Energy Storage Module

Abstract

To provide an energy storage module capable of easily engaging a busbar case to an end plate.SOLUTION: In an energy storage module 1, a busbar case 45 holds multiple busbars 41. The busbar case 45 has a first-end case 46, a second-end case 47, and a connection part 48. The first end case 46 engages with the first end plate 20. The second end case 47 is located at a distance in a first direction D1 with respect to the first end case 46 and engages with the second end plate 30. The connection part 48 connects the first end case 46 and the second end case 47 to each other. The connection part 48 has a first telescopic part 481 capable of stretching in a first direction D1.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] JP 2021-132016 A (Patent Document 1) discloses an energy storage device including a plurality of energy storage elements, a pair of end plates, a bus bar, and a bus bar frame. The energy storage elements have electrode terminals protruding in a first direction. The pair of end plates are arranged at positions sandwiching the plurality of energy storage elements in a second direction intersecting the first direction. The bus bar frame is an insulating member capable of regulating the position of the bus bar. The bus bar frame is arranged in the first direction of the plurality of energy storage elements and is attached to both of the pair of end plates. The bus bar frame is positioned with respect to the plurality of energy storage elements. As a result, the bus bar is positioned with respect to the plurality of energy storage elements and joined to the electrode terminals of the plurality of energy storage elements. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-132016 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a conventional energy storage module, the total length of the cells in the direction in which the pair of end plates are arranged, or the length of the busbar case (busbar frame) may differ from the design dimensions within the tolerance range. If these lengths differ relatively significantly from the design dimensions, it may be difficult to engage the pair of end plates with the busbar case (busbar frame) during manufacturing of the energy storage module.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide an energy storage module in which a busbar case can be easily engaged with an end plate. [Means for solving the problem]

[0006] An energy storage module according to an aspect of the present disclosure includes a plurality of cells, a first end plate, a second end plate, and a busbar module. The plurality of cells are arranged to be aligned in a first direction. Each of the plurality of cells has a pair of external terminals. The first end plate is arranged to be aligned on one side of the plurality of cells in the first direction. The second end plate is arranged to be aligned on the opposite side of the first end plate from the plurality of cells. The busbar module is arranged on one side in a second direction perpendicular to the first direction from the plurality of cells, the first end plate, and the second end plate. The busbar module includes a plurality of busbars and a busbar case. The plurality of busbars electrically connect the external terminals adjacent to each other in the first direction. The busbar case holds the plurality of busbars. The busbar case includes a first end case, a second end case, and a connection portion. The first end case engages with the first end plate. The second end case engages with the second end plate while being spaced apart from the first end case in the first direction. The connecting portion connects the first end case and the second end case to each other. The connecting portion has a first elastic portion that is elastic in a first direction.

[0007] According to the above configuration, even if the total length of the multiple cells in the first direction differs relatively greatly from the design dimension, the busbar case can be easily engaged with the first end plate and the second end plate by expanding and contracting the first expansion portion.

[0008] In one embodiment of the present disclosure, the connection section further includes a central case and a second telescopic section. The central case is connected to the first end case via the first telescopic section. The second telescopic section is telescopic in a first direction while connecting the central case and the second end case to each other.

[0009] According to the above configuration, even if the lengths of the multiple cells in the first direction differ relatively greatly from the design dimensions, the busbar case can be more easily engaged with the first end plate and the second end plate by expanding and contracting the second expandable portion in addition to the first expandable portion.

[0010] In one embodiment of the present disclosure, the first end plate has a base and an engaged portion. The base extends along the second direction. The engaged portion extends from the base along the first direction. A through hole extending along the second direction is formed in the engaged portion. The first end case has a columnar portion and an engaging portion. The columnar portion extends along the second direction and is inserted into the through hole. The engaging portion is located at the tip of the columnar portion and is capable of engaging with the engaged portion in the second direction.

[0011] According to the above configuration, the busbar case and the first end plate can be more firmly engaged in the second direction.

[0012] In one embodiment of the present disclosure, the central case has a protrusion that protrudes along the second direction. The protrusion is located between a pair of cells among the plurality of cells.

[0013] According to the above configuration, by inserting the protrusion between the cells when manufacturing the energy storage module, the position of the central case relative to the multiple cells in the first direction can be easily determined.

[0014] In one embodiment of the present disclosure, the energy storage module further includes a center plate disposed between the pair of cells. The center plate has a central engaged portion that engages with the protrusion.

[0015] According to the above configuration, by engaging the protruding portion with the central engaged portion during manufacturing of the energy storage module, the relative position of the central case in the first direction with respect to the multiple cells can be more easily determined.

[0016] In one embodiment of the present disclosure, the protrusion is fitted between the pair of cells so as to contact the pair of cells.

[0017] According to the above configuration, by fitting the protrusion between the cells when manufacturing the energy storage module, the relative position of the central case in the first direction with respect to the multiple cells can be more easily determined. Effect of the Invention

[0018] According to the present disclosure, the busbar case can be easily engaged with the end plate. [Brief description of the drawings]

[0019] [Figure 1] FIG. 2 is a plan view of an energy storage module according to an embodiment of the present disclosure. [Diagram 2] 1 is a plan view showing an energy storage module according to an embodiment of the present disclosure with some configuration omitted. [Diagram 3] 3 is a partial cross-sectional view of the electricity storage module of FIG. 1 as viewed from the direction of the arrows indicated by the line III-III. [Figure 4] 2 is an enlarged partial plan view showing a region IV in FIG. 1. FIG. [Diagram 5] FIG. 2 is a partial plan view showing a part of the bus bar module. [Figure 6] 6 is a partial cross-sectional view of the energy storage module of FIG. 1 as viewed in the direction of the arrows along line VI-VI. [Figure 7] 7 is a partial cross-sectional view of the electricity storage module of FIG. 6, as viewed in the direction of the arrows VII-VII. [Figure 8] 13 is a partial cross-sectional view of a power storage module according to a modified example of an embodiment of the present disclosure. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, an electric storage module according to an embodiment of the present disclosure will be described. In the following description of the embodiment, the same or corresponding parts in the drawings are denoted by the same reference characters, and description thereof will not be repeated.

[0021] Fig. 1 is a plan view of an energy storage module according to an embodiment of the present disclosure. Fig. 2 is a plan view showing an energy storage module according to an embodiment of the present disclosure with some configuration omitted. As shown in Figs. 1 and 2, an energy storage module 1 according to an embodiment of the present disclosure includes a plurality of cells 10, a first end plate 20, a second end plate 30, a bus bar module 40, and a center plate 50. Note that Fig. 2 illustrates the energy storage module 1 with the bus bar module 40 omitted. The energy storage module 1 is mounted on, for example, a vehicle.

[0022] An example of the multiple cells 10 is a lithium ion battery. The multiple cells 10 are arranged to be aligned in a first direction D1. Each of the multiple cells 10 has a pair of external terminals 11 aligned along a third direction D3 perpendicular to the first direction D1. One of the pair of external terminals 11 is a positive terminal, and the other is a negative terminal.

[0023] Each of the multiple cells 10 further has a case 12 having a substantially rectangular parallelepiped shape. The case 12 houses electrodes and the like. The case 12 is made of aluminum and the like. Each of the external terminals 11 protrudes from the case 12 along a second direction D2 perpendicular to both the first direction D1 and the third direction D3.

[0024] Each of the multiple cells 10 may be a battery having a liquid electrolyte housed within the case 12. Each of the multiple cells 10 may be a battery having a solid electrolyte housed within the case 12 (an all-solid-state battery).

[0025] The first end plate 20 is arranged in the first direction D1 so as to be further aligned on one side of the plurality of cells 10. The first end plate 20 is made of an insulating material, such as a synthetic resin.

[0026] Fig. 3 is a partial cross-sectional view of the energy storage module as viewed from the direction of the arrows III-III in Fig. 1. As shown in Fig. 3, the first end plate 20 has a base portion 21 and a locked portion 25.

[0027] The base portion 21 extends along the second direction D2. The base portion 21 has a flat plate-like outer shape extending along both the second direction D2 and the third direction D3.

[0028] The locked portion 25 extends from the base 21 in the first direction D1. The locked portion 25 extends on the opposite side to the multiple cells 10 as viewed from the base 21. The locked portion 25 extends from an end of the base 21 in the second direction D2. A through hole 251 extending along the second direction D2 is formed in the locked portion 25. As shown in FIG. 2, the locked portion 25 has a plurality of through holes 251 formed therein. The multiple through holes 251 are aligned in the third direction D3.

[0029] The second end plate 30 is arranged to be aligned with the multiple cells 10 on the opposite side of the first end plate 20 as viewed from the multiple cells 10. The second end plate 30 is arranged approximately line-symmetrically with respect to the first end plate 20 as viewed from the multiple cells 10. In addition, the second end plate 30 has an outer shape that is approximately line-symmetrical with respect to the first end plate 20 in the first direction D1.

[0030] Fig. 4 is a partial plan view showing an enlarged view of region IV in Fig. 1. Fig. 5 is a partial plan view showing a part of the busbar module. As shown in Figs. 1 to 5, the busbar module 40 is disposed on one side in the second direction D2 as viewed from the multiple cells 10, the first end plate 20, and the second end plate 30. The busbar module 40 has multiple busbars 41 and a busbar case 45. Note that Fig. 1 shows only the outer shape of the busbar case 45 in a plan view.

[0031] The multiple bus bars 41 electrically connect the external terminals 11 adjacent to each other in the first direction D1. Each of the multiple bus bars 41 electrically connects a positive electrode terminal of one cell 10 to a negative electrode terminal of another cell 10 adjacent to the one cell 10.

[0032] Each of the bus bars 41 has a pair of welded parts 411. The pair of welded parts 411 are positioned side by side in the first direction D1. The welded parts 411 have a flat plate-like outer shape extending along the first direction D1 and the third direction D3. The pair of welded parts 411 are welded to the external terminals 11, respectively, so that the bus bars 41 and the external terminals 11 are electrically connected to each other.

[0033] Busbar case 45 holds a plurality of busbars 41. Busbar case 45 is made of an insulating material, such as synthetic resin. Busbar case 45 has a first end case 46, a second end case 47, and a connection portion 48. In busbar case 45, first end case 46, second end case 47, and connection portion 48 are integrally molded with one another.

[0034] The first end case 46 holds the bus bar 41 so as to engage the bus bar 41 in the first direction D1 and the third direction D3. The first end case 46 holds at least one bus bar 41. In the present embodiment, the first end case 46 holds only one bus bar 41. The first end case 46 engages with the first end plate 20.

[0035] The first end case 46 has a columnar portion 461, a locking portion 462, and an abutment portion 463. The columnar portion 461 extends along the second direction D2 and is inserted into the through hole 251. The locking portion 462 is located at the tip of the columnar portion 461 and can be locked with the locked portion 25 in the second direction D2. The locking portion 462 has a claw-shaped outer shape. The abutment portion 463 at least abuts against the through hole 251 in the first direction D1. The abutment portion 463 extends along the second direction D2 and is inserted into the through hole 251. The abutment portion 463 is located apart from the columnar portion 461 in the first direction D1. The locking portion 462 protrudes from the columnar portion 461 on the opposite side to the abutment portion 463 when viewed from the columnar portion 461. The locking portion 462 has a tapered surface that approaches the abutment portion 463 toward the tip side of the columnar portion 461. This makes it easy to insert the columnar portion 461, the locking portion 462, and the abutment portion 463 into the through hole 251. In this manner, the first end case 46 engages with the first end plate 20 by a so-called snap-fit ​​shape.

[0036] Furthermore, the first end case 46 has a plurality of columnar portions 461, a plurality of locking portions 462, and a plurality of contact portions 463 so as to correspond to the plurality of through holes 251 in the first end plate 20, respectively.

[0037] The second end case 47 is located away from the first end case 46 in the first direction D1. The second end case 47 holds the bus bar 41 so as to engage the bus bar 41 in the first direction D1 and the third direction D3. The second end case 47 holds at least one bus bar 41. In this embodiment, the second end case 47 holds only one bus bar 41. The second end case 47 engages with the second end plate 30.

[0038] The second end case 47 is disposed approximately line-symmetrically with respect to the first end case 46 when viewed from the connection portion 48. The second end case 47 also has an outer shape that is approximately line-symmetrical with respect to the first end case 46 in the first direction D1.

[0039] The connecting portion 48 connects the first end case 46 and the second end case 47 to each other in the first direction D1. The connecting portion 48 has a first stretchable portion 481, a central case 482, and a second stretchable portion 483.

[0040] The first telescopic portion 481 is telescopic in the first direction D1. The first telescopic portion 481 is in the form of a leaf spring and is configured to be elastically deformable in the first direction D1. The first telescopic portion 481 is configured to be capable of biasing the first end case 46 and the central case 482 in a direction in which they move away from each other in the first direction D1. In turn, the first telescopic portion 481 is configured to be capable of biasing the first end case 46 and the second end case 47 in a direction in which they move away from each other in the first direction D1. In addition, the connection portion 48 has a plurality of first telescopic portions 481. The plurality of first telescopic portions 481 are positioned side by side in the third direction D3.

[0041] The specific shape of the first expandable portion 481 is not limited to a leaf spring shape. The first expandable portion 481 may be a hinge or a connecting mechanism that allows the first end case 46 and the central case 482 to slide relative to each other in the first direction D1.

[0042] The central case 482 is connected to the first end case 46 via the first telescopic portion 481. The central case 482 holds the bus bars 41 so as to lock the bus bars 41 in the first direction D1 and the third direction D3. The dimension of the central case 482 in the first direction D1 is longer than the dimensions of the first end case 46 and the second end case 47. This prevents the first end case 46 and the second end case 47 from sagging down from the central case 482 when the central case 482 is gripped during the manufacture of the energy storage module 1, making it easier to handle the bus bar module 40. It is preferable that the dimension of the central case 482 in the first direction D1 is at least twice the dimensions of the first end case 46 and the second end case 47 in the first direction D1.

[0043] FIG. 6 is a partial cross-sectional view of the power storage module of FIG. 1 as viewed from the direction of the arrows IV-IV. FIG. 7 is a partial cross-sectional view of the power storage module of FIG. 6 as viewed from the direction of the arrows VII-VII. As shown in FIG. 6 and FIG. 7, the central case 482 has a protruding portion 482a protruding along the second direction D2. The protruding portion 482a is located between a pair of cells 10 among the multiple cells 10. In this embodiment, the protruding portion 482a has a substantially cross-shaped outer shape as viewed from the second direction D2. The central case 482 has a plurality of protruding portions 482a. The multiple protruding portions 482a are aligned in the third direction D3.

[0044] The second telescopic portion 483 can be extended and retracted in the first direction D1 while connecting the central case 482 and the second end case 47 to each other. The second telescopic portion 483 is also in the shape of a leaf spring like the first telescopic portion 481, and is configured to be elastically deformable in the first direction D1. The second telescopic portion 483 urges the second end case 47 and the central case 482 in a direction in which they move away from each other in the first direction D1. In addition, the second telescopic portion 483 urges the first end case 46 and the second end case 47 in a direction in which they move away from each other in the first direction D1. In addition, the connection portion 48 has a plurality of second telescopic portions 483. The plurality of second telescopic portions 483 are positioned side by side in the third direction D3. Note that the second telescopic portion 483 is not limited to being in the shape of a leaf spring like the first telescopic portion 481.

[0045] The center plate 50 is disposed between the pair of cells 10. The center plate 50 is made of an insulating material, such as a synthetic resin.

[0046] The center plate 50 has a central engaged portion 51 that engages with the protruding portion 482a. The central engaged portion 51 is located at the end of the center plate 50 on the central case 482 side. The engaged portion 51 has a hole 511 that extends along the second direction D2. The protruding portion 482a is inserted into the hole 511. The protruding portion 482a abuts against the hole 511 in the first direction D1, thereby fixing the position of the protruding portion 482a relative to the center plate 50 in the first direction D1.

[0047] The energy storage module 1 further includes a plurality of spacers 60. The plurality of spacers are respectively positioned in the first direction D1 between the plurality of cells 10, between the cell 10 and the first end plate 20, between the cell 10 and the second end plate 30, and between the center plate 50 and the cell 10. The plurality of spacers 60 are made of an insulating material, such as synthetic rubber.

[0048] The energy storage module 1 further includes a restraining band 70. The restraining band 70 extends along the first direction D1. The restraining band 70 engages with the first end plate 20 and the second end plate 30, respectively. The restraining band 70 may be configured to be capable of acting in a direction compressing the multiple cells 10, the first end plate 20, the second end plate 30, the center plate 50, and the multiple spacers 60 arranged in the first direction D1, in the first direction D1. This determines the relative positions of the multiple cells 10, the first end plate 20, the second end plate 30, the center plate 50, and the multiple spacers 60.

[0049] As described above, the energy storage module 1 according to an embodiment of the present disclosure includes a plurality of cells 10, a first end plate 20, a second end plate 30, and a busbar module 40. The plurality of cells 10 are arranged to be aligned in a first direction D1. Each of the plurality of cells 10 has a pair of external terminals 11. The first end plate 20 is arranged to be aligned on one side of the plurality of cells 10 in the first direction D1. The second end plate 30 is arranged to be aligned on the opposite side of the plurality of cells 10 to the first end plate 20. The busbar module 40 is arranged on one side in a second direction D2 perpendicular to the first direction D1 as viewed from the plurality of cells 10, the first end plate 20, and the second end plate 30. The busbar module 40 includes a plurality of busbars 41 and a busbar case 45. The plurality of busbars 41 electrically connect the external terminals 11 adjacent to each other in the first direction D1. The busbar case 45 holds the plurality of busbars 41. The busbar case 45 has a first end case 46, a second end case 47, and a connecting portion 48. The first end case 46 engages with the first end plate 20. The second end case 47 engages with the second end plate 30 while being spaced apart from the first end case 46 in the first direction D1. The connecting portion 48 connects the first end case 46 and the second end case 47 to each other. The connecting portion 48 has a first expanding portion 481 that is expandable and contractable in the first direction D1.

[0050] According to the above configuration, even if the total length of the multiple cells 10 in the first direction D1 differs relatively greatly from the design dimension, the busbar case 45 can be easily engaged with the first end plate 20 and the second end plate 30 by expanding and contracting the first expansion portion.

[0051] In one embodiment of the present disclosure, the connection portion 48 further includes a central case 482 and a second telescopic portion 483. The central case 482 is connected to the first end case 46 via the first telescopic portion 481. The second telescopic portion 483 is telescopic in the first direction D1 while connecting the central case 482 and the second end case 47 to each other.

[0052] According to the above configuration, even if the lengths of the multiple cells 10 in the first direction D1 differ relatively greatly from the design dimensions, the busbar case 45 can be more easily engaged with the first end plate 20 and the second end plate 30 by expanding and contracting the second expandable portion in addition to the first expandable portion.

[0053] In one embodiment of the present disclosure, the first end plate 20 has a base 21 and a locked portion 25. The base 21 extends along the second direction D2. The locked portion 25 extends from the base 21 along the first direction D1. A through hole 251 extending along the second direction D2 is formed in the locked portion 25. The first end case 46 has a columnar portion 461 and a locking portion 462. The columnar portion 461 extends along the second direction D2 and is inserted into the through hole 251. The locking portion 462 is located at the tip of the columnar portion 461 and can be locked with the locked portion 25 in the second direction D2.

[0054] According to the above configuration, the busbar case 45 and the first end plate 20 can be more firmly engaged in the second direction D2. Furthermore, when the first expandable portion 481 is elastically deformed in the first direction D1, the biasing force from the first expandable portion 481 prevents the first end case 46 from moving away from the first end plate 20, and prevents the engagement between the first end case 46 and the first end plate 20 from being released. As a result, the first end case 46 can be easily assembled to the first end plate 20.

[0055] In one embodiment of the present disclosure, the central case 482 has a protruding portion 482a that protrudes along the second direction D2. The protruding portion 482a is located between a pair of cells 10 among the multiple cells 10.

[0056] According to the above configuration, by placing the protrusions 482a between the cells 10 when manufacturing the energy storage module 1, the relative position of the central case 482 in the first direction D1 with respect to the multiple cells 10 can be easily determined.

[0057] In one embodiment of the present disclosure, the energy storage module 1 further includes a center plate 50 disposed between the pair of cells 10. The center plate 50 has a central engaged portion 51 that engages with the protruding portion 482a.

[0058] According to the above configuration, by engaging the protruding portion 482a with the central engaged portion 51 during manufacture of the energy storage module 1, the relative position of the central case 482 in the first direction D1 with respect to the multiple cells 10 can be determined more easily.

[0059] Note that the protrusion 482a is not limited to the above structure, and does not have to be engaged with the center plate 50. Fig. 8 is a partial cross-sectional view of an electricity storage module according to a modified example of an embodiment of the present disclosure. In the modified example of the embodiment of the present disclosure, the protrusion 482b is fitted between the pair of cells 10 so as to contact the pair of cells 10. This makes it easier to determine the relative position of the central case 482 in the first direction D1 with respect to the multiple cells 10 by fitting the protrusion 482a between the cells 10 during manufacturing of the electricity storage module 1.

[0060] Moreover, the protrusion 482b has a tapered shape such that the width dimension in the first direction D1 decreases toward the tip side in the protruding direction. This makes it easy to fit the protrusion 482b between the pair of cells 10. Note that, in addition to the protrusion 482a described above, the center plate 50 may further have a protrusion 482b in this modified example that is different from the protrusion 482a described above.

[0061] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0062] REFERENCE SIGNS LIST 1 energy storage module, 10 cell, 11 external terminal, 12 case, 20 first end plate, 21 base, 25 engaged portion, 251 through hole, 30 second end plate, 40 busbar module, 41 busbar, 411 welded portion, 45 busbar case, 46 first end case, 461 columnar portion, 462 engaging portion, 463 abutment portion, 47 second end case, 48 connection portion, 481 first expandable portion, 482 center case, 482a, 482b protruding portions, 483 second expandable portion, 50 center plate, 51 engaged portion, 511 hole portion, 60 spacer, 70 restraining band.

Claims

1. A plurality of cells arranged to be aligned in a first direction; A first end plate arranged to be further aligned on one side of the plurality of cells in the first direction; A second end plate arranged to be further aligned with the plurality of cells on the opposite side of the first end plate from the plurality of cells; a busbar module arranged on one side in a second direction perpendicular to the first direction as viewed from the plurality of cells, the first end plate, and the second end plate, Each of the plurality of cells has a pair of external terminals; the bus bar module includes a plurality of bus bars electrically connecting external terminals adjacent to each other in the first direction, and a bus bar case that holds the plurality of bus bars, the busbar case has a first end case located on one side of the first end plate in the second direction and directly engaged with the first end plate, a second end case located apart from the first end case in the first direction and located on one side of the second end plate in the second direction and directly engaged with the second end plate, and a connection portion connecting the first end case and the second end case to each other, The connection portion has a first expansion / contraction portion that is expandable and contractible in the first direction, A storage module, wherein the first end case, the second end case, and the connection portion are integrally molded with each other.

2. The connection portion is a central case connected to the first end case via the first telescopic portion; The energy storage module according to claim 1 , further comprising a second expandable section that is expandable in the first direction while connecting the central case and the second end case to each other.

3. The first end plate is a base portion extending along the second direction; a locked portion extending from the base portion along the first direction and having a through hole extending along the second direction; The first end case comprises: A columnar portion extending along the second direction and inserted into the through hole; The energy storage module according to claim 1 or 2, further comprising a locking portion located at a tip of the columnar portion and capable of locking with the locked portion in the second direction.

4. the central case has a protruding portion protruding along the second direction, The energy storage module according to claim 2 , wherein the protrusion is located between a pair of cells among the plurality of cells.

5. Further comprising a center plate disposed between the pair of cells, The energy storage module according to claim 4 , wherein the center plate has a central engaged portion that engages with the protruding portion.

6. The energy storage module according to claim 4 , wherein the protrusion is fitted between the pair of cells so as to be in contact with the pair of cells.

Images