Battery pack case and battery pack, and vehicle containing them.

Abstract

A battery pack case, a battery pack, and a vehicle including the same are disclosed, comprising: a base plate that constitutes one surface of the battery pack case and has through holes formed therein that connect the internal space of the battery pack case to the outside; an external plate disposed at a distance from the outer surface of the base plate, blocking the through holes from being exposed to the outside and forming a separation space between itself and the base plate; and a vent valve provided on the external plate for selectively discharging fluid from the separation space.

Description

Technical Field

[0001] The present invention relates to a battery pack case, a battery pack, and a vehicle including the same, which can effectively discharge gas generated when a fire occurs inside the battery pack case provided with a cooling device and a cooling medium leaked from the cooling device to the outside, and prevent a short circuit of the battery cells.

Background Art

[0002] In recent years, in order to solve environmental problems such as abnormal weather, technologies for carbon reduction have been actively developed. In order to reduce carbon, instead of producing energy from fossil fuels, energy is produced in an environmentally friendly way, the produced energy is stored in the form of electrical energy, and the stored electrical energy is used in vehicles, various industrial sites, and households.

[0003] In order to utilize electrical energy for carbon reduction, the use of a battery that can store and draw out electrical energy is essential. Therefore, in order to sufficiently store electrical energy and use it without inconvenience, ensuring the performance of the battery is essential.

[0004] Batteries mainly utilize the oxidation-reduction reaction of metal ions, use metal ions at high density to increase the capacity, charge-discharge performance, and efficiency of the batteries, and much research has been conducted on substances constituting electrolytes and solid electrolytes. However, generally, as the performance of the battery develops, there is a problem of inferior stability.

[0005] In the case of batteries used in vehicles, industries, households, etc., they are manufactured in a physical unit called a pack. The battery pack has a function of preventing the transfer of fire to the outside even in case of an accident such as thermal runaway of the battery by incorporating and sealing a large number of battery cells inside the battery case, and protecting the internal battery cells from deterioration due to the influence of the external environment or damage due to physical reasons.

[0006] A battery pack incorporates numerous battery cells in a form that is an intermediate between modules and assemblies (CMAs, or Cell Module Assemblies). In the case of battery modules or assemblies, numerous battery cells are assembled into a single module or assembly, and these modules are fastened inside the pack case, thereby completing the battery pack. During battery maintenance, maintenance is made easier by performing it at the module or assembly level.

[0007] The numerous unit battery cells that make up a module or assembly consist of a positive electrode, a negative electrode, and an electrolyte. Since battery cells generate heat during charging and discharging, effective heat dissipation is necessary. Furthermore, from the perspective of battery modules, assemblies, and battery packs, efficient heat dissipation design is essential to prevent safety accidents.

[0008] On the other hand, batteries can deteriorate due to manufacturing errors, excessive charging and discharging, and aging. If battery deterioration continues, it can eventually lead to a fire. Therefore, it is necessary to take precautions to prevent fires from occurring due to batteries. To this end, it is important to continuously sense the battery's condition, recognize and respond to any problems in advance, and minimize damage in the event of an unexpected problem.

[0009] In particular, if battery degradation persists, battery cells can rapidly overheat, leading to a thermal runaway phenomenon that generates gas or flames. Once thermal runaway occurs in one battery cell, a chain reaction of heat propagation occurs, causing gas or flames to spread to adjacent battery cells or battery modules. Therefore, when thermal runaway occurs in a specific battery cell or battery module, it is essential to effectively vent the gases generated by the runaway while preventing the flames from spreading to other components in order to ensure the efficiency and safety of the battery.

[0010] On the other hand, in the case of a battery pack case that includes a cooling device installed to prepare for battery degradation, if a fire occurs inside the battery pack, the high heat may damage the cooling hoses, etc., and cause the cooling medium or foreign matter to leak from inside the battery pack case.

[0011] In the case of leaked cooling medium or foreign matter, it may be a conductive fluid, which could cause short circuits in battery cells or terminals. Therefore, when the cooling device is installed inside the battery pack case, a technology is needed to effectively and quickly discharge the cooling medium or foreign matter to the outside to prevent short circuits in the event of such an accident.

[0012] The matters described above as background technology are intended to facilitate understanding of the background of the present invention and are not intended to be considered prior art already known to those with ordinary skill in this art. [Overview of the Initiative] [Problems that the invention aims to solve]

[0013] The present invention was proposed to solve these problems and aims to provide a battery pack case, a battery pack, and a vehicle including them, which improve battery safety by facilitating the discharge of gas generated when a fire occurs in a specific battery cell or battery module inside the battery pack case, and by effectively discharging the cooling medium leaking from the cooling device installed inside the battery pack case to prevent short circuits.

[0014] The technical problems that this invention aims to solve are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those with ordinary skill in the art to which this invention pertains from the following description. [Means for solving the problem]

[0015] To achieve the above objective, the battery pack case according to the present invention includes: a base plate that constitutes one surface of the battery pack case and has through holes formed therein that connect the internal space of the battery pack case to the outside; an external plate that is disposed at a distance from the outer surface of the base plate, blocks the through holes from being exposed to the outside, and forms a separation space between itself and the base plate; and a vent valve provided on the external plate for selectively discharging fluid from the separation space.

[0016] In the case of the battery pack case according to the present invention, the outer plate may have side walls formed around it and be coupled to the base plate via the side walls, forming a separation space.

[0017] In the case of the battery pack case according to the present invention, the outer plate may be formed such that the portion corresponding to the through hole in the base plate protrudes outward toward the outside of the battery pack case.

[0018] In the case of the battery pack case according to the present invention, the vent valve of the outer plate may be formed at a location corresponding to the through hole of the base plate.

[0019] In the battery pack case according to the present invention, the outer plate is formed to be inclined outward from the area corresponding to the through hole, and the height of the separation space may decrease outward from the area corresponding to the through hole.

[0020] In the case of the battery pack case according to the present invention, the vent valve of the outer plate may be provided at the location where the separation distance between the base plate and the outer plate is maximum.

[0021] In the case of the battery pack case according to the present invention, a vent valve protection portion may be formed on the outer plate.

[0022] In the case of the battery pack case according to the present invention, the vent valve protection part of the external plate may be formed higher than the height of the vent valve along the outer peripheral surface of the vent valve at the location where the vent valve is formed.

[0023] In the case of the battery pack case according to the present invention, the vent valve protection part of the external plate may be integrally formed with the external plate.

[0024] In the case of the battery pack case according to the present invention, the vent valve of the external plate may be covered by a valve cover, and the valve cover may cover the vent valve from the outside of the external plate.

[0025] In the case of the battery pack case according to the present invention, the valve cover may be coupled to the external plate in either the width direction or the length direction of the external plate.

[0026] In the case of the battery pack case according to the present invention, the base plate constitutes the bottom surface of the battery pack case, the battery pack case houses a battery assembly inside, and the through holes of the base plate may be formed at locations between the plurality of battery assemblies built into the battery pack case.

[0027] In the case of the battery pack case according to the present invention, a cooling channel is provided between the battery assembly built into the battery pack case and the base plate, and the through holes of the base plate are formed at positions corresponding to the cooling ports of the cooling channel or the cooling hoses connected to the cooling ports, so that the cooling medium leaked from the cooling ports or the cooling hoses can flow into the through holes by its own weight.

[0028] In the case of the battery pack case according to the present invention, a filter cover or a filter net is formed in the through holes of the base plate, so that foreign substances can be blocked from flowing into the separation space.

[0029] In the case of the battery pack case according to the present invention, the filter cover is installed at a location facing the internal space of the battery pack case with the through hole, and a filter net may be formed at a location facing the outside of the battery pack case with the through hole.

[0030] In the case of the battery pack case according to the present invention, a flange is formed on the inner peripheral surface of the through hole so as to protrude toward the inside of the through hole, and the filter cover may be coupled to the flange.

[0031] In the case of the battery pack case according to the present invention, a plurality of support portions are formed on the flange so as to protrude toward the filter cover, and the filter cover may be seated on the support portions, whereby the filter cover and the flange may be separated.

[0032] In the case of the battery pack case according to the present invention, the filter cover may be fixed to the support portions, whereby the filter cover may be coupled to the base plate.

[0033] In the case of the battery pack case according to the present invention, the filter cover is seated inside the through hole in the form of a plate, the outer peripheral surface of the filter cover is separated from the inner peripheral surface of the through hole, and the internal space of the battery pack case and the separated space may communicate with each other through the separated gap.

[0034] In the case of the battery pack case according to the present invention, a sealing portion is provided along the periphery of the external plate, and the external plate may be coupled to the base plate with the sealing portion interposed therebetween. <哦000用0112>

[0035] In the case of the battery pack according to the present invention, it includes the battery pack case as described above.

[0036] y In the case of the vehicle according to the present invention, it includes the battery pack as described above.

Effects of the Invention

[0037] According to the battery pack case, battery pack, and vehicle including the present invention, in the event of a fire occurring in a battery pack with a cooling device installed inside, the gases caused by the fire are smoothly discharged, and the cooling medium leaking from the cooling device is effectively discharged, thereby preventing damage such as short circuits that occur inside the battery pack due to the leaked cooling medium.

[0038] The effects obtained by the present invention are not limited to those mentioned above, and other effects not mentioned above will be clearly understood by those with ordinary skill in the art to which the present invention pertains from the following description. [Brief explanation of the drawing]

[0039] [Figure 1] This figure shows a cross-section of a battery pack case according to one embodiment of the present invention.

[0040] [Figure 2] This is a view of the battery pack case shown in Figure 1, seen from above.

[0041] [Figure 3] This figure shows the through-holes in the battery pack case shown in Figure 1.

[0042] [Figure 4] This figure shows the battery pack case with the filter cover attached.

[0043] [Figure 5] This figure shows a cross-section of the battery pack case at the location of the through-hole shown in Figure 1.

[0044] [Figure 6] This figure shows a cross-section of the battery pack case at the vent valve location shown in Figure 1.

[0045] [Figure 7]This figure shows the state in which a vent valve protection section is formed at the vent valve location of the battery pack case shown in Figure 1.

[0046] [Figure 8] Figure 7 is an enlarged view of the vent valve protection section of the battery pack case shown.

[0047] [Figure 9] This figure shows the battery pack case shown in Figure 1 with a valve cover formed over the vent valve.

[0048] [Figure 10] Figure 9 shows a cross-section of the battery pack case with the valve cover formed.

[0049] [Figure 11] Figure 1 is a diagram showing a battery pack and vehicle to which the battery pack case shown is applied. [Modes for carrying out the invention]

[0050] In describing the embodiments disclosed herein, if a specific description of the relevant prior art is deemed to detract from the essence of the embodiments disclosed herein, such detailed description will be omitted. Furthermore, the accompanying drawings are provided to facilitate understanding of the embodiments disclosed herein and should not be understood as limiting the technical ideas disclosed herein, but rather as including all modifications, equivalents, or substitutions that fall within the concept and technical scope of the present invention.

[0051] A singular expression includes plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “includes” or “has” are intended to specify the presence of features, figures, stages, actions, components, parts, or combinations thereof as described in the specification, and should be understood not to preemptively exclude the possibility of the presence or addition of one or more other features, figures, stages, actions, components, parts, or combinations thereof.

[0052] The suffixes "module" and "part" used with respect to components in the following description are added or used interchangeably solely for the sake of ease of drafting the specification and do not have any distinct meaning or role in themselves. When a component is referred to as being "linked" or "connected" to another component, it should be understood that it is directly linked to or may be connected to the other component, but other components may exist in between. On the other hand, when a component is described as being "directly linked" or "directly connected" to another component, it should be understood that no other components exist in between.

[0053] The embodiments disclosed herein will now be described in detail with reference to the attached drawings, but regardless of the reference numerals in the drawings, identical or similar components will be given the same reference numerals, and redundant descriptions thereof will be omitted. Batteries heat up due to various reasons such as prolonged use, external physical shock, overcharging, or over-discharging. When the battery cells inside the battery heat up due to these various reasons, damage to the entire battery or a decrease in efficiency may occur. Therefore, a battery cell cooling system plays an important role for the efficiency and safety of the battery.

[0054] When battery cells overheat and catch fire due to various causes, a thermal runaway phenomenon can occur, where the temperature rises and the battery cell explodes. In a thermal runaway situation, gases and flames emitted from the battery cell propagate rapidly to adjacent battery cells and battery modules, creating a chain reaction that can cause a fire throughout the entire battery. On the other hand, battery cells can also experience short circuits due to various causes. When a short circuit occurs in a battery cell, a current larger than the normal range flows instantaneously through the conductor battery cell, causing the temperature to rise and potentially leading to the rupture or ignition of the battery cell and surrounding components. Therefore, technology to prevent short circuits in battery cells is necessary.

[0055] Furthermore, in the event of thermal runaway, not only the battery cells but also the cooling system installed inside the battery pack BP can be damaged in a high-temperature or high-pressure environment. Damage to the cooling system can cause the cooling medium or foreign matter present inside to leak out. The cooling medium or foreign matter discharged from the cooling system poses a risk of causing a short circuit in the battery cells inside the battery pack case.

[0056] Therefore, technical measures are needed to smoothly discharge gases generated during thermal runaway in specific battery cells or modules, as well as cooling media leaked from the cooling system, to the outside, while simultaneously filtering out flames and foreign matter generated by the thermal runaway, thereby improving battery stability.

[0057] Conventionally, a vent valve 500 was installed in the front-to-back direction of the battery pack BP to discharge gases generated during thermal runaway inside the battery pack BP and cooling media leaking due to damage to the cooling system caused by thermal runaway. However, in this case, due to the characteristics of the cooling media that accumulates at the lower end of the battery pack BP, smooth discharge to the vent valve 500 installed in the front-to-back direction of the battery pack BP did not occur, resulting in other damage inside the battery pack BP, such as heat propagation phenomena and electrical short circuits.

[0058] The present invention provides a battery pack case 10 that can effectively discharge gases and cooling medium to the outside, even if gases generated during thermal runaway and cooling medium leaking from a damaged cooling device accumulate at the lower end, by installing an external plate 300 on one side, such as the lower end of the battery pack BP, collecting cooling medium leaked from a damaged cooling device during thermal runaway, and forming a vent valve 500 on the external plate 300.

[0059] In this way, by installing the vent valve 500 at the lower end of the battery pack BP, the gas and cooling medium that accumulate at the lower end can be effectively discharged, thereby preventing other damage inside the battery pack BP, such as heat conduction and electrical short circuits. On the other hand, the vent valve 500 can be installed not only on the external plate 300 installed at the lower end of the battery pack BP, but also in the front-to-back direction of the battery pack BP, which can further improve the discharge effect of gas and cooling medium.

[0060] In the case of the battery pack case 10 of the present invention, as shown in Figure 1, it includes a base plate 100 of the battery pack BP which constitutes one of the lower surfaces of the battery pack case 10 and has a through hole 120 formed therein that connects the internal space of the battery pack case 10 to the outside; an external plate 300 which is disposed at a distance from the outer surface of the base plate 100 so as to block the through hole 120 from being exposed to the outside and to form a separation space 110 between the base plate 100 and the external plate 300; and a vent valve 500 provided on the external plate 300 which selectively discharges gas or cooling medium collected in the separation space 110 according to the internal pressure of the separation space 110. For example, when the pressure inside the separation space 110 reaches a preset value, the vent valve 500 automatically switches to an open state, and the gas or cooling medium collected inside the separation space 110 is discharged.

[0061] Multiple battery assemblies are housed inside the battery pack case 10. In the context of this invention, a battery assembly refers to a unit composed of multiple battery cells, and includes all concepts such as a battery module, which is a unit that assembles battery cells in the form of a case or housing, and a battery assembly, which is composed of a semi-assembled form such as a strap. It also includes cell-to-pack (CTP) type battery assemblies, in which multiple battery cells are assembled and directly fastened inside the battery pack case 10 without a battery assembly. In this invention, a battery assembly referred to as a "battery module," etc., is a concept that assembles multiple battery cells and is mounted inside the battery pack case 10, and includes various forms of unit assemblies.

[0062] The battery cells installed inside the battery pack case 10 are susceptible to overheating due to external impacts or heat generated during charging and discharging, and therefore require cooling. If the battery cells are not cooled properly, problems may arise with their efficiency and safety, which will affect the overall performance of the battery; therefore, the battery cells must be cooled.

[0063] In one embodiment of the present invention, a cooling channel 700 is installed at the bottom of the battery assembly as a cooling device for the battery cells, as shown in Figure 1. A cooling medium such as cooling water circulates inside the cooling channel 700, directly cooling the battery assembly by heat conduction. By using such a direct heat conduction cooling channel, the cooling efficiency can be increased, thereby improving the efficiency and safety of the battery.

[0064] Referring to Figures 1 and 2, a cooling hose 740 is installed in the cooling channel 700 to effectively facilitate the inflow and outflow of the cooling medium, and the cooling medium flows through the cooling hose 740 to cool the battery cells. The cooling hose 740 is then connected to the cooling channel 700 again through a cooling port 720. The cooling port 720 is a device for connecting the cooling medium flowing through the cooling hose 740 to the cooling channel 700, and plays a role in facilitating the efficient flow of the cooling medium. In this invention, in addition to the cooling channel 700, cooling hose 740, and cooling port 720, various other types of cooling devices can be configured to prepare for the heating of the battery cells.

[0065] In the case of cooling channels 700, cooling hoses 740, and cooling ports 720, etc., the connections with other devices inside the battery pack BP may be incomplete, or the connections may weaken over time. If a fire occurs inside the battery pack BP, the reduced durability may cause melting, potentially leading to leakage of the cooling medium or foreign matter present inside.

[0066] If cooling fluid or foreign matter leaks from cooling devices such as cooling channels 700, cooling hoses 740, and cooling ports 720 inside the battery pack case 10, problems such as breakdown of electrical insulation between multiple battery cells and terminals or short circuits may occur. Therefore, when cooling devices are installed inside the battery pack case 10, it is important to ensure that cooling fluid is smoothly discharged to the outside while foreign matter is effectively filtered in the event of abnormal battery conditions such as thermal runaway.

[0067] On the other hand, if thermal runaway occurs in a specific battery cell or battery module installed inside the battery pack case 10, gas or flames may be generated in that battery cell or battery module. Such gas or flames may propagate in a chain reaction to adjacent battery cells or battery modules, causing heat propagation that leads to ignition inside the battery pack case 10.

[0068] Therefore, if thermal runaway occurs in a specific battery cell or battery module, the gas leaking from that battery cell or module must be smoothly discharged to the outside, while the flame generated in the battery cell or module must be effectively filtered to prevent secondary damage inside or outside the battery.

[0069] For this purpose, in the present invention, as shown in Figure 3, through holes 120 are formed in the base plate 100, through which gases generated by thermal runaway or cooling media leaked from a cooling device damaged by thermal runaway can pass. In the illustrated embodiment or the base plate 100 referred to in the present invention, it is assumed that the base plate 100 constitutes the bottom surface of the battery pack case, but the base plate 100 is not necessarily limited to being located on the bottom surface and may be located in various directions of the battery pack case in which the battery assembly is installed.

[0070] Referring again to Figure 1, the base plate 100 constitutes the bottom surface of the battery pack case 10, which houses battery assemblies, and the through-holes 120 in the base plate 100 are formed between the multiple battery assemblies housed in the battery pack case 10. Cooling channels 700 are provided between the battery assemblies housed in the battery pack case 10 and the base plate 100 to directly cool the battery assemblies and battery cells. Cooling devices such as cooling channels 700, cooling hoses 740, or cooling ports 720 are installed on one side, including the lower end of the battery assemblies, so the through-holes 120 in the base plate 100 are located between the multiple battery assemblies housed in the battery pack case 10, allowing gases generated from each battery assembly, or cooling media leaking from cooling media damaged by thermal runaway, to pass through.

[0071] Therefore, in one embodiment, the through-hole 120 of the base plate 100 is formed at a position corresponding to the cooling port 720 of the cooling channel 700, or the cooling hose 740 connected to the cooling port 720, as shown in Figure 1, so that the cooling medium or foreign matter leaking from the cooling port 720 or cooling hose 740 flows into the through-hole 120 by its own weight. In this way, by forming the through-hole 120 of the base plate 100 at a position corresponding to the cooling port 720 or cooling hose 740, the cooling medium leaked due to thermal runaway is effectively discharged to the outside of the battery pack case 10, and any foreign matter contained in the leaked cooling medium can be filtered through a filter installed in the through-hole.

[0072] Referring to Figures 3 and 4, the through-hole 120 of the base plate 100 can be configured as either a filter cover 800 or a filter mesh 900. Since the through-hole 120 of the base plate 100 must discharge not only gases generated by thermal runaway but also cooling medium leaked from the cooling device, a filter cover 800 is primarily used to filter out flames or foreign matter, and a filter mesh 900 is secondarily used to minimize the inflow of flames or foreign matter to the outer plate 300, so that only gases or cooling medium flow through the through-hole 120.

[0073] As shown in Figures 4 and 5, the filter cover 800 is installed at the point where it faces the internal space of the battery pack case 10 from the through hole 120, thereby closing off a portion of the through hole 120. In the case of the filter mesh 900, it is installed at the point where it faces the external plate 300 of the through hole 120, blocking foreign matter from flowing into the separation space 110.

[0074] As shown in Figures 4 and 5, the filter cover 800 is seated inside the through-hole 120 in a plate shape, and the outer surface of the filter cover 800 is separated from the inner surface of the through-hole 120, forming a gap. Through the gap formed by the separation, the internal space of the battery pack case 10 and the separation space 110 are in communication with each other, allowing gas generated from thermal runaway or other causes from inside the battery pack case 10, or cooling medium leaked from the cooling device, to flow into the through-hole 120.

[0075] Since the filter cover 800 is formed in the internal space of the battery pack case 10, it is made of a fire-resistant metal to maintain durability even under abnormal conditions inside the battery pack case, such as thermal runaway. In one embodiment, it can be made of aluminum, which is easy to form, lightweight, and highly durable.

[0076] On the other hand, as shown in Figures 3 and 5, the through-hole 120 of the base plate 100 is provided with a filter mesh 900, which is a secondary filtering device to prevent foreign matter from flowing into the separation space 110. The filter mesh 900 is a device to secondarily prevent the inflow of foreign matter into the separation space 110 that could not be blocked by the primary filtering device, the filter cover 800, and is formed in a direction toward the outside from the through-hole 120. The filter mesh 900 has, for example, a mesh-like structure and can effectively block and suppress the inflow of foreign matter into the separation space 110. Similar to the filter cover 800, it may be molded from a fire-resistant material so as not to melt or be damaged by flames or the like in the event of an abnormal situation inside the battery pack case.

[0077] Furthermore, a flange 140 may be formed on the inner circumferential surface of the through-hole 120 of the base plate 100 so as to protrude inward from the through-hole 120, as shown in Figures 3 and 5. The flange 140 is a means for connecting the filter cover 800 to the through-hole 120 and can also serve as an indirect means for preventing or suppressing the inflow of flames or foreign matter through the through-hole 120; therefore, it may be molded integrally with the base plate 100 when the through-hole 120 is formed.

[0078] Referring to Figure 3, the flange 140 has multiple support portions 160, and the filter cover 800 can be seated on the support portions 160, thereby connecting the filter cover 800 to the through hole 120. In this case, by positioning the filter cover 800 and the flange 140 apart from each other, a gap can be created between the outer surface of the filter cover 800 and the inner surface of the through hole 120, thereby allowing gas or leaked cooling medium to flow in through the through hole 120.

[0079] Furthermore, as shown in Figure 5, the filter cover 800 can be joined to the base plate 100 by fixing the filter cover 800 through the support portion 160 located on the flange 140 of the through hole 120. Since the filter cover 800 is joined while remaining separated from the through hole 120, there is a risk that it may detach from the through hole 120 in the event of abnormal conditions of a high-temperature or high-pressure battery. Therefore, as shown in Figure 5, by fastening the filter cover 800 to the base plate 100 using the bolt fastening method 820, it is possible to prevent the filter cover 800 from detaching and to prevent or suppress the flow of flames generated during thermal runaway or foreign matter leaked from the cooling device into the separation space 110 between the base plate 100 and the outer plate 300. Of course, as long as the filter cover 800 can be effectively joined and fixed to the base plate 100, the embodiment is not limited to the one shown, and the filter cover 800 can be joined to the base plate 100 by various fastening methods.

[0080] The filter cover 800 and filter mesh 900 formed in the through-hole 120 must not only allow gases or cooling media generated during a fire such as thermal runaway inside the battery pack case to flow out to the outside, preventing foreign matter or flames from flowing out, but also prevent foreign matter from flowing back into the battery pack case, thereby isolating the internal atmosphere of the battery pack case from the outside and providing an advantage in thermal management.

[0081] As shown in Figure 1, the outer plate 300 is positioned at a distance from the outer surface of the base plate 100, blocking the through-hole 120 of the base plate 100 from being exposed to the outside, while simultaneously discharging gases generated by thermal runaway or leaked cooling medium to the outside through the vent valve 500 formed in the outer plate 300. Thus, the outer plate 300 forms a side wall along its circumference and is connected to the base plate 100 via the side wall to form a separation space 110.

[0082] Referring to Figure 1, the separation space 110 between the base plate 100 and the outer plate 300 is a place where fluids such as gas or cooling material discharged through the through hole 120 are stored. Normally, it is used as an empty space and plays a role in absorbing or dispersing shocks input from below. Furthermore, if thermal runaway occurs inside the battery pack case 10, the separation space 110 is used to store the gas or leaked cooling medium discharged through the through hole 120, and helps to discharge the gas or cooling medium to the outside through the vent valve 500 under a certain pressure.

[0083] On the other hand, in the event of a fire caused by flames or foreign matter that could not be contained through the filter cover 800 and filter mesh 900 of the through-hole 120, the external plate 300, which is attached to the lower part of the battery pack case 10, prevents the flames from flowing out to the outside with a cooling medium or the like. For example, the external plate 300 also serves as a firewall or fire extinguishing wall to prevent a fire that has started inside the battery pack case from spreading to the outside.

[0084] Since the outer plate 300 must store fluids such as gas or cooling medium that have passed through the through holes 120, the outer plate 300 may be formed such that the portion of the base plate 100 corresponding to the through holes 120 protrudes outward from the battery pack case, as shown in Figure 6. For example, as shown in Figure 6, the outer plate 300 may have a recessed plate shape coupled to the base plate 100, allowing gas or cooling medium discharged from the battery pack case 10 to be easily stored.

[0085] The outer plate 300 is provided with a vent valve 500 that operates under a constant pressure, as shown in Figures 1 and 6. The vent valve 500 is a relief-type valve that automatically opens when the pressure inside the outer plate 300 exceeds a certain value, releasing gas or cooling material stored in the outer plate 300 to the outside, thereby preventing additional battery abnormalities, such as short circuits, inside the battery pack case 10.

[0086] Therefore, as shown in Figure 1, the vent valve 500 of the outer plate 300 is formed at a position corresponding to the through hole 120 of the base plate 100. This allows the gas or cooling medium discharged through the through hole 120 to be stored around the vent valve 500 formed at the position corresponding to the through hole 120, and when the pressure of the stored gas or cooling medium exceeds a certain value, the vent valve 500 is opened, allowing the gas or cooling medium to be smoothly discharged to the outside.

[0087] As mentioned above, in the outer plate 300, the portion corresponding to the location where the through-hole 120 of the base plate 100 is formed protrudes outward to the outermost extent. As shown in Figures 1 and 6, the vent valve 500 is formed at the outermost protruding portion of the outer plate 300. This means that, as shown in Figure 6, when the outer plate 300 is located at the lower end of the battery pack case, the vent valve 500 is located at the lowest end of the outer plate 300. Therefore, by positioning the vent valve 500 at the lowest end of the outer plate 300, when the pressure of the gas or coolant stored in the outer plate 300 exceeds a certain value, the vent valve 500 can respond accurately to the internal pressure, thereby facilitating the discharge of the gas or coolant.

[0088] Referring to Figures 6 and 7, the outer plate 300 may be formed to slope outward from the point corresponding to the through hole 120, and the height of the separation space 110 may decrease outward from the point corresponding to the through hole 120. In one embodiment, similar to how the outer plate 300 is formed to protrude most at the point corresponding to the through hole 120, the vent valve 500 of the outer plate 300 is provided at the point where the separation distance between the base plate 100 and the outer plate 300 is maximum, as shown in Figure 6. This configuration allows the operation of the vent valve 500 to respond precisely to the pressure of the gas or cooling medium stored in the outer plate 300.

[0089] As shown in Figures 6 and 7, the outer plate 300 is formed to have an inclined surface 320 that slopes outward, so that the cooling medium or gas discharged through the through hole 120 is naturally guided along the inclined surface 320 toward the vent valve 500 of the outer plate 300. For example, batteries used in living environments such as vehicles V are not always located on flat surfaces, so by setting the inclined surface 320 of the outer plate 300, the gas discharged through the through hole 120 or leaked cooling medium can be guided to accumulate at the central point of the outer plate 300 where the vent valve 500 is located, thereby preventing or suppressing the problem of delayed discharge of gas or cooling medium from the vent valve 500.

[0090] Considering that the base plate 100 constitutes one side of the battery pack case, it may be made of a metal material, and in one embodiment, it may be made of aluminum, which is easy to mold, has excellent durability, and improves the ability to bond with surrounding panels and components.

[0091] In the case of the external plate 300, it is coupled to the outside of the battery pack case and exposed to the outside, so it is configured to ensure adequate rigidity. For example, the external plate 300 can be made of a highly rigid metal material, and in one embodiment, stainless steel may be used to provide high rigidity and prevent corrosion by the external environment.

[0092] Since the base plate 100 may be molded from a material with less rigidity than the outer plate 300, it can be molded thicker than the outer plate 300 to achieve balance. In this way, by varying the material and thickness of each plate, the overall weight, strength, and safety of the battery can be optimized.

[0093] A vent valve 500 is formed on the outer plate 300, and the vent valve 500 is also bonded to the outer surface of the outer plate 300 and exposed, so it is necessary to prevent damage to the vent valve 500. For this purpose, in the present invention, a vent valve 500 protection section 520 is installed on the outer plate 300, as shown in Figures 7 and 8. The vent valve 500 protection section 520 can be manufactured by forming the outer plate 300 at the location where the vent valve 500 is formed on the outer plate 300, along the outer circumferential surface of the vent valve 500, at a height higher than the vent valve 500. The vent valve 500 protection section 520 acts as a protective wall surrounding the vent valve 500 at a higher position than the vent valve 500, and therefore absorbs external impacts and prevents or suppresses the backflow of external foreign matter into the inside of the vent valve 500.

[0094] Therefore, by integrally molding the vent valve 500 protection part 520 with the outer plate 300, as shown in Figure 7, taking into consideration the location on the outer plate 300 where the vent valve 500 is mounted, the durability of the outer plate 300 and the vent valve 500 protection part 520 can be increased. In other embodiments, the vent valve 500 can also be protected not only by integral molding with the outer plate 300, but also by a device formed along the outer circumferential surface of the vent valve 500 and fastened to the outer plate 300.

[0095] Another means of protecting the vent valve 500 coupled to the outside of the outer plate 300 is a valve cover 540. The valve cover 540 is coupled and fixed to the outer plate 300, covering the entire surface of the vent valve 500 that is exposed to the outside, as shown in Figures 9 and 10. The valve cover 540 may be formed and coupled in the width direction of the outer plate 300, as shown in Figure 9, or it may be coupled in the length direction of the outer plate 300, as not shown.

[0096] The valve cover 540 may cover the vent valve 500 with both sides open in the longitudinal or widthwise direction of the outer plate 300. By molding the valve cover 540 so that both sides are open, the gas or cooling medium discharged through the vent valve 500 can be smoothly discharged to the outside, while the vent valve 500, which is exposed to the outside, can be effectively covered. Of course, as long as the gas or leaked cooling medium discharged through the vent valve 500 can be smoothly discharged to the outside, various forms of valve cover 540 can be considered, not only in the form with both sides open, but also in the form with all sides closed.

[0097] As shown in Figure 6 or Figure 10, the outer plate 300 is provided with a sealing portion 360 around its perimeter, and is connected to the base plate 100 by bolts 340 or the like, with the sealing portion 360 in between, thereby preventing the external propagation of gas or cooling medium, and at the same time blocking or suppressing the backflow of foreign matter from the outside.

[0098] On the other hand, Figure 11 shows a battery pack BP to which the battery pack case of the present invention is applied, and a state in which such a battery pack is installed in a vehicle V. The battery pack of the present invention can be applied to various industries other than vehicles V, one example being ESS (ELECTRIC ENERGY STORAGE SYSTEM).

[0099] According to the battery pack case and battery pack BP and vehicle V of the present invention, in the event of thermal runaway in a battery pack case with a cooling device installed inside, the gas generated by the thermal runaway or the cooling medium leaked due to damage to the cooling device can be effectively discharged to the outside through the vent valve 500, thereby preventing short circuits in the battery cells and heat transfer to adjacent battery cells.

[0100] Although specific embodiments of the present invention have been illustrated and described, it will be obvious to those ordinary in the art that the present invention can be improved and modified in various ways without departing from the technical spirit of the invention as provided by the following claims.

Claims

1. A base plate that forms one side of the battery pack case and has through holes formed therein that connect the internal space of the battery pack case to the outside; An outer plate disposed at a distance from the outer surface of the base plate, blocking the through-hole from being exposed to the outside, and forming a separation space between it and the base plate; and A vent valve provided on the external plate for selectively discharging fluid from the separated space; A battery pack case, including the battery pack case.

2. The outer plate has side walls formed around it and is connected to the base plate via the side walls, forming the separation space. The battery pack case according to claim 1, wherein the external plate is formed such that a portion corresponding to the through hole of the base plate protrudes outward toward the outside of the battery pack case.

3. The battery pack case according to claim 1, wherein the vent valve of the external plate is formed at a location corresponding to the through hole of the base plate.

4. The battery pack case according to claim 1, wherein the external plate is formed to be inclined outward from the point corresponding to the through hole, and the height of the separation space decreases outward from the point corresponding to the through hole.

5. The battery pack case according to claim 1, wherein the vent valve of the outer plate is provided at the location where the separation distance between the base plate and the outer plate is maximum.

6. The external plate has a vent valve protection portion formed therein. The battery pack case according to claim 1, wherein the vent valve protection portion is molded to be higher than the height of the vent valve at the location where the vent valve is formed, along the outer circumferential surface of the vent valve.

7. The battery pack case according to claim 6, wherein the vent valve protection portion is molded integrally with the outer plate.

8. The vent valve of the outer plate is covered by a valve cover, and the valve cover covers the vent valve on the outside of the outer plate. The battery pack case according to claim 1, wherein the valve cover is coupled to the outer plate in either the width direction or the length direction of the outer plate.

9. The base plate constitutes the bottom surface of the battery pack case, the battery pack case has a battery assembly built inside, and the through-holes in the base plate are formed at locations between the multiple battery assemblies built inside the battery pack case. A cooling channel is provided between the battery assembly built into the battery pack case and the base plate, and the through-hole in the base plate is formed at a position corresponding to the cooling port of the cooling channel or a cooling hose connected to the cooling port, so that a cooling medium leaking from the cooling port or the cooling hose flows into the through-hole by its own weight, as described in claim 1.

10. By forming a filter cover and a filter mesh in the through-hole of the base plate, foreign matter is prevented from flowing into the separation space. The battery pack case according to any one of claims 1 to 9, wherein the filter cover is installed in the portion of the through-hole facing the internal space of the battery pack case, and the filter mesh is formed in the portion of the through-hole facing the outside of the battery pack case.

11. A flange is formed on the inner circumferential surface of the through hole so as to protrude toward the inside of the through hole, and the filter cover is coupled to the flange. The flange is formed with a plurality of support portions that protrude toward the filter cover, The battery pack case according to claim 10, wherein the filter cover is seated on the support portion, thereby separating the filter cover from the flange, or the filter cover is fixed to the support portion, thereby connecting it to the base plate.

12. The battery pack case according to claim 11, wherein the filter cover is plate-shaped and seated inside the through-hole, the outer peripheral surface of the filter cover is separated from the inner peripheral surface of the through-hole, and the internal space of the battery pack case and the separated space are in communication through the separated gap.

13. The battery pack case according to claim 1, wherein the external plate has a sealing portion along its perimeter and is coupled to the base plate with the sealing portion in between.

14. A battery pack including the battery pack case described in claim 1.

15. A vehicle comprising the battery pack described in claim 14.

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