Battery module having a structure capable of rapid cooling and energy storage system including the battery module

Abstract

A battery module according to one embodiment of the present invention includes: a plurality of battery cells; a module housing for accommodating a cell stack including the plurality of battery cells; and a sprayer for penetrating the module housing on one side of the module housing in a stacking direction of the cell stack, wherein the sprayer includes: a connector positioned outside the module housing and connected to a supply pipe for supplying a cooling fluid; a sprayer head positioned inside the module housing and connected to the connector; and an insulating cover assembly including an insulating cover covering the sprayer head, and including an impeller assembly covering an opening formed at a side end portion in a longitudinal direction of the insulating cover.

Description

Technical Field

[0001] The present disclosure relates to a battery module having a structure allowing rapid cooling and an ESS including the same. More particularly, the present disclosure relates to a battery module having a structure capable of rapidly operating a sprinkler when high-temperature exhaust gas leaks into the interior of the battery module and an ESS including the same.

[0002] This application claims the priority of Korean Patent Application No. 10-2020-0027904 filed in Korea on March 5, 2020, the disclosure of which is incorporated herein by reference. Background Art

[0003] Currently commercialized secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries and lithium secondary batteries. Among these secondary batteries, lithium secondary batteries have attracted much attention because they have almost no memory effect compared to nickel-based secondary batteries to ensure free charging and discharging and also have extremely low discharge rates and high energy density.

[0004] Lithium secondary batteries mainly use lithium oxides and carbon materials as positive electrode active materials and negative electrode active materials, respectively. Lithium secondary batteries include: an electrode assembly, in which a positive electrode plate and a negative electrode plate coated with positive electrode active materials and negative electrode active materials, respectively, are arranged, and a separator is placed between the positive electrode plate and the negative electrode plate; and an exterior, i.e., a battery bag exterior, which is used to seal and store the electrode assembly together with an electrolyte.

[0005] Recently, secondary batteries are widely used not only in small devices such as portable electronic devices, but also in medium or large devices such as vehicles and energy storage systems. When used in such medium or large devices, a large number of secondary batteries are electrically connected to increase capacity and output. In particular, pouch-type secondary batteries are widely used in such medium-sized devices because pouch-type secondary batteries can be easily stacked.

[0006] Meanwhile, with recent demands for large-capacity structures and increased use as energy storage sources, demands for battery modules including a plurality of secondary batteries electrically connected in series and / or in parallel are increasing.

[0007] In addition, the battery module generally has a housing made of a metal material to protect or store a plurality of secondary batteries from external impacts. Meanwhile, the demand for high-capacity battery modules is increasing recently.

[0008] In the case of such a high-capacity battery module, if the temperature inside the battery module increases due to gas exhaust in at least some of the internal battery cells, great damage may occur. That is, if a thermal runaway phenomenon occurs due to the increase in internal temperature, the temperature of the high-capacity battery module may increase rapidly, and thus a large-scale fire and / or explosion may occur.

[0009] Therefore, there is a need to develop a rapid and thorough fire extinguishing technology to take immediate action when an abnormal temperature increase occurs due to gas exhaust in a battery cell inside a battery module. Summary of the invention

[0010] Technical issues

[0011] The present disclosure is designed to solve the problems of the related art, and thus the present disclosure aims to quickly operate a sprinkler when high-temperature exhaust gas leaks inside a battery module, thereby ensuring safety when using the battery module and the ESS.

[0012] However, the technical problems to be solved by the present disclosure are not limited to the above contents, and those skilled in the art will understand other purposes not mentioned herein through the following description.

[0013] Technical Solutions

[0014] In one aspect of the present disclosure, a battery module is provided, comprising: a plurality of battery cells; a module housing configured to accommodate a battery cell stack comprising the plurality of battery cells; and a sprayer disposed to pass through the module housing at one side in a stacking direction of the battery cell stack, wherein the sprayer comprises: a coupling positioned at an outer side of the module housing and connected to a supply pipe for supplying a cooling fluid; a sprayer head positioned at an inner side of the module housing and connected to the coupling; and an insulating cover assembly having an insulating cover configured to cover the sprayer head and an impeller assembly configured to cover an opening formed at a side end portion in a longitudinal direction of the insulating cover.

[0015] The sprinkler head may include: a glass bubble, which is configured to block a cooling fluid injection hole of the coupling and is configured to rupture when a temperature or a flow rate of gas inside the battery module increases beyond a reference value to open the cooling fluid injection hole; and a retaining bracket, which is configured to fix the glass bubble while surrounding the glass bubble.

[0016] The insulating cover may have a cover hole formed at a position corresponding to the glass bubbles.

[0017] The impeller assembly may include an impeller frame fixed to the insulating cover and an impeller disposed in an air inlet hole formed at the impeller frame and configured to rotate as air introduced through the air inlet hole flows toward the glass bubble.

[0018] The module housing may include: a pair of base covers, which are configured to cover the lower surface and the upper surface of the battery cell stack, respectively; a pair of side covers, which are configured to cover the side surfaces of the battery cell stack; a front cover, which is configured to cover the front surface of the battery cell stack; and a rear cover, which is configured to cover the rear surface of the battery cell stack.

[0019] The battery module may include a pair of bus bar frames respectively coupled to one side and the other side of the battery cell stack in a width direction.

[0020] The sprinkler head and insulation cover assembly may be disposed to pass through one longitudinal side of the rear cover and positioned in a hollow space formed between the bus bar frame and the side cover.

[0021] The other side end portion of the insulation cover may be coupled to an inner surface of the module case or to a coupling member provided through the module case.

[0022] A bonding layer may be interposed between the other side end portion of the insulation cover and the inner surface of the module case or between the other side end portion of the insulation cover and a coupling member provided through the module case.

[0023] When the temperature inside the module case increases so that the bonding force of the bonding layer is lost or reduced, the insulation cover assembly may be separated from the inner surface of the module case or from a coupling member provided through the module case.

[0024] The battery module may include at least one guide plate that is fixed inside the module housing and is obliquely mounted such that one longitudinal end of the at least one guide plate is oriented toward the impeller assembly.

[0025] The battery module may include: an air inlet formed through the front cover; an air outlet formed through the rear cover; and an expansion pad arranged on the inner side of the air inlet and the air outlet, and the expansion pad is configured to at least partially close the air inlet and the air outlet by expanding when it contacts a cooling fluid introduced into the battery module.

[0026] The expansion pad may be at least partially inserted into an accommodation groove formed at an inner surface of the module case.

[0027] The battery module may include mesh plates respectively arranged at both sides of the expansion pad to guide expansion movement of the expansion pad.

[0028] Meanwhile, the ESS according to an embodiment of the present disclosure includes a plurality of the battery modules according to the present disclosure as described above.

[0029] Beneficial Effects

[0030] According to an embodiment of the present disclosure, when high-temperature exhaust gas leaks inside a battery module, a sprinkler can be quickly operated, thereby ensuring safety when using the battery module and the ESS. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, are used to provide a further understanding of the technical features of the present disclosure, and thus the present disclosure is not to be construed as being limited to the accompanying drawings.

[0032] Figure 1 and Figure 2 is a perspective view showing a battery module according to an embodiment of the present disclosure.

[0033] Figure 3 and Figure 4 It shows Figure 1 and Figure 2 A view of the internal structure of a battery module shown in FIG.

[0034] Figure 5 is a view showing a sprinkler applied to the present disclosure.

[0035] Figure 6 is a view showing an impeller assembly applied to the present disclosure.

[0036] Figure 7 is a view showing a positional relationship between a sprinkler and a guide plate applied to the present disclosure.

[0037] Figure 8 is a view showing a portion of a front surface of a battery module according to an embodiment of the present disclosure so that an expansion pad disposed inside the battery module is revealed.

[0038] Figures 9 to 11 is a view showing a portion of a cross section of a battery module according to an embodiment of the present disclosure viewed from one side so that an expansion pad disposed inside the battery module is revealed. DETAILED DESCRIPTION

[0039] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms used in the specification and the appended claims should not be interpreted as limited to the general and dictionary meanings, but are interpreted based on the meaning and concept corresponding to the technical aspects of the present disclosure based on the principle of allowing the inventor to appropriately define the terms to obtain the best interpretation. Therefore, the descriptions presented herein are only preferred examples for illustrative purposes and are not intended to limit the scope of the present disclosure, so it should be understood that other equivalents and modifications may be made thereto without departing from the scope of the present disclosure.

[0040] First, refer to Figures 1 to 4 The overall structure of the battery module 1 according to the embodiment of the present disclosure is described.

[0041] refer to Figures 1 to 4 , the battery module 1 according to an embodiment of the present disclosure includes a plurality of battery cells 100 , a bus bar frame 200 , a module case 300 , an air inlet 400 , an air outlet 500 , and a sprayer 600 .

[0042] The battery cell 100 is arranged in plurality, and a plurality of battery cells 100 are stacked to form a battery cell stack. The battery cell 100 may be, for example, a pouch-type battery cell. The battery cell 100 includes a pair of electrode leads 110, which are led out on both sides in a longitudinal direction (a direction parallel to the Y-axis shown in the figure). At the same time, although not shown in the drawings, if necessary, the battery cell stack may further include a buffer pad disposed between battery cells 100 adjacent to each other. When the battery cell stack is accommodated in the module housing 300, the buffer pad allows the battery cell stack to be accommodated in a compressed state, thereby limiting movement caused by external impact and suppressing bulging of the battery cell 100.

[0043] The busbar frames 200 are provided in pairs, and a pair of busbar frames 200 covers one side and the other side of the battery cell stack in the width direction (the direction parallel to the Y axis in the figure). The electrode leads 110 of the battery cells 100 are led out through the slits formed at the busbar frames 200, and are bent and fixed to the busbars provided to the busbar frames 200 by welding or the like. That is, a plurality of battery cells 100 can be electrically connected by the busbars provided to the busbar frames 200.

[0044] The module housing 300 has a substantially rectangular parallelepiped shape and accommodates a battery cell stack therein. The module housing 300 includes: a pair of base covers 310, each configured to cover the lower surface and the upper surface (surfaces parallel to the XY plane) of the battery cell stack; a pair of side covers 320, each configured to cover the side surfaces (surfaces parallel to the XZ plane) of the battery cell stack; a front cover 330, each configured to cover the front surface (surface parallel to the YZ plane) of the battery cell stack; and a rear cover 340, each configured to cover the rear surface (surface parallel to the YZ plane) of the battery cell stack.

[0045] The air inlet 400 is formed at one side in the stacking direction of the battery cell stack (direction parallel to the X-axis), that is, at one side in the longitudinal direction of the battery module 1, and has a hole shape formed through the front cover 330. The air outlet 500 is formed at the other side in the stacking direction of the battery cell stack, that is, at the other side in the longitudinal direction of the battery module 1, and has a hole shape formed through the rear cover 340. The air inlet 400 and the air outlet 500 are located at diagonally opposite sides along the longitudinal direction of the battery module 1 (direction parallel to the X-axis).

[0046] Meanwhile, a hollow space is formed between the bus bar frame 200 and the side cover 320. That is, the hollow space is formed between one of the six outer surfaces of the module housing 300 facing one side and the other side in the longitudinal direction (direction parallel to the Y axis) of the battery cell 100 and the bus bar frame 200, and air for cooling the battery cell 100 flows in the hollow space. The hollow space is formed at each of the two sides in the width direction (direction parallel to the Y axis) of the battery module 1.

[0047] The air inlet 400 is formed at a position corresponding to a hollow space formed on one side in the width direction (direction parallel to the Y-axis) of the battery module 1, and the air outlet 500 is formed at a position corresponding to a hollow space formed on the other side in the width direction of the battery module 1.

[0048] In the battery module 1, the air introduced into the battery module 1 through the air inlet 400 cools the battery cells 100 while moving from the hollow space formed on one side in the width direction of the battery module 1 to the hollow space formed on the other side in the width direction of the battery module 1, and then leaves through the air outlet 500. That is, the battery module 1 corresponds to an air-cooled battery module.

[0049] Meanwhile, in the present disclosure, unlike its name, the air inlet 400 may also be used for cooling to serve as a passage for discharging heated air whose temperature rises. Likewise, unlike its name, the air outlet 500 may also be used as a passage for introducing external air for cooling. That is, an impeller for forced ventilation may be installed at the air inlet 400 and / or the air outlet 500, and the direction of air circulation may vary depending on the rotation direction of the impeller.

[0050] The sprayer 600 is connected to a supply pipe (not shown) that supplies a cooling fluid such as cooling water, and when the temperature inside the battery module 1 or the gas flow rate inside the battery module 1 increases beyond a certain level, the sprayer 600 operates to supply the cooling fluid into the battery module 1. In other words, if an abnormal situation occurs in the battery cell 100 to cause exhaust so that high-temperature gas is discharged, the sprayer 600 detects the high-temperature gas and operates. If the sprayer 600 operates in this manner, the cooling fluid can be supplied into the battery module 1 to prevent the battery cell 100 from catching fire and / or exploding due to overheating.

[0051] A portion of the sprayer 600 is exposed outside the rear cover 340, and another portion of the sprayer 600 is disposed through the rear cover 340 and is located in a hollow space formed between the bus bar frame 200 and the side cover 320. The sprayer 600 is installed at a side opposite to the air outlet 500 formed on one side of the rear cover 340 in the longitudinal direction (direction parallel to the Y axis).

[0052] The sprinkler 600 includes a connector 610, a sprinkler head 620 and an insulating cover assembly 630. The connector 610 is positioned at the outside of the module housing 300 and is connected to a supply pipe (not shown) that supplies the cooling fluid. That is, the connector 610 is made of a metal material and is a component for fastening an external supply pipe. The sprinkler head 620 is positioned on the inside of the module housing 300 and is connected to the connector 610. The insulating cover assembly 630 covers the sprinkler head 620, thereby preventing the sprinkler head 620 from directly contacting the electrode lead 110 of the battery cell 100 and / or the busbar of the busbar frame 200 to cause a short circuit. In addition, the insulating cover assembly 630 explained later has a function of causing the gas heated by the temperature rise inside the module housing 300 to flow to the sprinkler head 620 in a concentrated manner.

[0053] refer to Figure 5 The sprinkler head 620 includes a glass bulb 621 and a retaining bracket 622 .

[0054] The glass bulb 621 blocks the cooling fluid injection hole P of the coupling member 610, and if the temperature inside the battery module 1 or the flow rate of the internal gas heated by the exhaust gas increases beyond a reference value, the glass bulb 621 ruptures to open the cooling fluid injection hole P. The glass bulb 621 contains a liquid that expands as the temperature rises, and if exhaust occurs in at least some of the battery cells 100 inside the battery module 1 so that the high-temperature exhaust gas fills the battery module 1, the liquid expands. As the liquid expands, the internal pressure of the glass bulb 621 increases, and at the same time, if the external force of the gas acts together due to the high-pressure exhaust gas outside the glass bulb 621, the glass bulb 621 ruptures, so that the cooling fluid passes through the cooling fluid injection hole P to fill the inside of the module case 300. The retaining bracket 622 is made of a metal material, and surrounds the glass bulb 621 to fix the glass bulb 621 so that it does not move.

[0055] refer to Figure 5 and Figure 6 , the insulating cover assembly 630 includes an insulating cover 631 and an impeller assembly 632. The insulating cover 631 has a substantially hollow cylindrical shape surrounding the sprinkler head 620. The impeller assembly 632 is attached to an opening formed at one side end portion in the longitudinal direction (a direction parallel to the X-axis in the figure) of the insulating cover 631, and the coupling piece 610 provided through the rear cover 340 or the inner side of the rear cover 340 of the module housing 300 is coupled to the other side end portion in the longitudinal direction of the insulating cover 631.

[0056] The insulating cover 631 has at least one cover hole 631a formed at a position corresponding to the glass bubble 621. The cover hole 631a serves as a passage through which the high-temperature gas introduced into the insulating cover 631 through the impeller assembly 632 contacts the glass bubble 621 and then escapes to the outside of the insulating cover 631. In addition, the cover hole 631a may also serve as a passage through which the cooling fluid injected through the fluid injection hole P due to the rupture of the glass bubble 621 may be discharged to the outside of the insulating cover 631.

[0057] Meanwhile, a bonding layer (not shown) may be disposed between the other side end of the insulating cover 631 and the inner surface of the rear cover 340 of the module housing 300 or between the other side end of the insulating cover 631 and the coupling piece 610 disposed through the rear cover 340. If the temperature inside the module housing increases, the bonding force of the bonding layer may be lost or reduced, and thus the insulating cover 631 may be separated from the coupling piece 610 disposed through the rear cover 340 or the inner surface of the rear cover 340. If the insulating cover 631 surrounding the sprinkler head 620 is removed as described above, the cooling fluid is more smoothly supplied to the module housing 300, thereby improving the fire extinguishing efficiency and the cooling efficiency.

[0058] The impeller assembly 632 includes an impeller frame 632a and an impeller 632b. The impeller frame 632a is fixed at one longitudinal end of the insulating cover 631 and has an air inlet H having a size and shape corresponding to an opening formed at one longitudinal end of the insulating cover 631. The impeller 632b is arranged in the air inlet H of the impeller frame 632a and rotates due to the flow of air introduced toward the glass bulb 621 through the air inlet H. That is, the impeller 632b corresponds to an unpowered rotating device that rotates without a driving device such as a motor.

[0059] As the impeller 632b rotates, the flow of the air introduced into the insulating cover 631 is accelerated, so a larger amount of high-temperature gas can be supplied to the glass bubbles 621, so that the glass bubbles 621 are quickly broken. The gas contacting the glass bubbles 621 as described above is discharged to the outside of the insulating cover 631 through the cover hole 631a formed in the insulating cover 631.

[0060] like Figure 5 As shown, the rotation axis X of the impeller 632b can be formed at one side end in the longitudinal direction (direction parallel to the X-axis) of the retaining bracket 622, or alternatively, the rotation axis X can also be set to the impeller frame 632a itself.

[0061] refer to Figure 7 The battery module 1 according to the embodiment of the present disclosure may further include at least one guide plate G. The guide plate G is fixed in the module housing 300 and may be installed obliquely so that one side end of the guide plate G in the longitudinal direction (direction parallel to the X-axis) is oriented toward the impeller assembly 632. The guide plate G may be manufactured separately and attached to the side cover 320, or may be formed integrally with the side cover 320.

[0062] The gas having a strong tendency to move upward as the temperature inside the battery module 1 increases may be guided by the guide plate G to flow toward the sprayer 600 , thereby achieving rapid rupture of the glass bubbles 621 .

[0063] refer to Figure 8 The battery module 1 may further include an expansion pad E configured to at least partially close the air inlet 400 and the air outlet 500 so that the liquid level of the cooling fluid increases rapidly when the cooling fluid is supplied to the battery module 1 .

[0064] The expansion pad E is attached to the inner surface of the module housing 300 and has a size smaller than the opening area of ​​the air inlet 400 and the air outlet 500. When the battery module 1 is in normal use, the expansion pad E preferably has a size smaller than about 30% of the opening area of ​​the air inlet 400 and the air outlet 500, so that air can flow smoothly through the air inlet 400 and the air outlet 500. Meanwhile, although the drawings of the present disclosure only depict the situation where the expansion pad E is attached at the bottom of the inner surface of the module housing 300, the expansion pad E may also be attached to the top or side of the module housing 300.

[0065] The expansion pad E expands by contacting the cooling fluid introduced into the battery module 1 to close the air inlet 400 and the air outlet 500. The expansion pad E contains a resin that exhibits a very large expansion rate when absorbing moisture, for example, a resin whose volume increases by at least about two times or more compared to the initial volume when a sufficient amount of moisture is provided thereto. As a resin for the expansion pad E, for example, a non-woven fabric of a mixed SAF (super absorbent fiber) and polyester staple fibers can be mentioned. SAF is prepared by forming fibers using SAP (super absorbent polymer).

[0066] At the same time, when the air inlet 400 and the air outlet 500 are closed due to the expansion of the expansion pad E, this does not necessarily mean that the air inlet 400 and the air outlet 500 are completely closed so that the cooling fluid cannot leak, but also includes reducing the opening area of ​​the air inlet 400 and the air outlet 500 to reduce the amount of leakage.

[0067] By applying the expansion pad E, when a thermal runaway phenomenon occurs in at least some of the battery modules 1 and thus a cooling fluid is introduced into the battery module 1, the air inlet 400 and the air outlet 500 are closed. If the air inlet 400 and the air outlet 500 are closed as described above, the cooling fluid introduced into the battery module 1 does not escape to the outside, but stays inside the battery module 1, thereby quickly resolving the thermal runaway phenomenon occurring in the battery module 1.

[0068] refer to Fig. 9, the expansion pads E may be provided in pairs. In this case, a pair of expansion pads E are respectively attached to the upper and lower portions of the inner surface of the module housing 300. A pair of expansion pads E are attached at corresponding positions and contact each other when expanded to close the air inlet 400 and the air outlet 500.

[0069] refer to Fig.10 , the expansion gasket E may be fixed by inserting at least a portion of the expansion gasket E into a receiving groove 300 a formed to a predetermined depth at the inner surface of the module housing 300 .

[0070] refer to Fig.11 When the expansion pad E expands by absorbing moisture, the expansion movement of the expansion pad E can be guided by a pair of mesh plates 400a, 500a respectively arranged on both sides of the expansion pad E. The mesh plates 400a, 500a are mesh plates and have a structure that allows air and cooling fluid to pass through when the expansion pad E is not expanded.

[0071] Meanwhile, an ESS (Energy Storage System) according to an embodiment of the present disclosure includes a plurality of battery modules according to an embodiment of the present disclosure as described above.

[0072] The present disclosure has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the present disclosure, are given by way of illustration only, since various changes and modifications within the scope of the present disclosure will become apparent to those skilled in the art from this detailed description.

Claims

1. A battery module, comprising: Multiple battery cells; a module housing configured to accommodate a battery cell stack including the plurality of battery cells; as well as a sprayer disposed to penetrate the module housing at one side in a stacking direction of the battery cell stack, Wherein, the sprayer comprises: a coupling member positioned outside the module housing and connected to a supply pipe supplying a cooling fluid; a sprinkler head positioned inside the module housing and connected to the coupling; and an insulating cover assembly having: an insulating cover configured to cover the sprinkler head; and an impeller assembly configured to cover an opening formed at one side end portion in a longitudinal direction of the insulating cover, The spray head includes: a glass bubble, which is configured to block a cooling fluid injection hole of the coupling member and is configured to rupture when the temperature or flow rate of gas inside the battery module increases beyond a reference value to open the cooling fluid injection hole; and a retaining bracket, which is configured to fix the glass bubble while surrounding the glass bubble. The insulating cover has a cover hole, and the cover hole is formed at a position corresponding to the glass bulb. The impeller assembly includes: an impeller frame, which is fixed to the insulating cover; and an impeller, which is arranged in an air inlet hole formed at the impeller frame and is configured to rotate due to the flow of air introduced through the air inlet hole toward the glass bubble.

2. The battery module according to claim 1, wherein: The module housing comprises: a pair of base covers configured to cover a lower surface and an upper surface of the battery cell stack, respectively; a pair of side covers configured to cover side surfaces of the battery cell stack; a front cover configured to cover a front surface of the battery cell stack; and A rear cover is configured to cover a rear surface of the battery cell stack.

3. The battery module according to claim 2, wherein: The battery module includes a pair of bus bar frames respectively coupled to one side and the other side of the battery cell stack in a width direction.

4. The battery module according to claim 3, wherein: The sprinkler head and the insulation cover assembly are disposed to pass through one longitudinal side of the rear cover, and are positioned in a hollow space formed between the bus bar frame and the side cover.

5. The battery module according to claim 1, wherein: The other side end portion of the insulation cover is coupled to the coupling member provided through the module case or an inner surface of the module case.

6. The battery module according to claim 5, wherein: A bonding layer is interposed between the other side end portion of the insulation cover and the inner surface of the module case, or between the other side end portion of the insulation cover and the coupling member provided through the module case.

7. The battery module according to claim 6, wherein: When the temperature inside the module case increases so that the bonding force of the bonding layer is lost or reduced, the insulation cover assembly is separated from the coupling member provided through the module case or the inner surface of the module case.

8. The battery module according to claim 1, wherein: The battery module includes at least one guide plate that is fixed inside the module housing and is installed obliquely such that one longitudinal end of the at least one guide plate is oriented toward the impeller assembly.

9. The battery module according to claim 2, wherein: The battery module comprises: an air inlet formed through the front cover; an air outlet formed through the rear cover; and An expansion pad is arranged inside the air outlet and the air inlet and is configured to at least partially close the air inlet and the air outlet by expanding when contacting the cooling fluid introduced into the battery module.

10. The battery module according to claim 9, wherein: The expansion pad is at least partially inserted into an accommodation groove formed at an inner surface of the module case.

11. The battery module according to claim 9, wherein: The battery module includes mesh plates, which are respectively arranged on both sides of the expansion pad to guide the expansion movement of the expansion pad.

12. An energy storage system comprising a plurality of battery modules according to any one of claims 1 to 11.

Images