THE BATTERY PACKAGE INCLUDES THIS BATTERY PACK AND THE BATTERY HOUSING.

Abstract

The invention relates to a battery pack, a vehicle comprising such a battery pack, and a battery pack enclosure. A battery pack, according to one design of the invention, comprises: an enclosure creating the internal space and containing the battery pack cover; battery cells arranged within the enclosure; partitions dividing the internal space of the enclosure; and melting bolts fastening the battery pack cover and partitions. The melting bolts are constructed to melt at a predetermined temperature.

Description

battery pack

[0001] The present invention relates to a battery pack.

[0002] This application claims priority to Korean Patent Application No. 10-2024-0050779, filed April 16, 2024, and Korean Patent Application No. 10-2025-0004843, filed January 13, 2025, the entire contents of which are disclosed in the specification and drawings of those applications are incorporated herein by reference.

[0003] Recently, secondary batteries that can be repeatedly charged and discharged are widely used for powering or storing energy in not only small portable electronic devices such as smartphones, tablet PCs, and smart watches, but also medium and large devices such as electric vehicles (EVs) and energy storage systems (ESS), and active research is being conducted on them.

[0004] Currently commercialized secondary batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium secondary batteries. Among these, lithium secondary batteries are receiving attention for their advantages of being able to charge and discharge freely, having a very low self-discharge rate, and having a high energy density, as they have almost no memory effect compared to nickel-based secondary batteries.

[0005] These lithium secondary batteries primarily use lithium oxide and carbon materials as the positive and negative electrode active materials, respectively. Lithium secondary batteries comprise an electrode assembly comprising positive and negative plates coated with the positive and negative electrode active materials, respectively, with a separator interposed between them, and an outer case, i.e., a battery case, that seals and encloses the electrode assembly together with an electrolyte.

[0006] In general, lithium secondary batteries can be classified into can-type secondary batteries in which the electrode assembly is built into a metal can and pouch-type secondary batteries in which the electrode assembly is built into a pouch of an aluminum laminate sheet, depending on the shape of the outer packaging material.

[0007] Recently, secondary batteries are widely used for power and energy storage not only in small devices such as portable electronic devices but also in medium- to large-sized devices such as electric vehicles and energy storage systems (ESS). Multiple secondary batteries can be electrically connected and housed within a module case to form a single battery module. Each secondary battery within a battery module can be referred to as a battery cell. Furthermore, multiple such battery modules can be connected to form a single battery pack.

[0008] As secondary batteries in the form of battery modules and battery packs with multiple battery cells connected in this way begin to be widely used, fire and explosion accidents are occurring, and battery safety issues are emerging as an increasingly important issue.

[0009] However, when a battery pack contains multiple battery modules, each of which contains multiple battery cells, it may be vulnerable to a thermal chain reaction between battery modules or between battery cells. For example, if an event such as thermal runaway occurs within a single battery module, the propagation of this thermal runaway to other battery modules or cells must be prevented. If the propagation of thermal runaway between battery modules or cells is not properly prevented, an event occurring in a specific battery module or battery cell may trigger a chain reaction of thermal reactions in other battery modules or cells, potentially causing an explosion or fire, or potentially increasing its scale.

[0010] For example, if an event such as thermal runaway occurs in a single battery module, gas or flames may be randomly emitted to the outside. If the emission of gas or flames is not properly controlled, the gas or flames may be emitted toward other battery modules, potentially causing a thermal chain reaction in the other battery modules. In particular, the front side of the battery module may have module terminals, which may be electrically connected to other battery modules or battery packs, such as module bus bars. Therefore, if flames are emitted toward the front side of the battery module, the module terminals may be damaged within the battery pack, causing an electrical short. Furthermore, since other battery modules may be present at the front side of the battery module, if flames are emitted toward the front side of a specific battery module, the emitted flames may easily spread to other battery modules, potentially causing a fire to spread between battery modules.

[0011] Failure to properly control thermal transfer between battery modules or battery cells can lead to a sudden voltage drop in the battery module or battery pack. This can lead to a sudden shutdown of the device equipped with the battery module or battery pack, resulting in unexpected damage. For example, if a voltage drop in a battery pack occurs suddenly while an electric vehicle is in operation, there is no time to move the vehicle to a safe location.

[0012] Moreover, if thermal propagation between battery modules or cells fails to be properly controlled, resulting in a sudden fire or explosion, there is a high possibility of causing casualties. For example, if thermal runaway occurs in an electric vehicle, if a certain amount of time is not allowed for a full-blown fire to develop, occupants may not be able to escape safely.

[0013] The present invention provides a battery pack having an improved structure so as to appropriately control the emission of flames and the like generated inside a battery module, and a vehicle including the same.

[0014] In addition, the present invention provides a structure that facilitates expansion of the internal space of a battery pack when a thermal event occurs inside a battery module.

[0015] In addition, the present invention may provide a structure in which a pack cover can easily swell when a thermal event occurs inside a battery module.

[0016] Additionally, the present invention provides a structure in which the sealing of a battery pack is maintained when a thermal event occurs inside a battery module.

[0017] However, the technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0018] A battery pack according to one embodiment of the present invention comprises: a case providing an internal space and having a pack cover; battery cells positioned inside the case; a partition wall partitioning the internal space of the case; and a melting bolt connecting the pack cover and the partition wall, wherein the melting bolt is configured to melt at a specific temperature.

[0019] The melting bolt may be configured to melt when a thermal event occurs in the battery cell.

[0020] The above melting bolt may include a plastic material.

[0021] The battery pack further includes a nut positioned between the pack cover and the partition wall, and the melting bolt can pass through the pack cover and the nut and be inserted at least partially into the partition wall.

[0022] The above nut can be coupled to the inner surface of the pack cover.

[0023] The melting bolt comprises: a first part passing through the pack cover and the nut; and a second part extending from the first part and inserted into the partition wall, wherein the first part can be formed longer than the second part.

[0024] The above melting bolt may be configured such that the first part and the second part are separated when a thermal event occurs.

[0025] The above partition wall has an insertion hole into which the melting bolt is inserted, and the sum of the thickness of the pack cover and the thickness of the nut can be formed to be longer than the depth of the insertion hole.

[0026] The above melting bolts are provided in plurality, and the plurality of melting bolts can be arranged along the longitudinal direction of the partition wall.

[0027] The battery pack is installed inside the case and further includes a module case that accommodates the battery cell, and the module case may have a venting hole facing the pack cover.

[0028] A vehicle according to one aspect of the present invention comprises a battery pack of the present invention.

[0029] According to one embodiment of the present invention, a battery pack case comprises: a flat base plate; a side wall installed along the periphery of the base plate on an upper surface of the base plate; a flat pack cover coupled to an upper surface of the side wall to form an internal space together with the base plate; a partition wall installed on an upper surface of the base plate to partition the internal space; and a melting bolt that fastens the pack cover and the partition wall, wherein the melting bolt is configured to melt at a specific temperature.

[0030] The above melting bolt is configured to melt when a thermal event occurs in the battery cell.

[0031] The above melting bolt comprises a plastic material.

[0032] The battery pack case further includes a nut positioned between the pack cover and the partition wall, and the melting bolt passes through the pack cover and the nut and is at least partially inserted into the partition wall.

[0033] The melting bolt comprises a first part passing through the pack cover and the nut; and a second part extending from the first part and inserted into the partition wall, wherein the first part is formed longer than the second part.

[0034] The melting bolt is configured to separate the first part and the second part when a thermal event occurs in the battery cell.

[0035] A battery pack according to one aspect of the present invention includes the pack case.

[0036] According to at least one of the embodiments of the present invention, when gas or flame is generated inside a battery module, the discharge of such gas or flame can be appropriately controlled.

[0037] According to at least one of the embodiments of the present invention, the electrical safety of a battery pack can be improved.

[0038] According to at least one of the embodiments of the present invention, the sealing of the battery pack can be maintained even if a thermal event occurs inside the battery module.

[0039] According to at least one of the embodiments of the present invention, an explosion of the battery pack can be prevented or suppressed by expanding the internal space of the battery pack when a thermal event occurs inside the battery module.

[0040] 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.

[0041] FIG. 1 is a drawing showing a battery pack according to one embodiment of the present invention.

[0042] Figure 2 is a diagram showing a partial configuration of the battery pack of Figure 1.

[0043] Figure 3 is a diagram showing a partial configuration of the battery pack of Figure 2.

[0044] Figure 4 is a drawing showing the battery module of Figure 3.

[0045] Figure 5 is a diagram showing a partial configuration of the battery module of Figure 4.

[0046] Fig. 6 is a drawing showing a cross-sectional configuration along the cutting line C-C' of Fig. 2.

[0047] Fig. 7 is a drawing showing a cross-sectional configuration along the cutting line A-A' of Fig. 1.

[0048] Fig. 8 is a drawing showing a cross-sectional configuration along the cutting line A-A' of Fig. 1 when a thermal event occurs.

[0049] Fig. 9 is a drawing showing a cross-sectional configuration along the cutting line A-A' of Fig. 1 when a thermal event occurs.

[0050] Fig. 10 is a drawing showing a cross-sectional configuration along the cutting line B-B' of Fig. 1 when a thermal event occurs.

[0051] FIG. 11 is a perspective view illustrating an electric vehicle including a battery pack according to one embodiment of the present invention.

[0052] In some of the accompanying drawings, corresponding components are designated by the same reference numerals. Those skilled in the art will appreciate that the drawings illustrate elements simply and clearly and are not necessarily drawn to scale. For example, to facilitate understanding of various embodiments, the dimensions of some elements depicted in the drawings may be exaggerated relative to other elements. Furthermore, elements of known technology that are useful or essential in commercially feasible embodiments may often not be depicted so as not to obscure the spirit of various embodiments of the present invention.

[0053] Hereinafter, embodiments of the present invention will be described 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 construed as limited to their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concepts of terms to best explain his or her invention, they should be interpreted in a way that conforms to the technical spirit of the present invention.

[0054] Therefore, it should be understood that the embodiments described in this specification and the configurations illustrated in the drawings are only the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention, and that there may be various equivalents and modified examples that can replace them.

[0055] FIG. 1 is a drawing showing a battery pack (10) according to one embodiment of the present invention. FIG. 2 is a drawing showing a partial separation of the battery pack (10) of FIG. 1. FIG. 3 is a drawing showing a partial separation of the battery pack (10) of FIG. 2.

[0056] Referring to FIGS. 1 to 3, a battery pack (10) according to an embodiment of the present invention may include a pack case (100), a battery module (200), a partition wall (300), and a melting bolt (400).

[0057] A pack case (100) of a battery pack (10) may include a base plate (110), a side wall (120), and a pack cover (150). The base plate (110) may have a square shape. The base plate (110) may have a flat shape. The base plate (110) may form the exterior of the battery pack (10). The base plate (110) may provide an internal space of the battery pack (10).

[0058] The side wall (120) may be installed, fastened, joined, fixed, or attached to the upper surface of the base plate (110). According to one embodiment, the side wall (120) may be composed of four. The side wall (120) may be arranged along the perimeter of the base plate (110). The side wall (120) may form the exterior of the battery pack (10). The side wall (120) may provide an internal space.

[0059] The pack cover (150) may have a square plate shape. In one embodiment, the pack cover (150) may have a flat plate shape. The pack cover (150) may form the exterior of the battery pack (10). The pack cover (150) may cover the internal space of the battery pack (10).

[0060] The battery module (200) may refer to a secondary battery module. For example, the battery module (200) may be a pouch-type secondary battery. However, the shape of the battery module (200) is not limited to a pouch shape, and may have various shapes, such as a cylindrical shape or a rectangular parallelepiped shape. The battery module (200) may be provided in multiple numbers.

[0061] The partition wall (300) may include a first partition wall (310) and a second partition wall (320). The partition wall (300) may be provided in multiple numbers. The partition wall (300) may be installed, fastened, fixed, combined, or attached to the upper surface of the base plate (110) of the pack case (100). The partition wall (300) may partition the internal space of the battery pack (10). A battery module (200) may be positioned in the space partitioned by the partition wall (300). The partition wall (300) may be configured as a separate structure, or, for example, may be configured as an integral part with a portion of the pack case (100). According to one embodiment, the partition wall (300) may be configured as an integral part with the base plate (110) of the pack case (100).

[0062] The melting bolt (400) can fasten, join, install or secure the pack cover (150) and partition wall (300) of the pack case (100). According to one embodiment, the melting bolt (400) can include a material that melts at low temperatures.

[0063] According to this configuration of the present invention, the thermal safety of the battery pack (10) can be improved. When a thermal event occurs from the battery module (200), venting gas can be discharged. This can cause the pressure inside the battery pack (10) to rapidly increase. At this time, the melting bolt (400) can melt due to the temperature of the venting gas. This can cause the pack cover (150) and the partition wall (300) to separate. In addition, as the pack cover (150) swells outward, the space inside the battery pack (10) can be expanded. This can prevent an explosion of the battery pack (10).

[0064] Referring to FIGS. 1 to 3, a plurality of melting bolts (400) of a battery pack (10) according to an embodiment of the present invention may be provided. The plurality of melting bolts (400) may be arranged along the longitudinal direction of a partition wall (300). A first partition wall (310) of the partition wall (300) may extend along the left-right direction or the Y-axis direction. A second partition wall (320) of the partition wall (300) may extend along the front-back direction or the X-axis direction. The plurality of melting bolts (400) may be arranged along the longitudinal direction of the first partition wall (310) of the partition wall (300) or the longitudinal direction of the second partition wall (320) of the partition wall (300).

[0065] According to this configuration of the present invention, the thermal safety of the battery pack (10) can be improved. By combining a plurality of melting bolts (400) along the partition wall (300), the pack cover (150) can be stably combined. In addition, when a thermal event occurs in the battery module (200), the pack cover (150) can be inflated as a whole.

[0066] Referring to FIGS. 1 to 3, a battery pack (10) according to an embodiment of the present invention may include a venting device (500). According to one embodiment, the venting device (500) may be installed on a side wall (120) of a pack case (100). For example, the venting device (500) may be installed on a front side wall (120) of the pack case (100). For example, the venting device (500) may be a gas valve, and may be selectively switched between an open state and a closed state. When the pressure inside the pack case (100) increases, the venting device (500) may be switched to an open state to discharge gas. In addition, the venting device (500) may be switched to a closed state to block external air from flowing into the pack case (100). A plurality of venting devices (500) may be provided.

[0067] According to this configuration of the present invention, the thermal safety of the battery pack (10) can be improved. When a thermal event occurs from the battery module (200), the pressure inside the battery pack (10) can rapidly increase. At this time, the venting device (500) discharges the venting gas to the outside, and the pack cover (150) swells outward, thereby preventing or suppressing an explosion of the battery pack (10).

[0068] Fig. 4 is a drawing showing the battery module (200) of Fig. 3. Fig. 5 is a drawing showing a partial configuration of the battery module (200) of Fig. 4.

[0069] Referring to FIGS. 1 to 5, a battery pack (10) according to an embodiment of the present invention may include a plurality of battery modules (200). The battery module (200) may include a module case (210), a plurality of battery cells (220), a module pad (250), a busbar frame assembly (230), and an end cover (240).

[0070] The module case (210) may have a rectangular parallelepiped shape. The module case (210) may also be referred to as a frame (210). The module case (210) may provide a space therein. The module case (210) may include a top plate, a bottom plate, and a pair of side plates. In addition, the module case (210) may have an open front and back. The module case (210) may include a venting hole (211) in the top plate. The venting hole (211) may connect the inside and the outside of the module case (210).

[0071] A battery cell (220) may be accommodated inside a module case (210). A plurality of battery cells (220) may be stacked in the left-right direction or the Y-axis direction. The battery cell (220) may include a receiving portion (221) having an electrode assembly, a first sealing portion (222) protruding toward the front and rear sides of the receiving portion (221), and a second sealing portion (223) protruding toward the upper side of the receiving portion (221). In addition, the battery cell (220) may include an electrode lead (224) protruding toward the front and rear sides of the first sealing portion (222), respectively. Each battery cell (220) may extend along the front-back direction or the X-axis direction. The electrode lead (121) may protrude toward the front and rear of each battery cell (220).

[0072] The module pad (250) may be placed between a plurality of battery cells (220). The module pad (250) may be placed between at least some of the battery cells (220) and / or on the periphery of the stack. For example, the module pad (250) may be configured to be placed between adjacent battery cells (220) in four battery cells (220) stacked left and right.

[0073] These module pads (250) may be provided with an elastic material to enable swelling absorption of the battery cells (220). For example, the module pads (250) may be composed of a foam material such as polyurethane. Alternatively, the module pads (250) may be provided with a material capable of blocking heat or flames. For example, the module pads (250) may be provided with an insulating or fire-retardant material such as silicone or mica.

[0074] A busbar frame assembly (230) may be provided at the front and rear of each of the plurality of battery cells (220). The busbar frame assembly (230) may be electrically connected to the electrode leads (121) of the plurality of battery cells (220).

[0075] A pair of end covers (240) can be respectively coupled to the front and rear of the module case (210). A pair of end covers (240) can cover the front and rear of the module case (210). The end covers (240) can have a square shape.

[0076] The battery module (200) can be installed, fastened, combined, fixed or attached to the upper surface of the base plate (110) of the pack case (100). When a thermal event occurs from the battery module (200), venting gas (g) can be discharged through a venting hole (211) formed in the top plate of the module case (210). The venting hole (211) can face the inner surface of the pack cover (150) of the pack case (100). The venting gas (g) discharged through the venting hole (211) of the module case (210) can push the pack cover (150) of the pack case (100) outward, upward or in the Z-axis direction.

[0077] The battery module (200) may be located in a space defined by a partition wall (300) installed inside the pack case (100). In addition, the partition wall (300) may face at least one side of the battery module (200).

[0078] Fig. 6 is a drawing showing a cross-sectional configuration along the cutting line C-C' of Fig. 2. Fig. 7 is a drawing showing a cross-sectional configuration along the cutting line A-A' of Fig. 1.

[0079] Referring to FIGS. 6 and 7, a battery pack (10) according to an embodiment of the present invention may include a nut (152). The nut (152) may be positioned between the pack cover (150) and the partition wall (300). And the melting bolt (400) may pass through the nut (152). In addition, the melting bolt (400) may pass through the pack cover (150). And at least a portion of the melting bolt (400) may be inserted, fastened, coupled, or fixed to the partition wall (300).

[0080] The pack cover (150) may include a fastening hole (151). The partition wall (300) may include an insertion hole (301). The fastening hole (151) formed in the pack cover (150) and the insertion hole (301) formed in the partition wall (300) may each have a screw thread. The melting bolt (400) may be coupled to the screw threads of the fastening hole (151) formed in the pack cover (150), the nut (152), and the insertion hole (301) formed in the partition wall (300).

[0081] According to this configuration of the present invention, the pack cover (150) and the partition wall (300) can be stably combined, fastened, or fixed. The nut (152) can increase the bonding strength between the pack cover (150) and the partition wall (300).

[0082] Referring to FIGS. 6 and 7, the nut (152) of the battery pack (10) according to one embodiment of the present invention may be coupled to the inner surface of the pack cover (150). For example, the nut (152) may be welded to the inner surface of the pack cover (150). In addition, the nut (152) and the pack cover (150) may be formed integrally. The nut (152) may be positioned to face the fastening hole (151) formed in the pack cover (150).

[0083] According to this configuration of the present invention, the thermal safety of the battery pack (10) can be improved. Since the nut (152) is coupled to the inner surface of the pack cover (150), the bonding strength of the melting bolt (400) and the pack cover (150) can be higher than the bonding strength of the melting bolt (400) and the partition wall (300). Therefore, when a thermal event occurs in the battery module (200), the pack cover (150) and the partition wall (300) can be separated while the melting bolt (400) is coupled to the pack cover (150). In addition, the pack cover (150) can swell while being coupled to the melting bolt (400). Therefore, the fastening hole (151) can be maintained in a sealed state, and flames generated inside the battery pack (10) through the fastening hole (151) can be prevented from being exposed to the outside. Additionally, by sealing the fastening hole (151), external oxygen can be prevented from flowing into the interior of the battery pack (10).

[0084] Referring to FIGS. 6 and 7, the melting bolt (400) of the battery pack (10) according to one embodiment of the present invention may include a plastic material. Since the melting bolt (400) includes a plastic material, the bonding strength between the melting bolt (400) and the partition wall (300) may be reduced. Furthermore, since the melting bolt (400) includes a plastic material, it may easily melt.

[0085] According to this configuration of the present invention, the thermal safety of the battery pack (10) can be improved. When a thermal event occurs in the battery module (200), the melting bolt (400) melts or the connection between the melting bolt (400) and the partition wall (300) is separated, thereby easily inflating the pack cover (150) of the pack case (100).

[0086] Referring to FIGS. 6 and 7, a melting bolt (400) of a battery pack (10) according to an embodiment of the present invention may include a melting bolt head (410) and a melting bolt body (420). The melting bolt body (420) may extend downward or along the -Z-axis direction from the melting bolt head (410). The melting bolt body (420) may have a screw thread. In addition, the melting bolt body (420) may include a first part (421) and a second part (422). The first part (421) of the melting bolt body (420) may be a portion passing through the pack cover (150) and the nut (152). The first part (421) of the melting bolt body (420) may extend from the melting bolt head (410). In addition, the second part (422) of the melting bolt body (420) may extend downward from the first part (421) or along the -Z axis direction. The second part (422) of the melting bolt body (420) may be a portion inserted into the partition wall (300). In addition, the length (d1) of the first part (421) of the melting bolt body (420) may be formed to be longer than the length (d2) of the second part (422).

[0087] According to this configuration of the present invention, the thermal safety of the battery pack (10) can be improved. Since the first part (421) of the melting bolt body (420) is formed longer than the second part (422), the bonding strength of the melting bolt (400) and the pack cover (150) can be higher than the bonding strength of the melting bolt (400) and the partition wall (300). Therefore, when a thermal event occurs in the battery module (200), the pack cover (150) and the partition wall (300) can be separated while the melting bolt (400) is bonded to the pack cover (150). In addition, the pack cover (150) can swell while being bonded to the melting bolt (400). Therefore, the sealing of the fastening hole (151) formed in the pack cover (150) can be maintained.

[0088] Referring to FIGS. 6 and 7, the sum of the thickness (d3) of the pack cover (150) of the battery pack (10) according to one embodiment of the present invention and the thickness (d4) of the nut (152) may be formed to be longer than the depth (d2) of the insertion hole (301) formed in the partition wall (300). The sum of the thickness (d3) of the pack cover (150) and the thickness (d4) of the nut (152) may be configured to be substantially the same as the length (d1) of the first part (421) of the melting bolt body (420). In addition, the depth (d2) of the insertion hole (301) formed in the partition wall (300) may be configured to be substantially the same as the length (d2) of the second part (422) of the melting bolt body (420).

[0089] According to this configuration of the present invention, the thermal safety of the battery pack (10) can be improved. The bonding strength of the melting bolt (400) and the pack cover (150) can be higher than the bonding strength of the melting bolt (400) and the partition wall (300). Therefore, when a thermal event occurs in the battery module (200), the pack cover (150) and the partition wall (300) can be separated while the melting bolt (400) is bonded to the pack cover (150). In addition, the pack cover (150) can swell while being bonded to the melting bolt (400). Therefore, the sealing of the fastening hole (151) formed in the pack cover (150) can be maintained.

[0090] FIG. 8 is a drawing showing a cross-sectional configuration taken along the cutting line A-A' of FIG. 1 when a thermal event occurs. Referring to FIGS. 6 to 8, a melting bolt (400) according to an embodiment of the present invention may be configured to melt when a thermal event occurs in a battery module (200). At this time, the melting bolt (400) may be configured such that the first part (421) and the second part (422) of the melting bolt body (420) are separated. Venting gas (g) may be introduced between the nut (152) and the partition wall (300) to melt the melting bolt (400). As a result, the first part (421) and the second part (422) of the melting bolt body (420) may be separated. And, since the lower part of the first part (421) of the melting bolt body (420) is melted, the melting bolt (400) can seal the nut (152) more strongly. The second part (422) separated from the first part (421) of the melting bolt body (420) can be coupled to the insertion hole (301) formed in the partition wall (300).

[0091] According to this configuration of the present invention, the thermal safety of the battery pack (10) can be improved. By separating the first part (421) and the second part (422) of the melting bolt body (420), the sealing state of the fastening hole (151) formed in the pack cover (150) can be maintained.

[0092] FIG. 9 is a drawing showing a cross-sectional configuration taken along the cutting line A-A' of FIG. 1 when a thermal event occurs in the battery module (200). Referring to FIG. 9, the melting bolt (400) according to an embodiment of the present invention can be separated from the partition wall (300) when a thermal event occurs in the battery module (200). The pack cover (150) can be pressurized outward by the venting gas (g). As a result, the second part (422) of the melting bolt body (420) and the insertion hole (301) formed in the partition wall (300) can be released from the connection, and the second part (422) of the melting bolt body (420) can be separated from the partition wall (300). The pack cover (150) can swell while maintaining a state of connection with the melting bolt (400). At this time, the melting bolt (400) can have a longer pitch than a normal bolt. Due to this, the melting bolt (400) can be easily separated from the partition wall (300) when a thermal event occurs in the battery module (200).

[0093] FIG. 10 is a drawing showing a cross-sectional configuration taken along the cutting line B-B' of FIG. 1 when a thermal event occurs in the battery module (200). Referring to FIG. 10, when a thermal event occurs in the battery module (200), venting gas (g) may be discharged. The pressure caused by the venting gas (g) may push the pack cover (150) outward. As a result, the pack cover (150) may remain coupled to the melting bolts (400) and may be separated from the first partition wall (310) of the partition wall (300). In addition, as the plurality of melting bolts (400) and the first partition wall (310) of the partition wall (300) are separated, the pack cover (150) may be inflated as a whole. As a result, the space inside the battery pack (10) may be expanded. In addition, the venting gas (g) may be discharged to the outside through the venting device (500). This can prevent explosion of the battery pack (10).

[0094] The battery pack (10) according to the present invention may further include various other components in addition to the battery module (200), such as various components of the battery pack (10), such as a BMS, a bus bar, a relay, a current sensor, etc.

[0095] The battery pack (10) according to the present invention can be applied to automobiles such as electric vehicles or hybrid vehicles. Referring to FIG. 11, an electric vehicle (600) according to the present invention can include a battery pack (10) according to the present invention. In addition to the battery pack (10), the automobile (600) according to the present invention can further include various other components included in the automobile. For example, the automobile (600) according to the present invention can further include a body, a motor, a control device such as an ECU (electronic control unit), etc.

[0096] As described above, although the present invention has been described by limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical idea of ​​the present invention and the equivalent scope of the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

Claims

1. A case that provides internal space and has a pack cover; A battery cell located inside the case; A partition wall dividing the internal space of the above case; and, A battery pack comprising a melting bolt that connects the pack cover and the partition wall, The above melting bolt is a battery pack configured to melt at a specific temperature.

2. In paragraph 1, The above melting bolt, A battery pack configured to melt when a thermal event occurs in the above battery cells.

3. In paragraph 1, The above melting bolt, A battery pack containing plastic material.

4. In paragraph 1, Further comprising a nut positioned between the pack cover and the partition wall, The above melting bolt, A battery pack passing through the pack cover and the nut and at least a portion of which is inserted into the partition wall.

5. In paragraph 4, The above nuts, A battery pack coupled to the inner surface of the above pack cover.

6. In paragraph 4, The above melting bolts: A first part passing through the pack cover and the nut; and, A second part extending from the first part and inserted into the partition wall, The above first part, A battery pack formed longer than the second part.

7. In paragraph 6, The above melting bolt, A battery pack configured such that the first part and the second part are separated when a thermal event occurs in the battery cell.

8. In paragraph 4, The above partition wall is, It has an insertion hole into which the above melting bolt is inserted, The sum of the thickness of the above pack cover and the thickness of the above nut is A battery pack formed longer than the depth of the above insertion hole.

9. In paragraph 1, The above melting bolts are provided in multiples, The above plurality of melting bolts are, A battery pack arranged along the length of the above partition wall.

10. In paragraph 1, Further comprising a module case installed inside the case and accommodating the battery cell, The above module case is, A battery pack having a venting hole facing the above pack cover.

11. A vehicle including a battery pack as defined in paragraph 1.

12. Base plate in the shape of a flat plate; A side wall installed along the perimeter of the base plate on the upper surface of the base plate; A flat pack cover that is combined with the upper surface of the side wall and forms an internal space together with the base plate; A partition wall installed on the upper surface of the base plate to divide the internal space; and A battery pack case including a melting bolt that connects the pack cover and the partition wall, The above melting bolt is a battery pack case configured to melt at a specific temperature.

13. In paragraph 12, The above melting bolt, A battery pack case configured to melt when a thermal event occurs in the above battery cell.

14. In paragraph 12, The above melting bolt, Battery pack case containing plastic material.

15. In paragraph 12, Further comprising a nut positioned between the pack cover and the partition wall, The above melting bolt, A battery pack case passing through the pack cover and the nut and at least a portion of which is inserted into the partition wall.

16. In paragraph 15, The above melting bolts: A first part passing through the pack cover and the nut; and, A second part extending from the first part and inserted into the partition wall, The first part is a battery pack case formed to be longer than the second part.

17. In paragraph 16, The above melting bolt is a battery pack case configured to separate the first part and the second part when a thermal event occurs in the battery cell.

18. A battery pack comprising a battery pack case of Article 12.

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