JP2012015040A - Power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage device capable of adjusting temperatures of a plurality of power storage elements.
A power storage unit in which a plurality of power storage elements (10) are arranged in one direction, a pair of end plates (20) sandwiching the power storage unit in the arrangement direction of the plurality of power storage elements, and extending in the arrangement direction. The connecting members (61, 62) are connected to the pair of end plates, and apply a binding force to the power storage unit via the end plates, and the tray (70) is fixed to the bottom surface of the power storage unit by the connecting members. And having. The tray forms a passage for moving a heat exchange medium used for adjusting the temperature of the power storage element in the arrangement direction between the tray and the bottom surface of the power storage unit.
[Selection] Figure 2

Description

  The present invention relates to a power storage device having a structure for adjusting the temperature of a power storage element.

  When the assembled battery is configured using a plurality of single cells, as shown in Patent Document 1, the plurality of single cells are unitized using an end plate and a restraining band. Here, the insulating sheet is arrange | positioned at the lower surface of the assembled battery, and an insulating sheet is used in order to ensure the insulation between a cell and a restraint band.

JP 2009-205820 (paragraph 0054, FIG. 3)

  The objective of this invention provides the electrical storage apparatus which can adjust the temperature of an assembled battery using the member corresponding to the insulating sheet of patent document 1. FIG.

  A power storage device according to the present invention includes a power storage unit in which a plurality of power storage elements are arranged in one direction, a pair of end plates that sandwich the power storage unit in the arrangement direction of the plurality of power storage elements, and extends in the arrangement direction. The coupling member is coupled to the pair of end plates, and includes a coupling member for applying a binding force to the power storage unit via the end plate, and a tray fixed to the bottom surface of the power storage unit by the coupling member. Here, the tray forms a passage for moving the heat exchange medium used for adjusting the temperature of the power storage element in the arrangement direction between the bottom surface of the power storage unit.

  The tray can be pushed to the bottom side of the power storage unit by the connecting member. Thereby, the heat exchange medium which flows through a channel | path can be made hard to leak from between the bottom face of an electrical storage unit, and a tray. Here, if a seal member is disposed between the power storage unit and the tray, the passage can be sealed.

  The passage may be a passage for discharging the heat exchange medium after heat exchange with the power storage element. In this case, a path for supplying the heat exchange medium to each power storage element (a path extending in the arrangement direction of the power storage elements) can be provided at a position different from the bottom surface of the power storage unit and between the power storage units. . By providing each heat exchange medium supply passage at a position sandwiching the power storage unit, it is possible to easily reduce the size of the power storage device in the direction in which the two supply passages are arranged while securing the supply amount of the heat exchange medium.

  The electrode terminal of each power storage element can be positioned on the upper surface of the power storage unit. Thereby, it becomes easy to supply the heat exchange medium from the supply passage to each power storage element. That is, if there is an electrode terminal on the side where the heat exchange medium supply passage is arranged in the power storage element, the movement of the heat exchange medium may be hindered.

  Further, the connecting member can be made of metal, and the tray can be made of an insulating material (for example, resin). In this case, the insulating property between the connecting member and the power storage element can be ensured by the tray.

  According to the present invention, the passage through which the heat exchange medium moves can be formed using the tray fixed to the power storage unit by the connecting member.

It is a top view of the battery pack in Example 1 of this invention. It is AA sectional drawing of FIG. In Example 1, it is a figure which shows the structure of a discharge passage. In Example 1, it is a figure explaining attachment of a restraint band and a tray. In Example 1, it is a figure which shows the structure of a discharge passage. It is sectional drawing of the battery pack in Example 2 of this invention. It is a side view which shows the structure of the partition plate in Example 2. FIG. In Example 2, it is an enlarged view which shows the connection structure of a partition plate. In Example 2, it is an enlarged view which shows a part of partition plate. 6 is a side view of a battery pack in Example 2. FIG. It is a figure when the battery pack of Example 2 is seen from the discharge duct side.

  Examples of the present invention will be described below.

  A battery pack (corresponding to a power storage device) that is Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a schematic view of the battery pack of this embodiment as viewed from above, and FIG. 2 is a cross-sectional view taken along line AA in FIG. 1 and 2, an X axis, a Y axis, and a Z axis are axes that are orthogonal to each other, and in this embodiment, the Z axis is an axis that corresponds to the vertical direction.

  The battery pack 1 of the present embodiment is mounted on a vehicle, and examples of the vehicle include a hybrid vehicle and an electric vehicle. A hybrid vehicle is a vehicle that uses a fuel cell or an internal combustion engine in addition to the battery pack 1 as a power source for generating travel energy of the vehicle. An electric vehicle is a vehicle that uses only the battery pack 1 as a power source of the vehicle. If the battery pack 1 is mounted on the vehicle, the vehicle is driven by converting the electrical energy output from the battery pack 1 into kinetic energy, or the kinetic energy generated during braking of the vehicle is stored in the battery pack 1 as regenerative power. can do.

  The battery pack 1 has a plurality of single cells (corresponding to power storage elements) 10 arranged side by side in the X direction, and a pair of end plates 20 are arranged at both ends of the battery pack 1 in the X direction. ing. The pair of end plates 20 are used to apply the restraining force F1 to all the unit cells 10, and can be formed of, for example, resin. The restraining force F1 is a force that is generated when the pair of end plates 20 are displaced in a direction approaching each other, and is a force that presses the unit cell 10 from both sides in the X direction.

  Restraint bands (corresponding to connecting members) 61 and 62 extending in the X direction are fixed to the pair of end plates 20, thereby generating a restraining force F <b> 1. The restraining bands 61 and 62 can be made of metal, for example. As shown in FIG. 2, two restraining bands 61 are disposed on the upper surface of the battery pack 1, and two restraining bands 62 are disposed on the lower surface of the battery pack 1. In FIG. 1, the restraining bands 61 and 62 are omitted.

  The unit cell 10 includes a power generation element for charging and discharging contained in a battery case. The power generation element includes a positive electrode element, a negative electrode element, and an electrolyte layer disposed between the positive electrode element and the negative electrode element. It is configured. The battery case can be made of metal, for example. A positive terminal (also referred to as an electrode terminal) 11 and a negative terminal (also referred to as an electrode terminal) 12 are provided on the upper surface of the unit cell 10. The positive electrode terminal 11 is electrically and mechanically connected to the positive electrode element of the power generation element, and the negative electrode terminal 12 is electrically and mechanically connected to the negative electrode element of the power generation element.

  All the unit cells 10 constituting the battery pack 1 are electrically connected in series via the bus bar 40. Specifically, the bus bar 40 is connected to the positive electrode terminal 11 of one unit cell 10 and the negative electrode terminal 12 of the other unit cell 10 out of two unit cells 10 adjacent in the X direction. In addition, the battery pack 1 may include a plurality of single cells 10 electrically connected in parallel.

  As the unit cell 10, a secondary battery such as a nickel metal hydride battery or a lithium ion battery can be used. An electric double layer capacitor can be used instead of the secondary battery. The number of the single cells 10 can be appropriately set based on the required output of the battery pack 1 and the like. In the present embodiment, the plurality of single cells 10 are arranged in the X direction, but the present invention is not limited to this. For example, the battery pack 1 can be configured by configuring a single battery module (corresponding to a power storage element) with a plurality of single cells and arranging the plurality of battery modules in the X direction. In this case, each battery module has a positive electrode terminal and a negative electrode terminal, and a plurality of battery modules are electrically connected in series via the bus bar.

  A partition plate 30 is disposed between two unit cells 10 disposed adjacent to each other in the X direction, and the partition plate 30 can be formed of an insulating material such as a resin, for example. Each partition plate 30 supports one unit cell 10 of the two unit cells 10 sandwiching the partition plate 30. Specifically, the partition plate 30 is formed with a side surface portion 31 and a bottom surface portion 32 protruding in the X direction (see FIG. 2), and the side surface portion 31 and the bottom surface portion 32 are in contact with the outer peripheral surface of the unit cell 10. By doing so, the unit cell 10 is supported. Further, the two unit cells 10 arranged at both ends of the battery pack 1 in the X direction are supported by the end plate 20 and the partition plate 30.

  The partition plate 30 is sandwiched between two unit cells 10 and has two surfaces that come into contact with the two unit cells 10. One surface of the partition plate 30 is a flat surface, and the other surface of the partition plate 30 is an uneven surface. If the uneven surface of the partition plate 30 is brought into contact with the cell 10, a space for moving the heat exchange medium can be formed on the surface of the cell 10. Here, the unit cell 10 and the partition plate 30 in the present embodiment are included in the power storage unit of the present invention.

  In this embodiment, the heat exchange medium is moved as indicated by the arrows in FIG. 2, and the uneven surface of the partition plate 30 may be formed so that the heat exchange medium can move in this direction. For example, if the concave surface of the partition plate 30 is formed along the movement trajectory of the heat exchange medium shown in FIG. 2, the heat exchange medium can be easily moved along the predetermined movement trajectory.

  The heat exchange medium is used to adjust the temperature of the unit cell 10 by exchanging heat with the unit cell 10. When the battery pack 1 of this embodiment is mounted on a vehicle, air in the vehicle compartment can be used as a heat exchange medium. Here, the passenger compartment refers to a space in which passengers get on. The heat exchange medium is not limited to air, and other gases and liquids can also be used.

  When the unit cell 10 generates heat, a heat exchange medium for cooling is brought into contact with the unit cell 10, whereby the heat exchange medium can take away the heat of the unit cell 10 and suppress an increase in temperature of the unit cell 10. Further, when the unit cell 10 is excessively cooled, the unit cell 10 can be heated by bringing a heating heat exchange medium into contact with the unit cell 10 to heat the unit cell 10. Thus, by adjusting the temperature of the cell 10, it is possible to suppress the deterioration of the input / output characteristics of the cell 10.

  A first supply duct 51 and a second supply duct 52 are arranged on both side surfaces of the battery pack 1 in the Y direction. The first supply duct 51 and the second supply duct 52 move the heat exchange medium along the supply passages S <b> 1 and S <b> 2 to guide the heat exchange medium to the unit cell 10. The moving direction of the heat exchange medium in the supply ducts 51 and 52 is indicated by arrows (one example) in FIG. The heat exchange medium that has moved through the supply ducts 51 and 52 enters the space formed between the unit cell 10 and the partition plate 30 and moves along the surface of the unit cell 10. On the surface of the unit cell 10, the heat exchange medium moves and heat exchange is performed between the unit cell 10 and the heat exchange medium as indicated by an arrow (an example) in FIG. 2.

  Here, one supply duct can be configured by connecting the first supply duct 51 and the second supply duct 52 to each other on the upstream side of the movement path of the heat exchange medium. Moreover, if a fan is arrange | positioned on the movement path | route of a heat exchange medium and a fan is driven, a heat exchange medium can be forcedly moved. The fan can be provided in at least one of the supply ducts 51 and 52, or can be provided in the discharge duct 53 described later.

  As shown in FIG. 2, the heat exchange medium that moves along the surface of the unit cell 10 is directed to the discharge passage S <b> 3 provided in the lower part of the battery pack 1. The discharge passage S3 is a space surrounded by the partition plate 30 (particularly, the bottom surface portion 32) and the tray 70. The tray 70 extends in the X direction, and can be formed of an insulating material such as resin. If the tray 70 has an insulating function, the insulating property between the restraining band 62 (made of metal) and the unit cell 10 can be ensured.

  In addition, it is preferable to ensure insulation between the restraint band 61 (made of metal) and the unit cell 10 (particularly, the electrode terminals 11 and 12). Specifically, an insulating member may be disposed between the restraining band 61 and the unit cell 10.

  As shown in FIG. 3, a seal member 80 is disposed between the side edge portion 71 of the tray 70 and the bottom surface portion 32 of the partition plate 30, and the seal member 80 seals the discharge passage S3. Used to do. When fixing the restraining band 62 to the end plate 20, the tray 70 is pressed toward the bottom surface portion 32 of the partition plate 30 as indicated by an arrow F <b> 2 in FIG. 3. By pressing the tray 70 toward the bottom surface portion 32 of the partition plate 30, the seal member 80 can be deformed to improve the sealing performance in the discharge passage S3.

  The tray 70 has a protruding region 72 that protrudes below the battery pack 1 (downward in FIG. 3) from the position of contact with the restraining band 62. By providing the protruding region 72 on the tray 70, the discharge passage S3 can be enlarged.

  In this embodiment, the seal member 80 is used. However, the seal member 80 may be omitted, and the side edge portion 71 of the tray 70 may be brought into contact with the bottom surface portion 32 of the partition plate 30. Further, the tray 70 may not be pressed toward the bottom surface portion 32 of the partition plate 30, and the tray 70 may only be positioned with respect to the partition plate 30 by using the restraining band 62. However, the side edge portion 71 of the tray 70 is preferably in contact with the bottom surface portion 32 of the partition plate 30.

  A method of fixing the restraining bands 61 and 62 to the end plate 20 will be described with reference to FIGS. 4 and 5. 4 and 5 are side views when the battery pack 1 is viewed from the Y direction, and the supply ducts 51 and 52 are omitted.

  The restraint band 61 has connection portions 61 a and 61 b at both ends in the longitudinal direction, and the connection portions 61 a and 61 b are fixed to the pair of end plates 20 by rivets 90. The restraint band 62 has connection portions 62 a and 62 b at both ends in the longitudinal direction, and the connection portions 62 a and 62 b are fixed to the pair of end plates 20 by rivets 90. By fixing the restraining band 62 to the end plate 20, the tray 70 can be fixed while being pressed against the end plate 20 or the partition plate 30.

  The tray 70 has a wall portion 73 at one end in the X direction, and the tip of the wall portion 73 is in contact with the end plate 20. Further, as shown in FIG. 5, a discharge duct 53 is connected to the other end of the tray 70 in the X direction. Thereby, the heat exchange medium guided to the discharge passage S <b> 3 moves toward the discharge duct 53. The discharge duct 53 moves the heat exchange medium in a direction away from the battery pack 1. When the battery pack 1 is mounted on a vehicle, the discharge duct 53 can move the heat exchange medium to a vent duct (not shown) provided in the vehicle body.

  In this embodiment, the discharge passage S <b> 3 can be formed using the tray 70 while fixing the tray 70 using the restraining band 62.

  In the present embodiment, since the heat exchange medium is supplied to the unit cell 10 using the supply passages S1 and S2, the battery pack 1 is secured while ensuring the supply amount of the heat exchange medium necessary for temperature adjustment of the unit cell 10. Increase in size (in the Y direction) can be suppressed. Here, in the configuration described in Patent Document 1, of the spaces S1 and S2 described in the present embodiment, the space S1 is used as an intake passage and the space S2 is used as an exhaust passage.

  On the other hand, in the present embodiment, since the spaces S1 and S2 are used as the supply passages, the cross-sectional areas of the spaces S1 and S2 are the same as those in Patent Document 1 when attempting to secure the cross-sectional area of the intake passage described in Patent Document 1. It can be approximately half the cross-sectional area of the intake passage. Thereby, space S1, S2 can be reduced in the Y direction, and the battery pack 1 can be reduced in the Y direction.

  Moreover, the increase in the number of parts can be suppressed by providing the tray 70 with the function of ensuring the insulation between the restraining band 62 and the unit cell 10 and the function of forming the discharge passage S3. .

  In the present embodiment, the spaces S1 and S2 are used as the supply passage and the space S3 is used as the discharge passage. However, the present invention is not limited to this. For example, the space S3 can be used as the supply passage, and the spaces S1 and S2 can be used as the discharge passage. Further, in order to ensure the strength of the tray 70, ribs (not shown) protruding inside the tray 70 can be provided. Here, if the rib is formed along the moving direction (X direction) of the heat exchange medium, the flow of the heat exchange medium can be adjusted.

  A battery pack (power storage device) that is Embodiment 2 of the present invention will be described. Here, members having the same functions as those described in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. In the present embodiment, similarly to the first embodiment, supply passages S1 and S2 are provided on both side surfaces of the battery pack 1, and a discharge passage S3 is provided in the lower portion of the battery pack 1. In the present embodiment, the structures of the end plate 20 and the partition plate 30 are different from those in the first embodiment. Hereinafter, differences from the first embodiment will be mainly described.

  FIG. 6 is a cross-sectional view of the battery pack 1 according to the present embodiment, and corresponds to FIG. 2 described in the first embodiment. As shown in FIG. 6, each partition plate 30 has a duct portion 33, and the duct portion 33 is used to form the discharge passage S3. A restraining band 62 is disposed outside the duct portion 33.

  As shown in FIG. 7, the plurality of partition plates 30 are arranged side by side in the X direction, and the duct portions 33 in the two partition plates 30 adjacent in the X direction contact each other by receiving the restraining force F1. To do. And when the duct part 33 in the some partition plate 30 mutually contacts, discharge channel | path S3 demonstrated in Example 1 is formed.

  As shown in FIGS. 8 and 9, each duct portion 33 has a convex portion 33a at one end in the X direction and a concave portion 33b at the other end in the X direction. The convex portion 33 a and the concave portion 33 b constitute a part of the bottom surface of the duct portion 33.

  The convex portion 33a extends in the X direction and includes a first region 33a1 and a second region 33a2 as shown in FIG. The first region 33a1 constitutes an XY plane, and the second region 33a2 constitutes a YZ plane. The concave portion 33b is formed in a shape corresponding to the convex portion 33a, and has a first region 33b1 and a second region 33b2. The first region 33b1 constitutes the XY plane, and the second region 33a2 constitutes the YZ plane.

  The first region 33a1 of the convex portion 33a and the first region 33b1 of the concave portion 33b face each other in the Z direction and contact each other. The second region 33a2 of the convex portion 33a and the second region 33b2 of the concave portion 33b face each other in the X direction, and come into contact with each other by receiving the restraining force F1. By connecting the two duct parts 33 adjacent in the X direction using the convex part 33a and the concave part 33b, the duct part 33 can be easily connected, and the heat exchange medium hardly leaks from the duct part 33. can do.

  FIG. 10 is a side view of the battery pack 1 according to the present embodiment, in which the electrode terminals 11 and 12 of the unit cell 10 are omitted. Similarly to the partition plate 30, the pair of end plates 20 is also provided with a duct portion 21. Here, the duct portion 21 in one end plate 20 (the right end plate 20 in FIG. 10) does not penetrate, and only the side facing the duct portion 33 of the partition plate 30 is open. In other words, the surface of the duct portion 21 that faces the connection portion 62a of the restraining band 62 is closed, and the rivet 90 is fixed to this surface. The duct portion 21 has a convex portion 21 a extending in the X direction, and the convex portion 21 a is in contact with the concave portion 33 b of the partition plate 30. The convex portion 21 a of the end plate 20 has the same shape as the convex portion 33 a of the partition plate 30.

  The duct portion 22 in the other end plate 20 (the left end plate 20 in FIG. 10) passes through, but as shown in FIG. 11, has a region 22b to which the connection portion 62b of the restraining band 62 is connected. ing. Here, FIG. 11 is a view when the battery pack 1 is viewed from the discharge duct 53 side, and the discharge duct 53 is omitted. A discharge duct 53 is connected to the duct portion 22, and the discharge duct 53 is connected to the duct portion 22 at a portion avoiding the connection portion 62 b of the restraining band 62. Further, the duct portion 22 has a concave portion 22 a that contacts the convex portion 33 a of the partition plate 30.

  Also in the battery pack 1 of the present embodiment, the heat exchange medium moved to the supply passages S1 and S2 moves along the surface of the unit cell 10 and then moves to the discharge passage S3. And it is guide | induced to the discharge duct 35 from discharge path S3. Thereby, the temperature of the cell 10 can be adjusted.

  Also in this embodiment, the same effect as that of Embodiment 1 can be obtained. That is, by using the supply passages S1 and S2, the battery pack 1 can be reduced in size in the Y direction. Further, the restraining force F1 for restraining the plurality of single cells 10 can also be used for forming the discharge passage S3 by connecting the duct portions 33 of the plurality of partition plates 30 to each other.

  In the present embodiment, the spaces S1 and S2 are used as the supply passage and the space S3 is used as the discharge passage. However, the present invention is not limited to this. For example, the spaces S1 and S2 can be used as the discharge passage, and the space S3 can be used as the supply passage. Moreover, in order to ensure the strength of the duct portions 33, 21, and 22, ribs (not shown) that protrude toward the inside of the discharge passage S3 can be formed. Here, if the rib is formed along the moving direction (X direction) of the heat exchange medium, the flow of the heat exchange medium can be adjusted.

  This embodiment embodies the invention described below.

(1) a plurality of power storage elements arranged side by side in one direction;
A partition plate disposed between two adjacent power storage elements,
The partition plate is
A contact portion that is in contact with the power storage element and forms a moving space of a heat exchange medium used for temperature adjustment of the power storage element with the power storage element;
A duct part forming a part of a passage for moving the heat exchange medium in an arrangement direction of the plurality of power storage elements;
A power storage device comprising:

(2) having a restraining mechanism that gives restraining force in the arrangement direction to the plurality of power storage elements;
The power storage device according to (1), wherein the duct portions of the two partition plates adjacent in the arrangement direction are in close contact with each other under the restraining force.

(3) The restraint mechanism has a pair of end plates that sandwich the plurality of power storage elements in the arrangement direction.
Each end plate is
A contact portion that contacts the power storage element;
A duct portion that forms the passage together with the duct portion of the partition plate;
The power storage device according to (2), characterized by comprising:

(4) The duct portion in the two partition plates adjacent in the arrangement direction,
A first region extending in the arrangement direction and facing in a direction orthogonal to the arrangement direction;
The power storage device according to any one of (1) to (3), further including a second region that is orthogonal to the arrangement direction and is opposed to the arrangement direction.

  (5) In any one of (1) to (4), the passage is a passage for discharging the heat exchange medium after heat exchange is performed with the power storage element. The power storage device described.

(6) The passage is provided in a lower part of the power storage device,
A passage for supplying the heat exchange medium to each power storage element extends in the arrangement direction, and is provided at a position different from the lower part of the power storage device and sandwiching the plurality of power storage elements. The power storage device according to (5), wherein

1: Battery pack (power storage device) 10: Single battery (power storage element)
11: Positive terminal 12: Negative terminal 20: End plate 30: Partition plate 31: Side part 32: Bottom part 33: Duct part 40: Bus bar 51: First supply duct 52: Second supply duct 53: Exhaust ducts 61, 62 : Restraint band (connecting member)
70: Tray 71: Side edge 72: Protruding area 80: Seal member 90: Rivet

Claims (7)

A power storage unit in which a plurality of power storage elements are arranged in one direction;
In the arrangement direction of the plurality of power storage elements, a pair of end plates sandwiching the power storage unit;
Extending in the arrangement direction and connected to the pair of end plates, and a connecting member for applying a binding force to the power storage unit via the end plates;
A tray fixed to the bottom surface of the power storage unit by the connecting member,
The power storage device, wherein the tray forms a passage for moving a heat exchange medium used for temperature adjustment of the power storage element in the arrangement direction between the tray and a bottom surface of the power storage unit.   The power storage device according to claim 1, wherein the connecting member pushes the tray toward a bottom surface of the power storage unit.   3. The power storage device according to claim 1, further comprising a sealing member that is disposed between the power storage unit and the tray and that seals the passage. 4.   4. The power storage device according to claim 1, wherein the passage is a passage through which the heat exchange medium is discharged after heat exchange is performed with the power storage element. 5.   A passage for supplying the heat exchange medium to each power storage element extends in the arrangement direction, and is provided at a position different from the bottom surface of the power storage unit and sandwiching the power storage unit. The power storage device according to claim 4.   6. The power storage device according to claim 1, wherein each power storage element has an electrode terminal on an upper surface of the power storage unit. The connecting member is made of metal,
The power storage device according to claim 1, wherein the tray is made of an insulating material.

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