Battery module

Abstract

The battery module achieves both the prevention of external flames in the event of an abnormality and the assurance of cooling efficiency during normal operation. [Solution] The battery module 1 comprises an outer case 10 having a ventilation opening 11 formed on its longitudinal end face and an exhaust hole 16 formed on its upper surface; a cell holder 40 disposed inside the outer case 10 and housing a battery cell 30; a shielding member 60 disposed inside the outer case 10 in the longitudinal direction between the exhaust hole 16 and the cell holder 40 to block gas from directly leaking from the battery cell to the ventilation opening; a label 17 adhered to the outer case 10 to close the exhaust hole 16; and a cooling fan 50 that forces air cooling inside the outer case 10 by allowing air to enter and exit through the ventilation opening 11.

Description

Technical Field

[0001] This disclosure relates to a battery module.

Background Art

[0002] Patent Document 1 discloses a technique for inducing forced flow of a refrigerant by a cooling blower in a battery module. In this battery module, the refrigerant is inhaled from an intake port at one end in the longitudinal direction of the battery module and discharged from an exhaust port at the other end by forced air cooling of the cooling blower.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When a high-output battery cell is adopted in the battery module of Patent Document 1, when an abnormal ignition of the battery cell occurs, as the high-pressure gas heats up and the ejection amount increases, there is a risk that the flame will come out from the intake port or the exhaust port (an external flame will occur). Although it is conceivable to provide a separate exhaust hole for releasing gas so as not to generate such an external flame, there is a risk that the refrigerant induced by the cooling blower will leak from the exhaust hole, leading to a decrease in the cooling efficiency during normal times. Therefore, there is room for improvement from the viewpoint of achieving both prevention of external flames during abnormal times and ensuring cooling efficiency during normal times.

[0005] This disclosure aims to achieve both prevention of external flames during abnormal times and ensuring cooling efficiency during normal times in a battery module.

Means for Solving the Problems

[0006] This disclosure An outer casing having ventilation openings formed on the longitudinal end faces and exhaust holes formed on the top surface, A cell holder is arranged inside the aforementioned outer casing and houses the battery cells, A shielding member is positioned within the outer casing between the exhaust hole and the cell holder in the longitudinal direction to prevent gas from directly leaking from the battery cell to the ventilation opening. A label is attached to the outer casing so as to block the exhaust hole, A cooling fan that forces air into and out of the outer casing by allowing air to enter and exit through the ventilation opening, and We provide a battery module that includes the following features. [Effects of the Invention]

[0007] According to this disclosure, a battery module can achieve both prevention of external flames in abnormal situations and ensure cooling efficiency during normal operation. [Brief explanation of the drawing]

[0008] [Figure 1] An external perspective view of a battery module according to one embodiment of the present disclosure. [Figure 2] Disassembled perspective view of the battery module. [Figure 3] Cross-sectional view of the battery module along line III-III in Figure 1. [Figure 4] Cross-sectional view of the battery module along line IV-IV in Figure 3. [Figure 5] Cross-sectional view of the battery module along the VV line in Figure 4. [Modes for carrying out the invention]

[0009] This disclosure is, An outer casing having ventilation openings formed on the longitudinal end faces and exhaust holes formed on the top surface, A cell holder is arranged inside the aforementioned outer casing and houses the battery cells, A shielding member is positioned within the outer casing between the exhaust hole and the cell holder in the longitudinal direction to prevent gas from directly leaking from the battery cell to the ventilation opening. A label is attached to the outer casing so as to block the exhaust hole, A cooling fan that forces air into and out of the outer casing by allowing air to enter and exit through the ventilation opening, and We provide a battery module that includes the following features.

[0010] With the above configuration, under normal conditions, the exhaust vents are blocked by labels, ensuring cooling efficiency without reducing the cooling fan's airflow. In the event of an abnormality, the labels peel off as the internal pressure rises, opening the exhaust vents and allowing hot gases to escape. In particular, since the exhaust vents are located outside the shielding member in the longitudinal direction, the hot gases in the event of an abnormality will wrap around the shielding member and reach the exhaust vents. This prevents the hot gases released by the battery cells from directly ejecting to the outside and generating an external flame. Thus, it is possible to achieve both prevention of external flames in the event of an abnormality and ensuring cooling efficiency under normal conditions.

[0011] The exhaust hole may be composed of a plurality of punched holes.

[0012] With the above configuration, when applying the label, it is possible to apply it not only to the edge of the exhaust hole, but also to the entire surface of the exhaust hole. Therefore, the ease with which the label peels off can be easily adjusted.

[0013] The label may be adhered to the periphery of the exhaust hole.

[0014] According to the above configuration, the label can be easily peeled off in the event of an abnormality.

[0015] The battery module may include a guide member that protrudes downward from the inner surface of the upper wall of the exterior case and guides air flowing between the cell holder and the upper wall of the exterior case downward to keep it away from the exhaust hole. The guide member may have a tapered shape in which the amount of downward protrusion increases toward the longitudinal end.

[0016] According to the above configuration, the air flow associated with forced air cooling during normal operation can be diverted away from the exhaust hole by the guide member. Therefore, it is possible to prevent the label from being peeled off by the air flow associated with forced air cooling during normal operation.

[0017] The ventilation port may include an intake port formed in one end surface of the exterior case in the longitudinal direction. The exhaust hole may include an intake port side exhaust hole arranged close to the intake port in the longitudinal direction. The label may include an intake port side label that closes the intake port side exhaust hole. The shielding member may include a labyrinth wall having a labyrinth structure arranged between the intake port side exhaust hole and the cell holder in the longitudinal direction. The cooling fan may introduce air into the exterior case from the intake port.

[0018] According to the above configuration, high-temperature gas can be exhausted from the intake port side exhaust hole during abnormal operation, preventing external flame generation at the intake port. In addition, since the high-temperature gas discharged from the battery cell passes through a complex and intertwined flow path by the labyrinth wall, a cooling effect during the passage process and prevention of external flame generation can be further expected.

[0019] The ventilation port may include an exhaust port formed in the other end surface of the exterior case in the longitudinal direction. The exhaust hole may include an exhaust port side exhaust hole arranged close to the exhaust port in the longitudinal direction. The label may include an exhaust port side label that closes the exhaust port side exhaust hole. The shielding member may include a plate-shaped partition wall positioned between the intake-side exhaust hole and the cell holder in the longitudinal direction. The cooling fan may expel air into the outer casing through the exhaust port.

[0020] With the above configuration, in the event of an abnormality, high-temperature gas can be exhausted from the exhaust port on the outlet side, preventing the generation of an external flame at the outlet. Furthermore, because the partition wall prevents the high-temperature gas released from the battery cells from traveling in a straight line, the prevention of external flame generation can be further expected.

[0021] The exhaust port on the outlet side is larger than the exhaust port on the intake side. The cooling fan may be positioned close to the intake port.

[0022] With the above configuration, by making the exhaust holes (intake-side exhaust holes) located near the cooling fan relatively smaller, unintended label peeling during normal operation can be suppressed.

[0023] Embodiments of this disclosure will be described below with reference to the attached drawings.

[0024] The following describes specific examples of this disclosure in detail based on the drawings. In the following description, terms indicating specific directions or positions may be used as needed. The use of such terms is for the purpose of facilitating the understanding of the invention by referring to the drawings, and the meaning of these terms does not limit the technical scope of this disclosure. Furthermore, parts with the same reference numerals appearing in multiple drawings indicate the same or equivalent parts or components. In addition, the embodiments shown below illustrate specific examples of the technical concept of this disclosure and do not limit this disclosure to those described below. Furthermore, the dimensions, materials, shapes, and relative arrangements of the components described below are intended as examples, and are not intended to limit the scope of this disclosure to those specific examples unless otherwise specified. Also, the content described in one embodiment or example is applicable to other embodiments and examples. Furthermore, the size and positional relationships of the components shown in the drawings may be exaggerated to clarify the explanation.

[0025] Figure 1 shows an external perspective view of a battery module 1 according to one embodiment of the present disclosure.

[0026] [Application] Battery module 1 can be used, for example, as an emergency power source for battery backup units (BBUs), or as a power source for the drive motors of electric vehicles. However, the applications of battery module 1 are not limited, and it can be used as a power source for various other electrical devices.

[0027] [Outer case] The battery module 1 has a box-shaped outer case 10 that extends longitudinally from one end face 10a to the other end face 10b. In the drawing, the longitudinal direction of the battery module 1 is indicated by the X direction, the left-right direction by the Y direction, and the up-down direction by the Z direction. The arrows in the drawing indicate forward (X), left (Y), and upward (Z). However, the installation direction of the battery module 1 is not particularly limited.

[0028] An intake port 11a is provided on one end face 10a of the outer casing 10, connecting the inside and outside of the outer casing 10 in the longitudinal direction. An exhaust port 11b (see Figure 2 for details) is provided on the other end face 10b of the outer casing 10, connecting the inside and outside of the outer casing 10 in the longitudinal direction. The intake port 11a and the exhaust port 11b are also referred to as ventilation ports 11. As will be described later, a cooling fan 50 is arranged inside the outer casing 10 to forcibly cool the battery cells 30 by drawing in air through the intake port 11a and expelling air through the exhaust port 11b.

[0029] A connector 21 for connecting to a power supply is located on the other end face 10b of the outer casing 10. The connector 21 is positioned so as to be exposed on the other end face 10b of the battery module 1.

[0030] Figure 2 shows an exploded perspective view of the battery module 1.

[0031] The outer casing 10 of the battery module 1 includes a front case 12, a rear case 13, a lower case 14, and an upper case 15.

[0032] The front case 12 constitutes the front surface of the battery module 1 and is attached to the front ends of the lower case 14 and the upper case 15. The front case 12 defines one end surface 10a on which the aforementioned air intake 11a is provided.

[0033] The rear case 13 forms the rear surface of the battery module 1 and is attached to the rear ends of the lower case 14 and the upper case 15. The rear case 13 defines the other end face 10b on which the aforementioned discharge port 11b is provided.

[0034] The lower case 14 has a channel shape that opens upwards and forwards and backwards. The lower case 14 has a bottom wall 14a that extends on a horizontal plane, and a pair of side walls 14b that rise vertically from the left and right sides of the bottom wall 14a.

[0035] The upper case 15 has a channel shape that opens upward and forward and backward. The upper case 15 is attached to the lower case 14 so as to cover it from above and close the upper side of the lower case 14. The upper case 15 has an upper wall 15a that extends in a horizontal plane and a pair of side walls 15b that are suspended vertically from the left and right sides of the upper wall 15a.

[0036] An intake-side exhaust hole 16a is formed at the front end of the upper wall 15a of the upper case 15, connecting the inside and outside of the outer case 10 in the vertical direction. In the illustrated example, the intake-side exhaust hole 16a is composed of multiple punch holes. An outlet-side exhaust hole 16b is formed at the rear end of the upper wall 15a of the upper case 15, connecting the inside and outside of the outer case 10 in the vertical direction. In the illustrated example, the outlet-side exhaust hole 16b is composed of multiple punch holes. In the illustrated example, the outlet-side exhaust hole 16b is larger than the intake-side exhaust hole 16a. The intake-side exhaust hole 16a and the outlet-side exhaust hole 16b are collectively referred to as the exhaust hole 16. The shape of the exhaust hole 16 is not particularly limited and may be other shapes other than those shown.

[0037] The intake side exhaust hole 16a is closed by the intake side label 17a, and the exhaust side exhaust hole 16b is closed by the exhaust side label 17b. The intake side label 17a and the exhaust side label 17b are also referred to simply as label 17. Label 17 is adhered to the periphery of the exhaust hole 16 (hypothetically shown by the dashed line F) and attached to the upper wall 15a. However, the details of the adhesion position of label 17 are not particularly limited, and for example, it may be adhered to the entire surface. The adhesion method is also not particularly limited, and double-sided tape or adhesive can be used. For example, when using double-sided tape, the thickness of label 17 may be 0.5 mm and the thickness of double-sided tape may be 0.2 mm.

[0038] Label 17 may have information about the battery module 1, such as the model number, manufacturer's name, battery capacity, and rating, pre-printed on it. Label 17 is made of a resin such as polycarbonate or polypropylene, or a paper base material impregnated or coated with resin. In the illustrated example, the outer shape of label 17 is rectangular, but it is not particularly limited.

[0039] [Internal structure] Inside the outer casing 10 are electrical components 20, battery cells 30, cell holders 40 for housing the battery cells 30, and a cooling fan 50.

[0040] The electrical component 20 includes an electrical circuit such as a DC-DC converter and is connected to the connector 21. In the illustrated example, the electrical component 20 is schematically shown as a rectangular parallelepiped and is positioned close to the exhaust port 11b and directly below the exhaust port side exhaust hole 16b.

[0041] The battery cell 30 is a secondary battery cell with a rectangular or cylindrical outer casing. Each battery cell 30 has positive and negative electrodes. The positive and negative electrodes may be provided on one end face of the battery cell 30. Known secondary batteries such as lithium-ion batteries, nickel-metal hydride batteries, and nickel-cadmium batteries can be used as appropriate for such battery cells 30. The outer casing of the battery cell 30 is also equipped with a safety valve. The safety valve opens in response to an increase in the internal pressure of the outer casing, releasing the gas inside the outer casing to the outside.

[0042] The cell holder 40 is configured to connect battery cells 30 in series and parallel and arrange them in a predetermined orientation. The cell holder 40 has a lower holder 41 and an upper holder 42, and is configured to open and close vertically. In the illustrated example, the cell holder 40 houses 120 cylindrical battery cells 30 in a vertical orientation. The battery cells 30 are connected in a 10 series and 12 parallel configuration. Note that the number and arrangement of secondary battery cells, as well as the number of series and parallel connections, are not limited to this example, and any number and arrangement can be used as appropriate.

[0043] Various types of substrates 43 are arranged on the top and sides of the cell holder 40.

[0044] The cooling fan 50 forces air cooling inside the outer casing 10 by bringing air in and out through the ventilation opening 11. In the illustrated example, the cooling fan 50 is positioned close to the intake port 11a and causes air to flow from the intake port 11a to the exhaust port 11b.

[0045] Figure 3 shows a cross-sectional view of the battery module 1 along line III-III in Figure 1. Figure 4 shows a cross-sectional view of the battery module 1 along line IV-IV in Figure 3. For clarity of the illustration, some components such as the cooling fan 50 and cell holder 40 are virtually densely hatched, while hatching lines are omitted for some components such as the outer casing 10. This is also the case for subsequent cross-sectional views.

[0046] In the longitudinal direction, a labyrinth wall 61 and a partition wall 62 are positioned between the intake-side exhaust hole 16a and the cell holder 40. The labyrinth wall 61 has a labyrinth structure and forms a flow path (see arrow A1 in Figure 3) that bypasses the gas released from the battery cell 30 so that it does not travel in a straight line. The partition wall 62 is positioned inside the labyrinth wall 61 in the longitudinal direction and is a plate-shaped member that extends in the up, down, left, and right directions.

[0047] A partition wall 63 is positioned between the exhaust port side exhaust hole 16b and the cell holder 40 in the longitudinal direction. The partition wall 62 is a plate-shaped member positioned inside the labyrinth wall 61 in the longitudinal direction and extending in the up, down, left, and right directions.

[0048] The labyrinth wall 61 and partition walls 62 and 63 are also referred to as the shielding member 60 without distinction. However, partition wall 62 may be omitted. The shielding member 60 is positioned longitudinally within the outer case 10 between the exhaust hole 16 and the cell holder 40, and shields against direct gas leakage from the battery cell 30 to the ventilation opening 11. The air pressurized and sent from the intake port 11a to the exhaust port by the cooling fan 50 also passes through the shielding member 60.

[0049] Figure 5 shows a cross-sectional view of battery module 1 along the VV line in Figure 4.

[0050] Inside the outer casing 10, a gap S that serves as a flow path is defined between the cell holder 40 and the outer casing 10. Air pumped by the cooling fan 50 and gases released by the battery cell 30 flow through this gap S. In the illustrated example, the gap S is defined above and to the side of the cell holder 40, but its arrangement is not particularly limited.

[0051] Referring also to Figure 4, above the cell holder 40, a guide member 70 is positioned near the partition wall 63 in the gap S which forms the airflow path. The guide member 70 is attached to the inner surface of the upper wall 15a and protrudes downward from the inner surface of the upper wall 15a. The guide member 70 guides the air flowing between the cell holder 40 and the upper wall 15a of the outer case 10 downward so as to move it away from the exhaust port side exhaust hole 16b (see arrow A2). In the illustrated example, the guide member 70 has a tapered shape in which the amount of downward protrusion increases towards the longitudinal end (rear).

[0052] The battery module 1 of this embodiment provides the following effects and advantages.

[0053] Under normal conditions, the exhaust hole 16 is blocked by the label 17, ensuring cooling efficiency without a decrease in the airflow of the cooling fan 50. In the event of an abnormality, the label 17 peels off as the internal pressure rises, opening the exhaust hole 16 and allowing gas to escape. In particular, since the exhaust hole 16 is located outside the shielding member 60 in the longitudinal direction, the high-temperature gas in the event of an abnormality will wrap around the shielding member 60 and reach the exhaust hole 16. Therefore, it is possible to prevent the high-temperature gas from being directly ejected from the exhaust hole 16. Thus, it is possible to achieve both prevention of external flames in the event of an abnormality and ensuring cooling efficiency under normal conditions.

[0054] Since the exhaust hole 16 is composed of multiple punch holes, the label 17 can be made less likely to peel off by attaching it to the entire surface of the exhaust hole 16. Alternatively, by adhering the label 17 to the periphery of the exhaust hole 16, the label 17 can be made easier to peel off in case of malfunction. In other words, the ease with which the label 17 peels off can be easily adjusted.

[0055] The tapered guide member 70 keeps the airflow associated with forced air cooling away from the exhaust hole 16. Therefore, it is possible to prevent the label 17 from peeling off due to the airflow associated with forced air cooling.

[0056] In the event of an abnormality, high-temperature gas can be exhausted from the intake-side exhaust hole 16a and the outlet-side exhaust hole 16b, preventing the generation of external flames at the intake 11a and outlet 11b. Furthermore, because the high-temperature gas released from the battery cells passes through a complex network of flow paths due to the labyrinth wall 61, a cooling effect during the passage process and prevention of external flame generation can be expected to be further enhanced. In addition, because the high-temperature gas released from the battery cells 30 does not travel in a straight line due to the partition wall 63, prevention of external flame generation can be further enhanced.

[0057] The intake-side exhaust hole 16a is smaller than the outlet-side exhaust hole 16b, and by making the exhaust hole (intake-side exhaust hole 16a) located near the cooling fan 50 relatively smaller, unintended peeling of the label 17 under normal circumstances can be suppressed.

[0058] Although specific embodiments and variations of the present disclosure have been described above, the present disclosure is not limited to the above embodiments and can be implemented with various modifications within the scope of this invention. For example, a labyrinth wall may be provided adjacent to the partition wall 63 on the discharge port 11b side.

[0059] This disclosure may include the following aspects: (Aspect 1) An outer casing having ventilation openings formed on the longitudinal end faces and exhaust holes formed on the top surface, A cell holder is arranged inside the aforementioned outer casing and houses the battery cells, A shielding member is positioned within the outer casing between the exhaust hole and the cell holder in the longitudinal direction to prevent gas from directly leaking from the battery cell to the ventilation opening. A label is attached to the outer casing so as to block the exhaust hole, A cooling fan that forces air into and out of the outer casing by allowing air to enter and exit through the ventilation opening, and A battery module equipped with the following features. (Aspect 2) The battery module according to embodiment 1, wherein the exhaust hole is composed of a plurality of punch holes. (Aspect 3) The battery module according to embodiment 1 or 2, wherein the label is adhered to the periphery of the exhaust hole. (Aspect 4) A battery module according to any one of embodiments 1 to 3, comprising a guide member that protrudes downward from the inner surface of the upper wall of the outer case and guides the air flowing between the cell holder and the upper wall of the outer case downward so as to move away from the exhaust hole. (Aspect 5) The battery module according to embodiment 4, wherein the guide member has a tapered shape in which the amount of downward protrusion increases toward the end in the longitudinal direction. (Aspect 6) The ventilation opening includes an intake opening formed on one end face in the longitudinal direction of the outer casing, The exhaust hole includes an exhaust hole on the intake side that is located close to the intake port in the longitudinal direction. The label includes an inlet-side label that closes the inlet-side exhaust hole, The shielding member includes a labyrinth wall having a labyrinth structure positioned between the intake side exhaust hole and the cell holder in the longitudinal direction. The cooling fan is configured to draw air into the outer casing from the intake port, as described in any one of embodiments 1 to 5 of the battery module. (Aspect 7) The ventilation opening includes an exhaust port formed on the other end face in the longitudinal direction of the outer casing, The exhaust hole includes an exhaust port side exhaust hole located in close proximity to the outlet in the longitudinal direction, The label includes an outlet-side label that closes the outlet-side exhaust hole, The shielding member includes a plate-shaped partition wall positioned between the intake side exhaust hole and the cell holder in the longitudinal direction. The battery module according to embodiment 6, wherein the cooling fan expels air into the outer casing from the exhaust port. (Pattern 8) The exhaust port on the outlet side is larger than the exhaust port on the intake side. The battery module according to embodiment 7, wherein the cooling fan is located in close proximity to the intake port. [Explanation of Symbols]

[0060] 1 Battery Module 10 Outer Case 10a One end face 10b Other end surface 11 Ventilation vent 11a Inlet 11b Outlet 12 Front Case 13 Rear Case 14 Lower Cases 14a Bottom wall 14b Side wall 15 Upper Case 15a Upper wall 15b side wall 16 exhaust holes 16a Intake side exhaust hole 16b Exhaust port on the outlet side 17 Labels 17a Inlet side label 17b Label on the outlet side 20 Electrical components 21 Connectors 30 battery cells 40 Cell Holder 41 Lower holder 42 Upper holder 43 circuit boards 50 Cooling Fans 60 Shielding member 61 Labyrinth Wall 62 Partition Wall 63 Partition wall 70 Guide member

Claims

1. An outer casing having a ventilation opening formed on the longitudinal end face and an exhaust hole arranged so that its opening direction is perpendicular to the ventilation opening, A cell holder is arranged inside the aforementioned outer casing and houses the battery cells, A shielding member is positioned within the outer casing between the exhaust hole and the cell holder in the longitudinal direction, to prevent gas from directly leaking from the battery cell to the ventilation opening. A label is attached to the outer casing so as to block the exhaust hole, A cooling fan that forces air into and out of the outer casing by allowing air to enter and exit through the ventilation opening, and A battery module equipped with the following features.

2. The battery module according to claim 1, wherein the exhaust hole is composed of a plurality of punch holes.

3. The battery module according to claim 1 or 2, wherein the label is adhered to the periphery of the exhaust hole.

4. The battery module according to claim 1 or 2, further comprising a guide member that protrudes downward from the inner surface of the upper wall of the outer case and guides the air flowing between the cell holder and the upper wall of the outer case downward so as to move away from the exhaust hole.

5. The battery module according to claim 4, wherein the guide member has a tapered shape in which the amount of downward protrusion increases toward the end in the longitudinal direction.

6. The ventilation opening includes an intake opening formed on one end face in the longitudinal direction of the outer casing, The exhaust hole includes an exhaust hole on the intake side that is located close to the intake port in the longitudinal direction. The label includes an inlet-side label that closes the inlet-side exhaust hole, The shielding member includes a labyrinth wall having a labyrinth structure positioned between the intake side exhaust hole and the cell holder in the longitudinal direction. The battery module according to claim 1 or 2, wherein the cooling fan draws air into the outer casing from the intake port.

7. The ventilation opening includes an exhaust port formed on the other end face in the longitudinal direction of the outer casing, The exhaust hole includes an exhaust port side exhaust hole located in close proximity to the outlet in the longitudinal direction, The label includes an outlet-side label that closes the outlet-side exhaust hole, The shielding member includes a plate-shaped partition wall positioned between the intake side exhaust hole and the cell holder in the longitudinal direction. The battery module according to claim 6, wherein the cooling fan expels air into the outer casing from the exhaust port.

8. The exhaust port on the outlet side is larger than the exhaust port on the intake side. The battery module according to claim 7, wherein the cooling fan is positioned close to the intake port.

9. The battery module according to claim 1 or 2, wherein the exhaust hole is provided at one end of the outer casing in the longitudinal direction, in a position that overlaps with the cooling fan in the longitudinal direction.

10. An outer casing having a ventilation opening formed on the longitudinal end face and an exhaust hole arranged so that its opening direction is perpendicular to the ventilation opening, A cell holder is arranged inside the aforementioned outer casing and houses the battery cells, A shielding member is positioned within the outer casing between the exhaust hole and the cell holder in the longitudinal direction, to prevent gas from directly leaking from the battery cell to the ventilation opening. A label is attached to the outer casing so as to block the exhaust hole, A cooling fan that forces air into and out of the outer casing by allowing air to enter and exit through the ventilation opening, and Equipped with, The ventilation opening includes an intake opening formed on one end face in the longitudinal direction of the outer casing, The exhaust hole includes an exhaust hole on the intake side that is located close to the intake port in the longitudinal direction. The label includes an inlet-side label that closes the inlet-side exhaust hole, The cooling fan draws air into the outer casing through the intake port. The ventilation opening includes an exhaust port formed on the other end face in the longitudinal direction of the outer casing, The exhaust hole includes an exhaust port side exhaust hole located in close proximity to the outlet in the longitudinal direction, The label includes an outlet-side label that closes the outlet-side exhaust hole, The shielding member includes a plate-shaped partition wall positioned between the intake side exhaust hole and the cell holder in the longitudinal direction. The cooling fan expels air from the exhaust port into the outer casing. A battery module in which the exhaust port on the outlet side is larger than the exhaust port on the intake side.

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