Electricity storage device

Abstract

A power storage device (10) is provided with a power storage element (11), a bottomed cylindrical case (20) having an opening (21) at one end, and a sealing unit (30) for sealing the opening (21). The sealing unit (30) includes: a sealing body (31) including a first upper surface (31a) and a first lower surface (31b); and a reinforcing member (32) that includes a second upper surface (32a) and a second lower surface (32b), that is disposed such that the second lower surface (32b) faces the first upper surface (31a), and that has an elastic modulus greater than that of the sealing body (31). The housing (20) has, in the vicinity of the opening (21), a first pressing part (22) that presses the first side surface (31c) of the sealing body (31) and protrudes toward the inside of the housing (20), and a second pressing part (23) that presses the second upper surface (32a) of the reinforcing member (32). The sealing unit (30) has a first passage (33) that communicates with the outside of the power storage device (10) at a position closer to the inside in the radial direction of the case (20) than the second pressing part (23), and that opens to the side surface of the sealing unit (30). As a result, deformation of the sealing body when the internal pressure rises can be suppressed.

Description

Technical Field

[0001] The present disclosure relates to an electric storage device. Background Art

[0002] In the past, there is known an electrical storage device having an electrical storage element, a shell having an opening at one end, and a sealing body that seals the opening (for example, Patent Document 1). The shell of the electrical storage device of Patent Document 1 has: a first pressing portion that presses the side of the sealing body near the opening and protrudes toward the inside of the shell; and a venting portion that is located closer to one end than the most protruding vertex of the first pressing portion. The electrical storage device of Patent Document 1 is configured so that when the internal pressure rises due to the generation of gas, the generated gas is discharged to the outside from the venting portion.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2022 / 091862 Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, in the power storage device of Patent Document 1, the sealing body is greatly deformed in the axial direction of the power storage device during the process from the increase of internal pressure to the release of gas to the outside. In particular, when the power storage device is used in a modular manner, the size of the module needs to be designed to allow or absorb such deformation of the sealing body. Under such circumstances, one of the purposes of the present disclosure is to suppress the deformation of the sealing body when the internal pressure increases.

[0008] Means used to solve problems

[0009] One aspect of the present disclosure relates to an electric storage device. The electric storage device comprises: an electric storage element; a shell having a bottomed cylindrical shape, accommodating the electric storage element, and having an opening at one end; and a sealing unit, sealing the opening, the sealing unit comprising: a sealing body, including a first upper surface facing the outside of the shell and a first lower surface facing the inside; and a reinforcing member, including a second upper surface facing the outside of the shell and a second lower surface facing the inside, arranged in a manner that the second lower surface is opposite to the first upper surface of the sealing body, and having an elastic modulus greater than that of the sealing body, the shell having near the opening: a first pressing portion, pressing a first side surface of the sealing body connecting the first upper surface and the first lower surface, and protruding toward the inside of the shell; and a second pressing portion, pressing the second upper surface of the reinforcing member, the sealing unit having a first passage, the first passage being connected to the outside of the electric storage device at a position radially inward of the shell than the second pressing portion, and opening at a side surface of the sealing unit.

[0010] Effects of the Invention

[0011] According to the present disclosure, deformation of the sealing body when the internal pressure increases can be suppressed.

[0012] While the novel features of the present invention are described in the appended claims, both the organization and content of the present invention will be better understood through the following detailed description taken in conjunction with other objects and features of the application and with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a front cross-sectional view schematically showing the power storage device according to the first embodiment, and is a view of a cross section passing through the first passage (slit).

[0014] Figure 2 The three views schematically show the reinforcing member of the first embodiment, which are, from the top, a top view, a front view, and a bottom view.

[0015] Figure 3 It is a front cross-sectional view schematically showing the power storage device according to the second embodiment, and is a view of a cross section passing through the first passage (slit).

[0016] Figure 4 The three views schematically show the reinforcing member of the second embodiment, which are, from the top, a top view, a front view, and a bottom view.

[0017] Figure 5 It is a front cross-sectional view schematically showing the power storage device according to the third embodiment, and is a view of a cross section passing through the first passage.

[0018] Figure 6 The three views schematically show the reinforcing member of the third embodiment, which are, from the top, a top view, a front view, and a bottom view. DETAILED DESCRIPTION

[0019] The following examples are given to illustrate the embodiments of the power storage device of the present disclosure. However, the present disclosure is not limited to the examples described below. In the following description, specific numerical values ​​and materials are illustrated, but other numerical values ​​and materials can also be applied as long as the effects of the present disclosure can be obtained.

[0020] The electric storage device of the present disclosure includes an electric storage element, a case, and a sealing unit.

[0021] The storage element includes electrodes, electrolyte, etc. For example, when the storage device is an electrolytic capacitor, the storage element includes a winding body. The winding body is formed by winding a pair of electrodes with a separator between them. A pair of electrodes can be polarized electrodes, or one can be an anode and the other can be a cathode. For example, when the storage device is a secondary battery or a lithium ion capacitor, the storage element includes an electrode group. The electrode group is formed by winding a positive electrode and a negative electrode with a separator between them. The storage element may also include an electrolyte or a liquid component.

[0022] The housing is in the shape of a bottomed cylinder, has an opening at one end, and accommodates the storage element. The housing may be made of a metal such as aluminum, iron, or nickel. The shape of the housing is not particularly limited, and may be, for example, a bottomed cylinder.

[0023] The sealing unit seals the opening of the shell. The sealing unit has a sealing body and a reinforcing component. The sealing body includes a first upper surface facing the outside of the shell and a first lower surface facing the inside of the shell. The reinforcing component includes a second upper surface facing the outside of the shell and a second lower surface facing the inside of the shell, and is configured in a manner that the second lower surface is opposite to the first upper surface of the sealing body. The first upper surface of the sealing body and the second lower surface of the reinforcing component can be in contact with each other, or other components can be sandwiched between the two.

[0024] The sealing body is made of an elastic material (for example, a material containing an elastic resin). The shape of the sealing body may also correspond to the shape of the shell. For example, when the shell is a cylindrical shell with a bottom, the sealing body may also be a circular plate, and when the shell is a square cylindrical shell with a bottom, the sealing body may also be a square plate. The reinforcing component is made of a material (for example, a thermoplastic resin, a thermosetting resin, or a metal) having an elastic modulus greater than that of the material constituting the sealing body. Therefore, the elastic modulus of the reinforcing component is greater than that of the sealing body. The elastic modulus may also be, for example, Young's modulus. The shape of the reinforcing component may also correspond to the shape of the shell.

[0025] As the elastic resin constituting the sealing body, a rubber component is preferred. As the rubber component, butyl rubber (IIR), nitrile rubber (NBR), ethylene propylene rubber, ethylene propylene diene rubber (EPDM), chloroprene rubber (CR), isoprene rubber (IR), Hypalon rubber, silicone rubber, fluororubber, etc. can be used alone or in combination. Among them, butyl rubber, ethylene propylene rubber, fluororubber, etc. are preferred. In addition to the elastic resin, the elastic material may also include fillers, carbon black, processing aids, cross-linking aids, etc. as arbitrary components. The elastic modulus E1 of the elastic resin may also be, for example, less than 15 MPa.

[0026] As a material constituting the reinforcing member, a thermoplastic resin is preferred. As the thermoplastic resin, polypropylene (PP), polyethylene (PE), ABS resin (ABS), polystyrene (PS), vinyl chloride resin (PVC), polyethylene terephthalate (PET), etc. can be used alone or in combination. Among them, polypropylene is preferred. The elastic modulus E2 of the reinforcing member can also be, for example, 1.1 GPa or more.

[0027] The housing has a first pressing portion and a second pressing portion near the opening.

[0028] The first pressing portion presses the first side surface of the sealing body (i.e., the side surface of the sealing body connecting the first upper surface and the first lower surface) and protrudes toward the inner side of the shell. The inner diameter of the most protruding vertex of the first pressing portion may also be smaller than the outer diameter of the sealing body in a state where no load is applied. The first pressing portion may also be formed by, for example, grooving a portion of the opening to reduce the diameter.

[0029] The second pressing portion is disposed closer to one end of the housing, that is, the opening side, than the first pressing portion, and presses the second upper surface of the reinforcing member toward the inside of the housing. The second pressing portion may be formed by curling a portion of the endmost side of the opening, for example.

[0030] The above-mentioned sealing unit has a first passage that can function as an explosion-proof mechanism. The first passage is connected to the outside of the power storage device at a position radially inner than the second pressing portion of the shell. The first passage opens on the side of the sealing unit (that is, the side of the sealing body and / or the reinforcing component). Here, the first passage may also be opened on the side of the sealing unit only at a position closer to the second upper surface side (opening side) than the most protruding vertex of the first pressing portion. The first passage is not opened on the lower surface of the sealing unit (the surface facing the inner side of the shell). The first passage can also connect the inside and outside of the shell when the force acting on the first pressing portion from the sealing body due to the increase in the internal pressure of the shell is lower than a specified value.

[0031] Here, when the internal pressure of the shell rises due to the generation of gas, the sealing body tends to expand toward the outside of the shell in the axial direction of the shell. However, in the power storage device disclosed in the present invention, the axial expansion (or the deformation of the sealing body) can be suppressed by a reinforcing component with a large elastic modulus (that is, difficult to deform). Moreover, in a state where the expansion of the sealing body is suppressed, along with the increase in the internal pressure of the shell, the pressure of the gas acts on the area in the sealing body that contacts the first pressing part, and the area is displaced in a direction away from the first pressing part. Through this displacement, the force acting from the sealing body on the first pressing part (relative to the elastic reaction force of compression) becomes weaker. When the force is weakened to below a specified value, the gas in the shell passes between the sealing body and the first pressing part. The gas escapes from the inside of the shell to the outside of the shell via the first passage, so that the internal pressure of the power storage device is reduced, and safety can be ensured.

[0032] As described above, according to the present disclosure, by providing a reinforcing member with a large elastic modulus, deformation of the sealing body when the internal pressure of the housing increases can be suppressed. Furthermore, according to the present disclosure, the explosion-proof mechanism is activated to prevent accidental rupture of the power storage device such as the sealing unit from flying away.

[0033] The first passage may also be formed only in the reinforcing member in the sealing unit. In this configuration, since the first passage is not formed in the sealing body having a relatively small elastic modulus, the sealing body is less likely to deform when the internal pressure rises, compared with a case where the first passage is also formed in the sealing body. In addition, in the sealing unit, for example, the first passage may be formed across the reinforcing member and the sealing body.

[0034] The first passage may include a slit opened on the second upper surface of the reinforcing member. The slit may extend radially inward of the housing more than the second pressing portion. The slit may open on the side surface of the reinforcing member.

[0035] The slit may penetrate the reinforcing member in the thickness direction. In such a case, the slit may be formed only in the reinforcing member, or may be formed across the reinforcing member and the sealing body.

[0036] The slit may not penetrate the reinforcing member in the thickness direction. In this case, the slit may be formed only in the reinforcing member.

[0037] The outer peripheral portion of the second lower surface of the reinforcing member may also be in contact with the first upper surface of the sealing body throughout the entire circumference. According to this structure, the deformation of the sealing body when the internal pressure rises can be further suppressed. In addition, even if the outer peripheral edge of the second lower surface protrudes slightly outward than the outer peripheral edge of the first upper surface of the sealing body, as long as the outer peripheral portion of the second lower surface of the reinforcing member is in contact with the first upper surface of the sealing body at a position closer to the inside than the protruding portion throughout the entire circumference, it is equivalent to the structure of this paragraph.

[0038] The first passage may also have a first opening opened on the second upper surface of the reinforcing member and connected to the outside of the power storage device and a second opening opened on the side of the sealing unit, and the first passage passes through the inside of the sealing unit. The second opening may be opened on the side of the reinforcing member, may be opened on the side of the sealing body, or may be opened across both side surfaces.

[0039] The second pressing portion may also press the second upper surface of the reinforcing member over the entire circumference. According to this configuration, deformation of the sealing body when the internal pressure rises can be further suppressed. Moreover, when forming the second pressing portion, since the second pressing portion abuts against the second upper surface of the reinforcing member over the entire circumference, it is easy to form the second pressing portion with high precision.

[0040] There may be multiple first passages. In the case where multiple first passages are provided, the multiple first passages may be arranged at equal intervals in the circumferential direction of the housing. This can suppress asymmetrical deformation of the sealing body and improve the operational reliability of the explosion-proof mechanism formed by the first passages.

[0041] Hereinafter, an example of the power storage device disclosed in the present invention will be described in detail with reference to the accompanying drawings. The above-mentioned components can be applied to the components of the power storage device of the example described below. The components of the power storage device of the example described below can be changed based on the above description. In addition, the matters described below can also be applied to the above-mentioned embodiments. Among the components of the power storage device of the example described below, components that are not necessary for the power storage device disclosed in the present invention can be omitted. In addition, the figures shown below are schematic and do not accurately reflect the shape and number of actual components.

[0042] "Implementation Method 1"

[0043] Embodiment 1 of the present disclosure is described. Figure 1 and Figure 2 As shown, the electric storage device 10 of the present embodiment is configured as an electrolytic capacitor, and includes an electric storage element 11 , a case 20 , and a sealing unit 30 .

[0044] The storage element 11 includes a winding body. The winding body is formed by winding an anode foil and a cathode foil with a separator interposed therebetween. One end of lead tabs 12A and 12B is connected to the anode foil and the cathode foil, respectively. The winding body is formed while the lead tabs 12A and 12B are wound. Leads 13A and 13B are connected to the other ends of the lead tabs 12A and 12B, respectively.

[0045] The housing 20 is in the shape of a bottomed cylinder, has an opening 21 at one end, and accommodates the storage element 11. The housing 20 of the present embodiment is made of aluminum, but is not limited to this. The housing 20 of the present embodiment is in the shape of a bottomed cylinder, but is not limited to this. In the state before the first pressing portion 22 and the second pressing portion 23 described later are formed, the axial length of the housing 20 may be, for example, 60 to 80 mm. The outer diameter of the housing 20 may be, for example, 16 to 20 mm.

[0046] The sealing unit 30 seals the opening 21 of the shell 20. The thickness of the sealing unit 30 (the length in the axial direction of the shell 20) can also be, for example, 3 to 7 mm. The sealing unit 30 has a sealing body 31 and a reinforcing component 32. The sealing body 31 includes a first upper surface 31a facing the outside of the shell 20 and a first lower surface 31b facing the inside of the shell 20. The reinforcing component 32 includes a second upper surface 32a facing the outside of the shell 20 and a second lower surface 32b facing the inside of the shell 20, and is configured in a manner that the second lower surface 32b is opposite to the first upper surface 31a of the sealing body 31. In the present embodiment, the first upper surface 31a of the sealing body 31 and the second lower surface 32b of the reinforcing component 32 are in contact with each other.

[0047] The sealing body 31 is composed of an elastomer with rubber as a main component. The sealing body 31 of the present embodiment is in the shape of a disk, but is not limited to this. The thickness of the sealing body 31 may be, for example, 3.0 to 6.0 mm. The reinforcing component 32 is composed of a thermoplastic resin (for example, polypropylene). That is, the reinforcing component 32 is composed of a material having an elastic modulus greater than the elastic modulus of the constituent material of the sealing body 31. The reinforcing component 32 of the present embodiment is in the shape of a disk having the same diameter as the sealing body 31, but is not limited to this. The thickness of the reinforcing component 32 may be, for example, 1.0 to 3.0 mm.

[0048] The housing 20 includes a first pressing portion 22 and a second pressing portion 23 near the opening 21 .

[0049] The first pressing portion 22 presses the first side surface 31c of the sealing body 31 near the opening 21 and protrudes toward the inside of the housing 20. The inner diameter at the vertex 22a of the first pressing portion 22 is smaller than the outer diameter of the sealing body 31 in a state where no load is applied. The first pressing portion 22 of the present embodiment is formed by grooving a portion of the opening 21 to reduce the diameter, but is not limited thereto.

[0050] The second pressing portion 23 is arranged closer to one end side (i.e., the opening side) of the housing 20 than the first pressing portion 22, and presses the second upper surface 32a of the reinforcing member 32 toward the inside of the housing 20. In other words, the second pressing portion 23 presses the edge of the sealing unit 30 near the opening 21. The second pressing portion 23 of the present embodiment is formed by curling a portion of the opening 21, but is not limited thereto.

[0051] The sealing unit 30 has a first passage 33 that can function as an explosion-proof mechanism. The first passage 33 is formed only in the reinforcing member 32 in the sealing unit 30. The first passage 33 is connected to the outside of the power storage device 10 at a position closer to the radial inner side of the housing 20 than the second pressing portion 23. The first passage 33 is opened on the side of the sealing unit 30 only at a position closer to the second upper surface 32a side (opening side) than the most protruding vertex 22a of the first pressing portion 22. The vertex 22a of the first pressing portion 22 is an important part in ensuring the airtightness of the housing 20. From the perspective of ensuring the airtightness, it is advantageous that the first passage 33 does not open here.

[0052] The first passage 33 is formed by a slit 33a opened on the second upper surface 32a of the reinforcing member 32. The slit 33a of the present embodiment penetrates the reinforcing member 32 in the thickness direction. The slit 33a may extend radially inwardly by 0.2 to 2.0 mm from the radial inner end of the second pressing portion 23, for example. The width of the slit 33a (the length in the circumferential direction of the housing 20) may also be, for example, 0.2 to 0.5 mm. The slit 33a extends in the radial direction of the housing 20, but is not limited thereto.

[0053] like Figure 2 As shown in FIG. 1 , in this embodiment, four first passages 33 formed by slits 33a are provided, but the number of first passages 33 may be three or less or five or more. The four first passages 33 are arranged at equal intervals (every 90° in this example) in the circumferential direction of the housing 20. However, the plurality of first passages 33 may also be arranged at unequal intervals. Figure 2 In the figure, the through holes for passing the lead tabs 12A and 12B are omitted.

[0054] The portion of the opening 21 that is closer to the opening side than the apex 22a of the first pressing portion 22 may not be partially in contact with the sealing unit 30. That is, a gap may exist between the inner surface of the opening 21 and the side surface of the sealing unit 30 that is closer to the opening side than the apex 22a of the first pressing portion 22. When the gap exists, the first passage 33 may be connected to the gap.

[0055] Here, when the internal pressure of the housing 20 rises due to the generation of gas, the sealing body 31 tends to expand toward the outside of the housing 20 in the axial direction of the housing 20. However, in the power storage device 10 of this embodiment, the axial expansion (or the deformation of the sealing body 31) can be suppressed by the reinforcing member 32 having a large elastic modulus (that is, difficult to deform). Moreover, in a state where the expansion of the sealing body 31 is suppressed, along with the increase in the internal pressure of the housing 20, the pressure of the gas acts on the area in the sealing body 31 that contacts the first pressing part 22, and the area is displaced in a direction away from the first pressing part 22. Through this displacement, the force (elastic reaction force relative to compression) acting on the first pressing part 22 from the sealing body 31 becomes weaker. When the force is weakened to be lower than a specified value, the gas in the housing 20 passes between the sealing body 31 and the first pressing part 22. The gas escapes from the inside of the housing 20 to the outside of the housing 20 via the first passage 33, so that the internal pressure of the power storage device 10 is reduced, and safety can be ensured.

[0056] "Implementation Method 2"

[0057] Embodiment 2 of the present disclosure will be described. The configuration of the sealing unit 30 of the electrical storage device 10 of this embodiment is different from that of the above-described Embodiment 1. Hereinafter, the differences from the above-described Embodiment 1 will be mainly described.

[0058] like Figure 3 and Figure 4 As shown, the first passage 33 constituted as a slit 33a does not penetrate the reinforcing member 32 in the thickness direction. Moreover, the outer peripheral portion of the second lower surface 32b of the reinforcing member 32 is in contact with the first upper surface 31a of the sealing body 31 throughout the entire circumference. Two first passages 33 are provided at equal intervals (in this example, at intervals of 180°) along the circumferential direction of the housing 20.

[0059] "Implementation 3"

[0060] Embodiment 3 of the present disclosure will be described. The configuration of the sealing unit 30 of the electrical storage device 10 of this embodiment is different from that of the above-described Embodiment 1. Hereinafter, the differences from the above-described Embodiment 1 will be mainly described.

[0061] like Figure 5 and Figure 6 As shown, the first passage 33 of the present embodiment passes through the interior of the sealing unit 30 and has a first opening 33b and a second opening 33c. The first opening 33b opens on the second upper surface 32a of the reinforcing member 32 and communicates with the outside of the power storage device 10. The second opening 33c opens on the side of the sealing unit 30 (the side of the reinforcing member 32 in this example). Moreover, the second pressing portion 23 presses the second upper surface 32a of the reinforcing member 32 throughout the entire circumference. In the present embodiment, only one first passage 33 is provided.

[0062] The preferred embodiments of the present disclosure have been described, but the scope of the present disclosure should not be limited by the description. For example, as long as no technical contradiction occurs, the matters described in two or more claims arbitrarily selected from the multiple claims described in the appended claims can be combined.

[0063] "P.S."

[0064] The following techniques are disclosed through the description of the above embodiments.

[0065] (Technology 1)

[0066] An electric storage device comprising:

[0067] Storage element;

[0068] a bottomed cylindrical housing that accommodates the power storage element and has an opening at one end; and

[0069] A sealing unit seals the opening, wherein:

[0070] The sealing unit comprises:

[0071] a sealing body, comprising a first upper surface facing the outside of the shell and a first lower surface facing the inside; and

[0072] a reinforcing member including a second upper surface facing the outside of the housing and a second lower surface facing the inside, the second lower surface being arranged to face the first upper surface of the sealing body, and having an elastic modulus greater than that of the sealing body,

[0073] The housing has, near the opening:

[0074] a first pressing portion, pressing a first side surface of the sealing body connecting the first upper surface and the first lower surface, and protruding toward the inner side of the housing; and

[0075] a second pressing portion pressing the second upper surface of the reinforcing member,

[0076] The sealing unit has a first passage that communicates with the outside of the electrical storage device at a position radially inward of the case rather than the second pressing portion and opens at a side surface of the sealing unit.

[0077] (Technique 2)

[0078] The power storage device according to technique 1, wherein:

[0079] The first passage is formed only in the reinforcing member in the sealing unit.

[0080] (Technique 3)

[0081] The power storage device according to technology 1 or 2, wherein:

[0082] The first passage has a slit that opens on the second upper surface of the reinforcing member.

[0083] (Technique 4)

[0084] The power storage device as described in technology 3, wherein:

[0085] The slit penetrates the reinforcing member in the thickness direction.

[0086] (Technique 5)

[0087] The power storage device as described in technology 3, wherein:

[0088] The slit does not penetrate the reinforcing member in the thickness direction.

[0089] (Technique 6)

[0090] The power storage device as described in technology 5, wherein

[0091] An outer peripheral portion of the second lower surface of the reinforcing member is in contact with the first upper surface of the sealing body over the entire circumference.

[0092] (Technique 7)

[0093] The power storage device according to technology 1 or 2, wherein:

[0094] The first passage has a first opening that opens on the second upper surface of the reinforcing member and communicates with the outside, and a second opening that opens on a side surface of the sealing unit, and the first passage passes through the interior of the sealing unit.

[0095] (Technology 8)

[0096] The power storage device as described in technology 7, wherein

[0097] The second pressing portion presses the second upper surface of the reinforcing member over the entire circumference.

[0098] (Technique 9)

[0099] The power storage device according to any one of techniques 1 to 8, wherein:

[0100] The first passage opens on the side surface of the sealing unit only at a position closer to the second upper surface than the most protruding apex of the first pressing portion.

[0101] (Technology 10)

[0102] The power storage device according to any one of techniques 1 to 9, wherein:

[0103] A plurality of the first passages are provided.

[0104] (Technology 11)

[0105] The power storage device as described in technology 10, wherein

[0106] The plurality of first passages are arranged at equal intervals in the circumferential direction of the housing.

[0107] Although the present invention has been described in conjunction with the presently preferred embodiments, such disclosure should not be construed in a limiting manner. Upon reading the above disclosure, various modifications and changes will undoubtedly be apparent to those skilled in the art to which the present invention belongs. Therefore, the appended claims should be interpreted as including all modifications and changes that do not depart from the true spirit and scope of the present invention.

[0108] Industrial Applicability

[0109] The present disclosure can be used for an electric storage device.

[0110] Description of Reference Numerals

[0111] 10: Power storage equipment

[0112] 11: Storage element

[0113] 12A, 12B: Lead connector

[0114] 13A, 13B: Lead wire

[0115] 20: Shell

[0116] 21: Opening

[0117] 22: First pressing part

[0118] 22a: Vertex

[0119] 23: Second pressing part

[0120] 30: Sealing unit

[0121] 31: Sealing body

[0122] 31a: First upper surface

[0123] 31b: First lower surface

[0124] 31c: First side

[0125] 32: Strengthening parts

[0126] 32a: Second upper surface

[0127] 32b: Second lower surface

[0128] 33: First Passage

[0129] 33a: Slit

[0130] 33b: First opening

[0131] 33c: Second opening

Claims

1. An electric storage device comprising: Storage element; a bottomed cylindrical housing that accommodates the power storage element and has an opening at one end; and A sealing unit seals the opening, wherein: The sealing unit comprises: A sealing body, comprising a first upper surface facing the outside of the shell and a first lower surface facing the inside; as well as a reinforcing member including a second upper surface facing the outside of the housing and a second lower surface facing the inside, the second lower surface being arranged to face the first upper surface of the sealing body, and having an elastic modulus greater than that of the sealing body, The housing has, near the opening: a first pressing portion, pressing a first side surface of the sealing body connecting the first upper surface and the first lower surface, and protruding toward the inner side of the shell; as well as a second pressing portion pressing the second upper surface of the reinforcing member, The sealing unit has a first passage that communicates with the outside of the electrical storage device at a position radially inward of the case rather than the second pressing portion and opens at a side surface of the sealing unit.

2. The power storage device according to claim 1, wherein The first passage is formed only in the reinforcing member in the sealing unit.

3. The power storage device according to claim 1 or 2, wherein: The first passage has a slit that opens on the second upper surface of the reinforcing member.

4. The power storage device according to claim 3, wherein: The slit penetrates the reinforcing member in the thickness direction.

5. The power storage device according to claim 3, wherein: The slit does not penetrate the reinforcing member in the thickness direction.

6. The power storage device according to claim 5, wherein: An outer peripheral portion of the second lower surface of the reinforcing member is in contact with the first upper surface of the sealing body over the entire circumference.

7. The power storage device according to claim 1 or 2, wherein: The first passage has a first opening that opens on the second upper surface of the reinforcing member and communicates with the outside, and a second opening that opens on a side surface of the sealing unit, and the first passage passes through the interior of the sealing unit.

8. The power storage device according to claim 7, wherein: The second pressing portion presses the second upper surface of the reinforcing member over the entire circumference.

9. The power storage device according to claim 1 or 2, wherein: The first passage opens on the side surface of the sealing unit only at a position closer to the second upper surface than the most protruding apex of the first pressing portion.

10. The power storage device according to claim 1 or 2, wherein: A plurality of the first passages are provided.

11. The power storage device according to claim 10, wherein The plurality of first passages are arranged at equal intervals in the circumferential direction of the housing.

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