JP2019140100A - Power storage element - Google Patents

Abstract

To enhance the certainty of electrical path interruption by making a reversal film smoothly reversible.SOLUTION: A power storage element 10 includes: an electrode body 400 having a positive electrode focusing part 415 (tab); a lid 110 of a container 100 in which the electrode body 400 is housed; a positive electrode current collector 140 (conductive member) which reverses as the internal pressure of the lid 110 fluctuates and has an inversion film 141 for releasing electrical conduction with respect to the positive electrode converging unit 415; a lower gasket 120 (first insulating member) interposed between the positive electrode current collector 140 and the lid 110; and a caulking member 800 (second insulating member) which is arranged at a position opposite to the inversion film 141 and forms a vent hole 810 penetrating through the lid 110 and the lower gasket 120.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a power storage device including an inversion film.

  As a power storage element, a power storage element having a current interruption mechanism has been developed in order to ensure safety during overcharge, for example. Specifically, when a large current flows through the power storage element, the temperature in the power storage element rises, so that the active material of the electrode body and the electrolytic solution are decomposed to generate gas. As a result, when the internal pressure of the container increases, the electrical path is physically interrupted to stop the current from flowing further. As a blocking mechanism, a structure is known in which an electric path is blocked using an inversion film that is reversed by fluctuations in internal pressure of the container (see, for example, Patent Document 1).

JP 2014-235934 A

  By the way, in order to improve the certainty of the interruption | blocking of an electrical pathway, it is desired to invert an inversion film | membrane smoothly.

  For this reason, the present invention is to improve the certainty of blocking the electric path by enabling the inversion film to be smoothly inverted.

  In order to achieve the above object, an energy storage device according to one embodiment of the present invention includes an electrode body having a tab, a container that accommodates the electrode body, and an electrical continuity with the tab that is reversed in accordance with a change in internal pressure of the container. A conductive member having an inversion film to be released, a first insulating member interposed between the conductive member and the container, and a vent hole that is disposed at a position facing the inversion film to penetrate the container and the first insulating member And a second insulating member.

  According to this, since the air hole is provided at a position facing the inversion film, the inversion film can be smoothly inverted. Therefore, it is possible to improve the reliability of electrical interruption due to the inversion film.

  By the way, if the vent hole is simply provided for the container and the first insulating member, the boundary between the container and the first insulating member is exposed, and thus the airtightness may be hindered. For this reason, in the above electricity storage device, since the second insulating member forms a vent hole penetrating the container and the first insulating member, the boundary between the container and the first insulating member is sealed with the second insulating member. The Thereby, the insulation and airtightness in a ventilation hole are securable.

  The conductive member has an overlapping portion that overlaps the reversal film, the second insulating member passes through the overlapping portion, and the vent hole passes through the container, the first insulating member, and the conductive member. Yes.

  According to this, since the second insulating member forms a vent hole penetrating the container, the first insulating member, and the conductive member, the boundary between the container and the first insulating member and the conductive member and the first insulating member The boundary is sealed with the second insulating member. Thereby, the insulation and airtightness in a ventilation hole can be ensured more reliably.

  The power storage element includes an electrode terminal connected to the conductive member in a state of being joined to the container, and the inversion film is located at a position away from the shaft portion of the electrode terminal in the axial direction of the shaft portion. Has been placed.

  For example, when the shaft portion of the electrode terminal and the reversal film are in the same position as viewed in the axial direction, not only the shaft portion and the reversal film but also a space for reversing the reversal film must be provided on the same axis. Don't be. For this reason, the space inside the container is consumed.

  However, if the reversal film is disposed at a position distant from the shaft portion of the electrode terminal in the axial direction, the electrode terminal can be seen when the space for reversing the reversal film is viewed from a direction orthogonal to the axial direction. It can be overlaid on the shaft part. Therefore, space consumption inside the container can be suppressed. Thereby, a larger-sized electrode body can be accommodated in the container, and the battery capacity can be increased.

  Further, when viewed from a direction orthogonal to the axial direction, the space for reversing the reversal film overlaps with the shaft portion of the electrode terminal, so that the degree of freedom of the space is increased by the overlap. That is, the space for the inversion film to be inverted can be increased, and the inversion film can be smoothly inverted.

  The conductive member is a current collector that electrically connects the electrode terminal and the tab of the electrode body.

  According to this, since the conductive member is a current collector, it is not necessary to provide a conductive member dedicated to the inversion film. For this reason, the number of parts can be suppressed, and space consumption inside the container can also be suppressed. If the space consumption inside the container is suppressed, the space for reversing the inversion film can be increased accordingly, and the inversion film can be smoothly reversed.

  The power storage element includes a third insulating member interposed between the conductive member and the electrode body, and the inversion film penetrates the third insulating member and is joined to the tab of the electrode body.

  Since the tab of the electrode body is relatively low in rigidity, there is a risk of following the inversion of the inversion film. However, with the configuration described above, since the inversion film is joined to the tab in a state of passing through the third insulating member interposed between the conductive member and the electrode body, the third insulating member does not move the tab. It will be regulated. Therefore, the tab becomes difficult to follow the reversal of the reversal film, and the reliability of electrical interruption can be improved.

  In addition, an inversion space for accommodating the inverted inversion film is provided between the inversion film and the vent hole.

  According to this, since the inversion space for accommodating the inverted inversion film is provided between the inversion film and the vent hole, other members do not come into contact with the inversion film being inverted. That is, the inversion of the inversion film is less likely to be inhibited by other members, and the inversion film can be inverted smoothly. Therefore, the certainty of electrical interruption can be improved.

  Further, the inversion space is formed by the container projecting outward.

  According to this, since the inversion space is formed by the container projecting outward, the inversion space can be formed large while suppressing the space consumption inside the container as much as possible. Thereby, an electrode body having a large size can be accommodated in the container.

  According to the present invention, the reversal film can be smoothly reversed, thereby improving the certainty of blocking the electric path.

FIG. 1 is a perspective view showing an external appearance of a power storage device according to an embodiment. FIG. 2 is an exploded perspective view of the energy storage device according to the embodiment. FIG. 3 is an exploded perspective view of a portion excluding the container body and the insulating sheet from the power storage device according to the embodiment. FIG. 4 is a cross-sectional view showing the structure around the inversion film according to the embodiment. FIG. 5 is a cross-sectional view showing a state where the inversion film according to the embodiment is inverted. FIG. 6 is a cross-sectional view showing the structure around the inversion film according to the first modification. FIG. 7 is a cross-sectional view showing the structure around the inversion film according to the second modification. FIG. 8 is a cross-sectional view showing a structure around an inversion film according to Modification 3.

  Hereinafter, a power storage device according to an embodiment of the present invention and a modification thereof will be described with reference to the drawings. It should be noted that each of the embodiments and modifications thereof described below is a comprehensive or specific example. The numerical values, shapes, materials, constituent elements, arrangement positions and connection forms of the constituent elements, manufacturing steps, order of manufacturing steps, and the like shown in the following embodiments and modifications thereof are merely examples and are intended to limit the present invention. is not. In addition, among the constituent elements in the following embodiments and modifications thereof, constituent elements that are not described in the independent claims indicating the highest concept are described as arbitrary constituent elements. Each figure is a schematic diagram, and dimensions and the like are not necessarily shown strictly.

  In the following description and drawings, the direction in which the pair of electrode terminals included in the power storage element, the direction in which the pair of converging portions of the electrode body are aligned, or the opposing direction of the short side surface of the container is defined as the X-axis direction. Further, the opposing direction of the long side of the container, the short direction of the short side of the container, the thickness direction of the container, or the stacking direction of the electrode plates of the electrode body is defined as the Y-axis direction. Further, the direction in which the container body and the lid of the storage element are arranged, the longitudinal direction of the short side surface of the container, the axial direction of the shaft portion of the electrode terminal, or the vertical direction is defined as the Z-axis direction. These X-axis direction, Y-axis direction, and Z-axis direction are directions that intersect (orthogonal in this embodiment). Although the case where the Z-axis direction does not become the vertical direction may be considered depending on the usage mode, the Z-axis direction will be described below as the vertical direction for convenience of explanation. In the following description, for example, the X axis direction plus side indicates the arrow direction side of the X axis, and the X axis direction minus side indicates the opposite side to the X axis direction plus side. The same applies to the Y-axis direction and the Z-axis direction.

[1. Configuration of storage element]
First, a general description of the power storage element 10 according to the present embodiment will be described with reference to FIGS. FIG. 1 is a perspective view showing an external appearance of a power storage element 10 according to the embodiment. FIG. 2 is an exploded perspective view of the energy storage device 10 according to the embodiment. FIG. 3 is an exploded perspective view of a portion excluding the container main body 101 and the insulating sheet 500 from the power storage element 10 according to the embodiment.

  The storage element 10 is a secondary battery that can charge electricity and discharge electricity, and specifically, is a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. The power storage element 10 is, for example, a power source for an automobile (or a moving body) such as an electric vehicle (EV), a hybrid electric vehicle (HEV), or a plug-in hybrid electric vehicle (PHEV), a power source for electronic equipment, or a power storage power source. Applicable to etc. In addition, the electrical storage element 10 is not limited to a nonaqueous electrolyte secondary battery, A secondary battery other than a nonaqueous electrolyte secondary battery may be sufficient, and a capacitor may be sufficient as it. The electricity storage element 10 may be a primary battery that can use the stored electricity without being charged by the user. Further, the power storage element 10 may be an all-solid battery.

  As shown in these drawings, the storage element 10 includes a container 100, an electrode body 400, an insulating sheet 500, and a pair of side spacers 700. In addition, although electrolyte solution (nonaqueous electrolyte) is enclosed inside the container 100, illustration is abbreviate | omitted. There are no particular restrictions on the type of the electrolytic solution as long as it does not impair the performance of the electricity storage element 10, and various types can be selected.

  In the present embodiment, a lid structure 180 configured by arranging various elements on the lid 110 of the container 100 is disposed above the electrode body 400. In the container 100, one end of the electrode body 400 faces the lid structure 180.

  The container 100 includes a container body 101 having a rectangular cylindrical shape and a bottom, and a lid 110 that closes an opening of the container body 101. In the container 100, an electrode body 400, an insulating sheet 500, and a pair of side spacers 700 are accommodated. The container 100 has a structure in which the interior of the container 100 is sealed by welding the lid body 110 and the container body 101 after the electrode body 400 and the like are accommodated therein. The container 100 (the lid body 110 and the container body 101) is formed of a weldable metal such as stainless steel, aluminum, or an aluminum alloy, for example. The lid body 110 and the container body 101 are preferably formed of the same material, but may be formed of different materials. In addition, the lid 110 is provided with a liquid injection port 124 for injecting an electrolytic solution into the container 100. The liquid injection port 124 is closed by a liquid injection plug 126. In addition, the lid 110 may be provided with a gas discharge valve or the like that discharges the gas inside the container 100 when the internal pressure of the container 100 rises.

  The lid structure 180 includes a lid 110 of the container 100, a caulking member 800, a positive electrode terminal 200, a negative electrode terminal 300, upper gaskets 125 and 135, lower gaskets 120 and 130, a positive electrode current collector 140, a negative electrode current collector 150, and an insulation. A plate 170 is provided.

  The lid 110 is a plate-like member, and has a liquid injection port 124 and through holes 110a and 110b as shown in FIG. The liquid injection port 124 is a through-hole for injecting an electrolytic solution when the power storage element 10 is manufactured.

  Further, a through hole 127 is formed in the lid 110 between the through hole 110 a and the liquid injection port 124. A caulking member 800 is attached to the through hole 127. In FIG. 3, the caulking member 800 represents a state before caulking. Specifically, the caulking member 800 is formed in a cylindrical shape before caulking. The caulking member 800 is an example of a second insulating member. The caulking member 800 is made of, for example, polypropylene (PP), polyethylene (PE), polyphenylene sulfide resin (PPS), polyether ether ketone (PEEK), tetrafluoroethylene / perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene. (PTFE), polybutylene terephthalate (PBT), poly ether sulfone (PES) and other insulating resins.

  The upper gaskets 125 and 135 and the lower gaskets 120 and 130 are made of insulating resin such as PP, PE, PPS, PEEK, PFA, PTFE, PBT, and PES, for example.

  The upper gasket 125 is a member that electrically insulates the positive electrode terminal 200 and the lid 110. The upper gasket 125 is formed with a through hole 125a through which the shaft portion 210 (see FIG. 4) of the positive electrode terminal 200 passes. The lower gasket 120 is a member that electrically insulates the positive electrode current collector 140 and the lid 110 and is an example of a first insulating member. The lower gasket 120 has a first through hole 120a through which the shaft portion 210 of the positive electrode terminal 200 passes. The lower gasket 120 has a second through hole 121a that is aligned with the first through hole 120a in the X-axis direction. The caulking member 800 passes through the second through hole 121a.

  The upper gasket 135 is a member that electrically insulates the negative electrode terminal 300 from the lid 110. The upper gasket 135 is formed with a through hole 135a through which a shaft portion (not shown) of the negative electrode terminal 300 passes. The lower gasket 130 is a member that electrically insulates the negative electrode current collector 150 from the lid 110. The lower gasket 130 is formed with a through hole 130a through which the shaft portion of the negative electrode terminal 300 passes.

  The upper gaskets 125 and 135 may be referred to as upper packing, for example, and the lower gaskets 120 and 130 may be referred to as lower packing, for example. That is, in the present embodiment, the upper gaskets 125 and 135 and the lower gaskets 120 and 130 also have a function of sealing between the electrode terminal (200 or 300) and the container 100.

  As shown in FIGS. 1 to 3, the positive electrode terminal 200 is an electrode terminal electrically connected to the positive electrode of the electrode body 400 via the positive electrode current collector 140. The negative electrode terminal 300 is an electrode terminal electrically connected to the negative electrode of the electrode body 400 via the negative electrode current collector 150. That is, the positive electrode terminal 200 and the negative electrode terminal 300 lead the electricity stored in the electrode body 400 to the external space of the power storage element 10, and in order to store the electricity in the electrode body 400, It is an electrode terminal made of metal for introducing. The positive terminal 200 is made of aluminum or aluminum alloy, and the negative terminal 300 is made of copper or copper alloy.

  Further, the positive terminal 200 is provided with a shaft portion 210 (see FIG. 4) that fastens the container 100 and the positive electrode current collector 140. The negative electrode terminal 300 is provided with a shaft portion (not shown) that fastens the container 100 and the negative electrode current collector 150.

  The shaft portion 210 of the positive electrode terminal 200 is a portion (rivet) extending downward from the main body portion of the positive electrode terminal 200, and is inserted into the through hole 140 a of the positive electrode current collector 140 and caulked. Specifically, the shaft portion 210 of the positive electrode terminal 200 includes a through hole 125 a of the upper gasket 125, a through hole 110 a of the lid 110, a first through hole 120 a of the lower gasket 120, and a through hole of the positive electrode current collector 140. It is inserted into 140a and crimped. Thereby, the positive electrode terminal 200 and the positive electrode current collector 140 are electrically connected, and the positive electrode current collector 140 is fixed to the lid 110 together with the positive electrode terminal 200, the upper gasket 125, and the lower gasket 120.

  The shaft portion of the negative electrode terminal 300 is a portion (rivet) extending downward from the main body portion of the negative electrode terminal 300, and is inserted into the through hole 150 a of the negative electrode current collector 150 and caulked. Specifically, the shaft portion of the negative electrode terminal 300 is inserted into the through hole 135 a of the upper gasket 135, the through hole 110 b of the lid 110, the through hole 130 a of the lower gasket 130, and the through hole 150 a of the negative electrode current collector 150. Be caulked. Thereby, the negative electrode terminal 300 and the negative electrode current collector 150 are electrically connected, and the negative electrode current collector 150 is fixed to the lid 110 together with the negative electrode terminal 300, the upper gasket 135, and the lower gasket 130.

  The shaft portion 210 of the positive electrode terminal 200 may be formed as an integral part of the main body portion of the positive electrode terminal 200, and the shaft portion 210 manufactured as a separate component from the main body portion may be caulked or welded. You may fix to the main-body part of a positive electrode terminal by the method. The same applies to the relationship between the negative electrode terminal 300 and its shaft portion.

  As shown in FIG. 3, the positive electrode current collector 140 is disposed between the electrode body 400 and the lid body 110 and is a conductive member that electrically connects the positive electrode focusing portion 415 of the electrode body 400 and the positive electrode terminal 200. It is an example. The positive electrode current collector 140 is made of aluminum or an aluminum alloy. The positive electrode current collector 140 is formed with a through hole 140 a through which the shaft portion 210 of the positive electrode terminal 200 passes. In addition, the positive electrode current collector 140 is provided with an inversion film 141 bonded to the positive electrode focusing portion 415 of the electrode body 400.

  The negative electrode current collector 150 is a member that is disposed between the electrode body 400 and the lid body 110 and electrically connects the negative electrode focusing portion 425 of the electrode body 400 and the negative electrode terminal 300. The negative electrode current collector 150 is made of copper or a copper alloy. The negative electrode current collector 150 has a through hole 150 a through which the shaft portion of the negative electrode terminal 300 passes.

  The insulating plate 170 is an example of a third insulating member that is interposed between the positive electrode current collector 140 and the electrode body 400. The insulating plate 170 is formed in a substantially rectangular plate shape. A through hole 170 a that exposes the inversion film 141 is formed at a position corresponding to the inversion film 141 of the positive electrode current collector 140 in the insulating plate 170. The insulating plate 170 is made of, for example, an insulating resin such as PP, PE, PPS, PEEK, PFA, PTFE, PBT, or PES. The insulating plate 170 is preferably higher in rigidity than the positive electrode focusing portion 415 of the electrode body 400.

  The pair of side spacers 700 are disposed so as to overlap each of the pair of short side surfaces of the electrode body 400. The side spacer 700 is an insulating member formed of an insulating resin such as PP, PE, PPS, PEEK, PFA, PTFE, PBT, or PES. The side spacer 700 is fixed to the electrode body 400 with an adhesive tape 700 (see FIG. 2).

  The electrode body 400 includes a positive electrode plate, a negative electrode plate, and a separator, and is a power storage element (power generation element) that can store electricity, and is disposed inside the container 100. Specifically, the electrode body 400 is a stacked electrode body in which a positive electrode plate and a negative electrode plate are alternately arranged with a separator interposed therebetween. The positive electrode plate is an electrode plate in which a positive electrode active material layer is formed on a positive electrode base material layer that is a long strip-shaped current collector foil made of aluminum, an aluminum alloy, or the like. The negative electrode plate is an electrode plate in which a negative electrode active material layer is formed on a negative electrode base material layer that is a long strip-shaped current collector foil made of copper, a copper alloy, or the like. Note that as the current collector foil, a known material such as nickel, iron, stainless steel, titanium, baked carbon, a conductive polymer, conductive glass, or an Al—Cd alloy can be used as appropriate. Moreover, as a positive electrode active material and a negative electrode active material used for a positive electrode active material layer and a negative electrode active material layer, if it is an active material which can occlude-release lithium ion, a well-known material can be used suitably. Moreover, the separator can use the microporous sheet | seat which consists of resin, for example, and a nonwoven fabric.

  The electrode body 400 includes an electrode body main body 401 that is a part that generates and stores power, and a positive electrode focusing part 415 and a negative electrode focusing part 425 that are parts that exchange power between the electrode body main body 401 and the outside.

  The electrode body main body 401 is formed in a substantially rectangular parallelepiped shape as a whole. An adhesive tape 370 is attached to the upper portion of the electrode body 401 so as to avoid the positive electrode focusing portion 415 and the negative electrode focusing portion 425. In addition, adhesive tapes 370 are attached to the lower portion of the electrode body 401 at three locations. These adhesive tapes 370 prevent misalignment between the positive electrode plate, the negative electrode plate, and the separator.

  The positive electrode focusing portion 415 protrudes from the minus side in the X-axis direction on the top surface of the electrode body main body 401. The positive electrode focusing portion 415 is an example of a tab bonded to the inversion film 141. The positive electrode converging part 415 is formed by bundling portions where the positive electrode active material is not applied and the positive electrode base material layer is exposed in each positive electrode plate. The negative electrode focusing part 425 protrudes from the X axis direction plus side on the top surface of the electrode body main body 401. The negative electrode converging portion 425 is formed by bundling portions where the negative electrode active material is not applied and the negative electrode base material layer is exposed in each negative electrode plate.

  The positive electrode focusing portion 415 is bonded to the reversal film 141 of the positive electrode current collector 140, and the negative electrode focusing portion 425 is bonded to the flat surface portion of the negative electrode current collector 150. That is, the positive electrode focusing unit 415 is electrically connected to the positive electrode terminal 200 via the positive electrode current collector 140, and the negative electrode focusing unit 425 is electrically connected to the negative electrode terminal 300 via the negative electrode current collector 150. . Thereby, the electrode body 400 can exchange electric power with an external apparatus etc. via the positive electrode terminal 200 and the negative electrode terminal 300. FIG.

  Note that, for the bonding between the positive electrode converging unit 415 and the inversion film 141, a bonding method is employed in which the inversion film 141 can be separated from the positive electrode converging unit 415 when the inversion film 141 is inverted. Specifically, for example, welding such as ultrasonic welding or laser welding or adhesion is employed for joining the positive electrode focusing portion 415 and the reversal film 141. On the other hand, for joining the negative electrode focusing portion 425 and the negative electrode current collector 150, it is possible to employ fastening such as caulking or screwing in addition to the above-described welding and adhesion.

  Next, the inversion film 141 of the positive electrode current collector 140 and the surrounding structure will be described in detail. FIG. 4 is a cross-sectional view showing a structure around the inversion film 141 according to the embodiment. Specifically, FIG. 4 is a cross-sectional view of the cut surface including the IV-IV line in FIG.

  As shown in FIG. 4, the inversion film 141 has a circular shape in a plan view and has a concave shape that is recessed toward the inside of the container 100. The inversion film 141 passes through the through hole 170 a of the insulating plate 170 and is joined to the positive electrode converging portion 415 of the electrode body 400. Specifically, at least the apex portion of the inversion film 141 is joined to the positive electrode converging portion 415.

  On the lower surface of the lower gasket 120 (the surface on the positive electrode current collector 140 side), an annular recess 128 surrounding the entire circumference of the second through-hole 121a is formed. The recess 128 is thinner than the other parts of the lower gasket 120. The internal space of the recess 128 is a reversal space 129 that houses the reversed reversal film 141.

  Further, the inversion film 141 is disposed at a position away from the shaft portion 210 of the positive electrode terminal 200 in the axial direction of the shaft portion 210. Specifically, the inversion film 141 is disposed away from the positive side in the X-axis direction so as not to overlap the shaft portion 210. Thereby, the inversion film 141 and the inversion space 129 can be superimposed on the shaft portion 210 of the positive electrode terminal 200 when viewed from the direction orthogonal to the axial direction (Y-axis direction). Therefore, space consumption inside the container 100 can be suppressed.

  Further, a caulking member 800 that penetrates the second through hole 121 a of the lower gasket 120 and the through hole 127 of the lid 110 is provided in the recess 128. The caulking member 800 is cylindrical before being assembled (see FIG. 3). The caulking member 800 is attached to the lower gasket 120 and the lid 110 by being caulked by mechanical caulking, thermal caulking, or the like at the time of assembly. That is, the vent hole 810 of the caulking member 800 penetrates the lower gasket 120 and the lid body 110 to form an air flow path.

  After crimping, the caulking member 800 is in close contact with the inner peripheral surface forming the second through-hole 121a of the lower gasket 120 and the inner peripheral surface forming the through-hole 127 of the lid 110, and the lower gasket 120 and the lid 110 And seal the boundary. By this sealing, airtightness at the boundary between the lower gasket 120 and the lid 110 is ensured. Further, a through hole is formed at the center of the caulking member 800, and the through hole forms a vent hole 810 that penetrates the lid 110 and the lower gasket 120. Since the air hole 810 is provided at a position facing the reversal film 141, air can be released from the air hole 810 when the reversal film 141 is reversed, and the reversal film 141 can be smoothly reversed. .

[2. Blocking operation]
Next, an electrical cutoff operation of the electricity storage element 10 will be described.

  In a normal state, as shown in FIG. 4, the inversion film 141 is in a state of being joined to the positive electrode focusing portion 415. For example, when the storage element 10 is overcharged and becomes abnormal, the internal pressure of the container 100 becomes higher than that in the normal state. When the internal pressure of the container 100 rises, the reversal film 141 is reversed in response to fluctuations in the internal pressure of the container 100. During the reversal of the reversal film 141, the air in the reversal space 129 is discharged from the vent hole 810 to the outside of the container 100.

  FIG. 5 is a cross-sectional view showing a state where the inversion film 141 according to the embodiment is inverted. Specifically, FIG. 5 corresponds to FIG. As shown in FIGS. 4 and 5, the positive electrode converging unit 415 is in a state where movement toward the lid 110 side is restricted by the insulating plate 170. For this reason, even when the inversion film 141 is inverted, the positive electrode converging part 415 is difficult to follow the inversion of the inversion film 141, so that the inversion film 141 is separated from the positive electrode converging part 415. Thereby, the electrical conduction between the inversion film 141 and the positive electrode focusing portion 415 is interrupted. The inverted film 141 after inversion is accommodated in the inversion space 129.

[3. Effect]
As described above, according to the electricity storage device 10 according to the present embodiment, the electrode body 400 having the positive electrode focusing portion 415 (tab), the lid body 110 of the container 100 that houses the electrode body 400, and the container 100 A positive current collector 140 (conductive member) having a reversal film 141 that reverses in accordance with fluctuations in internal pressure and releases electrical conduction to the positive electrode converging portion 415, and is interposed between the positive current collector 140 and the lid 110. A lower gasket 120 (first insulating member), and a caulking member 800 (second insulating member) disposed at a position facing the reversal film 141 and forming a vent hole 810 penetrating the lid 110 and the lower gasket 120. It has.

  According to this, since the vent hole 810 is provided at a position facing the inversion film 141, the inversion film 141 can be smoothly inverted. Therefore, it is possible to improve the certainty of electrical interruption due to the inversion film 141.

  By the way, if the vent hole is simply provided for the lid 110 and the lower gasket 120, the boundary between the lid 110 and the lower gasket 120 is exposed, and thus the airtightness may be hindered. For this reason, in the electric storage element 10 described above, the caulking member 800 forms the vent hole 810 penetrating the lid 110 and the lower gasket 120, so that the boundary between the lid 110 and the lower gasket 120 is sealed with the caulking member 800. Stopped. Thereby, the insulation and airtightness in the ventilation hole 810 can be ensured.

  In addition, the storage element 10 includes a positive electrode terminal 200 (electrode terminal) connected to the positive electrode current collector 140 in a state of being joined to the lid body 110, and the inversion film 141 is connected to the shaft portion 210 of the positive electrode terminal 200. The shaft portion 210 is disposed at a position distant from the axial direction view.

  For example, when the shaft portion of the positive electrode terminal and the reversal film are in the same position as viewed in the axial direction, not only the shaft portion and the reversal film but also a space for reversing the reversal film must be provided on the same axis. Don't be. For this reason, the space inside the container is consumed.

  However, if the reversal film 141 is disposed at a position distant from the shaft portion 210 of the positive electrode terminal 200 in the axial direction as in the present embodiment, the space for reversing the reversal film 141 is reduced to the axis. When viewed from a direction orthogonal to the direction, the layer can be overlapped with the shaft portion 210 of the positive electrode terminal 200. Therefore, space consumption inside the container 100 can be suppressed. Accordingly, the electrode body 400 having a larger size can be accommodated in the container 100, and the battery capacity can be increased.

  In addition, when viewed from a direction orthogonal to the axial direction, a space (inversion space 129) for inverting the inversion film 141 overlaps the shaft portion 210 of the positive electrode terminal 200, so that the space is overlapped by the overlap. The degree of freedom increases. That is, the space for the inversion film 141 to be inverted can be increased, and the inversion film 141 can be smoothly inverted.

  The conductive member is a positive electrode current collector 140 (current collector) that electrically connects the positive electrode terminal 200 and the positive electrode converging portion 415 of the electrode body 400.

  According to this, since the conductive member is the positive electrode current collector 140, it is not necessary to provide a conductive member dedicated to the inversion film. For this reason, the number of parts can be suppressed, and the space consumption inside the container 100 can also be suppressed. If the space consumption inside the container 100 is suppressed, the space for the inversion film 141 to be inverted can be increased accordingly, and the inversion film 141 can be smoothly inverted.

  In addition, the storage element 10 includes an insulating plate 170 (third insulating member) interposed between the positive electrode current collector 140 and the electrode body 400, and the inversion film 141 penetrates the insulating plate 170 so as to pass through the electrode body 400. Are joined to the positive electrode focusing portion 415.

  Since the positive electrode converging unit 415 has relatively low rigidity, there is a risk of following the reversal of the reversal film 141. However, with the above-described configuration, since the inversion film 141 is bonded to the positive electrode converging portion 415 while passing through the insulating plate 170 interposed between the positive electrode current collector 140 and the electrode body 400, the insulating plate 170 regulates the movement of the positive electrode converging unit 415. Therefore, the positive electrode converging unit 415 is less likely to follow the reversal of the reversal film 141, and the reliability of electrical interruption can be improved.

  Further, an inversion space 129 for accommodating the inverted inversion film 141 is provided between the inversion film 141 and the vent hole 810.

  According to this, since the inversion space 129 that accommodates the inverted inversion film 141 is provided between the inversion film 141 and the vent hole 810, other members may come into contact with the inversion film 141 that is being inverted. Absent. That is, the inversion of the inversion film 141 is not easily inhibited by other members, and the inversion film 141 can be inverted smoothly. Therefore, the certainty of electrical interruption can be improved.

[4. Modified example]
(Modification 1)
The power storage element 10 according to the above embodiment has been described above, but the power storage element 10 may include a positive electrode current collector different from the above-described aspect. Thus, hereinafter, a modified example of the positive electrode current collector included in the power storage element 10 will be described focusing on differences from the above embodiment. In the following description, the same parts as those in the above embodiment may be denoted by the same reference numerals and the description thereof may be omitted.

  FIG. 6 is a cross-sectional view showing a structure around the inversion film 141 according to the first modification. Specifically, FIG. 6 is a diagram corresponding to FIG. As shown in FIG. 6, the positive electrode current collector 140 </ b> A shown in Modification 1 is provided with an overlapping portion 142 that overlaps the inversion film 141. The overlapping portion 142 is a portion that fits into the concave portion 128 of the lower gasket 120 and protrudes upward from the upper surface of the positive electrode current collector 140A. A space is formed between the overlapping portion 142 and the inversion film 141, and the space becomes an inversion space 129a. Further, a through hole 143 is formed in the overlapping portion 142. The through hole 143 communicates with the second through hole 121a of the lower gasket 120 and the through hole 127 of the lid 110.

  The caulking member 800A is attached to the positive electrode current collector 140, the lower gasket 120, and the lid 110. Specifically, the caulking member 800 </ b> A passes through the through hole 143 of the positive electrode current collector 140, the second through hole 121 a of the lower gasket 120, and the through hole 127 of the lid body 110, The gasket 120 and the lid 110 are crimped. That is, the vent hole 810 of the caulking member 800A penetrates the positive electrode current collector 140, the lower gasket 120, and the lid body 110 to form an air flow path.

  Note that the inversion film 141 is originally separated from the positive electrode current collector 140A. For example, after the crimping member 800 is assembled to the positive electrode current collector 140, the lower gasket 120, and the lid body 110, the reversal film 141 is welded or bonded to the positive electrode current collector 140A, whereby the positive electrode current collector 140A. Integrated into

  The caulking member 800A includes an inner peripheral surface forming the through hole 143 of the positive electrode current collector 140, an inner peripheral surface forming the second through hole 121a of the lower gasket 120, and an inner peripheral surface forming the through hole 127 of the lid 110. It is in close contact with. Accordingly, the caulking member 800A seals the boundary between the positive electrode current collector 140A and the lower gasket 120 and the boundary between the lower gasket 120 and the lid 110. This sealing ensures airtightness at the boundary between the positive electrode current collector 140 </ b> A and the lower gasket 120 and at the boundary between the lower gasket 120 and the lid 110.

  As described above, the caulking member 800A forms the vent hole 810 that penetrates the lid 110, the lower gasket 120, and the positive electrode current collector 140A, and therefore the boundary between the positive electrode current collector 140A and the lower gasket 120 and the lower gasket 120 are formed. The lid 110 is sealed with a caulking member 800. Thereby, the insulation and airtightness in the ventilation hole 810 can be ensured more reliably.

(Modification 2)
FIG. 7 is a cross-sectional view showing a structure around the inversion film 141 according to the second modification. Specifically, FIG. 7 corresponds to FIG. As shown in FIG. 7, the lid body 110 </ b> B according to the second modification is provided with a protrusion 118 that protrudes outward from the container 100 at a position corresponding to the inversion space 129 b. In the lid body 110 </ b> B, a recess 119 is formed on the surface opposite to the protrusion 118. A portion of the lower gasket 120B opposite to the recess 128b protrudes so as to fit into the recess 119. Thereby, the recessed part 128b can be made deeper and the magnitude | size of the inversion space 129b can also be enlarged.

  Thus, since the inversion space 129b is formed by the lid body 110 projecting outward, the inversion space 129b can be formed large while suppressing the space consumption inside the container 100 as much as possible. Thereby, the electrode body 400 having a large size can be accommodated in the container.

(Modification 3)
FIG. 8 is a cross-sectional view showing a structure around the inversion film 141 according to Modification 3. As shown in FIG. Specifically, FIG. 8 corresponds to FIG. In the following description, the same parts as those of Modification 1 may be denoted by the same reference numerals and the description thereof may be omitted. As shown in FIG. 8, a conductive plate 190 is joined to the positive electrode current collector 140 </ b> A according to Modification 3 instead of the insulating plate 170. The conductive plate 190 is disposed between the positive electrode current collector 140 and the positive electrode focusing portion 415. A plate-shaped insulator 195 is interposed between the conductive plate 190 and the positive electrode current collector 140.

  A concave portion 191 for accommodating the inversion film 141 is formed on the main surface of the conductive plate 190 on the positive electrode current collector 140A side. A through hole 196 is formed in a portion of the insulator 195 corresponding to the recess 191. The inversion film 141 is accommodated in the recess 191 through the through hole 196. As a result, the concave reversal film 141 that is recessed toward the inside of the container 100 can be accommodated in the recess 191, so that space consumption inside the container 100 can be suppressed. Therefore, the electrode body 400 having a larger size can be accommodated in the container 100, and the battery capacity can be increased.

  The bottom portion of the recess 191 is formed thinner than other portions of the conductive plate 190. The rigidity of the bottom of the recess 191 is higher than the rigidity of the positive electrode converging part 415. An inversion film 141 is bonded to the bottom of the recess 191. For joining the bottom of the recess 191 and the reversal film 141, for example, welding such as ultrasonic welding or laser welding or adhesion is employed. As described above, since the insulator 195 is interposed between the conductive plate 190 and the positive electrode current collector 140, the portion other than the joint portion with the reversal film 141 in the conductive plate 190 is the positive electrode current collector 140. And insulated.

  A positive electrode converging part 415 is joined to the main surface of the conductive plate 190 opposite to the positive electrode current collector 140a side. Specifically, the positive electrode focusing portion 415 is joined to the conductive plate 190 at a position away from the recess 191 in plan view. Thereby, the positive electrode current collector 140 </ b> A and the positive electrode focusing portion 415 are indirectly electrically connected via the conductive plate 190.

  In Modification 3, the positive electrode converging portion 414 is illustrated as being disposed on the outer side (X-axis direction plus side) than the concave portion 191 in the conductive plate 190, but the concave portion 191 in the conductive plate 190 is illustrated. It may be arranged on the inner side (X-axis direction minus side). In addition to the welding and adhesion described above, fastening such as caulking or screwing can be employed for joining the positive electrode focusing portion 415 and the conductive plate 190.

  When the inversion film 141 is inverted, the inversion film 141 is separated from the bottom of the recess 191 of the conductive plate 190. Thereby, the electrical continuity between the conductive plate 190 and the positive electrode current collector 140a is released. That is, the electrical continuity between the positive electrode converging unit 415 and the positive electrode current collector 140a is released.

  When the inversion film 141 is inverted, the inversion film 141 may release the electrical continuity by removing a part of the bottom portion of the recess 191 from the remaining portion and separating it. Further, the conductive plate 190 may have a flat plate shape in which the concave portion 191 is not formed.

  As described above, according to the third modification, even when the positive electrode current collector 140a and the positive electrode focusing portion 415 are indirectly connected via the conductive plate 190, the same operations and effects as the first modification are obtained. Can play.

  Further, the reversal film 141 is not joined to the positive electrode converging portion 415 having relatively low rigidity, but is joined to the concave portion 191 of the conductive plate 190. That is, the inversion film 141 is separated from the concave portion 191 of the conductive plate 190 at the time of inversion, but the concave portion 191 is less likely to follow like the positive electrode focusing portion 415. For this reason, the certainty of electrical interruption can be improved.

[5. Others]
As described above, the power storage device according to the present invention has been described based on the embodiment and the modifications thereof. However, the present invention is not limited to the above-described embodiments and modifications. Without departing from the gist of the present invention, various modifications conceived by those skilled in the art may be applied to the above-described embodiment or modification, or a form constructed by combining a plurality of the constituent elements described above. It is included in the range.

  For example, in the above embodiment, the stacked electrode body 400 in which the positive electrode plate and the negative electrode plate are alternately arranged with the separator interposed therebetween is exemplified. However, the electrode body may be a stacked electrode body in which a positive electrode plate and a negative electrode plate are folded in a bellows shape with a separator interposed therebetween. The electrode body may be a wound electrode body in which a positive electrode plate and a negative electrode plate are wound with a separator interposed therebetween.

  Moreover, in the said embodiment, the case where the inversion film 141, the insulating board 170, and the crimping member 800 were provided in the positive electrode side was illustrated. However, the reversal film, the insulating plate, and the crimping member can be provided on the negative electrode side. Further, an inversion film, an insulating plate, and a caulking member may be provided on each of the positive electrode side and the negative electrode side.

  Moreover, in the said embodiment, the case where the inversion space 129 was provided between the inversion film 141 and the ventilation hole 810 was illustrated. However, if the reversal film is flattened with the internal pressure fluctuation of the container and the junction between the reversal film and the positive electrode converging unit is released, the reversal space becomes unnecessary. In this case, “inversion” includes that the inversion film deforms flatly.

  Moreover, in the said embodiment, the crimping member 800 was illustrated as an example of a 2nd insulating member. However, the second insulating member may be anything as long as it has a vent hole penetrating the container and the first insulating member. Other examples of the second insulating member include blind rivets and pop rivets.

  The present invention is applicable to power storage elements such as lithium ion secondary batteries.

DESCRIPTION OF SYMBOLS 10 Power storage element 100 Container 101 Container main body 110, 110B Cover body 110a, 110b, 125a, 127, 130a, 135a, 140a, 143, 150a, 170a, 196 Through-hole 118 Protrusion 119, 128, 128b Recess 120, 120B Lower gasket (First insulation member)
120a First through hole 121a Second through hole 124 Injection port 125, 135 Upper gasket 126 Injection plug 129, 129a, 129b Inversion space 130 Lower gasket 140, 140A Positive electrode current collector (conductive member)
141 Inversion film 142 Overlapping part 150 Negative electrode current collector 170 Insulating plate (third insulating member)
180 Lid structure 190 Conductive plate 191 Recess 195 Insulator 200 Positive electrode terminal (electrode terminal)
210 Shaft portion 300 Negative electrode terminal 370, 380 Adhesive tape 400 Electrode body 401 Electrode body main body 415 Positive electrode focusing portion (tab)
425 Negative electrode converging part 500 Insulating sheet 700 Side spacer 800, 800A Caulking member (second insulating member)
810 Vent

Claims (7)

An electrode body having a dove;
A container for housing the electrode body;
A conductive member having a reversal film that reverses with an internal pressure variation of the container and releases electrical conduction to the tab;
A first insulating member interposed between the conductive member and the container;
A power storage device comprising: a second insulating member disposed at a position facing the reversal film and forming a vent hole penetrating the container and the first insulating member. The conductive member has an overlapping portion that overlaps the inversion film,
The second insulating member passes through the overlapping portion,
The power storage device according to claim 1, wherein the vent hole penetrates the container, the first insulating member, and the conductive member. In the state joined to the container, comprising an electrode terminal connected to the conductive member,
The power storage device according to claim 1, wherein the inversion film is disposed at a position away from the shaft portion of the electrode terminal as viewed in the axial direction of the shaft portion. The electric storage element according to any one of claims 1 to 3, wherein the conductive member is a current collector that electrically connects the electrode terminal and a tab of the electrode body. A third insulating member interposed between the conductive member and the electrode body;
The electric storage element according to claim 4, wherein the inversion film penetrates the third insulating member and is joined to a tab of the electrode body. The electric storage element according to any one of claims 1 to 5, wherein an inversion space that houses the inverted inversion film is provided between the inversion film and the vent hole. The electric storage element according to claim 6, wherein the inversion space is formed by the container projecting outward.

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