Energy storage device

Abstract

When discharging the gas generated by the battery pack to the outside through the exhaust duct, the gas should be discharged at a lower temperature. [Solution] An energy storage device comprising a battery pack having at least one battery cell and an exhaust duct for exhausting gas generated inside the battery pack, wherein the exhaust duct connects the inside of the battery pack to the outside of the energy storage device, and the exhaust duct has a first exhaust path through which gas generated inside the battery pack flows, a second exhaust path through which outside air flows, and a confluence where the first exhaust path and the second exhaust path merge, and the angle that the first exhaust path and the second exhaust path make toward the confluence is less than 90 degrees.

Description

Technical Field

[0006] , , ,

[0001] The present invention relates to a power storage device.

Background Art

[0002] Patent Document 1 discloses an abnormality detection device that detects the occurrence of smoke from a battery cell inside the case of a battery pack.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When smoke is generated in the case of a battery pack due to smoke from a battery cell, it is conceivable to discharge the smoke to the outside of the case and to discharge the smoke discharged from the case of the battery pack to the outside of the body of a vehicle or the like on which the battery pack is mounted. However, since the smoke discharged from the case of the battery pack is high-temperature exhaust gas, if the exhaust gas is discharged to the outside of the body while being high-temperature in a situation where there is a person near the body, there is a risk that the high-temperature gas will hit the person.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a power storage device capable of discharging the gas generated in a battery pack to the outside from an exhaust duct while lowering the temperature of the gas.

Means for Solving the Problems

[0006] The present invention relates to an energy storage device comprising a battery pack having at least one battery cell, and an exhaust duct for exhausting gas generated inside the battery pack, wherein the exhaust duct connects the inside of the battery pack to the outside of the energy storage device, and the exhaust duct has a first exhaust path through which gas generated inside the battery pack flows, a second exhaust path through which outside air flows, and a confluence where the first exhaust path and the second exhaust path merge, and the angle formed by the first exhaust path and the second exhaust path toward the confluence is less than 90 degrees. [Effects of the Invention]

[0007] In this invention, when the gas generated by the battery pack is discharged to the outside through the exhaust duct, the gas temperature can be lowered before discharge. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram showing an energy storage device in an embodiment. [Figure 2] This diagram illustrates how gas generated by the battery pack is discharged through the exhaust duct. [Figure 3] This is a diagram to explain the confluence section. [Figure 4] This diagram schematically shows the energy storage device in a modified example. [Figure 5] This diagram illustrates a modified example in which gas generated by the battery pack is discharged through the exhaust duct. [Modes for carrying out the invention]

[0009] The following describes in detail the energy storage device in the embodiments of the present invention. However, the present invention is not limited to the embodiments described below.

[0010] Figure 1 is a schematic diagram showing an energy storage device in an embodiment. The energy storage device 1 comprises a battery pack 2 and an exhaust duct 3. The energy storage device 1 is installed in small mobility vehicles, for example. In small mobility vehicles with a seating capacity of 1 to 2 people, the passengers are seated near the location where the energy storage device 1 is installed. The energy storage device 1 is configured so that if high-temperature gas is generated in the battery pack 2 due to smoke from the battery cells, the high-temperature gas will not come into contact with the passengers.

[0011] Battery pack 2 is a battery pack having multiple battery cells. Battery pack 2 has a pack case that houses the multiple battery cells. Battery pack 2 is designed to discharge smoke upward from the pack case. The battery cells are made of lithium-ion batteries. The battery cells have smoke exhaust valves provided on the top surface of the case. An exhaust duct 3 is located above the smoke exhaust valves of the battery cells.

[0012] The exhaust duct 3 discharges gas generated inside the battery pack 2 to the outside of the energy storage device 1. The exhaust duct 3 is located outside the battery pack 2 and has a flow path that allows gas generated by smoke from the battery cells to circulate outside the battery pack 2. For example, the exhaust duct 3 is made up of a duct member separate from the battery pack 2. The exhaust duct 3 is attached to the battery pack 2 from the outside of the pack case of the battery pack 2. The exhaust duct 3 connects the inside of the battery pack 2 to the outside of the energy storage device 1.

[0013] The exhaust duct 3 has a first exhaust path 10, a second exhaust path 20, a junction 30, a first inlet 41, a second inlet 42, and an outlet 50. The exhaust duct 3 has two inlets, including the first inlet 41 and the second inlet 42, and one outlet, including the outlet 50.

[0014] The first exhaust path 10 is an exhaust passage that circulates gas generated inside the battery pack 2 to the outside of the battery pack 2. The first exhaust path 10 forms a path from the first inlet 41 to the outlet 50. The first inlet 41 is the inlet of the first exhaust path 10, and the outlet 50 is the outlet of the first exhaust path 10. The first exhaust path 10 is a passage that circulates the high-temperature gas discharged from the battery pack 2 due to smoke generation from the battery cells toward the outside of the aircraft. The outside of the aircraft is synonymous with the outside of the energy storage device 1.

[0015] The first inlet 41 is an inlet through which gas generated inside the battery pack 2 flows into the exhaust duct 3. The first inlet 41 is positioned above the battery pack 2 so that gas discharged from the battery pack case flows in, and it opens downwards. As shown in Figure 2, gas discharged from the battery pack 2 due to smoke generation from the battery cells flows into the exhaust duct 3 from the first inlet 41.

[0016] The outlet 50 is an exhaust port that discharges the gas that has flowed through the first exhaust path 10. The outlet 50 is located below the first inlet 41 and opens outwards to the outside of the aircraft. In other words, the outlet 50 opens to atmospheric pressure. Since gas flows from a high-pressure side to a low-pressure side, gas flows through the first exhaust path 10 from the high-pressure first inlet 41 to the low-pressure outlet 50. In other words, because the outlet 50 opens to atmospheric pressure, when gas is generated in the battery cells and the internal pressure of the battery pack 2 becomes higher than atmospheric pressure, the first exhaust path 10 forms a gas flow from the first inlet 41 to the outlet 50. The gas that has flowed through the first exhaust path 10 is discharged to the outside of the aircraft from the outlet 50.

[0017] The first exhaust passage 10 includes a first flow path 11 and a second flow path 12. The first flow path 11 extends horizontally from the first inlet 41. The second flow path 12 extends downward in the vertical direction from the first flow path 11. The first flow path 11 is the upstream flow path, and the second flow path 12 is the downstream flow path. Inside the first exhaust passage 10, the gas flows from the first inlet 41 through the first flow path 11 and the second flow path 12 to the outlet 50. A confluence section 30 is provided in the middle of the second flow path 12. As shown in FIG. 2, the first exhaust passage 10 circulates the gas F1 flowing in from the first inlet 41 to the confluence section 30.

[0018] The confluence section 30 is a part where the gas F1 flowing through the first exhaust passage 10 and the air F2 flowing through the second exhaust passage 20 merge. As shown in FIG. 2, in the first exhaust passage 10, only the gas F1 flows upstream of the confluence section 30, and a gas F3 containing the gas F1 and the air F2 flows downstream of the confluence section 30.

[0019] Specifically, only the gas F1 flows inside the first flow path 11. The gas F1 inside the first flow path 11 flows horizontally. Only the air F2 flows inside the second exhaust passage 20. The air F2 inside the second exhaust passage 20 flows downward in the vertical direction. Inside the second flow path 12, only the gas F1 flows upstream of the confluence section 30, and a gas F3 containing the gas F1 and the air F2 flows downstream of the confluence section 30. The outlet 50 is provided downstream of the confluence section 30 and discharges the gas F3 mixed at the confluence section 30 to the outside of the power storage device 1. The gas F3 inside the second flow path 12 flows downward in the vertical direction.

[0020] The second exhaust path 20 is a confluence path through which the outside air taken in from the second inlet 42 flows. The second exhaust path 20 forms a path from the second inlet 42 to the confluence port 43. The second inlet 42 is the inlet of the second exhaust path 20, and the confluence port 43 is the outlet of the second exhaust path 20. The second inlet 42 opens upward and is an outside air inlet for sucking air in the atmosphere. For example, the second inlet 42 is provided above and in front of the confluence port 43. One end of the second exhaust path 20 on the second inlet 42 side opens to the atmosphere, and the other end on the confluence port 43 side is a flow path connected to the first exhaust path 10. Inside the second exhaust path 20, air F2 flows from the second inlet 42 toward the confluence port 43.

[0021] The confluence port 43 is a supply port for supplying the air F2 that has flowed through the second exhaust path 20 to the first exhaust path 10. The confluence port 43 opens to the second flow path 12 and communicates the second exhaust path 20 and the first exhaust path 10. The air F2 that has flowed through the inside of the second exhaust path 20 flows into the inside of the first exhaust path 10 through the confluence port 43. The second exhaust path 20 functions as a supply path for supplying the outside air sucked from the second inlet 42 to the confluence portion 30. As shown in FIG. 3, in the confluence portion 30, the angle θ formed by the first exhaust path 10 and the second exhaust path 20 toward the confluence portion 30 is less than 90 degrees. The angle θ formed by the direction in which the gas F1 flows in the second flow path 12 and the direction in which the air F2 flows from the confluence port 43 to the second flow path 12 is set to be 0 degrees or more and less than 90 degrees. The extending direction of the first exhaust path 10 and the extending direction of the second exhaust path 20 are determined so as to satisfy that the angle θ is 0 degrees or more and less than 90 degrees.

[0022] In the exhaust duct 3, gas flows through the first exhaust path 10 from the first inlet 41 to the outlet 50, creating a negative pressure at the confluence 30. This negative pressure draws in outside air from the second inlet 42 via the confluence port 43. Since gas flows from the shorter side to the longer side of the flow path, the first exhaust path 10 is longer than the second exhaust path 20. The flow path of the first exhaust path 10 from the confluence 30 to the outlet 50 is longer than that of the second exhaust path 20. Furthermore, the velocity of the gas flowing through the first exhaust path 10 is high. Therefore, in a flow path structure where the first exhaust path 10 and the second exhaust path 20 are connected via the confluence port 43, the gas from the second exhaust path 20 side is drawn into the side with higher velocity (the first exhaust path 10 side) via the confluence port 43.

[0023] Furthermore, the second inlet 42 has a cross-sectional area similar to that of the outlet 50 and opens in a different direction from the direction in which the outlet 50 opens. The outlet 50 is located below the battery pack 2 and opens downwards. The direction in which the outlet 50 opens and the direction in which the second inlet 42 opens are opposite. This prevents gas discharged from the outlet 50 from being drawn in through the second inlet 42.

[0024] Furthermore, in order to lower the temperature of the gas discharged from the outlet 50, the exhaust duct 3 needs to lower the temperature of the gas while it is flowing through the first exhaust path 10. The temperature of the outside air is lower than the temperature of the gas. Therefore, by drawing in outside air from the second inlet 42 and supplying that outside air to the first exhaust path 10 from the confluence port 43, the gas and air mix at the confluence 30, and the temperature of the gas can be lowered by the air.

[0025] As described above, according to this embodiment, by circulating the gas generated by the battery pack 2 through the exhaust duct 3, the gas can be discharged from the outlet 50 at a lower temperature.

[0026] The number of battery cells included in battery pack 2 is not limited. For example, battery pack 2 may contain only one battery cell. In other words, battery pack 2 only needs to have at least one battery cell.

[0027] Furthermore, the direction in which the outlet 50 opens is not limited to downwards, but may also be sideways. Similarly, the direction in which the second inlet 42 opens is not limited to upwards, but may also be sideways.

[0028] Furthermore, the exhaust duct 3 may have multiple second inlets 42. The exhaust duct 3 only needs to have a structure in which there are two inlets, including a first inlet 41 and a second inlet 42, for one outlet 50, and multiple second inlets 42 may be provided.

[0029] Furthermore, the exhaust duct 3 is not limited to being composed of duct components. For example, the exhaust duct 3 may be a structure made up of the aircraft frame or the like. Alternatively, the exhaust duct 3 may be partially composed of duct components and the remaining part may be made up of aircraft components. An example of a modified version of the energy storage device 1 is shown in Figures 4 and 5.

[0030] As shown in Figures 4 and 5, the modified energy storage device 1 is configured such that the exhaust duct 3 has multiple second inlets 42. Part of the exhaust duct 3 is made up of members 31 and 32 on the aircraft side. Member 31 is a member located above the battery pack 2. Member 32 is a member located below the battery pack 2. Both members 31 and 32 are made up of sheet metal case, insulation material, or insulation sheet on the aircraft side. [Explanation of Symbols]

[0031] 1. Energy storage device 2 Battery Packs 3. Exhaust duct 10. First exhaust path 11. First channel 12 Second channel 20. Second exhaust path 30 Confluence 41 Entrance 1 42 Second Entrance 50 exit

Claims

1. A battery pack having at least one battery cell, An exhaust duct for exhausting gas generated inside the battery pack, A power storage device comprising, The exhaust duct connects the inside of the battery pack to the outside of the energy storage device. The aforementioned exhaust duct is A first exhaust path through which the gas generated inside the battery pack flows, A second exhaust path through which outside air circulates, It has a confluence section where the first exhaust path and the second exhaust path merge, The angle formed by the first exhaust path and the second exhaust path toward the confluence is less than 90 degrees. A power storage device characterized by the following features.

2. The aforementioned exhaust duct is The first exhaust path has an inlet through which gas generated inside the battery pack flows in, The inlet of the second exhaust path, the second inlet through which the outside air flows in, It is provided downstream of the aforementioned confluence and has an outlet for discharging the gas mixed at the confluence to the outside of the energy storage device, The first exhaust path allows the gas flowing in from the first inlet to flow to the confluence section. The second exhaust path allows outside air flowing in from the second inlet to flow to the confluence section. The energy storage device according to feature 1.

3. The first exhaust path is formed to be longer than the second exhaust path. The energy storage device according to claim 2.

4. The first exhaust path is an airflow forming path that forms a gas flow from the first inlet to the outlet when the gas is generated and the internal pressure of the battery pack becomes higher than atmospheric pressure. The second exhaust path draws in outside air from the second inlet due to the negative pressure generated at the confluence point as the gas flows through the first exhaust path from the first inlet to the outlet. The energy storage device according to claim 3.

5. The second inlet has a cross-sectional area similar to that of the outlet and opens in a direction different from the opening direction of the outlet. The energy storage device according to feature 4.

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