Power storage device

Abstract

To provide an electricity storage device that can be improved in recyclability. [Solution] The energy storage device (10) includes a plurality of energy storage cells (100) arranged in a line along a first direction, an upper cover arranged above the plurality of energy storage cells, an adhesive member (400) that bonds the plurality of energy storage cells and the upper cover to one another, and an intervening member (450) made of rubber and interposed between the plurality of energy storage cells and the upper cover. The intervening member (450) extends in the first direction and includes a pair of intervening portions (452) positioned to sandwich the adhesive member (400) in a second direction that is perpendicular to both the first direction and the up-down direction. Each intervening portion (452) has an intervening space (S1) extending in the first direction.

Description

[Technical Field]

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

[0002] For example, JP 2022-525014 A discloses a power battery pack including a plurality of cells and a housing device. A module top plate having a cooling structure is disposed on the top surface of the plurality of cells. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2022-525014 Summary of the Invention [Problem to be solved by the invention]

[0004] In the electricity storage device described in JP-A-2022-525014, there is a demand for improved recyclability.

[0005] An object of the present disclosure is to provide an electricity storage device that can be improved in recyclability. [Means for solving the problem]

[0006] An energy storage device according to one aspect of the present disclosure includes a plurality of energy storage cells arranged in a line along a first direction, an upper cover arranged above the plurality of energy storage cells, an adhesive member that bonds the plurality of energy storage cells and the upper cover to each other, and an intervening member made of rubber and interposed between the plurality of energy storage cells and the upper cover, wherein the intervening member extends in the first direction and includes a pair of intervening portions positioned to sandwich the adhesive member in a second direction that is perpendicular to both the first direction and the up-down direction, and each of the pair of intervening portions has an intervening space extending in the first direction. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a power storage device that can be improved in recyclability. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram schematically illustrating a vehicle including a power storage device according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a perspective view schematically showing the power storage device, a frame member, a front component member, and a rear component member. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 5 is an enlarged view of the area indicated by the solid line V in FIG. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present disclosure will be described with reference to the accompanying drawings, in which the same or corresponding elements are designated by the same reference numerals.

[0010] Fig. 1 is a diagram schematically illustrating a vehicle including a power storage device according to an embodiment of the present disclosure. Fig. 2 is a perspective view schematically illustrating the power storage device, a frame member, and a vehicle frame. Fig. 3 is a cross-sectional view taken along line III-III in Fig. 2. Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 3.

[0011] 1, a vehicle 1 includes a vehicle body 2 and a power storage device 10. Examples of the vehicle 1 include a hybrid electric vehicle, a plug-in hybrid electric vehicle, and an electric vehicle (battery electric vehicle).

[0012] 1 and 2, the vehicle body 2 includes a frame member 20, a front component member 31, and a rear component member 32. The frame member 20 is disposed at the bottom of the vehicle body 2. The frame member 20 has a pair of first frames 21, a pair of second frames 22, and a cross frame 23.

[0013] The pair of first frames 21 face each other in a first direction. The first direction may be a direction parallel to the longitudinal direction of the vehicle 1. In the example shown in FIG. 2, the first frame 21 disposed at the front has a shape extending along a second direction perpendicular to both the first direction and the up-down direction. The first frame 21 disposed at the rear has a shape extending in the second direction and convex rearward. The second direction may be a direction parallel to the left-right direction (width direction) of the vehicle 1.

[0014] The pair of second frames 22 face each other in the second direction. Each second frame 22 has a shape extending along the first direction. An end of each second frame 22 in the first direction is connected to the first frame 21. The pair of second frames 22, together with the pair of first frames 21, are formed in a substantially rectangular tubular shape that surrounds the power storage device 10.

[0015] The cross frame 23 is disposed between the pair of first frames 21 and connects the pair of second frames 22. The cross frame 23 forms, for example, a seat cross.

[0016] The front component member 31 is connected to a front portion of the frame member 20. The rear component member 32 is connected to a rear portion of the frame member 20. Each of the component members 31, 32 may be formed by aluminum die casting.

[0017] The energy storage device 10 is attached to a frame member 20. As shown in Figs. 2 and 3, the energy storage device 10 is disposed below a cross frame 23. As shown in Figs. 1 to 4, the energy storage device 10 includes four energy storage stacks 11 to 14, a housing 200, a structural member 300, an adhesive member 400, an interposing member 450, a cooler 500, and a covering member 600. The number of energy storage stacks is not limited to four. The covering member 600 is not shown in Fig. 2.

[0018] Each of the power storage stacks 11 to 14 includes at least one power storage cell 100. In this embodiment, each of the power storage stacks 11 to 14 includes a power storage cell group including a plurality of (for example, 50) power storage cells 100 arranged side by side along the first direction. Each of the power storage stacks 11 to 14 may further include a plurality of spacers. Each spacer is arranged between a pair of adjacent power storage cells 100 in the power storage cell group. Each of the power storage stacks 11 to 14 is formed in the shape of a rectangular parallelepiped that is long in the first direction. As shown in FIG. 2, the four power storage stacks 11 to 14 are arranged side by side along the second direction.

[0019] 3, a pair of end plates 51 are provided on both sides of the plurality of storage cells 100 in the first direction to sandwich the plurality of storage cells 100 from both sides in the first direction. A monitoring unit (Smart Battery Management) 52 is arranged on the outside of each end plate 51 in the first direction.

[0020] As shown in Fig. 4, each energy storage cell 100 has a cell body 110 and a pair of external terminals 120. Note that Fig. 4 shows the energy storage cells 100 included in the first energy storage stack 11 and some of the energy storage cells 100 included in the second energy storage stack 12.

[0021] The cell body 110 has an electrode assembly 112 and a cell case 114. The thickness direction of the cell body 110 corresponds to the first direction. The width direction of the cell body 110 (the direction perpendicular to both the thickness direction and the up-down direction) corresponds to the second direction.

[0022] The electrode assembly 112 may be formed as a wound body in which a positive electrode sheet and a negative electrode sheet are wound with a separator interposed therebetween, or may be formed as a laminate in which a positive electrode sheet and a negative electrode sheet are stacked with a separator interposed therebetween. The electrode assembly 112 is formed in a shape that is long in the second direction.

[0023] The cell case 114 houses the electrode assembly 112. The cell case 114 is formed in a rectangular parallelepiped shape. The cell case 114 is made of a metal such as aluminum. The cell case 114 includes a valve mounting surface 114a and a terminal mounting surface 114b.

[0024] A safety valve SV is provided on the valve installation surface 114a. In this embodiment, the valve installation surface 114a is configured on the lower surface of the cell casing 114. However, the valve installation surface 114a may also be configured on the upper surface of the cell casing 114.

[0025] External terminals 120 are provided on the terminal installation surface 114b. In this embodiment, the terminal installation surface 114b is configured by a side surface of the cell case 114 in the second direction. That is, each external terminal 120 protrudes in the second direction from the side surface of the cell case 114 in the second direction. One of the pair of external terminals 120 protrudes from the side surface of the cell case 114 on one side in the second direction. The other of the pair of external terminals 120 protrudes from the side surface of the cell case 114 on the other side in the second direction.

[0026] The energy storage device 10 may include restraining members that restrain each of the energy storage stacks 11 to 14. As shown in FIG.

[0027] The lower restraint bands 53 are disposed below each power storage stack 11. Specifically, the lower restraint bands 53 restrain the lower corners of the external terminals 120 of each cell case 114 from both sides in the first direction.

[0028] The upper restraint bands 54 are disposed on the upper part of each power storage stack 11. Specifically, the upper restraint bands 54 restrain the upper corners of the external terminals 120 of each cell case 114 from both sides in the first direction.

[0029] The housing 200 houses a plurality of energy storage cells 100. In this embodiment, the housing 200 houses four energy storage stacks 11 to 14. As shown in FIG. 4 , the housing 200 has a lower case 210, an upper cover 220, and a panel member 230.

[0030] The lower case 210 is open upward and has a bottom wall 212 and a peripheral wall 215.

[0031] The bottom wall 212 is located below each of the power storage stacks 11 to 14. The bottom wall 212 may be formed in a flat plate shape.

[0032] Peripheral wall 215 stands upright from the peripheral edge of bottom wall 212. Peripheral wall 215 has a shape that surrounds the lower portions of each of power storage stacks 11-14 collectively.

[0033] The upper cover 220 is disposed above the plurality of energy storage cells 100. In this embodiment, the upper cover 220 is disposed above the four energy storage stacks 11 to 14. The upper cover 220, together with the lower case 210, accommodates the four energy storage stacks 11 to 14 in a sealed state. The periphery of the upper cover 220 is connected to the periphery of the lower case 210 by bolts or the like via a sealing member.

[0034] 4, the upper cover 220 has an upper wall 225. The upper wall 225 is provided above at least one energy storage cell 100. In this embodiment, the upper wall 225 is provided above the four energy storage stacks 11 to 14. The upper wall 225 has a top portion 225a and four recesses 225b.

[0035] The top portion 225a is formed flat and overlaps the ends of the power storage stacks in the second direction in the vertical direction.

[0036] Each recess 225b is recessed downward from the top portion 225a. Each recess 225b is formed flat. Each recess 225b is formed above the center of each energy storage stack 11 to 14 in the second direction. As shown in FIG. 4, the length of each recess 225b in the second direction is shorter than the length of the energy storage cell 100 in the second direction. Each recess 225b is in contact with the upper surface of the cell casing 114 via a thermally conductive adhesive 910.

[0037] The panel member 230 is provided below the lower case 210. The panel member 230 has a function of protecting the lower case 210. The panel member 230 may be formed in a flat plate shape. As shown in FIG. 4 , the peripheral edge of the panel member 230 is connected to the lower case 210 via a bracket 80.

[0038] The structural member 300 is provided on the bottom wall 212. Each of the power storage stacks 11 to 14, the bottom wall 212, and the structural member 300 defines a space S below each of the power storage stacks 11 to 14. In this embodiment, the structural member 300, together with each of the power storage stacks 11 to 14 and the bottom wall 212, defines a space S below each of the power storage stacks 11 to 14. That is, in this embodiment, four spaces S are formed inside the housing 200.

[0039] As shown in Fig. 3, each space S extends in a first direction. Each space S functions as a smoke exhaust path (hereinafter referred to as a "smoke exhaust path S"). The smoke exhaust path S is a path for discharging gas discharged from the safety valve SV of the energy storage cell 100 to the outside of the casing 200. Each smoke exhaust path S is connected to a common space within the casing 200 at an end of the smoke exhaust path S in the first direction.

[0040] As shown in FIG. 3, an explosion-proof valve 290 is provided in a portion of the peripheral wall 215 that faces the smoke exhaust path S in the first direction. The explosion-proof valve 290 is provided in the common space within the housing 200. The explosion-proof valve 290 releases pressure within the housing 200. The explosion-proof valve 290 opens when the pressure within the housing 200 reaches or exceeds a reference value. The explosion-proof valve 290 is configured as a check valve. As shown in FIG. 3, when gas is discharged from any of the energy storage cells 100, the gas spreads in the first direction through the smoke exhaust path S and is discharged to the outside of the housing 200 through the explosion-proof valve 290.

[0041] 4, the structural member 300 is in contact with both ends of the valve installation surface 114a of each energy storage cell 100 in the second direction and with the bottom wall 212. The structural member 300 may support each of the energy storage stacks 11 to 14. In this embodiment, the structural member 300 has a pair of base portions 310 and a pair of seal portions 320.

[0042] The pair of base portions 310 are connected to the bottom wall 212. The pair of base portions 310 are arranged at positions facing each other in the second direction (width direction) with the safety valve SV interposed therebetween.

[0043] Each seal portion 320 contacts the valve mounting surface 114a of the energy storage cell 100 and the base portion 310. Each seal portion 320 may be formed of urethane resin. Each seal portion 320 extends in a first direction. The inner surface of each seal portion 320 in the second direction contacts the smoke exhaust path S.

[0044] 4, the energy storage device 10 may have a reinforcing portion 360 that reinforces the bottom wall 212. The reinforcing portion 360 is disposed between a pair of energy storage stacks adjacent to each other in the second direction. Specifically, the reinforcing portion 360 is disposed between a pair of cell bodies 110 adjacent to each other in the second direction and below a pair of external terminals 120 adjacent to each other in the second direction. The reinforcing portion 360 overlaps in the up-down direction with both of the pair of external terminals 120 that face each other in the second direction.

[0045] The reinforcing portion 360 extends along the first direction. An end of the reinforcing portion 360 in the first direction may be in contact with the peripheral wall 215 or may be spaced apart from the peripheral wall 215. The reinforcing portion 360 is connected to the base portion 310. In the present embodiment, the reinforcing portion 360 is connected to the base portion 310 by welding or the like. That is, the reinforcing portion 360 functions as a connecting portion that connects a structural member 300 provided below one of a pair of adjacent power storage stacks (e.g., the first power storage stack 11 and the second power storage stack 12) to a structural member 300 provided below the other of the pair of power storage stacks. The reinforcing portion 360 has a shape that protrudes upward from the base portion 310.

[0046] The adhesive member 400 bonds the plurality of energy storage cells 100 included in each of the energy storage stacks 11 to 14 to the upper cover 220. As shown in FIGS. 4 and 5, the adhesive member 400 has a lower adhesive portion 410 and an upper adhesive portion 420.

[0047] The lower adhesive portion 410 is provided between the plurality of energy storage cells 100 and the upper restraining band 54 .

[0048] The upper adhesive portion 420 is provided between the upper restraint band 54 and the upper cover 220. More specifically, the upper adhesive portion 420 is provided between the upper surface of the upper restraint band 54 and the lower surface of the top portion 225a.

[0049] As shown in Fig. 5, the interposing member 450 is interposed between the upper cover 220 and the plurality of energy storage cells 100 included in each of the energy storage stacks 11 to 14. The interposing member 450 is made of rubber. The interposing member 450 extends in a first direction. In this embodiment, the interposing member 450 is provided between the upper restraining band 54 and the upper cover 220. However, the interposing member 450 may also be provided between the upper surfaces of the plurality of energy storage cells 100 and the upper cover 220.

[0050] As shown in FIGS. 5 and 6, the interposition member 450 has a pair of interposition portions 452 and a connecting portion 454 .

[0051] The pair of intervening portions 452 are provided at positions sandwiching the adhesive member 400 in the second direction. Each intervening portion 452 has an intervening space S1 extending in the first direction. The intervening space S1 is open upward. The intervening space S1 is closed by the top portion 225a. Note that each intervening portion 452 may be formed, for example, in a rectangular cylindrical shape, and the space inside the intervening portion 452 may constitute the intervening space S1. Each intervening space S1 is provided at a position overlapping with the upper adhesive portion 420 in the second direction.

[0052] The connecting portion 454 connects the ends of the pair of intervening portions 452 in the first direction. The connecting portion 454 has a connecting space S2 that communicates with each intervening space S1. The connecting space S2 is open upward. The connecting space S2 is closed by the ceiling portion 225a. Note that the connecting portion 454 may be formed, for example, in a rectangular cylindrical shape, and the space inside the connecting portion 454 may form the connecting space S2. The connecting space S2 is provided at a position that overlaps with the upper adhesive portion 420 in the first direction.

[0053] The intervening space S1 and the connecting space S2 are sized to allow a high-strength steel wire (such as a piano wire) P to be inserted therethrough. In particular, each intervening portion 452 functions as a rail portion through which the steel wire P can be inserted. In Figs. 5 and 6, the steel wire P is indicated by a two-dot chain line.

[0054] The cooler 500 cools at least one energy storage cell 100. A cooling medium (such as water) flows through the cooler 500. As shown in FIGS. 2 to 4, the cooler 500 is provided on the upper wall 225. More specifically, the cooler 500 is provided in the recess 225b of the upper wall 225.

[0055] The cooler 500 is in thermal contact with at least one energy storage cell 100 via the upper wall 225. In this embodiment, a thermally conductive adhesive 910 extending along the first direction is provided between the cooler 500 and the recess 225b. That is, in this embodiment, the cooler 500 is in thermal contact with each of the energy storage stacks 11 to 14 via the upper wall 225 and the thermally conductive adhesive 910. Note that being in thermal contact includes a case in which the cooler 500 is in contact with the energy storage cell 100 only via the upper wall 225, and a case in which the cooler 500 is in indirect contact with the energy storage cell 100 via a thermally conductive member (such as an adhesive or a fixing member).

[0056] The covering member 600 covers the cooler 500. The covering member 600 may be made of a material having heat insulating properties. Note that the covering member 600 is not shown in Figures 2 and 3.

[0057] The cooler 500 and the covering member 600 form at least a part of the floor 30 of the vehicle compartment (see FIG. 3). In addition to the cooler 500 and the covering member 600, the floor 30 of the vehicle compartment may include floor constituent members (such as a buffer member or carpet) placed on the covering member 600. Note that the floor constituent members are not shown in FIGS. 2 and 4.

[0058] In the energy storage device 10 described above, when gas is discharged downward from the safety valve SV due to a short circuit or the like in any of the energy storage cells 100, the gas flows into the smoke exhaust path S. The gas that flows into the smoke exhaust path S then spreads in a first direction and is discharged from the housing 200 through the explosion-proof valve 290 as shown in FIG. 3. This prevents the contents of the energy storage cells 100 (so-called debris) contained in the gas from adhering to the external terminals 120 of the energy storage cells 100, etc.

[0059] Furthermore, since the energy storage device 10 includes the intervening member 450, for example, a high-strength steel wire (such as a piano wire) P is inserted into each of the intervening spaces S1 and the connecting space S2, and the steel wire P is moved in the first direction to cut the intervening portion 452, the connecting portion 454, and the upper adhesive portion 420. This makes it possible to easily remove the upper cover 220 from the energy storage device 10. This improves recyclability.

[0060] It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0061] [Aspect 1] a plurality of storage cells arranged in a line along a first direction; an upper cover disposed above the plurality of power storage cells; an adhesive member that bonds the plurality of storage cells and the upper cover to each other; an interposition member made of rubber and interposed between the plurality of storage cells and the upper cover, the interposition member includes a pair of interposition portions extending in the first direction and provided at positions sandwiching the adhesive member in a second direction perpendicular to both the first direction and the up-down direction, The power storage device, wherein each of the pair of interposition portions has an interposition space extending in the first direction.

[0062] In this electricity storage device, for example, a high-strength steel wire (such as a piano wire) is inserted into each intervening space, and the intervening portion and the adhesive member are cut by moving the steel wire in a first direction. This allows the upper cover to be easily removed from the electricity storage device, thereby improving recyclability.

[0063] [Aspect 2] further comprising an upper restraint band that restrains the plurality of storage cells from both sides in the first direction; the upper restraint band is positioned above the plurality of energy storage cells, The adhesive member is a lower adhesive portion provided between the plurality of storage cells and the upper restraint band; an upper adhesive portion provided between the upper restraint band and the upper cover, 2. The power storage device of aspect 1, wherein each of the intervening spaces is provided at a position overlapping with the upper adhesive portion in the second direction.

[0064] In this embodiment, the upper adhesive portion can be cut by the steel wire, so that the upper cover can be removed while maintaining the adhesive state between the upper restraint band and the plurality of energy storage cells by the lower adhesive portion.

[0065] [Aspect 3] 3. The power storage device according to aspect 2, wherein the interposition member is provided between the upper restraint band and the upper cover.

[0066] [Aspect 4] the interposition member further includes a connecting portion connecting ends of the pair of interposition portions in the first direction, Aspect 4. The power storage device according to any one of aspects 1 to 3, wherein the connecting portion has a connecting space communicating with each of the intervening spaces.

[0067] [Aspect 5] 5. The power storage device according to aspect 4, wherein each of the intervening spaces and the connecting space is open upward.

[0068] It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present disclosure is defined by the claims rather than the description of the above embodiments, and further includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0069] REFERENCE SIGNS LIST 1 vehicle, 2 vehicle body, 10 energy storage device, 11 to 14 energy storage stack, 20 frame member, 21 first frame, 22 second frame, 23 cross frame, 31 front component member, 32 rear component member, 51 end plate, 52 monitoring unit, 53 lower restraint band, 54 upper restraint band, 100 energy storage cell, 110 cell body, 112 electrode body, 114 cell case, 114a valve installation surface, 114b terminal installation surface, 120 external terminal, 200 housing, 210 lower case, 212 bottom wall, 215 peripheral wall, 220 upper cover, 225 upper wall, 225a top portion, 225b recess, 230 panel member, 290 explosion-proof valve, 300 structural member, 310 base portion, 320 seal portion, 360 Reinforcement part, 400 adhesive member, 410 lower adhesive member, 420 upper adhesive member, 450 intervening member, 452 intervening member, 454 connecting part, 500 cooler, 600 covering member, 910 thermally conductive adhesive, S space (smoke exhaust path), S1 intervening space, S2 connecting space, SV safety valve.

Claims

1. a plurality of storage cells arranged in a line along a first direction; an upper cover disposed above the plurality of power storage cells; an adhesive member that bonds the plurality of storage cells and the upper cover to each other; an interposition member made of rubber and interposed between the plurality of storage cells and the upper cover, the interposition member includes a pair of interposition portions extending in the first direction and provided at positions sandwiching the adhesive member in a second direction perpendicular to both the first direction and the up-down direction, Each of the pair of interposition portions has an interposition space extending in the first direction.

2. further comprising an upper restraint band that restrains the plurality of storage cells from both sides in the first direction; the upper restraint band is positioned above the plurality of energy storage cells, The adhesive member is a lower adhesive portion provided between the plurality of storage cells and the upper restraint band; an upper adhesive portion provided between the upper restraint band and the upper cover, The power storage device according to claim 1 , wherein each of the intervening spaces is provided at a position overlapping with the upper adhesive portion in the second direction.

3. The power storage device according to claim 2 , wherein the interposition member is provided between the upper restraint band and the upper cover.

4. the interposition member further includes a connecting portion connecting ends of the pair of interposition portions in the first direction, The power storage device according to claim 1 , wherein the connecting portion has a connecting space communicating with each of the intervening spaces.

5. The power storage device according to claim 4 , wherein each of the intervening spaces and the connecting space is open upward.

Images