JP7110379B2 - Battery modules and battery packs - Google Patents

Description

The present invention provides a battery module having a plurality of cylindrical cells, a holder formed with a plurality of housing holes, each housing hole housing one cell, and a battery module in an exterior case. The present invention relates to a battery pack containing modules.

Japanese Patent No. 4761726 discloses a battery block assembly in which a plurality of battery blocks each having a plurality of cylindrical batteries connected in series are connected in parallel.

The technique described in Japanese Patent No. 4761726 has a problem that heat tends to stay in the central portion of the battery block assembly.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a battery module and a battery pack capable of suppressing a battery module (battery block assembly) from becoming overheated.

A first aspect of the present invention includes a plurality of cylindrical cells, and a plurality of cells having a substantially rectangular parallelepiped appearance and penetrating a first surface and a second surface facing the first surface. and a holder (for example, a cell holder 26 according to the mode for carrying out the invention described below) in which accommodation holes are formed and one of the cells is accommodated in each of the accommodation holes, the battery module comprising: or the second surface, a terminal portion connected to the electrode of the cell exposed to the outside of the accommodation hole, and a terminal portion integral with the terminal portion and formed by bending with respect to the terminal portion and extending along a side surface continuous with the first surface and the second surface of the holder and arranged so as to be in heat transfer with the side surface.

A second aspect of the present invention is a battery pack containing the above-described battery module in an exterior case, wherein the battery pack is provided on one side of the holder in the first direction, and It has a battery management device connected to the busbar on one side and managing the charging state of the battery module.

According to the battery module and the battery pack of the present invention, it is possible to prevent the battery module from overheating.

1 is a perspective view of a battery pack; FIG. 3 is a perspective view of a first battery module and a second battery module; FIG. 4 is an exploded perspective view of a first battery module and a second battery module; FIG. FIG. 4A is a diagram of the first battery module viewed from the Y-axis negative direction side. FIG. 4B is a diagram of the first battery module viewed from the positive Y-axis side. FIG. 5A is a diagram of the second battery module viewed from the Y-axis negative direction side. FIG. 5B is a diagram of the second battery module viewed from the positive Y-axis side. FIG. 4 is a schematic diagram showing current flow in a first battery module and a second battery module;

[First Embodiment]
[Battery pack configuration]
FIG. 1 is a perspective view of the battery pack 10. FIG. FIG. 2 is a perspective view of the first battery module 12 and the second battery module 14. FIG. The battery pack 10 is mounted on an electric motorcycle or the like and used as a power source. 1 and 2 show X, Y and Z axes that are orthogonal to each other. Also in other drawings described later, the X-axis, Y-axis and Z-axis corresponding to the X-axis, Y-axis and Z-axis of FIGS. 1 and 2 are shown. The battery pack 10 is mounted on an electric motorcycle or the like so that the negative side of the Z-axis faces downward in the direction of gravity. It should be noted that the Z-axis direction does not necessarily have to match the direction of gravity when the battery pack 10 is mounted on the electric motorcycle.

The battery pack 10 is composed of a metal case 16 and a first battery module 12 and a second battery module 14 housed inside the case 16 . The case 16 includes an outer case 18 formed in a cylindrical shape, a top case 20 that closes the opening of the outer case 18 on the Z-axis positive direction side, and a top case 20 that closes the opening of the outer case 18 on the Z-axis negative direction side. It is composed of a bottom case 22 . The bottom case 22 is provided with a connector (not shown) through which the battery pack 10 is connected to an electric motorcycle, a charging device, or the like.

[Configuration of battery module]
FIG. 3 is an exploded perspective view of the first battery module 12 and the second battery module 14. FIG. Each of the first battery module 12 and the second battery module 14 includes a plurality of cells 24, a cell holder 26 that accommodates the cells 24, bus bars 28a to 28p that connect the cells 24, and the first battery module 12 and the second battery module 14. It has a connection bus bar 30 that electrically connects the two battery modules 14 and a battery management device 32 that manages the states of the first battery module 12 and the second battery module 14 .

The cell 24 is a cylindrical lithium ion secondary battery. The single cell 24 is not limited to the lithium ion secondary battery, and may be another secondary battery such as a nickel hydrogen secondary battery or a nickel cadmium secondary battery.

The cell holder 26 has a substantially rectangular parallelepiped appearance, and the cell holder 26 has a substantially rectangular first surface 34 on the Y-axis negative direction side and a substantially rectangular second surface 36 on the Y-axis positive direction side. The long sides (first sides) of the first surface 34 and the second surface 36 are substantially parallel to the Z-axis direction, and hereinafter this direction may be referred to as the first direction. The short sides (second sides) of the first surface 34 and the second surface 36 are substantially parallel to the X-axis direction, and hereinafter this direction may be referred to as the second direction. A plurality of cylindrical accommodation holes 38 are formed in the cell holder 26 so as to penetrate between a first surface 34 and a second surface 36 facing each other in the Y-axis direction. One cell 24 is accommodated in one accommodation hole 38 .

(Configuration of first battery module)
FIG. 4A is a diagram of the first battery module 12 viewed from the Y-axis negative direction side. FIG. 4B is a diagram of the first battery module 12 viewed from the positive Y-axis side.

As shown in FIG. 4A, the unit cells 24 are accommodated in the accommodation holes 38 of the cell holder 26, and the positive electrodes of the unit cells 24 face the negative direction of the Y axis. They are arranged so that the number of lines facing the negative direction side is 18 lines. Further, as shown in FIG. 4B, the unit cells 24 are accommodated in the accommodation holes 38 of the cell holder 26, and the positive electrodes of the unit cells 24 face the positive direction of the Y-axis. They are arranged so that the number of lines facing the positive direction of the Y-axis is 24.

When the first battery module 12 is viewed from the Y-axis negative direction side or the Y-axis positive direction side, the seven cells 24 arranged in a straight line in the first direction are arranged in the second direction. are arranged in 6 rows. Unit cells 24 adjacent in the second direction are arranged with their centers shifted in the first direction.

Of the single cells 24 arranged in a row in the first direction, six cells 24 excluding the single cell 24 arranged at the end on the Z-axis positive direction side are located on the Y-axis negative direction side of the cell holder 26 . Alternatively, the electrodes exposed from the positive side of the Y-axis are arranged so as to have the same polarity.

In addition, among the cells 24 arranged in one row in the first direction, six cells 24 excluding the cell 24 arranged at the end on the Z-axis positive direction side, and these six cells 24 The electrode exposed from the Y-axis negative direction side or the Y-axis positive direction side of the cell holder 26 has a different polarity from the six cells 24 other than the cells 24 arranged at the end of the row adjacent to the row on the Z-axis positive direction side. are arranged so that

Furthermore, the six cells 24 arranged at the end on the Z-axis positive direction side are arranged so that the electrodes exposed from the Y-axis negative direction side or the Y-axis positive direction side of the cell holder 26 have the same polarity.

The first battery module 12 has eight bus bars 28a-28h. The busbars 28a-28h are plate members made of a conductive material.

Busbar 28a is attached to first surface 34 of cell holder 26 (FIG. 4A). Bus bar 28a is formed to extend in the first direction. The bus bar 28a includes a terminal portion 40a formed along the first surface 34 of the cell holder 26, and a side surface of the cell holder 26 in the negative X-axis direction. It has an extending portion 42a formed along the side surface on the direction side. The terminal portion 40a connects the positive electrodes of the six cells 24 in the first row from the X-axis negative direction side in parallel. The extending portion 42a is in contact with the side surface of the cell holder 26 on the negative side of the X axis. The extending portion 42a does not need to be in contact with the side surface of the cell holder 26 in the negative X-axis direction as long as it is arranged so as to be able to conduct heat with the side surface in the negative X-axis direction. Further, the busbar 28a is provided with an electrode portion 44a formed so as to protrude from the cell holder 26 in the Z-axis negative direction.

Busbar 28b is attached to second surface 36 of cell holder 26 (FIG. 4B). Bus bar 28b is formed to extend in the first direction. The bus bar 28b includes a terminal portion 40b formed along the second surface 36 of the cell holder 26, and a side surface on the X-axis negative direction side from the second surface 36 of the cell holder 26. It has an extending portion 42b formed along the side surface on the direction side. The terminal portion 40b connects the negative electrodes of the six cells 24 in the first row from the X-axis negative direction side in parallel, and connects the positive electrodes of the six cells 24 in the second row in parallel. Furthermore, the terminal portion 40b connects in series the negative electrodes of the six cells 24 in the first row from the X-axis negative direction side and the positive electrodes of the six cells 24 in the second row. The extending portion 42b is in contact with the side surface of the cell holder 26 on the negative side of the X axis. The extending portion 42b does not need to be in contact with the side surface of the cell holder 26 in the negative X-axis direction as long as it is arranged so as to be able to conduct heat with the side surface in the negative X-axis direction. Further, the busbar 28b is provided with a connecting portion 46b formed so as to protrude from the cell holder 26 in the Z-axis negative direction.

Busbar 28c is attached to first surface 34 of cell holder 26 (FIG. 4A). Bus bar 28c is formed to extend in the first direction. The bus bar 28c connects in parallel the negative electrodes of the six cells 24 in the second row from the end on the negative side of the X axis, and connects the positive electrodes of the six cells 24 in the third row in parallel. Further, the bus bar 28c connects in series the negative electrodes of the six cells 24 in the second row from the X-axis negative direction side and the positive electrodes of the six cells 24 in the third row. Further, the busbar 28c is provided with a connecting portion 46c formed so as to protrude from the cell holder 26 in the Z-axis negative direction.

A busbar 28d is attached to the second surface 36 of the cell holder 26 (Fig. 4B). Bus bar 28d is formed to extend in the first direction. The bus bar 28d connects in parallel the negative electrodes of the six cells 24 on the third row from the end on the X-axis negative direction side, and connects the positive electrodes of the six cells 24 on the fourth row in parallel. Furthermore, the bus bar 28d connects in series the negative electrodes of the six cells 24 in the third row from the X-axis negative direction side and the positive electrodes of the six cells 24 in the fourth row. Further, the busbar 28d is provided with a connection portion 46d formed so as to protrude from the cell holder 26 in the Z-axis negative direction.

Busbar 28e is attached to first surface 34 of cell holder 26 (FIG. 4A). Bus bar 28e is formed extending in the first direction. The bus bar 28e connects in parallel the negative electrodes of the six cells 24 on the fourth row from the end on the negative side of the X axis, and connects the positive electrodes of the six cells 24 on the fifth row in parallel. Furthermore, the bus bar 28e connects in series the negative electrodes of the six cells 24 in the fourth row from the X-axis negative direction side and the positive electrodes of the six cells 24 in the fifth row. Further, the bus bar 28e is provided with a connecting portion 46e formed so as to protrude from the cell holder 26 in the Z-axis negative direction.

Busbar 28f is attached to second surface 36 of cell holder 26 (FIG. 4B). Bus bar 28f is formed to extend in the first direction. The busbar 28f includes a terminal portion 40f formed along the second surface 36 of the cell holder 26, and a side surface on the positive X-axis side from the second surface 36 of the cell holder 26. It has an extending portion 42f formed along the side surface on the direction side. The terminal portion 40f connects in parallel the negative electrodes of the six cells 24 on the fifth row from the X-axis negative direction side, and connects the positive electrodes of the six cells 24 on the sixth row in parallel. Further, the terminal portion 40f connects in series the negative electrodes of the six cells 24 in the fifth row from the X-axis negative direction side and the positive electrodes of the six cells 24 in the sixth row. The extending portion 42f is in contact with the side surface of the cell holder 26 on the positive side of the X-axis. The extending portion 42f does not need to be in contact with the side surface of the cell holder 26 in the positive X-axis direction as long as it is arranged so as to be able to conduct heat with the side surface in the negative X-axis direction. Further, the busbar 28f is provided with a connecting portion 46f formed so as to protrude from the cell holder 26 in the Z-axis negative direction.

A busbar 28g is attached to the first surface 34 of the cell holder 26 (Fig. 4A). The busbar 28g is formed in a substantially L shape and is composed of a first busbar 28g1 formed extending in a first direction and a second busbar 28g2 formed extending in a second direction. there is The first bus bar 28g1 includes a first terminal portion 40g1 formed along the first surface 34 of the cell holder 26, and a first terminal portion 40g1 that is bent from the first surface 34 of the cell holder 26 toward the side surface in the positive direction of the X axis. , and a first extending portion 42g1 formed along the side surface on the X-axis positive direction side. The first terminal portion 40g1 connects in parallel the negative electrodes of the six cells 24 in the sixth row from the X-axis negative direction side. The first extending portion 42g1 is in contact with the side surface of the cell holder 26 on the positive side of the X axis. It should be noted that the first extending portion 42g1 does not have to contact the side surface of the cell holder 26 on the positive X-axis direction as long as it is arranged so as to be able to conduct heat with the side surface on the negative X-axis direction side. Further, the first bus bar 28g1 is provided with a connecting portion 46g formed so as to protrude from the cell holder 26 in the Z-axis negative direction. The second bus bar 28g2 includes a second terminal portion 40g2 formed along the first surface 34 of the cell holder 26, and a second terminal portion 40g2 that is bent from the first surface 34 of the cell holder 26 toward the side surface in the positive Y-axis direction. , a second extending portion 42g2 formed along the side surface on the Y-axis positive direction side. The second terminal portion 40g2 connects in parallel the positive electrodes of the six cells 24 arranged at the end on the Z-axis positive direction side. The first terminal portion 40g1 and the second terminal portion 40g2 are integrally formed. The positive electrode of the battery 24 is connected in series. The second extending portion 42g2 is in contact with the side surface of the cell holder 26 on the Z-axis positive direction side. It should be noted that the second extending portion 42g2 does not need to be in contact with the side surface of the cell holder 26 in the positive Z-axis direction as long as it is arranged so as to be able to conduct heat with the side surface in the positive Z-axis direction.

Busbar 28h is attached to second surface 36 of cell holder 26 (FIG. 4B). Bus bar 28h is formed to extend in the second direction. The bus bar 28h includes a terminal portion 40h formed along the second surface 36 of the cell holder 26, and a side surface of the cell holder 26 in the positive Z-axis direction. It has an extending portion 42h formed along the side surface on the direction side. The terminal portion 40h connects in parallel the negative electrodes of the six cells 24 arranged at the end on the Z-axis positive direction side. The extending portion 42h is in contact with the side surface of the cell holder 26 on the Z-axis positive direction side. The extending portion 42h need not be in contact with the side surface of the cell holder 26 in the positive Z-axis direction as long as it can be heat-transferred to the side surface in the positive Z-axis direction.

(Configuration of second battery module)
FIG. 5A is a diagram of the second battery module 14 viewed from the Y-axis negative direction side. FIG. 5B is a diagram of the second battery module 14 viewed from the positive Y-axis side.

As shown in FIG. 5A, when the cells 24 are housed in the housing holes 38 of the cell holder 26, the positive electrodes of the cells 24 face the negative direction of the Y axis, and the number of the cells 24 facing the Y axis is 24. They are arranged so that the number of lines facing the negative direction side is 18 lines. Further, as shown in FIG. 5B, the unit cells 24 are housed in the housing holes 38 of the cell holders 26, and the positive electrodes of the unit cells 24 face the positive direction of the Y-axis. They are arranged so that the number of lines facing the positive direction of the Y-axis is 24.

When the second battery module 14 is viewed from the Y-axis negative direction side or the Y-axis positive direction side, seven cells 24 are arranged in a straight line in the first direction, and are arranged in the second direction. are arranged in 6 rows. Unit cells 24 adjacent in the second direction are arranged with their centers shifted in the first direction.

Of the single cells 24 arranged in a row in the first direction, six cells 24 excluding the single cell 24 arranged at the end on the Z-axis positive direction side are located on the Y-axis negative direction side of the cell holder 26 . Alternatively, the electrodes exposed from the positive side of the Y-axis are arranged so as to have the same polarity.

In addition, among the cells 24 arranged in one row in the first direction, six cells 24 excluding the cell 24 arranged at the end on the Z-axis positive direction side, and these six cells 24 The electrode exposed from the Y-axis negative direction side or the Y-axis positive direction side of the cell holder 26 has a different polarity from the six cells 24 other than the cells 24 arranged at the end of the row adjacent to the row on the Z-axis positive direction side. are arranged so that

Furthermore, the six cells 24 arranged at the end on the Z-axis positive direction side are arranged so that the electrodes exposed from the Y-axis negative direction side or the Y-axis positive direction side of the cell holder 26 have the same polarity.

The second battery module 14 has eight bus bars 28i-28p. The busbars 28i-28p are plate members made of a conductive material.

Busbar 28i is attached to second surface 36 of cell holder 26 (FIG. 5B). Bus bar 28i is formed to extend in the first direction. The bus bar 28i includes a terminal portion 40i formed along the second surface 36 of the cell holder 26, and a side surface on the X-axis negative direction side from the second surface 36 of the cell holder 26. It has an extending portion 42i formed along the side surface on the direction side. The terminal portion 40i connects the negative electrodes of the six cells 24 in the first row from the X-axis negative direction side in parallel. The extending portion 42i is in contact with the side surface of the cell holder 26 on the negative side of the X axis. The extending portion 42i does not need to be in contact with the side surface of the cell holder 26 in the negative X-axis direction as long as it is arranged so as to be able to conduct heat with the side surface in the negative X-axis direction. Further, the busbar 28i is provided with an electrode portion 44i formed so as to protrude from the cell holder 26 in the Z-axis negative direction.

Busbar 28j is attached to first surface 34 of cell holder 26 (FIG. 5A). Bus bar 28j is formed extending in the first direction. The bus bar 28j includes a terminal portion 40j formed along the first surface 34 of the cell holder 26, and a side surface on the X-axis negative direction side from the first surface 34 of the cell holder 26. It has an extending portion 42j formed along the side surface on the direction side. The terminal portion 40j connects the positive electrodes of the six cells 24 in the first row from the X-axis negative direction side in parallel, and connects the negative electrodes of the six cells 24 in the second row in parallel. Furthermore, the terminal portion 40j connects in series the positive electrodes of the six cells 24 in the first row from the X-axis negative direction side and the negative electrodes of the six cells 24 in the second row. The extending portion 42j is in contact with the side surface of the cell holder 26 on the negative side of the X axis. It should be noted that the extending portion 42j need not be in contact with the side surface of the cell holder 26 in the negative X-axis direction as long as it is arranged so as to be able to conduct heat with the side surface in the negative X-axis direction. The busbar 28j is also provided with a connecting portion 46j that protrudes from the cell holder 26 in the Z-axis negative direction.

Busbar 28k is attached to second surface 36 of cell holder 26 (FIG. 5B). Bus bar 28k is formed to extend in the first direction. The bus bar 28k connects the positive electrodes of the six cells 24 in the second row from the end on the negative side of the X-axis in parallel, and connects the negative electrodes of the six cells 24 in the third row in parallel. Furthermore, the bus bar 28k connects in series the positive electrodes of the six cells 24 in the second row from the X-axis negative direction side and the negative electrodes of the six cells 24 in the third row. Further, the bus bar 28 k is provided with a connecting portion 46 k that protrudes from the cell holder 26 in the Z-axis negative direction.

Busbar 28l is attached to first surface 34 of cell holder 26 (FIG. 5A). Bus bar 28l is formed to extend in the first direction. The bus bar 28l connects in parallel the positive electrodes of the six cells 24 on the third row from the end on the X-axis negative direction side, and connects the negative electrodes of the six cells 24 on the fourth row in parallel. Furthermore, the bus bar 28l connects in series the positive electrodes of the six cells 24 in the third row from the X-axis negative direction side and the negative electrodes of the six cells 24 in the fourth row. Further, the busbar 28l is provided with a connecting portion 46l formed so as to protrude from the cell holder 26 in the Z-axis negative direction.

Busbar 28m is attached to second surface 36 of cell holder 26 (FIG. 5B). Bus bar 28m is formed to extend in the first direction. The bus bar 28m connects in parallel the positive electrodes of the six cells 24 on the fourth row from the end on the X-axis negative direction side, and connects the negative electrodes of the six cells 24 on the fifth row in parallel. Furthermore, the bus bar 28m connects in series the positive electrodes of the six cells 24 in the fourth row from the X-axis negative direction side and the negative electrodes of the six cells 24 in the fifth row. Further, the busbar 28m is provided with a connecting portion 46m formed so as to protrude from the cell holder 26 in the Z-axis negative direction.

Busbar 28n is attached to first surface 34 of cell holder 26 (FIG. 5A). Bus bar 28n is formed to extend in the first direction. The bus bar 28n includes a terminal portion 40n formed along the first surface 34 of the cell holder 26, and a side surface on the positive X-axis side from the first surface 34 of the cell holder 26. It has an extending portion 42n formed along the side surface on the direction side. The terminal portion 40n connects in parallel the positive electrodes of the six cells 24 on the fifth row from the X-axis negative direction side, and connects the negative electrodes of the six cells 24 on the sixth row in parallel. Furthermore, the terminal portion 40n connects the positive electrodes of the six cells 24 in the fifth row from the X-axis negative direction side and the negative electrodes of the six cells 24 in the sixth row in series. The extending portion 42n is in contact with the side surface of the cell holder 26 on the positive side of the X-axis. It should be noted that the extending portion 42n need not be in contact with the side surface of the cell holder 26 in the positive X-axis direction as long as it is arranged so as to be able to conduct heat with the side surface in the positive X-axis direction. Further, the busbar 28n is provided with a connecting portion 46n formed so as to protrude from the cell holder 26 in the Z-axis negative direction.

A busbar 28o is attached to the second surface 36 of the cell holder 26 (Fig. 5B). The busbar 28o is formed in a substantially L shape and is composed of a first busbar 28o1 formed extending in a first direction and a second busbar 28o2 formed extending in a second direction. there is The first bus bar 28o1 includes a first terminal portion 40o1 formed along the second surface 36 of the cell holder 26, and a first terminal portion 40o1 that is bent from the second surface 36 of the cell holder 26 toward the side surface in the positive direction of the X axis. , and a first extending portion 42o1 formed along the side surface on the X-axis positive direction side. The first terminal portion 40o1 connects the positive electrodes of the six cells 24 in the sixth row from the X-axis negative direction side in parallel. The first extending portion 42o1 is in contact with the side surface of the cell holder 26 on the X-axis positive direction side. The first extending portion 42o1 does not have to contact the side surface of the cell holder 26 in the positive X-axis direction as long as it is arranged so as to be able to conduct heat with the side surface in the positive X-axis direction. In addition, the first bus bar 28o1 is provided with a connecting portion 46o formed so as to protrude from the cell holder 26 in the Z-axis negative direction. The second bus bar 28o2 includes a second terminal portion 40o2 formed along the second surface 36 of the cell holder 26, and a second terminal portion 40o2 that is bent from the second surface 36 of the cell holder 26 toward the side surface on the Z-axis positive direction side. , a second extending portion 42o2 formed along the side surface on the Z-axis positive direction side. The second terminal portion 40o2 connects in parallel the negative electrodes of the six cells 24 arranged at the end on the Z-axis positive direction side. The second extending portion 42o2 is in contact with the side surface of the cell holder 26 on the Z-axis positive direction side. It should be noted that the second extending portion 42o2 need not be in contact with the side surface of the cell holder 26 in the positive Z-axis direction as long as it is arranged so as to be able to conduct heat with the side surface in the positive Z-axis direction.

The first terminal portion 40o1 and the second terminal portion 40o2 are integrally formed. is connected in series with the negative electrode of

Busbar 28p is attached to first surface 34 of cell holder 26 (FIG. 5A). Bus bar 28p is formed to extend in the second direction. The bus bar 28p includes a terminal portion 40p formed along the first surface 34 of the cell holder 26, and a side surface of the cell holder 26 in the positive Z-axis direction. It has an extending portion 42p formed along the side surface on the direction side. The terminal portion 40p connects in parallel the positive electrodes of the six cells 24 arranged at the end on the Z-axis positive direction side. The extending portion 42p is in contact with the side surface of the cell holder 26 on the Z-axis positive direction side. Note that the extending portion 42p does not have to contact the side surface of the cell holder 26 on the positive Z-axis direction as long as it is arranged so as to be able to conduct heat with the side surface on the Z-axis positive direction side.

(Connection between first battery module and second battery module)
Extending portion 42 h of bus bar 28 h of first battery module 12 and extending portion 42 p of bus bar 28 p of second battery module 14 are electrically connected by connecting bus bar 30 . Thereby, the first battery module 12 and the second battery module 14 are connected in series.

(Connection between first battery module and second battery module and battery management device)
The battery management device 32 is provided on the Z-axis negative direction side of the first battery module 12 and the second battery module 14 . The first battery module 12 and the battery management device 32 are connected by a connecting portion 46b of the busbar 28b, a connecting portion 46c of the busbar 28c, a connecting portion 46d of the busbar 28d, a connecting portion 46e of the busbar 28e, a connecting portion 46f of the busbar 28f, and a busbar 28g. are connected via a connecting portion 46g. The second battery module 14 and the battery management device 32 are connected by a connection portion 46j of the busbar 28j, a connection portion 46k of the busbar 28k, a connection portion 46l of the busbar 28l, a connection portion 46m of the busbar 28m, a connection portion 46n of the busbar 28n, and a busbar 28o. are connected via the connecting portion 46o of the .

(Structure of heat transfer sheet)
As shown in FIGS. 2 and 3, a heat transfer sheet 48 is provided between the exterior case 18 and the busbars 28a-28p. The heat transfer sheet 48 has insulating properties to prevent short circuits between the busbars 28a to 28p and the metallic outer case 18, and is made of a material that has thermal conductivity from the busbars 28a to 28p to the outer case 18. formed.

[Current flow in the battery pack]
In the battery pack 10, each of the first battery module 12 and the second battery module 14 constitutes one assembled battery, and the first battery module 12 and the second battery module 14 are connected in series by the connecting bus bar 30 as described above. It is

FIG. 6 is a schematic diagram showing current flows in the first battery module 12 and the second battery module 14. As shown in FIG. The current flows through the battery pack 10 as follows: busbar 28i→busbar 28j→busbar 28k→busbar 28l→busbar 28m→busbar 28n→busbar 28o→busbar 28p→connected busbar 30→busbar 28h→busbar 28g→busbar 28f→busbar 28e→busbar. 28d→busbar 28c→busbar 28b→busbar 28a. Therefore, electrode portion 44 a of bus bar 28 a serves as the positive electrode of first battery module 12 and second battery module 14 , and electrode portion 44 i of bus bar 28 i serves as the negative electrode of first battery module 12 and second battery module 14 .

[Effect]
A plurality of unit cells 24 are connected in parallel, and the plurality of unit cells 24 connected in parallel are regarded as a set, and a first battery module 12 and a second battery are formed as an assembled battery in which a plurality of sets of unit cells 24 are connected in series. By constructing the module 14, the voltage of the battery pack 10 can be increased and the capacity can be increased.

However, heat tends to accumulate inside the first battery module 12 and the second battery module 14 configured as an assembled battery as described above, which may accelerate the deterioration of the cells 24 .

Therefore, in the present embodiment, the busbars 28a, 28b, 28f, 28g, and 28h of the first battery module 12 are formed along side surfaces continuous with the first surface 34 and the second surface 36 of the cell holder 26, Extending portions 42a, 42b, 42f, 42g1, 42g2, and 42h are provided so as to be heat transferable with the side surfaces. Similarly, the busbars 28i, 28j, 28n, 28o, 28p of the second battery module 14 are formed along side surfaces that are continuous with the first surface 34 and the second surface 36 of the cell holder 26 to provide heat transfer with the side surfaces. Possibly arranged extensions 42i, 42j, 42n, 42o1, 42o2, 42p are provided.

As a result, in the first battery module 12, heat is normally transferred from the first surface 34 and the second surface 36 of the cell holder 26 to which the busbars 28a-28h are attached to the busbars 28a-28h. Heat is transferred to the extensions 42a, 42b, 42f, 42g1, 42g2, 42h from the side surfaces that are continuous with the first surface 34 and the second surface 36, respectively. Furthermore, heat is transferred to the exterior case 18 from the extensions 42a, 42b, 42f, 42g1, 42g2, and 42h. The heat transferred to the exterior case 18 is released to the outside. Therefore, it is possible to suppress the deterioration of the unit cells 24 by suppressing the high temperature inside the first battery module 12 . Similarly, in the second battery module 14 as well, heat is transferred from the side surface continuous with the first surface 34 and the second surface 36 to the extensions 42i, 42j, 42n, 42o1, 42o2, 42p. Furthermore, heat is transferred to the exterior case 18 from the extensions 42i, 42j, 42n, 42o1, 42o2, and 42p. The heat transferred to the exterior case 18 is released to the outside. It is possible to suppress the deterioration of the cell 24 by suppressing the high temperature inside the second battery module 14 .

Further, in the present embodiment, the battery management device 32 is provided on the Z-axis negative direction side of the first battery module 12 and the second battery module 14, and the battery management device 32 and the bus bars 28b, 28c of the first battery module 12, 28d, 28e, 28f and 28g are connected, and the battery management device 32 and the bus bars 28j, 28k, 28l, 28m, 28n and 28o of the second battery module 14 are connected.

Although the bottom case 22 needs to be provided with a connector (not shown), the provision of the connector creates an empty space in the bottom case 22 . In this embodiment, the empty space of the bottom case 22 can be used to accommodate the battery management device 32, so that the battery pack 10 can be made smaller.

Further, in the present embodiment, a heat transfer sheet 48 is provided between the busbars 28a to 28p and the outer case 18 made of metal. As a result, heat can be transferred from the busbars 28a to 28p to the exterior case 18 while preventing short circuits between the busbars 28a to 28p and the exterior case 18 .

[Modification]
Although the case 16 is made of metal in the first embodiment, it may be made of resin. When the case 16 is made of resin, the heat transfer sheet 48 may not be provided between the busbars 28a to 28p and the exterior case 18. FIG. In this case, the busbars 28a to 28p may be arranged so as to be heat transferable with the exterior case 18. As shown in FIG.

DESCRIPTION OF SYMBOLS 10... Battery pack 12, 14... Battery module 24... Cell holder 28a-28p... Bus bar 34... First surface 36... Second surface 38... Accommodating holes 40a, 40b, 40f, 40g1, 40g2, 40h, 40i, 40j, 40n, 40o1, 40o2 Terminal portions 42a, 42b, 42f, 42g1, 42g2, 42h, 42i, 42j, 42n, 42o1, 42o2, 42p Extension portion 48 Heat transfer sheet (heat transfer member)

Claims (10)

a plurality of cylindrical cells (24);
A plurality of accommodation holes (38) are formed through a first surface (34) and a second surface (36) opposed to the first surface (36), which have a substantially rectangular parallelepiped appearance. a holder (26) in which one cell is accommodated in the accommodation hole;
A battery module (12) comprising:
A plurality of bus bars (28a, 28b, 28f, 28g, 28h) are attached to the holder,
Each of the plurality of bus bars has terminal portions (40a, 40b, 40f, 40g1, 40g2, 40h), which is integral with the terminal portion, is formed by bending with respect to the terminal portion, and extends along a side surface continuous with the first surface and the second surface of the holder. and extending portions (42a, 42b, 42f, 42g1, 42g2, 42h) formed and disposed in heat transfer with the side surface. a plurality of cylindrical cells (24);
A plurality of accommodation holes (38) are formed through a first surface (34) and a second surface (36) opposed to the first surface (36), which have a substantially rectangular parallelepiped appearance. a holder (26) in which one cell is accommodated in the accommodation hole;
A battery module (12) comprising:
A plurality of bus bars (28a, 28b, 28f, 28g, 28h) are attached to the holder,
The plurality of busbars are a first busbar (28a), a second busbar (28b), a third busbar (28f), a fourth busbar (28h) and a fifth busbar (28g),
The first bus bar has a first terminal portion (40a) connected to the electrode of the unit cell exposed to the outside of the receiving hole on the first surface, and is integrated with the first terminal portion. It is bent with respect to the first terminal portion and is formed to extend along a third surface that is continuous with the first surface and the second surface of the holder. a first extension portion (42a), which is an extension portion arranged so as to be heat transferable;
The second bus bar, on the second surface, has a second terminal portion (40b) connected to the electrode of the cell exposed to the outside of the receiving hole, and is integrated with the second terminal portion, A second extension portion that is bent with respect to the second terminal portion, is formed to extend along the third surface of the holder, and is disposed so as to be heat-transferable with the third surface. 2 extensions (42b),
The third bus bar includes, on the second surface, a third terminal portion (40f) connected to the electrode of the cell exposed to the outside of the accommodation hole, and integral with the third terminal portion, It is formed to be bent with respect to the third terminal portion, is formed to extend along a fourth surface facing the third surface of the holder, and is arranged so as to be heat transferable with the fourth surface. and a third extension portion (42f) that is an extension portion that
The fourth bus bar includes, on the second surface, a fourth terminal portion (40h) connected to the electrode of the cell exposed to the outside of the accommodation hole, and integral with the fourth terminal portion, along a fifth surface that is bent with respect to the fourth terminal portion and that is continuous with the first surface, the second surface, the third surface, and the fourth surface of the holder; a fourth extension portion (42h) that is an extension portion that is formed so as to extend through and is disposed so as to be heat-transferable with the fifth surface;
The fifth bus bar is integrated with the fifth terminal portions (40g1, 40g2) connected to the electrodes of the cells exposed to the outside of the housing holes on the first surface, and the fifth terminal portions. , an extension portion that is bent with respect to the fifth terminal portion and that is formed to extend along the fourth surface of the holder so as to be heat-transferable with the fourth surface; A certain fifth extension portion (42g1) is integral with the fifth terminal portion, is formed to be bent with respect to the fifth terminal portion, and extends along the fifth surface of the holder. and a sixth extending portion (42g2) that is an extending portion that is formed so as to be heat communicable with the fifth surface. a plurality of cylindrical cells (24);
A plurality of accommodation holes (38) are formed through a first surface (34) and a second surface (36) opposed to the first surface (36), which have a substantially rectangular parallelepiped appearance. a holder (26) in which one cell is accommodated in the accommodation hole;
A battery module (12) comprising:
A plurality of busbars (28a, 28b, 28c, 28d, 28e, 28f, 28g, 28h) are attached to the holder,
Each bus bar has terminal portions (40a, 40b, 40c, 40d, 40e, 40f, 40g1) connected to the electrodes of the cells exposed to the outside of the housing holes on the first surface or the second surface. , 40g2, 40h) and along side surfaces that are integral with the terminal portion, are bent with respect to the terminal portion, and are continuous with the first surface and the second surface of the holder. an extension portion (42a, 42b, 42c, 42d, 42e, 42f, 42g1, 42g2, 42h) formed to extend along the side surface and arranged so as to be heat transferable with the side surface;
When the holder is viewed from the first surface or the second surface,
At least a portion (28g) of the plurality of bus bars are arranged in a first direction substantially parallel to the first sides of the first surface and the second surface, The battery module is formed in a substantially L shape extending in a second direction substantially parallel to a second side which is a side of the second surface and substantially orthogonal to the first side. The battery module according to claim 1 or 2,
When the holder is viewed from the first surface or the second surface,
At least some of the plurality of bus bars are arranged in a first direction substantially parallel to the first sides of the first surface and the second surface, and the first surface and the second surface. and extending in a second direction substantially parallel to a second side substantially perpendicular to the first side. The battery module according to any one of claims 1 to 4,
When the holder is viewed from the first surface or the second surface,
The battery module, wherein at least some of the plurality of bus bars are formed to extend in a first direction substantially parallel to first sides of the first surface and the second surface. The battery module according to any one of claims 3, 4 and 5,
When the holder is viewed from the first surface or the second surface,
At least some of the plurality of bus bars extend in a second direction substantially parallel to a second side that is a side of the first surface and the second surface and that is substantially orthogonal to the first side. A battery module formed to extend. A battery pack (10) containing the battery module according to any one of claims 1 to 6 in an exterior case (18). A battery pack containing the battery module according to any one of claims 1 to 6 in an exterior case,
provided on one side of the holder in a first direction substantially parallel to the first sides of the first surface and the second surface, and connected to the bus bar on one side of the holder in the first direction; A battery pack having a battery management device (32) that connects and manages the state of charge of the battery modules. The battery pack according to claim 7 or 8,
The exterior case is made of resin,
The battery pack, wherein the extending portion of the bus bar is arranged so as to be heat communicable with the exterior case. The battery pack according to claim 7 or 8,
The exterior case is made of metal,
A battery pack comprising a thermally conductive member (48) having insulating and thermally conductive properties between the busbar and the exterior case.

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