Battery module including an absorption member, battery rack including the battery module, and energy storage system

Abstract

A battery pack that reduces the risk of secondary fire or explosion is disclosed. To achieve this object, a battery module according to the present invention includes: two or more monomer assemblies, each of which has a plurality of secondary batteries; a module housing having an internal space for accommodating the two or more monomer assemblies therein; and an absorption member, which is disposed between the at least two or more monomer assemblies and is used to absorb the fire extinguishing liquid supplied into the module housing when contacting the fire extinguishing liquid.

Description

Technical Field

[0001] The present disclosure relates to a battery module having an absorbing member, and a battery rack and an energy storage system including the battery module. More particularly, the present disclosure relates to a battery pack that reduces the risk of secondary fire or explosion.

[0002] This application claims the priority of Korean Patent Application No. 10-2020-0004377 filed in Korea on January 13, 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, lithium secondary batteries, etc. Among them, lithium secondary batteries have attracted more attention than nickel-based secondary batteries due to their advantages such as free charging and discharging due to almost no memory effect, extremely low self-discharge rate, 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. The lithium secondary battery includes an electrode assembly and an exterior (i.e., the battery bag exterior), in which a positive electrode plate coated with a positive electrode active material and a negative electrode plate coated with a negative electrode active material are arranged, and a separator is placed between the positive electrode plate and the negative electrode plate, and the exterior hermetically accommodates the electrode assembly together with an electrolyte.

[0005] In recent years, 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 devices. When used in such medium-sized 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 and large devices due to the advantage of easy stacking.

[0006] At the same time, in recent years, with the increasing demand for large-capacity structures due to use as an energy storage source, there is an increasing demand for battery packs that include a plurality of battery cell assemblies containing a plurality of secondary batteries electrically connected in series and / or parallel, a battery module in which the plurality of battery cell assemblies are accommodated, and a battery management system (BMS).

[0007] In addition, the battery pack generally includes 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 packs is increasing in recent years.

[0008] However, a conventional battery pack or battery rack includes a plurality of battery modules. Therefore, if a fire or thermal runaway occurs at any battery cell assembly of each battery module, high temperature gas or flame may be transmitted to other adjacent battery cell assemblies, so a fire or thermal runaway may occur at other battery cell assemblies connected in series. Therefore, efforts to prevent secondary fire or explosion are increasing.

[0009] For example, there is an urgent need to develop a technology that can block heat so that the heat generated by a fire or thermal runaway is not transferred to other battery cell assemblies adjacent to the battery cell assembly where the fire or thermal runaway occurs.

[0010] In addition, a swelling phenomenon may occur as the battery cell assembly is charged and discharged, and internal side reactions (gas) may be generated along with the swelling phenomenon, and thus a technology capable of reducing the side reactions is required. Summary of the invention

[0011] Technical issues

[0012] The present disclosure is designed to solve the problems of the prior art, and therefore, the present disclosure aims to provide a battery module that reduces the risk of secondary fire or explosion.

[0013] These and other objects and advantages of the present disclosure can be understood from the following detailed description, and will become more fully apparent through the exemplary embodiments of the present disclosure. In addition, it will be readily understood that the objects and advantages of the present disclosure can be achieved by the means shown in the appended claims and combinations thereof.

[0014] Technical Solutions

[0015] In one aspect of the present disclosure, a battery module is provided, comprising: at least two battery cell assemblies, each of the at least two battery cell assemblies having a plurality of secondary batteries; a module housing having an internal space formed to accommodate the at least two battery cell assemblies therein; and an absorption member disposed between the at least two battery cell assemblies and configured to absorb a fire extinguishing liquid supplied into the module housing when in contact with the fire extinguishing liquid.

[0016] Furthermore, the absorbent member may include synthetic fibers configured to absorb the fire extinguishing liquid.

[0017] Furthermore, the synthetic fiber may expand in volume when absorbing the fire extinguishing liquid, and the synthetic fiber may be configured to contact an inner surface of an outer wall of the module housing due to the volume expansion.

[0018] Moreover, the secondary battery may be a pouch-type secondary battery, and the battery module may further include an extrusion member, which includes an elastic portion and at least two extrusion plates, the elastic portion being configured to elastically deform in length in two directions, and the at least two extrusion plates being connected to ends of the elastic portion in two directions and configured to hinder expansion of the battery cell assembly.

[0019] Furthermore, the absorption member may be located between the at least two pressing plates.

[0020] In addition, the absorption member may further include a guide plate configured to guide deformation of an appearance according to volume expansion of the synthetic fiber.

[0021] Furthermore, the synthetic fiber may have a perforation such that a portion of the elastic portion is positioned through the perforation, and the pressing plate may have a fixing groove such that one end or the other end of the elastic portion is inserted into the fixing groove.

[0022] Also, the absorption member may include: a porous body having a porous sponge form and configured to absorb the fire extinguishing liquid; and a plurality of absorption particles positioned to be distributed inside the porous body and configured to absorb the fire extinguishing liquid.

[0023] In addition, in another aspect of the present invention, a battery rack is provided, which includes: at least one battery module; and a fire extinguishing unit, which includes a fire extinguishing tank, a pipe, and a fire extinguishing valve, the fire extinguishing tank being configured to contain a fire extinguishing liquid therein, the pipe being connected from the fire extinguishing tank to the at least one battery module to supply the fire extinguishing liquid, and the fire extinguishing valve being configured to open an outlet when the internal gas of the battery module is heated to above a predetermined temperature, so that the fire extinguishing liquid is supplied from the fire extinguishing tank to the battery module.

[0024] Moreover, in another aspect of the present invention, an energy storage system is provided. The energy storage system includes at least one battery rack.

[0025] Beneficial effects

[0026] According to an embodiment of the present disclosure, since the battery module of the present disclosure includes an absorption member, which is placed between at least two battery cell assemblies and is configured to absorb the fire extinguishing liquid when it contacts the fire extinguishing liquid supplied to the module housing, when the fire extinguishing liquid is supplied to the battery module due to a fire or thermal runaway, the absorption member can absorb the fire extinguishing liquid, so the absorption member can form an insulating barrier that can hinder the transfer of heat between the battery cell assemblies. That is, the absorption member can hinder the heat transfer between the battery cell assemblies. Therefore, even if a fire or thermal runaway occurs in some secondary batteries of one battery cell assembly, it is possible to prevent fire or heat propagation from occurring at other adjacent battery cell assemblies. In this way, the safety of the battery module can be effectively improved.

[0027] Moreover, according to an embodiment of the present disclosure, since an extrusion member is further provided to include an elastic portion and at least two extrusion plates, the elastic portion is configured to be elastically deformed in two directions, and the at least two extrusion plates are respectively connected to the ends of the elastic portion in two directions and are configured to hinder the expansion of the battery cell assembly, the extrusion member can effectively prevent the battery cell assembly from expanding. Thus, the occurrence of side reactions at the battery cell assembly can be suppressed. That is, in the present disclosure, the service life of the battery cell assembly can be extended by the extrusion member.

[0028] In addition, according to the embodiment of the present disclosure, since the absorption member is located between at least two compression plates, the absorption member can stably maintain the compression plates in an upright state. In addition, if the absorption member expands in volume as it absorbs the fire extinguishing liquid, the compression plates can more forcefully compress the battery cell assembly that has thermal runaway, thereby effectively hindering the expansion of the battery cell assembly and effectively reducing the development of thermal runaway. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] 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. Thus, the present disclosure should not be construed as being limited to the accompanying drawings.

[0030] Figure 1 is a perspective view schematically showing a battery module according to an embodiment of the present disclosure.

[0031] Figure 2 is an exploded perspective view schematically showing components of a battery module according to an embodiment of the present disclosure.

[0032] Figure 3 is a stereoscopic view schematically showing some components of a battery module according to an embodiment of the present disclosure.

[0033] Figure 4 is a stereoscopic view schematically showing some components of a battery module according to an embodiment of the present disclosure.

[0034] Figure 5 is an exploded perspective view schematically showing some components of a battery module according to an embodiment of the present disclosure.

[0035] Figure 6 is a side cross-sectional view schematically showing that a fire extinguishing liquid is introduced into a battery module according to an embodiment of the present disclosure.

[0036] Figure 7 is a perspective view schematically showing some components of a battery module according to another embodiment of the present disclosure.

[0037] Figure 8 is a perspective view schematically showing some components of a battery module according to another embodiment of the present disclosure.

[0038] Fig. 9 is a perspective view schematically showing an energy storage system according to an embodiment of the present disclosure.

[0039] Fig.10 2 is a photograph schematically showing the synthetic fiber of the battery module according to an embodiment of the present disclosure before and after absorbing the fire extinguishing liquid. DETAILED DESCRIPTION

[0040] 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 should be interpreted based on the meanings and concepts corresponding to the technical aspects of the present disclosure on the basis of the principle that the inventor is allowed to appropriately define the terms to obtain the best interpretation.

[0041] Therefore, the descriptions presented herein are only preferred examples for illustration, and are not intended to limit the scope of the present invention. Therefore, it should be understood that other equivalents and modifications may be made thereto without departing from the scope of the present invention.

[0042] Figure 1 is a perspective view schematically showing a battery module according to an embodiment of the present disclosure. Figure 2 is an exploded perspective view schematically showing components of a battery module according to an embodiment of the present disclosure. Figure 3 Schematically shows some components of a battery module according to an embodiment of the present disclosure. Figure 3 , the appearance of the battery module 200 is shown, but the upper cover 212 of the module housing 210 is not included, so that the interior of the battery module 200 can be observed. For reference, Figure 2The X-axis arrow, Y-axis arrow, and Z-axis arrow shown in represent the left direction, the rear direction, and the upward direction, respectively.

[0043] refer to Figures 1 to 3 The battery module 200 according to the embodiment of the present disclosure may include at least two battery cell assemblies 100 , a module case 210 , and an absorbing member 220 .

[0044] Here, the battery cell assembly 100 may include a plurality of secondary batteries 110 stacked on each other in a front-rear direction. The secondary batteries 110 may be pouch-type secondary batteries 110. For example, Figure 2 As shown in , each of the two battery cell assemblies 100 may be configured such that 21 pouch-type secondary batteries 110 are stacked side by side on one another in the front-rear direction (Y direction).

[0045] In particular, the pouch type secondary battery 110 may include an electrode assembly (not shown), an electrolyte (not shown), and a pouch 116 .

[0046] When viewed along the F direction (such as Figure 1 ), each secondary battery 110 can be arranged to stand vertically (Z direction) on the ground so that the two wide sides are located in the front-to-back direction and the sealing portion is located in the upper, lower, and left-right directions. In other words, each secondary battery 110 can be configured to stand upright in the up-down direction. Meanwhile, in this specification, unless otherwise specified, the up-down, front-to-back, and left-to-right directions will be set based on when viewed along the F direction.

[0047] Here, the bag may be configured to have a concave shaped receiving portion. In addition, the electrode assembly and the electrolyte may be received in the receiving portion. In addition, each bag includes an outer insulating layer, a metal layer and an inner bonding layer, which may adhere to each other at the edge of the bag 116 to form a sealing portion. In addition, the step portions may be formed at the ends of the secondary battery 110 in the left and right directions (X direction), respectively, at which the positive electrode lead 110a and the negative electrode lead 110b are formed.

[0048] In addition, the electrode assembly is an assembly of an electrode plate coated with an electrode active material and a separator, and at least one positive electrode plate and at least one negative electrode plate may be provided in the electrode assembly with a separator interposed therebetween. In addition, a positive electrode sheet may be provided on the positive electrode plate of the electrode assembly, and at least one positive electrode sheet may be connected to a positive electrode lead 111a.

[0049] Here, the positive electrode lead 111 a has one end connected to the positive electrode sheet and the other end exposing the pouch 116 , and the exposed portion may serve as an electrode terminal of the secondary battery 110 , for example, a positive electrode terminal of the secondary battery 110 .

[0050] In addition, a negative electrode sheet is disposed on the negative electrode plate of the electrode assembly, and at least one negative electrode sheet may be connected to the negative electrode lead 111b. Furthermore, the negative electrode lead 111b may have one end connected to the negative electrode sheet and the other end exposing the bag 116, and the exposed portion may be used as an electrode terminal of the secondary battery 110, for example, a negative electrode terminal of the secondary battery 110.

[0051] In addition, if Figure 1 As shown in , when viewed directly in the F direction, the positive electrode lead 111a and the negative electrode lead 111b may be formed at the left and right ends opposite to each other (in the X direction) based on the center of the secondary battery 110. That is, the positive electrode lead 111a may be disposed at one end (left end) based on the center of the secondary battery 110. In addition, the negative electrode lead 111b may be disposed at the other end (right end) based on the center of the secondary battery 110.

[0052] For example, Figure 2 As shown in , each secondary battery 110 of the battery cell assembly 100 may be configured such that a positive electrode lead 111 a and a negative electrode lead 111 b protrude in left and right directions.

[0053] Here, the terms indicating directions such as "front", "rear", "left", "right", "up", and "down" used in this specification may differ depending on the position of the observer or the form in which the object is placed. However, in this specification, for convenience of explanation, directions such as "front", "rear", "left", "right", "up", and "down" are distinguishably expressed based on the case of observation in the F direction.

[0054] Therefore, according to such a configuration of the present disclosure, in one secondary battery 110 , there is no interference between the positive electrode lead 111 a and the negative electrode lead 111 b , thereby increasing the area of ​​the electrode lead 111 .

[0055] In addition, the positive electrode lead 111a and the negative electrode lead 111b may be configured in a plate shape. Specifically, the positive electrode lead 111a and the negative electrode lead 111b may protrude in the horizontal direction (X direction) with their wide sides standing toward the front-rear direction.

[0056] Here, the horizontal direction may refer to a direction parallel to the ground when the secondary battery 110 is placed on the ground, and may also refer to at least one direction on a plane perpendicular to the up-down direction.

[0057] In addition, the volume of the pouch-type secondary battery 110 may expand and shrink with charge and discharge. That is, the entire volume of the battery cell assembly 100 including the plurality of secondary batteries 110 may expand and shrink with charge and discharge.

[0058] However, the battery module 200 according to the present disclosure is not limited to the above-mentioned pouch-type secondary battery 110 , and various types of secondary batteries 110 known at the time of filing the present application may be employed.

[0059] In addition, at least two battery cell assemblies 100 may be arranged in the front-rear direction. Figure 2 As shown in , two battery cell assemblies 100 are arranged in the front-rear direction, and a predetermined distance may be provided between the two battery cell assemblies 100 .

[0060] Meanwhile, an inner space may be formed in the module housing 210 to accommodate the battery cell assembly 100. Specifically, the module housing 210 may include an upper cover 212, a substrate 214, a front cover 215, and a rear cover 216.

[0061] Specifically, the substrate 214 may have an area larger than bottom surfaces of at least two battery cell assemblies 100 so that at least two battery cell assemblies 100 are mounted on an upper portion of the substrate 214. The substrate 214 may have a plate shape extending in a horizontal direction.

[0062] In addition, the upper cover 212 may include a top portion 212a and a side portion 212b. The top portion 212a may have a plate shape extending in a horizontal direction to cover the upper portion of the battery cell assembly 100. The side portion 212b may have a plate shape extending downward from the left and right ends of the top portion 212a to cover the left and right portions of the battery cell assembly 100.

[0063] In addition, the side portion 212b may be coupled to a portion of the base plate 214. For example, Figure 2 As shown in , the upper cover 212 may include a top 212a having a plate shape extending in the front, rear, left and right directions. The upper cover 212 may include two side portions 212b extending downward from the left and right ends of the top 212a, respectively. In addition, the lower ends of the two side portions 212b may be respectively connected to the left and right ends of the base plate 214. In this case, the connection method may be a male-female connection or welding.

[0064] Furthermore, the side portion 212b may be partially raised inwardly toward the secondary battery 110 to form a curling portion B1. Figure 2 As shown in FIG. 2 , eight inwardly retracted bead portions B1 may be formed at one side portion 212 b .

[0065] In addition, the front cover 215 may be configured to cover the front of the plurality of secondary batteries 110. For example, the front cover 215 may have a plate shape larger than the front surface of the plurality of secondary batteries 110. The plate shape may stand upright in the up and down directions.

[0066] Further, a portion of the outer periphery of the front cover 215 may be coupled to the base plate 214. For example, a lower portion of the outer periphery of the front cover 215 may be coupled to a front end of the base plate 214. Further, an upper portion of the outer periphery of the front cover 215 may be coupled to a front end of the upper cover 212. Here, the coupling method may be bolt coupling.

[0067] In addition, the rear cover 216 may be configured to cover the rear of the battery cell assembly 100. For example, the rear cover 216 may have a plate shape larger than rear surfaces of the plurality of secondary batteries 110.

[0068] In addition, a portion of the outer periphery of the rear cover 216 may be coupled to the base plate 214. For example, a lower portion of the outer periphery of the rear cover 216 may be coupled to the rear end of the base plate 214. Further, an upper portion of the outer periphery of the rear cover 216 may be coupled to the rear end of the upper cover 212. Here, the coupling method may be bolt coupling.

[0069] Therefore, according to the configuration of the present disclosure, since the module case 210 has a structure capable of stably protecting the plurality of secondary batteries 110 from external impact, the safety of the battery module 200 against external impact may be improved.

[0070] Meanwhile, the battery module 200 of the present disclosure may further include a module BMS 290 configured to control charging and discharging of the battery cell assembly 100. The module BMS 290 may include various sensors and circuits to sense the temperature and current of the battery module 200. The sensors and circuits are not shown in the figure.

[0071] Meanwhile, the absorption member 220 may be disposed between at least two battery cell assemblies 100. The absorption member 220 may be configured to absorb the fire extinguishing liquid when contacting the fire extinguishing liquid supplied into the module case 210. For example, the absorption member 220 may include a super absorbent polymer, or super absorbent fibers formed by spinning the super absorbent polymer into a web form.

[0072] Here, the super absorbent fiber is a fiber made of a super absorbent material and has the ability to retain liquid, so the super absorbent fiber absorbs liquid so that it cannot flow well. Moreover, the super absorbent fiber has no odor and is in the form of a textile fiber. For example, Fig.10 The photographs in show the state of superabsorbent synthetic fibers before and after absorbing water. If synthetic fibers absorb water, the volume of the synthetic fibers may increase.

[0073] Here, the superabsorbent fiber may be configured to absorb a fire extinguishing liquid (water) having a weight of about 500 to 1,000 times its own weight. Thus, the volume of the synthetic fiber may expand by at least three times or more. For example, the superabsorbent polymer may include at least one of a starch-based material, a cellulose-based material, and a synthetic polymer-based material.

[0074] Here, the battery module 200 may be configured to supply a fire extinguishing liquid into the battery module 200 when a fire or thermal runaway occurs at the battery cell assembly 100. For example, the fire extinguishing liquid may be water or a concentrated solution of an inorganic salt such as potassium carbonate. Preferably, the fire extinguishing liquid may be water. For example, referring to Figures 1 to 3 , fire extinguishing liquid (not shown) may be injected into the battery module 200 through an injection hole H3 formed in the rear cover 216 of the module housing 210 .

[0075] In addition, the front surface or the rear surface of the absorbing member 220 may have a size corresponding to the front surface or the rear surface of the battery cell assembly 100. For example, the absorbing member 220 may have a size capable of covering the entire surface of the battery cell assembly 100. That is, when viewed from the front, the battery cell assembly 100 may have a sufficient size to be hidden by the absorbing member 220 and not be visible.

[0076] Thus, according to this configuration of the present disclosure, since the absorption member 220 is disposed between at least two battery cell assemblies 100 and is configured to absorb the fire extinguishing liquid when contacting the fire extinguishing liquid supplied into the module housing 210, when the fire extinguishing liquid is supplied into the battery module 200 due to a fire or thermal runaway, the absorption member 220 can absorb the fire extinguishing liquid, so the absorption member 220 can form a heat insulating barrier capable of hindering the transfer of heat between the battery cell assemblies 100. That is, the absorption member 220 can hinder the heat transfer between the battery cell assemblies 100. Thus, even when a fire or thermal runaway occurs in some secondary batteries 110 of one battery cell assembly 100, it is possible to prevent the occurrence of a fire or heat propagation at other adjacent battery cell assemblies 100. In this way, the safety of the battery module 200 can be effectively improved.

[0077] Figure 4 is a perspective view schematically showing some components of a battery module according to an embodiment of the present disclosure. Figure 5 is an exploded perspective view schematically showing some components of a battery module according to an embodiment of the present disclosure.

[0078] and Figure 2 and Figure 3 Reference together Figure 4 and Figure 5 , the absorption member 220 may include a synthetic fiber 222. The synthetic fiber 222 may have a rectangular pad shape. The front and rear surfaces of the synthetic fiber 222 may have sizes corresponding to the front and rear surfaces of the battery cell assembly 100. When absorbing the fire extinguishing liquid, the synthetic fiber 222 may expand in volume, thereby changing the size of the synthetic fiber 222. In addition, the synthetic fiber 222 may have elasticity so as to be deformed according to pressure.

[0079] In addition, the synthetic fiber 222 may be configured to absorb fire extinguishing liquid. The synthetic fiber 222 may include a superabsorbent fiber formed by spinning a superabsorbent polymer into a web form. Here, the superabsorbent polymer may be configured to absorb about 500 to 1,000 times its own weight of fire extinguishing liquid (water). For example, the superabsorbent polymer may be a superabsorbent polymer product of LG Chemical Co., Ltd. of South Korea. For example, the synthetic fiber 222 may be manufactured by batch polymerizing acrylic acid and methyl acrylate used as raw materials in water, then extracting the polymerized polymer therefrom and spinning the polymer into a web form.

[0080] Therefore, according to the configuration of the present disclosure, since the absorption member 220 includes the synthetic fiber 222 configured to absorb the fire extinguishing liquid, when the fire extinguishing liquid is supplied into the battery module 200, the absorption member 220 absorbs the fire extinguishing liquid, so the absorption member can form a barrier to hinder the heat transfer between the battery cell assemblies 100. Therefore, even if a fire or thermal runaway occurs in some secondary batteries 110 of one battery cell assembly 100, it is possible to prevent the fire or heat propagation from occurring at other adjacent battery cell assemblies 100. In this way, the safety of the battery module 200 can be effectively improved.

[0081] Reference again Figure 4 and Figure 5, the battery module 200 according to the embodiment of the present disclosure may further include an extrusion member 260. Specifically, the extrusion member 260 may include an elastic portion 262 and at least two extrusion plates 266a, 266b. Here, the elastic portion 262 may be a component configured to undergo elastic deformation in length in two directions. More specifically, the elastic portion 262 may include a cylinder 262a, which is configured to change in length in two directions. The cylinder 262a may include a cylindrical first pillar having a solid shaft and a cylindrical second pillar having a hollow shaft. The two longitudinal ends of the cylinder 262a may have a larger diameter than the solid shaft and the hollow shaft so as to be respectively connected and fixed to the extrusion plates 266a, 266b. For example, if the length of the cylinder 262a in the longitudinal direction decreases as the first and second struts are connected, the internal pressure within the hollow shaft increases, which can generate a thrust for lengthening the cylinder 262a, that is, generating thrust in both directions (longitudinal directions) of the shaft.

[0082] In addition, the elastic part 262 may further include a spring 262b, which is configured to surround the cylinder 262a. The spring 262b may be configured to surround the solid shaft and the hollow shaft of the cylinder 262a. In addition, the spring 262b may be squeezed toward the center of the cylinder 262a in the axial direction by the two ends of the cylinder 262a with a large diameter. That is, the spring 262b may be configured to change the length of the spring 262b in the elastic direction according to the change of the length of the cylinder 262a. For example, if the length of the cylinder 262a is reduced, the spring 262b arranged in the cylinder 262a may be elastically contracted by being squeezed by the two ends of the cylinder 262a. The spring 262b may be configured to generate elastic force to elongate the cylinder 262a.

[0083] In addition, the extrusion plates 266a, 266b may be made of polycarbonate or ABS material. At least two extrusion plates 266a, 266b may be configured so that both ends in both directions are respectively coupled to both ends of the elastic portion 262. Both ends of the cylinder 262a of the elastic portion 262 may be respectively coupled to at least two extrusion plates 266a, 266b.

[0084] For example, Figure 5As shown in , the extrusion member 260 may include a first extrusion plate 266a located at the front based on the synthetic fiber 222 and a second extrusion plate 266b located at the rear. One end of the cylinder 262a of the elastic part 262 may be coupled to the first extrusion plate 266a, and the other end of the cylinder 262a may be coupled to the second extrusion plate 266b. At this time, each of the extrusion plates 266a, 266b may have a fixing groove H2 so that one end or the other end of the elastic part 262 is inserted into the fixing groove H2.

[0085] For example, Figure 5 As shown in FIG. 1 , nine fixing grooves H2 may be formed in each of the first extrusion plate 266a and the second extrusion plate 266b. One end of the cylinder 262a of the elastic portion 262 may be inserted and fixed in the fixing groove H2 of the first extrusion plate 266a, and the other end of the cylinder 262a may be inserted and fixed in the fixing groove H2 of the second extrusion plate 266b.

[0086] In addition, each of the pressing plates 266a, 266b may be configured to hinder expansion of the battery cell assembly 100. That is, the pressing plates 266a, 266b may be configured to press one surface of the battery cell assembly 100. For example, Figure 3 As shown in , the pressing member 260 may be disposed between two battery cell assemblies 100. If the two battery cell assemblies 100 are volumetrically expanded, the first pressing plate 266a of the pressing member 260 may press the rear surface of the battery cell assembly 100 located at the front in the front direction, and the second pressing plate 266b may press the front surface of the battery cell assembly 100 located at the rear in the rear direction.

[0087] Therefore, according to the configuration of the present disclosure, since the pressing member 260 is further provided to include an elastic portion 262 configured to be elastically deformed in two directions and at least two pressing plates 266a, 266b, the elastic portion 262 being configured to be elastically deformed in two directions, the at least two pressing plates 266a, 266b being respectively coupled to both ends of the elastic portion 262 in two directions and being configured to hinder the expansion of the battery cell assembly 100, the pressing member 260 can effectively prevent the battery cell assembly 100 from expanding. Thus, it is possible to suppress the occurrence of side reactions at the battery cell assembly 100. That is, in the present disclosure, the service life of the battery cell assembly 100 can be extended by the pressing member 260.

[0088] At the same time, again with Figure 4 Reference together Figure 5, the absorption member 220 may be located between at least two extrusion plates 266a, 266b. For example, the front surface of the synthetic fiber 222 of the absorption member 220 may be configured to face the rear surface of the first extrusion plate 266a, and the rear surface of the synthetic fiber 222 of the absorption member 220 may be configured to face the front surface of the second extrusion plate 266b.

[0089] Therefore, according to the configuration of the present disclosure, since the absorption member 220 is located between at least two pressing plates 266a, 266b, the absorption member 220 can stably maintain the pressing plates 266a, 266b in an upright state. In addition, if the absorption member 220 expands in volume as it absorbs the fire extinguishing liquid, the pressing plates 266a, 266b can more forcefully press the battery cell assembly 100 that has thermal runaway, thereby effectively hindering the expansion of the battery cell assembly 100 and effectively reducing the development of thermal runaway.

[0090] In addition, the synthetic fiber 222 may have a perforation H1 formed therein. The perforation H1 may be configured such that a portion of the elastic portion 262 penetrates the perforation H1 and is positioned through the perforation H1. Figure 5 As shown in FIG. 2 , nine through holes H1 may be formed in the synthetic fiber 222. Nine elastic parts 262 may be respectively inserted into the nine through holes H1.

[0091] Figure 6 is a side cross-sectional view schematically showing that a fire extinguishing liquid is introduced into a battery module according to an embodiment of the present disclosure.

[0092] refer to Figure 6 , the synthetic fiber 222 of the absorption member 220 of the present disclosure may be configured to contact the inner surface of the outer wall of the module housing 210 .

[0093] Specifically, the absorption member 220 may be configured such that the synthetic fibers 222 contact the inner surface of the outer wall of the module housing 210 by volume expansion. That is, if a fire extinguishing liquid (water) is introduced into the battery module 200 due to a fire or thermal runaway in at least a portion of the secondary batteries 110 of the battery cell assembly 100, the synthetic fibers 222 of the absorption member 220 may absorb the fire extinguishing liquid and deform by causing volume expansion as much as the absorption. The synthetic fibers 222 may be deformed to contact the inner surface of the outer wall of the module housing 210 by volume expansion. For example, Figure 6 As shown in FIG. 2 , the upper end of the synthetic fiber 222 of the absorption member 220 may contact the inner surface of the upper cover 212 of the module case 210 .

[0094] In addition, when a fire or thermal runaway occurs at the battery cell assembly 100 and the module housing 210 is heated, the fire extinguishing liquid absorbed by the absorbing member 220 can be vaporized by the synthetic fiber 222 contacting the inner surface of the outer wall of the module housing 210. Thus, the absorbing member 220 can effectively cool the module housing 210 by generating evaporation heat of the fire extinguishing liquid. Therefore, in the present disclosure, it is possible to prevent the temperature of other adjacent battery modules 200 from increasing due to the high temperature of the module housing 210, thereby preventing the thermal runaway from propagating to other battery modules 200 adjacent to the battery module 200 where the thermal runaway occurs.

[0095] Figure 7 is a perspective view schematically showing some components of a battery module according to another embodiment of the present disclosure.

[0096] and Figure 4 Reference together Figure 7 , Figure 7 The battery module 200 may further include a guide plate 250 disposed in the absorbing member 220 .

[0097] Specifically, the guide plate 250 may be configured to guide deformation according to volume expansion of the synthetic fiber 222. The guide plate 250 may be configured to be in close contact with the left and right surfaces of the synthetic fiber 222, respectively. Figure 7 As shown in , the absorbent member 220 of the present disclosure may include a first guide plate 250 located on the left side and a second guide plate 250 located on the right side based on the synthetic fiber 222. The first guide plate 250 may be positioned to be coupled to the pressing plates 266a, 266b and a portion of the left side of the synthetic fiber 222. The second guide plate 250 may be positioned to be coupled to the pressing plates 266a, 266b and a portion of the right side of the synthetic fiber 222. That is, when the synthetic fiber 222 undergoes volume expansion, the guide plate 250 may hinder the expansion in the left-right direction (X-axis direction), thereby causing the synthetic fiber 222 to expand upward.

[0098] Therefore, according to the configuration of the present disclosure, since the absorbing member 220 further includes the guide plate 250 configured to guide the appearance deformation according to the volume expansion of the synthetic fiber 222, the synthetic fiber 222 can be caused to deform so that the synthetic fiber 222 can contact the module case 210 or transmit the pressing force to the adjacent battery cell assembly 100. Thus, when a fire occurs at the battery module 200, heat propagation can be more effectively prevented.

[0099] Figure 8is a perspective view schematically showing some components of a battery module according to another embodiment of the present disclosure.

[0100] and Figure 3 Reference together Figure 8 , Figure 8 The absorbing member 220 of the battery module 200 may further include a porous body.

[0101] Specifically, the porous body 280 may be configured to absorb the fire extinguishing liquid by using a capillary phenomenon. The porous body 280 may have a porous sponge shape. For example, the porous body 280 may be a sponge.

[0102] In addition, the porous body 280 may be configured to accommodate a plurality of absorbent particles 285 therein. Here, the plurality of absorbent particles 285 may be super absorbent polymers. The super absorbent polymer may be configured to absorb a fire extinguishing liquid (water) weighing 500 to 1,000 times its own weight. Thus, the super absorbent polymer may be provided in the form of a plurality of absorbent particles 285. If the super absorbent polymer absorbs water, the volume of the super absorbent polymer may expand by at least three times or more. For example, the super absorbent polymer may include at least one of a starch-based material, a cellulose-based material, and a synthetic polymer-based material.

[0103] In addition, a plurality of absorbing particles 285 may be configured to be distributed inside the porous body 280. In this case, the porous body 280 may be configured to absorb the fire extinguishing liquid when in contact with the fire extinguishing liquid, and transfer the fire extinguishing liquid to the plurality of absorbing particles 285 accommodated therein.

[0104] In addition, the porous body 280 may be configured to be placed between the pressing plates 266a, 266b. The porous body 280 may have a front surface and a rear surface whose sizes correspond to the front surfaces and rear surfaces of the pressing plates 266a, 266b, respectively.

[0105] Therefore, according to this configuration of the present disclosure, since the absorption member 220 further includes the porous body 280 having a porous sponge form and configured to absorb the fire extinguishing liquid and a plurality of absorption particles configured to absorb the fire extinguishing liquid, the speed at which the absorption member 220 absorbs the fire extinguishing liquid can be effectively increased. Thus, the absorption member 220 can quickly hinder heat transfer between at least two battery cell assemblies 100. Ultimately, in the present disclosure, it is possible to effectively prevent fire or thermal runaway from spreading between battery cell assemblies 100.

[0106] Reference again Figure 2The battery module 200 of the present disclosure may further include a module BMS 290 configured to control the charging and discharging of the battery cell assembly 100. The module BMS 290 may include various sensors and circuits for sensing the temperature and current of the battery module 200. The sensors and circuits are not shown in the figure.

[0107] Meanwhile, the bus bar assembly 270 may include at least one bus bar 272 and at least one bus bar frame 276 on which the bus bar 272 is mounted.

[0108] Specifically, the bus bar 272 may be an alloy containing a metal having excellent electrical conductivity, such as copper, nickel, or aluminum. The bus bar 272 may be configured to electrically connect the plurality of secondary batteries 110 to each other. That is, the bus bar 272 may be configured to contact a portion of the electrode lead 111. The bus bar 272 may have a plate shape. For example, Figure 2 As shown in , the bus bar 272 may have a plate shape extending in the front-rear direction and the up-down direction.

[0109] In addition, the busbar frame 276 may include an electrically insulating material. For example, the busbar frame 276 may include a plastic material. More specifically, the plastic material may be polyvinyl chloride.

[0110] For example, Figure 2 As shown in , the battery module 200 may include four bus bar assemblies 270. The bus bar assemblies 270 may be respectively located at the left and right sides of the battery cell assembly 100. Each of the four bus bar assemblies 270 may include four bus bars 272 and a bus bar frame 276, and the four bus bars 272 are installed at the outer side of the bus bar frame 276.

[0111] Fig. 9 is a perspective view schematically showing an energy storage system according to an embodiment of the present disclosure.

[0112] refer to Fig. 9 , the energy storage system 400 according to an embodiment of the present disclosure may include at least one battery rack 300. Two or more battery racks 300 may be arranged in one direction.

[0113] In addition, the battery rack 300 according to the embodiment of the present disclosure may include at least one battery module 200 and a fire extinguishing unit 320. In addition, the battery rack 300 may include a battery rack case 310 in which at least one battery module 200 is accommodated.

[0114] Specifically, the fire extinguishing unit 320 may include a fire extinguishing tank 322 , a pipeline 323 and a fire extinguishing valve 325 .

[0115] First, the fire extinguishing tank 322 may contain a fire extinguishing liquid (not shown). For example, the fire extinguishing tank 322 may have a capacity of 59L, the compressed gas may be 8 bar of nitrogen, and the fire extinguishing liquid may be 40L of water. Here, if water is used as the fire extinguishing liquid, when water is sprayed into the interior of the battery module 200, the water has a heat-resistant effect as well as a fire extinguishing and cooling effect, which is particularly effective in preventing heat propagation when high-temperature gas and flames are generated due to thermal runaway. Thus, it is possible to effectively prevent fire or thermal runaway from propagating between multiple battery modules 200.

[0116] In addition, the pipe 323 may be configured to be connected to supply the fire extinguishing liquid from the fire extinguishing tank 322 to each of the at least two battery modules 200. For example, the pipe 323 may have a material that is not corroded by water. For example, the pipe 323 may have stainless steel. The pipe 323 may be configured to have one end connected to the discharge hole 321 of the fire extinguishing tank 322. The other end of the pipe 323 may have a shape extending to the inside of each of the at least two battery modules 200.

[0117] For example, the pipe 323 may be connected to a discharge hole 321 through which the fire extinguishing liquid in the fire extinguishing tank 322 is discharged. Figure 1 and Figure 2 As shown in , the pipe 323 may be connected to the discharge hole 321 of the fire extinguishing tank 322 .

[0118] In addition, the fire extinguishing valve 325 may be configured to supply the fire extinguishing liquid from the fire extinguishing tank 322 to the battery module 200 when the internal gas (air) of the battery module 200 is heated to a predetermined temperature or above. That is, the fire extinguishing valve 325 may be configured to open an outlet so that the fire extinguishing liquid can be injected into the battery module 200 exceeding the predetermined temperature. The fire extinguishing valve 325 may be an active valve capable of controlling the valve to be opened or closed by receiving a signal from the fire extinguishing unit 320. More specifically, the active valve may be a control valve, an electric valve, a solenoid valve, or a pneumatic valve.

[0119] In addition, the active valve may be configured to supply the fire extinguishing liquid from the fire extinguishing tank 322 to the battery module 200 whose internal temperature rises above a predetermined temperature. If the internal temperature of the battery module 200 is higher than the predetermined temperature, the control unit 350 located below the top plate may sense the internal temperature so that the active valve is actively opened by the control unit 350. In this case, the control unit 350 may be located on the battery module 200 disposed at the top T of the plurality of battery modules 200.

[0120] The fire extinguishing unit 320 may include a control unit 350. Specifically, the control unit 350 may be configured to open the active valve when the temperature sensor senses a temperature higher than a predetermined temperature. For example, the control unit 350 may be configured to transmit a signal for controlling the active valve.

[0121] At the same time, although terms indicating directions such as up, down, left, right, front and rear directions are used in the specification, it is obvious to those skilled in the art that these terms are only used to indicate relative positions for ease of explanation and may vary based on the position of the observer or the object.

[0122] 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.

[0123] Reference numerals

[0124] 200: Battery module 100: Battery cell assembly

[0125] 110: Secondary battery 210: Module housing

[0126] 220: Absorbent member 222: Synthetic fiber

[0127] 250: Guide plate

[0128] 260: pressing member 262, 266: elastic part, pressing plate

[0129] 270: busbar assembly 272, 276: busbar, busbar frame

[0130] H1: Perforation H2: Fixing groove

[0131] 280: porous body 285: absorbent particles

[0132] 320: Fire extinguishing unit 325: Fire extinguishing valve

[0133] 322: Fire extinguisher 323: Pipeline

[0134] 300: Battery rack 400: Energy storage system

Claims

1. A battery module, comprising: at least two battery cell assemblies, each of the battery cell assemblies having a plurality of secondary batteries; a module housing having an internal space formed to accommodate the at least two battery cell assemblies therein; as well as an absorbing member disposed between the at least two battery cell assemblies and configured to absorb the fire extinguishing liquid supplied into the module housing when contacting the fire extinguishing liquid, The absorption member includes synthetic fibers, the volume of which expands when the synthetic fibers absorb the fire extinguishing liquid, and the synthetic fibers are configured such that the upper ends of the synthetic fibers contact the inner surface of the upper cover of the module housing due to the volume expansion.

2. The battery module according to claim 1, wherein: The secondary battery is a pouch type secondary battery, and The battery module further includes an extrusion member, which includes an elastic portion and at least two extrusion plates, the elastic portion being configured to elastically deform in length in two directions, the at least two extrusion plates being connected to both ends of the elastic portion in two directions and configured to hinder expansion of the battery cell assembly.

3. The battery module according to claim 2, wherein: The absorption member is located between the at least two compression plates.

4. The battery module according to claim 2, wherein: The absorbent member further includes a guide plate configured to guide deformation of an appearance according to the volume expansion of the synthetic fiber.

5. The battery module according to claim 2, wherein: The synthetic fiber has perforations such that a portion of the elastic portion is positioned through the perforations, and The pressing plate has a fixing groove such that one end or the other end of the elastic part is inserted into the fixing groove.

6. A battery rack, comprising: At least one battery module according to any one of claims 1 to 5; and A fire extinguishing unit, the fire extinguishing unit comprising a fire extinguishing tank, a pipe and a fire extinguishing valve, the fire extinguishing tank being configured to contain a fire extinguishing liquid therein, the pipe being connected from the fire extinguishing tank to the at least one battery module to supply the fire extinguishing liquid, the fire extinguishing valve being configured to open an outlet when internal gas of the battery module is heated to above a predetermined temperature so that the fire extinguishing liquid is supplied from the fire extinguishing tank to the battery module.

7. An energy storage system comprising at least one battery rack according to claim 6.

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