Electric storage device

Abstract

To provide an energy storage device that has a hierarchical structure including multiple floors and is capable of suppressing heat damage.SOLUTION: The energy storage device has a hierarchical structure including multiple floors. The energy storage device includes: battery stacks arranged on one of multiple floors; and a heat shield member arranged to face the battery stack between the upper floor located above that floor and the battery stack.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a power storage device having a hierarchical structure including a plurality of levels.

Background Art

[0002] Patent Document 1 discloses an in-vehicle battery pack. The in-vehicle battery pack includes two battery stacks arranged in two upper and lower stages inside a casing.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The inventor of the present application has first recognized the following problems regarding a power storage device having a hierarchical structure including a plurality of levels. That is, in the case of a hierarchical structure, the influence of heat generated at a certain level is likely to spread to the upper levels. For example, when thermal runaway occurs in a battery cell of a battery stack arranged at a certain level, high-temperature gas is generated from the battery cell, and there is a risk that the high-temperature gas will cause heat damage to components arranged at the upper level.

[0005] One object of the present disclosure is to provide a technique capable of suppressing heat damage in a power storage device having a hierarchical structure including a plurality of levels.

Means for Solving the Problems

[0006] The first aspect relates to a power storage device having a hierarchical structure including a plurality of levels. The power storage device includes a battery stack arranged at a certain level among a plurality of levels, and Between an upper floor located above a certain floor and a battery stack, a heat insulating member arranged to face the battery stack is provided.

[0007] The second aspect further has the following features in addition to the first aspect. The power storage device further includes a heat insulating layer between the heat insulating member and the upper floor.

[0008] The third aspect further has the following features in addition to the second aspect. The heat insulating layer is an air layer.

[0009] The fourth aspect further has the following features in addition to any one of the first to third aspects. The floor of the upper floor is an aluminum member.

[0010] The fifth aspect further has the following features in addition to any one of the first to fourth aspects. The heat insulating member is iron.

[0011] The sixth aspect further has the following features in addition to any one of the first to fifth aspects. The power storage device further includes a floor heat insulating member arranged between the floor of the upper floor and the components installed thereon.

Advantages of the Invention

[0012] According to the first aspect, the heat insulating member is arranged to face the battery stack between the battery stack on a certain floor and the upper floor. This heat insulating member suppresses heat transfer to the upper floor. Therefore, even if a thermal runaway occurs in the battery stack and high-temperature gas is generated, the influence of the heat of the high-temperature gas on the upper floor is suppressed. That is, heat damage to the upper floor is suppressed.

[0013] According to the second aspect, the heat insulating layer is interposed between the heat insulating member and the upper floor. This heat insulating layer suppresses direct heat conduction from the heat insulating member heated by the high-temperature gas to the floor of the upper floor. Therefore, heat damage to the upper floor is further suppressed.

[0014] According to the third aspect, it is possible to realize the heat insulating layer at low cost.

[0015] According to the fourth aspect, the upper floor is made of aluminum members. As described above, since the influence of the heat of the high-temperature gas on the upper floor is suppressed, aluminum members can be actively adopted as the upper floor. By using aluminum members, it is possible to reduce the weight of the power storage device while ensuring rigidity. In addition, since the power storage device has a hierarchical structure, the floor area is reduced and the power storage device becomes compact. A lightweight and compact power storage device is preferable from the viewpoint of portability.

[0016] According to the fifth aspect, it is possible to realize the heat shielding member at low cost.

[0017] According to the sixth aspect, a floor heat shielding member is disposed between the upper floor and the components thereon. Thereby, the heat transfer from the lower floor to the components is further suppressed. That is, the heat damage to the components disposed on the upper floor is further suppressed.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

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Figure 4

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Figure 8

Best Mode for Carrying Out the Invention

[0019] Embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0020] 1. Energy storage device having a hierarchical structure FIG. 1 is a schematic diagram showing an example of a battery pack 1 which is an energy storage device. The battery pack 1 has one or more battery stacks 20. One battery stack 20 is configured by stacking a large number of battery cells. For example, the battery stack 20 is a lithium-ion battery.

[0021] The battery pack 1 shown in FIG. 1 has a hierarchical structure including a plurality of levels. And two or more battery stacks 20 are arranged on each of two or more levels. That is, a plurality of battery stacks 20 are dispersedly arranged on different levels. Such a hierarchical structure contributes to reducing the floor area of the battery pack 1 and is preferable from the viewpoint of portability.

[0022] In the following description, the Z direction is the stacking direction of a plurality of levels. Typically, the Z direction is the vertical direction. The XY plane is a horizontal plane orthogonal to the Z direction.

[0023] In the example shown in FIG. 1, the battery pack 1 has a three-level structure composed of the first level LV1 to the third level LV3. The first level LV1 to the third level LV3 are stacked in order in the Z direction. That is, the second level LV2 is located above the first level LV1, and the third level LV3 is located above the second level LV2. In the first level LV1, the battery stack 20-1 is arranged on the floor 10-1. In the second level LV2, the battery stack 20-2 is arranged on the floor 10-2. In the third level LV3, the high-voltage component 30 is arranged on the floor 10-3.

[0024] The casing (housing) of the battery pack 1 including the beds 10-1 to 10-3 is a metal member. For example, the casing of the battery pack 1 is an aluminum member such as an aluminum alloy. By using an aluminum member, it is possible to reduce the weight of the battery pack 1 while ensuring rigidity. The battery pack 1 having a hierarchical structure and containing a large amount of aluminum member is lightweight and compact, and is preferable from the viewpoint of portability.

[0025] 2. Suppression of heat damage The inventor of the present application has first recognized the following problems regarding the battery pack 1 having the hierarchical structure as described above. That is, in the case of a hierarchical structure, the influence of heat generated at a certain level easily spreads to the upper level.

[0026] For example, FIG. 2 shows a case where thermal runaway occurs in the battery cells of the battery stack 20-1 arranged on the first floor LV1. In this case, high-temperature gas is generated from the battery stack 20-1, and the high-temperature gas blows onto the bed 10-2 on the second floor LV2. As a result, the temperature of the bed 10-2 on the second floor LV2 rises, and the temperature of the battery stack 20-2 arranged above the bed 10-2 also rises. In this way, the heat caused by the thermal runaway of the battery stack 20-1 on the first floor LV1 is transmitted to the second floor LV2, and heat damage is applied to the battery stack 20-2 on the second floor LV2. If unacceptable heat damage is applied to the battery stack 20-2, there is a possibility that thermal runaway may also occur in the battery stack 20-2.

[0027] In particular, when an aluminum member is used as the bed 10-2 for weight reduction, the heat of the first floor LV1 easily spreads to the second floor LV2. In addition, there is also a possibility that the aluminum member bed 10-2 may melt due to the high-temperature gas. If the bed 10-2 melts, there is a possibility that the high-temperature gas may directly flow from the first floor LV1 into the second floor LV2.

[0028] As another example, FIG. 3 shows a case where thermal runaway occurs in the battery cells of the battery stack 20-2 disposed on the second floor LV2. In this case, high-temperature gas is generated from the battery stack 20-2, and the high-temperature gas blows onto the floor 10-3 of the third floor LV3. As a result, the temperature of the floor 10-3 of the third floor LV3 rises, and the temperature of the high-voltage component 30 disposed above the floor 10-3 also rises. In this way, the heat caused by the thermal runaway of the battery stack 20-2 on the second floor LV2 is transmitted to the third floor LV3, and heat damage is applied to the high-voltage component 30 on the third floor LV3. When unacceptable heat damage is applied to the high-voltage component 30, there is a risk that a protective member such as a coating will melt and a short circuit will occur.

[0029] In particular, when an aluminum member is used as the floor 10-3 for weight reduction, the heat from the second floor LV2 is likely to be transmitted to the third floor LV3. Also, there is a risk that the aluminum member floor 10-3 will melt due to the high-temperature gas. If the floor 10-3 melts, there is a risk that the high-temperature gas will flow directly from the second floor LV2 into the third floor LV3.

[0030] A chain reaction from the state shown in FIG. 2 to the state shown in FIG. 3 can also occur. That is, thermal runaway occurs in the battery stack 20-1 on the first floor LV1, and the high-temperature gas generated from the battery stack 20-1 causes heat damage to the second floor LV2. As a result, thermal runaway also occurs in the battery stack 20-2 on the second floor LV2, and the high-temperature gas generated from the battery stack 20-2 causes heat damage to the third floor LV3. Due to such a chain reaction, there is a risk that the inside of the battery pack 1 will become even hotter and under higher pressure.

[0031] Therefore, the present embodiment proposes a technique capable of suppressing heat damage in the battery pack 1 having a hierarchical structure.

[0032] FIG. 4 is a schematic diagram for explaining an example of the battery pack 1 according to the present embodiment. The battery pack 1 according to the present embodiment includes a heat insulating member 40-i for blocking heat transfer from the lower floor LVi (i = 1, 2) to the upper floor LV(i + 1). More specifically, the heat insulating member 40-i is disposed so as to face the battery stack 20-i between the battery stack 20-i disposed on the lower floor LVi and the upper floor LV(i + 1). For example, the heat insulating member 40-i is a plate-shaped heat insulating plate, which is substantially parallel to the XY plane and disposed over the entire surface. Thereby, even if a thermal runaway occurs in the battery stack 20-i and high-temperature gas is generated, it is suppressed that the high-temperature gas blows onto the floor 10-(i + 1) of the upper floor LV(i + 1). That is, heat transfer from the lower floor LVi to the upper floor LV(i + 1) is suppressed. As a result, heat damage to the components disposed on the upper floor LV(i + 1) is suppressed.

[0033] For example, a heat insulating member 40-1 is disposed between the battery stack 20-1 on the first floor LV1 and the floor 10-2 on the second floor LV2. The heat insulating member 40-1 blocks heat from the first floor LV1 to the second floor LV2. Even if a thermal runaway occurs in the battery stack 20-1 on the first floor LV1 and high-temperature gas is generated, it is suppressed that the high-temperature gas blows onto the floor 10-2 of the second floor LV2. Thereby, heat damage to the battery stack 20-2 disposed on the second floor LV2 is suppressed.

[0034] As another example, a heat insulating member 40-2 is disposed between the battery stack 20-2 on the second floor LV2 and the floor 10-3 on the third floor LV3. The heat insulating member 40-2 blocks heat from the second floor LV2 to the third floor LV3. Even if a thermal runaway occurs in the battery stack 20-2 on the second floor LV2 and high-temperature gas is generated, it is suppressed that the high-temperature gas blows onto the floor 10-3 of the third floor LV3. Thereby, heat damage to the high-voltage component 30 disposed on the third floor LV3 is suppressed.

[0035] The heat insulation member 40 is designed not to melt away by the high-temperature gas resulting from the thermal runaway of the battery stack 20-i. In that sense, the heat insulation member 40 can also be called a "heat-resistant member". Typically, the heat insulation member 40 is a metal member. For example, the heat insulation member 40 is an iron member. When the heat insulation member 40 is a heat insulation plate, for example, the heat insulation plate is an iron plate. By using iron, the heat insulation member 40 can be realized at low cost. However, the heat insulation member 40 is not limited to iron. Any material that is resistant to high temperatures can be used as the heat insulation member 40. For example, the heat insulation member 40 may be a thick aluminum plate that does not melt away.

[0036] FIG. 5 is a schematic diagram for explaining another example of the battery pack 1 according to the present embodiment. When the heat insulation member 40-i is in direct contact with the floor 10-(i + 1) of the upper floor LV(i + 1), direct heat conduction occurs from the heat insulation member 40-i heated by the high-temperature gas to the floor 10-(i + 1). In order to prevent such direct heat conduction from the heat insulation member 40-i to the floor 10-(i + 1) of the upper floor LV(i + 1), it is preferable that a heat insulation layer 50-i is interposed between the heat insulation member 40-i and the upper floor LV(i + 1). By such a heat insulation layer 50-i, heat damage to the components arranged on the upper floor LV(i + 1) is further suppressed.

[0037] The heat insulation layer 50 is, for example, an air layer. The heat insulation layer 50 can be realized at low cost by the air layer. As another example, the heat insulation layer 50 may be constituted by a heat insulation member such as glass fiber. By forming the heat insulation layer 50 using a heat insulation member, the heat insulation property is further improved.

[0038] As described above, according to the present embodiment, heat transfer from a certain floor LVi to the upper floor LV(i + 1) is suppressed. Even if thermal runaway occurs in the battery stack 20-i on a certain floor LVi and high-temperature gas is generated, the influence of the heat of the high-temperature gas on the upper floor LV(i + 1) is suppressed. That is, heat damage to the components arranged on the upper floor LV(i + 1) is suppressed. Thereby, the components arranged on the upper floor LV(i + 1) are protected.

[0039] In addition, since heat damage to the components arranged on the upper floor LV(i + 1) is suppressed, it becomes possible to actively adopt an aluminum member as the floor 10-(i + 1) of the upper floor LV(i + 1). By using the aluminum member, it becomes possible to reduce the weight of the battery pack 1 while ensuring rigidity. Further, since the battery pack 1 has a hierarchical structure, the floor area is reduced and the battery pack 1 becomes compact. The lightweight and compact battery pack 1 is preferable from the viewpoint of portability.

[0040] 3. Configuration Example FIG. 6 is a perspective view showing a configuration example of the battery pack 1 according to the present embodiment.

[0041] The first floor LV1 includes a floor 10-1, a heat insulating paper 15-1, a battery stack 20-1, and a heat insulating member 40-1. The floor 10-1 is substantially parallel to the XY plane. For example, the floor 10-1 is an aluminum member. The battery stack 20-1 is disposed on the floor 10-1 via the heat insulating paper 15-1 (heat insulating member on the floor). In other words, the heat insulating paper 15-1 is disposed between the floor 10-1 and the battery stack 20-1. The heat insulating paper 15-1 is, for example, a building member such as Tiger board. The heat insulating member 40-1 is disposed so as to face the battery stack 20-1 between the battery stack 20-1 and the floor 10-2 of the second floor LV2. The heat insulating member 40-1 is substantially parallel to the XY plane. For example, the heat insulating member 40-1 is an iron plate.

[0042] The second floor LV2 includes a floor 10-2, a heat insulation paper 15-2, a battery stack 20-2, and a heat insulation member 40-2. The floor 10-2 is substantially parallel to the XY plane. For example, the floor 10-2 is an aluminum member. The battery stack 20-2 is disposed on the floor 10-2 via the heat insulation paper 15-2 (a heat insulation member on the floor). In other words, the heat insulation paper 15-2 is disposed between the floor 10-2 and the battery stack 20-2. The heat insulation paper 15-2 is, for example, a building member such as a Tiger board. The heat insulation member 40-2 is disposed so as to face the battery stack 20-2 between the battery stack 20-2 and the floor 10-3 of the third floor LV3. The heat insulation member 40-2 is substantially parallel to the XY plane. For example, the heat insulation member 40-2 is an iron plate.

[0043] The third floor LV3 includes a floor 10-3, a heat insulation paper 15-3, and high voltage components 30 (not shown). The floor 10-3 is substantially parallel to the XY plane. For example, the floor 10-3 is an aluminum member. The high voltage components 30 are disposed on the floor 10-3 via the heat insulation paper 15-3 (a heat insulation member on the floor). In other words, the heat insulation paper 15-3 is disposed between the floor 10-3 and the high voltage components 30. The heat insulation paper 15-3 is, for example, a building member such as a Tiger board.

[0044] The first floor LV1 to the third floor LV3 are stacked in order in the Z direction. The cover 70 houses the hierarchical structure composed of the first floor LV1 to the third floor LV3. Preferably, the cover 70 is an aluminum member such as an aluminum alloy.

[0045] FIG. 7 shows a configuration example around the heat insulation member 40-1 of the first floor LV1. Above the heat insulation member 40-1, there is a floor 10-2 of the second floor LV2. In the example shown in FIG. 7, the floor 10-2 of the second floor LV2 is installed on the heat insulation member 40-1 of the first floor LV1 via one or more connecting members 60-1. In other words, a connecting member 60-1 is interposed between the heat insulation member 40-1 of the first floor LV1 and the floor 10-2 of the second floor LV2. Thereby, an air layer 50A-1 is formed between the heat insulation member 40-1 of the first floor LV1 and the floor 10-2 of the second floor LV2. This air layer 50A-1 functions as a heat insulation layer 50-1.

[0046] FIG. 8 shows a configuration example around the heat insulation member 40-2 of the second floor LV1. Above the heat insulation member 40-2, there is a floor 10-3 of the third floor LV3. In the example shown in FIG. 8, the floor 10-3 of the third floor LV3 is installed on the heat insulation member 40-2 of the second floor LV2 via one or more connecting members 60-2. In other words, a connecting member 60-2 is interposed between the heat insulation member 40-2 of the second floor LV2 and the floor 10-3 of the third floor LV3. Thereby, an air layer 50A-2 is formed between the heat insulation member 40-2 of the second floor LV2 and the floor 10-3 of the third floor LV3. This air layer 50A-2 functions as a heat insulation layer 50-2.

[0047] 4. Effects As described above, according to the present embodiment, the heat insulation member 40-i is arranged so as to face the battery stack 20-i between the battery stack 20-i of the floor LVi and the upper floor LV(i + 1). This heat insulation member 40-i suppresses heat transfer from the floor LVi to the upper floor LV(i + 1). Therefore, even if thermal runaway occurs in the battery stack 20-i of the floor LVi and high-temperature gas is generated, the influence of the heat of the high-temperature gas on the upper floor LV(i + 1) is suppressed. That is, heat damage to the components arranged on the upper floor LV(i + 1) is suppressed. Thereby, the components arranged on the upper floor LV(i + 1) are protected.

[0048] A heat insulation layer 50-i (for example, air layer 50A-i) may be interposed between the heat insulation member 40-i and the upper floor LV(i + 1). In this case, direct heat conduction from the heat insulation member 40-i heated by high-temperature gas to the floor 10-(i + 1) of the upper floor LV(i + 1) is suppressed. Therefore, heat damage to the components arranged on the upper floor LV(i + 1) is further suppressed.

[0049] As shown in FIG. 6, a heat insulation paper 15-(i + 1) may be arranged between the floor 10-(i + 1) of the upper floor LV(i + 1) and the components (battery stack 20 or high-voltage component 30) thereon. Such a heat insulation paper 15-(i + 1) further suppresses heat from the lower floor from being transmitted to the components. That is, heat damage to the components arranged on the upper floor LV(i + 1) is further suppressed.

[0050] In addition, since heat damage to the components arranged on the upper floor LV(i + 1) is suppressed, it becomes possible to actively adopt an aluminum member as the floor 10-(i + 1) of the upper floor LV(i + 1). By using the aluminum member, it becomes possible to reduce the weight of the battery pack 1 while ensuring rigidity. Further, since the battery pack 1 has a hierarchical structure, the floor area is reduced and the battery pack 1 becomes compact. The lightweight and compact battery pack 1 is preferable from the viewpoint of portability.

[0051] The portable battery pack 1 is useful as a home storage battery. However, the application destination of the battery pack 1 is not limited to the home storage battery. For example, the battery pack 1 may be applied to an in-vehicle storage battery.

Explanation of Signs

[0052] 1 Battery pack (power storage device) 10 Floor 15 Heat insulation paper 20 Battery stack 30 High-voltage component 40 Heat insulation member 50 Heat insulation layer 50A Air layer 60 Connecting member 70 Cover

Claims

1. A power storage device having a hierarchical structure including a plurality of floors, a battery stack disposed on the floor of a certain floor among the plurality of floors, components disposed on the floor of the upper floor located above the certain floor, a heat insulating member disposed so as to face the battery stack between the floor of the upper floor and the battery stack, a connecting member interposed in part between the heat insulating member and the floor of the upper floor, and an air layer as a heat insulating layer interposed between the heat insulating member and the floor of the upper floor at a position other than the connecting member and comprising a power storage device.

2. The power storage device according to Claim 1, wherein the floor of the upper floor is an aluminum member a power storage device.

3. The power storage device according to Claim 1, wherein the heat insulating member is iron a power storage device.

4. The power storage device according to any one of Claims 1 to 3, further comprising a floor heat insulating member disposed between the floor of the upper floor and the components a power storage device.

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