Electric power storage module

Abstract

This electric power storage module (10) comprises: a plurality of electric power storage devices (20); and a holder (40) that holds the plurality of electric power storage devices (20). The holder (40) has a plurality of housing portions (41) and a plurality of ribs (45), each of the plurality of electric power storage devices (20) being housed in a respective one of the plurality of housing portions (41), and the plurality of ribs (40) being provided on a plurality of inner peripheral surfaces of the plurality of housing portions (41) and holding side peripheral surfaces of the plurality of electric power storage devices (20).

Description

Energy storage module

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

[0002] An electric storage module is used as a power source equipped with a plurality of electric storage devices. The electric storage module may be mounted on a vehicle. In an electric storage module mounted on a vehicle, if an impact load is applied, for example, during a side collision of the vehicle, the load may be applied to the electric storage devices, causing the electric storage devices to deform and become unsafe. For example, Patent Document 1 discloses a technology in which a recessed shape provided in a holder breaks the holder during a side collision of the vehicle, thereby preventing the load from being applied to the electric storage devices.

[0003] JP 2015-156320 A

[0004] There is room for further improvement in safety for energy storage modules, not just in vehicles.

[0005] The energy storage module according to the present disclosure comprises a plurality of energy storage devices and a holder that holds the plurality of energy storage devices, the holder having a plurality of storage sections and a plurality of ribs, each of the plurality of energy storage devices being housed in a corresponding one of the plurality of storage sections, and the plurality of ribs being provided on a plurality of inner surfaces of the plurality of storage sections and holding a plurality of side surfaces of the plurality of energy storage devices.

[0006] The energy storage module of the present disclosure can improve safety.

[0007] FIG. 1 is a perspective view showing an electric storage module as an example of an embodiment; FIG. 2 is an axial cross-sectional view showing an electric storage device; FIG. 3 is a plan view showing an electric storage module as an example of an embodiment; FIG. 4 is an axial cross-sectional view showing an electric storage module as an example of an embodiment; FIG. 5 is a view for explaining a case where an impact load is applied to the electric storage module; FIG. 6 is a plan view showing a lower holder as an example of an embodiment; and FIG. 7 is a bottom view showing the lower holder as an example of an embodiment.

[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] The power storage module of the present disclosure may be provided in a power storage pack. The power storage pack is a power source provided in the body of an electric vehicle and has a housing in which multiple power storage modules are arranged. Furthermore, the power storage module of the present disclosure may be provided in the body of the vehicle.

[0012] The energy storage module 10 includes a plurality of energy storage devices 20, an upper holder 40 that holds upper axial portions of the plurality of energy storage devices 20, and a lower holder 50 that holds central and lower axial portions of the energy storage devices 20. In the following, the components of the energy storage module 10 may be described using the axial or radial direction of the cylindrical energy storage devices 20 described below. The energy storage module 10 is fixed to the vehicle body or an energy storage pack by bolts or the like that pass through fixing holes 57 formed in the lower holder 50.

[0013] Although details will be described later, the upper holder 40 has an accommodation portion 41 that accommodates the power storage device 20, and a plurality of ribs 45 that are formed in the accommodation portion 41 and that hold the side peripheral surface of the power storage device 20 (see FIG. 4). The lower holder 50 has an accommodation portion 51 that accommodates the power storage device 20, and a plurality of ribs 55 that are formed in the accommodation portion 51 and that hold the side peripheral surface of the power storage device 20 (see FIG. 4). The upper holder 40 and the lower holder 50 can improve the safety of the power storage module 10.

[0014] [Power Storage Device] The power storage device 20 as an example of an embodiment will be described in detail with reference to FIGS. 1 and 2. FIG.

[0015] 1 , the plurality of power storage devices 20 may be packed as densely as possible within the power storage module 10, taking safety into consideration, and adjacent power storage devices 20 may be arranged in close proximity to each other. Alternatively, four power storage devices 20 may be arranged on all four sides of one power storage device 20. For example, the power storage devices 20 are arranged such that six power storage devices 20 surround one power storage device 20 in a plan view (or arranged in a staggered pattern).

[0016] 2 , a cylindrical lithium-ion secondary battery is used as the power storage device 20 in this example, but a nickel-metal hydride battery, a capacitor, or the like 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 accommodates 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 lead 27 that electrically connects the positive electrode 21 and the sealing body 26, and a negative electrode lead 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.

[0017] 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 placed on this annular protrusion inside the outer can 25. Furthermore, the opening end of the outer can 25 is crimped so that it tilts toward the inside of the outer can 25, with the gasket 29 placed 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.

[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 pressure. Furthermore, 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 lead 27 may extend through a through-hole formed in the insulating plate 30. The negative electrode lead 28 may extend through a through-hole formed in the insulating plate 30 or may extend by bypassing the insulating plate 30. In the energy storage device 20, as described above, the positive electrode terminal may be provided on the top surface of the sealing body 26, and the negative electrode terminal may be provided on the crimped shoulder of the outer can 25.

[0019] [Upper Holder] The upper holder 40 as an example of an embodiment will be described with reference to FIGS. 1 and 3 to 5. FIG.

[0020] 1 , 3 , and 4 , as described above, the upper holder 40 holds the axial upper portions of the plurality of power storage devices 20. The upper holder 40 has a housing portion 41 that houses the power storage device 20, and a plurality of ribs 45 that are formed in the housing portion 41 and that hold the side peripheral surfaces of the power storage device 20.

[0021] The upper holder 40 is made of, for example, a thermoplastic resin. Thermoplastic resins are broadly classified into general-purpose plastics and engineering plastics, and examples thereof include polyethylene, polypropylene, polyamide, and ABS.

[0022] The accommodation portions 41 are formed in a circular shape when viewed in the axial direction. For example, in a plan view, the accommodation portions 41 are formed such that six accommodation portions 41 surround one accommodation portion 41. The accommodation portions 41 include a top surface portion 42 that faces the upper end surface (top surface) of the power storage device 20, and an opening 43 that is formed in the top surface portion 42 and exposes the top surface of the power storage device 20. The accommodation portions 41 accommodate the power storage device 20 with a predetermined gap between them and the side peripheral surface of the power storage device 20.

[0023] As described above, the ribs 45 hold the side circumferential surfaces of the energy storage device 20. As a result, the energy storage device 20 is held by the ribs 45 and accommodated in the accommodation portion 41 with a predetermined gap between the side circumferential surfaces of the energy storage device 20 and the accommodation portion 41. That is, a gap is provided between the side circumferential surfaces of the energy storage device 20 and the inner circumferential surface of the accommodation portion 41. Furthermore, a crushable zone is formed by the ribs 45 and the predetermined gap. When an impact load is applied to the energy storage module 10, the ribs 45 begin to deform (e.g., plastically deform) or break at a stress lower than the stress at which the energy storage device 20 begins to deform. As a result, the ribs 45 break during a collision, absorbing the impact load and protecting the energy storage device 20 from the impact. As a result, the energy storage device 20 is not placed in an unsafe state, and the safety of the energy storage module 10 can be improved.

[0024] As shown in FIG. 5 , when an impact load is applied to the cylindrical energy storage module 10, one of the multiple ribs 45 breaks or plastically deforms, leaving nothing to hold the energy storage device 20. This allows the energy storage device 20 to move or rotate within the accommodation section 41, thereby absorbing the impact load applied to the energy storage device 20. Furthermore, breaking the rib 45 expands the area of ​​the accommodation section 41 over which the energy storage device 20 can move or rotate, further absorbing the impact load applied to the energy storage device 20. This reduces the impact load applied to the energy storage device 20, prevents the energy storage device 20 from becoming unsafe, and improves the safety of the energy storage module 10. In this case, three or more ribs 45 may be provided for one accommodation section 41, and it is particularly preferable to provide three ribs 45. This is because if one of the three ribs 45 is deformed or broken, it becomes difficult for the remaining two ribs 45 to restrain the energy storage device 20.

[0025] In the following, a case where an impact load is applied from one side in the longitudinal direction of the energy storage module 10 (the left side in the drawing of FIG. 3) will be described.

[0026] 1, 3, and 4, three ribs 45 are formed at 120° intervals in a plane perpendicular to the axial direction. One of the three ribs 45 is formed on one side in the longitudinal direction, and two of the three ribs 45, 45, are formed at positions 120° and 240°, respectively, when the other side in the longitudinal direction is set to 0°. As a result, the ribs 45, 45 formed on the other side in the longitudinal direction are more likely to be destroyed before the energy storage device 20 is deformed by an impact load.

[0027] The rib 45 is formed to protrude radially inward from the housing portion 41. The radial length of the rib 45 is the same as the size of the gap between the side peripheral surface of the power storage device 20 and the housing portion 41.

[0028] The axial length (height) of the rib 45 is formed to be slightly shorter than the axial length of the accommodation portion 41. Note that the axial length of the rib 45 is not limited to the above. The rib 45 is formed from the lower end of the accommodation portion 41 to a position separated by a slight gap from the top surface portion 42. The rib 45 is also formed below a hole 46 formed in the top surface portion 42. The hole 46 is a space necessary for molding the rib 45 in the upper holder 40 when the upper holder 40 is molded using a mold.

[0029] The number, size and arrangement of the ribs in the present disclosure are not limited to the number, size and arrangement of the ribs 45 in this embodiment, and may be any number, size and arrangement that will break and form a crushable zone when an expected impact load is applied, based on the magnitude and direction of the expected impact load applied to the upper holder 40 and the strength of the ribs.

[0030] [Lower Holder] The lower holder 50 as an example of an embodiment will be described with reference to FIGS. 1, 4, 6 and 7. FIG.

[0031] As described above, the lower holder 50 holds the axial central and lower portions of the plurality of power storage devices 20. The lower holder 50 has a housing portion 51 that houses the power storage devices 20, a plurality of ribs 55 that are formed in the housing portion 51 and that hold the side peripheral surfaces of the power storage devices 20, and fixing holes 57 for fixing the lower holder 50. The lower holder 50 is made of the same material as the upper holder 40.

[0032] The accommodation portions 51 are formed in a circular shape when viewed in the axial direction. For example, in a plan view, the accommodation portions 51 are formed such that six accommodation portions 51 surround one accommodation portion 51. The accommodation portions 51 include a bottom surface portion 52 that faces the lower end surface (bottom surface) of the power storage device 20, and an opening portion 53 that is formed in the bottom surface portion 52 and exposes the bottom surface of the power storage device 20. The accommodation portions 51 accommodate the power storage device 20 with a predetermined gap between them and the side peripheral surface of the power storage device 20.

[0033] As described above, the ribs 55 hold the side peripheral surfaces of the energy storage device 20. As a result, the energy storage device 20 is held by the ribs 55 and is housed in the housing portion 51 with a predetermined gap between the side peripheral surfaces of the energy storage device 20 and the housing portion 51. Furthermore, a crushable zone consisting of the ribs 55 and the predetermined gap is formed, and when an impact load is applied to the energy storage module 10, the ribs 55 break, thereby absorbing the impact load and protecting the energy storage device 20 from the impact. As a result, the energy storage device 20 does not become unsafe, and the safety of the energy storage module 10 can be improved.

[0034] When an impact load is applied to the energy storage module 10, the function and effect of being able to absorb the impact load applied to the energy storage device 20 are the same as those of the upper holder 40 described above, and therefore a description thereof will be omitted.

[0035] In the following, a case where an impact load is applied from one side in the longitudinal direction of the energy storage module 10 (the left side in the drawing of FIG. 6) will be described.

[0036] Three ribs 55 are formed at 120° intervals in the circumferential direction on the side peripheral surface of the energy storage device 20. One of the three ribs 55 is formed on one side in the longitudinal direction, and two of the three ribs 55, 55, are formed at positions 120° and 240°, respectively, when the other side in the longitudinal direction is set to 0°. As a result, the two ribs 55, 55 formed on the other side in the longitudinal direction are deformed or destroyed before the energy storage device 20 is deformed by an impact load.

[0037] The axial length (height) of the rib 55 is the same as the height of the rib 45 formed on the upper holder 40. The rib 55 is formed at the lower end of the lower holder 50. The rib 55 is also formed above a hole 56 formed in the bottom surface portion 52. The hole 56 is a space necessary for molding the rib 55 in the lower holder 50 when the lower holder 50 is molded using a mold.

[0038] The number, size and arrangement of the ribs in the present disclosure are not limited to the number, size and arrangement of the ribs 55 in this embodiment, and may be any number, size and arrangement that will break and form a crushable zone when the expected impact load is applied, based on the magnitude and direction of the expected impact load applied to the lower holder 50 and the strength of the ribs.

[0039] The present disclosure is further described by the following embodiments.

[0040] Configuration 1: An energy storage module comprising: a plurality of energy storage devices; and a holder that holds the plurality of energy storage devices, the holder having a plurality of storage sections and a plurality of ribs, each of the plurality of energy storage devices being housed in a corresponding one of the plurality of storage sections, the plurality of ribs being provided on a plurality of inner circumferential surfaces of the plurality of storage sections and holding a plurality of side circumferential surfaces of the plurality of energy storage devices.

[0041] Configuration 2: The energy storage module according to Configuration 1, wherein a first storage section is one of the plurality of storage sections, a first power storage device is one of the plurality of power storage devices, a first inner circumferential surface is one of the plurality of inner circumferential surfaces of the plurality of storage sections, a first side circumferential surface is one of the plurality of side circumferential surfaces, the first inner circumferential surface is an inner circumferential surface of the first storage section, the first power storage device is housed in the first storage section, the first side circumferential surface is a side circumferential surface of the first power storage device, and a gap is provided between the first inner circumferential surface of the first storage section and the first side circumferential surface of the first power storage device.

[0042] Configuration 3: The energy storage module according to configuration 2, wherein three or more ribs are included in the plurality of ribs, and the three or more ribs are positioned on the same plane perpendicular to the axial direction of the energy storage device.

[0043] Configuration 4: The energy storage module according to configuration 2, wherein three ribs are included in the plurality of ribs, and the three ribs are provided in the first housing portion.

[0044] Configuration 5: The energy storage module according to Configuration 3, wherein the three or more ribs are provided at equal intervals in the circumferential direction of the first side peripheral surface of the first energy storage device.

[0045] Configuration 6: The energy storage module according to any one of Configurations 1 to 5, wherein, when a load is applied to the energy storage module, a stress at which one of the plurality of ribs begins to deform is lower than a stress at which one of the plurality of energy storage devices begins to deform.

[0046] Configuration 7: The energy storage module according to any one of configurations 1 to 6, wherein each of the plurality of energy storage devices is cylindrical.

[0047] Configuration 8: The energy storage module according to any one of configurations 1 to 7, wherein the plurality of ribs are provided at a position that holds one end of the energy storage device in the axial direction.

[0048] It should be noted that the present disclosure is not limited to the above-described embodiments and their variations, 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.

[0049] REFERENCE SIGNS LIST 10 Energy storage module 20 Energy storage device 21 Positive electrode 22 Negative electrode 23 Separator 24 Electrode group 25 Outer can 25A Groove 26 Sealing body 27 Positive electrode lead 28 Negative electrode lead 29 Gasket 30 Insulating plate 40 Upper holder (holder) 41 Storage section 42 Top surface 43 Opening 45 Rib 46 Hole 50 Lower holder (holder) 51 Storage section 52 Bottom surface 53 Opening 55 Rib 56 Hole 57 Fixing hole

Claims

1. A plurality of power storage devices; a holder for holding the plurality of power storage devices; Equipped with the holder has a plurality of receiving portions and a plurality of ribs, each of the plurality of power storage devices is accommodated in a corresponding one of the plurality of accommodation sections; the plurality of ribs are provided on a plurality of inner circumferential surfaces of the plurality of housing portions and hold a plurality of side circumferential surfaces of the plurality of power storage devices. Energy storage module.

2. The energy storage module according to claim 1, the first storage section is one of the plurality of storage sections, the first power storage device is one of the plurality of power storage devices, the first inner circumferential surface is one of the inner circumferential surfaces of the plurality of accommodating portions, the first peripheral side surface is one of the plurality of peripheral side surfaces; the first inner circumferential surface is an inner circumferential surface of the first accommodating portion, the first power storage device is accommodated in the first accommodation portion, the first side peripheral surface is a side peripheral surface of the first power storage device, a gap is provided between the first inner circumferential surface of the first housing portion and the first side circumferential surface of the power storage device; Energy storage module.

3. The energy storage module according to claim 2, three or more ribs are included in the plurality of ribs; the three or more ribs are located on the same plane perpendicular to the axial direction of the power storage device; Energy storage module.

4. The energy storage module according to claim 2, Three ribs are included in the plurality of ribs; The three ribs are provided in the first housing portion. Energy storage module.

5. The energy storage module according to claim 3, The three or more ribs are provided at equal intervals in the circumferential direction of the first side circumferential surface of the first power storage device. Energy storage module.

6. The energy storage module according to claim 1, When a load is applied to the energy storage module, a stress at which one of the plurality of ribs begins to deform is lower than a stress at which one of the plurality of energy storage devices begins to deform. Energy storage module.

7. The energy storage module according to claim 1, Each of the plurality of power storage devices has a cylindrical shape. Energy storage module.

8. The energy storage module according to claim 1, The plurality of ribs are provided at positions to hold one end of the plurality of power storage devices in the axial direction. Energy storage module.