Battery system and vehicle including same

Abstract

Disclosed are a battery system and a vehicle including same, the battery system comprising: a battery module; a pack case having the battery module installed therein; and resilient parts installed between the pack case and the battery module, pressing the battery module relative to the pack case, and the ends of which are supported by the pack case or the battery module through a cap made of a fire-resistant material.

Description

Battery system and vehicle including same

[0001] The present invention relates to a battery system with improved safety in an abnormal battery situation and a vehicle including the same.

[0002] Recently, technologies for carbon reduction are being actively developed to address environmental issues such as extreme temperatures. To achieve this, energy must be produced using environmentally friendly methods rather than relying on fossil fuels. This energy must be stored as electricity, and the stored electricity must be used in vehicles, various industrial sites, and homes.

[0003] To utilize electric energy for carbon reduction, the use of batteries capable of storing and extracting electric energy is essential. Therefore, ensuring battery performance is essential to sufficiently store electric energy and ensure hassle-free use.

[0004] Batteries primarily utilize redox reactions of metal ions. To increase battery capacity, charge / discharge performance, and efficiency, high-density metal ions are used. Extensive research is also being conducted on electrolyte components and solid electrolytes. However, as battery performance advances, stability generally declines.

[0005] Batteries used in vehicles, industrial applications, and homes are manufactured as physical units called packs. Battery packs contain multiple battery cells within a sealed case, preventing fire from spreading to the outside in the event of a battery overheating or other accident. They also protect the internal battery cells from deterioration caused by the external environment or physical damage.

[0006] Battery packs are comprised of multiple battery cells housed in an intermediate form called a module. A battery module is constructed by assembling multiple battery cells into a single module, which is then fastened within the pack case to complete the battery pack. Maintenance is facilitated by allowing maintenance to be performed on a module-by-module basis.

[0007] The multiple unit battery cells that make up a battery module are comprised of anodes, cathodes, and electrolytes. Because battery cells generate heat during charging and discharging, effective heat dissipation is essential. Furthermore, from the perspective of the battery module and battery pack, designing for efficient heat dissipation is essential to prevent safety accidents.

[0008] Meanwhile, batteries can deteriorate due to manufacturing errors, excessive charging and discharging, and aging. If battery deterioration persists, it can ultimately lead to fire. Therefore, proactive measures are necessary to prevent battery fires. To achieve this, it's crucial to continuously monitor the battery's condition, proactively detect and respond to problems, and minimize damage in the event of an unexpected problem.

[0009] In particular, when a flame occurs in a specific cell of a specific module among multiple battery modules within a battery pack, the flame must be prevented from spreading to other adjacent battery cells, and the flame must also be prevented from spreading to other adjacent modules. Therefore, from the perspective of the battery module, the gas venting of the defective battery cell must be smooth, while preventing or delaying the venting gas or flame from affecting other cells or modules as much as possible.

[0010] The matters described as background technology above are only intended to enhance understanding of the background of the present invention, and should not be taken as an admission that they correspond to prior art already known to those of ordinary skill in the art.

[0011] The present invention has been proposed to solve such problems, and aims to provide a battery system and a vehicle including the same, which can improve battery safety by preventing fire from spreading to adjacent cells or modules when a fire occurs in a specific battery cell or battery module, while also facilitating gas venting.

[0012] The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0013] In order to achieve the above object, the battery system according to the present invention comprises: a battery module; a pack case having the battery module installed therein; and an elastic member installed between the pack case and the battery module, pressurizing the battery module with respect to the pack case, and having an end supported on the pack case or the battery module through a cap made of a fire-resistant material.

[0014] In the battery system according to the present invention, a venting portion may be formed on the outer surface of the battery module facing the pack case, and the elastic portion may be positioned at a point avoiding the venting portion.

[0015] In the battery system according to the present invention, the elastic member is composed of a first cap, a second cap, and an elastic body, and the elastic body can be positioned between the first cap and the second cap.

[0016] In the battery system according to the present invention, the first cap of the elastic part can be in close contact with the inner surface of the pack case, and the second cap can be in close contact with the outer surface of the battery module.

[0017] In the battery system according to the present invention, the first cap or the second cap of the elastic part is attached to the inner surface of the pack case or the outer surface of the battery module with an adhesive, and the adhesive may be formed of a heat-resistant material.

[0018] In the battery system according to the present invention, the first cap of the elastic member is fixed in a state of being inserted into the second cap, so that the elastic member can be maintained in a compressed state between the first cap and the second cap.

[0019] In the battery system according to the present invention, the first cap of the elastic member is pulled out from the second cap by gas or flame generated in the battery module, and the elastic member can be stretched due to the pulling out of the first cap.

[0020] In the battery system according to the present invention, the first cap of the elastic member is pulled out from the second cap due to an increase in the temperature inside the pack case, and the elastic member can be stretched due to the pulling out of the first cap.

[0021] In the battery system according to the present invention, the first cap of the elastic member is fixedly inserted into the second cap, and the first cap can be separated from the second cap when the second cap expands due to high temperature.

[0022] In the battery system according to the present invention, the first cap of the elastic part is fixed by adhesive while being inserted into the second cap, and when the adhesive strength is lost due to high temperature, the first cap can be separated from the second cap.

[0023] In the battery system according to the present invention, a plurality of elastic members are provided between the pack case and the battery module, and the elasticity of the elastic members can increase as they get closer to the center of the pack case.

[0024] In the battery system according to the present invention, the elastic portion closer to the center of the pack case may have a greater elastic modulus or compression amount than the elastic portion further away from the center of the pack case.

[0025] In the battery system according to the present invention, a module cover may be combined with a battery module to cover one side of the battery module, and an elastic member may be provided between the pack case and the module cover.

[0026] In the battery system according to the present invention, the elastic member is placed at a point between the pack case and the module cover and can be fixed to the module cover.

[0027] In the battery system according to the present invention, one end of the elastic member may be fixed to the module cover and the other end may be spaced apart from the pack case.

[0028] In the battery system according to the present invention, the elastic member is stretched by gas, flame, or high temperature inside the pack case, and when the elastic member is stretched, both ends of the elastic member can be supported by the pack case and the module cover, respectively.

[0029] In the battery system according to the present invention, the pack case includes a case body with one side open and a pack lid that closes the case body, and the elastic part can be positioned between the pack lid and the battery module.

[0030] In the battery system according to the present invention, when gas, flame, or high temperature occurs inside the pack case, the gap between the pack lead and the battery module increases due to expansion of the pack lead, and the elastic part is extended as much as the gap between the pack lead and the battery module increases, and the battery module can be pressurized based on the pack lead.

[0031] The vehicle according to the present invention includes a battery system as described above.

[0032] According to the battery system of the present invention and the vehicle including the same, when a fire occurs in a specific battery cell or battery module, the spread of the fire to other adjacent cells or modules is prevented, and at the same time, in the case of a problematic battery cell or battery module, gas venting is facilitated, thereby improving the safety of the battery system and the upper system utilizing the same as a whole.

[0033] The effects that can be obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention belongs from the description below.

[0034] Figure 1 is a drawing showing a battery system according to one embodiment of the present invention.

[0035] Fig. 2 is a drawing showing an elastic part of the battery system illustrated in Fig. 1.

[0036] Figure 3 is a cross-sectional view showing a case where an elastic member is provided at the upper portion of the battery system of the present invention.

[0037] Fig. 4 is a cross-sectional view showing a case where an elastic member is provided on the side of the battery system of the present invention.

[0038] Fig. 5 is a drawing showing the elastic part illustrated in Fig. 2 in an extended state.

[0039] Fig. 6 is a drawing showing the elastic part illustrated in Fig. 3 in an extended state.

[0040] Fig. 7 is a drawing showing the elastic part illustrated in Fig. 4 in an extended state.

[0041] Figures 8 to 10 are drawings showing various embodiments of the elastic member of the present invention.

[0042] FIG. 11 is a drawing for explaining the difference in elasticity at each point in a battery system according to one embodiment of the present invention.

[0043] Figure 12 is a drawing showing a battery pack and a vehicle to which the battery system of the present invention is applied.

[0044] In describing the embodiments disclosed in this specification, detailed descriptions of related known technologies will be omitted if it is determined that such detailed descriptions may obscure the gist of the embodiments disclosed in this specification. In addition, the attached drawings are provided solely to facilitate understanding of the embodiments disclosed in this specification, and the technical concepts disclosed in this specification are not limited by the attached drawings, and should be understood to include all modifications, equivalents, and substitutes included within the spirit and technical scope of the present invention.

[0045] Terms that include ordinal numbers, such as "first," "second," etc., may be used to describe various components, but these components are not limited by these terms. These terms are used solely to distinguish one component from another. Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0046] In this specification, terms such as "include" or "have" are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, and should be understood as not excluding in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof. The suffixes "module" and "part" used for components in the following description are given or used interchangeably only for the convenience of writing the specification, and do not in themselves have distinct meanings or roles.

[0047] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0048] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Regardless of the drawing numbers, identical or similar components will be given the same reference numbers and redundant descriptions thereof will be omitted.

[0049] As shown in Fig. 1, the battery system comprises a battery module (300) formed by a plurality of battery cells, and a battery pack formed by a plurality of battery modules (300). The battery module (300) mentioned in the present invention refers to an assembly of a plurality of battery cells, and includes not only a case where a plurality of battery cells are stacked and built into a sealed, separate housing, but also various cases where a plurality of battery cells are assembled into a single unit assembly in the form of an assembly, such as a strap or frame.

[0050] Meanwhile, if thermal runaway occurs in some battery cells or battery modules (300) inside the battery pack, gas or flames emitted from the cells or modules (300) may spread to other adjacent cells or modules (300) inside the battery pack. In such a case, secondary damage due to fire in the entire battery pack or flame spread to the outside may occur very quickly due to flame or gas attack between adjacent battery cells or modules (300). Therefore, it is necessary to minimize and delay as much as possible the possibility of flame spread from a battery cell or battery module (300) where thermal runaway has occurred to adjacent battery cells or modules (300).

[0051] In the past, when thermal runaway occurred in some cells or modules (300) inside a battery pack, a large pressure was generated due to gas or flames emitted from the cells or modules (300), and due to this momentary high pressure, a phenomenon occurred in which the module cover (320) covering the module (300) was lifted, causing the gas or flames to spread to adjacent cells or modules (300), resulting in a problem in which the gas or flames spread rapidly inside the battery pack.

[0052] According to the present invention, in such cases, the venting of gas or flame of a cell in which a problem has occurred is smoothly performed without resistance, and at the same time, the module cover (320) stably pressurizes and covers the module (300) without being lifted, so that the gas or flame does not spread to adjacent cells or modules (300).

[0053] Specifically, a module cover (320) is attached to the battery module (300) of the present invention as shown in FIG. 1. The battery module (300) is composed of a plurality of battery cells, and the module cover (320) is attached to the top or side of the cells to protect the battery module (300) in the event of a fire in an adjacent module (300). In the illustrated embodiment, the module cover (320) is shown attached to the top of the module (300), but the module cover (320) is not necessarily limited thereto, and may be fixed to various points, such as the side or bottom of the module (300), to cover the cells forming the module (300).

[0054] Meanwhile, the module cover (320) may be formed of a fire-resistant material such as mica (a mica material) to protect the cells of the battery module (300) from gas or flame. By forming it with such a material, the module cover (320) blocks high-temperature external gas or flame from entering the module (300).

[0055] In addition, the module cover (320) must be configured to vent gas or flames in the event of thermal runaway of the battery cell. Accordingly, a venting portion (322) is formed in the module cover (320) as shown in FIG. 1. The venting portion (322) should normally cover the battery module (300) to prevent the inflow of external gas or flames, and in the event of thermal runaway of a cell located below it, only the venting portion (322) at the required point should be activated to allow the venting of gas or flames generated internally. To this end, the venting portion (322) is shaped such that only a portion is cut off, as shown in the drawing, so that it is opened to the outside only when necessary. In addition, various shapes of venting portions (322) may be applied as long as they satisfy the condition of performing the function of covering well in normal times and opening to high pressure only when necessary.

[0056] The venting portion (322) is separated from the module cover (320) when a battery cell located below the venting portion (322) experiences thermal runaway, thereby forming a venting hole, and allows gases and flames generated in the cell to be vented to the outside of the module (300) through the formed venting hole. In addition, since the propagation of flames to adjacent battery cells must be prevented simultaneously with venting in the venting hole, the module cover (320) must prevent the propagation of flames by providing good venting at the point where high pressure is applied and covering the cells well at the neighboring point. In other words, even if a high temperature and high pressure atmosphere is created inside the module cover (320), the module cover (320) must well pressurize the module (300).

[0057] In the past, to achieve this role, foam rope made of a material such as foam silicone was applied to pressurize the module cover (320) from the pack lid (140), but there was a problem that the foam rope was deformed thermally in a high temperature situation due to thermal runaway, thereby weakening the pressing force. In addition, due to the weakened pressing force of the foam rope, the module cover (320) was lifted, causing the spread of gas or flame to adjacent cells or modules (300), and increasing the risk of structural collapse inside the battery pack, so that the stability of the battery pack could not be sufficiently secured.

[0058] Accordingly, in the case of the present invention, pressurization is performed with a material having fire resistance rather than foam rope. In addition, the configuration performing the pressurization is supported by a cap made of a fire-resistant, insulating material when supporting the module cover (320) or the pack case (100). Through this, even when a flame occurs, the module cover (320) is continuously pressurized without a change in its elasticity, thereby preventing the spread of the flame, and further, pressurization is performed without damaging the existing venting effect. In addition, even if pressurization is performed with a metal material to ensure fire resistance, the risk of a short circuit between the module (300) and the pack case (100) can be reduced because the cap supporting it is made of an insulating material.

[0059] Specifically, the present invention provides a battery system including an elastic member (500) supported between a pack case (100) and a battery module (300), and wherein the elastic member (500) has an end supported by a cap made of a fire-resistant material.

[0060] The battery module (300) includes a module cover (320), and a venting portion (322) including a venting hole that can discharge gas or flame to the outside when a battery cell thermally overheats is provided on the outer surface of the battery module (300) facing the pack case (100), and the elastic portion (500) is arranged to avoid the venting portion (322) as shown in Fig. 1. Through this arrangement, gas or flame can be smoothly vented to the outside when a battery cell thermally overheats, and at the same time, flame spread to adjacent battery cells or modules (300) can be effectively prevented.

[0061] As shown in Fig. 5, the elastic member (500) is composed of a first cap (520), a second cap (560) and an elastic body (540) at both ends, and the elastic body (540) is positioned between the first cap (520) and the second cap (560). The first cap (520) and the second cap (560), which are at both ends of the elastic member (500), may be composed of a fire-resistant material because they must prevent the spread of gas or flame to adjacent cells or modules (300) when thermal runaway occurs inside a battery cell or battery module (300). In addition, the end caps must be made of mica or the like among fire-resistant materials because they must have insulating properties and be lightweight.

[0062] In the case of the elastic body (540) of the elastic part (500) that applies pressure, it must be resistant to high temperature and high pressure gas or flame, so a spring made of metal material, etc. can be considered. However, when using the elastic body (540) made of metal material, it is essential to secure insulation between the pack case (100) and the battery module (300), so the cap covering both ends of the elastic part (500) must have not only fire resistance but also insulation. Through the selection of the cap material, the elastic part (500) of the present invention transmits the necessary pressing force to the module (300) side while also securing insulation in a thermal runaway situation. Of course, the battery system of the present invention is not limited to the materials or shapes presented above.

[0063] The pack case (100) may be composed of a case body (120) and a pack lid (140) for assembly. The case body (120) may have an open top, an open bottom, or in some cases, an open side, and the pack lid (140) functions to close the open side of the case body (120). As shown in Fig. 1, the case body (120) forms an internal space with a bottom surface and side walls, and has an open top surface, through which a battery module (300) is mounted internally. In addition, the open top surface of the case body (120) is closed by the pack lid (140). In the event of thermal runaway of the battery module (300), the inside of the pack case (100) is formed as a high temperature and high pressure environment, so the pack lid (140) can easily undergo thermal deformation due to expansion when gas or flames are generated due to thermal runaway in the battery cell or battery module (300). Due to this expansion, a gap may be created between the expanded part and the module cover (320), and the pressing force for pressing the module cover (320) may be reduced, causing the module cover (320) to lift off.

[0064] The present invention is to minimize the risk of heat transfer by preventing the module cover (320) of the battery module (300) from being lifted even when the case body (120) or the pack lid (140) expands, while simultaneously facilitating the venting of gas.

[0065] In the case of the elastic member (500), it is installed between the pack case (100) and the battery module (300), and the first cap (520) of the elastic member (500) is fixed in a state inserted into the second cap (560) so that the elastic body (540) is maintained in a compressed state between the first cap (520) and the second cap (560). When thermal runaway occurs in a battery cell or battery module (300), the battery module (300) or module cover (320) is lifted due to high-pressure gas and high-temperature flame, and is easily exposed to the spread of gas or flame to adjacent cells or modules (300). As shown in Fig. 3, in order to prevent the battery module (300) or module cover (320) from being lifted even when thermal runaway occurs, the first cap (520) of the elastic part (500) may be provided in close contact with the lower end of the pack lid (140) and the second cap (560) may be provided in close contact with the upper end of the module cover (320). When the lower end of the pack lid (140) and the upper end of the module cover (320) are in close contact, they may be attached and fixed with an adhesive. In this case, the adhesive may be formed of a heat-resistant material that can withstand high temperature and high pressure environments caused by thermal runaway.

[0066] Meanwhile, as shown in Fig. 4, the first cap (520) and the second cap (560) of the elastic member (500) may also be positioned on the side of the battery system. In this case, the first cap (520) may be positioned in close contact with the side of the case body (120), and the second cap (560) may be positioned in close contact with the side of the battery module (300). When positioned in close contact with the side of the case body (120) or the battery module (300), the cap may be attached and fixed with an adhesive. In this case, the adhesive must be made of a heat-resistant material.

[0067] The elastic member (500) may be provided in close contact with the case body (120) or the pack lid (140) and the battery module (300) or the module cover (320). In this case, since the elastic member (500) is exposed to momentary high pressure or high temperature when thermal runaway occurs in the battery cell or battery module (300), it is important to fix the first cap (520) and the second cap (560) with a heat-resistant adhesive. Only by using a heat-resistant adhesive can the elastic member (500) be fixed without deformation of the adhesive even in high pressure or high temperature situations, and since the first cap (520) and the second cap (560) are made of a fire-resistant material, the elastic member (500) can also be fixed without deformation. Accordingly, even if thermal runaway occurs, the case body (120) or pack lid (140) and the battery module (300) or module cover (320) can be stably supported, thereby minimizing or temporally delaying the spread of gas or flame to adjacent cells or modules (300).

[0068] Meanwhile, since there is a possibility of misassembly when assembling the pack lid (140) and the case body (120) if the elastic part (500) is stretched even before assembly, it is preferable that the elastic part (500) be such that the first cap (520) and the second cap (560) are mutually assembled and the elastic body (540) is maintained in a compressed state between them during and after assembly. Accordingly, as shown in FIG. 2, the first cap (520) of the elastic part (500) is fixed in a state inserted into the second cap (560), and the elastic body (540) is maintained in a compressed state between the first cap (520) and the second cap (560).

[0069] However, in the case where a thermal runaway situation occurs, the elastic member (500) needs to have a configuration in which the first cap (520) and the second cap (560) can be separated and the elastic body (540) can be stretched, as shown in FIG. 5. Referring to FIG. 8, the first cap (520) and the elastic body (540) of the elastic member (500) can be inserted into the second cap (560) in a forced fit manner. In this case, the first cap (520) of the elastic member (500) is normally kept in a state of being fitted to the second cap (560), but is pulled out from the second cap (560) as the temperature inside the pack case (100) rises due to gas or flame generated from the battery cell or battery module (300), and the elastic body (540) is extended and operates due to the pulling out of the first cap (520).

[0070] Since the first cap (520) and the elastic body (540) of the elastic member (500) must be inserted into the inside of the second cap (560), the inner diameter of the second cap (560) has the same shape as the outer diameter of the first cap (520). Through this, the first cap (520) and the second cap (560) are mutually assembled in a forced fit format.

[0071] Fig. 9 is a drawing showing an elastic member (500) according to another embodiment of the present invention. In this case, a ring or protrusion (580) is formed between the first cap (520) and the second cap (560), and when the first cap (520) is inserted into the second cap (560), it can be compressed in a hooked and fixed form. In the case of compression in a hooked and fixed form, when the ring or protrusion (580) softens in a high pressure or high temperature situation due to thermal runaway, the first cap (520) is pulled out from the second cap (560), and the pull-out of the first cap (520) causes the elastic body (540) to extend and operate. In the case of this hook-and-loop fastening type, it can be manufactured by forming a ring or a protrusion (580) together on the inner surface when forming the second cap (560) or attaching a ring or a protrusion (580) to the inner surface of the second cap (560) or the outer surface of the first cap (520). There can be one or more rings or protrusions (580), and they can be arranged between the first cap (520) and the second cap (560) to increase the bonding strength. By fastening using this hook-and-loop fastening method, a mutual mechanical connection can be implemented without a separate adhesive.

[0072] In another embodiment of the present invention, as shown in FIG. 10, the outer surface of the first cap (520) and the inner surface of the second cap (560) may be fixed using an adhesive (590). In this case, the adhesive (590) causes the elastic body (540) to operate when the adhesive component melts due to high-temperature gas or flame. The adhesive (590) serves to fix both ends when the first cap (520) is inserted into the second cap (560), and when the adhesive strength of the adhesive (590) is lost in a high-pressure or high-temperature situation due to thermal runaway, the first cap (520) is separated from the second cap (560) and elongated. Therefore, the adhesive (590) must be made of a material that maintains adhesive strength at room temperature but has a reduced adhesive strength at high temperatures.

[0073] The first cap (520) and the second cap (560) are formed in the shape of a stopper with one side open, as shown in FIGS. 2 and 5. Specifically, the first cap (520) and the second cap (560) have a bottom surface that makes surface contact with the case body (120) or the pack lid (140) and the battery module (300) or the module cover (320), and have a side wall connected thereto, and the opposite side of the bottom surface is configured in an open shape, and the open sides are formed in a shape in which they face each other. Of course, the first cap (520) and the second cap (560) may be formed in various shapes as long as surface contact is possible, in addition to a circular shape as shown in FIG. 2. In addition, the first cap (520) and the second cap (560) may be made of a fire-resistant material because they must prevent the spread of gas or flame to adjacent cells or modules (300) when thermal runaway occurs inside the battery cell or battery module (300), and among the fire-resistant materials, they may be made of mica or the like because they must have insulating properties and be lightweight. Through the shape and surface contact method of the first cap (520) and the second cap (560), the assembly stability of the battery system of the present invention can be increased, and at the same time, the elasticity of the elastic part (500) can be increased when thermal runaway occurs, thereby minimizing or temporally delaying heat spread to adjacent cells or modules (300) when thermal runaway occurs.

[0074] The pack case (100) may be composed of a case body (120) and a pack lid (140) for assembly. In the case of a battery mounted on a vehicle, the performance against collision must be secured, and in the event of a fire inside, the fire must be prevented from spreading to the outside, so the pack case (100) may be formed of a metal material. In addition, among metals, the pack case may be formed of aluminum because it must have formability and be light in weight. In the case of a pack case (100) made of a metal material such as aluminum, thermal deformation due to expansion may occur in a high-pressure or high-temperature environment due to thermal runaway in some battery cells or battery modules (300), and the amount of expansion may vary depending on the location even within one pack case (100).

[0075] Referring to FIG. 11, in the case of the outer portion (B) away from the center of the pack case (100), the case body (120) is formed in a housing shape with the side and bottom surfaces integrally molded, and the pack lid (140) is also connected to the case body (120) in various ways such as welding, adhesion, mechanical fastening, etc., so that even if thermal runaway occurs, the amount of expansion is relatively small. On the other hand, in the case of the central portion (A) of the pack case (100), the case body (120) is formed in a wide surface shape in order to mount the battery module (300), and the pack lid (140) is not directly connected to the case body (120), so that when thermal runaway occurs, the amount of expansion becomes the point where the maximum occurs. That is, when thermal runaway occurs, the pack lid (140) expands more the closer it is to the center portion (A).

[0076] Considering that a plurality of elastic members (500) may be provided between the pack case (100) and the battery module (300) and that the expansion amount of the pack lid (140) may vary at each point, it is reasonable to arrange the plurality of elastic members (500) such that the elastic modulus or compression amount of the elastic body (540) is larger the closer they are to the central portion (A) of the pack lid (140). By arranging the elastic member (540) having a larger elastic modulus or compression amount the closer they are to the central portion (A) of the pack lid (140), the elastic force of the elastic member (500) increases the closer they are to the central portion (A) of the pack lid (140), and accordingly, the elastic members (500) inside the pack case (100) can operate in a balanced manner, thereby sufficiently securing the stability of the entire battery system. In this case, in the case where the lengths of the elastic bodies (540) of the elastic bodies (500) in the plurality of elastic parts (500) present inside the pack case (100) are the same, the elastic force can be adjusted by using materials with different elastic moduli, and in the case where the elastic moduli of the elastic bodies (540) are the same, the elastic force can be tuned differently by varying the lengths of the elastic bodies (540) to vary the amount of compression.

[0077] A module cover (320) is attached to the battery module (300) of the present invention. The module cover (320) covers one side of the battery module (300) to protect the battery module (300) and the battery cells located therein from gas or flame. An elastic member (500) may be provided between the pack case (100) and the module cover (320) to prevent the spread of gas or flame to adjacent cells or modules (300) in the event of thermal runaway in the battery cell or battery module (300). When high-pressure gas or high-temperature flame occurs at this location, the elastic part (500) is extended as shown in FIG. 6, and the first cap (520) or the second cap (560) of the elastic part (500) is supported by the pack case (100) or the module cover (320), respectively, thereby pressurizing the module cover (320) based on the pack case (100), thereby preventing gas or flame from entering the battery module (300).

[0078] In another embodiment, the elastic member (500) is disposed between the pack case (100) and the module cover (320), and one end of the elastic member (500) may be fixed only to the module cover (320). As described above, the amount of expansion due to thermal runaway inside the pack case (100) may vary depending on the location. In addition, the amount of expansion increases as it approaches the center (A) of the pack lid (140), so that the pack lid (140) expands in an arch shape as a result. Accordingly, when expanding, the center (A) of the pack lid (140) expands in a relatively horizontal plane, whereas points other than the center expand in a diagonally inclined plane. In such a case, if the elastic member (500) is attached to the pack case (100) as well as the module cover (320), when the pack case (100) expands due to thermal runaway, the elastic member (500) attached to the diagonally inclined surface of the pack case (100) may have unstable surface contact, and may not be able to sufficiently pressurize the battery module (300) or the module cover (320) with respect to the pack case (100). Therefore, the elastic member (500) may be provided so that one end is fixed to the module cover (320) and the other end is spaced apart from the pack case (100), and is fixed only to the module cover (320) side. Afterwards, when thermal runaway occurs in the battery cell or battery module (300), the elastic part (500) is stretched by the gas or flame inside the pack case (100), and when the elastic part (500) is stretched, both ends of the elastic part (500) are supported by the pack case (100) and the module cover (320), so that the module cover (320) can be sufficiently pressurized based on the pack case (100).

[0079] Meanwhile, the pack case (100) may include a case body (120) with one side open and a pack lid (140) that closes the open portion of the case body (120), and an elastic member (500) may be provided between the pack lid (140) and the battery module (300). When high-pressure gas or high-temperature flame is generated due to thermal runaway in the battery cell or battery module (300), the pack lid (140) expands, and as the pack lid (140) expands, the distance between the pack lid (140) and the battery module (300) also increases, and the elastic member (500) provided between the pack lid (140) and the battery module (300) may be extended by the distance between the pack lid (140) and the battery module (300) so that both ends may be supported by the pack lid (140) and the battery module (300), respectively. Accordingly, the elastic member (500) can pressurize the battery module (300) based on the pack lead (140) to prevent the propagation of gas or flame to adjacent battery cells or battery modules (300) and delay heat propagation in terms of time.

[0080] The battery system according to the present invention can be applied to battery systems of various vehicles, such as internal combustion engine vehicles, electric vehicles, hybrid vehicles, and fuel cell vehicles, and in addition to vehicles, it can be applied to battery systems in various fields, such as industrial ESS (Energy Storage System), household ESS, and small battery packs.

[0081] Although the present invention has been illustrated and described with respect to specific embodiments thereof, it will be apparent to those skilled in the art that the present invention may be variously improved and modified without departing from the technical spirit of the present invention as defined by the following claims.

Claims

1. Battery module; A pack case with the battery module installed inside; and A battery system comprising an elastic member installed between the pack case and the battery module, pressurizing the battery module with the pack case as a reference, and having an end supported on the pack case or the battery module through a cap made of a fire-resistant material.

2. In claim 1, A battery system characterized in that a venting portion is formed on the outer surface of the battery module facing the pack case, and the elastic portion is positioned at a point that avoids the venting portion.

3. In claim 1, A battery system characterized in that the elastic member is composed of a first cap, a second cap, and an elastic body, and the elastic body is positioned between the first cap and the second cap.

4. In claim 3, A battery system characterized in that the first cap of the elastic part is in close contact with the inner surface of the pack case, and the second cap is in close contact with the outer surface of the battery module.

5. In claim 3, A battery system characterized in that the first cap or the second cap of the elastic part is attached to the inner surface of the pack case or the outer surface of the battery module with an adhesive, and the adhesive is formed of a heat-resistant material.

6. In claim 3, The first cap of the elastic part is fixed in a state of being inserted into the second cap, so that the elastic body is maintained in a compressed state between the first cap and the second cap, A battery system characterized in that the first cap of the elastic part is pulled out from the second cap due to gas or flame generated from the battery module or an increase in the internal temperature of the pack case, and the elastic body is stretched due to the pulling out of the first cap.

7. In claim 6, A battery system characterized in that the first cap of the elastic member is fixedly inserted into the second cap, and the first cap is separated from the second cap when the second cap expands due to high temperature.

8. In claim 6, A battery system characterized in that the first cap of the elastic part is fixed by adhesive while being inserted into the second cap, and the first cap is separated from the second cap when the adhesive strength is lost due to high temperature.

9. In claim 1, The elastic member is provided in multiple numbers between the pack case and the battery module, and the elasticity of the elastic member increases as it gets closer to the center of the pack case. A battery system characterized in that the elastic portion closer to the center of the pack case has a greater elastic modulus or compression amount than the elastic portion further away from the center of the pack case.

10. In claim 1, The above battery module is coupled with a module cover to cover one side of the battery module, and the elastic part is provided between the pack case and the module cover. A battery system characterized in that the elastic member is positioned between the pack case and the module cover and is fixed to the module cover.

11. In claim 10, A battery system characterized in that one end of the elastic member is fixed to the module cover and the other end is spaced apart from the pack case.

12. In claim 10, A battery system characterized in that the elastic member is stretched by gas, flame, or high temperature inside the pack case, and when the elastic member is stretched, both ends of the elastic member are supported by the pack case and the module cover, respectively.

13. In claim 1, A battery system characterized in that the pack case includes a case body with one side open and a pack lid that closes the case body, and the elastic part is located between the pack lid and the battery module.

14. In claim 13, A battery system characterized in that when gas or flame or high temperature occurs inside the pack case, the gap between the pack lead and the battery module increases due to expansion of the pack lead, and the elastic part expands as much as the gap between the pack lead and the battery module increases and pressurizes the battery module based on the pack lead.

15. A vehicle characterized by including the battery system of claim 1.

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