Secondary battery

Abstract

To provide a battery whose shape can be changed safely, or to provide a battery that can be repeatedly bent.SOLUTION: Provided is a battery having a first lead, a second lead, a first current collector, and a second current collector. The first current collector has: a first portion bonded with the first lead; and a second portion coated with a first active material. The second current collector has: a third portion bonded with the second lead; and a fourth portion coated with a second active material. The first lead, the second portion, and the fourth portion have portions overlapped with each other. The second lead, the second portion, and the fourth portion have portions overlapped with each other.SELECTED DRAWING: Figure 8

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 the internal structure of 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] Mobile information terminal devices such as smartphones and tablet terminals are being actively developed. In addition, such electronic devices are required to be lightweight and small. .

[0004] In recent years, the development of wearable electronic devices has become more and more popular. Examples of wearable devices include wristwatch-type devices worn on the arm and head-mounted devices. Examples include goggle-type or goggle-type devices, and necklace-type devices worn around the neck. For example, a wristwatch-type device has a small display instead of a traditional clock face. In addition, various information other than the time can be provided to the user. The devices are also attracting attention for their use in medical treatment and for self-management of health conditions, and are being put to practical use. .

[0005] Portable devices often have secondary batteries that can be repeatedly charged. Since small secondary batteries are used in portable devices, the secondary batteries are lightweight, small, and have a long life. It is required that time be available.

[0006] 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]

[0007] [Patent Document 1] International Publication No. 2012 / 140709 Summary of the Invention [Problem to be solved by the invention]

[0008] In portable devices, the battery occupies a large proportion of the device's volume. By making the battery so that it can be placed in the limited space inside the housing, This allows devices to be made smaller. Until now, it has been difficult to place batteries in moving parts of equipment, but If this battery could be realized, it would be possible to create devices with better design.

[0009] However, secondary batteries are prone to heat generation and fire if the exterior is damaged. Even when a film is used for the packaging, it is common to cover it with a hard outer casing. However, this structure does not assume that the secondary battery will be bent or otherwise deformed. When the sensor is mounted on a child device, there is a problem in that the location where the sensor can be placed is limited.

[0010] In addition, when conventional secondary batteries are repeatedly bent, not only can the exterior body be damaged, but the electrodes inside the exterior body can also be damaged. There was a risk of short circuits between the electrodes or damage to the electrodes themselves, posing safety concerns.

[0011] 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 repeatedly bent.

[0012] Another object of one embodiment of the present invention is to provide a battery having a large capacity per volume. Another object of the present invention is to provide a highly reliable battery.

[0013] 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]

[0014] One aspect of the present invention is a semiconductor device comprising a first lead, a second lead, a first current collector, and a second current collector. The first current collector has a first portion joined to the first lead and a second portion joined to the first lead. and a second portion on which the first active material is applied. The second current collector is joined to a second lead. The first lead has a third portion coated with a second active material, and a fourth portion coated with a second active material. The second portion and the fourth portion have overlapping portions, and the second lead and the second The first portion and the fourth portion have an overlapping portion.

[0015] In the above, it is preferable that the fixing member is insulating. The board, the first current collector, and the second current collector are fixed by a fixing member at their overlapping portions. The second lead, the first current collector, and the second current collector are fixed by a fixing member at their overlapping portions. It is preferable that the substrate is fixed to the substrate.

[0016] In the above, the first current collector is folded back between the first portion and the second portion, It is preferable that the first lead, the first portion, and the second portion have overlapping portions. The second current collector is folded back between the third portion and the fourth portion, and the second lead is It is preferable that the first portion, the third portion, and the fourth portion have overlapping portions.

[0017] In the above, the first current collector is arranged so that the surface to be joined with the first lead faces outward. The second current collector is folded back so that the surface to be joined with the second lead is on the outside. It is preferable that the above is done.

[0018] In the above, it is preferable that the insulating member includes a first insulating member and a second insulating member. At this time, the first portion and the second portion overlap with each other via the first insulating member, and the third portion It is preferable that the first and fourth portions overlap with each other via the second insulating member. The edge member covers the first portion and the first lead, and the second insulating member covers the third portion and the second lead. It is preferable to cover the leads.

[0019] In the above, it is preferable that the device has an exterior body. In this case, the exterior body is a film and is folded in two so as to sandwich the first current collector and the second current collector. In addition, the exterior body is preferably a pair of first shields sandwiching the first and second current collectors. and a second seal portion overlapping the first lead and the second lead. In addition, the exterior body is preferably a second current collector in a region overlapping the first current collector and the second current collector. It is preferable that the sealing portion has a wave shape that is approximately parallel to the sealing portion.

[0020] In the above, the first seal portion and the second seal portion are flat and not corrugated. It is preferable that there is.

[0021] In the above, the first seal portion and the end portion of the first current collector or the end portion of the second current collector The distance between the first current collector and the second current collector is 0.8 times or more and 3.0 times or less the thickness of the laminate including the first current collector and the second current collector. It is preferable that the ratio is equal to or less than twice the normal ratio.

[0022] In the above, the distance between the pair of first seal portions and the width or width of the first current collector are The difference between the width of the first current collector and the width of the second current collector is 1.6 times the thickness of the laminate including the first current collector and the second current collector. It is preferable that the ratio is 6.0 or more.

[0023] Another aspect of the present invention is a semiconductor device comprising a first current collector, a second current collector, a first lead, and a second A method for producing a battery having leads, comprising: stacking a first current collector and a second current collector; a first current collector and a first lead, and a second current collector and a second lead, A second step of bonding the first current collector, the second current collector, the first lead, and the second lead. and a third step of fixing the board with a fixing member.

[0024] In the above, between the second step and the third step, a part of the first current collector is , and a fourth step of folding back a portion of the second current collector.

[0025] In addition, in the above, instead of the first step, a plurality of first collectors and a plurality of second collectors are The fifth step preferably comprises stacking a plurality of conductive bodies. A stack of first current collectors offset from one another and a stack of a plurality of second current collectors offset from one another. It's Tep. Effect of the Invention

[0026] 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 repeatedly bent. Or, it is possible to provide a battery with a large capacity per volume. Or, we can provide highly reliable batteries. [Brief description of the drawings]

[0027] [Figure 1] 4 is a flowchart of a method for producing a battery according to an embodiment. [Diagram 2] 2 shows a current collector 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] 1A to 1C are diagrams illustrating a method for manufacturing a battery according to an embodiment; [Figure 8] 1A to 1C are diagrams illustrating a method for manufacturing a battery according to an embodiment; [Figure 9] 4 is a flowchart of a method for producing a battery according to an embodiment. [Figure 10] 1A to 1C are diagrams illustrating a method for manufacturing a battery according to an embodiment; [Figure 11] 1A to 1C are diagrams illustrating a method for manufacturing a battery according to an embodiment; [Figure 12] 1A to 1C are diagrams illustrating a method for manufacturing a battery 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] 1 is an electronic device according to an embodiment. [Figure 16] 1 is an electronic device according to an embodiment. [Figure 17] 1 is an external photograph according to Example 1. [Figure 18] 1 is an external photograph according to Example 1. [Figure 19] 1 is an external photograph according to Example 1. [Figure 20] 3 is a photograph showing the appearance of a battery according to Example 1. [Figure 21] 4 is a transmission X-ray image of a battery according to Example 2. [Figure 22] 4 is a transmission X-ray image of a battery according to Example 2. [Figure 23] 11 is an X-ray CT image of a battery according to Example 2. [Figure 24] 5 shows charge and discharge characteristics of the battery according to Example 2. [Diagram 25] 5 shows charge and discharge characteristics of the battery according to Example 2. [Figure 26] 5 shows charge and discharge characteristics of the battery according to Example 2. [Figure 27] 4 is a transmission X-ray image of a battery according to Example 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] 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.

[0029] 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 hatch pattern may be the same and no particular symbol may be used.

[0030] In each figure described in this specification, the size, layer thickness, or area of ​​each component is indicated by the following formula: The figures may be exaggerated for clarity and are not necessarily limited to scale. stomach.

[0031] 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.

[0032] (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. .

[0033] The battery according to one embodiment of the present invention includes a first current collector and a second current collector disposed inside a film-like exterior body. The first current collector is either a positive electrode current collector or a negative electrode current collector. The second current collector is the other of the positive electrode current collector and the negative electrode current collector. Each lead has a pair of leads extending from the inside to the outside of the exterior body. Each is joined to the first current collector or the second current collector.

[0034] The first current collector and the second current collector each have a protruding portion (also called a tab portion) in a plan view. The tab portion has a joining portion (also called a first portion) to which the lead is joined. In addition, the first current collector and the second current collector have a portion coated with an active material (electrode portion, Also referred to as the second portion.

[0035] In this specification and the like, the configuration contained inside the exterior body is referred to as an electrode laminate, a laminate, or an electrode. The electrode laminate is composed of at least a first current collector and a second current collector. The electrode laminate also includes a lead joined to the first current collector, and a second current collector. The electrode laminate may include a lead to be joined to the first current collector and a second current collector. A separator and an electrolytic solution may be provided between the electrodes. In this case, the separator may not be provided.

[0036] The battery may also have a plurality of first current collectors and a plurality of second current collectors. The greater the number of current collectors that are connected, the greater the capacity of the battery.

[0037] One aspect of the invention is a semiconductor device comprising a lead, a second portion of the first current collector, and a second portion of the second current collector. The lead and the first current collector have portions that are fixed to each other by a fixing member. The body is not only joined at the part where the tab overlaps, but is also fixed at parts other than the tab. Similarly, the lead and the second current collector are further fixed at a portion other than the tab portion.

[0038] Here, the lead and the first current collector are fixed only by the tab portion, and the lead and the second current collector are Consider a case where the battery is fixed only by the tab. If the battery is repeatedly bent or deformed, When the first current collector and the second current collector are rotated, the first current collector and the second current collector are also repeatedly deformed. In the current collector, the tab portion is a portion where the active material layer is not applied, and is thicker than the other portions. The width of the tab portion is smaller than that of the second portion on which the active material layer is applied. The tab portion has a lower mechanical strength than the other parts of the current collector. Therefore, the first current collector and the second current collector are repeatedly deformed. When the tabs are exposed to heat, cracks are likely to occur in the tabs and their bases. In such a case, the tab portion may break.

[0039] In one embodiment of the present invention, the first current collector and the second current collector are connected via the tab portion. The lead and the second part of the current collector are fixed to each other using a fixing member. This makes it possible to realize a structure in which the tab section is less likely to deform. No matter what type of deformation is applied, it is difficult for problems to occur, and a highly reliable battery can be realized.

[0040] In addition, the first current collector and the second current collector are fixed to each other by the fixing member. It is preferable that the electrodes are not fixed to each other. This prevents the electrodes from being damaged by the fixing member when the battery is bent. The fixed parts act as fulcrums and the current collectors shift relative to each other, causing stress on each collector. This can prevent the current collectors from being damaged. This allows it to be bent with less force.

[0041] As an example of a preferred configuration, the tab portions of the first current collector and the second current collector are connected to the lead. The area between the joint and the electrode portion where the active material is applied is folded back. A part of the tab portion including the joint portion (first portion) of the first current collector and the second current collector, and a part of the lead The part and the electrode portion (second portion) are fixed by a fixing member.

[0042] Here, it is preferable that the tab portion is folded back in a curved state rather than bent. For example, the radius of curvature is 5 times or more, preferably 10 times or more, more preferably 10 times or more, the thickness of the tab portion. It is preferable that the tab portion is bent at least 20 times and less than 50 times. Depending on the material of the current collector, the radius of curvature of the folded part may be less than 5 times the thickness of the tab part. In this case, the tab may break when folded back. Also, if the radius of curvature is too large ( For example, if the capacity is increased by more than 50 times, the thickness of the battery will become too large.

[0043] When the tab portion is folded back, the tab portion of one current collector and the other current collector having a different polarity are folded back. If the current collectors on the other side come into contact with each other, there is a risk of an electrical short circuit. It is preferable to insulate a part of the surface of the current collector. It is preferable to sandwich an insulating member between the tab portion and the insulating member. is more preferred.

[0044] In addition, when the tab is folded back, it should be folded so that the surface that is bonded to the lead is on the outside. It is preferable to repeat the process.

[0045] In another preferred embodiment, the lead is connected to the tab portion. The lead is shaped to extend to the electrode portion. These may be fixed by a fixing member.

[0046] In addition, the exterior body covering the first current collector and the second current collector has a plurality of periodically connected electrodes in one direction. It is preferable to use a corrugated film that is connected to the exterior body. The stress caused by bending is relieved by deformation that changes the wave period and amplitude, and the exterior It can prevent the body from being damaged.

[0047] In addition, one side of the exterior body is folded so as to sandwich the first current collector and the second current collector, The seal is formed by crimping the remaining three sides of the first current collector and the second current collector. In this case, the part that overlaps with the lead is called the top seal part, The other portion can be called a side seal portion.

[0048] At this time, the width direction of the first current collector or the second current collector (the direction parallel to the top seal portion) By providing a gap between the end of the first seal and the side seal, the first It is possible to suppress friction between the current collector or the second current collector and the exterior body. The distance between the first current collector or the second current collector and the side seal portion is The thickness of the laminate obtained by laminating the first and second current collectors is 0.8 times or more, preferably 0.9 times or more, more preferably It is preferable that the ratio is 1.0 or more and 3 or less, and more preferably 2 or less. Alternatively, for example, the distance between the pair of side seals and the width of the first current collector or the second current collector The difference is preferably 1.6 times or more the thickness of the laminate in which the first current collector and the second current collector are laminated. The ratio is preferably 1.8 times or more, more preferably 2.0 times or more, and is preferably 4 times or less. stomach.

[0049] In addition, the end of the first current collector or the second current collector in the width direction and the side seal of the exterior body are In order to provide a gap between the two, the shape of the exterior body is molded in advance (also called pre-molding). It is preferable that the preforming step is performed, for example, before the step of forming the side seal. The position where the first current collector overlaps with the end of the first current collector in the width direction and the position where the second current collector overlaps with the end of the first current collector in the width direction and the position where the side seal is to be made in the later process are to be made. The exterior body may be press molded so as to provide a gentle curve between the part to be covered and the part to be covered.

[0050] For example, if preforming is not performed, the first current collector may be formed, for example, when forming the side seal. Or, a portion where the exterior body is bent is formed with the end portion in the width direction of the second current collector as a fulcrum. On the other hand, when the above-mentioned preformed exterior body is used, the side seal is formed. This makes it difficult for such bent portions to form. It is possible to more effectively prevent the current collector or the second current collector from rubbing against the exterior body, It is possible to realize a battery that has high resistance to deformation such as repeated bending.

[0051] A more specific example will be described below with reference to the drawings.

[0052] [Production method example 1] An example of a method for manufacturing a battery according to one embodiment of the present invention will be described below. 4 is a flowchart showing a method for producing the battery shown in FIG.

[0053] [About the current collector] First, a current collector included in a battery according to one embodiment of the present invention will be described. 1A and 11B are schematic top views of a current collector 11a and a current collector 11b, respectively.

[0054] One of the current collectors 11a and 11b serves as a positive electrode current collector and the other serves as a negative electrode current collector. In this embodiment, the current collector 11a functions as a negative electrode current collector, and the current collector 11b functions as a positive electrode current collector. Used as an electrical conductor.

[0055] The current collector 11a has a tab portion 21a and an electrode portion 22a that functions as an electrode of the battery. The tab portion 21a is a protruding portion of the current collector 11a and has a width smaller than that of the electrode portion 22a. An active material layer 13a is applied to the electrode portion 22a.

[0056] The current collector 11b has a tab portion 21b and an electrode portion 22b that functions as an electrode of the battery. The tab portion 21b is a protruding portion of the current collector 11b and has a width smaller than that of the electrode portion 22b. An active material layer 13b is applied to the electrode portion 22b.

[0057] Here, the current collector 11a and the current collector 11b have an active material layer 13a or an active material layer 13b on only one surface. Preferably, one side of the substrate is coated with a layer of polymeric material 13b, and the other side is uncoated.

[0058] Here, it is preferable that the width Wa of the current collector 11a is different from the width Wb of the current collector 11b. In FIG. 2(A) and (B), the width Wa of the current collector 11a is larger than the width Wb of the current collector 11b. This shows an example of a case where

[0059] The above is the explanation of the current collector.

[0060] Next, a method for manufacturing a battery will be described with reference to the flowchart shown in FIG. 1 and FIGS. He explains.

[0061] [Step S01] First, a plurality of current collectors 11a and 11b are prepared and stacked while being shifted in the length direction. do.

[0062] FIG. 3(A) is a perspective schematic diagram showing a laminated structure. 1, the active material layer 13a and the active material layer 13b are not shown.

[0063] FIG. 3(A) shows an example in which four current collectors 11a and four current collectors 11b are used. Two current collectors 11a are arranged on the outside, and a pair of current collectors 11b and a pair of current collectors 11c are arranged on the inside. The current collectors 11a are arranged alternately. The surfaces of the layers 13a (not shown) opposite to the coated surfaces are arranged in contact with each other. The pair of current collectors 11b are arranged such that the surfaces opposite to the coated surfaces of active material layers 13b (not shown) face each other. That is, the current collector 11a and the current collector 11b are arranged so that the active material The active material layer 13a and the active material layer 13b are located between two adjacent current collectors 11a and between two adjacent current collectors 11a and The active material layer is not provided between the current collectors 11b. In this case, the pair of current collectors 11a and the pair of current collectors 11b can be easily displaced from each other. As described later, the current collectors of the same polarity slide against each other, causing the current collectors to move when the battery is bent. This can reduce the stress applied to the device itself.

[0064] As shown in FIG. 3A, a gap indicated by a dashed line is provided between the current collector 11a and the current collector 11b. A separator 14 may be disposed. The separator 14 has a width larger than that of the current collector 11b. It is preferable to use the following:

[0065] Here, the laminated structure is not limited to the structure shown in FIG. 3(A). For example, as shown in FIG. As shown in FIG. 1, a separator 14 is disposed on the outer side of each of the two outermost current collectors 11a. This can prevent the current collector 11a from coming into contact with an exterior body described later. Therefore, it is possible to prevent the exterior body from being damaged due to friction between the exterior body and the current collector 11a. In this case, the separator 14 may be wider than the current collector 11a. It is preferable that

[0066] FIG. 4B shows an example in which one current collector 11b is provided between two current collectors 11a. Here, the current collector 11b has a configuration in which the active material layer 13b is coated on both sides. By adopting such a configuration, the battery can be made thin, and the The capacity per unit weight can be increased. In addition, the battery itself can be made thinner. Furthermore, the current collector 11a has an active material layer 13a (see FIG. Since the opposite surfaces of the current collectors 11 (not coated) are arranged to contact each other, The a's slide easily against each other, which makes it possible to bend the battery with less force.

[0067] FIG. 4C shows a configuration in which a pair of current collectors 11b are sandwiched between one separator 14a. Here, the separator 14a is folded back and then joined at its periphery to form a bag shape. By using such a separator 14a, the pair of current collectors 11 Even if the position of b is misaligned, it is possible to prevent an electrical short circuit between the positive electrode and the negative electrode. .

[0068] In FIG. 4(D), the two outermost current collectors 11a are also separators, unlike FIG. 4(C). As a result, the exterior body and the current collector 11a are rubbed against each other, causing the exterior body to It can prevent the body from being damaged.

[0069] FIG. 3(B) shows a state in which the current collector 11a and the current collector 11b are stacked. For clarity, the separator 14 is not shown hereinafter.

[0070] As shown in FIG. 3B, the current collectors 11a and the current collectors 11b are connected to each other by tabs. The tab portion 21b is relatively shifted in the direction in which the tab portion 21a or the tab portion 21b is provided (in the direction indicated by the arrow). By displacing these in advance, it is possible to stack them in a staggered manner, as described below. In addition, the current collector 11a and the current collector 11b are bent in order to offset the misalignment that occurs when the current collector 11a and the current collector 11b are bent in order to offset the misalignment. Specifically, the positions of the plurality of electrode parts 22a and the electrode parts 22b can be aligned. At this time, the tab portions 21a of all the current collectors 11a are arranged so as to overlap each other. Similarly, it is preferable to stack the current collectors 11b in such a manner that the tab portions 21b of all the current collectors 11b overlap each other. It is preferable to laminate the layers so that a portion is formed.

[0071] As shown in FIG. 3B, the pair of current collectors 11a and the pair of current collectors 11b arranged on the inner side The electric elements 11b do not need to be arranged in a staggered manner.

[0072] [Step S02] Next, as shown in FIG. 3(C), the tab portion 21a of the current collector 11a and the tab portion 21b of the current collector 11b are The leads 12a and 12b are bonded to the tab portion 21b. Sonic welding or the like can be used.

[0073] Here, since the tab portion 21a of the current collector 11a is arranged in a shifted manner, The joint 15a between the tab portion 21a and the lead 12a encloses the tab portion 21a of the entire current collector 11a. It is important that the range includes the tab portion 21b of the current collector 11b and the lead 12b. The same is true for the joint 15b.

[0074] In addition, in FIGS. 3(A), (B), and (C), a plurality of current collectors 11a and 11b are arranged in the same The example shows a case where a plurality of current collectors 11a and 11b having different lengths are used. In FIG. 5(A) and (B), the current collector 11a is longer in the longitudinal direction as it approaches the joining surface side. In this example, the tab portion 11b is used. Since the tab portion 21a and the tab portion 21b do not shift in the length direction, the connection between the leads 12a and 12b is In addition, in FIG. 5(A) and (B), the length of the tab portion 21a or the tab portion 21b is The current collectors 11a and 11b have the same length, and the electrode portions 22a and 22b have different lengths. b was used, but as shown in FIG. 5(C), the length of the electrode portion 22a or the electrode portion 22b was the same. The length of the tab portion 21a or the length of the tab portion 21b are different. A conductive body 11b may also be used.

[0075] [Step S03] Next, the tab portion 21a and a part of the lead 12a, and the tab portion 21b and a part of the lead 12b are are insulated from each other.

[0076] FIG. 6A shows a lead 12a and a lead 12b, which are connected to a plurality of current collectors 11a and FIG. 11b is a perspective view of the state where it is joined to the first embodiment.

[0077] As shown in FIG. 6B, a part of the tab portion 21a of the current collector 11a and a part of the lead 12a By covering these with the insulating member 16a, the surfaces can be insulated. It is preferable that the edge member 16a is provided so as to cover the joint portion 15a. A part of the tab portion 21b and a part of the lead 12b are covered with an insulating member 16b.

[0078] The insulating members 16a and 16b are then folded back around the current collectors 11a and 11b. As a result, the folded portion of the current collector 11b is in contact with the surface of the current collector 11a. This prevents these from being electrically shorted. In the case where the two current collectors 11a are located on the outermost side as shown in FIG. a is originally electrically connected, and there is no problem even if they come into contact, so current collection The insulating member 16a on the body 11a side does not need to be provided.

[0079] As shown in FIG. 6C, a part of the tab portion 21a of the current collector 11a and a part of the lead 12a A part of the lead 12b is covered with the insulating layer 11b, a part of the tab portion 21b of the current collector 11b, and a part of the lead 12b. A configuration in which an edge member 16 is provided may also be used.

[0080] The insulating members 16a, 16b, and 16 are preferably made of polyimide tape. Insulating tape such as tape can be preferably used. This prevents the battery from shifting when it is deformed. The insulating material is not limited to this, and may be in various forms such as a bag or a sheet. The material is made by applying a liquid resin material to the surface of the part to be insulated and then hardening it. It may be used.

[0081] In addition, the insulating member prevents electrical shorting when the tab portion 21a or the tab portion 21b is folded back. The purpose of this is to prevent the electrode from being damaged, and the position where it is placed is not limited to the above. For example, the electrode part 2 The insulating layer 22 may be provided to cover the electrode portion 22a and the electrode portion 22b, or may be attached to a part of the surface of these portions. In addition, when the tab portion 21b is folded back, the folded back portion of the tab portion 21b and the current collector 1 An insulating member may be disposed between the first and second electrodes 1a.

[0082] [Step S04] Next, the tab portions 21a and 21b are folded back.

[0083] At this time, the surface of the tab portion 21a to be joined to the lead 12a and the surface of the tab portion 21b to be joined to the lead 12a are The tab portion 21a and the tab portion 21b are folded back so that the surface to be joined with the tab portion 21a and the tab portion 21b are positioned on the outside. It is preferred.

[0084] FIG. 7(A) shows the state of the joint portion 15a side when the tab portion 21a and the tab portion 21b are folded back. 7(B) is a perspective view of FIG. 7(A) rotated 180 degrees. For the sake of clarity, hereinafter, the insulating members 16a and 16b, or the insulating member 16, It is not stated explicitly.

[0085] As shown in FIG. 7A, a part of the lead 12a and a part of the lead 12b are The tab portion 21a is disposed so as to overlap with the electrode portion 22a of the current collector 11a and the electrode portion 22b of the current collector 11b. It is preferable to fold the tab portion 21b. Similarly, the tab portions 21a and 21b are also folded. It is preferable that the electrode portion 22a and the electrode portion 22b are bent so as to overlap each other.

[0086] [Step S05] Next, the leads 12a, 12b, the electrode portions 22a, and the electrode portions 22b are attached to the fixing member 17. Fix it by.

[0087] FIG. 8(A) is a perspective view of the joint portion 15a side when the fixing member 17 is provided, and FIG. 8B) is a perspective view when FIG. 8(A) is rotated 180 degrees.

[0088] The fixing member 17 can be preferably an insulating tape such as a polyimide tape. The fixing member 17 is not limited to this, and may be a rubber ring (rubber band) or any other suitable material. Alternatively, an insulating material such as a resin material molded into a desired shape may be used.

[0089] In this manner, the electrode member 10 can be produced.

[0090] As shown in FIG. 8A and other figures, the electrode member 10 has a tab portion 21a and a tab portion 21b folded back. The joints 15a and 15b overlap with parts of the electrode portions 22a and 22b. Therefore, compared with a configuration in which the tab portion 21a and the tab portion 21b are not folded back, Therefore, the length in the longitudinal direction can be shortened. Because it can be made more compact, the capacity per unit volume can be increased.

[0091] [Step S06] Next, the electrode member 10 is covered with an exterior body together with the electrolyte, and the periphery of the exterior body is sealed (sealed). )do.

[0092] Through the above steps, a battery of one embodiment of the present invention can be manufactured.

[0093] [Production method example 2] The following describes a battery manufacturing method example that is partially different from the above-mentioned manufacturing method example 1 with reference to the drawings. Here, explanations of parts that overlap with those described above may be omitted.

[0094] FIG. 9 is a flow chart showing the fabrication method exemplified below.

[0095] [Step S11] First, as shown in FIG. 10(A), a plurality of current collectors 11a and 11b are prepared. Unlike the first example of the manufacturing method, the pieces are stacked without being intentionally misaligned. do.

[0096] [Step S12] Next, as shown in FIG. 10(B), the tab portion 21a of the current collector 11a and the current collector 11b are The leads 12a and 12b are joined to the tab portions 21b, respectively.

[0097] At this time, the leads 12a and 12b partially overlap the electrode portions 22a and 22b. The shape shall be such that

[0098] [Step S13] Next, in order to prevent an electrical short circuit between the lead 12b and the current collector 11a, An insulating member 18 is provided between them to insulate the lead 12b from the current collector 11a.

[0099] In FIG. 11(A), an insulating member 18 is wound around a part of the current collector 11a and a part of the current collector 11b. The following example shows this.

[0100] The configuration of the insulating member 18 is not limited to this, and any other insulating member may be used as long as it can insulate the leads and current collectors of different poles. In FIG. 12(A), a current collector 11a and a lead 12b are arranged. In FIG. 12B, an example in which an insulating member 18a is disposed only between the 1 shows an example in which the portion of the lead 12b overlapping with the current collector 11a is covered with an insulating member 18b. In FIG. 12C, the portion of the lead 12a overlapping with the current collector 11a and An example is shown in which the portion of the lead 12b that overlaps with the current collector 11a is sandwiched by an insulating member 18c.

[0101] The insulating member 18, the insulating member 18a, and the insulating member 18b are the same as the insulating member 16, etc. Similar materials can be used.

[0102] [Step S14] Next, as shown in FIG. 11(B), the lead 12a, the lead 12b, the electrode portion 22a, The pole portion 22b is fixed by a fixing member 17.

[0103] In this manner, the electrode member 10a can be produced.

[0104] According to this example of the manufacturing method, since there is no step of folding back the tab portion 21a and the tab portion 21b, , and thus productivity can be improved.

[0105] [Step S15] Next, the electrode member 10a is covered with an exterior body together with the electrolyte, and the periphery of the exterior body is sealed (sealed). (stop).

[0106] Through the above steps, a battery of one embodiment of the present invention can be manufactured.

[0107] The above is a description of an example of a method for producing a battery.

[0108] [Battery configuration example] In the following, a configuration example of a battery using the electrode member exemplified in the above-mentioned manufacturing method example will be described with reference to the drawings. Here, we will explain a configuration example of a battery that is particularly suitable for applications where the battery is repeatedly bent. Reveal.

[0109] FIG. 13(A) shows a schematic top view of the battery 50. Also, FIGS. 13(B1), (B2), and (C ) are cut along the lines C1-C2, C3-C4, and A1- A schematic cross-sectional view at A2 is shown.

[0110] The battery 50 includes an exterior body 51 and an electrode member 10 housed inside the exterior body 51. The lead 12a and the lead 12b of the electrode member 10 extend outside the outer casing 51. In addition to the electrode members 10, an electrolyte (not shown) is enclosed inside the exterior body 51. It is being done.

[0111] The exterior body 51 has a film-like shape and is folded in two so as to sandwich the electrode member 10. The exterior body 51 includes a folded portion 61, a pair of sealed portions 62, a sealed portion 63, and The pair of seal portions 62 are provided to sandwich the electrode member 10 and are also called side seals. In addition, the sealing portion 63 is formed by sealing the lead 12a and the lead 12b in the overlapping portion. It can also be called a top seal.

[0112] The exterior body 51 has a corrugated shape in which ridge lines 71 and valley lines 72 are arranged alternately at the portion where it overlaps with the electrode member 10. In addition, the seal portion 62 and the seal portion 63 of the exterior body 51 preferably have a corrugated shape. It is preferable that the sealing portion 63 is flat and has no curve. There may be a step at the portion where it overlaps with the gate 12b.

[0113] The configuration of the electrode member 10 can be as described above.

[0114] FIG. 13(B1) is a cross section cut at the portion overlapping with the ridge line 71, and FIG. 13(B2) is a cross section cut at the portion overlapping with the ridge line 71. 13(B1) and (B2) are cross sections cut at the portion overlapping with the valley line 72. 0 and corresponds to a cross section in the width direction of the electrode member 10.

[0115] Here, the end of the electrode member 10 in the width direction, that is, the end of the current collector 11a or the current collector 11b The distance between the battery 50 and the seal portion 62 is defined as La. When the current collectors 11a and 11b are aligned, they are displaced from each other in the longitudinal direction, as described later. At that time, if the distance La is too short, the outer casing 51 and the current collector 11a or the current collector 11 b may rub strongly against the exterior body 51, and the exterior body 51 may be damaged. If the metal film were exposed, it would be corroded by the electrolyte. Therefore, it is preferable to set the distance La as long as possible. If it is too large, the volume of the battery 50 will increase.

[0116] In addition, the thicker the electrode member 10 is, the more the edge of the current collector 11a or the current collector 11b and the shielding layer 11b are formed. It is preferable to increase the distance La between the hole portion 62 and the base portion 63 .

[0117] More specifically, when the thickness of the electrode member 10 is t, the distance La is 0. 8 times or more and 3.0 times or less, preferably 0.9 times or more and 2.5 times or less, more preferably 1.0 times It is preferable that the distance La is in this range, so that the compact Moreover, a battery having high reliability against bending can be realized.

[0118] In addition, when the distance between the pair of seal portions 62 is a distance Lb, the distance Lb is It is preferable that the width of the current collector 11a is sufficiently larger than the width of the current collector 11a (here, the width Wa of the current collector 11a). Therefore, when the battery 50 is repeatedly bent or deformed, the electrode member 10 and the exterior body 51 Even if the electrode member 10 comes into contact with the electrode member 10, a part of the electrode member 10 can be displaced in the width direction. This effectively prevents the exterior body 51 from rubbing against each other.

[0119] For example, the distance Lb between the pair of seal portions 62 and the width Wa of the current collector 11a (or the The difference between the width Wb of the electrode member 10 and the width Wb of the electrode member 11 is preferably 1.6 times or more and 6.0 times or less than the thickness t of the electrode member 10. The ratio should be preferably 1.8 times or more and 5.0 times or less, and more preferably 2.0 times or more and 4.0 times or less. is preferred.

[0120] In other words, it is preferable that the distance Lb, the width Wa, and the thickness t satisfy the following relationship: .

[0121]

number

[0122] Here, a is 0.8 or more and 3.0 or less, preferably 0.9 or more and 2.5 or less, and more preferably Most of the time, the ratio is between 1.0 and 2.0.

[0123] FIG. 13(C) is a cross section including the lead 12a, and shows the battery 50 and the electrode member 10 along the length. It corresponds to the cross section in the direction of the arrow.

[0124] FIG. 13D is a cross section of the electrode member 10a in place of the electrode member 10. 1 shows a schematic diagram.

[0125] As shown in FIG. 13C, at the bent portion 61, the end portion in the longitudinal direction of the electrode member 10 That is, a space 73 is provided between the end of the current collector 11a or the current collector 11b and the exterior body 51. It is preferable to do so.

[0126] FIG. 14 shows a schematic cross-sectional view of the battery 50 when it is bent. This corresponds to the cross section taken along the line B1-B2 in the drawing.

[0127] When the battery 50 is bent, the part of the exterior body 51 located on the outside of the bend stretches, and the part located on the inside The other part is deformed so as to shrink. More specifically, the part located outside the exterior body 51 is The amplitude of the wave is reduced and the period of the wave is increased. The part located at is deformed so that the wave amplitude becomes large and the wave period becomes small. In this way, the deformation of the exterior body 51 reduces the stress applied to the exterior body 51 due to bending. Therefore, the material that constitutes the exterior body 51 does not need to expand or contract. 1 can bend the battery 50 with little force without breaking.

[0128] In addition, as shown in FIG. 14, the current collector 11a and the current collector 11b are misaligned relative to each other. In this manner, the electrode member 10 is deformed. At this time, the plurality of current collectors 11a of the electrode member 10 The current collectors 11b are fixed at one end on the seal portion 63 side by the fixing member 17. The amount of deviation increases toward the bent portion 61. This relieves the stress on the electrode member 10, and the current collectors 11a and 11b themselves expand and contract. As a result, the battery 50 can be bent without damaging the electrode member 10. do.

[0129] In addition, in the case of a battery using a solid electrolyte or a highly viscous gel electrolyte, the electrode member When the entire electrode 10 is covered with the electrolyte, the current collector 11a and the current collector 11b are less likely to be displaced relative to each other. Therefore, the stress relaxation cannot be expected. A plurality of laminates each having an electrolyte layer between the first and second electrodes are prepared, and the laminates are stacked. As a result, even when a solid electrolyte or a gel electrolyte having a high viscosity is used, The current collector 11a and the current collector 11b may be configured to be shifted relative to each other.

[0130] In addition, by providing a space 73 between the electrode member 10 and the exterior body 51, the electrode member The current collector 11a and the current collector 11b located inside the neutral plane of the coil 10 are in contact with the exterior body 51. The two electrodes can be relatively displaced without any distortion.

[0131] The battery exemplified in this configuration example was not damaged in the exterior body or in the electrode members even when repeatedly bent and stretched. This battery is less susceptible to damage and its battery characteristics are also less likely to deteriorate.

[0132] The above is a description of an example of the battery configuration.

[0133] [About each component] Hereinafter, the electrode member and each component of the battery according to one embodiment of the present invention will be described.

[0134] [Positive electrode] The positive electrode is composed of a positive electrode current collector and a positive electrode active material layer formed on the positive electrode current collector. The positive electrode active material layer can be formed on one or both surfaces of the positive electrode current collector.

[0135] The positive electrode current collector is made of metals such as stainless steel, gold, platinum, aluminum, and titanium, and A material having high electrical conductivity and not eluted at the potential of the positive electrode, such as an alloy of Elements that improve heat resistance, such as silicon, titanium, neodymium, scandium, and molybdenum Aluminum alloys containing silicide can be used. The metal may be a metal element that reacts with silicon to form a silicide. The group elements are zirconium, titanium, hafnium, vanadium, niobium, tantalum, There are chromium, molybdenum, tungsten, cobalt, nickel, etc. The positive electrode current collector is a foil Plate (sheet), net, punched metal, expanded metal, etc. The thickness of the positive electrode current collector is preferably 5 μm or more and 30 μm or less. In addition, an undercoat layer made of graphite or the like may be provided on the surface of the positive electrode current collector. good.

[0136] The positive electrode active material layer contains not only the positive electrode active material, but also a binder (binder) to improve the adhesion of the positive electrode active material. d) The positive electrode active material layer may contain a conductive assistant for increasing the conductivity of the positive electrode active material layer.

[0137] The positive electrode active material used in the positive electrode active material layer has an olivine type crystal structure, a layered rock salt type crystal structure, There are composite oxides having a crystalline structure or a spinel structure. For example, LiFeO2, LiCoO2, LiNiO2, LiMn2O4, V2O5, Cr2 Compounds such as O5 and MnO2 are used.

[0138] In particular, LiCoO2 has a large capacity and is more stable in air than LiNiO2. It is preferable because it has the advantages of being thermally stable compared to LiNiO2.

[0139] In addition, lithium-containing manganese-containing spinel crystal structures such as LiMn2O4 are also available. The material contains a small amount of lithium nickel oxide (LiNiO2 or LiNi 1-x M x O2(0 <x< 1) By mixing (M=Co, Al, etc.), the characteristics of the secondary battery using this can be improved. This is preferable.

[0140] 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, LiFe a Mn b PO4, LiNi a Co b PO4, LiNi a Mn b PO4(a+b is less than 1, 0 <a<1、0<b<1)、Li Fe c Nid Co e PO4, LiFe c Ni d Mn e PO4, LiNi c Co d Mn e P O4 (c + d + e is 1 or less, 0 < c < 1, 0 < d < 1, 0 < e < 1), LiFe f Ni g Co 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 other lithium compounds can be used as materials.

[0141] In particular, LiFePO4 satisfies well the requirements for a cathode active material, such as safety, stability, high capacity density, and the presence of lithium ions that can be extracted during initial oxidation (charging). Therefore, it is preferable.

[0142] 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. As a representative example of the general formula Li (2-j) MSiO4, there are 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) Ni k Col SiO4, Li (2-j) Ni k Mn l SiO4 (where k + l is less than or equal to 1, 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 (where m + n + q is less than or equal to 1, 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 less than or equal to 1, 0 < r < 1, 0 < s < 1, 0 < t < 1, 0 < u < 1), etc. can be used as materials for lithium compounds.

[0143] Also, as the positive electrode active material, A x M2(XO4)3 (A = Li, Na, Mg, M = Fe, Mn, Ti, V, Nb, X = S, P, Mo, W, As, Si) represented by the general formula can be used. As the NASICON type compound, there are Fe2(MnO4)3, Fe2(SO4)3, Li3Fe2(PO4)3, etc. Also, as the positive electrode active material, L i2MPO4F, Li2MP2O7, Li5MO4 (M = Fe, Mn) represented by the general formula compounds, perovskite type fluorides such as NaFeF3, FeF3, metal chalcogenides (sulfides, selenides, tellurides) such as TiS2, MoS2 oxides having an inverse spinel type crystal structure such as LiMVO4, vanadium oxide systems (V2O5, V6O ), etc. 13, LiV 3O8, etc.), manganese oxides, organic sulfur compounds, and other materials can be used.

[0144] 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.), For example, NaFeO2 or Na 2 / 3 [Fe 1 / 2 Mn 1 / 2 ]O2 and other sodium-containing layered oxides are used as the positive electrode active material. It can be used.

[0145] In addition, a material in which a plurality of the above materials are combined may be used as the positive electrode active material. For example, A solid solution of a combination of the above materials can be used as the positive electrode active material. For example, L iCo 1 / 3 Mn 1 / 3 Ni 1 / 3 A solid solution of O2 and Li2MnO3 is used as the positive electrode active material. There can be.

[0146] A conductive material such as a carbon layer may be provided on the surface of the positive electrode active material layer. By providing a conductive material, the conductivity of the electrode can be improved. The carbon layer is coated on the positive electrode by mixing carbohydrates such as glucose during the firing of the positive electrode active material. It can be formed.

[0147] The average particle size of the primary particles of the granular positive electrode active material layer is 50 nm to 100 μm. It would be good to have one.

[0148] The conductive additives include acetylene black (AB), graphite particles, and carbon black. Nanotubes, graphene, fullerene, etc. can be used.

[0149] The conductive additive can form an electronic conductive network in the positive electrode. This makes it possible to maintain an electrical conduction path between the positive electrode active material layers. By adding a conductive additive, it is possible to realize a positive electrode active material layer with high electronic conductivity. can.

[0150] In addition to the typical polyvinylidene fluoride (PVDF), polyimide is also used as a binder. , polytetrafluoroethylene, polyvinyl chloride, ethylene propylene diene poly styrene-butadiene rubber, acrylonitrile-butadiene rubber, fluororubber, Uses polyvinyl acetate, polymethyl methacrylate, polyethylene, nitrocellulose, etc. It is possible.

[0151] The preferred range of the binder content relative to the total amount of the positive electrode active material layer depends on the particle size of the active material. The content may be appropriately set, and preferably, it can be set to 1 wt% or more and 10 wt% or less. For example, it can be 2wt% or more and 8wt% or less, or 3wt% or more and 5wt% or less. The content of the conductive assistant with respect to the total amount of the positive electrode active material layer is 1 wt% or more and 10 wt% or less. The content is preferably 1 wt % or less and more preferably 1 wt % or more and 5 wt % or less.

[0152] When forming a positive electrode active material layer using a coating method, the positive electrode active material, a binder, and a conductive additive are mixed. The positive electrode paste (slurry) is then applied onto a positive electrode current collector and dried.

[0153] [Negative electrode] The negative electrode is composed of a negative electrode current collector and a negative electrode active material layer formed on the negative electrode current collector. The negative electrode active material layer can be formed on one or both surfaces of the negative electrode current collector.

[0154] The negative electrode current collector is made of metals such as stainless steel, gold, platinum, iron, copper, titanium, and alloys of these metals. It is possible to use materials that have high conductivity and do not alloy with carrier ions such as lithium. In addition, the heat resistance of silicon, titanium, neodymium, scandium, molybdenum, etc. can be improved. The negative electrode current collector may be an aluminum alloy containing an element that enhances the resistance to oxidation. Plate (sheet), net, punched metal, expanded metal, etc. It is preferable to use a negative electrode current collector having a thickness of 5 μm or more and 30 μm or less. In addition, an undercoat layer made of graphite or the like may be provided on the surface of the negative electrode current collector. good.

[0155] The negative electrode active material layer contains not only the negative electrode active material, but also a binder (binder) to improve the adhesion of the negative electrode active material. d) The negative electrode active material layer may contain a conductive assistant for increasing the conductivity of the negative electrode active material layer.

[0156] The negative electrode active material is a material that allows the dissolution and deposition of lithium, or the insertion and desorption of lithium ions. As long as the material is a material having a high conductivity, it is not particularly limited. The material for the negative electrode active material layer can be lithium metal or lithium titanate. In addition to lithium, examples of the materials include carbon-based materials and alloy-based materials that are commonly used in the field of energy storage.

[0157] Lithium metal 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.

[0158] Carbon-based materials include graphite, graphitizable carbon (soft carbon), and non-graphitizable carbon (hard carbon). carbon nanotubes, graphene, carbon black, etc. .

[0159] Graphite includes mesocarbon microbeads (MCMB), coke-based artificial graphite, and pitted graphite. Examples of the graphite include artificial graphite such as titanium-based artificial graphite, and natural graphite such as spheroidized natural graphite.

[0160] When lithium ions are inserted between the layers of graphite (the formation of lithium-graphite intercalation compounds), At times, it shows a low potential similar to that of lithium metal (0.1 to 0.3 V vs. Li / L) i + This allows lithium-ion batteries to exhibit high operating voltages. Graphite has a relatively high capacity per unit volume, small volume expansion, is inexpensive, and is a lithium It is preferable since it has advantages such as higher safety compared to metals.

[0161] 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, examples of the alloy material include Mg, Ca, Al, Si, Ge, Sn, and Pb. , Sb, Bi, Ag, Au, Zn, Cd, Hg, In, etc. Such elements have a large capacity compared to carbon, and silicon in particular has a theoretical capacity of The capacity is 4200mAh / g, which is extremely high. For this reason, the use of silicon as the negative electrode active material As alloy materials using such elements, for example, Mg2Si, Mg2 Ge, Mg2Sn, SnS2, V2Sn3, FeSn2, CoSn2, Ni3Sn2, C u6Sn5, Ag3Sn, Ag3Sb, Ni2MnSb, CeSb3, LaSn3, La Examples include 3Co2Sn7, CoSb3, InSb, SbSn, etc.

[0162] In addition, the negative electrode active material is SiO, SnO, SnO2, titanium oxide (TiO2), lithium Li4Ti5O 12 ), lithium-graphite intercalation compound (Li x C6), Niobium oxide (Nb2O5), tungsten oxide (WO2), molybdenum oxide (MoO2) The oxides may be used.

[0163] 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.

[0164] 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, A composite nitride of lithium and a transition metal can be used as the material.

[0165] 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.

[0166] When forming the negative electrode active material layer using the coating method, the negative electrode active material and the binder are mixed and applied to the negative electrode. The paste (slurry) is prepared and applied to the negative electrode current collector and then dried. A conductive additive may be added to the paste.

[0167] In addition, graphene may be formed on the surface of the negative electrode active material layer. When the material is reconstituted, the volume change due to the absorption and release of carrier ions during the charge and discharge cycles is As a result, the adhesion between the negative electrode current collector and the negative electrode active material layer decreases, and the battery characteristics deteriorate during charging and discharging. Therefore, graphene is formed on the surface of the negative electrode active material layer containing silicon. Even if the volume of silicon changes during the charge / discharge cycle, the negative electrode current collector and the negative electrode active material This is preferable because it is possible to suppress a decrease in adhesion with the material layer and reduce deterioration of the battery characteristics. stomach.

[0168] In addition, a coating such as an oxide may be formed on the surface of the negative electrode active material layer. The film formed by the decomposition of the liquid can release the charge consumed during its formation. In order to prevent this, a film of oxide or the like is formed on the negative electrode active material layer in advance. By providing it on the surface, the occurrence of irreversible capacity can be suppressed or prevented.

[0169] The coating for coating such a negative electrode active material layer may include niobium, titanium, vanadium, tantalum, etc. , tungsten, zirconium, molybdenum, hafnium, chromium, aluminum or The oxide film of any one of these elements and lithium is a silicon oxide film, or Such a coating can be used to prevent the negative electrode surface from being damaged by the decomposition products of conventional electrolytes. This is a sufficiently dense film compared to the coating formed on

[0170] For example, niobium oxide (Nb2O5) has an electrical conductivity of 10 -9 Low S / cm and high Therefore, the niobium oxide film prevents the electrochemical decomposition reaction between the negative electrode active material and the electrolyte. On the other hand, the lithium diffusion coefficient of niobium oxide is 10 -9 cm 2 / sec, and high It has high lithium ion conductivity. Therefore, it is possible for lithium ions to pass through it. Silicon oxide or aluminum oxide may also be used.

[0171] The film that covers the negative electrode active material layer can be formed by, for example, a sol-gel method. The sol-gel method is a process in which a solution of metal alkoxides and metal salts is reacted with water through hydrolysis and polycondensation. The reaction causes the gel to lose its fluidity, and then the gel is baked to form a thin film. Since the Ru-gel method is a method for forming a thin film from a liquid phase, the raw materials must be mixed homogeneously at the molecular level. For this reason, the raw material for the metal oxide film in the solvent stage is added with a negative electrode active material such as graphite. By adding the active material, it is possible to easily disperse the active material in the gel. A coating can be formed on the surface of the material layer. By using the coating, the capacity of the battery can be reduced. It is possible to prevent the bottom from falling out.

[0172] [Separator] Materials for forming the separator include cellulose, polypropylene (PP), Polyethylene (PE), polybutene, nylon, polyester, polysulfone, polyacrylic fluoride, polyvinylidene fluoride, tetrafluoroethylene, polyphenylene sulfur In addition, non-woven fabric such as glass fiber and glass fiber can be used. A composite membrane of fiber and polymer fiber may also be used.

[0173] [Electrolyte] The electrolytic solution is an electrolyte in which carrier ions can move and which are carrier ions. The electrolyte is made of a material that contains lithium ions. Representative examples of the electrolyte are LiPF6, LiC lO4, LiAsF6, LiBF4, LiCF3SO3, Li(CF3SO2)2N, L Lithium salts such as Li(C2F5SO2)2N and Li(SO2F)2N are used. The materials may be used alone or in any combination and ratio of two or more. .

[0174] In particular, when high-temperature processing is performed during the molding of rubber, etc., the electrolyte must have high heat resistance. For example, it is preferable to use an imide salt having a high thermal decomposition temperature.

[0175] 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 (PC), Dimethyl carbonate diethyl carbonate (DEC), ethyl methyl carbonate (EMC), These include tyrolactone, acetonitrile, dimethoxyethane, and tetrahydrofuran. One or more of these can be used. In addition, a high molecular weight polymer that can be gelled as a solvent for the electrolyte can be used. By using a polymer material or adding a polymer material for gelation to the electrolyte, leakage etc. can be reduced. The safety against heat and shock is improved. In addition, the storage battery can be made thinner and lighter. Representative examples of polymeric materials include silicone gel, acrylic gel, acrylonitrile gel, Polyethylene oxide gel, polypropylene oxide gel, fluorine-based polymer In addition, ionic liquids (which are flame-retardant and non-volatile at room temperature) are used as solvents for electrolytes. By using one or more molten salts, the internal temperature of the battery can be reduced due to internal short circuits and overcharging. Even if the temperature rises, the battery can be prevented from exploding or catching fire. Ionic liquids are salts that are in a mobile state and have high ion mobility (conductivity). and an anion. The ionic liquid is ethylmethylimidazolium (EMI) cationic liquid. Ionic liquids containing ions, or N-methyl-N-propylpiperidinium (PP 13 )mosquito Examples include ionic liquids that contain thiones.

[0176] In particular, when high-temperature processing is performed, the electrolyte solvent should be made of a material with a high boiling point. For example, it is preferable to use propylene carbonate (PC).

[0177] [Exterior body] There are various types of secondary battery structures. In this embodiment, a film is used as the exterior body. The film used to form the exterior is a metal film (aluminum, stainless steel). Plastic films made of organic materials, organic materials (organic resins, nickel steel, etc.), Hybrid material films containing inorganic materials (such as ceramics) and carbon A single layer film selected from inorganic films (carbon film, graphite film, etc.) The metal film is embossed. By forming concave or convex portions by embossing, the exterior body exposed to the outside air can be easily The increased surface area provides excellent heat dissipation.

[0178] In addition, when the shape of the secondary battery is changed by applying an external force, the exterior of the secondary battery is Bending stress may be applied from the outside, causing deformation or partial destruction of the exterior body. By forming a concave or convex part on the exterior, the distortion caused by the stress applied to the exterior body can be reduced. This can reduce the strain on the secondary battery. Strain is a measure of deformation that indicates the displacement of a material point within an object relative to the reference (initial) length of the object. By forming a recess or protrusion on the exterior body, strain caused by applying force from the outside of the battery can be reduced. This makes it possible to suppress the influence of the battery deterioration within an acceptable range, thereby providing a highly reliable battery. It is possible.

[0179] The above is a description of each component.

[0180] This embodiment may be combined, at least in part, with other embodiments described in this specification. It can be implemented in combination.

[0181] (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.

[0182] 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.

[0183] 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.

[0184] 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. .

[0185] 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.

[0186] 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. 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.

[0187] 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.

[0188] 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.

[0189] FIG. 15A 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.

[0190] FIG. 15B 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.

[0191] Figure 15(D) shows an example of a bendable mobile phone. If the mobile phone 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. 15(F) 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 portion of the mobile phone shown in FIG. 15(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. 15(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. 15(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.

[0192] In addition, the power storage device described in the first embodiment may be installed in a wearable device as shown in FIG. It can be installed.

[0193] For example, the present invention can be mounted on a glasses-type device 400 as shown in FIG. The mirror type device 400 has a frame 400a and a display unit 400b. By installing a power storage device in the temple of the REM 400a, the weight balance is good and it can be used continuously. The glasses-type device 400 may be long-lasting.

[0194] It can also be installed in a headset type device 401. The microphone 401 includes at least a microphone unit 401a, a flexible pipe 401b, and an earphone. The flexible pipe 401b and the earphone section 401c store electricity. An apparatus may be provided.

[0195] It can also be mounted on a device 402 that can be attached directly to the body. A power storage device 402b can be provided in a thin housing 402a of the battery 02.

[0196] It can also be mounted on a device 403 that can be attached to clothing. A power storage device 403b can be provided in the thin housing 403a.

[0197] The present invention can also be implemented in a wristwatch type device 405. The wristwatch type device 405 is a display The display unit 405a and the belt unit 405b are provided. A power storage device may be provided.

[0198] The display unit 405a displays not only the time but also various other information such as incoming e-mails and phone calls. It is possible.

[0199] The wristwatch type device 405 is a wearable device that is worn directly on the arm. Therefore, sensors for measuring the user's pulse, blood pressure, etc. may be installed. It can also accumulate health data and be used to help maintain health.

[0200] Also, it can be mounted on a belt-type device 406. The belt-type device 406 includes: The belt portion 406a and the wireless power receiving portion 406b are included. A power storage device can be mounted on the vehicle.

[0201] FIG. 16B is a projection diagram illustrating an example of the external appearance of the information processing device 200. The information processing device 200 described in the embodiment includes a calculation device 210, an input / output device 220, and a display unit 2 30 and a power storage device 250.

[0202] The information processing device 200 includes a communication unit, which supplies information to a network and It also has a function to acquire information from the network. The image information may be generated based on the received information. The teaching materials can be received and displayed in classrooms at schools or universities, etc., and used as textbooks. Or, materials distributed in a conference room of a company or the like can be received and displayed.

[0203] This embodiment may be combined, at least in part, with other embodiments described in this specification. It can be implemented in combination. EXAMPLES

[0204] In this example, a battery according to one embodiment of the present invention was manufactured. It was prepared based on the method illustrated in Example 1.

[0205] A positive electrode current collector made of aluminum foil having a positive electrode active material layer on one side and a negative electrode current collector made of aluminum foil having a negative electrode active material layer on the other side. Six negative electrode current collectors made of copper foil were prepared. LiCoO2 was used as the positive electrode active material. Graphite was used as the negative electrode active material.

[0206] The positive electrode current collectors are stacked with the surfaces opposite to the coated surfaces facing each other, and then attached to a pair of positive electrode current collectors. A bag-shaped separator was used to cover the tube.

[0207] Next, as shown in FIG. 17(A), a positive electrode current collector covered with a separator and a negative electrode current collector Then, as shown in FIG. 17(B), the positive electrode current collector and the The leads were joined to the tabs of the positive and negative electrode current collectors by ultrasonic welding. is an enlarged view of FIG. 17(B).

[0208] Next, as shown in FIG. 18(A), a polyimide insulating material is applied to cover the pair of joints. Figure 18(B) is a photograph of the device turned over, and Figure 18(C) is a photograph of the device turned over. This is an enlarged view of (A).

[0209] Next, the tabs of the positive electrode current collector and the negative electrode current collector were folded back. In order to fix the tab portion, the positive electrode current collector, and the negative electrode current collector, a polyimide tape was used as a fixing member. Figure 19(B) is a photo of the joint side, and Figure 19(A) is the reverse side. 19(C) is an enlarged view of FIG. 19(B).

[0210] Through the above steps, the electrode member was completed.

[0211] Next, the electrode member is sandwiched between exterior bodies to form side seals and top seals. So, I created a battery.

[0212] The exterior is made of polypropylene, aluminum foil, and nylon laminated in that order, with a thickness of approximately A 70μm aluminum laminate film was used. The wave pitch was 2mm, and the distance between the convex and concave portions was 1. The film was processed so that the height difference was 0.5 mm.

[0213] The film is sealed using a flat surface mold (heat bar). The side seal was made with a 1 mm wide heat bar, and the top seal was made with a lead A 2 mm wide heat bar with a groove formed in the position facing the part was used.

[0214] Figures 20(A) and (B) show the external appearance of the battery. The side seals are extremely flat and the area near the edge of the film is The wave period is longer and the amplitude is smaller at one part of the film than at the center. It can be seen that the part is deformed.

[0215] The above is the description of the first embodiment.

[0216] This embodiment may be any embodiment or example at least partially described herein. can be implemented in appropriate combination. EXAMPLES

[0217] In the following, a battery according to one embodiment of the present invention and a comparative battery were fabricated, and their internal structures were described. The results of photographing the structure and evaluating the electrical properties before and after repeated bending tests will be explained. .

[0218] [Sample preparation] First, the following three types of samples (Comparative Sample 1, Comparative Sample 2, Sample 1) were prepared.

[0219] The positive electrode current collector is made of aluminum foil with a width of 9 mm, and the negative electrode current collector is made of copper foil with a width of 10 mm. Here, a positive electrode current collector and a negative electrode current collector each having an active material layer on one side were used. Six sheets of each were laminated.

[0220] Sample 1 was prepared in the same manner as in Example 1. Sample 1 also contained A pre-embossed aluminum laminate film with a width of 16 mm was used.

[0221] For comparative samples 1 and 2, the fixed portion between the lead and the current collector was only the joint. Similar to sample 1, comparative sample 1 and comparative sample 2 were also embossed in advance. The exterior of the comparative sample 1 was made of an aluminum laminate film with a width of The exterior of the comparative sample 2 was made of a 15 mm aluminum laminate film. An aluminum laminate film with a width of 16 mm was used.

[0222] [Observation of internal structure] The prepared comparative sample 2 and sample 1 were subjected to X-ray computed tomography (X-ray computed tomography). The inside of the battery was observed using a microtomography (CT).

[0223] 21(A), (B), and (C) show X-ray photographs taken of Comparative Sample 2. FIG. 21(A) is a photograph taken in a lateral direction, FIG. 21(B) is a photograph taken in a plan view, and FIG. 21(C) is an enlarged photograph of the tab portion and its vicinity in FIG. 21(A).

[0224] Since X-rays penetrate lighter elements more easily, the exterior and positive electrode made of aluminum foil are used. The electrode current collector and the like are shown as transparent images.

[0225] As shown in FIG. 21(C), the joint between the lead and the tab is in the region having the active material layer of the current collector. The area is provided at a position separate from the laminated portion.

[0226] 22(A), (B), and (C) show X-ray photographs taken of Sample 1. As shown in Fig. 2(C), the tab of the current collector is folded back. It was confirmed that the joint with the lead overlapped the part where the current collector was laminated.

[0227] The only difference between Comparative Sample 1 and Comparative Sample 2 is the width of the exterior body, so the figure is omitted. Omitted.

[0228] [Bending and stretching test] Next, the bending and stretching test was repeatedly performed on Comparative Sample 1, Comparative Sample 2, and Sample 1. The bending and straightening test was performed by repeatedly bending the specimen at a radius of curvature of 25 mm and then leaving it flat. I did.

[0229] After 6,000 bending and stretching tests, the exterior of the comparative sample 1 was damaged and electrolyte leakage was observed. The damaged part of the exterior body of the comparative sample 1 was where the exterior body and the end of the negative electrode current collector were in contact with each other. It was located in that area.

[0230] On the other hand, the exterior body of Comparative Sample 2 and Sample 1 did not break even after 10,000 bending and stretching tests. There was no leakage of electrolyte.

[0231] [Observation of internal structure 1] Figure 23 (A), (B), and (C) show X-ray CT images of the cross sections of each sample before bending and stretching tests. FIG. 23(A) shows Comparative Sample 1, FIG. 23(B) shows Comparative Sample 2, and FIG. 23(C) shows Test Sample 3. This is a cross section of material 1 taken along the valley line of the exterior body.

[0232] Here, the value of a in formula (2) was estimated. Here, L is the distance between a pair of side seals. The distance between the negative electrode current collectors is 1 mm, W is the width of the negative electrode current collector, and t is the thickness of the electrode member (the distance between the two negative electrode current collectors located on the outside). (the distance).

[0233]

number

[0234] The estimated value of a for Comparative Sample 1 was 0.66. The estimated a value for sample 1 was 1.04, and the estimated a value for sample 2 was 1.03. I did.

[0235] From the above results, in the comparative sample 1, the gap between the end of the negative electrode current collector and the side seal on one side The width of the gap was found to be less than 0.7 times the thickness. In sample 1, the end of the negative electrode current collector came into contact with the exterior body, causing the exterior body to be damaged. It turns out that a space of 100 degrees is insufficient.

[0236] On the other hand, in the comparative sample 2 and the sample 1, the gap between the end of the negative electrode current collector and the side seal was The width of the wire is 0.8 times or more the thickness. The results of the bending and stretching test showed that the wire Since no damage was observed, it is clear that there is sufficient space between them. Confirmed.

[0237] [Charge / discharge characteristics] The charge / discharge characteristics of each sample were measured before and after the bending and stretching test.

[0238] 24(A) and (B) show the characteristics of the comparative sample 1. FIG. 24(A) shows the results of the bending and stretching test. Fig. 24(B) shows the characteristics before and after 3000 bending and stretching tests. In the graph, the vertical axis indicates voltage and the horizontal axis indicates capacity per unit weight of the positive electrode active material. As shown in Figures 24(A) and (B), a decrease in capacity was confirmed by bending and stretching tests. .

[0239] Figures 25(A) and (B) show the characteristics of the comparative sample 2. Figure 25(B) shows the characteristics of the comparative sample 2 after 10,000 bending cycles. The characteristics after the bending test. As shown above, no damage was observed in the exterior body of the comparative sample 2. However, a decrease in capacity was confirmed by bending and stretching tests.

[0240] 26(A) and (B) show the characteristics of Sample 1. FIG. 26(B) shows the characteristics after 10,000 bending cycles. The characteristics after the bending and stretching test. In sample 1, the capacity hardly decreased after the bending and stretching test. The discharge capacity before the bending test was 134.0 [mAh / g]. In contrast, the discharge capacity after the test was 133.3 mAh / g.

[0241] [Observation of internal structure 2] Next, the comparative sample 2 and sample 1 were subjected to a bending and stretching test 10,000 times. X-ray photographs were taken to observe the internal structure.

[0242] FIG. 27(A) shows a lateral X-ray photograph of the vicinity of the tab portion of Comparative Sample 2. As shown in the area enclosed in the box, it was confirmed that part of the negative electrode current collector was broken. Therefore, it is considered that the decrease in capacity is caused by the breakage of the tab portion.

[0243] FIG. 27(B) shows a lateral X-ray photograph of the vicinity of the tab portion of sample 1. It was confirmed that there was almost no change when compared with the X-ray photograph before the procedure (Figure 22(C)). Done.

[0244] From the above results, it can be seen that the battery according to one embodiment of the present invention hardly loses capacity even when repeatedly bent and stretched. Almost no leakage was observed, confirming that this is an extremely reliable battery.

[0245] The above is a description of the second embodiment.

[0246] This embodiment may be any embodiment or example at least partially described herein. can be implemented in appropriate combination. [Explanation of symbols]

[0247] 10 Electrode material 10a Electrode member 11a Current collector 11b Current collector 12a Lead 12b Lead 13a Active material layer 13b Active material layer 14 Separator 14a Separator 15a Joint 15b Joint 16 Insulating materials 16a Insulating material 16b Insulating material 17 Fixing member 18 Insulating materials 18a Insulating material 18b Insulating material 18c Insulating material 21a Tab section 21b Tab section 22a Electrode part 22b Electrode part 50 batteries 51 Exterior body 61 Bending section 62 Seal part 63 Seal part 71 Ridgeline 72 Valley Line 73 Space 200 Information processing device 210 Arithmetic equipment 220 I / O device 230 Display section 250 Power storage device 290 Communications Department 400 Glasses-type device 400a frame 400b Display section 401 Headset-type device 401a Microphone section 401b Flexible Pipe 401c Earphone section 402 Devices 402a Case 402b Energy storage device 403 Device 403a Case 403b Energy storage device 405 Wristwatch-type device 405a Display section 405b Belt section 406 Belt-type device 406a Belt section 406b Wireless power receiving unit 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

Claims

1. The electrode member includes an exterior body having a valley line and a ridge line, and an electrode member housed in the exterior body, The electrode member has a positive electrode and a negative electrode, In a cross section of the exterior body along the ridge line, The exterior body has a first seal portion and a second seal portion located opposite to the first seal portion, A secondary battery, wherein a first end of the first seal portion is adjacent to a second end of the electrode member, and a distance from the first end to the second end satisfies 0.8 times or more and 3.0 times or less the thickness of the electrode member.

2. The electrode member includes an exterior body having a valley line and a ridge line, and an electrode member housed in the exterior body, The electrode member has a positive electrode and a negative electrode, In a cross section of the exterior body along the ridge line, The exterior body has a first seal portion and a second seal portion located opposite to the first seal portion, the first seal portion and the second seal portion both have flat regions; A secondary battery, wherein a first end of a flat region of the first seal portion is adjacent to a second end of the electrode member, and a distance from the first end to the second end satisfies 0.8 times or more and 3.0 times or less the thickness of the electrode member.

3. The electrode member includes an exterior body having a valley line and a ridge line, and an electrode member housed in the exterior body, The electrode member has a positive electrode and a negative electrode, In a cross section of the exterior body along the ridge line, The exterior body has a first seal portion and a second seal portion located opposite to the first seal portion, A secondary battery, wherein a first end of the first seal portion faces a third end of the second seal portion, a distance from the first end to the third end is Lb, a thickness of the electrode member is t, and a width of the electrode member is Wa, and a satisfies the following formula (1), and is 0.8 or more and 3.0 or less. [0010]

4. The electrode member includes an exterior body having a valley line and a ridge line, and an electrode member housed in the exterior body, The electrode member has a positive electrode and a negative electrode, In a cross section of the exterior body along the ridge line, The exterior body has a first seal portion and a second seal portion located opposite to the first seal portion, the first seal portion and the second seal portion both have flat regions; a first end of a flat region of the first seal portion faces a third end of a flat region of the second seal portion, a distance from the first end to the third end is Lb, a thickness of the electrode member is t, and a width of the electrode member is Wa, where a is 0.8 or more and 3.0 or less, satisfying the following formula (1). [0025]

5. In any one of claims 1 to 4, The secondary battery, wherein the exterior body has a structure in which polypropylene, aluminum foil, and nylon are laminated in this order.

Images