Power storage device

Abstract

To suppress formation of a short-circuit path between a terminal part of a power storage module and a case.SOLUTION: The energy storage apparatus 100 includes an energy storage unit 110 and a housing case 90 which houses the energy storage unit 110. The housing case 90 includes an upper case 91 and a lower case 92 disposed below the upper case 91. The lower case 92 includes a bottom wall 921 and a peripheral wall 922 erected from a peripheral edge portion of the bottom wall 921. A recess 50 recessed downward is formed in the bottom wall 921. The energy storage unit 110 includes at least one terminal part 619 to 624 which is disposed below the center of the energy storage unit 110 in the vertical direction. The recess 50 is formed below at least one of the terminal units 619 to 624.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to an electricity storage device. [Background technology]

[0002] For example, Japanese Patent Application Laid-Open No. 2022-165717 (Patent Document 1) discloses a battery pack (electricity storage device) having a power storage module and a lower case with a flat bottom. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-165717 Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, a power storage module is formed with a smoke exhaust section that exhausts gas from within the power storage module. This gas contains conductive foreign matter (debris). Therefore, when gas is exhausted from the smoke exhaust section, conductive foreign matter accumulates inside the case, which may cause a short circuit between the terminals of the power storage module and the case. In addition, condensation water generated by cooling the power storage cells included in the power storage module may cause a short circuit between the terminals of the power storage module and the case.

[0005] An object of the present disclosure is to prevent a short circuit path from being formed between a terminal portion of an energy storage module and a case. [Means for solving the problem]

[0006] An energy storage device according to an aspect of the present disclosure includes an energy storage unit and a housing case that houses the energy storage unit. The housing case includes an upper case and a lower case arranged below the upper case. The lower case includes a bottom wall and a peripheral wall that stands up from a peripheral edge of the bottom wall. A recess that is recessed downward is formed in the bottom wall. The energy storage unit includes at least one terminal portion that is arranged below the center of the energy storage unit in the up-down direction. The recess is formed below the at least one terminal portion.

[0007] Preferably, the electric storage device is mounted on a vehicle. The electric storage device further includes a case smoke exhaust valve provided in the housing case and configured to exhaust gas from within the electric storage device. The recess is formed to extend in the front-to-rear direction of the vehicle. The electric storage device is formed with a space that communicates with one end of the recess in the front-to-rear direction of the vehicle and extends upward. The case smoke exhaust valve is provided in a portion of the housing case that defines the space.

[0008] Preferably, the energy storage unit includes an energy storage module. The energy storage module includes an upper module and a lower module disposed below the upper module. A first smoke exhaust section for exhausting gas within the upper module is formed on an upper surface of the upper module. A second smoke exhaust section for exhausting gas within the lower module is formed on a lower surface of the lower module. The case smoke exhaust valve is provided at the center of the storage case or above the center of the storage case in the vertical direction.

[0009] Preferably, the energy storage unit includes an energy storage module, and a smoke exhaust valve for exhausting gas from within the energy storage module is formed on a bottom surface of the energy storage module. The case smoke exhaust valve is provided below the center of the storage case in the up-down direction.

[0010] Preferably, the power storage device is mounted on a vehicle. The power storage device further includes a sensor for detecting water. The recess is formed to extend in a front-to-rear direction of the vehicle. The sensor is provided at one end of the recess in the front-to-rear direction of the vehicle.

[0011] Preferably, the vehicle includes an electric device connected to the sensor, the electric device being disposed above the power storage device and being located rearward of the center of the power storage device in the front-to-rear direction of the vehicle, and the one end being a rear end of the recess in the front-to-rear direction of the vehicle.

[0012] Preferably, the power storage device is mounted on a vehicle. The peripheral wall includes a first side wall and a second side wall spaced apart in the vehicle width direction. The power storage unit includes a first power storage module and a second power storage module spaced apart in the vehicle width direction from the first power storage module. The at least one terminal includes a first terminal provided on the first power storage module and a second terminal provided on the second power storage module. The power storage device further includes a first reinforcing member provided on the lower case and protruding upward from the bottom wall, and a second reinforcing member provided on the lower case and protruding upward from the bottom wall, spaced apart in the vehicle width direction from the first reinforcing member. The first reinforcing member and the second reinforcing member are formed to extend in the front-rear direction of the vehicle. The first side wall, the first power storage module, the first reinforcing member, the second power storage module, the second reinforcing member, and the second side wall are arranged in this order along the vehicle width direction. The recess includes a first groove formed below the first terminal and a second groove formed below the second terminal. The first groove is formed to extend in the front-rear direction of the vehicle and includes a first bottom surface extending in the front-rear direction of the vehicle. The second groove is formed to extend in the front-rear direction of the vehicle and includes a second bottom surface extending in the front-rear direction of the vehicle. The distance between the first power storage module and the first side wall is shorter than the distance between the first terminal and the first bottom surface. The distance between the first power storage module and the first reinforcing member is shorter than the distance between the first terminal and the first bottom surface. The distance between the second power storage module and the first reinforcing member is shorter than the distance between the second terminal and the second bottom surface. The distance between the second power storage module and the second reinforcing member is shorter than the distance between the second terminal and the second bottom surface.

[0013] Preferably, the power storage device is mounted on a vehicle. The recess is formed to extend in the front-to-rear direction of the vehicle. The recess includes a first region having a first depth and a second region having a second depth deeper than the first depth. The second region is located rearward of the first region on the vehicle. [Effects of the Invention]

[0014] According to the present disclosure, it is possible to prevent a short circuit path from being formed between the terminal portion of the energy storage module and the case. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a side view schematically illustrating a vehicle including an electricity storage device according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic exploded perspective view of the power storage device 100 shown in FIG. [Figure 3] 10 is a view of the lower case 92 seen from above the electricity storage device 100. FIG. [Figure 4] FIG. 2 is a diagram schematically illustrating an electricity storage unit 110. [Figure 5] 1 is a view of the inside of the power storage device 100 viewed from above the power storage device 100 with the upper case 91 removed from the power storage device 100. FIG. [Figure 6] 1 is a view of the inside of the power storage device 100 viewed from above the power storage device 100 with the coolers 31 to 33 and components positioned above the coolers 31 to 33 removed. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 5. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 5. [Figure 9] 8 is a cross-sectional view of the power storage device 100 and the equipment unit 120 taken along line VIII-VIII in FIG. 5. FIG. [Figure 10] 10 is a cross-sectional view of an electricity storage device according to a fourth modification taken along the front-rear direction of the vehicle. FIG. [Figure 11] 11 is a cross-sectional view of an electricity storage device according to a fifth modification taken along the front-rear direction of the vehicle. FIG. [Figure 12] 13 is a cross-sectional view of an electricity storage device according to a sixth modification taken along the front-rear direction of the vehicle. FIG. [Figure 13] 13 is a cross-sectional view of an electricity storage device according to a seventh modification taken along the front-rear direction of the vehicle. FIG. [Figure 14] 13 is a side view of a power storage cell included in a power storage device according to Modification 8. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments and modifications according to the present disclosure will be described with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated. Note that the embodiments and modifications described below may be selectively combined as appropriate.

[0017] [Embodiment] A power storage device according to an embodiment of the present disclosure will be described with reference to FIGS.

[0018] 1 is a side view schematically illustrating a vehicle equipped with a power storage device according to an embodiment of the present disclosure. The power storage device 100 according to the embodiment of the present disclosure is a power storage device that stores electric power for driving, and is mounted on a vehicle 150. The vehicle 150 runs using the electric power stored in the power storage device 100. Examples of the vehicle 150 include a hybrid vehicle, a plug-in hybrid vehicle, a fuel cell vehicle, and an electric vehicle. The power storage device 100 is disposed below a floor panel of the vehicle 150.

[0019] The vehicle 150 includes an equipment unit 120. The equipment unit 120 includes, for example, an electronic control unit and a junction box.

[0020] FIG. 2 is a schematic exploded perspective view of the power storage device 100 shown in FIG. 1. In the present disclosure, the X direction, the Y direction, and the Z direction are perpendicular to one another. For example, the X direction is the front-to-rear direction of the vehicle 150 (see FIG. 1), and the Y direction is the width direction of the vehicle 150. The X1 direction is the direction from the rear side of the vehicle 150 toward the front side of the vehicle 150. The X2 direction is the direction from the front side of the vehicle 150 toward the rear side of the vehicle 150. The Y1 direction is the direction from the right side of the vehicle 150 toward the left side of the vehicle 150. The Y2 direction is the direction from the left side of the vehicle 150 toward the right side of the vehicle 150. The Z direction is the up-down (vertical) direction. The Z1 direction is the direction from the bottom side of the vehicle 150 toward the top side of the vehicle 150. The Z2 direction is the direction from the top side of the vehicle 150 toward the bottom side of the vehicle 150. In this disclosure, the Z1 direction is also referred to as the upper side or top side, and the Z2 direction is also referred to as the lower side or bottom side.

[0021] The power storage device 100 according to this embodiment is, for example, a battery pack. The power storage device 100 includes a housing case 90, a sensor 70, a power storage unit 110, and coolers 31-33.

[0022] The accommodating case 90 accommodates the sensor 70, the power storage unit 110, and the coolers 31 to 33. More specifically, the accommodating case 90 includes an upper case 91 and a lower case 92. The lower case 92 is disposed below the upper case 91. The sensor 70, the power storage unit 110, and the coolers 31 to 33 are accommodated in a space formed by the upper case 91 and the lower case 92. The power storage device 100 further includes a reinforcing member. The reinforcing member is provided in the lower case 92. In addition, a recess recessed downward is formed in a bottom wall 921 of the lower case 92.

[0023] 2 and 3, the lower case 92, the reinforcing members provided in the lower case 92, and the recessed portion formed in the bottom wall 921 of the lower case 92 will be described. Fig. 3 is a view of the lower case 92 as seen from above the power storage device 100. Note that, in Fig. 3, the reinforcing members 811 to 814 and 821 to 826 are hatched to make the drawing easier to read.

[0024] The lower case 92 includes a bottom wall 921 and a peripheral wall 922. The peripheral wall 922 stands upright from the peripheral edge of the bottom wall 921. The peripheral wall 922 is formed in a substantially rectangular cylindrical shape. The peripheral wall 922 includes side walls 931 to 934. The side walls 931 and 932 are spaced apart in the Y direction. The side walls 933 and 934 are spaced apart in the X direction.

[0025] The power storage device 100 further includes reinforcing members 811-814 and 821-826. The reinforcing members 811-814 and 821-826 are provided on the lower case 92. Each of the reinforcing members 811-814 and 821-826 is formed so as to protrude upward from a bottom wall 921 of the lower case 92. Each of the reinforcing members 811-814 and 821-826 is fixed (for example, fastened) to the bottom wall 921. Each of the reinforcing members 811-814 and 821-826 is, for example, a plate-shaped member made of metal.

[0026] Each of the reinforcing members 811 to 814 is formed to be long in the Y direction, and is fixed (for example, fastened) to the bottom wall 921. The reinforcing members 811, 812, 813, and 814 are arranged in this order along the X direction at intervals.

[0027] Reinforcing members 821 and 822 are formed to extend in the X direction between reinforcing members 811 and 812. Reinforcing members 821 and 822 are arranged with an interval in the Y direction.

[0028] Reinforcing members 823 and 824 are formed to extend in the X direction between reinforcing members 812 and 813. Reinforcing members 823 and 824 are arranged at an interval in the Y direction.

[0029] Reinforcing members 825 and 826 are formed to extend in the X direction between reinforcing members 813 and 814. Reinforcing members 825 and 826 are arranged at an interval in the Y direction.

[0030] A recess 50 recessed downward is formed in the bottom wall 921. More specifically, the recess 50 is formed to extend in the X direction. The recess 50 includes grooves 51 to 56. Each of the grooves 51 to 56 is formed to extend in the X direction. The grooves 51 to 56 are provided in this order at intervals along the Y direction.

[0031] The power storage unit 110 shown in Fig. 2 will be described with reference to Fig. 4 to Fig. 6. Fig. 4 is a diagram schematically showing the power storage unit 110.

[0032] The power storage unit 110 includes power storage modules M1 to M9. The power storage module M1, the power storage module M2, and the power storage module M3 are arranged in this order along the Y direction. The power storage module M2 is arranged at an interval in the Y2 direction relative to the power storage module M1. The power storage module M3 is arranged at an interval in the Y2 direction relative to the power storage module M2.

[0033] The power storage module M4, the power storage module M5, and the power storage module M6 are arranged in this order along the Y direction. The power storage module M5 is arranged at a distance from the power storage module M4 in the Y2 direction. The power storage module M6 is arranged at a distance from the power storage module M5 in the Y2 direction.

[0034] The power storage module M7, the power storage module M8, and the power storage module M9 are arranged in this order along the Y direction. The power storage module M8 is arranged at a distance from the power storage module M7 in the Y2 direction. The power storage module M9 is arranged at a distance from the power storage module M8 in the Y2 direction.

[0035] The power storage module M1, the power storage module M4, and the power storage module M7 are arranged in this order along the X direction. The power storage module M4 is arranged at a distance from the power storage module M1 in the X2 direction. The power storage module M7 is arranged at a distance from the power storage module M4 in the X2 direction.

[0036] The power storage module M2, the power storage module M5, and the power storage module M8 are arranged in this order along the X direction. The power storage module M5 is arranged at a distance from the power storage module M2 in the X2 direction. The power storage module M8 is arranged at a distance from the power storage module M5 in the X2 direction.

[0037] The power storage module M3, the power storage module M6, and the power storage module M9 are arranged in this order along the X direction. The power storage module M6 is arranged at a distance from the power storage module M3 in the X2 direction. The power storage module M9 is arranged at a distance from the power storage module M6 in the X2 direction.

[0038] Each of the power storage modules M1 to M9 includes an upper module and a lower module arranged below the upper module.

[0039] More specifically, the power storage module M1 includes an upper module 1 and a lower module 2 arranged below the upper module 1. The power storage module M2 includes an upper module 6 and a lower module 3 arranged below the upper module 6. The power storage module M3 includes an upper module 5 and a lower module 4 arranged below the upper module 5. The power storage module M4 includes an upper module 7 and a lower module 8 arranged below the upper module 7. The power storage module M5 includes an upper module 12 and a lower module 9 arranged below the upper module 12. The power storage module M6 includes an upper module 11 and a lower module 10 arranged below the upper module 11. The power storage module M7 includes an upper module 13 and a lower module 14 arranged below the upper module 13. The power storage module M8 includes an upper module 18 and a lower module 15 arranged below the upper module 18. The power storage module M9 includes an upper module 17 and a lower module 16 disposed below the upper module 17.

[0040] Upper module 1, upper module 6, and upper module 5 are arranged in this order along the Y direction. Lower module 2, lower module 3, and lower module 4 are arranged in this order along the Y direction. A cooler 31 is arranged between upper modules 1, 5, and 6 and lower modules 2 to 4. That is, upper modules 1, 5, and 6 are arranged above cooler 31, and lower modules 2 to 4 are arranged below cooler 31. Cooler 31 is configured to cool power storage modules M1 to M3 (upper modules 1, 5, and 6 and lower modules 2 to 4).

[0041] The upper module 7, the upper module 12, and the upper module 11 are arranged in this order along the Y direction. The lower module 8, the lower module 9, and the lower module 10 are arranged in this order along the Y direction. A cooler 32 is arranged between the upper modules 7, 11, and 12 and the lower modules 8 to 10. That is, the upper modules 7, 11, and 12 are arranged above the cooler 32, and the lower modules 8 to 10 are arranged below the cooler 32. The cooler 32 is configured to cool the power storage modules M4 to M6 (the upper modules 7, 11, and 12 and the lower modules 8 to 10).

[0042] Upper module 13, upper module 18, and upper module 17 are arranged in this order along the Y direction. Lower module 14, lower module 15, and lower module 16 are arranged in this order along the Y direction. A cooler 33 is arranged between upper modules 13, 17, and 18 and lower modules 14 to 16. That is, upper modules 13, 17, and 18 are arranged above cooler 33, and lower modules 14 to 16 are arranged below cooler 33. Cooler 33 is configured to cool power storage modules M7 to M9 (upper modules 13, 17, and 18 and lower modules 14 to 16).

[0043] Each of the upper modules 1, 5 to 7, 11 to 13, 17, and 18 and the lower modules 2 to 4, 8 to 10, and 14 to 16 includes a plurality of storage cells 111 (see FIGS. 7 and 8) and cell cases (for example, cell cases 1a, 2a, 3a, 4a, 5a, and 6a shown in FIG. 7) that house the plurality of storage cells 111. Each storage cell 111 has a rectangular parallelepiped shape that is elongated in the Y direction. Each storage cell 111 includes a battery body and a cell can that houses the battery body. In each of the upper modules 1, 5 to 7, 11 to 13, 17, and 18 and the lower modules 2 to 4, 8 to 10, and 14 to 16, the plurality of storage cells 111 are arranged side by side in the X direction.

[0044] Each storage cell 111 may have a rectangular parallelepiped shape that is long in the X direction. In that case, in each of the upper modules 1, 5 to 7, 11 to 13, 17, and 18 and the lower modules 2 to 4, 8 to 10, and 14 to 16, the multiple storage cells 111 are arranged side by side in the Y direction.

[0045] A first smoke exhaust section is formed on the upper surface of each upper module to exhaust gas from within the upper module. In this embodiment, the first smoke exhaust section is a smoke exhaust port. More specifically, a first smoke exhaust section 801 is formed on the upper surface of upper module 1 to exhaust gas from within upper module 1. A first smoke exhaust section 805 is formed on the upper surface of upper module 5 to exhaust gas from within upper module 5. A first smoke exhaust section 806 is formed on the upper surface of upper module 6 to exhaust gas from within upper module 6. A first smoke exhaust section 807 is formed on the upper surface of upper module 7 to exhaust gas from within upper module 7. A first smoke exhaust section 811 is formed on the upper surface of upper module 11 to exhaust gas from within upper module 11. A first smoke exhaust section 812 is formed on the upper surface of upper module 12 to exhaust gas from within upper module 12. A first smoke exhaust section 813 is formed on the upper surface of the upper module 13 to exhaust gas inside the upper module 13. A first smoke exhaust section 817 is formed on the upper surface of the upper module 17 to exhaust gas inside the upper module 17. A first smoke exhaust section 818 is formed on the upper surface of the upper module 18 to exhaust gas inside the upper module 18.

[0046] A second smoke exhaust section is formed on the underside of each lower module to exhaust gas from within the lower module. In this embodiment, the second smoke exhaust section is a smoke exhaust port. More specifically, a second smoke exhaust section 802 is formed on the underside of lower module 2 to exhaust gas from within lower module 2. A second smoke exhaust section 803 is formed on the underside of lower module 3 to exhaust gas from within lower module 3. A second smoke exhaust section 804 is formed on the underside of lower module 4 to exhaust gas from within lower module 4. A second smoke exhaust section 808 is formed on the underside of lower module 8 to exhaust gas from within lower module 8. A second smoke exhaust section 809 is formed on the underside of lower module 9 to exhaust gas from within lower module 9. A second smoke exhaust section 810 is formed on the underside of lower module 10 to exhaust gas from within lower module 10. A second smoke exhaust section 814 is formed on the underside of lower module 14 to exhaust gas from within lower module 14. A second smoke exhaust section 815 is formed on the underside of the lower module 15 to exhaust gas from within the lower module 15. A second smoke exhaust section 816 is formed on the underside of the lower module 16 to exhaust gas from within the lower module 16.

[0047] The power storage unit 110 includes 18 terminal portions arranged above the center of the power storage unit 110 in the vertical direction (Z direction) and 18 terminal portions arranged below the center of the power storage unit 110 in the vertical direction (Z direction). Here, the terminal portions will be described with reference to Figs. 5 and 6.

[0048] Fig. 5 is a view of the interior of the power storage device 100 viewed from above the power storage device 100 with the upper case 91 removed from the power storage device 100. Note that, for ease of viewing the drawing, the reinforcing members 811-814 and the coolers 31-33 are hatched in Fig. 5. Also, for ease of viewing the drawing, the first smoke exhaust sections formed on the top surfaces of the upper modules are omitted in Fig. 5.

[0049] Referring to FIG. 5, when the interior of the energy storage device 100 is viewed from above the energy storage device 100, upper modules 1, 5 to 7, 11 to 13, 17, and 18, which are arranged above the coolers 31 to 33, are visible. Each upper module includes a positive electrode terminal portion and a negative electrode terminal portion. The positive electrode terminal portion and the negative electrode terminal portion of each upper module are arranged above the center of the energy storage unit 110 in the up-down direction (Z direction). In this embodiment, the positive electrode terminal portion and the negative electrode terminal portion of each upper module are arranged on the upper surface of the energy storage cell 111 (see FIGS. 7 and 8) of the upper module.

[0050] More specifically, the upper module 1 includes a positive electrode terminal 601 and a negative electrode terminal 602. The positive electrode terminal 601 and the negative electrode terminal 602 are disposed on the upper surfaces of the power storage cells 111 of the upper module 1. The upper module 5 includes a positive electrode terminal 603 and a negative electrode terminal 604. The positive electrode terminal 603 and the negative electrode terminal 604 are disposed on the upper surfaces of the power storage cells 111 of the upper module 5. The upper module 6 includes a positive electrode terminal 605 and a negative electrode terminal 606. The positive electrode terminal 605 and the negative electrode terminal 606 are disposed on the upper surfaces of the power storage cells 111 of the upper module 6. The upper module 7 includes a positive electrode terminal 607 and a negative electrode terminal 608. The positive electrode terminal 607 and the negative electrode terminal 608 are disposed on the upper surfaces of the power storage cells 111 of the upper module 7. The upper module 11 includes a positive electrode terminal 609 and a negative electrode terminal 610. The positive electrode terminal 609 and the negative electrode terminal 610 are disposed on the upper surfaces of the storage cells 111 of the upper module 11. The upper module 12 includes a positive electrode terminal 611 and a negative electrode terminal 612. The positive electrode terminal 611 and the negative electrode terminal 612 are disposed on the upper surfaces of the storage cells 111 of the upper module 12. The upper module 13 includes a positive electrode terminal 613 and a negative electrode terminal 614. The positive electrode terminal 613 and the negative electrode terminal 614 are disposed on the upper surfaces of the storage cells 111 of the upper module 13. The upper module 17 includes a positive electrode terminal 615 and a negative electrode terminal 616. The positive electrode terminal 615 and the negative electrode terminal 616 are disposed on the upper surfaces of the storage cells 111 of the upper module 17. The upper module 18 includes a positive electrode terminal 617 and a negative electrode terminal 618. The positive electrode terminal 617 and the negative electrode terminal 618 are disposed on the upper surfaces of the storage cells 111 of the upper module 18.

[0051] The positions of the positive and negative terminal portions of each upper module are not limited to the upper surfaces of the energy storage cells 111 of the upper module. The positive and negative terminal portions of each upper module may be located above the center of the energy storage unit 110 in the vertical direction (Z direction).

[0052] Fig. 6 is a view of the inside of the power storage device 100 viewed from above the power storage device 100, with the coolers 31 to 33 and components located above the coolers 31 to 33 removed. Note that, in Fig. 6, the reinforcing members 811 to 814 and 821 to 826 are hatched to make the drawing easier to see.

[0053] Referring to Figure 6, when the coolers 31 to 33 and the components located above the coolers 31 to 33 are removed and the interior of the energy storage device 100 is viewed from above the energy storage device 100, the lower modules 2 to 4, 8 to 10, 14 to 16, which are located below the coolers 31 to 33, and the reinforcing members 811 to 814, 821 to 826 can be seen.

[0054] Reinforcing member 821 is disposed between lower module 2 and lower module 3. Reinforcing member 822 is disposed between lower module 3 and lower module 4. Lower modules 2 to 4 are disposed between reinforcing member 811 and reinforcing member 812.

[0055] Reinforcing member 823 is disposed between lower module 8 and lower module 9. Reinforcing member 824 is disposed between lower module 9 and lower module 10. Lower modules 8 to 10 are disposed between reinforcing member 812 and reinforcing member 813.

[0056] Reinforcing member 825 is disposed between lower module 14 and lower module 15. Reinforcing member 826 is disposed between lower module 15 and lower module 16. Lower modules 14 to 16 are disposed between reinforcing member 813 and reinforcing member 814.

[0057] Each lower module includes a positive electrode terminal portion and a negative electrode terminal portion. The positive electrode terminal portion and the negative electrode terminal portion of each lower module are arranged below the center of the energy storage unit 110 in the vertical direction (Z direction). In this embodiment, the positive electrode terminal portion and the negative electrode terminal portion of each lower module are arranged on the lower surface of the energy storage cell 111 of that lower module.

[0058] More specifically, the lower module 2 includes a positive electrode terminal 619 and a negative electrode terminal 620. The positive electrode terminal 619 and the negative electrode terminal 620 are disposed on the lower surfaces of the storage cells 111 of the lower module 2. The lower module 3 includes a positive electrode terminal 621 and a negative electrode terminal 622. The positive electrode terminal 621 and the negative electrode terminal 622 are disposed on the lower surfaces of the storage cells 111 of the lower module 3. The lower module 4 includes a positive electrode terminal 623 and a negative electrode terminal 624. The positive electrode terminal 623 and the negative electrode terminal 624 are disposed on the lower surfaces of the storage cells 111 of the lower module 4. The lower module 8 includes a positive electrode terminal 625 and a negative electrode terminal 626. The positive electrode terminal 625 and the negative electrode terminal 626 are disposed on the lower surfaces of the storage cells 111 of the lower module 8. The lower module 9 includes a positive electrode terminal 627 and a negative electrode terminal 628. The positive electrode terminal 627 and the negative electrode terminal 628 are disposed on the lower surfaces of the storage cells 111 of the lower module 9. The lower module 10 includes a positive electrode terminal 629 and a negative electrode terminal 630. The positive electrode terminal 629 and the negative electrode terminal 630 are disposed on the lower surfaces of the storage cells 111 of the lower module 10. The lower module 14 includes a positive electrode terminal 631 and a negative electrode terminal 632. The positive electrode terminal 631 and the negative electrode terminal 632 are disposed on the lower surfaces of the storage cells 111 of the lower module 14. The lower module 15 includes a positive electrode terminal 633 and a negative electrode terminal 634. The positive electrode terminal 633 and the negative electrode terminal 634 are disposed on the lower surfaces of the storage cells 111 of the lower module 15. The lower module 16 includes a positive electrode terminal portion 635 and a negative electrode terminal portion 636. The positive electrode terminal portion 635 and the negative electrode terminal portion 636 are disposed on the lower surface of the power storage cell 111 of the lower module 16.

[0059] The positions of the positive electrode terminal portion and the negative electrode terminal portion of each lower module are not limited to the lower surfaces of the energy storage cells 111 of the lower module. The positive electrode terminal portion and the negative electrode terminal portion of each lower module may be disposed below the center of the energy storage unit 110 in the vertical direction (Z direction).

[0060] 4 to 6, the electrical connections of the power storage unit 110 will be described. The upper modules 1, 5 to 7, 11 to 13, 17, and 18 and the lower modules 2 to 4, 8 to 10, and 14 to 16 are connected in series by bus bars.

[0061] The positive electrode terminal 601 of the upper module 1 is the overall positive electrode terminal of the power storage unit 110. The negative electrode terminal 602 of the upper module 1 and the positive electrode terminal 619 of the lower module 2 are connected by a bus bar 211. The negative electrode terminal 620 of the lower module 2 and the positive electrode terminal 621 of the lower module 3 are connected by a bus bar 212. The negative electrode terminal 622 of the lower module 3 and the positive electrode terminal 623 of the lower module 4 are connected by a bus bar 213. The negative electrode terminal 624 of the lower module 4 and the positive electrode terminal 603 of the upper module 5 are connected by a bus bar 214. The negative electrode terminal 604 of the upper module 5 and the positive electrode terminal 605 of the upper module 6 are connected by a bus bar 215. The negative electrode terminal 606 of the upper module 6 and the positive electrode terminal 607 of the upper module 7 are connected by a bus bar 251.

[0062] The negative electrode terminal 608 of the upper module 7 and the positive electrode terminal 625 of the lower module 8 are connected by a bus bar 221. The negative electrode terminal 626 of the lower module 8 and the positive electrode terminal 627 of the lower module 9 are connected by a bus bar 222. The negative electrode terminal 628 of the lower module 9 and the positive electrode terminal 629 of the lower module 10 are connected by a bus bar 223. The negative electrode terminal 630 of the lower module 10 and the positive electrode terminal 609 of the upper module 11 are connected by a bus bar 224. The negative electrode terminal 610 of the upper module 11 and the positive electrode terminal 611 of the upper module 12 are connected by a bus bar 225. The negative electrode terminal 612 of the upper module 12 and the positive electrode terminal 613 of the upper module 13 are connected by a bus bar 252.

[0063] The negative electrode terminal 614 of the upper module 13 and the positive electrode terminal 631 of the lower module 14 are connected by a bus bar 231. The negative electrode terminal 632 of the lower module 14 and the positive electrode terminal 633 of the lower module 15 are connected by a bus bar 232. The negative electrode terminal 634 of the lower module 15 and the positive electrode terminal 635 of the lower module 16 are connected by a bus bar 233. The negative electrode terminal 636 of the lower module 16 and the positive electrode terminal 615 of the upper module 17 are connected by a bus bar 234. The negative electrode terminal 616 of the upper module 17 and the positive electrode terminal 617 of the upper module 18 are connected by a bus bar 235. The negative electrode terminal 618 of the upper module 18 is the overall negative electrode terminal of the energy storage unit 110.

[0064] The electrical connections of the power storage unit 110 are not limited to those described with reference to Figs. 4 to 6. The number of power storage modules included in the power storage unit 110 is not limited to nine. The number of power storage modules included in the power storage unit 110 may be one or more.

[0065] The recess 50 will be described in more detail with reference to Figures 6 to 8. Figure 7 is a cross-sectional view taken along line VII-VII in Figure 5. Figure 8 is a cross-sectional view taken along line VIII-VIII in Figure 5.

[0066] Referring to FIG. 7 , the side wall 931, the power storage module M1, the reinforcing member 821, the power storage module M2, the reinforcing member 822, the power storage module M3, and the side wall 932 are arranged in this order along the Y direction. The side wall 931 is an example of a "first side wall" in the present disclosure, and the side wall 932 is an example of a "second side wall" in the present disclosure. The power storage module M1 is an example of a "first power storage module" in the present disclosure. The power storage module M2 is an example of a "second power storage module" in the present disclosure. The reinforcing member 821 is an example of a "first reinforcing member" in the present disclosure, and the reinforcing member 822 is an example of a "second reinforcing member" in the present disclosure.

[0067] As described above, the power storage module M1 includes the upper module 1 and the lower module 2. The power storage module M2 includes the upper module 6 and the lower module 3. The power storage module M3 includes the upper module 5 and the lower module 4.

[0068] The power storage module M1 is provided with four terminal portions. More specifically, the power storage module M1 is provided with positive terminal portions 601, 619 and negative terminal portions 602, 620.

[0069] The positive electrode terminal 601 and the negative electrode terminal 602 are disposed above the center of the energy storage unit 110 in the vertical direction (Z direction). An imaginary line P1 indicates the position of the center of the energy storage unit 110 in the vertical direction (Z direction). More specifically, the positive electrode terminal 601 and the negative electrode terminal 602 are provided on the upper surface of the energy storage cell 111 of the upper module 1. In this embodiment, the positive electrode terminal 601 and the negative electrode terminal 602 protrude upward from the cell case 1a of the upper module 1. The cell case 1a includes an upper wall 1b and a lower wall disposed at an interval in the vertical direction (Z direction). A first smoke exhaust section 801 for exhausting gas from within the upper module 1 is formed in the upper wall 1b.

[0070] The positive electrode terminal 619 and the negative electrode terminal 620 are each an example of a "first terminal" in the present disclosure. The positive electrode terminal 619 and the negative electrode terminal 620 are disposed below the center of the energy storage unit 110 in the vertical direction (Z direction). More specifically, the positive electrode terminal 619 and the negative electrode terminal 620 are provided on the lower surface of the energy storage cell 111 of the lower module 2. In this embodiment, the positive electrode terminal 619 and the negative electrode terminal 620 protrude downward from the cell case 2a of the lower module 2. The cell case 2a includes an upper wall and a lower wall 2b disposed at an interval in the vertical direction (Z direction). A second smoke exhaust section 802 for exhausting gas from within the lower module 2 is formed in the lower wall 2b.

[0071] The power storage module M2 is provided with four terminals. More specifically, the power storage module M2 is provided with positive terminals 605 and 621 and negative terminals 606 and 622.

[0072] The positive electrode terminal 605 and the negative electrode terminal 606 are disposed above the center of the power storage unit 110 in the vertical direction (Z direction). More specifically, the positive electrode terminal 605 and the negative electrode terminal 606 are provided on the upper surfaces of the power storage cells 111 of the upper module 6. In this embodiment, the positive electrode terminal 605 and the negative electrode terminal 606 protrude upward from the cell case 6a of the upper module 6. The cell case 6a includes an upper wall 6b and a lower wall that are disposed at an interval in the vertical direction (Z direction). A first smoke exhaust section 806 that exhausts gas from within the upper module 6 is formed in the upper wall 6b.

[0073] The positive electrode terminal 621 and the negative electrode terminal 622 are each an example of a "second terminal" in the present disclosure. The positive electrode terminal 621 and the negative electrode terminal 622 are disposed below the center of the power storage unit 110 in the vertical direction (Z direction). More specifically, the positive electrode terminal 621 and the negative electrode terminal 622 are provided on the lower surface of the power storage cell 111 of the lower module 3. In this embodiment, the positive electrode terminal 621 and the negative electrode terminal 622 protrude downward from the cell case 3a of the lower module 3. The cell case 3a includes an upper wall and a lower wall 3b disposed at an interval in the vertical direction (Z direction). A second smoke exhaust section 803 for exhausting gas from within the lower module 3 is formed in the lower wall 3b.

[0074] The power storage module M3 is provided with four terminals. More specifically, the power storage module M3 is provided with positive terminals 603 and 623 and negative terminals 604 and 624.

[0075] The positive electrode terminal 603 and the negative electrode terminal 604 are disposed above the center of the power storage unit 110 in the vertical direction (Z direction). More specifically, the positive electrode terminal 603 and the negative electrode terminal 604 are provided on the upper surface of the power storage cell 111 of the upper module 5. In this embodiment, the positive electrode terminal 603 and the negative electrode terminal 604 protrude upward from the cell case 5a of the upper module 5. The cell case 5a includes an upper wall 5b and a lower wall that are disposed at an interval in the vertical direction (Z direction). A first smoke exhaust section 805 that exhausts gas from within the upper module 5 is formed in the upper wall 5b.

[0076] The positive electrode terminal 623 and the negative electrode terminal 624 are disposed below the center of the energy storage unit 110 in the vertical direction (Z direction). More specifically, the positive electrode terminal 623 and the negative electrode terminal 624 are provided on the lower surface of the energy storage cell 111 of the lower module 4. In this embodiment, the positive electrode terminal 623 and the negative electrode terminal 624 protrude downward from the cell case 4a of the lower module 4. The cell case 4a includes an upper wall and a lower wall 4b disposed at an interval in the vertical direction (Z direction). A second smoke exhaust section 804 for exhausting gas from inside the lower module 4 is formed in the lower wall 4b.

[0077] Positive electrode terminals 607, 609, 611, 613, 615, 617 and negative electrode terminals 608, 610, 612, 614, 616, 618 (see FIG. 5) are provided on the upper surfaces of the corresponding storage cells 111 of the upper modules and protrude upward from the cell cases of the upper modules. Positive electrode terminals 625, 627, 629, 631, 633, 635 and negative electrode terminals 626, 628, 630, 632, 634, 636 (see FIG. 6) are provided on the lower surfaces of the corresponding storage cells 111 of the lower modules and protrude downward from the cell cases of the lower modules.

[0078] 6 and 7, a recess 50 recessed downward is formed in the bottom wall 921 of the lower case 92. The recess 50 is formed to extend in the X direction. The recess 50 is formed below the positive electrode terminal portions and negative electrode terminal portions of the lower modules 2 to 4, 8 to 10, and 14 to 16. The recess 50 includes grooves 51 to 56. The depth of the region of the recess 50 located on the front side of the vehicle 150 (see FIG. 1) is the same as the depth of the region of the recess 50 located on the rear side of the vehicle 150. In the present disclosure, "substantially the same" means that some error due to manufacturing variations and the like is included.

[0079] Groove portion 51 and groove portion 52 are each an example of a "first groove portion" in the present disclosure. Groove portion 51 is formed below positive electrode terminal portions 619, 625, and 631. Groove portion 51 is formed to extend in the X direction and includes a bottom surface 51a extending in the X direction. Groove portion 52 is formed below negative electrode terminal portions 620, 626, and 632. Groove portion 52 is formed to extend in the X direction and includes a bottom surface 52a extending in the X direction. Bottom surface 51a and bottom surface 52a are each an example of a "first bottom surface" in the present disclosure.

[0080] 6 to 8, groove 53 and groove 54 are each an example of a "second groove" in the present disclosure. Groove 53 is formed below positive electrode terminals 621, 627, and 633. Groove 53 is formed to extend in the X direction and includes a bottom surface 53a extending in the X direction. Groove 54 is formed below negative electrode terminals 622, 628, and 634. Groove 54 is formed to extend in the X direction and includes a bottom surface 54a extending in the X direction. Bottom surface 53a and bottom surface 54a are each an example of a "second bottom surface" in the present disclosure.

[0081] 6 and 7, groove 55 is formed below positive electrode terminal portions 623, 629, and 635. Groove 55 is formed to extend in the X direction and includes a bottom surface 55a extending in the X direction. Groove 56 is formed below negative electrode terminal portions 624, 630, and 636. Groove 56 is formed to extend in the X direction and includes a bottom surface 56a extending in the X direction.

[0082] 7, the distance r1 between the power storage module M1 and the sidewall 931 is shorter than the distance d1 between the positive electrode terminal portion 619 and the bottom surface 51a. The distance r1 between the power storage module M1 and the sidewall 931 is also shorter than the distance d2 between the negative electrode terminal portion 620 and the bottom surface 52a.

[0083] The distance r2 between the power storage module M1 and the reinforcing member 821 is shorter than the distance d1 between the positive electrode terminal portion 619 and the bottom surface 51a. The distance r2 between the power storage module M1 and the reinforcing member 821 is also shorter than the distance d2 between the negative electrode terminal portion 620 and the bottom surface 52a.

[0084] The distance r3 between the power storage module M2 and the reinforcing member 821 is shorter than the distance d3 between the positive electrode terminal 621 and the bottom surface 53a. The distance r3 between the power storage module M2 and the reinforcing member 821 is also shorter than the distance d4 between the negative electrode terminal 622 and the bottom surface 54a.

[0085] The distance r4 between the power storage module M2 and the reinforcing member 822 is shorter than the distance d3 between the positive electrode terminal 621 and the bottom surface 53a. The distance r4 between the power storage module M2 and the reinforcing member 822 is also shorter than the distance d4 between the negative electrode terminal 622 and the bottom surface 54a.

[0086] The distance r5 between the power storage module M3 and the reinforcing member 822 is shorter than the distance d5 between the positive electrode terminal portion 623 and the bottom surface 55a. The distance r5 between the power storage module M3 and the reinforcing member 822 is also shorter than the distance d6 between the negative electrode terminal portion 624 and the bottom surface 56a.

[0087] A distance r6 between the power storage module M3 and the sidewall 932 is shorter than a distance d5 between the positive electrode terminal 623 and the bottom surface 55a. In addition, the distance r6 between the power storage module M3 and the sidewall 932 is shorter than a distance d6 between the negative electrode terminal 624 and the bottom surface 56a.

[0088] 6 and 8, the power storage device 100 has a space formed therein that communicates with one end of the recessed portion 50 in the X direction and extends upward. In this embodiment, the power storage device 100 has a space S1 formed therein that communicates with a rear end of the recessed portion 50 in the X direction and extends upward. The rear end of the recessed portion 50 is the end of the two ends of the recessed portion 50 in the X direction that is located on the rear side of the vehicle 150 (see FIG. 1).

[0089] The rear end portion of each of the grooves 51 to 56 in the X direction communicates with the space S1. The rear end portion of each of the grooves 51 to 56 is the end, of the two ends of each of the grooves 51 to 56 in the X direction, that is located on the rear side of the vehicle 150. The rear end portion 53b shown in FIG. 8 is the end, of the two ends of the groove 53 in the X direction, that is located on the rear side of the vehicle 150. The volume of the space S1 is larger than the volume of each of the grooves 51 to 56.

[0090] The energy storage device 100 further includes a case smoke vent valve 85 (see FIG. 8) that discharges gas from within the energy storage device 100. The case smoke vent valve 85 may be configured as, for example, a check valve. The case smoke vent valve 85 is provided in the storage case 90. More specifically, the case smoke vent valve 85 is provided in a portion of the storage case 90 that defines the space S1. In this embodiment, the case smoke vent valve 85 is provided above the center of the storage case 90 in the up-down direction (Z direction) in the portion of the storage case 90 that defines the space S1. An imaginary line P2 shown in FIG. 8 indicates the center position of the storage case 90 in the up-down direction (Z direction). In the example shown in FIG. 8, the case smoke vent valve 85 is provided in the upper case 91 that defines the space S1.

[0091] The recess 50 and space S1 function as a smoke exhaust path for gas exhausted from the power storage modules M1 to M9 (see FIG. 4). More specifically, the recess 50 and space S1 function as a smoke exhaust path for gas exhausted mainly from the lower modules 2 to 4, 8 to 10, and 14 to 16. Gas exhausted from the lower modules 2 to 4, 8 to 10, and 14 to 16 flows mainly through the recess 50 to space S1 and is exhausted to the outside of the power storage device 100 through the case smoke exhaust valve 85. In contrast, gas exhausted from the upper modules 1, 5 to 7, 11 to 13, 17, and 18 (see FIG. 4) flows mainly above the upper modules to space S1 and is exhausted to the outside of the power storage device 100 through the case smoke exhaust valve 85. For example, as shown in FIG. 8, gas discharged from the upper module 6 flows mainly above the upper module 6 to the space S1 and is discharged from the case smoke exhaust valve 85 to the outside of the electricity storage device 100.

[0092] By forming the recess 50 below the terminal portion that is arranged below the center of the power storage unit 110 in the up-down direction (Z direction), the distance between the terminal portion and the accommodating case 90 (more specifically, the lower case 92) becomes longer. This makes it possible to prevent a short circuit path from being formed between the terminal portion and the accommodating case 90 (more specifically, the lower case 92) due to conductive foreign matter contained in the gas discharged from the power storage modules M1 to M9. It also makes it possible to prevent a short circuit path from being formed between the terminal portion and the accommodating case 90 (more specifically, the lower case 92) due to condensation water generated when the high-temperature power storage cells 111 are cooled.

[0093] The energy storage device 100 is formed with a space S1 that communicates with one end of the recess 50 in the X direction and extends upward, and the case smoke exhaust valve 85 is provided in a portion of the accommodating case 90 that defines the space S1, so that the recess 50 and the space S1 function as a smoke exhaust path for gas exhausted from the energy storage modules M1 to M9. Therefore, the gas exhausted from the energy storage modules M1 to M9 can be efficiently exhausted to the outside of the energy storage device 100.

[0094] Since the case smoke exhaust valve 85 is located above the center of the storage case 90 in the vertical direction (Z direction) in the part of the storage case 90 that defines the space S1, not only the gas discharged from the lower modules 2 to 4, 8 to 10, 14 to 16 but also the gas discharged from the upper modules 1, 5 to 7, 11 to 13, 17, 18 can be efficiently discharged outside the energy storage device 100.

[0095] Not only gas but also blast is discharged from the first smoke exhaust sections 801, 805-807, 811-813, 817, and 818 and the second smoke exhaust sections 802-804, 808-810, and 814-816 (see FIG. 4). Because the volume of the space S1 is larger than the volume of each of the groove sections 51-56, the blast discharged from the first smoke exhaust sections 801, 805-807, 811-813, 817, and 818 and the second smoke exhaust sections 802-804, 808-810, and 814-816 can be retained in the space S1. This prevents the blast from being discharged from the case smoke exhaust valve 85.

[0096] Due to the magnitude relationship between distances r1, r2, d1, and d2 (see FIG. 7), gas discharged from second smoke exhaust section 802 is more likely to be discharged to space S1 through grooves 51 and 52. This makes it possible to prevent gas discharged from second smoke exhaust section 802 from spreading into housing case 90 through the gap between power storage module M1 and side wall 931 or the gap between power storage module M1 and reinforcing member 821.

[0097] Due to the magnitude relationship between distances r3, r4, d3, and d4 (see FIG. 7), gas discharged from second smoke exhaust section 803 is more likely to be discharged to space S1 through grooves 53 and 54. This makes it possible to prevent gas discharged from second smoke exhaust section 803 from spreading into accommodating case 90 through the gap between power storage module M2 and reinforcing member 821 or the gap between power storage module M2 and reinforcing member 822.

[0098] Due to the magnitude relationship between distances r5, r6, d5, and d6 (see FIG. 7), gas discharged from second smoke exhaust section 804 is more likely to be discharged into space S1 through grooves 55 and 56. This makes it possible to prevent gas discharged from second smoke exhaust section 804 from passing through the gap between power storage module M3 and reinforcing member 822 or the gap between power storage module M3 and side wall 932 and spreading into housing case 90.

[0099] The sensor 70 will be described with reference to Fig. 6 and Fig. 9. Fig. 9 is a cross-sectional view of the power storage device 100 and the equipment unit 120 taken along line VIII-VIII in Fig. 5. As shown in Fig. 6, the sensor 70 includes sensors 71 to 76.

[0100] Each of the sensors 71 to 76 detects water. Each of the sensors 71 to 76 is provided at one end of the recessed portion 50 in the X direction. In this embodiment, each of the sensors 71 to 76 is provided at the rear end of the recessed portion 50 in the X direction. More specifically, the sensor 71 is provided at the rear end of the groove 51 in the X direction. The sensor 72 is provided at the rear end of the groove 52 in the X direction. The sensor 73 is provided at the rear end 53b of the groove 53 in the X direction (see FIG. 9). The sensor 74 is provided at the rear end of the groove 54 in the X direction. The sensor 75 is provided at the rear end of the groove 55 in the X direction. The sensor 76 is provided at the rear end of the groove 56 in the X direction. Each of the sensors 71 to 76 is disposed rearward of the center of the power storage device 100 in the X direction with respect to the vehicle 150 (see FIG. 1). An imaginary line P3 shown in FIG. 9 indicates the center position of the power storage device 100 in the X direction.

[0101] The equipment unit 120 is disposed above the power storage device 100 and is disposed rearward of the center of the power storage device 100 in the X direction of the vehicle 150. The equipment unit 120 includes an electronic control unit 121 and a junction box 122. The electronic control unit 121 is an example of "electrical equipment" in the present disclosure. The electronic control unit 121 is disposed above the power storage device 100 and is disposed rearward of the center of the power storage device 100 in the X direction of the vehicle 150. The electronic control unit 121 is connected to each of the sensors 71 to 76. The electronic control unit 121 receives a notification from each of the sensors 71 to 76 notifying that water has been detected, and controls the power storage device 100 based on the notification.

[0102] By providing sensors 71-76 in the grooves 51-56, respectively, it is possible to quickly detect condensed water that has accumulated in the grooves. As the vehicle 150 accelerates, the condensed water that has accumulated in each of the grooves 51-56 moves to the rear end of each of the grooves 51-56 in the X direction. Therefore, by providing sensors 71-76 at the rear end of the recess 50 in the X direction, it is possible to quickly detect condensed water.

[0103] Furthermore, by arranging both electronic control unit 121 and sensors 71 to 76 rearward of vehicle 150 relative to the center of power storage device 100 in the X direction, wiring between each of sensors 71 to 76 and electronic control unit 121 becomes easier.

[0104] As described above, in this embodiment, the recess 50 is formed below the terminal portion that is disposed below the center of the power storage unit 110 in the up-down direction (Z direction). This increases the distance between the terminal portion and the accommodating case 90 (more specifically, the lower case 92). This makes it possible to prevent a short circuit path from being formed between the terminal portion and the accommodating case 90 (more specifically, the lower case 92) due to conductive foreign matter contained in the gas discharged from the power storage modules M1 to M9. Furthermore, it is possible to prevent a short circuit path from being formed between the terminal portion and the accommodating case 90 (more specifically, the lower case 92) due to condensation water generated when the high-temperature power storage cells 111 are cooled.

[0105] In the above embodiment, the power storage unit 110 includes 18 terminal portions as terminal portions arranged below the center of the power storage unit 110 in the vertical direction (Z direction), but this is not limited to this. The power storage unit 110 only needs to include at least one terminal portion as a terminal portion arranged below the center of the power storage unit 110 in the vertical direction (Z direction), and the recess 50 only needs to be formed below the at least one terminal portion.

[0106] [Variation 1] Each of the first smoke exhaust sections 801, 805 to 807, 811 to 813, 817, and 818 may be a cell smoke exhaust valve provided in the power storage cell 111. Furthermore, each of the first smoke exhaust sections 801, 805 to 807, 811 to 813, 817, and 818 may have a smoke exhaust port covered with a resin member or the like, and may be configured so that the resin member breaks when the temperature or pressure becomes high.

[0107] Each of the second smoke exhaust sections 802 to 804, 808 to 810, and 814 to 816 may be a cell smoke exhaust valve provided in the power storage cell 111. Furthermore, each of the second smoke exhaust sections 802 to 804, 808 to 810, and 814 to 816 may have a smoke exhaust port covered with a resin member or the like, and may be configured so that the resin member breaks when the temperature or pressure becomes high.

[0108] [Variation 2] Instead of the space S1, the energy storage device 100 may have a front space that communicates with the front end of the recess 50 in the X direction and extends upward. The front end of the recess 50 is the end of the two ends of the recess 50 in the X direction that is located closer to the front of the vehicle 150. When the energy storage device 100 has the front space, the front end of each of the grooves 51 to 56 communicates with the front space. The front end of each of the grooves 51 to 56 is the end of the two ends of each of the grooves 51 to 56 in the X direction that is located closer to the front of the vehicle 150. The front end 53c shown in FIG. 8 is the end of the two ends of the groove 53 in the X direction that is located closer to the front of the vehicle 150. The volume of the front space is larger than the volume of each of the grooves 51 to 56. The case smoke exhaust valve 85 may be provided in a portion of the housing case 90 that defines the front space.

[0109] The front space is formed in the energy storage device 100, and the case smoke exhaust valve 85 is provided in a portion of the accommodating case 90 that defines the front space, so that the recess 50 and the front space function as a smoke exhaust path for gas exhausted from the energy storage modules M1 to M9. Therefore, the gas exhausted from the energy storage modules M1 to M9 can be efficiently exhausted to the outside of the energy storage device 100.

[0110] [Variation 3] Each of the sensors 71 to 76 may be provided at the front end portion in the X direction of the recessed portion 50. As an example, the sensor 73 may be provided at the front end portion 53c of the groove portion 53 in the X direction (see FIG. 8).

[0111] As the vehicle 150 decelerates, the condensed water accumulated in each of the grooves 51 to 56 moves to the front end of each of the grooves 51 to 56. Therefore, by providing each of the sensors 71 to 76 at the front end of the recess 50 in the X direction, the condensed water can be detected quickly.

[0112] It should be noted that sensors for detecting water may be provided at both the front end of the recess 50 in the X direction and the rear end of the recess 50 in the X direction.

[0113] [Variation 4] Fig. 10 is a cross-sectional view taken along the front-rear direction of the vehicle of a power storage device according to Modification 4. Fig. 10 shows a cross-sectional view taken along line VIII-VIII (see Fig. 5) when a power storage device 100A according to Modification 4 is used instead of power storage device 100.

[0114] Energy storage device 100A according to modification 4 differs from energy storage device 100 in the position of case smoke vent valve 85. In energy storage device 100A according to modification 4, case smoke vent valve 85 is provided at the center of storage case 90 in the up-down direction (Z direction) in a portion of storage case 90 that defines space S1. Virtual line P4 indicates the position of the center of storage case 90 in the up-down direction (Z direction) in modification 4. In the example shown in FIG. 10 , case smoke vent valve 85 is provided in lower case 92 that defines space S1.

[0115] Since the case smoke exhaust valve 85 is located in the center of the storage case 90 in the vertical direction (Z direction) in the part of the storage case 90 that defines the space S1, not only the gas discharged from the lower modules 2 to 4, 8 to 10, 14 to 16 (see Figure 4), but also the gas discharged from the upper modules 1, 5 to 7, 11 to 13, 17, 18 (see Figure 4) can be efficiently discharged outside the energy storage device 100A.

[0116] [Variation 5] Fig. 11 is a cross-sectional view taken along the front-rear direction of the vehicle of a power storage device according to Modification 5. Fig. 11 shows a cross-sectional view taken along line VIII-VIII (see Fig. 5) when a power storage device 100B according to Modification 5 is used instead of power storage device 100.

[0117] Energy storage device 100B according to Modification 5 differs from energy storage device 100 in the position of case smoke vent valve 85. In energy storage device 100B according to Modification 5, case smoke vent valve 85 is provided in a portion of storage case 90 that defines space S1, below the center of storage case 90 in the up-down direction (Z direction). Virtual line P5 indicates the center position of storage case 90 in the up-down direction (Z direction) in Modification 5. In the example shown in FIG. 11 , case smoke vent valve 85 is provided in lower case 92 that defines space S1.

[0118] The case smoke exhaust valve 85 is located below the center of the storage case 90 in the vertical direction (Z direction) in the portion of the storage case 90 that defines the space S1, so that gas discharged from the lower modules 2 to 4, 8 to 10, 14 to 16 (see Figure 4) can be efficiently discharged outside the energy storage device 100B.

[0119] [Variation 6] Fig. 12 is a cross-sectional view taken along the front-rear direction of the vehicle of a power storage device according to Modification 6. Fig. 12 shows a cross-sectional view taken along line VIII-VIII (see Fig. 5) when a power storage device 100C according to Modification 6 is used instead of power storage device 100.

[0120] The power storage device 100C according to the sixth modification differs from the power storage device 100 in that the power storage device 100C is provided with a power storage unit 110C instead of the power storage unit 110 (see FIG. 4), and in the position of the case smoke exhaust valve 85. The power storage device 100C includes a power storage unit 110C instead of the power storage unit 110. The power storage unit 110C includes only lower modules 2 to 4, 8 to 10, and 14 to 16 (see FIG. 4) as power storage modules. As described above, a second smoke exhaust section (for example, second smoke exhaust sections 802 to 804, 808 to 810, and 814 to 816 shown in FIG. 4) that exhausts gas from within the lower module is formed on the lower surface of each of the lower modules 2 to 4, 8 to 10, and 14 to 16. The second smoke exhaust sections 802 to 804, 808 to 810, and 814 to 816 in the sixth modification are examples of the "smoke exhaust section" in the present disclosure.

[0121] In a power storage device 100C according to the sixth modification, the case smoke exhaust valve 85 is provided in a portion of the storage case 90 that defines the space S1, below the center of the storage case 90 in the up-down direction (Z direction). An imaginary line P6 indicates the position of the center of the storage case 90 in the up-down direction (Z direction) in the sixth modification. In the example shown in FIG. 12, the case smoke exhaust valve 85 is provided in a lower case 92 that defines the space S1.

[0122] The case smoke exhaust valve 85 is located below the center of the storage case 90 in the vertical direction (Z direction) in the portion of the storage case 90 that defines the space S1, so that gas discharged from the lower modules 2 to 4, 8 to 10, and 14 to 16 can be efficiently discharged outside the energy storage device 100C.

[0123] [Variation 7] Fig. 13 is a cross-sectional view along the front-rear direction of the vehicle of a power storage device according to Modification 7. Fig. 13 shows a cross-sectional view taken along line VIII-VIII (see Fig. 5) when a power storage device 100D according to Modification 7 is used instead of power storage device 100. An imaginary line P7 indicates the center position of storage case 90 in the up-down direction (Z direction) in Modification 7.

[0124] Energy storage device 100D according to the seventh modification differs from energy storage device 100 in that recess 50A is formed in bottom wall 921 of lower case 92 instead of recess 50. Recess 50A differs from recess 50 in that the depth of a region of recess 50A located on the front side of vehicle 150 is different from the depth of a region of recess 50A located on the rear side of vehicle 150.

[0125] The recess 50A is formed to extend in the X direction. The recess 50A includes a first region 531 having a first depth d11 and a second region 532 having a second depth d12 deeper than the first depth d11. The recess 50A includes six grooves instead of the grooves 51 to 56. Each of the six grooves includes a first region 531 having the first depth d11 and a second region 532 having a second depth d12 deeper than the first depth d11. FIG. 13 shows a groove 53A instead of the groove 53. The groove 53A includes a first region 531 having the first depth d11 and a second region 532 having a second depth d12 deeper than the first depth d11. The second region 532 is located further rearward of the first region 531 with respect to the vehicle 150 (see FIG. 1).

[0126] While the vehicle 150 is traveling, conductive foreign matter contained in the gas discharged from the power storage modules M1 to M9 tends to accumulate on the rear side of the vehicle 150. Furthermore, while the vehicle 150 is traveling, condensed water in the recess 50A tends to accumulate on the rear side of the vehicle 150. Therefore, since the depth of the region of the recess 50A located on the rear side of the vehicle 150 is deeper than the depth of the region of the recess 50A located on the front side of the vehicle 150, it is possible to prevent a short circuit from being formed between the terminal portion and the accommodating case 90 (more specifically, the lower case 92).

[0127] 4 to 6, the electric potential of the electric storage module is higher as it is positioned closer to the rear of the vehicle 150. The electric storage module with a higher potential is more likely to short-circuit between the terminal portion and the accommodating case 90 (more specifically, lower case 92). Therefore, by making the depth of the region of the recess 50A located on the rear side of the vehicle 150 deeper than the depth of the region of the recess 50A located on the front side of the vehicle 150, it is possible to prevent a short-circuit path from being formed between the terminal portion and the accommodating case 90 (more specifically, lower case 92).

[0128] The depth of the recess 50A may be gradually increased toward the rear of the vehicle 150.

[0129] [Variation 8] The energy storage device according to Modification 8 differs from the energy storage device 100 in the form of the energy storage cell. In the above embodiment, the energy storage cell 111 includes a battery body and a cell can that houses the battery body. In contrast, in Modification 8, the energy storage cell is a laminate cell as shown in FIG.

[0130] FIG. 14 is a side view of a storage cell included in a power storage device according to Modification 8. The storage cell 111E is an example of a storage cell included in the power storage device according to Modification 8. The storage cell 111E is a laminate cell having a rectangular parallelepiped shape that is long in the Y direction. More specifically, the storage cell 111E has a cell main body 111c and a laminate film 111d. The laminate film 111d encases the cell main body 111c. The laminate film 111d has welded portions 111e (hatched portions in FIG. 14) formed by welding edges of the laminate film 111d together. The welded portions 111e are formed at the Y1-side end, the Y2-side end, and the Z1-side end of the laminate film 111d.

[0131] The welded portion 111e on the Y1 side is formed to extend along the Z direction and has a length L1 in the Z direction. The welded portion 111e on the Y2 side is formed to extend along the Z direction and has a length L2 in the Z direction. The welded portion 111e on the Z1 side is formed to extend along the Y direction and has a length L3 in the Y direction. The length L3 is greater than both the length L1 and the length L2 (for example, five times or more).

[0132] A positive electrode terminal 111a is provided at one end of the storage cell 111E in the Y direction, and a negative electrode terminal 111b is provided at the other end of the storage cell 111E in the Y direction.

[0133] In the energy storage device according to the eighth modification, a plurality of energy storage cells 111E are arranged side by side in the X direction in each of the upper modules 1, 5 to 7, 11 to 13, 17, and 18 and the lower modules 2 to 4, 8 to 10, and 14 to 16 (see FIG. 4).

[0134] Each storage cell 111E may be a laminated cell having a rectangular parallelepiped shape that is long in the X direction. In that case, in each of the upper modules 1, 5 to 7, 11 to 13, 17, and 18 and the lower modules 2 to 4, 8 to 10, and 14 to 16, the multiple storage cells 111E are arranged side by side in the Y direction.

[0135] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0136] 1, 5-7, 11-13, 17, 18 upper module, 1a, 2a, 3a, 4a, 5a, 6a cell case, 1b, 5b, 6b upper wall, 2-4, 8-10, 14-16 lower module, 2b, 3b, 4b lower wall, 31, 32, 33 cooler, 50, 50A recess, 51, 52, 53, 53A, 54, 55, 56 groove, 51a, 52a, 53a, 54a, 55a, 56a bottom, 53b rear end, 53c front end, 70-76 sensor, 85 case smoke exhaust valve, 90 storage case, 91 upper case, 92 lower case, 100, 100A, 100B, 100C, 100D energy storage device, 110, 110C Energy storage unit, 111, 111E energy storage cell, 111a positive terminal, 111b negative terminal, 111c cell main body, 111d laminate film, 111e welding part, 120 equipment unit, 121 electronic control unit, 122 junction box, 150 vehicle, 211 to 215, 221 to 225, 231 to 235, 251, 252 bus bar, 531 first area, 532 second area, 601, 603, 605, 607, 609, 611, 613, 615, 617, 619, 621, 623, 625, 627, 629, 631, 633, 635 Positive terminal, 602,604,606,608,610,612,614,616,618,620,622,624,626,628,630,632,634,636 Negative electrode terminal section, 801,805,806,807,811,812,813,817,818 First smoke exhaust section, 802~804,808~810,814~816 Second smoke exhaust section, 811~814,821~826 Reinforcement member, 921 Bottom wall, 922 Peripheral wall, 931~934 Side wall, L1, L2, L3 length, M1, M2, M3, M4, M5, M6, M7, M8, M9 Storage module, P1, P2, P3, P4, P5, P6, P7 virtual line, S1 space, d1, d2, d3, d4, d5, d6, r1, r2, r3, r4, r5, r6 distance, d11 first depth, d12 second depth.

Claims

1. A power storage unit; a storage case that stores the power storage unit, the storage case includes an upper case and a lower case disposed below the upper case, the lower case includes a bottom wall and a peripheral wall extending from a peripheral edge of the bottom wall, A recess recessed downward is formed in the bottom wall, the power storage unit includes at least one terminal portion that is arranged below a center of the power storage unit in the up-down direction, The recess is formed below the at least one terminal portion.

2. The power storage device is mounted on a vehicle, The power storage device further includes a case smoke exhaust valve provided in the housing case and configured to exhaust gas from within the power storage device, The recess is formed to extend in the front-rear direction of the vehicle, a space is formed in the power storage device, the space being in communication with one end of the recess in the front-rear direction of the vehicle and extending upward; The power storage device according to claim 1 , wherein the case smoke exhaust valve is provided in a portion of the storage case that defines the space.

3. the power storage unit includes a power storage module; The storage module includes: an upper module; a lower module disposed below the upper module, a first smoke exhaust section for exhausting gas from within the upper module is formed on an upper surface of the upper module; a second smoke exhaust section for exhausting gas from within the lower module is formed on the lower surface of the lower module; The power storage device according to claim 2 , wherein the case smoke exhaust valve is provided at a center of the storage case or above a center of the storage case in the up-down direction.

4. the power storage unit includes a power storage module; a smoke exhaust section for exhausting gas from within the power storage module is formed on the lower surface of the power storage module, The power storage device according to claim 2 , wherein the case smoke exhaust valve is provided below a center of the storage case in the up-down direction.

5. The power storage device is mounted on a vehicle, the power storage device further includes a sensor that detects water; The recess is formed to extend in the front-rear direction of the vehicle, The power storage device according to claim 1 , wherein the sensor is provided at one end of the recess in the front-rear direction of the vehicle.

6. the vehicle includes an electrical device connected to the sensor; the electrical device is disposed above the power storage device and is disposed rearward of the vehicle relative to a center of the power storage device in a front-to-rear direction of the vehicle, The power storage device according to claim 5 , wherein the one end is a rear end of the recess in the front-rear direction of the vehicle.

7. The power storage device is mounted on a vehicle, the peripheral wall includes a first side wall and a second side wall spaced apart in a width direction of the vehicle, The power storage unit is a first power storage module; a second power storage module arranged at a distance from the first power storage module in the width direction of the vehicle, The at least one terminal portion is a first terminal portion provided on the first power storage module; a second terminal portion provided on the second power storage module, The power storage device is a first reinforcing member provided in the lower case and formed to protrude upward from the bottom wall; a second reinforcing member provided in the lower case, formed to protrude upward from the bottom wall, and disposed at a distance from the first reinforcing member in the width direction of the vehicle, the first reinforcing member and the second reinforcing member are formed to extend in the front-rear direction of the vehicle, the first side wall, the first electricity storage module, the first reinforcing member, the second electricity storage module, the second reinforcing member, and the second side wall are arranged in this order along a width direction of the vehicle, The recessed portion is a first groove portion formed below the first terminal portion; a second groove portion formed below the second terminal portion, the first groove portion is formed to extend in a front-rear direction of the vehicle and includes a first bottom surface extending in the front-rear direction of the vehicle, the second groove portion is formed to extend in a front-rear direction of the vehicle and includes a second bottom surface extending in the front-rear direction of the vehicle, a distance between the first power storage module and the first side wall is shorter than a distance between the first terminal portion and the first bottom surface; a distance between the first power storage module and the first reinforcing member is shorter than a distance between the first terminal portion and the first bottom surface; a distance between the second power storage module and the first reinforcing member is shorter than a distance between the second terminal portion and the second bottom surface; The power storage device according to claim 1 , wherein a distance between the second power storage module and the second reinforcing member is shorter than a distance between the second terminal portion and the second bottom surface.

8. The power storage device is mounted on a vehicle, The recess is formed to extend in the front-rear direction of the vehicle, the recess includes a first region having a first depth and a second region having a second depth greater than the first depth; The power storage device according to claim 1 , wherein the second region is located rearward of the vehicle relative to the first region.

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