Power storage device

Abstract

To provide an electricity storage device capable of improving the bending rigidity of an upper wall. [Solution] The energy storage device (10) includes a first energy storage stack (11) including a plurality of energy storage cells (100) arranged in a first direction, a second energy storage stack (12) including a plurality of energy storage cells (100) and facing the first energy storage stack (11) in a second direction, an upper wall (225) covering the first energy storage stack and the second energy storage stack, and a reinforcing member (250) provided on the upper wall. The upper wall (225) includes a top portion (225a) located above and between the first energy storage stack (11) and the second energy storage stack (12). The reinforcing member (250) is provided on the top portion (225a).

Description

[Technical Field]

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

[0002] For example, Japanese Patent Publication No. 2022-525014 discloses a power battery pack including a plurality of cells and a housing device. The housing device includes a module top plate. [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 room for improvement, particularly in improving the bending rigidity of the upper wall that covers the electricity storage stack.

[0005] An object of the present disclosure is to provide an electricity storage device capable of improving the bending rigidity of an upper wall. [Means for solving the problem]

[0006] A storage device according to one aspect of the present disclosure comprises a first storage stack including a plurality of storage cells arranged in a first direction; a second storage stack including a plurality of storage cells arranged in the first direction and facing the first storage stack in a second direction perpendicular to both the first direction and the vertical direction; an upper wall covering the first storage stack and the second storage stack; and a reinforcing member provided on the upper wall, wherein the upper wall includes a top portion located above the first storage stack and the second storage stack, and the reinforcing member is provided on the top portion. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide an electricity storage device capable of improving the bending rigidity of the upper wall. [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. 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 reinforcing member 250, a support member 300, a connecting portion 400, 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 further includes restraining members that restrain the plurality of energy storage cells 100 included in each of the energy storage stacks 11 to 14 from both sides in the first direction. As shown in Fig. 4, the restraining members include a lower restraining band 53 and an upper restraining band 54.

[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 located above and between a pair of power storage stacks adjacent to each other in the second direction. The top portion 225a is formed flat. The top portion 225a overlaps in the up-down direction with the ends of each power storage stack in the second 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 support member 300 is provided on the bottom wall 212. The support member 300 supports each of the power storage stacks 11 to 14. The support member 300 includes a first lower connection portion 301, a second lower connection portion 302, and an end lower connection portion 303. In this embodiment, the lower connection portions 301 to 303 have corresponding structures, and therefore, only the first lower connection portion 301 will be described below.

[0039] The first lower connection portion 301 connects the bottom wall 212 and the first power storage stack 11. The first lower connection portion 301 has a support portion 310 and an adhesive member 320.

[0040] The support portion 310 is provided on the bottom wall 212. The support portion 310 is disposed at a position spaced apart from the safety valve SV in the second direction (width direction). The support portion 310 is disposed below the end of the cell casing 114 in the second direction. The support portion 310 has an upwardly convex shape. The support portion 310 is made of metal. The edge of the support portion 310 is connected to the bottom wall 212 by welding or the like.

[0041] The adhesive member 320 connects the support portion 310 and the first power storage stack 11. The adhesive member 320 may be made of urethane resin. The adhesive member 320 extends in a first direction. The adhesive member 320 bonds the top surface of the support portion 310 and the valve mounting surface 114a of each cell casing 114 included in the first power storage stack 11. In the present embodiment, the adhesive member 320 bonds the lower restraint band 53 and the first power storage stack 11.

[0042] The second lower connection portion 302 connects the bottom wall 212 and the second power storage stack 12. The end lower connection portion 303 connects the bottom wall 212 and the outer end portion in the second direction of the power storage stacks (in this embodiment, the first power storage stack 11 and the fourth power storage stack 14) that are arranged outermost in the second direction.

[0043] Each of the power storage stacks 11 to 14, the bottom wall 212, and the support member 300 defines a space S below each of the power storage stacks 11 to 14. In this embodiment, the support 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.

[0044] 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.

[0045] 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.

[0046] In this embodiment, the power storage device 10 includes an upper connection portion. As shown in FIG. 4, the upper connection portion includes a first upper connection portion 61 and a second upper connection portion 62.

[0047] The first upper connection portion 61 connects the first power storage stack 11 and the top portion 225a. The first upper connection portion 61 bonds the top surface of each cell case 114 of the first power storage stack 11 to the top portion 225a. In this embodiment, the first upper connection portion 61 bonds the upper restraint band 54 to the first power storage stack 11.

[0048] The second upper connection portion 62 connects the second power storage stack 12 and the top portion 225a. The second upper connection portion 62 bonds the top surface of each cell case 114 of the second power storage stack 12 to the top portion 225a. In this embodiment, the second upper connection portion 62 bonds the upper restraint band 54 to the second power storage stack 12.

[0049] The connecting portion 400 connects the first lower connection portion 301 and the second lower connection portion 302. Specifically, the connecting portion 400 connects the support portion 310 of the first lower connection portion 301 and the support portion 310 of the second lower connection portion 302. The connecting portion 400 is connected to each support portion 310 by welding or the like.

[0050] The connecting portion 400 has a shape that protrudes upward from the support portion 310. The connecting portion 400 is disposed between the lower restraint band 53 attached to the first power storage stack 11 and the lower restraint band 53 attached to the second power storage stack 12. The connecting portion 400 is disposed below a pair of external terminals 120 that are adjacent to each other in the second direction. The connecting portion 400 overlaps in the up-down direction with both of the pair of external terminals 120 that face each other in the second direction. The connecting portion 400 extends along the first direction. An end of the connecting portion 400 in the first direction may be in contact with the peripheral wall 215 or may be spaced apart from the peripheral wall 215.

[0051] 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.

[0052] 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).

[0053] 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.

[0054] 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.

[0055] The reinforcing member 250 is provided on the upper wall 225. Specifically, the reinforcing member 250 is fixed to the top portion 225a by adhesion, welding, or the like. The reinforcing member 250 extends in a first direction. The reinforcing member 250 may be formed in a flat plate shape. The reinforcing member 250 has a thickness greater than that of the top portion 225a. Note that the reinforcing member 250 is not shown in FIG. 2. The reinforcing member 250 overlaps with the first upper connecting portion 61 and the second upper connecting portion 62 in the up-down direction. The reinforcing member 250 may be in contact with the covering member 600 in the second direction. The reinforcing member 250 has a thickness greater than that of the covering member 600.

[0056] 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.

[0057] Furthermore, in this energy storage device 10, the reinforcing member 250 is provided on the top portion 225a located above and between the first energy storage stack 11 and the second energy storage stack 12, thereby improving the bending rigidity of the top portion 225a. Therefore, damage to the top portion 225a is suppressed when an external force (bending moment indicated by an arrow in FIG. 4) that causes the top portion 225a to be convex downward or upward acts on the energy storage device.

[0058] It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0059] [Aspect 1] a first storage stack including a plurality of storage cells arranged in a first direction; a second power storage stack including a plurality of power storage cells aligned in the first direction and facing the first power storage stack in a second direction perpendicular to both the first direction and the vertical direction; an upper wall covering the first power storage stack and the second power storage stack; a reinforcing member provided on the upper wall, the upper wall includes a top portion located above and between the first power storage stack and the second power storage stack, The reinforcing member is provided on the top portion of the power storage device.

[0060] In this energy storage device, a reinforcing member is provided on the top portion located above the first and second energy storage stacks, improving the bending rigidity of the top portion and thus reducing damage to the top portion when an external force that causes the top portion to be convex downward or upward acts on the energy storage device.

[0061] [Aspect 2] a bottom wall disposed below the first power storage stack and the second power storage stack; a first lower connection portion that connects the bottom wall and the first power storage stack; a second lower connection portion that connects the bottom wall and the second power storage stack; a first upper connection portion that connects the first power storage stack and the top portion; The power storage device of aspect 1, further comprising: a second upper connection portion that connects the second power storage stack and the top portion.

[0062] In this aspect, the bottom wall, the electricity storage stack, and the upper wall are integrated via the lower connection portions and the upper connection portions, thereby further improving the bending rigidity of the electricity storage device.

[0063] [Aspect 3] a connecting portion that connects the first lower connecting portion and the second lower connecting portion, The first lower connection portion is a first support portion provided on the bottom wall; a first adhesive member connecting the first support portion and the first power storage stack, The second lower connection portion is a second support portion provided on the bottom wall; a second adhesive member connecting the second support portion and the second power storage stack, 3. The power storage device according to aspect 2, wherein the connecting portion connects the first support portion and the second support portion and has an upwardly convex shape.

[0064] In this embodiment, the bending rigidity of the electricity storage device is further improved.

[0065] [Aspect 4] The power storage device according to aspect 2 or 3, wherein the reinforcing member overlaps with the first upper connection portion and the second upper connection portion in the vertical direction and has a thickness greater than a thickness of the top portion.

[0066] In this embodiment, the bending rigidity of the top portion is further improved.

[0067] [Aspect 5] a cooler disposed on the upper wall and configured to cool the first power storage stack and the second power storage stack; a covering member that covers the cooler, The upper wall further includes a recess recessed downward from the top portion, the cooler is disposed in the recess, 5. The power storage device according to any one of aspects 1 to 4, wherein the reinforcing member has a thickness greater than a thickness of the covering member.

[0068] In this embodiment, the bending rigidity of the top portion is further improved.

[0069] 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]

[0070] 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, 61 first upper connection portion, 62 second upper connection portion, 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, 250 reinforcing member, 290 explosion-proof valve, 300 Support member, 301 first lower connection portion, 302 second lower connection portion, 303 end lower connection portion, 310 support portion, 320 adhesive member, 400 connecting portion, 500 cooler, 600 covering member, 910 thermally conductive adhesive, S space (smoke exhaust path), SV safety valve.

Claims

1. a first storage stack including a plurality of storage cells arranged in a first direction; a second power storage stack including a plurality of power storage cells aligned in the first direction and facing the first power storage stack in a second direction perpendicular to both the first direction and the vertical direction; an upper wall covering the first power storage stack and the second power storage stack; a reinforcing member provided on the upper wall, the upper wall includes a top portion located above and between the first power storage stack and the second power storage stack, The reinforcing member is provided on the top portion of the power storage device.

2. a bottom wall disposed below the first power storage stack and the second power storage stack; a first lower connection portion that connects the bottom wall and the first power storage stack; a second lower connection portion connecting the bottom wall and the second power storage stack; a first upper connection portion that connects the first power storage stack and the top portion; The power storage device according to claim 1 , further comprising: a second upper connection portion that connects the second power storage stack and the top portion.

3. a connecting portion that connects the first lower connecting portion and the second lower connecting portion, The first lower connection portion is a first support portion provided on the bottom wall; a first adhesive member connecting the first support portion and the first power storage stack, The second lower connection portion is a second support portion provided on the bottom wall; a second adhesive member connecting the second support portion and the second power storage stack, The power storage device according to claim 2 , wherein the connecting portion connects the first support portion and the second support portion and has an upwardly convex shape.

4. The power storage device according to claim 2 , wherein the reinforcing member overlaps the first upper connection portion and the second upper connection portion in the vertical direction and has a thickness greater than a thickness of the top portion.

5. a cooler disposed on the upper wall and configured to cool the first power storage stack and the second power storage stack; a covering member that covers the cooler, The upper wall further includes a recess recessed downward from the top portion, the cooler is disposed in the recess, The power storage device according to claim 1 , wherein the reinforcing member has a thickness greater than a thickness of the covering member.

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