JP2018160334A - Battery module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery module capable of suppressing interference between a restraint bolt and an end plate. A battery module (1A) includes an array (2) formed by arranging a plurality of battery cells (3), and an elastic member (4) unevenly arranged on one side of an array direction D of the battery cells (3) in the array (2). A pair of end plates 6 and 7 that sandwich the array body 2 in the array direction D and a restraint bolt 12 that connects the pair of end plates 6 and 7 to each other are provided, and a restraint load is applied to the array body 2 in the array direction D. And a restraint member 8A to be added. The restraint member 8A includes an inner fastening portion 13 that fastens the one end plate 6 from the inner side and an outer fastening portion 14 that fastens it from the outer side at the coupling position P of the restraint bolt 12. [Selection diagram] Figure 1

Description

  The present invention relates to a battery module.

  As a conventional battery module, for example, there is one described in Patent Document 1. This conventional battery module includes an array body in which a plurality of battery cells are arrayed, an elastic member disposed at one end of the array body in the array direction of the battery cells, and a pair of end plates that sandwich the array body in the array direction. And a restraining member that applies a restraining load to the array body in the array direction. The restraining member includes a restraining bolt inserted into an insertion hole provided in each end plate, and a pair of nuts screwed to the protruding portions of the restraining bolt protruding outward from each end plate. The restraint load is applied to the array by tightening the pair of end plates from the outside with these nuts.

JP 2001-236937 A

  In the battery module as described above, for example, when an impact load is applied due to vibration of a vehicle to be mounted, it is conceivable that the position of the restraint bolt in the insertion hole varies. When the position of the restraint bolt changes, the restraint bolt interferes with the end plate, and an excessive load may be applied to the restraint bolt at the interference position. In particular, in the end plate closer to the elastic member, the elastic member is deformed by an impact load, so that the position of the restraint bolt in the insertion hole is likely to fluctuate, causing a problem that the restraint bolt interferes with the end plate. It seems to be easier.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a battery module that can suppress interference between a restraining bolt and an end plate.

  A battery module according to an aspect of the present invention includes an array formed by arranging a plurality of battery cells, an elastic member that is unevenly arranged on one side of the array in the array direction of the battery cells, and an array arranged A pair of end plates sandwiched in the direction, and a restraint member that connects the pair of end plates to each other, and a restraining member that applies a restraining load in the array direction to the array body. An inner fastening portion for fastening one end plate from the inner side and an outer fastening portion for fastening from the outer side.

  In this battery module, the end plate on one side is tightened from both sides by the inner fastening portion and the outer fastening portion at the binding position of the restraint bolt, and a large axial force (fastening force) is generated between the both fastening portions. It is possible to firmly fix the restraint bolt. For this reason, interference with a restraint volt | bolt and an end plate can be suppressed. Furthermore, in this battery module, since the elastic member is unevenly arranged among the pair of end plates, the restraint bolt is fixed to the one end plate that is likely to interfere with the restraint bolt. For this reason, interference with a restraint volt | bolt and an end plate can be suppressed effectively.

  Moreover, the inner side fastening part may be comprised by the nut screwed together by the thread part of the restraint bolt. In this case, the configuration can be simplified.

  The restraint bolt is a stepped bolt in which a screw portion having a diameter smaller than that of the cylindrical portion is provided on the distal end side of the cylindrical portion, and the inner fastening portion is configured by a step portion between the cylindrical portion and the screw portion. It may be. In this case, the number of parts can be reduced.

  Moreover, the inner side fastening part may be comprised by the collar part provided in the restraint bolt. In this case, the number of parts can be reduced. Further, the area of the contact surface between the inner fastening portion and the end plate can be easily secured.

  Moreover, the outer side fastening part may be comprised by the head of the restraint bolt. In this case, the configuration can be simplified and the number of parts can be reduced.

  Moreover, the outer side fastening part may be comprised by the nut screwed together by the thread part of the restraint bolt. In this case, the configuration can be further simplified.

  Further, a stepped portion for engaging the inner fastening portion and the restraining bolt in the rotational direction to prevent the restraining bolt from rotating may be provided on the inner surface of the one end plate. In this case, it can suppress that a restraint volt | bolt rotates together at the time of the fastening of an outer side fastening part.

  Further, a stepped portion for engaging the outer fastening portion and the restraining bolt in the rotation direction to prevent the restraining bolt from rotating may be provided on the outer surface of the one end plate. In this case, it can suppress that a restraint bolt rotates together at the time of fastening of an inner side fastening part.

  According to the present invention, interference between the restraint bolt and the end plate can be suppressed.

It is a schematic sectional drawing which shows the battery module which concerns on 1st Embodiment. It is a schematic sectional drawing which shows the battery module which concerns on 2nd Embodiment. It is a schematic sectional drawing which shows the battery module which concerns on 3rd Embodiment. It is a schematic sectional drawing which shows the battery module which concerns on 4th Embodiment. It is a schematic sectional drawing which shows the battery module which concerns on 5th Embodiment. (A) And (b) is the schematic which shows the example of a step part.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the following description, the same reference numerals are used for the same or corresponding elements, and duplicate descriptions are omitted.

  FIG. 1 is a schematic cross-sectional view showing the battery module according to the first embodiment. As shown in the figure, the battery module 1A according to the first embodiment includes an array body 2 in which a plurality of battery cells 3 are arrayed, and a pair of end plates 6 and 7 sandwiching the array body 2 in the array direction D. And a restraining member 8A for applying a restraining load to the array body 2 in the array direction D. The array body 2 further includes an elastic member 4 and a middle plate 5.

  The battery cell 3 constituting the array 2 is a nonaqueous electrolyte secondary battery such as a lithium ion secondary battery. In the present embodiment, the array body 2 includes eight battery cells 3. Adjacent battery cells 3 are bonded with, for example, a double-sided tape. Each battery cell 3 may be arranged in a state of being held by a resin cell holder. A heat transfer plate may be disposed between adjacent battery cells 3.

  Each battery cell 3 is formed by housing an electrode assembly and an electrolytic solution in a hollow case having a substantially rectangular parallelepiped shape, for example. A pair of electrode terminals (not shown) are provided apart from each other on the top surface of the case. One of the electrode terminals is a positive electrode terminal connected to the positive electrode of the electrode assembly, and the other of the electrode terminals is a negative electrode terminal connected to the negative electrode of the electrode assembly. Adjacent battery cells 3 and 3 are arranged so that the positive electrode terminal and the negative electrode terminal are adjacent to each other, and are connected in series by connecting the adjacent positive electrode terminal and the negative electrode terminal with a bus bar member. .

  The elastic member 4 is used for the purpose of preventing damage to the battery cell 3, the end plates 6 and 7 and the restraining member 8A due to restraining load when the battery cell 3 expands. The elastic member 4 is formed in a rectangular plate shape by, for example, urethane rubber sponge. The elastic members 4 are arranged unevenly on one side in the arrangement direction D in the array 2. In the present embodiment, the elastic member 4 is disposed at one end of the array body 2 in the array direction D. Examples of other forming materials of the elastic member 4 include ethylene propylene diene rubber (EPDM), chloroprene rubber, and silicon rubber. The elastic member 4 is not limited to rubber but may be a spring material or the like.

  The middle plate 5 is, for example, a resin plate member. The middle plate 5 has a substantially rectangular plate shape corresponding to the shape of the battery cell 3 when viewed from the arrangement direction D, and the middle plate 5 is formed between the battery cell 3 and the elastic member 4 located on the most one side in the arrangement direction D. Arranged between. The middle plate 5 suppresses variation in load applied to each battery cell 3 from the elastic member 4. At the four corners of the middle plate 5, there are provided insertion holes 5a through which the restraint bolts 12 described later are inserted.

  The end plates 6 and 7 are, for example, metal plate members. As with the middle plate 5, the end plates 6 and 7 have a substantially rectangular plate shape corresponding to the shape of the battery cell 3 when viewed from the arrangement direction D. One end plate 6 is disposed so as to contact the elastic member 4. The other end plate 7 is disposed so as to contact the battery cell 3 located on the most other side in the arrangement direction D. At the four corners of the end plates 6 and 7, insertion holes 6a and 7a for inserting the restraining bolts 12 are provided, respectively.

  The edge 6b of the end plate 6 is provided with a fixing piece 9 used for fixing to the outside (here, the housing 10). The fixed piece 9 projects from the edge 6 b of the end plate 6 at a substantially right angle to the end plate 6. The fixing piece 9 is provided with a plurality of insertion holes 9 a through which the fixing bolts 11 are inserted along the edge 6 b of the end plate 6. A similar fixing piece 9 is also provided on the edge 7 b of the end plate 7. The battery module 1 is fixed to the casing 10 by screwing the fixing bolts 11 passed through the insertion holes 9 a into the bolt holes 10 a provided in the casing 10.

  The restraining member 8 </ b> A is composed of a restraining bolt 12, an inner fastening portion 13, and an outer fastening portion 14. The restraint bolt 12 is a long bolt having a head portion 12a, and a screw portion 12b is formed at the tip. The threaded portion 12b is a portion of the restraint bolt 12 where a screw thread is provided to which the inner fastening portion 13 and the outer fastening portion 14 are screwed together. The restraint bolt 12 is stretched between the pair of end plates 6 and 7 and connects the end plates 6 and 7 to each other. The restraining member 8 </ b> A includes a restraining bolt 12 that connects the pair of end plates 6, 7 at a position near the fixing piece 9, and a restraining bolt 12 that connects the pair of end plates 6, 7 at a position away from the fixing piece 9. 2 each.

  The restraint bolt 12 is passed through the insertion holes 5a, 6a, and 7a so that the middle plate 5 and the end plates 6 and 7 are inserted from the end plate 7 side. An outer fastening portion 14 formed of a hexagonal nut is screwed to the screw portion 12b of the restraint bolt 12 protruding from the end plate 6. The outer fastening portion 14 fastens the end plate 6 from the outside in the arrangement direction D, and sandwiches the pair of end plates 6 and 7 between the head 12 a of the restraining bolt 12. As a result, the battery cell 3, the elastic member 4 and the middle plate 5 are sandwiched and unitized, and a predetermined restraining load is applied to the battery cell 3, the elastic member 4 and the middle plate 5 via the end plates 6 and 7. Has been. This restraining load is balanced with the elastic repulsion force of the elastic member 4 and is, for example, about several hundred N.

  Further, an inner fastening portion 13 constituted by a nut having the same shape as the outer fastening portion 14 is screwed to the screw portion 12 b of the restraining bolt 12. The inner fastening portion 13 fastens the end plate 6 from the inner side in the arrangement direction D, and sandwiches the end plate 6 with the outer fastening portion 14 at the coupling position P of the restraint bolt 12. The coupling position P of the restraint bolt 12 is a position corresponding to the restraint bolt 12 in the end plate 6, and more specifically, is a peripheral portion of the insertion hole 6a. A large axial force acts on the end plate 6 by being tightened from both sides by the fastening force of the inner fastening portion 13 and the outer fastening portion 14. This axial force is larger than the restraining load, for example, about several thousand N. In addition, the shape of the inner side fastening part 13 and the outer side fastening part 14 is not restricted to hexagonal shape, Other shapes, such as circular shape, may be sufficient.

  Next, an example of the assembly process of the battery module 1A will be described. First, the plurality of battery cells 3, the elastic member 4, the middle plate 5, and the end plate 7 are arranged along the arrangement direction D, and the restraint bolts 12 are inserted into the middle plate 5 and the end plate 7 from the end plate 7 side. Subsequently, the inner fastening portion 13 is screwed into the screw portion 12 b of the restraining bolt 12. At this time, the inner fastening portion 13 is positioned at a position inside the assembly position of the end plate 6 and outside the assembly position of the middle plate 5 so as not to hinder the work in a subsequent process.

  Subsequently, the end plate 6 is disposed outside the elastic member 4, and the restraint bolt 12 is inserted through the end plate 6. Subsequently, the outer fastening portion 14 is screwed into the screw portion 12 b of the restraint bolt 12, and a predetermined restraint load is applied to the battery cell 3, the elastic member 4, and the middle plate 5. Subsequently, by rotating the inner fastening portion 13 and moving it toward the outside in the arrangement direction D, the end plate 6 is fastened from both sides by the inner fastening portion 13 and the outer fastening portion 14, and a predetermined axial force is applied to the end plate 6. Act. Thus, the battery module 1A is manufactured. In order to improve assemblability, the clearance between the insertion holes 6a and 7a of the end plates 6 and 7 and the shaft portion of the restraining bolt 12 is the clearance between the insertion hole 5a of the middle plate 5 and the shaft portion of the restraining bolt 12. It is larger than the clearance between.

  As described above, in the battery module 1A of the present embodiment, the end plate 6 is fastened from both sides by the inner fastening portion 13 and the outer fastening portion 14 at the coupling position P of the restraint bolt 12, and the inner fastening portion 13 and the outer fastening portion 14 are secured. The restraint bolt 12 can be firmly fixed to the end plate 6 by generating a large axial force (fastening force) therebetween. For this reason, interference with the restraint bolt 12 and the end plate 6 can be suppressed. Furthermore, in the battery module 1A, the elastic bolt 4 is unevenly arranged in the pair of end plates 6 and 7, and therefore, the restraining bolt 12 with respect to the end plate 6 that easily interferes with the restraining bolt 12. To fix. For this reason, interference with the restraint bolt 12 and the end plate 6 can be suppressed effectively.

  In the battery module 1 </ b> A, the inner fastening portion 13 is configured by a nut that is screwed into the screw portion 12 b of the restraining bolt 12. For this reason, a structure can be simplified. Further, in the battery module 1, the outer fastening portion 14 is configured by a nut that is screwed into the screw portion 12 b of the restraining bolt 12. For this reason, the configuration can be further simplified.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, you may be comprised like the battery module 1B of 2nd Embodiment shown by FIG. In the restraining member 8B of the second embodiment, the restraining bolt 12 is a stepped bolt in which a screw portion 12d having a smaller diameter than the cylindrical portion 12c is provided on the distal end side of the cylindrical portion 12c, and the inner fastening portion 13 is a cylinder. It is comprised by the level | step-difference part 12e between the part 12c and the screw part 12d. The step portion 12e has, for example, a step surface perpendicular to the arrangement direction D. Such a constraining bolt 12 is formed, for example, by scraping the tip portion of a cylindrical base material and providing a screw portion 12d at the tip portion. A screw portion 12f is provided on the proximal end side of the cylindrical portion 12c, and a double nut 15 is screwed to the screw portion 12f. In the second embodiment, a pair of end plates 6 and 7 are sandwiched between the outer fastening portion 14 and the double nut 15. Further, the end plate 6 is sandwiched between the stepped portion 12e (inner fastening portion 13) and the outer fastening portion 14. A normal nut may be used in place of the double nut 15, but the use of the double nut 15 can prevent loosening when the elastic member 4 contracts.

  In the assembly process of the battery module 1B of the second embodiment, first, after the restraint bolt 12 is inserted through the end plate 6, the outer fastening portion 14 is screwed into the screw portion 12b of the restraint bolt 12, and the end plate 6 is attached. The inner fastening portion 13 (step 12e) and the outer fastening portion 14 are tightened from both sides. Subsequently, the plurality of battery cells 3, the elastic member 4, the middle plate 5, and the end plate 6 are arranged along the arrangement direction D, and the restraint bolts 12 are inserted into the middle plate 5 and the end plate 7 from the end plate 6 side. . Subsequently, a double nut 15 is screwed into the screw portion 12 f of the restraint bolt 12, and a predetermined restraint load is applied to the battery cell 3, the elastic member 4, and the middle plate 5. Thus, the battery module 1B is manufactured.

  Also according to the second embodiment, similarly to the first embodiment, the restraint bolt 12 can be firmly fixed to the end plate 6, and interference between the restraint bolt 12 and the end plate 6 can be suppressed. Moreover, in 2nd Embodiment, the restraint volt | bolt 12 is a stepped volt | bolt by which the screw part 12d smaller diameter than the said cylindrical part 12c was provided in the front end side of the cylindrical part 12c, and the inner side fastening part 13 is the cylindrical part 12c. Since the step portion 12e is between the screw portion 12d and the screw portion 12d, the number of parts can be reduced.

  Moreover, you may be comprised like the battery module 1C of 3rd Embodiment shown by FIG. In the restraining member 8 </ b> C of the third embodiment, the inner fastening portion 13 is configured by a flange portion 12 g provided on the restraining bolt 12. The flange portion 12g has an annular shape, for example, and is coupled to one end portion side of the restraint bolt 12 by welding or the like. Similarly to the second embodiment, a double nut 15 is screwed to a screw portion 12f provided on the other end side of the restraining bolt 12, and a pair of end plates is provided between the outer fastening portion 14 and the double nut 15. 6 and 7 are sandwiched. Further, the end plate 6 is sandwiched between the flange portion 12g (inner fastening portion 13) and the outer fastening portion 14. The battery module 1C of the third embodiment is manufactured by the same assembly process as that of the second embodiment.

  Also in the third embodiment, similarly to the first embodiment, the restraint bolt 12 can be firmly fixed to the end plate 6, and interference between the restraint bolt 12 and the end plate 6 can be suppressed. Moreover, in 3rd Embodiment, since it is comprised by the collar part 12g provided in the restraint volt | bolt 12, the number of parts can be reduced. Moreover, the area of the contact surface of the inner side fastening part 13 and the end plate 6 is easily securable by changing the diameter of the collar part 12g.

  Moreover, you may be comprised like battery module 1D of 4th Embodiment shown by FIG. In the restraining member 8 </ b> D of the fourth embodiment, the outer fastening portion 14 is configured by the head 12 h of the restraining bolt 12. A screw portion 12 i into which the inner fastening portion 13 is screwed is provided at a portion adjacent to the head portion 12 h in the restraint bolt 12. Similar to the second and third embodiments, the double nut 15 is screwed to the screw portion 12f provided on the opposite side of the head 12h of the restraining bolt 12, and the outer fastening portion 14 and the double nut 15 are connected to each other. A pair of end plates 6 and 7 are sandwiched between them. Further, the end plate 6 is sandwiched between the inner fastening portion 13 and the head portion 12h (outer fastening portion 14). The inner side fastening part 13 is comprised with the nut similarly to the said 1st Embodiment. The restraint bolt 12 is inserted through the middle plate 5 and the end plate 7 from the end plate 6 side. In the assembly process of the battery module 1D of the fourth embodiment, first, after the restraint bolt 12 is inserted through the end plate 6, the inner fastening portion 13 is screwed into the threaded portion 12i of the restraint bolt 12, and the end plate 6 is attached. Tighten from both sides by the inner fastening part 13 and the outer fastening part 14 (head 12h). The other points are the same as in the second embodiment.

  Also in the fourth embodiment, similarly to the first embodiment, the restraint bolt 12 can be firmly fixed to the end plate 6, and interference between the restraint bolt 12 and the end plate 6 can be suppressed. Further, in the fourth embodiment, since the outer fastening portion 14 is configured by the head 12h of the restraining bolt 12, the configuration can be simplified and the number of parts can be reduced.

  Moreover, you may be comprised like the battery module 1E of 5th Embodiment shown by FIG.5 and FIG.6 (a). In the fifth embodiment, in the third embodiment, a step portion for engaging the inner surface 6c of the end plate 6 in the rotational direction of the inner fastening portion 13 and the restraining bolt 12 to prevent the restraining bolt 12 from rotating. 16 is provided. In this example, by providing the protruding portion 17 protruding from the surface 6 c of the end plate 6, a step portion 16 is formed between the surface 6 c and the protruding portion 17. In the restraining member 8E of the fifth embodiment, the collar portion 12g has a hexagonal shape as viewed from the arrangement direction D, as shown in FIG. The protrusions 17 have a rectangular shape when viewed from the arrangement direction D, and a pair of protrusions 17 are provided around each flange 12g so as to sandwich the flange 12g. The pair of protrusions 17 facing each other with the flange 12g interposed therebetween are arranged in parallel to each other, and the distance between the pair of protrusions 17 is equal to or more than the distance between the two opposite surfaces of the flange 12g. Slightly larger. At the time of assembly, the inner fastening portion 13 is disposed between the pair of projecting portions 17 (step portions 16), and the inner fastening portion 13 and the projecting portion 17 are engaged in the rotation direction of the restraint bolt 12. Thereby, it can suppress that the restraint volt | bolt 12 turns together at the time of the fastening of the outer side fastening part 14 (circulation).

  Furthermore, in the fifth embodiment, as shown in FIG. 6B, the pair of projecting portions 17 are provided with the projecting portions 17a projecting in the opposite directions, and the projecting portions 17a enter the flange 12g. A recess 12j may be provided. In this case, the protrusion 17a and the recess 12j are engaged in the rotational direction of the restraint bolt 12, so that the rotation of the restraint bolt 12 when the outer fastening portion 14 is fastened can be further suppressed. In the fifth embodiment, the step portion 16 is formed by the provision of the protruding portion 17 protruding from the surface 6 c of the end plate 6. However, the inner fastening portion 13 is formed on the surface 6 c of the end plate 6. You may form by providing the recessed part to enter. Moreover, the step part 16 may be added to the said 2nd Embodiment. Further, in the fourth embodiment, the stepped portion for engaging the outer fastening portion 14 (head 12h) and the restraining bolt 12 in the rotational direction to prevent the restraining bolt 12 from rotating on the outer surface of the end plate 6. May be provided. Also in this case, the stepped portion may be formed by providing a protruding portion that protrudes from the outer surface of the end plate 6, or a recess in which the outer fastening portion 14 enters the outer surface of the end plate 6. It may be formed by being provided. Moreover, in the said 5th Embodiment, the inner side fastening part 13 may be comprised with the nut screwed together by the screw part 12d. In this case, for example, the inner fastening portion 13 is positioned by being screwed to the screwing limit of the screw portion 12d (abut against the end portion of the screw portion 12d). About the assembly process, after positioning the inner side fastening part 13, the assembly procedure similar to 2nd Embodiment is employable. Moreover, in the said 4th Embodiment, the outer side fastening part 14 is comprised by the nut screwed together by the screw part provided in the front-end | tip part of the restraint bolt 12, and it is outside fastening to the outer surface of the end plate 6. FIG. A stepped portion may be provided for engaging the portion (nut) 14 and the restraining bolt 12 in the rotational direction to prevent the restraining bolt 12 from rotating. In this case, the outer fastening portion 14 is positioned by being screwed to the screwing limit of the screw portion, for example. This screw portion is provided separately from the screw portion 12i.

  Moreover, in the said 1st Embodiment, although the elastic member 4 was arrange | positioned at the one end of the arrangement | sequence direction D in the array body 2, if it has been unevenly distributed and arrange | positioned in the array body 2 at the one side of the array direction D, it will be. For example, it may be arranged between adjacent battery cells 3 on one end side. The number and arrangement of the elastic members 4 are not limited. For example, a plurality of elastic members 4 may be arranged between the arrangement ends of the array 2 and / or between the battery cells 3. In the above embodiment, after the outer fastening portion 14 is fastened, the inner fastening portion 13 and / or the outer fastening portion 14 and the end plate 6 may be joined by welding. In this case, the restraint bolt 12 can be more firmly fixed to the end plate 6.

DESCRIPTION OF SYMBOLS 1A ... Battery module, 2 ... Array, 3 ... Battery cell, 4 ... Elastic member, 6, 7 ... End plate, 8A ... Restraint member, 12 ... Restraint bolt, 12c ... Cylindrical part, 12d ... Screw part, 12e ... Step Part, 12g ... collar part, 12h ... head, 13 ... inner fastening part, 14 ... outer fastening part, 16 ... step part, D ... arrangement direction.

Claims (8)

An array formed by arranging a plurality of battery cells;
An elastic member that is unevenly arranged on one side of the arrangement direction of the battery cells in the array;
A pair of end plates sandwiching the array in the array direction;
A restraint bolt that connects the pair of end plates to each other, and a restraint member that applies a restraint load in the array direction to the array,
The said restraining member is a battery module containing the inner side fastening part which fastens the said one end plate from the inner side in the coupling position of the said restraint bolt, and the outer side fastening part which fastens from the outer side.   The battery module according to claim 1, wherein the inner fastening portion is configured by a nut screwed into a screw portion of the restraining bolt. The constraining bolt is a stepped bolt in which a screw portion having a smaller diameter than the cylindrical portion is provided on the tip side of the cylindrical portion,
The battery module according to claim 1, wherein the inner fastening portion is configured by a step portion between the cylindrical portion and the screw portion.   The battery module according to claim 1, wherein the inner fastening portion is configured by a flange provided on the restraining bolt.   The battery module according to claim 1, wherein the outer fastening portion is configured by a head portion of the restraining bolt.   The battery module according to any one of claims 1 to 4, wherein the outer fastening portion is configured by a nut screwed into a screw portion of the restraining bolt.   2. A stepped portion is provided on the inner surface of the end plate on the one side to engage the inner fastening portion in the rotational direction of the restraint bolt and prevent the restraint bolt from rotating. The battery module as described in any one of -6.   The outer surface of the one end plate is provided with a stepped portion for engaging the outer fastening portion and the restraining bolt in the rotational direction to prevent the restraining bolt from rotating. The battery module as described in any one of -6.

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