JP2021193639A - Battery module - Google Patents

Abstract

To stably bind batteries in a battery module, while at the same time maintaining their capacity.SOLUTION: A battery module 1 comprises: a battery laminate 2 having a plurality of laminated batteries 10; a pair of end plates 4, made of first metal, which is disposed on both ends of the battery laminate 2 in a lamination direction X of the batteries 10; binding members 6 which engage with the pair of end plates 4 so as to bind the plurality of batteries 10; and a buffer member 8 which is interposed between each of the end plates 4 and the batteries 10, and at least part of which is made of second metal having a Young's modulus lower than that of the first metal.SELECTED DRAWING: Figure 1

Description

The present invention relates to a battery module.

For example, as a power source that requires a high output voltage, such as for a vehicle, a battery module in which a plurality of batteries are electrically connected is known. Generally, such a battery module is laid between a battery laminate having a plurality of stacked batteries, a pair of end plates arranged at both ends of the battery laminate in the battery stacking direction, and a pair of end plates. It is equipped with a bind bar that restrains a plurality of batteries in the stacking direction.

Batteries may expand with use. When each battery expands, the battery module expands significantly in the battery stacking direction. As a result, a load is applied to the end plate and the bind bar, so that the confined state of the battery may become unstable. On the other hand, Patent Document 1 discloses a battery module in which a rubber elastic member is provided between a battery located at an end in a stacking direction and an end plate. In this battery module, the expansion of the battery is allowed by the elastic member being compressed and deformed when the battery expands. As a result, the load applied to the end plate and the bind bar can be reduced, and a plurality of batteries can be stably constrained.

Japanese Unexamined Patent Publication No. 2017-50200

In recent years, there has been a demand for higher capacity battery modules, and in order to meet this demand, higher capacity batteries are being promoted. As the capacity of the battery increases, the amount of expansion of the battery may increase. In particular, at the end of life (EOL) of the battery, the amount of expansion of the battery can increase significantly. In a structure in which rubber is interposed between the battery and the end plate as in the battery module described above, the battery may expand excessively because the rubber allows the battery to expand. As the battery expands, the volume inside the battery naturally increases. When the volume inside the battery becomes large, the water level of the electrolytic solution may decrease and the contact area between the electrode body and the electrolytic solution may decrease. When the contact area between the electrode body and the electrolytic solution is reduced, various problems such as a decrease in battery capacity and an increase in internal resistance may occur. Therefore, if the battery expands excessively, the capacity of each battery and thus the capacity of the battery module may decrease.

The present invention has been made in view of these circumstances, and an object of the present invention is to provide a technique for achieving both stable restraint of a battery in a battery module and maintenance of capacity.

One aspect of the invention is a battery module. This battery module includes a battery laminate having a plurality of stacked batteries, a pair of end plates composed of a first metal and arranged at both ends of the battery laminate in the battery stacking direction, and a pair of end plates. A restraining member that engages and restrains a plurality of batteries, and a cushioning member that is interposed between the end plate and the battery and is composed of a second metal having a younger rate smaller than that of the first metal, at least in part. To prepare for.

It should be noted that any combination of the above components and the conversion of the expression of the present invention between methods, devices, systems and the like are also effective as aspects of the present invention.

According to the present invention, it is possible to achieve both stable restraint of the battery in the battery module and maintenance of the capacity.

It is an exploded perspective view of the battery module which concerns on embodiment. FIG. 2A is a schematic view of the cushioning member as seen from the stacking direction of the batteries. FIG. 2B is a cross-sectional view taken along the line AA in FIG. 2A. FIG. 3A is a schematic view of the end plate seen from the stacking direction of the batteries. FIG. 3B is a cross-sectional view taken along the line BB of FIG. 3A. FIG. 4A is a schematic view of the end plates, cushioning members, and batteries that are assembled to each other when viewed from the stacking direction of the batteries. FIG. 4B is a cross-sectional view taken along the line CC in FIG. 4A. It is sectional drawing which shows typically a part of the battery module which concerns on Embodiment 2. FIG.

Hereinafter, the present invention will be described with reference to the drawings based on the preferred embodiments. The embodiments are not limited to the invention, but are exemplary, and all the features and combinations thereof described in the embodiments are not necessarily essential to the invention. The same or equivalent components, members, and processes shown in the drawings shall be designated by the same reference numerals, and duplicate description thereof will be omitted as appropriate. In addition, the scale and shape of each part shown in each figure are set for convenience in order to facilitate explanation, and are not limitedly interpreted unless otherwise specified. In addition, when terms such as "first" and "second" are used in the present specification or claims, these terms do not represent any order or importance unless otherwise specified, and have a certain structure. Is to distinguish between and other configurations. In addition, some of the members that are not important for explaining the embodiment in each drawing are omitted and displayed.

FIG. 1 is an exploded perspective view of the battery module according to the embodiment. In addition, in FIG. 1, the cushioning member 8 is schematically shown. The battery module 1 includes a battery laminate 2, a pair of end plates 4, a restraining member 6, and a cushioning member 8.

The battery laminate 2 has a plurality of batteries 10 and a separator 12. Each battery 10 is a rechargeable secondary battery such as a lithium ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, or the like. The battery 10 is a so-called square battery, and has a flat rectangular parallelepiped outer can 14. A substantially rectangular opening (not shown) is provided on one surface of the outer can 14, and an electrode body, an electrolytic solution, or the like is housed in the outer can 14 through the opening. A sealing plate 16 for sealing the outer can 14 is provided at the opening of the outer can 14.

The sealing plate 16 is provided with a positive electrode output terminal 18 near one end in the longitudinal direction and a negative electrode output terminal 18 near the other end. The pair of output terminals 18 are electrically connected to the positive electrode plate and the negative electrode plate constituting the electrode body, respectively. Hereinafter, the output terminal 18 of the positive electrode is referred to as a positive electrode terminal 18a, and the output terminal 18 of the negative electrode is referred to as a negative electrode terminal 18b. When it is not necessary to distinguish the polarity of the output terminal 18, the positive electrode terminal 18a and the negative electrode terminal 18b are collectively referred to as an output terminal 18. The outer can 14, the sealing plate 16, and the output terminal 18 are conductors, for example, made of metal. The sealing plate 16 and the opening of the outer can 14 are joined by welding or the like. Each output terminal 18 is inserted into a through hole (not shown) formed in the sealing plate 16. An insulating sealing member (not shown) is interposed between each output terminal 18 and each through hole.

In the present embodiment, for convenience of explanation, the surface of the outer can 14 on the side where the sealing plate 16 is provided is the upper surface of the battery 10, and the surface facing the upper surface of the outer can 14 is the bottom surface of the battery 10. Further, the battery 10 has two main surfaces connecting the upper surface and the bottom surface. This main surface is the surface having the largest area among the six surfaces of the battery 10. Further, the main surface is a long side surface connected to the long sides of the upper surface and the bottom surface. The remaining two surfaces excluding the top surface, the bottom surface, and the two main surfaces are the side surfaces of the battery 10. This side surface is a short side surface connected to the short sides of the top and bottom surfaces. Further, in the battery laminate 2, the surface on the upper surface side of the battery 10 is the upper surface of the battery laminate 2, the surface on the bottom surface side of the battery 10 is the bottom surface of the battery laminate 2, and the surface on the short side surface side of the battery 10 is the battery. It is the side surface of the laminated body 2. Further, the upper surface side of the battery laminate 2 is upward in the vertical direction, and the bottom surface side of the battery laminate 2 is downward in the vertical direction. These directions and positions are defined for convenience. Therefore, for example, the portion defined as the upper surface in the present invention does not mean that the portion defined as the bottom surface is always located above the portion defined as the bottom surface.

The sealing plate 16 is provided with a valve portion 20 between the pair of output terminals 18. The valve portion 20, also called a safety valve, is a mechanism for discharging the gas generated inside the battery 10. The valve portion 20 is configured so that the valve can be opened when the internal pressure of the outer can 14 rises above a predetermined value to release the gas inside. The valve portion 20 is composed of, for example, a thin-walled portion provided in a part of the sealing plate 16 and thinner than the other portion, and a linear groove formed on the surface of the thin-walled portion. In this configuration, when the internal pressure of the outer can 14 rises, the thin-walled portion is torn from the groove to open the valve. The valve portion 20 of each battery 10 is connected to an exhaust duct (not shown), and the gas inside the battery is discharged from the valve portion 20 to the exhaust duct.

The plurality of batteries 10 are stacked at predetermined intervals so that the main surfaces of adjacent batteries 10 face each other. In addition, "stacking" means arranging a plurality of members in any one direction. Therefore, stacking the batteries 10 includes arranging a plurality of batteries 10 horizontally. Further, each battery 10 is arranged so that the output terminals 18 face the same direction. In the present embodiment, for convenience, each battery 10 is arranged so that the output terminal 18 faces upward in the vertical direction. The two adjacent batteries 10 are laminated so that the positive electrode terminal 18a of one battery 10 and the negative electrode terminal 18b of the other battery 10 are adjacent to each other. The positive electrode terminal 18a and the negative electrode terminal 18b are electrically connected via a bus bar (not shown). The output terminals 18 having the same polarity in the plurality of adjacent batteries 10 may be connected in parallel by a bus bar to form a battery block, and the battery blocks may be connected in series.

The separator 12 is also called an insulating spacer, and is made of, for example, a resin having an insulating property. Examples of the resin constituting the separator 12 include thermoplastic resins such as polypropylene (PP), polybutylene terephthalate (PBT), polycarbonate (PC), and Noryl (registered trademark) resin (modified PPE).

The separator 12 has a plurality of first insulating members 12a and a pair of second insulating members 12b. Each first insulating member 12a is arranged between two adjacent batteries 10 and electrically insulates between the two batteries 10. Each second insulating member 12b extends in the stacking direction X of the batteries 10 and abuts on the side surface of each battery 10. As a result, each battery 10 and the restraining member 6 are electrically insulated from each other. If necessary, the second insulating member 12b may be configured to electrically insulate the bus bar (not shown) from the restraining member 6.

A plurality of ribs 12c arranged in the stacking direction X of the battery 10 are provided on the surface of the second insulating member 12b facing the battery 10. The spacing between adjacent ribs 12c corresponds to the dimension between the main surfaces of the battery 10. When the second insulating member 12b is fitted to the side surface of each battery 10, the plurality of ribs 12c press the bottom surface of each battery 10. As a result, the positioning of each battery 10 in the direction Z is performed.

The battery laminate 2 is sandwiched between a pair of end plates 4. The pair of end plates 4 are arranged at both ends of the battery laminate 2 in the stacking direction X of the battery 10. The pair of end plates 4 are arranged adjacent to each other via the first insulating member 12a with the batteries 10 located at both ends in the stacking direction X. Each end plate 4 is made of a metal plate made of a first metal. The first metal is exemplified by at least one selected from the group consisting of iron, stainless steel and aluminum. By arranging the first insulating member 12a between the end plate 4 and the battery 10, both are insulated.

The restraint member 6 is also called a bind bar and is a long member long in the stacking direction X of the battery 10. In the present embodiment, the pair of restraint members 6 are arranged in the direction Y orthogonal to the stacking direction X of the battery 10, that is, in the direction in which the positive electrode terminal 18a, the valve portion 20, and the negative electrode terminal 18b are arranged. A battery laminate 2 and a pair of end plates 4 are arranged between the pair of restraint members 6. Each restraint member 6 has a rectangular flat surface portion 6a parallel to the side surface of the battery 10 and an eaves portion 6b protruding from the upper side and the lower side of the flat surface portion 6a toward the battery 10.

By engaging the pair of end plates 4 with the flat surface portion 6a of each restraining member 6, the plurality of batteries 10 are restrained in the stacking direction X. A contact plate 22 is fixed to the surface of the flat surface portion 6a facing each end plate 4 by welding or the like. The contact plate 22 is a member long in the direction Z in which the upper surface and the bottom surface of the battery 10 are lined up, and has a groove portion 22a on the surface facing the end plate 4. The bottom surface of the groove portion 22a is provided with a through hole 22b extending to a surface of the contact plate 22 in contact with the flat surface portion 6a. In the present embodiment, the three through holes 22b are arranged in the groove portion 22a at predetermined intervals in the direction Z.

The flat surface portion 6a is provided with a through hole 7 at a position corresponding to the through hole 22b of the contact plate 22. Further, the end plate 4 has a convex portion 4a long in the direction Z on the surface facing the flat surface portion 6a. The shape of the convex portion 4a corresponds to the shape of the groove portion 22a. The convex portion 4a is provided with a fastening hole 4b at a position corresponding to the through hole 22b of the contact plate 22.

The restraining member 6 and the end plate 4 are connected by fitting the convex portion 4a into the groove portion 22a. With the convex portion 4a fitted in the groove portion 22a, the through hole 7 of the restraining member 6, the through hole 22b of the contact plate 22, and the fastening hole 4b of the end plate 4 overlap each other. By inserting a fastening member 24 such as a screw, the end plate 4 and the restraining member 6 are fixed.

When the size of the battery laminate 2 in the stacking direction X increases due to the expansion of the battery 10, a force in the shearing direction is applied to the convex portion 4a. Further, a force is applied to the restraining member 6 in the direction in which both ends are pulled. As a result, the increase in the dimensions of the battery laminate 2 and the expansion of the battery 10 can be suppressed. In general, metal has a stronger tensile strength than a bending strength.

Fixing portions 26 are arranged at both ends of the restraint member 6 in the stacking direction X. The battery module 1 is fixed to a fixing target such as a housing of a battery pack or a vehicle body by a fixing portion 26. The fixing portion 26 has a through hole 26a through which a fastening member (not shown) is inserted. The fixing target has a fastening hole (not shown), and the fastening hole and the through hole 26a are overlapped with each other, and the fastening member is inserted through the fastening hole to fix the battery module 1 to the fixing target. The fixing portion 26 may be fixed to the fixing target by another method such as welding.

The cushioning member 8 is a member that presses the battery 10 in the stacking direction X while appropriately allowing the battery 10 to expand. Hereinafter, the shape and arrangement of the cushioning member 8 will be described in detail with reference to FIGS. 2 (A) to 4 (B).

FIG. 2A is a schematic view of the cushioning member as seen from the stacking direction of the batteries. FIG. 2B is a cross-sectional view taken along the line AA in FIG. 2A. FIG. 3A is a schematic view of the end plate seen from the stacking direction of the batteries. FIG. 3B is a cross-sectional view taken along the line BB of FIG. 3A. FIG. 4A is a schematic view of the end plates, cushioning members, and batteries that are assembled to each other when viewed from the stacking direction of the batteries. FIG. 4B is a cross-sectional view taken along the line CC in FIG. 4A. Note that FIG. 4A shows a state in which the battery 10 is seen through, and the separator 12 is not shown. Further, in FIG. 4B, the illustration of the internal structure of the battery 10 is omitted.

The cushioning member 8 is interposed between the end plate 4 and the battery 10. The cushioning member 8 comes into contact with the battery 10 via the first insulating member 12a of the separator 12. At least a part of the cushioning member 8 is made of a second metal having a Young's modulus smaller than that of the first metal constituting the end plate 4. As a matter of course, the Young's modulus of the second metal is larger than the Young's modulus of a resin such as rubber. The type of the second metal is selected so that the force applied by the expansion of the battery 10 does not exceed the proof stress of the second metal. As the second metal, at least one selected from the group consisting of magnesium and magnesium alloys is exemplified. As an example, the Young's modulus of the second metal is 40 to 50 GPa, and the proof stress is 150 to 300 MPa. The Young's modulus of the first metal is 60 to 220 GPa.

The cushioning member 8 of the present embodiment has a plurality of fragment portions 28 and a support plate 30. Each fragment portion 28 has a rectangular parallelepiped shape or a square columnar shape, and is composed of a second metal. The support plate 30 is a plate-shaped member that supports a plurality of fragment portions 28. The support plate 30 may be made of the same first metal as the end plate 4, or may be made of the same second metal as the fragment portion 28. Further, the support plate 30 may be made of a metal different from the first metal and the second metal.

Each fragment 28 is arranged in a matrix on the main surface of the support plate 30. Each fragment 28 has any one surface joined to the main surface of the support plate 30. When the support plate 30 is made of the second metal, the plurality of fragment portions 28 and the support plate 30 may be integrally molded. It is desirable that the protrusion heights of the fragment portions 28 from the main surface of the support plate 30 are the same.

The support plate 30 is arranged so as to spread parallel to the main surface 4c of the end plate 4. That is, the support plate 30 spreads parallel to the YZ plane orthogonal to the stacking direction X of the battery 10. Therefore, the plurality of fragment portions 28 are arranged parallel to the main surface 4c of the end plate 4.

The end plate 4 has a recess 32 facing the battery 10 side on the main surface 4c facing the battery 10 side. That is, the end plate 4 is assembled to the battery laminate 2 so that the opening of the recess 32 faces the battery 10 side. The recess 32 is arranged approximately in the center of the main surface 4c when viewed from the stacking direction X of the battery 10. Further, the opening shape of the recess 32 is similar to the contour of the support plate 30 seen from the stacking direction X. The cushioning member 8 is arranged in the recess 32 so that the support plate 30 faces the bottom surface side of the recess 32 and the plurality of fragment portions 28 face the battery 10 side.

The depth of the recess 32 is equivalent to the dimension of the cushioning member 8 in the direction in which the fragment portion 28 and the support plate 30 are aligned. Therefore, with the cushioning member 8 arranged in the recess 32, the surface of each fragment 28 facing the battery 10 side and the main surface 4c of the end plate 4 facing the battery 10 side are arranged in the same plane. Will be done. Therefore, with the end plate 4 assembled to the battery laminate 2, each fragment 28 and the main surface 4c of the end plate 4 come into contact with the battery 10 via the first insulating member 12a. The depth of the recess 32 is such that the surface of each fragment 28 facing the battery 10 side is larger than the main surface 4c of the end plate 4 facing the battery 10 side in a state where the cushioning member 8 is arranged in the recess 32. , May be configured to project outward. In the case of this configuration, it is preferable that the protrusion amount of each fragment portion 28 is designed so that the load applied to each fragment portion 28 does not exceed the proof stress limit of the second metal.

Further, the recess 32 of the end plate 4 is arranged so as to overlap the center 10C of the battery 10 when viewed from the stacking direction X of the battery 10. Therefore, the cushioning member 8 is arranged so as to overlap the center 10C of the battery 10 when viewed from the stacking direction X of the battery 10. The center 10C of the battery 10 is, for example, the geometric center of the contour shape of the battery 10 as seen from the stacking direction X, or the geometric center of gravity.

As described above, the battery module 1 according to the present embodiment is composed of a battery laminate 2 having a plurality of stacked batteries 10 and a first metal, and is a battery laminate 2 in the stacking direction X of the batteries 10. A pair of end plates 4 arranged at both ends of the above, a restraining member that engages with the pair of end plates 4 to restrain a plurality of batteries 10, and at least a part thereof are interposed between the end plates 4 and the batteries 10. However, it includes a cushioning member 8 made of a second metal having a younger rate than that of the first metal.

When the battery 10 expands due to charging or the like, the battery 10 is greatly deformed in the stacking direction X as compared with the direction Y and the direction Z. As a result, a force in the stacking direction X is applied to the end plate 4 and the cushioning member 8. Further, when a force is applied to the pair of end plates 4, a force in the direction of being pulled in the stacking direction X is applied to the restraining member 6. On the other hand, the shock absorber 8 of the present embodiment has at least a part made of a second metal having a Young's modulus smaller than that of the first metal constituting the end plate 4. Therefore, when the battery 10 expands, the cushioning member 8 is preferentially elastically deformed. As a result, the stress generated in the end plate 4 and the restraining member 6 due to the expansion of the battery 10 can be relieved, and the state in which the plurality of batteries 10 are restrained can be stably maintained.

On the other hand, since the second metal has a higher Young's modulus than the resin such as rubber, the expansion of the battery 10 can be suppressed as compared with the resin. As a result, the amount of displacement of the battery 10 in the stacking direction X can be reduced. For example, the displacement amount of the battery 10 is suppressed to 1 mm or less, more preferably 0.4 mm or less. Therefore, it is possible to suppress a decrease in the water level of the electrolytic solution due to an increase in the battery volume, and as a result, it is possible to suppress a decrease in the capacity of each battery 10. In particular, the shock absorber 8 balances the function of elastically deforming to allow the expansion of the battery 10 when the battery 10 reaches EOL and the expansion amount of the battery 10 is significantly increased, and the function of suppressing the expansion of each battery 10. It works well.

Therefore, according to the present embodiment, it is possible to achieve both stable restraint of the battery 10 in the battery module 1 and maintenance of the capacity. Further, since the cushioning member 8 allows the dimensional change of the battery 10, the rigidity required for the end plate 4 and the restraining member 6 can be reduced. Therefore, it is possible to avoid an increase in size, weight, and cost of the battery module 1 due to ensuring the rigidity of the end plate 4 and the restraint member 6.

Further, the cushioning member 8 of the present embodiment has a plurality of fragment portions 28 made of a second metal. The plurality of fragment portions 28 are arranged parallel to the main surface 4c of the end plate 4. Therefore, the battery 10 is pressed by the plurality of fragment portions 28. In this way, by dividing the portion of the cushioning member 8 made of the second metal into a plurality of portions, that is, forming the plurality of fragment portions 28, the portion can be more easily elastically deformed. Therefore, the load applied to the end plate 4 and the restraining member 6 due to the expansion of the battery 10 can be more reliably reduced. Further, it is possible to reduce the possibility that the force applied to the cushioning member 8 due to the expansion of the battery 10 exceeds the proof stress of the second metal.

Further, the cushioning member 8 has a support plate 30 that supports a plurality of fragment portions 28. As a result, it is possible to avoid complicating the assembly of the battery module 1 by providing the plurality of fragment portions 28. Further, the end plate 4 has a recess 32 in the main surface 4c facing the battery 10 side. Then, the cushioning member 8 is arranged in the recess 32. As a result, the cushioning member 8 can be easily positioned. Further, it is possible to suppress the increase in size of the battery module 1 by providing the cushioning member 8.

Further, the cushioning member 8 is arranged so as to overlap the center 10C of the battery 10 when viewed from the stacking direction X of the battery 10. When the battery 10 expands, the center 10C of the battery 10 has a larger displacement amount in the stacking direction X than other portions. Therefore, by arranging the cushioning member 8 so as to overlap the center 10C, the load applied to the end plate 4 and the restraining member 6 due to the expansion of the battery 10 can be more reliably reduced.

(Embodiment 2)
The battery module according to the second embodiment has the same configuration as that of the first embodiment except that the installation posture of the cushioning member is different. Hereinafter, the battery module according to the present embodiment will be mainly described with a configuration different from that of the first embodiment, and the common configuration will be briefly described or omitted. FIG. 5 is a cross-sectional view schematically showing a part of the battery module according to the second embodiment. Note that FIG. 5 omits the illustration of the internal structure of the restraint member 6 and the battery 10.

Similar to the first embodiment, the battery module 1 according to the present embodiment includes a battery laminate 2, a pair of end plates 4, a restraining member 6, and a cushioning member 8. The cushioning member 8 is interposed between the end plate 4 and the battery 10. The cushioning member 8 has a plurality of fragment portions 28 and a support plate 30. Each fragment 28 is made of a second metal and is arranged on the main surface of the support plate 30.

In the present embodiment, the support plate 30 is arranged closer to the battery 10 than the plurality of fragment portions 28 in a state where the cushioning member 8 is assembled to the end plate 4. That is, the support plate 30 is interposed between the plurality of fragment portions 28 and the battery 10. The tips of the plurality of fragment portions 28 abut on the bottom surface of the recess 32. Therefore, in the first embodiment, the cushioning member 8 is in contact with the battery 10 at a plurality of points, but in the present embodiment, the cushioning member 8 is in contact with the battery 10 on the surface. As a result, the possibility that the outer can 14 is uneven due to the battery 10 being pressed against the cushioning member 8 can be reduced. As a result, it is possible to suppress a decrease in the power generation performance of the battery 10.

The embodiments of the present invention have been described in detail above. The above-described embodiment merely shows a specific example in carrying out the present invention. The contents of the embodiments do not limit the technical scope of the present invention, and many design changes such as changes, additions, and deletions of components are made without departing from the ideas of the invention defined in the claims. Is possible. The new embodiment with the design change has the effects of the combined embodiment and the modification. In the above-described embodiment, the contents that can be changed in design are emphasized by adding notations such as "in the present embodiment" and "in the present embodiment". Design changes are allowed even if there is no content. Any combination of the above components is also effective as an aspect of the present invention. The hatching attached to the cross section of the drawing does not limit the material of the object to which the hatching is attached.

The cushioning member 8 may be provided only on one end plate 4. The cushioning member 8 may be joined to the end plate 4. For example, the cushioning member 8 may be composed of only a plurality of fragment portions 28, and the plurality of fragment portions 28 may be directly joined to the end plate 4. The portion of the cushioning member 8 made of the second metal may be a single flat plate. The cushioning member 8 may be entirely made of the second metal. The number of batteries 10 included in the battery laminate 2 is not particularly limited. The structure of each part of the battery module 1, including the shape of the separator 12 and the fastening structure between the end plate 4 and the restraining member 6, can be appropriately changed.

1 Battery module, 2 Battery laminate, 4 End plate, 4c Main surface, 6 Restraint member, 8 Cushioning member, 10 Battery, 10C center, 28 Fragment, 30 Support plate, 32 Recess.

Claims (6)

A battery laminate having a plurality of stacked batteries,
A pair of end plates composed of a first metal and arranged at both ends of the battery laminate in the battery stacking direction,
A restraining member that engages with the pair of end plates to restrain the plurality of batteries,
A cushioning member that is interposed between the end plate and the battery and is at least partially composed of a second metal having a Young's modulus smaller than that of the first metal.
A battery module characterized by being equipped with. The cushioning member has a plurality of fragment portions composed of the second metal, and has a plurality of fragment portions.
The battery module according to claim 1, wherein the plurality of fragment portions are arranged in parallel with the main surface of the end plate. The battery module according to claim 2, wherein the cushioning member has a support plate that supports the plurality of fragments. The battery module according to claim 3, wherein the support plate is arranged on the battery side of the plurality of fragment portions. The end plate has a recess on the main surface facing the battery side.
The battery module according to any one of claims 1 to 4, wherein the cushioning member is arranged in the recess. The battery module according to any one of claims 1 to 5, wherein the cushioning member is arranged so as to overlap the center of the battery when viewed from the stacking direction of the battery.

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