JP4457931B2 - Battery module - Google Patents

Description

  The present invention relates to a battery module employed in a battery pack mounted on a vehicle such as an electric vehicle.

  In recent years, an electric vehicle using an electric motor as a drive source and a so-called hybrid electric vehicle combining an electric motor as a drive source and another drive source have been put into practical use. In such a vehicle, a battery for supplying electricity as energy to the electric motor is mounted. As this battery, for example, a secondary battery represented by a nickel-cadmium battery, a nickel-hydrogen battery, a lithium ion battery, or the like that can be repeatedly charged and discharged is used.

  The secondary battery is configured by a battery module in which battery cells are stacked, and the battery module is mounted on a vehicle in a state where the battery module is housed in a battery case. A battery pack including the battery case, the battery module housed in the battery case, and other internal components is referred to as a battery pack.

  FIGS. 7 to 9 are diagrams showing a schematic configuration of a battery pack 100B using a lithium ion battery in the background art, and FIG. 7 is an exploded perspective view of the battery pack 100B in order to partially understand the internal structure. It is broken. 8 is a partial cross-sectional view of the battery module 10D housed inside, and FIG. 9 is a partially exploded perspective view of the battery module 10D housed inside.

  As shown in FIG. 7, the battery module 10 </ b> D is accommodated in a battery case having an upper case 1 and a lower case 2. The upper case 1 and the lower case 2 are fastened using bolts (not shown) or the like. As shown in FIGS. 8 and 9, the battery module 10 </ b> D accommodates a plurality of lithium ion battery cells 15 whose electrodes are covered with a laminate film in a stacked state. Each lithium ion battery cell 15 is sandwiched between a first frame body 12 and a second frame body 13 that surround the seal portion 15e to which the laminate film of the lithium ion battery cell 15 is welded from the side surface side. The first frame 12 is disposed so as to surround a region where the lithium ion battery cells 15 are in contact with each other, and the second frame 13 does not contact the body portion 15b of the adjacent lithium ion battery cells 15. The slit bar 13c for defining the cooling air passage A1 for radiating the heat from the lithium ion battery cell 15 is provided. Termination frames 11 are arranged at both ends of the stacked lithium ion battery cells 15, and a cooling air passage A <b> 2 for radiating heat from the lithium ion battery cells 15 is also defined in the termination frame 11. A slit frame 11c is provided.

  The plurality of first frame body 12, second frame body 13, and terminal frame body 11 that are stacked are sandwiched by the restraining band 50, so that the seal portion 15 e of the lithium ion battery cell 15 is the first frame body. 12, the second frame body 13 and the terminal frame body 11 are sandwiched, and the form of the battery module 10D is maintained.

  Here, the battery module 10 is sandwiched by the restraining band 50 in the stacking direction of the lithium ion battery cells 15, but when a large external force is applied in a direction crossing the stacking direction, the first frame A force is applied in a direction (shear direction) in which the body 12, the second frame 13, and the end frame 11 are displaced from each other. As shown in the cross-sectional view of FIG. 8, since the lithium ion battery cells 15 are arranged over the respective frames, when the frames are largely displaced from each other, the lithium ion battery cells 15 are formed at the outer periphery of each frame. There is a risk of shearing the ion battery cell 15.

Patent Documents 1 to 3 listed below disclose a technique in which battery cells packed with a laminate film are stacked and held by a frame. However, none of the patent documents mentions a problem that the battery cells may be sheared at the outer peripheral portion of each frame when the frames greatly deviate from each other in the shear direction.
JP 2002-319383 A JP 2004-066332 A JP 2002-042753 A

  The problem to be solved by the present invention is that there is a risk of shearing the battery cells at the outer peripheral portion of each frame when the frames are greatly displaced in the shear direction in the frame that holds and holds the battery cells. There is a point. Therefore, the present invention provides a structure that does not shear the battery cell even when an external force is applied to the frame that holds and holds the battery cell in a direction that intersects the direction in which the battery cells are stacked. An object is to provide a battery module provided.

  The battery module according to the present invention is a battery module in which a plurality of battery cells, which are housed in a battery case constituting a battery pack, are covered with a laminate film and have a seal portion welded around the battery cell, are held in a stacked state. A first frame frame that surrounds the seal portion of the battery cell from one side surface; the first frame frame includes a contact portion that contacts the seal portion from the side surface; and the seal A first frame body provided with an extension portion extending in the stacking direction of the battery cells beyond the end of the portion, and a second frame frame surrounding the seal portion of the battery cells from the other side surface, A second frame body that sandwiches the seal portion together with the abutting portion of the first frame body and is fitted into an internal space of the first frame body defined by the extension portion, Body and the second frame member and the battery cell group in which the battery cell is sandwiched by are stacked.

  According to the battery module based on this invention, it has the structure by which the battery cell group by which the battery cell was clamped by the 1st frame and the 2nd frame was comprised, and this battery cell group was laminated | stacked. Thus, even if an external force is applied to the battery module in a direction intersecting the battery cell stacking direction, that is, in the shearing direction, the first frame is fitted with the second frame. There is no misalignment between the body and the second frame. As a result, the battery cell held between the first frame body and the second frame body is not sheared due to displacement between the first frame body and the second frame body. In this case, the battery cell can be held in a safe state.

  Hereinafter, each embodiment of a battery module based on the present invention will be described with reference to the drawings. In addition, the same reference number is attached | subjected about the same or equivalent part as the battery pack demonstrated by the said background art, and the overlapping description is not repeated. In addition, since the feature of the present invention is that the structure of the frame that sandwiches the seal portion of the battery cell from both sides, the structure of this frame will be described in detail in each of the following embodiments. Further, as an example of the secondary battery, a lithium ion battery cell 15 in a sealed pack shape covered with a laminate film is used.

(Embodiment 1)
First, the battery pack according to the present embodiment will be described with reference to FIGS. 1 to 3. FIG. 1 is an exploded perspective view of battery pack 100A according to the present embodiment, and is partially broken to understand the internal structure. 2 is a partial cross-sectional view of the battery module 10A housed inside, and FIG. 3 is a partially exploded perspective view of the battery module 10A housed inside.

  As shown in FIG. 1, the battery module 10 </ b> A in the present embodiment is housed in a battery case having an upper case 1 and a lower case 2. As shown in FIGS. 2 and 3, the battery module 10 </ b> A contains a plurality of lithium ion battery cells 15 in a stacked state. Each lithium ion battery cell 15 is sandwiched between a first frame body 31 and a second frame body 41 that surround the seal portion 15e to which the laminate film of the lithium ion battery cell 15 is welded from the side surface side. Note that the lithium ion battery cell 15 positioned at the end is sandwiched between the terminal frame 21 and the second frame 41 having the same function as the first frame 31.

  The first frame body 31 has a first frame frame 31a that surrounds the seal portion 15e of the lithium ion battery cell 15 from one side surface side. The first frame frame 31a contacts the seal portion 15e from the side surface side. An abutting portion 31b that comes into contact with and an extending portion 31c that extends beyond the end of the seal portion 15e in the stacking direction of the lithium ion battery cells 15 are provided. The contact portion 31b and the extension portion 31c are provided on both sides of the first frame frame 31a and are provided so as to surround the outer peripheral portion of the first frame frame 31a. Further, the first frame 31 has a slit that defines a cooling air passage forming portion for forming a cooling air passage A1 through which the cooling air passes in a contact area with the body portion 15b of the lithium ion battery cell 15. A bar 31e is provided, and a cooling air passage hole 31h communicating with the cooling air passage A1 is provided on the outer peripheral surface of the first frame 31a. In addition, in order to arrange two lithium ion battery cells 15 in the lateral direction, an auxiliary frame 31d that partitions the central region is provided.

  The second frame body 41 is provided with a second frame frame 41a that surrounds the seal portion 15e of the lithium ion battery cell 15 from the other side surface side, and an auxiliary frame 41b that partitions the central region, and the first frame body 31 is provided. The seal portion 15e is sandwiched together with the abutting portion 31b, and is fitted into the internal space of the first frame 31 defined by the extension portion 31c. Therefore, the shape defined by the inner surface of the extension portion 31c and the shape defined by the outer peripheral surface of the second frame body 41 are substantially the same shape. The first frame body 31 and the second frame body 41 configured as described above constitute a battery cell group 80B in which the lithium ion battery cells 15 are sandwiched.

  Similarly to the first frame 31, the end frame 21 also has an end frame 21 a that surrounds the seal portion 15 e of the lithium ion battery cell 15 from one side, and the end frame 21 a includes A contact portion 21b that contacts the seal portion 15e from the side surface side and an extension portion 21c that extends beyond the end portion of the seal portion 15e in the stacking direction of the lithium ion battery cells 15 are provided. Furthermore, the termination frame 21 also has a slit frame 21e that defines a cooling air passage forming portion for forming a cooling air passage A2 through which cooling air passes in a contact region with the body portion 15b of the lithium ion battery cell 15. A cooling air passage hole 21h communicating with the cooling air passage A1 is provided on the outer peripheral surface of the terminal frame 31a. The shape defined by the inner surface of the extension 21c of the terminal frame 21 is also substantially the same as the shape defined by the outer peripheral surface of the second frame 41. A battery cell group 80A in which the lithium ion battery cells 15 are sandwiched by the terminal frame 21 and the second frame 41 having the above-described configuration is configured.

  Based on the above configuration, the battery cell group 80A is disposed at both ends, and a plurality of battery cell groups 80B are disposed between the battery cell groups 80B and sandwiched by the restraining band 50, whereby the present embodiment as shown in FIG. Thus, the form of the battery module 10A is maintained.

  As described above, according to the battery module 10 </ b> A based on the present embodiment, the battery cell groups 80 </ b> A and 80 </ b> B in which the lithium ion battery cell 15 is sandwiched between the first frame 31, the terminal frame 21, and the second frame 41. The battery cell groups 80A and 80B are stacked. Thereby, even if an external force is applied to the battery module 10 </ b> A in a direction crossing the stacking direction of the battery cells 15, that is, in a shearing direction, the second frame 41 is fitted into the first frame 31 and the terminal frame 21. Therefore, there is no positional deviation between the first frame 31 and the end frame 21 and the second frame 41. As a result, the first frame 31, the end frame 21, and the second frame 41 are held in the lithium ion battery cell 15 held in a sandwiched state by the first frame 31, the end frame 21, and the second frame 41. There is no shear due to the positional deviation between and the lithium ion battery cell 15 can be held in a safe state in the battery module 10A.

(Embodiment 2)
Next, the battery pack in the present embodiment will be described with reference to FIG. 4 and FIG. 4 is a partial cross-sectional view of battery module 10B in the present embodiment housed in the battery pack, and FIG. 5 is a partial exploded view of battery module 10B in the present embodiment housed in the battery pack. It is a perspective view.

  The basic configuration of the battery module 10B in the present embodiment is the same as that of the battery module 10A in the first embodiment, and the difference is that the battery cell groups adjacent in the stacking direction as shown in FIGS. In 80A and 80B, the adjacent second frames are shared. Specifically, as shown in the cross-sectional view of FIG. 4, the second frame 61 in the present embodiment is between the adjacent first frame 31 and the terminal frame 21 and adjacent to the first frame. Between the body 31 and the 1st frame 31, it has the shape fitted in the internal space of both frames.

  As mentioned above, also in battery module 10B based on this Embodiment, the effect similar to battery module 10B in the said Embodiment 1 can be obtained. Furthermore, in the battery cell groups 80A and 80B adjacent in the stacking direction, the adjacent second frame body 61 is used in common, so that the number of parts is reduced and the second frame body 61 is connected to the battery cell group 80A. , 80B are connected to each other, so that the rigidity of the battery module 10B in the shearing direction can be increased.

  FIG. 6 shows a cross-sectional structure of a battery module 10C, which is a modification of the battery module 10B. Similarly to the battery module 10B, the second frame 71 is used in common, and further, lithium ion A slit bar 71e that defines a cooling air passage forming portion for forming a cooling air passage A1 through which the cooling air passes is provided in a contact area of the battery cell 15 with the body portion 15b. Thus, by forming the cooling air passage A1, the cooling effect of the lithium ion battery cell 15 can be further enhanced.

  In each of the above embodiments, a configuration that defines the cooling air passage forming portion is employed. However, the present invention is characterized in that the battery module includes a first frame (including a terminal frame) and a second frame. A battery cell group having a battery cell sandwiched between frames is provided, and the battery cell group is stacked. Therefore, it is possible to adopt a configuration of a battery module that does not have a cooling air passage forming portion. Further, the present invention can be applied not only to lithium ion battery cells but also to battery cells having an equivalent configuration.

  Therefore, the above-described embodiments disclosed herein are illustrative in all respects and are not restrictive. The technical scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a disassembled perspective view of the battery pack in Embodiment 1 based on this invention. It is a fragmentary sectional view of the battery module accommodated in the inside of the battery pack in Embodiment 1 based on this invention. It is a partial exploded perspective view of the battery module accommodated in the inside of the battery pack in Embodiment 1 based on this invention. It is a fragmentary sectional view of the battery module accommodated in the inside of the battery pack in Embodiment 2 based on this invention. It is a partial exploded perspective view of the battery module accommodated in the inside of the battery pack in Embodiment 2 based on this invention. It is a fragmentary sectional view of the battery module accommodated in the inside of the battery pack in the other form of Embodiment 2 based on this invention. It is a disassembled perspective view of the battery pack in background art. It is a fragmentary sectional view of the battery module accommodated in the inside of the battery pack in background art. It is a partial exploded perspective view of the battery module accommodated in the inside of the battery pack in background art.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Upper case, 2 Lower case, 10A, 10B, 10C Battery module, 15 Lithium ion battery cell, 15b Body part, 15e Seal part, 21 Termination frame body, 21a Termination frame frame, 21b Contact part, 21c Extension part, 31 , 61, 71 Second frame, 31a First frame, 31b Abutting portion, 31c Extension, 31d Auxiliary frame, 31e, 71e Slit bar, 31h Cooling air passage hole, 41 Second frame, 41a Second Frame frame, 41b auxiliary frame, 50 restraint band, 80A, 80B battery cell group, 100A battery pack, A1, A2 Cooling air passage.

Claims (4)

A battery module that is housed in a battery case that constitutes a battery pack, is covered with a laminate film, and has a seal portion that is welded around the battery cell.
A first frame frame that surrounds the seal portion of the battery cell from one side surface; a contact portion that contacts the seal portion from the side surface; and an end of the seal portion A first frame body provided with an extension part extending in the stacking direction of the battery cells beyond the part,
A second frame that surrounds the seal portion of the battery cell from the other side surface; sandwiches the seal portion together with the abutment portion of the first frame body; and is defined by the extension portion. A second frame fitted into the internal space of the one frame,
A battery module in which battery cell groups in which the battery cells are sandwiched between the first frame body and the second frame body are stacked.   2. The battery module according to claim 1, wherein the first frame body has a cooling air passage forming portion that allows cooling air to pass therethrough in a contact region with the body portion of the battery cell.   The battery module according to claim 1, wherein the second frame bodies adjacent to each other are shared in the battery cell groups adjacent in the stacking direction.   4. The battery module according to claim 3, wherein the second frame body has a cooling air passage forming portion that allows cooling air to pass through in a contact region with the body portion of the battery cell.

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