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 accommodating a cell stack including the plurality of battery cells; a sprayer penetrating the module housing from one side in a stacking direction of the cell stack; and a thermal expansion block disposed in a hollow space in the module housing to thermally expand according to a temperature increase inside the module housing.

Description

Technical Field

[0001] The present disclosure relates to a battery module having a structure that allows rapid cooling and an ESS including the battery module. More specifically, the present disclosure relates to a battery module having a structure that can quickly increase the liquid level of a cooling fluid (e.g., cooling water) for fire extinguishing and cooling when a sprinkler is operated due to exhaust gas leakage inside the battery module and an ESS including the battery module.

[0002] This application claims priority to Korean Patent Application No. 10-2020-0024462 filed in Korea on February 27, 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 them, lithium secondary batteries have attracted much attention because they have almost no memory effect compared to nickel-based secondary batteries, thus ensuring free charging and discharging, and also have very 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 covered with positive electrode active materials and negative electrode active materials, respectively, are provided, 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 the 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, as the demand for large-capacity structures has recently been increasing in conjunction with use as an energy storage source, the demand for a battery module including a plurality of secondary batteries electrically connected in series and / or in parallel has also been increasing.

[0007] In addition, the battery module generally has an outer case 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 recently increasing.

[0008] In the case of such a high-capacity battery module, if the temperature inside the battery module increases due to degassing 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 the 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 complete fire extinguishing technology to take immediate measures when an abnormal temperature rise occurs due to gas exhaust in the battery cells inside the 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 relates to quickly increasing the liquid level of a cooling fluid (e.g., cooling water) used for fire extinguishing and cooling to ensure rapid fire extinguishing and cooling when a sprinkler is operated due to exhaust gas leakage inside a battery module, and the present disclosure relates to an ESS including the battery module.

[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 based on the following description.

[0013] Technical Solution

[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 cell stack including the plurality of battery cells; a sprayer disposed to pass through the module housing at one side in a stacking direction of the cell stack; and a thermal expansion block disposed in a hollow space inside the module housing and configured to thermally expand as the temperature inside the module housing increases.

[0015] The module housing may include: a pair of base covers, which are configured to cover the lower surface and the upper surface of the cell stack, respectively; a pair of side covers, which are configured to cover the side surfaces of the cell stack; a front cover, which is configured to cover the front surface of the cell stack; and a rear cover, which is configured to cover the rear surface of the cell stack.

[0016] The battery module may include a pair of bus bar frames respectively coupled to one side and the other side of the cell stack in a width direction.

[0017] The thermal expansion block may be provided in plurality and fixed to be spaced apart from each other along a longitudinal direction of the battery module on a base cover configured to cover a lower surface of the cell stack and disposed between the bus bar frame and a side cover.

[0018] The thermal expansion block may be provided in plural, and the plurality of thermal expansion blocks may be respectively placed between the platform portions of the battery cells adjacent to each other.

[0019] The thermal expansion block may include a thermal expansion foaming agent.

[0020] The sprinkler may include: a connector located at the outside of the module housing and connected to a supply pipe for supplying a cooling fluid; a sprinkler head located at the inside of the module housing and connected to the connector; and an insulating cover including a fixing portion and a cover portion, the fixing portion being fixed to the module housing, the cover portion being fixed to the fixing portion through a bonding layer, and the cover portion being configured to separate from the fixing portion above a reference temperature as the bonding force of the bonding layer decreases or is lost.

[0021] The sprayer may be provided to pass through one longitudinal side of the rear cover and be located in a hollow space formed between the bus bar frame and the side cover.

[0022] The cover part may be hinged to the fixing part, and opened by downward rotation relative to the sprinkler head based on the hinge part above a reference temperature.

[0023] 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 disposed at an inner side of the air inlet and the air outlet and configured to at least partially close the air inlet and the air outlet by expanding when in contact with a cooling fluid introduced into the battery module.

[0024] The expansion pad may be attached to an inner surface of the module housing.

[0025] The expansion pad may be at least partially inserted into an accommodation groove formed at an inner surface of the module case.

[0026] The battery module may include mesh plates respectively disposed at both sides of the expansion pad to guide expansion movement of the expansion pad.

[0027] The air inlet and the air outlet may be formed at positions corresponding to a hollow space formed between the bus bar frame and the side cover.

[0028] Meanwhile, an energy storage system (ESS) according to an embodiment of the present disclosure includes a plurality of battery modules according to the present disclosure.

[0029] Beneficial effects

[0030] According to an embodiment of the present disclosure, when the sprinkler is operated due to exhaust gas leakage inside the battery module, the liquid level of cooling fluid (eg, cooling water) for fire extinguishing and cooling can be quickly increased, thereby allowing rapid cooling and fire extinguishing. 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. Therefore, the present disclosure is not interpreted 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 It is shown in Figure 1 and Figure 2 A view of the internal structure of a battery module depicted in FIG.

[0034] Figure 4 and Figure 5 is a view showing an internal structure of a battery module according to an embodiment of the present disclosure, thereby demonstrating a thermal expansion block applied in the present disclosure.

[0035] Figure 6 is a view showing an internal structure of a battery module according to an embodiment of the present disclosure, in which an insulating cover applied in the present disclosure is opened.

[0036] Figure 7 is a perspective view showing an insulating cover applied in 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, thereby illustrating an expansion pad provided inside the battery module.

[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 a side, thereby illustrating an expansion pad provided inside the battery module. 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 meaning and dictionary meaning, 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 for 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 equivalent schemes and modifications may be made thereto without departing from the scope of the present disclosure.

[0040] First, refer to Figures 1 to 3 The overall structure of the battery module 1 according to the embodiment of the present disclosure is described.

[0041] refer to Figures 1 to 3 , a 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 single 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 at 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 figure, if necessary, the single cell stack may further include a buffer pad disposed between battery cells 100 adjacent to each other. When the single cell stack is accommodated in the module housing 300, the buffer pad allows the single cell stack to be accommodated in a compressed state, thereby limiting the movement caused by external impact and suppressing the bulging phenomenon of the battery cell 100.

[0043] The busbar frames 200 are arranged in pairs, and a pair of busbar frames 200 covers one side and the other side of the 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 through the busbars provided to the busbar frames 200.

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

[0045] The air inlet 400 is formed at one side in the stacking direction of the cell stack (the 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 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 (the direction parallel to the X-axis).

[0046] At the same time, a hollow space is formed between the bus bar frame 200 and the side cover 320. That is, a hollow space in which air for cooling the battery cell 100 flows 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. 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 at one side in the width direction (a direction parallel to the Y-axis line) of the battery module 1, and the air outlet 500 is formed at a position corresponding to a hollow space formed at 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 a hollow space formed at one side in the width direction of the battery module 1 to a hollow space formed at the other side in the width direction of the battery module 1, and then is discharged 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 the name of the air inlet 400, the air inlet 400 may also be used for cooling to serve as a passage for exhausting the rising heated air. In addition, unlike the name of the air outlet 500, the air outlet 500 may also be used as a passage for introducing external air for cooling. That is, an impeller for forced exhaust may be installed at the air inlet 400 and / or the air outlet 500, and the direction of air circulation may be changed according to 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 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 provided to pass 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 in the longitudinal direction (direction parallel to the Y axis) of the rear cover 340.

[0052] The sprinkler 600 includes a connector 610, a sprinkler head 620, and an insulating cover 630. The connector 610 is located at the outside of the module housing 300 and is connected to a supply pipe (not shown) that supplies a 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 located at the inside of the module housing 300 and is connected to the connector 610. The insulating cover 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 and causing a short circuit.

[0053] refer to Figure 4 , Figure 6 and Figure 7 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 coupler 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 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 fills the inside of the module case 300 through the cooling fluid injection hole P. 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] The insulating cover 630 includes a fixing portion 631 and a cover portion 632. The fixing portion 631 is attached to the rear cover 340 by clamping. That is, a portion of the fixing portion 631 is located at the outer side of the rear cover 340, and another portion of the fixing portion 631 is located at the inner side of the rear cover 340. The cover portion 632 extends from the fixing portion 631 in a direction substantially perpendicular to the fixing portion, and covers the sprinkler head 620.

[0056] The cover portion 632 includes a first area 632a facing the cell stack and the busbar frame 200 and a second area 632b other than the first area. The first area 632a is formed so that the closed area is larger than the open area, and the second area 632b is formed so that the open area is larger than the closed area. The cover portion 632 is at least partially open to allow the cooling fluid sprayed through the cooling fluid spray hole P to be smoothly supplied into the module housing 300.

[0057] In addition, the open area of ​​the first region 632a is smaller than the open area of ​​the second region 632b, so as to minimize the possibility of a short circuit caused by contact between the retaining bracket 622 and the electrode lead 110 and / or contact between the retaining bracket 622 and the bus bar. At the same time, the first region 632a may have at least one cover hole H for spraying a cooling fluid.

[0058] At the same time, the cover portion 632 is coupled to the fixing portion 631 fixed to the module housing 300 in a detachable structure. The bonding layer A is placed between the fixing portion 631 and the cover portion 632 so that when the battery module 1 is in normal use, the fixing portion 631 and the cover portion 632 remain coupled to each other. However, if exhaust occurs at the battery cell 100 to leak high-temperature gas, causing the temperature inside the module housing 300 to rise above the reference temperature, the bonding layer A melts and the bonding force of the bonding layer A is reduced or lost. Therefore, the cover portion 632 is separated from the fixing portion 631 by spraying the cooling fluid or before spraying the cooling fluid.

[0059] Other fixing elements other than the bonding layer A may not be applied to the connection between the fixing portion 631 and the cover portion 632, or a hinge structure may be additionally applied to the connection in addition to the bonding layer A, as shown in the figure. If a hinge structure is applied to connect the fixing portion 631 and the cover portion 632 to each other, the cover portion 632 is opened as the hinge portion rotates and as the bonding force of the bonding layer A decreases or is lost.

[0060] When the cover portion 632 is separated from the fixing portion 631 in this manner, the cover portion 632 no longer serves as an element that interferes with the spraying of the cooling fluid from the cooling fluid spraying hole P, thereby enabling smooth fire extinguishing and cooling.

[0061] refer to Figures 3 to 5 The battery module 1 includes a plurality of thermal expansion blocks B. The thermal expansion blocks B are disposed in the hollow space inside the module housing 300 so that when a cooling fluid is supplied into the module housing 300, the liquid level of the cooling fluid increases rapidly. When the temperature inside the module housing 300 rises above a reference temperature due to exhaust at the battery cells 100 to generate high-temperature exhaust gas, the thermal expansion blocks B expand, thereby reducing the volume of the hollow space inside the module housing 300.

[0062] If the volume of the hollow space inside the module housing 300 is reduced due to the expansion of the thermal expansion block B, the liquid level of the cooling fluid increases more quickly when the same amount of cooling fluid is sprayed, thereby allowing rapid fire extinguishing and cooling.

[0063] The thermal expansion block B may include, for example, a thermal expansion foaming agent whose volume increases according to a temperature increase. The thermal expansion foaming agent may have, for example, a core-shell structure including an acrylic thermoplastic resin containing a hydrocarbon compound therein.

[0064] refer to Figure 3 and Figure 4, a plurality of thermal expansion blocks B are fixed to be spaced apart from each other along the longitudinal direction (direction parallel to the X-axis) of the battery module 1 on the base cover 310 covering the lower surface of the cell stack, and a plurality of thermal expansion blocks B may be disposed in the hollow space between the bus bar frame 200 and the side cover 320.

[0065] In addition, refer to Figure 5 , a plurality of thermal expansion blocks B may be disposed between the platform portions T of the battery cells 100 adjacent to each other among the plurality of battery cells 100 included in the cell stack. Here, the platform portion T refers to a partial area of ​​the sealing portion 100b of the battery cell 100. That is, the pouch-type battery cell 100 includes a receiving portion 100a in which an electrode assembly (not shown) is received and a sealing area 100b extending from the periphery of the receiving portion 100a. Here, a portion of the sealing area 100b located in the direction in which the electrode lead 110 is drawn out is referred to as the platform portion T.

[0066] As described above, if the thermal expansion blocks B are respectively disposed between the platform parts T adjacent to each other, it is possible to utilize the dead space, thereby improving the fire extinguishing and cooling efficiency without reducing the energy density.

[0067] Meanwhile, in order to maximize the effect of increasing the liquid level of the cooling fluid, the thermal expansion block B may be applied not only to the hollow space between the bus bar frame 200 and the side cover 320 , but also between adjacent terrace portions T. As shown in FIG.

[0068] refer to Figure 8 The battery module 1 may further include an expansion pad E, which is configured to at least partially close the air inlet 400 and the air outlet 500, so that when the cooling fluid is supplied to the battery module 1, the liquid level of the cooling fluid increases rapidly by minimizing the amount of coolant fluid leaking to the outside.

[0069] The expansion pad E is attached to the inner surface of the module housing 300 and has a size smaller than the open 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 open 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 that 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.

[0070] 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, such as a resin that increases in volume by at least about two times or more compared to the initial volume when a sufficient amount of moisture is provided to the resin. As a resin for the expansion pad E, for example, a non-woven fabric in which SAF (super absorbent fiber) and polyester staple fibers are mixed can be mentioned. SAF is prepared by forming fibers using SAP (super absorbent polymer).

[0071] 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 does not leak, but also includes a situation where the open area of ​​the air inlet 400 and the air outlet 500 is reduced to reduce the amount of leakage.

[0072] 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.

[0073] 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.

[0074] 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 .

[0075] 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, which are respectively arranged at 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 the mesh plates 400a, 500a when the expansion pad E is not expanded.

[0076] Meanwhile, an ESS (Energy Storage System) according to an embodiment of the present disclosure includes a plurality of the battery modules according to the embodiment of the present disclosure as described above.

[0077] 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 cell stack including the plurality of battery cells; a sprayer disposed to penetrate the module housing at one side in a stacking direction of the cell stack; and a heat expansion block disposed in a hollow space inside the module housing and configured to thermally expand as a temperature inside the module housing increases, Wherein, the module housing comprises: a pair of base covers, the pair of base covers being configured to cover a lower surface and an upper surface of the cell stack, respectively; a pair of side covers configured to cover side surfaces of the cell stack; a front cover configured to cover a front surface of the cell stack; and a rear cover configured to cover a rear surface of the cell stack, The battery module includes a pair of bus bar frames, which are respectively connected to one side and the other side of the cell stack in a width direction. The thermal expansion block is provided in plurality, and the plurality of thermal expansion blocks are fixed on the base cover configured to cover the lower surface of the cell stack, spaced apart from each other along the longitudinal direction of the battery module, and provided between the bus bar frame and the side cover.

2. The battery module according to claim 1, wherein: The thermal expansion blocks are arranged in plural numbers, and The plurality of thermal expansion blocks are respectively placed between the platform portions of the battery cells adjacent to each other.

3. The battery module according to claim 1, wherein: The thermal expansion block includes a thermal expansion foaming agent.

4. The battery module according to claim 1, wherein: The sprayer comprises: a coupler located at an outside of the module housing and connected to a supply pipe supplying a cooling fluid; a sprinkler head located at an inner side of the module housing and connected to the coupler; and The insulating cover comprises a fixing portion and a cover portion, wherein the fixing portion is fixed to the module housing, the cover portion is fixed to the fixing portion through a bonding layer, and is configured to separate from the fixing portion above a reference temperature as the bonding force of the bonding layer decreases or is lost.

5. The battery module according to claim 4, wherein: The sprayer is provided to penetrate one longitudinal side portion of the rear cover and is located in a hollow space formed between the bus bar frame and the side cover.

6. The battery module according to claim 4, wherein: The cover part is hinged to the fixing part, and is opened by downward rotation of the hinge part relative to the sprinkler head above the reference temperature.

7. The battery module according to claim 4, 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 disposed at an inner side of 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.

8. The battery module according to claim 7, wherein: The expansion pad is attached to an inner surface of the module housing.

9. The battery module according to claim 7, wherein: The expansion pad is at least partially inserted into an accommodation groove formed at an inner surface of the module case.

10. The battery module according to claim 7, wherein: The battery module includes mesh plates respectively disposed at both sides of the expansion pad to guide expansion movement of the expansion pad.

11. The battery module according to claim 7, wherein: The air inlet and the air outlet are formed at positions corresponding to a hollow space formed between the bus bar frame and the side cover.

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

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