Secondary battery

Abstract

To provide a secondary battery resistant to external force by solving the problem in which, in a case where a film is used in a package of a secondary battery, the film is less strong than a metal can and a current collector disposed in a region surrounded by the package or an active material layer provided on a surface of the current collector, for example, may be damaged by an external force.SOLUTION: A buffer material is provided in a region surrounded by a package in a secondary battery. Specifically, the buffer material is disposed around a current collector and housed so that a sealing part of the package (film) is disposed outside the buffer material.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] One aspect of the present invention relates to an article, a method, or a manufacturing method. Alternatively, the present invention relates to a process, a machine, a manufacture, or a composition of matter. One aspect of the present invention relates to a method for manufacturing a semiconductor device, a display device, a light-emitting device, a power storage device, a lighting device, or an electronic device. In particular, it relates to an electronic device and its operating system. Note that in this specification, the electronic device generally refers to all devices having a secondary battery, and an electro-optical device having a secondary battery, an information terminal device having a secondary battery, etc. are all electronic devices.

[0002]

Background Art

[0003] Electronic devices carried by users and electronic devices worn by users are actively being developed. For example, a thin portable book is described in Patent Document 1.

[0004] Electronic devices carried by users and electronic devices worn by users operate using a secondary battery as a power source. Electronic devices carried by users are desired to be used for a long time, and for this purpose, a large-capacity secondary battery may be used. Incorporating a large-capacity secondary battery into an electronic device has a problem that the large-capacity secondary battery is large and heavy. Therefore, the development of a small or thin and large-capacity secondary battery that can be incorporated into a portable electronic device is underway.

[0005] In addition, the secondary battery has a structure in which a metal can is used as an exterior body and an electrolyte etc. is housed inside the metal can.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] When a metal can is used as the exterior body, there is a problem that the weight of the secondary battery itself increases. Also, In order to realize a thin secondary battery, it is difficult to manufacture a thin metal can by forming, and it is also difficult to produce a secondary battery using a thin metal can.

[0008] When a film containing a laminate of a metal foil (such as aluminum or stainless steel) and a resin (a heat-sealable resin) is used as the exterior body, it is lighter than a secondary battery using a metal can, and a thin secondary battery can be produced. Or, one aspect of the present invention aims to provide a novel power storage device, a novel secondary battery, etc. Note that the description of these problems does not prevent the existence of other problems. Note that one aspect of the present invention does not necessarily need to solve all of these problems. Note that other problems will become apparent from the description in the specification, drawings, claims, etc., and it is possible to extract these other problems from the description in the specification, drawings, claims, etc.

Means for Solving the Problems

[0009] When a film is used for the exterior body of a secondary battery, the strength of the film is weaker than that of a metal can, and when a force is applied from the outside, there is a risk of damaging the current collector disposed in the region surrounded by the exterior body, or the active material layer provided on the surface of the current collector, etc. The current collector is connected to the lead electrode. ​​​​​​​​A protrusion (also referred to as an electrode tab portion) is provided for the purpose, and when an external force is applied and the secondary battery is bent, damage such as cracks is caused to a part of the current collector around the protrusion (electrode tab portion), leading to damage of the secondary battery.

[0010] In a secondary battery, a buffer material is provided in a region surrounded by an exterior body. Specifically, the buffer material is disposed around the current collector, and the sealing portion of the exterior body (film) is disposed outside the buffer material so as to accommodate. In order to increase the capacity, a unit having at least a current collector serving as a positive electrode, a separator, and a current collector serving as a negative electrode is provided in a plurality of layers in the region surrounded by the exterior body, but the buffer material is provided between the outermost current collector and the exterior body. Also, the buffer material is thicker than the separator is used. Also, the buffer material is thicker than the current collector. Also the buffer material may be a sheet formed by rolling up a sheet using the same material as the separator.

[0011] Examples of the shape of the buffer material include a flat plate shape, a rod shape, a spherical shape (such as plastic beads, glass beads etc.), a rectangular parallelepiped shape, etc. For example, it may have a shape having slits in a sheet-like plastic film. Also, a plurality of buffer materials may be accommodated in the region surrounded by the exterior body well, and they may have different sizes and shapes. For example, an aggregate formed by bundling a plurality of fibrous threads (glass fibers) may be used as the buffer material. Also, an aggregate (woven fabric) formed by knitting threads made of an organic resin like a cloth may be used. Also, a shape formed by rolling up a sheet-like material or a shape formed by folding a sheet-like material may be used. Specifically, a thin flat plate-shaped buffer material (plastic film) having an area wider than the current collector overlaps with the current collector so as to One of the configurations disclosed in this specification is a film and a The area surrounded by the film includes a first current collector, an active material layer, a second current collector, and a buffer material. It is a secondary battery, and the cushioning material is a plastic film. The area of the plastic film is , which is wider than the overlapping area of the first current collector and the second current collector.

[0012] In addition, when the outer shape of the current collector and the frame-shaped buffer material are interlocked, a flat shape that combines them is formed. The device is stored in an area surrounded by the exterior body so that the shape is approximately rectangular. Even if the collector and the frame-shaped cushioning material are not in contact in the enclosed area, the periphery of the exterior body is sealed by thermocompression. In this case, the boundary between the current collector and the frame-shaped buffer material becomes unclear from the outside. The exterior of the pond is thinned by thermocompression at the periphery, and the laminate (first current collector, separator) is in the center. The thickness is greater than the periphery because of the presence of a second collector, a second current collector, etc., and there is a gap between the center and the periphery. The outer surface of the secondary battery is thicker than the outer edge due to the placement of cushioning material. A first lead electrode electrically connected to the first current collector of the laminate is protruding and exposed, and a second A second lead electrode electrically connected to the current collector is also protruded and exposed.

[0013] The materials for the buffer material include insulators (plastic, rubber (natural rubber, synthetic rubber), glass, It is preferable that the material used as the buffer material is a material having elasticity (e.g., nonwoven fabric, paper, etc.). Synthetic rubber, such as silicone rubber, fluororubber, chloroprene rubber, nitrile butadiene rubber, ethylene propylene rubber, styrene butadiene rubber, etc.) are preferred. The buffer material has a higher elastic modulus than the separator. It may be a porous material having bubbles inside the material (for example, expanded polystyrene or a sponge rubber made of the above synthetic rubber material formed into a sheet). Also, a gelling material may be used as the material of the cushioning material. Further, as long as the surface of the cushioning material has an insulating surface, a conductive material can also be used. For example, as the material of the cushioning material, a material obtained by coating the surface of carbon fiber with an organic resin, or

[0014] a material obtained by forming an inorganic insulating film, such as a silicon oxide film, on the surface of a metal foil (such as an aluminum foil, a copper foil, or a stainless steel foil), or a material obtained by coating the surface of a metal foil with an organic resin can be used. In a secondary battery, by providing a cushioning material in the region surrounded by the exterior body, a current collector or the like can be housed in a stable position. Also, when the secondary battery is bent into a desired shape, the cushioning material can also be bent into a curved shape so as to achieve the desired shape, and it can also contribute to maintaining the bent shape of the secondary battery. Further, it can also have a function of restricting the secondary battery from bending more than necessary. The cushioning material can also function as a skeleton of the secondary battery. Moreover, it is not limited to providing the cushioning material in the region surrounded by the exterior body, and the cushioning material may be provided so that a part of the cushioning material is exposed. In this case, the cushioning material itself functions as a part of the exterior body, that is, one of the sealing materials. Also, depending on the form of the electronic device, in order to bend the secondary battery mounted on the electronic device, it is desirable for the cushioning material to bend, and it is preferable for the material of the cushioning material to have flexibility.

[0015] In a secondary battery, by providing a cushioning material in the region surrounded by the exterior body, a current collector or the like can be housed in a stable position. Also, when the secondary battery is bent into a desired shape, the cushioning material can also be bent into a curved shape so as to achieve the desired shape, and it can also contribute to maintaining the bent shape of the secondary battery. Further, it can also have a function of restricting the secondary battery from bending more than necessary. The cushioning material can also function as a skeleton of the secondary battery. Moreover, it is not limited to providing the cushioning material in the region surrounded by the exterior body, and the cushioning material may be provided so that a part of the cushioning material is exposed. In this case, the cushioning material itself functions as a part of the exterior body, that is, one of the sealing materials. Also, depending on the form of the electronic device, in order to bend the secondary battery mounted on the electronic device, it is desirable for the cushioning material to bend, and it is preferable for the material of the cushioning material to have flexibility. In a secondary battery, by providing a cushioning material in the region surrounded by the exterior body, a current collector or the like can be housed in a stable position. Also, when the secondary battery is bent into a desired shape, the cushioning material can also be bent into a curved shape so as to achieve the desired shape, and it can also contribute to maintaining the bent shape of the secondary battery.

[0016] Moreover, it is not limited to providing the cushioning material in the region surrounded by the exterior body, and the cushioning material may be provided so that a part of the cushioning material is exposed. In this case, the cushioning material itself functions as a part of the exterior body, that is, one of the sealing materials. In this case, the cushioning material itself functions as a part of the exterior body, that is, one of the sealing materials. In this case, the cushioning material itself functions as a part of the exterior body, that is, one of the sealing materials.

[0017] Also, depending on the form of the electronic device, in order to bend the secondary battery mounted on the electronic device, it is desirable for the cushioning material to bend, and it is preferable for the material of the cushioning material to have flexibility. In a secondary battery, by providing a cushioning material in the region surrounded by the exterior body, a current collector or the like can be housed in a stable position. Also, when the secondary battery is bent into a desired shape, the cushioning material can also be bent into a curved shape so as to achieve the desired shape, and it can also contribute to maintaining the bent shape of the secondary battery. Even if the amount of the electrolyte inside the battery decreases due to deterioration over time, the presence of the cushioning material prevents the occurrence of bending or suppresses changes in the appearance of the secondary battery. Further, when an impact force is applied to the secondary battery, since there is a cushioning material in the region surrounded by the exterior body, the concentration of the impact force at a single point is alleviated, and the local bending of the secondary battery is suppressed, thereby preventing damage to the secondary battery. Or, one aspect of the present invention is an electric storage body characterized by having a plurality of first current collectors each functioning as a positive electrode and a plurality of second current collectors each functioning as a negative electrode in a region surrounded by an exterior body. The electric storage body according to one aspect of the present invention can be deformed in the range of a curvature radius of 10 mm or more, preferably 30 mm or more. The film that is the exterior body of the electric storage body is composed of one or two sheets. In the case of an electric storage body having a laminated structure, the cross-sectional structure of the curved battery has a structure sandwiched between two curves of the film that is the exterior body. Here, the curvature radius of the surface will be described with reference to FIG. 7. In FIG. 7(A), in a plane 1701 obtained by cutting a curved surface 1700, a part of a curve 1702 that is the shape of the curved surface included in the curved surface 1700 is approximated by an arc of a circle, and the radius of the circle is defined as a curvature radius 1703, and the center of the circle is defined as a curvature center 1704. FIG. 7(B) shows a top view of the curved surface 1700. FIG. 7(C) shows a cross-sectional view obtained by cutting the curved surface 1700 with the plane 1701. When the curved surface is cut with a plane, the curvature radius of the curve appearing in the cross section varies depending on the angle of the plane with respect to the curved surface and the cutting position. However, in this specification and the like, the smallest curvature radius is defined as the curvature radius of the surface.

[0018] Even if the amount of the electrolyte inside the battery decreases due to deterioration over time, the presence of the cushioning material prevents the occurrence of bending or suppresses changes in the appearance of the secondary battery. Further, when an impact force is applied to the secondary battery, since there is a cushioning material in the region surrounded by the exterior body, the concentration of the impact force at a single point is alleviated, and the local bending of the secondary battery is suppressed, thereby preventing damage to the secondary battery. Or, one aspect of the present invention is an electric storage body characterized by having a plurality of first current collectors each functioning as a positive electrode and a plurality of second current collectors each functioning as a negative electrode in a region surrounded by an exterior body.

[0019] The electric storage body according to one aspect of the present invention can be deformed in the range of a curvature radius of 10 mm or more, preferably 30 mm or more. The film that is the exterior body of the electric storage body is composed of one or two sheets. In the case of an electric storage body having a laminated structure, the cross-sectional structure of the curved battery has a structure sandwiched between two curves of the film that is the exterior body. Here, the curvature radius of the surface will be described with reference to FIG. 7. In FIG. 7(A), in a plane 1701 obtained by cutting a curved surface 1700, a part of a curve 1702 that is the shape of the curved surface included in the curved surface 1700 is approximated by an arc of a circle, and the radius of the circle is defined as a curvature radius 1703, and the center of the circle is defined as a curvature center 1704. FIG. 7(B) shows a top view of the curved surface 1700. FIG. 7(C) shows a cross-sectional view obtained by cutting the curved surface 1700 with the plane 1701. When the curved surface is cut with a plane, the curvature radius of the curve appearing in the cross section varies depending on the angle of the plane with respect to the curved surface and the cutting position. However, in this specification and the like, the smallest curvature radius is defined as the curvature radius of the surface.

[0020] Here, the curvature radius of the surface will be described with reference to FIG. 7. In FIG. 7(A), in a plane 1701 obtained by cutting a curved surface 1700, a part of a curve 1702 that is the shape of the curved surface included in the curved surface 1700 is approximated by an arc of a circle, and the radius of the circle is defined as a curvature radius 1703, and the center of the circle is defined as a curvature center 1704. FIG. 7(B) shows a top view of the curved surface 1700. FIG. 7(C) shows a cross-sectional view obtained by cutting the curved surface 1700 with the plane 1701. When the curved surface is cut with a plane, the curvature radius of the curve appearing in the cross section varies depending on the angle of the plane with respect to the curved surface and the cutting position. However, in this specification and the like, the smallest curvature radius is defined as the curvature radius of the surface. In FIG. 7(A), in a plane 1701 obtained by cutting a curved surface 1700, a part of a curve 1702 that is the shape of the curved surface included in the curved surface 1700 is approximated by an arc of a circle, and the radius of the circle is defined as a curvature radius 1703, and the center of the circle is defined as a curvature center 1704. FIG. 7(B) shows a top view of the curved surface 1700. FIG. 7(C) shows a cross-sectional view obtained by cutting the curved surface 1700 with the plane 1701. When the curved surface is cut with a plane, the curvature radius of the curve appearing in the cross section varies depending on the angle of the plane with respect to the curved surface and the cutting position. However, in this specification and the like, the smallest curvature radius is defined as the curvature radius of the surface. When the curved surface is cut with a plane, the curvature radius of the curve appearing in the cross section varies depending on the angle of the plane with respect to the curved surface and the cutting position. However, in this specification and the like, the smallest curvature radius is defined as the curvature radius of the surface.

[0021] When a power storage body that sandwiches a content 1805 including an electrode, an electrolytic solution, etc. with two films as an exterior body is bent, the curvature radius 1 802 of the film 1801 on the side closer to the curvature center 1800 of the power storage body is smaller than the curvature radius 1804 of the film 1803 on the side farther from the curvature center 1800 (Fig. 8(A)). When the power storage body is bent so that the cross section is an arc shape, compressive stress is applied to the surface of the film closer to the curvature center 1800, and tensile stress is applied to the surface of the film farther from the curvature center 1800 (Fig. 8(B)). When a pattern formed by a concave portion or a convex portion is formed on the surface of the exterior body, even if such compressive stress or tensile stress is applied, the influence of strain can be suppressed within an allowable range. Therefore, the power storage body can be deformed within a range where the curvature radius of the exterior body on the side closer to the curvature center is 10 mm or more, preferably 30 mm or more. Note that the cross-sectional shape of the power storage body is not limited to a simple arc shape, and it can be a shape having a part of an arc, for example, the shape shown in Fig. 8(C), a wave shape (Fig. 8(D)), an S shape, etc. When the curved surface of the power storage body has a shape having a plurality of curvature centers, among the curvature radii at each of the plurality of curvature centers, in the curved surface with the smallest curvature radius, the curvature radius of the exterior body closer to the curvature center of the two exterior bodies is 10 mm or more, preferably 30 mm or more. The power storage body can be deformed within this range.

[0022]

[0023] Note that one aspect of the present invention can be applied to various power storage devices. For example, as an example of a power storage device, there are a battery, a primary battery, a secondary battery, a lithium ion secondary battery (including a lithium ion polymer secondary battery), a lithium air battery, etc. Furthermore, the power storage ​​​​​​​​​​ As another example of the device, it can also be applied to a capacitor. For example, the negative electrode of one aspect of the present invention is combined with the positive electrode of the electric double layer to form a capacitor such as a lithium ion capacitor. It is also possible to configure.

Advantages of the Invention

[0024] The degree to which the secondary battery is deformed by an externally applied force, that is, a part of the internal structure of the secondary battery can be adjusted by the material and arrangement of the buffer material. For example, even if the secondary battery is about to be bent suddenly, the bending can be suppressed to such an extent that the internal structure is not damaged due to the presence of the buffer material. Therefore, the buffer material can protect the internal structure from being damaged by an externally applied bending force. Or, a new power storage device, a new secondary battery, etc. can be provided. It should be noted that the description of these effects does not prevent the existence of other effects. It should be noted that one aspect of the present invention does not necessarily have all of these effects. In addition, other effects will be obvious from the description in the specification, drawings, claims, etc., and it is possible to extract these other effects from the description in the specification, drawings, claims, etc. come. In addition, the description of these effects does not prevent the existence of other effects. It should be noted that one aspect of the present invention does not necessarily have all of these effects. In addition, other effects will be obvious from the description in the specification, drawings, claims, etc., and it is possible to extract these other effects from the description in the specification, drawings, claims, etc. effects will be obvious from the description in the specification, drawings, claims, etc., and it is possible to extract these other effects from the description in the specification, drawings, claims, etc.

Brief Description of the Drawings

[0025]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

[0026] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following description, and various modifications in form and details are possible by those skilled in the art. The present invention should not be construed as being limited to the description of the following embodiments. It is not something that can be done.

[0027] In each figure described in this specification, the size of each component, the thickness of a layer, or the area is The figures may be exaggerated or abbreviated for clarity. This is not limited to rules.

[0028] In this specification, ordinal numbers such as "first" and "second" are used to avoid confusion of components. It does not indicate any order or ranking such as the order of processes or stacking. In addition, even if a term is not accompanied by an ordinal number in this specification, etc., it is possible to avoid confusion of the constituent elements. To avoid this, ordinal numbers may be used in the claims.

[0029] (Embodiment 1) FIG. 1(A) shows an example of a schematic diagram of a power storage unit. An example is shown in Figure 2(A).

[0030] The power storage unit 100 of one embodiment of the present invention includes a positive electrode 101, a separator 103, and an outer casing 107. and a negative electrode 102, a buffer material 110, and at least an electrolytic solution. As for the structure of the power storage body, there are various structures. In the present embodiment, a film is used for forming the exterior body 107.

[0031] The film for forming the exterior body 107 is a metal film (a metal or alloy such as aluminum, stainless steel, nickel steel, gold, silver, copper, titanium, nichrome, iron, tin, tantalum, niobium, molybdenum, zirconium, zinc, etc. which becomes a metal foil), a plastic film made of an organic material, a hybrid material film containing an organic material (such as an organic resin and a fiber) and an inorganic material (such as a ceramic), or a single-layer film selected from carbon-containing inorganic films (such as a carbon film and a graphite film) or a laminated film composed of a plurality of these is used. a plastic film made of an organic material, a hybrid material film containing an organic material (such as an organic resin and a fiber) and an inorganic material (such as a ceramic), a carbon-containing inorganic film (such as a carbon film and a graphite film), a single-layer film selected from these or a laminated film composed of a plurality of these is used.

[0032] In the present embodiment, as the buffer material 110, a sheet-like plastic film having a larger area than the positive electrode 101 is used. Also, in the present embodiment, the buffer material 110 uses a plastic film thicker than the separator 103. Also, the buffer material 110 may have slits. Also, the buffer material 110 is not limited to a rectangle and may have a shape with four rounded corners. If there is an acute angle in the shape of the buffer material 110, when the power storage body is bent, the corner may damage the film of the exterior body. Therefore, chamfering the corner portion of the buffer material 110 can provide a highly reliable power storage body. The material of the buffer material 110 uses an insulating material, for example, a sheet-like plastic film having a larger area than the positive electrode 101 is used. Also, in the present embodiment, the buffer material 110 uses a plastic film thicker than the separator 103. Also, the buffer material 110 may have slits. Also, the buffer material 110 is not limited to a rectangle and may have a shape with four rounded corners. If there is an acute angle in the shape of the buffer material 110, when the power storage body is bent, the corner may damage the film of the exterior body. Therefore, chamfering the corner portion of the buffer material 110 can provide a highly reliable power storage body. The material of the buffer material 110 uses an insulating material, for example, a sheet-like plastic film having a larger area than the positive electrode 101 is used. Also, in the present embodiment, the buffer material 110 uses a plastic film thicker than the separator 103. Also, the buffer material 110 may have slits. Also, the buffer material 110 is not limited to a rectangle and may have a shape with four rounded corners. If there is an acute angle in the shape of the buffer material 110, when the power storage body is bent, the corner may damage the film of the exterior body. Therefore, chamfering the corner portion of the buffer material 110 can provide a highly reliable power storage body. The material of the buffer material 110 uses an insulating material, for example, a sheet-like plastic film having a larger area than the positive electrode 101 is used. Also, in the present embodiment, the buffer material 110 uses a plastic film thicker than the separator 103. Also, the buffer material 110 may have slits. Also, the buffer material 110 is not limited to a rectangle and may have a shape with four rounded corners. If there is an acute angle in the shape of the buffer material 110, when the power storage body is bent, the corner may damage the film of the exterior body. Therefore, chamfering the corner portion of the buffer material 110 can provide a highly reliable power storage body. The material of the buffer material 110 uses an insulating material, for example, a sheet-like plastic film having a larger area than the positive electrode 101 is used. Also, in the present embodiment, the buffer material 110 uses a plastic film thicker than the separator 103. Also, the buffer material 110 may have slits. Also, the buffer material 110 is not limited to a rectangle and may have a shape with four rounded corners. If there is an acute angle in the shape of the buffer material 110, when the power storage body is bent, the corner may damage the film of the exterior body. Therefore, chamfering the corner portion of the buffer material 110 can provide a highly reliable power storage body. The material of the buffer material 110 uses an insulating material, for example, a sheet-like plastic film having a larger area than the positive electrode 101 is used. Also, in the present embodiment, the buffer material 110 uses a plastic film thicker than the separator 103. Also, the buffer material 110 may have slits. Also, the buffer material 110 is not limited to a rectangle and may have a shape with four rounded corners. If there is an acute angle in the shape of the buffer material 110, when the power storage body is bent, the corner may damage the film of the exterior body. Therefore, chamfering the corner portion of the buffer material 110 can provide a highly reliable power storage body. The material of the buffer material 110 uses an insulating material, for example, a sheet-like plastic film having a larger area than the positive electrode 101 is used. Also, in the present embodiment, the buffer material 110 uses a plastic film thicker than the separator 103. Also, the buffer material 110 may have slits. Also, the buffer material 110 is not limited to a rectangle and may have a shape with four rounded corners. If there is an acute angle in the shape of the buffer material 110, when the power storage body is bent, the corner may damage the film of the exterior body. Therefore, chamfering the corner portion of the buffer material 110 can provide a highly reliable power storage body. The material of the buffer material 110 uses an insulating material, for example, PP, PE, polyester such as PET and PBT, polyamide such as nylon 6 and nylon 66, an inorganic vapor deposition film, or paper may be used.

[0033] By providing the buffer material 110 in the region surrounded by the exterior body of the electrical storage body, the current collector and the like can be stored in a stable position. When bending the electrical storage body into a desired shape, the buffer material can also be bent into a shape so as to achieve the desired shape, and can also contribute to maintaining the bent shape of the electrical storage body. Moreover, it is also possible to provide a function of restricting the electrical storage body from bending more than necessary. The buffer material can also function as the skeleton of the electrical storage body. By providing the buffer material 110 in the region surrounded by the exterior body of the electrical storage body, the influence due to the strain caused by applying a force from the outside of the electrical storage body can be suppressed within an allowable range. Therefore, a reliable electrical storage body can be provided.

[0034] Also, by providing the buffer material 110 in the region surrounded by the exterior body of the electrical storage body, if the surface of the buffer material 110 is a smooth plastic film, the current collector in contact with the surface of the buffer material 110 and the exterior body in contact with the surface of the buffer material 110 slide, so that an electrical storage body that is also strong against repeated bending can be provided.

[0035] Note that the positive electrode 101 is referred to as a positive electrode including those provided with a positive electrode active material layer or the like on one side or both sides of a current collector (such as aluminum). The negative electrode 102 is referred to as a negative electrode including those provided with a negative electrode active material layer or the like on one side or both sides of a current collector (such as copper). Also, the positive electrode 101 is electrically connected to the positive electrode lead 104, and the negative electrode 102 is electrically connected to the negative electrode lead 105. The positive electrode lead 104 and the negative electrode lead 105 are also referred to as lead electrodes or lead terminals. A part of the positive electrode lead 104 and the negative electrode lead 105 is disposed outside the exterior body. Moreover, the charging and discharging of the electrical storage body 100 are performed via the positive electrode lead 104 and the negative electrode lead 105. ​

[0036] Here, the flow of current during the charging of the secondary battery will be described with reference to FIG. 1(B). When a secondary battery using lithium is regarded as a single closed circuit, the movement of lithium ions and the flow of current are in the same direction. Note that in a secondary battery using lithium, the anode (positive electrode) and the cathode (negative electrode) are reversed during charging and discharging, and the oxidation reaction and the reduction reaction are reversed. Therefore, the electrode with a higher reaction potential is called the positive electrode, and the electrode with a lower reaction potential is called the negative electrode. Thus, in this specification, regardless of whether it is during charging, discharging, or when a reverse pulse current is flowing, or when a charging current is flowing, the positive electrode is called the "positive electrode" or the "+ electrode (plus electrode)", and the negative electrode is called the "negative electrode" or the "- electrode (minus electrode)". When using terms such as anode (positive electrode) and cathode (negative electrode) related to oxidation reactions and reduction reactions, the terms will be reversed during charging and discharging, which may cause confusion. Therefore, the terms anode (positive electrode) and cathode (negative electrode) will not be used in this specification. If the terms anode (positive electrode) and cathode (negative electrode) are used, it is necessary to specify whether it is during charging or discharging, and also to indicate which corresponds to the positive electrode (plus electrode) and the negative electrode (minus electrode). FIG. 1(B) shows that a charger is connected to the two terminals, and the power storage body 100 is charged. As the charging of the power storage body 100 progresses, the potential difference between the electrodes increases. In FIG. 1(B), the current flows from the external terminal (positive electrode lead 104) of the power storage body 100 towards the positive electrode current collector (positive electrode 101), and within the power storage body 1 00, it flows from the positive electrode 101 towards the negative electrode 102, and from the negative electrode towards the external terminal (negative electrode lead 105) of the power storage body 100. The direction of the current flowing in this way is defined as the positive direction. That is, during charging, regardless of whether it is during charging, discharging, or when a reverse pulse current is flowing, or when a charging current is flowing, the positive electrode is called the "positive electrode" or the "+ electrode (plus electrode)", and the negative electrode is called the "negative electrode" or the "- electrode (minus electrode)". When using terms such as anode (positive electrode) and cathode (negative electrode) related to oxidation reactions and reduction reactions, the terms will be reversed during charging and discharging,

[0037] A charger is connected to the two terminals shown in FIG. 1(B), and the power storage body 100 is charged. As the charging of the power storage body 100 progresses, the potential difference between the electrodes increases. In FIG. 1(B), the current flows from the external terminal (positive electrode lead 104) of the power storage body 100 towards the positive electrode current collector (positive electrode 101), and within the power storage body 1 00, it flows from the positive electrode 101 towards the negative electrode 102, and from the negative electrode towards the external terminal (negative electrode lead 105) of the power storage body 100. The direction of the current flowing in this way is defined as the positive direction. That is, during charging, regardless of whether it is during charging, discharging, or when a reverse pulse current is flowing, or when a charging current is flowing, the positive electrode is called the "positive electrode" or the "+ electrode (plus electrode)", and the negative electrode is called the "negative electrode" or the "- electrode (minus electrode)". The direction of the current flowing from the external terminal (positive electrode lead 104) of the power storage body 100 towards the positive electrode current collector (positive electrode 101), then within the power storage body 100 from the positive electrode 101 towards the negative electrode 102, and from the negative electrode towards the external terminal (negative electrode lead 105) of the power storage body 100 is taken as the positive direction. That is, during charging, The direction in which the electric current flows is defined as the direction of the current.

[0038] In this embodiment, for the sake of simplicity, an example is shown in which a set of a positive electrode 101 and a negative electrode 102 are housed in an exterior body However, in order to increase the capacity of the power storage element, a plurality of sets of positive electrodes 101 and negative electrodes 102 may be housed in the exterior body 107.

[0039] As shown in FIG. 2(A), an example is shown in which a buffer material 110, a positive electrode 101, a separator 103, and a negative electrode 102 are arranged inside the exterior body 107. In FIG. 2(A), for simplicity the exterior body 107, the positive electrode lead 104, and the negative electrode lead 105 are not shown.

[0040] As a material for forming the separator 103, cellulose, polypropylene (PP) , polyethylene (PE), polybutene, nylon, polyester, polysulfone, polyacrylonitrile, polyvinylidene fluoride, porous insulators such as tetrafluoroethylene, etc. can be used. Also, a non-woven fabric such as glass fiber or a separator in which glass fiber and polymer fiber are combined may be used.

[0041] In this embodiment, the configuration of the power storage element is, for example, the thickness of the separator 103 is about 15 μm or more and 30 μm or less, the current collector of the positive electrode 101 is about 10 μm or more and about 40 μm or less, the positive electrode active material layer is about 50 μm or more and about 100 μm or less, the negative electrode active material layer is about 50 μm or more and about 100 μm or less, and the current collector of the negative electrode 102 is about 5 μm or more and about 40 μm or less.

[0042] Also, in FIG. 2(A), an example is shown in which a sheet-like separator 103 is used, but a bag -like one may be used. Also, one separator is bent, and a positive It may be installed inside the outer casing 107 so that the anode (or the negative electrode) is positioned.

[0043] Also, the position of the buffer material 110 is not limited to that shown in Fig. 2(A). For example, as shown in Fig. 2(B), the buffer material 110 may be provided on the side in contact with the negative electrode 102.

[0044] Also, the buffer material 110 is not limited to one, and a plurality of them may be used. For example, as shown in Fig. 2(C), a configuration having the positive electrode 101, the separator 103, and the negative electrode 102 between the first buffer material 110a and the second buffer material 110b may be used.

[0045] Examples of the positive electrode active material used for the positive electrode active material layer of the power storage body 100 include composite oxides having an olivine-type crystal structure, a layered rock salt-type crystal structure, or a spinel-type crystal structure. As the positive electrode active material, for example, compounds such as LiFeO2, LiCoO2, LiNiO2, LiMn2O4, V2O 5, Cr2O5, and MnO2 are used.

[0046] Alternatively, a composite material (general formula LiMPO4 (M is one or more of Fe(II), Mn(II), Co(I I), Ni(II))) can be used. Representative examples of the general formula LiMPO4 include LiFePO4, LiNiPO4, LiCoPO4, LiMnPO4, LiFe a Ni b PO4, LiFe a Co b PO4, LiFe a Mn b PO4, LiNi a Co b PO4, LiNi a Mn b PO4 (a + b is 1 or less, 0 < a < 1, 0 < b < 1), LiF e c Nid Co e PO4, LiFe c Ni d Mn e PO4, LiNi c Co d Mn e PO 4 (c + d + e is 1 or less, 0 < c < 1, 0 < d < 1, 0 < e < 1), LiFe f Ni g C o h Mn i PO4 (f + g + h + i is 1 or less, 0 < f < 1, 0 < g < 1, 0 < h < 1, 0 <i < 1) and the like of lithium compounds can be used as materials.

[0047] Or, a composite material such as a 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. 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, Li (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) Ni k 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 N in Co q SiO4, Li (2-j) Fe m Ni n Mn q SiO4, Li (2-j) Ni m Co n Mn q SiO4 (where m + n + q is 1 or less, 0 < m < 1, 0 < n < 1, 0 < q < 1) , Li (2-j) Fe r Ni s Co t Mn u SiO4 (where r + s + t + u is 1 or less, 0 < r < 1, 0 < s < 1, 0 < t < 1, 0 < u < 1), etc. can be used as materials for lithium compounds and so on.

[0048] Also, as the positive electrode active material, A x M2(XO4)3 (A = Li, Na, Mg, M = Fe, M n, Ti, V, Nb, Al, X = S, P, Mo, W, As, Si) represented by the general formula can be used as the NASICON type compound. Examples of 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, Mo S2, etc., oxides having a reverse spinel type crystal structure such as LiMVO4, vanadium oxide systems (V2O5, V6O 13 , L iV3O8, etc.), manganese oxides, organic sulfur compounds, etc. can be used as materials.

[0049] Note that the carrier ions are alkali metal ions other than lithium ions, alkaline earth metals In the case of ions, instead of lithium, an alkali metal (e.g., sodium) is used as the positive electrode active material. alkaline earth metals (e.g., calcium, strontium, barium, etc.), Alternatively, metals such as aluminum, beryllium, or magnesium may be used.

[0050] The separator 103 is made of cellulose (paper) or polypropylene with holes. An insulator such as polyethylene can be used.

[0051] The electrolyte solution uses a material that has lithium ions as the electrolyte, and the carrier ions are mobile. Representative examples of electrolytes are LiPF6, LiClO4, LiAsF6, and LiBF4 , LiCF3SO3, Li(CF3SO2)2N, Li(C2F5SO2)2N, etc. These electrolytes may be used alone or in any combination of two or more. It may be used in any combination and ratio.

[0052] The solvent of the electrolyte solution is a material in which carrier ions can move. As the solvent, an aprotic organic solvent is preferred. Representative examples of the aprotic organic solvent include: Ethylene carbonate (EC), propylene carbonate, dimethyl carbonate, diene Diethyl 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. Furthermore, it is possible to make the storage battery thinner and lighter. Representative polymer materials that can be gelled are Examples include silicone gel, acrylic gel, acrylonitrile gel, polyethylene oxide There are side gels, polypropylene oxide gels, fluoropolymer gels, etc. Also, as the solvent of the electrolyte, one or more ionic liquids (room temperature molten salts) that are flame retardant and hardly volatile are used, so that even if the internal temperature rises due to internal short circuit, overcharge, etc. of the storage battery, rupture or ignition of the storage battery can be prevented. Note that the ionic liquid is a salt in a fluid state and has a high ionic mobility (conductivity). Also, the ionic liquid contains a cation and an anion. Examples of the ionic liquid include ionic liquids containing an ethylmethylimidazolium (EMI) cation, or ionic liquids containing an N-methyl-N-propylpiperidinium (PP ) cation. 13

[0053] Alternatively, instead of the electrolyte, a solid electrolyte having an inorganic material such as a sulfide-based or oxide-based material, or a solid electrolyte having a polymer material such as a PEO (polyethylene oxide)-based material can be used. When using a solid electrolyte, it is not necessary to install a separator or a spacer. Also, since the entire battery can be solidified, there is no risk of liquid leakage and the safety is dramatically improved.

[0054] As the negative electrode active material used in the negative electrode active material layer of the power storage body 100, a material capable of dissolving and depositing lithium or inserting and desorbing lithium ions can be used, and lithium metal, carbon-based materials, alloy-based materials, etc. can be used.

[0055] Lithium metal has a low oxidation-reduction potential (-3.045 V with respect to the standard hydrogen electrode) and a large specific capacity per unit weight and volume (3860 mAh / g and 2062 mAh / cm 3

[0056] ​​​​​​​​​​​As carbon-based materials, there are graphite, graphitizable carbon (soft carbon), non-graphitizable carbon (hard carbon), carbon nanotubes, graphene, carbon black, and the like.

[0057] As graphite, there are artificial graphite such as mesocarbon microbeads (MCMB), coke-based artificial graphite, and pitch -based artificial graphite, and natural graphite such as spheroidized natural graphite.

[0058] When lithium ions are inserted into graphite (when forming a lithium-graphite intercalation compound), graphite shows a potential as low as that of metallic lithium (0.1~0.3V vs. Li / Li + ). Therefore, lithium-ion secondary batteries can exhibit a high operating voltage. Furthermore, graphite has advantages such as a relatively high capacity per unit volume, small volume expansion, low cost, and high safety compared to metallic lithium, and is thus preferable.

[0059] As the negative electrode active material, alloy-based materials or oxides capable of performing charge and discharge reactions through alloying and dealloying reactions with lithium can also be used. When the carrier ion is a lithium ion, examples of alloy-based materials include materials containing at least one of Al, Si, Ge, Sn, Pb, Sb, Bi, Ag, Au, Zn, Cd, In, Ga, etc. Such elements have a large capacity with respect to carbon, and in particular, silicon has a theoretical capacity of 4200 mAh / g, which is extremely high. Therefore, it is preferable to use silicon as the negative electrode active material. Examples of alloy-based materials using such elements include Mg2Si, Mg2Ge, Mg2Sn, SnS 2, V2Sn3, FeSn2, CoSn2, Ni3Sn2, Cu6Sn5, Ag3Sn, Ag3Sb, Ni2MnSb, CeSb3, LaSn3, La3Co2Sn7, CoSb 3. There are InSb, SbSn, etc. Note that SiO refers to a powder of silicon oxide containing a silicon-rich part, and SiO (2 > y > 0) can also be expressed as such. For example, SiO y includes a material selected from one or more of Si2O3, Si3O4, or Si2O, or a mixture of Si powder and silicon dioxide SiO2. Also, SiO may contain other elements (such as carbon, nitrogen , iron, aluminum, copper, titanium, calcium, manganese, etc.). That is , it refers to a material containing a plurality selected from single crystal Si, amorphous Si, polycrystalline Si, Si2O3, Si3O4, Si2O, S iO2, and SiO is a colored material. In the case of SiO without SiO if it is x (X is 2 or more), it is colorless and transparent or white and can be distinguished . However, after manufacturing a secondary battery using SiO as a negative electrode active material and repeating charge and discharge , when SiO is oxidized, it may be transformed into SiO2.

[0060] Also, as the negative electrode active material, oxides such as SiO, SnO, SnO2, titanium dioxide (TiO2), lithium titanate (Li4Ti5O 12 ), lithium-graphite intercalation compound (Li x C6), niobium pentoxide (Nb2O5), tungsten oxide (WO2), molybdenum oxide (MoO2 ) can be used.

[0061] Also, as the negative electrode active material, Li with an Li3N-type structure, which is a complex nitride of lithium and transition metals 3-x M x N (M = Co, Ni, Cu) can be used. For example, Li 2.6 Co 0.4 N3 exhibits a large charge-discharge capacity (900 mAh / g, 1890 mAh / cm 3 ) and is preferable. It is preferable.

[0062] When using a complex nitride of lithium and a transition metal, since the negative electrode active material contains lithium ions, it can be preferably combined with materials such as V2O5 and Cr3O8 that do not contain lithium ions as the positive electrode active material. Even when using a material containing lithium ions for the positive electrode active material, by previously desorbing the lithium ions contained in the positive electrode active material, a complex nitride of lithium and a transition metal can be used as the negative electrode active material.

[0063] In addition, a material that undergoes a conversion reaction can also be used as the negative electrode active material. For example, transition metal oxides such as cobalt oxide (CoO), nickel oxide (NiO), and iron oxide (FeO), which do not undergo an alloying reaction with lithium, may be used as the negative electrode active material. As materials that undergo a conversion reaction, further, oxides such as Fe2O3, CuO, Cu2O, RuO2, and Cr2O 3, sulfides such as CoS 3, nitrides such as Zn3N2, Cu3N, and G 0.89 e3N4, phosphides such as NiP2, FeP2, and CoP3, and fluorides such as FeF3 and BiF3 also occur. Since the potential of the above fluorides is high, they may be used as the positive electrode active material.

[0064] In addition to the negative electrode active material described above, the negative electrode active material layer may also have a binder (binder) for enhancing the adhesion of the active material and a conductive aid for enhancing the conductivity of the negative electrode active material layer.

[0065] Moreover, it is not limited to providing a buffer material in the region surrounded by the exterior body, and the buffer material may be provided such that a part of the buffer material is exposed. When adhesively bonding the outer peripheral edge of the exterior body 107 by thermocompression bonding, it may be sealed by thermocompression bonding with the bonding region overlapping a part of the sheet-like buffer material. In this case, the sheet-like buffer material is fixed at the portion in contact with the bonding region.

[0066] In this embodiment, an example of a small battery used in a portable information terminal or the like has been shown, but it is not particularly limited, and it can also be applied to a large battery mounted on a vehicle or the like.

[0067] (Embodiment 2) In Embodiment 1, an example using a sheet-like buffer material has been shown, but in this embodiment, a buffer material having a shape different from that of Embodiment 1 is used, and an example with a different installation position is shown.

[0068] FIG. 3(A) shows an example of a schematic diagram of an electricity storage body. Also, FIG. 3(B) shows an example of the internal structure surrounded by the exterior body of the electricity storage body. In FIG. 3, the same reference numerals are used for the parts common to FIG. 1, and detailed description will be omitted here for the sake of simplicity.

[0069] An electricity storage body 300 according to one aspect of the present invention includes a positive electrode 101, a separator 103, a negative electrode 102, a first buffer material 310a, a second buffer material 310b, and an electrolytic solution in the exterior body 107. at least.

[0070] In the embodiment, as the first buffer material 310a and the second buffer material 310b, a rod-shaped elastic body (material having elasticity) thicker than the separator 103 is used.

[0071] As shown in FIGS. 3(A) and 3(B), the first buffer material 310a and the second buffer material 310b The positive electrode 101, the separator 103, and the negative electrode 102 are disposed between them.

[0072] The outer periphery of the exterior body 107 is bonded by thermocompression. The film has a polypropylene layer on the surface, and only the thermo-compressed area adheres. It becomes an area.

[0073] In this embodiment, the adhesive region 311 is in contact with the first buffer material 310a, and the side surface of the power storage unit 300 is When the buffer material is placed inside the power storage unit without being exposed, The cross section is wedge-shaped to make the step around the sealing part gentler. The second buffer material 310b is in contact with the buffer material 310b, and the second buffer material 310b is exposed on the side surface of the power storage unit 300. The first buffer material 310a and the second buffer material 310b also function as sealing materials.

[0074] The first buffer material 310a and the second buffer material 310b are made of a material that is more durable than a separator. Use a material with a higher elastic modulus than the material itself. For example, use rubber (natural rubber, synthetic rubber, etc.). It is preferable to select a material that is unlikely to undergo a chemical reaction when in contact with the electrolyte. In this case, silicone rubber is used, which is resistant to chemical reactions when it comes into contact with the electrolyte. The materials used for the first buffer material 310a and the second buffer material 310b are It is preferable to coat or surface treat the electrode with a material that has high solvent resistance to the electrolyte.

[0075] The first buffer material 310a and the second buffer material 310b are made of a material suitable for thermocompression bonding. A material that adheres by this method is used.

[0076] By providing the first buffer material 310a and the second buffer material 310b, the power storage body 300 can be bent even when bent, a configuration in which wrinkles are less likely to be formed in the film of the exterior body at the outer peripheral portion of the power storage body 300 can be achieved

[0077] Also, in order to increase the capacity of the power storage body 300, when a plurality of combinations of laminations of the positive electrode 101, the separator 103, and the negative electrode 1 02 are stacked and housed in the exterior body, the total thickness becomes thick and the difference in thickness from the peripheral portion becomes large, resulting in a step in the film of the exterior body. To reduce this step it is preferable to provide the first buffer material 310a and the second buffer material 310b

[0078] Also, by increasing the lengths of the first buffer material 310a and the second buffer material 310b a space may be provided so that the current collector or the like can slide even when the power storage body 300 is bent

[0079] Also, an example using two elastic bodies of the first buffer material 310a and the second buffer material 310b has been shown but it is not particularly limited, and a U-shaped single elastic material may be used as the buffer material. Also, a frame shaped single elastic material may be used as the buffer material

[0080] Also, this embodiment can be combined with Embodiment 1. For example, between the first buffer material 310a and the second buffer material 310b, the positive electrode 101, the separator 103, and the negative electrode 10 2 are installed so as to be positioned, and a sheet-like plastic film may be further used as the third buffer material and housed inside the power storage body

[0081] (Embodiment 3) In this embodiment, unevenness is formed on the film of the exterior body by pressing, for example, embossing​​​ An example is shown in which a sheet-like plastic film is used as the cushioning material 110 in the region surrounded by the exterior body. is shown.

[0082] In this embodiment, an example of manufacturing a lithium-ion secondary battery using a film having an embossed pattern on its surface is shown with reference to FIG. 4. In FIG. 4, the same reference numerals are used for the parts common to FIG. 1, and detailed descriptions are omitted here for simplicity. First, a sheet made of a flexible substrate is prepared. The sheet is a laminate having an adhesive layer (also called a heat-sealing layer) on one or both surfaces of a metal film. The adhesive layer uses a heat-fusible resin film containing polypropylene or polyethylene. In this embodiment, as the sheet, a metal sheet is used which has a nylon resin on the surface of an aluminum foil and a laminate of an acid-resistant polypropylene film and a polypropylene film on the back surface of the aluminum foil. This sheet is cut to prepare a film. And then, this film is embossed to form unevenness on the film surface and a visible pattern. Here, an example is shown in which the embossing is performed after cutting the sheet, but the order is not particularly limited, and the embossing may be performed before cutting the sheet and then cutting it. Also, it may be cut after folding the sheet and performing thermocompression bonding. is omitted.

[0083] Note that embossing is a type of pressing process in which an embossing roll with unevenness on its surface is pressed against the film to form unevenness corresponding to the unevenness of the embossing roll on the film surface. One side or both sides of the metal film has an adhesive layer (also called a heat-sealing layer). The adhesive layer uses a heat-fusible resin film containing polypropylene or polyethylene. In this embodiment, a metal sheet provided with a nylon resin on one surface of an aluminum foil and a laminate of an acid-resistant polypropylene film and a polypropylene film on the back surface of the aluminum foil is used. This sheet is cut to prepare a film. And then, this film is embossed to form unevenness on the film surface and a visible pattern. Here, an example is shown in which the embossing is performed after cutting the sheet, but the order is not particularly limited, and the embossing may be performed before cutting the sheet and then cutting it. Also, it may be cut after folding the sheet and performing thermocompression bonding. Note that embossing is a type of pressing process in which an embossing roll with unevenness on its surface is pressed against the film to form unevenness corresponding to the unevenness of the embossing roll on the film surface. is used. This sheet is cut to prepare a film.

[0084] And then, this film is embossed to form unevenness on the film surface and a visible pattern. Here, an example is shown in which the embossing is performed after cutting the sheet, but the order is not particularly limited, and the embossing may be performed before cutting the sheet and then cutting it. Also, it may be cut after folding the sheet and performing thermocompression bonding. Note that embossing is a type of pressing process in which an embossing roll with unevenness on its surface is pressed against the film to form unevenness corresponding to the unevenness of the embossing roll on the film surface. is not particularly limited, and the embossing may be performed before cutting the sheet and then cutting it. It may also be cut after folding the sheet and performing thermocompression bonding.

[0085] Note that embossing is a type of pressing process in which an embossing roll with unevenness on its surface is pressed against the film to form unevenness corresponding to the unevenness of the embossing roll on the film surface. The embossing roll with unevenness on its surface is pressed against the film to form unevenness corresponding to the unevenness of the embossing roll on the film surface. An embossing roll is a roll with a pattern engraved on its surface.

[0086] Furthermore, the method is not limited to using an embossing roll, and an embossing plate may also be used. In addition, the present invention is not limited to embossing, and any other processing may be used as long as a relief is formed on a part of the film. stomach.

[0087] In this embodiment, the film 411 is provided with projections and depressions on both sides to form a pattern. Fold it in the center, overlap the two corners that sandwich the bent part, and glue the three sides together. It has a sealed structure.

[0088] Next, the film 411 is folded in the center to form the state shown in FIG. 4(A).

[0089] As shown in FIG. 4(B), the secondary battery is made up of a positive electrode 101, a separator 103, and a negative electrode The positive electrode 101 and the negative electrode 102 are laminated together, and the buffer material 110 is prepared. The current collectors used are stainless steel, gold, platinum, zinc, iron, nickel, copper, aluminum, Metals such as titanium and tantalum, and their alloys, are highly conductive and have low carriers such as lithium. Materials that do not alloy with ions can be used. Also, silicon, titanium, neodymium Aluminum alloys to which elements such as scandium and molybdenum, which improve heat resistance, have been added. Gold can be used. It can also be made of a metal element that reacts with silicon to form silicide. The metal element that reacts with silicon to form silicide is zirconium. Titanium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten There are stainless steel, cobalt, nickel, etc. The current collectors are available in foil, plate (sheet), mesh, etc. , cylindrical, coil, punched metal, expanded metal, or other shapes may be used as appropriate. It is preferable to use a current collector having a thickness of 5 μm or more and 40 μm or less. For the sake of simplicity, a laminated assembly of a positive electrode 101, a separator 103, and a negative electrode 102 is shown here. Although an example of combining the two and storing them in one exterior body was shown, in order to increase the capacity of the secondary battery, In this embodiment, 12 combinations are stacked and stored in the exterior body. Stored in the exterior housing.

[0090] Then, two lead electrodes having a sealing layer 415 shown in FIG. 4(C) are prepared. Also called lead terminals, these are used to pull out the positive or negative electrodes of a secondary battery to the outside of the exterior film. As the lead electrodes, the positive electrode lead 104 is made of aluminum, and the negative electrode lead 1 05 uses nickel-plated copper.

[0091] Then, the positive electrode lead 104 and the protruding portion of the positive electrode 101 are electrically connected by ultrasonic welding or the like. Then, the negative electrode lead 105 and the protruding portion of the negative electrode 102 are electrically connected by ultrasonic welding or the like. Connect to the target.

[0092] Then, in order to leave one side for the electrolyte, two sides of the film 411 are heat-pressed. During the thermocompression bonding, the sealing layer 415 provided on the lead electrode also melts, and the lead electrode and the film 411 are fixed. Then, in a reduced pressure atmosphere or an inert atmosphere, A desired amount of electrolyte is dropped onto the inside of the bag-shaped film 411. The remaining unpressurized edges of the film are sealed by thermocompression.

[0093] In this manner, the power storage unit 400 shown in FIG. 4(D) can be manufactured.

[0094] The obtained power storage body 400 has a pattern with unevenness on the surface of the film 411 that serves as the exterior body. Also, the end face region is a thermocompression bonding region, and this part also has a pattern with unevenness on the surface. Compared with the central part, the unevenness in the thermocompression bonding region is small, but it can relieve the stress applied when the secondary battery is bent. By adopting a structure that relieves the strain caused by the stress, the secondary battery can be bent or deformed without (the exterior body, etc.) being damaged, and long-term reliability can be ensured.

[0095] Also, a sample having the above configuration is prepared without the electrolytic solution, and an X-ray photograph in the case of cutting along the dotted line A1 - A2 is shown in FIG. 4(E). In FIG. 4(E), it can be confirmed that there are unevenness on the exterior film and there is a gap between the lower exterior film and the current collector. In X-rays, the plastic film is not photographed, and a sheet-like plastic film (thickness 300 μm) is provided in this gap.

[0096] The sheet-like plastic film provided as a buffer material can prevent the unevenness of the exterior film from directly contacting the current collector and being damaged when the power storage body is bent.

[0097] This embodiment can be freely combined with Embodiment 1 or Embodiment 2.

[0098]

[0099] (Embodiment 4) In this embodiment, an example of an electronic device incorporating the power storage body obtained by using any one of Embodiments 1 to 3 is shown.

[0100] As an electronic device to which a power storage body is applied, for example, a head-mounted display, a goggle-type display (also referred to as a television or a television receiver), a desktop personal computer such as a type or a notebook type, a monitor for a computer, a digital camera, a digital video camera, a digital photo frame, an electronic notebook, an electronic book terminal, an electronic translator, a toy, a voice input device such as a microphone, an electric shaver, an electric toothbrush, an electronic high-frequency heating device such as a range, an electric rice cooker, an electric washing machine, an electric vacuum cleaner, a water heater, a fan, hair dryer, air conditioning equipment such as a humidifier, a dehumidifier, and an air conditioner, a dishwasher, a dish dryer clothes dryer, futon dryer, electric refrigerator, electric freezer, electric refrigerator-freezer, DNA storage freezer, flashlight, power tool, smoke detector, alarm device such as a gas alarm device and a crime prevention alarm device, industrial robot, hearing aid, cardiac pacemaker, X-ray imaging device, radiation measuring device, electric massager, health equipment and medical equipment such as a dialysis device, a mobile phone (also referred to as a mobile phone or a mobile phone device ), a portable game machine, a personal digital assistant, a lighting device, headphones, a stereo, a remote controller, a clock such as a table clock or a wall clock, a cordless telephone handset, a transceiver, a pedometer, calculator, a portable or stationary audio playback device such as a digital audio player, a pachinko machine or any large game machine and the like can be mentioned.

[0101] The power storage body obtained by using any one of Embodiments 1 to 3 has an outer package that is thin and flexible film, which is attached to a support structure having a curved surface and can be deformed following the curved surface portion in a region with a large radius of curvature of the support structure.

[0102] In addition, flexible storage batteries can be mounted on the interior or exterior walls of houses and buildings, or on automobiles. It is also possible to incorporate it along the curved surface of the interior or exterior of the vehicle.

[0103] FIG. 5A shows an example of a mobile phone. The mobile phone 7400 has a housing 7401. In addition to the display unit 7402 incorporated in the The mobile phone 7400 is equipped with a speaker 7405, a microphone 7406, and the like. It has a body 7407.

[0104] FIG. 5B shows the mobile phone 7400 in a curved state. When the entire casing 0 is deformed by an external force and curved, the casing 7 provided inside the casing The state of the bent power storage unit 7407 is shown in FIG. The power storage unit 7407 is a laminated battery (also called a laminated battery or a film-covered battery). The power storage unit 7407 is fixed in a bent state. 07 has a lead electrode 7408 electrically connected to a current collector 7409. For example, A buffer material is provided in the area surrounded by the film of the exterior body of the power storage unit 7407. This structure has high reliability even when the mobile phone 740 is bent. 0 is the slot for inserting a SIM card and for connecting USB devices such as USB memory. A connector portion for connecting the power supply and the power source may be provided.

[0105] Figure 5(D) shows an example of a bendable mobile phone. If the mobile phone is bent in the shape shown in FIG. 5(E), it can be made into a bangle-type mobile phone. 100 includes a housing 7101, a display unit 7102, operation buttons 7103, and a power storage unit 7104. FIG. 5F shows a state of the power storage unit 7104 that can be bent. When the battery 104 is bent and worn on the user's arm, the housing is deformed and one part of the battery 7104 is The curvature of part or the whole changes. Specifically, the curvature radius is between 10 mm and 150 mm. Within this range, a part or the whole of the main surface of the housing or the power storage unit 7104 changes. 7104 has a lead electrode 7105 electrically connected to a current collector 7106. For example, a buffer material is provided in the area surrounded by the film of the exterior body of the power storage unit 7104. The structure is such that the body 7104 can maintain high reliability even if it is bent many times with its curvature changed. In this way, the mobile phone shown in Figure 5(D) can change into multiple shapes. To realize this, at least a housing 7101, a display unit 7102, and It is also desirable that the power storage unit 7104 be flexible.

[0106] In addition, the mobile phone 7100 has a slot for inserting a SIM card and a USB memory stick. A connector for connecting a USB device such as the above may be provided.

[0107] Another example of using a mobile phone is shown in Figure 5(D), where the mobile phone is folded in the center. If the center part of the mobile phone is further expanded, it can be made into the shape shown in Figure 5(G). The mobile phone is folded so that the ends overlap as shown in Figure 5(H) to make it smaller. It can be made small enough to fit in a user's pocket. Figures 5(D), 5(G), and 5(H) If only the deformation shown in FIG. 1 is observed, the power storage unit 7104 is not bent. When it is dropped or subjected to other impacts, the thin power storage body 71 disposed inside will also be impacted. If a cushioning material is provided in the region surrounded by the film of the exterior body of the power storage body 7104, these impacts can be mitigated, and a robust secondary battery can be realized. Therefore, the power storage body 7104 provided with a cushioning material in the region surrounded by the film of the exterior body can realize a highly reliable mobile phone whether the mobile phone is bent or not. 04 is also impacted. If a cushioning material is provided in the region surrounded by the film of the exterior body of the power storage body 7104, these impacts can be mitigated, and a robust secondary battery can be realized. Therefore, the power storage body 7104 provided with a cushioning material in the region surrounded by the film of the exterior body can realize a highly reliable mobile phone whether the mobile phone is bent or not. Also, FIG. 6(A) shows an example of a vacuum cleaner. By equipping the vacuum cleaner with a secondary battery, it can be cordless. Since a dust collection space for sucking and storing dust is secured inside the vacuum cleaner, the smaller the space occupied by the power storage body 7604, the more preferable. Therefore, it is useful to dispose a power storage body 7604 that is thin and can be bent between the outer surface and the dust collection space. Also, FIG. 6(A) shows an example of a vacuum cleaner. By equipping the vacuum cleaner with a secondary battery, it can be cordless. Since a dust collection space for sucking and storing dust is secured inside the vacuum cleaner, the smaller the space occupied by the power storage body 7604, the more preferable. Therefore, it is useful to dispose a power storage body 7604 that is thin and can be bent between the outer surface and the dust collection space. Also, FIG. 6(A) shows an example of a vacuum cleaner. By equipping the vacuum cleaner with a secondary battery, it can be cordless. Since a dust collection space for sucking and storing dust is secured inside the vacuum cleaner, the smaller the space occupied by the power storage body 7604, the more preferable. Therefore, it is useful to dispose a power storage body 7604 that is thin and can be bent between the outer surface and the dust collection space.

[0108] Also, FIG. 6(A) shows an example of a vacuum cleaner. By equipping the vacuum cleaner with a secondary battery, it can be cordless. Since a dust collection space for sucking and storing dust is secured inside the vacuum cleaner, the smaller the space occupied by the power storage body 7604, the more preferable. Therefore, it is useful to dispose a power storage body 7604 that is thin and can be bent between the outer surface and the dust collection space. Also, FIG. 6(A) shows an example of a vacuum cleaner. By equipping the vacuum cleaner with a secondary battery, it can be cordless. Since a dust collection space for sucking and storing dust is secured inside the vacuum cleaner, the smaller the space occupied by the power storage body 7604, the more preferable. Therefore, it is useful to dispose a power storage body 7604 that is thin and can be bent between the outer surface and the dust collection space. Also, FIG. 6(A) shows an example of a vacuum cleaner. By equipping the vacuum cleaner with a secondary battery, it can be cordless. Since a dust collection space for sucking and storing dust is secured inside the vacuum cleaner, the smaller the space occupied by the power storage body 7604, the more preferable. Therefore, it is useful to dispose a power storage body 7604 that is thin and can be bent between the outer surface and the dust collection space. Also, FIG. 6(A) shows an example of a vacuum cleaner. By equipping the vacuum cleaner with a secondary battery, it can be cordless. Since a dust collection space for sucking and storing dust is secured inside the vacuum cleaner, the smaller the space occupied by the power storage body 7604, the more preferable. Therefore, it is useful to dispose a power storage body 7604 that is thin and can be bent between the outer surface and the dust collection space. Also, FIG. 6(A) shows an example of a vacuum cleaner. By equipping the vacuum cleaner with a secondary battery, it can be cordless. Since a dust collection space for sucking and storing dust is secured inside the vacuum cleaner, the smaller the space occupied by the power storage body 7604, the more preferable. Therefore, it is useful to dispose a power storage body 7604 that is thin and can be bent between the outer surface and the dust collection space.

[0109] The vacuum cleaner 7600 includes an operation button 7603 and a power storage body 7604. Also, FIG. 6(B) shows the state of the power storage body 7604 that can be bent. The power storage body 7604 is provided with a cushioning material in the region surrounded by the film of the exterior body, and has a highly reliable structure in the state where the power storage body 7604 is bent. The power storage body 7604 has a lead electrode 7601 electrically connected to the negative electrode and a lead electrode 7602 electrically connected to the positive electrode. The vacuum cleaner 7600 includes an operation button 7603 and a power storage body 7604. Also, FIG. 6(B) shows the state of the power storage body 7604 that can be bent. The power storage body 7604 is provided with a cushioning material in the region surrounded by the film of the exterior body, and has a highly reliable structure in the state where the power storage body 7604 is bent. The power storage body 7604 has a lead electrode 7601 electrically connected to the negative electrode and a lead electrode 7602 electrically connected to the positive electrode. The vacuum cleaner 7600 includes an operation button 7603 and a power storage body 7604. Also, FIG. 6(B) shows the state of the power storage body 7604 that can be bent. The power storage body 7604 is provided with a cushioning material in the region surrounded by the film of the exterior body, and has a highly reliable structure in the state where the power storage body 7604 is bent. The power storage body 7604 has a lead electrode 7601 electrically connected to the negative electrode and a lead electrode 7602 electrically connected to the positive electrode. The vacuum cleaner 7600 includes an operation button 7603 and a power storage body 7604. Also, FIG. 6(B) shows the state of the power storage body 7604 that can be bent. The power storage body 7604 is provided with a cushioning material in the region surrounded by the film of the exterior body, and has a highly reliable structure in the state where the power storage body 7604 is bent. The power storage body 7604 has a lead electrode 7601 electrically connected to the negative electrode and a lead electrode 7602 electrically connected to the positive electrode. The vacuum cleaner 7600 includes an operation button 7603 and a power storage body 7604. Also, FIG. 6(B) shows the state of the power storage body 7604 that can be bent. The power storage body 7604 is provided with a cushioning material in the region surrounded by the film of the exterior body, and has a highly reliable structure in the state where the power storage body 7604 is bent. The power storage body 7604 has a lead electrode 7601 electrically connected to the negative electrode and a lead electrode 7602 electrically connected to the positive electrode.

[0110] As another example of the power storage body 7604 with two lead electrodes exposed on one short side of the exterior body, FIG. 6(C) shows the state of the power storage body 7605 that can be bent. The power storage body 7605 has a configuration in which a current collector or a lead electrode is exposed on each of the two short sides of the exterior body. As another example of the power storage body 7604 with two lead electrodes exposed on one short side of the exterior body, FIG. 6(C) shows the state of the power storage body 7605 that can be bent. The power storage body 7605 has a configuration in which a current collector or a lead electrode is exposed on each of the two short sides of the exterior body. As another example of the power storage body 7604 with two lead electrodes exposed on one short side of the exterior body, FIG. 6(C) shows the state of the power storage body 7605 that can be bent. The power storage body 7605 has a configuration in which a current collector or a lead electrode is exposed on each of the two short sides of the exterior body. By providing a buffer material in the area surrounded by the film on the exterior of the 7605, it can be bent. and highly reliable.

[0111] 6D shows an example of an internal structure of the power storage unit 7605. As shown in FIG. It is composed of a positive electrode 101, a separator 103, and two negative electrodes 102. 103 is folded, and the positive electrode 101 is placed between them. The positive electrode active material layer is shown here as a combination of a positive electrode and two negative electrodes. In order to increase the capacity of the power storage unit 7605, a combination of more positive and negative electrodes is used. Also, a buffer material 110 is provided in contact with one of the negative electrodes 102. The buffer material 110 is It is placed in the area surrounded by the film of the power storage unit 7605, and reinforces the mechanical strength of the power storage unit 7605. It plays a role in

[0112] The thin power storage unit 7604 is manufactured by the method for manufacturing a secondary battery having a laminate structure described in Embodiment 3. It can be made by

[0113] The thin power storage unit 7604 has a laminate structure and is bent and fixed. The device 7600 has a display unit 7606 that displays the remaining power of a thin power storage unit 7604. The display surface of the display portion 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 a thin storage battery 7604. Once enough power is charged, you can use the vacuum cleaner without the cord. The thin power storage unit 7604 may be charged wirelessly without using a connection cord. By providing a buffer material in the area surrounded by the film of the exterior body of the power storage unit 7604, it is possible to improve resistance to shock. <,> High reliability.

[0114] In addition, when a bendable power storage body is mounted on a vehicle, next-generation clean energy automobiles such as hybrid vehicles (HEVs), electric vehicles (EVs), or plug-in hybrid vehicles (PHEVs) can be realized. Also, power storage bodies that can be bent can be mounted on mobile bodies such as agricultural machinery, motorized bicycles including electric assist bicycles, motorcycles, electric wheelchairs, electric carts, small or large ships, submarines, airplanes such as fixed-wing aircraft and rotary-wing aircraft , rockets, artificial satellites, space exploration vehicles and planetary exploration vehicles, and spaceships.

Explanation of Signs

[0115] 100 Power storage body 101 Positive electrode 102 Negative electrode 103 Separator 104 Positive electrode lead 105 Negative electrode lead 107 Exterior body 110 Buffer material 110a Buffer material 110b Buffer material 300 Power storage body 310a Buffer material 310b Buffer material 311 Adhesive area 400 Power storage body 411 Film 415 Sealing layer 1700 Curved surface 1701 Plane 1702 Curve 1703 Radius of curvature 1704 Center of curvature 1800 Center of curvature 1801 Film 1802 Radius of curvature 1803 Film 1804 Radius of curvature

Claims

1. having a film, a secondary battery having a positive electrode having a first current collector, a negative electrode having a second current collector, a first buffer material, a second buffer material, and a separator in a region surrounded by the film, the secondary battery having a function of being bendable, in plan view, the separator is disposed between the first buffer material and the second buffer material, the first buffer material is not in contact with the first current collector and the second current collector, the second buffer material is not in contact with the first current collector and the second current collector, the first buffer material and the second buffer material are each thicker than the separator, the first buffer material has a function of being bendable and a function of being slidable with respect to the film, the second buffer material has a function of being bendable and a function of being slidable with respect to the film. A secondary battery.

2. having a film, a secondary battery having a positive electrode having a first current collector, a negative electrode having a second current collector, a first buffer material, a second buffer material, and a separator in a region surrounded by the film, the secondary battery having a function of being bendable, the end portion of the separator has a region protruding from the end portion of the second current collector, in plan view, the separator is disposed between the first buffer material and the second buffer material, the shapes of the first buffer material and the second buffer material are rod-shaped, the first buffer material is not in contact with the first current collector and the second current collector, the second buffer material is not in contact with the first current collector and the second current collector, the first buffer material and the second buffer material are each thicker than the separator, the first buffer material has a function of being bendable and a function of being slidable with respect to the film, the second buffer material has a function of being bendable and a function of being slidable with respect to the film. A secondary battery.

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