Battery pack and energy storage system (ESS) including it

Abstract

The present invention relates to a battery pack including: a pack case having a plurality of battery cells and a plurality of unit plates configured to house the plurality of battery cells, wherein the pack case is provided with a vent portion disposed on at least one of the plurality of unit plates and configured to discharge gas discharged from the battery cells to the outside, and wherein at least some of the unit plates are formed with vent spaces configured to extend toward the vent portion and allow the gas to flow.

Description

[Technical Field]

[0001] The present invention relates to a battery pack and an energy storage system (ESS) including the same.

[0002] This application claims priority based on Korean Patent Application No. 10-2023-0119306, filed on September 7, 2023, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings thereof.

[0003] This application claims priority based on Korean Patent Application No. 10-2023-0153945, filed on November 8, 2023, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings thereof. [Background technology]

[0004] Secondary batteries, which have high applicability across a range of products and electrical properties such as high energy density, are widely used not only in portable devices but also in electric vehicles (EVs), hybrid electric vehicles (HEVs), energy storage systems (ESSs), etc. These secondary batteries not only have the temporary advantage of dramatically reducing the use of fossil fuels, but also have the advantage of producing no by-products associated with energy use, and are therefore attracting attention as a new energy source that is environmentally friendly and improves energy efficiency.

[0005] Depending on the charge / discharge capacity of the battery pack required for an electric vehicle (EV), hybrid electric vehicle (HEV), or energy storage system (ESS), a battery pack may be constructed by connecting multiple battery cells in series or parallel. A common method is to first construct a battery pack containing at least one battery cell, and then use this battery pack to construct a battery pack or battery rack by adding other components. Recently, cell-to-pack (CTP) battery packs have also been manufactured, in which multiple battery cells are directly housed in a pack housing without being modularized.

[0006] However, in the case of a battery pack containing such a large number of lithium secondary batteries, the damage caused by a fire or explosion is bound to be even more severe. A fire in a battery pack begins when the battery cells inside it experience an abnormal temperature rise and generate internal gas. If the internal pressure of the battery cell rises above a certain level, venting occurs, and high-temperature gas and high-temperature sparks containing electrode active material and aluminum particles are ejected to the outside of the battery cell.

[0007] Therefore, in order to ensure the stability of the battery pack during use, when a thermal event such as thermal runaway occurs inside the battery pack, the venting gas must be quickly released to the outside of the battery pack so that the internal pressure of the battery pack does not increase any further.

[0008] If such vent gases are not properly released to the outside, the internal pressure of the battery pack may increase, causing damage to other battery cells, the pack case, and other battery pack components.In addition, the internal pressure of the battery pack may increase, causing even more serious problems, such as the battery pack exploding, so it is very important to release the vent gases to the outside.

[0009] For this reason, conventional battery packs have been provided with vents in the pack case to allow hot vent gases and the like to be discharged to the outside of the pack case when a thermal event occurs in a particular battery cell or battery pack.

[0010] However, in a battery pack with this configuration, gas may move not only in the direction of the vent but also in all directions, increasing the rate at which thermal runaway occurs between the battery cells. In particular, because the space between the battery cell and the flat top plate that covers the top of the battery cell is very narrow, it is difficult to secure a flow path for the vent gas to move to the vent, which causes a further increase in the internal pressure of the battery pack.

[0011] Therefore, when a thermal event occurs inside the battery pack, there is a need for a technology that allows high-temperature gases to be directionally vented toward the vent portion and quickly discharged to the outside of the battery pack.

[0012] In addition, the need for technology to ensure a space within the battery pack through which vent gas can flow and prevent the internal pressure of the battery pack from increasing has been raised. Summary of the Invention [Problem to be solved by the invention]

[0013] Therefore, the present invention has been made to solve the above-mentioned problems, and provides a battery pack and an energy storage system (ESS) including the same that can ensure safety and reliability when an abnormality occurs in a battery cell.

[0014] 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 given below. [Means for solving the problem]

[0015] In order to solve the above problems, a battery pack according to one aspect of the present invention includes a plurality of battery cells; and a pack case having a plurality of unit plates and configured to house the plurality of battery cells, the pack case having a vent portion disposed on at least one of the plurality of unit plates and configured to discharge gas discharged from the battery cells to the outside, and at least some of the unit plates have a vent space formed therein that is configured to extend toward the vent portion and allow the gas to flow.

[0016] The unit plates may include a top plate configured to cover an upper portion of the battery cell and having the vent space formed therein.

[0017] The top plate may include a main body portion and a flow path portion configured such that at least a portion of the main body portion protrudes upward to form the vent space.

[0018] The unit plates may include end plates configured to cover both sides of a cell array configured by stacking the plurality of battery cells, and the end plates may include coupling grooves configured to receive the top plate.

[0019] The end plate may be provided with a protrusion configured such that its terminal portion protrudes at least partially above the top plate, and the flow path portion may be disposed in a space formed between the protrusions.

[0020] A plurality of the vent portions may be provided, and a plurality of the flow passage portions may be provided to correspond to the positions of the vent portions.

[0021] The flow path portion may be disposed to extend along a longitudinal direction of the battery cell.

[0022] The flow path portion may include a portion configured such that the volume of the vent space gradually increases toward the vent portion.

[0023] The flow path portion may have a wavy shape in a cross section of at least one side surface.

[0024] The top plate may include a guide portion configured such that at least a portion of the main body portion is inclined upward toward the flow path portion.

[0025] The battery pack may include a plurality of cell arrays each formed by stacking the plurality of battery cells, and the top plate may include a recess disposed between adjacent cell arrays and configured to allow at least a portion of the flow path portion to protrude downward.

[0026] The top plate may be configured such that at least a portion thereof protrudes downward to prevent the gas from moving in a stacking direction of the plurality of battery cells.

[0027] The top plate may include a first rib configured such that at least a portion of the main body protrudes downward and is interposed between the battery cells.

[0028] The battery pack may further include a blocking member interposed between the battery cells, and the first rib may include an insertion groove configured to receive the blocking member.

[0029] The top plate may include a second rib configured such that at least a portion of the flow path portion protrudes downward and is interposed between the battery cells.

[0030] The vent portion may include a vent hole formed through at least a portion of the unit plate, and a cover portion configured to cover at least a portion of the vent hole.

[0031] The cover portion may be configured so that at least a portion of the unit plate protrudes outward.

[0032] The vent may include a discharge hole formed by opening a lower portion of the cover.

[0033] And, an energy storage system (ESS) according to the present invention may include a battery pack according to the present invention. [Effects of the Invention]

[0034] According to one aspect of the present invention, vent gas generated when an abnormality occurs in a battery cell can be smoothly discharged to the outside of the pack case, effectively preventing an increase in internal pressure inside the pack case, thereby ensuring the safety and reliability of the battery pack.

[0035] Furthermore, according to one aspect of the present invention, vent gas can be smoothly discharged to the outside of the pack case, thereby preventing damage to components of the battery pack due to the vent gas.

[0036] Furthermore, according to one aspect of the present invention, vent gas generated when an abnormality occurs in a battery cell can be directionally vented, thereby minimizing thermal damage to other battery cells inside the battery pack.

[0037] This makes it possible to prevent or delay events such as fires and explosions caused by thermal runaway in the battery pack or the device to which it is attached.

[0038] In addition to these, the present invention can have various other effects, which will be explained in the sections for each embodiment, and explanations of effects that can be easily inferred by those skilled in the art will be omitted.

[0039] 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]

[0040] [Figure 1] 1 is an overall perspective view of a battery pack according to an embodiment of the present invention; [Figure 2] 1 is an exploded perspective view of a battery pack according to an embodiment of the present invention; [Figure 3] 3 is a cross-sectional view of a battery pack according to an embodiment of the present invention, for example, Fig. 3 may be a cross-sectional view taken along the line II' in Fig. 1 . [Figure 4] FIG. 4 is an enlarged view of part A in FIG. 3. [Figure 5] 4A and 4B are diagrams illustrating a direction in which vent gas flows inside a battery pack according to an embodiment of the present invention. [Figure 6] FIG. 10 is an overall perspective view of a battery pack according to another embodiment of the present invention. [Figure 7]FIG. 10 is a cross-sectional view of a battery pack according to yet another embodiment of the present invention. [Figure 8] FIG. 10 is a cross-sectional view of a battery pack according to yet another embodiment of the present invention. [Figure 9] FIG. 10 is an overall perspective view of a battery pack according to yet another embodiment of the present invention. [Figure 10] FIG. 10 is a cross-sectional view of the battery pack in FIG. 9. [Figure 11] 11 is a cross-sectional view of a battery pack according to still another embodiment of the present invention, for example, Fig. 11 may be a cross-sectional view taken along the line II-I' in Fig. 1. [Figure 12] FIG. 10 is a cross-sectional view of a battery pack according to yet another embodiment of the present invention. [Figure 13] FIG. 10 is a cross-sectional view of a battery pack according to yet another embodiment of the present invention. [Figure 14] 14 is a front perspective view of a battery pack according to an embodiment of the present invention, specifically, a view illustrating a direction in which vent gas is discharged from a battery pack according to an embodiment of the present invention. [Figure 15] FIG. 1 is a front view of a battery pack according to an embodiment of the present invention. [Figure 16] 16 is a cross-sectional view of a battery pack according to an embodiment of the present invention, For example, Fig. 16 may be a view showing a portion of the front side as viewed along arrows II-II' in Fig. 1. DETAILED DESCRIPTION OF THE INVENTION

[0041] 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 this specification and claims should not be construed as being limited to their ordinary or dictionary meanings, but should be construed as meanings and concepts corresponding to the technical ideas of the present invention, in accordance with the principle that the inventor can appropriately define the concepts of terms himself / herself in order to best describe the invention. Therefore, it should be understood that the embodiment described in this specification and the configuration shown in the drawings are merely a preferred embodiment of the present invention and do not represent the entire technical ideas of the present invention, and therefore, various equivalent and modified embodiments may be available as of the time of filing this application.

[0042] The present invention includes a wide variety of embodiments, and the following description will be focused on the differences between the embodiments, omitting redundant explanations of substantially the same or similar configurations.

[0043] Meanwhile, in the present invention, directional terms such as up, down, left, right, front, and back can be used, but these terms are used merely for ease of explanation, and it will be obvious to those skilled in the art that these terms may vary depending on the position of the object in question, the position of the observer, etc.

[0044] For example, in an embodiment of the present invention, the illustrated X-axis direction may refer to the left-right direction, the Y-axis direction may refer to the front-to-back direction that is perpendicular to the X-axis direction on a horizontal plane (XY plane), and the Z-axis direction may refer to the up-down direction (vertical direction) that is perpendicular to both the X-axis direction and the Y-axis direction.

[0045] FIG. 1 is an overall perspective view of a battery pack according to one embodiment of the present invention, and FIG. 2 is an exploded perspective view of a battery pack according to one embodiment of the present invention. Also, FIG. 3 is a cross-sectional view of a battery pack according to one embodiment of the present invention. For example, FIG. 3 may be a cross-sectional view taken along the line I-I' in FIG. 1. Furthermore, FIG. 4 is an enlarged view of portion A in FIG. 3, and FIG. 5 is a view illustrating the direction in which vent gas flows inside a battery pack according to one embodiment of the present invention.

[0046] 1 to 5, a battery pack 10 according to an embodiment of the present invention includes a battery cell 100 and a pack case 200.

[0047] 2, the battery may include a plurality of battery cells 100. Although not shown, the plurality of battery cells 100 may include an electrode assembly, a cell case that houses the electrode assembly, and an electrode lead that is connected to the electrode assembly and extends to the outside of the cell case to function as an electrode terminal. In this case, the plurality of battery cells 100 may be electrically connected to each other.

[0048] The battery cell 100 may be a pouch-type secondary battery. The cell case of such a pouch-type secondary battery may be configured in the shape of a pouch in which a metal layer made of aluminum is interposed between polymer layers.

[0049] The multiple battery cells 100 may be arranged side by side in the left-right direction (X-axis direction) while standing upright in the vertical direction (Z-axis direction), as shown in Fig. 2. In this case, the seal portion of each battery cell 100 may face the front-rear direction (Y-axis direction) and the up-down direction (Z-axis direction), and the storage portion may face the left-right direction (X-axis direction).

[0050] A plurality of battery cells 100 may be stacked in the left-right direction (X-axis direction) to form a cell array C. As shown in Fig. 2, a plurality of cell arrays C may be arranged in the front-rear direction (Y-axis direction).

[0051] Meanwhile, the present invention is not limited in any way by the specific type or shape of the battery cell 100, and a wide variety of battery cells 100 known at the time of filing of the present invention can be used to configure the battery pack 10 of the present invention. For example, the battery cell 100 can be configured as a prismatic battery.

[0052] Furthermore, the battery pack 10 according to an embodiment of the present invention may include a bus bar assembly and / or terminals electrically connected to the plurality of battery cells 100 housed therein.

[0053] Meanwhile, the pack case 200 may be configured to accommodate a plurality of battery cells 100. That is, the pack case 200 may provide an accommodation space for accommodating a plurality of battery cells 100. In order to safely protect the battery cells 100 accommodated therein, the pack case 200 may be made of or may include a material capable of ensuring mechanical rigidity, such as a metal such as steel or stainless steel (SUS) or plastic.

[0054] The pack case 200 may include a plurality of unit plates. The unit plates may be configured to cover all of the top, bottom, and side surfaces of the stacked cell arrays C.

[0055] Such a pack case 200 may be provided with a vent portion 300. The vent portion 300 may be configured to exhaust gas generated in the battery cells 100 housed therein to the outside of the pack case 200. The vent portion 300 may be provided in at least one of the plurality of unit plates.

[0056] The vent unit 300 may be provided in the form of a hole that penetrates between the inside and outside of the pack case 200. Alternatively, the vent unit 300 may be provided in the form of a vent device that is configured to be attachable to a hole in the pack case 200 and that activates when vent gas is generated inside the pack case 200.

[0057] The pack case 200 may be configured to form a vent space S through which gas discharged from the battery cells 100 flows. The vent space S may be formed in at least some of the unit plates among the plurality of unit plates. The vent space S may be formed in a unit plate located on a side of the battery cell 100 where the gas is vented, and the position where the vent space S is formed may vary depending on the venting direction of the gas. For example, as in the embodiment shown in FIGS. 1 to 4, when gas is vented to the top of the battery cell 100, the vent space S may be formed in a unit plate configured to cover the top of the battery cell 100 among the unit plates.

[0058] According to the above-described embodiment of the present invention, when an abnormal state occurs in the battery pack 10, a vent space S is secured between the pack case 200 and the battery cell 100, thereby enabling vent gas to be smoothly discharged to the outside of the pack case 200.

[0059] Furthermore, according to the above-described embodiment of the present invention, the vent gas can be smoothly discharged to the outside of the pack case 200, thereby preventing the vent gas from damaging components of the battery pack 10, such as other battery cells 100 and the pack case 200.

[0060] In this case, the vent space S may be configured to extend toward the vent portion 300. That is, the vent space S may be configured to guide the gas toward the vent portion 300. This allows the gas collected in the vent space S to move toward the vent portion 300.

[0061] According to the above-described embodiment of the present invention, when an abnormal state occurs in the battery pack 10, gas generated in the battery cell 100 and guided to the vent space S can be smoothly discharged to the outside of the pack case 200 through the vent portion 300. As a result, when an abnormal state occurs in the battery cell 100, an increase in internal pressure inside the pack case 200 can be effectively prevented, thereby ensuring the safety and reliability of the battery pack 10. Furthermore, according to the above-described embodiment of the present invention, when an abnormal state occurs in the battery pack 10, further chain fires of other battery cells 100 can be suppressed or delayed.

[0062] 1 to 4 , the unit plates of the pack case 200 may include a top plate 210. The top plate 210 may be configured to cover the tops of the plurality of battery cells 100. That is, the top plate 210 may be disposed to form the top surface of the pack case 200. The top plate 210 protects components housed therein, such as the battery cells 100, and may prevent vent gas discharged from the battery cells 100 from being discharged to the outside of the pack case 200, particularly to the top.

[0063] According to one embodiment of the present invention, the vent space S may be formed in the top plate 210. Specifically, the top plate 210 may include a main body portion 211 and a flow path portion 212. The main body portion 211 may be configured to cover the top of the battery cell 100. The main body portion 211 may be disposed flat in the shape of a generally rectangular plate.

[0064] The flow path portion 212 may be configured so as to form a vent space S. The flow path portion 212 may be configured so that at least a portion of the main body portion 211 protrudes upward (in the +Z-axis direction). The flow path portion 212 may be configured in a shape that is integrated with the main body portion 211. Furthermore, the flow path portion 212 may be formed in a shape in which a portion of the outer surface of one main body portion 211 is recessed outward. The flow path portion 212 may be formed by plastic extrusion molding the top plate 210.

[0065] As a result, when viewed from the outside, the flow path portion 212 protrudes further outward than the main body portion 211, whereas when viewed from the inside, the flow path portion 212 can be formed in the shape of a groove that is recessed further outward than the main body portion 211. A vent space S can be formed in the inner space of such flow path portion 212 that protrudes outward.

[0066] A plurality of flow path portions 212 can be provided, which allows a plurality of vent spaces S to be provided. As a result, even if an abnormality occurs in any one of the battery cells 100, the vent gas can move to the vent space S that is closest to the battery cell 100 where the abnormality occurred.

[0067] The main body portion 211 can guide vent gas and the like toward the vent space S inside the pack case 200. Specifically, because the flow path portion 212 protrudes upward, the pressure in the space between the flow path portion 212 and the battery cell 100 becomes lower than the pressure in the space between the main body portion 211 and the battery cell 100. As a result, as shown by the thick arrow in FIG. 4 , the vent gas can be discharged upward from the battery cell 100 and move along the inner surface of the upper part of the main body portion 211 toward the vent space S, where the pressure is relatively low.

[0068] According to the above-described embodiment of the present invention, the internal volume of the pack case 200 can be secured, thereby more effectively preventing an increase in the internal pressure of the battery pack 10. In addition, the pressure difference allows the vent gas to naturally flow into the vent space S, thereby inducing directional venting.

[0069] According to one embodiment, a fire extinguishing unit may be provided in the vent space S. The fire extinguishing unit may be filled with a fire extinguishing material. The fire extinguishing unit may be configured to be melted by high-temperature gas, flame, or the like, and the fire extinguishing material filled therein may be discharged. According to the above-described embodiment of the present invention, when gas, flame, or the like generated in the battery cell 100 flows into the vent space S, the fire extinguishing unit is activated to quickly absorb the heat of the high-temperature gas, flame, or the like, and quickly extinguish the fire. This reduces or prevents heat transmission between the battery cells 100, ensuring safety.

[0070] The structure of the pack case 200 will be described in detail below with reference to Figures 1 to 5. The unit plates of the pack case 200 can include a top plate 210, a base plate 220, an end plate 230, a front plate 240, and a rear plate 250.

[0071] The base plate 220 may be configured so that the plurality of battery cells 100 are placed on its upper surface. The base plate 220 may form the lower surface of the pack case 200 and may be configured in the shape of a generally rectangular plate. The base plate 220 may have a flat upper surface so that the plurality of battery cells 100 are stably placed on it.

[0072] The end plate 230, the front plate 240, and the rear plate 250 may extend upward from each edge (periphery) of the base plate 220. The end plate 230, the front plate 240, and the rear plate 250 may be arranged to cover the side surfaces of the multiple battery cells 100.

[0073] More specifically, the front plate 240 may be located at the front end (-Y axis direction) of the base plate 220 and configured to cover the front surface of the cell array C. The rear plate 250 may be located at the rear end (+Y axis direction) of the base plate 220 and configured to cover the back surface of the cell array C.

[0074] In addition, the end plates 230 may be located at the ends of both sides (+X-axis direction and −X-axis direction) of the base plate 220 and configured to cover both side surfaces of the cell array C configured by stacking a plurality of battery cells 100. That is, the end plates 230 may be configured to cover both side surfaces in the stacking direction of the cell array C. A plurality of end plates 230 may be provided and arranged in the front-rear direction. As a result, the end plates 230 can be arranged along the left-right direction on both side surfaces of the cell array C and arranged to face each other.

[0075] The top plate 210 may be configured to cover an upper open end of an internal space defined by the base plate 220, the end plate 230, the front plate 240, and the rear plate 250. In particular, referring to FIG. 4 , the top plate 210 may be configured to be coupled to the end plate 230. Specifically, the top plate 210 may be fitted into an upper end of the end plate 230 and coupled thereto. The end plate 230 may be provided with a coupling groove 231 configured to allow the top plate 210 to be fitted therein. The coupling groove 231 may be provided at the upper end of the end plate 230.

[0076] According to the above-described embodiment of the present invention, the top plate 210 can fix the end plates 230 disposed on both sides of the cell array C. This can prevent the end plates 230 from expanding in the left-right direction when the battery cells 100 swell. Furthermore, according to the above-described embodiment of the present invention, when the top of the battery pack 10 swells during use, both sides of the top plate 210 can be fixed by the end plates 230.

[0077] 4, the upper end of the end plate 230 may be configured to have a stepped shape. That is, the upper end of the end plate 230 may be configured to have a shape that is at least partially concave inward. Specifically, the end plate 230 may be provided with a protrusion 232. The protrusion 232 may be configured so that an end portion of the end plate 230 at least partially protrudes upward. In particular, the protrusion 232 may be configured to protrude further upward than the top plate 210.

[0078] The protrusions 232 can be arranged further outward than the coupling grooves 231. This allows the top plate 210 to be coupled between the protrusions 232 arranged on the two end plates 230, and a space can be formed between the protrusions 232 in the horizontal direction along the extension direction of the plane of the top plate 210.

[0079] The flow path portion 212 can be disposed in the space formed between the protrusions 232. In this case, the height at which the flow path portion 212 protrudes from the main body portion 211 can be configured to be smaller than or equal to the height at which the protrusions 232 protrude from the main body portion 211.

[0080] According to the above-described embodiment of the present invention, since the flow path portion 212 is disposed in the space formed by the protrusion portion 232, even if the flow path portion 212 is disposed to protrude further outward than the body portion 211, the height of the battery pack 10 does not increase. As a result, the volume of the battery pack 10 can be minimized, and the efficiency of the battery pack 10 can be improved.

[0081] On the other hand, as shown in FIG. 1, the top plate 210 and the base plate 220 may be arranged to protrude further outward than the front plate 240 and the rear plate 250.

[0082] According to the above-described embodiment of the present invention, when an abnormality occurs in the battery pack 10, it is possible to prevent gas discharged through the vent 300 from moving to the upper or lower part of the battery pack 10. Therefore, when a plurality of battery packs 10 of the present invention are included in another device in the vertical direction, it is possible to prevent heat from being transmitted to adjacent battery packs 10.

[0083] Furthermore, particles can be collected in the space created by the protrusion of the top plate 210, which protrudes further forward and backward than the front plate 240 and the rear plate 250. That is, the top plate 210 may include a collection portion at least a portion of which protrudes outward and is configured to collect particles.

[0084] Particles and flames that tend to travel in a straight line may be emitted from the battery cells 100 and move toward the vent portion 300 while colliding with the internal structure of the pack case 200. However, according to the above-described embodiment of the present invention, it is possible to prevent particles and the like in the protruding space from being emitted to the outside of the pack case 200. This makes it possible to prevent particles from reacting with oxygen outside the pack case 200 and causing a flame. Therefore, according to the above-described aspect of the present invention, it is possible to ensure the safety and reliability of the battery pack 10.

[0085] Meanwhile, a plurality of vents 300 may be provided. In particular, the vents 300 may be located on at least some of the unit plates of the pack case 200. For example, the vents 300 may be provided on the front plate 240 and the rear plate 250, respectively.

[0086] The vent portions 300 may be formed separately on two or more unit plates, or two or more vent portions 300 may be formed on one unit plate. A plurality of vent portions 300 may be provided on each of the front plate 240 and the rear plate 250. For example, referring to FIG. 2 , six vent portions 300 may be provided on each of the front plate 240 and the rear plate 250, for a total of 12 vent portions 300 included in the battery pack 10.

[0087] The plurality of vent portions 300 may be arranged on one unit plate so as to be spaced apart from each other in the horizontal or vertical direction. The plurality of vent portions 300 may also be arranged symmetrically with respect to each other with respect to the centers of the front plate 240 and the rear plate 250.

[0088] According to the above-described embodiment of the present invention, when an abnormal event occurs in a battery cell 100, high-temperature gas and the like can be discharged in both directions of the pack case 200 through the vents 300 symmetrically arranged on both sides of the pack case 200. Furthermore, according to the above-described embodiment of the present invention, gas can be discharged first to the vent 300 closest to the specific battery cell 100 where the thermal event occurred, so that gas can be discharged quickly depending on the location where the thermal event occurred.

[0089] In particular, the electrode leads of the battery cells 100 or empty spaces may be located on the unit plate side where the vent portions 300 are located. This makes it easier to more quickly discharge gas generated in the battery cells 100 and present inside the pack case 200 to the outside of the pack case 200.

[0090] Meanwhile, the number and positions of the vent portions 300 explained based on the embodiment of FIGS. 1 to 5 are merely examples, and it goes without saying that they can be changed to various other numbers and positions.

[0091] As described above, the vent units 300 may be arranged in a plurality of columns and rows. In this case, a plurality of flow path units 212 may also be provided. The plurality of flow path units 212 may be provided to correspond to the positions of the vent units 300. For example, as shown in FIG. 2, the vent units 300 are arranged in two rows and three columns on each of the front plate 240 and the rear plate 250, and three flow path units 212 may be provided to correspond to the number of columns in which the vent units 300 are arranged.

[0092] According to the above-described embodiment of the present invention, gas flowing through each vent space S can be discharged to the outside of the pack case 200 through the vent portion 300 corresponding to each vent space S. This allows for more efficient directional venting.

[0093] FIG. 6 is an overall perspective view of a battery pack according to another embodiment of the present invention.

[0094] 6 in conjunction with FIG. 1 , the flow path portion 212 may be formed to correspond to the gas discharge direction. The flow path portion 212 may be arranged to extend along the longitudinal direction of the battery cell 100. That is, the flow path portion 212 may be arranged to extend along a horizontal direction perpendicular to the stacking direction of the battery cells 100. Furthermore, the extension direction of the flow path portion 212 may be configured to face the vent portion 300. For example, the flow path portion 212 may be configured to extend along the front-rear direction, which is the arrangement direction of the front plate 240 and the rear plate 250.

[0095] The flow channel portion 212 may be arranged in a straight line extending toward the vent portion 300, as in the embodiment shown in Figure 1. Alternatively, the flow channel portion 212 may include a bent portion along the way.

[0096] As a result, as shown by the thick arrows in Fig. 4, the gas can move toward the upper part of the battery cell 100 and move to the vent space S. Also, as shown by the thick arrows in Fig. 5, the gas can be guided toward the front plate 240 and rear plate 250 on which the vent portion 300 is disposed by the flow path portion 212 configured to extend elongatedly toward the vent portion 300.

[0097] According to the above-described embodiment of the present invention, when an abnormality occurs in the battery pack 10, the gas generated in the battery cell 100 can move toward the vent portion 300 without being diffused in all directions.

[0098] The flow path portion 212 may include a portion configured so that the volume of the vent space S gradually increases as it approaches the vent portion 300. For example, as in the embodiment shown in FIG. 6 , the flow path portion 212 may include a portion configured so that the width of the flow path portion 212 gradually increases as it approaches the vent portion 300. Alternatively, the flow path portion 212 may include a portion configured so that the height of the flow path portion 212 gradually increases as it approaches the vent portion 300. Thus, even within a single flow path portion 212, the volumes of the vent spaces S are configured to differ from one another, thereby enabling the vent gas to be guided toward the vent portion 300. That is, as it approaches the vent portion 300, the volume of the vent space S formed by the flow path portion 212 gradually increases, thereby reducing the relative pressure, and allowing the vent gas to move more smoothly toward the vent portion 300.

[0099] FIG. 7 is a cross-sectional view of a battery pack according to yet another embodiment of the present invention.

[0100] 7, the flow path portion 212 may have a wave-like shape in the cross section of at least one side. That is, the upper surface of the flow path portion 212 may be arranged in a wave, triangular, or wedge shape. At least one side of the flow path portion 212 may be configured in a shape in which regularly or irregularly protruding portions and inwardly recessed portions are repeated along the stacking direction of the battery cells 100.

[0101] In this case, some of the gas, sparks, and flames that flow into the vent space S will continuously collide with the wave-shaped structure formed in the flow path portion 212. Therefore, according to the above-described embodiment of the present invention, the paths of sparks, flames, and the like that tend to travel in a straight line are extended, thereby further suppressing the flow of sparks, flames, and the like that moves toward the vent portion 300.

[0102] Furthermore, according to the above-described embodiment of the present invention, the gas is smoothly discharged along the longitudinal direction in which the vent space S extends, thereby preventing damage to the components of the battery pack 10 due to high heat.

[0103] FIG. 8 is a cross-sectional view of a battery pack according to yet another embodiment of the present invention.

[0104] The top plate 210 may include a guide portion 213. The guide portion 213 may be configured to guide gas between the main body portion 211 and the battery cells 100 to the flow path portion 212. For example, as in the embodiment shown in FIG. 8 , the guide portion 213 may be configured such that at least a portion of the main body portion 211 is inclined upward toward the flow path portion 212. According to this embodiment of the present invention, gas generated in the battery cells 100 located below the main body portion 211 can move more smoothly toward the flow path portion 212.

[0105] FIG. 9 is an overall perspective view of a battery pack according to still another embodiment of the present invention, and FIG. 10 is a cross-sectional view of the battery pack of FIG.

[0106] As described above, the battery cells 100 may be stacked in the left-right direction to form a cell array C. In this case, a plurality of cell arrays C may be arranged in the front-rear direction (Y-axis direction), which is a horizontal direction perpendicular to the stacking direction of the battery cells 100. For example, as in the embodiment shown in FIG. 2, two cell arrays C may be arranged in the front-rear direction.

[0107] The top plate 210 may be configured to prevent the gas from moving between the cell arrays C. For example, as in the embodiment shown in FIGS. 9 and 10 , the top plate 210 may include a recess 214. The recess 214 may be disposed between adjacent cell arrays C. The recess 214 may be configured to separate the vent space S of the flow path portion 212.

[0108] The recess 214 may be configured so that at least a portion of the flow path portion 212 protrudes downward. The recess 214 may be disposed so as to be recessed further inward than the flow path portion 212 when viewed from the outside. Adjacent cell arrays C may be disposed at a predetermined interval, and the recess 214 may be configured to be in contact with a structure disposed between the cell arrays C.

[0109] According to the above-described embodiment of the present invention, the space between the cell arrays C through which gas can move is minimized, so that even if a thermal event occurs in one of the cell arrays C, it is possible to minimize the possibility that gas, flames, etc. will be transferred to other cell arrays C. In other words, gas, etc. generated in the cell array C where the thermal event occurred can be discharged to the outside of the pack case 200 through the vent space S and vent portion 300 on the side where the cell array C where the thermal event occurred is located. This makes it possible to prevent the propagation of thermal runaway between adjacent cell arrays C.

[0110] Fig. 11 is a cross-sectional view of a battery pack according to yet another embodiment of the present invention. For example, Fig. 11 may be a cross-sectional view taken along the line II' in Fig. 1. Also, Figs. 12 and 13 are cross-sectional views of battery packs according to still another embodiment of the present invention.

[0111] The top plate 210 may be configured so that at least a portion thereof protrudes downward to prevent the gas from moving in the stacking direction of the plurality of battery cells 100. In other words, the top plate 210 may be configured to divide the battery cells 100 into a plurality of groups.

[0112] According to the above-described embodiment of the present invention, the gap between the battery cell 100 and the top plate 210 is minimized, which makes it possible to prevent the propagation of thermal runaway to other adjacent battery cells 100. As a result, even if a thermal event occurs in one of the battery cells 100 in one group, the possibility of gas, flame, or the like transferring to the battery cells 100 in another group can be minimized.

[0113] Specifically, with reference to FIG. 11, the top plate 210 may include a first rib 215 .

[0114] The first rib 215 may be disposed such that at least a portion of the main body 211 of the top plate 210 protrudes downward. As a result, the first rib 215 is located inside the battery pack 10 and does not increase the height of the battery pack 10, nor does it cause a change in appearance. In addition, the first rib 215 may be located in an empty space within the battery pack 10 and does not affect the energy density of the battery pack 10.

[0115] The first rib 215 may be configured to be interposed between adjacent battery cells 100 among the plurality of battery cells 100. In particular, the first rib 215 may be configured to be fitted between the seal portions of the battery cells 100 located at the top. The first rib 215 may be disposed between the battery cells 100, and may be disposed on top of the blocking member 500 when the blocking member 500 is disposed, as shown in FIG. 12 .

[0116] Furthermore, the first rib 215 may be configured in a shape that extends along the longitudinal direction (Y-axis direction) of the battery cell 100. The first rib 215 may be provided in the same shape or length as the battery cell 100. The length of the first rib 215 may be provided to correspond to the length of the battery cell 100. This makes it possible for the first rib 215 to block both sides of the battery cell 100, thereby blocking the movement of gas and the like.

[0117] The top plate 210 may be extrusion manufactured so that the first ribs 215 are integrally disposed on the top plate 210. According to the above-described embodiment of the present invention, since the first ribs 215 are integrally disposed on the top plate 210, a process of joining the first ribs 215 to the top plate 210 is omitted, and damage to the joining portions between the first ribs 215 and the top plate 210 is minimized.

[0118] The first rib 215 may be made of a material that is highly heat-resistant and / or fire-resistant, and configured to maintain an airtight structure even under high temperatures and high pressures. For example, the first rib 215 may be made of a fire-resistant plastic material.

[0119] A plurality of first ribs 215 may be arranged along one direction. The one direction may be defined as the direction in which the battery cells 100 are stacked, i.e., the left-right direction (X-axis direction). In this case, one first rib 215 may be arranged on each of the main body portions 211 arranged between the flow path portions 212. For example, when three flow path portions 212 are formed, two first ribs 215 may be arranged to divide the battery cells 100 into three groups. Vent gas generated in the space partitioned by the first ribs 215 can smoothly move to the flow path portions 212 in the space between the main body portion 211 and the top plate 210.

[0120] According to the above-described embodiment of the present invention, the battery cells 100 can be firmly partitioned and separated into a plurality of groups by the first ribs 215. Therefore, even if a thermal event occurs in one of the battery cells 100, vent gas, flames, etc. are prevented from overcoming the first ribs 215 and transferring in the stacking direction of the battery cells 100, thereby ensuring the safety and reliability of the battery pack 10.

[0121] 12 , a battery pack 10 according to an embodiment of the present invention may include an isolation member 500. The isolation member 500 may be configured to be disposed between battery cells 100 to separate the plurality of battery cells 100. In particular, a plurality of isolation members 500 may be disposed along one direction in which the battery cells 100 are arranged. The isolation member 500 may be provided in a form in which it is disposed for at least one or more battery cells 100. As a result, the plurality of battery cells 100 and the isolation members 500 disposed therebetween may form one cell stack C.

[0122] The isolating member 500 may be provided as an insulating pad that is thinner than the battery cell 100. The isolating member 500 may be made of a material that is highly heat-resistant and / or fire-resistant. Alternatively, the isolating member 500 may be made of a material such as silicone or aerogel in the shape of a compressive pad.

[0123] According to the above-described embodiment of the present invention, the battery cells 100 are partitioned or separated from one another, thereby preventing gas, flame, etc. from passing through the blocking member 500 and transferring to other adjacent blocking members 500. Furthermore, according to the above-described embodiment of the present invention, the blocking member 500 can contribute to the structural rigidity of the battery cell 100 by compressing the battery cell 100 when a swelling phenomenon occurs in which the battery cell 100 swells.

[0124] Meanwhile, taking into consideration ease of assembly, assembly tolerance, etc., the top plate 210 and the blocking member 500 may be disposed so as to be spaced apart by a predetermined distance. In such a case, if a thermal event occurs in one battery cell 100, vent gas, flames, etc. may be transferred to another adjacent battery cell 100 through the certain distance formed between the blocking member 500 and the top plate 210.

[0125] Even if no gap is formed between the blocking member 500 and one side of the top plate 210, if there is no separate device for fixing the blocking member 500, the blocking member 500 may be warped and deformed by the pressure of the vent gas or flame, causing the blocking member 500 to move left and right. As a result, a gap may be formed between the blocking member 500 and the top plate 210, and the vent gas may be transferred to other adjacent battery cells 100 through the gap.

[0126] Therefore, the first rib 215 may include an insertion groove 215a configured to allow the blocking member 500 to be inserted therein. The insertion groove 215a may be configured such that a lower end portion of the first rib 215 is at least partially recessed inward. This allows the first rib 215 to be configured to fix the blocking member 500 interposed between the battery cells 100.

[0127] According to the above-described embodiment of the present invention, the space between the top plate 210 and the blocking member 500 can be minimized to firmly separate and separate the battery cells 100. As a result, when a thermal event occurs in the battery cells 100, vent gas, flames, and the like are prevented from transferring in the stacking direction of the battery cells 100, thereby ensuring the safety and reliability of the battery pack 10.

[0128] Furthermore, according to the above-described embodiment of the present invention, the first rib 215 fixes the blocking member 500 to the top plate 210, thereby suppressing warpage and deformation of the blocking member 500. In other words, even if a thermal event occurs, it is possible to reduce the possibility that the resulting high-temperature, high-pressure vent gas or flame will push out the blocking member 500 and transfer to other battery cells 100. As a result, when thermal runaway propagates between battery packs 10, it is possible to effectively prevent or delay the propagation of thermal runaway between battery cells 100.

[0129] 13, the top plate 210 may include a second rib 216. The second rib 216 may be provided so that at least a portion of the flow path portion 212 of the top plate 210 protrudes downward.

[0130] The second rib 216 may be configured to be interposed between adjacent battery cells 100 among the plurality of battery cells 100. In particular, the second rib 216 may be configured to be fitted between the seal portions of the battery cells 100 located at the top. The second rib 216 may be disposed between the battery cells 100, and may be disposed on top of the blocking member 500 when the blocking member 500 is disposed, as shown in FIG. 12 .

[0131] Furthermore, the second ribs 216 may be configured in a shape that extends along the longitudinal direction (Y-axis direction) of the battery cell 100. The second ribs 216 may be provided in the same shape or length as the battery cell 100. The length of the second ribs 216 may be provided to correspond to the length of the battery cell 100. This makes it possible for the second ribs 216 to block both sides of the battery cell 100, thereby blocking the movement of gas and the like.

[0132] The top plate 210 may be extrusion manufactured so that the second ribs 216 are integrally disposed on the top plate 210. According to the above-described embodiment of the present invention, since the second ribs 216 are integrally disposed on the top plate 210, the process of connecting the second ribs 216 to the top plate 210 is omitted, and damage to the connecting portions between the second ribs 216 and the top plate 210 is minimized.

[0133] The second rib 216 may be made of a material that is highly heat-resistant and / or fire-resistant, and configured to maintain an airtight structure even under high temperatures and high pressures. For example, the second rib 216 may be made of a fire-resistant plastic material.

[0134] A plurality of second ribs 216 may be arranged along one direction. The one direction may be defined as the direction in which the battery cells 100 are stacked, that is, the left-right direction (X-axis direction).

[0135] According to the above-described embodiment of the present invention, by dividing and separating the vent space S in the flow path portion 212 by the second rib 216, it is possible to prevent the propagation of thermal runaway between the battery cells 100 even within one flow path portion 212. Therefore, even if a thermal event occurs in one of the battery cells 100, vent gas, flames, etc. are prevented from overcoming the second rib 216 and transferring in the stacking direction of the battery cells 100, thereby ensuring the safety and reliability of the battery pack 10.

[0136] Fig. 14 is a front perspective view of a battery pack according to one embodiment of the present invention. Specifically, Fig. 14 is a view illustrating a direction in which vent gas is discharged from a battery pack according to one embodiment of the present invention. Fig. 15 is a front view of a battery pack according to one embodiment of the present invention. Fig. 16 is a cross-sectional view of a battery pack according to one embodiment of the present invention. For example, Fig. 16 may be a view illustrating a portion of the front side of a cross-section taken along the line II-II' in Fig. 1.

[0137] 14 to 16, the vent unit 300 may include a vent hole 310 and a cover unit 320. Specifically, as in the embodiment shown in Fig. 16, the vent hole 310 may be formed penetrating at least a portion of the unit plate, and the cover unit 320 may be configured to cover at least a portion of the vent hole 310.

[0138] The cover portion 320 may be provided on the outer surface of the unit plate of the pack case 200 in which the vent hole 310 is formed. The cover portion 320 may be configured such that at least a portion of the unit plate protrudes outward.

[0139] The cover part 320 can guide the direction in which exhaust gas is discharged from the vent hole 310. According to the above-described embodiment of the present invention, the cover part 320 can guide the gas inside the pack case 200 to be vented in a specific direction, i.e., to the outside of the pack case 200. In addition, the gas discharged to the outside of the pack case 200 can be prevented from flowing back into the pack case 200. Furthermore, according to the above-described embodiment of the present invention, it is possible to block the flow of oxygen into the pack case 200 through the vent hole 310. As a result, the generation of a flame in the battery pack 10 can be prevented or suppressed.

[0140] According to the above-described embodiment of the present invention, the cover portion 320 is configured to cover the vent hole 310 from the outside, thereby making it possible to prevent foreign matter such as dust from entering the inside of the pack case 200 through the vent hole 310. This ensures the dustproof function of the battery pack 10, thereby ensuring the safety and reliability of the battery pack 10.

[0141] The cover 320 may be configured to prevent moisture from penetrating into the pack case 200 through the vent hole 310. Alternatively, the cover 320 may have any structure and be made of any material as long as it can prevent moisture from penetrating. For example, the cover 320 may be made of a waterproof material. According to the above-described embodiment of the present invention, moisture can be prevented from flowing into the battery pack 10 through the vent hole 310, thereby ensuring the waterproof function of the battery pack 10.

[0142] 16, the cover portion 320 may be configured so that only the lower portion is open. To this end, the cover portion 320 may be configured to cover both sides and the front of the vent hole 310. In particular, the cover portion 320 may be configured to cover the upper side of the vent hole 310. As a result, the vent portion 300 may include a discharge hole 330 formed by opening the lower portion of the cover portion 320.

[0143] According to the above-described embodiment of the present invention, when high-temperature gases are discharged to the outside of the pack case 200 through the discharge holes 330 formed at the bottom in the event of thermal runaway or the like, the discharged gases can be prevented from heading toward the upper side. That is, according to the embodiment of the present invention, a directional vent is provided at the bottom of the battery pack 10, thereby improving the safety of users located at the upper side.

[0144] The battery pack 10 according to one embodiment of the present invention may further include a cooling unit 400. The cooling unit 400 may be configured to allow a cooling medium to flow. The cooling unit 400 may include an inlet port 410 and an outlet port 420. The inlet port 410 may be configured to allow the cooling medium to flow into the inside of the pack case 200, and the outlet port 420 may be configured to allow the cooling medium to be discharged to the outside of the pack case 200.

[0145] The inlet port 410 and the outlet port 420 may be provided on one side of the pack case 200. For example, as shown in Fig. 15, the inlet port 410 and the outlet port 420 may be provided on the side where the front plate 240 is located. In this case, the vent unit 300 may be provided on the side of the pack case 200 where the inlet port 410 and the outlet port 420 are provided, i.e., the front plate 240.

[0146] Hoses through which the cooling medium flows may be connected to the inlet port 410 and the outlet port 420. According to the above-described embodiment of the present invention, the cover 320 is provided in a portion where condensation is likely to occur due to the cooling medium, thereby preventing moisture generated by the condensation from flowing into the pack case 200.

[0147] An energy storage system (ESS) according to one embodiment of the present invention includes a battery pack 10 according to the present invention. The ESS may include, for example, a battery container including a plurality of battery packs 10 and a container housing configured so that the plurality of battery packs 10 can be stacked therein. The ESS may include one or more such battery systems.

[0148] In addition, the present invention may include various battery systems including the battery pack 10 according to the present invention. For example, a battery charging system, a battery replacement system, a battery repair system, etc. according to the present invention may be the battery system according to the present invention.

[0149] The present invention may also include a vehicle including the battery pack 10 according to the present invention. The vehicle according to the present invention may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle includes four-wheeled vehicles and two-wheeled vehicles. The vehicle may operate by receiving a supply of power from the battery pack 10 according to an embodiment of the present invention.

[0150] While preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above, and it goes without saying that various modifications can be made by a person having ordinary skill in the art to which the invention pertains without departing from the gist of the present invention as claimed in the claims, and these modified embodiments should not be understood individually from the technical ideas and perspectives of the present invention. [Explanation of symbols]

[0151] 10 Battery Pack 100 battery cells 200 pack case 210 Top Plate 211 Main body 212 Flow path section S Vent space 213 Guide section 214 recess 215 First Rib 215a Inset groove 216 Second Rib 217 Collection section 220 base plate 230 End Plate 231 Connection groove 232 Protrusion 240 Front Plate 250 rear plate 300 Vent 310 Vent hole 320 Cover 330 Discharge hole 400 Cooling Unit 410 Inlet Port 420 exhaust port 500 Blocking member

Claims

1. a plurality of battery cells; a pack case including a plurality of unit plates and configured to house the plurality of battery cells, the pack case having a vent portion disposed on at least one of the plurality of unit plates and configured to discharge gas discharged from the battery cells to the outside; Including, a vent space configured to extend toward the vent portion and through which the gas can flow is formed in at least some of the unit plates.

2. The battery pack according to claim 1 , wherein the unit plates include a top plate configured to cover an upper portion of the battery cell and in which the vent space is formed.

3. The top plate is a main body; a flow path portion configured such that at least a portion of the main body portion protrudes upward to form the vent space; 3. The battery pack of claim 2, comprising:

4. The unit plates include end plates configured to cover both sides of a cell array configured by stacking the plurality of battery cells, The battery pack according to claim 3 , wherein the end plate includes a coupling groove configured to receive the top plate.

5. The end plate is provided with a protrusion configured such that a terminal portion thereof protrudes at least partially above the top plate; The battery pack according to claim 4 , wherein the flow path portion is disposed in a space formed between the protrusions.

6. A plurality of the vent portions are provided, The battery pack according to claim 3 , wherein a plurality of the flow passage portions are provided so as to correspond to the positions of the vent portions.

7. The battery pack according to claim 3 , wherein the flow path portion is disposed to extend along a longitudinal direction of the battery cell.

8. The battery pack according to claim 3 , wherein the flow path portion includes a portion configured such that a volume of the vent space gradually increases toward the vent portion.

9. The battery pack according to claim 3 , wherein the flow path portion has a wavy shape in a cross section of at least one side surface.

10. The top plate is The battery pack according to claim 3 , wherein at least a portion of the main body includes a guide portion configured to incline upward toward the flow path portion.

11. a plurality of cell arrays each including a stack of the battery cells; The battery pack according to claim 3 , wherein the top plate includes a recess disposed between adjacent cell arrays and configured so that at least a portion of the flow path portion protrudes downward.

12. The battery pack according to claim 3 , wherein at least a portion of the top plate protrudes downward to prevent the gas from moving in a stacking direction of the plurality of battery cells.

13. The battery pack according to claim 12 , wherein the top plate includes a first rib configured to be interposed between the battery cells by at least a portion of the main body protruding downward.

14. The battery further includes a blocking member interposed between the battery cells, The battery pack according to claim 13 , wherein the first rib includes a fitting groove configured to fit the blocking member therein.

15. The battery pack according to claim 12 , wherein the top plate includes a second rib configured such that at least a portion of the flow path portion protrudes downward and is interposed between the battery cells.

16. The vent portion is a vent hole formed through at least a portion of the unit plate; a cover configured to cover at least a portion of the vent hole; 10. The battery pack of claim 1, comprising:

17. The battery pack according to claim 16 , wherein the cover portion is configured so that at least a portion of the unit plate protrudes outward.

18. The battery pack of claim 17 , wherein the vent includes a discharge hole formed by opening a lower portion of the cover.

19. 19. An energy storage system (ESS) comprising a battery pack according to any one of claims 1 to 18.

Images