Battery Module

Abstract

The present invention relates to a battery module, and aims to provide a battery module that ensures a path for discharging gas to the outside in an abnormal situation and reduces the volume occupied by the path in normal times. The battery module (10) of the present invention includes: a battery stack (13); a battery cooling duct (11), in which air for cooling the battery stack (13) flows; and a gas exhaust duct (12), in which gas generated from the battery stack (13) flows. In addition, in the battery module (10), the middle part of the gas cooling duct (11) is built into the gas exhaust duct (12) in a reduced diameter state.

Description

Technical Field

[0001] The present invention relates to a battery module, and more particularly to a battery module having a duct for guiding gas generated from a battery to the outside in the event of an abnormality. Background Art

[0002] Hybrid vehicles and electric vehicles are equipped with large batteries for supplying power to electric motors that provide driving force for the vehicles. In addition, such vehicles are provided with a mechanism for cooling the batteries and a mechanism for guiding gas generated from the batteries to the outside in the event of an abnormality.

[0003] Patent document 1 describes a structure for discharging gas generated from an electric power device. Specifically, there is a gas discharge port for discharging the gas to the outside, one end of an exhaust passage connected to the gas discharge port is closed, and the other end of the exhaust passage is open to the outside. In this way, the gas can be discharged to the outside reliably, and the exhaust gas can be prevented from flowing back into the vehicle interior.

[0004] Patent document 2 describes a battery structure in which a cooling channel and an exhaust channel are separated and formed. Specifically, a cooling channel for cooling the battery electrode and an exhaust channel through which gas leaked from the battery electrode passes are separated and formed. This structure can prevent the gas leaked from the battery from mixing into the cooling channel when an abnormality occurs.

[0005] Patent document 3 describes a battery pack having a duct portion for discharging gas generated from a battery. Specifically, the duct portion has a smoke exhaust passage formed across the entire length of the battery cells in the stacking direction. This structure can effectively cool the battery cells and improve the discharge performance of the battery.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: (Japanese) Patent Publication No. 2006-185894

[0009] Patent Document 2: (Japanese) Patent Publication No. 2011-171052

[0010] Patent Document 3: (Japanese) Patent Publication No. 2018-18754 Summary of the invention

[0011] Problems to be solved by the invention

[0012] However, in the inventions described in the above-mentioned patent documents, it is not easy to arrange the air passage of the gas generated in an abnormal situation compactly inside the vehicle body.

[0013] Specifically, although the invention described in Patent Document 1 is provided with an exhaust duct for releasing the gas generated in an abnormal situation to the outside of the vehicle, since the exhaust duct is formed across the entire length of the battery, the volume occupied by the exhaust duct increases, resulting in a problem of enlargement of the battery module.

[0014] The invention described in Patent Document 2 forms a cooling passage and a discharge passage separately. Therefore, even with this invention, the discharge passage occupies a large volume, which may occupy the effective volume in the vehicle cabin.

[0015] In the invention described in Patent Document 3, since a smoke exhaust passage for exhausting gas in an abnormal situation is formed across the longitudinal direction of the battery pack, this invention also has a problem in that the volume occupied by the smoke exhaust passage is large.

[0016] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a battery module that ensures a path for discharging gas to the outside in an abnormal situation and reduces the volume occupied by the path in normal times.

[0017] Means of solving problems

[0018] The battery module of the present invention is characterized in that it includes: a battery stack; a battery cooling duct, in which air for cooling the battery stack flows; and a gas exhaust duct, in which gas generated from the battery stack flows, wherein the middle portion of the gas exhaust duct is built into the battery cooling duct in a reduced diameter state.

[0019] In addition, the battery module of the present invention is characterized in that air in a vehicle cabin is introduced from one end side of the battery cooling duct, and air that cools the battery stack is returned to the vehicle cabin from the other end side of the battery cooling duct.

[0020] Furthermore, the battery module of the present invention is characterized in that the battery stack is disposed inside the vehicle cabin.

[0021] Furthermore, the battery module of the present invention is characterized in that the gas exhaust duct is made of a material softer than that of the battery cooling duct.

[0022] In addition, the battery module of the present invention is characterized in that a valve is provided in the middle portion of the gas exhaust pipe; when the gas is generated from the battery stack, the valve closes the gas exhaust pipe, causing the gas exhaust pipe to expand in diameter inside the battery cooling pipe; when the internal pressure of the gas exhaust pipe reaches a certain value, the valve is released, allowing the gas to be discharged to the outside of the vehicle through the gas exhaust pipe.

[0023] Furthermore, the battery module of the present invention is characterized in that the outer surface of the gas exhaust duct in the expanded state is in substantially close contact with the inner surface of the battery cooling duct.

[0024] Furthermore, the battery module of the present invention is characterized in that a portion of the gas exhaust duct pulled out from the battery cooling duct is provided in a contracted shape, thereby forming a contracted portion.

[0025] Effects of the Invention

[0026] The battery module of the present invention is characterized in that it includes: a battery stack; a battery cooling duct, in which air for cooling the battery stack flows; and a gas exhaust duct, in which gas generated from the battery stack flows, wherein the middle portion of the gas exhaust duct is built into the battery cooling duct in a reduced diameter state. Therefore, by building the middle portion of the gas exhaust duct into the battery cooling duct, the space occupied by the gas exhaust duct can be reduced, thereby increasing the effective volume in the vehicle cabin. In addition, since the gas exhaust duct is housed in the battery cooling duct in a reduced diameter state, the volume occupied by the gas exhaust duct inside the battery cooling duct can be reduced, thereby preventing the gas exhaust duct from obstructing the flow of gas inside the cooling duct.

[0027] In addition, the battery module of the present invention is characterized in that air in the vehicle cabin is introduced from one end of the battery cooling duct, and air for cooling the battery stack is returned to the vehicle cabin from the other end of the battery cooling duct. Therefore, the air for cooling the battery stack circulates through the battery cooling duct, so the battery cooling duct can be arranged near the gas exhaust duct, and the battery cooling duct can be used as a laying path for the gas exhaust duct.

[0028] In addition, the battery module of the present invention is characterized in that the battery stack is arranged inside the vehicle cabin. Therefore, when the battery stack is arranged inside the vehicle cabin, although it is necessary to ensure a gas exhaust duct for exhausting gas to the outside of the vehicle cabin, since the present invention stores at least a part of the gas exhaust duct in the battery cooling duct, the gas exhaust duct does not occupy the effective space inside the vehicle cabin.

[0029] In addition, the battery module of the present invention is characterized in that the gas exhaust duct is made of a material softer than the battery cooling duct. Therefore, by using a soft material as the gas exhaust duct, when gas is generated from the battery stack, the gas exhaust duct can be easily expanded by utilizing the pressure of the gas.

[0030] In addition, the battery module of the present invention is characterized in that a valve is provided in the middle of the gas exhaust duct; when the gas is generated from the battery stack, the valve closes the gas exhaust duct, causing the gas exhaust duct to expand in diameter inside the battery cooling duct; when the internal pressure of the gas exhaust duct reaches a certain value, the valve is released to discharge the gas to the outside of the vehicle through the gas exhaust duct. Therefore, by providing a simple structure of a valve in the middle of the gas exhaust duct, when gas is generated from the battery stack, the pressure of the gas can be used to expand the gas exhaust duct made of soft material inside the battery cooling duct.

[0031] In addition, the battery module of the present invention is characterized in that the outer surface of the gas exhaust duct in the unfolded state is substantially in close contact with the inner surface of the battery cooling duct. Therefore, the gas exhaust duct in the unfolded state can be used to block the inside of the battery cooling duct, thereby preventing gas from flowing out into the vehicle interior space through the battery cooling duct.

[0032] In addition, the battery module of the present invention is characterized in that the portion of the gas exhaust duct pulled out from the battery cooling duct is set in a contracted shape, thereby forming a contraction portion. Therefore, by generating a pressure loss in the contraction portion, the gas exhaust duct can be expanded inside the battery cooling duct by utilizing the gas pressure generated during an abnormality. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a side cross-sectional view showing a vehicle equipped with a battery module according to an embodiment of the present invention;

[0034] Figure 2 is a schematic diagram showing a battery module according to an embodiment of the present invention;

[0035] 3(A) and 3(B) are diagrams showing a battery module according to an embodiment of the present invention; FIG. 3(A) is a schematic diagram showing a battery module; FIG. 3(B) is a cross-sectional view of a battery cooling duct;

[0036] 4(A) and 4(B) are diagrams showing a battery module according to an embodiment of the present invention; FIG. 4(A) is a schematic diagram showing a battery module; FIG. 4(B) is an enlarged diagram showing a contraction portion;

[0037] 5(A) and 5(B) are diagrams showing a battery module according to an embodiment of the present invention; FIG. 5(A) is a schematic diagram showing a battery module; FIG. 5(B) is a cross-sectional view of a battery cooling duct;

[0038] 6(A) and 6(B) are diagrams showing a battery module according to an embodiment of the present invention; FIG. 6(A) is a schematic diagram showing a battery module; and FIG. 6(B) is a cross-sectional view of a battery cooling duct.

[0039] Explanation of symbols

[0040] 10 Battery Module

[0041] 11 Battery cooling duct

[0042] 12 Gas exhaust pipe

[0043] 13 Battery stack

[0044] 14 valve

[0045] 15 Pull-in section

[0046] 16 Pull-out section

[0047] 17 Contraction

[0048] 20 Vehicles

[0049] 21 Car room

[0050] 22 seats

[0051] 23 Bulkhead DETAILED DESCRIPTION

[0052] The battery module 10 of the present embodiment will be described below with reference to the accompanying drawings. In the following description, the same components are denoted by the same reference numerals in principle, and repeated descriptions are omitted.

[0053] Reference Figure 1 , a vehicle 20 having the battery module 10 of the present embodiment is described. The vehicle 20 is, for example, an electric vehicle or a hybrid vehicle. When the vehicle 20 is an electric vehicle, the vehicle 20 travels using an electric motor that rotates using the electric power supplied from the battery module 10 as a driving source. When the vehicle 20 is a hybrid vehicle, the vehicle 20 travels using one or both of the above-mentioned electric motor and the engine as driving sources.

[0054] The battery module 10 is disposed obliquely below and behind the rear seat 22 and is covered by a partition 23. Here, the battery module 10 may also be disposed below the seat 22. For example, a lithium battery may be used as the battery module 10. The battery module 10 is also referred to as a battery pack.

[0055] The battery stack 13 , the battery cooling duct 11 , and the gas exhaust duct 12 together form a battery module 10 .

[0056] In this embodiment, the battery stack 13 is arranged inside the vehicle cabin 21 where passengers are seated. Therefore, when gas is generated from the battery stack 13 in an abnormal situation, in order to ensure the safety of passengers, the gas must be released to the outside of the vehicle cabin 21. In this embodiment, the gas is released to the outside of the vehicle using the gas exhaust duct 12, thereby preventing the gas from flowing into the vehicle cabin 21 in an abnormal situation.

[0057] Figure 2 1 shows a schematic battery module 10. The battery module 10 includes a battery stack 13, a gas exhaust duct 12, and a battery cooling duct 11. The battery module 10 has the function of cooling the battery stack 13 when the battery stack 13 is charged and discharged, and releasing the gas generated in an abnormality to the outside.

[0058] The battery cooling duct 11 connects the storage container storing the battery stack 13 and the vehicle cabin 21. Air is transported from the vehicle cabin 21 to the battery stack 13, and air is returned from the battery stack 13 to the vehicle cabin 21 through the battery cooling duct 11. Although not shown in the figure, a blower fan that transports air from the vehicle cabin 21 to the battery stack 13 may be provided. In the figure, the flow of air flowing through the battery cooling duct 11 is indicated by arrows.

[0059] The gas exhaust duct 12 is a discharge path for releasing the gas generated from the battery stack 13 in an abnormal situation to the outside of the vehicle. One end of the gas exhaust duct 12 is connected to the gas exhaust valve of each battery constituting the battery stack 13. The other end of the gas exhaust duct 12 is connected to the outside of the vehicle.

[0060] In the present embodiment, the middle portion of the gas exhaust duct 12 is built into the battery cooling duct 11 in a folded state. As a result, the volume occupied by the gas exhaust duct 12 can be reduced when no gas is generated from the battery module 10. In particular, when the battery stack 13 is enlarged, the amount of gas generated in an abnormal situation will also increase, so the gas exhaust duct 12 also tends to be enlarged. In the battery module 10 of the present embodiment, the gas exhaust duct 12 is built into the battery cooling duct 11 in a reduced diameter state. Therefore, even if the battery stack 13 is enlarged, the volume occupied by the gas exhaust duct 12 can be reduced, thereby suppressing the increase in the overall size of the battery module 10.

[0061] 3(A) and 3(B) , the structure of the battery module 10 will be described in detail. Fig. 3(A) is a schematic diagram showing a partial enlargement of the battery module 10, and Fig. 3(B) is a cross-sectional view taken along line AA of Fig. 3(A) .

[0062] Referring to FIG. 3(A), as described above, the middle portion of the gas exhaust duct 12 is housed in the battery cooling duct 11. The gas exhaust duct 12 is pulled into the battery cooling duct 11 from the pull-in portion 15, which is the middle portion of the battery cooling duct 11, and is pulled out from the pull-out portion 16 of the battery cooling duct 11 to the outside of the battery cooling duct 11. That is, the gas exhaust duct 12 is built into the battery cooling duct 11 between the pull-in portion 15 and the pull-out portion 16.

[0063] In addition, a valve 14 is interposed in the portion of the gas exhaust pipe 12 pulled out from the pull-out portion 16. The valve 14 is in a closed state until the inside of the gas exhaust pipe 12 reaches a certain value, and becomes an open state when the inside of the gas exhaust pipe 12 exceeds the certain value. By interposing the valve 14 in the gas exhaust pipe 12, as described later, the gas exhaust pipe 12 can be expanded and deployed inside the battery cooling pipe 11 by utilizing the gas pressure generated in an abnormal situation.

[0064] Referring to FIG. 3(B), the gas exhaust duct 12 is built into the battery cooling duct 11 in a state of reduced diameter. Here, the gas exhaust duct 12 is built into the lower part of the battery cooling duct 11 in a folded state. Thus, when no gas is generated from the battery stack 13, the area occupied by the gas exhaust duct 12 in the cross section of the battery cooling duct 11 can be reduced, and the effective area for air circulation to cool the battery stack 13 can be ensured to a large extent.

[0065] 4(A) and 4(B) , another form of the battery module 10 will be described. FIG4(A) is a schematic diagram partially showing the battery module 10 , and FIG4(B) is a diagram partially showing the gas exhaust duct 12 .

[0066] 4(A) , here, a contraction portion 17 is formed in the portion of the gas exhaust duct 12 that is led out from the pull-out portion 16 to the outside.

[0067] Referring to FIG. 4(B), the gas exhaust pipe 12 is partially contracted to form a contraction portion 17. The resistance at the contraction portion 17 is large, so the same effect as the valve 14 shown in FIG. 3(A) and FIG. 3(B) can be obtained. Specifically, when gas is generated from the battery stack 13, pressure loss occurs in the contraction portion 17, so the internal pressure of the gas exhaust pipe 12 increases, and the gas exhaust pipe 12 expands and expands inside the battery cooling pipe 11. In addition, since the contraction portion 17 is formed by a part of the gas exhaust pipe 12, the cost can be reduced.

[0068] 5(A) and 5(B) , the function of the battery module 10 in the case where gas is generated from the battery stack 13 in an abnormal situation will be described. FIG5(A) is a partially enlarged view of the battery module 10 in this case, and FIG5(B) is a cross-sectional view taken along line AA of FIG5(A) in this case.

[0069] 5(A), when gas is generated from the battery stack 13 in an abnormal situation, the generated gas flows into the gas exhaust pipe 12. At this time, as described above, the downstream end side of the gas exhaust pipe 12 is closed by the valve 14, so the pressure of the gas flowing into the gas exhaust pipe 12 causes the gas exhaust pipe 12 to expand and expand inside the battery cooling pipe 11.

[0070] While the internal pressure of the gas exhaust duct 12 is below a certain value, the valve 14 closes the gas exhaust duct 12. When the internal pressure of the gas exhaust duct 12 exceeds a certain value, the valve 14 opens the gas exhaust duct 12. Therefore, the gas exhaust duct 12 expands and spreads inside the battery cooling duct 11 until the internal pressure of the gas exhaust duct 12 reaches a certain value.

[0071] FIG5(B) shows the cross section of the battery cooling duct 11 and the gas exhaust duct 12 after expansion and deployment. Here, since the gas is filled into the gas exhaust duct 12, the gas exhaust duct 12 is expanded and deployed. The gas exhaust duct 12 is expanded and deployed so that the gas exhaust duct 12 occupies almost the entire cross section of the battery cooling duct 11. For example, the outer surface of the gas exhaust duct 12 is substantially in close contact with the inner surface of the battery cooling duct 11.

[0072] Thus, a space for gas circulation can be ensured inside the gas exhaust duct 12 .

[0073] In addition, the gas exhaust duct 12 blocks the internal space of the battery cooling duct 11. Therefore, even if gas leaks from the gas exhaust duct 12 inside the battery cooling duct 11, the leaked gas can be prevented from flowing to the vehicle interior side.

[0074] The gas exhaust duct 12 is made of a material that is more flexible than the battery cooling duct 11. Specifically, PP (polypropylene) or PA (polyamide) can be used as the material of the battery cooling duct 11. By using such a hard resin as the material of the battery cooling duct 11, deformation of the battery cooling duct 11 can be prevented, and the internal area of ​​the battery cooling duct 11 can be sufficiently and largely ensured.

[0075] On the other hand, as the gas exhaust duct 12, for example, a soft material such as rubber can be used. Therefore, in normal times when no gas is generated from the battery stack 13, as shown in FIG3(B), the gas exhaust duct 12 can be folded to ensure space for cooling air circulation inside the battery cooling duct 11. In addition, when gas is generated from the battery stack 13 in an abnormal situation, as shown in FIG5(B), the gas exhaust duct 12 can be expanded and unfolded inside the battery cooling duct 11 to ensure a larger space for gas circulation inside the gas exhaust duct 12.

[0076] 6(A) and 6(B), when the internal pressure of the gas exhaust pipe 12 reaches a certain value, the valve 14 is in an open state, so the gas generated from the battery stack 13 is released to the outside of the vehicle through the valve 14 and the gas exhaust pipe 12. Therefore, harmful gas can be prevented from flowing into the interior of the vehicle cabin 21.

[0077] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments.

[0078] Reference Figure 2 The gas exhaust duct 12 is built into the battery cooling duct 11 through which air flows after cooling the battery stack 13 , but the gas exhaust duct 12 may also be built into the battery cooling duct 11 through which air flows before cooling the battery stack 13 .

Claims

1. A battery module, characterized in that: include: Battery stack; a battery cooling duct, in which air for cooling the battery stack circulates; as well as a gas exhaust pipe through which the gas generated from the battery stack flows, The gas exhaust duct includes a first portion located at an inlet end of the gas exhaust duct and receiving gas exhausted from the battery stack, and the inlet end of the gas exhaust duct extends outside the battery cooling duct in a manner not to contact air for cooling the battery stack. The second portion of the gas exhaust duct is located downstream and is connected to the first portion by a gas exhaust flow path. The second portion penetrates the battery cooling duct and extends inside the battery cooling duct. The second portion of the gas exhaust duct is contracted and received in the battery cooling duct. When cooling air passes over the second portion contracted and received in the battery cooling duct, the cooling air contacts the second portion contracted and received in the battery cooling duct. When the second portion contracts in the battery cooling duct, it is arranged at the lower part of the inner side of the battery cooling duct.

2. The battery module according to claim 1, characterized in that: The third portion of the gas exhaust duct penetrates the battery cooling duct and extends to the outside at a position downstream of the position where the second portion penetrates the battery cooling duct and extends inside.

3. The battery module according to claim 1, characterized in that: The second portion of the gas exhaust duct is completely received within the battery cooling duct both when contracted and when expanded.

4. The battery module according to any one of claims 1 to 3, characterized in that: The battery cooling duct has a first end and a second end, The battery cooling air is introduced from the vehicle interior into the battery cooling duct via the first end portion to cool the battery stack, and is returned to the vehicle interior via the second end portion. The battery cooling duct includes a tube portion having a closed cross-section, and the tube portion of the gas exhaust duct housed in the tube portion of the battery cooling duct is contracted in the battery cooling duct to contact the cooling air passing over the tube portion contracted and housed in the tube portion of the battery cooling duct. When the tube portion expands, the tube portion blocks the tube portion, thereby preventing exhaust gas leaking from the gas exhaust duct from flowing into the vehicle interior.

Images