Battery pack

Abstract

A battery pack is disclosed. The battery pack according to one embodiment of the present invention may comprise: a case in which an inner space is provided and which has a pack cover; a battery cell positioned inside the case; a partition wall partitioning the inner space of the case; an adhesive member disposed on the partition wall; and a bolt having a head attached to the adhesive member, and a body passing through the pack cover.

Description

battery pack

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

[0002] This application claims priority to Korean Patent Application No. 10-2024-0070922, filed May 30, 2024, the entire disclosure of which is incorporated herein by reference.

[0003] As demand for portable electronic devices such as smartphones, tablet PCs, and smartwatches increases significantly and electric vehicles become increasingly widespread, research is actively being conducted on the batteries used in these devices, especially secondary batteries that can be repeatedly charged and discharged.

[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] 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.

[0009] In particular, if an event such as thermal runaway occurs in a single battery module, gas or flames may be randomly discharged to the outside. If the discharge of gas or flames is not properly controlled, there is a risk that the gas or flames may be discharged toward other battery modules, 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 configured to electrically connect to other battery modules or battery packs, such as module bus bars. Therefore, if flames are discharged toward the front side of such a 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 discharged toward the front side of a specific battery module, the discharged flames may easily spread to other battery modules, potentially causing a fire to spread between battery modules.

[0010] 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.

[0011] 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.

[0012] Accordingly, the present invention has been created to solve the above problems, and its purpose is to provide 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 an automobile including the same.

[0013] In addition, the present invention may provide a structure that facilitates expansion of the internal space of a battery pack when a thermal event occurs.

[0014] In addition, the present invention may provide a structure in which a pack cover can be easily inflated when a thermal event occurs.

[0015] Additionally, the present invention may provide a structure in which a seal is maintained when a thermal event occurs.

[0016] 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.

[0017] In order to achieve the above-described purpose, a battery pack according to one embodiment of the present invention may include a case providing an internal space and having a pack cover; a battery cell positioned inside the case; a partition wall partitioning the internal space of the case; an adhesive member positioned on the partition wall; and a bolt having a head attached to the adhesive member and a body penetrating the pack cover.

[0018] Additionally, the battery pack may further include a nut positioned on the outside of the pack cover and fastened to the bolt.

[0019] Additionally, the pack cover can be brought into contact with the head.

[0020] Additionally, the head may be configured to separate from the partition wall when a thermal event occurs.

[0021] In addition, the partition wall has a receiving groove formed at the top, and the adhesive member can be placed in the receiving groove.

[0022] In addition, the head has a through hole, and the adhesive member can be filled into the through hole.

[0023] Additionally, the battery pack may further include a stopper attached to the upper surface of the head and covering the through hole.

[0024] Additionally, the battery pack may further include a gasket disposed between the head and the pack cover.

[0025] A vehicle according to one aspect of the present invention comprises a battery pack of the present invention.

[0026] 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.

[0027] According to at least one of the embodiments of the present invention, the electrical safety of a battery pack can be improved.

[0028] According to at least one of the embodiments of the present invention, the sealing of the battery pack can be maintained even when a thermal event occurs.

[0029] According to at least one of the embodiments of the present invention, an explosion of the battery pack can be prevented by expanding the internal space of the battery pack when a thermal event occurs.

[0030] 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.

[0031] FIG. 1 is a drawing showing a battery pack according to one embodiment of the present invention.

[0032] Figure 2 is a diagram showing a partial configuration of the battery pack of Figure 1.

[0033] Figure 3 is a drawing showing the battery module of Figure 2.

[0034] Figure 4 is a diagram showing a partial configuration of the battery module of Figure 3.

[0035] Fig. 5 is a drawing showing a part of the configuration of the battery pack of Fig. 2.

[0036] Fig. 6 is a drawing showing a part of a cross-sectional configuration along the cutting line A-A' of Fig. 1.

[0037] Fig. 7 is a drawing showing a cross-sectional configuration along the cutting line B-B' of Fig. 6.

[0038] Fig. 8 is a drawing showing a part of a cross-sectional configuration along the cutting line A-A' of Fig. 1.

[0039] Figure 9 is a diagram showing the change in Figure 8 when a thermal event occurs.

[0040] Fig. 10 is a drawing showing an example of a modified cross-sectional configuration along the cutting line A-A' of Fig. 1.

[0041] Figure 11 is a diagram showing the change in Figure 10 when a thermal event occurs.

[0042] 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 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 aligns with the technical spirit of the present invention.

[0043] Accordingly, 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 it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0044] FIG. 1 is a drawing showing a battery pack according to one embodiment of the present invention. FIG. 2 is a diagram showing a partial configuration of the battery pack of FIG. 1.

[0045] Referring to FIGS. 1 and 2, a battery pack according to an embodiment of the present invention may include a case (100), a battery cell, a partition wall (300), an adhesive member (302), and a bolt (400). The case (100) 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. The base plate (110) may provide an internal space of the battery pack.

[0046] The side wall (120) can be installed, fastened, joined, fixed, or attached to the upper surface of the base plate (110). The side wall (120) can be composed of four pieces. The side wall (120) can be arranged along the perimeter of the base plate (110). The side wall (120) can form the exterior of the battery pack. The side wall (120) can provide an internal space.

[0047] The pack cover (150) may have a square plate shape. The pack cover (150) may have a flat plate shape. The pack cover (150) may form the exterior of the battery pack. The pack cover (150) may cover the internal space of the battery pack.

[0048] The battery cell (220) may refer to a secondary battery. In particular, the battery cell (220) may be a pouch-type secondary battery. However, the shape of the battery cell (220) is not limited to a pouch shape, and may have various shapes, such as a cylindrical shape or a rectangular parallelepiped shape. The battery cell (220) may be provided in multiple numbers.

[0049] The partition wall (300) may include a first partition wall (310) and a second partition wall (320). A plurality of partition walls (300) may be provided. The partition wall (300) may be installed, fastened, fixed, joined, or attached to the upper surface of the base plate (110). The partition wall (300) may partition the internal space of the battery pack. Battery cells (220) may be positioned in the space partitioned by the partition wall (300).

[0050] The adhesive member (302) may be placed on top of the partition wall (300). Additionally, the adhesive member (302) may be placed on the top of the partition wall (300). The adhesive member (302) may be configured to melt when exposed to high temperatures when a thermal event occurs.

[0051] The bolt (400) may have a head (410) and a body (430). The head (410) may be attached to an adhesive member (302). The head (410) may have a square plate shape. Since the head (410) has a square shape, the bonding area with the partition wall (300) may be increased. The head (410) may be fixed, coupled, attached, or installed to the partition wall (300) via the adhesive member (302). The body (430) may protrude upward or in the +Z-axis direction from the head (410). The head (410) and the body (430) may be formed integrally. The body (430) may have a screw thread. In addition, the body (430) may penetrate the pack cover (150).

[0052] According to this configuration of the present invention, the thermal safety of the battery pack can be improved. When a thermal event occurs from the battery cell (220), venting gas (g) may be discharged. This may cause the pressure inside the battery pack to rapidly increase. At this time, the temperature of the venting gas (g) may melt the adhesive member (302). This may cause the bolt (400) and the partition wall (300) to separate. In addition, the pack cover (150) may swell outward, thereby expanding the space inside the battery pack. This may prevent an explosion of the battery pack.

[0053] Referring to FIGS. 1 and 2, a battery pack according to an embodiment of the present invention may include a nut (152). The nut (152) may be located on the outside of the pack cover (150). In addition, the nut (152) may be fastened to a bolt (400). The nut (152) may be coupled to a thread of a body (430). The pack cover (150) may have a fastening hole (151). The body (430) may pass through the fastening hole (151). In addition, the nut (152) may be located on the pack cover (150) and coupled with the body (430). The nut (152) may seal the fastening hole (151).

[0054] According to this configuration of the present invention, the thermal safety of the battery pack can be improved. Even if the bolt (400) and partition wall (300) separate during a thermal event, the fastening hole (151) can remain sealed due to the combination of the nut (152) and the body (430). Consequently, high-temperature gases or flames generated within the battery pack can be prevented from being discharged to the outside.

[0055] In addition, according to this configuration of the present invention, oxygen from outside the battery pack can be blocked from flowing in through the fastening hole (151). As a result, thermal events can be blocked from propagating inside the battery pack.

[0056] Referring to FIGS. 1 and 2, a battery pack according to an embodiment of the present invention may include a plurality of bolts (400). The plurality of bolts (400) may be arranged along the longitudinal direction of the partition wall (300). The first partition wall (310) may extend along the left-right direction or the Y-axis direction. The second partition wall (320) may extend along the front-back direction or the X-axis direction. The plurality of bolts (400) may be arranged along the longitudinal direction of the first partition wall (310) or the longitudinal direction of the second partition wall (320).

[0057] According to this configuration of the present invention, the thermal safety of the battery pack can be improved. By connecting multiple bolts (400) along the partition wall (300), the pack cover (150) can be stably connected. Furthermore, when a thermal event occurs, the pack cover (150) can be inflated as a whole.

[0058] Referring to FIGS. 1 and 2, a battery pack according to an embodiment of the present invention may include a venting device (500). The venting device (500) may be installed on a side wall (120). For example, the venting device (500) may be installed on a front side wall (120). For example, the venting device (500) may be a gas valve. The venting device (500) may open to discharge gas when the pressure inside the case (100) increases. In addition, the venting device (500) may block external air from flowing into the case (100). A plurality of venting devices (500) may be provided.

[0059] According to this configuration of the present invention, the thermal safety of the battery pack can be improved. When a thermal event occurs from the battery cell (220), the pressure inside the battery pack can rapidly increase. Due to the release of the bolt (400) and the partition wall (300), the pack cover (150) swells outward, and the venting gas (g) is discharged to the outside through the venting device (500), thereby preventing an explosion of the battery pack.

[0060] FIG. 3 is a drawing showing the battery module (200) of FIG. 2. FIG. 4 is a drawing showing a partial configuration of the battery module (200) of FIG. 3. Referring to FIGS. 1 to 4, a battery pack 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 pad (250), a busbar frame assembly (230), and an end cover (240).

[0061] 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 case (100) 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).

[0062] A battery cell (220) may be accommodated inside a module case (210). A plurality of battery cells (220) may be stacked along the front-back direction or the X-axis direction. The battery cell (220) may include a receiving portion (221) having an electrode assembly, a first sealing portion (222) protruding to the left and right sides of the receiving portion (221), and a second sealing portion (223) protruding upward from the receiving portion (221). In addition, the battery cell (220) may include an electrode lead (224) protruding to the left and right sides of the first sealing portion (222), respectively. Each battery cell (220) may extend along the left-right direction or the Y-axis direction. The electrode lead (121) may protrude to the left and right sides of each battery cell (220).

[0063] The pad (250) may be placed between a plurality of battery cells (220). The 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 pad (250) may be configured to be placed between every four battery cells (220) stacked in the front-back direction.

[0064] These pads (250) may be provided with an elastic material to enable swelling absorption of the battery cells (220). For example, the pads (250) may be composed of a foam material such as polyurethane. Alternatively, the pads (250) may be provided with a material capable of blocking heat or flames. For example, the pads (250) may be provided with an insulating or fire-retardant material such as silicone or mica.

[0065] A busbar frame assembly (230) may be provided on each of the left and right sides of a 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).

[0066] A pair of end covers (240) can be respectively coupled to the left and right sides of the module case (210). The pair of end covers (240) can cover the front and back sides of the module case (210). The end covers (240) can have a square shape.

[0067] The battery module (200) may be installed, fastened, combined, fixed, or attached to the upper surface of the base plate (110). When a thermal event occurs from the battery module (200), venting gas (g) may be discharged through the venting hole (211). The venting hole (211) may face the inner surface of the pack cover (150). The venting gas (g) discharged through the venting hole (211) may push the pack cover (150) outward, upward, or in the Z-axis direction.

[0068] The battery module (200) may be located in a space partitioned by a partition wall (300). In addition, the partition wall (300) may face at least one side of the battery module (200).

[0069] Fig. 5 is a drawing showing a part of the configuration of the battery pack of Fig. 2. Fig. 6 is a drawing showing a part of the cross-sectional configuration along the cutting line A-A' of Fig. 1. Fig. 7 is a drawing showing a part of the cross-sectional configuration along the cutting line B-B' of Fig. 6. Fig. 8 is a drawing showing a part of the cross-sectional configuration along the cutting line A-A' of Fig. 1.

[0070] Referring to FIGS. 5 to 8, a pack cover (150) according to an embodiment of the present invention may be brought into contact with the upper surface of a head (410). The head (410) may further include a connecting portion (420). The connecting portion (420) may be formed around the periphery of the body (430). The connecting portion (420) may improve the rigidity of the portion where the head (410) and the body (430) are connected. The pack cover (150) may be fixed, coupled, fastened, or installed between the head (410) and the nut (152). The pack cover (150) may be in close contact with the head (410) or the nut (152). In addition, the pack cover (150) may be in close contact with the connecting portion (420).

[0071] According to this configuration of the present invention, the thermal stability of the battery pack can be improved. While the pack cover (150) is stably connected to the partition wall (300), the sealing of the fastening hole (151) can be sealed.

[0072] Referring to FIGS. 5 to 8, a partition wall (300) of a battery pack according to an embodiment of the present invention may have a receiving groove (301) at the top. The receiving groove (301) may be configured to have a depth in the downward direction or the -Z-axis direction. In addition, an adhesive member (302) may be placed in the receiving groove (301). For example, the receiving groove (301) may have a depth of about 1 mm. In addition, the receiving groove (301) may have a shape corresponding to the shape of the head (410). In addition, the head (410) may be received in the receiving groove (301).

[0073] According to this configuration of the present invention, the assembly tolerance of the battery pack can be reduced. Due to the receiving groove (301), the amount of adhesive material (302) applied can be precisely controlled. As a result, the height deviation of each bolt (400) after the plurality of bolts (400) are attached to the partition wall (300) can be reduced. In addition, by attaching the pack cover (150) to the plurality of bolts (400), the assembly tolerance of the battery pack can be reduced.

[0074] Referring to FIGS. 5 to 8, a head (410) of a battery pack according to an embodiment of the present invention may have a through hole (411). An adhesive member (302) may be filled into the through hole (411). A plurality of through holes (411) may be provided. In addition, an adhesive member (302) may be filled into each of the plurality of through holes (411).

[0075] According to this configuration of the present invention, since the adhesive member (302) is filled in the through hole (411), the bolt (400) can be more strongly attached to the partition wall (300). As a result, even if vibration or impact is applied to the battery pack, the pack cover (150) and the partition wall (300) can be stably maintained in a combined state.

[0076] Referring to FIGS. 5 to 8, a battery pack according to an embodiment of the present invention may further include a stopper (412). The stopper (412) may be attached, coupled, or fixed to the upper surface of the head (410). The stopper (412) may have a sheet shape with a thin thickness. For example, the stopper (412) may be a tape. The stopper (412) may cover the through hole (411). In addition, the stopper (412) may be provided in multiple numbers. In addition, the stopper (412) may cover a plurality of through holes (411).

[0077] According to this configuration of the present invention, the assembly tolerance of the battery pack can be reduced. The stopper (412) can limit the maximum amount of the adhesive material (302) that can be filled into the through hole (411). The stopper (412) can prevent the adhesive material (302) from being filled to overflow the through hole (411). As a result, the amount of the adhesive material (302) applied can be precisely controlled. As a result, after the plurality of bolts (400) are attached to the partition wall (300), the deviation in the height of each bolt (400) can be reduced. In addition, by attaching the pack cover (150) to the plurality of bolts (400), the assembly tolerance of the battery pack can be reduced.

[0078] In addition, according to this configuration of the present invention, the pack cover (150) and the bolt (400) can be stably fastened. The stopper (412) prevents the adhesive material (302) from overfilling the through hole (411), thereby allowing the pack cover (150) to be stably attached to the head (410).

[0079] FIG. 9 is a diagram illustrating changes in FIG. 8 when a thermal event occurs. Referring to FIGS. 8 and 9, the head (410) of the battery pack according to an embodiment of the present invention may be configured to separate from the partition wall (300) when a thermal event occurs. When a thermal event occurs, the adhesive member (302) may melt due to high-temperature gas. As a result, the head (410) may separate from the partition wall (300). In addition, the pack cover (150) may expand upward, outward, or in the +Z-axis direction. Even when the pack cover (150) expands, the sealing of the fastening hole (151) may be maintained.

[0080] FIG. 10 is a drawing showing an example of a variation of a cross-sectional configuration taken along the cutting line A-A' of FIG. 1. FIG. 11 is a drawing showing a change in FIG. 10 when a thermal event occurs. Referring to FIGS. 10 and 11, a battery pack according to an embodiment of the present invention may further include a gasket (160). The gasket (160) may be positioned between the head (410) and the pack cover (150). The gasket (160) may include a highly ductile metal material. The gasket (160) may be compressively deformed between the head (410) and the pack cover (150). In addition, the gasket (160) may seal between the pack cover (150) and the head (410).

[0081] According to this configuration of the present invention, the thermal safety of the battery pack can be improved by sealing the pack cover (150) and the head (410).

[0082] In addition, according to this configuration of the present invention, the assembly tolerance of the battery pack can be reduced. Due to the adhesive member (302), a deviation in the height of each bolt (400) may occur after a plurality of bolts (400) are attached to the partition wall (300). At this time, since the gasket (160) is positioned between the pack cover (150) and the head (410), the pack cover (150) can be stably fastened, joined, or fixed to the partition wall (300).

[0083] In addition, the battery pack according to the present invention may further include various other components in addition to the battery module, such as various battery pack components known at the time of filing of the present invention, such as a BMS, a bus bar, a relay, a current sensor, etc.

[0084] The battery pack according to the present invention can be applied to automobiles such as electric vehicles or hybrid vehicles. Specifically, the automobile according to the present invention may include the battery pack according to the present invention. Furthermore, the automobile according to the present invention may further include various other components, in addition to the battery pack. For example, the automobile according to the present invention may further include a body, a motor, a control device such as an electronic control unit (ECU), and the like.

[0085] 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; Partition wall dividing the internal space of the above case; An adhesive member placed on top of the above partition wall; and A battery pack comprising a bolt having a head attached to the adhesive member and a body penetrating the pack cover.

2. In paragraph 1, A battery pack further comprising a nut positioned on the outside of the pack cover and fastened to the bolt.

3. In paragraph 1, The above pack cover is, A battery pack in contact with the above head.

4. In paragraph 1, The above head, A battery pack configured to separate from the partition wall when a thermal event occurs.

5. In paragraph 1, The above partition wall is, It has a receiving groove formed at the top, The above adhesive member is, A battery pack placed in the above-mentioned receiving home.

6. In paragraph 1, The above head, Equipped with a through hole, The above adhesive member is, A battery pack filled in the above through hole.

7. In paragraph 6, A battery pack further comprising a stopper attached to the upper surface of the head and covering the through hole.

8. In paragraph 1, A battery pack further comprising a gasket disposed between the head and the pack cover.

9. A vehicle comprising a battery pack according to any one of claims 1 to 8.

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