulfur compounds can be used.

[0149] In addition, the carrier ion may be an alkali metal ion or an alkaline earth ion other than the lithium ion. In the case of metal ions, instead of lithium, an alkali metal (e.g., sodium) is used as the positive electrode active material. thorium, potassium, etc.), alkaline earth metals (e.g. calcium, strontium, barium, etc.), Sodium, beryllium, magnesium, etc. may also be used.

[0150] The separator 73 may be made of cellulose (paper) or polypropylene with holes. For example, an insulator such as polyethylene can be used.

[0151] The electrolytic solution 77 is an electrolyte in which carrier ions can move and A material containing lithium ions is used. Representative examples of the electrolyte are LiPF6, L iClO4, LiAsF6, LiBF4, LiCF3SO3, Li(CF3SO2)2N , Li(C2F5SO2)2N, and other lithium salts. Two or more of them may be used in any combination and in any ratio.

[0152] As the solvent for the electrolyte, a material in which carrier ions can move is used. The solvent is preferably an aprotic organic solvent. Representative examples of the aprotic organic solvent include , Ethylene carbonate (EC), Propylene carbonate, Dimethyl carbonate, Di Ethyl carbonate (DEC), γ-butyrolactone, acetonitrile, dimethoxyethane tetrahydrofuran, etc., and one or more of these can be used. By using a polymer material that gels as a solvent for the electrolyte, safety against leakage, etc. is improved. In addition, it is possible to make the storage battery thinner and lighter. Examples include silicone gel, acrylic gel, acrylonitrile gel, and polyethylene glycol. Examples of gels include oxide-based gels, polypropylene oxide-based gels, and fluorine-based polymer gels. In addition, a flame-retardant and non-volatile ionic liquid (room-temperature molten salt) was used as the solvent for the electrolyte. By using multiple batteries, the battery can withstand an internal short circuit or an increase in internal temperature due to overcharging. This can prevent the battery from exploding or catching fire. Ionic liquids have high ion mobility (conductivity). The ionic liquid includes an ionic liquid containing an ethylmethylimidazolium (EMI) cation. Liquid, or N-methyl-N-propylpiperidinium (PP 13 ) Cation-containing i On liquid etc.

[0153] In addition, instead of the electrolyte solution, a solid electrolyte having an inorganic material such as a sulfide or oxide is used. It is possible to use a solid electrolyte containing a polymer material such as PEO (polyethylene oxide). When a solid electrolyte is used, the installation of a separator or spacer becomes unnecessary. Since the entire battery can be made solid, there is no risk of leakage, and safety is dramatically improved.

[0154] The negative electrode active material of the negative electrode active material layer 79 may be formed by dissolving and depositing lithium or by dissolving lithium. Materials that allow ion insertion and desorption can be used, including metallic lithium, carbon-based materials, and alloys. Materials such as those based on fluorine can be used.

[0155] Metallic lithium has a low redox potential (-3.045 V vs. the standard hydrogen electrode) and is lightweight. and high specific capacity per volume (3860mAh / g and 2062mAh / cm 3 ) is therefore preferable.

[0156] Carbon-based materials include graphite, graphitizable carbon (soft carbon), and non-graphitizable carbon (hard carbon). carbon nanotubes, graphene, fullerene, carbon black, etc. There is.

[0157] Graphite includes mesocarbon microbeads (MCMB), coke-based artificial graphite, and pitted graphite. These include artificial graphite such as titanium-based artificial graphite, and natural graphite such as spheroidized natural graphite.

[0158] Graphite is formed when lithium ions are inserted into graphite (lithium-graphite intercalation compound is formed) It shows a low potential similar to that of metallic lithium (0.1V to 0.3V vs.Li / L i + This allows the lithium-ion secondary battery to exhibit a high operating voltage. Graphite has a relatively high capacity per unit volume, a small volume expansion, is inexpensive, and is a metal. It is preferable because it has advantages such as higher safety compared to lithium.

[0159] As a negative electrode active material, it can carry out charge and discharge reactions by alloying and dealloying reactions with lithium. Possible alloy materials or oxides can also be used. In this case, the alloy material may be, for example, Al, Si, Ge, Sn, Pb, Sb, Bi The material includes at least one of Ag, Au, Zn, Cd, In, Ga, etc. Such elements have a large capacity compared to carbon, and silicon in particular has a theoretical capacity of 4200mAh / g Therefore, it is preferable to use silicon as the negative electrode active material. Examples of alloy materials using elements include Mg2Si, Mg2Ge, Mg2Sn, and Sn S2, V2Sn3, FeSn2, CoSn2, Ni3Sn2, Cu6Sn5, Ag3Sn ,Ag3Sb,Ni2MnSb,CeSb3,LaSn3,La3Co2Sn7,CoS Examples include b3, InSb, SbSn, etc.

[0160] In addition, the negative electrode active material is SiO, SnO, SnO2, titanium dioxide (TiO2), lithium Li4Ti5O 12 ), lithium-graphite intercalation compound (Li x C6) , niobium pentoxide (Nb2O5), tungsten oxide (WO2), molybdenum oxide (MoO 2) and other oxides can be used. Note that SiO refers to SiO containing silicon-rich portions. It refers to powder of silicon oxide, SiO y It can also be written as (2>y>0). For example, SiO is a material containing one or more selected from Si2O3, Si3O4, or Si2O It also includes a mixture of Si powder and silicon dioxide SiO2. SiO2 can also contain other elements (carbon, Nitrogen, iron, aluminum, copper, titanium, calcium, manganese, etc. That is, SiO is single crystal Si, amorphous Si, polycrystalline Si, Si2O3, Si3O4, It refers to a material containing multiple materials selected from SiO and SiO2. SiO is also a colored material. It is not SiO but SiO x (x is 2 or more), it is colorless, transparent, or white. However, secondary batteries are made using SiO as the material. If SiO is oxidized after repeated charging and discharging, it will change to SiO2. There are cases like this.

[0161] In addition, the negative electrode active material is a composite nitride of lithium and transition metals, which has a Li3N structure. Li 3-x M x N (M=Co, Ni, Cu) can be used. For example, Li 2. 6Co 0.4 N3 has a large charge / discharge capacity (900mAh / g, 1890mAh / cm 3 )of This is preferable.

[0162] When a composite nitride of lithium and transition metals is used, the negative electrode active material contains lithium ions, In addition, materials that do not contain lithium ions, such as V2O5 and Cr3O8, are used as the positive electrode active material. In addition, when a material containing lithium ions is used as the positive electrode active material, However, by first removing the lithium ions from the positive electrode active material, As the nitride, a complex nitride of lithium and a transition metal can be used.

[0163] In addition, a material that undergoes a conversion reaction can be used as the negative electrode active material. For example, lithium oxide such as cobalt oxide (CoO), nickel oxide (NiO), and iron oxide (FeO) A transition metal oxide that does not undergo an alloying reaction with the metal may be used as the negative electrode active material. Further materials that can cause reactions include Fe2O3, CuO, Cu2O, RuO2, Cr2 Oxides such as O3, CoS 0.89 , NiS, CuS and other sulfides, Zn3N2, Cu3N, Nitrides such as Ge3N4, phosphides such as NiP2, FeP2, CoP3, FeF3, BiF This also occurs with fluorides such as 3. Note that the above fluorides have a high potential, so they are not used as positive electrode active materials. It's fine.

[0164] In addition to the above-mentioned negative electrode active material, the negative electrode active material layer 79 contains a material for improving the adhesion of the active material. The negative electrode active material layer 79 may contain a binder, a conductive assistant, etc. for increasing the conductivity of the negative electrode active material layer 79. good.

[0165] The secondary battery is configured as follows: for example, the thickness of the separator 73 is about 15 μm or more and about 30 μm or less; The positive electrode current collector 72 is about 10 μm or more and about 40 μm or less, and the positive electrode active material layer 78 is about 50 μm or more and about 100 μm or less, the negative electrode active material layer 79 is about 50 μm or more and about 100 μm or less, and the negative electrode current collector 74 The thickness of the film-like exterior body 11 may be set to about 5 μm or more and about 40 μm or less. The protrusions in the film-like exterior body 11 are about 20 μm or more and about 500 μm or less. The height of the protrusions in the film-like exterior body 11 is about 5 μm or more and about 400 μm or less. If the height of the portion is 2 mm or more, the thickness of the entire secondary battery becomes too thick.

[0166] It is preferable that the capacity of a battery per unit volume is large. The capacity of a battery per unit volume is expressed as follows: The larger the volume of the battery portion of the entire secondary battery, the larger the capacity of the film-shaped exterior body 11 When the height of the protrusions in the secondary battery is increased and the thickness of the entire secondary battery is increased, the area per unit volume of the secondary battery is increased. The proportion of batteries becomes smaller and the capacity of the batteries also becomes smaller.

[0167] In addition, a layer made of polypropylene is provided on the surface of the film to be laminated. Only the thermocompression bonded portion becomes the adhesive layer.

[0168] FIG. 10(E) shows an example in which the lower side of the film-like exterior body 11 is fixed and pressure-bonded. In this case, the upper part is bent significantly and a step is formed, so the bent part When a plurality of combinations of the above-mentioned laminations, for example, eight or more combinations, are provided between the film-like exterior body 11, If the step is large, there is a risk that too much stress will be applied to the upper film-like exterior body 11. In addition, this causes a large misalignment between the end of the upper film and the end of the lower film. In that case, there may be a step on the lower film to prevent the edge from being misaligned. Alternatively, a pressure may be applied at the center so that the stress is uniform.

[0169] In addition, if a large misalignment occurs, part of the edge of one film may be stuck to the other film. There is an area that does not overlap with the film. Cut out this area and attach it to the edge of the upper film and the lower The edges of the films may be aligned to correct the misalignment.

[0170] Here, the flow of current during charging of a secondary battery will be explained with reference to FIG. When a secondary battery is considered as a closed circuit, the movement of lithium ions and the flow of electric current are in the same direction. In secondary batteries that use lithium, the anode and cathode are charged and discharged. (cathode) is switched, and the oxidation and reduction reactions are switched, so the reaction potential The electrode with the higher reaction potential is called the positive electrode, and the electrode with the lower reaction potential is called the negative electrode. In this case, even if the battery is charging, discharging, or applying a reverse pulse current, Even when an electric current flows through it, the positive electrode is called the "positive electrode" or "+ electrode (plus electrode)" and the negative electrode is The negative electrode is called the "negative electrode" or "-electrode (minus electrode)". When the terms anode (positive electrode) and cathode (negative electrode) are used, the following occurs during charging and discharging: This can be confusing because the anode and cathode are the opposite. The term "cathode" is not used in this specification. When using the terms cathode and positive electrode, specify whether they are charging or discharging. It will also be indicated whether it corresponds to a positive pole (positive pole) or a negative pole (negative pole).

[0171] A charger is connected to the two terminals shown in FIG. 11 to charge the battery 10. As the charge advances, the potential difference between the electrodes increases. Electrons flow toward the positive electrode current collector 72, and within the battery 10, electrons flow from the positive electrode current collector 72 to the negative electrode current collector The direction of the current flowing from the negative electrode to the external terminal of the battery 10 is called the positive direction. In other words, the direction of the current is the same as the direction of the charging current.

[0172] [Example of electrode laminate] An example of the structure of a laminate having a plurality of laminated electrodes will be described below.

[0173] FIG. 12(A) shows a positive electrode current collector 72, FIG. 12(B) shows a separator 73, and FIG. 12(C) shows a negative electrode 12(D) shows a sealing layer 75 and a lead electrode 76; FIG. 12(E) shows a film 1A and 1B are top views of the respective exterior bodies 11 having the shape shown in FIG.

[0174] In each figure of FIG. 12, the dimensions are approximately equal, and the dimensions enclosed by the dashed line in FIG. 12(E) are The area 71 has almost the same dimensions as the separator in FIG. 12(B). The regions between the dashed lines and the ends are joints 33 and 34, respectively.

[0175] FIG. 13(A) shows an example in which a positive electrode active material layer 78 is provided on both sides of a positive electrode current collector 72. In detail, the negative electrode current collector 74, the negative electrode active material layer 79, the separator 73, the positive electrode active material layer 7 8, positive electrode current collector 72, positive electrode active material layer 78, separator 73, negative electrode active material layer 79, negative electrode current collector 74 are arranged in this order. is shown in Figure 13(B).

[0176] In addition, although an example using two separators is shown in FIG. 13(A), one The separator is folded and both ends are sealed to form a bag, and the positive electrode current collector 72 is housed in the bag. It is also possible to use a structure in which the positive electrode current collector 72 is housed in a pouch-shaped separator. A positive electrode active material layer 78 is formed.

[0177] It is also possible to provide the negative electrode active material layer 79 on both sides of the negative electrode current collector 74. In FIG. 1C, a negative electrode current collector 74 is disposed between two negative electrode current collectors 74 each having a negative electrode active material layer 79 on only one side thereof. Three negative electrode current collectors 74 each having a negative electrode active material layer 79 and four positive electrode current collectors 76 each having a positive electrode active material layer 78 on both sides. This shows an example of a secondary battery having one positive electrode current collector 72 and eight separators 73 sandwiched therebetween. In this case, too, instead of using eight separators, four pouch-shaped separators may be used.

[0178] By increasing the number of layers, the capacity of the secondary battery can be increased. A positive electrode active material layer 78 is provided on both sides of the negative electrode current collector 74, and a negative electrode active material layer 79 is provided on both sides of the negative electrode current collector 74. This allows the thickness of the secondary battery to be reduced.

[0179] FIG. 14(A) shows a structure in which a positive electrode active material layer 78 is provided on only one side of a positive electrode current collector 72 and a negative electrode current collector 74 is provided on only one side of the negative electrode current collector 74. The figure shows a secondary battery formed by providing a negative electrode active material layer 79 on only one side of the battery. Then, the negative electrode active material layer 79 is provided on one surface of the negative electrode current collector 74, and the negative electrode active material layer 79 is in contact with the negative electrode active material layer 79. The separator 73 is laminated so that the negative electrode active material layer 79 is not in contact with the separator 73. The surface of the positive electrode current collector 73 is the positive electrode active material layer 78 formed on one side of the positive electrode current collector 72. On the surface of the positive electrode current collector 72, another positive electrode active material layer 78 is provided on one side. In this case, the positive electrode current collector 72 is in contact with the positive electrode active material layer 78. The separators 7 are then arranged so that the surfaces on which the separators 7 are not formed face each other. 3 is formed on one side of the negative electrode current collector 74, and the negative electrode active material layer 79 is formed on the other side of the negative electrode current collector 74. The laminated structure of FIG. 14(A) is cut by a plane 90. A cross-sectional view of the device is shown in FIG.

[0180] In FIG. 14(A), two separators are used, but one separator is folded and both are The ends are sealed to form a bag shape, and two positive electrode current collectors 72 with a positive electrode active material layer 78 disposed on one side are placed between the two. You can also insert one sheet.

[0181] FIG. 14(C) shows a diagram in which a plurality of the laminated structures of FIG. 14(A) are laminated. In the negative electrode current collector 74, the surfaces on which the negative electrode active material layer 79 is not formed are arranged facing each other. In FIG. 14(C), twelve positive electrode current collectors 72, twelve negative electrode current collectors 74, and twelve 1 shows how separators 73 are stacked.

[0182] A positive electrode active material layer 78 is provided on only one surface of the positive electrode current collector 72, and a negative electrode active material layer 78 is provided on only one surface of the negative electrode current collector 74. The structure in which the positive electrode active material layer 79 is provided and laminated is such that the positive electrode active material layer 78 is provided on both sides of the positive electrode current collector 72. In comparison with a structure in which the negative electrode active material layer 79 is provided on both sides of the negative electrode current collector 74, the thickness of the secondary battery is However, if the positive electrode active material layer 78 of the positive electrode current collector 72 is not formed, The surface of the positive electrode current collector 72 is opposed to a surface of the positive electrode current collector 72 on which the positive electrode active material layer 78 is not formed. Similarly, the negative electrode active material layer 79 of the negative electrode current collector 74 is formed. The surface on which the negative electrode active material layer 79 is not formed faces the surface of another negative electrode current collector 74 on which the negative electrode active material layer 79 is not formed. Metals are in contact with each other. When metals are in contact with each other, friction is strong. The surfaces where the metals are in contact tend to slide easily. When the secondary battery is inserted, the metal slides inside the battery, making it easy to bend.

[0183] The protruding portions of the positive electrode current collector 72 and the negative electrode current collector 74 are also called tab portions. When bending the secondary battery, the tabs of the positive electrode current collector 72 and the negative electrode current collector 74 are easily cut off. This is because the tab part has a long and narrow shape and is prone to stress at the base of the tab part. This is the case.

[0184] A positive electrode active material layer 78 is provided on only one surface of the positive electrode current collector 72, and a negative electrode active material layer 78 is provided on only one surface of the negative electrode current collector 74. The structure in which the electrode active material layer 79 is provided and laminated is such that the surfaces where the positive electrode current collectors 72 contact each other and the surfaces where the negative electrode current collectors The surfaces where the current collectors 74 contact each other have low friction resistance, and the battery is deformed. In addition, the positive electrode current collector 72 can be easily released from the stress caused by the difference in the radius of curvature when the positive electrode current collector 72 is rotated. A positive electrode active material layer 78 is provided on only one surface of the negative electrode current collector 74, and a negative electrode active material layer 79 is provided on only one surface of the negative electrode current collector 74. Since the total thickness of the tab portion also increases in the laminated structure, the positive electrode active material is applied to both sides of the positive electrode current collector 72. In comparison with a structure in which a negative electrode active material layer 79 is provided on both sides of the negative electrode current collector 74, the stress is distributed This spreads the wire out and makes it less likely to break at the tab.

[0185] When stacking in this manner and fixing and electrically connecting all the positive electrode current collectors 72, Furthermore, in addition to the positive electrode current collector 72, the lead electrode is also overlapped and ultrasonically welded. Sonic welding provides an efficient method of making electrical connections.

[0186] By overlapping the tab with the tab of another positive electrode current collector and applying pressure while applying ultrasonic waves, Ultrasonic welding can be performed.

[0187] The separator 73 prevents the positive electrode current collector 72 and the negative electrode current collector 74 from being electrically shorted. For example, as shown in FIG. 15(A), each separator 73 If the width of the positive electrode current collector 72 and the negative electrode current collector 74 is made larger than that of the positive electrode current collector 72 and the negative electrode current collector 74, deformation such as bending may occur. Even if the relative positions of the positive electrode current collector 72 and the negative electrode current collector 74 are misaligned, they do not come into contact with each other. In addition, as shown in FIG. 15(B), a single separator 73 is used. The separator 73 may be folded in a belly shape or may be folded in a manner similar to that shown in FIG. 15(C) in which one separator 73 is connected to a positive electrode current collector 72. When the positive electrode current collector 72 and the negative electrode current collector 74 are wound alternately, This is preferable because the two do not come into contact even if the relative positions are misaligned. A part of the separator 73 is provided so as to cover the side surface of the laminated structure of the positive electrode collector 72 and the negative electrode collector 74. The following shows an example of a

[0188] In addition, although the positive electrode active material layer 78 and the negative electrode active material layer 79 are not shown in each drawing of FIG. The above-mentioned methods for forming these may be used. In the above example, the positive electrode current collectors 72 are alternately arranged. The negative electrode current collectors 74 may be configured to be continuous with each other.

[0189] In this embodiment, a rectangular film is folded in the center and the two edges are overlapped to seal it. However, the shape of the film is not limited to a rectangle. The shape may be any shape with symmetry other than a rectangle, such as a polygon such as a square, a circle, or a star.

[0190] In this embodiment, an example of a small battery for use in a portable information terminal or the like is shown, but the present invention is not particularly limited. The present invention can be applied not only to batteries but also to large batteries to be mounted on vehicles, etc.

[0191] In this embodiment, an example in which the present invention is applied to a lithium ion secondary battery has been shown. One aspect of the invention is not limited to this. Various secondary batteries, for example, lead acid batteries, lithium ion batteries, etc. Polymer secondary battery, nickel-metal hydride battery, nickel-cadmium battery, nickel Iron batteries, nickel-zinc batteries, silver oxide-zinc batteries, solid-state batteries, air batteries, etc. Alternatively, the present invention can be applied to various power storage devices, for example. For example, it can be applied to primary batteries, capacitors, lithium ion capacitors, etc. In addition, solar cells, optical sensors, touch sensors, display devices, FPCs (flexible printing) substrate), optical films (polarizing plates, retardation plates, prism sheets, light reflecting sheets, light diffusing sheets It is also possible to apply this to other applications such as

[0192] This embodiment may be combined, at least in part, with other embodiments described in this specification. It can be implemented in combination.

[0193] (Embodiment 2) In this embodiment, a battery obtained by using the first embodiment, particularly a battery incorporating a secondary battery, is used. An example of a child device is shown.

[0194] The secondary battery obtained by using the first embodiment has a thin and flexible film exterior. This allows it to be deformed into a flexible shape.

[0195] Do not allow parts of electronic equipment, such as a watch, to come into contact with parts of the user's body (wrist, arm, etc.). In other words, by having a user wear an electronic device, the user feels that the electronic device is lighter than its actual weight. The electronic device has an exterior shape with a curved surface that fits a part of the user's body. By using flexible secondary batteries, the secondary batteries can be fixed in a shape suitable for electronic devices. It can be installed.

[0196] In addition, when the user moves the part of the body where the electronic device is worn, the electronic device may move along with the part of the body. Even if the electronic device has a curved surface, the user feels uncomfortable and perceives the electronic device as a nuisance. Therefore, flexible secondary batteries are used in parts of electronic devices that may be deformed. By providing a pond, at least a part of the electronic device can be deformed according to the movement of the body. It is possible to provide an electronic device that does not cause a user to feel uncomfortable. .

[0197] Alternatively, the external shape of the electronic device is not limited to curved or complex shapes, but may be simple. For example, in an electronic device with a simple external shape, The number and size of components that can be housed in a device are determined by the volume of space created by the electronic device's housing. In many cases, a flexible secondary battery is placed in the gap between other components, This makes it possible to effectively utilize the space defined by the housing of the child device, and also allows for miniaturization.

[0198] In addition, wearable devices include wearable cameras, wearable microphones, Wearable input devices such as wearable sensors, wearable displays, and wearable Wearable output devices such as wearable speakers and wearable devices that combine these functions This includes input / output terminals. In addition, wearable devices are devices that can control each device, calculate data, or includes a processing device, typically a wearable computer having a CPU. A wearable device is a device that stores, transmits, and receives data. Generally speaking, this also includes portable information terminals and memory.

[0199] As an example of an electronic device that uses a secondary battery with a flexible shape, Display devices such as front displays and goggle displays, televisions (television receivers), (also called a mobile phone), personal computers such as desktop computers and notebook computers, monitors, digital cameras, digital video cameras, digital photo frames, Child notebooks, e-book terminals, electronic translators, toys, voice input devices such as microphones, electric shells, etc. electric toothbrushes, microwave ovens and other high-frequency heating devices, electric rice cookers, electric washing machines, electric sweepers Air conditioners such as vacuum cleaners, water heaters, electric fans, hair dryers, humidifiers, dehumidifiers, and air conditioners Equipment, dishwasher, dish dryer, clothes dryer, futon dryer, electric refrigerator, electric freezer, Air-freezer refrigerators, freezers for storing DNA, flashlights, power tools, smoke detectors, gas alarms and fire extinguishers Security alarms and other alarm systems, industrial robots, hearing aids, cardiac pacemakers, X-ray equipment, Radiation measuring devices, health and medical equipment such as electric massagers and dialysis machines, mobile phones (mobile Telephones, also known as mobile phone devices, portable game machines, personal digital assistants, lighting devices, headphones , stereos, remote controllers, clocks such as table clocks and wall clocks, cordless telephones Mobile or stationary devices such as mobile phones, transceivers, pedometers, calculators, digital audio players, etc. Examples include audio playback devices and large game machines such as pachinko machines.

[0200] In addition, the secondary battery having a flexible shape can be attached to the inner or outer walls of a house or a building, or to an automobile. It can also be incorporated into curved interior or exterior surfaces of a vehicle.

[0201] FIG. 16A shows an example of a mobile phone. A mobile phone 7400 includes a housing 740. In addition to the display unit 7402 incorporated in the 1, the operation buttons 7403, the external connection port 7404, The mobile phone 7400 is equipped with a speaker 7405, a microphone 7406, and the like. It has a secondary battery 7407.

[0202] FIG. 16B shows the mobile phone 7400 in a curved state. When the 00 is deformed by an external force and curved, the secondary The secondary battery 7407 is also bent. At this time, the state of the bent secondary battery 7407 is as shown in FIG. C). The secondary battery 7407 is a laminated structure storage battery (laminated structure battery, film exterior The secondary battery 7407 is fixed in a bent state. The secondary battery 7407 has a lead electrode 7408 electrically connected to a current collector 7409. For example, the exterior film of the secondary battery 7407 is embossed, This structure has high reliability even when the battery 7407 is bent. The 7400 has a slot for inserting a SIM card and a USB device such as a USB memory stick. A connector portion for connecting the sensor may be provided.

[0203] Figure 16(D) shows an example of a bendable mobile phone. If it is bent into a certain shape, it can be made into a bangle-type mobile phone as shown in FIG. The phone 7100 includes a housing 7101, a display unit 7102, an operation button 7103, and a secondary battery 71 FIG. 16F shows the secondary battery 7104 in a bent state. When the device 104 is bent and worn on the user's arm, the housing is deformed and the secondary battery 7104 is Part or all of the curvature changes. Specifically, the radius of curvature is between 10 mm and 150 mm. Within the range, a part or the whole of the main surface of the case or the secondary battery 7104 changes. The secondary battery 7104 has a lead electrode 7105 electrically connected to a current collector 7106. For example, a press process is used to form multiple projections and recesses on the surface of the film of the exterior body of the secondary battery 7104. The secondary battery 7104 has been bent many times with its curvature changed, resulting in high reliability. The mobile phone 7100 is designed to maintain reliability. It is equipped with a slot for connecting a USB memory stick and a connector for connecting a USB device. Also, when the central part of the mobile phone shown in FIG. 16(D) is folded, the mobile phone shown in FIG. ) You can also fold the center of the mobile phone further to make it look like this. As shown in FIG. 16(H), the ends of the mobile phone are overlapped to make it smaller and fit in the user's pocket. In this way, the mobile phone shown in FIG. 16(D) can be made to a size that can be inserted into a mobile phone. It is an electronic device that can change shape, and in order to achieve this, it must have at least a housing of 7 It is desirable that the display portion 7102 and the secondary battery 7104 have flexibility.

[0204] FIG. 17(A) shows an example of a vacuum cleaner. By providing a secondary battery in the vacuum cleaner, It can be made cordless, and the inside of the vacuum cleaner has a dust collection space to suck up and store dirt. Therefore, the smaller the space occupied by the secondary battery 7604, the better. and a bendable secondary battery 7604 is disposed between the outer surface and the dust collection space. It is useful to do so.

[0205] The vacuum cleaner 7600 includes an operation button 7603 and a secondary battery 7604. FIG. 7(B) shows the secondary battery 7604 in a bent state. The secondary battery 7604 is attached to the filter of the exterior body. The embossing is done on the surface of the battery, so the secondary battery 7604 has a highly reliable structure even when bent. The secondary battery 7604 is composed of a lead electrode 7601 electrically connected to the negative electrode, It has a lead electrode 7602 electrically connected to the positive electrode.

[0206] As an example of a secondary battery in which one current collector is exposed on one short side of the exterior body, FIG. 17C shows a secondary battery 7605 in a bent state. 7605, a part of the positive electrode current collector 72 is exposed from one short side of the exterior body, and the other short side of the exterior body is exposed. A part of the negative electrode current collector 74 is exposed from the side of the secondary battery 7605. The outer casing is also embossed, making it bendable and highly reliable. Alternatively, one lead electrode may be exposed on one short side.

[0207] The thin secondary battery 7604 is manufactured by the method for manufacturing the laminated secondary battery shown in the embodiment mode 1. It can be prepared using

[0208] The thin secondary battery 7604 has a laminate structure and is bent and fixed. The vacuum cleaner 7600 has a display unit 7606 that displays the remaining power of a thin secondary battery 7604. The display surface of the display unit 7606 is curved to match the shape of the outer surface of the vacuum cleaner. The vacuum cleaner has a connection cord for connecting to an outlet, and is equipped with a thin secondary battery 7. Once the 604 has enough power charged, you can unplug the cord and use the vacuum cleaner. In addition, the thin secondary battery 7604 is charged wirelessly without using a connection cord. You may go.

[0209] In addition, by installing bendable secondary batteries in vehicles, hybrid vehicles (HEVs), Next-generation clean energy vehicles such as electric vehicles (EV) and plug-in hybrid vehicles (PHEV) This will also enable agricultural machinery and motorized bicycles, including electrically assisted bicycles. Cars, motorcycles, electric wheelchairs, electric carts, small or large boats, submarines, fixed-wing aircraft and rotary For use in moving vehicles such as aircraft, rockets, satellites, space probes, planetary probes, and spacecraft. It can also be equipped with a bendable secondary battery.

[0210] 18A and 18B show examples of vehicles using one embodiment of the present invention. 8100 is an electric vehicle that uses an electric motor as a power source for running; or The vehicle can be powered by either an electric motor or an engine. Hybrid vehicles are used in automobiles. When installing a laminated secondary battery in a vehicle, multiple laminations are required. A battery module that integrates laminated secondary batteries is installed in one or more locations. By using one embodiment of the present invention, the secondary battery itself can be made smaller and lighter. For example, a secondary battery with a curved surface can be installed on the inside of the tire to realize a vehicle with a long driving range. In addition, secondary batteries of various shapes can be placed in the gaps of the vehicle, This allows for more space for cars and passengers inside the vehicle. The secondary battery not only drives the electric motor, but also the headlights 8101 and the room light. The light emitting device, such as a light bulb (not shown), can be powered.

[0211] In addition, the secondary battery is used for the displays of the automobile 8100 such as the speedometer and tachometer. The secondary battery can supply power to the navigation device of the automobile 8100. The present invention can provide power to semiconductor devices such as gating systems.

[0212] The automobile 8200 shown in FIG. 18B has a plug-in secondary battery. It is possible to charge the battery by receiving power from an external charging facility using a contactless charging method or other methods. FIG. 18B shows a case where a charging device mounted on a vehicle 8200 is connected to a ground-mounted charging device 8021. The secondary battery is shown being charged via a cable 8022. Charging methods and connector standards are specified using CHAdeMO (registered trademark) or Combo. The charging device 8021 may be a charging station installed in a commercial facility. It may also be a household power source. For example, plug-in technology allows for an external power supply. The secondary battery mounted on the automobile 8200 can be charged by the ACDC. This can be achieved by converting AC power into DC power via a conversion device such as a converter.

[0213] Although not shown, a power receiving device is mounted on the vehicle and receives power from a ground power transmitting device in a non-contact manner. In this case, the power transmission device is installed on the road or on the exterior wall. By incorporating this, charging can be done not only when the vehicle is stopped but also while the vehicle is moving. The power transmission method may be used to transmit and receive power between two vehicles. A solar cell may be provided on the exterior of the vehicle to charge the secondary battery when the vehicle is stopped or running. For contactless power supply, an electromagnetic induction method or a magnetic field resonance method can be used.

[0214] According to one aspect of the present invention, the degree of freedom in the installation location of the secondary battery is increased, and vehicle design can be made more efficient. According to one embodiment of the present invention, the characteristics of a secondary battery can be improved. Therefore, the secondary battery itself can be made small and lightweight. This will contribute to reducing the weight of the vehicle, which will improve the vehicle's range. The secondary battery mounted on the vehicle can also be used as a power supply source for other purposes besides the vehicle. It is possible to avoid using commercial power sources during peak power demand periods.

[0215] This embodiment may be combined, at least in part, with other embodiments described in this specification. It can be implemented in combination. EXAMPLES

[0216] In this example, a bendable battery as exemplified in Embodiment 1 is used as a battery according to one embodiment of the present invention. We will explain the results of making a battery (lithium ion secondary battery) that can be used for Reveal.

[0217] Lithium-ion secondary batteries use LiCoO2 as the positive electrode active material and The product is made of graphite and has an embossed aluminum laminate film for the exterior. The cathode was fabricated according to the fabrication method exemplified in Example 1. Six copper foil collectors with a negative electrode active material layer on one side and six copper foil collectors with a negative electrode active material layer on the other side were alternately laminated. The thickness of the electrode laminate was about 1.5 mm.

[0218] The exterior is made of polypropylene, aluminum foil, and nylon laminated in that order, with a thickness of approximately A 110μm aluminum laminate film was used. The wave pitch was 2mm, and the convex and concave portions The film was processed so that the difference in height was 0.5 mm.

[0219] The film is joined using a mold (heat bar) with a flat surface. The pair of joining layers (side seals) perpendicular to the ridges and valleys of the waves were A 1mm heat bar is used, and the pressure is 600kPa / cm 2 , and press at a temperature of 175 degrees. On the other hand, the bonding layer (top seal) parallel to the ridges and valleys of the waves was formed. A 2mm wide heat bar with a groove at the position opposite the board was used, and a pressure of 125kP was applied. a / cm 2 It was formed by pressing at a temperature of 175 degrees.

[0220] Here, two types of samples were prepared as follows. One was a sample with a bent part. The film is then folded so that the phase of the waves in the overlapping areas is shifted by approximately 180 degrees. The film was folded so that the ridges and valleys of the waves roughly overlapped. The sample was prepared as sample 1. The flattening was performed using a heat bar press method with a pressure of 60 kPa. / cm 2 At a temperature of 100 degrees, the area of ​​about 6 mm width bounded by the ridge of the wave is flat. The transformation was carried out.

[0221] The other is that the waves are in phase with each other, i.e. the crest of one side overlaps with the valley of the other side. The film was folded as shown in Fig. 2 and used as sample 2.

[0222] The two samples were subjected to X-ray computed tomography (X-ray computed tomography). The inside of the secondary battery was observed using a raphy.

[0223] 19(A) and (B) show the external appearance of sample 1, and FIG. 19(C) and (D) show the external appearance of sample 2. As shown in the photographs, the joints of both Sample 1 and Sample 2 are extremely flat. In both cases, the film was formed at the center near the edge of the film. A part of the film is deformed so that the wave period is longer and the wave amplitude is smaller than that of the It was confirmed that this was the case.

[0224] 20(A) and (B) show X-ray photographs taken of Sample 1. FIG. 20(A) is a plan view, and FIG. 20(B) is a lateral view. The bend is curved so that the farther it is from the joint (side seal), the more inward it is positioned. In addition, as shown in FIG. 20(B), the electrode laminate and the filter It was found that a space was formed between the

[0225] 21(A) and (B) show X-ray photographs taken of sample 2. Similarly, the bent part is curved inward as it moves away from the joint. It was also found that a space was formed between the electrode laminate and the film. I did.

[0226] FIG. 22(A) shows an enlarged X-ray CT image of the bent portion of sample 1 viewed from the lateral direction. In sample 1, the shape of the bent part is a beautiful arc that is roughly symmetrical. From this photograph, it was also found that the distance between the electrode laminate and the inner wall of the film was It was about 2.2 mm near the center and about 2.0 mm near the edge. As shown in the figure, the folded parts of the film are formed to connect the ridges of the waves, The space inside the film is wide in the thickness direction, and the end of the electrode laminate is in contact with the surface of the film. It was confirmed that this was not the case.

[0227] FIG. 22(B) shows an enlarged X-ray CT image of the bent portion of sample 2 viewed from the lateral direction. In sample 2, the shape of the folded part is asymmetrical and irregular. In addition, in sample 2, the distance between the electrode laminate and the inner wall of the film was approximately 2.4 m at maximum. While there is a part of m, there is also a narrow part of about 1.3 mm, which is sufficient compared to sample 1. It was found that the space was not secured. Furthermore, as shown in FIG. 22(B), One end of the body is in contact with the film, so when the battery is bent, It was found that there was a risk of these becoming rubbed off.

[0228] From the above results, it was found that the shape of the folded part can be changed by shifting the phase of the wave of the film by 180 degrees. It was confirmed that the shape of the film could be made symmetrical in the thickness direction. By flattening the part of the wall that is to be connected to the ridges, the waves are formed in the part where the space is formed. It was found that a larger space could be formed in the thickness direction without being positioned. EXAMPLES

[0229] The results of the tensile test of the film are described below.

[0230] The film used in the test was the same as that used in Example 1. The test specimen was , and cut into a rectangle measuring 15 mm x 100 mm.

[0231] In the tensile test, the test piece is clamped on the top and bottom, and the distance between them is changed in the direction of tension. The force required to pull the clamps was then measured. The distance between the clamps before pulling was set to 50 mm. The EZ-Graph (manufactured by Shimadzu Corporation) was used.

[0232] Figure 23 shows the results of the tensile test. The horizontal axis shows the displacement of the test piece, and the vertical axis shows the tensile strength. The displacement changes linearly with a gentle slope up to about 4 mm, and the wave-like This shows that the embossed shape of the This indicates that the film can be deformed with a small force. is higher, indicating that the test piece itself is stretched.

[0233] Based on the above, we developed an embossed laminated film that can be easily stretched, and By using this for the exterior body, it is possible to provide a battery that can be flexibly bent and stretched. EXAMPLES

[0234] In this example, a battery of one embodiment of the present invention was manufactured, and the influence of a bending test on sealing performance was investigated. Specifically, the bending test was performed on samples that were not subjected to the bending test, and the amount of the film inside the sample was measured. The amount of water infiltration was measured.

[0235] The battery used in this example was prepared in the same manner as Sample 1 in Example 1, except for the film bonding temperature. That is, the film was folded so that the ridges and valleys of the waves roughly overlapped each other. The film was bent at a temperature of 1 The reaction was carried out at 85°C.

[0236] The battery we made has a top seal length of about 15 mm and a side seal length of about 52 mm. The electrolyte used was about 400 μL of propylene carbonate (PC). Ta.

[0237] The amount of water that penetrated into the film was measured using the following method. Prepare a pressure cooker and place the battery you made inside the pressure cooker so that it is submerged in water. Then, heat the battery at 120℃. The pressure cooker was placed in a thermostatic chamber maintained at a certain temperature, and the battery was boiled by heating for approximately 25.5 hours. After that, the battery was removed, the film was opened in the glove box, and 400 μL of PC was added. After the added PC was mixed with the electrolyte inside the battery, the mixture was poured into the battery for about 0. 3 g was collected. The amount of water in the collected mixture was measured using a water meter. The moisture content was measured using a Karl Fischer moisture meter (Kyoto Kogyo Co., Ltd., MKC610). The amount of moisture that has penetrated into the room is calculated by subtracting the amount of moisture originally contained in the PC itself from the amount of moisture measured. The estimate was made by subtracting the above.

[0238] The following four types of batteries were used to measure the amount of moisture infiltration. The second is to bend the battery 10,000 times at a radius of curvature of 40 mm. The third was a battery that was heated at 160°C for 15 min. The fourth was a battery that was heated at 160°C for 15 minutes (condition 3). The specimen was then repeatedly bent and stretched 10,000 times with a curvature radius of 40 mm (condition 4). be.

[0239] FIG. 24(A) shows the amount of moisture that penetrated into the batteries under Conditions 1 and 2. The number of measurements for condition 1 was 5, and the number of measurements for condition 2 was 7. Condition 2 showed similar results to condition 1. It was confirmed that the sealing performance of the film did not decrease even if it was exposed to water immersion under condition 2. One sample was found to have a particularly high moisture content, but the amount was less than 110 ppm. This is a sufficient value for the pond sealing performance.

[0240] FIG. 24B shows the amount of moisture that penetrated into the batteries under conditions 3 and 4. The number of measurements for condition 3 was 5, and the number of measurements for condition 4 was 3. It was confirmed that sufficient sealing performance was observed even after heating. It was confirmed that the sealing performance did not decrease even if the material was repeatedly bent and stretched. Moreover, there is also a tendency for the sealing performance to be slightly improved under condition 4 compared to condition 3.

[0241] As described above, the battery of one embodiment of the present invention is resistant to repeated bending and stretching and to a high-temperature environment. It was confirmed that the compound had sufficient resistance. EXAMPLES

[0242] In this example, batteries were produced using exterior bodies of different thicknesses, and the force required for bending was measured. .

[0243] In this example, batteries using the following three types of exterior bodies (sample 3, sample 4, and sample 5) were produced. The exterior materials used for each were polypropylene, aluminum foil, and nylon, in that order. Sample 3 is an aluminum laminate film with the aluminum foil thickness of about The thickness of the aluminum foil used in sample 4 was 40 μm, and the total thickness was about 110 μm. The thickness of the aluminum foil used in sample 5 was about 30 μm and the total thickness was about 70 μm. A film having a thickness of about 20 μm and a total thickness of about 50 μm was used.

[0244] Samples 3, 4, and 5 were prepared in the same manner as in Example 3, except for the material of the exterior body. It was made.

[0245] Next, the force required for bending the three samples was measured by the following method. 25(A) and (B) show schematic diagrams for explaining the measurement method. The measurement device has a concave portion on the bottom. The curvature of the curved surfaces of the concave member and the convex member is The radius is 30 mm. The sample is supported at both ends by the edges of the recess in the recessed material. Then, as shown in FIG. 25(B), while pressing the convex part of the convex member against the sample, By displacing the convex member downward, the sample is curved from a flat state. The force required to bend the sample was evaluated by measuring the force required to displace it downward. For the measurement, a small tabletop precision universal testing machine (EZ-Graph) manufactured by Shimadzu Corporation was used.

[0246] The measurement results are shown in Figure 26. In Figure 26, the horizontal axis represents the amount of displacement of the convex member, and the vertical axis represents the amount of displacement of the convex member. In Fig. 26, the force required for bending increases from about 6 mm of displacement. The reason for this is that the bottom surface of the sample comes into contact with the top surface of the recessed material, and the force acting to crush the sample is large. This is due to its dominance.

[0247] In the range of displacement of 6 mm or less, the force required for bending was 2 N or less for all samples. It can be seen that the battery is very flexible.

[0248] As shown in FIG. 26, the larger the displacement of each sample, that is, the larger the radius of curvature of the sample, the greater the It was confirmed that the smaller the bending force, the greater the bending force required. The smaller the radius of curvature, the greater the force that tries to return to the original shape. In particular, the exterior is made of a corrugated film, which improves the restoration of the exterior. is presumed to be dominant.

[0249] In addition, when comparing the samples, as shown in Figure 26, the thinner the exterior body is, the less bending is required. For example, comparing sample 3 and sample 5 at a displacement of 4 mm, This means that the difference in the force required for bending is about twice as much, which is equivalent to the difference in thickness. In addition, when comparing sample 4 and sample 5, the difference in the force required for bending is about 1.3 times, and the difference in thickness is The difference is about 1.4 times, which is also the same as the difference in thickness. It was confirmed that the force required for lifting tends to be proportional to the thickness of the film used for the exterior body. .

[0250] As described above, the battery of one embodiment of the present invention can be prevented from bending by using a corrugated film for an exterior body. It was confirmed that the force required for charging the battery was extremely small. It was confirmed that it was possible to bend it with less force. EXAMPLES

[0251] In this example, a wristwatch band incorporating a battery of one embodiment of the present invention was manufactured.

[0252] First, the method for producing the band will be described. The band was produced by the following method. A method for manufacturing the electrode will be described with reference to FIG.

[0253] First, the lower die and the first upper die are pressed together with the molding material sandwiched between them. The molding material is then hardened while the lower mold and the first upper mold are pressed together. A molded body was prepared (FIGS. 27(A) and (B)). As shown in FIG. 27(B), A groove was formed in a part of the lower molded body.

[0254] Next, the first upper mold was removed, and the battery was placed in the groove of the lower molded body (Figure 1). 27(C)).

[0255] Then, with the molding material placed between the battery and the second upper die, the second upper die and the lower die are pressed together. The molding material was then hardened while the second upper and lower dies were joined together (Figure 2). 7(D)).

[0256] After that, the second upper and lower dies were removed to create a band with a built-in battery (Figure 2 7(E)).

[0257] In this example, sample 6 uses a millable silicone raw material as the molding material, and Sample 7 was prepared using a liquid silicone raw material. Sample 6 was prepared using the same material as in Example 4. A battery prepared in the same manner as Sample 3 described above was used, and Sample 7 was prepared using the same method as in Example 4. The samples were prepared in the same manner as in Sample 5.

[0258] Figure 28(A) shows a photograph of the top surface of sample 6. It can be seen that the battery is built in. Also, Figure 28 (B) shows the part of the band where the battery is located. This is a photo of what it looks like when bent.

[0259] 29(A) and (B) show photographs of the top and side appearances of Sample 7. The rubber molding of sample 1 is a darker milky white color than sample 6, but is slightly transparent. It can be seen that the corrugated shape of the battery exterior is maintained without being crushed. C) is a photograph of the band when the battery is bent. Sample 7 is the same as Sample 6. Compared to the conventional type, the thickness of the film used for the exterior is thinner, which improves flexibility and allows it to bend with less force. It was confirmed that this can be achieved.

[0260] As described above, the battery according to one embodiment of the present invention is formed by molding rubber over the exterior body. It is possible to create a rubber molded body with a built-in battery. In this example, a watch band is used. However, the present invention is not limited to this and can be applied to any rubber molded article. EXAMPLES

[0261] In this example, a battery according to one embodiment of the present invention was manufactured and a bending and stretching test was performed. explain.

[0262] In this example, the following three types of samples, Sample 8, Sample 9, and Sample 10, were prepared.

[0263] The exterior materials used for Samples 8, 9, and 10 were polypropylene, aluminum, and It is an aluminum laminate film in which aluminum foil and nylon are laminated in order. The thickness of the foil was about 20 μm, and the total thickness was 50 μm. The film was processed so that the height difference between the convex and concave surfaces was 0.5 mm. Ta.

[0264] Samples 8, 9, and 10 are the same as Example 1 except for the film folding method. It was prepared using a similar method.

[0265] Sample 8 is designed so that the wave phases are shifted by 180 degrees, i.e., the crests and valleys of the waves overlap. The film is folded so that it fits snugly against the surface.

[0266] Specimen 9 is designed so that the waves do not coincide in phase, specifically, so that the phases of the waves are shifted by about 90 degrees. The film is folded in this manner.

[0267] The sample 10 is arranged so that the wave phases are in agreement, that is, the ridge line of one side overlaps the valley line of the other side. The film is folded like this.

[0268] Figure 30(A), (B), and (C) show X-ray transmission images of sample 8, sample 9, and sample 10, respectively. Due to the film bonding process, there are some areas where the phases of the waves in the pair of films are slightly out of sync. However, it can be seen that the shape is generally as intended.

[0269] Next, a bending test was carried out on each of Samples 8, 9, and 10. The bending and straightening motion is performed between a radius of curvature of 40 mm (bending) and a radius of curvature of 150 mm (stretching). The process was repeated 10,000 times.

[0270] Photographs of the appearance of each sample after the bending and stretching test are shown in Figures 31(A), (B), and (C).

[0271] As shown in FIG. 31(A), sample 8 did not show any significant change in appearance even after the bending test. In addition, as shown by the broken line in Figure 31(B), sample 9 had deformation in part of the side seal. However, no electrolyte leakage occurred. As shown by the dashed line in (C), a large distortion was observed in the side seal area. In sample 10, leakage of electrolyte was confirmed after 10,000 bending tests.

[0272] From the above, it is considered that the film is more stable than the condition where the wave phase of the film is matched (sample 10). When the wave phase was shifted (samples 8 and 9), deformation of the side seal was less likely to occur. In particular, under the condition where the phase of the film wave is shifted by 180 degrees (sample 8), There was almost no deformation in the side seal area, and good results were obtained.

[0273] Next, the amount of moisture that penetrated into the film of Sample 8 and Sample 9 was measured, and the sealing ability was evaluated. The amount of moisture intrusion was measured in the same manner as in Example 3. As for 0, since electrolyte leakage was confirmed as mentioned above, no evaluation was performed. Regarding sample 8 and sample 9, two samples were prepared under the same conditions and subjected to bending tests. The evaluation was carried out.

[0274] FIG. 32 shows the measured amount of moisture penetration.

[0275] In sample 8, the amount of moisture penetration was less than 100 ppm for all samples, and 1000 It was confirmed that good sealing performance was maintained even after 0 bending tests. Although the aluminum foil of Sample 8 is a thinner film than that of the sample shown in Example 3, It was confirmed that the sealing performance was equivalent regardless of the material.

[0276] On the other hand, the amount of moisture penetration in sample 9 was greater than that in sample 8. This is because, as shown in FIG. B) From the external appearance photograph, there is a part near the side seal that is prone to localized deformation. Therefore, repeated deformation of the part in question may cause metal fatigue, resulting in cracking of the aluminum foil. This is believed to be the result of the formation of a rack and the deterioration of sealing performance. It is presumed that the aluminum foil is extremely thin compared to Example 3, which resulted in a significant difference in sealing performance. can be.

[0277] In addition, the high-temperature, high-pressure water treatment in the pressure cooker used in this test is a harsher environment than the practical range. The test was conducted under mild conditions, and the bending test did not result in leakage of electrolyte from sample 9. It is assumed that sufficient sealing performance for practical use has been secured.

[0278] From the above results, it can be concluded that the bending and stretching motions are repeated under the condition that the phase of the film wave is shifted. It was confirmed that there was no problem such as electrolyte leakage even if the film was folded. It was confirmed that there was almost no deterioration in sealing performance when the phase was shifted by 180 degrees. In other words, the closer the film wave phase is to a 180 degree shift, the greater the bending and stretching. It can be said that this increases the resistance to repeated bending. EXAMPLES

[0279] In this example, the deformation of the film exterior body having a corrugated shape when the battery is bent was calculated. The results will be explained.

[0280] Two models (Model 1 and Model 2) were used for the calculation. Model 1 is shown in Figure 3. 3(A1) and (A2), and Model 2 is shown in Fig. 33(B1) and (B2), respectively. 33(A1) and (B1) are perspective views of Model 1 and Model 2, respectively. (A2) and (B2) are side views of Model 1 and Model 2, respectively.

[0281] The calculation model is explained below. First, two corrugated films are used as the battery exterior. The film is assumed to be arranged with a space between them and bonded at the ends in the width direction. The elasticity was calculated from the results of the tensile test of the aluminum laminate film obtained in Example 2. The Young's modulus was set at 4.9×10 9 Pa, yield stress is 2×10 7 Pa, tangent modulus 6. 3×10 7 The electrode area was set to 0.02 Pa and the Poisson's ratio was set to 0.3. The structure does not have layers.

[0282] The battery exterior of Model 1 is made up of a pair of films arranged with the wave phases shifted by 180 degrees. The battery exterior of Model 2 is made of a pair of films that are arranged so that the wave phases match. It is arranged.

[0283] The battery exterior was designed to deform along the surface of a rigid body. The rigid body was curved with a radius of curvature of 25 mm. For convenience of calculation, the contact area between the ridge of the battery and the rigid body is To set the conditions, part of the rigid body was made comb-shaped.

[0284] In addition, a cylindrical rigid body is placed near the end of the battery, as shown by the arrow in Figure 33(A2) etc. The battery was deformed by displacing it vertically.

[0285] For the calculation, ANSYS Mechanical APDL 14.0 was used. The mesh conditions for the calculation model were as follows: element type: 285 (3D 4-joint 4-face) A solid body was used.

[0286] The calculated stress values ​​did not show any significant difference between Model 1 and Model 2. .

[0287] Figure 34(A) and (B) show the shape of Model 1 after deformation, and Figure 35(A) and (B) shows the shape of Model 2 after deformation. 33(A2) and (B2), respectively, and FIG. 34(B) and FIG. 35(B) are respectively, This corresponds to Figures 33(A2) and (B2) when viewed from the opposite side (back side).

[0288] Focusing on the shape after bending, Model 1 shows that each part is evenly deformed in response to bending. In contrast, Model 2 was found to have significant distortion. The calculation results for el1 are shown in Figures 34(A) and (B), which show symmetric shapes. In contrast, in Figures 35(A) and (B) showing the calculation results for Model 2, the asymmetric shape In particular, when viewed from the side of FIG. 35(A), the front side of the battery exterior is rigid. It can be seen that the shape of the object has changed and become distorted, rising from the surface.

[0289] Here, the battery exterior is made up of a pair of upper and lower films fixed together at the side seal portion. The seal is located almost on the neutral plane of the battery exterior. Therefore, when the battery exterior is bent, The side seals do not expand or contract, and the corrugated area between the pair of side seals mainly changes shape. This will take shape.

[0290] Also, when one of the films is bent, the valley line near the neutral plane is The film deforms from the starting point. The ridge between the two valleys is located on both sides of the ridge. The film deforms in accordance with the deformation of the two valleys. Therefore, the part between the two adjacent valleys on either side of the neutral plane is deformed. It is assumed that this part is the most easily deformed part.

[0291] In Model 1, the phase difference between the waves is 180 degrees, so the two waves adjacent to each other on either side of the neutral plane The valley line distance is the shortest, making it easy to bend.

[0292] Furthermore, in Model 1, when the battery exterior is viewed from the side, the two adjacent parts on either side of the neutral plane The straight lines connecting the two valleys pass through the center of the bend. As shown in (B), it is presumed that Model 1 was deformed into a shape with less distortion.

[0293] On the other hand, in Model 2, the phases of the waves are the same, so the two adjacent waves on either side of the neutral plane The distance of the valley line is the longest, making it difficult to bend.

[0294] Furthermore, in Model 2, when focusing on one valley line, the part located on the opposite side of the neutral plane In other words, the part that is most susceptible to deformation is the There are two of them for each valley line. Also, when the battery exterior is viewed from the side, There are also two lines connecting this to the nearest valley line, but neither of them passes through the center of the bend. The difference between Model 1 and Model 2 is that the two cross at the valley line. The two easily deformed parts corresponding to the part do not deform to the same degree, but rather It is expected that one of them will deform more than the other.

[0295] However, it is not clear which is more easily deformed, so we decided to bend the battery exterior. When the two most deformable parts are both deformed significantly, The large distortion areas shown in Figures 35(A) and (B) are considered to fall into this category. This also means that, as shown in Example 6, the sample 10 with the wave phases aligned was This coincides well with the results of the test in which a large distorted area was formed in the side seal.

[0296] From the above, as shown in Model 2, a battery exterior structure in which the wave phases are perfectly matched can be constructed. The structure is not suitable for bending, so it is desirable to have a structure that shifts the wave phase. Furthermore, as shown in Model 1, the battery with the wave phase shifted by 180 degrees The exterior structure is the most desirable form. [Explanation of symbols]

[0297] 10 batteries 11 Exterior body 12 Laminate 13 electrodes 13a electrode 13b Electrode 21 Ridgeline 21a Ridgeline 21b Ridgeline 22 Valley Line 22a valley line 22b Valley line 25 Space 31 parts 31a part 31b part 32 Bending section 33 Joint 34 Joint 41 electrode 42 electrodes 43 Electrode 50 Film Type 51 Type 52 Type 53 Type 54 55 Embossing roll 55a Convex 56 Embossing roll 56a Convex part 57 Rolls 60 Direction of travel 61 Film 62 Film 63 Convex 64 Space 71 areas 72 Positive electrode current collector 73 Separator 74 Negative electrode current collector 75 Sealing layer 76 Lead Electrode 77 Electrolyte 78 Cathode active material layer 79 Negative electrode active material layer 80 planes 90 plane 7100 Mobile Phone 7101 Case 7102 Display section 7103 Operation button 7104 Secondary battery 7105 Lead electrode 7106 Current collector 7400 Mobile Phone 7401 Case 7402 Display section 7403 Operation button 7404 External connection port 7405 Speaker 7406 Mike 7407 Secondary battery 7408 Lead electrode 7409 Current collector 7600 Vacuum cleaner 7601 Lead electrode 7602 Lead electrode 7603 Operation button 7604 Secondary battery 7605 Secondary battery 7606 Display section 8021 Charging device 8022 Cable 8100 Automobiles 8101 Headlight 8200 Automobiles

Claims

1. A band having an electrode laminate and an exterior body, and incorporating a bendable battery, the exterior body has a film-like shape and is folded in two so as to sandwich the electrode stack, the exterior body has a pair of first portions, a second portion, a pair of third portions, and a fourth portion, The pair of first portions overlap each other, the first portion is a portion surrounded by the second portion, the third portion, and the fourth portion, and includes a portion overlapping the electrode stack; the second portion is located between a pair of the first portions and is a folded portion, The pair of third portions are positioned opposite to each other so as to sandwich the first portion therebetween and are strip-shaped portions extending in a direction intersecting the second portion, the fourth portion is a band-shaped portion located on the opposite side of the first portion from the second portion, Within the exterior housing, the electrode stack and the second portion are not in contact with each other, and a space is formed between the electrode stack and the second portion; a distance between an end portion of the electrode stack on the second portion side inside the exterior body and a surface inside the exterior body is πt / 6 or more, where 2t is a thickness of the electrode stack; The exterior body is a band having a periodically continuous wave shape in one direction.

2. A watch having the band according to claim 1.

Images