JP6717213B2 - Battery module - Google Patents

Description

The present invention relates to a battery module.

As a battery module, there is one disclosed in Patent Document 1, for example. The battery module described in Patent Document 1 has a plurality of batteries arranged side by side in one direction and a heat exchanger arranged on the lower side in the vertical direction orthogonal to the direction in which the plurality of batteries are arranged. The battery module described in Patent Document 1 includes a flexible gel between the plurality of batteries and the heat exchanger in order to improve the thermal conductivity between the plurality of batteries and the heat exchanger. Intervenes.

In assembling the battery module described in Patent Document 1, for example, a gel is applied to the upper surface of the heat exchanger, and a plurality of batteries arranged side by side are pressed against the upper surface of the gel. As a result, the gel is deformed and surely adheres to the adhesion surface, which is the gel-side surface of the plurality of batteries. Therefore, it is possible to suppress an increase in thermal resistance in the heat transfer path from each battery to the heat exchanger due to the fact that the gel does not adhere to the contact surface of the battery.

JP, 2014-127321, A

However, in the battery module, the position of the contact surface of the plurality of batteries in the vertical direction may be displaced due to a dimensional error of each battery or an assembly error of the plurality of batteries. In this case, the vertical distance between the contact surface of each battery and the heat exchanger varies, and the vertical thickness of the gel disposed between the contact surface of each battery and the heat exchanger also varies. Occurs. As a result, the thermal resistance in the heat transfer path from each battery to the heat exchanger varies. This is because the thermal resistance in the heat transfer path from each battery to the heat exchanger depends on the thickness of the gel arranged between each battery and the heat exchanger. As a result, it is not possible to uniformly cool each battery by the heat exchanger, and there is a risk that temperature variations will occur in a plurality of batteries.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a battery module that can suppress variations in cooling performance of each battery by a heat exchanger.

One aspect of the present invention is a heat exchanger (2),
A heat spreader (3) in thermal contact with the heat exchanger;
A heat conducting portion (4) that is in thermal contact with the upper surface (31) of the heat diffusion portion;
A plurality of batteries (5) arranged to be in thermal contact with the heat conducting portion from at least the upper side of the heat conducting portion and to be overlapped with the heat diffusion portion and the heat conducting portion in the vertical direction (Z); Have
The thermal diffusion portion has a higher thermal conductivity than the thermal conduction portion,
When the lower surface of the battery is defined as a reference surface (51), the reference surfaces of the plurality of batteries are arranged at a plurality of vertical positions,
The upper surface of the heat spreader has a plurality of facing portions (311) that vertically face the reference surfaces of the plurality of batteries,
When the battery whose reference surface is located at the lowermost end of the plurality of batteries is defined as the lowermost battery (501), the upper and lower sides of the reference surface of the batteries other than the lowermost battery of the plurality of batteries are defined. At least one of the facing portions facing each other in the direction is located above the facing portion facing in the vertical direction with the reference surface of the lowermost battery ,
The heat diffusion portion is made of metal,
The reference surface of each of the batteries is in the battery module (1) that is not in contact with the heat diffusion portion .

In the battery module, at least one of the facing portions vertically facing a reference surface of a battery other than the lowermost battery among the plurality of batteries is more than the facing portion vertically facing the reference surface of the lowermost battery. It is located on the upper side. Therefore, it is possible to suppress variations in vertical intervals between the reference surfaces of the plurality of batteries and the plurality of facing portions on the upper surface of the heat diffusion portion. As a result, it is possible to suppress variations in the thickness of the regions of the heat conducting portion that vertically overlap the reference surfaces of the plurality of batteries. Therefore, it is possible to suppress variations in the thermal resistance value in the heat transfer path from each battery to the heat diffusion portion.

As described above, according to the above aspect, it is possible to provide the battery module capable of suppressing the variation in the cooling performance of each battery by the heat exchanger.
The reference numerals in parentheses described in the claims and the means for solving the problems indicate the corresponding relationship with the specific means described in the embodiments described later, and limit the technical scope of the present invention. Not a thing.

1 is an overall sectional view of a battery module in Embodiment 1. FIG. FIG. 3 is a top view of the battery module according to the first embodiment. FIG. 3 is a sectional view taken along the line III-III of FIG. The partially expanded view of FIG. 3 is a perspective view of a heat diffusion unit according to the first embodiment. FIG. 3 is an overall cross-sectional view of a battery module according to Embodiment 2. FIG. The whole sectional view of the battery module in Embodiment 3. FIG. 6 is a perspective view of a heat diffusion unit according to the third embodiment. The whole sectional view of the battery module in Embodiment 4. FIG. 10 is a sectional view taken along the line AA of FIG. 9. FIG. 11 is a cross-sectional view for explaining the method for manufacturing the battery module according to the fourth embodiment, which is a diagram before deformation of the thin metal plate. FIG. 12 is a cross-sectional view for explaining the method for manufacturing the battery module according to the fourth embodiment, which is a diagram in a state after the metal thin plate is deformed.

(Embodiment 1)
An embodiment of the battery module will be described with reference to FIGS. 1 to 5.
As shown in FIG. 1, the battery module 1 of the present embodiment has a heat exchanger 2, a heat diffusion portion 3, a heat conduction portion 4, and a plurality of batteries 5. The heat diffusion portion 3 is in thermal contact with the heat exchanger 2. The thermal diffusion section 3 has a higher thermal conductivity than the thermal conduction section 4. The heat conducting portion 4 is in thermal contact with the upper surface 31 of the heat diffusion portion 3. The plurality of batteries 5 are in thermal contact with the heat conducting unit 4 from at least the upper side of the heat conducting unit 4. As shown in FIGS. 1 and 3, the heat diffusion portion 3 and the heat conduction portion 4 are arranged at positions overlapping in the vertical direction Z. The direction in which the heat diffusion portion 3 and the heat conduction portion 4 are arranged is referred to as the vertical direction Z. The heat conducting portion 4 side with respect to the heat diffusing portion 3 in the vertical direction Z is the upper side, and the opposite side is the lower side.

As shown in FIG. 1, when the lower surface of the battery 5 is defined as the reference surface 51, the reference surfaces 51 of the plurality of batteries 5 are arranged at a plurality of positions in the vertical direction Z. The upper surface 31 of the heat diffusion portion 3 has a plurality of facing portions 311 facing the reference surfaces 51 of the plurality of batteries 5 in the vertical direction Z. Here, among the plurality of batteries 5, the battery 5 whose reference surface 51 is located at the bottom end is defined as the bottom end battery 501. At this time, at least one of the facing portions 311 facing the reference surface 51 of the batteries 5 other than the lowermost end battery 501 among the plurality of batteries 5 in the vertical direction Z has a lower surface than the reference surface 51 of the lowermost end battery 501 and the vertical direction Z. Is located above the facing portion 311 facing the.

The battery module 1 is used as a power source of the device. For example, the battery module 1 can be used as a power source for driving a rotating electric machine for an internal combustion engine.

In the present embodiment, the battery 5 is a lithium ion secondary battery. The battery 5 is a so-called can-type battery whose outer package is made of metal such as iron or aluminum. As shown in FIGS. 1 to 3, the battery 5 has a battery main body 50 and a pair of terminals 52 protruding upward from the battery main body 50. The lower surface of the battery body 50 is the reference surface 51. In the present embodiment, the reference surface 51 is a plane orthogonal to the vertical direction Z and is a surface facing downward.

The battery 5 has a flat plate shape having a thickness in one of the directions orthogonal to the vertical direction Z. In the present embodiment, the plurality of batteries 5 have the same shape except for the dimension in the vertical direction Z. As shown in FIG. 1 and FIG. 2, the plurality of batteries 5 are arranged in a line direction X orthogonal to the vertical direction Z to form a battery structure 10. Further, the battery structure 10 is constrained in the arrangement direction X. The plurality of batteries 5 are arranged side by side in the thickness direction of the batteries 5 to form the battery structure 10. In the battery structure 10, an insulating material 101 for preventing the battery bodies 50 from electrically contacting each other is arranged between the adjacent batteries 5.

The battery structure 10 is restrained in the arrangement direction X by the restraint members 100 from both sides in the arrangement direction X. The restraint member 100 includes a pair of end plates 11 arranged on both sides of the battery structure 10 and a connecting member 12 that connects the pair of end plates 11. Both ends of the connecting member 12 are fixed to the end plates 11. Thereby, the battery structure 10 is constrained in the arrangement direction X by the restraint members 100 from both sides in the arrangement direction X. A heat insulating material 13 is arranged between the end plate 11 and the battery 5 arranged at the end of the arrangement direction X. Further, if the battery structure 10 is restrained in the arranging direction X, another restraining means can be adopted.

As shown in FIG. 1, in the present embodiment, the positions of the reference planes 51 in the vertical direction Z of the plurality of batteries 5 are displaced. In other words, the positions of the reference planes 51 in the vertical direction Z of the batteries 5 do not match. In the present embodiment, there are a plurality of batteries 5 whose reference plane 51 is located at the lowermost end. Similarly, there are a plurality of uppermost batteries 502 whose reference plane 51 is located at the uppermost end. It should be noted that the plurality of batteries 5 are configured such that the positions of the terminals 52 of each battery 5 are aligned with each other when the battery structure 10 is configured. That is, the plurality of batteries 5 are arranged so that the positions of the upper ends of the batteries 5 are aligned in the vertical direction Z. The plurality of batteries 5 are arranged on the upper surface of the heat conducting portion 4 arranged on the upper surface 31 of the heat diffusion portion 3.

The heat diffusion portion 3 is made of aluminum, for example. Note that the heat diffusion portion 3 is not limited to this, and another material may be used as long as it has a higher thermal conductivity than the heat conduction portion 4 described later. Of the plurality of facing portions 311 of the heat diffusion portion 3, the facing portion 311 facing the reference surface 51 of the uppermost end battery 502 in the vertical direction Z is the facing portion facing the reference surface 51 of the lowermost end battery 501 in the vertical direction Z. It is located above 311. Furthermore, in the present embodiment, the intervals in the vertical direction Z between the plurality of facing portions 311 of the heat diffusion portion 3 and the reference surfaces 51 of the plurality of batteries 5 are equal to each other.

As shown in FIGS. 1 and 5, the heat diffusion portion 3 has a base portion 32 and a small area portion 33. The base portion 32 is formed so as to overlap all of the plurality of batteries 5 in the vertical direction Z. The small area portion 33 is arranged on the upper surface of the base portion 32 and has an area smaller than that of the base portion 32 when viewed in the vertical direction Z. The base portion 32 and the small area portion 33 are joined to each other in a heat conductive manner by welding or the like.

The base 32 has a flat plate shape having a thickness in the vertical direction Z. The area of the base 32 when viewed in the vertical direction Z is equal to or larger than the area of the battery structure 10 when viewed in the vertical direction Z. Then, the base 32 is arranged at least in a position where the entire battery structure 10 overlaps in the vertical direction Z.

As shown in FIG. 1, in the present embodiment, the small area portion 33 is arranged so as to overlap the reference surface 51 of one battery 5 in the vertical direction Z. In the present embodiment, the area of the small area portion 33 when viewed in the vertical direction Z is formed to be equal to the area of the reference surface 51, but the present invention is not limited to this, and even if it is larger than the area of the reference surface 51. May be smaller.

The small area portions 33 are appropriately arranged according to how the reference surfaces 51 of the plurality of batteries 5 are displaced in the vertical direction Z. That is, the small area portion 33 is arranged such that the facing portions 311 of the heat diffusion portion 3 and the reference surface 51 of each battery 5 have the same vertical interval Z. In the present embodiment, the small area portions 33 are arranged below the batteries 5 other than the lowest end battery 501 among the plurality of batteries 5. In the region between the batteries 5 and the base 32 in the vertical direction Z, a plurality of small area portions 33 are formed in the thickness direction in a region where the dimension between the batteries 5 and the base 32 in the vertical direction Z is relatively large. Are stacked in. As a result, the position of the upper surface 31 of the heat diffusion portion 3 in the vertical direction Z is adjusted. In the present embodiment, a plurality of small area portions 33 are stacked between the uppermost battery 502 and the base portion 32 in the vertical direction Z. In this embodiment, all the small area portions 33 have the same shape as each other. It should be noted that the plurality of small area portions 33 are not limited to all having the same shape. For example, at least one small area portion 33 and at least one small area portion 33 of the other small area portions 33 while making the areas of the small area portions 33 when viewed in the vertical direction Z equal to each other. In the interval, the dimension in the vertical direction Z may be different from each other. Moreover, the area of each of the plurality of small area portions 33 when viewed in the vertical direction Z is not limited to the same area. Hereinafter, the gap in the vertical direction Z between the plurality of facing portions 311 of the heat diffusion portion 3 and the reference surface 51 of each battery 5 may be referred to as the vertical gap.

Here, the plurality of vertical intervals being equal to each other includes the case where the plurality of vertical intervals are not the same but substantially the same. For example, when the plurality of vertical intervals are substantially the same as each other, and when the design values in the vertical directions are the same value d1, the absolute value of the difference between each vertical interval and the design value d1 is It may be the case where it is 10% or less of the value d1.

The heat conducting portion 4 is arranged between the upper surface 31 of the heat diffusion portion 3 and the reference surface 51 of each battery 5. The heat conduction part 4 is in close contact with the upper surface 31 of the heat diffusion part 3 and the reference surface 51 of each battery 5. In the present embodiment, the heat conducting portion 4 has a shape in which one plate is bent several times in its thickness direction. The heat conducting portion 4 is preferably elastically deformable. Further, the heat conducting portion 4 preferably has electrical insulation. The heat conducting portion 4 can be made of, for example, silicone.

When assembling the battery module 1, for example, the heat conducting portion 4 is first arranged on the upper surface 31 of the heat diffusion portion 3. Next, the reference surfaces 51 of the plurality of batteries 5 in the battery structure 10 are pressed against the heat conducting section 4. As a result, the heat conducting portion 4 is elastically deformed and brought into close contact with the reference surfaces 51 of the plurality of batteries 5 and the upper surface 31 of the heat diffusion portion 3.

As shown in FIG. 4, a region of the heat conducting unit 4 that overlaps the reference planes 51 of the plurality of batteries 5 in the vertical direction Z is defined as an overlapping region 41. The plurality of overlapping regions 41 in the heat conducting portion 4 have the same thickness T. Here, the plurality of overlapping regions 41 having the same thickness T includes the case where the plurality of overlapping regions 41 have substantially the same thickness T, although they are not the same. When the thicknesses T of the plurality of overlapping regions 41 are substantially the same as each other, when the design values of the dimensions of the overlapping regions 41 in the vertical direction Z are set to the same value d2, the vertical direction Z of each overlapping region 41 is The absolute value of the difference between the dimension and the design value d2 may be 10% or less of the design value d2.

As shown in FIG. 1, the overlapping regions 41 in the heat conducting portion 4 are connected by the connecting region 42. The connecting region 42 includes one formed on a surface orthogonal to the vertical direction Z and one formed so as to be inclined with respect to the surface orthogonal to the vertical direction Z. When the positions of the overlapping regions 41 connected by the connecting regions 42 in the vertical direction Z are the same, the connecting regions 42 are formed on a plane orthogonal to the vertical direction Z. On the other hand, if the positions of the overlapping regions 41 connected to the connecting regions 42 in the vertical direction Z are different from each other, the connecting regions 42 are formed to be inclined with respect to the plane orthogonal to the vertical direction Z.

The heat exchanger 2 is in surface contact with the lower surface of the heat diffusion portion 3. As shown in FIG. 3, in the present embodiment, the heat exchanger 2 includes a refrigerant passage 21 for circulating a cooling medium inside. However, the present invention is not limited to this, and the heat exchanger 2 may not have the refrigerant passage 21 inside. The heat exchanger 2 may be in contact with the heat diffusion portion 3, and may be in contact with, for example, the side surface of the heat diffusion portion 3.

Next, the function and effect of this embodiment will be described.
In the battery module 1, at least one of the facing portions 311 facing the reference surface 51 of the batteries 5 other than the lowermost battery 501 among the plurality of batteries 5 in the up-down direction Z is located above and below the reference surface 51 of the lowermost battery 501. It is located above the facing portion 311 facing the direction Z. Therefore, it is possible to suppress variations in the intervals in the vertical direction Z between the reference surfaces 51 of the plurality of batteries 5 and the plurality of facing portions 311 of the upper surface 31 of the heat diffusion portion 3. As a result, it is possible to suppress variations in the thickness of the regions of the heat conduction unit 4 that overlap the reference planes 51 of the plurality of batteries 5 in the vertical direction Z. Therefore, it is possible to suppress variations in the thermal resistance value in the heat transfer path from each battery 5 to the heat diffusion portion 3.

Further, among the plurality of facing portions 311 of the heat diffusion portion 3, the facing portion 311 facing the reference surface 51 of the uppermost end battery 502 in the vertical direction Z faces the reference surface 51 of the lowermost end battery 501 in the vertical direction Z. It is located above the facing portion 311. Therefore, it is easy to reduce the difference in thermal resistance between the overlapping regions 41, which is likely to increase in thermal resistance.

Further, the intervals in the vertical direction Z between the plurality of facing portions 311 of the heat diffusion portion 3 and the reference surfaces 51 of the plurality of batteries 5 are equal to each other. Therefore, it is easy to make the thicknesses T of the plurality of overlapping regions 41 in the heat conducting portion 4 equal to each other. As a result, it is possible to further suppress variation in the thermal resistance value in the heat transfer path from each battery 5 to the heat diffusion portion 3.

Further, the heat diffusion portion 3 has a base portion 32 and a small area portion 33. Thereby, it is easy to appropriately configure the thermal diffusion unit 3 depending on how the reference planes 51 of the plurality of batteries 5 are displaced in the vertical direction Z. That is, by appropriately arranging the small area portion 33 on the upper surface of the base portion 32, the interval in the vertical direction Z between the facing portion 311 of the upper surface 31 of the heat diffusion portion 3 and the reference surface 51 of the plurality of batteries 5 is set to be mutually different. Can be equivalent. Therefore, the productivity of the battery module 1 can be improved.

The plurality of batteries 5 form a battery structure 10. The battery structure 10 is constrained in the arrangement direction X. Therefore, it is possible to prevent the positions of the plurality of batteries 5 in the vertical direction Z from deviating from the pre-use state due to vibrations or shocks generated in the battery module 1 when the battery module 1 is used. As a result, the interval between the reference surface 51 of each battery 5 and the facing portion 311 of the upper surface 31 of the heat diffusion portion 3 in the up-down direction Z changes from time to time from each battery 5 to the heat diffusion portion 3. It is possible to prevent the fluctuation of the thermal resistance value in the heat transfer path. In addition, it is easy to prevent the performance of each battery 5 from changing with time.

As described above, according to the present embodiment, it is possible to provide the battery module that can suppress the variation in the cooling performance of each battery by the heat exchanger.

(Embodiment 2)
As shown in FIG. 6, the present embodiment is an embodiment in which the shape of the small area portion 33 is changed from that of the first embodiment. The small area portion 33 is formed such that the dimension in the vertical direction Z is the same as the dimension in the vertical direction Z between the upper surface of the base portion 32 and the lower surface of the overlapping region 41 of the heat conducting portion 4. That is, in the present embodiment, by adjusting the size of the small area portion 33 in the vertical direction Z, the position of the facing portion 311 of the upper surface 31 of the thermal diffusion portion 3 in the vertical direction Z is adjusted.

Others are the same as in the first embodiment.
In addition, among the reference numerals used in the second and subsequent embodiments, the same reference numerals as those used in the already-described embodiments represent the same components and the like as those in the already-described embodiments, unless otherwise specified.

Also in the present embodiment, the same operational effect as that of the first embodiment is obtained.

(Embodiment 3)
In this embodiment, as shown in FIGS. 7 and 8, the heat diffusion portion 3 is made of one member. For example, the heat diffusion portion 3 is integrally formed by cutting one metal. In other words, the heat diffusion portion 3 is not configured by joining a plurality of members.
Others are the same as in the first embodiment.

In the present embodiment, it is easy to improve the thermal conductivity of the thermal diffusion portion 3. Thereby, the cooling performance of the battery 5 by the heat exchanger 2 can be further improved.
Other than that, the same effects as those of the first embodiment are obtained.

(Embodiment 4)
As shown in FIGS. 9 to 12, the present embodiment is an embodiment in which the heat diffusion portion 3 has a plurality of metal thin plates 34 stacked in the vertical direction Z with the thickness direction being the vertical direction Z. The thin metal plate 34 has flexibility in the vertical direction Z. The thin metal plate 34 is flexible enough to be easily bent when a force in the vertical direction Z is applied from the outside. The thickness of the metal thin plate 34 having flexibility in the vertical direction Z is appropriately selected according to the hardness of the metal that constitutes the metal thin plate 34. In the present embodiment, the metal thin plate 34 has a thickness in the up-down direction Z smaller than that of the heat conducting portion 4.

In this embodiment, the heat exchanger 2 is in contact with the side surface of the heat diffusion portion 3.
In addition, it has the same structure as that of the first embodiment.

Next, an example of a method of manufacturing the battery module 1 of this embodiment will be described.
First, as shown in FIG. 11, a plurality of flat metal thin plates (hereinafter referred to as flat thin plates 340) are laminated in the thickness direction. Then, the heat conducting portion 4 having a constant thickness is arranged on the uppermost surface of the plurality of laminated flat thin plates 340. In this state, the heat conducting portion 4 has a flat shape along the uppermost surface of the flat thin plate 340. Then, the elastically deformable elastic member 15 is arranged on the lowermost surface of the plurality of laminated flat thin plates 340. Then, a high-rigidity plate 16 that is difficult to deform is arranged on the lower surface of the elastic member 15. Here, the structure including the heat conducting portion 4, the plurality of flat thin plates 340, the elastic member 15, and the high-rigidity plate 16 is referred to as a pre-deformation assembly 17.

Then, the plurality of batteries 5 are arranged in the arranging direction X to form the battery structure 10, and are constrained in the arranging direction X by the constraining member 100. Then, the pre-deformation assembly 17 and the battery structure 10 are brought close to each other, and the upper surface of the heat conducting portion 4 of the pre-deformation assembly 17 is brought into contact with the reference surfaces 51 of the plurality of batteries 5 of the battery structure 10. From this state, the pre-deformation assembly 17 is pushed further upward, that is, toward the battery structure 10. As a result, the force that pushes the pre-deformation assembly 17 upward acts on the flat thin plate 340 via the high-rigidity plate 16 and the elastic member 15. As a result, as shown in FIG. 12, the plurality of flat thin plates 340 are deformed into a shape along the reference planes 51 of the plurality of batteries 5 of the battery structure 10, and become the final shape, that is, the shape of the metal thin plate 34 described above. .. At this time, the upper surface of the elastic member 15 is deformed according to the shape change of the lower surfaces of the plurality of flat thin plates 340. As a result, it is easy to uniformly apply a force to the entire flat thin plate 340. Further, as the shape of the flat thin plate 340 changes, the shape of the heat conducting portion 4 also changes to a shape along the upper surface of the flat thin plate 340.
Through the above, the battery module 1 can be manufactured.

In this embodiment, it is easy to improve the productivity of the battery module 1. That is, as described above, by pressing the flat thin plate 340 toward the reference surfaces 51 of the plurality of batteries 5, the thermal diffusion unit 3 can be easily configured.
Other than that, the same effects as those of the first embodiment are obtained.

The present invention is not limited to the above-described embodiments, and can be applied to various embodiments without departing from the spirit of the invention.

For example, in each of the above embodiments, the battery is a lithium ion secondary battery, but the battery is not limited to this, and various batteries can be adopted. For example, the battery may be a nickel hydrogen battery or the like. Further, the battery is not limited to the can type battery, and may be a so-called laminated type battery having an exterior formed of, for example, a laminated film. Further, the battery may be a battery pack in which a plurality of unit cells are housed in a pack case.

Further, in each of the above-described embodiments, the configuration in which the surface on the side opposite to the terminal side of each battery is brought into contact with the heat conducting portion is shown, but the present invention is not limited to this. For example, in the battery, a side surface, which is a surface that is orthogonal to both the protruding direction of the terminal and the thickness direction of the battery, may be used as a reference surface, and the reference surface may be in contact with the heat conducting portion.

DESCRIPTION OF SYMBOLS 1 Battery module 2 Heat exchanger 3 Thermal diffusion part 31 Upper surface of thermal diffusion part 311 Opposing part 4 Thermal conduction part 5 Battery 501 Bottommost battery 51 Reference plane Z Vertical direction

Claims (7)

A heat exchanger (2),
A heat spreader (3) in thermal contact with the heat exchanger;
A heat conducting portion (4) that is in thermal contact with the upper surface (31) of the heat diffusion portion;
A plurality of batteries (5) arranged to be in thermal contact with the heat conducting portion from at least the upper side of the heat conducting portion and to be overlapped with the heat diffusion portion and the heat conducting portion in the vertical direction (Z); Have
The thermal diffusion portion has a higher thermal conductivity than the thermal conduction portion,
When the lower surface of the battery is defined as a reference surface (51), the reference surfaces of the plurality of batteries are arranged at a plurality of vertical positions,
The upper surface of the heat spreader has a plurality of facing portions (311) that vertically face the reference surfaces of the plurality of batteries,
When the battery whose reference surface is located at the lowermost end of the plurality of batteries is defined as the lowermost battery (501), the upper and lower sides of the reference surface of the batteries other than the lowermost battery of the plurality of batteries are defined. At least one of the facing portions facing each other in the direction is located above the facing portion facing in the vertical direction with the reference surface of the lowermost battery ,
The heat diffusion portion is made of metal,
The battery module (1) , wherein the reference surface of each battery is not in contact with the heat diffusion portion . Of the plurality of batteries, the reference surface of the uppermost battery is defined as the uppermost battery (502) when the reference surface is located at the uppermost end. 2. The battery module according to claim 1, wherein the facing portion that faces in the up-down direction is located above the facing portion that faces in the up-down direction with the reference surface of the lowermost battery. The battery module according to claim 1 or 2, wherein the plurality of facing portions of the heat diffusion portion and the reference surfaces of the plurality of batteries have the same vertical spacing. The heat diffusion portion is arranged on the upper surface of the base portion (32) formed to overlap all of the plurality of batteries in the vertical direction, and has an area when viewed in the vertical direction from that of the base portion. Battery module according to any one of claims 1 to 3, having a small small area (33). The battery module according to any one of claims 1 to 3, wherein the heat diffusion portion is made of one member. 4. The heat spreader according to claim 1, wherein the heat spreader has a plurality of metal thin plates (34) stacked in a vertical direction with the thickness direction being a vertical direction, and the metal thin plates are flexible in the vertical direction. The battery module according to any one of claims. 7. The battery structure according to claim 1, wherein the plurality of batteries are arranged in a line direction orthogonal to the vertical direction to form a battery structure (10), and the battery structure is constrained in the line direction. The battery module according to one item.

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