A battery pack with a structure that reduces the temperature of venting gas and blocks the emission of sparks into outside of pack case

Abstract

A battery pack according to the present invention comprises at least one battery module; a pack case accommodating the battery module; and a fire-prevention venting unit disposed in a gas venting path provided to guide gas generated from the battery module to exit to the outside of the pack case, wherein the fire-prevention venting unit comprises: a temperature reduction tunnel portion formed of a porous metal; and a mesh covering at least one of the inlet and outlet of the temperature reduction tunnel portion.

Description

Technology Field

[0001] The present invention relates to a battery pack, and more specifically, to a battery pack in which safety measures are applied to prevent ignition of structures surrounding the battery pack or other battery packs caused by high-temperature venting gas and sparks (particles) being generated and discharged outside the battery pack without filtration during thermal runaway of a battery module. Background Technology

[0002] Recently, as the demand for portable electronic products such as laptops, video cameras, and mobile phones has increased rapidly, and the commercialization of robots and electric vehicles has begun in earnest, research on high-performance secondary batteries capable of repeated charging and discharging is actively underway.

[0003] Currently commercialized rechargeable batteries include nickel-cadmium, nickel-hydrogen, nickel-zinc, and lithium-ion batteries. In particular, lithium-ion batteries are gaining attention for their advantages over nickel-based batteries, such as the ability to freely charge and discharge due to almost no memory effect, a very low self-discharge rate, and high energy density.

[0004] While secondary batteries are sometimes used individually, they are generally configured with multiple secondary batteries electrically connected in series and / or parallel. In particular, multiple secondary batteries can be housed within a single module case while electrically connected to each other to form a single battery module. Furthermore, battery modules can be used individually or two or more can be electrically connected in series and / or parallel to form higher-level devices such as battery packs.

[0005] Recently, as issues such as power shortages and eco-friendly energy have come to the forefront, Energy Storage Systems (ESS) for storing generated electricity are receiving increased attention. Notably, utilizing such energy storage systems facilitates the construction of systems like Smart Grid Systems, enabling the easy regulation of power supply and demand in specific regions or cities.

[0006] Battery packs used in energy storage systems may require significantly larger capacities compared to small and medium-sized packs. Consequently, battery packs typically contain a large number of battery modules. Furthermore, to increase energy density, multiple battery modules are often densely packed into a very confined space.

[0007] However, when multiple battery modules are densely packed in a confined space like this, they can be vulnerable to fire. For example, thermal propagation may occur in a single battery module, resulting in the release of high-temperature gas from at least one battery cell. Furthermore, such gas release may trigger high-temperature sparks, which may contain active material detached from the electrodes inside the battery cell or molten aluminum particles. If these high-temperature sparks and gases come into contact with oxygen, it can lead to a fire in the battery pack.

[0008] In particular, if a fire occurs in a specific battery cell or module, it can spread to surrounding battery cells, modules, or other battery packs. Especially since energy storage systems have a high density of batteries in a confined space, extinguishing a fire is not easy once it occurs. Furthermore, considering the scale and role of energy storage systems, a fire in a battery pack poses a significant risk of causing serious property damage and loss of life. Therefore, it is necessary to prevent the spread of fire even in the event of a thermal runaway. The problem to be solved

[0009] Accordingly, the present invention is devised to solve the above-mentioned problems and aims to provide a battery pack configured to prevent ignition of structures surrounding the battery pack or other battery packs even if high-temperature gas or sparks are generated in some battery modules due to thermal runaway, etc., and an energy storage system including the same.

[0010] However, the technical problems that the present invention aims to solve are not limited to those described above, and other unmentioned problems will be clearly understood by those skilled in the art from the description of the invention below. means of solving the problem

[0011] A battery pack according to one aspect of the present invention for achieving the above-mentioned purpose is,

[0012] The device comprises at least one battery module; a pack case accommodating the battery module; and a fire-prevention venting unit disposed in a gas venting path provided to guide gas generated from the battery module to exit to the outside of the pack case, wherein the fire-prevention venting unit may include a temperature-reducing tunnel section formed of a porous metal; and a mesh covering at least one of the inlet and outlet of the temperature-reducing tunnel section.

[0013] The above mesh net may include an inlet mesh net and an outlet mesh net that cover the inlet and outlet of the temperature reduction tunnel section, respectively.

[0014] The above temperature reduction tunnel section may include a plurality of gas passages formed in a grid structure extending between the inlet mesh and the outlet mesh.

[0015] The hole size of the inlet mesh or the outlet mesh can be formed to be smaller than the cross-sectional size of each gas passage.

[0016] Each of the above gas passages is provided with a plurality of valves, and the plurality of valves may each include upper valves that are spaced apart from each other and extend diagonally from the ceiling surface of the gas passage, and lower valves that are alternately arranged with the upper valves and extend diagonally from the bottom surface of the gas passage.

[0017] The above fire prevention venting unit may be detachably provided in a case hole that is provided on the wall of the pack case and forms an outlet of the gas venting path.

[0018] The above fire prevention venting unit may be arranged in multiple numbers at predetermined intervals along the gas venting path inside the pack case.

[0019] The fire prevention venting unit may be disposed on the gas venting path corresponding to one of the above-mentioned battery modules and another adjacent battery module.

[0020] The above temperature reduction tunnel section may further include an outer frame formed with a hollow structure that can be forcibly fitted inside.

[0021] The outer frame has two openings, one on one side and one on the other, and the mesh net can be integrally fixedly connected to one of the two openings and rotatably connected to the other.

[0022] The above outer frame can be fixedly coupled inside the pack case.

[0023] The above at least one battery module is two or more battery modules arranged in series, and may further include a heat transfer blocking unit interposed between adjacent battery modules to block heat transfer between the battery modules.

[0024] The above heat transfer blocking unit is formed in a structure in which a first thermal insulation pad, a first thermal conductive sheet made of metal, a second thermal insulation pad, a second thermal conductive sheet made of metal, and a third thermal insulation pad are stacked in a unidirectional manner, and the first thermal conductive sheet and the second thermal conductive sheet may be formed to be in surface contact with the upper surface of the pack case.

[0025] According to another aspect of the present invention, an energy storage system comprising the battery pack described above may be provided. Effects of the invention

[0026] According to the present invention, even if high-temperature venting gas and sparks are generated during thermal runaway of a battery module, ignition of external structures around the battery pack or other battery packs can be suppressed.

[0027] Specifically, according to the configuration of the fire-prevention venting unit of the present invention, the venting gas is discharged to the outside of the pack case at a lowered temperature, and high-temperature sparks are filtered internally and blocked from being discharged to the outside of the battery pack. Therefore, it is possible to prevent ignition from occurring in structures surrounding the battery pack or in other battery packs.

[0028] In addition to the above, the present invention may have various other effects, which are described in each embodiment, or effects that can be easily inferred by those skilled in the art, etc., will be omitted. Brief explanation of the drawing

[0029] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings. FIG. 1 is a schematic diagram illustrating the main configuration of a battery pack according to one embodiment of the present invention. Figure 2 is an exploded perspective view of the fire prevention venting unit of Figure 1. Figure 3 is a cross-sectional view of the fire-prevention venting unit of Figure 1. FIG. 4 is a drawing corresponding to FIG. 3, illustrating a modified example of the fire prevention venting unit of FIG. 3. FIG. 5 is a schematic diagram illustrating the main configuration of a battery pack according to another embodiment of the present invention. Figure 6 is a drawing illustrating the battery modules and heat transfer blocking unit of Figure 5. FIG. 7 is a diagram illustrating the thermal insulation and heat dissipation structure between battery modules of a battery pack according to another embodiment of the present invention. FIG. 8 is a perspective view illustrating the fire prevention venting unit of FIG. 5. FIG. 9 is an exploded perspective view of the fire prevention venting unit of FIG. 8. FIG. 10 is a drawing corresponding to FIG. 9, illustrating a modified example of a fire-prevention venting unit. FIG. 11 is a schematic diagram illustrating the main configuration of a battery pack according to another embodiment of the present invention. Specific details for implementing the invention

[0030] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, and should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0031] Therefore, it should be understood that the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention, and that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0032] FIG. 1 is a schematic diagram illustrating the main configuration of a battery pack according to one embodiment of the present invention, FIG. 2 is an exploded perspective view of the fire prevention venting unit of FIG. 1, and FIG. 3 is a cross-sectional view of the fire prevention venting unit of FIG. 1.

[0033] Referring to FIGS. 1 to 3, a battery pack (10) according to one embodiment of the present invention includes a battery module (100), a pack case (200), and an ignition prevention venting unit (300).

[0034] The battery module (100) may be configured to store and supply energy by having one or more secondary batteries (110). Additionally, one or more battery modules (100) may be included in a battery pack (10). In particular, to improve the capacity and / or output of the battery pack (10), a plurality of battery modules (100) may be included in the battery pack (10), as shown in FIG. 1. At this time, a plurality of battery modules (100) may be arranged in at least one direction.

[0035] The battery module (100) may include secondary batteries (110) and, although not illustrated, components for electrically connecting the secondary batteries (110), components for sensing voltage, temperature, etc., a circuit board, a connector, and a module housing for accommodating them.

[0036] The above secondary battery (110) may be a pouch-type secondary battery (110) including an electrode assembly, an electrolyte, and a pouch-type case.

[0037] For example, multiple pouch-type secondary batteries (110) can be stored inside a module housing in the form of a cell stack formed by standing upright in the vertical direction (Z-axis direction) and stacking in the horizontal direction (X-axis direction). At this time, the electrode leads of each pouch-type secondary battery (110) can be in direct contact with each other or electrically connected through a busbar, etc.

[0038] Of course, the secondary battery (110) may be of a different form than a pouch type, such as a cylindrical or prismatic secondary battery in which the battery case is made of a metal can.

[0039] The above module housing may be configured to accommodate one or more secondary batteries (110) in its internal space.

[0040] For example, the module housing may comprise a rectangular tubular housing frame consisting of an upper plate, a lower plate, and two side plates. Some plates included in the housing frame, such as the lower plate and the two side plates, may be configured in an integrated form. In this case, the integrated form of the lower plate and the two side plates may be approximately U-shaped.

[0041] A cell stack is housed in the limited internal space of such a housing frame, and the secondary battery (110) cells are electrically connected. At this time, the electrode leads of adjacent secondary battery (110) cells can be welded to a single busbar so that all secondary battery (110) cells are connected in series or parallel. Here, the busbar refers to a conductor in the form of a metal bar.

[0042] A front cover and a rear cover can be mounted respectively on the front and rear of the housing frame, where the electrode leads and busbars of the secondary battery cells (110) are welded. The front cover and the rear cover can be formed of an insulating material, such as plastic, to prevent a risk of short circuits at the electrical connection points. Additionally, the front cover or the rear cover can be used as a place to install external terminals and connectors of the module.

[0043] The pack case (200) is a component for housing multiple battery modules (100) and can be manufactured with a sealed structure made of a material with high mechanical strength to protect the multiple battery modules (100) from external physical and chemical elements. For convenience of drawing, the pack case (200) is briefly illustrated in FIG. 1 as a box shape with a rectangular surface, but the pack case (200) is equipped with an upper cover (210) in the form of a plate that forms the upper surface and a lower cover (220) that forms the bottom surface and wall surface, and the upper cover (210) and the lower cover (220) can be configured to be mutually joined and sealed by bolting, hooking, sealing, adhesive, etc.

[0044] Additionally, the pack case (200) has a case hole (201) (see FIG. 5). The case hole (201) may be provided on one side of the pack case (200), for example, on the wall of the lower cover (220), and may be configured so that air can pass through to the inside and outside of the pack case (200) by perforating an area of ​​the wall.

[0045] The above case hole (201) serves to prevent deformation of the pack case (200) by eliminating the pressure difference between the inside and outside of the battery pack (10), and can also serve as a gas outlet to discharge the venting gas to the outside of the battery pack (10) when venting gas is generated in some battery modules (100) inside the battery pack (10). This case hole (201) can be described as the end of the gas venting path, that is, the outlet of the gas venting path, to guide the venting gas generated in the battery modules (100) to exit to the outside of the pack case (200).

[0046] The fire prevention venting unit (300) is a structure configured to allow flames, sparks, and other foreign substances to pass through while allowing venting gas to pass through and lowering the temperature. The fire prevention venting unit (300) of this embodiment may be configured to be detachably attached to the case hole (201). For example, the fire prevention venting unit (300) may be configured to cover the case hole (201) and be attached to the outer wall of the pack case (200). Although not shown, sufficient fixation and airtightness can be secured between the fire prevention venting unit (300) and the pack case (200) by using bolts and sealants.

[0047] Specifically, the fire-prevention venting unit (300) includes a temperature-reducing tunnel section (310) formed of porous metal and two mesh nets (320), as shown in FIGS. 2 and 3.

[0048] The temperature reduction tunnel section (310) may be formed of a metal material with excellent thermal conductivity and rigidity, such as aluminum, and configured to have a plurality of gas passages (311) that are extended in a grid structure. Additionally, the inlet and outlet of the temperature reduction tunnel section (310) may be configured to be covered by a mesh net (320).

[0049] As the high-temperature venting gas passes through the temperature reduction tunnel section (310), heat is absorbed into the body of the temperature reduction tunnel section (310), thereby lowering the temperature. In particular, due to the porous structure formed in the metal temperature reduction tunnel section (310), a large contact area between the venting gas and the temperature reduction tunnel section (310) is secured, thereby increasing the amount of heat dissipated by the venting gas.

[0050] In addition, when the venting gas passes through the multiple narrow gas passages (311) of the present embodiment, the pressure of the venting gas increases and its speed increases. The convective heat transfer coefficient is proportional to the air flow velocity. Therefore, the energy loss of the venting gas due to the increase in pressure and the convective heat transfer rate due to the increase in flow velocity increase, so the temperature difference of the venting gas before and after passing through the temperature reduction tunnel section (310) becomes significantly larger. Therefore, even if high-temperature venting gas is generated inside the battery pack (10), when the venting gas passes through the temperature reduction tunnel section (310) and is discharged to the outside of the battery pack (10), the temperature is lowered, so it does not act as a factor that could cause ignition in structures outside the battery pack (10) or other battery packs (10). In addition, in the case of flames, movement may be inhibited or extinguished due to a trapping phenomenon within the multiple narrow gas passages (311) of the temperature reduction tunnel section (310).

[0051] As a variation, a plurality of valves (312, 313) may be further configured in each gas passage (311) as a means to promote vortex flow in each gas passage (311) of the temperature reduction tunnel section (310).

[0052] For example, as illustrated in FIG. 4, a plurality of valves may include upper valves (312) and lower valves (313), wherein the upper valves (312) are spaced apart from each other and each is configured to extend diagonally from the ceiling surface of the gas passage (311), and the lower valves (313) are alternately arranged with the upper valves (312) and each is configured to extend diagonally from the bottom surface of the gas passage (311).

[0053] According to the internal configuration of the gas passage (311), the flow of venting gas is shown in only one gas passage (311) in FIG. 4 for the sake of simplification of the drawing, and a vortex is significantly generated as the venting gas passes through the narrow gas passage (311). Therefore, the heat loss, i.e., the convective heat transfer rate, that escapes from the venting gas to the temperature reduction tunnel section (310) is further increased. Therefore, the temperature reduction tunnel section (310) according to this modified example can act more advantageously in lowering the temperature of the venting gas.

[0054] The mesh screen (320) is configured to block high-temperature sparks that may travel along with the venting gas, and includes an inlet mesh screen (320a) and an outlet mesh screen (320b) that cover the inlet and outlet of the temperature reduction tunnel section (310), respectively. Here, the spark refers to active material or molten aluminum particles detached from the electrode inside the secondary battery (110). If high-temperature sparks are discharged outside the battery pack (10) without being filtered during the venting gas discharge, the risk of ignition of structures around the battery pack (10) or other battery packs (10) becomes very high.

[0055] In the case of a battery pack (10) according to the prior art, there are examples where a mesh net is applied as a means to block the inflow of foreign substances or sparks. However, in the prior art, the mesh net is often damaged, such as by twisting or being punctured, due to the pressure when venting gas is ejected. The present invention is configured so that the mesh net (320) is not easily damaged even when the venting gas ejection pressure is strong, by combining a mesh net (320) at the inlet and outlet of the temperature reduction tunnel section (310).

[0056] For example, as shown in FIGS. 2 to 3, a mesh net (320) is combined with the inlet and outlet of the temperature reduction tunnel section (310), so that the entire area of ​​the mesh net (320) can be supported by the temperature reduction tunnel section (310), which is a metal structure, so that it can be prevented from warping or perforation even under the pressure of the venting gas.

[0057] The inlet mesh (320a) and the outlet mesh (320b) can be configured such that the size of each hole forming the mesh is relatively very small compared to the cross-sectional size (vent size) of the gas passage (311) of the temperature reduction tunnel section (310). Accordingly, ordinary spark particles that are not ultrafine in size can be blocked and cannot pass through the inlet mesh (320a) or the outlet mesh (320b). Since these meshes (320) come into contact with high-temperature sparks, they can be composed of a metal or a refractory material (e.g., mica) that does not easily undergo thermal melting even at high temperatures.

[0058] Accordingly, according to the fire prevention venting unit (300) of the present embodiment configured as described above, even if high-temperature venting gas is generated inside the battery pack (10), high-temperature sparks are not discharged to the outside, and only the venting gas is discharged to the outside with its temperature lowered, thereby preventing ignition from occurring in structures around the battery pack (10) or in other battery packs (10).

[0059] Next, a battery pack (20) according to another embodiment of the present invention will be described with reference to FIGS. 5 to 10.

[0060] FIG. 5 is a schematic diagram illustrating the main configuration of a battery pack (20) according to another embodiment of the present invention, FIG. 6 is a diagram illustrating the battery modules (100) of FIG. 5 and a heat transfer blocking unit (400), FIG. 7 is a diagram illustrating the thermal insulation and heat dissipation structure between the battery modules (100) of the battery pack (20) according to another embodiment of the present invention, and FIG. 8 is a perspective view illustrating the fire prevention venting unit (300A) of FIG. 5.

[0061] The same reference numbers as those in the aforementioned embodiments indicate the same components. Duplicate descriptions of the same components will be omitted, and the description will focus on the differences from the aforementioned embodiments.

[0062] A battery pack (20) according to another embodiment of the present invention is configured such that a plurality of fire-prevention venting units (300A) are provided at predetermined intervals along a gas venting path inside the pack case (200), and further includes a heat transfer blocking unit (400) for blocking heat transfer between battery modules (100).

[0063] First, regarding the heat transfer blocking unit (400), the heat transfer blocking unit (400) is configured to block heat from propagating to an adjacent battery module (100) in the event of thermal runaway of one battery module (100). It may be configured in a structure that includes a first insulation pad (410), a first thermal conductive sheet (420), a second insulation pad (430), a second thermal conductive sheet (440), and a third insulation pad (450), and is stacked in one direction (X-axis direction) in the order described above. As shown in FIGS. 5 and 6, a plurality of battery modules (100) are arranged continuously in the X-axis direction with their side portions facing each other, and one heat transfer blocking unit (400) may be arranged between two adjacent battery modules (100).

[0064] The first insulation pad (410), the second insulation pad (430), and the third insulation pad (450) may each be composed of a pad or film formed from a foam or ceramic fiber material having a porous structure, and may be manufactured in various sizes and shapes as needed. In this embodiment, the second insulation pad (430) is divided into two unit second insulation pads (430a, 430b), but this is just one example, and the second insulation pad (430) may be composed of one or three or more.

[0065] And the first thermal conductive sheet (420) and the second thermal conductive sheet (440) can be formed in the form of thin sheets made of a material with excellent thermal conductivity, such as aluminum or graphite.

[0066] Specifically, the first insulation pad (410) is configured to wrap around a portion of the side and top surface of the left battery module (100) as shown in FIG. 7, and the first thermal conductive sheet (420) has its top edge folded to correspond to the first insulation pad (410), and the top surface of the first thermal conductive sheet (420) can be configured to come into contact with the top cover (210) of the pack case (200), that is, the top surface of the pack case (200).

[0067] And the third insulation pad (450) and the second thermal conductive sheet (440) may be arranged symmetrically with respect to the second insulation pad (430) and the first thermal conductive sheet (420) to form a shape that wraps around a portion of the side and top surface of the right battery module (100).

[0068] According to the above configuration, if a thermal runaway occurs in the left battery module (100) illustrated in FIG. 7, the heat from the left battery module (100) must pass through five stages (1st insulation > 1st heat dissipation > 2nd insulation > 2nd heat dissipation > 3rd insulation) to be transferred to the right battery module (100). That is, heat is blocked at the first insulation pad (410), and the heat coming from the first insulation pad (410) is conducted to the pack case (200) through the first heat conductive sheet (420). That is, the heat from the first heat conductive sheet (420) is distributed to the pack case (200), which has a relatively very large heat capacity. Additionally, the heat from the first thermal conductive sheet (420) is blocked a second time by the second insulation pad (430), and the heat passing over the second insulation pad (430) is once again dispersed to the pack case (200) through the second thermal conductive sheet (440) and blocked a third time by the third insulation pad (450). Therefore, since most of the heat is blocked or escapes to the outside during the process of going through the five steps, the heat passing from the left battery module (100) to the right battery module (100) can be said to be very minimal.

[0069] In addition, a battery pack (10) according to another embodiment of the present invention can be configured such that when venting gas is generated in a battery module (100), the flow of venting gas inside the pack case (200) flows along a specific path by surrounding each battery module (100) with a flame-prevention venting unit (300A), a heat transfer blocking unit (400), and a pack case (200).

[0070] For example, as illustrated in FIG. 5, the upper and lower ends of the second insulation pad (430) are in contact with the upper and lower surfaces of the pack case (200), respectively, and the rear end (a narrow surface arranged vertically) of the second insulation pad (430) is in contact with one side wall of the pack case (200), thereby blocking the flow of venting gas toward the upper (+Z-axis direction), lower (-Z-axis direction), both side parts (±X-axis direction), and rear (+Y-axis direction) of each battery module (100), and forming a gas venting path that flows toward the front (-Y-axis direction), moves along one edge of the pack case (200) in the -X-axis direction, and exits to the outside through the case hole (201). At this time, a partition wall (W) may be added to shield the side of the outermost battery module (100) that does not come into contact with other battery modules (100).

[0071] And, according to another embodiment of the present invention, the fire prevention venting unit (300A) may be arranged at predetermined intervals along the gas venting path.

[0072] Preferably, in order to prevent high-temperature sparks from spreading to other battery modules (100) even if venting gas and sparks occur in some battery modules (100), it is preferable to place each fire-prevention venting unit (300A) on a corresponding gas venting path between one battery module (100) and an adjacent battery module (100).

[0073] At this time, one side of the fire prevention venting unit (300A) is configured to contact the front of the second insulation pad (430), and the upper and lower surfaces and the other side of the fire prevention venting unit (300A) are configured to contact or seal the upper and lower surfaces and the wall in the -Y axis direction of the pack case (200), respectively, so that when venting gas is generated in the battery module (100), it cannot escape from the case hole (201) without passing through the fire prevention venting unit (300A).

[0074] Meanwhile, a flame-prevention venting unit (300A) according to another embodiment of the present invention may include a temperature reduction tunnel section (310), an inlet mesh (320a), an outlet mesh (320b), and an outer frame (330), as illustrated in FIGS. 8 and 9.

[0075] That is, compared to the previously described embodiment, the flame-prevention venting unit (300A) of the present embodiment further includes an outer frame (330) that is fixedly coupled inside the pack case (200).

[0076] As shown in FIG. 9, the outer frame (330) is formed with a hollow structure and has two openings, one on one side and one on the other, and can be configured to allow the temperature reduction tunnel section (310) to be forcibly fitted inside through the openings. This outer frame (330) serves to protect the temperature reduction tunnel section (310) from external impact. Additionally, a bracket (not shown) may be attached to the outer side of the outer frame or formed integrally, and the bracket and the pack case (200) may be connected by bolts to be usefully used to fix the flame-prevention venting unit (300A) inside the pack case (200).

[0077] And the mesh net (320) can be attached to the two open ends of the outer frame (330) by any one of bolting, welding, or bonding.

[0078] As another variation, the mesh net (320) may be configured to be integrally fixedly connected to one of the two openings of the outer frame (330) and rotatably connected to the other. For instance, as shown in FIG. 10, the top of one opening of the outer frame (330) and the top of the mesh net (320) may be connected by a hinge (333) so that the mesh net (320) can be lifted to house the temperature reduction tunnel section (310) inside the outer frame (330). Additionally, after the temperature reduction tunnel section (310) is housed inside the outer frame (330), the outer frame (330) and the mesh net (320) may be configured such that the mesh net (320) is locked by hooking the hook hole (334) provided at the bottom of the mesh net (320) onto a latch (335) provided at the bottom of one opening of the outer frame (330). In this case, compared to bolting, welding, or bonding methods, the assembly process of the mesh net (320) to the outer frame (330) is simple, so rework can be made easier when it is necessary to replace or maintain the temperature reduction tunnel section (310) or the mesh net (320) afterwards.

[0079] FIG. 11 is a schematic diagram illustrating the main configuration of a battery pack (30) according to another embodiment of the present invention.

[0080] A battery pack (30) according to another embodiment of the present invention, compared with the battery pack (10) of the aforementioned embodiment, comprises a configuration in which gas venting paths are formed on both side edges inside the pack case (200) and flame-prevention venting units (300A) are disposed in each gas venting path.

[0081] As illustrated in FIG. 11, in the present embodiment, when venting gas is generated in the battery module (100), the venting gas is configured to leak out to the front (-Y-axis direction) and rear (+Y-axis direction) of the battery module (100) and to move along both side edges of the pack case (200), so that the external discharge of the venting gas can proceed more quickly than in the previously described embodiment. Therefore, the battery pack (30) according to the present embodiment can be effective in suppressing the intensification of internal ignition.

[0082] An energy storage system according to the present invention may include one or more battery packs according to the present invention. In particular, to have a large energy capacity, the energy storage system may include a plurality of battery packs according to the present invention in a form in which they are electrically connected to each other. 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 the present invention. Furthermore, such an energy storage system may be used in various places or devices, such as smart grid systems or electric charging stations.

[0083] Meanwhile, although terms indicating directions such as up, down, left, right, front, and back have been used in this specification, these terms are used merely for convenience of explanation, and it is obvious to those skilled in the art that they may vary depending on the location of the object or the position of the observer.

[0084] As described above, although the present invention has been explained by limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs. Explanation of the symbols

[0085] 10, 20, 30: Battery pack 100: Battery module 110 : Secondary battery 200 : Pack case 201: Case hole 210: Top cover 220 : Lower cover 300 : Fire prevention venting unit 310: Temperature reduction tunnel section 311: Gas passage 320 : Mesh net 320a : Entrance mesh net 320b : Exit mesh 330 : Outer frame 400: Heat transfer blocking unit 410: First insulation pad 420: 1st thermal conductive sheet 430: 2nd insulation pad 440: 2nd thermal conductive sheet 450: 3rd insulation pad

Claims

Claim 1 A battery pack comprising: at least one battery module; a pack case having a case hole formed by perforating a portion of a wall surface and accommodating the battery module; and at least one fire-prevention venting unit disposed in a gas venting path provided to guide gas generated from the battery module to exit to the outside of the pack case, wherein the fire-prevention venting unit comprises: a temperature reduction tunnel section formed of a porous metal and having a plurality of gas passages extended in a grid structure; a mesh covering at least one of the inlet and outlet of the temperature reduction tunnel section; and an outer frame formed with a hollow structure in which the temperature reduction tunnel section can be accommodated, and which covers the case hole and is coupled to the pack case. Claim 2 A battery pack according to claim 1, characterized in that the mesh net includes an inlet mesh net and an outlet mesh net that respectively cover the inlet and outlet of the temperature reduction tunnel section. Claim 3 delete Claim 4 A battery pack according to claim 1, characterized in that the mesh is formed such that the hole size is smaller than the cross-sectional size of each gas passage. Claim 5 A battery pack according to claim 1, wherein each of the above gas passages is provided with a plurality of valves, and each of the plurality of valves includes upper valves that are spaced apart from each other and extend diagonally from the ceiling surface of the gas passage, and lower valves that are alternately arranged with the upper valves and extend diagonally from the bottom surface of the gas passage. Claim 6 delete Claim 7 A battery pack according to claim 1, characterized in that the fire prevention venting units are arranged in plurality at predetermined intervals along the gas venting path inside the pack case. Claim 8 A battery pack according to claim 7, characterized in that the fire prevention venting unit is disposed on the gas venting path corresponding to one of the battery modules and another adjacent battery module. Claim 9 delete Claim 10 A battery pack according to claim 1, wherein the outer frame has two openings, one on one side and one on the other, and the mesh net is integrally fixedly connected to one of the two openings and rotatably connected to the other. Claim 11 A battery pack according to claim 1, characterized in that the outer frame is fixedly coupled inside the pack case. Claim 12 A battery pack according to claim 1, wherein the at least one battery module comprises two or more battery modules arranged in series, and further comprises a heat transfer blocking unit interposed between adjacent battery modules to block heat transfer between the battery modules. Claim 13 A battery pack according to claim 12, wherein the heat transfer blocking unit is formed in a structure in which a first thermal insulation pad, a first thermal conductive sheet made of metal, a second thermal insulation pad, a second thermal conductive sheet made of metal, and a third thermal insulation pad are stacked in a unidirectional manner, and the first thermal conductive sheet and the second thermal conductive sheet are formed to be in surface contact with the upper surface of the pack case. Claim 14 An energy storage system comprising a battery pack according to any one of paragraphs 1, 2, 4, 5, 7, 8 and 10 through 13.

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