Power storage device

Abstract

To provide a technique capable of quickly diffusing, within a case, gas generated in an upper battery module or a lower battery module.SOLUTION: A storage battery unit 1 includes a lower battery module 2b including a plurality of battery cells, an upper battery module 2a including a plurality of battery cells, a battery module case 3 for accommodating the lower battery module 2b and the upper battery module 2a, and an upper battery module base 4 configured to divide an internal space 10 of the battery module case 3 into an upper housing space 12 for accommodating the upper battery module 2a and a lower housing space 11 for accommodating the lower battery module 2b. In the upper battery module base 4, a gap 15 is formed for the release of gas generated in one of the upper housing space 12 or the lower housing space 11 into the other.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an electricity storage device. [Background technology]

[0002] Patent Document 1 discloses a support structure for battery modules stacked in two stages in the vertical direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-099257 Summary of the Invention [Problem to be solved by the invention]

[0004] When waste material is discharged from the safety valve of a battery cell included in a battery module located at the bottom, the waste material may not be able to be quickly dispersed within the case.

[0005] An object of the present disclosure is to provide a technique for quickly diffusing gas generated from an upper battery module or a lower battery module within a case. [Means for solving the problem]

[0006] The present invention provides an energy storage device including a lower battery module including a plurality of battery cells, an upper battery module including a plurality of battery cells, a case accommodating the lower battery module and the upper battery module, and a partition plate dividing the interior space of the case into an upper accommodation space accommodating the upper battery module and a lower accommodation space accommodating the lower battery module, wherein the partition plate is formed with a gas flow path for allowing gas generated in either the upper accommodation space or the lower accommodation space to escape to the other. With the above configuration, gas generated in either the upper accommodation space or the lower accommodation space can be allowed to escape to the other, thereby allowing gas generated from the upper battery module or the lower battery module to be quickly diffused within the case.

[0007] The partition plate may include a plurality of cylindrical bodies extending parallel to one another. According to the above configuration, the rigidity of the partition plate can be improved.

[0008] The partition plate may protrude outward from the upper and lower battery modules in a plan view. With this configuration, the partition plate can absorb impacts acting on the case from the side, thereby effectively protecting the upper and lower battery modules from impacts.

[0009] The case may further include a pressure release valve disposed above the partition plate. With this configuration, the gas inside the case can be released from a higher position than when the pressure release valve is disposed below the partition plate.

[0010] The power storage device may further include an electronic device, which is disposed between the upper battery module and the pressure release valve in a plan view. The above configuration contributes to miniaturization of the power storage device. [Effects of the Invention]

[0011] According to the present disclosure, gas generated from the upper battery module or the lower battery module can be quickly diffused within the case. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. [Figure 2] FIG. 2 is another cross-sectional view of the storage battery unit. [Figure 3] FIG. 2 is a plan cross-sectional view of the storage battery unit. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention will be described below through embodiments of the invention, but the invention according to the claims is not limited to the following embodiments. Furthermore, not all of the configurations described in the embodiments are necessarily essential means for solving the problems. For clarity of explanation, the following description and drawings have been omitted and simplified as appropriate. In each drawing, the same elements are given the same reference numerals, and repeated explanations are omitted as necessary.

[0014] FIG. 1 shows a cross-sectional view of a storage battery unit 1. The storage battery unit 1 is a specific example of an electricity storage device. As an example, the storage battery unit 1 is incorporated into a residential stationary storage battery system. Residential stationary storage battery systems are often installed in a narrow space between a house and the boundary between neighboring properties. Therefore, the storage battery unit 1, which is particularly large among the components of a residential stationary storage battery system, is required to be miniaturized. To miniaturize the storage battery unit 1, a multi-tiered configuration is typically adopted in which multiple battery modules 2 included in the storage battery unit 1 are stacked one above the other.

[0015] As shown in FIG. 1, the plurality of battery modules 2 include two upper battery modules 2a and two lower battery modules 2b. The number of upper battery modules 2a may be one or three or more. The number of lower battery modules 2b may be one or three or more. The storage battery unit 1 includes the plurality of battery modules 2, a battery module case 3, an upper battery module floor 4, and a plurality of brackets 5. The battery module case 3 is a specific example of a case. The upper battery module floor 4 is a specific example of a partition plate.

[0016] The battery module case 3 houses a plurality of battery modules 2. The battery module case 3 includes a lower case 6 and an upper case .

[0017] The lower case 6 is configured as a bottomed box that opens upward. The lower case 6 includes a bottom 6a, a rectangular cylindrical wall 6b that is annular in plan view and protrudes upward from the periphery of the bottom 6a, and an annular flange 6c that protrudes outward in plan view from the upper end of the rectangular cylindrical wall 6b.

[0018] The upper case 7 is configured as a bottomed box that opens downward. The upper case 7 includes a bottom 7a, a rectangular cylindrical wall 7b that is annular in plan view and protrudes downward from the periphery of the bottom 7a, and an annular flange 7c that protrudes outward in plan view from the lower end of the rectangular cylindrical wall 7b.

[0019] The flanges 6c and 7c are joined together by bolting, typically with a plurality of bolts 9, in a state where they face each other vertically with a gasket 8 sandwiched therebetween.

[0020] The multiple brackets 5 are fixed to the inner surface of the rectangular cylindrical wall 6b of the lower case 6. The upper battery module floor 4 is fixed to the multiple brackets 5, typically by bolting. In this way, the upper battery module floor 4 is supported by the lower case 6 via the multiple brackets 5.

[0021] By providing the upper battery module floor 4 in the battery module case 3, the internal space 10 of the battery module case 3 is divided into a lower accommodation space 11 below the upper battery module floor 4 and an upper accommodation space 12 above the upper battery module floor 4. In the lower accommodation space 11, two lower battery modules 2b are arranged adjacent to each other in the horizontal direction. In the upper accommodation space 12, two upper battery modules 2a are arranged adjacent to each other in the horizontal direction. As a result, the multiple lower battery modules 2b and the multiple upper battery modules 2a are arranged above and below each other with the upper battery module floor 4 sandwiched between them. The two upper battery modules 2a are arranged above the two lower battery modules 2b. The two upper battery modules 2a and the two lower battery modules 2b are arranged facing each other above and below with the upper battery module floor 4 sandwiched between them. The two upper battery modules 2a are supported by the upper battery module floor 4. The two lower battery modules 2b are supported on the bottom 6a of the lower case 6.

[0022] Fig. 2 shows another cross-sectional view of the storage battery unit 1. The cross-sectional view shown in Fig. 2 shows a cross-section parallel to the cross-section shown in Fig. 1. The cross-sectional view shown in Fig. 2 shows the storage battery unit 1 cut at a cross-section where the multiple brackets 5 do not exist.

[0023] As shown in FIG. 2, the upper battery module floor 4 is bent into a corrugated cross section to ensure rigidity. Furthermore, the upper battery module floor 4 includes a plurality of cylindrical bodies 13 extending parallel to one another. The plurality of cylindrical bodies 13 extend horizontally. The plurality of cylindrical bodies 13 constitute a portion of the upper battery module floor 4. As an example, the plurality of cylindrical bodies 13 includes three cylindrical bodies 13. The three cylindrical bodies 13 are composed of a first cylindrical body 13a, a second cylindrical body 13b, and a third cylindrical body 13c. The first cylindrical body 13a, the second cylindrical body 13b, and the third cylindrical body 13c are arranged in this order. One of the two upper battery modules 2a is mounted on the first cylindrical body 13a and the second cylindrical body 13b, and the other is mounted on the second cylindrical body 13b and the third cylindrical body 13c.

[0024] The upper battery module floor 4 protrudes outward from the plurality of battery modules 2 in a plan view. In other words, the upper battery module floor 4 has an outward protrusion 16 that extends annularly to surround the plurality of battery modules 2 in a plan view. In yet other words, the outward protrusion 16 protrudes away from the plurality of battery modules 2 in a plan view. For example, in a plan view, the outward protrusion 16 protrudes on the opposite side of one of the two upper battery modules 2a across from the other upper battery module 2a in the direction in which the two upper battery modules 2a are arranged, and protrudes on the opposite side of the other upper battery module 2a across from the other upper battery module 2a. The outward protrusion 16 is disposed between the peripheral wall 3a of the battery module case 3 and the plurality of battery modules 2. Because the upper battery module floor 4 has an outward protrusion 16, when an impact acts on the battery module case 3 from the side and the peripheral wall 3a of the battery module case 3 deforms inward, the outward protrusion 16 actively buckles and deforms to absorb the impact, thereby preventing the impact from acting on the multiple battery modules 2.

[0025] A gap 15 is formed in the upper battery module floor 4. In this embodiment, the gap 15 is formed between the upper battery module floor 4 and the peripheral wall 3a of the battery module case 3. However, instead, the gap 15 may be at least one hole formed in the upper battery module floor 4 itself. The gap 15 is a specific example of a gas flow path. The presence of the gap 15 allows gas generated from the upper battery module 2a in the upper accommodating space 12 to escape to the lower accommodating space 11. Similarly, the presence of the gap 15 allows gas generated from the lower battery module 2b in the lower accommodating space 11 to escape to the upper accommodating space 12. The upper battery module floor 4 completely covers the undersides of the two upper battery modules 2a. Therefore, gas generated from the lower battery module 2b does not directly hit the upper battery module 2a. This prevents gas generated from the lower battery module 2b from directly hitting the upper battery module 2a and heating the upper battery module 2a, thereby preventing further gas generation from the upper battery module 2a. The gas generated from the lower battery module 2b collides with the upper battery module floor 4, as shown by the thick arrow in Figure 2, and flows outward in a plan view. When it eventually reaches the gap 15, it passes through the gap 15 and enters the upper storage space 12. As a result, the gas generated from the lower battery module 2b diffuses within the battery module case 3 without directly colliding with the upper battery module 2a, and dissipates heat to the battery module case 3 and the internal space 10, lowering the temperature of the gas itself. The lower gas temperature alleviates the pressure increase in the internal space 10 of the battery module case 3.

[0026] Fig. 3 shows a plan cross-sectional view of the storage battery unit 1. As shown in Fig. 3, a pressure release valve 20 is provided in the rectangular cylindrical wall 7b of the upper case 7. When the pressure inside the battery module case 3 exceeds a predetermined value, the pressure release valve 20 releases gas inside the battery module case 3 to the outside of the battery module case 3, thereby suppressing an increase in pressure inside the battery module case 3. The pressure release valve 20 also contributes to safety when gas is released from the battery module case 3 via the pressure release valve 20.

[0027] As shown in Fig. 3, the storage battery unit 1 further includes an electronic device 21. The electronic device 21 is typically, but not limited to, a control board for the storage battery unit 1. In the plan view shown in Fig. 3, the electronic device 21 is disposed between the upper battery module 2a and the pressure release valve 20. This allows the storage battery unit 1 to be made smaller in size in the height direction.

[0028] The preferred embodiment of the present disclosure has been described above, and the above embodiment has the following features.

[0029] The battery unit 1 (power storage device) includes a lower battery module 2b including multiple battery cells, an upper battery module 2a including multiple battery cells, a battery module case 3 (case) that houses the lower battery module 2b and the upper battery module 2a, and an upper battery module floor 4 (partition plate) that divides the internal space 10 of the battery module case 3 into an upper accommodation space 12 that houses the upper battery module 2a and a lower accommodation space 11 that houses the lower battery module 2b. The upper battery module floor 4 is formed with a gap 15 (gas flow path) that allows gas generated in either the upper accommodation space 12 or the lower accommodation space 11 to escape to the other. With this configuration, gas generated in either the upper accommodation space 12 or the lower accommodation space 11 can escape to the other, allowing gas generated from the upper battery module 2a or the lower battery module 2b to diffuse quickly within the case.

[0030] 2, the upper battery module floor 4 includes a plurality of cylindrical bodies 13 extending parallel to one another. According to the above configuration, the rigidity of the upper battery module floor 4 can be effectively improved.

[0031] 2, the upper battery module floor 4 protrudes outward from the upper battery module 2a and the lower battery module 2b in plan view. With the above configuration, the upper battery module floor 4 can absorb impacts acting from the side on the battery module case 3, thereby effectively protecting the upper battery module 2a and the lower battery module 2b from the impacts.

[0032] 3, the battery unit 1 further includes a pressure release valve 20 provided in the battery module case 3. The pressure release valve 20 is also located above the upper battery module floor 4. With the above configuration, gas inside the battery module case 3 can be released from a higher position compared to when the pressure release valve 20 is located below the upper battery module floor 4.

[0033] 3, the storage battery unit 1 further includes an electronic device 21. In plan view, the electronic device 21 is disposed between the upper battery module 2a and the pressure release valve 20. This configuration contributes to miniaturization of the storage battery unit 1. [Explanation of symbols]

[0034] 1 Battery unit 2 Battery Module 2a Upper battery module 2b Lower battery module 3 Battery module case 3a Peripheral wall 4 Upper battery module floor 5 Bracket 6 Lower case 6a bottom 6b Square tube wall 6c flange 7 Upper case 7a bottom 7b Square tube wall 7c flange 8 Gaskets 9 volts 10. Interior Space 11 Lower storage space 12 Upper storage space 13 Cylinder 13a 1st cylinder 13b Second cylinder 13c Third cylinder 15 Gap 16 Outward protrusion 20 Pressure relief valve 21 Electronic equipment

Claims

1. a lower battery module including a plurality of battery cells; an upper battery module including a plurality of battery cells; a case that accommodates the lower battery module and the upper battery module; a partition plate that divides the internal space of the case into an upper accommodating space that accommodates the upper battery module and a lower accommodating space that accommodates the lower battery module; Including, The partition plate is formed with a gas flow path for releasing gas generated in either the upper storage space or the lower storage space to the other. Energy storage device.

2. The power storage device according to claim 1, The partition plate includes a plurality of cylindrical bodies extending parallel to each other. Energy storage device.

3. The power storage device according to claim 1, the partition plate protrudes outward from the upper battery module and the lower battery module in a plan view; Energy storage device.

4. The power storage device according to claim 1, Further comprising a pressure release valve provided in the case, The pressure release valve is disposed above the partition plate. Energy storage device.

5. The power storage device according to claim 4, Further comprising electronic equipment; the electronic device is disposed between the upper battery module and the pressure release valve in a plan view. Energy storage device.

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