Power storage device

Abstract

To provide a power storage device that can inhibit deformation of a stack in a vertical direction (the direction in which the stack and a smoke exhaust duct overlap with each other) while inhibiting increase of the number of parts.SOLUTION: A power storage device 100 includes: a stack 10 formed of a plurality of battery cells 11 arrayed in an X direction (array direction); a smoke exhaust duct 30 which is placed on the stack 10 so as to extend in the X direction; a bus bar module 40 including a plurality of bus bars 41 connected to the stack 10; and a sponge 50 (elastic body) placed on the smoke exhaust duct 30. The bus bar module 40 is provided so as to cover at least a part of the smoke exhaust duct 30. The sponge 50 is placed between the bus bar module 40 and the smoke exhaust duct 30.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] Japanese Patent Application Laid-Open Publication No. 2015-022965 (Patent Document 1) discloses a battery stack formed by stacking multiple battery cells. The battery stack is equipped with a smoke exhaust duct that extends in the stacking direction. The smoke exhaust duct is fixed by being attached to a smoke exhaust duct mounting rail provided on the battery stack. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-022965 Summary of the Invention [Problem to be solved by the invention]

[0004] Here, the battery stack may deform in an undulating manner in the vertical direction (the direction in which the stack overlaps the smoke exhaust duct) due to the expansion of each of the multiple battery cells. Therefore, it is desired to suppress the vertical deformation of the stack while suppressing an increase in the number of parts.

[0005] The present disclosure has been made to solve the above-mentioned problems, and its purpose is to provide an energy storage device that can suppress deformation of the stack in the vertical direction (the direction in which the stack and the smoke exhaust duct overlap) while suppressing an increase in the number of parts. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, there is provided an energy storage device including a stack formed by arranging a plurality of battery cells in an arrangement direction, a smoke exhaust duct arranged in the stack so as to extend in the arrangement direction, a busbar module including a plurality of busbars connected to the stack, and an elastic body arranged in the smoke exhaust duct. The busbar module is arranged to cover at least a portion of the smoke exhaust duct. The elastic body is arranged between the busbar module and the smoke exhaust duct.

[0007] In the energy storage device according to one aspect of the present disclosure, as described above, the elastic body is disposed between the busbar module and the smoke exhaust duct. This allows the busbar module to press against the smoke exhaust duct via the elastic body. As a result, the smoke exhaust duct pressed by the busbar module can suppress deformation of the stack in the vertical direction (the direction in which the stack and the smoke exhaust duct overlap). Furthermore, compared to when a separate member is provided to suppress deformation of the stack, the busbar module can suppress the deformation. Therefore, it is possible to suppress deformation of the stack in the vertical direction while suppressing an increase in the number of parts.

[0008] In the energy storage device according to the above aspect, the elastic body preferably includes a central elastic body disposed at a position corresponding to a central portion of the stack in the arrangement direction. With this configuration, movement of the battery cell disposed at the center of the plurality of battery cells in the arrangement direction can be more reliably restricted.

[0009] In the power storage device according to the above aspect, the elastic body preferably includes an end elastic body disposed at an end of the smoke exhaust duct in the arrangement direction. With this configuration, movement of the battery cells provided at positions corresponding to the ends of the smoke exhaust duct can be more reliably restricted.

[0010] In the energy storage device according to the above aspect, the busbar module preferably includes a frame member supporting a plurality of busbars. The plurality of busbars press the frame member toward the stack. At least a portion of the frame member is disposed to pass on the opposite side of the elastic body from the stack, thereby covering at least a portion of the smoke exhaust duct. With this configuration, the force of the busbars pressing the frame member toward the stack can be utilized to press the smoke exhaust duct with the at least a portion of the frame member via the elastic body.

[0011] In this case, preferably, the plurality of bus bars include a first bus bar provided on one side of the smoke exhaust duct in a cross direction that crosses the arrangement direction, and a second bus bar provided on the other side of the smoke exhaust duct in the cross direction. Each of the first bus bar and the second bus bar presses the frame member toward the stack. With this configuration, the frame member can be pressed toward the stack from both sides of the smoke exhaust duct in the cross direction. This allows the smoke exhaust duct to be fixed more stably. [Effects of the Invention]

[0012] According to the present disclosure, it is possible to suppress deformation of the stack in the vertical direction (the direction in which the stack and the smoke exhaust duct overlap) while suppressing an increase in the number of parts. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a perspective view illustrating a configuration of an electricity storage device according to an embodiment. [Figure 2] FIG. 1 is a perspective view illustrating a battery cell according to an embodiment. [Figure 3] FIG. 2 is a partially enlarged view of the sponge and its surroundings in FIG. 1. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0015] In this specification, one and the other of the X directions will be referred to as the X1 direction and the X2 direction, respectively. Furthermore, one and the other of the Y directions perpendicular to the X direction will be referred to as the Y1 direction and the Y2 direction, respectively. Furthermore, one and the other of the Z directions perpendicular to each of the X and Y directions will be referred to as the Z1 direction and the Z2 direction, respectively.

[0016] <Overall structure> 1 is a perspective view showing the overall configuration of a power storage device 100 according to this embodiment. The power storage device 100 is used, for example, as a power source for driving a vehicle such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), or an electric vehicle (BEV: Battery Electric Vehicle). Note that the power storage device 100 may also be used in electrical equipment other than a vehicle (for example, a stationary battery).

[0017] The electricity storage device 100 includes a stack 10, a die-cast case 20, a smoke exhaust duct 30, a bus bar module 40, and a sponge 50. The sponge 50 is an example of the "elastic body" of the present disclosure.

[0018] The stack 10 includes a plurality of battery cells 11. The plurality of battery cells 11 in the stack 10 are arranged (stacked) in the X direction. The energy storage device 100 includes two stacks 10. The two stacks 10 are arranged side by side in the Y direction perpendicular to the X direction. The X direction and the Y direction are examples of the "arrangement direction" and the "intersecting direction," respectively, in the present disclosure.

[0019] 2, a gas release valve 11b, a positive electrode terminal 11c, and a negative electrode terminal 11d are provided on the Z1-side upper surface 11a of each of the multiple battery cells 11. The gas release valve 11b is provided in the center of the upper surface 11a in the Y direction. The positive electrode terminal 11c is provided at the end of the upper surface 11a on the Y2 side. The negative electrode terminal 11d is provided at the end of the upper surface 11a on the Y1 side.

[0020] 1 , the die-cast case 20 is made of, for example, aluminum. The die-cast case 20 is configured to accommodate the stack 10. Specifically, the die-cast case 20 is provided with two accommodation holes 21. A stack 10 is accommodated in each of the two accommodation holes 21. The accommodation holes 21 hold (fix) the stack 10 so as to restrict movement of the stack 10 in each of the X and Y directions.

[0021] The smoke exhaust duct 30 is disposed on the stack 10. Specifically, the smoke exhaust duct 30 is disposed on the top surface 10a on the Z1 side of the stack 10. The smoke exhaust duct 30 is not fixed (fastened, adhered, or engaged) to the top surface 10a of the stack 10 with a jig or the like. In other words, the smoke exhaust duct 30 is simply placed on the top surface 10a. The top surface 10a is a surface formed by arranging the Z1-side top surfaces 11a of each of the multiple battery cells 11 in the X direction.

[0022] The smoke exhaust duct 30 is arranged in the stack 10 so as to extend in the X direction. One smoke exhaust duct 30 is arranged in the stack 10. The smoke exhaust duct 30 is arranged so as to extend from the battery cell 11 at the end of the stack 10 on the X1 side to the battery cell 11 at the end of the stack 10 on the X2 side. Note that multiple smoke exhaust ducts 30 arranged side by side in the X direction may be arranged in the stack 10.

[0023] The smoke exhaust duct 30 has a U-shape when viewed along the X direction. Specifically, the smoke exhaust duct 30 has a pair of wall portions 31 extending perpendicular to the Y direction. The smoke exhaust duct 30 also includes a top plate portion 32 connecting the pair of wall portions 31. The top plate portion 32 extends perpendicular to the Z direction. In other words, the top plate portion 32 extends along the upper surface 10a of the stack 10. The smoke exhaust duct 30 is also open on the stack 10 side (Z2 side).

[0024] As a result, smoke exhausted from the gas exhaust valve 11b (see FIG. 2) provided on the upper surface 11a of the battery cell 11 is introduced into the smoke exhaust duct 30. The smoke exhaust duct 30 then circulates the introduced smoke along the X direction. As a result, the smoke introduced into the smoke exhaust duct 30 is moved to a predetermined location.

[0025] The smoke exhaust duct 30 is made of insulating resin such as polyphenol or polypropylene. The smoke exhaust duct 30 has a higher rigidity (Young's modulus) than the frame member 42 described below. In other words, the smoke exhaust duct 30 is less likely to deform than the frame member 42.

[0026] 1, the bus bar module 40 includes a plurality of bus bars 41, a frame member 42, an FPC (Flexible Printed Circuit) board 43, and a connector 44. The frame member 42 supports the plurality of bus bars 41.

[0027] The bus bar module 40 is provided so as to cover at least a portion (for example, the entire surface) of the smoke exhaust duct 30 from the Z1 side. Each of the multiple bus bars 41 is connected to the stack 10 (the positive terminal 11c or the negative terminal 11d of the battery cell 11).

[0028] A busbar module 40 is arranged in each of the two stacks 10. In FIG. 1, for convenience, the busbar module 40 is illustrated as being arranged only in the stack 10 on the Y1 side, but in reality, the busbar module 40 is also arranged in the stack 10 on the Y2 side.

[0029] 1, a busbar arrangement region 41a in which a plurality of busbars 41 are arranged side by side in the X direction is indicated by a dashed line. For simplification, only two busbars 41 are shown in the busbar arrangement region 41a in FIG.

[0030] The plurality of bus bars 41 (bus bar arrangement region 41a) are provided on one side (Y1 side) and the other side (Y2 side) of the smoke exhaust duct 30 in the Y direction. Each of the plurality of bus bars 41 provided on the Y1 side of the smoke exhaust duct 30 is an example of a "first bus bar" in the present disclosure. Each of the plurality of bus bars 41 provided on the Y2 side of the smoke exhaust duct 30 is an example of a "second bus bar" in the present disclosure.

[0031] The FPC board 43 is supported by a frame member 42 (a frame central portion 42a described below) between the plurality of bus bars 41 on the Y1 side and the plurality of bus bars 41 on the Y2 side. The FPC board 43 is electrically connected to each of the plurality of bus bars 41 on the Y1 side and the plurality of bus bars 41 on the Y2 side. This connects the plurality of bus bars 41 on the Y1 side to the plurality of bus bars 41 on the Y2 side in series. The connector 44 transmits information relating to the voltage values of the plurality of battery cells 11 from the FPC board 43 to an ECU (Electric Control Unit) (not shown) of the vehicle or the like.

[0032] The sponge 50 is disposed in the smoke exhaust duct 30. Specifically, the sponge 50 is disposed on the outer surface 32a of the top plate portion 32 of the smoke exhaust duct 30.

[0033] The sponge 50 includes sponges 51 arranged at both ends of the smoke exhaust duct 30 in the X direction. The sponge 51 on the X1 side is provided at a position corresponding to the end of the stack 10 on the X1 side. The sponge 51 on the X2 side is provided at a position corresponding to the end of the stack 10 on the X2 side. The sponge 51 is an example of the "end elastic body" of the present disclosure.

[0034] The sponge 50 also includes a sponge 52 arranged at a position corresponding to the center of the stack 10 in the X direction (the center of the smoke exhaust duct 30 in the X direction). Two sponges 52 are provided in the smoke exhaust duct 30. However, the number of sponges 52 may be one. The sponge 52 is also an example of the "central elastic body" of the present disclosure.

[0035] Fig. 3 is a partially enlarged view of the periphery of sponge 50 in Fig. 1. As shown in Fig. 3, sponge 50 has a flat plate shape. Sponge 50 has a thickness T in the Z direction. Sponge 50 also has a width W1 in the X direction. Sponge 50 also has a width W2 in the Y direction. Thickness T is smaller than both width W1 and width W2. Width W1 and width W2 are also approximately equal.

[0036] Here, the stack 10 is fitted into the housing hole 21 of the die-cast case 20, and is therefore compressed at a constant pressure in both the X and Y directions. Furthermore, each of the multiple battery cells 11 may deform and expand due to heat or the like. Due to these factors, a force may act on each of the multiple battery cells 11 in the stack 10, tending to move them toward the Z1 side. In this case, the stack 10 tends to deform in a wavy manner in the Z direction. To address this, it is desirable to suppress deformation of the stack 10 in the Z direction while suppressing an increase in the number of parts.

[0037] Therefore, in this embodiment, the sponge 50 is disposed between the bus bar module 40 and the smoke exhaust duct 30. The sponge 50 is supported from the Z2 side by the smoke exhaust duct 30, and is pressed from the Z1 side by the bus bar module 40. As a result, the sponge 50 is compressed by the smoke exhaust duct 30 and the bus bar module 40.

[0038] With the above configuration, the busbar module 40 can press against the smoke exhaust duct 30 via the sponge 50. As a result, the smoke exhaust duct 30 pressed by the busbar module 40 can suppress the stack 10 from undulating in the vertical direction (Z direction). Furthermore, compared to a case where a separate member for suppressing deformation of the stack 10 is provided, the busbar module 40 can suppress the above deformation. Therefore, it is possible to suppress the vertical deformation of the stack 10 while suppressing an increase in the number of parts. Furthermore, because the stack 10 is pressed by the smoke exhaust duct 30, which has a relatively high rigidity, it is possible to more effectively suppress the deformation of the stack 10 in the Z direction.

[0039] 4, the sponge 50 is pressed by the frame member 42 of the bus bar module 40. The frame member 42 has a frame center portion 42a and a frame edge portion 42b. The sponge 50 is pressed by the frame center portion 42a.

[0040] The frame central portion 42a is provided in the center of the frame member 42 in the Y direction. The frame edge portion 42b is provided on the outer periphery of the frame member 42. The frame central portion 42a is formed integrally with the frame edge portion 42b.

[0041] The frame central portion 42a has a shape that follows the smoke exhaust duct 30. Specifically, the frame central portion 42a has a U-shape similar to that of the smoke exhaust duct 30 in a cross section taken along the Y direction. A portion of the frame central portion 42a is disposed so as to pass through the sponge 50 on the opposite side (Z1 side) from the stack 10. As a result, the frame central portion 42a is disposed so as to cover at least a portion of the smoke exhaust duct 30.

[0042] The frame edge portion 42b is provided on each of the Y1-side end portion of the frame member 42 and the Y2-side end portion of the frame member 42. The frame edge portion 42b is provided with an engagement portion 42c that engages with the bus bar 41. The engagement portion 42c provided on the Y1-side frame edge portion 42b engages with the Y1-side end portion 41b of the Y1-side bus bar 41. The engagement portion 42c provided on the Y2-side frame edge portion 42b engages with the Y2-side end portion 41c of the Y2-side bus bar 41. The engagement portion 42c is provided to support the end portion 41b (41c) of the bus bar 41 from the stack 10 side (Z2 side).

[0043] Furthermore, the frame central portion 42a is provided with engaging portions 42d that engage with the plurality of bus bars 41. In the example shown in Fig. 4, the engaging portions 42d engage with the Y2-side ends 41d of the Y1-side bus bars 41. The engaging portions 42d are provided so as to support the ends 41d of the bus bars 41 from the stack 10 side (Z2 side). Although not shown in Fig. 4, the frame central portion 42a has engaging portions 42d that engage with the Y2-side bus bars 41 at positions in the X direction different from those shown in Fig. 4.

[0044] The bus bar module 40 also includes a bus bar 45 that is provided to connect the FPC board 43 and the bus bar 41. In the example shown in Fig. 4, the bus bar 45 is connected to the FPC board 43 and the bus bar 41 on the Y2 side. As a result, the FPC board 43 and the bus bar 41 are electrically connected through the bus bar 45.

[0045] Each of the bus bars 41 is joined to a battery cell 11 (positive terminal 11c or negative terminal 11d) by solder 60. Due to the joining force between the bus bar 41 and the battery cell 11 by the solder 60, the bus bar 41 presses (biases) the engaging portions 42c (and 42d) on the Y1 and Y2 sides toward the stack 10 (Z1 side).

[0046] Here, the frame central portion 42a and the frame edge portion 42b are integrally formed. Therefore, when the engaging portion 42c of the frame edge portion 42b is pressed by the bus bar 41, the frame central portion 42a is pulled toward the stack 10 (Z2 side). Furthermore, the engaging portion 42d of the frame central portion 42a is pressed toward the stack 10 by the bus bar 41. As a result, the sponge 50 is pressed toward the stack 10 by the frame central portion 42a.

[0047] 4, the bus bar 45 is connected to the bus bar 41 and the FPC board 43 by solder (not shown). As a result, the frame central portion 42a is pressed (biased) toward the stack 10 (Z1 side) by the bonding force of the solder (not shown). As a result, the sponge 50 is pressed toward the stack 10 by the frame central portion 42a.

[0048] As described above, in this embodiment, the sponge 50 is disposed between the busbar module 40 and the smoke exhaust duct 30. This allows the sponge 50 to receive the pressing force from the busbar module 40 to the smoke exhaust duct 30. As a result, the smoke exhaust duct 30 can be fixed in place by the pressing force of the busbar module 40. Furthermore, the sponge 50 can prevent the busbar module 40 and the smoke exhaust duct 30 from coming into direct contact with each other. As a result, the sponge 50 can cushion any collision between the busbar module 40 and the smoke exhaust duct 30.

[0049] In the above embodiment, the sponge 50 is disposed at each of the end and center portions in the X direction of the smoke exhaust duct 30, but the present disclosure is not limited to this. For example, the sponge 50 may be disposed at only one of the end portions or center portion in the X direction of the smoke exhaust duct 30. That is, the sponge 50 may be disposed only at a position corresponding to the center of the stack 10 in the X direction, or only at a position corresponding to the end portion of the stack 10 in the X direction.

[0050] Furthermore, the sponge 50 may be disposed in a location other than the end and center of the smoke exhaust duct 30 in the X direction.

[0051] In the above embodiment, an example has been described in which the frame member 42 of the bus bar module 40 presses the sponge 50 toward the stack 10, but the present disclosure is not limited to this. For example, the sponge 50 may be pressed toward the stack 10 by the FPC board 43 or the bus bar 41.

[0052] In the above embodiment, an example has been described in which the width W1 of the sponge 50 in the X direction and the width W2 of the sponge 50 in the Y direction are approximately equal, but the present disclosure is not limited to this. For example, the width W1 may be greater than the width W2. For example, the width W1 may be approximately equal to the length of the smoke exhaust duct 30 in the X direction.

[0053] The configurations (processing) of the above-described embodiment and the above-described modifications may be combined with each other.

[0054] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0055] 10 stack, 11 battery cell, 30 smoke exhaust duct, 40 busbar module, 41 busbar, 42 frame member, 50 sponge (elastic body), 51 sponge (end elastic body), 52 sponge (central elastic body), 100 power storage device, X direction (arrangement direction).

Claims

1. a stack formed by arranging a plurality of battery cells in an arrangement direction; a smoke exhaust duct disposed in the stack so as to extend in the arrangement direction; a busbar module including a plurality of busbars connected to the stack; an elastic body disposed in the smoke exhaust duct, the bus bar module is provided to cover at least a portion of the smoke exhaust duct, The elastic body is disposed between the bus bar module and the smoke exhaust duct.

2. The power storage device according to claim 1 , wherein the elastic bodies include a central elastic body that is arranged at a position corresponding to a central portion of the stack in the arrangement direction.

3. The power storage device according to claim 1 , wherein the elastic bodies include end elastic bodies arranged at ends of the smoke exhaust ducts in the arrangement direction.

4. the bus bar module includes a frame member supporting the plurality of bus bars; the plurality of bus bars press the frame member toward the stack, 3. The energy storage device according to claim 1, wherein at least a portion of the frame member is arranged to pass through the elastic body on the opposite side from the stack, thereby covering at least a portion of the smoke exhaust duct.

5. the plurality of bus bars include a first bus bar provided on one side of the smoke exhaust duct in a cross direction crossing the arrangement direction, and a second bus bar provided on the other side of the smoke exhaust duct in the cross direction, The power storage device according to claim 4 , wherein each of the first bus bar and the second bus bar presses the frame member toward the stack.

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