JP5527172B2 - Power storage device - Google Patents

Description

  The present invention relates to a power storage device in which a plurality of power storage elements are arranged in one direction and has a passage for moving a gas discharged from each power storage element.

  The unit cell is provided with a valve for discharging gas generated inside the unit cell to the outside of the unit cell. When an assembled battery is configured using a plurality of unit cells, a duct is arranged along the arrangement direction of the plurality of unit cells, and the gas discharged from the valve of each unit cell is guided to the duct.

JP 2009-170258 A JP 2010-1113888 A JP 2004-022338 A

  If a dedicated duct is used to move the gas discharged from the valve along a predetermined path, the number of parts increases by the amount of the duct. On the other hand, in the configuration described in Patent Document 2, the assembled battery is restrained by using a duct that discharges gas. However, depending on the size of the unit cell, the duct becomes large and difficult to handle.

  The objective of this invention provides the electrical storage apparatus which can suppress the number of parts and can form the movement path | route of the gas discharged | emitted from the valve.

A power storage device according to the present invention includes a plurality of power storage elements arranged side by side in a predetermined direction, a pair of end plates sandwiching the plurality of power storage elements in the predetermined direction, and extending in a predetermined direction and fixed to the pair of end plates. And a plurality of connecting members arranged at positions sandwiching the plurality of power storage elements, and a case for housing the plurality of power storage elements. Each power storage element includes a valve for discharging gas generated inside the power storage element to the outside of the power storage element. The plurality of connecting members include two connecting members. The two connecting members are arranged side by side on a region sandwiching the valve on one surface of the power storage element provided with the valve. The two connecting members are in contact with the inner wall surface of the case and form a moving space for the gas discharged from the valve together with the case.

  The connecting member can be fixed to the inner wall surface of the case using a bolt. By fixing the connecting member and the case with bolts, the rigidity of the case can be improved. Thereby, it can suppress that a case deform | transforms toward the inner side or the outer side of an electrical storage apparatus. Here, the connecting member can be provided with a region through which the bolt penetrates and along the inner wall surface of the case. Thereby, in the state which made the connection member contact the inner wall surface of a case, a connection member and a case can be easily fixed with a volt | bolt.

  The valve can be provided on the upper surface of the power storage element. Thereby, the gas generated inside the electric storage element can be easily discharged from the valve.

  A partition member formed of an insulating material can be disposed between two power storage elements adjacent in a predetermined direction. Here, when the connecting member is formed of metal, the connecting member can be brought into contact with the partition member, and the connecting member can be separated from the power storage element. In the configuration in which the connecting member is separated from the power storage element, a gap is generated between the moving space formed by the connecting member and the power storage element. Therefore, the gas discharged from the valve can be easily guided to the moving space by positioning the guide portion formed on the partition member with respect to the gap.

  The moving space described above can be used not only as a moving space for the gas discharged from the valve, but also as a moving space for a heat exchange medium used for adjusting the temperature of the power storage element. The heat exchange medium that moves in the moving space may be a heat exchange medium before adjusting the temperature of the power storage element, or may be a heat exchange medium after adjusting the temperature of the power storage element. Specifically, the moving space can be used as an intake passage or an exhaust passage.

According to the present invention, by using the connecting member, a binding force can be applied to the plurality of power storage elements via the pair of end plates. Moreover, the movement path | route of the gas discharged | emitted from the valve can be formed by using a connection member. Furthermore , the size of the gas movement path can be changed simply by changing the interval between the two connecting members.

1 is an external view of a battery stack that is Example 1. FIG. 1 is a cross-sectional view of a battery pack that is Example 1. FIG. In Example 1, it is a front view of a partition member. It is AA sectional drawing of FIG. In Example 1, it is a figure explaining the movement path | route of the gas discharged | emitted from the valve. In Example 1, it is a figure explaining the movement path | route of the air used for temperature control of a cell.

  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. FIG. 1 is an external view of a battery stack in the present embodiment. FIG. 2 is a cross-sectional view of the battery pack of this example when cut along the YZ plane. 1 and 2, an X axis, a Y axis, and a Z axis are orthogonal to each other. In this embodiment, an axis corresponding to the vertical direction is a Z axis.

  The battery pack of this embodiment can be mounted on a vehicle. Vehicles include hybrid cars and electric cars. A hybrid vehicle is a vehicle provided with other power sources such as a fuel cell and an internal combustion engine in addition to a battery pack as a power source for running the vehicle. An electric vehicle is a vehicle that uses only a battery pack as a power source of the vehicle.

  As illustrated in FIG. 1, the battery stack 1 includes a plurality of single cells (corresponding to power storage elements) 10, and the plurality of single cells 10 are arranged in the X direction. As shown in FIG. 2, the battery stack 1 is covered with a pack case 50. The battery pack 100 is configured by housing the battery stack 1 in the pack case 50. The pack case 50 includes an upper case 51 and a lower case 52. The upper case 51 and the lower case 52 can be formed of metal, for example.

  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 (capacitor) can be used instead of the secondary battery. The unit cell 10 is a so-called rectangular unit cell, and the exterior surface of the unit cell 10 orthogonal to the arrangement direction (X direction) of the plurality of unit cells 10 is configured by a flat surface (YZ plane). Yes.

  The number of the single cells 10 can be appropriately set based on the required output of the battery stack 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. Specifically, one battery module (corresponding to a power storage element) can be configured using a plurality of single cells 10 and the plurality of battery modules can be arranged in the X direction.

  A positive electrode terminal 11 and a negative electrode terminal 12 are provided on the upper surface of the unit cell 10. The battery case constituting the exterior of the unit cell 10 houses a power generation element. The power generation element includes, for example, a positive electrode element, a negative electrode element, and a separator (electrolyte solution) disposed between the positive electrode element and the negative electrode element. Including). In the positive electrode element, a positive electrode active material layer is formed on the surface of a current collector plate. In the negative electrode element, a negative electrode active material layer is formed on the surface of a current collector plate. The positive electrode terminal 11 is electrically and mechanically connected to the positive electrode element of the power generation element. The negative electrode terminal 12 is electrically and mechanically connected to the negative electrode element of the power generation element.

  The plurality of single cells 10 arranged side by side in the X direction are electrically connected in series. Specifically, the positive terminal 11 of the unit cell 10 and the negative terminal 12 of another unit cell 10 are electrically connected by a bus bar. In the present embodiment, two bus bar modules 20 are used to electrically connect the plurality of single cells 10 in series. Each bus bar module 20 can be composed of a plurality of bus bars and a plate that supports the plurality of bus bars. The plate can be formed of an insulating material such as resin.

  As shown in FIG. 2, a valve 13 is provided on the upper surface of the unit cell 10. The valve 13 is used to discharge gas generated inside the unit cell 10 to the outside of the unit cell 10. Since the inside of the unit cell 10 is hermetically sealed, when gas is generated inside the unit cell 10, the internal pressure of the unit cell 10 increases as the gas is generated. When the internal pressure of the unit cell 10 reaches the operating pressure of the valve 13, the valve 13 changes from the closed state to the open state. Thereby, the gas generated inside the cell 10 can be discharged to the outside of the cell 10.

  The valve 13 is disposed between the positive electrode terminal 11 and the negative electrode terminal 12 in the Y direction. In this embodiment, the valve 13 is disposed at a position where the distance from the positive electrode terminal 11 and the negative electrode terminal 12 is equal. . The position where the valve 13 is provided can be set as appropriate. Here, by providing the valve 13 on the upper surface of the unit cell 10 as in this embodiment, the gas generated inside the unit cell 10 can be easily discharged from the valve 13.

  As the valve 13, a so-called destructive valve or a so-called return valve can be used. A destructive valve is a valve that changes irreversibly from a closed state to an open state. For example, a destructive valve can be formed by forming a stamp on a part of the battery case. A reset valve is a valve that reversibly changes between a closed state and an open state. That is, the valve changes between a closed state and an open state according to the magnitude relationship between the internal pressure of the single cell 10 and the external pressure. The return-type valve can be constituted by, for example, a lid that blocks a gas movement path and a spring that biases the lid in one direction.

  A partition member 30 is disposed between two unit cells 10 adjacent in the X direction. The partition member 30 can be formed of an insulating material such as resin. FIG. 3 shows a view when the partition member 30 is viewed from the X direction, and FIG. 4 is a cross-sectional view taken along line AA of FIG.

  The partition member 30 has a plurality of ribs 31 protruding in the X direction on the surface facing the single cell 10. Each rib 31 extends in the Z direction, and the plurality of ribs 31 are arranged in the Y direction. Here, the number of ribs 31 and the interval between two ribs 31 adjacent in the Y direction can be set as appropriate. In the partition member 30, the surface opposite to the surface on which the ribs 31 are formed, in other words, the surface facing the other unit cell 10 is a flat surface.

  A space S <b> 3 is formed between the unit cell 10 and the partition member 30 by the tips of the ribs 31 in the X direction coming into contact with the unit cell 10. The space S3 is a space where air for adjusting the temperature of the unit cell 10 moves. When the battery pack 100 is mounted on a vehicle, the temperature of the unit cell 10 can be adjusted using air in the passenger compartment. The passenger compartment is a space where passengers get on. By introducing air into the space S3, heat exchange can be performed between the air and the unit cell 10.

  In the present embodiment, air is used to adjust the temperature of the unit cell 10, but the present invention is not limited to this, and a gas other than air or a liquid can be used. That is, any fluid that can exchange heat with the unit cell 10 may be used.

  When the temperature of the unit cell 10 increases due to charging / discharging or the like, the temperature increase of the unit cell 10 can be suppressed by bringing cooling air into contact with the unit cell 10. Further, when the unit cell 10 is excessively cooled, the temperature decrease of the unit cell 10 can be suppressed by bringing heating air into contact with the unit cell 10.

  A guide portion 32 protruding in the X direction is formed on the upper portion of the partition member 30. The guide part 32 is provided on the surface on which the rib 31 is formed and on the surface on which the rib 31 is not formed. The lower end surface of the guide part 32 is in contact with the upper surface of the unit cell 10. Moreover, the upper end surface of the guide part 32 contacts the 1st connection member 42 mentioned later.

  A pair of end plates 41 are disposed at both ends of the battery stack 1 in the X direction. The first connecting member 42 extends in the X direction, and both ends of the first connecting member 42 are fixed to the pair of end plates 41. Specifically, fixing portions 42a are provided at both ends of the first connecting member 42, and the fixing portions 42a are fixed to the end plate 41 using, for example, bolts. The fixing method of the 1st connection member 42 and the end plate 41 can be selected suitably. In addition to the fixing method using bolts, for example, a fixing method using rivets or a fixing method such as welding can be used.

  Two first connecting members 42 are arranged on the upper surface of the battery stack 1. The two first connecting members 42 are located between the positive electrode terminal 11 and the negative electrode terminal 12 of the unit cell 10. Further, the distance between the two first connecting members 42 in the Y direction is larger than the length of the valve 13 in the Y direction. That is, one first connection member 42 is disposed on the positive electrode terminal 11 side with respect to the valve 13, and the other first connection member 42 is disposed on the negative electrode terminal 12 side with respect to the valve 13.

  On the other hand, as shown in FIGS. 2 to 4, two second connecting members 43 are also arranged on the lower surface of the battery stack 1, and both ends of the second connecting member 43 are fixed to a pair of end plates 41. ing. The fixing method of the second connecting member 43 and the end plate 41 can be set as appropriate similarly to the first connecting member 42. The 1st connection member 42 and the 2nd connection member 43 can be formed with a metal, for example.

  When viewed from the X direction, the first connecting member 42 and the second connecting member 43 are disposed at positions sandwiching the plurality of unit cells 10. In this way, by fixing the first connecting member 42 and the second connecting member 43 to the pair of end plates 41, a binding force can be applied to the plurality of single cells 10. The restraining force is a force that sandwiches the unit cell 10 in the X direction. By applying a binding force to the unit cell 10, for example, expansion of the unit cell 10 can be suppressed. In the present embodiment, by using the two first connecting members 42 and the two second connecting members 43, it is possible to prevent the binding force from concentrating on one place, and to achieve a uniform binding force with respect to the unit cell 10. Can be given.

  As shown in FIG. 2, the first connecting member 42 disposed on the upper surface of the battery stack 1 has a first region 42 a along the XZ plane and a second region 42 b along the XY plane. . The second region 42 b of the first connecting member 42 is in contact with the inner wall surface of the upper case 51 and is fixed to the upper case 51 by a bolt 44. The position where the first connecting member 42 and the upper case 51 are fixed using the bolts 44 can be set as appropriate.

  By fixing the two first connecting members 42 to the upper case 51, a space S <b> 1 is formed by the upper case 51, the two first connecting members 42, and the partition member 30. Since the space S1 is located immediately above the valve 13 of each unit cell 10, the gas discharged from the valve 13 moves to the space S1. Since the space S1 extends in the X direction, the gas from the valve 13 travels in the X direction.

  In the present embodiment, the second region 42b of the first connecting member 42 faces the space S1, but is not limited to this configuration. Specifically, the second region 42b can be disposed on the side opposite to the valve 13 with respect to the first region 42a. In this case, a space S <b> 1 is formed by the first region 42 a of the first connecting member 42, the upper case 51, and the partition member 30.

  On the other hand, about the 2nd connection member 43 arrange | positioned at the lower surface of the battery stack 1, the shape of the cross section orthogonal to a longitudinal direction (X direction) is formed in the rectangular shape. The second connecting member 43 is in contact with the inner wall surface of the lower case 52, and a space S <b> 2 is formed by the second connecting member 43, the lower case 52, and the partition member 30. The space S2 extends in the X direction.

  In this embodiment, as shown in FIG. 5, an intake duct 61 is connected to the space S2. FIG. 5 shows a part of the intake duct 61. The intake duct 61 is used to supply air used for temperature adjustment of the unit cell 10 to the inside of the pack case 50 (specifically, the space S2). When the battery pack 100 is mounted on a vehicle, the intake duct 61 can be arranged so that the intake port of the intake duct 61 faces the vehicle interior.

  As shown in FIG. 6, the air guided from the intake duct 61 into the pack case 50 moves along the space S <b> 2 formed by the two second connecting members 43. Here, by driving the blower, air can be moved from the intake duct 61 into the pack case 50. The blower can be provided in the intake duct 61 or in the exhaust duct 62 described later.

  The air moving in the space S2 moves to the space S3 formed between the unit cell 10 and the partition member 30. In FIG. 6, the space S3 is omitted. While the air moves in the space S <b> 3, the temperature of the unit cell 10 is adjusted by heat exchange between the air and the unit cell 10. The air after heat exchange moves from the space S3 to the space S1. The air that has moved to the space S <b> 1 moves toward the exhaust duct 62. The arrows shown in FIGS. 5 and 6 indicate the moving direction of air (one example).

  Here, when the gas is discharged from the valve 13 of the unit cell 10, the gas moves along the space S <b> 1 and is guided to the exhaust duct 62. 5 and 6, a part of the exhaust duct 62 is shown. When the battery pack 100 is mounted on the vehicle, the air after heat exchange and the gas discharged from the valve 13 can be discharged to the outside of the vehicle through the exhaust duct 62.

  In the configuration shown in FIGS. 5 and 6, the intake duct 61 and the exhaust duct 62 are arranged on both end faces of the pack case 50 in the X direction, respectively, but this is not restrictive. That is, it is only necessary that air is supplied to the inside of the pack case 50 and the air after heat exchange can be discharged to the outside of the pack case 50. For example, the intake duct 61 and the exhaust duct 62 can be connected to one end face of the pack case 50 in the X direction. Further, the temperature of the unit cell 10 can be adjusted by moving the air in the direction opposite to the air moving direction shown in FIGS. 5 and 6.

  In the present embodiment, the first connecting member 42 and the upper case 51 are fixed using the bolts 44, but the second region 42 b of the first connecting member 42 can be simply brought into contact with the inner wall surface of the upper case 51. Good. By bringing the first connecting member 42 into contact with the inner wall surface of the upper case 51, the deformation of the upper case 51 can be suppressed.

  When a space is formed between the upper case 51 and the first connecting member 42, when an external force is applied to the upper case 51 from the outside of the battery pack 100, the upper case 51 faces the inside of the battery pack 100. May be deformed. If the first connecting member 42 is in contact with the inner wall surface of the upper case 51 as in the present embodiment, even if the upper case 51 receives an external force, it is prevented from being deformed inside the battery pack 100. be able to.

  On the other hand, when the gas from the valve 13 moves to the space S1, the pressure in the space S1 may increase. Depending on the pressure increase in the space S1, the upper case 51 may be deformed toward the outside of the battery pack 100. In this case, if the 1st connection member 42 and the upper case 51 are fixed using the volt | bolt 44, a deformation | transformation of the upper case 51 accompanying the pressure rise of the space S1 can be suppressed.

  Moreover, since the 1st connection member 42 and the upper case 51 can be closely_contact | adhered if the volt | bolt 44 is used, the gas which moves the space S1 will leak from between the 1st connection member 42 and the upper case 51. FIG. Can be suppressed.

  In the present embodiment, the second region 42b of the first connecting member 42 and the upper case 51 are overlapped and fixed by the bolts 44, but the present invention is not limited to this. That is, it is only necessary that the first connecting member 42 and the upper case 51 can be fixed using bolts. For example, in a configuration in which a part of the first connecting member 42 penetrates the upper case 51 and protrudes to the outside of the battery pack 100, a part of the first connecting member 42 protruding from the upper case 51 and the upper case 51 are It can be fixed using a bolt.

  As described above, the partition member 30 is provided with the guide portion 32, and the guide portion 32 is in contact with the first connecting member 42 and the unit cell 10. Thereby, it is possible to prevent the gas discharged from the valve 13 from leaking from the space formed between the first connecting member 42 and the unit cell 10. When the battery case of the unit cell 10 is made of metal, it is preferable to keep the metal first connecting member 42 away from the unit cell 10.

  In the present embodiment, the metal first connecting member 42 is exposed, but the metal first connecting member 42 can be covered with a cover formed of an insulating material. Here, the entire surface of the first connecting member 42 can be covered with a cover, or a part of the first connecting member 42 can be covered with the cover. That is, it is only necessary that the first connecting member 42 and the unit cell 10 can be insulated by using the cover. When covering the 1st connection member 42 with a cover, a cover can be made to contact the upper surface of the cell 10. In this case, the guide portion 32 described in this embodiment can be omitted.

  According to the present embodiment, the first connecting member 42 has a function of giving a restraining force to the plurality of single cells 10 and a function of forming a movement path of the gas discharged from the valve 13. Thus, the number of parts can be reduced by giving a plurality of functions to one member (the first connecting member 42).

  In the present embodiment, since the two first connecting members 42 are used, the space S1 can be easily formed. Specifically, the space S1 can be changed only by changing the interval between the first connecting members 42. On the other hand, in the configuration described in Patent Document 2, when the space S1 is increased in size, a duct having a gas discharging function and an assembled battery restraining function is increased in size.

  Moreover, the rigidity of the upper case 51 can be improved by fixing the first connecting member 42 to the upper case 51. Furthermore, the battery stack 1 can be positioned inside the pack case 50 by fixing the first connecting member 42 to the upper case 51. Thereby, it is possible to prevent the battery stack 1 from being displaced inside the pack case 50.

  In the present embodiment, the space S <b> 1 becomes a passage through which the gas discharged from the valve 13 moves and a passage through which the air after heat exchange with the unit cell 10 moves. Thereby, the space S1 in the pack case 50 can be used efficiently.

  In this embodiment, the rib 31 extending in the Z direction is formed in the partition member 30 to move the air used for temperature adjustment of the unit cell 10 in the Z direction. However, the present invention is not limited to this. Absent. It suffices if an air moving space is formed between the partition member 30 and the unit cell 10. For example, air can be moved in the Y direction. In this case, the space S1 sandwiched between the two first connecting members 42 serves as a passage through which only the gas discharged from the valve 13 moves.

  In the present embodiment, the two first connecting members 42 are arranged on the upper surface of the battery stack 1 and the two second connecting members 43 are arranged on the lower surface of the battery stack 1, but this is not restrictive. . The number of connecting members arranged on the upper and lower surfaces of the battery stack 1 can be set as appropriate. However, the number of connecting members forming the space S1 needs to be at least two. Here, as a modification of the present embodiment, another connecting member can be disposed between the two first connecting members 42.

1: Battery stack 10: Single battery (storage element)
11: Positive terminal 12: Negative terminal 13: Valve 20: Bus bar module 30: Partition member 31: Rib 32: Guide portion 41: End plate 42: First connecting member 42a: First region 42b: Second region 43: Second Connecting member 44: Bolt 50: Pack case 51: Upper case 52: Lower case 61: Intake duct 62: Exhaust duct 100: Battery pack (power storage device)

Claims (7)

A plurality of power storage elements arranged side by side to a Jo Tokoro direction,
A pair of end plates sandwiching the plurality of power storage elements in the predetermined direction;
A plurality of connecting members extending in the predetermined direction and fixed to the pair of end plates, and arranged at positions sandwiching the plurality of power storage elements;
A power storage device to have a, and a case for accommodating the plurality of power storage devices,
Each of the electricity storage elements includes a valve for discharging the gas generated therein,
The plurality of connecting members include two connecting members,
The two connecting members are arranged side by side on a region sandwiching the valve in one surface of the electricity storage element provided with the valve,
Before SL two coupling members are in contact with the inner wall surface of the case, together with the case, power storage device and forming a moving space of the discharged gas from the valve. The power storage device according to claim 1, wherein the connecting member forming the moving space is fixed to an inner wall surface of the case using a bolt. The power storage device according to claim 2, wherein the connecting member forming the moving space has a region through which the bolt penetrates and along an inner wall surface of the case. The power storage device according to any one of claims 1 to 3, wherein the one surface is an upper surface of the power storage element. A partition member disposed between the two power storage elements adjacent in the predetermined direction and formed of an insulating material;
The partition member, the moving space in contact with the metal of the connecting member forming the power storage according to any one of claims 1 4, characterized in that release the coupling member from the energy storage device apparatus. The partition member has a guide portion that protrudes in the predetermined direction, is positioned between the metal connecting member and the power storage element, and guides the gas discharged from the valve to the moving space. The power storage device according to claim 5. The power storage device according to claim 1, wherein a heat exchange medium used for temperature adjustment of the power storage element moves in the moving space.

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