Battery module, battery pack, and vehicle including same

Abstract

Provided is a battery module capable of improving cooling performance of a battery cell by directly cooling the battery cell. The battery module of the present invention includes: a cell module assembly including multiple battery cells; a module case configured to support a lower portion and a side surface of the cell module assembly and to open an upper portion of the cell module assembly; and a top cooling cover assembly coupled to the module case to cover an upper portion of the cell module assembly to form a sealing structure, and cooling the battery cells downwards from above by an insulating oil direct-spray method.

Description

Battery modules, battery packs and vehicles including the same

[0001] The present invention relates to a battery module, a battery pack, and a vehicle including the same, and more particularly, to a battery module, a battery pack, and a vehicle including the same, having a structure in which a coolant for cooling the battery cells is directly applied to the battery cells by spraying. This application claims priority to Korean Patent Application No. 10-2023-0179773, filed on December 12, 2023, and all contents disclosed in the specification and drawings of that application are incorporated herein by reference.

[0002] Secondary batteries, which offer high applicability across product categories and possess electrical properties such as high energy density, are being used not only in portable devices but also in electric vehicles powered by electrical power sources. These batteries are attracting attention as an environmentally friendly and energy-efficient energy source, not only because they can dramatically reduce fossil fuel use, but also because they produce no byproducts from energy use.

[0003] Due to the need for high output and large capacity in medium- to large-sized devices such as automobiles, battery modules consisting of multiple battery cells electrically connected together, as well as medium- to large-sized battery packs comprising these modules, are used. In battery modules and battery packs, the importance of technologies that efficiently cool the heat generated by battery cells is growing as demand for battery capacity increases. Cooling of battery modules and battery packs is a critical factor in improving the performance of electric vehicles.

[0004] Conventional battery modules utilize either bottom cooling using a heat sink or side cooling using cooling tubes. These methods utilize water cooling, indirectly cooling the battery cells through the flow of coolant through the internal channels of the heat sink or cooling tubes.

[0005] In the case of battery modules that use indirect water cooling using coolant, there is a limit to their cooling performance because the coolant does not come into direct contact with the battery cells but rather comes into indirect contact through the module housing that accommodates the battery cells.

[0006] Furthermore, because bottom- or side-cooling methods require a long heat transfer path, there are limitations to improving cooling performance. Specifically, bottom-cooling methods require heat generated from the battery cells to be transferred to a heat sink on one side of the module housing for cooling, making it difficult to establish a heat transfer path to the other side. Consequently, the temperature difference between one end of the battery cell and the other can be exacerbated, leading to unsatisfactory overall cooling efficiency.

[0007] Furthermore, the cooling effect of battery cells located farther away from the coolant inlet decreases compared to those located closer to the coolant inlet. This is because the temperature of the coolant increases due to the heat transferred from the battery cells as it enters the inlet of the battery module, circulates, and then discharges. As a result, by the time the coolant discharges through the outlet of the battery module, the cooling effect of the battery cells has decreased. This also leads to the problem of temperature differences between battery cells inevitably existing depending on their location within the battery module.

[0008] If temperature fluctuations are not addressed, they can lead to safety and durability issues in battery modules. Poor cooling efficiency can accelerate battery cell deterioration, or prevent rapid response when thermal runaway occurs in some battery cells. This can lead to thermal runaway propagation and, in severe cases, fire or explosion of the battery module or battery pack containing it. This can lead to not only property damage but also safety concerns.

[0009] Recently, battery modules are being developed that incorporate potting resin into water-cooled modules to prevent thermal diffusion (TP). However, this increases weight and cost. It also results in a loss in manufacturing time.

[0010] To solve the problems of this indirect water cooling method, development of a battery module having a cooling structure in which the refrigerant for cooling is directly introduced into the module housing and can come into direct contact with the battery cells is required.

[0011] Battery modules with this direct cooling structure must be designed to prevent temperature variations between battery cells, depending on their location within the module. Furthermore, airtightness must be maintained to prevent coolant from leaking outside the module housing.

[0012] The problem to be solved by the present invention is to provide a battery module capable of improving the cooling performance of a battery cell by directly cooling the battery cell.

[0013] Another problem to be solved by the present invention is to provide a battery module in which the temperature difference between battery cells is reduced or eliminated depending on the location of the battery cells within the battery module.

[0014] Another problem that the present invention seeks to solve is to provide a battery pack and a vehicle including such a battery module.

[0015] The battery module of the present invention for solving the above-described problem comprises: a cell module assembly including a plurality of battery cells; a module case supporting the lower part and side surfaces of the cell module assembly and having an open upper part of the cell module assembly; and a top cooling cover assembly coupled to the module case to cover the upper part of the cell module assembly to form a sealed structure, and cooling the battery cells from top to bottom by directly injecting insulating oil.

[0016] The above module case may include a bottom plate on which the cell module assembly is mounted on an upper surface; and a module frame that fixes the cell module assembly mounted on the bottom plate.

[0017] The above top cooling cover assembly may include a plurality of cooling pipes.

[0018] Preferably, the top cooling cover assembly may include a top cover having an accommodation space on the inside and an open bottom; and a plurality of cooling pipes assembled in the accommodation space and having bottom surfaces exposed to the upper portion of the battery cell.

[0019] The top cover may include a plurality of inlet ports on one side and a plurality of pipe covers on the other side.

[0020] An O-ring may be interposed between the above inlet port and the assembly surface of the top cover.

[0021] The above pipe cover can be assembled by insert press fitting into the above top cover.

[0022] The cooling pipe is open at the center along the length so that the insulating oil can flow inside, and one end of the cooling pipe is connected to the inlet port and the other end of the cooling pipe can be closed by being assembled with the pipe cover.

[0023] The cooling pipes may extend in the longitudinal direction of the battery module along the rows in which the battery cells are arranged and may be spaced apart from each other along the width direction of the battery module.

[0024] A plurality of perforated holes for spraying the insulating oil may be formed in the above cooling pipe.

[0025] The above perforated holes are formed on the lower surface side of the cooling pipe and can be positioned in a zigzag manner along the length of the cooling pipe.

[0026] The battery module may further include a venting device capable of discharging internal air pressure to the outside.

[0027] The above venting device may be included in the top cover.

[0028] A gasket interposed between the above module frame and the bottom plate may further be included.

[0029] The module frame may be inserted into the rim of the bottom plate, and the gasket may be positioned between the inner surface of the rim of the bottom plate and the outer surface of the module frame.

[0030] An insulating sheet may further be included on the bottom plate.

[0031] An outlet port for circulation of the insulating oil may be provided in the module case.

[0032] The battery pack of the present invention includes one or more battery modules of the present invention.

[0033] The vehicle of the present invention comprises one or more battery modules of the present invention.

[0034] The above battery module can be supplied with insulating oil and hydraulic pressure from the oil pump of the above vehicle.

[0035] The above vehicle includes a vehicle cooling system, and insulating oil from the vehicle cooling system is supplied to the battery module, and the insulating oil cools battery cells within the battery module and is then discharged from the battery module, cooled in the vehicle cooling system, and then supplied to the battery module again to be circulated.

[0036] The vehicle according to the present invention may further include a pressure control valve for controlling the flow rate and hydraulic pressure of insulating oil supplied to the battery module.

[0037] According to one aspect of the present invention, direct cooling of battery cells is achieved through the injection of insulating oil. This method directly cools the battery cells, thereby increasing heat transfer efficiency compared to conventional water-cooled indirect cooling methods. Consequently, by directly cooling the battery cells, the cooling performance of the battery cells can be improved.

[0038] According to the present invention, since it does not utilize a method of circulating coolant within the battery module, there is no problem of the coolant temperature near the outlet of the battery module rising, thereby reducing the cooling effect of the battery cells. Furthermore, according to the present invention, each battery cell can be uniformly cooled regardless of its location within the battery module. This minimizes the temperature difference between the cells. Therefore, cooling efficiency can be further improved by minimizing the temperature difference between each battery cell.

[0039] According to the present invention, there is no need to apply potting resin to prevent TP. Therefore, there is no increase in the weight or cost of the battery module, and no loss in manufacturing time.

[0040] According to the present invention, it is possible to use insulating oil that is circulated through the vehicle cooling system of an automobile while maintaining airtightness so that the insulating oil does not leak.

[0041] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0042] FIG. 1 is a perspective view of a battery module according to one embodiment of the present invention.

[0043] Figure 2 is an exploded perspective view of a battery module according to one embodiment of the present invention.

[0044] FIG. 3 is an exploded perspective view of the top cooling cover assembly included in the battery module of FIG. 1.

[0045] Figure 4 is a top view of a battery cell array within a battery module.

[0046] Figure 5 is a bottom view of the cooling pipe.

[0047] Figure 6 is a cross-sectional view taken along line AA' of Figure 1.

[0048] Figure 7 is a drawing showing a method of spraying insulating oil inside a battery module.

[0049] Figure 8 is a schematic diagram of a battery pack according to one embodiment of the present invention.

[0050] Figure 9 is a schematic diagram of a vehicle according to one embodiment of the present invention.

[0051] Fig. 10 is a drawing for explaining an insulating oil circulation structure in a vehicle according to one embodiment of the present invention.

[0052] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, it should be noted that the terms and words used in this specification and claims should not be interpreted as limited to their typical or dictionary meanings, and should be interpreted with meanings and concepts that conform to the technical spirit of the present invention based on the principle that the inventor can appropriately define the concept of the term to best explain his or her own invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are only some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. Therefore, it should be understood that various equivalents and modified examples may exist as of the time of this application.

[0053] Fig. 1 is a perspective view of a battery module according to one embodiment of the present invention. Fig. 2 is an exploded perspective view of a battery module according to one embodiment of the present invention.

[0054] Referring to FIGS. 1 and 2, a battery module (10) according to one embodiment of the present invention may be a three-dimensional structure having a predetermined length, width, and height in the X-axis, Y-axis, and Z-axis directions, respectively. In addition, the battery module (10) includes a cell module assembly (100), a module case (200), and a top cooling cover assembly (300).

[0055] The battery module (10) may have an approximately rectangular parallelepiped appearance due to the combination of the module case (200) and the top cooling cover assembly (300). When the battery module (10) is mounted on an electric vehicle such as an EV or HEV, the mounting space is limited due to the vehicle components arranged at a high degree of integration. Therefore, it is preferable that the battery module (10) be formed into a rectangular parallelepiped structure so that it can be mounted in a narrow space such as between the driver's seat and the passenger seat.

[0056] In the battery module (10), the cell module assembly (100) includes a plurality of battery cells (110). The battery cell (110) refers to a secondary battery including an electrode assembly, an electrolyte, and a pouch case that accommodates the electrode assembly, and may be provided as a cylindrical secondary battery, a pouch-shaped secondary battery, or a square secondary battery. Hereinafter, in the present embodiment, the description will be limited to the cylindrical secondary battery as shown in FIG. 2. The battery cells (110) may be a plurality of cylindrical batteries that are arranged in rows and columns and stand upright. For example, the battery cell (110) may be a 4680-type battery cell. Here, 4680 represents a form factor. The first two numbers in the form factor represent the diameter of the secondary battery, and the remaining numbers represent the height of the secondary battery. The 4680 cell has higher efficiency and larger size than the existing 18650 or 21700 cells.

[0057] The module case (200) supports the lower and side surfaces of the cell module assembly (100), and the upper portion of the cell module assembly (100) is open. The module case (200) may be a single component.

[0058] As another example, the module case (200) may include a bottom plate (210) and a module frame (230). The bottom plate (210) may cover the lower surface of the cell module assembly (100). The bottom plate (210) may be formed as a roughly plate-shaped body having an area on which the cell module assembly (100) may be mounted. The cell module assembly (100) is mounted on the upper surface of the bottom plate (210). The bottom plate (210) may be made of a metal material or may be manufactured as a plastic injection molded product. For example, the bottom plate (210) may be formed of a plastic material (e.g., polycarbonate, etc.) having both insulating and flame retardant properties. When made of a metal material, or to provide further insulating properties, an insulating sheet (220) may be further included on the bottom plate (210). For example, the insulating sheet (220) may be a polycarbonate sheet. As another example, an insulating coating layer may be included on the upper surface of the bottom plate (210). The insulating coating layer may be formed by coating, applying, or attaching an insulating material selected from the group consisting of silicone resin, polyamide, and rubber. With this insulating coating layer configuration, the insulating coating effect can be maximized with a minimal amount of coating. In addition, since the insulating coating layer is applied to the upper surface of the bottom plate (210), the insulation between the battery cell (110) and the bottom plate (210) can be strengthened.

[0059] The module frame (230) secures the cell module assembly (100) mounted on the bottom plate (210). In the illustrated example, the module frame (230) is composed of a plurality of bar-type members including cylindrical curved sections on one or both sides to match the shape of the outer surface of the battery cells (110) that can be arranged along the row; however, the shape of the module frame (230) is not limited thereto and may vary.

[0060] The bottom plate (210) and the module frame (230) can be assembled with each other. The assembly can be accomplished by various methods, such as fitting, bolting, bonding, or welding. The module frame (230) can also be made of a metal material or manufactured as a plastic injection molding. For example, the bottom plate (210) can be formed of a plastic material (e.g., polycarbonate) that has both insulating and flame retardant properties. If the bottom plate (210) is made of a metal material, or to provide further insulation, an insulating coating layer may be included on the inner surface of the module frame (230). The insulating coating layer may be formed by coating, applying, or attaching an insulating material selected from the group consisting of silicone resin, polyamide, and rubber. With this insulating coating layer configuration, the insulating coating effect can be maximized with a minimal coating amount. In addition, since the insulating coating layer is applied to the inner surface of the module frame (230), the insulation between the battery cell (110) and the module frame (230) can be enhanced.

[0061] The battery module (10) of the present invention cools the battery cells (110) through direct injection of a coolant. The coolant may be coolant, but is preferably a liquid with insulating properties. In particular, it is an insulating oil. The battery module (10) of the present invention or a battery pack including the same may be installed in a vehicle such as an electric vehicle, and the insulating oil may be an oil similar to the vehicle's engine oil or gear oil.

[0062] Coolants used in existing battery modules lack insulating properties. Cracks in the flow path can occur due to seal failure or impact, leading to a risk of short circuits, fire, or explosion if coolant leaks into electrical components. Furthermore, vehicle coolants are a mixture of water and antifreeze, and their vaporization characteristics require periodic replacement. Insulating oils have high voltage resistance. According to the present invention, insulating oils can be used to prevent short circuits and safety issues caused by leakage. Because insulating oils do not vaporize, they can be used semi-permanently without replacement.

[0063] The present invention cools the battery cell (110) by directly injecting the coolant onto the battery cell (110). According to the present invention, in particular, the insulating oil can be injected from the top of the battery cell (110) in a downward direction using an oil-cooled direct cooling method. The top cooling cover assembly (300) included in the battery module (10) of the present invention refers to an assembly component for directly cooling the battery cell (110) by injecting the coolant from the top of the battery cell (110) in a downward direction.

[0064] The top cooling cover assembly (300) is coupled to the module case (200) to cover the upper portion of the cell module assembly (100) and form a sealed structure. In doing so, the battery cell (110) is cooled from top to bottom by direct injection of insulating oil.

[0065] FIG. 3 is an exploded perspective view of the top cooling cover assembly included in the battery module of FIG. 1.

[0066] Referring to FIG. 3, the basic unit of the top cooling cover assembly (300) is a plurality of cooling pipes (320). According to an embodiment of the present invention, the top cooling cover assembly (300) further includes a top cover (310). The cooling pipes (320) and the top cover (310) may be assembled as an integral part. Even without the top cover (310), a structure in which the plurality of cooling pipes (320) are positioned on the upper portion of the cell module assembly (100) may also be possible.

[0067] The top cover (310) has an internal storage space and is open at the bottom. This structure can contribute to reducing the weight of the battery module (10). It can also facilitate coupling with the module case (200).

[0068] For example, the top cover (310) may have a flat box lid shape including a rectangular surface (311) and four side walls (312a to 312d) extending downward from the surface (311). Since the inside is hollow, the weight of the battery module (10) can be reduced, and a cooling pipe (320) can be installed on the side walls (312a, 312c) facing each other.

[0069] The top cover (310) may be made of an insulating resin for electrical insulation. For example, the top cover (310) may be manufactured from a plastic injection molding. Such a top cover (310) not only offers the advantage of ensuring insulation from the battery cell (110), but also offers convenience in processing and reduces manufacturing time.

[0070] The cooling pipe (320) is assembled into the above-described receiving space and its bottom surface is exposed to the upper portion of the battery cell (110). The cooling pipe (320) is a structure in which insulating oil flows. The cooling pipe (320) has an open center (C) along its length so that insulating oil can flow inside. The cooling pipe (320) may be made of steel. Since it must withstand hydraulic pressure, it is preferable that the material of the cooling pipe (320) be a steel material with rigidity.

[0071] The cooling pipe (320) extends in the longitudinal direction of the battery module (10) along the rows in which the battery cells (110) are arranged and is spaced apart from each other along the width direction of the battery module (10).

[0072] Meanwhile, in this embodiment, the cooling pipe (320) has a circular cross-section, but a steel pipe with a square cross-section may also be used.

[0073] Figure 4 is a top view of a battery cell array within a battery module. Figure 5 is a bottom view of a cooling pipe.

[0074] Referring to FIGS. 4 and 5, a plurality of perforated holes (325) for spraying insulating oil are formed in the cooling pipe (320). The perforated holes (325) are formed on the bottom surface of the cooling pipe (320) and may be positioned in a zigzag manner along the length of the cooling pipe (320).

[0075] In Figures 4 and 5, the spraying pattern of the insulating oil is illustrated by arrows. The position, number, spacing, and spraying angle of the perforated holes (325) of the cooling pipe (320) can be adjusted so that there is no battery cell that is not touched by the insulating oil.

[0076] For example, the insulating oil spray shape by the perforation hole (325) can be configured to be a full cone pattern that can spray insulating oil in the angular space between two arrows drawn in one perforation hole (325). The full cone pattern can spray the entire circular surface, and the spray angle can be adjusted. Instead, the insulating oil spray shape by the perforation hole (325) can be configured to be a solid pattern that can spray in each direction of two arrows drawn in one perforation hole (325). The solid pattern can refer to a straight-line spray shape, and a spray angle of 2 degrees or less.

[0077] Referring again to FIG. 3, the top cover (310) may include a plurality of inlet ports (330) on one side and a plurality of pipe covers (340) on the other side. For example, the inlet ports (330) may be positioned on one side wall (312a) of the top cover (310) and the pipe covers (340) may be positioned on the other side wall (312c) of the top cover (310).

[0078] An inlet port (330) is provided in the top cover (310) and is connected to one end of a cooling pipe (320). The inlet port (330) is formed on one longitudinal side of the cooling pipe (320). An O-ring (350) may be interposed between the inlet port (330) and the assembly surface of the top cover (310) to prevent backflow of insulating oil due to high-pressure flow rate and to seal. The O-ring (350) is a waterproof component that prevents the insulating oil from leaking out of the battery module (10). The inlet port (330) may be inserted into the cooling pipe (320). The insulating oil flowing in from the inlet port (330) may flow within the center (C) of the cooling pipe (320).

[0079] A pipe cover (340) is applied to generate / maintain pressure within the tube. This allows for uniform cooling performance even at battery cell (110) locations relatively far from the inlet port (330). The pipe cover (340) may be assembled by insertion into the top cover (310).

[0080] A pipe cover (340) is formed on the other end of the cooling pipe (320) in the longitudinal direction. The pipe cover (340) may be a cylindrical plug with one end open. The other end of the cooling pipe (320) may be inserted into the pipe cover (340) and assembled. As a result, the other end of the cooling pipe (320) may be closed. In the present embodiment, the cooling pipe (320) is inserted into the pipe cover (340).

[0081] The assembly process is as follows. The top cover (310) is provided in a form in which the pipe cover (340) is inserted and assembled into the top cover (310). The cooling pipe (320) is inserted from one side of the top cover (310) and the end of the cooling pipe (320) is inserted into the pipe cover (340) located on the other side of the top cover (310). The assembly position of the cooling pipe (320) can be guided through the pipe cover (340) already located on the top cover (310). Then, an O-ring (350) is placed between the inlet port (330) and the assembly surface of the top cover (310) and the inlet port (330) is inserted into the remaining end of the cooling pipe (320) to complete the assembly. The above assembly process can be easily performed through the configuration in which the cooling pipe (320) is inserted into the pipe cover (340) and the inlet port (330) is inserted into the cooling pipe (320).

[0082] One end of the cooling pipe (320) is connected to an inlet port (330) located on one side wall (312a) of the top cover (310), and multiple stages of the cooling pipe (320) are assembled with a pipe cover (340) located on the other side wall (312c) of the top cover (310), so that the cooling pipe (320) is mounted on the side walls (312a, 312c). Insulating oil that flows into the inside of the cooling pipe (320) from one end of the cooling pipe (320) through the inlet port (330) can flow to the other end of the cooling pipe (320) that is closed by the pipe cover (340). While the insulating oil, which is a refrigerant, flows inside the cooling pipe (320), it can be sprayed toward the battery cell (110) located below the cooling pipe (320) through the perforated hole (325) formed in the cooling pipe (320).

[0083] The two ends of the cooling pipe (320) can be firmly supported through assembly with the top cover (310). Since the inlet port (330) and the pipe cover (340) are provided, even if movement of the battery module (10) occurs, the movement of the cooling pipe (320) within the battery module (10) is restricted in all directions, including up, down, left, right, forward, and backward, thereby preventing the movement. The cooling pipe (320), which may be made of steel, is heavier than other peripheral components, so even a small movement has a significant impact on the peripheral components. According to the present invention, the two ends of the cooling pipe (320) are firmly supported through assembly with the top cover (310), thereby providing structural integrity to the top cooling cover assembly (300) as an integrated component. Movement of the cooling pipe (320) within the battery module (10) is prevented, thereby ensuring the performance of the battery module (10) and enabling the battery module (10) to be used safely for a long time. In addition, the top cooling cover assembly (300), which is an integrated component, is easy to handle during assembly because it is one component, and it can be simply combined with the module case (200) to create a sealed structure, thereby increasing assembly efficiency and productivity.

[0084] The connection between the top cooling cover assembly (300) and the module case (200) can be achieved through various methods, such as fitting, bolting, bonding, or welding. If necessary, a waterproof component, such as a sealing strip, may be positioned on the assembly surface of the top cooling cover assembly (300) and the module case (200) to ensure waterproof performance, and the top cooling cover assembly (300) and the module case (200) may be assembled together.

[0085] Fig. 6 is a cross-sectional view taken along line AA' of Fig. 1. Fig. 7 is a drawing showing a method of spraying insulating oil inside a battery module.

[0086] Referring to FIGS. 2, 6, and 7 together, insulating oil (20) can be introduced (In in FIG. 7) from the outside of the battery module (10) through the inlet port (330). The insulating oil (20) flows inside the cooling pipe (320) and is sprayed toward the battery cell (110) through the perforated hole (325) as indicated by the arrow in FIG. 7. Since the sprayed insulating oil (20) flows from the top to the bottom of the battery cell (110), a gasket (240) for sealing the insulating oil (20) between the module frame (230) and the bottom plate (210) may be further included. The gasket (240) is a waterproof component that prevents the insulating oil (20) from leaking out of the battery module (10). More specifically, a module frame (230) may be inserted into the edge of the bottom plate (210), and a gasket (240) may be positioned between the inner surface of the edge of the bottom plate (210) and the outer surface of the module frame (230). The gasket (240) may be a band shape that follows the shape of the edge of the bottom plate (210).

[0087] The gasket (240) may be made of a material that exhibits a predetermined elasticity so that it can stably exert a desired sealing force by the pressure applied during bonding, and may be compressed or deformed in the vertical direction by the pressure. The gasket (240) may be made of a rubber material or the like, and may be made of EPDM material, for example.

[0088] In the case of a battery module having a direct cooling structure, it is necessary to maintain airtightness so that the refrigerant does not leak out of the module housing. According to the present invention, a waterproof structure can be implemented through an O-ring (350) and a gasket (240). In other words, an O-ring (350) and a gasket (240) can be inserted between parts requiring sealing and waterproof performance can be implemented through pressure. The O-ring (350) and the gasket (240) can have a sufficient thickness between the parts requiring sealing. Accordingly, when the parts requiring sealing are joined, pressure is generated to compress the O-ring (350) and gasket (240) interposed therebetween, so that the parts requiring sealing can be completely sealed. An excellent sealed waterproof structure can be implemented without a particularly complicated assembly and manufacturing process, without causing defects or increasing costs.

[0089] The battery module (10) is provided with a discharge port (250) for the circulation of insulating oil (20). Preferably, the discharge port (250) may be provided in the module case (200). The insulating oil (20) sprayed toward the battery cell (110) performs a cooling function by flowing in direct contact with the battery cell (110) from the top to the bottom of the battery cell (110), and then moves to the outside of the battery module (10) through the discharge port (250) (Out in FIG. 7).

[0090] In this way, the present invention applies an oil-cooled direct cooling method that has superior cooling heat transfer efficiency to water-cooled indirect cooling. The battery module (10) of the present invention can receive insulating oil (20) and hydraulic pressure from the oil pump of a vehicle equipped with the battery module (10). By spraying insulating oil (20) through the perforated holes (325) of the cooling pipe (320), each battery cell (110) can be uniformly and directly cooled.

[0091] Insulating oil (20) introduced at high pressure through the inlet port (330) is sprayed onto the battery cell (110) through the perforated hole (325) of the cooling pipe (320), thereby directly cooling the battery cell (110). Thus, the sprayed insulating oil (20) flows from the top to the bottom of the battery cell (110) and directly cools the entire battery cell (110). At the same time, since the cooling pipe (320) does not come into contact with the battery cell (110) like a conventional heat sink or cooling tube and the hydraulic pressure is maintained, it is possible to minimize the temperature difference by implementing an equal cooling performance between the battery cells (110) regardless of the location of the battery cell (110) within the battery module (10) or the distance from the inlet port (330).

[0092] Thereafter, the insulating oil (20) accumulated in the battery module (10) can be discharged and circulated through the discharge port (250). The insulating oil (20) discharged through the discharge port (250) can be re-cooled through the vehicle's cooling system, thereby repeating the cooling method described above.

[0093] When directly cooling the battery cells (110) with insulating oil (20), it is desirable to ensure that there are no parts where the insulating oil flow path is blocked and cooling becomes difficult. For example, it is desirable to leave a gap between the battery cells (110) so that the insulating oil (20) can flow along the space between the battery cells (110). Furthermore, a gap may also be left between the module frame (230) and the bottom plate (210) so that the insulating oil (20) can flow. An appropriate structure may be applied to the joint portion of the bottom plate (210) and the module frame (230) so that the module frame (230) can be floated with a gap on the bottom plate (210). In addition, a gasket (240) may be provided at the corresponding structural location as described above.

[0094] Meanwhile, referring back to FIGS. 1 to 3, the battery module (10) of the present invention may further include a venting device (360) for maintaining a constant internal pressure within the battery module (10). The venting device (360) may be a breather. The venting device (360) may discharge the internal air pressure within the battery module (10), which has increased due to insulating oil, to the outside. This allows the internal pressure within the battery module (10) to be maintained constant. This venting device (360) may further be included in the top cover (310).

[0095] According to the present invention, cooling efficiency is increased by directly injecting cooled insulating oil onto the battery cells (110) from above. Depending on the arrangement of the battery cells (110), perforated holes (325) may be formed in a zigzag pattern in the cooling pipes (320). By arranging the perforated holes (325) in a zigzag pattern rather than in a straight line, the maximum number of battery cells (110) can be directly cooled within a minimum volume. In addition, uniform cooling performance can be achieved among the battery cells (110).

[0096] Cooling pipes (320) are independently arranged along each row of battery cells (110). By arranging multiple cooling pipes independently rather than in a single assembly, flow loss within the pipe can be minimized and pressure-balanced injection can be achieved. The cooling pipes (320) extend along the length direction and are spaced apart from each other along the width direction.

[0097] Meanwhile, the insulating oil may contain additives to maximize cooling capacity. For example, it may be used by mixing microcapsules containing phase change material (hereinafter referred to as PCM). When using insulating oil containing PCM-containing microcapsules, in case of heat generation of the battery cell (110), the insulating oil first absorbs energy, and when heat generation continues, secondary energy absorption is possible through phase change of the PCM material. For example, if 288 KJ / kg of paraffin-based PCM material and a phase change temperature of 70°C are applied: Assuming 1 cell heat generation of 300 kJ, 1.1 kg of PCM in the module, 0.8 g / cm 3 Insulating oil containing the above-mentioned material can be applied. The insulating oil may also contain a substance having a fire-extinguishing function. Accordingly, even if a fire occurs within the battery module (10), the fire can be quickly extinguished using the above-mentioned fire-extinguishing substance.

[0098] As another example, insulating oil such as 3M Novec can be used. Such insulating oil has excellent insulating performance, allowing cooling through direct contact with the battery cell (110), and has a variety of boiling points, allowing phase change cooling to be applied.

[0099] By controlling the rate of inflow and discharge of insulating oil, the inside of the battery module (10) can be filled with insulating oil for immersion cooling, or cooling can be performed without filling it.

[0100] When the insulating oil is filled to a full capacity, unbalanced cooling can be prevented from occurring depending on the angle when the battery is in operation, such as when driving an electric vehicle on an incline. According to the present invention, cooling can be performed by flowing the insulating oil in a fully filled state inside the battery module (10).

[0101] According to the present invention, cooling can be performed by flowing insulating oil within the battery module (10) without it being fully charged. When used without being fully charged, cooling utilizing the phase change of the insulating oil is advantageous.

[0102] According to the present invention, there is no need to apply potting resin to prevent TP. Therefore, the weight and cost of the battery module (10) do not increase, and there is no loss in manufacturing time.

[0103] Meanwhile, a battery pack according to one embodiment of the present invention includes one or more battery modules (10) according to one embodiment of the present invention as described above. In addition, a vehicle according to one embodiment of the present invention includes a battery module (10) or battery pack according to one embodiment of the present invention as described above.

[0104] Figure 8 is a schematic diagram of a battery pack according to one embodiment of the present invention.

[0105] A battery pack (400) according to one embodiment of the present invention may include one or more battery modules (10) according to one embodiment of the present invention as described above. The battery pack (400) according to the present invention may further include components of a battery pack known at the time of filing of the present invention, such as a BMS, a current sensor, a fuse, etc. for integrated control of charging and discharging of one or more battery modules (10). The BMS estimates the states of battery cells (110) in the battery pack (400) and manages the battery pack (400) using the estimated state information. For example, it estimates and manages state information of the battery pack (400), such as the SOC (State Of Charge), SOH (State Of Health), maximum input / output power allowance, and output voltage of the battery pack (400). In addition, using this state information, charging or discharging of the battery pack (400) can be controlled, and further, a replacement time for the battery pack (400) can also be estimated. The BMS manages and monitors the status of the battery cell (110), such as voltage, current, and temperature, and maintains the battery pack (400) in an optimal state based on this. In other words, the BMS efficiently manages the battery pack (400) of an electric vehicle to ensure stable driving of the electric vehicle, predicts the time for battery pack (400) replacement, and detects abnormalities in the battery pack (400) in advance to control the vehicle to prevent car accidents.

[0106] The battery modules (10) can be arranged neatly in a pack case (410) in a nearly rectangular shape, and each battery module (10) is connected to secure the power required for driving the vehicle.

[0107] The pack case (410) is a container for fixing and storing battery modules (10) and is a rectangular box. In addition, this pack case (410) can be disposed at a predetermined location within the vehicle.

[0108] In addition, the battery pack (400) according to the present invention can be configured so that the module case (200) described above can directly function as a pack case. In this case, battery pack components such as a BMS, busbar, and relay may be included within the module case (200). In this case, it is also called a cell-to-pack because the battery cells (110) are directly housed within the pack case.

[0109] The battery pack (400) according to an embodiment of the present invention can be applied to various devices. Representative examples of such devices include electric bicycles, electric vehicles, and hybrid vehicles, but the present invention is not limited thereto. The battery pack (400) is suitable for use as a battery pack for electric vehicles. In addition, it can also be used as an energy source for an Energy Storage System (ESS). An ESS refers to a standalone system that stores power of several hundred kWH or more. An ESS is a core component of the renewable energy industry. Since renewable energy sources such as solar and wind power cannot produce power at a desired time, it is important to store the power and make it available for use when needed. The battery pack (400) according to an embodiment of the present invention can have an energy density and capacity suitable for use as an energy source for such an ESS.

[0110] Figure 9 is a schematic diagram of a vehicle according to one embodiment of the present invention.

[0111] A vehicle (500) according to one embodiment of the present invention may include one or more battery packs (400) according to one embodiment of the present invention or battery modules (10) according to one embodiment of the present invention. The vehicle (500) according to the present invention may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle (500) includes a four-wheeled vehicle and a two-wheeled vehicle. The vehicle (500) operates by receiving power from the battery pack (400) or the battery module (10) according to one embodiment of the present invention.

[0112] In addition to the battery pack (400) or battery module (10) according to an embodiment of the present invention, the automobile (500) may further include various other components included in the automobile, such as a body or a motor.

[0113] The battery pack (400) or battery module (10) may be installed at a predetermined location within the vehicle (500). The battery pack (400) or battery module (10) may be electrically connected to the motor of the vehicle (500) via an inverter. The battery pack (400) or battery module (10) may be used as an electric energy source to provide driving force to the motor of the vehicle (500) and drive the vehicle (500). In this case, the battery pack (400) or battery module (10) is configured to have a high nominal voltage of 100 V or more. The battery pack (400) or battery module (10) may be charged or discharged by the inverter according to the driving of the motor and / or the internal combustion engine. The battery pack (400) or battery module (10) may be charged by a regenerative charging device combined with a brake.

[0114] In this way, the battery pack (400) or battery module (10) equipped in the automobile (500) can provide the electric energy required for various operations of the automobile (500). In addition, since the battery pack (400) or battery module (10) has the various effects mentioned above, the automobile (500) including it can also have all of those effects.

[0115] Fig. 10 is a drawing for explaining an insulating oil circulation structure in a vehicle according to one embodiment of the present invention.

[0116] The battery module (10) or the battery pack (400) including the same can be cooled using the cooling insulating oil of the vehicle (500) in which it is mounted. The insulating oil is discharged to the outside of the battery module (10) through the discharge port (250), and the insulating oil circulated through the vehicle cooling system (510) is introduced back into the battery module (10) through the inlet port (330) in a circulation path. At this time, heat exchange / transfer of the insulating oil can be performed through the radiator of the vehicle cooling system (510).

[0117] In this way, when the battery module (10) or battery pack (400) of the present invention is installed in a vehicle (500) and used, the circulation path of the insulating oil is as follows. It includes a circulation structure of vehicle cooling system (510) → cooling of battery cell (110) inside battery module (10) → discharge outside battery module (10) → vehicle cooling system (510).

[0118] In this way, the automobile (500) includes a vehicle cooling system (510), and the insulating oil of the vehicle cooling system (510) is supplied to the battery module (10), and the insulating oil cools the battery cells (110) in the battery module (10), and then is discharged from the battery module (10), cooled in the vehicle cooling system (510), and then supplied to the battery module (10) again to be circulated.

[0119] During such a cooling cycle, a pressure control valve (520) may be applied before the insulating oil flows into the inlet port (330). The pressure control valve (520) may be an electronically controlled solenoid valve. By receiving a current reflecting monitoring values ​​according to the battery status and vehicle driving status, the flow rate and hydraulic pressure of the insulating oil flowing into the battery module (10) can be controlled. Depending on the operation of the pressure control valve (520), the insulating oil can flow in a uniform amount, and the flow of the insulating oil can be guided so that the flow rate of the insulating oil is maintained above a certain level.

[0120] To be more specific, the automobile (500) includes an ECU (Engine Control Unit) (530) that controls various electrical devices of the automobile (500). The ECU (530) can perform various controls such as braking, acceleration, steering, and charging. The ECU (530) can communicate with the BMS (420) of the battery module (10) or battery pack (400) using a CAN (Controller Area Network) communication protocol, etc.

[0121] When the BMS (420) checks the voltage, current, etc. of the battery cell (110) and transmits the obtained battery status information to the ECU (530), the ECU (530) can be configured to transmit a current reflecting the monitoring value according to the battery status and vehicle driving status to the pressure control valve (520). The pressure control valve (520) can receive the corresponding current and control the flow rate and hydraulic pressure of the insulating oil flowing into the battery module (10).

[0122] In this way, according to the present invention, it is possible to use insulating oil circulated through the vehicle cooling system (510) of an automobile (500) while maintaining airtightness so that the insulating oil does not leak.

[0123] The present invention has been described with reference to specific embodiments. However, those skilled in the art will clearly understand that various modifications can be implemented within the technical scope of the present invention. Therefore, the embodiments disclosed above should be considered illustrative rather than limiting. In other words, the true scope of the present invention is set forth in the claims, and all differences within the scope equivalent thereto should be construed as being encompassed by the present invention.

[0124] [Explanation of symbols]

[0125] 10: Battery module 100: Cell module assembly

[0126] 110: Battery cell 200: Module case

[0127] 210: Bottom plate 220: Insulating sheet

[0128] 230: Module frame 240: Gasket

[0129] 250: Exhaust port 300: Top cover cooling assembly

[0130] 310: Top cover 320: Cooling pipe

[0131] 330: Inlet port 340: Pipe cover

[0132] 350: O-ring 360: Venting device

[0133] 400: Battery pack 410: Pack case

[0134] 420: BMS 500: Automobile

[0135] 510: Vehicle cooling system 520: Pressure control valve

[0136] 530: ECU

Claims

1. A cell module assembly comprising a plurality of battery cells; A module case supporting the lower and side surfaces of the cell module assembly and having an upper portion of the cell module assembly open; and A battery module including a top cooling cover assembly that is coupled to the module case to cover the upper portion of the cell module assembly to form a sealed structure and cools the battery cell from top to bottom by directly injecting insulating oil.

2. In the first paragraph, the module case, A bottom plate on which the above cell module assembly is mounted on the upper surface; and A battery module characterized by including a module frame that secures the cell module assembly mounted on the bottom plate.

3. In the first paragraph, the top cooling cover assembly, A top cover having an inner storage space and an open bottom; and A battery module characterized by including a plurality of cooling pipes assembled in the above-mentioned receiving space and having a bottom surface exposed to the upper portion of the battery cell.

4. A battery module according to claim 3, characterized in that it includes a plurality of inlet ports on one side of the top cover and a plurality of pipe covers on the other side of the top cover.

5. A battery module according to claim 4, characterized in that an O-ring is interposed between the inlet port and the assembly surface of the top cover.

6. A battery module according to claim 4, characterized in that the pipe cover is inserted and assembled into the top cover.

7. In the fourth paragraph, the cooling pipe is characterized in that the center is open along the length so that the insulating oil can flow inside, one end of the cooling pipe is connected to the inlet port, and the other end of the cooling pipe is assembled with the pipe cover and closed. A battery module.

8. A battery module according to claim 7, characterized in that the cooling pipes extend in the longitudinal direction of the battery module along the rows in which the battery cells are arranged and are spaced apart from each other along the width direction of the battery module.

9. A battery module according to claim 7, characterized in that a plurality of perforated holes for spraying the insulating oil are formed in the cooling pipe.

10. A battery module according to claim 9, characterized in that the perforation holes are formed on the lower surface side of the cooling pipe and are positioned in a zigzag manner along the longitudinal direction of the cooling pipe.

11. A battery module according to claim 3, characterized in that the top cover further includes a venting device capable of discharging internal air pressure of the battery module to the outside.

12. A battery module according to claim 2, further comprising a gasket interposed between the module frame and the bottom plate.

13. A battery module according to claim 12, characterized in that the module frame is inserted into the edge of the bottom plate and the gasket is positioned between the inner surface of the edge of the bottom plate and the outer surface of the module frame.

14. A battery module according to claim 2, characterized in that it further includes an insulating sheet on the bottom plate.

15. A battery module according to claim 1, characterized in that a discharge port for circulation of the insulating oil is provided in the module case.

16. A battery pack comprising at least one battery module according to any one of claims 1 to 15.

17. A vehicle characterized by including at least one battery module according to any one of claims 1 to 15.

18. A vehicle according to claim 17, characterized in that the battery module receives insulating oil and hydraulic pressure from an oil pump of the vehicle.

19. In paragraph 18, the vehicle includes a vehicle cooling system, An automobile characterized in that the insulating oil of the vehicle cooling system is supplied to the battery module, the insulating oil cools the battery cells in the battery module, and then is discharged from the battery module, cooled in the vehicle cooling system, and then supplied to the battery module again and circulated.

20. An automobile characterized in that in claim 18, the automobile further comprises a pressure control valve for controlling the flow rate and hydraulic pressure of insulating oil supplied to the battery module.

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