Power storage device and vehicle mounting structure for said power storage device

Abstract

Provided is a power storage device of which the internal space utilization efficiency is improved. A power storage device (1) according to one embodiment of the present disclosure is provided with: a first battery cell and a second battery cell that are arranged in a first direction; and a reinforcement member (4) disposed between the first battery cell and the second battery cell. The first battery cell and the second battery cell are each provided with a pair of electrode terminals respectively disposed on a pair of surfaces opposite each other in the first direction. The power storage device (1) is provided with a conductive member that is connected to one of the pair of electrode terminals of the first battery cell. The conductive member overlaps the reinforcement member (4) when viewed from the vertical direction.

Description

Electricity storage device and vehicle mounting structure for said electricity storage device

[0001] The present disclosure relates to an electricity storage device and a vehicle mounting structure for the electricity storage device.

[0002] For example, the energy storage device of Patent Document 1 has a configuration in which the inside of the case is divided into multiple spaces by cross beams and vertical beams, and battery modules are housed in these spaces and fixed to the cross beams or vertical beams with screws or the like.

[0003] Japanese Patent Application Laid-Open No. 2023-134546

[0004] The present applicant has found the following problem: In the electricity storage device of Patent Document 1, for example, the space above the vertical beam is not effectively utilized, and there is room for further improvement in the space utilization efficiency inside the electricity storage device.

[0005] The present disclosure has been made in consideration of such problems, and provides an electricity storage device and a vehicle mounting structure for the electricity storage device that contribute to improving the efficiency of space utilization inside the electricity storage device.

[0006] An energy storage device according to one aspect of the present disclosure comprises: a first battery cell and a second battery cell aligned in a first direction; and a first reinforcement member disposed between the first battery cell and the second battery cell, wherein the first battery cell and the second battery cell each have a pair of electrode terminals disposed on a pair of surfaces facing each other in the first direction; the energy storage device comprises a first conductive member connected to one of the pair of electrode terminals of the first battery cell; and the first conductive member overlaps with the first reinforcement member when viewed from the top-bottom direction.

[0007] The above-mentioned energy storage device preferably includes a second conductive member connected to one of a pair of electrode terminals of the second battery cell that faces the first battery cell in the first direction, and the second conductive member preferably overlaps with the first reinforcement member when viewed from the top-bottom direction.

[0008] The above-mentioned energy storage device includes a third battery cell arranged alongside the first battery cell in a second direction perpendicular to the first direction and the vertical direction, and having a pair of electrode terminals arranged on opposing surfaces in the first direction, and it is preferable that the first conductive member is connected to one of the pair of electrode terminals of the third battery cell.

[0009] The above-mentioned energy storage device comprises: a fourth battery cell having a pair of electrode terminals arranged on a pair of surfaces facing each other in the first direction; a second reinforcement member arranged between the first battery cell and the fourth battery cell; and a third conductive member connected to the other electrode terminal of the first battery cell, wherein it is preferable that the first battery cell is arranged between the second battery cell and the fourth battery cell in the first direction, and the third conductive member overlaps with the second reinforcement member when viewed from the top-bottom direction.

[0010] The above-mentioned energy storage device preferably includes an equipment base that is disposed above the first battery cell and on which an electronic device is disposed, and the equipment base preferably overlaps with the first reinforcement member when viewed from the vertical direction.

[0011] The above-described power storage device preferably includes a rigid member that overlaps the first reinforcement member when viewed from a second direction perpendicular to the first direction and the up-and-down direction and extends in the second direction.

[0012] The above-mentioned energy storage device preferably includes a first cover arranged below the first battery cell, and the first cover preferably extends in a second direction perpendicular to the first direction and the vertical direction, and has a downwardly convex rib.

[0013] The above-mentioned energy storage device preferably includes: a second cover disposed above the first battery cell; and a load transmission member connecting the first cover and the second cover between the first battery cell and the second battery cell.

[0014] In the above-described power storage device, it is preferable that the load transmission member is connected to the second cover via the first reinforcement member.

[0015] In the above-described electricity storage device, the load transmitting member preferably has insulating properties.

[0016] The above-described power storage device preferably includes: a third cover disposed below the first cover; and a connecting member connecting the first cover and the third cover.

[0017] In the above-described power storage device, the first battery cell preferably includes a safety valve at a portion that overlaps with a rib of the first cover when viewed in the up-down direction.

[0018] In the above-mentioned energy storage device, it is preferable that the distance between the first reinforcement member and the surface on which the one electrode terminal of each of the first battery cell and the second battery cell is arranged in the first direction is narrower than the distance between the first conductive member and the second conductive member.

[0019] In the above-described power storage device, it is preferable that the sum of the thickness of the first conductive member and the thickness of the second conductive member in the first direction is smaller than the width dimension of the first reinforcement member.

[0020] In the above-described energy storage device, it is preferable that the first battery cell includes a safety valve on a surface of the first battery cell on which the one electrode terminal is arranged, and that the safety valve overlaps with the first reinforcement member when viewed from the first direction.

[0021] In the above-described electricity storage device, it is preferable that the first reinforcement member has a hollow structure and has an opening in a portion facing the safety valve.

[0022] In the above-described electricity storage device, the opening is preferably covered with a heat insulating member.

[0023] In the above-described electricity storage device, the heat insulating member preferably includes an easily breakable portion.

[0024] In the vehicle mounting structure for the above-mentioned storage battery device, at least one of the fixing points arranged in the first direction and a second direction perpendicular to the vertical direction at the fixing points between the storage battery device and a vehicle frame member of the vehicle overlaps with the first reinforcement member in the vertical direction when viewed from the second direction.

[0025] In the vehicle mounting structure for the above-mentioned storage device, it is preferable that the fixing points on both sides of the fixing points aligned in the second direction at the fixing points between the storage device and the vehicle frame member of the vehicle overlap with the first reinforcement member in the vertical direction when viewed from the second direction.

[0026] According to the present disclosure, it is possible to realize an electricity storage device and a vehicle mounting structure for the electricity storage device that contribute to improving the efficiency of space utilization inside the electricity storage device.

[0027] 1 is a diagram showing a state in which the energy storage device of Embodiment 1 is mounted on a vehicle. FIG. 2 is an exploded view showing a simplified version of the energy storage device of Embodiment 1. FIG. 3 is an XZ cross-sectional view of the energy storage device of Embodiment 1. FIG. 4 is a YZ cross-sectional view of the energy storage device of Embodiment 1. FIG. 5 is a view showing an arrangement of battery modules, reinforcement members, and rigid members of the energy storage device of Embodiment 1, as viewed from the Z-axis + side. FIG. 6 is a view for explaining an arrangement of battery modules and reinforcement members of Embodiment 1. FIG. 7 is a view showing a representative example of a load transmission member in the energy storage device of Embodiment 1. FIG. 8 is a perspective view showing a state in which rigid members are fixed to a lower case in the energy storage device of Embodiment 1. FIG. 9 is a perspective view showing the energy storage device and a frame of Embodiment 1. FIG. 10 is a view showing an arrangement of safety valves of battery cells and openings of reinforcement members in the energy storage device of Embodiment 2, as viewed from the X-axis + side. FIG. 11 is a view showing an arrangement of safety valves of battery cells and openings of reinforcement members in the energy storage device of Embodiment 2, as viewed from the Y-axis + side. FIG. 12 is a perspective view for explaining a configuration of a heat insulating member in the energy storage device of Embodiment 2. FIG. 13 is a view showing another representative example of a load transmission member.

[0028] Specific embodiments to which the present disclosure is applied will be described in detail below with reference to the drawings. However, the present disclosure is not limited to the following embodiments. For clarity of explanation, the following description and drawings have been simplified as appropriate. For clarity of explanation, the following description will be made using a three-dimensional (XYZ) coordinate system.

[0029] <First Embodiment> Fig. 1 is a diagram showing a state in which a power storage device of this embodiment is mounted on a vehicle. Power storage device 1 is suitable as a power storage device mounted on vehicle 100, for example, as shown in Fig. 1. Here, the + side of the X axis is the front side of vehicle 100, and the - side of the X axis is the rear side of vehicle 100. The + side of the Y axis is the left side of vehicle 100, and the - side of the Y axis is the right side of vehicle 100. The + side of the Z axis is the upper side of vehicle 100, and the - side of the Z axis is the lower side of vehicle 100. In other words, it is assumed that vehicle 100 is placed on a horizontal plane.

[0030] Fig. 2 is an exploded view showing a simplified view of the energy storage device of the present embodiment. Fig. 3 is an XZ cross-sectional view of the energy storage device of the present embodiment. Fig. 4 is a YZ cross-sectional view of the energy storage device of the present embodiment. Fig. 5 is a view of the arrangement of the battery modules, reinforcement members, and rigid members of the energy storage device of the present embodiment as seen from the Z axis + side. Fig. 6 is a view for explaining the arrangement of the battery modules and reinforcement members of the present embodiment.

[0031] As shown in Figures 2 to 5, the energy storage device 1 includes a battery module 2, a pack case 3, reinforcement members 4, load transmission members 5, a shear panel (third cover) 6, connection members 7, rigid members 8, electronic devices 9, an equipment base 10, and a cover 11.

[0032] 3 and 4, the battery module 2 includes a plurality of battery cells 21. The battery cell 21 is formed by housing an electrode body inside a battery case 22 as shown in FIG.

[0033] 4 and 6, a first electrode terminal 23, either a positive electrode terminal or a negative electrode terminal, is provided at the end on the + side of the Y axis of the battery case 22, and a second electrode terminal 24, either a positive electrode terminal or a negative electrode terminal, is provided at the end on the - side of the Y axis of the battery case 22. In this case, a safety valve 25 for venting ejected matter such as gas from the battery case 22 is preferably provided at the end on the - side of the Z axis of the battery case 22.

[0034] Such battery cells 21 are stacked in the X-axis direction so that the positive electrode terminals and negative electrode terminals are alternately arranged in the X-axis direction (second direction) on each of the Y-axis + side and Y-axis - side of the battery module 2.

[0035] As shown in FIG. 6, on the positive side of the Y axis of the battery module 2, the first electrode terminals 23 adjacent in the X axis direction are electrically connected by a first bus bar 26, which is a typical example of a conductive member.

[0036] 6, on the negative Y-axis side of the battery module 2, the second electrode terminals 24 adjacent to each other in the X-axis direction are electrically connected by a second bus bar 27, which is a representative example of a conductive member. As a result, the multiple battery cells 21 are electrically connected in series.

[0037] 2 to 5, the pack case 3 houses the battery module 2. The pack case 3 includes an upper case (second cover) 31 and a lower case (first cover) 32.

[0038] As shown in Figures 2 to 4, for example, the upper case 31 includes a storage section 31a that protrudes toward the +Z axis side and has an internal space capable of storing the battery module 2, and a flange section 31b that protrudes outward from the periphery of the storage section 31a.

[0039] As shown in Figures 2 to 4, for example, the lower case 32 has a storage section 32a that is recessed toward the negative Z-axis side and has an internal space capable of storing the battery module 2, and a flange section 32b that protrudes outward from the periphery of the storage section 32a.

[0040] The negative sidewall portion 32c of the housing portion 32a of the lower case 32 on the X-axis side may be disposed substantially parallel to the YZ plane, as shown in Fig. 3. The negative side of the X-axis in the flange portion 32b of the lower case 32 may be provided with a flat portion 32d to which the rigid member 8 (described later) can be fixed.

[0041] 4, the lower case 32 may include a first rib 32e and a second rib 32f. The first rib 32e is, for example, a recessed portion that is convex toward the negative side of the Z axis and extends in the X axis direction. The first ribs 32e are arranged at intervals in the Y axis direction.

[0042] 4, the second ribs 32f are recesses that are convex toward the negative side of the Z axis and extend in the X axis direction. The second ribs 32f are disposed between the first ribs 32e in the Y axis direction, for example.

[0043] By providing the accommodation portion 32a of the lower case 32 with the first rib 32e and the second rib 32f in this manner, the bending rigidity of the lower case 32, and therefore of the energy storage device 1, about the Y axis can be improved.

[0044] 2 and 6, the battery modules 2 are arranged at a predetermined interval in the Y-axis direction (first direction) inside the accommodation portion 31a of the upper case 31 and the accommodation portion 32a of the lower case 32, and the flange portion 31b of the upper case 31 and the flange portion 32b of the lower case 32 are joined with an adhesive member. Preferably, three or more battery modules 2 are arranged in the Y-axis direction.

[0045] 4, the first rib 32e may be arranged to overlap at least a portion of the safety valve 25 of the battery cell 21 of each battery module 2 when viewed from the Z-axis direction. This allows the first rib 32e to function as a discharge path for ejected material discharged from the safety valve 25 of the battery cell 21. The ejected material may be discharged to the outside via a discharge valve provided in the pack case 3.

[0046] 4, the second ribs 32f may be disposed between adjacent battery modules 2 in the Y-axis direction when viewed from the X-axis direction. In other words, the battery modules 2 are disposed between the second ribs 32f adjacent to each other in the Y-axis direction.

[0047] The reinforcement members 4 are rigid members that receive a load in the X-axis direction when the load is input to the energy storage device 1. As shown in Figures 4 to 6, the reinforcement members 4 are disposed between the battery modules 2 adjacent in the Y-axis direction in the space on the negative Z-axis side of the first bus bar 26 and the second bus bar 27 that face each other in the Y-axis direction, and extend in the X-axis direction.

[0048] For example, as shown in FIG. 3, it is preferable that the end of the reinforcement member 4 on the positive side of the X-axis reaches the vicinity of the end of the accommodation portion 32a of the lower case 32 on the positive side of the X-axis, and the end of the reinforcement member 4 on the negative side of the X-axis reaches the vicinity of the end of the accommodation portion 32a of the lower case 32 on the negative side of the X-axis.

[0049] As shown in FIG. 4, for example, the reinforcement member 4 is generally hat-shaped with a protruding portion 4a that protrudes toward the +Z-axis side when viewed from the X-axis direction, and the end portion of the reinforcement member 4 on the -Z-axis side is fixed to the surface on the +Z-axis side of the accommodation portion 32a of the lower case 32.

[0050] This can improve the rigidity in the X-axis direction of the energy storage device 1. Furthermore, the reinforcement member 4 can function as a reinforcing member for the lower case 32, improving the bending rigidity of the lower case 32, and therefore the energy storage device 1, about the Y-axis.

[0051] At this time, the protrusion 4a of the reinforcement member 4 is arranged, for example, as shown in Figure 6, between adjacent battery modules 2 in the Y-axis direction, and is arranged so as to overlap at least a portion of the first bus bar 26 and the second bus bar 27 that face each other in the Y-axis direction when viewed from the Z-axis direction.

[0052] This can improve the space utilization efficiency of the space on the +Z-axis side of the reinforcement member 4, and contribute to the miniaturization of the energy storage device 1. However, the shape of the reinforcement member 4 is not limited, and it may be any member that is long in the X-axis direction.

[0053] 4, the negative side portion of the reinforcement member 4 on the Z axis may be housed in the second rib 32f of the housing portion 32a of the lower case 32. This allows the area on the positive side of the Z axis of the housing portion 32a of the lower case 32, where the battery module 2 is disposed, to be flattened.

[0054] As shown in FIG. 6 , the distance C1 between the protrusion 4 a of the reinforcement member 4 and the surface of the battery cell 21 on the side where the first electrode terminal 23 of the battery case 22 is arranged, and the distance C2 between the protrusion 4 a of the reinforcement member 4 and the surface of the battery cell 21 on the side where the second electrode terminal 24 of the battery case 22 is arranged, are preferably narrower than the distance C3 between the first bus bar 26 and the second bus bar 27 that face each other in the Y-axis direction.

[0055] As shown in Figure 6, in the Y-axis direction, it is preferable that the sum of the thickness T1 of the first bus bar 26 and the thickness T2 of the second bus bar 27 that face each other in the Y-axis direction is smaller than the width dimension W1 of the protrusion 4a of the reinforcement member 4.

[0056] As a result, when a load is input to the energy storage device 1 from the Y-axis direction and the battery modules 2 are pushed in the Y-axis direction, the battery cells 21 can be brought into contact with the protrusions 4a of the reinforcement members 4 before the first bus bars 26 and the second bus bars 27 that face each other in the Y-axis direction come into contact with each other. This makes it possible to prevent short circuits between adjacent battery modules 2 in the Y-axis direction.

[0057] The load transmission member 5 transmits a load between the upper case 31 and the lower case 32. For example, as shown in FIG. 4 , the load transmission member 5 is disposed between the battery modules 2 adjacent to each other in the Y-axis direction and extends in the X-axis direction.

[0058] The load transmission member 5 has a substantially T-shape when viewed from the X-axis direction, as shown in Fig. 4, and includes a first portion 5a and a second portion 5b. Fig. 7 is a diagram showing a representative example of the load transmission member in the power storage device of this embodiment.

[0059] The first portion 5a is a plate disposed approximately parallel to the XZ plane. The length of the first portion 5a in the X-axis direction is preferably approximately equal to the length of the reinforcement member 4 in the X-axis direction. The first portion 5a may be, for example, a flat plate approximately parallel to the XZ plane, or a corrugated plate that oscillates in the Y-axis direction as shown in FIG. 7 when viewed from the Z-axis direction.

[0060] The first portion 5a may be made of, for example, metal or rigid resin. As shown in FIG. 4, the first portion 5a is disposed between adjacent battery modules 2 in the Y-axis direction. The negative end of the first portion 5a on the Z-axis side is fixed to the protruding portion 4a of the reinforcement member 4.

[0061] 4, the second portion 5b is a flat plate disposed on the positive side of the Z axis relative to the first portion 5a and disposed substantially parallel to the XY plane. The length of the second portion 5b in the X axis direction may be substantially equal to the length of the reinforcement member 4 in the X axis direction.

[0062] The second portion 5b may be made of, for example, metal or rigid resin. The substantially central portion in the Y-axis direction of the end portion of the second portion 5b on the negative Z-axis side is fixed to the end portion of the first portion 5a on the positive Z-axis side, as shown in FIG. 4. The positive Z-axis side end portion of the second portion 5b is in substantial contact with the negative Z-axis side surface of the housing portion 31a of the upper case 31.

[0063] As a result, when a load is input to the power storage device 1 from the + side of the Z axis, the load can be efficiently released to the lower case 32 via the load transmission member 5. Furthermore, when a load is input to the power storage device 1 from the - side of the Z axis, the load can be efficiently released to the upper case 31 via the load transmission member 5.

[0064] This makes it possible to suppress the input of load to the battery cells 21 and to suppress damage to the battery cells 21. In particular, in this embodiment, the load input to the energy storage device 1 from the Z-axis + side can be effectively released to the reinforcement members 4 via the load transmission members 5, thereby further suppressing damage to the battery cells 21.

[0065] Preferably, at least the first portion 5a of the load transmission member 5 has insulating properties. This can prevent contact between the first bus bar 26 and the second bus bar 27 that face each other in the Y-axis direction when a load is input to the energy storage device 1 from the Y-axis direction and the battery modules 2 are pushed in the Y-axis direction. This can prevent short-circuiting between the battery modules 2 that are adjacent in the Y-axis direction.

[0066] In addition, if a surface pressure distribution member or the like is arranged between the battery module 2 and the upper case 31 to distribute the load input to the storage device 1 from the Z-axis + side, the Z-axis + side end of the second part 5b of the load transmission member 5 should be in approximate contact with the storage section 31a of the upper case 31 via the surface pressure distribution member.

[0067] 3 and 4, the shear panel 6 covers the lower case 32 from the negative side along the Z axis. The shear panel 6 includes, for example, a recess 6a recessed toward the negative side of the Z axis to ensure deformation space for the shear panel 6 toward the positive side along the Z axis, and a flange 6b protruding outward from the periphery of the recess 6a. The flange 6b of the shear panel 6 may be fixed to the periphery of the lower case 32, for example.

[0068] 4 , the connecting member 7 is disposed between the lower case 32 and the shear panel 6 so as to overlap at least a portion of the reinforcement member 4 when viewed from the Z-axis direction, and connects the lower case 32 and the shear panel 6. When viewed from the X-axis direction, the connecting member 7 is, for example, hat-shaped with a protruding portion 7a that protrudes toward the +Z-axis side, and extends in the X-axis direction.

[0069] 4, the negative end of the connecting member 7 on the Z axis side is fixed to the positive Z axis side surface of the recess 6a of the share panel 6. This allows the connecting member 7 to function as a reinforcing member for the share panel 6. The positive Z axis side end of the protruding portion 7a of the connecting member 7 is in substantial contact with the negative Z axis side surface of the accommodation portion 32a of the lower case 32.

[0070] As a result, when an impact is applied to the share panel 6 from the negative side of the Z axis, the transmission of the impact at the recess 6a of the share panel 6 can be stopped by the connecting member 7, and the EA (Energy Absorption) stroke can be reduced.

[0071] Therefore, compared to a typical energy storage device, the space in the Z-axis direction in which the shear panel 6 deforms when an impact is applied to the shear panel 6 is smaller, which contributes to the miniaturization of the energy storage device 1. Furthermore, the bending rigidity of the shear panel 6 around the Y-axis can be improved, allowing the shear panel 6 to be made thinner. As a result, the weight of the energy storage device 1 can be reduced.

[0072] Furthermore, when an impact is applied to the shear panel 6 from the negative side of the Z axis, the load caused by the impact can be released to the reinforcement member 4 via the connecting member 7. Therefore, there is no need to use a rigid structure like the shear panels of general energy storage devices, and the shear panel 6 can be made thinner. As a result, the weight of the energy storage device 1 can be reduced.

[0073] At this time, for example, bolts inserted through through holes formed in the shear panel 6, the connecting member 7, and the lower case 32 can be screwed into weld nuts housed inside the reinforcement member 4 to fix the shear panel 6 and the connecting member 7 to the reinforcement member 4. This makes it possible to suppress vibration of the shear panel 6.

[0074] The rigid member 8, which will be described in detail later, is a transmission member for dissipating a load input to the energy storage device 1 from the X-axis direction to the frame 101 of the vehicle 100 via the reinforcement member 4 and the rigid member 8. The rigid member 8 has high rigidity relative to, for example, the upper case 31 and the lower case 32.

[0075] 8 is a perspective view showing a state in which the rigid member is fixed to the lower case in the energy storage device of this embodiment. The rigid member 8 is formed of a rigid material such as metal, and includes a base portion 8 a, a side wall portion 8 b, and a rib 8 c, as shown in FIGS. 3, 5, and 8.

[0076] 3 and 5, the base portion 8a may be a flat plate that is substantially parallel to the XY plane and has a shape that is substantially the same as the flat portion 32d of the flange portion 32b of the lower case 32 when viewed from the Z-axis direction. However, the base portion 8a may have any shape that allows it to be fixed to the flange portion 32b of the lower case 32.

[0077] The side wall portion 8b is a flat plate that is approximately parallel to the YZ plane, as shown in Figures 3, 5, and 8, for example. The side wall portion 8b protrudes from the end of the base portion 8a on the +X-axis side toward the -Z-axis side. In this case, the side wall portion 8b may include thick portions 8d that are spaced apart in the Y-axis direction. The thick portions 8d may have, for example, an approximately semi-cylindrical shape that is convex toward the -X-axis side when viewed from the Z-axis direction, but the shape is not limited thereto.

[0078] 3, 5, and 8, the rib 8c protrudes from the base portion 8a toward the negative Z-axis side and protrudes from the thick portion 8d of the side wall portion 8b toward the negative X-axis side. The rib 8c is, for example, a plate body that is approximately parallel to the XZ plane, and the thickness in the Z-axis direction may decrease toward the negative X-axis side.

[0079] As shown in Figures 3, 5 and 8, such a rigid member 8 is fixed to the lower case 32 by fixing the base portion 8a of the rigid member 8 to the flat portion 32d of the flange portion 32b of the lower case 32 from the Z-axis - side, with the end of the side wall portion 8b of the rigid member 8 on the X-axis + side being in approximate contact with the side wall portion 32c of the accommodation portion 32a of the lower case 32.

[0080] 5, the rib 8c is arranged so as to overlap at least a portion of the reinforcement member 4 when viewed from the X-axis direction. In other words, the reinforcement member 4 and the rigid member 8 are arranged substantially in series in the X-axis direction, so that the load in the X-axis direction can be transmitted between them.

[0081] Therefore, when a load is input to the storage device 1 from the X-axis + side, the reinforcement member 4 pushed toward the X-axis - side comes into contact with the rigid member 8 through the side wall portion 32c of the accommodation portion 32a of the lower case 32, and can push the rigid member 8 toward the X-axis - side.

[0082] Furthermore, when a load is input to the energy storage device 1 from the negative side of the X-axis, the rigid member 8 pushed toward the positive side of the X-axis comes into contact with the reinforcement member 4 through the side wall portion 32c of the accommodation portion 32a of the lower case 32, and can push the reinforcement member 4 toward the positive side of the X-axis.

[0083] The electronic device 9 is, for example, a satellite battery module (SBM) that monitors the voltage and other conditions of each battery module 2, or an electronic control unit (ECU) that monitors the overall condition of the battery modules 2 based on the monitoring results of the SBM. The electronic device 9 may also be a relay (for example, a system main relay (SMR)), a fuse, a DC-DC converter, a temperature sensor, a current sensor, etc. The electronic device 9 is disposed on the positive side of the Z axis with respect to the upper case 31 of the pack case 3, as shown in FIGS. 2 and 3 .

[0084] 2 and 3, the equipment base 10 supports the electronic device 9. The equipment base 10 may be made of, for example, metal or rigid resin, and the electronic device 9 is fixed to the end of the equipment base 10 on the +Z-axis side. The equipment base 10 may be fixed to, for example, a portion of the upper case 31 of the pack case 3 on the -X-axis side of the surface on the +Z-axis side.

[0085] In this case, it is preferable that the equipment base 10 is arranged so as to overlap at least a portion of the reinforcement member 4 and the rigid member 8 when viewed from the Z-axis direction, and that the equipment base 10, the reinforcement member 4, and the rigid member 8 are connected so as to be able to transmit a load. This allows the load of the electronic device 9 and the equipment base 10 to be released to the reinforcement member 4 via the load transmission member 5, and also to the rigid member 8.

[0086] 2 and 3, the cover 11 covers the electronic device 9 and the device base 10 from the +Z-axis side. The cover 11 is fixed, for example, to a portion of the +Z-axis side surface of the upper case 31 of the pack case 3 on the -X-axis side.

[0087] Next, a mounting structure of the energy storage device 1 of this embodiment on the vehicle 100 will be described. Fig. 9 is a perspective view showing the energy storage device and a frame of this embodiment. As shown in Fig. 9, the frame 101 forms a vehicle framework member of the vehicle 100.

[0088] As shown in Figure 9, the frame 101 includes a main body 101a formed in a frame shape when viewed from the Z-axis direction, and a beam 101b fixed to the main body 101a so as to span between a portion of the main body 101a on the +Y-axis side extending in the X-axis direction and a portion of the main body 101a on the -Y-axis side extending in the X-axis direction.

[0089] 9, the beam portions 101b may be, for example, seat cross members extending in the Y-axis direction to which a seat of the vehicle 100 is fixed. The beam portions 101b may be, for example, spaced apart in the X-axis direction.

[0090] For such a frame 101, the energy storage device 1 may be configured such that the flange portion 31b of the upper case 31 and the flange portion 32b of the lower case 32 of the pack case 3 in the energy storage device 1 are fixed to the main body portion 101a of the frame 101 from the negative side of the Z axis, as shown in Figures 3 and 4.

[0091] In this case, as shown in Figure 5, among the fixing points P1 to the main body 101a of the frame 101 in the energy storage device 1 arranged in the X-axis direction, at least one fixing point P1 should be positioned approximately on an extension line of the X-axis direction of the reinforcement member 4 and the rigid member 8 when viewed from the Z-axis direction.

[0092] In this embodiment, as shown in Fig. 5 , of the fixing points P1 aligned in the X-axis direction, the fixing points P1 on both sides are disposed approximately on an extension line in the X-axis direction of the reinforcement member 4 and the rigid member 8 when viewed from the Z-axis direction. Note that in Fig. 5 , the fixing points P1 on both sides in the X-axis direction are clarified by hatching.

[0093] As a result, when viewed from the X-axis direction, at least a portion of the reinforcement member 4 and the rigid member 8 and the fixed point P1 to the main body portion 101a of the frame 101 in the storage device 1 are arranged to overlap in the Z-axis direction.

[0094] Therefore, when a load is input to the energy storage device 1 from the + side of the X axis and the reinforcement member 4 is pushed toward the - side of the X axis, it comes into contact with the rigid member 8 through the side wall portion 32c of the accommodation portion 32a of the lower case 32 and pushes the rigid member 8 toward the - side of the X axis, so that the load can be efficiently released from the rigid member 8 pushed toward the - side of the X axis to the frame 101.

[0095] Furthermore, when a load is input to the energy storage device 1 from the negative side of the X-axis, and the rigid member 8 pushed toward the positive side of the X-axis comes into contact with the reinforcement member 4 via the side wall portion 32c of the accommodation portion 32a of the lower case 32, thereby pushing the reinforcement member 4 toward the positive side of the X-axis, the load can be effectively released from the reinforcement member 4 pushed toward the positive side of the X-axis to the frame 101.

[0096] In this way, the reinforcement member 4, the rigid member 8, and the fixed point P1 of the energy storage device 1 to the frame 101 of the vehicle 100 are arranged in series in the X-axis direction, so that the load input to the energy storage device 1 from the X-axis direction can be effectively released to the frame 101 of the vehicle 100. Therefore, damage to the energy storage device 1 can be suppressed.

[0097] 5, it is preferable that the negative end of the rib 8c of the rigid member 8 in the X-axis direction reaches near a fixed point P1 to the main body 101a of the frame 101 of the energy storage device 1 when viewed from the Z-axis direction. This allows the load input to the energy storage device 1 from the X-axis direction to be efficiently released to the frame 101 of the vehicle 100.

[0098] 3, the upper case 31 of the power storage device 1 may form the floor surface (floor panel) of the passenger compartment of the vehicle 100. When forming the passenger compartment of the vehicle 100, a floor mat, a floor silencer, or the like may be disposed on the surface of the upper case 31 of the power storage device 1 on the +Z-axis side.

[0099] In this way, when the upper case 31 of the energy storage device 1 forms the floor of the passenger compartment of the vehicle 100, there is no need to provide a separate floor on the frame 101 as in a typical vehicle. This makes it possible to reduce the weight of the vehicle 100. The upper case 31 of the energy storage device 1 may be fixed to the beam portion 101b of the frame 101.

[0100] In the energy storage device 1 of this embodiment, when viewed from the Z-axis direction, at least one of the first bus bar 26 and the second bus bar 27 that face each other in the Y-axis direction is arranged to overlap at least a part of the protruding portion 4 a of the reinforcement member 4. This improves the space utilization efficiency of the space on the +Z-axis side of the reinforcement member 4, which can contribute to the miniaturization of the energy storage device 1.

[0101] In the energy storage device 1 of this embodiment, if the load transmission member 5 is arranged so as to be able to transmit a load between the upper case 31 and the lower case 32, when a load is input to the energy storage device 1 from the +Z-axis side, the load can be efficiently released to the lower case 32 via the load transmission member 5. Furthermore, when a load is input to the energy storage device 1 from the -Z-axis side, the load can be efficiently released to the upper case 31 via the load transmission member 5.

[0102] This makes it possible to suppress the input of load to the battery cells 21 and to suppress damage to the battery cells 21. In particular, when the end of the load transmission member 5 on the negative Z-axis side is fixed to the protruding portion 4a of the reinforcement member 4, the load input to the energy storage device 1 from the positive Z-axis side can be effectively released to the reinforcement member 4 via the load transmission member 5, thereby further suppressing damage to the battery cells 21.

[0103] In the energy storage device 1 of this embodiment, if at least the first portion 5a of the load transmission member 5 has insulating properties, when a load is input to the energy storage device 1 from the Y-axis direction and the battery modules 2 are pushed in the Y-axis direction, contact between the first bus bar 26 and the second bus bar 27 that face each other in the Y-axis direction can be suppressed. Therefore, short-circuiting between adjacent battery modules 2 in the Y-axis direction can be suppressed.

[0104] In the energy storage device 1 of this embodiment, when the rigid members 8 are provided so as to substantially overlap at least a portion of the reinforcement members 4 when viewed from the X-axis direction, the reinforcement members 4 and the rigid members 8 are disposed substantially in series in the X-axis direction, and the load input to the energy storage device 1 from the X-axis direction can be borne by the reinforcement members 4 and the rigid members 8. This makes it possible to reduce the load input to the battery cells 21 and suppress damage to the battery cells 21.

[0105] In the energy storage device 1 of this embodiment, when viewed from the Z-axis direction, the equipment base 10 is disposed so as to overlap at least a portion of the reinforcement member 4 and the rigid member 8, and when the equipment base 10 is connected to the reinforcement member 4 and the rigid member 8 so as to be able to transmit a load, the load of the electronic device 9 and the equipment base 10 can be released to the reinforcement member 4 via the load transmission member 5, and also to the rigid member 8. This makes it possible to reduce the load input to the battery cells 21, and to suppress damage to the battery cells 21.

[0106] In the energy storage device 1 of this embodiment, when the lower case 32 has at least one of the first rib 32e or the second rib 32f extending in the X-axis direction, the bending rigidity of the energy storage device 1 around the Y-axis can be improved.

[0107] In the energy storage device 1 of this embodiment, when the connecting member 7 is disposed between the lower case 32 and the shear panel 6 so as to overlap with at least a portion of the reinforcement member 4 when viewed from the Z-axis direction, and connects the lower case 32 and the shear panel 6, when an impact is applied to the shear panel 6 from the negative side of the Z axis, the transmission of the impact to the recess 6 a of the shear panel 6 can be stopped by the connecting member 7, and the EA stroke can be reduced.

[0108] Therefore, compared to a typical energy storage device, the space in the Z-axis direction in which the shear panel 6 deforms when an impact is applied to the shear panel 6 is smaller, which contributes to the miniaturization of the energy storage device 1. Furthermore, the bending rigidity of the shear panel 6 around the Y-axis can be improved, allowing the shear panel 6 to be made thinner. As a result, the weight of the energy storage device 1 can be reduced.

[0109] Furthermore, when an impact is applied to the shear panel 6 from the negative side of the Z axis, the load caused by the impact can be released to the reinforcement member 4 via the connecting member 7. Therefore, there is no need to use a rigid structure like the shear panels of general energy storage devices, and the shear panel 6 can be made thinner. As a result, the weight of the energy storage device 1 can be reduced.

[0110] In the energy storage device 1 of this embodiment, when viewed from the Z-axis direction, the first rib 32e of the lower case 32 is positioned so as to overlap at least a portion of the safety valve 25 of the battery cell 21 of the battery module 2, and the first rib 32e can function as an exhaust path for ejected material discharged from the safety valve 25 of the battery cell 21.

[0111] In the vehicle mounting structure of the energy storage device 1 of this embodiment, at the fixed points P1 of the energy storage device 1 to the frame 101 of the vehicle 100, of the fixed points P1 lined up in the X-axis direction, at least one fixed point P1 is located approximately on an extension line of the X-axis direction of the reinforcement member 4 and the rigid member 8 when viewed from the Z-axis direction.

[0112] As a result, the reinforcement member 4 and the fixed point P1 of the energy storage device 1 to the frame 101 of the vehicle 100 are disposed in series in the X-axis direction, and the load input to the energy storage device 1 from the X-axis direction can be effectively released to the frame 101 of the vehicle 100. Therefore, damage to the energy storage device 1 can be suppressed.

[0113] <Embodiment 2> Fig. 10 is a diagram showing the arrangement of the safety valves of the battery cells and the openings of the reinforcement members in the energy storage device of this embodiment, as viewed from the + side of the X axis. Fig. 11 is a diagram showing the arrangement of the safety valves of the battery cells and the openings of the reinforcement members in the energy storage device of this embodiment, as viewed from the + side of the Y axis. Fig. 12 is a perspective view for explaining the configuration of the heat insulating member in the energy storage device of this embodiment.

[0114] The energy storage device 41 of this embodiment has a configuration substantially identical to that of the energy storage device 1 of embodiment 1, and therefore a redundant description will be omitted. However, as shown in Figures 10 to 12, the inside of the reinforcement member 4 can be used as a discharge path for ejected material discharged from the battery cells 21.

[0115] 10 and 11, a safety valve 42 is provided on at least one of the surfaces on the +Y-axis side or the -Y-axis side of the battery case 22 of the battery cell 21. For example, among the reinforcement members 4 aligned in the Y-axis direction, a safety valve 42 may be provided on each of the opposing surfaces of the battery cells 21 that are arranged adjacent to each other with every other reinforcement member 4 therebetween.

[0116] 10 and 11 , when viewed in the Y-axis direction, the safety valve 42 is arranged so as to overlap at least a portion of the protruding portion 4 a of the reinforcement member 4. The protruding portion 4 a of the reinforcement member 4 has a hollow structure, and an opening 4 b is formed in the portion facing the safety valve 42 of each battery cell 21 in the Y-axis direction.

[0117] 10 and 11, openings 4b may be provided in the side wall portions that face each other in the Y-axis direction in the protruding portions 4a of every other reinforcement member 4. The openings 4b may be covered with a heat insulating member 43 as shown in FIG.

[0118] 12, the heat insulating member 43 is a sheet member having heat insulating properties, and has a shape that is slightly larger than the opening 4b of the reinforcement member 4 when viewed from the Y-axis direction. The heat insulating member 43 may be formed with an easily breakable portion 43a.

[0119] The easily breakable portion 43a can be formed, for example, by perforations as shown in Figure 12, and is arranged along a shape that is approximately the same as the periphery of the opening 4b of the reinforcement member 4 when viewed from the Y-axis direction.

[0120] In such a storage device 41, for example, if ejected material is discharged in the Y-axis direction from inside the battery cell 21 through the safety valve 42, the force of the ejected material will cause the insulating member 43 to break at the easily breakable portion 43a, opening the opening 4b of the reinforcement member 4.

[0121] The ejected material then enters the interior of the reinforcement member 4 through the opening 4b of the reinforcement member 4 and passes through the interior of the protruding portion 4a of the reinforcement member 4. This allows the interior of the protruding portion 4a of the reinforcement member 4 to be used as an exhaust path. The ejected material is then preferably exhausted to the outside via an exhaust valve provided in the pack case 3.

[0122] In this way, the power storage device 41 of this embodiment can use the interior of the reinforcement member 4 as a discharge path for ejected material discharged from the battery cells 21. This improves the space utilization efficiency inside the power storage device 41, which can contribute to the miniaturization of the power storage device 41.

[0123] The present disclosure is not limited to the above-described embodiments, and can be modified as appropriate within the scope of the present disclosure.

[0124] For example, in the above embodiment, the battery cells 21 are stacked in the X-axis direction, but they may also be stacked in the Y-axis direction, and accordingly, the arrangement of the reinforcement members 4, rigid members 8, etc. may be changed as appropriate.

[0125] For example, in the above embodiment, the reinforcement member 4 and the lower case 32 are configured as separate members, but they may be integrally formed by die casting, etc. This can improve the rigidity of the lower case.

[0126] For example, in the above embodiment, the first bus bar 26 and the second bus bar 27 that face each other in the Y-axis direction are arranged so as to overlap the protrusions 4a of the reinforcement members 4 when viewed in the Z-axis direction, but it is sufficient that at least a portion of at least one of the bus bars is arranged so as to overlap the reinforcement members 4. Furthermore, the bus bars are not limited to bus bars, and any conductive member that is connected to the electrode terminals of the battery cells 21 may be used.

[0127] For example, the shape of the load transmission member 5 in the above embodiment is an example, and may be, for example, a shape such as the load transmission member 51 shown in Figure 13, in which a first portion 51a having a small thickness in the Y-axis direction and a second portion 51b having a large thickness in the Y-axis direction are repeatedly arranged in the X-axis direction.

[0128] For example, although the energy storage devices 1, 41 in the above-described embodiments include the shear panels 6 and the connecting members 7, the shear panels 6 and the connecting members 7 may be omitted. The shape of the connecting members 7 is an example, and they may have any shape that can connect the shear panels 6 and the lower case 32 so as to be able to transmit a load. The arrangement of the connecting members 7 is also an example, and they do not have to be arranged so as to overlap with the reinforcement members 4 when viewed from the Z-axis direction.

[0129] For example, the arrangement and shape of the device base 10 in the above embodiment are merely examples, and any arrangement and shape may be used as long as the electronic device 9 can be fixed to the pack case 3. Furthermore, the electronic device 9, the device base 10, etc. may be omitted.

[0130] For example, the shape of the rigid member 8 in the above embodiment is merely an example, and it is sufficient if the shape is such that, when viewed from the X-axis direction, a load can be transmitted between the reinforcement member 4 and the frame 101 of the vehicle 100. Also, the rigid member 8 may be omitted.

[0131] In short, the energy storage device of the present disclosure only needs to have a minimum configuration in which, when viewed from the Z-axis direction, at least a portion of the conductive member connected to one of the electrode terminals of the battery cells 21 facing each other in the Y-axis direction is arranged so as to overlap with the reinforcement member 4.

[0132] This application claims priority based on Japanese Patent Application No. 2024-66911, filed April 17, 2024, the disclosure of which is incorporated herein in its entirety by reference.

[0133] REFERENCE SIGNS LIST 1 Energy storage device 2 Battery module 3 Pack case 4 Reinforcement member 4a Protrusion 4b Opening 5 Load transfer member 5a First portion 5b Second portion 6 Shear panel 6a Recess 6b Flange 7 Connecting member 7a Protrusion 8 Rigid member 8a Base 8b Side wall 8c Rib 8d Thick portion 9 Electronic device 10 Device base 11 Cover 21 Battery cell 22 Battery case 23 First electrode terminal 24 Second electrode terminal 25 Safety valve 26 First bus bar 27 Second bus bar 31 Upper case 31a Storage portion 31b Flange 32 Lower case 32a Storage portion 32b Flange 32c Side wall 32d Flat portion 32e First rib 32f Second rib DESCRIPTION OF SYMBOLS 41 Electricity storage device 42 Safety valve 43 Heat insulating member 43a Easy-to-break portion 51 Load transfer member 51a First portion 51b Second portion 100 Vehicle 101 Frame 101a Main body 101b Beam portion C1 Distance between protruding portion of reinforcement member and surface of battery cell on side where first electrode terminal of battery case is arranged C2 Distance between protruding portion of reinforcement member and surface of battery cell on side where second electrode terminal of battery case is arranged C3 Distance between first bus bar and second bus bar opposing in Y-axis direction P1 Fixed point of electricity storage device to vehicle frame T1 Thickness of first bus bar T2 Thickness of second bus bar W1 Width dimension of protruding portion of reinforcement member

Claims

1. An energy storage device comprising: a first battery cell and a second battery cell aligned in a first direction; and a first reinforcement member disposed between the first battery cell and the second battery cell, wherein the first battery cell and the second battery cell have a pair of electrode terminals respectively disposed on a pair of surfaces opposing each other in the first direction; the energy storage device also comprises a first conductive member connected to one of the pair of electrode terminals of the first battery cell; and the first conductive member overlaps with the first reinforcement member when viewed from above and below.

2. The energy storage device according to claim 1, further comprising a second conductive member connected to one of a pair of electrode terminals of the second battery cell that faces the first battery cell in the first direction, and wherein the second conductive member overlaps with the first reinforcement member when viewed from the top-bottom direction.

3. The energy storage device according to claim 1, further comprising a third battery cell arranged alongside the first battery cell in a second direction perpendicular to the first direction and the up-down direction, with a pair of electrode terminals arranged on opposing surfaces in the first direction, and the first conductive member being connected to one of the pair of electrode terminals of the third battery cell.

4. The energy storage device according to claim 3, comprising: a fourth battery cell having a pair of electrode terminals arranged on a pair of surfaces facing each other in the first direction; a second reinforcement member arranged between the first battery cell and the fourth battery cell; and a third conductive member connected to the other electrode terminal of the first battery cell, wherein the first battery cell is arranged between the second battery cell and the fourth battery cell in the first direction, and the third conductive member overlaps with the second reinforcement member when viewed from the top-bottom direction.

5. The energy storage device according to any one of claims 1 to 4, further comprising an equipment base disposed above the first battery cell and on which an electronic device is placed, the equipment base overlapping the first reinforcement member when viewed from the vertical direction.

6. A storage device according to any one of claims 1 to 4, comprising a rigid member that overlaps with the first reinforcement member when viewed from a second direction perpendicular to the first direction and the vertical direction and extends in the second direction.

7. An energy storage device according to any one of claims 1 to 4, comprising a first cover arranged below the first battery cell, the first cover extending in a second direction perpendicular to the first direction and the up-down direction, and having a downwardly convex rib.

8. The energy storage device according to claim 7, comprising: a second cover disposed above the first battery cell; and a load transfer member connecting the first cover and the second cover between the first battery cell and the second battery cell.

9. The electricity storage device according to claim 8, wherein the load transmission member is connected to the second cover via the first reinforcement member.

10. The electricity storage device according to claim 9, wherein the load transmitting member has insulating properties.

11. The energy storage device according to claim 7, comprising: a third cover disposed below the first cover; and a connecting member connecting the first cover and the third cover.

12. The energy storage device according to claim 7, wherein the first battery cell is provided with a safety valve at a portion that overlaps with a rib of the first cover when viewed from the top-bottom direction.

13. The energy storage device described in claim 2, wherein the distance in the first direction between the first reinforcement member and the surface on which the one electrode terminal of each of the first battery cell and the second battery cell is arranged is narrower than the distance between the first conductive member and the second conductive member.

14. The energy storage device according to claim 2, wherein the sum of the thickness of the first conductive member and the thickness of the second conductive member in the first direction is smaller than the width dimension of the first reinforcement member.

15. A storage device according to any one of claims 1 to 4, wherein the first battery cell is provided with a safety valve on a surface on the side where the one electrode terminal of the first battery cell is arranged, and when viewed from the first direction, the safety valve overlaps with the first reinforcement member.

16. The electricity storage device according to claim 15, wherein the first reinforcement member has a hollow structure and is provided with an opening in a portion facing the safety valve.

17. The electricity storage device according to claim 16, wherein the opening is covered with a heat insulating member.

18. The electricity storage device according to claim 17, wherein the heat insulating member has an easily breakable portion.

19. A vehicle mounting structure for an electric storage device as described in any one of claims 1 to 4, wherein at least one of the fixing points arranged in the first direction and a second direction perpendicular to the vertical direction at the fixing points between the electric storage device and a vehicle frame member of the vehicle overlaps with the first reinforcement member in the vertical direction when viewed from the second direction.

20. A vehicle mounting structure for an electric storage device as described in claim 19, wherein, of the fixing points aligned in the second direction at the fixing points between the electric storage device and a vehicle frame member of the vehicle, the fixing points on both sides overlap with the first reinforcement member in the vertical direction when viewed from the second direction.

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