JP7694766B2 - Power storage device and battery pack - Google Patents

Description

This disclosure relates to a battery pack installed in a vehicle.

Patent Document 1 discloses an electrolyte regeneration device for a flow battery. This electrolyte regeneration device is configured to store oxidized or reduced electrolyte in a positive electrode electrolyte storage section and a negative electrode electrolyte storage section. A battery module that includes the flow battery as a unit cell is used as a power source for vehicles, etc.

Special table 2019-533890 publication

For example, it is conceivable to house a positive electrode side device and a negative electrode side device, such as the positive electrode electrolyte storage unit and the negative electrode electrolyte storage unit described in Patent Document 1, together with one or more battery cells in a battery pack case. When such a positive electrode side device and a negative electrode side device are separately constructed and arranged side by side in the case, the battery pack is required to have a structure that can suppress an electrical short circuit between the positive electrode side device and the negative electrode side device when an impact load is applied to the battery pack.

The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide an energy storage device or a battery pack having a simple structure that can suppress an electrical short circuit between a positive side relay and a negative side relay when an impact load acts on the energy storage device or the battery pack.

The power storage device according to the first aspect of the present disclosure is mounted on a vehicle. The power storage device includes a plurality of battery cells, and a positive side relay and a negative side relay arranged apart from each other in the vehicle width direction. The positive side relay and the negative side relay are arranged in a location close to one end of the power storage device relative to the plurality of battery cells in the vehicle front-rear direction. A structural member extending across the vehicle width direction is provided between the positive side relay and the negative side relay and the plurality of battery cells. The positive side relay is arranged on one side of the center of the power storage device in the vehicle width direction, and the negative side relay is arranged on the other side of the center.

In the first aspect, the plurality of battery cells may include battery cell stacks adjacent to each other in a vehicle front-rear direction, and the power storage device may further include a structural member disposed between the adjacent battery cell stacks and extending along the vehicle width direction.

The power storage device according to a second aspect of the present disclosure is mounted on a vehicle. The power storage device includes a plurality of battery cells, and a positive side relay and a negative side relay arranged apart from each other in the vehicle width direction. The positive side relay and the negative side relay and the plurality of battery cells are arranged side by side in the vehicle front-rear direction. The power storage device further includes a structural member arranged between the positive side relay and the negative side relay and the plurality of battery cells and extending across the vehicle width direction. The positive side relay is arranged on one side of the center of the power storage device in the vehicle width direction, and the negative side relay is arranged on the other side of the center.

In a second aspect, the plurality of battery cells may include battery cell stacks adjacent to each other in a vehicle front-rear direction, and the power storage device may further include a structural member disposed between the adjacent battery cell stacks and extending along the vehicle width direction.

A power storage device according to a third aspect of the present disclosure is mounted on a vehicle. The power storage device includes a plurality of battery cells, a positive relay and a negative relay arranged apart from each other in a vehicle width direction, and an end wall formed to surround the plurality of battery cells and the positive relay and the negative relay when viewed from above the vehicle. The positive relay and the negative relay are arranged closer to one end of the end wall in the vehicle front-rear direction than the plurality of battery cells. The power storage device further includes a structural member arranged between the positive relay and the negative relay and the plurality of battery cells and extending across the vehicle width direction. The positive relay is arranged on one side of the center of the end wall in the vehicle width direction, and the negative relay is arranged on the other side of the center.

In a third aspect, the plurality of battery cells may include battery cell stacks adjacent to each other in a vehicle front-rear direction, and the power storage device may further include a structural member disposed between the adjacent battery cell stacks and extending along the vehicle width direction.

A battery pack according to a fourth aspect of the present disclosure is mounted on a vehicle. The battery pack includes a plurality of battery cells, a positive relay and a negative relay arranged apart from each other in a vehicle width direction, and a case that houses the plurality of battery cells and the positive relay and the negative relay. The positive relay and the negative relay are arranged in a location close to one end of the case relative to the plurality of battery cells in the vehicle front-rear direction. The case includes a structural member that is arranged between the positive relay and the negative relay and the plurality of battery cells and extends across the vehicle width direction. The positive relay is arranged on one side of the center of the case in the vehicle width direction, and the negative relay is arranged on the other side of the center.
In a fourth aspect, the plurality of battery cells may include battery cell stacks adjacent to each other in the vehicle front-rear direction, and the battery pack may further include a structural member disposed between the adjacent battery cell stacks and extending along the vehicle width direction.

According to the power storage device or battery pack according to the present disclosure , when an impact load is applied , it is possible to suppress an electrical short circuit between the positive relay and the negative relay with a simple structure.

1 is a diagram illustrating a schematic structure of a battery pack according to an embodiment; 1A to 1C are diagrams for explaining the effects of the structure of the battery pack according to the embodiment. 10 is a diagram illustrating a schematic structure of a battery pack according to a first modified example of the embodiment. FIG. 13 is a diagram illustrating a schematic structure of a battery pack according to a second modified example of the embodiment. FIG.

Below, the embodiments of the present disclosure will be described with reference to the attached drawings. In the embodiments shown below, when the number, quantity, amount, range, etc. of each element is mentioned, the technical idea of the present disclosure is not limited to the mentioned number, unless otherwise specified or clearly specified in principle. Furthermore, the structures, etc. described in the embodiments shown below are not necessarily essential to the technical idea of the present disclosure, unless otherwise specified or clearly specified in principle.

1. Structure of the Battery Pack FIG. 1 is a diagram showing a schematic structure of a battery pack 10 according to an embodiment. The battery pack 10 includes a battery cell 12, a positive side relay 14, a negative side relay 16, and a case 18. The battery cell 12 does not necessarily have to be multiple, and may be one, but basically, as shown in FIG. 1, there are multiple battery cells 12. The case 18 houses the battery cell 12, the positive side relay 14, and the negative side relay 16. The battery pack 10 is mounted on a vehicle and supplies power to an electric motor for driving the vehicle. FIG. 1 shows the internal structure of the battery pack 10 when viewed from above the vehicle.

The case 18 has an approximately rectangular parallelepiped shape as an example. More specifically, the case 18 has an approximately rectangular parallelepiped skeletal structure as a basic structure. The case 18 includes a vehicle mounting portion and is fixed to a vehicle structural member via the vehicle mounting portion. Typically, the case 18 is fastened to the vehicle structural member at the vehicle mounting portion using fasteners such as bolts (not shown), but may be fixed by other methods such as welding. In FIG. 1, only the positive electrode side vehicle mounting portion 20 and the negative electrode side vehicle mounting portion 22 on the vehicle front side, which are part of the vehicle mounting portion, are shown. The vehicle mounting portions 20 and 22 are fastened to a vehicle structural member (e.g., a suspension member) on the vehicle front side via fasteners. The vehicle mounting portions 20 and 22 may be formed integrally with the case 18 or may be separate.

In the battery pack 10, the plurality of battery cells 12 are formed in a plate shape and arranged in a stacked manner. In the example shown in FIG. 1, the stacking direction of the battery cells 12 is parallel to the vehicle width direction (vehicle left-right direction) D1. However, the stacking direction is not particularly limited, and may be parallel to the vehicle front-rear direction D2, for example. In the example shown in FIG. 1, the plurality of battery cells 12 include eight sets of stacks of six battery cells 12 connected in series. These eight sets of stacks are connected in series to form a battery assembly. Each stack of the battery cells 12 is fixed to the case 18 via a pair of end plates (not shown).

The positive relay 14 and the negative relay 16 are aligned along the vehicle width direction D1 and configured as separate units. The positive relay 14 and the negative relay 16 are disposed near one end of the case 18 (the end on the vehicle front side in the example shown in FIG. 1 ) with respect to the multiple battery cells 12 in the vehicle front-rear direction D2 and are fixed to the case 18. In the example shown in FIG. 1 , the vehicle front-rear direction D2 corresponds to an example of the "second direction" according to the present disclosure.

The positive electrode side relay 14 and the negative electrode side relay 16 are, for example , a system main relay . Specifically, the vehicle is equipped with a power control unit (PCU) including an inverter to control the power supplied from the battery pack 10 to the electric motor. The positive electrode side and negative electrode side relays 14, 16 are disposed between the battery assembly of the multiple battery cells 12 and the PCU on the positive electrode side and the negative electrode side, respectively. In the example shown in FIG. 1, the vehicle width direction D1 corresponds to an example of a "first direction" according to the present disclosure.

The case 18 of this embodiment includes a first skeletal structural member 24, a second skeletal structural member 26, a positive electrode side skeletal structural member 28, and a negative electrode side skeletal structural member 30. In the following description, the end wall of the case 18 on the side of the one end (i.e., the end toward the front of the vehicle) is referred to as an end wall 32. The end wall of the case 18 located on the opposite side of the one end in the vehicle longitudinal direction D2 (i.e., the rear side of the vehicle) is referred to as an end wall 34. The end walls 32 and 34 are also included in the skeletal structural members that form the skeleton of the case 18. In the example shown in FIG. 1, the end walls 32 and 34 extend along the vehicle width direction D1.

The second skeletal structural member 26 is disposed between the positive and negative relays 14, 16 and the plurality of battery cells 12 (battery assembly), and extends along the vehicle width direction D1 to form the skeleton of the case 18.

The first skeletal structural member 24 extends in the vehicle front-rear direction D2 between the positive relay 14 and the negative relay 16, and is formed so as to connect between the end wall 32 on the one end side and the "skeletal portion S" of the case 18. In the example shown in FIG. 1, first, the second skeletal structural member 26 corresponds to the skeletal portion S referred to here (the "skeletal portion" according to the present disclosure). That is, the first skeletal structural member 24 connects between the end wall 32 and the second skeletal structural member 26.

In the example shown in FIG. 1, the end wall 34 located on the opposite side of the end wall 32 also corresponds to an example of the skeleton portion S. That is, the first skeleton structural member 24 connects the end wall 32 and the end wall 34. In other words, in the structural example shown in FIG. 1, the first skeleton structural member 24 connects the end wall 32 and the second skeleton structural member 26, and is extended in the vehicle fore-and-aft direction D2 so as to also connect the second skeleton structural member 26 and the end wall 34.

By providing the first and second skeletal structural members 24, 26, when viewed from above the vehicle (i.e., as shown in FIG. 1 ), a skeletal structure can be formed so that the positive relay 14 is surrounded by the outer wall (including the end wall 32) of the case 18 and the first and second skeletal structural members 24, 26. The same applies to the negative relay 16.

In addition, in the example shown in FIG. 1, an additional skeletal structural member 36 is provided between each of the four adjacent stacks of battery cells 12 arranged in the vehicle longitudinal direction. Each skeletal structural member 36 extends along the vehicle width direction D1, similar to the second skeletal structural member 26, to form a skeleton. Therefore, each skeletal structural member 36 can be said to correspond to another example of the skeletal portion S described above.

More specifically, the positive side vehicle mounting portion 20 has a first fixed point P1 with the vehicle at a position away from the end wall 32 in the vehicle longitudinal direction D2 on the side of the positive side relay 14 in the vehicle width direction D1. The positive side skeletal structural member 28 extends along the vehicle longitudinal direction D2 with a straight line L1 that passes through the first fixed point P1 as viewed from above the vehicle and is parallel to the vehicle longitudinal direction D2 as a central axis, and is formed to connect between the end wall 32 and the second skeletal structural member 26. The positive side relay 14 is formed and arranged in a space surrounded by the outer wall (including the end wall 32) of the case 18 and the first and second skeletal structural members 24, 26 so as to avoid the positive side skeletal structural member 28.

Similarly, the negative electrode side vehicle mounting portion 22 has a second fixed point P2 with the vehicle at a position away from the end wall 32 in the vehicle longitudinal direction D2 on the side of the negative electrode side relay 16 in the vehicle width direction D1. The negative electrode side skeletal structural member 30 extends along the vehicle longitudinal direction D2 with a straight line L2 that passes through the second fixed point P2 when viewed from above the vehicle and is parallel to the vehicle longitudinal direction D2 as a central axis, and is formed to connect between the end wall 32 and the second skeletal structural member 26. The negative electrode side relay 16 is formed and arranged in a space surrounded by the outer wall of the case 18 and the first and second skeletal structural members 24, 26 so as to avoid the negative electrode side skeletal structural member 30. The case 18 does not necessarily have to have both the positive electrode side vehicle mounting portion 20 and the negative electrode side vehicle mounting portion 22, and may have only one of them.

2. Effects Fig. 2 is a diagram for explaining the effects of the structure of the battery pack 10 according to the embodiment. More specifically, Fig. 2 shows only the structure around the positive relay 14 and the negative relay 16 in the battery pack 10. Fig. 2 also shows a situation in which a large impact load caused by a collision of the front part of the vehicle acts on the battery pack 10 via the negative vehicle mounting part 22, as an example.

2 is input to the negative vehicle mounting portion 22 in an example not including the first skeletal structural member 24, the case 18 may be crushed so that the end walls 32 move toward the rear of the vehicle on both the positive relay 14 side and the negative relay 16 side, possibly causing damage to both the positive relay 14 and the negative relay 16. As a result, there is a concern that an electrical short circuit may occur between the positive relay 14 and the negative relay 16.

In contrast, the battery pack 10 of the present embodiment includes the first skeletal structural member 24 disposed between the positive relay 14 and the negative relay 16, as described above. The first skeletal structural member 24 extends along the vehicle longitudinal direction D2 (second direction) and connects the end wall 32 and the skeletal portion S of the case 18. As a result, when a large input is applied to the negative vehicle mounting portion 22 from the vehicle longitudinal direction D2 as in the example shown in FIG. 2, the case 18 is deformed as follows. That is, since the first skeletal structural member 24 functions as a reinforcing member, the case 18 is deformed such that a portion of the end wall 32 located on the negative relay 16 side with respect to a connection point P3 between the end wall 32 and the first skeletal structural member 24 in the vehicle width direction D1 (first direction) falls toward the negative relay 16 like a seesaw with the connection point P3 as a fulcrum. Therefore, only the negative relay 16 is damaged, and the case 18 is less likely to be deformed to crush the positive relay 14. That is, the impact on the positive relay 14 is mitigated, and the positive relay 14 is easily protected. This also applies to the case where an impact load is input to the positive vehicle mounting portion 20, which is the opposite of the example shown in Fig. 2, and only the positive relay 14 is damaged, and the negative relay 16 is easily protected. In other words, the resistance of the battery pack 10 to impacts can be improved.

As described above, by providing the first skeletal structural member 24, when an impact load is input to the case 18 from the vehicle front-rear direction D2 on the side of the positive relay 14 or the side of the negative relay 16, it is possible to make it difficult for both the positive relay 14 and the negative relay 16 to be damaged. In this way, according to the structure of the battery pack 10, it is possible to suppress an electrical short circuit between the positive relay 14 and the negative relay 16 with a simple structure.

The above-mentioned effect of utilizing the first skeletal structural member 24 can be obtained even without the second skeletal structural member 26. In addition, the second skeletal structural member 26 extending in the vehicle width direction D1 can form a skeletal structure surrounding each of the positive side relay 14 and the negative side relay 16 in cooperation with the outer wall (including the end wall 32) of the case 18 and the first skeletal structural member 24. This makes it possible to effectively suppress deformation of the case 18 located around the positive side relay 14 or the negative side relay 16 that receives the above-mentioned impact load input from the vehicle front-rear direction D2.

In the example shown in FIG. 1, the first skeletal structural member 24 is connected (extended) to the end wall 34 opposite to the end wall 32 that receives the input of the impact load. As a result, compared to an example shown in FIG. 3 described later in which the first skeletal structural member 44 extends only to the second skeletal structural member 26, the first skeletal structural member 24, to which the input of the impact load from the vehicle longitudinal direction D2 (the vehicle front side in FIG. 1) acts, can be received by using not only the second skeletal structural member 26 but also the end wall 34. In other words, the first skeletal structural member 24 can be more sufficiently prevented from moving toward the rear side of the vehicle due to the input. As a result, it is possible to more effectively prevent the deformation of the case 18 (mainly the end wall 32) caused by the input from affecting the positive side relay 14 or the negative side relay 16 on the non-input side. In addition, in the example shown in FIG. 1, a skeletal structural member 36 extending in the vehicle width direction D1 is provided between the stacks of battery cells 12 adjacent to each other in the vehicle longitudinal direction D2. The first skeletal structural member 24 is also connected to these skeletal structural members 36 which correspond to the skeletal portion S. Therefore, by utilizing the skeletal structural members 36 as well, a structure can be obtained which can more sufficiently withstand the first skeletal structural member 24 against the above-mentioned input.

Furthermore, the case 18 includes a positive electrode side skeletal structural member 28 and a negative electrode side skeletal structural member 30. This makes it possible to support the end wall 32 at a position where the impact load from the vehicle front-rear direction D2 acts, thereby making it possible to more effectively suppress deformation of the case 18 located around the positive electrode side relay 14 or the negative electrode side relay 16 that receives the input of the impact load.

3. Modifications The "first skeletal structural member" according to the present disclosure may be configured, for example, as follows. FIG. 3 is a diagram that shows a schematic structure of a battery pack 40 according to a first modification of the embodiment. The case 42 of the battery pack 40 shown in FIG. 3 includes a first skeletal structural member 44. The first skeletal structural member 44 is configured to connect only between the end wall 32 and the second skeletal structural member 26. That is, the end of the first skeletal structural member 44 in the vehicle longitudinal direction D2 is supported by the second skeletal structural member 26 (skeletal portion S). Therefore, even in such a configuration example, the second skeletal structural member 26 can receive the impact load acting on the first skeletal structural member 24 from the vehicle longitudinal direction D2, and therefore, an effect of suppressing an electrical short circuit between the positive side relay 14 and the negative side relay 16 can be obtained.

Fig. 4 is a diagram showing a schematic structure of a battery pack 50 according to a second modified example of the embodiment. The case 52 of the battery pack 50 shown in Fig. 4 includes the first skeletal structural member 24 like the case 18 shown in Fig. 1, but does not include the second skeletal structural member 26 and the skeletal structural member 36, unlike the case 18. Even in this configuration example, the end wall 34 (skeletal portion S) alone can receive the impact load acting on the first skeletal structural member 24 from the vehicle front-rear direction D2, so that an effect of suppressing an electrical short circuit between the positive relay 14 and the negative relay 16 can be obtained.

In addition, in an example having a skeletal structural member 36 disposed between stacks of adjacent battery cells 12, such as the examples shown in Figures 1 and 3 above, the "first skeletal structural member" according to the present disclosure may be configured to connect to a skeletal structural member 36 corresponding to another example of the "skeletal portion S" instead of the end wall 34 or the second skeletal structural member 26.

1 to 4, the positive relay 14 and the negative relay 16 are disposed near the end wall 32 on the front side of the vehicle. However, instead of such an example, the "positive relay " and the "negative relay " according to the present disclosure may be disposed, for example, near the end wall of the case on the rear side of the vehicle. According to such an example, it is possible to obtain an effect of suppressing an electrical short circuit between the positive relay and the negative relay in response to input of an impact load from the rear side of the vehicle.

Furthermore, in the "battery pack" disclosed herein, the "first direction" is not limited to the vehicle width direction D1, and therefore the "second direction" is not limited to the vehicle front-rear direction.

10, 40, 50 Battery pack 12 Battery cell 14 Positive electrode relay
16 Negative relay
Reference Signs 18, 42, 52 Battery pack case 20 Positive electrode side vehicle mounting portion 22 Negative electrode side vehicle mounting portion 24, 44 First skeletal structural member 26 Second skeletal structural member 28 Positive electrode side skeletal structural member 30 Negative electrode side skeletal structural member 32, 34 End wall 36 Skeletal structural member

Claims (8)

A power storage device mounted on a vehicle,
A plurality of battery cells;
A positive relay and a negative relay arranged apart from each other in a vehicle width direction;
a case that accommodates the plurality of battery cells, the positive relay, and the negative relay;
Equipped with
the positive electrode relay and the negative electrode relay are disposed forward of the plurality of battery cells ,
the positive electrode relay is disposed on one side with respect to a center of the power storage device in the vehicle width direction,
the negative relay is disposed on the other side of the center ,
The case includes a framework member that extends across the vehicle width direction and forms a framework of the case between the positive and negative relays and the plurality of battery cells.
Energy storage device. The power storage device according to claim 1 ,
the plurality of battery cells include battery cell stacks adjacent to each other in a vehicle front-rear direction,
The power storage device further includes a framework member that is disposed between the adjacent battery cell stacks and extends along the vehicle width direction to form a framework of the case . A power storage device mounted on a vehicle,
A plurality of battery cells;
A positive relay and a negative relay arranged apart from each other in a vehicle width direction;
a case that accommodates the plurality of battery cells, the positive relay, and the negative relay;
Equipped with
the positive side relay and the negative side relay and the plurality of battery cells are arranged in line with each other at a front side of a vehicle, and the positive side relay and the negative side relay are arranged in line with each other at a rear side of the vehicle,
the positive electrode relay is disposed on one side with respect to a center of the power storage device in the vehicle width direction,
the negative relay is disposed on the other side of the center ,
The case includes a framework member that extends across the vehicle width direction and forms a framework of the case between the positive and negative relays and the plurality of battery cells.
Energy storage device. The power storage device according to claim 3,
the plurality of battery cells include battery cell stacks adjacent to each other in a vehicle front-rear direction,
The power storage device further includes a framework member that is disposed between the adjacent battery cell stacks and extends along the vehicle width direction to form a framework of the case . A power storage device mounted on a vehicle,
A plurality of battery cells;
A positive relay and a negative relay arranged apart from each other in a vehicle width direction;
an end wall of a case that accommodates the plurality of battery cells, the positive side relay, and the negative side relay, the end wall being formed so as to surround the plurality of battery cells, the positive side relay, and the negative side relay when viewed from above the vehicle;
Equipped with
the positive relay and the negative relay are disposed at a location closer to one end of the end wall at a front portion of the vehicle than the plurality of battery cells ;
the positive relay is disposed on one side with respect to a center of the end wall in the vehicle width direction,
the negative relay is disposed on the other side of the center ,
The case includes a framework member that extends across the vehicle width direction and forms a framework of the case between the positive and negative relays and the plurality of battery cells.
Energy storage device. The power storage device according to claim 5,
the plurality of battery cells include battery cell stacks adjacent to each other in a vehicle front-rear direction,
The power storage device further includes a member that is disposed between the adjacent battery cell stacks, extends along the vehicle width direction, and forms a framework of the case . A battery pack to be mounted on a vehicle,
A plurality of battery cells;
A positive relay and a negative relay arranged apart from each other in a vehicle width direction;
a case that accommodates the plurality of battery cells, the positive relay, and the negative relay;
Equipped with
the positive electrode relay and the negative electrode relay are disposed forward of the plurality of battery cells ,
the positive relay is disposed on one side with respect to a center of the case in the vehicle width direction,
the negative relay is disposed on the other side of the center ,
The case includes a framework member that extends across the vehicle width direction and forms a framework of the case between the positive and negative relays and the plurality of battery cells.
Battery pack. 8. The battery pack according to claim 7,
the plurality of battery cells include battery cell stacks adjacent to each other in a vehicle front-rear direction,
The case further includes a framework member that is disposed between the adjacent battery cell stacks and extends along the vehicle width direction to form a framework of the case .

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