Electrochemical cell arrangement and electronic device

Abstract

To provide an electrochemical cell arrangement structure capable of suppressing a rise in internal pressure of an electrochemical cell.SOLUTION: An arrangement structure of a battery 1 includes: the battery 1 having an electrode body 40 having a positive electrode body and a negative electrode body, an exterior body 10 which houses the electrode body 40 at the inside thereof and in which through holes 24, 34 are formed, and a terminal board 60 which is electrically connected to the electrode body 40 and joined to peripheral parts 25, 35 of the through holes 24, 34 at the inside of the exterior body 10 to block the through holes 24, 34; a contact 80 in contact with the terminal board 60 from the outside; and substrates 70 with the battery 1 sandwiched therebetween, each of which is fixedly arranged with respect to the contact 80 on a side opposite to the contact 80.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an electrochemical cell arrangement and an electronic device. [Background technology]

[0002] Conventionally, electrochemical cells such as lithium ion secondary batteries and electrochemical capacitors have been widely used as power sources for small electronic devices such as smartphones, wearable devices, and hearing aids. For example, the following Patent Document 1 discloses an electrochemical cell including an electrode body and an exterior body having a first laminate member and a second laminate member and housing the electrode body. In general, in this type of electrochemical cell, the interior is kept airtight by the exterior body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-85214 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the inside of an electrochemical cell is heated due to a short circuit between the terminals (external short circuit) or the like, gas may be generated inside the exterior body, causing the internal pressure of the cell to rise. If the internal pressure of the cell rises, the exterior body may expand and burst, which may damage the electronic device equipped with the electrochemical cell. Therefore, it is desirable to develop a structure for electrochemical cells that suppresses the rise in internal pressure.

[0005] Therefore, the present invention provides an electrochemical cell arrangement structure capable of suppressing an increase in the internal pressure of an electrochemical cell, and an electronic device equipped with the electrochemical cell arrangement structure. [Means for solving the problem]

[0006] The electrochemical cell arrangement structure of the present invention is characterized in that it comprises an electrochemical cell having an electrode body having a positive electrode body and a negative electrode body, an outer casing that houses the electrode body and has a through hole formed therein, and a terminal that is electrically connected to the electrode body and joined to the peripheral portion of the through hole inside the outer casing to block the through hole, a contact that contacts the terminal from the outside, and a fixing member that is fixedly arranged relative to the contact on the opposite side of the electrochemical cell to the contact.

[0007] According to the present invention, since the electrochemical cell is disposed between the contacts and the fixing member that are fixedly disposed relative to each other, when the internal structure of the electrochemical cell is heated due to an external short circuit or the like, causing the exterior body to expand, the terminals are pressed toward the inside of the exterior body by the contacts. Here, when the joint between the exterior body and the terminals softens due to an increase in temperature of the electrochemical cell, the terminals pressed toward the inside of the exterior body by the contacts peel off at the joint with the exterior body. This forms a leak path that communicates between the inside and outside of the electrochemical cell, allowing the fluid inside the electrochemical cell to escape. Therefore, an increase in the internal pressure of the electrochemical cell can be suppressed.

[0008] In the above-described electrochemical cell arrangement structure, the contact may restrict displacement of the terminal toward the outside of the exterior body.

[0009] According to the present invention, when the exterior body expands, it is possible to restrict the terminal from being displaced outward together with the exterior body, thereby preventing peeling from occurring at the joint between the exterior body and the terminal, thereby obtaining an arrangement structure of an electrochemical cell that achieves the above-mentioned advantageous effects.

[0010] In the above-described electrochemical cell arrangement, the contact may press the terminal toward the inside of the exterior body.

[0011] According to the present invention, when the joint between the exterior body and the terminal softens due to a temperature rise of the electrochemical cell, even if the expansion of the exterior body is insufficient, the pressing force applied from the contact to the terminal can cause separation at the joint between the exterior body and the terminal. Therefore, an electrochemical cell arrangement structure that achieves the above-mentioned functions and effects can be obtained.

[0012] The above-mentioned electrochemical cell arrangement structure may further include an annular sealing member formed of a thermoplastic resin and joined to a peripheral portion of the through hole, and the terminal may be joined to the sealing member and also joined to the peripheral portion of the through hole via the sealing member.

[0013] According to the present invention, it is possible to improve the airtightness of the joint between the exterior body and the terminal, as compared with a configuration in which the terminal is directly joined to the exterior body.

[0014] In the above-described electrochemical cell arrangement structure, the exterior body may be formed of a flexible film material.

[0015] According to the present invention, the exterior body can be easily expanded by an increase in the internal pressure of the electrochemical cell. Here, since the contacts are in contact with the terminals from the outside, the displacement of the terminals due to the expansion of the exterior body is restricted. Therefore, tensile stress is generated at the joint between the exterior body and the terminals due to the expansion of the exterior body. As a result, when the joint between the exterior body and the terminals is softened due to an increase in temperature of the electrochemical cell, peeling can be caused at the joint between the exterior body and the terminals due to the tensile stress. Therefore, the above-mentioned leak path can be easily formed as the internal pressure of the electrochemical cell increases. Therefore, the increase in the internal pressure of the electrochemical cell can be more reliably suppressed.

[0016] The above-mentioned electrochemical cell arrangement structure may further include an opposing member that is arranged on the opposite side of the electrochemical cell from the fixing member and spaced apart from the outer casing, supporting the contacts, and a spacer that is interposed between the opposing member and the outer casing.

[0017] According to the present invention, the contacts can be fixedly disposed relative to the electrochemical cell by the spacer and the opposing member without impeding the expansion of the exterior body.

[0018] In the above-described electrochemical cell arrangement structure, the spacer may be out of contact with the peripheral portion of the through hole in the exterior body.

[0019] According to the present invention, since the expansion of the periphery of the through hole can be tolerated, tensile stress can be generated at the joint between the exterior body and the terminal as the exterior body expands. As a result, when the joint between the exterior body and the terminal softens due to a rise in temperature of the electrochemical cell, peeling can be caused at the joint between the exterior body and the terminal due to the tensile stress. Therefore, the above-mentioned leak path can be easily formed as the internal pressure of the electrochemical cell increases. Therefore, the increase in the internal pressure of the electrochemical cell can be more reliably suppressed.

[0020] An electronic device according to the present invention is characterized by comprising the above-described arrangement structure of electrochemical cells.

[0021] According to the present invention, damage to the electrochemical cell due to expansion or bursting can be suppressed.

[0022] In the electronic device, the fixing member may be a circuit board.

[0023] According to the present invention, since there is no need to provide a fixing member separately from the circuit board, an electronic device that achieves the above-mentioned advantageous effects while suppressing an increase in the number of parts can be obtained. Effect of the Invention

[0024] According to the present invention, an increase in the internal pressure of the electrochemical cell can be suppressed. [Brief description of the drawings]

[0025] [Figure 1] FIG. 1 is a perspective view of a battery according to a first embodiment. [Diagram 2] FIG. 1 is a cross-sectional view of a battery according to a first embodiment. [Diagram 3] 1 is a cross-sectional view of an electronic device according to a first embodiment. [Figure 4] FIG. 2 is a cross-sectional view illustrating the function of the battery arrangement structure of the first embodiment. [Diagram 5] FIG. 2 is a cross-sectional view illustrating the function of the battery arrangement structure of the first embodiment. [Figure 6] FIG. 11 is a cross-sectional view of an electronic device according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, components having the same or similar functions are given the same reference numerals. Then, duplicated descriptions of those components may be omitted. In the following description, a lithium ion secondary battery (hereinafter simply referred to as "battery"), which is a type of non-aqueous electrolyte secondary battery, is taken as an example of an electrochemical cell.

[0027] First Embodiment (battery) A battery 1 of the first embodiment will be described with reference to FIGS. Fig. 1 is a perspective view of the battery of the first embodiment, and Fig. 2 is a cross-sectional view of the battery of the first embodiment. As shown in FIG. 1 and FIG. 2, the battery 1 is formed in a flat shape. The battery 1 is a so-called button-type battery formed in a circular shape in a plan view seen from the thickness direction. The battery 1 includes an electrode body 40 of a power generating element having a positive electrode body and a negative electrode body, an electrolyte impregnated in the electrode body 40, an exterior body 10 that accommodates the electrode body 40 and has through holes 24, 34 formed therein, an annular sealing member 50 joined to the periphery 25, 35 of the through holes 24, 34 inside the exterior body 10, and a terminal plate 60 (terminal) that is electrically connected to the electrode body 40 and is joined to the sealing member 50 inside the exterior body 10 to close the through holes 24, 34. In the following description, the thickness direction of the battery 1 is referred to as the up-down direction.

[0028] The electrode body 40 includes a positive electrode body including a positive electrode active material, a negative electrode body including a negative electrode active material, and a separator interposed between the positive electrode body and the negative electrode body. The positive electrode active material is a composite oxide including lithium and a transition metal, such as lithium cobalt oxide, lithium titanate, lithium manganate, etc. The negative electrode active material is, for example, silicon oxide, graphite, hard carbon, lithium titanate, LiAl, etc. The electrode body 40 is formed in a circular shape in a plan view corresponding to the shape of the internal space of the exterior body 10. For example, the electrode body 40 is a so-called laminated electrode in which a sheet-like positive electrode body and a negative electrode body are overlapped and wound flatly with a separator interposed therebetween. However, the configuration of the electrode body 40 is not limited to this, and may be a so-called pellet-type electrode body in which a positive electrode body and a negative electrode body are provided on both sides of a separator.

[0029] The exterior body 10 forms the outer shell of the battery 1. The exterior body 10 includes a housing section 11 in which the electrode body 40 is housed, and a sealing section 12 that is bent along the outer periphery 11a of the housing section 11. The sealing section 12 is bent along the outer periphery 11a of the housing section 11 by, for example, drawing.

[0030] The exterior body 10 also includes a first container 20 and a second container 30 sandwiching the electrode body 40 therebetween. The first container 20 and the second container 30 are each formed of a flexible laminate film (film material). The laminate film has a metal layer (metal foil), a resin fusion layer provided on the overlapping surface (inner surface) to cover the metal foil, and a resin protective layer provided on the outer surface to cover the metal foil. The metal layer is formed using a metal material that blocks outside air and water vapor, such as stainless steel or aluminum. The fusion layer on the overlapping surface is formed using a thermoplastic resin, such as polyolefin polyethylene or polypropylene. The protective layer on the outer surface is formed using, for example, the above-mentioned polyolefin, polyester such as polyethylene terephthalate, nylon, or the like.

[0031] The first container 20 includes a circular first bottom wall portion 21 and a first peripheral wall portion 22 extending in a cylindrical shape from the outer periphery of the first bottom wall portion 21. A first through hole 24 is formed in the first bottom wall portion 21. For example, the first through hole 24 is formed in the center of the first bottom wall portion 21.

[0032] The second container 30 comprises a circular second bottom wall portion 31, a second peripheral wall portion 32 extending cylindrically from the outer periphery of the second bottom wall portion 31, and a folded portion 33 folded from the opening edge of the second peripheral wall portion 32 toward the outside of the second peripheral wall portion 32 and extending toward the second bottom wall portion 31.

[0033] The second bottom wall portion 31 is disposed on the opposite side to the first bottom wall portion 21 of the first container 20 across the electrode body 40. The second bottom wall portion 31 is formed to have an outer diameter slightly smaller than that of the first bottom wall portion 21 of the first container 20. A second through hole 34 is formed in the second bottom wall portion 31. For example, the second through hole 34 is formed in the center of the second bottom wall portion 31.

[0034] The second peripheral wall portion 32 extends from the outer periphery of the second bottom wall portion 31 toward the first bottom wall portion 21 of the first container 20. The second peripheral wall portion 32 forms the outer periphery 11a of the storage portion 11. The bent portion 33 is bent into a cylindrical shape from an end portion of the second peripheral wall portion 32 on the first bottom wall portion 21 side toward the second bottom wall portion 31 side along the second peripheral wall portion 32. The bent portion 33 is disposed outwardly with a gap relative to the second peripheral wall portion 32.

[0035] The second circumferential wall portion 32 is disposed on the inner side of the first circumferential wall portion 22 and on the inner side of the bent portion 33. The bent portion 33 is disposed on the inner side of the first circumferential wall portion 22. The fusion layer of the bent portion 33 and the fusion layer of the first circumferential wall portion 22 are heat fused together.

[0036] The fusion layer of the bent portion 33 and the fusion layer of the first peripheral wall portion 22 are thermally fused to form the sealing portion 12. Thus, the outer periphery of the storage portion 11 is sealed by the sealing portion 12. As a result, the first container 20 and the second container 30 are overlapped to form the exterior body 10. The sealing portion 12 is formed in a cylindrical shape on the outside of the storage portion 11, and is bent along the outer periphery 11a of the storage portion 11.

[0037] In the accommodation section 11, a sealed space in which the electrode body 40 is disposed is formed by overlapping the first container 20 and the second container 30. Specifically, the accommodation section 11 is defined by a first bottom wall section 21, a second bottom wall section 31, and a second peripheral wall section 32, and is formed in a circular shape in a plan view.

[0038] The seal member 50 includes a first seal member 51 and a second seal member 52. The first seal member 51 and the second seal member 52 are each formed by shaping a sealant film into a circular shape. The sealant film contains a thermoplastic resin such as a polyolefin such as polyethylene or polypropylene. For example, the sealant film is formed by covering a nonwoven fabric with a thermoplastic resin.

[0039] The first seal member 51 is joined to the periphery 25 of the first through hole 24 in the exterior body 10 from the inside of the exterior body 10. The first seal member 51 is heat-sealed to the inner surface (fusion layer) of the exterior body 10 over the entire overlapping surface with the exterior body 10. The outer diameter of the first seal member 51 is larger than the inner diameter of the first through hole 24. The outer peripheral edge of the first seal member 51 overlaps the exterior body 10 over the entire circumference of the first through hole 24 in a plan view. As a result, the first seal member 51 is joined to the periphery 25 of the first through hole 24 over the entire circumference. The inner diameter of the first seal member 51 is smaller than the inner diameter of the first through hole 24. As a result, the first seal member 51 protrudes inwardly over the entire circumference of the first through hole 24 in a plan view. The periphery of the through hole does not necessarily have to include the opening edge of the through hole. That is, the inner diameter of the first seal member 51 may be larger than the inner diameter of the first through hole 24 , and the first seal member 51 may not be joined to at least a portion of the opening edge of the first through hole 24 .

[0040] The second seal member 52 is joined to the periphery 35 of the second through hole 34 in the exterior body 10 from the inside of the exterior body 10. The second seal member 52 is heat-sealed to the inner surface (fusion layer) of the exterior body 10 over the entire overlapping surface with the exterior body 10. The outer diameter of the second seal member 52 is larger than the inner diameter of the second through hole 34. The outer peripheral edge of the second seal member 52 overlaps the exterior body 10 over the entire circumference of the second through hole 34 in a plan view. As a result, the second seal member 52 is joined to the periphery 35 of the second through hole 34 over the entire circumference. The inner diameter of the second seal member 52 is smaller than the inner diameter of the second through hole 34. As a result, the second seal member 52 protrudes over the entire circumference inside the second through hole 34 in a plan view. The inner diameter of the second seal member 52 may be larger than the inner diameter of the second through hole 34, and the second seal member 52 may not be joined to at least a portion of the opening edge of the second through hole 34.

[0041] Terminal board 60 is joined to sealing member 50, and thereby joined to peripheral portions 25, 35 of through holes 24, 34 via sealing member 50. Terminal board 60 includes a first terminal board 61 joined to first sealing member 51 to close first through hole 24, and a second terminal board 62 joined to second sealing member 52 to close second through hole 34.

[0042] The first terminal plate 61 is electrically connected to the negative electrode body of the electrode body 40. The first terminal plate 61 is formed of, for example, copper or nickel. The first terminal plate 61 is exposed to the outside of the exterior body 10 through the first through hole 24 and functions as a negative terminal of the battery 1. The first terminal plate 61 is joined to the inner periphery of the first seal member 51 from the inside of the exterior body 10. The first terminal plate 61 is joined to the first seal member 51 over the entire circumference. The first terminal plate 61 is heat fused to the first seal member 51 over the entire overlapping surface with respect to the first seal member 51. The outer diameter of the first terminal plate 61 is larger than the inner diameter of the first seal member 51 and smaller than the outer diameter of the first seal member 51. As a result, the outer peripheral edge of the first terminal plate 61 is joined to the first seal member 51 over the entire circumference. The outer diameter of the first terminal plate 61 is larger than the inner diameter of the first through hole 24. The outer peripheral edge of first terminal board 61 overlaps exterior body 10 over the entire periphery of first through hole 24 in plan view.

[0043] The second terminal plate 62 is electrically connected to the positive electrode body of the electrode body 40. The second terminal plate 62 is formed of, for example, highly corrosion-resistant stainless steel or aluminum. The second terminal plate 62 is exposed to the outside of the exterior body 10 through the second through hole 34 and functions as a positive electrode terminal of the battery 1. The second terminal plate 62 is joined to the inner periphery of the second seal member 52 from the inside of the exterior body 10. The second terminal plate 62 is joined to the second seal member 52 over the entire circumference. The second terminal plate 62 is heat-sealed to the second seal member 52 over the entire overlapping surface with respect to the second seal member 52. The outer diameter of the second terminal plate 62 is larger than the inner diameter of the second seal member 52 and smaller than the outer diameter of the second seal member 52. As a result, the outer peripheral edge of the second terminal plate 62 is joined to the second seal member 52 over the entire circumference. The outer diameter of the second terminal plate 62 is larger than the inner diameter of the second through hole 34. The outer peripheral edge of second terminal board 62 overlaps with exterior body 10 over the entire periphery of second through hole 34 in plan view.

[0044] (electronic equipment) The configuration of an electronic device 2 equipped with the battery 1 will be described with reference to Fig. 3. The electronic device 2 is, for example, a wireless earphone, a wearable device, a smartphone, a digital camera, or the like.

[0045] FIG. 3 is a cross-sectional view of the electronic device of the first embodiment. As shown in Figure 3, the electronic device 2 includes a substrate 70 arranged to sandwich the battery 1 from above and below, a contact 80 supported by the substrate 70 and in contact with the terminal board 60 from the outside, and a spacer 90 interposed between the substrate 70 and the exterior body 10 of the battery 1.

[0046] The substrate 70 includes a first circuit board 71 (fixing member, opposing member) and a second circuit board 72 (fixing member, opposing member). The first circuit board 71 and the second circuit board 72 are each a printed wiring board formed of a rigid substrate. The first circuit board 71 and the second circuit board 72 are arranged so that their front and back surfaces face up in the vertical direction. The first circuit board 71 and the second circuit board 72 are arranged on opposite sides of the battery 1 and face the exterior body 10. The first circuit board 71 is arranged below the exterior body 10 of the battery 1 with a gap therebetween. The second circuit board 72 is arranged above the exterior body 10 of the battery 1 with a gap therebetween. The first circuit board 71 and the second circuit board 72 are arranged fixedly to each other. The substrate 70 supports the battery 1 with its approach to the battery 1 restricted by the spacer 90 interposed between the substrate 70 and the battery 1.

[0047] The contact 80 includes a first contact 81 supported by the first circuit board 71 and a second contact 82 supported by the second circuit board 72. The first contact 81 and the second contact 82 are each formed of a conductive material such as metal, and are connected to printed wiring on the board 70.

[0048] The first contact 81 is supported by the first circuit board 71, and is fixedly disposed on the opposite side of the second circuit board 72 with the battery 1 in between. The first contact 81 is mounted on the first circuit board 71 at a location that overlaps the first terminal plate 61 of the battery 1 in a plan view. The first contact 81 is pressed against the exposed portion of the first terminal plate 61 from below. The first contact 81 is formed so that the contact point at the tip can move downward in an upward biased state. As a result, the first contact 81 presses the first terminal plate 61 toward the inside of the exterior body 10. The first contact 81 is disposed so that it cannot come into contact with the exterior body 10 and the first seal member 51.

[0049] The second contact 82 is supported by the second circuit board 72, and is fixedly disposed relative to the first circuit board 71 on the opposite side of the battery 1 from the first circuit board 71. The second contact 82 is mounted on the second circuit board 72 at a location that overlaps the second terminal plate 62 of the battery 1 in a plan view. The second contact 82 is pressed against the exposed portion of the second terminal plate 62 from above. The second contact 82 is formed so that the contact point at the tip can move upward in a downwardly biased state. As a result, the second contact 82 presses the second terminal plate 62 toward the inside of the exterior body 10. The second contact 82 is disposed so that it cannot come into contact with the exterior body 10 and the second seal member 52.

[0050] In this embodiment, each contact 80 is formed so that the tip can be elastically displaced in the vertical direction relative to the base. Each contact 80 is formed so that the tip can be displaced only a predetermined distance in the direction toward the outside of the exterior body 10 by abutting against the base in the compression direction. For example, the predetermined distance is set within a range in which the terminal plate 60 can be displaced in the direction toward the outside of the exterior body 10 until the battery 1 explodes due to the expansion of the exterior body 10 when the contact 80 is not in contact with the terminal plate 60. In this way, the contact 80 restricts the displacement of the terminal plate 60 toward the outside of the exterior body 10 to a predetermined distance. The contact 80 may restrict the displacement of the terminal plate 60 toward the outside of the exterior body 10 to a predetermined distance by a restoring force (pressing force) that increases with compression due to the displacement of the contact point. The contact 80 may also be formed so as not to be deformable in the vertical direction. In this case, the predetermined distance is set to approximately 0. In addition, the specified distance may be set within a range within which the terminal plate 60 can be displaced in a direction toward the outside of the exterior body 10 as the exterior body 10 expands before the battery 1 comes into contact with the substrate 70 when the contact 80 is not in contact with the terminal plate 60.

[0051] The spacer 90 includes a first spacer 91 interposed between the first circuit board 71 and the exterior body 10 of the battery 1, and a second spacer 92 interposed between the second circuit board 72 and the exterior body 10 of the battery 1. Each spacer 90 includes an electronic component 93 mounted on the board 70, and a buffer member 94 interposed between the electronic component 93 and the exterior body 10. However, each spacer 90 does not necessarily need to include at least one of the electronic component and the buffer member.

[0052] The first spacer 91 is in contact with a portion of the exterior body 10 that is outside the joint between the first terminal plate 61 and the exterior body 10 in a plan view. The first spacer 91 is distributed and arranged at a plurality of locations. However, the first spacer 91 may extend in an arc shape or an annular shape following the outer shape of the exterior body 10. The joint between the first terminal plate 61 and the exterior body 10 is the joint between the first terminal plate 61 and the first seal member 51, and the joint between the first seal member 51 and the exterior body 10. This prevents the first spacer 91 from contacting the periphery 25 of the first through hole 24 of the exterior body 10. The first spacer 91 restricts the battery 1 and the first circuit board 71 from approaching each other by more than a predetermined distance.

[0053] The second spacer 92 is in contact with a portion of the exterior body 10 that is outside the joint between the second terminal plate 62 and the exterior body 10 in a plan view. The second spacer 92 is distributed and disposed at a plurality of locations. However, the second spacer 92 may extend in an arc or annular shape following the outer shape of the exterior body 10. The joint between the second terminal plate 62 and the exterior body 10 is the joint between the second terminal plate 62 and the second seal member 52, and the joint between the second seal member 52 and the exterior body 10. This prevents the second spacer 92 from contacting the periphery 35 of the second through hole 34 of the exterior body 10. The second spacer 92 restricts the battery 1 and the second circuit board 72 from approaching each other by more than a predetermined distance.

[0054] (Effect of battery arrangement) The function of the above-mentioned battery 1 arrangement structure will be described. When an external short circuit or the like occurs due to a short circuit between the terminals of the battery 1, the terminal plate 60, the current collector of the electrode body 40, and the like may heat up and generate heat. In this case, the electrolyte and the like evaporates, the internal pressure of the battery 1 increases, and the exterior body 10 expands. When the battery 1 has a flat shape as in this embodiment, the expansion in the thickness direction becomes significant. That is, as shown in FIG. 4, when the internal pressure of the battery 1 increases, the exterior body 10 expands toward the first circuit board 71 and the second circuit board 72 so as to fill the gaps between the exterior body 10 and the first circuit board 71 and the second circuit board 72, respectively.

[0055] According to the arrangement structure of the battery 1 in this embodiment, the battery 1 is arranged between the first contact 81 and the second circuit board 72, which are arranged fixedly to each other, and between the second contact 82 and the first circuit board 71, which are arranged fixedly to each other, so that at least when the exterior body 10 expands, the terminal board 60 is pressed toward the inside of the exterior body 10 by the contact 80.

[0056] Here, when the temperature of the battery 1 rises, at least one of the seal member 50 and the inner surface (bonding layer) of the exterior body 10 softens at the joint between the exterior body 10 and the terminal plate 60. When the joint between the exterior body 10 and the terminal plate 60 softens, the terminal plate 60, which is pressed toward the inside of the exterior body 10 by the contact 80, peels off at the joint with the exterior body 10. As a result, a leak path that communicates between the inside and the outside of the battery 1 is formed. For example, the leak path is formed before the exterior body 10 comes into contact with the substrate 70. The places where peeling occurs in the joint between the exterior body 10 and the terminal plate 60 are at least one of the interface between the exterior body 10 and the seal member 50, the interface between the seal member 50 and the terminal plate 60, and the seal member 50 itself. In the illustrated example, peeling occurs at the interface between the second seal member 52 and the second terminal plate 62. As a result, at least one of the gas and the electrolyte inside the battery 1 can escape. Therefore, an increase in the internal pressure of the battery 1 can be suppressed.

[0057] Furthermore, the contacts 80 restrict displacement of the terminal plate 60 toward the outside of the exterior body 10. With this configuration, when the exterior body 10 expands, it is possible to restrict the terminal plate 60 from being displaced toward the outside together with the exterior body 10. This makes it possible to cause peeling at the joint between the exterior body 10 and the terminal plate 60. Therefore, an arrangement structure of the battery 1 that achieves the above-mentioned functions and effects can be obtained.

[0058] Furthermore, the contacts 80 press the terminal plate 60 towards the inside of the exterior body 10. With this configuration, when the joint between the exterior body 10 and the terminal plate 60 softens due to a rise in temperature of the battery 1, even if the expansion of the exterior body 10 is insufficient, the pressing force applied from the contacts 80 to the terminal plate 60 can cause separation at the joint between the exterior body 10 and the terminal plate 60. Therefore, an arrangement structure of the battery 1 that achieves the above-mentioned functions and effects can be obtained.

[0059] Terminal board 60 is joined to seal member 50, and is joined to peripheral portions 25, 35 of through holes 24, 34 via seal member 50. With this configuration, it is possible to improve the airtightness of the joint between exterior body 10 and terminal board 60, compared to a configuration in which the terminal board is directly joined to the exterior body.

[0060] The exterior body 10 is formed of a flexible laminate film. With this configuration, the exterior body 10 can be easily expanded by an increase in the internal pressure of the battery 1. Here, since the contacts 80 are in contact with the terminal plate 60 from the outside, the displacement of the terminal plate 60 accompanying the expansion of the exterior body 10 is restricted. Therefore, a tensile stress is generated at the joint between the exterior body 10 and the terminal plate 60 as the exterior body 10 expands. As a result, when the joint between the exterior body 10 and the terminal plate 60 is softened due to an increase in temperature of the battery 1, peeling can be caused at the joint between the exterior body 10 and the terminal plate 60 by the tensile stress. Therefore, the above-mentioned leak path can be easily formed as the internal pressure of the battery 1 increases. Therefore, the increase in the internal pressure of the battery 1 can be more reliably suppressed.

[0061] A spacer 90 is interposed between the substrate 70 and the exterior body 10. With this configuration, the contacts 80 can be fixedly disposed relative to the battery 1 by the spacer 90 and the substrate 70 without inhibiting the expansion of the exterior body 10.

[0062] The first spacer 91 is not in contact with the peripheral portion 25 of the first through hole 24 of the exterior body 10. With this configuration, expansion of the peripheral portion 25 of the first through hole 24 can be tolerated, so that tensile stress can be generated at the joint between the exterior body 10 and the first terminal plate 61 as the exterior body 10 expands. As a result, when the joint between the exterior body 10 and the terminal plate 60 softens due to a rise in temperature of the battery 1, separation can be caused at the joint between the exterior body 10 and the first terminal plate 61 by the tensile stress. Therefore, an increase in the internal pressure of the battery 1 can be more reliably suppressed.

[0063] The electronic device 2 of the present embodiment has the above-described arrangement structure of the battery 1. This configuration can prevent damage caused by expansion or explosion of the battery 1. Furthermore, by using the first circuit board 71 and the second circuit board 72, the above-described arrangement structure of the battery 1 is formed without providing any member in addition to the circuit boards, so that the electronic device 2 can be obtained that achieves the above-described effects while preventing an increase in the number of parts.

[0064] <Second embodiment> (battery) A battery 101 according to the second embodiment will be described with reference to Fig. 6. Note that the configuration other than that described below is similar to that of the first embodiment.

[0065] FIG. 6 is a cross-sectional view of an electronic device according to the second embodiment. 6, the battery 101 of the second embodiment includes an exterior body 110 instead of the exterior body 10 of the first embodiment. The exterior body 110 is made of metal. The exterior body 110 includes a negative electrode can 111 and a sealing plate 112.

[0066] The negative electrode can 111 is formed in a bottomed cylindrical shape and houses the electrode body 40 therein. The negative electrode body of the electrode body 40 is electrically connected to the negative electrode can 111. A sealing plate 112 closes the opening of the negative electrode can 111. The outer peripheral edge of the sealing plate 112 is joined to the edge of the opening of the negative electrode can 111 over the entire periphery. As a result, the entire exterior body 110 is integrated and functions as a negative electrode terminal.

[0067] A through hole 114 is formed in the center of the sealing plate 112. A terminal plate 160 is joined to a peripheral portion 115 of the through hole 114 via a sealing member 150. The sealing member 150 and the terminal plate 160 correspond to the second sealing member 52 and the second terminal plate 62 of the first embodiment. The structure of the connection portion between the exterior body 110 and the terminal plate 160 is similar to the structure of the connection portion between the exterior body 10 and the second terminal plate 62 of the first embodiment. The positive electrode body of the electrode body 40 is electrically connected to the terminal plate 160. The terminal plate 160 is exposed to the outside of the exterior body 110 through the through hole 114 and functions as a positive terminal of the battery 101.

[0068] (electronic equipment) The configuration of electronic device 102 including battery 101 will be described. Electronic device 102 of the present embodiment differs from the electronic device of the first embodiment in that first contact 81 is in pressure contact with the bottom of negative electrode can 111 and second contact 82 is in pressure contact with terminal board 160.

[0069] (Effect of battery arrangement) The function of the above-mentioned arrangement of the battery 101 will be described. According to the arrangement structure of the battery 101 in this embodiment, the battery 101 is arranged between the second contact 82 and the first circuit board 71, which are fixedly arranged relative to each other, so that the terminal board 160 is pressed toward the inside of the exterior body 110 by the second contact 82.

[0070] When the temperature of the battery 101 rises, the seal member 150 softens at the joint between the exterior body 110 and the terminal plate 160. This causes peeling to occur at the joint between the exterior body 110 and the terminal plate 160 due to the pressing force applied from the second contact 82 to the terminal plate 160. This forms a leak path that communicates between the inside and outside of the battery 101, allowing at least one of the gas and the electrolyte inside the battery 101 to escape. This makes it possible to suppress an increase in the internal pressure of the battery 101.

[0071] The present invention is not limited to the above-described embodiment explained with reference to the drawings, and various modifications are possible within the technical scope of the present invention. For example, in the above embodiment, a secondary battery has been described as an example of an electrochemical cell, but the present invention is not limited to this, and the above-described configuration may be applied to an electric double layer capacitor, a primary battery, etc. Also, a lithium ion secondary battery has been described as an example of a battery, but the present invention is not limited to this, and the battery may be a secondary battery other than a lithium ion secondary battery, such as a metal lithium secondary battery. When the above-described configuration is applied to an electric double layer capacitor, the electric double layer capacitor has a pair of electrodes that are functionally indistinguishable from positive and negative, but one electrode can be regarded as the negative electrode body and the other electrode as the positive electrode body.

[0072] In the above embodiment, the electrode body 40 is formed in a circular shape in a plan view, but the shape of the electrode body is not limited to this. For example, the electrode body may be formed in an oval shape, a diamond shape, a rectangular shape, an L-shape, a T-shape, or the like in a plan view.

[0073] In the above embodiment, the substrate 70 is formed of a rigid substrate, but is not limited to this configuration. The substrate may be a flexible substrate and supported by a rigid member such as a housing, thereby supporting the contacts and the spacer fixedly relative to the battery.

[0074] In the above embodiment, the terminal board 60 is indirectly joined to the exterior body 10 via the seal member 50, but the present invention is not limited to this configuration. The terminal board may be directly joined to the periphery of the through hole in the exterior body by thermal fusion of the fusion layer of the laminate film.

[0075] In addition, in the above first embodiment, the first container 20 and the second container 30 of the exterior body 10 are formed from a laminate film, but at least one of the first container and the second container may be formed from a metal can.

[0076] In the above embodiment, the battery 1, 101 is held on the substrate 70 by the spacer 90, but this configuration is not limited to this. For example, by fixing a frame arranged to surround the battery to the substrate, it is possible to at least suppress deviation of the battery from the substrate. In this case, the spacer between the battery and the substrate may be omitted.

[0077] In the first embodiment, the terminal board 60 is exposed on both sides of the battery 1 in the thickness direction, but this configuration is not limited to this. For example, a pair of terminals may be exposed on one side of the battery, and a pair of contacts that contact the terminals may be disposed on one side of the battery, with a fixed member such as a board facing the battery on the opposite side of the pair of contacts.

[0078] In the second embodiment, the entire exterior body 110 functions as the negative electrode terminal and the first contact 81 is in contact with the bottom of the negative electrode can 111, but this configuration is not limited to this. For example, the bottom of the negative electrode can 111 may be supported by a fixing member such as a substrate, and the contact may be arranged to be in contact with the outer peripheral surface of the negative electrode can 111.

[0079] In addition, within the scope of the spirit of the present invention, it is possible to replace the components in the above-described embodiments with well-known components as appropriate, and the above-described embodiments may be combined as appropriate. [Explanation of symbols]

[0080] REFERENCE SIGNS LIST 1,101...battery (electrochemical cell) 2,102...electronic device 10,110...exterior body 24...first through hole (through hole) 25,35,115...periphery 34...second through hole (through hole) 35...periphery 40...electrode body 50,150...sealing member 60...terminal plate (terminal) 70...substrate (fixing member, opposing member) 80...contact 90...spacer 114...through hole

Claims

1. an electrochemical cell including: an electrode body having a positive electrode body and a negative electrode body; an exterior body that houses the electrode body and has a through hole formed therein; and a terminal that is electrically connected to the electrode body and is joined to a peripheral portion of the through hole inside the exterior body to close the through hole; a contact for contacting the terminal from the outside; a fixing member disposed on the opposite side of the electrochemical cell from the contacts and fixed to the contacts; an opposing member that is disposed on the opposite side of the electrochemical cell from the fixing member and is spaced apart from the exterior body and supports the contacts; Equipped with The contact and the opposing member are not in contact with the exterior body. Electrochemical cell arrangement.

2. The contact restricts displacement of the terminal toward the outside of the exterior body.

2. The electrochemical cell arrangement of claim 1.

3. The contact presses the terminal toward the inside of the exterior body.

3. An arrangement structure of electrochemical cells according to claim 1 or 2.

4. The sealing member is formed of a thermoplastic resin and is joined to a peripheral portion of the through hole. The terminal is joined to the sealing member and is joined to the peripheral portion of the through hole via the sealing member.

4. An arrangement structure of electrochemical cells according to claim 1.

5. The exterior body is formed of a flexible film material.

5. An arrangement structure of electrochemical cells according to any one of claims 1 to 4.

6. An arrangement structure of an electrochemical cell described in any one of claims 1 to 5, further comprising a spacer interposed between the opposing member and the outer casing.

7. The spacer is not in contact with the peripheral portion of the through hole of the exterior body.

7. The electrochemical cell arrangement of claim 6.

8. An electronic device comprising the arrangement structure of electrochemical cells according to any one of claims 1 to 7.

9. The fixing member is a circuit board.

9. The electronic device according to claim 8.

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