Battery pack with improved safety

Abstract

A battery pack according to an embodiment of the present invention includes a cell module assembly including a battery cell stack in which a plurality of battery cells are stacked, a pack case that houses the cell module assembly and has an open-topped shape, and a fire tank that covers the upper surface of the cell module assembly. The fire tank includes an internal space that contains a fire extinguishing agent, and a plurality of fragile portions that are relatively thin portions of a base plate of the fire tank and melt and open when the battery cells overheat, and portions of the base plate of the fire tank that are located over electrode leads of the battery cells protrude downward toward the electrode leads of the battery cells.

Description

[Technical Field]

[0001] The present invention relates to a battery pack, and more particularly to a battery pack configured to ensure safety even when a thermal event occurs.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0033765, filed March 15, 2023, and Korean Patent Application No. 10-2024-0033265, filed March 8, 2024, and all contents disclosed in the documents of said Korean patent application are incorporated herein by reference. [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 over nickel-based secondary batteries, such as almost no memory effect, freedom in charging and discharging, a very low self-discharge rate, and high energy density.

[0004] Such lithium secondary batteries mainly use lithium-based oxides and carbon materials as the positive and negative electrode active materials, respectively, and include an electrode assembly in which positive and negative electrode plates coated with the positive and negative electrode active materials are arranged with a separator sandwiched between them, and an exterior case, i.e., a battery case, that hermetically houses the electrode assembly together with an electrolyte.

[0005] Generally, lithium secondary batteries can be classified into can-type secondary batteries, in which the electrode assembly is housed in a metal can, and pouch-type secondary batteries, in which the electrode assembly is housed in a pouch made of an aluminum laminate sheet, depending on the shape of the exterior material.

[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, there has been a recent trend toward the use of residential battery packs for storing power.

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

[0008] One of the most important issues in such battery pack configurations is safety. In particular, if a thermal event occurs in one of the multiple battery cells included in the battery pack, the propagation of such an event to other battery cells must be suppressed. If thermal propagation between battery cells is not properly suppressed, this may cause thermal events in various battery cells included in the battery pack, leading to larger problems such as fire or explosion of the battery pack. Furthermore, fire or explosion in a battery pack may cause significant damage to the lives and property of surrounding people. In particular, in the case of a residential battery pack, fire or explosion may threaten the safety of the people living in the home and may spread to a residential fire, causing greater damage. Summary of the Invention [Problem to be solved by the invention]

[0009] Therefore, the present invention has been made to solve the above problems, and aims to provide a battery pack and the like having an improved structure that can appropriately control thermal events that occur inside the battery pack.

[0010] In particular, flames often emerge from the electrode leads of battery cells during thermal events, and the objective is to extinguish these flames early, quickly, and effectively.

[0011] 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 description of the invention described below. [Means for solving the problem]

[0012] To achieve the above object, a battery pack according to one aspect of the present invention includes a cell module assembly having one or more battery cells, a pack case that houses the cell module assembly in an internal space, and a fire tank that holds a fire extinguishing agent and is arranged on top of the cell module assembly.

[0013] Here, the fire extinguishing tank may be configured to discharge a fire extinguishing agent toward the cell module assembly when heat is applied from the cell module assembly.

[0014] The fire tank may be configured to be at least partially melted by heat applied from the cell module assembly.

[0015] The fire extinguishing tank may be configured to melt due to vent gas emitted from the battery cell or the temperature of the battery cell.

[0016] The fire tank may hold a fire extinguishing agent in a liquid state.

[0017] The fire extinguishing tank may be configured such that the thickness of the base plate varies depending on the position.

[0018] The fire extinguishing tank may have a weakened portion having a relatively small thickness located in a central portion between the cells stacked horizontally.

[0019] The pack cases may be configured to be stackable in the vertical direction.

[0020] In order to achieve the above object, an energy storage device according to another aspect of the present invention includes one or more battery packs according to the present invention.

[0021] According to one embodiment of the present invention, a battery pack includes a cell module assembly including a battery cell stack in which a plurality of battery cells are stacked, and a bus bar housing assembly in which electrode leads of the battery cells are coupled to bus bar electrodes; a pack case in which the cell module assembly is housed and has an open top; and a fire tank covering the top surface of the cell module assembly, wherein the fire tank includes an internal space for containing a fire extinguishing agent, and a plurality of fragile portions in which a base plate of the fire tank is formed to be relatively thin and which melt and open due to a thermal event of the battery cells, and at least portions of the base plate of the fire tank located over the electrode leads of the battery cells may have a shape that protrudes downward toward the electrode leads of the battery cells.

[0022] The base plate of the fire extinguisher tank may have a step, and the height of the portion located on the electrode leads of the battery cells may be lower than the height of at least the portion located on the bus bar housing assembly.

[0023] The base plate of the fire tank may have a step, and the height of the portion located on the electrode lead of the battery cell may be the same as or lower than the height of the portion where the main body of the battery cell is located.

[0024] A portion of the base plate of the fire tank that is located above an electrode lead of the battery cell may be adjacent to the electrode lead.

[0025] A shape of the portion located on the electrode lead of the battery cell that protrudes downward toward the electrode lead of the battery cell may be located on an outer surface of the bus bar housing assembly.

[0026] The fragile portions may be linear and arranged parallel to one peripheral edge of the fire extinguishing tank, and each fragile portion may be arranged parallel to each other, and the longitudinal direction of the fragile portion and the longitudinal direction of the battery cell may be perpendicular to each other.

[0027] The weak portions may be linear and arranged parallel to one peripheral edge of the fire tank, the weak portions may be arranged parallel to each other, the longitudinal direction of the weak portions and the longitudinal direction of the battery cells may be parallel to each other, and the weak portions may be arranged between two adjacent battery cells.

[0028] The fragile portion may also be provided on a portion of the battery cell that is located above the electrode lead and that protrudes downward toward the electrode lead of the battery cell.

[0029] A thickness of a portion of the battery cell located on an electrode lead and protruding downward toward the electrode lead may be the same as a thickness of the fragile portion.

[0030] The fire tank may be made from plastic injection molding.

[0031] The cell module assembly may include a pair of end plates disposed parallel to the battery cells at both ends of the stack of battery cells, and the pair of end plates may connect the pair of bus bar housings.

[0032] The cell module assembly may include straps that respectively connect upper and lower sides of the pair of end plates of the battery cell stack to strengthen binding of the cell module assembly.

[0033] The base plate may have a step, and a height of a portion where the plurality of fragile portions are arranged may be lower from a lower surface of the battery pack than a portion located on the strap.

[0034] The extinguishing agent may be in a liquid state.

[0035] A plurality of the battery packs may be provided, and the battery packs may be connected to each other by mechanical or electrical connection.

[0036] The plurality of battery packs can be stacked in the vertical direction.

[0037] The plurality of battery packs may be electrically connected in series so that various voltage ranges of the plurality of battery packs can be realized.

[0038] The plurality of battery packs may be electrically connected in parallel so that the storage capacities of the plurality of battery packs can be diversified.

[0039] To achieve the above object, an energy storage device according to another aspect of the present invention includes one or more of the above-described battery packs according to the present invention. [Effects of the Invention]

[0040] According to one aspect of the present invention, a battery pack with improved safety can be provided.

[0041] In particular, according to one embodiment of the present invention, even if a thermal event occurs inside the battery pack, such a thermal event can be quickly controlled.

[0042] Furthermore, if problems such as thermal runaway or fire occur in some of the multiple battery cells included in the battery pack, it is possible to effectively prevent such problems from spreading to other modules.

[0043] Furthermore, according to one aspect of the present invention, it is possible to provide a battery pack that has a simple structure but has enhanced thermal safety, and does not require the addition of new parts for adding a fire extinguishing agent, thereby providing a battery pack that is easy to manufacture and economical.

[0044] In particular, according to one embodiment of the present invention, flames often emerge from the electrode leads of a battery cell during a thermal event, but these flames can be extinguished quickly and effectively in the early stages.

[0045] Furthermore, according to one aspect of the present invention, there is no need to design a special waterproof and vibration-proof structure.

[0046] According to one aspect of the present invention, by stacking a plurality of battery packs of the same type, products with various voltage ranges and / or storage capacities can be provided.

[0047] In addition, various other additional effects can be achieved by various embodiments of the present invention. These various effects of the present invention will be described in detail in each embodiment, and explanations of effects that can be easily understood by those skilled in the art will be omitted. [Brief explanation of the drawings]

[0048] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention to be given later, serve to further understand the technical concept of the present invention. Therefore, the present invention should not be interpreted as being limited to only the matters depicted in such drawings. [Figure 1] 1 is an exploded perspective view schematically illustrating a configuration of a battery pack according to an embodiment of the present invention. [Figure 2] 2 is a diagram schematically showing a configuration for discharging a fire extinguishing agent in the battery pack of FIG. 1. FIG. [Figure 3] FIG. 10 is a perspective view schematically illustrating the configuration of a battery pack according to another embodiment of the present invention. [Figure 4] 4 is a cross-sectional view taken along the line A4-A4' in FIG. 3. [Figure 5] FIG. 10 is an exploded perspective view schematically illustrating the configuration of a battery pack according to yet another embodiment of the present invention. [Figure 6] FIG. 6 is a perspective view of a cell module assembly included in the battery pack of FIG. 5. [Figure 7]6 is a perspective view of a blocking member included in the battery pack of FIG. 5. FIG. [Figure 8] FIG. 8 is an exploded perspective view of the blocking member of FIG. 7. [Figure 9] 8 shows a diagram in which the blocking member and the battery cell of FIG. 7 are arranged side by side. [Figure 10] FIG. 6 is a perspective view of a pack case included in the battery pack of FIG. 5. [Figure 11] 11 is a diagram illustrating the cell module assembly of FIG. 10 being housed in a pack case. FIG. [Figure 12] 11 is a diagram illustrating the cell module assembly of FIG. 10 being housed in a pack case. FIG. [Figure 13] FIG. 6 is a perspective view of a fire extinguishing tank included in the battery pack of FIG. 5. [Figure 14] FIG. 14 is a perspective cross-sectional view of the fire extinguishing tank of FIG. 13. [Figure 15] This is a cross-sectional view of the lower tank of the fire extinguishing tank viewed from above. [Figure 16] FIG. 16 is a perspective cross-sectional view of a modified embodiment of the fire extinguishing tank shown in FIGS. 5 to 15. [Figure 17] FIG. 16 is a perspective view of a battery pack in which all of the components of the battery pack described above with reference to FIGS. 5 to 15 are combined together. [Figure 18] FIG. 6 is a perspective view of a fire tank in a partially modified version of the fire tank of the battery pack of FIGS. 1 to 5. [Figure 19] FIG. 19 is a front view of the fire tank of FIG. 18. [Figure 20] 19 shows a cross-sectional view of the fire tank of FIG. 18 when positioned on a cell module assembly. [Figure 21] 19 is a front view of the fire tank of the battery pack of FIG. 18, in which the fire tank is partially modified. [Figure 22] FIG. 18 is a perspective view schematically showing the battery pack of FIGS. 1 to 17. [Figure 23] 23 is a diagram showing an embodiment in which the pack cases shown in FIG. 22 are stacked in different numbers. [Figure 24]23 is a diagram showing an embodiment in which the pack cases shown in FIG. 22 are stacked in different numbers. DETAILED DESCRIPTION OF THE INVENTION

[0049] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms and phrases used in the specification and claims should not be interpreted in a limited manner to their ordinary or dictionary meanings, but should be interpreted in a manner that is consistent with the technical concept of the present invention, in accordance with the principle that the inventor can appropriately define the concept of the term in order to best describe his / her invention.

[0050] Therefore, it should be understood that the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiment of the present invention and do not fully represent the technical ideas of the present invention, and that there may be various equivalents and modifications that can replace them at the time of this application.

[0051] In order to clearly explain the present invention, parts unnecessary for the explanation will be omitted and the same reference numerals will be used throughout the specification to refer to the same or similar components.

[0052] Furthermore, the size and thickness of each component shown in the drawings are arbitrarily shown for the convenience of explanation, and the present invention is not necessarily limited to those shown in the drawings. In the drawings, thicknesses are exaggerated to clearly show various layers and regions. In the drawings, thicknesses of some layers and regions are exaggerated for the convenience of explanation.

[0053] Furthermore, when a layer, film, region, plate, or other part is said to be "on" another part, this includes not only the case where it is "directly on" the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly on" another part, it means that there is no other part in between. Furthermore, being "on" a reference part means being located above or below the reference part, and does not necessarily mean being located "on" in the opposite direction of gravity.

[0054] Also, throughout the specification, when a part "comprises" a certain element, this means that it can further include other elements, rather than excluding other elements, unless otherwise specified.

[0055] Furthermore, throughout the specification, when we refer to "in a plane," we mean when the subject is viewed from above, and when we refer to "in cross section," we mean when the subject is viewed from the side, across a vertical cross section.

[0056] FIG. 1 is an exploded perspective view schematically showing the configuration of a battery pack according to an embodiment of the present invention.

[0057] Referring to FIG. 1, a battery pack according to the present invention includes a cell module assembly 100, a pack case 300, and a fire tank 400.

[0058] The cell module assembly 100 may include one or more battery cells 110. Here, each battery cell 110 may represent a secondary battery. The secondary battery may include an electrode assembly, an electrolyte, and a battery case. In particular, the battery cells 110 included in the cell module assembly 100 may be pouch-type secondary batteries. However, other types of secondary batteries, such as cylindrical batteries and prismatic batteries, may also be used in the cell module assembly 100 of the present invention.

[0059] A plurality of secondary batteries may be stacked on one another to form a cell module assembly 100. That is, the cell module assembly 100 may be formed in the form of a battery cell stack. For example, a plurality of battery cells 110 may be stacked in a horizontal arrangement (X-axis direction) with each battery cell 110 standing vertically (Z-axis direction in the drawing). Each battery cell 110 may have an electrode lead, which may be located at both ends or one end of each battery cell 110. A secondary battery with electrode leads protruding in both directions is called a bidirectional cell, and a secondary battery with electrode leads protruding in one direction is called a unidirectional cell. FIG. 1 illustrates a bidirectional cell. However, the present invention is not limited to the specific type or shape of such a secondary battery, and various types of secondary batteries known at the time of filing of the present invention may be used in the cell module assembly 100 of the present invention.

[0060] The pack case 300 may be configured to have an empty space formed therein for accommodating the cell module assemblies 100. For example, the pack case 300 may be configured in a box shape as shown in Fig. 1. The box-shaped pack case 300 may be integrally molded or may be manufactured by connecting at least one surface to an adjacent surface.

[0061] The fire tank 400 may contain a fire extinguishing agent. In particular, the fire tank 400 may have an internal space, and the fire extinguishing agent may be contained in the internal space. For example, as shown in FIG. 1, the fire tank 400 may include a lower tank 410 and an upper cover 420. Here, the lower tank 410 may be configured in a box shape with an open top, providing a space capable of containing the fire extinguishing agent. The upper cover 420 may be configured to cover the open top of the lower tank 410 and seal the fire extinguishing agent-containing space of the lower tank 410.

[0062] The fire tank 400 can be housed inside the pack case 300. In particular, the fire tank 400 may be disposed above the cell module assembly 100 in the internal space of the pack case 300.

[0063] According to this embodiment of the present invention, a thermal event in the cell module assembly 100 can be more easily controlled by discharging the extinguishing agent from the fire tank 400 located on the upper side of the cell module assembly 100. In particular, the extinguishing agent discharged from the fire tank 400 can easily move downward by gravity. Therefore, the heat and fire in the cell module assembly 100 can be more easily suppressed by the extinguishing agent.

[0064] In particular, when the cell module assembly 100 includes a plurality of battery cells 110 arranged horizontally, i.e., in the left-right direction (X-axis direction), as shown in Fig. 1, when fire extinguishing agent is discharged from the fire tank 400 located above, the fire extinguishing agent can be easily supplied to all of the battery cells 110. Therefore, according to this embodiment, a thermal event in the entire cell module assembly 100 can be suppressed more effectively.

[0065] The fire extinguishing tank 400 may be configured to discharge a fire extinguishing agent toward the cell module assembly 100 when heat is applied from the cell module assembly 100. This will be described in more detail with reference to FIG.

[0066] FIG. 2 is a diagram schematically showing a configuration for discharging a fire extinguishing agent in the battery pack of FIG.

[0067] 2, a fire tank 400 is located above the cell module assembly 100. Among the multiple battery modules stacked in the left-right direction (e.g., the X-axis direction in the drawing), a thermal event such as overheating, fire, or thermal runaway may occur in a specific battery cell 110, as indicated by A1. In this case, the heat generated in the battery cell 110 may be applied to the fire tank 400, for example, to a portion indicated by A2 in FIG. 2. Then, a fire extinguishing agent may be discharged from the fire tank 400, as indicated by arrow A3.

[0068] In particular, the fire tank 400 may be configured so that at least a portion thereof melts due to heat applied from the cell module assembly 100. For example, in the configuration of Fig. 2, the portion of the fire tank 400 indicated by A2 can be melted by heat. Then, the fire extinguishing agent can be discharged through the melted portion as indicated by arrow A3.

[0069] For this purpose, at least a portion of the fire extinguishing tank 400 may be made of a material that can be melted by heat applied from the cell module assembly 100. For example, the entire fire extinguishing tank 400 may be made of a plastic material. In particular, the fire extinguishing tank 400 may be made of a plastic injection molding type.

[0070] The fire tank 400 may be configured to melt due to heat or vent gas emitted from the battery cell 110. For example, if thermal runaway occurs in the battery cell 110 and vent gas is emitted, the vent gas may be at a high temperature above a certain temperature. The fire tank 400 may be configured with a material and / or shape that can melt due to such high-temperature vent gas. Alternatively, if thermal runaway occurs in the battery cell 110, the battery cell 110 may be at a higher temperature than normal even if no vent gas is emitted. The fire tank 400 may be configured with a material and / or shape that can melt due to heat applied from the battery cell 110 in such an abnormally high temperature state.

[0071] In particular, the fire extinguishing tank 400 may be configured so that the base plate 411 melts due to the high temperature of the heat and / or gas generated during an event in the battery cell 110. In this case, the fire extinguishing agent can flow into the melted portion at the bottom of the fire extinguishing tank 400 and be discharged downward. Therefore, the fire extinguishing agent can be quickly injected toward the cell module assembly 100.

[0072] According to this embodiment of the present invention, the extinguishing agent is injected in a projectile-melting manner to effectively suppress a thermal event within the battery pack while minimizing propagation of the thermal event between the battery cells 110.

[0073] The fire tank 400 may contain a liquid fire extinguishing agent. In this case, the fire extinguishing agent may be referred to as a fire extinguishing liquid. For example, the fire tank 400 may contain water or other coolants as a fire extinguishing agent. The fire tank 400 may also contain antifreeze as a fire extinguishing agent. In particular, when a battery pack is used in cold seasons such as winter or in cold regions such as polar regions, the fire tank 400 may contain antifreeze as a fire extinguishing agent, which does not easily freeze even at low temperatures. Furthermore, in the case of a residential battery pack, which may be placed outdoors, antifreeze may be provided as a fire extinguishing agent.

[0074] The fire tank 400 may be configured so that the thickness of the base plate 411 varies depending on the position, which will be described in more detail with reference to FIGS.

[0075] Figure 3 is a perspective view schematically illustrating the configuration of a battery pack according to another embodiment of the present invention. For ease of explanation, some components are shown transparently in Figure 3. Also, Figure 4 is a cross-sectional view taken along line A4-A4' in Figure 3. Regarding various embodiments included in this specification, including this embodiment, detailed descriptions of parts that are identical or similar to those described in other embodiments will be omitted, and differences will be mainly described.

[0076] 3 and 4, the fire extinguishing tank 400 may include a base plate 411 and a side wall 412. Here, the side wall 412 may be configured to protrude upward from a corner of the base plate 411. The bottom and sides of the fire extinguishing tank 400 are defined by the base plate 411 and the side wall 412, thereby forming a space for holding an extinguishing agent. At this time, the top of the fire extinguishing tank 400 may be sealed by the pack case 300. That is, as shown in FIG. 4, the pack case 300 includes a lower case 300a and an upper case 300b, and the top of the fire extinguishing tank 400 is covered by the upper case 300b, thereby holding an extinguishing agent inside the fire extinguishing tank 400. Alternatively, the fire extinguishing tank 400 may be configured to include an upper cover 420, as shown in FIG. 1, to seal the top of the extinguishing agent holding space.

[0077] In the fire tank 400 having the base plate 411, the base plate 411 may be formed to have different thicknesses in different parts. In particular, the fire tank 400 may be configured to have a thinner thickness in a specific part, such as the part indicated by 411a in Figures 3 and 4. For example, the base plate 411 of the fire tank 400 may be formed in the form of a plastic injection molding having a thickness of 1 mm overall, and the part indicated by 411a may be configured to have a thickness of 0.5 mm.

[0078] In particular, the thinned portion of the base plate 411 of the fire tank 400 can function as the weak portion 411a. That is, when the temperature rises in the cell module assembly 100, the weak portion 411a can be damaged first. When the weak portion 411a is damaged, the extinguishing agent stored inside the fire tank 400 can be discharged to the cell module assembly 100 side through the weak portion 411a.

[0079] A plurality of fragile portions 411a may be provided. For example, the fragile portions 411a may have a shape that is narrow in width and long in length. That is, the fragile portions 411a may have a linear shape that is arranged parallel to one periphery of the fire tank 400, or the fragile portions 411a may be arranged parallel to each other.

[0080] According to this embodiment, when vent gas or a fire occurs due to thermal runaway in the cell module assembly 100, there is no need to provide a separate structure for injecting a fire extinguishing agent such as cooling water. Therefore, a simple structure can be realized for injecting a fire extinguishing agent into the battery pack. Furthermore, in this configuration, when an event occurs, the fire extinguishing agent can be discharged through the thin, weakened portion 411a, so the area where the fire extinguishing agent is discharged can be specified in advance.

[0081] In the above embodiment, as shown in Fig. 4, a plurality of fragile portions 411a may be provided in one fire tank 400. Furthermore, the plurality of fragile portions 411a may be arranged on the base plate 411 of the fire tank 400, spaced apart by a predetermined distance, along the stacking direction of the cell module assemblies 100. For example, in the cell module assembly 100, a plurality of battery cells 110 may be stacked in the left-right direction (X-axis direction), and on the base plate 411 of the fire tank 400 located on top of such cell module assembly 100, a plurality of fragile portions may also be arranged in the left-right direction, spaced apart from each other.

[0082] In particular, the fire tank 400 may be configured such that the weakened portion 411a having a relatively small thickness is located in the center between the horizontally stacked cells.

[0083] For example, in the configuration of FIG. 4, two battery cells 110, B1 and B2, are arranged adjacent to each other in the left-right direction on the left side of the cell module assembly 100. In this case, the leftmost weak portion 411a among the multiple weak portions 411a may be arranged between B1 and B2 in the left-right direction. In other words, the weak portion 411a is located above B1 and B2 in the up-down direction (Z-axis direction), but is located between B1 and B2 in the horizontal direction (X-axis direction). Furthermore, in addition to B1 and B2, one weak portion 411a may be arranged in the space between every two adjacent battery cells 110 in the horizontal direction.

[0084] According to this embodiment of the present invention, if a thermal event occurs in a particular battery cell 110 and heat is applied to the upper vulnerable portion 411a, the vulnerable portion 411a may be damaged. Then, the extinguishing agent may be discharged through the damaged vulnerable portion 411a and flow into the space between adjacent battery cells 110, as indicated by the arrows in FIG. 4 .

[0085] Therefore, this embodiment can more effectively prevent the transmission of a thermal event between battery cells 110. Furthermore, the embodiment of the present invention allows for concentrated injection of fire extinguishing agent around a battery cell 110 where a thermal event such as overheating or ignition has occurred, thereby enabling more effective cooling and fire extinguishing operations. Therefore, with this embodiment, if a fire or other event occurs inside the battery, fire extinguishing agent can be injected at the appropriate time and place without any other parts other than the fire tank 400.

[0086] FIG. 5 is an exploded perspective view schematically showing the configuration of a battery pack according to still another embodiment of the present invention.

[0087] Referring to FIG. 5, the battery pack includes a cell module assembly 100, a blocking member 200, a pack case 300, a fire tank 400, an outer cover 500, and an electrical connection unit (600, electrical unit).

[0088] 5, the cell module assembly 100 may be stacked such that the plurality of battery cells 110 are arranged in a horizontal direction (e.g., the X-axis direction) and are vertically aligned (e.g., the Z-axis direction in the drawing) in a stacked configuration. In this case, the longitudinal direction of the battery cells 110 is, for example, the Y-axis direction in the drawing.

[0089] FIG. 6 is a perspective view of a cell module assembly 100 included in the battery pack of FIG.

[0090] For reference, to more clearly show the components included in the cell module assembly 100, Figure 6 shows the remaining components excluding the plurality of battery cells 110. The plurality of battery cells 110 may be regular pouch-type battery cells or prismatic battery cells.

[0091] 6, a pair of bus bar housing assemblies 130 are disposed on the front and rear surfaces of a stack of multiple battery cells 110. Each of the bus bar housing assemblies 130 is disposed in a direction perpendicular to the longitudinal direction of the battery cells 110 (for example, the X-axis direction in the drawing). The bus bar housing assembly 130 includes openings through which the electrode leads 110a of the battery cells 110 pass, and the electrode leads 110a of each of the multiple battery cells 110 are coupled to bus bar electrodes disposed on the outer surface of the bus bar housing assembly 130.

[0092] A pair of end plates 120 are provided on both side ends of the stack of multiple battery cells 110. The end plates 120 are arranged parallel to and side by side with the battery cells 110. The pair of end plates 120 connects the pair of bus bar housing assemblies 130 together.

[0093] At least one strap 140 may be included on each of the upper and lower sides between the pair of end plates 120, connecting the pair of end plates 120. The strap 140 strengthens the binding of the cell module assembly 100. More specifically, the strap 140 strengthens the binding between the pair of end plates 120 and the stack of multiple battery cells 110 disposed therebetween. This makes it possible to prevent the stack of multiple battery cells 110 from becoming misaligned.

[0094] As the description of the cell module assembly 100 overlaps with that of FIG. 1, please refer to the description above in relation to FIG.

[0095] Meanwhile, as shown in Fig. 5, a predetermined number of battery cells 110 can be grouped and stored. Also, as shown in Figs. 5 to 9, a blocking member 200 is provided between a group of a plurality (a predetermined number) of battery cells 110 and an adjacent group of a plurality (a predetermined number of battery cells 110).

[0096] Fig. 7 is a perspective view of the blocking member 200 included in the battery pack of Fig. 5. Fig. 8 is an exploded perspective view of the blocking member 200 of Fig. 7. Fig. 9 shows the blocking member 200 of Fig. 7 and a battery cell 110 arranged side by side.

[0097] The blocking member 200 may be configured to be interposed between adjacent battery cells 110 to block heat. For example, if a thermal event occurs in some of the battery cells 110 and heat or high-temperature vent gas is generated, the blocking member 200 can suppress or block the generated heat and gas from transferring to adjacent battery cells 110. The blocking member 200 can also serve to block flames, sparks, and the like that are emitted from a particular battery cell 110.

[0098] The blocking member 200 has a generally plate-like shape. The blocking member 200 may be configured in the form of a plate that stands vertically. Furthermore, the blocking member 200 may have a height that is the same as or similar to the height of the battery cells 110 that also stand vertically. The height of the blocking member 200 may be smaller or larger than the height of the battery cells 110.

[0099] A plurality of blocking members 200 may be included depending on the number of battery cells. As described above, the blocking members 200 may be stacked together with the battery cells 110 to form the cell module assembly 100.

[0100] According to this embodiment of the present invention, in a battery pack including a plurality of battery cells 110, the blocking member 200 can effectively prevent the propagation of thermal runaway between the cells.

[0101] The blocking member 200 may also be large and have a triple-layer structure. For example, a pair of expansion pads 220 may be provided on each side of a support plate 210. The support plate 210 maintains the shape and rigidity of the blocking member 200 and blocks flames and sparks that may be ejected from the battery cells 110 between the battery cells 110. The support plate 210 may be made of, for example, a metal material. The expansion pads 220 reduce the pressure applied to the battery cells 110 by the support plate 210 when the battery cells 110 expand. The expansion pads 220 may be made of, for example, a silicone material or a soft plastic material.

[0102] On the other hand, the support plate 210 includes a plurality of through holes 230 formed by penetrating the support plate 210 in the vertical direction, as shown in detail in Figures 7 and 8, and the plurality of through holes 230 are arranged along the longitudinal direction of the support plate 210.

[0103] When a fire extinguishing agent (fire extinguishing liquid) is poured into the cell module assembly 100 from the fire tank 400 located above the cell module assembly 100, the fire extinguishing agent (fire extinguishing liquid) also enters the multiple through-holes 230. In other words, as the fire extinguishing agent (fire extinguishing liquid) remains in the multiple through-holes 230, the battery cell 110 in which a thermal event has occurred can be more effectively cooled and extinguished.

[0104] The plurality of through holes 230 may be open on both the upper and lower surfaces of the support plate 210. Alternatively, the plurality of through holes 230 may be open only on the upper surface, with the lower surface closed so that the extinguishing agent (extinguishing liquid) can remain in the through holes 230 for a longer period of time. In the former case, if the support plate 210 of the blocking member 200 is disposed so as to be in close contact with the lower inner surface of the pack case 300, the extinguishing agent (extinguishing liquid) can remain in the through holes 230 for a longer period of time, as in the latter case.

[0105] Fig. 10 is a perspective view of the pack case 300 included in the battery pack of Fig. 5. Figs. 11 and 12 are diagrams illustrating how the cell module assembly 100 of Fig. 10 is housed in the pack case 300.

[0106] 10, the pack case 300 may be configured in a box shape. The box-shaped pack case 300 may be integrally molded or may be manufactured by connecting at least one surface to an adjacent surface.

[0107] The pack case 300 includes at least one vent port 320. A filter is attached to the vent port 320.

[0108] When a thermal event occurs in a battery cell 110 housed inside the pack case 300, vent gas generated in the battery cell 110 can be discharged through the vent port 320. The vent gas discharged from the vent port 320 can be discharged to the outside of the external cover 500 via the space between the pack case 300 and the external cover 500 (500, see FIG. 5).

[0109] 11 and 12, the cell module assembly 100 shown in FIG. 6 may be housed in the internal space of an auxiliary case 310 and then attached to the pack case 300. By temporarily housing the cell module assembly 100 in the internal space of the auxiliary case 310 and then finally housing it in the pack case 300, the rigidity of the cell module assembly 100 can be supplemented and misalignment of the stack of multiple battery cells 110 in the cell module assembly 100 can be prevented. The auxiliary case 310 may be made of, for example, metal or stainless steel.

[0110] Fig. 13 is a perspective view of fire tank 400 included in the battery pack of Fig. 5. Fig. 14 is a perspective cross-sectional view of fire tank 400 of Fig. 13, showing a cross-section along line A5-A5' in Fig. 5. Fig. 15 is a top cross-sectional view of lower tank 410 of fire tank 400 viewed from above.

[0111] 13, the fire extinguishing tank 400 includes a lower tank 410 and an upper cover 420, as described above in FIG. 1. The lower tank 410 and the upper cover 420 may be manufactured separately and then hermetically coupled, or may be manufactured as an integrated unit. The upper cover 420 may additionally include an inlet 430 through which a fire extinguishing agent can be injected. The inlet 430 may be closed with a lid to seal the fire extinguishing tank 400.

[0112] 14, the thinner portion of the base plate 411 of the lower tank 410 can function as the weak portion 411a. That is, when a thermal event occurs in the battery cell 110 of the cell module assembly 100, the weak portion 411a, which is relatively thin, can be damaged first. When the weak portion 411a is damaged and an opening is formed in the base plate 411, the extinguishing agent held inside the fire tank 400 can be discharged to the cell module assembly 100 side through the weak portion 411a.

[0113] A plurality of fragile portions 411a may be provided. For example, the fragile portions 411a may have a shape that is narrow in width and long in length. That is, the fragile portions 411a may have a linear shape that is arranged parallel to one periphery of the fire tank 400, or the fragile portions 411a may be arranged parallel to each other.

[0114] On the other hand, according to this embodiment, the longitudinal direction of the battery cell 110 (for example, the X-axis direction in the drawing) and the longitudinal direction of the vulnerable portion 411a (for example, the X-axis direction in the drawing) may be perpendicular to each other. In other words, multiple vulnerable portions 411a are arranged intersecting the longitudinal direction of the battery cell 110. This allows the extinguishing agent to be supplied simultaneously across the entire battery cell 110 in which a thermal event has occurred, via the multiple open vulnerable portions 411a, along the longitudinal direction of the battery cell 110, and the fire in the battery cell 110 in which a thermal event has occurred can be extinguished more efficiently and quickly.

[0115] 14, the base plate 411 of the lower tank 410 has a step. In particular, the base plate 411 of the lower tank 410 protrudes downward toward the portion where the electrode lead 110a of the battery cell 110 is located. During a thermal event, flames are more likely to be emitted from the lead portion of the battery cell 110 than from other portions of the battery cell 110. The fire extinguishing tank 400, i.e., the base plate 411 of the lower tank 410, is positioned as close as possible to the portion where the electrode lead 110a of the battery cell 110 is located, so that a fire in the battery cell 110 can be extinguished early, quickly, and effectively.

[0116] In the base plate 411 of the lower tank 410, the portion located on the electrode lead 110a of the battery cell 110 may have the same height as or be lower than the portion where the main body 110b of the battery cell 110 is located. For example, as shown in Fig. 14, the height of the base plate 411 of the lower tank 410 corresponding to the portion where the electrode lead 110a of the battery cell 110 is located may be the lowest.

[0117] The width (height in the Z-axis direction) of the electrode lead 110a is smaller than the width of the main body 110b of the battery cell 110 (see FIG. 9). When the battery cell 110 is stood vertically so that its width direction coincides with the Z-axis direction, the height from the bottom of the electrode lead 110a in the Z-axis direction is smaller than the height from the bottom of the main body 110b of the battery cell 110 in the Z-axis direction. Accordingly, the base plate 411 of the lower tank 410 of the fire extinguisher tank 400 can have a lower height at the portion corresponding to the electrode lead 110a of the battery cell 110 than at the portion corresponding to the main body 110b of the battery cell 110.

[0118] 14 again, the base plate 411 is roughly divided into the following sections: a section A7 located on the main body 110b side of the battery cell 110, a section A8 that abuts against the strap 140 of the pack case 100, sections A9 and A10 located on the electrode lead 110a side, and a section A11 located on the bus bar housing assembly 130 side.

[0119] The portions A9 and A10 located on the electrode lead 110a side have a shape that protrudes toward the electrode lead 110a side. In addition, the portions A9 and A10 located on the electrode lead 110a side have a shape that protrudes toward the electrode lead 110a side at least more than the portion A11 located on the bus bar housing assembly 130 side. In some cases, as shown in FIGS. 13 and 14 , the height of the base plate 411 of the portions A9 and A10 located on the electrode lead 110a side may be the shortest. In addition, the height of the base plate 411 of the portions A9 and A10 located on the electrode lead 110a side may be the same as the height of the portion A7 located on the main body 110b side of the battery cell 110. However, depending on the environment in which the present invention is implemented, the height of the base plate 411 of the portions A9 and A10 located on the electrode lead 110a side may be the shortest than the height of the portion A7 located on the main body 110b side of the battery cell 110, as shown in FIGS. 13 and 14 .

[0120] Furthermore, the portions A9 and A10 located on the electrode lead 110a side and having a protruding shape toward the electrode lead 110a may be disposed on the outer surface of the bus bar housing assembly 130. In addition, the outer surface of the bus bar housing assembly 130 refers to the surface where the electrode lead 110a is coupled to the bus bar electrode. However, the present invention is not necessarily limited thereto, and as long as there is a space between the inner surface of the bus bar housing assembly 130 and the battery cell 110, the corresponding portion may also have a protruding shape.

[0121] In short, according to one embodiment of the present invention, the base plate 411 of the lower tank 410 of the fire tank 400 includes a portion that protrudes downward toward the electrode lead 110a of the battery cell 110. By arranging the base plate 411 of the lower tank 410 of the fire tank 400 as close as possible to the electrode lead 110a as well as the main body 110b of the battery cell 110, when an overheating or ignition condition occurs in the battery cell 110, rapid initial suppression can be achieved, more effectively preventing the occurrence of dangerous conditions such as secondary explosions due to the transfer of heat or flames to adjacent battery cells 110. In addition, by arranging the fire tank 400 as close as possible to the electrode lead 110a, which is the part of the battery cell 110 that is most likely to ignite and from which flames are most likely to erupt, a thermal event occurring in the battery cell 110 can be responded to quickly and effectively. 6 for the cell module assembly 100, the height of the cell module assembly 100 is not constant due to the positions of the straps 140 and the bus bar housing assembly 130. Regardless of this, if the height of the base plate 411 of the lower tank 410 of the fire tank 400 were constant overall, a space would be created between the base plate 411 of the fire tank 400 and the upper surface of the cell module assembly 100. In this case, the space would hinder the transfer of heat from the heated battery cells 110 to the weak parts 411a, delaying fire extinguishing accordingly.

[0122] When the battery cell 110 overheats, the weak part 411a is arranged directly adjacent to the battery cell 110 whose temperature has risen, so that the weak part 411a is immediately broken, allowing the battery cell 110 to be quickly cooled and the fire to be extinguished.

[0123] In other words, the lower surface of the base plate 411 of the fire tank 400 and the upper surface of the cell module assembly 100 have shapes that generally match each other. As a result, the fire tank 400 is disposed in closer contact with the cell module assembly 100, which allows for more effective cooling of battery cells 110 that have risen in temperature and for more rapid injection of fire extinguishing agent into battery cells 110 that have overheated or caught fire. In addition, the fire tank 400 can efficiently accommodate a larger amount of fire extinguishing agent. In other words, if the height of the base plate 411 of the lower tank 410 of the fire tank 400 is uniform overall, the fire tank 400 can accommodate less fire extinguishing agent by the amount of empty space.

[0124] 14, the fragile portions 411a may be provided in the portion A7 located on the main body 110b side of the battery cell 110 and in the portions A9 and A10 located on the electrode lead 110a side, but the present invention is not limited to what is shown in the figure and various modifications and changes are possible, such as the fragile portions 411a also being provided in the portion A8 that abuts against the strap 140. Furthermore, the number and shape of the fragile portions 411a are not limited to what is shown in the figure and various modifications and changes are possible.

[0125] Similarly, although not shown in Fig. 14, the base plates 411 of the portions A9 and A10 located on the electrode lead 110a side may also have a structure including a fragile portion 411a. Alternatively, as shown in Fig. 14, the base plates 411 of the portions A9 and A10 located on the electrode lead 110a side may not have a separate fragile portion 411a, but may have a thickness thin enough that an opening can be formed in the base plates of A9 and A10 when a thermal event occurs. For example, the thickness of the base plates 411 of A9 and A10 may be substantially the same as the thickness of the fragile portion 411a.

[0126] 14 and 15, of the portions A9 and A10 located on the electrode lead 110a side, the portion A9 is also disposed adjacent to the electrical connection unit 600. Of the portions A9 and A10 located on the electrode lead 110a side, the portion A9 is located on the side of the electrical connection unit 600 described below, is located in the upper part of the space between the electrical connection unit 600 and the bus bar housing assembly 130, and can protrude downward toward the electrode lead 110a.

[0127] Meanwhile, the portion marked A11 in Fig. 14 is a portion located on the bus bar housing assembly 130, and in order to accommodate an embodiment in which the heights of the bus bar housing assemblies 130 at both ends are different (see Fig. 6), Fig. 14 shows that the heights of the portions marked A11 on both sides are designed to be different accordingly. However, this corresponds to only one embodiment, and it should be noted that the heights of the portions marked A11 on both sides of the present invention are not necessarily limited to those shown in Fig. 14.

[0128] In some cases, although not shown in the present invention, the A9 portion can be fabricated to mate with the upper structure of the electrical connection unit 600. In other words, if the A9 portion is also located on the electrical connection unit 600, it may have a step depending on the height of the electrical connection unit 600. Also, in some cases, as shown in Fig. 17, a connector 610 passes through the A9 portion so that the cell module assemblies 100 can be electrically connected to each other when multiple battery packs 110 are stacked, and the A9 portion may have a connector through-hole 440 for this purpose.

[0129] However, the present invention is not limited thereto, and it is sufficient that the portions A9 and A10 located on the electrode lead 110a side of the base plate 411 of the lower tank 410 of the fire extinguisher tank 400 have a shape that protrudes toward the electrode lead 110a side, and various modifications and changes are possible in various environments in which the present invention is realized and in the design and structure of the battery pack. Of course, by changing the structure and / or position of the electrical connection unit 600 and the connector 610, the fire extinguisher tank 400 may not have the connector through-hole portion 440 as shown in Figures 18 to 20. The fire extinguishing agent provided in the fire extinguisher tank 400 may be in the form of, for example, a fire extinguishing liquid, and repeated explanations will be omitted and reference will be made to the above.

[0130] Fig. 16 shows a modified embodiment of the fire tank shown in Figs. 5 to 15, in which the height of the base plate 411 at portions A9 and A10 located on the electrode lead 110a side is modified. Fig. 16 shows a perspective cross-sectional view similar to Fig. 14.

[0131] The embodiment of FIG. 16 shows a modified version that can be realized when, as in FIG. 14, portions A9 and A10 located on the electrode lead 110a side protrude and there is insufficient space for arranging portions A9 and A10 located on the electrode lead 110a side due to other components (e.g., PCB) arranged on the bus bar housing assembly 130. In addition, in FIG. 16, portions A9 and A10 located on the electrode lead 110a side protrude toward the electrode lead 110a at least further than portion A11 located on the bus bar housing assembly 130. Therefore, the base plate 411 of the fire tank 400 is positioned as close as possible to the electrode lead 110a side (relative to the height of the bus bar housing assembly 130), thereby improving fire extinguishing performance in the event of a thermal event. Other explanations overlap with those described above with reference to FIGS. 13 to 15, so please refer to those parts.

[0132] FIG. 17 is a perspective view of a battery pack in which all of the components of the battery pack described above with reference to FIGS. 5 to 16 are combined together.

[0133] In addition, where the explanation of the battery pack in FIGS. 5 to 17 overlaps with the explanation of the battery pack in FIGS. 1 to 4, reference will be made to what has been described above with reference to FIGS.

[0134] Figures 18 to 20 show modified examples of the battery pack of Figures 1 to 5. Figure 18 is a perspective view of the fire tank 400, Figure 19 is a front view of the fire tank 400, and Figure 20 is a cross-sectional view of the fire tank 400 when positioned on the cell module assembly 100. For ease of understanding, the lower tank 410 of the fire tank 400 is shown.

[0135] 18 to 20 are shown without the electrical connection unit (600, electrical unit, see FIG. 5). For example, FIGS. 18 to 20 may show that the battery pack is realized by a battery module unit that is smaller in scale than the battery pack of FIG. 5, and the battery pack shown in FIG. 20 may be realized by changing the position at which the electrical connection unit 600 of FIG. 5 is arranged. In the cases of FIGS. 18 to 20, the fire tank 400 does not necessarily have to have the connector through-hole portion 440.

[0136] 18 to 20, portions A9 and A10 located on the electrode lead 110a are also made to protrude downward. As a result, in the same way as described above with respect to Figures 13 to 15, if a fire first breaks out on the electrode lead 110a side of the battery cell 110, the fire can be more effectively extinguished.

[0137] In the base plate 411 of the lower tank 410, the portion located on the electrode lead 110a of the battery cell 110 may have the same height as or a different height from the portion located on the main body 110b of the battery cell 110. As shown in Fig. 19, the height of the base plate at the portion A10 located on the electrode lead 110a of the battery cell 110 and the portion A7 located on the main body (110b, see Fig. 9) of the battery cell 110 may be the same. Alternatively, in some cases, the height of the base plate at the portion A10 located on the electrode lead 110a of the battery cell 110 and the portion A7 located on the main body 110b of the battery cell 110 may be different.

[0138] Fig. 21 shows a front view of the fire tank, which is a partial modification of the fire tank of the battery pack of Fig. 18. As shown in Fig. 21, the height of the portion A10 located at the electrode lead 110a may be the lowest. For other explanations, refer to the above-mentioned Figs. 1 to 16.

[0139] Meanwhile, a plurality of pack cases 300 may be provided so as to be stackable in the vertical direction, which will be described in more detail with reference to FIG.

[0140] Fig. 22 is a perspective view schematically showing the configuration of at least a portion of the battery pack of the present invention shown in Figs. 1 to 17. Figs. 23 and 24 are views showing an embodiment in which a plurality of pack cases 300 shown in Fig. 22 are stacked.

[0141] Referring to FIG. 22 , the pack case 300 may include a bottom and sidewalls. The cell module assemblies 100 can be accommodated in the internal space of the pack case 300, and the top of the cell module assemblies 100 is covered with a fire tank 400 to form a battery pack. For reference, in FIG. 22 , the height of the upper side of the pack case 300 is shown to be greater than the height of the upper surface of the fire tank 400. However, FIG. 22 is a schematic view and is merely one embodiment, and the present invention is not limited to what is shown in FIG. 22 . In other words, various modifications are possible, such as the opposite, the height of the upper surface of the fire tank 400 may be greater than the height of the upper side of the pack case 300, or the height of the upper surface of the fire tank 400 may be the same as the height of the upper side of the pack case 300.

[0142] A plurality of pack cases 300 as shown in Fig. 22 may be provided to form a stacked structure of battery packs as shown in Fig. 23 or 24. In this case, the battery pack of Fig. 22 may be one unit pack. A plurality of such unit packs may be provided to form a modular stacked overall battery pack as shown in Fig. 23 or 24.

[0143] More specifically, for example, the configuration in Fig. 23 shows a configuration in which three unit packs D are stacked vertically. And the configuration in Fig. 24 shows a configuration in which five unit packs D are stacked vertically. The present invention is not limited to the illustrated configuration, and can be realized by changing the number of unit packs D in various ways according to the environment in which the present invention is realized.

[0144] For example, if the present invention is implemented as a battery pack in an energy storage system (ESS), various voltage bands and / or storage capacities of the energy storage system can be realized by adjusting the number of unit battery packs. According to this embodiment of the present invention, a single unit pack having a common structure can be stacked in various ways, and products with various voltage bands and / or storage capacities can be created by adjusting the number of stacked packs. For example, by adjusting the number of stacked packs of the same unit pack, a low-voltage product as shown in FIG. 23 and a high-voltage product as shown in FIG. 24 can both be realized. This improves economy and compatibility compared to products limited to a specific voltage band. Furthermore, this embodiment may realize products with a wider range of capacities depending on the number of stacked packs.

[0145] In other words, when stacked unit packs are connected in series, products with various voltage ranges can be realized depending on the number of stacked packs.Furthermore, when stacked unit packs are connected in parallel, products with various capacities (storage capacities) can be realized depending on the number of stacked packs.

[0146] In particular, each unit pack D may include a cell module assembly 100 therein. Also, as described above, each unit pack D includes a connector 610 so that the cell module assemblies 100 can be electrically connected to each other when stacked. In particular, such connectors 610 may be configured to be coupled to each other by stacking each unit pack D vertically.

[0147] Furthermore, in the above embodiment, each unit pack D can accommodate a fire tank 400 along with the cell module assembly 100. That is, each unit pack D includes the fire tank 400 on top of the cell module assembly 100, as described above. A battery pack stacked with multiple unit packs has a stacked structure of fire tank 400-cell module assembly 100-fire tank 400-cell module assembly 100 from top to bottom. The stacked battery pack of the present invention having this structure can be configured by increasing (expanding) the number of cell module assemblies 100 to configure a battery pack in order to increase various voltage ranges and / or storage capacity, while also safely responding to thermal events such as fires in the cell module assemblies 100. Therefore, this embodiment of the present invention further improves the safety of the battery pack.

[0148] Referring again to FIG. 22, another example of a coupling method between vertically stacked battery packs (pack cases 300) is as follows. The upper end of the side wall of the pack case 300 may have a step recessed inward, such as the coupling step C1. For example, this step may be a portion where the thickness of the side wall of the pack case 300 is thin. Also, although not shown in FIG. 22, the bottom of the pack case 300 may have a coupling recess into which the coupling step C1 of the side wall is inserted. That is, when different pack cases 300 are stacked vertically, the coupling step C1 formed on the upper end of the side wall of the lower pack case 300 may be inserted into the coupling recess formed on the bottom of the upper pack case 300. As a result, when multiple pack cases 300 are stacked vertically and coupled, the outer surface of the pack case 300 may have an overall flat shape.

[0149] Meanwhile, the coupling method for the fastening structure between vertically stacked battery packs is not limited to that shown in FIG. 22 and / or FIG. 10, and various other coupling methods can be modified or changed and applied to the present invention.

[0150] The battery pack of the present invention can also be connected to a battery management system (BMS, not shown). The battery management system monitors and manages the battery pack. The battery management system may be located on the top layer of a stack of battery packs. However, the location of the battery management system is not limited to the above and can be variously modified and changed according to the method and environment in which the present invention is implemented.

[0151] In addition to the above-described components, the battery pack according to the present invention may further include various other components included in the battery pack. For example, the battery pack according to the present invention may include various electrical components for controlling or managing the charging and discharging of the battery pack, such as a battery management system (BMS), relays, fuses, and current sensors.

[0152] An energy storage system (ESS) according to the present invention includes one or more of the battery packs according to the present invention described above. In addition to the battery pack, the energy storage system according to the present invention may further include other components commonly included in an energy storage system.

[0153] Meanwhile, although terms indicating directions such as up, down, left, and right may be used in this specification, it will be obvious to those skilled in the art that such terms are used merely for the convenience of explanation and will differ depending on the position of the object of interest, the position of the observer, etc.

[0154] Although the present invention has been described above using limited examples and drawings, the present invention is not limited thereto, 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 equivalent scope of the claims set forth below. [Explanation of symbols]

[0155] 100: Cell module assembly 110: Battery cell 120: End plate 130: Busbar housing assembly 200: Blocking member 210: Support plate 220: Inflatable pad 230:Through hole 300: Pack case 300a: Lower case 300b: Upper case 310: Auxiliary case 320: Vent 400: Fire tank 410: Lower tank 411: Base plate 411a: Weak area 412: Side wall 420: Upper cover 430: Inlet 440: Connector through hole 500:External cover 600: Electrical connection unit 610: Connector

Claims

1. A battery pack, a cell module assembly including a battery cell stack in which a plurality of battery cells are stacked, and a bus bar housing assembly in which electrode leads of the battery cells are coupled to bus bar electrodes; a pack case that houses the cell module assembly and has an open top; a fire tank covering an upper surface of the cell module assembly; Including, The fire extinguishing tank is an interior space containing a fire extinguishing agent; a plurality of weak points that are formed in a relatively thin portion of the base plate of the fire tank and melt and open due to a thermal event of the battery cell; Including, At least a portion of the base plate of the fire tank that is located above the electrode leads of the battery cells includes a shape that protrudes downward toward the electrode leads of the battery cells. Battery pack.

2. The base plate of the fire extinguishing tank has a step, a height of a portion of the battery cell located on the electrode lead is lower than a height of a portion of the battery cell located on the bus bar housing assembly; The battery pack according to claim 1 .

3. The base plate of the fire extinguishing tank has a step, The height of the portion of the battery cell located on the electrode lead is equal to or lower than the height of the portion of the battery cell located on the main body. The battery pack according to claim 1 .

4. a portion of the base plate of the fire extinguisher tank that is located on the electrode lead of the battery cell is adjacent to the electrode lead; The battery pack according to claim 1 .

5. a portion of the battery cell located on the electrode lead, the portion protruding downward toward the electrode lead of the battery cell, is located on an outer surface of the bus bar housing assembly; The battery pack according to claim 1 .

6. The weak portions are linear and arranged parallel to one circumferential edge of the fire extinguisher tank, and the weak portions are arranged parallel to each other; the longitudinal direction of the fragile portion and the longitudinal direction of the battery cell are perpendicular to each other; The battery pack according to claim 1 .

7. The weak portions are linear and arranged parallel to one circumferential edge of the fire extinguisher tank, and the weak portions are arranged parallel to each other; the longitudinal direction of the fragile portion and the longitudinal direction of the battery cell are parallel to each other, the weakened portion is disposed between two adjacent battery cells; The battery pack according to claim 1 .

8. the fragile portion is also provided in a portion of the battery cell that is located on an electrode lead and that protrudes downward toward the electrode lead of the battery cell. The battery pack according to claim 1 .

9. a thickness of a portion of the battery cell located on the electrode lead that protrudes downward toward the electrode lead is the same as a thickness of the fragile portion; The battery pack according to claim 1 .

10. The fire extinguishing tank is a plastic product. The battery pack according to claim 1 .

11. The cell module assembly comprises: a pair of end plates disposed parallel to the battery cells at both ends of the stack of battery cells, the pair of end plates connecting the pair of bus bar housings; The battery pack according to claim 1 .

12. The cell module assembly comprises: straps respectively connecting upper and lower sides of the pair of end plates of the battery cell stack to strengthen binding of the cell module assembly; The battery pack according to claim 11.

13. the base plate has a step, a height of the portion where the plurality of fragile portions are arranged from a lower surface of the battery pack lower than a height of the portion located on the strap; The battery pack according to claim 12.

14. The extinguishing agent is a liquid extinguishing agent. The battery pack according to claim 1 .

15. The battery pack is provided in a plurality of pieces, The plurality of battery packs are connected to each other by mechanical or electrical connections. The battery pack according to claim 1 .

16. The plurality of battery packs can be stacked in the vertical direction. The battery pack according to claim 15.

17. The plurality of battery packs are electrically connected in series so that various voltage ranges of the plurality of battery packs can be realized. The battery pack according to claim 15.

18. The plurality of battery packs are electrically connected in parallel so that the storage capacities of the plurality of battery packs can be diversified. The battery pack according to claim 15.

19. 19. An energy storage device comprising a battery pack according to any one of claims 1 to 18.

Images