Battery pack with improved safety

Abstract

To provide a battery pack advantageous for effective control of a thermal event and maintenance.SOLUTION: A battery pack according to an embodiment of the present disclosure includes a battery module 100 having at least one battery cell, a fire extinguishing tank 200 configured to hold a fire extinguishing liquid and disposed at an upper portion of the battery module and having a through-hole, and a cover member 300 provided at the through-hole of the fire extinguishing tank and configured to open or close the through-hole according to a change in the internal pressure of the fire extinguishing tank, wherein the cover member is configured to be opened or closed in a direction to compensate for the change in the internal pressure of the fire extinguishing tank.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This application claims priority based on Korean Patent Application No. 10-2021-018 5390 filed on December 22, 2021, and Korean Patent Application No. 10-2022-01 46362 filed on November 4, 2022, and the contents disclosed in the specifications and drawings of those applications are incorporated into this application in their entirety.

[0002] The present invention relates to a battery, and more particularly to a battery pack with improved safety and durability, and an energy storage system including the same. [Background technology]

[0003] Currently, commercially available secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium secondary batteries. Of these, lithium secondary batteries are attracting attention due to their advantages of being free to charge and discharge because they have almost no memory effect compared to nickel-based secondary batteries, a very low self-discharge rate, and a high energy density.

[0004] This type of lithium secondary battery mainly uses a lithium-based oxide and a carbon material as the positive and negative electrode active materials, respectively, and includes a secondary battery cell in which a separator is sandwiched between positive and negative electrode plates coated with the positive and negative electrode active materials, and an exterior material, such as a battery case, that encloses the secondary battery cell together with an electrolyte.

[0005] Generally, lithium secondary batteries are classified according to the shape of their exterior packaging into can-type secondary batteries in which an electrode assembly is housed in a metal can, and pouch-type secondary batteries in which an electrode assembly is housed in a pouch made of an aluminum laminate sheet.

[0006] Such secondary batteries are widely used not only in small devices such as portable electronic devices but also in medium- to large-sized devices such as electric vehicles and energy storage systems (ESS), and their usage is rapidly increasing. Furthermore, residential energy storage systems have recently become widely used to store and supply power for use in buildings such as homes and offices. The core component of such residential energy storage systems is the battery pack.

[0007] Various battery packs, including those used in residential ESSs, include multiple battery cells (secondary batteries) to increase capacity and / or output. In particular, to increase the energy density of the battery pack, multiple battery cells are often densely packed into a very small space.

[0008] One of the most important issues in the construction of such battery packs is safety. In particular, if a thermal event occurs in one of the battery cells included in the battery pack, it is necessary to prevent the propagation of such an event to other battery cells. Furthermore, a battery cell experiencing thermal runaway may emit vent gas, which can cause thermal runaway in other battery cells, resulting in thermal propagation.

[0009] If a thermal event in a particular battery cell is not properly suppressed, it can cause a cascade of events in multiple battery cells within a battery pack, potentially leading to larger problems such as fire or explosion of the entire battery pack. Furthermore, a fire or explosion in a battery pack can cause significant damage to nearby people and property. In particular, in the case of residential battery packs, a fire or explosion could threaten the safety of the home's occupants and escalate into a house fire, causing further damage. Therefore, it is necessary to quickly and effectively suppress thermal events generated by battery cells contained in a battery pack.

[0010] Various methods have been proposed to control such thermal events within battery packs. One of the most common methods is to suppress fires and heat using fire extinguishing fluid. This extinguishing fluid is sometimes stored in a sealed storage space (tank), but the state of the extinguishing fluid can change depending on various conditions, such as the battery pack's installation environment and the type of fluid. In particular, when a battery pack is installed outdoors and the outside temperature is low, such as in polar regions or during winter, the extinguishing fluid may freeze. This can cause changes in the internal pressure of the tank, potentially leading to tank damage or cracks.

[0011] Furthermore, the tank may be configured to be sealed, which may prevent the fire extinguishing liquid from smoothly flowing out of the tank. Also, if the fire extinguishing liquid decreases in the tank due to fire suppression or evaporation, tank maintenance including replenishing the fire extinguishing liquid is required. Summary of the Invention [Problem to be solved by the invention]

[0012] The present invention has been made in consideration of the above problems, and has an object to provide a battery pack or the like that effectively controls thermal events and is advantageous in terms of maintenance.

[0013] However, the technical problems that the present invention aims to solve are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the detailed description of the invention described below. [Means for solving the problem]

[0014] To achieve the above-mentioned object, a battery pack according to one aspect of the present invention may include: a battery module having one or more battery cells; a fire tank that holds a fire extinguishing liquid and is disposed on top of the battery module, the fire tank having a through hole formed therein; and a cover member that is provided on the through hole of the fire tank, the cover member being configured to open or close the through hole in response to a change in internal pressure of the fire tank.

[0015] Here, the fire extinguishing tank may include a rupturable member that is configured to be rupturable under predetermined conditions and that is configured to allow the fire extinguishing liquid to flow out when ruptured.

[0016] Furthermore, the battery pack according to the present invention may further include a control module connected to the battery module and configured to manage the battery module, and the fire extinguishing tank may be installed between the battery module and the control module.

[0017] Furthermore, the cover member may be configured to open and close in a direction that compensates for changes in the internal pressure of the fire extinguishing tank.

[0018] Furthermore, the cover member may include a first cover configured to open when the internal pressure of the fire tank increases.

[0019] Furthermore, the first cover may be configured to be openable in an outward direction.

[0020] Furthermore, the fire extinguishing tank may include an inner tank that holds the fire extinguishing liquid in an interior space, and an outer tank that at least partially surrounds the outside of the inner tank, and the first cover may be attached to the outer tank.

[0021] Furthermore, the first cover may be located on the side of the fire tank.

[0022] Furthermore, the cover member may include a second cover configured to be opened when the internal pressure of the fire extinguishing tank is reduced.

[0023] Furthermore, the second cover may be configured to be openable in an inward direction.

[0024] Furthermore, the fire extinguishing tank may include an inner tank that holds the fire extinguishing liquid in an interior space, and an outer tank that at least partially surrounds the outside of the inner tank, and the second cover may be attached to the inner tank.

[0025] Furthermore, the second cover may be located on the upper side of the fire extinguishing tank.

[0026] Furthermore, the cover member may be configured to switch from an open state to a closed state when the pressure difference between the internal pressure of the fire extinguisher tank and the external atmospheric pressure falls within a certain level.

[0027] In order to achieve the above object, an energy storage system according to another aspect of the present invention includes a battery pack according to the present invention. [Effects of the Invention]

[0028] According to one aspect of the present invention, a battery pack with improved safety can be provided.

[0029] In particular, according to one embodiment of the present invention, when a thermal event such as a thermal runaway condition occurs in a battery cell or the like, the propagation of the thermal runaway condition can be prevented by injecting a fire extinguishing liquid, thereby reducing the possibility of a larger problem such as a fire or explosion occurring.

[0030] Furthermore, even if a fire breaks out in the battery cell, the fire can be quickly extinguished, preventing it from spreading to surrounding areas such as living spaces.

[0031] Furthermore, according to one embodiment of the present invention, when the fire extinguishing liquid is discharged from the inside of the fire extinguishing tank to the battery cell side, the discharge of the fire extinguishing liquid can be carried out smoothly.

[0032] Furthermore, according to one aspect of the present invention, the durability of the components that store the fire extinguishing liquid can be improved, and in particular, the fire extinguishing tank can be prevented from being broken or damaged even in a situation where the fire extinguishing liquid is frozen.

[0033] Furthermore, according to one aspect of the present invention, maintenance of the battery pack, particularly the fire tank, is convenient, which has an advantageous effect of reducing costs.

[0034] In addition to the above, various other effects can be achieved by various embodiments of the present invention. Such various effects of the present invention will be described in detail in the sections of each embodiment, and explanations of effects that can be easily understood by those skilled in the art will be omitted.

[0035] The drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further understand the technical concepts of the present invention as well as the content of the invention, and therefore the present invention should not be interpreted as being limited to only the matters depicted in the drawings. [Brief explanation of the drawings]

[0036] [Figure 1]1 is a perspective view showing a configuration of a battery pack according to an embodiment of the present invention; [Figure 2] FIG. 2 is an exploded perspective view of the configuration of FIG. 1. [Figure 3] FIG. 3 is an enlarged view of a portion A1 of FIG. [Figure 4] FIG. 1 is a perspective view of the configuration of a fire extinguishing tank according to an embodiment of the present invention, viewed from below. [Figure 5] 1 is an exploded perspective view of a fire extinguishing tank according to an embodiment of the present invention; FIG. [Figure 6] FIG. 2 is an enlarged cross-sectional view of a portion of a fire tank according to one embodiment of the present invention. [Figure 7] FIG. 1 is a diagram illustrating an example of a configuration for injecting a fire-extinguishing liquid into a battery pack according to an embodiment of the present invention. [Figure 8] FIG. 10 is an enlarged cross-sectional view of another portion of the fire extinguishing tank according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0037] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms and words used in the specification and claims should not be construed as being limited to their ordinary or dictionary meanings, but should be construed as having meanings and concepts corresponding to the technical ideas of the present invention, in accordance with the principle that the inventors themselves can appropriately define the concepts of terms in order to best explain the invention.

[0038] Therefore, it should be understood that the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and that there may be various equivalents and modifications that can be substituted therefor at the time of this application.

[0039] Meanwhile, although directional terms such as up, down, left, right, front, and back can be used in this specification, it will be obvious to those skilled in the art of the present invention that these terms are used merely for the convenience of explanation and may vary depending on the position of the object in question, the position of the observer, etc.

[0040] Fig. 1 is a perspective view showing the configuration of a battery pack according to an embodiment of the present invention, Fig. 2 is an exploded perspective view of the configuration of Fig. 1, and Fig. 3 is an enlarged view of a portion A1 of Fig. 2.

[0041] 1 to 3, a battery pack according to the present invention includes a battery module 100, a fire tank 200, and a cover member 300.

[0042] The battery module 100 may include one or more battery cells. Here, each battery cell may be a secondary battery. The secondary battery may include an electrode assembly, an electrolyte, and a battery case. Furthermore, the battery cells provided in the battery module 100 may be pouch-type secondary batteries. However, other types of secondary batteries, such as cylindrical batteries and prismatic batteries, may also be employed in the battery module 100 of the present invention.

[0043] The battery module 100 may also include a module case for accommodating the battery cells. In particular, the module case has an empty space therein, and multiple battery cells can be accommodated in the empty space. For example, as shown in FIG. 1, the module case may be formed in a substantially rectangular parallelepiped shape and configured to stand upright in a vertical direction (Z-axis direction) perpendicular to the ground.

[0044] The fire tank 200 may hold a fire extinguishing liquid, i.e., a liquid fire extinguishing agent. The fire extinguishing liquid may be any of a variety of substances capable of suppressing or suppressing a fire or lowering its temperature. For example, the fire extinguishing liquid may be water or a liquid containing water. The fire tank 200 may also include a tank housing for holding the fire extinguishing liquid in its interior space.

[0045] Furthermore, the fire tank 200 may be disposed on the upper portion of the battery module 100. In particular, the fire tank 200 may be configured to be detachable. For example, a tank housing of the fire tank 200 may be configured to be attachable to and detachable from the module case of the battery module 100 from above.

[0046] The fire tank 200 may have a through hole formed therein, as indicated by H in Figures 2 and 3. Such through hole H may be configured to connect the internal space of the fire tank 200 with the external space. Here, the through hole H may be located at a position higher than the water surface of the extinguishing liquid stored in the internal space of the fire tank 200.

[0047] The cover member 300 may be provided on the through hole H of the fire tank 200. The cover member 300 may be configured to open or close the through hole H of the fire tank 200. For example, the cover member 300 may be hinged at a portion indicated by I in FIG. 3 , and the through hole H of the fire tank 200 may be opened or closed by pivoting the hinge. That is, as shown in FIG. 3 , one end of the cover member 300 is attached to the fire tank 200 by a hinged connection, and the other end is detached from the through hole H in the direction indicated by arrow B1, thereby opening the through hole H. The cover member 300 may be rotated in the direction opposite to arrow B1 in FIG. 3 , with the other end covering the through hole H, thereby closing the through hole H. A sealant such as rubber or silicone may be provided at a portion of the cover member 300 that closes the through hole H to ensure sealing properties. Meanwhile, depending on the position of the through hole H, the cover member 300 may also be positioned higher than the surface of the fire-extinguishing liquid.

[0048] In particular, the cover member 300 may be configured to open and close the through-hole H in response to changes in the internal pressure of the fire tank 200. That is, the cover member 300 may be configured to automatically open and close when the internal pressure of the fire tank 200 becomes higher or lower than a predetermined pressure by a certain level or more. In addition to being automatically opened and closed, the cover member 300 may also be configured to be manually opened and closed.

[0049] According to this embodiment of the present invention, the safety of the battery pack can be significantly improved by the fire extinguishing tank 200 located on the upper side of the battery module 100. In particular, if an abnormal situation occurs in the battery pack, for example, if a thermal runaway situation or a fire occurs inside the battery module 100, the fire can be suppressed or extinguished using the fire extinguishing liquid. In addition, the temperature of the battery module 100 can be lowered to prevent the thermal runaway situation or overheating situation. Therefore, an abnormal situation such as a fire or overheating situation in the battery pack can be prevented from increasing the risk of fire or explosion in other parts outside the battery pack. Furthermore, according to one aspect of the present invention, the injection of the fire extinguishing liquid can be performed more smoothly.

[0050] Furthermore, according to this embodiment of the present invention, the cover member 300 is automatically opened and closed in response to changes in the internal pressure, thereby preventing damage or breakage of the fire tank 200 due to changes in the internal pressure, thereby significantly improving the durability of the fire tank 200 and the battery pack including the same.

[0051] In addition, in one embodiment of the present invention, the fire extinguishing tank 200 may be configured so that the fire extinguishing liquid falls freely toward the battery module 100.

[0052] That is, because the fire extinguishing tank 200 is located above the battery module, a separate power source for moving the fire extinguishing liquid toward the battery module 100 is not required, and the fire extinguishing liquid can be rapidly injected. For example, referring to the embodiment of FIG. 2, the fire extinguishing liquid is injected toward the battery module 100 as shown by arrow B2, and this injection process may occur naturally in a free fall manner. Therefore, according to this embodiment of the present invention, efficient thermal control can be performed on battery cells whose temperatures have risen due to thermal runaway or the like.

[0053] The fire tank 200 may include a rupture member 210, which will be explained in more detail with further reference to FIG.

[0054] FIG. 4 is a perspective view of the configuration of a fire extinguishing tank 200 according to one embodiment of the present invention, seen from below.

[0055] 4, a rupture member 210 may be provided at the bottom of the fire extinguishing tank 200. Such a rupture member 210 may rupture under predetermined conditions. Furthermore, the rupture member 210 may be configured to allow the fire extinguishing liquid to flow out when ruptured.

[0056] To this end, the rupture member 210 may be configured to communicate with the interior space of the fire tank 200. For example, the fire tank 200 may be generally sealed, but may have an input hole formed therein. The rupture member 210 may be inserted into the input hole to close the input hole. When the rupture member 210 ruptures, the input hole is opened, allowing the extinguishing liquid contained in the fire tank 200 to flow out. In particular, when the rupture member 210 ruptures, the extinguishing liquid may be injected into the battery module 100 in a free-fall manner. At least one rupture member 210 may be provided in one fire tank 200. For example, as shown in FIG. 4, four rupture members 210 may be provided in one fire tank 200.

[0057] Furthermore, the rupture member 210 may be configured to break under conditions such as temperature and pressure. For example, the rupture member 210 may be configured to rupture under conditions of a certain temperature or above and / or a certain pressure or above. In particular, the rupture member 210 may be configured to rupture due to vent gas. That is, if an event such as thermal runaway occurs in the battery module 100, vent gas may be generated and discharged from the battery module 100. In this case, the rupture member 210 may be configured to be ruptured by the heat or pressure of the vent gas, or may be formed of a material or shape that can rupture due to the heat or pressure of the vent gas.

[0058] 4, the rupture member 210 may be formed as a glass bulb. For example, an input hole may be formed in the fire tank 200, and the glass bulb may be inserted and fastened into the input hole. Furthermore, when the glass bulb comes into contact with the vent gas, it may break, causing the fire extinguishing liquid in the fire tank 200 to be sprayed outward, particularly toward the battery module 100.

[0059] According to this embodiment, the fire-extinguishing tank 200 and the battery pack including the same can be easily configured, and a configuration for injecting fire-extinguishing liquid into the battery module side can be more easily realized. Also, according to this embodiment, a configuration for rupturing the rupturable member 210 by vent gas generated from the battery module 100 can be more easily realized.

[0060] Furthermore, the rupture member 210 may be implemented in various materials or shapes that can rupture in response to changes in conditions such as heat, pressure, etc. For example, the rupture member 210 may be implemented in the form of a vinyl material or an injection molding.

[0061] The battery module 100 may have an opening formed to communicate with the internal space. For example, the battery module 100 may have an opening formed at the upper end, as indicated by O1 in Fig. 2. The opening O1 may also communicate with the internal space of a module case in which the battery cells are located.

[0062] Here, the rupture member 210 may be configured to be at least partially inserted into the opening O1 of the battery module 100. For example, the rupture member 210 may be inserted into the interior space of the battery module 100 through the opening O1.

[0063] According to this embodiment of the present invention, the fire-extinguishing liquid can easily flow into the internal space of the battery module 100. Therefore, it is possible to more effectively respond to a thermal event occurring inside the battery module 100, such as thermal runaway, gas emission, or fire. Furthermore, the internal space of the battery module 100 may include battery cells that are directly affected by a thermal event. Therefore, according to the above embodiment, the fire-extinguishing liquid may be directly sprayed onto the battery cells. This may be more advantageous in suppressing or preventing the occurrence of a fire, etc.

[0064] Furthermore, according to this embodiment of the present invention, the rupture member 210, such as a glass bulb, can respond more quickly to vent gas. That is, when vent gas is generated in the internal space of the battery module 100, the vent gas can be discharged to the outside of the battery module 100 through the opening O1. In other words, the opening O1 can function as an outlet for vent gas from the battery module 100. Furthermore, when the opening O1 is located on the upper side of the battery module 100, a large amount of vent gas can be discharged toward the opening O1 located at the top.

[0065] In this case, if a glass bulb is located in the area where the vent gas is discharged, the glass bulb may burst quickly when the vent gas is generated. Therefore, in the event of a thermal event, more rapid injection of fire-extinguishing liquid may be possible. Furthermore, injection of fire-extinguishing liquid may not require a separate operating power source or control configuration. Furthermore, in this case, the fire-extinguishing liquid may be injected directly into the vent gas as it is being discharged, thereby reducing the temperature of the vent gas and suppressing the emission of external ignition sources, such as flames or sparks, contained in the vent gas.

[0066] Meanwhile, the opening O1 formed in the battery module 100 is not necessarily provided for the purpose of discharging vent gas or the like. For example, the opening O1 provided at the upper end of the battery module 100 shown in FIG. 2 and the like may be provided for the purpose of transporting the battery module 100. That is, the opening O1 may be configured to provide a space into which a worker or a transport device can insert fingers or a gripping tool to grip the battery module 100 when transporting the battery module 100. Alternatively, the opening O1 may be provided as a configuration for inserting a control module 400 or a fire extinguishing tank 200, which will be described later.

[0067] The battery pack according to the present invention may further include a control module 400, as shown in FIGS.

[0068] The control module 400 may be electrically connected to the battery module 100. The control module 400 may be configured to manage the battery module 100. In particular, the control module 400 may be configured to control the charging and discharging operations of the battery module 100. The control module 400 may also be configured to measure, calculate, receive, or control various electrical, physical, and chemical characteristics of the battery module 100, the battery cells included therein, or the surrounding environment. For example, the control module 400 may measure, calculate, or control the voltage, current, temperature, state of charge (SOC), state of health (SOH), internal resistance, and the like of the battery cells or the battery module 100.

[0069] The control module 400 can receive operating power from the battery module 100 to manage the battery module 100. The control module 400 can also exchange various data with the battery module 100 or other external devices via a wired or wireless communication network. The control module 400 can include various electrical components such as a battery management system (BMS), a relay, and a current sensor. The control module 400 can also include a control housing that houses these electrical components.

[0070] The control module 400 may also include pack terminals. Such pack terminals may be configured to connect the battery pack to an external charging device or discharging device. For example, the pack terminals may include a socket, plug, connector, or the like for connecting to a commercial power source or a load. In this case, the control module 400 may include a power supply path for transmitting and receiving charging power and discharging power between the pack terminals and the battery module 100. Such a power supply path may function as a path for transmitting and receiving charging and discharging power between the pack terminals and the battery module 100.

[0071] In such an embodiment, the fire tank 200 may be mounted between the battery module 100 and the control module 400. In particular, the battery module 100 may be located below the control module 400. In this case, the fire tank 200 may be located above the battery module 100 and below the control module 400.

[0072] In this case, the fire tank 200 may be configured to be connectable to the battery module 100 and the control module 400. For example, the lower end of the fire tank 200 may be fastened to the upper end of the battery module 100 by a method such as bolt connection or hook connection. Also, the upper end of the fire tank 200 may be fastened to the lower end of the control module 400 by a method such as bolt connection or hook connection.

[0073] The fire tank 200 may also include a connecting member for connecting between the battery module 100 and the control module 400. For example, the fire tank 200 may include a cable extending in the vertical direction, with connectors provided on both ends of the cable. In this case, the connector provided on the upper end of the cable may be connected to the connector of the control module 400, and the connector provided on the lower end of the cable may be connected to the connector of the battery module 100. Furthermore, the cable may provide an electrical connection between the battery module 100 and the control module 400 through such connection.

[0074] According to this embodiment of the present invention, in a battery pack including a battery module 100 and a control module 400, by interposing a fire extinguishing tank 200 between the battery module 100 and the control module 400, it is possible to respond to thermal events in both the battery module 100 and the control module 400.

[0075] In addition, the cover member 300 may be configured to open and close in a direction that compensates for a pressure change inside the fire tank 200. That is, when a change occurs in the internal pressure of the fire tank 200, the cover member 300 may open and close in a direction that reduces the pressure change.

[0076] For example, when a pressure change occurs in the direction in which the internal pressure of the fire tank 200 increases, the cover member 300 can be opened and closed so that the internal pressure of the fire tank 200 decreases again. In another example, when a pressure change occurs in the direction in which the internal pressure of the fire tank 200 decreases, the cover member 300 can be opened and closed so that the internal pressure of the fire tank 200 increases again.

[0077] In this way, the compensating action of the cover member 300 can prevent pressure changes inside the fire tank 200 from exceeding a certain level. Therefore, it is possible to prevent damage to the fire tank 200 due to pressure changes inside the fire tank 200, while also enabling smooth discharge of the fire extinguishing liquid.

[0078] The cover member 300 may include one or more unit covers. Furthermore, when the cover member 300 includes a plurality of unit covers, the fire tank 200 may be formed with through holes H corresponding to each unit cover.

[0079] 2 and 3, the cover member 300 may include a first cover 310 as a unit cover. In particular, the first cover 310 may be configured to open when the internal pressure of the fire tank 200 increases.

[0080] For example, referring to FIG. 3, a first hole H1 may be formed on one side of the fire tank 200 as a through-hole H. The first cover 310 may be configured to be able to open and close the first hole H1. As a more specific example, when the internal pressure of the fire tank 200 is at a normal level, the first cover 310 may maintain the first hole H1 in a closed state. However, when the internal pressure of the fire tank 200 increases above a certain level, the first cover 310 may rotate in the direction of arrow B1 in FIG. 3. At this time, the first hole H1 may be opened.

[0081] According to this embodiment of the present invention, when the internal pressure of the fire extinguisher tank 200 increases, gas inside the fire extinguisher tank 200 can be discharged to the outside through the first hole H1. In particular, a drop in the outside temperature can cause the fire extinguisher liquid to freeze, and in such a frozen state, the volume of the fire extinguisher liquid, such as water, can increase. At this time, the internal pressure of the fire extinguisher tank 200 can increase, and the first cover 310 can open the first hole H1, allowing the gas inside the fire extinguisher tank 200 to be discharged to the outside. In this way, by preventing the internal pressure of the fire extinguisher tank 200 from continuing to increase, it is possible to prevent the fire extinguisher tank 200 from being damaged, broken, or exploding.

[0082] Furthermore, battery packs used in residential energy storage systems and the like are generally used outdoors. Therefore, depending on the usage environment, such as in winter or in polar regions, the fire extinguishing liquid may freeze. However, according to the above embodiment, even if such a situation occurs, damage or breakage of the fire extinguishing tank 200 and the glass bulb contained therein can be effectively prevented.

[0083] Furthermore, in this embodiment, the first cover 310 may be configured to be openable outward. For example, when the internal pressure of the fire tank 200 increases, the first cover 310 may be configured to open outward, as shown by arrow B1 in FIG. 3. This opening action may allow gas inside the fire tank 200 to be discharged to the outside.

[0084] According to this embodiment of the present invention, the opening operation of the first cover 310 can be performed more smoothly. That is, the first cover 310 can be opened to discharge gas inside the fire tank 200 to the outside due to an increase in the internal pressure of the fire tank 200, and when opened outward in this manner, the opening operation can be performed more easily. In addition, in this case, the first cover 310 does not prevent gas inside the fire tank 200 from entering the first hole H1. Therefore, the internal gas can be more smoothly discharged to the outside.

[0085] The fire extinguishing tank 200 may include a plurality of unit tanks, which will be described in more detail with reference to FIGS.

[0086] Fig. 5 is an exploded perspective view of a fire extinguishing tank 200 according to one embodiment of the present invention. Fig. 6 is an enlarged cross-sectional view of a portion of the fire extinguishing tank 200 according to one embodiment of the present invention. For example, Fig. 6 can be said to show the right portion of the cross section taken along line A2-A2' in Fig. 1.

[0087] 5 and 6, the fire extinguishing tank 200 may include an inner tank 201 and an outer tank 202. The inner tank 201 has an empty space therein, and can directly hold a fire extinguishing liquid indicated by L in this empty space. In particular, the inner tank 201 may be configured in a sealed form to contain the fire extinguishing liquid L. For example, the inner tank 201 may be configured to have an airtightness performance of Ingress Protection (IP) class 55 or higher so that the fire extinguishing liquid L does not leak under normal conditions. Furthermore, the external tank 202 may be configured to be larger than the inner tank 201 and to contain the inner tank 201 in its internal space. Therefore, it can be said that the fire extinguishing tank 200 has at least a double structure. Furthermore, the external tank 202 may be configured to at least partially surround the outside of the inner tank 201. For example, the external tank 202 may surround the entire or part of the inner tank 201 from the outside.

[0088] In such an embodiment, the first cover 310 may be attached to the external tank 202. For example, with reference to Figures 5 and 6, the first cover 310 may be attached to the right side of the external tank 202. In particular, the first cover 310 may be attached to an outer surface of the external tank 202 and may be opened by hingedly pivoting outward, as shown by arrow B1'.

[0089] For example, if the fire extinguishing liquid stored in the internal tank 201 freezes, the volume of the fire extinguishing liquid may expand as shown by arrow B3 in Fig. 6. At this time, if the pressure at the upper end of the fire extinguishing liquid in the internal tank 201 increases, the first cover 310 may be opened. Then, when the first cover 310 is opened, gas inside the fire extinguishing tank 200 may be discharged to the outside. That is, gas inside the fire extinguishing tank 200 may be discharged to the outside space in the direction shown by arrow B3' in Fig. 6.

[0090] According to this embodiment of the present invention, it is possible to easily open the first cover 310. Therefore, when the internal pressure of the fire tank 200 increases, gas can be quickly and smoothly discharged.

[0091] Meanwhile, the first hole H1, which is the through hole H to which the first cover 310 is attached, may be configured to communicate between the inner tank 201 and the outer tank 202. For example, the first hole H1 may include a first inner hole formed in the inner tank 201 and a first outer hole formed in the outer tank 202. The first inner hole and the first outer hole may be connected as a single hole. In this case, the connection between the first inner hole and the first outer hole may be sealed with an O-ring or the like made of a material such as rubber or silicone. Alternatively, a single pipe may pass through the first inner hole and the first outer hole, and the internal space of such a pipe may function as the first hole H1. The pipe may be made of various materials, such as polymer or rubber. In this embodiment, as shown by arrow B3' in FIG. 6, gas inside the fire tank 200 can be discharged to the outside of the fire tank 200 through the first hole H1 formed by the connection between the first inner hole and the first outer hole.

[0092] In this embodiment, the first cover 310 may be configured to allow the fire extinguishing liquid to be injected from the outside into the interior space of the fire extinguishing tank 200. This will be described in more detail with further reference to FIG.

[0093] FIG. 7 is a diagram illustrating an example of a configuration for injecting a fire-extinguishing liquid into a battery pack according to an embodiment of the present invention.

[0094] Referring to FIG. 7, when the first cover 310 is opened to expose the first hole H1, extinguishing liquid can be injected into the first hole H1. The first cover 310 can be manually opened regardless of changes in the internal pressure of the fire tank 200, particularly the internal pressure of the inner tank 201. Also, as shown in FIG. 7, extinguishing liquid can be injected into the fire tank 200 by connecting one end of a hose C to the first hole H1. For example, extinguishing liquid can be replenished by injecting the extinguishing liquid in the direction opposite to the arrow B3' in the embodiment diagram of FIG. 6. In this case, extinguishing liquid can be replenished outside the outer tank 202, and the first outer hole and the first inner hole can be connected in a sealed state. Therefore, the extinguishing liquid injected through the first outer hole can flow into the interior space of the inner tank 201 through the first inner hole.

[0095] According to this embodiment, when the extinguishing liquid is used or when the extinguishing liquid in the interior space of the fire tank 200 is insufficient due to evaporation or leakage, the extinguishing liquid can be replenished through the first cover 310. This makes it easier to perform maintenance of the battery pack. In addition, by always maintaining the extinguishing liquid at a certain level or above, the safety assured by the fire tank 200 can be continuously maintained.

[0096] Also, the first cover 310 may be located on the side of the fire tank 200. For example, the first cover 310 may be located on the right side of the external tank 202 as shown in some drawings. In particular, the first cover 310 may be located at a position exposed to the outside of the fire tank 200.

[0097] According to this embodiment of the present invention, the internal gas exhaust process shown in Fig. 6 can be performed more smoothly. Also, according to this embodiment of the present invention, the fire extinguishing liquid injection process shown in Fig. 7 can be performed more conveniently.

[0098] Furthermore, the fire extinguishing tank 200 may have other components, such as the battery module 100 and the control module 400, on the top and / or bottom thereof. Therefore, when the first cover 310 is located on the side of the fire extinguishing tank 200, the process of venting the internal gas to the outside and the process of injecting the fire extinguishing liquid can be easily performed without interference from these other components.

[0099] On the other hand, the first hole H1 opened and closed by the first cover 310 may have a shape that extends long in the horizontal direction (X-axis direction) in Figure 6, but the present invention is not necessarily limited to such a shape of the first hole H1.

[0100] For example, the first hole H1 may be configured to be inclined at a predetermined angle with respect to the horizontal direction. For example, the first hole H1 may have an inclined portion configured to be lower from the outside toward the inside. In particular, the outer inlet of the first hole H1 may be positioned higher than the inner inlet.

[0101] This inclined configuration can more reliably prevent the extinguishing liquid from leaking to the outside through the first hole H1 when the water level rises due to freezing of the extinguishing liquid, etc. Furthermore, as shown in FIG. 7, when extinguishing liquid is poured into the fire tank 200, the poured extinguishing liquid falls onto the surface of the extinguishing liquid already present inside the fire tank 200, thereby reducing foaming. This allows the extinguishing liquid to be sufficiently replenished, and prevents the internal pressure from deviating from the design value after the extinguishing liquid is replenished. This prevents functional degradation and malfunction of the cover member 300, which opens and closes according to the internal pressure of the fire tank 200.

[0102] Additionally, the battery pack according to the present invention may further include an observation window.

[0103] For example, as shown by W in Fig. 4, an observation window W may be provided on one side, for example, the side, of the fire extinguishing tank 200. Such an observation window W may be made of a transparent or translucent material and may be provided to allow observation of the fire extinguishing liquid held in the internal space of the fire extinguishing tank 200. Furthermore, when the fire extinguishing tank 200 includes an internal tank 201 and an external tank 202, the observation windows W may be provided on both the internal tank 201 and the external tank 202, and may be located at positions corresponding to each other.

[0104] According to such an embodiment of the present invention, by directly checking the level and condition of the fire extinguishing liquid, it is possible to know or predict in advance when the fire extinguishing liquid needs to be replenished. Furthermore, according to the above embodiment, by knowing the condition of the fire extinguishing liquid, it is possible to check the overall condition of the fire extinguishing tank 200 and the battery pack, for example, whether or not there is any damage. Therefore, according to the above embodiment, maintenance (repair) of the fire extinguishing tank 200 and the battery pack can be easily performed.

[0105] In addition, the cover member 300 may include a second cover 320 as a unit cover. In particular, the second cover 320 may be configured to open when the pressure inside the fire tank 200 decreases. This will be described in more detail with reference to FIG. 8.

[0106] 8 is an enlarged cross-sectional view of another part of the fire extinguishing tank 200 according to one embodiment of the present invention. For example, it can be said that FIG. 8 shows the right part of the cross section taken along the line A3'-A3' in FIG.

[0107] 8, a second hole H2 may be formed as a through-hole H on one side of the fire tank 200. The second hole H2 may be formed at a position different from the first hole H1. In addition, the second cover 320 may be configured to open and close the second hole H2.

[0108] As a more specific example, if the internal pressure of the fire tank 200 is above a certain level, the second cover 320 may maintain the second hole H2 closed. However, if the internal pressure of the fire tank 200 decreases below the certain level, the second cover 320 may hinge and rotate as shown by arrow B4 in Figure 8. At this time, the second hole H2 may be opened.

[0109] According to this embodiment of the present invention, when the internal pressure of the fire tank 200 drops, gas outside the fire tank 200 can flow into the interior through the second hole H2. That is, as shown by arrow B5 in Fig. 8, gas outside the fire tank 200 can flow into the interior of the fire tank 200 through the second hole H2.

[0110] In particular, if an event such as thermal runaway occurs in the battery module 100 located below the fire tank 200 and fire extinguishing liquid L is injected into the battery module 100 as indicated by arrow B2 in FIG. 2, the water level inside the fire tank 200 may drop as indicated by B6 in FIG. 8. At this time, the internal pressure of the fire tank 200 may decrease, and this decrease in pressure may slow down the injection rate of the fire extinguishing liquid L into the battery module 100 or even prevent the injection itself. However, as in the embodiment of FIG. 8, when the second cover 320 is opened in response to the decrease in pressure inside the fire tank 200, external gas flows into the fire tank 200, thereby maintaining the internal pressure of the fire extinguishing tank 200 at a normal level. Therefore, the fire extinguishing liquid L can continue to be rapidly and smoothly discharged toward the battery module 100.

[0111] The second cover 320 may be configured to be openable inward. For example, the second cover 320 may be attached to the inner surface of the fire tank 200. When the internal pressure of the fire tank 200 decreases, the second cover 320 may be configured to open toward the interior space of the fire tank 200, as shown by arrow B4 in FIG. 8. This opening action may allow gas outside the fire tank 200 to flow into the interior space.

[0112] According to this embodiment of the present invention, the opening operation of the second cover 320 can be performed more smoothly. That is, as the internal pressure of the fire tank 200 decreases, the second cover 320 can be opened to allow gas outside the fire tank 200 to flow inside, and in this case, when the second cover 320 opens inward, the opening operation can be performed more easily. Also, in this case, when external gas flows into the second hole H2, the process of the external gas flowing in can be performed more smoothly without being obstructed by the second cover 320.

[0113] Furthermore, as described above, the fire extinguisher tank 200 may include the inner tank 201 and the outer tank 202. In this case, the second cover 320 may be attached to the inner tank 201. For example, referring to FIG. 8, the second cover 320 may be attached to the inner surface of the inner tank 201 and configured to open inward. In this case, the portion of the inner tank 201 where the second cover 320 is located, i.e., the portion where the second hole H2 is formed, may not be surrounded by the outer tank 202. For example, as shown by E in FIG. 5, the outer tank 202 may be formed with an open internal space. In addition, the portion of the inner tank 201 where the second cover 320 is provided may be located in the portion of the outer tank 202 where such an open space E is formed.

[0114] According to this embodiment of the present invention, the opening operation of the second cover 320 and the resulting inflow of external gas can be more easily performed. In particular, in the above embodiment, the second cover 320 can be easily opened inward. This also simplifies the structure of the fire tank 200, which can contribute to reducing the weight of the battery pack. Furthermore, the second hole H2 may be formed only in the internal tank 201, and does not need to be separately formed in the external tank 202. In this embodiment, when the second cover 320 attached to the inside of the internal tank 201 is opened, external air can immediately enter the internal tank 201.

[0115] The second cover 320 may be located on the upper side of the fire tank 200. For example, as shown in Figures 2, 5, and 8, the second hole H2 and the second cover 320 attached thereto may be located on the upper surface side of the fire tank 200.

[0116] In particular, when the cover member 300 includes both the first cover 310 and the second cover 320, the first cover 310 may be provided on the side of the fire tank 200, and the second cover 320 may be provided on the top of the fire tank 200. In this embodiment of the present invention, the first cover 310 and the second cover 320 are formed at different positions, so that the opening and closing operations of the first cover 310 and the second cover 320 do not interfere with each other.

[0117] Furthermore, according to the above embodiment, by supplying outside air into the fire tank 200 from above, it is possible to uniformly distribute gas pressure from above the fire extinguishing liquid toward the fire extinguishing liquid. Therefore, regardless of the position of the glass valve through which the fire extinguishing liquid is discharged, the fire extinguishing liquid can be discharged smoothly. Furthermore, according to the above embodiment, even if vent gas flows from the lower side of the fire extinguishing tank 200, the vent gas can be prevented from flowing into the fire extinguishing tank 200 through the second cover 320.

[0118] Furthermore, according to the above example, unlike the embodiment of Fig. 7, the process of inserting the hose C or the like into the interior of the inner tank 201 through the first hole H1 to inject the fire-extinguishing liquid is not obstructed by the second cover 320. Furthermore, according to the above example, since the battery pack is provided on an inclined surface, even if the water level in the internal space of the inner tank 201 is inclined, it is possible to prevent the problem of the fire-extinguishing liquid leaking to the outside through the second hole H2.

[0119] Meanwhile, in an embodiment in which the fire extinguishing tank 200 includes an internal tank 201 and an external tank 202, the internal tank 201 and the external tank 202 may be configured to be at least partially separated from each other. In particular, referring to the embodiment of FIG. 5, the external tank 202 may be configured to surround four side surfaces (left side surface, right side surface, front surface, and rear surface) of the internal tank 201, excluding the top and bottom surfaces. In this case, the internal tank 201 and the external tank 202 may be configured to be separated from each other in the left-right direction in the portion where the internal tank 201 is surrounded by the external tank 202. For example, in the embodiments of FIGS. 6 and 8, the side surfaces of the internal tank 201 and the external tank 202 may be configured to be at least partially separated from each other in the left-right direction. For example, the right side wall of the internal tank 201 and the right side wall of the external tank 202 may be configured to form an empty space therebetween.

[0120] In this case, the fire extinguishing liquid inside the fire extinguishing tank 200 can be more safely maintained. In particular, even if an impact is applied to the side of the fire extinguishing tank 200, the dual structure of the external tank 202 and the internal tank 201 and the empty space formed between them can mitigate the transmission of the impact. In this way, damage to the fire extinguishing tank 200, particularly the internal tank 201, due to impact or vibration can be prevented, thereby preventing abnormal leakage of the fire extinguishing liquid.

[0121] In addition, when vent gas is discharged, the separated space between the inner tank 201 and the outer tank 202 may function as a vent path. For example, vent gas discharged from the battery module 100 to the lower part of the fire tank 200 may flow along the lower surface of the fire tank 200, and then flow through the separated space between the side of the inner tank 201 and the outer tank 202, and be discharged to the outside. In this case, a vent path may be formed inside the fire tank 200, and the vent direction may be controlled.

[0122] The cover member 300 may be configured to switch from an open state to a closed state when the pressure difference between the internal pressure of the fire tank 200 and the external atmospheric pressure becomes within a certain level.

[0123] 6, when the level of the fire extinguishing liquid rises as indicated by arrow B3 due to freezing of the fire extinguishing liquid stored in the internal tank 201, the first cover 310 may rotate in the direction indicated by arrow B1', i.e., counterclockwise, to an open state. Then, when the air inside the internal tank 201 is released as indicated by arrow B3', and the pressure difference between the inside and outside of the internal tank 201 becomes constant or within a certain level, the first cover 310 may again rotate in the direction opposite to arrow B1', i.e., clockwise, to a closed state.

[0124] In this case, the cover member 300 may include an elastic body. For example, the first cover 310 may have a spring, particularly a torsion spring, attached to a hinge portion indicated by I1 in FIG. 6. In this case, when the internal pressure of the internal tank 201 exceeds the elastic force of the torsion spring, the first cover 310 may be opened. Then, when the internal gas is discharged to a certain extent and the internal pressure of the internal tank 201 becomes lower than the elastic force of the torsion spring, the first cover 310 may be closed.

[0125] 8, when the fire-extinguishing liquid stored in the internal tank 201 is poured into the battery module 100 and the level of the fire-extinguishing liquid drops as indicated by arrow B6, the second cover 320 may rotate in the direction indicated by arrow B4, i.e., clockwise, to an open state. After a certain amount of outside air has entered the internal tank 201, the second cover 320 again rotates in the opposite direction to arrow B4, i.e., counterclockwise, to a closed state.

[0126] An elastic body such as a spring may also be attached to the second cover 320. For example, a torsion spring may be attached to the hinge portion indicated by I2 in FIG. 8. In this case, when a pressure difference between the inside and outside of the inner tank 201 occurs at a level that exceeds the elastic force of the torsion spring, the second cover 320 may be opened. Then, when a certain amount of outside air flows in and the pressure difference between the inside and outside becomes smaller than the elastic force of the torsion spring, the second cover 320 may be closed.

[0127] According to this embodiment of the present invention, it is possible to easily realize a configuration in which the cover member 300 is automatically opened and closed in response to changes in the internal pressure of the fire tank 200. In particular, according to the above embodiment, no separate power source or control is required for both the opening and closing operations of the cover member 300. Furthermore, according to the above embodiment, when the internal pressure of the fire tank 200 becomes approximately the same as the external pressure, the cover member 300 is automatically and quickly closed, thereby more reliably preventing the outflow of fire extinguishing liquid and the inflow of external foreign matter through the through hole H.

[0128] An energy storage system according to the present invention includes one or more battery packs according to the present invention described above. Furthermore, the energy storage system according to the present invention may further include typical components of an energy storage system in addition to such a battery pack. In particular, the energy storage system according to the present invention may be a residential (building) energy storage system used to store energy in homes, buildings, etc.

[0129] Although the present invention has been described above using limited embodiments and drawings, the present invention is not limited to these, and it goes without saying that various modifications and variations can be made by a person having ordinary knowledge in the technical field to which the present invention pertains within the technical spirit of the present invention and the scope of equivalents of the claims. [Explanation of symbols]

[0130] 100 Battery Module 200 Fire Tank 201 Inner Tank 202 External Tank 210 Bursting member 300 Cover member 310 First Cover 320 Second Cover 400 Control Module H through hole H1 1st hole H2 2nd hole L Fire extinguishing liquid W observation window

[0131] [Appendix 1] a battery module having one or more battery cells; a fire tank for holding a fire extinguishing liquid and disposed above the battery module, the fire tank having a through hole formed therein; a cover member provided on the through hole of the fire extinguisher tank, the cover member being configured to open or close the through hole in response to a change in the internal pressure of the fire extinguisher tank; Including the battery pack. [Appendix 2] 2. The battery pack according to claim 1, wherein the fire-extinguishing tank is configured to be rupturable under a predetermined condition and includes a rupture member configured to allow the fire-extinguishing liquid to flow out upon rupture. [Appendix 3] the battery pack further includes a control module connected to the battery module and configured to manage the battery module; 3. The battery pack of claim 1, wherein the fire tank is mounted between the battery module and the control module. [Appendix 4] 4. The battery pack according to any one of claims 1 to 3, wherein the cover member is configured to open and close in a direction that compensates for changes in the internal pressure of the fire tank. [Appendix 5] 5. The battery pack according to any one of claims 1 to 4, wherein the cover member comprises a first cover configured to be opened when the internal pressure of the fire extinguisher tank increases. [Appendix 6] 6. The battery pack according to claim 5, wherein the first cover is configured to be openable in an outward direction. [Appendix 7] The fire extinguishing tank includes an inner tank that holds the fire extinguishing liquid in an interior space thereof, and an outer tank that at least partially surrounds the outside of the inner tank; 7. The battery pack of claim 5, wherein the first cover is attached to the external tank. [Appendix 8] Supplementary notes 5 to 7: The battery pack according to any one of claims 5 to 7, wherein the first cover is located on a side of the fire tank. [Appendix 9] The battery pack according to any one of appendixes 1 to 8, wherein the cover member includes a second cover configured to be opened when the internal pressure of the fire extinguisher tank is reduced. [Appendix 10] 10. The battery pack according to claim 9, wherein the second cover is configured to be openable inward. [Appendix 11] The fire extinguishing tank includes an inner tank that holds the fire extinguishing liquid in an interior space thereof, and an outer tank that at least partially surrounds the outside of the inner tank; 11. The battery pack of claim 9 or 10, wherein the second cover is attached to the inner tank. [Appendix 12] 12. The battery pack according to any one of claims 9 to 11, wherein the second cover is located on an upper side of the fire tank. [Appendix 13] A battery pack described in any one of Appendices 1 to 12, wherein the cover member is configured to switch from an open state to a closed state when the pressure difference between the internal pressure of the fire extinguisher tank and the external atmospheric pressure becomes within a certain level. [Appendix 14] 14. An energy storage system comprising the battery pack of any one of claims 1 to 13.

Claims

1. a battery module having one or more battery cells; a fire tank for holding a fire extinguishing liquid and disposed above the battery module, the fire tank having a through hole formed therein; a cover member provided on the through hole of the fire extinguisher tank, the cover member being configured to open or close the through hole in response to a change in the internal pressure of the fire extinguisher tank; Including, The cover member is configured to open and close in a direction that compensates for changes in the internal pressure of the fire extinguisher tank.

2. 2. The battery pack according to claim 1, wherein the fire-extinguishing tank is configured to be rupturable under a predetermined condition and includes a rupture member configured to allow the fire-extinguishing liquid to flow out upon rupture.

3. the battery pack further includes a control module connected to the battery module and configured to manage the battery module; The battery pack according to claim 1 , wherein the fire tank is mounted between the battery module and the control module.

4. The battery pack according to claim 1 , wherein the cover member comprises a first cover configured to be opened when the internal pressure of the fire tank increases.

5. The battery pack according to claim 4 , wherein the first cover is configured to be openable in an outward direction.

6. The fire extinguishing tank includes an inner tank that holds the fire extinguishing liquid in an interior space thereof, and an outer tank that at least partially surrounds the outside of the inner tank; The battery pack according to claim 5 , wherein the first cover is attached to the external tank.

7. The battery pack according to claim 4 , wherein the first cover is located on a side of the fire tank.

8. The battery pack according to claim 1 , wherein the cover member comprises a second cover configured to be opened when the internal pressure of the fire tank is reduced.

9. The battery pack according to claim 8 , wherein the second cover is configured to be openable inward.

10. The fire extinguishing tank includes an inner tank that holds the fire extinguishing liquid in an interior space thereof, and an outer tank that at least partially surrounds the outside of the inner tank; The battery pack according to claim 9 , wherein the second cover is attached to the inner tank.

11. The battery pack according to claim 8 , wherein the second cover is located on an upper side of the fire tank.

12. 2. The battery pack according to claim 1, wherein the cover member is configured to switch from an open state to a closed state when a pressure difference between an internal pressure of the fire extinguisher tank and an external atmospheric pressure falls within a certain level.

13. 13. An energy storage system comprising a battery pack according to any one of claims 1 to 12.

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