Energy storage device

Abstract

The objective is to obtain an energy storage device that can suppress short circuits even in the event of leakage, in a structure in which cylindrical energy storage cells with different potentials are housed in a single case. [Solution] The energy storage device 10 includes a plurality of cylindrical energy storage cells 30, 32 configured to store energy, a first housing section capable of housing the plurality of cylindrical energy storage cells 30 with their axial directions aligned, and a second housing section capable of housing cylindrical energy storage cells 32 having electrodes on one side in the axial direction that are at a different potential from the electrodes on one side in the axial direction of the cylindrical energy storage cells 30 housed in the first housing section, and a cell holder 16 provided between the first housing section and the second housing section, with a partition wall 16Z extending axially beyond the cylindrical energy storage cells 30, 32 to separate the first housing section and the second housing section.

Description

Technical Field

[0001] The present invention relates to a power storage device.

Background Art

[0002] Patent Document 1 discloses a battery pack (power storage device) in which a plurality of cylindrical secondary batteries are housed in one case.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in a structure in which a plurality of secondary batteries (cylindrical power storage cells) are housed in one accommodation space as in the power storage device disclosed in Patent Document 1 above, when electrolyte leaks from the secondary battery, there is a possibility of short circuit between the cylindrical power storage cells having different potentials.

[0005] In consideration of the above fact, an object of the present invention is to obtain a power storage device that can suppress a short circuit even in the case of liquid leakage in a structure in which cylindrical power storage cells having different potentials are housed in one case.

Means for Solving the Problems

[0006] The energy storage device according to claim 1 comprises a plurality of cylindrical energy storage cells configured to store energy, a first housing capable of housing the plurality of cylindrical energy storage cells with their axial directions aligned, and a second housing capable of housing the cylindrical energy storage cells having an electrode on one side in the axial direction that is at a different potential from the electrode on one side in the axial direction of the cylindrical energy storage cell housing the first housing, and a cell holder provided between the first housing and the second housing with a partition wall that extends axially beyond the cylindrical energy storage cells and separates the first housing and the second housing.

[0007] The energy storage device according to claim 1 comprises a plurality of cylindrical energy storage cells configured to store energy, and these cylindrical energy storage cells are housed in a cell holder. The cell holder is configured to accommodate the plurality of cylindrical energy storage cells with their axial directions aligned, and comprises a first housing section and a second housing section. Here, the potential on one side of the axial direction of the cylindrical energy storage cells housed in the first housing section and the second housing section is different. Furthermore, a partition wall is provided between the first housing section and the second housing section, extending axially beyond the cylindrical energy storage cells to separate the first housing section and the second housing section. As a result, even if a cylindrical energy storage cell housed in the first housing section or the second housing section leaks electrolyte, the partition wall prevents the electrolyte from entering the adjacent housing section.

[0008] The energy storage device according to claim 2 is further comprising, in claim 1, a cover that is in contact with the partition wall and closes the openings of the first storage section and the second storage section.

[0009] In the energy storage device according to claim 2, since the openings of the first and second storage sections are closed by the cover, even if the liquid level of leaked electrolyte rises, it is possible to prevent the electrolyte from entering the adjacent storage section.

[0010] The energy storage device according to claim 3 is characterized in that, in claim 2, an elastic sealing member is interposed between the partition wall and the cover.

[0011] In the energy storage device according to claim 3, the sealing member can more effectively suppress the ingress of electrolyte. Furthermore, because the sealing member is elastic, even if the cover is locally deformed, the sealing member deforms in accordance with the deformation, thereby preventing a gap from forming between the cover and the partition wall.

[0012] In the energy storage device according to claim 4, the sealing member extends to the outside of the partition wall portion, as described in claim 3.

[0013] In the energy storage device according to claim 4, since the sealing member extends to the outside of the partition wall, it is possible to effectively prevent leaked electrolyte from entering between the cover and the elastic body.

[0014] The energy storage device according to claim 5 is characterized in that, in claim 2, the cover is made of a material with higher rigidity than the cell holder.

[0015] In the energy storage device according to claim 5, since the cover has higher rigidity than the cell holder, deformation of the cover can be suppressed even when an external force is applied, and a gap between the cover and the cell holder can be suppressed.

[0016] The energy storage device according to claim 6 is provided in claim 3, wherein an insulating member is provided at the portion where the cover and the sealing member are in contact.

[0017] In the energy storage device according to claim 6, when the cover is made of a conductive material, even if the leaked electrolyte moves to the cover side via the sealing member, electrical conductivity between the cylindrical energy storage cell and the cover can be suppressed, preventing leakage.

[0018] The energy storage device according to claim 7, in claim 1, comprises a cylindrical energy storage cell comprising a cylindrical case body for housing an electrode body and a lid that closes the opening of the case body by being crimped onto the case body, wherein the crimped portion of the cylindrical energy storage cell is in contact with the partition wall portion when the cylindrical energy storage cell is housed in the cell holder.

[0019] In the power storage device according to claim 7, since the caulked portion of the cylindrical power storage cell is in contact with the partition portion, the partition portion can suppress the leakage of the electrolytic solution from the caulked portion.

[0020] The power storage device according to claim 8 includes, in claim 1, a conductive member that electrically connects the cylindrical power storage cell housed in the first housing portion and the cylindrical power storage cell housed in the second housing portion, and the conductive member includes a positive electrode side connection portion extending along the positive electrode terminal of the cylindrical power storage cell in one of the first housing portion and the second housing portion, a negative electrode side connection portion extending along the negative electrode terminal of the other cylindrical power storage cell, and a connection portion connecting the positive electrode side connection portion and the negative electrode side connection portion along the side wall of the cell holder.

[0021] In the power storage device according to claim 8, the conductive member includes a positive electrode side connection portion, a negative electrode side connection portion, and a connection portion. Thereby, the cylindrical power storage cell housed in the first housing portion and the cylindrical power storage cell housed in the second housing portion can be electrically connected.

[0022] The power storage device according to claim 9 includes, in claim 8, a plurality of the conductive members, and in the cell holder, a return portion that widens toward the tip is provided between adjacent connection portions.

[0023] In the power storage device according to claim 9, since a return portion is provided between adjacent connection portions, even when the leaked electrolytic solution flows into the connection portion of the conductive member, the return portion can suppress the electrolytic solution from entering the adjacent connection portion.

[0024] The power storage device according to claim 10 includes, in claim 8, the positive electrode side connection portion, the negative electrode side connection portion, and the connection portion are integrally formed.

[0025] In the power storage device according to claim 10, by integrally forming the positive electrode side connection portion, the negative electrode side connection portion, and the connection portion, the number of components can be reduced.

[0026] The power storage device according to claim 11, in claim 8, a gap filler is filled on the negative electrode terminal side of the cylindrical power storage cell in the cell holder.

[0027] In the power storage device according to claim 11, even if the electrolytic solution leaked from the positive electrode side of the cylindrical power storage cell flows into the negative electrode side, the negative electrode side is sealed by the gap filler, so that the leakage of the electrolytic solution from the cell holder can be suppressed.

Advantages of the Invention

[0028] As described above, according to the power storage device of the present invention, in a structure in which cylindrical power storage cells having different potentials are housed in one case, a short circuit can be suppressed even in case of liquid leakage.

Brief Description of Drawings

[0029] [Figure 1] It is a schematic perspective view of a battery pack including the power storage device according to the first embodiment. [Figure 2] It is a schematic exploded perspective view of the power storage device according to the first embodiment. [Figure 3] It is a bottom view seen from the bottom side of the power storage device. [Figure 4] It is a cross-sectional view showing a state cut along line 4-4 of FIG. 2. [Figure 5] It is a cross-sectional view of an enlarged main part showing the main part of FIG. 4. [Figure 6] It is a schematic exploded perspective view of the power storage device according to the second embodiment. [Figure 7] It is a schematic exploded perspective view of the power storage device according to the third embodiment. [Figure 8] It is a plan view of a cell holder constituting the power storage device according to the fourth embodiment. [Figure 9] It is an enlarged cross-sectional view of the main part of the power storage device according to the fifth embodiment.

Modes for Carrying Out the Invention

[0030] <The First Embodiment> Figure 1 is a schematic perspective view of a battery pack 100 including a battery module 10 as an energy storage device according to the first embodiment. For example, the battery pack 100 of this embodiment is used as a secondary battery mounted under the floor of a vehicle and is configured to store power for supplying to a drive motor (not shown).

[0031] Furthermore, the battery pack 100 can be installed in a wide range of vehicles that utilize electricity as at least part of their drive source, including electric assist bicycles, small mobility vehicles, BEVs (Battery Electric Vehicles), hybrid vehicles (HVs), and plug-in hybrid vehicles (PHEVs).

[0032] As shown in Figure 1, the battery pack 100 of this embodiment includes a substantially box-shaped case 102, and the case 102 houses a plurality of battery modules 10 as energy storage devices. In this embodiment, as an example, four battery modules 10 are housed, but it is not limited to this, and five or more battery modules 10 may be housed, or three or fewer battery modules 10 may be housed.

[0033] (Overall configuration of the battery module) Figure 2 is a schematic exploded perspective view of the battery module 10 according to this embodiment. As shown in Figure 2, the battery module 10 consists of a module body 12 and a cover 14. In Figure 2, for the sake of explanation, the direction indicated by the arrow UP is referred to as the upward / downward direction of the battery module 10, the direction indicated by the arrow FR is referred to as the forward direction of the battery module 10, and the direction indicated by the arrow LH is referred to as the left side in the left-right direction when the battery module 10 is viewed from the front. However, the up / down, front / back, and left / right directions are used for convenience and do not necessarily coincide with the direction of the vehicle in which the battery module 10 is actually mounted. The same applies to the other drawings.

[0034] The cover 14 is formed in a roughly L-shape and includes a cover upper portion 14A that covers the upper surface of the module body 12 and a cover side portion 14B that covers the front surface of the module body 12. In this embodiment, the cover 14's cover upper portion 14A and cover side portion 14B are integrally formed from a metal with higher rigidity than the cell holder 16, but the material and shape of the cover 14 can be changed as appropriate, and this is not limited to this.

[0035] Figure 3 is a bottom view of the module body 12 of this embodiment, as seen from the bottom side, and Figure 4 is a cross-sectional view showing the state when cut along line 4-4 in Figure 2. As shown in Figures 2 to 4, the module body 12 is composed of a cell holder 16, cylindrical energy storage cells 30, 32, 34, 36, and busbars 18, 20, 22, 24, 26 as conductive members.

[0036] (Cell holder) The cell holder 16 is formed from resin in a hollow, roughly rectangular parallelepiped shape, and its outer surface is composed of a left wall portion 16A, a left front wall portion 16B, a right wall portion 16C, a right front wall portion 16D, a rear wall portion 16E, an upper wall portion 16F, and a lower wall portion 16G.

[0037] As shown in Figure 2, the left wall portion 16A constitutes the left side surface of the cell holder 16 and extends in the front-rear and up-down directions. The left front wall portion 16B is formed in a roughly triangular shape and constitutes the left front surface of the cell holder 16, with the left end of the left front wall portion 16B connected to the front end of the left wall portion 16A.

[0038] The right wall portion 16C constitutes the right side of the cell holder 16 and extends in the front-rear and up-down directions. The right front wall portion 16D is formed in a roughly triangular shape and constitutes the front right side of the cell holder 16, with the right end of the right front wall portion 16D connected to the front end of the right wall portion 16C.

[0039] As shown in Figure 3, the rear wall portion 16E constitutes the rear surface of the cell holder 16 and extends in the left-right and up-down directions.

[0040] As shown in Figure 4, the upper wall portion 16F constitutes the upper surface of the cell holder 16, and multiple circular holes 16JU, 16KU, 16LU, and 16MU are formed in the upper wall portion 16F. Details of these circular holes 16JU, 16KU, 16LU, and 16MU will be described later.

[0041] The lower wall portion 16G constitutes the lower surface of the cell holder 16, and multiple circular holes 16JL, 16KL, 16LL, and 16ML are formed in the lower wall portion 16G. Details of these circular holes 16JL, 16KL, 16LL, and 16ML will be described later.

[0042] Here, the cell holder 16 houses multiple cylindrical energy storage cells 30, 32, 34, and 36. These cylindrical energy storage cells are, for example, cylindrical cells configured to store energy, and lithium-ion secondary batteries and nickel-metal hydride secondary batteries are used. However, the invention is not limited to these, and rectangular cylindrical cells may also be used as cylindrical energy storage cells.

[0043] (Cylindrical energy storage cell) The cylindrical energy storage cells 30 are housed in an arrangement of eight on the left side of the battery module 10. Specifically, the cylindrical energy storage cells 30 are housed in pairs horizontally, with the vertical direction as the axial direction, and four such rows are arranged in the front-to-back direction.

[0044] A positive electrode terminal is provided at one axial end (upper end) of the cylindrical energy storage cell 30, and a negative electrode terminal is provided at the other axial end (lower end) of the cylindrical energy storage cell 30. Furthermore, a circular hole 16JU is formed above the cylindrical energy storage cell 30, and the circular hole 16JU is formed to be smaller in diameter than the diameter of the cylindrical energy storage cell 30. In addition, a circular hole 16JL is formed below the cylindrical energy storage cell 30, and the circular hole 16JL is formed to be smaller in diameter than the diameter of the cylindrical energy storage cell 30.

[0045] A first partition wall 16X1 is provided between adjacent cylindrical energy storage cells 30 in the left-right direction. The first partition wall 16X1 is integrally formed with the cell holder 16 by resin and extends in the vertical direction.

[0046] The cylindrical energy storage cells 32 are housed to the right of the area where the cylindrical energy storage cells 30 are housed, and eight cylindrical energy storage cells 32 are arranged in an axial direction with the vertical direction as the axis. Similar to the cylindrical energy storage cells 30, the cylindrical energy storage cells 32 are arranged in four rows in the front-to-back direction, with two cells housed in the left-to-right direction.

[0047] A positive electrode terminal is provided at one axial end (upper end) of the cylindrical energy storage cell 32, and a negative electrode terminal is provided at the other axial end (lower end) of the cylindrical energy storage cell 32. Furthermore, a circular hole 16KU is formed above the cylindrical energy storage cell 32, and the circular hole 16KU is formed to be smaller in diameter than the diameter of the cylindrical energy storage cell 32. In addition, a circular hole 16KL is formed below the cylindrical energy storage cell 32, and the circular hole 16KL is formed to be smaller in diameter than the diameter of the cylindrical energy storage cell 32.

[0048] A second partition wall 16X2 is provided between adjacent cylindrical energy storage cells 32 in the left-right direction. The second partition wall 16X2 is integrally formed with the cell holder 16 by resin and extends in the vertical direction.

[0049] The cylindrical energy storage cells 34 are housed to the right of the area where the cylindrical energy storage cells 32 are housed, and eight cylindrical energy storage cells 34 are arranged in an axial direction with the vertical direction as the axis. Similar to the cylindrical energy storage cells 30, the cylindrical energy storage cells 34 are arranged in four rows in the front-to-back direction, with two cells housed in the left-to-right direction.

[0050] A positive terminal is provided at one axial end (upper end) of the cylindrical energy storage cell 34, and a negative terminal is provided at the other axial end (lower end) of the cylindrical energy storage cell 34. Furthermore, a circular hole 16LU is formed above the cylindrical energy storage cell 34, and the circular hole 16LU is formed to be smaller in diameter than the diameter of the cylindrical energy storage cell 34. In addition, a circular hole 16LL is formed below the cylindrical energy storage cell 34, and the circular hole 16LL is formed to be smaller in diameter than the diameter of the cylindrical energy storage cell 34.

[0051] A third partition wall 16X3 is provided between adjacent cylindrical energy storage cells 34 in the left-right direction. The third partition wall 16X3 is integrally formed with the cell holder 16 by resin and extends in the vertical direction.

[0052] The cylindrical energy storage cells 36 are housed to the right of the area where the cylindrical energy storage cells 34 are housed, and eight cylindrical energy storage cells 36 are arranged in an axial direction with the vertical direction as the axis. Similar to the cylindrical energy storage cells 30, the cylindrical energy storage cells 36 are arranged in four rows in the front-to-back direction, with two cells housed in the left-to-right direction.

[0053] A positive electrode terminal is provided at one axial end (upper end) of the cylindrical energy storage cell 36, and a negative electrode terminal is provided at the other axial end (lower end) of the cylindrical energy storage cell 36. Furthermore, a circular hole 16MU is formed above the cylindrical energy storage cell 36, and the circular hole 16MU is formed to be smaller in diameter than the diameter of the cylindrical energy storage cell 36. In addition, a circular hole 16ML is formed below the cylindrical energy storage cell 36, and the circular hole 16ML is formed to be smaller in diameter than the diameter of the cylindrical energy storage cell 36.

[0054] A fourth partition wall 16X4 is provided between adjacent cylindrical energy storage cells 36 in the left-right direction. The fourth partition wall 16X4 is integrally formed with the cell holder 16 by resin and extends in the vertical direction.

[0055] As described above, in this embodiment, 32 cylindrical energy storage cells are housed in the cell holder 16, and eight cylindrical energy storage cells are arranged in a single battery group with the vertical direction as the axial direction, resulting in a so-called "8 parallel 4 series" type battery assembly. However, the embodiment is not limited to this, and the number of batteries housed in the cell holder 16 and the number of battery groups are not particularly limited.

[0056] The method for housing the cylindrical energy storage cells in the cell holder 16 is not particularly limited. For example, the cell holder 16 may be molded in a state where it is divided into upper and lower halves, and the cylindrical energy storage cells may be housed in one of the halves, with the other half being joined together. Alternatively, the circular holes 16JU, 16KU, 16LU, and 16MU may each be formed to have a larger diameter than the cylindrical energy storage cells 30, 32, 34, and 36. In this case, after housing the cylindrical energy storage cells 30, 32, 34, and 36, each cylindrical energy storage cell may be restrained to prevent it from coming out.

[0057] A partition wall 16Y1, similar to the first partition wall 16X1, is provided between the first housing section, which houses the cylindrical energy storage cell 30, and the second housing section, which houses the cylindrical energy storage cell 32. The partition wall 16Y1 is integrally formed with the cell holder 16 and extends in the vertical direction.

[0058] Therefore, the cylindrical energy storage cell 30 on the right is housed between the first partition wall 16X1 and the first storage compartment partition wall 16Y1. The cylindrical energy storage cell 30 on the left is housed between the left wall portion 16A of the cell holder 16 and the first partition wall 16X1.

[0059] A partition wall 16Y2 is provided between the second housing section, which houses the cylindrical energy storage cell 32, and the third housing section, which houses the cylindrical energy storage cell 34. The partition wall 16Y2 is integrally formed with the cell holder 16 and extends in the vertical direction.

[0060] Therefore, the cylindrical energy storage cell 32 on the right is housed between the second partition wall 16X2 and the second storage compartment partition wall 16Y2. The cylindrical energy storage cell 32 on the left is housed between the first storage compartment partition wall 16Y1 and the second partition wall 16X2.

[0061] A partition wall 16Y3 is provided between the third housing section, which houses the cylindrical energy storage cell 34, and the fourth housing section, which houses the cylindrical energy storage cell 36. The partition wall 16Y3 is integrally formed with the cell holder 16 and extends in the vertical direction.

[0062] Therefore, the cylindrical energy storage cell 34 on the right is housed between the third partition wall 16X3 and the third housing partition wall 16Y3. The cylindrical energy storage cell 34 on the left is housed between the second housing partition wall 16Y2 and the third partition wall 16X3. Furthermore, the cylindrical energy storage cell 36 on the left wall is housed between the third housing partition wall 16Y3 and the fourth partition wall 16X4, and the cylindrical energy storage cell 36 on the right is housed between the fourth partition wall 16X4 and the right wall portion 16C of the cell holder 16.

[0063] (Bus bar) As shown in Figure 2, the cell holder 16 is provided with a busbar 18 as a conductive member, and the busbar 18 has a positive electrode side connection portion 18A.

[0064] The positive electrode connection portion 18A is superimposed on the upper surface of the upper wall portion 16F of the cell holder 16 in the first housing portion in which the cylindrical energy storage cell 30 is housed, and extends in the front-rear direction along the positive electrode terminal of the cylindrical energy storage cell 30. Furthermore, the positive electrode connection portion 18A and the positive electrode terminal of the cylindrical energy storage cell 30 are connected by a conductor (not shown).

[0065] Furthermore, eight communication holes 18D are formed in the positive electrode connection portion 18A at positions corresponding to the cylindrical energy storage cell 30. Each communication hole 18D is formed at a position corresponding to the circular hole 16JU and is approximately the same size as the circular hole 16JU (see Figure 4).

[0066] As shown in Figure 3, the busbar 18 is equipped with a negative electrode side connection portion 18C. The negative electrode side connection portion 18C is superimposed on the lower surface of the lower wall portion 16G of the cell holder 16 in the second housing portion in which the cylindrical energy storage cell 32 is housed, and extends in the front-rear direction along the negative electrode terminal of the cylindrical energy storage cell 32. Furthermore, the negative electrode side connection portion 18C and the negative electrode terminal of the cylindrical energy storage cell 32 are connected by a conductor (not shown).

[0067] Furthermore, eight communication holes 18D are formed in the negative electrode connection portion 18C at positions corresponding to the cylindrical energy storage cell 32 and the circular hole 16KL, and are approximately the same size as the circular hole 16KL (see Figure 4).

[0068] As shown in Figure 2, the connecting portion 18B is formed in a shape that slopes to the right from top to bottom when viewed from the front, and the connecting portion 18B connects the positive electrode side connecting portion 18A and the negative electrode side connecting portion 18C. Specifically, the upper end of the connecting portion 18B is connected to the front end of the positive electrode side connecting portion 18A, and the lower end of the connecting portion 18B is connected to the front end of the negative electrode side connecting portion 18C. As a result, the cylindrical energy storage cell 30 housed in the first housing and the cylindrical energy storage cell 32 housed in the second housing are electrically connected by the busbar 18.

[0069] In this embodiment, the busbar 18 has a positive terminal connection portion 18A, a connecting portion 18B, and a negative terminal connection portion 18C that are integrally formed, so the busbar 18 is roughly U-shaped with the rear side open. The same applies to the busbars 20 and 22 which will be described later.

[0070] As shown in Figure 2-4, the busbar 20 is formed in a substantially U-shape, including a positive electrode connection portion 20A, a connecting portion 20B, and a negative electrode connection portion 20C, similar to the busbar 18. The positive electrode connection portion 20A extends in the front-rear direction along the positive electrode terminal of the cylindrical energy storage cell 32 in the second housing portion where the cylindrical energy storage cell 32 is housed. The positive electrode connection portion 20A and the positive electrode terminal of the cylindrical energy storage cell 32 are connected by a conductor (not shown).

[0071] The positive electrode connection portion 20A has eight communication holes 20D, and each communication hole 20D is formed in a position corresponding to the circular hole 16KU and is approximately the same size as the circular hole 16KU.

[0072] The negative electrode connection portion 20C of the busbar 20 extends in the front-rear direction along the negative electrode terminal of the cylindrical energy storage cell 34 in the third housing portion where the cylindrical energy storage cell 34 is housed. Furthermore, the negative electrode connection portion 20B and the negative electrode terminal of the cylindrical energy storage cell 34 are connected by a conductor (not shown).

[0073] The negative electrode connection portion 20B has eight communication holes 20E, and each communication hole 20E is formed in a position corresponding to the circular hole 16LL and is approximately the same size as the circular hole 16LL.

[0074] The connecting portion 20B of the busbar 20 is formed in a shape that slopes to the right from top to bottom when viewed from the front, and the connecting portion 20B connects the positive electrode side connecting portion 20A and the negative electrode side connecting portion 20C. Specifically, the upper end of the connecting portion 20B is connected to the front end of the positive electrode side connecting portion 20A, and the lower end of the connecting portion 20B is connected to the front end of the negative electrode side connecting portion 20C. As a result, the cylindrical energy storage cell 32 housed in the second housing and the cylindrical energy storage cell 34 housed in the third housing are electrically connected by the busbar 20.

[0075] The busbar 22, like the busbar 18, is formed in a substantially U-shape and includes a positive electrode side connection portion 22A, a connecting portion 22B, and a negative electrode side connection portion 22C. The positive electrode side connection portion 22A extends in the front-rear direction along the positive electrode terminal of the cylindrical energy storage cell 34 in the third housing portion in which the cylindrical energy storage cell 34 is housed. The positive electrode side connection portion 22A and the positive electrode terminal of the cylindrical energy storage cell 34 are connected by a conductor (not shown).

[0076] The positive electrode connection portion 22A has eight communication holes 22D, and each communication hole 22D is formed in a position corresponding to the circular hole 16LU and is approximately the same size as the circular hole 16LU.

[0077] The negative electrode side connection portion 22C of the busbar 22 extends in the front-rear direction along the negative electrode terminal of the cylindrical energy storage cell 36 in the fourth housing portion where the cylindrical energy storage cell 36 is housed. Furthermore, the negative electrode side connection portion 22B and the negative electrode terminal of the cylindrical energy storage cell 36 are connected by a conductor (not shown).

[0078] The negative electrode connection portion 22B has eight communication holes 22E, and each communication hole 22E is formed in a position corresponding to the circular hole 16LL and is approximately the same size as the circular hole 16LL.

[0079] The connecting portion 22B of the busbar 22 is formed in a shape that slopes to the right as it goes from top to bottom when viewed from the front, and the connecting portion 22B connects the positive electrode side connecting portion 22A and the negative electrode side connecting portion 22C. Specifically, the upper end of the connecting portion 22B is connected to the front end of the positive electrode side connecting portion 22A, and the lower end of the connecting portion 22B is connected to the front end of the negative electrode side connecting portion 22C. As a result, the cylindrical energy storage cell 34 housed in the third housing and the cylindrical energy storage cell 36 housed in the fourth housing are electrically connected by the busbar 22.

[0080] As shown in Figures 2 and 4, a busbar 24 is provided on the positive terminal side of the cylindrical energy storage cell 36. The busbar 24 is substantially flat and has eight communication holes 24A formed at positions corresponding to the cylindrical energy storage cell 36. The busbar 24 and the positive terminal of the cylindrical energy storage cell 36 are connected by a wire (not shown).

[0081] As shown in Figures 3 and 4, a busbar 26 is provided on the negative terminal side of the cylindrical energy storage cell 30. The busbar 26 is substantially flat and has eight communication holes 26A formed at positions corresponding to the cylindrical energy storage cell 30. The busbar 26 and the negative terminal of the cylindrical energy storage cell 30 are connected by a wire (not shown).

[0082] Here, the eight cylindrical energy storage cells 30 housed in the first housing are at the same potential. Similarly, the eight cylindrical energy storage cells 32 housed in the second housing are also at the same potential. On the other hand, there is a potential difference between the electrode on one axial side of the cylindrical energy storage cell 30 and the electrode on one axial side of the cylindrical energy storage cell 32, so the electrodes on one axial side of the cylindrical energy storage cell 30 and the electrode on one axial side of the cylindrical energy storage cell 32 have different potentials.

[0083] Furthermore, the potentials of the eight cylindrical energy storage cells 32 and the eight cylindrical energy storage cells 34 are different, and the potentials of the eight cylindrical energy storage cells 34 and the eight cylindrical energy storage cells 36 are different. In other words, the potentials are different for each storage section.

[0084] As shown in Figure 4, the lower surface of the cell holder 16 is filled with gap filler 44. The gap filler 44 covers the entire lower surface of the module body 12. As a result, the entire negative terminal side of the cylindrical energy storage cells 30, 32, 34, and 36 is covered by the gap filler 44.

[0085] (Partition wall) Figure 5 is an enlarged cross-sectional view of the main parts of Figure 4. In particular, Figure 5 is an enlarged view of the main parts of the first housing partition wall 16Y1 that separates the first housing section, which houses the cylindrical energy storage cell 30, from the second housing section, which houses the cylindrical energy storage cell 32. The second housing partition wall 16Y2 that separates the second housing section from the third housing section, and the third housing partition wall 16Y3 that separates the third housing section from the fourth housing section, have a similar configuration.

[0086] As shown in Figure 5, a partition wall portion 16Z is provided at the upper end of the partition wall 16Y1 of the first storage section. The partition wall portion 16Z is integrally formed with the partition wall 16Y1 of the first storage section and extends upward from the upper wall portion 16F of the cell holder 16. In other words, the partition wall portion 16Z extends axially from the cylindrical energy storage cells 30 and 32, separating the first storage section from the second storage section.

[0087] Since the partition wall 16Z is wider than the partition wall 16Y1 of the first storage section, a portion of the upper surface of the cylindrical energy storage cell 30 and a portion of the upper surface of the cylindrical energy storage cell 32 are covered from above by this partition wall 16Z.

[0088] Specifically, the cylindrical energy storage cell 30 is composed of a cylindrical case body 30A that houses an electrode body (not shown) and a lid 30B that closes the opening of the case body 30A. The lid 30B is configured to close the opening at the upper end of the case body 30A by being crimped onto it, and a crimped portion 30C is formed along the outer circumference of the upper end of the cylindrical energy storage cell 30. The partition wall 16Z is in contact with the outer circumference of the cylindrical energy storage cell 30, including the crimped portion 30C, when the cylindrical energy storage cell 30 is housed in it.

[0089] The cylindrical energy storage cell 32, like the cylindrical energy storage cell 30, is composed of a cylindrical case body 32A that houses an electrode body (not shown) and a lid 32B that closes the opening of the case body 32A. A crimped portion 32C is formed along the outer circumference of the upper end of the cylindrical energy storage cell 32, and the partition wall 16Z is in contact with the outer circumference of the cylindrical energy storage cell 32, including the crimped portion 32C, when the cylindrical energy storage cell 32 is housed within it.

[0090] Furthermore, a sealing member 42 is provided on the upper surface of the partition wall portion 16Z, and the partition wall portion 16Z is pressed against the cover upper portion 14A of the cover 14 via the sealing member 42. The sealing member 42 provided between the cover 14 and the partition wall portion 16Z is made of an elastic material, such as resin or rubber.

[0091] The sealing member 42 may be bonded to the partition wall portion 16Z using an adhesive or the like. Alternatively, the sealing member 42 may be held between the cover 14 and the partition wall portion 16Z. Furthermore, the sealing member 42 may be molded by two-color molding when the cell holder 16 is molded. In this case, the cell holder 16 and the sealing member 42 may be molded as a single unit by using a resin softer than the molding resin of the cell holder 16 and performing two-color molding.

[0092] In this embodiment, the sealing member 42 is sandwiched between the partition wall portion 16Z and the sealing member 42, causing it to elastically deform and extend to the outside of the partition wall portion 16Z. However, the invention is not limited to this, and a sealing member wider than the partition wall portion 16Z may be used in an unloaded state.

[0093] The partition wall portion 16Z and the sealing member 42 are also provided at the upper end of the second housing partition wall 16Y2 and the upper end of the third housing partition wall 16Y3. In addition, the upper ends of the left wall portion 16A, the right wall portion 16C, the right front wall portion 16D, and the rear wall portion 16E of the cell holder 16 each have portions that extend upward from the cylindrical energy storage cells 30, 32, 34, and 36, similar to the partition wall portion 16Z, and are in contact with the cover upper portion 14A of the cover 14 via the sealing member 42.

[0094] (action) Next, the operation of the battery module 10 according to this embodiment will be explained.

[0095] As shown in Figure 4, the battery module 10 according to this embodiment includes a plurality of cylindrical energy storage cells 30, 32, 34, and 36 configured to store energy, and these cylindrical energy storage cells 30, 32, 34, and 36 are housed in a cell holder 16. The cell holder 16 is configured to house the plurality of cylindrical energy storage cells 30, 32, 34, and 36 with their axial directions aligned. The cell holder 16 also includes a first housing section in which cylindrical energy storage cell 30 is housed, and a second housing section in which cylindrical energy storage cell 32, which has a different potential from cylindrical energy storage cell 30, is housed.

[0096] As shown in Figure 5, a partition wall 16Z is provided between the first housing and the second housing, extending axially beyond the cylindrical energy storage cells 30 and 32 to separate the first housing and the second housing. This prevents the electrolyte from entering the adjacent housing even if, for example, electrolyte leaks from the positive terminal side of the cylindrical energy storage cell 30 housed in the first housing. In other words, a short circuit can be suppressed even if electrolyte leaks.

[0097] Furthermore, a partition wall 16Z is provided between the second and third housing sections, and also between the third and fourth housing sections. These partition walls 16Z prevent the electrolyte from entering housing sections with different potentials.

[0098] Furthermore, in this embodiment, as shown in Figure 4, the openings of the first, second, third, and fourth storage compartments are closed by the cover upper portion 14A of the cover 14. This prevents the electrolyte from entering adjacent storage compartments even if the liquid level of the leaked electrolyte rises.

[0099] In particular, in this embodiment, since the sealing member 42 is interposed between the partition wall 16Z and the cover 14, the sealing member 42 can more effectively suppress the intrusion of electrolyte. Furthermore, because the sealing member 42 is elastic, even if the cover 14 is locally deformed, the sealing member 42 deforms in accordance with the deformation, thereby suppressing the formation of a gap between the cover 14 and the partition wall 16Z. In addition, when assembling the cover 14 to the module body 12, the sealing member 42 can absorb assembly tolerances, thus improving the yield compared to a structure without the sealing member 42.

[0100] Furthermore, in this embodiment, since the sealing member 42 extends to the outside of the partition wall portion 16Z, it is possible to effectively prevent leaked electrolyte from entering the space between the cover 14 and the sealing member 42. In other words, even if the electrolyte level rises to approximately the upper end of the partition wall portion 16Z, it is possible to prevent the electrolyte from accumulating between the partition wall portion 16Z and the sealing member 42.

[0101] Furthermore, in this embodiment, since the cover 14 has higher rigidity than the cell holder 16, deformation of the cover 14 can be suppressed even when an external force is applied to the battery module 10, and a gap between the cover 14 and the cell holder 16 can be suppressed.

[0102] Furthermore, in this embodiment, as shown in Figure 5, since the crimped portion 30C of the cylindrical energy storage cell 30 is in contact with the partition portion 16Z, leakage of electrolyte from the crimped portion 30C can be suppressed. The same applies to the other cylindrical energy storage cells 32, 34, and 36.

[0103] Furthermore, in this embodiment, as shown in Figures 2 and 3, the busbar 18 is configured to include a positive electrode side connection portion 18A, a connecting portion 18B, and a negative electrode side connection portion 18C, and these are integrally formed. This makes it possible to reduce the number of conductive component parts while maintaining electrical conductivity between the cylindrical energy storage cell 30 housed in the first housing and the cylindrical energy storage cell 32 housed in the second housing. The same applies to busbars 20 and 22.

[0104] Furthermore, in this embodiment, as shown in Figure 4, the negative electrode terminal side of the cell holder 16 is sealed by a gap filler 44. This prevents the electrolyte from leaking to the outside of the cell holder 16, even if electrolyte leaks from the positive electrode side of the cylindrical energy storage cell 30 and flows into the negative electrode side, thanks to the gap filler 44.

[0105] <Second Embodiment> Next, a power storage device according to the second embodiment will be described. Components similar to those in the first embodiment will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0106] Figure 6 is a schematic exploded perspective view of the energy storage device according to the second embodiment. As shown in Figure 6, the battery module 50 as the energy storage device according to this embodiment includes a module body 12 similar to that of the first embodiment.

[0107] In this embodiment, the module body 12 is configured to include an upper case 52 that closes the upper opening and a front case 54 that closes the front side of the module body 12. The upper case 52 is substantially rectangular in shape when viewed from above and is made of a metal or the like that which has higher rigidity than the cell holder 16, but is not limited to this. Similarly, the front case 54 is substantially rectangular in shape when viewed from the front and is made of a metal or the like that which has higher rigidity than the cell holder 16, but is not limited to this.

[0108] Here, the upper case 52 extends to the upper end surface of the front case 54, and the upper case 52 and the front case 54 are mechanically fastened together by bolts and nuts. At this time, the space between the upper case 52 and the front case 54 is sealed by a sealing member (not shown).

[0109] (action) Next, the operation of the battery module 50 according to this embodiment will be explained.

[0110] In the battery module 50 of this embodiment, compared to the first embodiment, the case is separated into an upper case 52 and a front case 54, making assembly to the module body 12 easier. Other functions are the same as in the first embodiment.

[0111] <Third Embodiment> Next, a power storage device according to the third embodiment will be described. Components similar to those in the first embodiment will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0112] Figure 7 is a schematic exploded perspective view of the energy storage device according to the third embodiment. As shown in Figure 7, the battery module 60 as the energy storage device according to this embodiment includes a module body 12 similar to that of the first embodiment.

[0113] Furthermore, in this embodiment, a case 62 is provided to cover the module body 12, and the case 62 is composed of a cover upper portion 62A, a cover side portion 62B, and a case lower portion 62C.

[0114] The cover upper portion 62A is formed in a substantially rectangular plate shape in plan view so as to cover the upper surface of the module body 12. The cover side portion 62B extends downward from the front end of the cover upper portion 62A and is formed in a substantially rectangular plate shape in front view so as to cover the front surface of the module body 12. Furthermore, the case lower portion 62C extends rearward from the lower end of the cover side portion 62B and is formed in a substantially rectangular plate shape in plan view, similar to the cover upper portion 62A. For this reason, the case 62 in this embodiment is formed in a substantially U-shape with the rear side open.

[0115] The case 62 is formed of a metal or the like that has higher rigidity than the cell holder 16, but is not limited to this, and the material of the case 62 may be changed as appropriate.

[0116] (action) Next, the operation of the battery module 60 according to this embodiment will be explained.

[0117] In the battery module 60 of this embodiment, the lower surface of the module body 12 is covered by the case 62. Therefore, unlike in the first embodiment, leakage of electrolyte from the lower surface of the module body 12 can be suppressed without filling the lower surface of the module body 12 with a gap filler 44. Other functions are the same as in the first embodiment.

[0118] <Fourth Embodiment> Next, a power storage device according to the fourth embodiment will be described. Components similar to those in the first embodiment will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0119] Figure 8 is a plan view of the module body 72 that constitutes the battery module 70 as an energy storage device according to the fourth embodiment. As shown in Figure 8, the module body 72 is composed of a cell holder 16, bus bars 18, 20, 22, and 24.

[0120] Here, the cell holder 16 of this embodiment differs in some structural aspects from the cell holder 16 of the first embodiment. Specifically, the cell holder 16 is composed of a left wall portion 16A, a right wall portion 16C, and a rear wall portion 16E.

[0121] A partition wall 16Y1 is provided between the first accommodation section, which is equipped with a bus bar 18, and the second accommodation section, which is equipped with a bus bar 20, to separate the two accommodation sections. A partition wall 16Z is provided at the upper end of this partition wall 16Y1.

[0122] Furthermore, a second accommodation partition wall 16Y2 is provided between the second accommodation section, where the bus bar 20 is provided, and the 23rd accommodation section, where the bus bar 22 is provided, to separate the two accommodation sections. A partition wall 16Z is provided at the upper end of this second accommodation partition wall 16Y2.

[0123] Furthermore, a partition wall 16Y3 is provided between the third accommodation section, which is equipped with a bus bar 22, and the fourth accommodation section, which is equipped with a bus bar 24, to separate the two accommodation sections. A partition wall 16Z is provided at the upper end of this partition wall 16Y3.

[0124] In this embodiment, the cell holder 16 is equipped with multiple barbs. A barb 74A is provided at the front end of the left wall portion 16A. Since the barb 74A is formed to widen towards the tip (forward), the front end of the left wall portion 16A is bent to the right.

[0125] The front end of the partition wall 16Y1 of the first accommodation section is provided with a return section 74B and a return section 74C. Both the return section 74B and the return section 74C are formed to widen towards their respective ends. Specifically, the return section 74B extends to the left, and the return section 74C extends to the right. Therefore, the return sections 74B and 74C are located between the connecting section 18B of the bus bar 18 and the connecting section 20B of the bus bar 20, and extend in opposite directions.

[0126] The front end of the partition wall 16Y2 of the second accommodation section is provided with a return section 74D and a return section 74E. Both the return section 74D and the return section 74E are formed to widen towards their respective ends. Specifically, the return section 74D extends to the left, and the return section 74E extends to the right. Therefore, the return sections 74D and 74E are located between the connecting section 20B of the bus bar 20 and the connecting section 22B of the bus bar 22, and extend in opposite directions.

[0127] A return section 74F is provided at the front end of the partition wall 16Y3 of the third storage area. The return section 74F is formed to widen towards the tip, so that the right front wall section 16D extends to the left of the partition wall 16Y3 of the third storage area.

[0128] (action) Next, the operation of the battery module 70 according to this embodiment will be explained.

[0129] In the battery module 70 according to this embodiment, even if electrolyte leaks from the first housing and flows downward along the connecting portion 18B of the busbar 18, the return portions 74A and 74B can prevent the electrolyte from entering the adjacent second housing.

[0130] Similarly, even if electrolyte leaks from the second and third storage sections, the return sections 74C, 74D, 74E, and 74F can prevent the electrolyte from entering the two adjacent storage sections. Other functions are the same as in the first embodiment.

[0131] <Fifth Embodiment> Next, a power storage device according to the fifth embodiment will be described. Components similar to those in the first embodiment will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0132] Figure 9 is an enlarged cross-sectional view of the main part of the battery module 80 as an energy storage device according to the fifth embodiment. As shown in Figure 9, in the battery module 80 according to this embodiment, an insulating member 82 is provided on the lower surface of the cover 14.

[0133] The battery module 80 includes a module body 12 similar to that of the first embodiment. The opening at the top of the module body 12 is closed by the cover upper portion 14A of the cover 14. An insulating member 82 is provided on the lower surface of the cover upper portion 14A.

[0134] The insulating member 82 is made of an insulating material and is attached to the cover upper portion 14A by methods such as coating, attaching, or bonding. In this embodiment, as an example, the insulating member 82 is provided over the entire lower surface of the cover upper portion 14A, but it is not limited to this, and the insulating member 82 may be provided only in the portion where the cover 14 and the sealing member 42 are in contact.

[0135] Since the sealing member 42 is sandwiched between the insulating member 82 and the partition wall portion 16Z, there is no gap between the sealing member 42 and the insulating member 82 (cover upper portion 14A).

[0136] (action) Next, the operation of the battery module 80 according to this embodiment will be explained.

[0137] In the battery module 80 of this embodiment, since an insulating member 82 is provided at the point where the cover 14 and the sealing member 42 are in contact, even if the cover 14 is made of a conductive material and leaked electrolyte moves along the sealing member 42 towards the cover 14, electrical conductivity between the cylindrical energy storage cell 30 or cylindrical energy storage cell 32 and the cover 14 can be suppressed, preventing leakage. The same applies to other cylindrical energy storage cells. Furthermore, other functions are the same as in the first embodiment.

[0138] Although the embodiments and modified versions of the battery modules 10, 50, 60, 70, and 80 have been described above, the invention is not limited thereto and can be implemented in various forms without departing from the spirit of the present invention. For example, in the above embodiments, as shown in Figure 2, the module body 12 is covered by a cover 14 on the upper and front sides, but the invention is not limited thereto. For example, a case that covers the four side surfaces and the top surface of the module body 12 may be used.

[0139] Furthermore, in the above embodiment, as shown in Figure 4, a sealing member 42 is sandwiched between the partition wall 16Z and the cover 14, but the invention is not limited to this. For example, the sealing member may be attached to the entire lower surface of the cover 14. In this case, the sealing member can prevent the electrolyte from coming into contact with the cover 14 without the need to provide a separate insulating member.

[0140] Furthermore, in the above embodiment, as shown in Figure 5, the sealing member 42 is configured to extend outward beyond the partition wall portion 16Z, but the embodiment is not limited to this. Even if a sealing member narrower than the partition wall portion 16Z is used, as long as the cover 14 is in close contact with the sealing member, it is possible to suppress the intrusion of electrolyte into adjacent storage portions.

[0141] Furthermore, the structure may be configured without interposing a sealing member 42 between the cover 14 and the partition wall portion 16Z. For example, if the upper end of the partition wall portion 16Z is elastically deformable, sealing can be achieved by pressing the partition wall portion 16Z with the cover 14 even without a sealing member. Alternatively, the upper end of the partition wall portion may be shaped to gradually widen. In this case, a lip portion will be formed on the partition wall portion.

[0142] The following additional information is disclosed regarding the above embodiment.

[0143] (Note 1) Multiple cylindrical energy storage cells configured to store energy, A cell holder comprising: a first housing capable of housing multiple cylindrical energy storage cells with their axial directions aligned; a second housing capable of housing cylindrical energy storage cells having a different potential from those housing the cylindrical energy storage cells in the first housing; and a partition wall between the first housing and the second housing, extending axially beyond the cylindrical energy storage cells to separate the first housing and the second housing; A power storage device having the following features. (Note 2) The energy storage device according to Appendix 1, further comprising a cover that is in contact with the partition wall and closes the openings of the first and second storage sections. (Note 3) The energy storage device according to Appendix 2, wherein an elastic sealing member is interposed between the partition wall and the cover. (Note 4) The energy storage device according to Appendix 3, wherein the sealing member extends outward from the partition wall portion. (Note 5) The energy storage device according to any one of Appendix 2 to Appendix 4, wherein the cover is formed of a material with higher rigidity than the cell holder. (Note 6) An insulating member is provided at the portion where the cover and the sealing member come into contact, as described in any one of Appendix 3 to Appendix 5. (Note 7) The cylindrical energy storage cell comprises a cylindrical case body that houses an electrode body and a lid that closes the opening of the case body by being crimped onto the case body. The crimped portion of the cylindrical energy storage cell is in contact with the partition wall portion when the cylindrical energy storage cell is housed in the cell holder, as described in any one of Appendix 1 to Appendix 6 of the energy storage device. (Note 8) The device includes a conductive member that electrically connects the cylindrical energy storage cell housed in the first housing and the cylindrical energy storage cell housed in the second housing, The energy storage device according to any one of Appendix 1 to Appendix 7, wherein the conductive member comprises a positive electrode side connecting portion extending along the positive electrode terminal of one of the cylindrical energy storage cells in the first housing portion and the second housing portion, a negative electrode side connecting portion extending along the negative electrode terminal of the other cylindrical energy storage cell, and a connecting portion that connects the positive electrode side connecting portion and the negative electrode side connecting portion along the side wall of the cell holder. (Note 9) Multiple conductive members are provided, The energy storage device according to Appendix 8, wherein, in the holder, a barb portion that widens towards the tip is provided between adjacent connecting portions. (Note 10) The energy storage device according to Appendix 8 or 9, wherein the positive electrode side connection portion, the negative electrode side connection portion, and the connecting portion are integrally formed. (Note 11) The energy storage device according to any one of the appendices 8 to 10, wherein a gap filler is filled on the negative terminal side of the cylindrical energy storage cell in the cell holder. [Explanation of Symbols]

[0144] 10, 50, 60, 70, 80 Battery Modules (Energy Storage Devices) 14, 62 cases 16 Cell holder 16Z Bulkhead 18, 20, 22 Busbars (conductive components) 30, 32, 34, 36 Cylindrical Energy Storage Cells 30A, 32A Case Body 30B, 32B lid body 30C, 32C crimping section 42 sealing member 44 Gap Filler 74A, 74B, 74C, 74D, 74E, 74F Return section 82 Insulating material

Claims

1. Multiple cylindrical energy storage cells, A cell holder comprising: a first housing capable of housing multiple cylindrical energy storage cells with their axial directions aligned; a second housing capable of housing cylindrical energy storage cells in which an electrode with a different potential from the electrode located on one side in the axial direction of the cylindrical energy storage cell housing in the first housing is located on one side in the axial direction; and a partition wall portion is provided between the first housing and the second housing, extending to one side in the axial direction from the cylindrical energy storage cells and separating the first housing and the second housing. A power storage device having the following features.

2. The energy storage device according to claim 1, further comprising a cover that is in contact with the partition wall and closes the openings of the first and second storage sections.

3. The energy storage device according to claim 2, wherein an elastic sealing member is interposed between the partition wall and the cover.

4. The energy storage device according to claim 3, wherein the sealing member extends to the outside of the partition wall portion.

5. The energy storage device according to claim 2, wherein the cover is formed of a material with higher rigidity than the cell holder.

6. An insulating member is provided at the portion where the cover and the sealing member are in contact, as described in claim 3.

7. The cylindrical energy storage cell comprises a cylindrical case body that houses an electrode body and a lid that closes the opening of the case body by being crimped onto the case body. The energy storage device according to claim 1, wherein the crimped portion of the cylindrical energy storage cell is in contact with the partition wall portion when the cylindrical energy storage cell is housed in the cell holder.

8. The device includes a conductive member that electrically connects the cylindrical energy storage cell housed in the first housing and the cylindrical energy storage cell housed in the second housing, The energy storage device according to claim 1, wherein the conductive member comprises a positive electrode side connecting portion extending along the positive electrode terminal of one of the cylindrical energy storage cells in the first housing portion and the second housing portion, a negative electrode side connecting portion extending along the negative electrode terminal of the other cylindrical energy storage cell, and a connecting portion that connects the positive electrode side connecting portion and the negative electrode side connecting portion along the side wall of the cell holder.

9. Multiple conductive members are provided, The energy storage device according to claim 8, wherein a barb portion that widens toward the tip is provided between adjacent connecting portions in the cell holder.

10. The energy storage device according to claim 8, wherein the positive electrode side connection portion, the negative electrode side connection portion, and the connecting portion are integrally formed.

11. The energy storage device according to claim 8, wherein a gap filler is filled on the negative electrode terminal side of the cylindrical energy storage cell in the cell holder.

Images