Electricity storage module

Abstract

An electricity storage module (10) comprises a cylindrical electricity storage device (20) that has an inner terminal and an outer terminal, an upper holder (40) that holds the upper end of the electricity storage device (20) in a first axis, and a negative electrode lead (62). A positive electrode terminal and a negative electrode terminal are disposed in the electricity storage device (20), wherein: the negative electrode terminal is disposed outside the positive electrode terminal in the radial direction of the electricity storage device (20); and the negative electrode lead (62) is connected to the negative electrode terminal. The upper holder (40) has a housing part (41) that houses the upper end part of the electricity storage device (20). The housing part (41) is formed with: a second opening part (44) that exposes a part of the negative electrode terminal to which the negative electrode lead (62) is connected; and a gap (45) that is provided at a position different from the second opening part (44) in the radial direction orthogonal to the axial direction and forms a prescribed gap with the negative electrode terminal.

Description

Energy storage module

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

[0002] An energy storage module is used as a power supply having a plurality of energy storage devices. In the energy storage module, a positive electrode and a negative electrode are arranged on one side of the energy storage device, and a positive electrode lead and a negative electrode lead are arranged on one side of the energy storage module (for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2021-136238

[0004] Since the power storage module is used for a long period of time, it is required that the reliability be maintained for a long period of time.

[0005] The energy storage module according to the present disclosure includes a cylindrical energy storage device having an inner terminal and an outer terminal, a holder configured to hold one end of the energy storage device along a first axis, and an outer lead, wherein the inner terminal and the outer terminal are arranged at the one end of the energy storage device, the outer terminal is arranged radially outward of the inner terminal in the direction of the diameter of the energy storage device, the outer lead is connected to the outer terminal, the holder is formed with a housing portion configured to house the one end of the energy storage device, and the housing portion is formed with an outer opening exposing a portion of the outer terminal to which the outer lead is connected, and a void provided at a position different from the outer opening along a second axis perpendicular to the first axis and forming a predetermined gap between the outer terminal and the holder.

[0006] According to the energy storage module of the present disclosure, reliability can be improved.

[0007] FIG. 1 is a perspective view showing an electricity storage module as an example of an embodiment; FIG. 2 is an axial cross-sectional view showing an electricity storage device as an example of an embodiment; FIG. 3 is a plan view showing an upper holder as an example of an embodiment; FIG. 4 is a perspective view showing an upper holder as an example of an embodiment, viewed from the bottom side; FIG. 5 is a perspective view showing an upper holder as another example of an embodiment, viewed from the bottom side; FIG. 6 is a perspective view showing an upper holder as another example of an embodiment, viewed from the bottom side; FIG. 7 is a schematic view showing the flow of a method for replacing an electricity storage device; and FIG. 8 is a schematic view showing the flow of a method for replacing an electricity storage device of a comparative example.

[0008] An example of an embodiment of the present disclosure will be described in detail below. In the following description, specific shapes, materials, directions, numerical values, etc. are examples for facilitating understanding of the present disclosure, and can be appropriately changed according to the application, purpose, specifications, etc.

[0009] [Electricity Storage Module] An electric power storage module 10 as an example of an embodiment will be described with reference to FIG.

[0010] The power storage module 10 is mounted on an electric vehicle as a power source for the motor that drives the electric vehicle. However, the power storage module of the present disclosure is not limited to being mounted on an electric vehicle, and may be used as a power source for motor-driven electric devices such as power tools, power-assisted bicycles, electric motorcycles, electric wheelchairs, electric tricycles, and electric carts. Furthermore, the use of the power storage module of the present disclosure is not limited, and may 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.

[0011] In the following, the components of the energy storage module 10 may be described using the axial direction (first axis), radial direction, or circumferential direction of a cylindrical energy storage device 20 described later.

[0012] The energy storage module 10 includes a plurality of energy storage devices 20, an upper holder 40 as a holder for holding the upper sides of the energy storage devices 20, a lower holder 50 for holding the lower sides of the energy storage devices 20, and a current collecting plate 60 arranged on the upper surface of the upper holder 40, connecting positive terminals as first terminals to each other and connecting negative terminals as second terminals to each other.

[0013] The multiple power storage devices 20 may be packed as densely as possible within the power storage module 10 while taking safety into consideration, and adjacent power storage devices 20 may be arranged in close proximity to each other. For example, the power storage devices 20 may be arranged such that six power storage devices 20 surround one power storage device 20 in a plan view (or arranged in a staggered pattern). Furthermore, the multiple power storage devices may be arranged such that the power storage devices closest to each other are located on all four sides.

[0014] [Power Storage Device] The power storage device 20 as an example of an embodiment will be described in detail with reference to FIG.

[0015] In this embodiment, a cylindrical lithium-ion secondary battery is used as the power storage device 20, but a nickel-metal hydride battery, a capacitor, etc. may also be used. The power storage device 20 includes an electrode group 24, for example, in which 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 insulates and seals an opening provided at one axial end of the outer can 25, a foil-shaped positive electrode tab 27 that electrically connects the positive electrode 21 and the sealing body 26, and a negative electrode tab 28 that electrically connects the negative electrode 22 and the outer can 25. An insulating gasket 29 may be disposed between the outer periphery of the sealing body 26 and the inner circumferential surface of the opening of the outer can 25.

[0016] An annular groove 25A is formed on the outer peripheral surface of the outer can 25, on the opening side. This groove 25A is formed as an annular protrusion on the inner peripheral surface of the outer can 25. The gasket 29 and sealing body 26 are disposed on this annular protrusion within the outer can 25. Furthermore, the opening end of the outer can 25 is crimped so as to bend toward the inside of the outer can 25, with the gasket 29 disposed on the inner peripheral side. The crimped opening end and the protrusion sandwich the sealing body 26 in the axial direction via the gasket 29, thereby sealing the opening of the outer can 25.

[0017] 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 pressure. An insulating plate 30 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 or between the electrode group 24 and the protrusion (groove 25A). When the insulating plate 30 is provided, the positive electrode tab 27 may extend through a through-hole formed in the insulating plate 30. The negative electrode tab 28 may extend through a through-hole formed in the insulating plate 30 or may extend around the insulating plate 30.

[0018] In the energy storage device 20, a positive electrode terminal as a first terminal is configured on the top surface of the sealing body 26, and a negative electrode terminal as a second terminal is configured on the shoulder 25B of the outer can 25. A positive electrode lead 61 as a first lead of the current collector 60 is joined by welding to the top surface of the sealing body 26, which is the positive electrode terminal as the first terminal. A negative electrode lead 62 as a second lead of the current collector 60 is joined by welding to the shoulder 25B of the outer can 25, which is the negative electrode terminal as the second terminal. Note that in the energy storage module of the present disclosure, the first terminal may be the negative electrode, and the second terminal may be the positive electrode.

[0019] The first terminal may be referred to as an "inner terminal" and the second terminal may be referred to as an "outer terminal."

[0020] Furthermore, the positive electrode lead 61 may be referred to as a "first lead" or an "inner lead", and the negative electrode lead 62 may be referred to as a "second lead" or an "outer lead".

[0021] [Method for Replacing the Power Storage Device in the Comparative Example] A method for replacing the power storage device 120 in the power storage module 110 in the comparative example will be described with reference to FIG. 8 .

[0022] In the energy storage module 110, when a malfunction occurs in one of the multiple energy storage devices 120, only the malfunctioning energy storage device 120 may be replaced. A method for replacing the energy storage device 120 in the energy storage module 110 of the comparative example will be described below. The energy storage module 110 and the energy storage device 120 of the comparative example have substantially the same configurations as the energy storage module 10 and the energy storage device 20 described above.

[0023] In step S101, current collector plates 160 are removed from all of the power storage devices 120 in the power storage module 110. More specifically, positive electrode leads 161 and negative electrode leads 162 are removed from all of the power storage devices 120. At this time, weld marks WM remain on the positive electrode terminals (top surfaces of sealing bodies 126) and negative electrode terminals (shoulder portions 125B of outer cans 125) of the power storage devices 120. In step S102, upper holder 140 is removed from the power storage module 110.

[0024] In step S103, only the defective power storage device 120 is removed from the power storage module 110. In step S104, the replaced power storage device 120 is attached to the power storage module 110. In step S105, the upper holder 140 is attached to the power storage module 110. At this time, the welding mark WM of the negative electrode lead 162 removed in step S101 may interfere with the upper holder 140.

[0025] In step S106, current collector plates 160 are attached to all of the power storage devices 120 in the power storage module 110. More specifically, positive electrode leads 161 and negative electrode leads 162 are attached to all of the power storage devices 120. At this time, in the power storage devices 120 that are not to be replaced, the welding marks WM of the positive electrode leads 161 removed in step S101 may hinder re-welding.

[0026] Therefore, the configuration of the upper holder 40 of the energy storage module 10 and the joining location of the positive electrode lead 61 for solving the above-mentioned problems will be described below.

[0027] [Upper Holder] The upper holder 40 will be described with reference to FIGS.

[0028] As described above, the upper holder 40 is a member that holds the upper side of the power storage device 20. As will be described in detail later, when replacing one of the power storage devices 20 in the power storage module 10, the positive electrode lead 61 and the negative electrode lead 62 are removed from the power storage device 20 that is not to be replaced and the positive electrode lead 61 and the negative electrode lead 62 are welded again, the weld marks WM of the power storage device 20 that is not to be replaced do not interfere with the welding when the positive electrode lead 61 or the negative electrode lead 62 is welded again. This allows one of the power storage devices 20 in the power storage module 10 to be replaced multiple times, and therefore the reliability of the power storage module 10 can be maintained for a long period of time.

[0029] The upper holder 40 is formed of, for example, a thermoplastic resin. Thermoplastic resins are broadly classified into general-purpose plastics and engineering plastics, and examples thereof include polycarbonate, polybutylene terephthalate, polyethylene, polypropylene, polyamide, and ABS. The upper holder 40 is formed with a storage section 41, a top surface 42, a first opening 43, a second opening 44, and a gap 45, each of which will be described in detail below. Note that, in the upper holder 40, the storage section 41 and the top surface 42 do not need to be formed as a single molded piece. The storage section 41 and the top surface 42 may each be formed as separate members, and the upper holder 40 may be formed by assembling the two members.

[0030] The first opening 43 may be referred to as an "inner opening" and the second opening 44 may be referred to as an "outer opening."

[0031] The accommodation section 41 is a portion that accommodates the upper end portion of the power storage device 20. The accommodation section 41 is formed in a circular shape when viewed from the axial direction. For example, in a plan view, the accommodation sections 41 are formed such that six accommodation sections 41 surround one accommodation section 41. A top surface section 42 is formed in the accommodation section 41. The top surface section 42 is a portion that faces the upper end surface (top surface) of the power storage device 20. A first opening 43, a second opening 44, and a gap 45, each of which will be described in detail later, are formed in the top surface section 42. The first opening 43 and the second opening 44 may be arranged with a gap between them, or may be connected to form a single opening.

[0032] The first opening 43 is a portion that exposes the top surface of the sealing body 16 of the power storage device 20, which is a positive terminal serving as a first terminal. A positive electrode lead 61 of the current collector plate 60 serving as a first lead is joined by welding to the top surface of the sealing body 16 exposed from the first opening 43. The first opening 43 is formed in a circular shape at approximately the center of the top surface 42 in a plan view (in a second axis (plane) perpendicular to the first axis). As will be described in detail later, the positive electrode lead 61 is joined by welding offset from the center of the top surface of the sealing body 16 of the power storage device 20 in a plan view (in a second axis (plane) perpendicular to the first axis).

[0033] The second opening 44 is a portion that exposes a shoulder 25B of the exterior can 25 of the power storage device 20, which is a negative terminal serving as a second terminal. A negative lead 62 of the current collector plate 60 serving as a second lead is joined by welding to the shoulder 25B of the exterior can 25 exposed from the second opening 44.

[0034] The gap 45 is a portion where, when the negative electrode lead 62 of the current collector plate 60 is removed from the shoulder portion 25B of the outer casing 25 of all of the power storage devices 20 in the power storage module 10 and the negative electrode lead 62 is welded again to the shoulder portion 25B of the outer casing 25 of all of the power storage devices 20, the power storage device 20 not to be replaced is rotated by approximately 180° in a plan view (on a second axis (plane) perpendicular to the first axis) and the weld mark WM of the power storage device 20 not to be replaced is located. This allows one of the power storage devices 20 in the power storage module 10 to be replaced, thereby maintaining the reliability of the power storage module 10 for a long period of time.

[0035] The void 45 is formed in the top surface 42 as a groove (recess) so as to form a predetermined gap with the shoulder 25B of the outer can 25, which is the negative terminal serving as the second terminal. It is preferable that a plurality of voids 45 are formed. It is also preferable that the second opening 44 and the plurality of voids 45 are formed at equal intervals in the circumferential direction of the power storage device 20 (circular housing 41). When the weld marks WM are formed on the outer circumferential surface of the power storage device 20, the voids 45 may be formed on the inner circumferential surface of the housing 41. Furthermore, the voids 45 may be through-holes penetrating the top surface 42, provided that they are formed intermittently in the circumferential direction. Furthermore, in order to stably hold the power storage device 20 in the housing 41, the voids 45 may be positioned away from the first opening 43 in the radial direction of the power storage device 20.

[0036] An upper holder 40 as another example of the embodiment will be described with reference to FIGS. 5 and 6. FIG.

[0037] 5 , the second openings 44 and the plurality of voids 45 are formed at equal intervals of 120° on the top surface 42 (outer periphery) of the accommodation portion 41. With this configuration, when replacing one of the power storage devices 20 in the power storage module 10, the negative electrode leads 62 of the current collector plates 60 are removed from the shoulder portions 25B of the outer casings 25 of all of the power storage devices 20 and the negative electrode leads 62 are welded again to the shoulder portions 25B of the outer casings 25 of all of the power storage devices 20, by rotating the power storage device 20 not to be replaced by approximately 120° in the circumferential direction, the weld marks WM are positioned in the voids 45.

[0038] 6 , the second openings 44 and the plurality of voids 45 are formed at equal intervals of 90° on the top surface 42 (outer periphery) of the accommodation portion 41. With this configuration, when replacing one of the power storage devices 20 in the power storage module 10, the negative electrode leads 62 of the current collector plates 60 are removed from the shoulder portions 25B of the outer casings 25 of all of the power storage devices 20 and the negative electrode leads 62 are welded again to the shoulder portions 25B of the outer casings 25 of all of the power storage devices 20, by rotating the power storage device 20 not to be replaced by approximately 90° in a plan view, the weld marks WM are positioned in the voids 45.

[0039] [Lower Holder] The lower holder 50 will be described again with reference to FIG.

[0040] As described above, the lower holder 50 is a member that holds the lower side of the power storage device 20. The lower holder 50 is made of, for example, a thermoplastic resin. Thermoplastic resins are broadly classified into general-purpose plastics and engineering plastics, and polyethylene, polypropylene, polyamide, ABS, etc. are used.

[0041] [Current Collector Plate] The current collector plate 60 will be described with reference to FIGS. 1, 3 and 4. FIG.

[0042] As described above, the current collector plate 60 is a member disposed on the upper surface of the upper holder 40, connecting the positive electrode terminals as first terminals to each other and connecting the negative electrode terminals as second terminals to each other. The current collector plate 60 is formed of a conductive metal plate. The current collector plate 60 is formed with a positive electrode lead 61 as a first lead extending from an end of the current collector plate 60, a negative electrode lead 62 as a second lead extending from an end of the current collector plate 60, and an opening 63, each of which will be described in detail later.

[0043] As described above, the positive electrode lead 61 as a first lead is a portion that connects positive electrode terminals (top surfaces of the sealing bodies 26 of the power storage devices 20) as first terminals to each other. The positive electrode lead 61 is joined by welding to the top surface of the sealing body 26 exposed from the first opening 43 of the upper holder 40. The positive electrode lead 61 is formed in a strip shape and extends into the opening 63. The positive electrode lead 61 is joined by welding offset from the center of the top surface of the sealing body 26 of the power storage device 20 in a plan view (in a second axis (plane) perpendicular to the first axis).

[0044] This prevents the welding marks WM of the power storage device 20 that is not to be replaced from interfering with the welding when the positive electrode leads 61 are welded again to the top surfaces of the sealing bodies 26 of all of the power storage devices 20 when replacing one of the power storage devices 20 in the power storage module 10 by removing the positive electrode leads 61 of the current collector plates 60 from the top surfaces of the sealing bodies 26 of all of the power storage devices 20. This allows one of the power storage devices 20 in the power storage module 10 to be replaced multiple times, thereby maintaining the reliability of the power storage module 10 over a long period of time.

[0045] As described above, the negative electrode lead 62 serving as the second lead is a portion that connects the negative electrode terminals (the shoulder portions 25B of the outer can 25 of the power storage device 20) serving as second terminals together. The negative electrode lead 62 is joined by welding to the shoulder portion 25B of the outer can 25 of the power storage device 20 that is exposed from the second opening 44 of the upper holder 40. The negative electrode lead 62 is formed in a strip shape and extends inside the opening 63. The openings 63 are formed at positions corresponding to the first openings 43 of the upper holder 40.

[0046] [Method for Replacing the Power Storage Device] A method for replacing the power storage device 20 in the power storage module 10 will be described with reference to FIG.

[0047] In the energy storage module 10, when a malfunction occurs in one of the plurality of energy storage devices 20, there are cases where only the malfunctioning energy storage device 20 is replaced. A method for replacing the energy storage device 20 in the energy storage module 10 will be described below.

[0048] In step S11, the current collector plates 60 are removed from all of the power storage devices 20 in the power storage module 10. More specifically, the positive electrode leads 61 and the negative electrode leads 62 are removed from all of the power storage devices 20. At this time, weld marks WM remain on the positive electrode terminals (top surfaces of the sealing bodies 26) and negative electrode terminals (shoulder portions 25B of the outer cans 25) of the power storage devices 20. In step S12, the upper holder 40 is removed from the power storage module 10.

[0049] In step S13, only the defective power storage device 20 is removed from the power storage module 10. In step S14, the replaced power storage device 20 is attached to the power storage module 10, and the power storage devices 20 not to be replaced are rotated by a predetermined angle (e.g., 180°) in a plan view. In step S15, the upper holder 40 is attached to the power storage module 10. At this time, the weld mark WM of the negative electrode lead 62 removed in step S11 is placed in the gap 45 of the upper holder 40.

[0050] In step S16, current collector plates 60 are attached to all of the power storage devices 20 in the power storage module 10. More specifically, positive electrode leads 61 and negative electrode leads 62 are attached to all of the power storage devices 20. At this time, in the power storage devices 20 that are not to be replaced, the welding marks WM of the positive electrode leads 61 removed in step S11 are offset from the center in a plan view, and do not hinder re-welding. Note that in step S11, only the power storage device 20 in which a malfunction has occurred is removed from the current collector plate 60, and in step S16, a power storage device 20 in a normal state removed from another power storage module 10 may be accommodated in the accommodation section 41 where the malfunctioning power storage device 20 was located, and a new welding mark WM may be formed at a position offset from the previous welding mark WM to reuse the power storage device 20.

[0051] Summary The present disclosure is further described by the following embodiments.

[0052] Configuration 1: An energy storage module comprising: a cylindrical energy storage device having an inner terminal and an outer terminal; a holder that holds one end of the energy storage device along a first axis; and an outer lead, wherein the inner terminal and the outer terminal are arranged at the one end of the energy storage device, the outer terminal is arranged outward of the inner terminal in a radial direction of the energy storage device, and the outer lead is connected to the second terminal, the holder is formed with a housing portion that houses the one end of the energy storage device, and the housing portion is formed with: an outer opening that exposes a portion of the outer terminal to which the outer lead is connected, and a void that is provided at a position different from the outer opening along a second axis that is perpendicular to the first axis and forms a predetermined gap with the outer terminal.

[0053] Configuration 2: The energy storage module according to configuration 1, comprising a plurality of energy storage devices, each of the plurality of energy storage devices being the energy storage device, and the plurality of energy storage devices being held by the holder.

[0054] Configuration 3: The energy storage module according to Configuration 1 or 2, wherein a plurality of voids are formed in the housing portion, the void is one of the plurality of voids, and the plurality of voids are formed to be aligned along a circumferential direction of the energy storage device.

[0055] Configuration 4: The energy storage module according to any one of configurations 1 to 3, wherein the outer opening and the plurality of voids are formed at equal intervals in the circumferential direction.

[0056] Configuration 5: The energy storage module according to any one of configurations 1 to 4, wherein the plurality of voids are formed on a surface of the holder in the housing portion that faces the one end of the energy storage device.

[0057] Configuration 6: The energy storage module according to any one of configurations 1 to 5, wherein each of the plurality of voids is a groove or a through-hole formed in a surface facing the one end of the energy storage device.

[0058] Configuration 7: The energy storage module according to any one of configurations 1 to 6, further comprising an inner lead connected to the inner terminal, wherein an inner opening is formed in the accommodation portion of the holder to expose a portion of the inner terminal to which the inner lead is connected, and the inner lead is connected to the inner terminal offset from a center of the inner terminal along the second axis.

[0059] Configuration 8: The energy storage module according to any one of configurations 1 to 7, wherein the inner opening and the gap are spaced apart in a radial direction of the energy storage device.

[0060] Configuration 9: The energy storage module according to any one of configurations 1 to 8, wherein the inner opening and the outer opening are in communication with each other.

[0061] Configuration 10: The energy storage module according to any one of configurations 1 to 9, wherein the energy storage device includes: an electrode group including a first electrode and a second electrode; an outer can having a cylindrical tube portion that houses the electrode group and has an opening formed at one end of the tube portion; and a sealing body that closes the opening while being insulated from the outer can, wherein the sealing body is electrically connected to the first electrode, and the outer can is electrically connected to the second electrode.

[0062] It should be noted that the present disclosure is not limited to the above-described embodiment and its modifications, and it goes without saying that various modifications and improvements are possible within the scope of the matters described in the claims of the present application.

[0063] REFERENCE SIGNS LIST 10 Energy storage module 20 Energy storage device 21 Positive electrode (first electrode) 22 Negative electrode (second electrode) 23 Separator 24 Electrode group 25 Outer can 25A Groove portion 25B Shoulder portion (second terminal or outer terminal) 26 Sealing body (first terminal or inner terminal) 27 Positive electrode tab 28 Negative electrode tab 29 Gasket 30 Insulating plate 40 Upper holder (holder) 41 Storage portion 42 Top surface portion 43 First opening (inner opening) 44 Second opening (outer opening) 45 Gap 50 Lower holder 60 Current collecting plate 61 Positive electrode lead (first lead or inner lead) 62 Negative electrode lead (second lead or outer lead) 63 Opening 110 Energy storage module 120 Energy storage device 140 Upper holder 160: Current collecting plate 161: Positive electrode lead (first lead or inner lead) 162: Negative electrode lead (second lead or outer lead)

Claims

1. An energy storage module comprising: a cylindrical energy storage device having an inner terminal and an outer terminal; a holder that holds one end of the energy storage device on a first axis; and an outer lead, wherein the inner terminal and the outer terminal are arranged at the one end of the energy storage device, the outer terminal is arranged outward of the inner terminal in a radial direction of the energy storage device, and the outer lead is connected to the outer terminal, the holder is formed with a housing portion that houses the one end of the energy storage device, and the housing portion is formed with an outer opening that exposes a part of the outer terminal to which the outer lead is connected, and a void that is provided at a position different from the outer opening on a second axis perpendicular to the first axis and forms a predetermined gap with the outer terminal.

2. An energy storage module according to claim 1, comprising a plurality of energy storage devices, each of the plurality of energy storage devices being the energy storage device, and the plurality of energy storage devices being held by the holder.

3. An energy storage module as claimed in claim 1, wherein a plurality of voids are formed in the housing portion, the void being one of the plurality of voids, and the plurality of voids are formed so as to be aligned along the circumferential direction of the energy storage device.

4. An energy storage module according to claim 3, wherein the outer opening and the plurality of gaps are formed at equal intervals in the circumferential direction.

5. An energy storage module according to claim 4, wherein the plurality of gaps are formed on a surface of the holder in the housing portion that faces the one end of the energy storage device.

6. An energy storage module according to claim 5, wherein each of the plurality of gaps is a groove or a through hole formed in a surface facing the one end of the energy storage device.

7. An energy storage module as described in claim 1, further comprising an inner lead connected to the inner terminal, the housing portion of the holder having an inner opening exposing a portion of the inner terminal to which the inner lead is connected, and the inner lead is connected offset from a center of the inner terminal on the second axis.

8. An energy storage module according to claim 7, wherein the inner opening and the gap are arranged apart in a radial direction of the energy storage device.

9. The energy storage module according to claim 8, wherein the inner opening and the outer opening are in communication with each other.

10. A storage module according to any one of claims 1 to 9, wherein the storage device comprises: an electrode group including a first electrode and a second electrode; an outer can having a cylindrical tubular portion housing the electrode group and having an opening formed at one end of the tubular portion; and a sealing body that closes the opening while being insulated from the outer can, wherein the sealing body is electrically connected to the first electrode, and the outer can is electrically connected to the second electrode.

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