Improved safety of battery packs

Abstract

The present invention discloses a battery pack capable of effectively suppressing heat transfer between battery modules to improve safety. The battery pack according to one aspect of the present invention includes a plurality of battery modules each including one or more battery cells for storing and discharging energy and stacked in at least one direction, a pack case disposed on at least one side of the plurality of battery modules to cover at least a portion of an exterior of the plurality of battery modules and having one or more openings, and a melt member disposed at the opening of the pack case to seal the opening and melted by heat generated from one or more battery modules of the plurality of battery modules to open the opening.

Description

[Technical field]

[0001] This application claims priority to Korean Patent Application No. 10-2021-0132742 filed on October 6, 2021, and the entire contents disclosed in the specification and drawings of that application are incorporated herein by reference.

[0002] The present invention relates to a battery, and more particularly to a battery pack and an energy storage system including the same that can improve safety even when an event such as thermal runaway occurs. [Background technology]

[0003] In recent years, as the demand for portable electronic products such as smartphones and smart pads has grown rapidly and the commercialization of robots, electric vehicles, and the like has progressed in earnest, active research has been conducted on high-performance secondary batteries that can be repeatedly charged and discharged.

[0004] Currently, commercially available secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium secondary batteries, etc. In particular, lithium secondary batteries have attracted attention for their advantages of being free to charge and discharge since they hardly have a memory effect compared to nickel-based secondary batteries, and having a very low self-discharge rate and high energy density.

[0005] Although a secondary battery may be used alone, it is generally configured in a form in which a plurality of secondary batteries are electrically connected to each other in series and / or parallel. In particular, a plurality of secondary batteries may be housed inside one module case in a state in which they are electrically connected to each other to configure one battery module. The battery module may be used alone, or two or more may be electrically connected to each other in series and / or parallel to configure a higher level device such as a battery pack. Here, the battery module and the battery pack may be used interchangeably.

[0006] Recently, as issues such as power shortages and environmentally friendly energy are being raised, energy storage systems (ESS) for storing generated power are attracting much attention. Typically, when such energy storage systems are used, it is easy to build a power management system such as a smart grid system, so that power supply and demand can be easily adjusted in a specific region or city. In addition, as commercialization of electric vehicles progresses, such energy storage systems can also be applied to electric charging stations that can charge electric vehicles.

[0007] In the case of a battery pack used in such an energy storage system, a plurality of battery modules may be accommodated in the internal space of the pack case. The battery modules may be connected in series and / or in parallel to each other to increase the output, capacity, etc. of the battery pack. Furthermore, in order to increase the energy density of the battery pack, the battery modules may be densely packed together in a very narrow space.

[0008] However, in such a battery pack configuration, if a thermal event such as thermal runaway occurs in a specific battery module, a huge amount of heat may be generated and released from the battery module. The released heat may be transferred to other surrounding battery modules, and this transfer of heat may cause a problem in that the thermal runaway situation may be propagated to the other battery modules.

[0009] In particular, in the case of a conventional battery pack, a pack case is often configured in a box-like or monoframe (tube) shape, and a plurality of battery modules are housed in the internal space of the pack case. However, in such a conventional battery pack configuration, there is a concern that the pack case may cause a problem in that it promotes heat transfer between the battery modules. That is, the heat generated from an event module, which is a battery module in which a thermal event has occurred, may be directly transferred to an adjacent battery module using a method such as thermal radiation, or may be transferred via the pack case using a method of thermal conduction. In particular, when the heat is transferred via the pack case, there is a concern that a problem may occur in that the heat may be transferred to a battery module that is not adjacent to the event module but is far away.

[0010] Therefore, according to the conventional battery pack configuration, heat is easily transferred between the multiple battery modules contained inside the pack case, and the propagation of thermal runaway cannot be properly suppressed. Such propagation of thermal runaway may cause serious damage, not only to the breakdown or damage of the battery pack, but also to the risk of causing a fire or spreading the fire. Summary of the Invention [Problem to be solved by the invention]

[0011] Therefore, the present invention has been made in consideration of the above problems, and an object of the present invention is to provide a battery pack and an application device including the same, which can effectively suppress heat transfer between battery modules and improve safety.

[0012] However, the technical problems that the present invention aims to solve are not limited to the problems described above, and other problems not mentioned will be clearly understood by those skilled in the art from the detailed description of the invention described below. [Means for solving the problem]

[0013] In order to achieve the above-mentioned objects, according to one aspect of the present invention, a battery pack includes a plurality of battery modules, each having one or more battery cells and configured to store and release energy, stacked in at least one direction; a pack case disposed on at least one side of the plurality of battery modules, covering at least a portion of an exterior of the plurality of battery modules, and having one or more openings; and a melt member disposed at an opening of the pack case to seal the opening, and melted by heat generated from one or more battery modules of the plurality of battery modules to open the opening.

[0014] Here, the pack case may be configured to guide gas generated from one or more battery modules among the plurality of battery modules, and the melt member may be configured to be melted by the generated gas.

[0015] In addition, the plurality of battery modules may be arranged in a line in the left-right direction and configured to discharge vent gas to the front or rear, and the pack case may be arranged at least one of the front and rear of the plurality of battery modules.

[0016] Furthermore, the pack case may include a main body portion located in front of or behind the plurality of battery modules, and folding portions configured by folding upper and lower ends of the main body portion.

[0017] Furthermore, the openings may be formed in both the body portion and the folded portion.

[0018] Furthermore, the opening may be configured to have an elongated shape extending in a direction perpendicular to the stacking direction of the plurality of battery modules.

[0019] Furthermore, the opening may be formed such that at least a portion of the opening is located between the plurality of battery modules.

[0020] Furthermore, the pack case may be located on at least one of the front and rear sides of the plurality of battery modules, and the plurality of battery modules may be configured such that at least a portion of the battery modules are spaced apart from each other by a predetermined distance and the spaced apart portions are exposed in at least one of the upper and lower directions.

[0021] In order to achieve the above object, according to another aspect of the present invention, an energy storage system includes a battery pack according to the present invention.

[0022] Furthermore, in order to achieve the above object, a vehicle according to yet another aspect of the present invention includes a battery pack according to the present invention. Effect of the Invention

[0023] According to the present invention, in a battery pack including a plurality of battery modules, it is possible to suppress the transmission of heat between the battery modules.

[0024] In particular, when heat is generated in a particular battery module due to an event such as thermal runaway, the generated heat can be effectively blocked from being transferred to other modules via the pack case.

[0025] Furthermore, in accordance with an aspect of one implementation of the present invention, the transfer of heat that may continue to be generated after gas has been vented from the event module can be reduced.

[0026] Therefore, according to this aspect of the present invention, the thermal safety of the battery pack can be further improved.

[0027] Furthermore, according to one embodiment of the present invention, it is possible to improve the effect of blocking heat transfer between modules while ensuring the duct function and structural stability of the pack case.

[0028] In addition to the above, various other effects can be achieved by various embodiments of the present invention. Such various effects of the present invention will be described in detail in the respective examples, and the description of the effects that can be easily understood by those skilled in the art will be omitted.

[0029] The drawings attached to this specification are intended to illustrate preferred embodiments of the present invention and serve to facilitate a further understanding of the technical ideas 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 description of the drawings]

[0030] [Figure 1] 1 is a perspective view illustrating a schematic configuration of a battery pack according to an embodiment of the present invention; [Diagram 2] FIG. 2 is an exploded perspective view of a portion of the configuration of FIG. [Diagram 3] FIG. 2 is a perspective view showing one battery module included in a battery pack according to an embodiment of the present invention. [Figure 4] FIG. 4 is a partial perspective view of FIG. 3 with some components removed. [Diagram 5] 1 is a top-down cross-sectional view of a configuration of a battery pack according to an embodiment of the present invention. [Figure 6] FIG. 2 is a front view of a portion of a battery pack according to an embodiment of the present invention, showing the configuration before an event occurs. [Figure 7] FIG. 2 is a front view of a portion of a battery pack according to an embodiment of the present invention, showing the configuration after an event occurs. [Figure 8] FIG. 2 is a perspective view showing the configuration of a portion of a pack case in a battery pack according to one embodiment of the present invention. [Figure 9] 9 is a diagram showing a configuration in which the folded portions at the upper and lower ends of the pack case shown in FIG. 8 are extended. [Figure 10] FIG. 2 is a front view showing a schematic configuration of a portion of a pack case according to one embodiment of the present invention. [Figure 11] 2 is a cross-sectional view showing a partial configuration of a battery pack according to an embodiment of the present invention as viewed from the front. [Figure 12] FIG. 11 is a development view showing a schematic configuration of a partial pack case according to another embodiment of the present invention. [Figure 13] 13 is a cross-sectional view illustrating a schematic configuration of a portion of a pack case according to still another embodiment of the present invention. FIG. [Figure 14] 13 is a cross-sectional view illustrating a schematic configuration of a portion of a pack case according to still another embodiment of the present invention. FIG. [Figure 15] 13 is a cross-sectional view illustrating a schematic configuration of a portion of a pack case according to still another embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings. Prior to this, the terms and words used in the present specification and claims are not to be construed as being limited to their ordinary or dictionary meanings, but are to be construed as having meanings and concepts corresponding to the technical ideas of the present invention, in accordance with the principle that the inventors themselves can appropriately define the concepts of terms in order to best describe the invention.

[0032] Therefore, it should be understood that the embodiment described in this specification and the configurations shown in the drawings are merely the most preferred embodiment of the present invention and do not represent the entire technical idea of ​​the present invention, and therefore there may be various equivalents and modifications that can be substituted therefor at the time of this application.

[0033] FIG. 1 is a perspective view that shows a schematic configuration of a battery pack according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view of a portion of the configuration of FIG.

[0034] 1 and 2, a battery pack according to the present invention includes a battery module 100, a pack case 200, and a melt member 300.

[0035] The battery module 100 may be configured to include one or more battery cells 110 to store and release energy. Here, each battery cell 110 may refer to a secondary battery. A plurality of battery modules 100 may be included in a battery pack. In particular, in order to improve the capacity and / or output of the battery pack, a plurality of battery modules 100 may be included in the battery pack as shown in FIGS. 1 and 2. In this case, the plurality of battery modules 100 may be stacked in at least one direction. As an example, FIGS. 1 and 2 show a configuration in which eight battery modules 100 are arranged in the X-axis direction (left-right direction).

[0036] An example of a more specific configuration of such a battery module 100 is more specifically shown in FIGS.

[0037] Fig. 3 is a perspective view showing one battery module 100 included in a battery pack according to an embodiment of the present invention, and Fig. 4 is a partial perspective view in which some components of Fig. 3 have been removed.

[0038] 3 and 4, the battery module 100 may include a battery cell 110 (secondary battery).

[0039] Here, the battery cell 110 may include an electrode assembly, an electrolytic solution (electrolyte), and a battery case. Although a pouch-type secondary battery is shown in Fig. 3 and Fig. 4, other types of secondary batteries, such as cylindrical batteries and square batteries, may also be included in the battery module 100.

[0040] A plurality of such secondary batteries may be included. For example, as shown in the figure, a cell assembly may be configured in a form in which a plurality of pouch-type secondary batteries are stacked vertically in a horizontal state. In this case, the electrode leads 111 of each battery may be in direct contact with each other, or may be electrically connected via a bus bar or the like.

[0041] Also, the battery module 100 may include a module terminal 140. For example, the electrode leads 111 of each battery cell 110 may be located at the front and / or rear side of the battery module 100, and the module terminal 140 may be located in a form electrically connected to the electrode leads 111. In particular, the module terminal 140 may be configured to be located at the front and / or rear side of the battery module 100 and protrude forward and / or backward. Furthermore, each battery module 100 may include a positive module terminal (+) and a negative module terminal (-) as the module terminal 140. In this case, the positive module terminal (+) and the negative module terminal (-) may be located on the same side of the battery module 100, for example, on the front side (-Y axis direction) as shown in the figure. Such a module terminal 140 may allow the secondary battery (battery cell) 110 included in the battery module 100 to be electrically connected to other components outside the battery module 100, for example, other battery modules 100.

[0042] The pack case 200 may be disposed on at least one side of the plurality of battery modules 100. The pack case 200 may be configured to cover at least a portion of the exterior of the battery modules 100. Furthermore, the pack case 200 may be configured to define an internal space and to house the plurality of battery modules 100 in the internal space. That is, the pack case 200 may be configured to surround at least a portion of the exterior of the stack of battery modules 100.

[0043] 1 and 2, the pack case 200 may include a front case 210, a rear case 220, and a side case 230. In this case, the pack case 200 is located at the front end, rear end, and left side of the stack of battery modules 100, and can be said to cover those portions of the stack of battery modules 100.

[0044] A pack terminal may be provided on at least one side of such pack case 200. Such a pack terminal may function as a terminal capable of transmitting and receiving power to and from an external charging device or discharging device for the battery pack.

[0045] In particular, in the present invention, the pack case 200 may be formed with one or more openings, such as the portion indicated by O in Fig. 2. Such an opening O may be configured to penetrate the pack case 200. That is, the opening O may be configured to penetrate between the inside and the outside of the pack case 200. Furthermore, a plurality of openings O may be formed in the pack case 200. For example, referring to Fig. 2, a plurality of openings O may be formed in each of the front case 210 and the rear case 220.

[0046] Such an opening O may be formed in the shape of a hole penetrating the center portion of pack case 200, or may be formed in a shape cut out from an end portion of pack case 200 to a predetermined location.

[0047] The melt member 300 may be disposed in an opening O formed in the pack case 200 to seal the opening O. In this case, the melt member 300 may be coupled to the pack case 200 in various ways. For example, the melt member 300 may be coupled and fixed to the pack case 200 in a form of being fitted into the opening O formed in the pack case 200 or a groove separately formed therein. Alternatively, the melt member 300 may be coupled to the pack case 200 by various other fastening methods such as adhesive, heat fusion, welding, bolt fastening, etc. And, the melt member 300 may be coupled to the pack case 200 to partially or entirely close the opening O. That is, the melt member 300 may be coupled to the opening O so that the inside of the pack case 200 is not exposed to the outside through the opening O.

[0048] In particular, the melt member 300 may be configured to be melted by heat to open the opening O. Furthermore, when an event such as thermal runaway occurs in any one or more battery modules 100 among the plurality of battery modules 100 included in the battery pack, heat may be generated. Such heat may be generated from heat generated in the battery module 100 side, vent gas discharged from the battery module 100 side, or flames. The melt member 300 may be configured to be meltable by heat generated from any battery module 100 in this manner. For this reason, the melt member 300 may be configured in a form that is melted by heat generated from the battery module 100, or may be configured from a material that is melted by heat generated from the battery module 100. Furthermore, the melt member 300 may be configured from a material having a lower melting point than the pack case 200. For example, the pack case 200, particularly the front case 210 and the rear case 220 in FIG. 2, may be configured from a steel material, and the melt member 300 may be configured from a plastic material. Since the plastic material may have a lower melting point than the steel material, the melt member 300 may melt even if the pack case 200 does not melt due to the heat generated from the battery module 100.

[0049] The melt member 300 can be configured to be meltable by heat generated from the battery module 100 and to open the opening O by such melting.

[0050] This will be explained in more detail with reference to FIGS.

[0051] Fig. 5 is a cross-sectional view of a battery pack according to an embodiment of the present invention, viewed from above. Figs. 6 and 7 are front views of a portion of a battery pack according to an embodiment of the present invention, showing the configurations before and after an event occurs, respectively. For example, Figs. 6 and 7 can be said to be front views of part A1 in Fig. 5. More specifically, Fig. 6 shows the configuration before the melt material 300 is melted, and Fig. 7 shows the configuration after the melt material 300 is melted.

[0052] First, referring to FIG. 5, if a thermal runaway event occurs in any one of the battery modules 100 (M5) among the multiple battery modules 100 (M1 to M8) included in the battery pack, heat may be transferred from the battery module 100 (M5) to the pack case 200, as shown by the arrow.

[0053] At this time, as shown in Fig. 6, a plurality of melt members 300 may be present on the pack case 200 side. At this time, as shown in the portion indicated by A2 in Fig. 7, if heat is generated and transferred from any one of the battery modules 100 (M5), at least a portion of the melt members 300 may be melted by the heat transferred from the battery module 100 (M5). Therefore, as shown in Fig. 7, at least a portion of the plurality of melt members 300 may be melted, and the melted melt members 300 may be separated from the openings O. Therefore, the melt members 300 may be unable to block at least a portion of the openings O any more, and may be made to open them.

[0054] According to this embodiment, when heat is abnormally generated from a specific battery module 100, the heat transfer between the battery modules 100 can be effectively blocked by opening a part of the opening O of the pack case 200. In particular, when abnormal heat is generated from the module M5 in the embodiment of FIG. 5, the generated heat may move along the pack case 200 in the stacking direction of the battery modules 100, from the left to the right, as shown by the arrow in FIG. 7. At this time, the melt member 300 may be melted by the heat discharged from the module M5, thereby exposing the opening O of the pack case 200 as shown in FIG. 7. Then, the opening O blocks the transfer of heat in the horizontal direction (the X-axis direction in FIG. 7), thereby suppressing the transfer of heat to other battery modules 100.

[0055] For example, in the embodiment of FIG. 5, when heat is generated from the module M5, the generated heat is effectively prevented from being transferred to other adjacent modules, such as the modules M4 and M6. In addition, the heat transfer through the pack case 200 can be prevented from being transferred to other non-adjacent battery modules 100, such as the modules M3 and M7. Furthermore, as shown in FIG. 7, if some openings O are exposed, air can flow in and out of the openings O. Therefore, the heat insulating effect of such openings O can be further increased.

[0056] Furthermore, when the thermal conductivity of melt component 300 is lower than that of pack case 200, it is possible to suppress the horizontal transfer of heat through pack case 200 even before melt component 300 is melted.

[0057] The pack case 200 may be configured to guide gas when gas is generated from one or more of the battery modules 100 included in the battery pack. In particular, the pack case 200 may guide the exhaust direction of the gas by allowing the vent gas to flow along an inner surface. In this case, it can be said that at least a part of the pack case 200 functions as a duct in the battery pack. In addition, the pack case 200 may have an exhaust port H1 formed on at least one side so that the vent gas can be exhausted to the outside.

[0058] In this configuration, the melt member 300 may be configured to be melted by the vent gas discharged from the battery module 100. That is, the vent gas discharged from the battery module 100 may have a high temperature. Furthermore, the vent gas discharged from the battery module 100 may contain flames, sparks, high-temperature electrodes or active material particles, etc. Therefore, the melt member 300 can be melted by contacting or being adjacent to such high-temperature vent gas.

[0059] In particular, a plurality of battery modules 100 included in the battery pack may be arranged side by side in the left-right direction as shown in Figures 2 and 5. Each battery module 100 may be configured to exhaust vent gas forward or backward as shown in Figure 5.

[0060] In particular, the battery module 100 may include a module case 120 and a busbar assembly 130, as shown in FIGS.

[0061] Here, the module case 120 may be configured to accommodate one or more secondary batteries in the internal space. For example, as shown in the figure, the module case 120 may include an upper plate 121, a lower plate 122, and a side plate 123. By combining such multiple plates, a battery assembly may be accommodated in a limited internal space.

[0062] Here, some of the plates included in the module case 120, for example, the lower plate 122 and the side plate 123 (left plate, right plate), may be configured to be integrated with each other. In this case, the integrated shape of the lower plate 122 and the side plate 123 may be substantially U-shaped. Alternatively, the lower plate 122, the side plate 123, and the upper plate 121 may be configured to be integrated with each other into a tubular monoframe (single plate). The plates of such a module case 120 may define an internal space in a state where they are joined together. And, a cell assembly may be accommodated in such an internal space.

[0063] The module case 120 may be configured to have at least one side open, and may be configured so that the electrode lead 111 of the cell assembly is positioned in such an open portion.

[0064] In particular, the battery module 100 may include a busbar assembly 130 and may be coupled to an open portion of the module case 120. For example, as shown in FIGS. 3 and 4, the busbar assembly 130 may be coupled to the front and rear open portions of the module case 120. Electrode leads 111 of the battery assembly may be located in the front and rear portions of the module case 120. The busbar assembly 130 may then be coupled to the electrode leads 111. As a more specific example, the busbar assembly 130 may include a busbar housing 131 and a module busbar 132, as shown in FIGS. 3 and 4.

[0065] Here, the bus bar housing 131 may be made of an electrically insulating material, for example, a plastic material. The bus bar housing 131 may be configured so that the module bus bar 132 is placed and fixed thereon. The module bus bar 132 may be made of an electrically conductive material, for example, a metal material. The module bus bar 132 may be configured to electrically connect two or more electrode leads 111 to each other or to be connected to one or more electrode leads 111, and to transmit sensing information to a control unit such as a battery management system (BMS).

[0066] In this manner, the battery module 100 included in the battery pack according to the present invention may be configured such that only certain portions, for example, the front and rear sides where the busbar assembly 130 is located, are open, and the remaining portions are sealed. In this case, when vent gas or the like is generated inside the battery module 100, the vent gas or the like may be induced to be discharged only to the open portions of the module case 120, for example, the front and rear sides where the busbar assembly 130 is located. In particular, the busbar assembly 130 may be formed with slits so that the electrode leads 111 can pass through. At this time, the vent gas (including sparks, flames, etc.) inside the module may be discharged to the outside of the module case 120 toward the front and rear sides of the module case 120 through the slits of the busbar assembly 130 as shown in FIG. 5.

[0067] In this configuration, the pack case 200 may be disposed at least one of the front and rear of the plurality of battery modules 100. For example, as shown in Fig. 2 and Fig. 5, a front case 210 and a rear case 220 as the pack case 200 may be disposed at the front and rear sides of the eight battery modules 100, respectively, and function as front and rear ducts.

[0068] According to this embodiment of the present invention, when vent gas is generated in any one of the battery modules 100, the vent gas can be guided to the exhaust port H1 side by the front case 210 and / or the rear case 220 for at least a predetermined time. After the vent gas is discharged to a certain extent, the amount of discharged vent gas may gradually decrease. In the process of discharging the vent gas, the melt member 300 can be at least partially melted by the heat of the vent gas, and thus, as shown in FIG. 7, at least a portion of the opening O of the pack case 200 can be opened. After the opening O of the pack case 200 is opened, the opening O suppresses the conduction of heat through the pack case 200, particularly the duct. Therefore, the propagation of thermal runaway between the battery modules 100 due to the heat conduction through the pack case 200, particularly the pack case 200 functioning as a duct, can be more effectively prevented.

[0069] Meanwhile, when the pack case 200, for example, the front case 210 and the rear case 220, function as a duct, the pack case 200 may be configured to maintain the function of the duct for a certain period of time at the beginning of a thermal event occurring in a specific battery module 100. For this purpose, the melt member 300 may be configured from a material that can be maintained for a certain period of time without immediately melting when the vent gas is discharged, or may be configured in a shape that can be maintained for a certain period of time without immediately melting when the vent gas is discharged. For example, when the front case 210 and the rear case 220 are made of a steel material, the melt member 300 may be configured from a material that has a lower melting point than the material of the pack case 200, but may be configured from a heat-resistant plastic material that has a melting point above a certain temperature. Here, as the heat-resistant plastic, a wide variety of plastic materials known at the time of filing the present invention can be used. For example, as the melt member 300 of the present invention, a wide variety of heat-resistant plastics such as silicone-based, fluorine-based, and phenolic resin-based can be used. More specifically, the melt member 300 is a plastic material that maintains its mechanical strength under temperature conditions of 300 to 600°C and in air, and may contain substances such as aromatic polyamide, polyimide, polysulfone, polybenzimidazole, and polyphenylene oxide.

[0070] According to this embodiment of the present invention, in the early stage of the discharge of vent gas, the melt member 300 closes the opening O of the pack case 200, so that the function of the duct of the pack case 200 can be maintained as is. However, if the discharge amount of the vent gas decreases below a certain level or disappears after a certain time has passed, the need to maintain the function of the duct of the pack case 200 may decrease. At this time, when the melt member 300 melts and the opening O of the pack case 200 is exposed, the opening O suppresses the conduction of heat through the pack case 200.

[0071] However, the material and characteristics of the melt member 300, particularly the melting point of the melt member 300, may be selected in various ways depending on the type, structure, and performance of the battery cell 110, the battery module 100, and the battery pack. For example, the material of the melt member 300 may be selected in consideration of the temperature rise caused by the vent gas and the time required for discharging the vent gas when the battery pack experiences thermal runaway. As a more specific example, the melt member 300 may be formed of a heat-resistant plastic material that can melt after the time required for discharging the vent gas when the battery pack experiences thermal runaway.

[0072] The pack case 200 may be configured with a folded upper and lower ends, which will be described in more detail with reference to FIG.

[0073] Fig. 8 is a perspective view showing a configuration of a part of the pack case 200 in a battery pack according to an embodiment of the present invention. In particular, Fig. 8 can be said to be an enlarged view showing the configuration of the rear case 220 in the battery pack shown in Figs. 1 and 2. However, in Fig. 8, for ease of explanation, a part of the melt member 300 is shown removed from a part of an opening O of the pack case 200.

[0074] Referring to FIG. 8, the pack case 200, particularly the front case 210 and the rear case 220, may include a body portion 201 and a folding portion 202. Here, the body portion 201 may be located in front or rear of the plurality of battery modules 100. For example, the body portion 201 of the rear case 220 as shown in FIG. 8 may be arranged in a vertically standing form and located rearward with respect to the eight battery modules 100. That is, the body portion 201 of the rear case 220 may be configured in a form facing the rear side of each battery module 100, for example, the bus bar assembly 130 at the rear side of each battery module 100. As another example, the body portion 201 of the front case 210 may be arranged in a vertically standing form and located in a form facing the front side of each battery module 100. In particular, since vent gas may be discharged to the front and rear sides of the battery module 100, it can be said that the surface of the body portion 201 is arranged in a direction perpendicular to the discharge direction of such vent gas.

[0075] The folding portion 202 may be configured in a folded shape at the upper and lower ends of the body 201. In particular, the folding portion 202 may be configured in a folded shape at the upper and lower ends of the body 201 in an inward direction where the battery modules 100 are located. The folding portion 202 may be configured to enclose the upper and lower parts of the front end or rear end of the plurality of battery modules 100.

[0076] Both the body part 201 and the bending part 202 may be configured in a plate shape. In particular, the body part 201 and the bending part 202 may be configured in an integrated shape as a single plate. In this case, the body part 201 and the bending part 202 may be configured in a shape in which the upper end and the lower end of a single plate are bent in the same direction, i.e., in the direction in which the battery module 100 is located.

[0077] In this embodiment, a portion of the bent portion 202 may be coupled and fixed to a front end or a rear end of the battery module 100. For example, a fastening hole may be formed on the end side of the bent portion 202, as shown by H2 in FIG. 8. Then, the bent portion 202 may be coupled to a plurality of battery modules 100 by bolting through the fastening hole H2. The fastening configuration between the bent portion 202 and the battery module 100 may also be realized by various other fastening methods.

[0078] In such an embodiment of the present invention, the pack case 200 has a simple structure and can be easily combined with the battery module 100. In addition, according to such an embodiment, the pack case 200 can easily achieve a duct function. That is, if a space is formed between the main body 201 of the pack case 200 and the front end or rear end of the battery module 100, there is a possibility that vent gas will flow into such a space.

[0079] In such a pack case 200 configuration, the opening O may be formed in both the main body portion 201 and the folded portion 202. For example, referring to the configuration of the rear case 220 shown in FIG. 8, the opening O may be formed in all of the main body portion 201, the upper end folded portion 202, and the lower end folded portion 202. That is, the opening O may include a first opening O1 formed in the main body portion 201 and a second opening O2 formed in the folded portion 202. Furthermore, the first opening O1 and the second opening O2 may be formed in a hole shape in the main body portion 201 and the folded portion 202, respectively. Here, the first opening O1 and the second opening O2 may be formed in a shape that is not connected to each other and is separated by a predetermined distance. For example, the first opening O1 may be formed in a shape that penetrates the center part of the main body portion 201 except for a part of the upper end and a part of the lower end, and the second opening O2 may be formed in a shape that penetrates the center part of the folded portion 202 except for a part of the front end and a part of the rear end.

[0080] Each of these openings O may be coupled to a melt member 300. That is, in this embodiment, the melt member 300 may include a first member 301 coupled to the first opening O1 and a second member 302 coupled to the second opening O2.

[0081] According to such an embodiment of the present invention, the structural stability of the pack case 200 is ensured to a certain level or more, and when the melt member 300 is melted to expose the opening O of the pack case 200, the effect of suppressing heat conduction through the opening O can be further improved. Furthermore, since the opening O is formed in the pack case 200 from the upper end to the lower end, it is possible to effectively restrict the transfer of heat in the stacking direction of the battery modules 100, i.e., in the left-right direction.

[0082] Particularly, in the above embodiment, the first opening O1 and the second opening O2 may be formed in a straight line. This will be described in more detail with reference to FIG. 9. FIG. 9 is a diagram showing a configuration in which the folded portions 202 at the upper and lower ends of the pack case 200 shown in FIG. 8 are extended. That is, FIG. 9 can be said to be a development view of the configuration of FIG. 8. However, in FIG. 9, the melt member 300 is omitted for ease of illustration. In FIG. 9, when the pack case 200 is folded approximately 90° around the dotted lines C1 and C2, respectively, the configuration of the pack case 200 shown in FIG. 8 can be obtained.

[0083] 9, one first opening O1 formed in the main body 201 and two second openings O2 formed in the upper and lower bent portions 202 may be aligned in a straight line. That is, as shown in the embodiment of FIG. 9, the three openings O1 and O2 may be arranged on a straight line such that their centers are aligned with the straight line C3. Furthermore, in the embodiment of FIG. 9, the eight first openings O1 may be arranged in a straight line with one different second opening O2 formed in the upper bent portion 202 and one different second opening O2 formed in the lower bent portion 202.

[0084] According to such an embodiment of the present invention, the number of paths through which heat is transferred through the pack case 200 can be reduced. For example, referring to the configuration of FIG. 9, in the above embodiment, the path through which heat can be transferred in the horizontal direction (X-axis direction) through the pack case 200 can be the space between the first opening O1 and the second opening O2, as shown by A3 and A3'. In the above embodiment, the distance between the first opening O1 and the second opening O2 is shortened, so that the number of paths through which heat can be transferred in the stacking direction (X-axis direction) of the battery modules 100 can be reduced. Therefore, the transfer of heat between the battery modules 100 through the pack case 200 can be more effectively suppressed.

[0085] Also, at least some of the openings O may be configured to have an elongated shape extending in one direction. For example, referring to FIG. 9, the first opening O1 may be configured to have an elongated shape extending in the up-down direction (Z-axis direction). In this case, the stacking direction of the multiple battery modules 100 can be said to be the X-axis direction, and therefore the Z-axis direction can be said to be a direction perpendicular to the stacking direction of the battery modules 100. Therefore, the first opening O1 can be said to have an elongated shape extending in a direction perpendicular to the stacking direction of the battery modules 100.

[0086] 9, the second opening O2 may be formed at the upper and lower ends of the first opening O1. Therefore, the first opening O1 may be configured to have an elongated shape in the direction in which the second opening O2 is located.

[0087] According to such a configuration of the present invention, the area of ​​the opening O is not increased with respect to the pack case 200, but the ability to suppress the transfer of heat in the stacking direction of the battery modules 100 can be ensured. That is, according to the above embodiment, the opening O can block the horizontal transfer of heat through the pack case 200. In addition, in the above embodiment, a plurality of openings O can be arranged in the horizontal direction, and the horizontal separation distance between the openings O can be ensured to be longer than a certain level. Therefore, the mechanical stability of the pack case 200 can be ensured. In particular, the melt member 300 can be coupled to the opening O, but the thermal and mechanical stability of the melt member 300 may be inferior to that of the pack case 200. According to the above embodiment, the area of ​​the pack case 200 is ensured to be large, so that not only the mechanical stability of the pack case 200 can be ensured in a normal state, but also the pack case 200 can well withstand the high temperature and high pressure of the vent gas even in an emergency situation in which the vent gas is discharged. Therefore, problems such as loss of structural stability of the pack case 200, particularly problems such as the pack case 200 collapsing in an emergency, can be prevented.

[0088] The opening O may be formed such that at least a portion thereof is located between the plurality of battery modules 100. This will be described in more detail with reference to FIG.

[0089] Fig. 10 is a front view that shows a schematic configuration of a portion of the pack case 200 according to an embodiment of the present invention. For example, Fig. 10 is a view of a portion of the configuration of the front case 210 in the battery pack configuration of Fig. 2 as viewed from the outside of the battery pack. However, for ease of explanation, the battery modules 100 located inside the pack case 200 are shown by dotted lines.

[0090] 10, an opening O is formed in the pack case 200. At this time, the opening O may be formed in a shape in which at least a portion is located between the battery modules 100 (M1, M2, M3). That is, the opening O located on the left side in FIG. 10 extends in the vertical direction (Z-axis direction) and may be located between the M1 module and the M2 module in the horizontal direction (X-axis direction). Also, the opening O located on the right side in FIG. 10 may be located between the M2 module and the M3 module in the horizontal direction (X-axis direction). In particular, the center line of the opening O in the horizontal direction may be located between the battery modules 100.

[0091] According to such a configuration of the present invention, it is possible to firmly realize the suppression function of the heat transfer between the modules through the opening O. In addition, in this case, it is possible to prevent the melt member 300 from being removed too early by the vent gas discharged to the front or rear side of the battery module 100. That is, when the vent gas is discharged from the battery module 100, the vent gas can be discharged to the front or rear side of the battery module 100 as shown in FIG. 5. In this case, if the opening O directly faces the discharge portion of the vent gas of the battery module 100, the melt member 300 arranged at the opening O may be removed or detached from the opening O earlier than the intended timing due to the high pressure of the vent gas. If the opening O is opened too early, the vent gas is discharged to the opening O, and there is a risk that the vent gas induction function of the pack case 200, i.e., the function of the duct, cannot be normally realized. However, as in the above embodiment, when the opening O is not located in a portion directly facing the front or rear side of the battery module 100, but is located in a portion between the battery modules 100 in the X-axis direction, the vent gas discharged from the battery module 100 can be prevented from being directed directly toward the opening O. Therefore, the melt member 300 can hold the vent gas for a certain period of time or more until it is discharged to the outside through the pack case 200, and it is possible to prevent the problem that the duct function of the pack case 200 cannot be properly realized.

[0092] 1 and 2, the pack case 200 may be located at least one of the front and rear sides of the plurality of battery modules 100 stacked in the left-right direction. The plurality of battery modules 100 may be configured such that at least a portion of each of the battery modules 100 is spaced apart from each other by a predetermined distance. This will be described in more detail with reference to FIG. 11.

[0093] FIG. 11 is a cross-sectional view showing a partial configuration of a battery pack according to one embodiment of the present invention as viewed from the front.

[0094] 11, a plurality of battery modules 100 are stacked in the horizontal direction (X-axis direction), and each battery module 100 may be arranged to be spaced apart by a predetermined distance in the stacking direction. That is, a predetermined space may be formed between the plurality of battery modules 100, as shown by A4 in FIG. 11. Air may be present in this space. In particular, the plurality of battery modules 100 may be configured such that the separated portions are exposed in the upward and / or downward directions. In this case, air outside the battery pack may flow in and out of the separated spaces between the battery modules 100.

[0095] Further referring to FIG. 1 and FIG. 2, a front case 210 and a rear case 220 may be located at the front and rear of the stack of battery modules 100, respectively. Most of the space between the front case 210 and the rear case 220 may be exposed at the top and bottom. That is, the stack of battery modules 100 may be configured such that only a portion of the front end and the rear end are covered by the front case 210 and the rear case 220, and most of the top and bottom of each battery module 100 are exposed to the outside. In other words, a significant portion of each battery module 100 may be exposed to the outside without being covered by the pack case 200. At this time, the space between each battery module 100 may also be exposed to the outside. In particular, the separation space A4 between the battery modules 100 may be formed in a shape extending elongated in the front-rear direction (Y-axis direction) of the battery pack.

[0096] According to such an embodiment of the present invention, air may exist in the spaces between the battery modules 100 and function as a heat insulating layer. Therefore, the heat transfer ability between the battery modules 100 may be further improved. Furthermore, since the spaces between the battery modules 100 are exposed to the outside, hot air may be discharged from the spaces between the battery modules 100 to the outside, and cold air from the outside may flow into the spaces between the battery modules 100.

[0097] In addition, a heat insulating member or a fire blocking member having heat insulating properties may be interposed in the isolation space A4 between the battery modules 100 in FIG.

[0098] In such an embodiment, the opening O of the pack case 200 located on the front and / or rear side of the battery pack may be configured to communicate with the separated space between such battery modules 100. That is, when the melt member 300 is removed from the opening O by vent gas or the like, the opening O may be provided at a position that allows communication with the separated space between the modules.

[0099] According to such a configuration of the present invention, the effect of suppressing heat transfer between the battery modules 100 can be further improved by communication between the insulating spaces between the battery modules 100 and the opening O. Furthermore, the separated spaces between the battery modules 100, i.e., the insulating spaces, can be connected to the outside not only at the upper and lower parts but also through the opening O of the pack case 200. Therefore, the air ventilation effect for the separated spaces between the battery modules 100 is increased, and the heat shielding performance between the battery modules 100 can be further improved.

[0100] Fig. 12 is a development view showing a schematic configuration of a pack case 200 according to another embodiment of the present invention. In particular, Fig. 12 can be said to be a modified example of the embodiment shown in Fig. 9. In Fig. 12 as well, the melt member 300 coupled to the opening O of the pack case 200 is omitted. In various embodiments of the present invention including this embodiment, detailed descriptions of parts that are the same or similar to those described in other embodiments will be omitted, and the description will focus on parts that differ.

[0101] 12, a plurality of openings O may be formed in the pack case 200. In particular, a plurality of openings O may be formed in the horizontal direction (X-axis direction) and a plurality of openings O may be formed in the vertical direction (Z-axis direction). In this case, the separation spaces between the plurality of openings O arranged in the vertical direction may be arranged alternately in the horizontal direction. That is, in the openings O adjacent to each other in the left-right direction, the portion in which the openings O are not formed is as shown by the portion A6. Then, the portions between the openings of such A6 portions or the ends of the openings are arranged in the horizontal direction, but the adjacent A6 portions are not located at the same position in the vertical direction (Z-axis direction) and may be arranged in a staggered manner so as to be located at different positions from each other. In other words, the A6 portions adjacent to each other in the horizontal direction may be arranged at different heights from each other in the up-down direction.

[0102] According to such an embodiment of the present invention, the conduction of heat through the pack case 200 is more effectively suppressed by the opening O. For example, when a thermal event occurs at the portion indicated by A5 in FIG. 12, the heat may be transmitted in the left-right direction through the pack case 200. Here, if the melt member 300 is removed and the opening O of the pack case 200 is opened, the heat may be mainly conducted to the portion indicated by A6. At this time, since the adjacent portions of A6 are located at different heights, the heat cannot move linearly in the X-axis direction, but may move in a curved shape as indicated by the arrow. Therefore, the horizontal movement path of the heat through the pack case 200 becomes longer, so that the amount of heat transfer is reduced and the heat transfer speed can be reduced. Therefore, the problem of heat transfer through the pack case 200 between the battery modules 100 arranged in the horizontal direction is more effectively suppressed.

[0103] Fig. 13 is a cross-sectional view that shows a schematic configuration of a portion of a pack case 200 according to still another embodiment of the present invention. For example, Fig. 13 shows a modified example of the cross-sectional configuration about the line C4-C4' in Fig. 12, and shows a configuration in a state where the melt member 300 has been removed. In particular, Fig. 13 shows one embodiment of a view looking down from above on the horizontal cross-sectional configuration of the rear case 220 as shown in Fig. 8.

[0104] 13, an opening O is formed in the pack case 200, and a protrusion as indicated by P may be formed around the opening O. Such a protrusion P may be formed to protrude from the inner surface of the pack case 200, i.e., the surface facing the battery module 100, toward the inside where the battery module 100 is located. In this case, the protrusion P may be formed in various ways, such as a shape in which a part of the pack case 200 is bent, or a shape in which a separate component is attached to the pack case 200.

[0105] According to such an embodiment of the present invention, even if the vent gas continues to be discharged from the battery module 100 in a state where the melt member 300 is melted and the opening portion O is opened, it is possible to reduce the outflow of the vent gas to the outside of the pack case 200 through the opening portion O. That is, the vent gas discharged from the battery module 100 can flow along the inner surface of the pack case 200. At this time, even if the opening portion O is opened, the flow direction of the vent gas can be bent from the periphery of the opening portion O to the inward direction as shown by the arrow in FIG. 13 due to the protrusion P formed around the opening portion O. Therefore, the possibility that the vent gas will be discharged to the outside through the opening portion O is reduced. Therefore, in this case, even if the melt member 300 is removed, the vent gas guide function of the pack case 200 can be continued to be performed at a certain level or more.

[0106] Moreover, according to this embodiment, the melt member 300 can be easily coupled via the protrusion P. For example, the melt member 300 can be coupled to the opening O of the pack case 200 in a form in which a part of the melt member 300 is inserted into the protrusion P. Therefore, the coupling property between the melt member 300 and the pack case 200 can be improved.

[0107] 14 is a cross-sectional view that shows a schematic configuration of a portion of a pack case 200 according to still another embodiment of the present invention. In particular, FIG. 14 shows another modified example of the configuration of FIG.

[0108] In the embodiment of FIG. 13 described above, the protrusion P is configured to have a shape that protrudes vertically from the inner surface of the pack case 200. However, as in the embodiment of FIG. 14, the protrusion P may be configured to have a shape that is inclined at a predetermined angle with respect to the inner surface of the pack case 200. In particular, the protrusion P may be configured to have a shape that is inclined in the direction opposite to the opening O. For example, in the configuration of FIG. 14, the protrusion P located on the left side of the opening O may be formed to have a shape that is inclined leftward (−X-axis direction) as it progresses toward the inside (−Y-axis direction). And the protrusion P located on the right side of the opening O may be formed to have a shape that is inclined rightward (+X-axis direction) as it progresses toward the inside (−Y-axis direction).

[0109] According to such an embodiment of the present invention, it is possible to more effectively prevent the vent gas from being discharged to the opening O when the opening O is open. That is, as shown by the arrow in FIG. 14, the direction of the vent gas flowing along the inner surface of the pack case 200 is changed by the protrusion at an angle greater than 90° near the opening O. This makes it possible to reduce the possibility that the vent gas will head toward the opening O. Therefore, in this case, the performance of the pack case 200 in guiding the vent gas can be further improved.

[0110] 15 is a cross-sectional view showing a schematic configuration of a portion of a pack case 200 according to still another embodiment of the present invention. The configuration of FIG. 15 can be said to be yet another modified example of the configuration of FIG.

[0111] Referring to the configuration of FIG. 15, the protrusion P is formed around the opening O on the inner surface of the pack case 200, but can be configured to have a shape that is inclined toward the opening as it progresses inward. That is, the protrusion P can be configured to have a shape that covers a part of the opening O without completely sealing the opening. Furthermore, when the pack case 200 functions as a duct, the protrusion P can be configured to have a shape that is inclined toward the exhaust port H1 of the pack case 200 as it approaches the battery module 100. Furthermore, such a protrusion P can be located on the opposite side of the exhaust port H1 around each opening O. That is, in the case of the embodiment configuration of FIG. 15, it can be said that the exhaust port H1 is formed at the right end of the pack case 200, and the protrusion P is located at the left end of the opening O1 and is configured to have a shape that is inclined toward the right as it progresses inward.

[0112] According to such an embodiment of the present invention, even when melt member 300 is removed from opening O, it is possible to minimize the outflow of vent gas to opening O, while smoothly directing the vent gas toward exhaust port H1. Therefore, even when melt member 300 is removed, the function of the duct of pack case 200 can be well maintained.

[0113] The battery pack according to the present invention may further include various other components of a battery pack known at the time of filing of the present invention, such as a battery management system (BMS), a current sensor, a fuse, etc.

[0114] An energy storage system according to the present invention may include one or more battery packs according to the present invention. In particular, the energy storage system may include a plurality of battery packs according to the present invention electrically connected to each other to have a large energy capacity. In addition, the energy storage system according to the present invention may further include various other components of an energy storage system known at the time of filing of the present invention. Furthermore, such an energy storage system may be used in various locations and devices, such as a smart grid system or an electric charging station.

[0115] Furthermore, an automobile according to the present invention may include one or more battery packs according to the present invention. In addition to such a battery pack, an automobile according to the present invention may further include various other components included in the automobile. For example, an automobile according to the present invention may further include a vehicle body, a motor, a control device such as an electronic control unit (ECU), and the like, in addition to the battery pack according to the present invention.

[0116] Meanwhile, directional terms such as up, down, left, right, front, and back may be used in this specification, but these terms are merely for convenience of explanation, and it will be obvious to those skilled in the art of the present invention that these terms may change depending on the position of a target object, the position of an observer, etc. Furthermore, the terms inside and outside may be used in this specification, but unless otherwise specified, the inside direction of each component means the direction toward the center of the battery pack or the component, and the outside direction means the opposite direction.

[0117] Although the present invention has been described above using limited embodiments 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 scope of the technical concept of the present invention and the scope of the claims. [Explanation of symbols]

[0118] 100 Battery Module 110 Battery Cell 111 Electrode lead 120 Module Case 121 Upper Plate 122 Lower Plate 123 Side Plate 130 Busbar Assembly 131 Busbar housing 132 module busbar 140 Module Terminal 200 pack case 201 Main body 202 Bending part 210 Front case 220 Rear case 230 Side Case 300 Melt material 301 First member 302 Second member O opening O1 First opening O2 2nd opening H1 outlet H2 fastening hole P protrusion

Claims

1. a plurality of battery modules, each of which comprises one or more battery cells and configured to store and release energy, stacked in at least one direction; a pack case disposed on at least one side of the plurality of battery modules, covering at least a portion of an exterior of the plurality of battery modules, and having one or more openings; a melt member disposed in an opening of the pack case to seal the opening and configured to be melted by heat generated from one or more battery modules among the plurality of battery modules to open the opening; Including, the pack case is configured to guide a generated gas when the gas is generated from one or more battery modules among the plurality of battery modules; The melt member is configured to be melted by the generated gas; The battery modules are arranged in a left-right direction and vent gas is discharged to the front or rear. the pack case is disposed in at least one of the front and rear of the plurality of battery modules, the pack case includes a main body portion located in front of or behind the plurality of battery modules, and a folding portion formed by folding an upper end and a lower end of the main body portion, The opening is formed in both the main body portion and the folded portion.

2. The battery pack according to claim 1 , wherein the opening is configured to have an elongated shape extending in a direction perpendicular to a stacking direction of the plurality of battery modules.

3. The battery pack according to claim 1 , wherein the opening is at least partially located between the plurality of battery modules.

4. the pack case is located on at least one of a front side and a rear side of the plurality of battery modules, The battery pack according to claim 1 , wherein at least a portion of the plurality of battery modules is spaced apart from each other by a predetermined distance, and the spaced apart portions are exposed in at least one of an upper portion and a lower portion.

5. 5. An energy storage system comprising a battery pack according to any one of claims 1 to 4.

6. A motor vehicle comprising a battery pack according to any one of claims 1 to 4.

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