JP5594592B2 - Battery module and battery pack - Google Patents

Description

  The present invention relates to a battery module used in an electric vehicle, a hybrid car, and the like, and a battery pack in which battery modules are connected side by side, and more specifically, discharged from an end plate or a single battery for bundling the cells connected side by side. The present invention relates to a battery module and an assembled battery including an exhaust duct that discharges gas.

  Batteries used in electric cars and hybrid cars are designed to increase voltage with battery modules in which single cells are connected in series, or assembled batteries in which battery modules are connected in series. The design is considered.

  A lithium-ion battery, which is an example of a unit cell, includes a sheet-like positive electrode plate, a sheet-like separator, and a sheet-like negative electrode plate, and a spirally wound power generation element and a necessary amount of electrolyte. It has a configuration housed in a case.

  Moreover, in order to ensure safety, the unit cell is provided with a safety valve in the case. That is, in the unit cell, when the electrolyte in the case is gasified at the time of failure or other abnormality, the safety valve is opened to release this gas to the outside of the case so that the case does not rupture.

  The unit cell includes a container-like case main body whose case is opened at the upper surface and a cover plate that closes the opening of the case main body, and the positive electrode terminal and the negative electrode terminal protrude from the cover plate. A plurality of such cells are arranged, and the positive and negative terminals of the adjacent single cells are connected, that is, connected in series, so that the battery module is further increased as a battery module having a large output. Used as an assembled battery connected to

  Patent Document 1 discloses an invention relating to a battery system provided with an exhaust duct for smoothly exhausting gas discharged from a safety valve in a desired direction.

  In this battery system, a discharge port of a safety valve is provided on a terminal surface of a single cell (“battery cell” in Patent Document 1), and a pair of end plates are sandwiched from both end surfaces of a battery block in which a plurality of the single cells are connected. The circuit board to which the electronic component is fixed is arranged so as to face the terminal plane of the battery block, and an exhaust duct (“gas exhaust duct” in Patent Document 1) connected to the exhaust port of the safety valve is the battery block. It is arranged between the terminal plane and the circuit board.

  The exhaust duct is fixed to the end plate, and an end formed in a cylindrical shape protrudes from the end plate, and an exhaust duct is connected to the end, and the gas exhausted from the exhaust port of the safety valve is exhausted from the exhaust duct and the exhaust duct. Is quickly discharged from the duct. Further, the exhaust duct is provided with a connecting piece for fixing to the end plate with a set screw.

JP 2010-80135 A

  Since the battery system described in Patent Document 1 is provided with a connecting piece on the exhaust duct and the exhaust duct is fixed to the end plate with a set screw, the assembly is troublesome. In addition, in the battery system described in Patent Document 1, the gas discharged from the exhaust port of the safety valve is exhausted vigorously from the exhaust duct, which may adversely affect the surroundings.

  In view of the above, the present invention mainly provides a battery module in which the exhaust duct and the end plate can be efficiently connected, and, secondarily, the momentum of the gas discharged from the exhaust duct can be reduced. It is another object of the present invention to provide an assembled battery in which battery modules are connected side by side.

In the battery module according to the present invention, the cells having the safety valve provided in the case are connected side by side, the exhaust duct is provided by a hood covering the aligned safety valves, and the end plates are respectively stacked on the arranged outermost cells. A battery module in which two end plates are fixed with a plurality of unit cells sandwiched therebetween, and at least one of the end plates can fit the hood in the same direction as the unit cell is sandwiched between the end plates. A conduction port, comprising a conduction port communicating with the exhaust duct and an exhaust port communicating with the conduction port.

  According to this battery module, the end plate is provided with a conduction port that communicates with the exhaust duct and an exhaust port that communicates with the conduction port. It is possible to have a multi-function having a function of discharging the gas in the intended direction.

  Further, in the battery module according to the present invention, the safety valve is formed on both end surfaces of the case, so that two exhaust ducts are formed, and one end plate communicates with one exhaust duct through a conduction port. The other exhaust duct may be closed, the other end plate may communicate with the other exhaust duct through a conduction port, and one exhaust duct may be closed.

  According to this battery module, one end of one exhaust duct communicates with the conduction port of one end plate, the other end of one exhaust duct is blocked by the other end plate, and one end (one side of the other exhaust duct) The other end of the exhaust duct communicates with the conduction port of the other end plate, and the other end of the other exhaust duct (the same side as one end of the one exhaust duct) is blocked by one end plate. Thus, the gas in one exhaust duct and the gas in the other exhaust duct are discharged in opposite directions.

  Further, in the battery module according to the present invention, the end plate includes an inner plate overlaid on the unit cell, an outer plate arranged at a distance from the inner plate, and a band plate surrounding the outer periphery of both side plates. It is preferable that a closed space is provided, and that the closed space is provided with a conduction port serving as an inlet and an exhaust port serving as an outlet, and is arranged so that the conduction port and the exhaust port do not face each other.

  According to this battery module, when the gas in the exhaust duct flows into the conduction port of the end plate, it hits the outer plate, flows in the closed space surrounded by the inner plate, the outer plate, and the strip plate, and is discharged from the exhaust port. Therefore, it is possible to reduce the momentum of the gas flowing from the exhaust duct into the introduction port.

  In the battery module according to the present invention, it is preferable that a partition plate that meanders the flow path from the conduction port to the exhaust port is provided between the inner plate and the outer plate.

  According to this battery module, the partition plate provided on the end plate meanders the flow path, thereby increasing the distance from the conduction port to the exhaust port and further reducing the momentum of the gas discharged from the exhaust port. Can do. Furthermore, the partition plate acts as a rib and can reinforce the end plate.

  In the battery module according to the present invention, one or more flame retardants may be placed in the closed space.

  According to this battery module, one or a plurality of flame retardants are placed in the closed space, so that the gas flowing in the closed space is made flame retardant and the harmfulness of the gas discharged from the exhaust port is reduced. Can be reduced.

  Moreover, the assembled battery according to the present invention is an assembled battery in which battery modules are connected side by side, and the end plate provided in any of the battery modules according to the present invention is at least one of the outermost batteries. It is characterized by being stacked on a single cell.

  According to this assembled battery, the battery module can be fixed by being sandwiched between the multifunctional end plates.

  According to the present invention, a battery module or an assembled battery in which the outermost unit cell in which end plates each having a conduction port and an exhaust port are arranged is sandwiched and the conduction port communicates with the exhaust duct is provided. The end plate can be multi-functionalized.

It is a disassembled perspective view which shows 1st Embodiment of the battery module which concerns on this invention. It is a disassembled perspective view which shows 2nd Embodiment of the battery module which concerns on this invention. It is an assembly perspective view which shows 2nd Embodiment of the battery module which concerns on this invention. It is a disassembled perspective view which shows 3rd Embodiment of the battery module which concerns on this invention.

[First Embodiment]
A battery module according to a first embodiment of the present invention will be described with reference to FIG. The battery module is formed by connecting a plurality of unit cells 10,..., And the unit cells 10 on both sides are sandwiched between end plates 20.

  The unit cell 10 is a case in which a power generation element (not shown) in which a sheet-like positive electrode plate, a separator, and a negative electrode plate are overlapped and wound in a flat spiral shape is housed in a case 11. The opening of the box-shaped case main body 12 having an open upper surface is closed by a cover plate (not shown), and the positive terminal 14 and the negative terminal 15 protrude from the cover plate 13. The case main body 12 has a bottomed cylindrical shape in which a pair of side plate portions 12a facing each other at a narrow interval and a pair of end plate portions 12b facing each other at a wide interval are provided on the periphery of a rectangular bottom plate portion (not shown). The safety valve 16 is provided on one end plate portion 12b.

  And the unit cell 10 and the unit cell 10 are arranged so that the side plate parts 12a face each other, and the positive electrode terminal 14 and the negative electrode terminal 15 of the adjacent unit cell 10 are connected by the bus bar 17, so that a large output is achieved. It is planned. The battery module is provided with a gap 18 through which cooling air flows between the side plate portions 12a and the side plate portions 12a of the adjacent unit cells 10. Further, each cover plate is covered with a cover 19 so as to avoid both terminals 14 and 15 of all the arranged cells 10.

  The safety cells 16 are arranged in a straight line by arranging the plurality of single cells 10... And the exhaust duct 30 is provided by covering the safety valve 16 with the hood 31. Therefore, the safety valve 16 is located between the holding part 32 and the holding part 32. Moreover, a pair of holding | maintenance part 32 holding the both-sides edge of this food | hood 31 is being fixed ranging over the end plate part 12b of the single cell 10, ....

  For example, the hood 31 is formed in a U-shaped groove shape such as a U-shaped cross section or an arc shape (not shown), and both side edges are bent outward, and the pair of holding portions 32 are formed on the opposing surfaces. It is assumed that facing grooves are formed, and the workability of mounting the hood 31 to the pair of holding portions 32 can be improved by fitting both side edges of the hood 31 into the grooves of the pair of holding portions 32. . However, although not shown, the hood 31 is shaped like a U-shaped groove with a U-shaped cross section, each holding portion 32 forms an outward groove, and each side edge of the hood 31 is connected to each holding portion 32. You may make it fit in a groove | channel, or you may fix the food | hood 31 to a pair of holding | maintenance part 32 with a screw | thread.

  In the battery module, end plates 20 are overlapped on the exposed side plates 12a of the cells 10 at both ends (only one end plate 20 is shown), and a plurality of rods (not shown) are attached to both end plates 20. ) Is spanned and tightened so that the distance between both end plates 20 is narrowed, thereby fixing the unit cells 10 connected in parallel.

  The end plate 20 includes a conduction port 21 that communicates with the exhaust duct 30 and an exhaust port 22 that communicates with the conduction port 21. That is, when the end plate 20 is overlaid on the side plate portion 12a of the unit cell 10, the conduction port 21 and the exhaust duct 30 are continuous. For example, by setting the outer diameter of the exhaust duct 30 and the inner diameter of the conduction port 21 and opening the side where the conduction port 21 overlaps the end plate portion 12 b of the unit cell 10, the exhaust duct 30 is connected to the conduction port 21. So that the workability of connecting the exhaust duct 30 and the conduction port 21 is improved, and the gas in the exhaust duct 30 is less likely to leak at this connection portion and flows into the conduction port 21. can do.

  Further, when the exhaust duct 30 is in the shape of a rectangular tube as shown in the figure, the conduction port 21 is also formed in a rectangular tube shape so that both can be connected smoothly. Therefore, according to the form of the exhaust duct 30, the conduction port 21 and the exhaust port 22 are cylindrical or other cylindrical shapes.

  Further, the conduction port 21 and the exhaust port 22 may be provided in both end plates 20, or only in one end plate 20 and not in the other end plate 20, so that the other end of the exhaust port 22 is provided. It may be in a closed state.

  In any case, since the end plate 20 includes the conduction port 21 and the exhaust port 22, the plurality of unit cells 10,... Connected side by side are fixed to the side plate portion 12 a of the outermost unit cell 10. By stacking the end plate 20, the unit cell 10 can be fixed and the exhaust duct 30 and the conduction port 21 and the exhaust port 22 of the end plate 20 can be made continuous.

  Therefore, in this battery module, when a certain cell 10 is in an abnormal state and gas is generated in the case 11, the safety valve 16 is opened, and the gas is exhausted from the case 11 into the exhaust duct 30, and the end plate 20. Are discharged from the conduction port 21 and the exhaust port 22 in the desired direction.

[Second Embodiment]
A battery module according to a second embodiment of the present invention will be described with reference to FIGS. In the battery module according to the second embodiment, the end plate 20 has an inner plate 23 and an outer plate 24 arranged at an interval, and a closed space 26 is provided by a band plate 25 surrounding the inner plate 23 and the outer plate 24. It is characterized by being. A conduction port 21 communicating with the exhaust duct 30 is provided at one end (the right end in the drawing) of the outer plate 24, and an exhaust port 22 is provided at the other end (the left end in the drawing) of the outer plate 24. Moreover, the inner side plate 23 is piled up on the side plate part 12a of the outermost unit cell 10 arranged.

  A partition plate 27 is provided between the inner plate 23 and the outer plate 24 to meander the flow path from the conduction port 21 to the exhaust port 22. The partition plate 27 is provided on the inner plate 23 as shown, or is provided on the outer plate 24, or on both the inner plate 23 and the outer plate 24 (not shown). The inner plate 23 and the outer plate 24 are reinforced.

  The band plate 25 includes a peripheral wall portion 25a provided from the outer peripheral edge of the inner plate 23 toward the outer plate 24, and a peripheral wall portion 25b provided from the outer peripheral edge of the outer plate 24 toward the inner plate 23. Are combined so that one of the peripheral wall portions 25a and 25b is fitted into the other peripheral wall portion 25b and 25a. However, the band plate 25 may be configured by a peripheral wall portion 25 a provided only on either the inner plate 23 or the outer plate 24. Further, the peripheral wall portion 25 a provided on the inner plate 23 is provided with a discontinuous portion that connects the conduction port 21 and the closed space 26 at one end (right end in the drawing) of the inner plate 23.

  The illustrated end plate 20 is provided with a conduction port 21 at one end (the right end in the drawing) of the outer plate 24 and an exhaust port 22 at the other end (the left end in the drawing) of the outer plate 24. The partition plate 27 is provided so that the flow path branches in two directions from the conduction port 21 and becomes a maze and merges at the exhaust port 22. Although not shown, the conduction port 21 may be provided at one end portion (the right end portion in the drawing) of the outer plate 24, and the exhaust port 22 may be provided at the center of the outer plate 24. You may provide the partition plate 27 so that it may become a shape.

  In any case, one or more flame retardants (not shown) are placed in the flow path.

  3, such an end plate 20 is overlaid on the outermost side plate portion 12a of the unit cells 10,... Connected side by side (the end plate overlaid on the front side unit cell 10 in the drawing). Although only 20 is shown, the end plate is actually stacked on the back side cell 10 as well). Then, the exhaust duct 30 and the conduction port 21 of the end plate 20 communicate with each other. Further, a plurality of rods (not shown) are bridged between both end plates 20 and tightened so that the distance between both end plates 20 becomes narrow, so that a battery module in which the cells 10,.

  When the unit cell 10 constituting the battery module is in an abnormal state, gas is generated in the case 11 and the safety valve 16 is opened, so that the gas exhausted into the exhaust duct 30 is discharged from the end plate 20. It flows to the conduction port 21. Then, the gas is decelerated by flowing in the meandering flow path of the end plate 20 and is discharged from the exhaust port 22. In addition, the gas is changed to a gas that is difficult to burn by the flame retardant contained in the flow path, and is discharged from the exhaust port 22.

[Third Embodiment]
A battery module according to a third embodiment of the present invention will be described with reference to FIG. In this battery module, safety valves 16 (see FIG. 1) are provided on both end plate portions 12b of the unit cell 10, and two exhaust ducts 30a and 30b are provided. Here, in the drawings, the front exhaust duct 30a is referred to as a first exhaust duct 30a, and the rear exhaust duct 30b is referred to as a second exhaust duct 30b.

  In the drawing, the first end plate 20a is superimposed on the side surface portion 12a (see FIG. 1) of the unit cell 10 exposed on the near side, and the first end plate 20a is exposed on the side surface portion of the unit cell 10 exposed on the back side. Two end plates 20b are stacked. Both the end plates 20a and 20b have basically the same configuration as the end plate 20 described in the second embodiment (the same parts as those in the second embodiment are denoted by the same reference numerals), but the first plate. The end plate 20a is provided with a lid portion 28 for closing one end portion (left end portion in the drawing) of the second exhaust duct 30b, and the second end plate 20b is provided at the other end portion (right end in the drawing) of the first exhaust duct 30a. Part) is provided with a lid (not shown). The lid 28 may be provided on the inner plate 23 or the outer plate 24.

  In this battery module, gas generated in the unit cell 10 flows from the first exhaust duct 30a toward the first end plate 20a and is discharged from the exhaust port 22, but the lid plate of the second end plate 20b. Is not discharged from the other end (the right end in the drawing). Further, the gas exhausted into the second exhaust duct 30b flows from the second end plate 20b toward the second end plate 20b and is exhausted from the exhaust port 22. However, one end portion of the gas is exhausted by the lid portion 28 of the first end plate 20a. It is not discharged from the left end in the drawing. Accordingly, a gas flow in one direction is created for each of the exhaust ducts 30a and 30b.

[Other Embodiments]
In the battery module provided with the first exhaust duct 30a and the second exhaust duct 30b described in the third embodiment, the end plate 20 superimposed on the exposed unit cell 10 is electrically connected to both ends. It is assumed that the opening 21 is provided in the center and the exhaust port 22 is provided at the center, and the end plate 20 that is overlaid on the unit cell 10 exposed on the other side may block both the exhaust ducts 30a and 30b.

  In addition, a flame retardant may be put in the end plate 20 of the first embodiment, and conversely, a flame retardant should not be put in the end plate 20 of the second and third embodiments. May be. Further, the end plate 20 of the second and third embodiments may be provided with a closed space 26 in which the flow path is not meandered by the partition plate 27.

  In addition, although not shown in figure, the battery module in any said embodiment becomes an assembled battery used as a battery of a motor vehicle etc. by connecting two or more side by side. However, as a matter of course, the end plate 20 is not interposed between the assembled batteries and is stacked on both outermost unit cells 10. Alternatively, the end plate 20 may be overlaid on one outermost unit cell, and a conventional end plate may be overlaid on the other outermost unit cell.

  In any case, the end plate 20 includes a communication port 21 and an exhaust port 22 that communicate with each other, or a closed space 26 is provided by the inner plate 23, the outer plate 24, and the band plate 25, or by the partition plate 27. A flow path such as a maze is provided.

10 ... Cell 11 ... Case 16 ... Safety valve 20 ... End plate 20a ... End plate 20b ... End plate 21 ... Conduction port 22 ... Exhaust port 23 ... Inner plate 24 ... Outer plate 25 ... Belt Plate 26 ...... Closed space 27 ... Partition plate 30 ... Exhaust duct 30a ... Exhaust duct 30b ... Exhaust duct

Claims (6)

Unit cells with safety valves are connected side by side in the case, exhaust ducts are provided by a hood that covers the safety valves arranged side by side, end plates are stacked on each of the outermost unit cells arranged, and the two end plates have a plurality of A battery module that holds and fixes a single cell,
The at least one end plate is a conduction port in which the hood can be fitted in the same direction as a direction in which the unit cell is sandwiched between the end plates, and communicates with the conduction port and the conduction port. A battery module comprising an exhaust port.   Since the safety valve is formed on both end faces of the case, two exhaust ducts are formed, one end plate communicates with one exhaust duct through a conduction port, and the other exhaust duct is closed, The battery module according to claim 1, wherein the end plate communicates with the other exhaust duct through a conduction port and closes the one exhaust duct. The end plate provides a closed space by an inner plate overlaid on the unit cell, an outer plate arranged at a distance from the inner plate, and a band plate surrounding the outer periphery of both side plates, and the closed space. The battery module according to claim 1, wherein a conduction port serving as an inlet and an exhaust port serving as an outlet are provided in the battery module, and the conduction port and the exhaust port are disposed so as not to face each other. 4. The battery module according to claim 3, wherein a partition plate for meandering a flow path from the conduction port to the exhaust port is provided between the inner plate and the outer plate. 5. The battery module according to claim 3, wherein one or a plurality of flame retardants are placed in the closed space. A battery pack in which battery modules are connected side by side,
6. An assembled battery, wherein the end plate provided in the battery module according to claim 1 is overlaid on at least one of the outermost unit cells.

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