TECHNICAL FIELD
The present disclosure relates to a battery module, a battery pack and a vehicle including the same, and more particularly, to a battery module with improved stability against fire or explosion, a battery pack and a vehicle including the same. 10
The present application claims priority to Korean Patent Application No. 10-2020-0121768 filed on September 21, 2020 in the Republic of Korea, the disclosures of which are incorporated herein by reference.
BACKGROUND ART 15
In recent years, the demand for portable electronic products such as notebooks, video cameras, mobile phones, or the like is rapidly increasing, and the development of electric vehicles, energy storage batteries, robots, satellites, or the like is in earnest. For this reason, high-performance secondary batteries enabling repeated charging and discharging are being actively researched. 20
Secondary batteries commercialized at the present include nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries, and lithium secondary batteries. Among them, lithium secondary batteries are in the spotlight due to advantages such as
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free charging and discharging by little memory effect compared to nickel-based secondary batteries, and very low self-discharge rate and high energy density.
The lithium secondary battery mainly uses a lithium-based oxide and a carbon material as a positive electrode active material and a negative electrode active material, respectively. Also, the lithium secondary battery includes an electrode assembly in which 5 a positive electrode plate and a negative electrode plate respectively coated with the positive electrode active material and the negative electrode active material are disposed with a separator being interposed therebetween, and an exterior, namely a battery case, for hermetically storing the electrode assembly together with an electrolyte.
In addition, the lithium secondary battery may be classified depending on the 10 exterior shape into a can-type secondary battery in which an electrode assembly is included in a metal can and a pouch-type secondary battery in which an electrode assembly is included in a pouch made of an aluminum laminate sheet.
In particular, the demand for large-capacity battery modules applied to electric vehicles or the like is increasing recently. Such a large-capacity battery module includes 15 a plurality of battery cells. Thus, when a fire or explosion occurs in a part of the plurality of battery cells, high-temperature fragments of the electrode assembly, flames, and high-temperature gas are discharged to adjacent other battery cells to increase the temperature thereof. Accordingly, thermal runaway, fire, or the like may be propagated to adjacent other battery cells to cause a secondary explosion, thereby increasing the damage. 20
DISCLOSURE
Technical Problem
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The present disclosure is designed to solve the problems of the related art, and therefore the present disclosure is directed to providing a battery module with improved stability against fire or explosion, a battery pack and a vehicle including the same.
These and other objects and advantages of the present disclosure may be understood from the following detailed description and will become more fully apparent 5 from the exemplary embodiments of the present disclosure. Also, it will be easily understood that the objects and advantages of the present disclosure may be realized by the means shown in the appended claims and combinations thereof.
Technical Solution 10
In one aspect of the present disclosure, there is provided a battery module, comprising:
a plurality of battery cells, each having electrode terminals respectively formed at an upper portion and a lower portion thereof;
a module case configured to accommodate the plurality of battery cells and having 15 a plurality of exposure holes configured to expose the upper portion or the lower portion of the battery cell; and
a screen member located at any one or more of an upper portion and a lower portion of the module case and having a plate shape, the screen member being configured to have a ventilation hole with a smaller size than the exposure hole. 20
Also, two or more ventilation holes may be provided in a region of the screen member that faces the exposure hole.
In addition, the ventilation hole may be configured to have a diameter gradually
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decreasing in an outward direction.
Also, the ventilation hole may be shaped so that the screen member is perforated in a zigzag form.
Moreover, the battery module may further comprise a connection plate interposed between the screen member and the module case and having electric conductivity, the 5 connection plate including a body portion having a plate shape extending in a horizontal direction, a connection portion extending from the body portion to contact the electrode terminal, and a connection hole formed by opening a part of the body portion so that the connection portion is located in the opening thereof.
In addition, the connection plate may include an extension portion configured to 10 protrusively extend in a horizontal direction from an outer circumference of the connection hole to hide a part of the connection hole.
Further, the module case may include a plurality of cover portions configured to protrude toward the connection plate from an outer circumference of the plurality of exposure holes, respectively, the cover portion having a hollow and being shaped to have 15 an open top end.
Also, the cover portion may include a bending part bent at the open top end to extend in a horizontal direction to hide a part of the connection hole of the connection plate.
In addition, in another aspect of the present disclosure, there is also provided a battery pack, comprising at least one battery module as above. 20
Moreover, in another aspect of the present disclosure, there is also provided a vehicle, comprising at least one battery module as above.
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Advantageous Effects
According to an embodiment of the present disclosure, the battery module according to the present disclosure includes the screen member. This structure may physically block the movement of a high-temperature active material discharged from the exploded battery cell to adjacent battery cells while maintaining the function of ejecting 5 the gas and flame generated when the battery cell is ignited. By doing so, when any one of the plurality of battery cells behaves abnormally (electric short, thermal runaway), if the battery cell explodes to eject the internal material to the outside, gas and flame are ejected through the exposure hole, but the movement of the high-temperature active material is suppressed by the screen member. Therefore, it is possible to prevent the ejected internal 10 material from moving to other adjacent battery cells through other adjacent exposure holes. That is, by forming the ventilation hole to be smaller than the exposure hole, the screen member may allow the high-temperature gas ejected through the exposure hole to pass through the ventilation hole, but prevents the ejected fragments of the electrode assembly from passing through the ventilation hole. Accordingly, in the present disclosure, it is 15 possible to prevent chain ignition, such as propagating of thermal runaway, fire or explosion to other battery cells, thereby greatly improving the safety.

WHAT IS CLAIMED IS:
1. A battery module, comprising:
a plurality of battery cells, each having electrode terminals respectively formed at an upper portion and a lower portion thereof; 5
a module case configured to accommodate the plurality of battery cells and having a plurality of exposure holes configured to expose the upper portion or the lower portion of the battery cell; and
a screen member located at any one or more of an upper portion and a lower portion of the module case and having a plate shape, the screen member being configured 10 to have a ventilation hole with a smaller size than the exposure hole.
2. The battery module according to claim 1,
wherein two or more ventilation holes are provided in a region of the screen member that faces the exposure hole. 15
3. The battery module according to claim 1,
wherein the ventilation hole is configured to have a diameter gradually decreasing in an outward direction.
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4. The battery module according to claim 1,
wherein the ventilation hole is shaped so that the screen member is perforated in a zigzag form.
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5. The battery module according to claim 1, further comprising:
a connection plate interposed between the screen member and the module case and having electric conductivity, the connection plate including a body portion having a plate shape extending in a horizontal direction, a connection portion extending from the body 5 portion to contact the electrode terminal, and a connection hole formed by opening a part of the body portion so that the connection portion is located in the opening thereof.
6. The battery module according to claim 5,
wherein the connection plate includes an extension portion configured to 10 protrusively extend in a horizontal direction from an outer circumference of the connection hole to hide a part of the connection hole.
7. The battery module according to claim 5,
wherein the module case includes a plurality of cover portions configured to 15 protrude toward the connection plate from an outer circumference of the plurality of exposure holes, respectively, the cover portion having a hollow and being shaped to have an open top end.
8. The battery module according to claim 7, 20
wherein the cover portion includes a bending part bent at the open top end to extend in a horizontal direction to hide a part of the connection hole of the connection plate.
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9. A battery pack, comprising at least one battery module according to any one of claims 1 to 8.
10. A vehicle, comprising at least one battery module according to any one of claims 1 to 8.