Power storage module

Abstract

To provide a power storage module capable of securing a joint region between a negative electrode of a power storage device and a negative electrode lead while securing an insulation distance between a positive electrode of the power storage device and the negative electrode lead.SOLUTION: The power storage device includes at least one cylindrical power storage device 20 and an upper holder 30 that holds an upper end side of the power storage device 20, a positive electrode terminal and a negative electrode terminal are disposed at an upper end portion of the power storage device 20, the negative electrode terminal is disposed outside the positive electrode terminal in a radial direction of the power storage device 20, the power storage device further includes a negative electrode lead 50 connected to the negative electrode terminal from outside in the radial direction, and the upper holder 30 has a restriction portion 34 located inside at least a part of the negative electrode lead 50 in the radial direction.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to an energy storage module. [Background technology]

[0002] Conventionally, a power storage module is known as a power source including a plurality of power storage devices. For example, the power storage module disclosed in Patent Document 1 includes a plurality of cylindrical batteries. In this cylindrical battery, the sealing body serves as a positive terminal and the outer can serves as a negative terminal, with a negative lead joined to the shoulder (the crimped open end) of the outer can. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2019 / 058938 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-described energy storage module, if the negative electrode lead protrudes radially inward from the outer can when the negative electrode lead is welded to the shoulder of the outer can, it may be impossible to maintain an insulating distance between the negative electrode lead and the sealing body. On the other hand, if the radial length of the bonding area between the negative electrode lead and the outer can is reduced in order to maintain an insulating distance between the negative electrode lead and the sealing body, it becomes difficult to ensure a sufficient bonding area for bonding.

[0005] An object of the present disclosure is to provide an energy storage module that can ensure an insulating distance between the positive electrode and negative electrode lead of an energy storage device while ensuring a bonding area between the negative electrode and negative electrode lead of the energy storage device. [Means for solving the problem]

[0006] An energy storage module according to one embodiment of the present disclosure comprises at least one cylindrical energy storage device and a holder that holds one side of the energy storage device, wherein a first terminal and a second terminal are arranged at an end of one side of the energy storage device, the second terminal is arranged radially outward of the first terminal in the energy storage device, and the module further comprises a lead connected to the second terminal from the radially outer side, and the holder has a restricting portion that is positioned radially inward of at least a portion of the lead. [Effects of the Invention]

[0007] According to one embodiment of the present disclosure, contact between the positive electrode and the negative electrode lead of the power storage device can be suppressed. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a side cross-sectional view showing an example of an electric storage module according to an embodiment; [Figure 2] FIG. 2 is a detailed view showing an extracted portion A of FIG. 1. [Figure 3] FIG. 2 is a plan view of the upper holder as seen from below. [Figure 4] FIG. 4 is a detailed view (plan view) showing an extracted portion B of FIG. 3. [Figure 5] FIG. 5 is a perspective view of part B in FIG. 4 as seen from below. [Figure 6] FIG. 2 is a perspective view of the accommodation portion of the upper holder and the negative electrode lead as viewed from above. [Figure 7] FIG. [Figure 8] FIG. 10 is a perspective view of an upper holder of an electricity storage module as another example of the embodiment, as viewed from above. [Figure 9] 8 is a cross-sectional view taken along CC in FIG. 7. [Figure 10] FIG. 10 is a plan view showing a negative electrode lead of an electricity storage module that is another example of the embodiment. [Figure 11] FIG. 11 is a perspective view of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The shapes, materials, and quantities described below are merely examples and can be changed as appropriate depending on the specifications of the energy storage module.

[0010] An energy storage module 10, which is one example of an embodiment, will be described using Fig. 1. Fig. 1 is a side cross-sectional view showing the energy storage module 10. In the following description, the energy storage module 10 and the energy storage device 20 will be described with the side where an upper holder 30 serving as a holder holds the energy storage device 20 being the upper side in the up-down direction. However, the upper holder 30 side may also be the lower side of the energy storage module 10.

[0011] The power storage module 10 is primarily used as a power source for motive power. The power storage module 10 is used as a power source for motor-driven electric devices such as electric vehicles, power tools, power-assisted bicycles, electric motorcycles, electric wheelchairs, electric tricycles, and electric carts. However, the uses of the power storage module 10 are not limited, and the module may also be used as a power source for various electric devices used indoors and outdoors, such as vacuum cleaners, radios, lighting devices, digital cameras, and video cameras.

[0012] 1, the energy storage module 10 includes a plurality of cylindrical energy storage devices 20, an upper holder 30 as a holder for holding the upper end sides of each of the energy storage devices 20, a lower holder 40 for holding the lower end sides of each of the energy storage devices 20, a first current collector (not shown) on which a positive electrode lead connected to a first terminal (positive electrode terminal) of the energy storage device 20 is formed, and a second current collector (not shown) on which a negative electrode lead 50 (see FIG. 2) is formed as a lead connected to a second terminal (negative electrode terminal) of the energy storage device 20. The upper holder 30 and the negative electrode lead 50 will be described in detail below.

[0013] The electricity storage device 20 will be described with reference to Fig. 2. Fig. 2 is a detailed view of part A in Fig. 1. Below, each member will be described according to the radial and circumferential directions of the cylindrical shape of the electricity storage device 20.

[0014] A cylindrical lithium ion secondary battery is used as the power storage device 20. The power storage device 20 is not limited to a lithium ion secondary battery, and may be a nickel-metal hydride battery, a capacitor, or the like.

[0015] As will be described in detail later, a positive electrode terminal as a first terminal and a negative electrode terminal as a second terminal are arranged at the upper end of the power storage device 20, with the negative electrode terminal being arranged radially outward of the positive electrode terminal. More specifically, the positive electrode terminal is arranged on the top surface of a sealing body 26, which will be described later. Furthermore, the negative electrode terminal is arranged on a crimped open end (hereinafter, shoulder 25C) of an outer can 25, which will be described later.

[0016] The electricity storage device 20 includes an electrode group 24 in which, for example, a strip-shaped positive electrode 21 and a strip-shaped negative electrode 22 are wound with a strip-shaped separator 23 interposed therebetween, a cylindrical outer can 25 that houses the electrode group 24 together with an electrolyte solution, a sealing body 26 that seals the opening of the outer can 25 in an insulated state, a foil-shaped positive electrode tab 27 that electrically connects the positive electrode 21 and the sealing body 26, and a negative electrode tab (not shown) that electrically connects the negative electrode 22 and the outer can 25. An insulating gasket 28 is disposed between the outer periphery of the sealing body 26 and the inner circumferential surface of the opening of the outer can 25.

[0017] An annular groove 25A is formed on the outer peripheral surface of the outer can 25 on the opening side. This groove 25A corresponds to an annular protrusion 25B formed on the inner peripheral surface of the outer can 25. The gasket 28 and sealing body 26 are placed on this annular protrusion 25B within the outer can 25. Furthermore, a shoulder 25C of the outer can 25 is crimped so as to be inclined toward the inside of the outer can 25 with the gasket 28 placed on the inner peripheral side. The crimped shoulder 25C and protrusion 25B sandwich the sealing body 26 in the vertical direction via the gasket 28, thereby sealing the opening of the outer can 25. Note that the shoulder 25C does not have to have the above-mentioned configuration. For example, the opening of the outer can 25 may be sealed by having a terminal plate in the center of the sealing body 26 and a conductive joint portion disposed on the outermost periphery of the sealing body 26 while being insulated from the terminal plate, and by welding the opening edge to this joint portion. At this time, the negative electrode lead 50 may be connected to the top surface of the joint portion.

[0018] The sealing body 26 may be provided with a current interrupter (CID) or an exhaust valve that ruptures when the pressure inside the outer can 25 reaches or exceeds a predetermined level. Furthermore, an insulating plate 29 for insulating the electrode group 24 from the outer can 25 may be provided between the electrode group 24 and the protruding portion 25B. If the insulating plate 29 is provided, the positive electrode tab 27 may extend through a through-hole formed in the insulating plate 29. Furthermore, an insulating plate for insulating the electrode group 24 from the outer can 25 may be provided between the electrode group 24 and the bottom of the outer can 25. The negative electrode tab may extend through a through-hole formed in the insulating plate or may extend around the insulating plate.

[0019] In the energy storage device 20, as described above, the positive electrode terminal is configured on the top surface of the sealing body 26, and a positive electrode lead connected to the positive electrode current collector foil is joined thereto. Also, in the energy storage device 20, as described above, the negative electrode terminal is configured on the crimped shoulder portion 25C of the exterior can 25, and a negative electrode tab connected to the negative electrode current collector foil is joined to the bottom of the exterior can 25. The negative electrode lead 50 is joined to the shoulder portion 25C of the exterior can 25 from the radially outer side of the energy storage device 20.

[0020] The upper holder 30 will be described with reference to Figs. 3 to 7. Fig. 3 is a plan view of the upper holder 30 as viewed from below. Fig. 4 is a detailed view (plan view) of an extracted portion B of Fig. 3. Fig. 5 is a perspective view of portion B of Fig. 4 as viewed from below. Fig. 6 is a perspective view of the accommodation portion 31 of the upper holder 30 as viewed from above. Fig. 7 is a side cross-sectional view of the upper holder 30.

[0021] The upper holder 30 is a member that holds the upper end sides of the multiple electricity storage devices 20. The upper holder 30 is made of a thermoplastic resin. Thermoplastic resins are broadly classified into general-purpose plastics and engineering plastics, and polyethylene, polypropylene, polyamide, ABS, etc. are used. A first current collector and a second current collector may be arranged side by side on the top surface of the upper holder 30 in the direction in which the top surface of the upper holder 30 expands. The first current collector may have multiple positive electrode leads and electrically connect the multiple electricity storage devices 20, and the second current collector may be connected to negative electrode leads and negative terminals of the multiple electricity storage devices 20, electrically connecting the multiple electricity storage devices 20. The first current collector and the second current collector may be stacked on top of each other with an insulating plate interposed therebetween.

[0022] 3, a plurality of accommodating portions 31 are formed on the bottom surface of the upper holder 30, and each accommodating an upper end side of each power storage device 20. The upper end sides of the power storage devices 20 are fitted into the accommodating portions 31, whereby the upper end sides of the power storage devices 20 are held by the upper holder 30.

[0023] 4 to 7, the storage section 31 is formed in the bottom surface of the upper holder 30 as a recess including a ceiling section 31A having a bottom surface facing the upper end surface of the energy storage device 20, and a wall section 31B having an inner surface facing the side surface of the energy storage device 20.

[0024] Around the accommodating portion 31, an opening 32 is formed that exposes the top surface of the sealing body 26 of the energy storage device 20 to the upper surface of the upper holder 30, a cutout portion 33 that exposes the shoulder portion 25C of the outer can 25 of the energy storage device 20 from the upper surface of the upper holder 30, and a restricting portion 34 that is located radially inward of at least a portion of the negative electrode lead 50.

[0025] The opening 32 is a circular opening in the ceiling 31A of the housing 31. The diameter of the opening 32 is smaller than the inner diameter of the wall 31B. The opening 32 exposes the top surface of the sealing body 26 of the electricity storage device 20 from the upper surface of the upper holder 30. Therefore, the top surface of the sealing body 26 can be joined to the positive electrode lead through the opening 32. The bottom of the ceiling 31A may be in contact with the electricity storage device 20.

[0026] The cutout portion 33 is formed by cutting out a portion of the edge of the opening 32. The cutout portion 33 allows a portion of the shoulder portion 25C of the outer can 25 of the energy storage device 20 to be exposed from the upper surface of the upper holder 30. The edge of the cutout portion 33 on the upper surface of the upper holder 30 preferably has a slope that slopes downward toward the inside in the radial direction of the energy storage device 20. This reduces stress applied to the negative electrode lead 50 when the negative electrode lead 50 is bent and abuts against the shoulder portion 25C. Therefore, a joining tool, jig, or the like used to join the negative electrode lead 50 to the shoulder portion 25C of the outer can 25 can be placed close to the negative electrode lead 50, improving workability. The top surface of the restricting portion 34 may be located lower than the top surface of the region of the upper holder 30 where the cutout portion 33 is formed. This configuration makes it easier to accommodate the negative electrode lead 50 in the cutout portion 33.

[0027] As described above, the restricting portion 34 is a portion located inside at least a portion of the negative electrode lead 50 in the radial direction of the electricity storage device 20. In other words, the restricting portion 34 restricts the negative electrode lead 50 from moving inward from the predetermined radial position. The predetermined position is preferably the radial inner end position of the shoulder portion 25C of the outer can 25 of the electricity storage device 20 (the opening end position of the outer can 25). However, in the present invention, the restricting portion 34 does not necessarily position the entire negative electrode lead 50 on the shoulder portion 25C (outside the top surface of the sealing body). A portion of the negative electrode lead 50 may overlap the top surface of the sealing body without abutting it. Needless to say, this also includes a configuration in which the negative electrode lead 50 fits into a window formed by the restricting portion 34 and the cutout portion 33.

[0028] The restricting portion 34 is located radially inside the cutout portion 33 and is formed so as to bridge over both circumferential surfaces of the cutout portion 33 (portions of the ceiling portion 31A that connect to both ends of the cutout portion 33). The outer surface 34A of the restricting portion 34 and the negative electrode lead 50 may be in contact with each other or slightly spaced apart in the radial direction of the electricity storage device 20, and the negative electrode lead 50 may be joined to the shoulder portion 25C of the outer can 25.

[0029] The restricting portion 34 restricts the position of the negative electrode lead 50 to the outside of a predetermined radial position, thereby ensuring an insulating distance between the top surface (positive electrode terminal) of the sealing body 26 of the electricity storage device 20 and the negative electrode lead 50. Furthermore, if a conductive foreign object enters the upper holder 30 from the outside, the risk of a short circuit between the top surface of the sealing body 26 and the negative electrode lead 50 due to the foreign object can be reduced.

[0030] Furthermore, since the restricting portion 34 can ensure an insulating distance from the top surface of the sealing body 26, it is not necessary to reduce the radial length of the negative electrode lead 50 in consideration of the insulating distance from the top surface of the sealing body 26, and the radial length of the negative electrode lead 50 can be made sufficiently large. This makes it possible to ensure a bonding area between the negative electrode lead 50 and the shoulder portion 25C (negative electrode terminal) of the outer can 25 of the electricity storage device 20.

[0031] The restricting portion 34 has an inclined portion 34B that is formed from the upper surface toward the outer surface 34A and drops in the radial direction of the electricity storage device 20, gradually decreasing outward. The inclined portion 34B makes it easier to accommodate the negative electrode lead 50 in the cutout portion 33 using a joining tool, a jig, or the like when the negative electrode lead 50 is brought into contact with the shoulder portion 25C of the outer can 25 in order to join the negative electrode lead 50 to the shoulder portion 25C.

[0032] The restricting portion 34 may have a bottom surface 34C, and the bottom surface 34C may be in contact with the electricity storage device 20. This prevents the negative electrode lead 50 or foreign matter from slipping under the restricting portion 34, i.e., into the gap between the electricity storage device 20 and the restricting portion 34. The bottom surface 34C may be in contact with the shoulder portion 25C. With this configuration, the only area of ​​the electricity storage device 20 that is exposed from within the cutout portion 33 is the shoulder portion 25C. Therefore, compared to a configuration in which the restricting portion 34 is located more inward than the shoulder portion 25C in the radial direction of the electricity storage device 20, short-circuiting of the negative electrode lead 50 can be further suppressed.

[0033] 4 to 7, the wall portion 31B of the storage portion 31 is formed with a pressing portion 35 that presses the side surface of the storage device 20 toward the side where the regulating portion 34 is formed, and a support portion 36 that supports the side surface of the storage device 20.

[0034] The pressing portion 35 and the support portion 36 press the electricity storage device 20 radially toward the support portion 36 in the accommodation portion 31 of the upper holder 30, absorbing radial dimensional variations between the upper holder 30 and the electricity storage device 20 and relative positional deviations between the upper holder 30 and the electricity storage device 20, thereby displacing the electricity storage device 20 in the direction of the pressing portion 35. This prevents the shoulder portion 25C from being insufficiently exposed through the window defined by the cutout portion 33 and the restricting portion 34 due to dimensional tolerances and assembly tolerances of the electricity storage device 20 and the upper holder 30. This prevents poor bonding between the shoulder portion 25C and the negative electrode lead 50 due to insufficient exposure. Incidentally, even when only the pressing portion 35 is used without the support portion 36, variation in the amount of exposure of the shoulder portion 25C from the cutout portion 33 can be reduced compared to a configuration without the pressing portion 35.

[0035] The pressing portion 35 is a portion that presses the side peripheral surface of the outer can 25 of the electricity storage device 20 in the circumferential direction toward the side where the restricting portion 34 is formed, at a position facing the restricting portion 34 in the circumferential direction. The pressing portion 35 presses the electricity storage device 20 in the radial direction toward the side where the restricting portion 34 and the support portion 36 are formed. Therefore, the pressing portion 35 and the restricting portion 34 may be located on opposite sides of the electricity storage device 20. However, as long as a pressing force toward the restricting portion 34 is generated, the pressing portion 35 does not necessarily have to be located symmetrically with respect to the central axis of the upper holder 30.

[0036] The pressing portion 35 extends downward from the ceiling surface of a recess 35A formed on the edge of the wall 31B of the storage portion 31. Therefore, the pressing portion 35 is located within or adjacent to the recess 35A. This configuration facilitates integral molding of the pressing portion formed on the upper holder 30. Furthermore, a through-hole may be formed on the upper surface of the upper holder 30 at a position closest to the pressing portion 35 in a plan view of the upper holder 30. This through-hole facilitates integral molding of the pressing portion 35 when molding using a mold. The tip of the pressing portion 35 has a protrusion 35B that protrudes radially inward of the electricity storage device 20. The protrusion 35B is formed to protrude radially inward beyond the wall 31B of the storage portion 31 in a plan view. Furthermore, a plurality of pressing portions 35 may be provided for one storage portion 31.

[0037] The support portion 36 is a portion that supports the side peripheral surface of the outer can 25 of the energy storage device 20 at approximately the same position in the circumferential direction as the restricting portion 34. The support portion 36 is formed as a groove shape that extends in the up-down direction in the wall portion 31B of the housing portion 31. The support portion 36 supports the side peripheral surface of the outer can 25 of the energy storage device 20 by abutting the groove-shaped opening edge portion of the wall portion 31B of the housing portion 31 with the side peripheral surface of the energy storage device 20. In this case, the inner peripheral surface of the wall portion 31B that faces the energy storage device 20 and the side peripheral surface of the energy storage device 20 may have different curvatures. This difference in curvature allows the portion of the energy storage device 20 that is housed in the support portion 36 to more reliably abut against the opening edge portion. One method for making the curvatures different is, for example, to make the diameter of the inner peripheral surface of the wall portion 31B different from the diameter of the side peripheral surface of the energy storage device 20.

[0038] The support portion 36 is not limited to a groove shape extending in the vertical direction. For example, it may be formed as two protrusions such as ribs that protrude inward from the wall portion 31B of the housing portion 31 and extend in the vertical direction. In this case, each protrusion abuts against the side peripheral surface of the electricity storage device 20, thereby supporting the side peripheral surface of the outer can 25 of the electricity storage device 20. Furthermore, the support portions 36 may be provided at a plurality of locations on the wall portion 31B. Furthermore, they do not have to be located at approximately the same position in the circumferential direction of the electricity storage device. They may be spaced apart from each other in the circumferential direction.

[0039] An upper holder 60 of the power storage module 10, which is another example of the embodiment, will be described with reference to Fig. 8 and Fig. 9. Fig. 8 is a perspective view of the accommodating section 61 of the upper holder 60 as seen from above. Fig. 9 is a cross-sectional view taken along line DD of Fig. 7. In Fig. 9, the shape of the power storage device 20 is omitted.

[0040] As described above, the upper holder 30 is a member that holds the upper end sides of the multiple electricity storage devices 20. The upper holder 60 has the same configuration as the upper holder 30 described above except for the restricting portion 64, and therefore only the restricting portion 64 will be described below. Specifically, the accommodating portion 61, the opening 62, the notched portion 63, the pressing portion 65, and the supporting portion 66 formed in the upper holder 60 have the same configuration as the accommodating portion 31, the opening 32, the notched portion 33, the pressing portion 35, and the supporting portion 36 formed in the upper holder 30 described above.

[0041] The restricting portion 64 is located radially inward of at least a portion of the negative electrode lead 50 in the energy storage device 20. In other words, the restricting portion 64 restricts the negative electrode lead 50 from moving radially inward beyond a predetermined position. The predetermined position is preferably the radial inner end position of the shoulder portion 25C of the outer can 25 of the energy storage device 20 (the opening end position of the outer can 25).

[0042] 8 and 9, the restricting portion 64 is formed radially inside the cutout portion 63, extending from one ceiling portion 61A that forms the cutout portion 63. In other words, the restricting portion 64 is formed in the cutout portion 63 as a cantilever beam with the tip end as a free end. It is preferable that the gap between the tip end of the restricting portion 64 and the other ceiling portion 61A is smaller than the length of the restricting portion 64.

[0043] The negative electrode lead 50 may be joined to the shoulder portion 25C of the outer can 25 in a state in which the outer surface 64A of the restricting portion 64 and the tip portion 50A of the negative electrode lead 50 (see FIG. 6) are in contact with each other or slightly spaced apart in the radial direction of the electricity storage device 20.

[0044] Like the above-described restricting portion 34, the restricting portion 64 can ensure an insulating distance between the top surface (positive electrode) of the sealing body 26 of the energy storage device 20 and the negative electrode lead 50, and can also ensure a bonding area between the negative electrode lead 50 and the shoulder portion 25C (negative electrode) of the outer can 25 of the energy storage device 20.

[0045] The restricting portion 64 has an inclined portion 64B formed from the upper surface toward the outer surface 64A. This makes it easier to accommodate the negative electrode lead 50 in the cutout portion 33 using a joining tool, a jig, or the like when joining the negative electrode lead 50 to the shoulder portion 25C of the outer can 25.

[0046] The restricting portion 64 also has a bottom surface 64C that slopes downward toward the tip end. The restricting portion 64 is formed such that the bottom surface 64C at the tip end of the restricting portion 64 is positioned lower in the up-down direction than the ceiling portion 61A in the up-down direction. This allows the restricting portion 64 to actively abut against the top surface of the electricity storage device 20. Therefore, the restricting portion 64 can prevent the negative electrode lead 50 from slipping between the restricting portion 64 and the electricity storage device 20.

[0047] For example, if a gap occurs between the energy storage device 20 and the ceiling portion 61A of the upper holder 60 due to dimensional tolerances in the shape of the energy storage device 20 or the upper holder 60, or a relative positional misalignment between the energy storage device 20 and the upper holder 60 due to assembly tolerances, the vertical position of the bottom surface 64C at the tip side of the regulating portion 64 is located lower than the vertical position of the ceiling portion 61A, so that the bottom surface 64C of the regulating portion 64 abuts against the energy storage device 20, preventing the negative electrode lead 50 from slipping under the regulating portion 64.

[0048] On the other hand, when no gap is formed between the electricity storage device 20 and the ceiling portion 61A of the upper holder 60, the restricting portion 64 is formed to extend from one of the ceiling portions 61A, and therefore the tip side of the restricting portion 64 is slightly bent upward, and the bottom surface 64C of the restricting portion 64 abuts against the electricity storage device 20, preventing the negative electrode lead 50 from slipping under the restricting portion 64. Note that in the restricting portion 64, the bottom surface 64C on the tip side protrudes downward. However, the bottom surface 64C on the base side of the restricting portion 64 may protrude downward. Furthermore, as long as the restricting portion 64 is bendable, the entire bottom surface 64C of the restricting portion 64 may protrude without being biased toward the tip side or the base side. Furthermore, as long as the restricting portion 64 is bendable, it may have a shape supported at both ends rather than a cantilever shape like the restricting portion 64.

[0049] The negative electrode lead 70 of the electricity storage module 10, which is another example of the embodiment, will be described with reference to Fig. 10 and Fig. 11. Fig. 10 is a plan view showing the negative electrode lead 70. Fig. 11 is a perspective view of Fig. 10.

[0050] As described above, the negative electrode lead 70 is a portion that is connected to the shoulder 25C (negative electrode terminal) of the outer can 25 of the electricity storage device 20 that is visible through the cutout 33 of the upper holder 30. The negative electrode lead 70 can be applied to either the electricity storage module 10 having the upper holder 30 or the electricity storage module 10 having the upper holder 60, but below, an example in which the negative electrode lead 70 is applied to the electricity storage module 10 having the upper holder 30 will be described.

[0051] 10 and 11 , the negative electrode lead 70 has a joint portion 71 joined to a shoulder portion 25C (negative electrode terminal) of the exterior can 25 of the electricity storage device 20 and a connection portion 72 connecting the joint portion 71 to the main body of the second current collector (not shown). The joint portion 71 includes wall portions 71A formed by standing on both ends of the electricity storage device 20 in the circumferential direction (in a broad sense, a direction intersecting with the radial direction). The wall portions 71A are formed, for example, by bending. The wall portions 71A may be formed by joining separate members to both ends of the circumferential direction of the connection portion 72. The vertical size of the wall portions 71A may be smaller than the height of the wall portions 71A protruding from the notch portions 33 on the top surface of the upper holder 60. Note that even if the vertical size of the wall portions 71A is smaller than the gap between the electricity storage device 20 and the restricting portion 64, the possibility of the wall portions 71A getting caught in the gap can be reduced compared to a joint portion without the wall portions 71A. Furthermore, if the vertical size of the wall portion 71A is larger than the gap, the possibility of the object getting into the gap can be significantly reduced.

[0052] For example, even if a gap occurs between the storage device 20 and the ceiling portion 31A of the upper holder 30 due to dimensional tolerances in the shape of the storage device 20 or the upper holder 30, or a relative positional misalignment due to assembly tolerances between the storage device 20 and the upper holder 30, the wall portion 71A increases the vertical size (height) of the negative electrode lead 70, thereby preventing the negative electrode lead 70 from slipping into the gap.

[0053] On the other hand, it is also conceivable to form a wall portion at the tip of joint 71 by bending the tip (inner end side in the radial direction) of joint 71, but when a positive electrode current collector foil including a positive electrode lead and a negative electrode current collector foil including negative electrode lead 70 are produced by punching from a single metal foil, the tip of joint 71 of negative electrode lead 70 and the tip of the positive electrode lead are often close to each other in the metal foil before punching. In such cases, it may be difficult to form a wall portion at the tip of joint 71.

[0054] Therefore, by bending at least one end of the joint portion 71 in the circumferential direction (broadly speaking, the direction intersecting with the radial direction) to form a wall portion 71A, it is possible to prevent the negative electrode lead 70 from slipping under the restricting portion 34.

[0055] It should be noted that the present invention is not limited to the above-described embodiment and its modifications, and various changes and modifications are possible within the scope of the claims of this application. [Explanation of symbols]

[0056] 10 Energy storage module, 20 Energy storage device, 21 Positive electrode, 22 Negative electrode, 23 Separator, 24 Electrode group, 25 Outer can, 25A Groove portion, 25B Convex portion, 25C Shoulder portion, 26 Sealing body, 27 Positive electrode tab, 28 Gasket, 29 Insulating plate, 30 Upper holder, 31 Housing portion, 31A Ceiling portion, 31B Wall portion, 32 Opening, 33 Notch portion, 34 Restricting portion, 34A Outer surface, 34B Sloped portion, 34C Bottom surface, 35 Pressing portion, 35A Concave portion, 35B Convex portion, 36 Support portion, 40 Lower holder, 50 Negative electrode lead, 50A Tip portion, 60 Upper holder, 61A Ceiling portion, 63 Notch portion, 64 Restricting portion, 64A Outer surface, 64B Inclined portion, 64C bottom surface, 70 negative lead, 71 joint portion, 71A wall portion, 72 connection portion

Claims

1. at least one cylindrical storage device; a holder for holding one side of the electricity storage device; Equipped with a first terminal and a second terminal are arranged at one end of the power storage device; the second terminal is disposed outward of the first terminal in a radial direction of the power storage device, a lead connected to the second terminal from the outside in the radial direction; the holder has a restricting portion located inside at least a portion of the lead in the radial direction, the negative electrode lead has a first portion connected to the second terminal, a second portion located outward from the first portion in the radial direction, and a third portion disposed between the first portion and the second portion and connected to the first portion and the second portion; the third portion is bent from the second portion so as to extend in a height direction of the power storage device, a bent portion is formed between the third portion and the second portion, and the bent portion extends in a direction intersecting, in the radial direction, a direction in which the first portion and the restricting portion are arranged; Energy storage module.

2. The energy storage module according to claim 1, the holder has an opening for exposing the first terminal and a notch formed around the opening for exposing the second terminal; The restricting portion is formed with both ends supported within the cutout portion. Energy storage module.

3. The energy storage module according to claim 1 or 2, the holder has a pressing portion that presses a side peripheral surface of the power storage device toward a side where the restricting portion is provided. Energy storage module.

4. The energy storage module according to claim 3, the pressing portion includes a protrusion that abuts against a side peripheral surface of the power storage device, Energy storage module.

5. The energy storage module according to claim 3 or 4, the pressing portion is located within a recess formed in a wall of a housing portion of the holder that houses the power storage device, or is adjacent to the recess. Energy storage module.

6. The energy storage module according to any one of claims 3 to 5, the holder has a support portion that supports a side peripheral surface of the power storage device. Energy storage module.

7. The energy storage module according to claim 6, the support portion is a groove portion formed on a surface of the holder facing a side peripheral surface of the power storage device, Energy storage module.

8. The energy storage module according to any one of claims 1 to 7, The bottom of the restricting portion and the second terminal are in contact with each other. Energy storage module.

9. The energy storage module according to any one of claims 1 to 8, a sloped portion extending from the top surface of the restricting portion to the outer surface; Energy storage module.

10. The energy storage module according to claim 2, The top surface of the restricting portion is located lower than the top surface of the notch portion of the holder. Energy storage module.

11. The energy storage module according to any one of claims 1 to 10, The power storage device is an electrode assembly including a first electrode and a second electrode; an outer can that houses the electrode assembly together with an electrolyte and has a cylindrical tube portion and one end of the tube portion that is open; a sealing body that closes the open end of the outer can together with an insulating gasket, the sealing body is electrically connected to the first electrode, the outer can is electrically connected to the second electrode, one end of the outer can bends radially inward and contacts the outer periphery of the sealing body via the gasket; the first terminal is the sealing body, the second terminal is one end of the outer can; Energy storage module.

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