JP2015018706A - Power storage device module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power storage device module in which the electrolyte, ejected upon actuation of a pressure release valve, is prevented from having an impact on a power storage device where the pressure release valve has not been actuated.SOLUTION: A battery module 10 includes a plurality of secondary batteries 11, where the lids 14 are juxtaposed while being located on the same plane, and a duct 30 spanning the plurality of lids 14. The battery module 10 has an exhaust passage 34 in the duct 30. A communication port 35 opening from the exhaust passage 34 toward each pressure release valve 18 is provided in the battery side wall 31 of the duct 30, and a check valve 41 for closing each communication port 35 and interlocked with actuation of the pressure release valve 18 to release the communication port 35 is provided.

Description

  The present invention relates to a power storage device module including a plurality of power storage devices arranged side by side with end walls positioned on the same plane and including a duct extending over the plurality of end walls.

  Vehicles such as EVs (Electric Vehicles) and PHVs (Plug in Hybrid Vehicles) are equipped with a battery module in which a secondary battery serving as a power storage device that stores electric power supplied to an electric motor is made into a plurality of modules. Each secondary battery is configured by housing an electrode assembly and an electrolytic solution in a case. The case of the secondary battery is provided with a pressure release valve that opens the case when the pressure in the case increases. When the inside of the case is opened by the pressure release valve, the electrolyte solution or combustible gas vaporized from the electrolyte solution is ejected from the case, but the battery module is provided with a duct for discharging the electrolyte solution. (For example, refer to Patent Document 1).

  As shown in FIG. 7A, the power storage device module 80 of Patent Document 1 is arranged in parallel in the width direction in a state where five lithium ion secondary batteries 81 are electrically connected in series. Aluminum restraint plates 83 are disposed at both ends, and the two restraint plates 83 are restrained by an iron restraint band 84 and integrated. A safety valve (pressure release valve) (not shown) is provided on the upper surface of each lithium ion secondary battery 81. The power storage element module 80 is provided with a duct member 85 made of an insulating member, and the duct member 85 is fixed to the restraining plate 83 with screws 89.

  As shown in FIG. 7B, the duct member 85 has a box shape extending in the stacking direction of the lithium secondary battery 81, and the bottom surface 85 a is in contact with the top surface 81 a of the lithium secondary battery 81. The duct member 85 has a through hole 85b at a position facing the safety valve of the lithium secondary battery 81, and an exhaust hole 85c for discharging internal gas is opened on one side surface in the direction in which the lithium secondary battery 81 is arranged. doing.

  When the safety valve of the lithium secondary battery 81 is actuated, the electrolyte gas or electrolyte sprayed from the safety valve is discharged into the duct member 85 from the through hole 85b. The electrolyte flowing into the duct member 85 is discharged from the discharge hole 85 c at a position away from the lithium ion secondary battery 81 by the duct member 85.

JP 2007-265658 A

  However, in Patent Document 1, the electrolyte or gas that has flowed into the duct member 85 from the through hole 85b passes through another through hole 85b and falls on the lithium ion secondary battery 81 whose safety valve is not open. There is a risk that.

  It is an object of the present invention to provide a power storage device module capable of preventing the influence of an ejected electrolyte from reaching a power storage device in which the pressure release valve is not operated when the pressure release valve is operated.

  In order to solve the above problems, the power storage device module includes a pressure release valve that opens the case when the electrode assembly and the electrolyte are accommodated in the case, and the internal pressure of the case exceeds the open pressure. A power storage device module including a plurality of power storage devices on an end wall of a case, wherein the plurality of power storage devices are arranged side by side with the end walls positioned on the same plane, and including a duct straddling the plurality of end walls The duct has a discharge path, the wall of the duct has a communication port that opens from the discharge path toward each pressure release valve, closes each communication port, and The gist is to provide a valve portion that opens the communication port in conjunction with the operation of the pressure release valve.

  According to this, when the internal pressure of the case rises and the internal pressure exceeds the open pressure of the pressure release valve, the pressure release valve operates to open the case. And while an electrolyte solution spouts from the inside of a case, an open pressure acts on a valve part via a communicating port. Then, the valve portion operates in conjunction with the pressure release valve to release the closed state of the communication port, the communication port is opened, and the communication port communicates with the discharge path. As a result, the electrolyte and gas ejected from the case are discharged from the communication port to the discharge path. At this time, only the valve portion that opposes the activated pressure release valve is operated, and the other valve portions are not operated and the communication port is closed. For this reason, it is prevented that the electrolyte solution discharged | emitted by the discharge path leaks out of a duct from another communicating port.

  Further, in the power storage device module, the valve portion opens when the open pressure acts to allow the electrolyte to flow into the discharge path from the outside of the duct, and the pressure acting on the valve portion is It is preferable that the check valve be closed when the pressure is lower than the open pressure to prevent the electrolyte from flowing out of the duct from the discharge passage.

  According to this, when the open pressure acting on the check valve decreases or the pressure in the discharge passage exceeds the open pressure, the communication port is closed by the valve portion. For this reason, even if the pressure release valve is activated and the valve portion is activated, the communication port is closed at the valve portion after the pressure in the power storage device has dropped, and the power storage device connected to the pressure release valve is connected to the communication port. The conduction with the outside can be cut off. In addition, after the pressure release valve is activated, outside air is prevented from flowing into the power storage device.

The power storage device module preferably includes a heat insulating material interposed between the outer surface of the wall portion and the outer surface of the end wall around the pressure release valve.
According to this, even if the electrolyte is ignited in the duct and the duct is heated, it is difficult to transfer the heat of the duct to the power storage device by the heat insulating material, and the influence of the heat on the power storage device can be reduced. it can.

Moreover, about an electrical storage apparatus module, it is preferable that the opening area when the said valve part act | operates is larger than the opening area when the said pressure release valve act | operates.
According to this, when the pressure release valve is operated and the case is opened, since the opening area of the valve portion is large, the valve portion does not prevent the electrolyte from being ejected.

Further, in the power storage device module, an operating pressure of the valve unit is smaller than an opening pressure of the pressure release valve.
According to this, when a pressure release valve operates and an open pressure acts on a valve part, a valve part can be operated reliably.

  The power storage device is a secondary battery.

  ADVANTAGE OF THE INVENTION According to this invention, when a pressure release valve act | operates, it can prevent that the influence of the injected electrolyte solution reaches the electrical storage apparatus which the pressure release valve has not act | operated.

The perspective view which shows a battery module. The disassembled perspective view which shows a part of battery module. (A) is a perspective view which shows a duct, (b) is a perspective view which shows a duct from the communicating port side, (c) is sectional drawing which shows a duct. The perspective view which shows an annuloplasty plate. (A) is a partial cross-sectional view showing the mounting structure of the duct of the battery module, (b) is an enlarged cross-sectional view showing the positional relationship between the check valve and the pressure release valve of the duct, and (c) is the check valve and the pressure release. The cross-sectional view which shows the positional relationship with a valve. Sectional drawing which shows a state when a pressure release valve and a non-return valve act | operate. (A) And (b) is a figure explaining background art.

Hereinafter, an embodiment in which a power storage device module is embodied as a battery module will be described with reference to FIGS.
As shown in FIG. 1, the battery module 10 is configured by arranging a plurality of secondary batteries 11 held by a battery holder 60 in parallel.

  As shown in FIGS. 2 and 6, the electrode assembly 12 and the electrolytic solution 19 are accommodated in the case 13 of each secondary battery 11. The case 13 includes a rectangular parallelepiped case main body 24 having an opening, and a rectangular flat plate-shaped lid body 14 that closes the opening of the case main body 24. Both the case main body 24 and the lid body 14 are made of metal (for example, stainless steel or aluminum). In addition, the secondary battery 11 of the present embodiment is a square battery whose appearance is a square, and is a lithium ion battery.

  The case main body 24 has a bottomed rectangular tube shape, is a rectangular flat plate-shaped bottom wall 22c, and is erected from the bottom wall 22c, and is widest from the two rectangular first side walls 22a and the bottom wall 22c. And two other second side walls 22b orthogonal to the two first side walls 22a. A positive electrode terminal 15 and a negative electrode terminal 16 are electrically connected to the electrode assembly 12 housed in the case 13. The positive electrode terminal 15 and the negative electrode terminal 16 are respectively attached with ring-shaped insulating rings 17 a for insulating from the case 13. The positive electrode terminal 15 and the negative electrode terminal 16 are exposed outside the case 13 from the lid body 14.

  The secondary battery 11 has a pressure release valve 18 in the lid body 14 that opens the case 13 and releases the pressure to the atmosphere when the internal pressure of the case 13 exceeds the open pressure. The pressure release valve 18 has a thin plate shape that is thinner than the plate thickness of the lid body 14. The pressure release valve 18 is located at the bottom of a recess 14 a that is recessed in the upper surface of the lid body 14 and is formed integrally with the lid body 14. When the pressure release valve 18 is broken, an opening having an opening area substantially the same as the planar shape of the recess 14a is formed in the lid body 14, and the case 13 is opened. As shown by an arrow Y in FIG. The electrolytic solution 19 and the decomposition gas of the electrolytic solution 19 are ejected from the inside 13. In the present embodiment, the lid body 14 corresponds to an end wall provided with the pressure release valve 18.

  As shown in FIG. 2, the battery holder 60 that holds each secondary battery 11 includes a holder main body 61 that has a U-shaped frame shape, and a rectangular parallelepiped mounting portion 62 that protrudes from four corners of the outer surface of the holder main body 61. Have. The holder body 61 is integrated with the secondary battery 11 so as to surround the case body 24 from the periphery. In the secondary battery 11 integrated with the battery holder 60, the pair of first side walls 22 a are exposed to the outside from the holder body 61. Each attachment portion 62 is provided with an insertion hole 62 a through which the bolt B <b> 1 is inserted so as to penetrate in the thickness direction of the battery holder 60.

  And let the longitudinal direction of the 1st side wall 22a be the longitudinal direction of the secondary battery 11, and let the transversal direction of the surface where the positive electrode terminal 15 and the negative electrode terminal 16 protrude in the cover body 14 be the thickness direction of the secondary battery 11. The plurality of secondary batteries 11 are stacked with the heat radiation plate 71 and the heat transfer sheet 72 interposed between the adjacent secondary batteries 11 and between the first side walls 22a. Therefore, the secondary batteries 11 are juxtaposed in the thickness direction along the longitudinal direction of the battery module 10.

  As shown in FIGS. 1 and 2, end plates 53 are provided at both ends of the battery modules 10 in the parallel arrangement direction. The end plate 53 includes a base portion 54 having a rectangular flat plate shape and a rectangular flat plate-like protruding portion 55 protruding from the four corners of the base portion 54. The protruding portion 55 is provided with an insertion hole 55 a through which the bolt B <b> 1 is inserted so as to penetrate in the thickness direction of the protruding portion 55.

  In the battery module 10, the bolt B <b> 1 inserted into the insertion hole 55 a of one end plate 53 is inserted into the insertion hole 62 a of each battery holder 60 and also inserted into the insertion hole 55 a of the other end plate 53. The bolt B1 is integrally assembled by being screwed to the nut N. Therefore, all the secondary batteries 11 are sandwiched between the end plates 53 from the juxtaposed direction. In the battery module 10, all the lids 14 are exposed from between the pair of attachment portions 62 of the battery holder 60 and are located on the same plane.

  As shown in FIG. 1, the battery module 10 includes a long rectangular tube-like shape and a resin-made duct 30 that straddle all the lids 14 and that are disposed between a pair of mounting portions 62 of each battery holder 60. . The duct 30 includes a discharge path 34 inside thereof, and the discharge path 34 is open at both ends in the longitudinal direction of the duct 30. The duct 30 includes a battery side wall portion 31 that faces the lid body 14.

  As shown in FIGS. 3A to 3C, the duct 30 has a plurality of communication ports 35 communicating with the discharge path 34 in the battery side wall portion 31, and the plurality of communication ports 35 are the longitudinal sides of the battery side wall portion 31. It is provided at equal intervals in the direction. The battery side wall portion 31 includes a quadrangular annular protrusion 31a that protrudes from the outer periphery of each communication port 35 to the outer surface side of the battery side wall portion 31. The protrusion 31a includes a rectangular annular and resin heat insulating material. 33 is attached. Therefore, the communication port 35 is entirely surrounded by the heat insulating material 33, and the heat insulating material 33 protrudes from the outer surface of the battery side wall portion 31.

  And as shown to Fig.5 (a)-(c), the duct 30 is arrange | positioned in the state which each communication port 35 opens toward each pressure release valve 18 of the battery module 10. FIG. Each heat insulating material 33 of the duct 30 is interposed between the outer surface of the battery side wall portion 31 and the outer surface of the lid body 14, and is in close contact with the outer surface of the battery side wall portion 31 and the outer surface of the lid body 14. Is sealed. The heat insulating material 33 insulates between the duct 30 and the lid body 14 and suppresses heat transfer from the duct 30 to the lid body 14.

The duct 30 includes a valve forming plate 40 disposed in the discharge path 34.
As shown in FIG. 4, the valve forming plate 40 has a rectangular shape having the same planar shape as the inner surface of the battery side wall portion 31. The valve forming plate 40 includes a plurality of valve forming slits 40 a that penetrate the valve forming plate 40 in the thickness direction and are cut into a plane U shape, and the valve forming slits 40 a are equally spaced in the longitudinal direction of the valve forming plate 40. It is provided every other. The valve forming plate 40 includes a check valve 41 at a portion surrounded by each valve forming slit 40a. Assuming that an imaginary line connecting both free ends of the valve forming slit 40a linearly on the surface of the valve forming plate 40 is a reference line L, the check valve 41 can be elastically deformed with the reference line L as a folding line.

  As shown in FIGS. 5A to 5C, the valve forming plate 40 is fixed to the inner surface of the battery side wall 31 with each check valve 41 facing each communication port 35 independently. ing. The check valve 41 covers the entire communication port 35 from the discharge path 34 side. Further, a peripheral edge portion 41 b surrounding the communication port 35 on the surface (outer surface) of the check valve 41 on the secondary battery 11 side is locked around the communication port 35. Therefore, the check valve 41 cannot be displaced to the secondary battery 11 side from the battery side wall portion 31. The operating pressure for opening the check valve 41 is lower than the opening pressure of the pressure release valve 18.

Next, the operation of the battery module 10 will be described.
Now, it is assumed that, in a certain secondary battery 11 among the plurality of secondary batteries 11 of the battery module 10, the internal pressure of the case 13 increases and exceeds the open pressure.

  Then, as shown in FIG. 6, the pressure release valve 18 is broken, the recess 14 a is opened to open the case 13, and the gas in which the electrolytic solution 19 is vaporized or the electrolytic solution 19 is ejected from the case 13. . The check valve 41 is subjected to the same pressure as the internal pressure of the case 13, that is, an open pressure, from the outer surface side of the battery side wall portion 31. Then, in conjunction with the operation of the pressure release valve 18, the check valve 41 is elastically deformed in a direction in which the reference line L is a folding line and the reference line L is a valley fold, and the check valve 41 is discharged into the discharge path 34. It is pushed up in the direction of protruding inward. That is, the check valve 41 operates. Then, the region surrounded by the valve forming slit 40a and the reference line L is opened. At this time, the opening area of the region opened by the operation of the check valve 41 is larger than the opening area of the recess 14a. Then, as shown by an arrow Y, the electrolyte and gas ejected from the case 13 pass through the communication port 35 and the region surrounded by the valve formation slit 40a and the reference line L and are discharged to the discharge path 34 ( Inflow). That is, the check valve 41 opens when an open pressure acts, and allows the electrolyte 19 to flow into the discharge path 34 from the outside of the duct 30.

  After that, when the internal pressure of the case 13 decreases and the pressure acting on the check valve 41 decreases, the check valve 41 uses the return force to its original shape as a reference line L as a fold line and the reference line L Is displaced in the direction in which it is folded in a mountain, and the region surrounded by the annuloplasty slit 40a and the reference line L is displaced toward the closing direction. In the check valve 41, the peripheral edge 41 b of the surface on the secondary battery 11 side is locked around the communication port 35, and the communication port is in a state where further displacement toward the secondary battery 11 is restricted. 35 is closed (valve closed). For this reason, the check valve 41 prevents the electrolytic solution 19 from flowing out of the duct 30 from the discharge passage 34.

According to the above embodiment, the following effects can be obtained.
(1) The duct 30 of the battery module 10 includes a check valve 41 facing the pressure release valve 18 of each secondary battery 11, and the check valve 41 opens the communication port 35 unless the pressure release valve 18 operates. Blocked. For this reason, even if one or a plurality of pressure release valves 18 in the plurality of secondary batteries 11 are operated and the electrolyte is discharged from the case 13 to the discharge path 34, the other check valves 41 that are closed are closed. Thus, it is possible to prevent the electrolyte 19 and gas in the discharge path 34 from falling on the secondary battery 11 in which the pressure release valve 18 is not operated.

  (2) In the check valve 41, the peripheral edge 41 b on the outer surface on the secondary battery 11 side is locked around the communication port 35 in the battery side wall 31, and is directed from the battery side wall 31 toward the secondary battery 11. Displacement is no longer possible. For this reason, even if the pressure in the discharge path 34 increases and the check valve 41 is pressed toward the secondary battery 11, the check valve 41 does not open and the communication port 35 remains closed. Can do. Therefore, it is possible to prevent the electrolytic solution 19 and decomposition gas in the discharge path 34 from falling on the secondary battery 11 in which the pressure release valve 18 is not operated.

  (3) The duct 30 includes a heat insulating material 33, and the heat insulating material 33 is interposed between the outer surface of the battery side wall portion 31 and the outer surface of the lid body 14. For this reason, even if it ignites in the duct 30 and the duct 30 is heated, it is difficult to transfer the heat to the secondary battery 11 by the heat insulating material 33, and the influence of the heat on the secondary battery 11 can be reduced. .

  (4) The operating pressure of the check valve 41 is lower than the opening pressure of the pressure release valve 18. For this reason, if the pressure release valve 18 operates, the check valve 41 can be operated reliably. Moreover, the malfunction which the check valve 41 act | operates although the pressure release valve 18 is not act | operating can be eliminated.

  (5) The opening area when the check valve 41 is operated is larger than the opening area when the pressure release valve 18 is operated. For this reason, the periphery of the valve forming slit 40a in the valve forming plate 40 can smoothly discharge the electrolytic solution 19 to the discharge path 34 without preventing the discharge of the electrolytic solution 19.

  (6) Since the duct 30 is made of resin, when the gas is ignited in the duct 30, heat is trapped in the duct 30, and heat is not easily transmitted to the secondary battery 11. Therefore, the influence of the heat which the secondary battery 11 receives when it ignites can be made small.

  (7) The communication port 35 is sealed by the heat insulating material 33. For this reason, it is possible to prevent the electrolytic solution 19 and the gas discharged into the discharge path 34 through the communication port 35 from leaking out of the duct 30 from the communication port 35.

  (8) The check valve 41 is formed by the valve forming plate 40 so that the check valve 41 can be elastically deformed. For this reason, after the check valve 41 is actuated, when the pressure acting on the check valve 41 becomes low, the check valve 41 can close the communication port 35 by its own restoring force. Therefore, even if the pressure release valve 18 is operated, after a predetermined time when the pressure in the secondary battery 11 decreases, the secondary battery 11 and the outside (the discharge path 34 in the duct 30) via the communication port 35 are connected. Can be cut off. In addition, this prevents outside air from flowing into the secondary battery 11 and prevents contact between the high-temperature electrolyte 19 in the secondary battery 11 and the outside air.

In addition, you may change the said embodiment as follows.
The operating pressure of the check valve 41 may be the same as the opening pressure of the pressure release valve 18.
The opening area of the region surrounded by the valve forming slit 40a and the reference line L that is opened when the check valve 41 is activated is the same as the opening area of the recess 14a that is opened when the pressure relief valve 18 is activated. There may be.

○ The heat insulating material 33 may be omitted.
○ The valve portion may not be the check valve 41, but may be a safety valve that is destroyed when the opening pressure is applied, or opens when the opening pressure is applied, but returns even when the opening pressure stops working. There may be no valve (not closing).

  ○ Although the valve forming plate 40 is provided in the duct 30 and the check valve 41 is provided, the valve forming groove is directly formed in the battery side wall portion 31 of the duct 30 and the check valve is provided inside the valve forming groove. Also good. And when a non-return valve act | operates, it is good also as a structure by which a communicating port is formed in the area | region enclosed by the valve formation groove | channel and the reference line L. FIG.

In the embodiment, the heat insulating material 33 is provided so as to surround each communication port 35, but a sealing member such as an O-ring may be provided instead of the heat insulating material 33.
The pressure release valve 18 may be provided in the case body 24 instead of the lid body 14. In this case, one of the peripheral walls of the case main body 24 provided with the pressure release valve 18 forms an end wall, and the plurality of secondary batteries 11 have the side walls of the case main body 24 positioned on the same plane. And a duct 30 is provided so as to straddle the side wall.

The shape of the case 13 may be a columnar shape or an elliptical column shape.
The power storage device may be a nickel metal hydride secondary battery or an electric double layer capacitor.

  DESCRIPTION OF SYMBOLS 10 ... Battery module as an electrical storage apparatus module, 11 ... Secondary battery as an electrical storage apparatus, 12 ... Electrode assembly, 13 ... Case, 14 ... Lid as end wall, 18 ... Pressure release valve, 19 ... Electrolyte solution, DESCRIPTION OF SYMBOLS 30 ... Duct, 31 ... Battery side wall part as a wall part of a duct, 33 ... Thermal insulation, 34 ... Discharge path, 35 ... Communication port, 41 ... Check valve as a valve part.

Claims (6)

A plurality of power storage devices each having an electrode assembly and an electrolyte contained in a case, and having a pressure release valve on an end wall of the case that opens the case when the internal pressure of the case exceeds the open pressure; The power storage device is a power storage device module that is arranged in parallel with the end walls positioned on the same plane, and includes a duct straddling the plurality of end walls,
A discharge path inside the duct;
On the wall of the duct, there is a communication port that opens from the discharge path toward each pressure release valve,
A power storage device module including a valve portion that closes each communication port and opens the communication port in conjunction with the operation of the pressure release valve.   The valve portion opens when the opening pressure is applied, allows the electrolyte to flow into the discharge passage from the outside of the duct, and closes when the pressure acting on the valve portion is lower than the opening pressure. The power storage device module according to claim 1, wherein the power storage device module is a check valve that prevents the electrolyte from flowing out of the duct from the discharge path.   The power storage device module according to claim 1 or 2, further comprising a heat insulating material interposed between an outer surface of the wall portion and an outer surface of the end wall around the pressure release valve.   4. The power storage device module according to claim 1, wherein an opening area when the valve unit is activated is larger than an opening area when the pressure release valve is activated. 5.   The power storage device module according to any one of claims 1 to 4, wherein an operating pressure of the valve portion is smaller than an opening pressure of the pressure releasing valve.   The said electrical storage apparatus is a secondary battery, The electrical storage apparatus module as described in any one of Claims 1-5.