Battery pack

Abstract

A battery pack is disclosed. A battery pack according to an embodiment of the present invention may comprise: a case providing a space therein and having a pack cover; a battery stack located inside the case and having a plurality of battery cells; a top cover located between the battery stack and the pack cover; and a heat insulating cover having a top part coupled to the upper surface of the top cover and a first side part covering one side of the battery stack.

Description

battery pack

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

[0002] This application claims priority to Korean Patent Application No. 10-2024-0114173, filed on August 26, 2024, the entire contents of which are disclosed in the specification and drawings of which are 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 capable of blocking the propagation of a thermal event when a thermal event occurs.

[0014] In addition, the present invention may improve the productivity of a battery pack by providing a battery pack having a battery unit having a simpler structure than a battery module.

[0015] In addition, the present invention may improve the energy density of a battery pack by providing a battery pack having a battery unit that is lighter in weight than a battery module with the same energy capacity.

[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 an embodiment of the present invention may include a case providing a space therein and having a pack cover; a battery stack positioned inside the case and having a plurality of battery cells; a top cover positioned between the battery stack and the pack cover; and an insulating cover having a top part coupled to an upper surface of the top cover and a first side part covering one side of the battery stack.

[0018] Additionally, the insulating cover includes a second side part covering the other side of the battery stack, and the battery stack can be positioned between the first side part and the second side part.

[0019] Additionally, the top part, the first side part, and the second side part can be formed integrally.

[0020] Additionally, the case may include a base plate on which the battery stack is placed, and the battery pack may further include a first partition wall that covers the first side part and is fastened to the base plate.

[0021] Additionally, the battery pack may further include a second partition wall covering the second side part and fastened to the base plate.

[0022] Additionally, the top cover may have a first venting hole.

[0023] Additionally, the battery pack may further include an inner cover positioned between the top cover and the battery stack.

[0024] Additionally, the inner cover may have a dividing line facing the first venting hole.

[0025] Additionally, the top part may have a second venting hole facing the first venting hole.

[0026] A vehicle according to one aspect of the present invention comprises a battery pack of the present invention.

[0027] 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.

[0028] According to at least one of the embodiments of the present invention, the electrical safety of a battery pack can be improved.

[0029] According to at least one of the embodiments of the present invention, propagation of a thermal event can be suppressed.

[0030] According to at least one of the embodiments of the present invention, the productivity of a battery pack can be improved.

[0031] According to at least one of the embodiments of the present invention, the energy density of a battery pack can be improved.

[0032] 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.

[0033] FIG. 1 is a drawing showing a battery pack according to one embodiment of the present invention.

[0034] Figure 2 is a diagram showing a partial configuration of the battery pack of Figure 1.

[0035] Figure 3 is a drawing showing the battery unit of Figure 2.

[0036] Figure 4 is a diagram showing a partial configuration of the battery unit of Figure 3.

[0037] Fig. 5 is a diagram showing a partial separation of the battery stack of Fig. 4.

[0038] Figure 6 is a drawing showing the combination of a battery stack, a busbar frame assembly, and an insulating cover.

[0039] Figure 7 is a drawing showing the combination of the configuration of Figure 6 and the inner cover.

[0040] Figure 8 is a drawing showing the combination of the configuration of Figure 7 and the top cover.

[0041] Figure 9 is a drawing showing the combination of the configuration of Figure 8 and the insulating cover.

[0042] Figure 10 is a drawing showing the combination of the configuration of Figure 9 and the partition wall.

[0043] Fig. 11 is a drawing showing a cross-sectional configuration along the cutting line A-A' of Fig. 3.

[0044] FIG. 12 is a drawing showing a vehicle according to one embodiment of the present invention.

[0045] 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.

[0046] 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.

[0047] FIG. 1 is a drawing showing a battery pack (1000) according to one embodiment of the present invention. FIG. 2 is a drawing showing a partial separation of the battery pack (1000) of FIG. 1. FIG. 3 is a drawing showing a battery unit (200) of FIG. 2. FIG. 4 is a drawing showing a partial separation of the battery unit (200) of FIG. 3.

[0048] Referring to FIGS. 1 to 4, a battery pack (1000) may include a case (100). The case (100) may include a base plate (110). 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 (1000). The base plate (110) may provide an internal space of the battery pack (1000).

[0049] The case (100) may include a side wall (120). The side wall (120) may be installed, fastened, joined, fixed, or attached to the upper surface of the base plate (110). The side wall (120) may be composed of four pieces. 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 (1000). The side wall (120) may provide an internal space.

[0050] The battery pack (1000) may include a battery unit (200). The battery unit (200) may have a rectangular parallelepiped shape. The battery unit (200) may be provided in multiple numbers. The multiple battery units (200) may be positioned inside the case (100). The multiple battery units (200) may be installed, coupled, fastened, fixed, or attached to the base plate (110).

[0051] The battery unit (200) may include a battery stack (201). The battery stack (201) may include a plurality of battery cells (220). In this case, the battery cell (220) may refer to a secondary battery. In particular, the battery cell (220) may be a secondary battery having a pouch shape. However, the shape of the battery cell (220) is not limited to the pouch shape, and may have various shapes such as a cylindrical shape or a rectangular parallelepiped shape. The plurality of battery stacks (201) may be installed, coupled, fastened, fixed, or attached to the base plate (110).

[0052] Each battery cell (220) may extend in the front-back direction or along the X-axis direction. A plurality of battery cells (220) may be stacked along the left-right direction or along the Y-axis direction. A plurality of battery cells (220) may be stacked to form a battery stack (201).

[0053] The case (100) may include a pack cover (150). 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 (1000). The pack cover (150) may cover the internal space of the battery pack (1000). The pack cover (150) may be positioned on top of the battery unit (200). The pack cover (150) may be positioned on top of the battery stack (201).

[0054] The battery unit (200) may include a top cover (260). The top cover (260) may be positioned above the battery stack (201). The top cover (260) may be positioned between the battery stack (201) and the pack cover (150).

[0055] The battery unit (200) may include an insulating cover (270). The insulating cover (270) may include a material with low thermal conductivity. The insulating cover (270) may include a material with high heat resistance. The insulating cover (270) may include a material with high fire resistance. The insulating cover (270) may include a material with high heat dissipation performance.

[0056] An insulating cover (270) may surround the battery stack (201). The insulating cover (270) may include a top part (271). The top part (271) may have a sheet shape. The top part (271) may be positioned above the top cover (260). The top part (271) may be fastened, joined, attached, installed, or fixed to the upper surface of the top cover (260).

[0057] The insulating cover (270) may include a first side part (272). The first side part (272) may cover one side of the battery stack (201). The first side part (272) may cover the right side of the battery stack (201). The top part (271) and the first side part (272) may be formed integrally. The first side part (272) may extend downward from the top part (271) or along the -Z-axis direction.

[0058] When a thermal event occurs from the battery cell (220), the insulating cover (270) can suppress or block heat transfer. The insulating cover (270) can suppress or block heat transfer to an adjacent battery unit (200) or battery stack (201). The insulating cover (270) can improve the thermal safety of the battery unit (200). The insulating cover (270) can improve the thermal safety of the battery pack (1000).

[0059] Referring to FIGS. 1 to 4, the battery pack (1000) may include a venting device (500). The venting device (500) may be installed on the side wall (120). For example, the venting device (500) may be installed on the 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). The venting device (500) may be provided in multiple numbers.

[0060] The battery pack (1000) may include a partition wall (310). The partition wall (310) may include a first partition wall (311) and a second partition wall (312). A plurality of partition walls (310) may be provided. The partition wall (310) may be installed, fastened, fixed, combined, or attached to the upper surface of the base plate (110). The partition wall (310) may partition the internal space of the battery pack (1000). The partition wall (310) may be installed, fastened, fixed, combined, or attached to the inner surface of the side wall (120). The partition wall (310) may be provided on each of both sides of the battery unit (200).

[0061] The battery pack (1000) may include a center partition wall (320). The center partition wall (320) may be installed, fastened, fixed, joined, or attached to the upper surface of the base plate (110). The center partition wall (320) may partition the internal space of the battery pack (1000). The center partition wall (320) may be installed, fastened, fixed, joined, or attached to the inner surface of the side wall (120).

[0062] FIG. 5 is an exploded view of a portion of the battery stack (201) of FIG. 4. Referring to FIGS. 1 to 5, the battery stack (201) may include a battery cell (220). The battery cell (220) may include a receiving portion (221) having an electrode assembly, a first sealing portion (222) protruding forward and backward from 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 forward and backward from the first sealing portion (222), respectively. Each battery cell (220) may extend in the front-back direction or along the X-axis direction. The electrode lead (224) may protrude forward and backward from each battery cell (220).

[0063] The battery stack (201) may include pads (250). The pads (250) may be positioned between a plurality of battery cells (220). The pads (250) may be positioned between at least some of the battery cells (220) and / or on the periphery of the stack. For example, the pads (250) may be configured to be positioned 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] The battery stack (201) may include an insulating sheet (290). The insulating sheet (290) may be placed on the outermost surface of the battery stack (201). The insulating sheet (290) may include a material having electrical insulation properties. The insulating sheet (290) may be provided on both sides of the battery stack (201).

[0066] FIG. 6 is a drawing showing the combination of a battery stack (201), a busbar frame assembly (231, 232), and an insulating cover (241, 242). Referring to FIGS. 4 to 6, the front busbar frame assembly (231) may be electrically connected to a front electrode lead (224) of the battery stack (201). The front busbar frame assembly (231) may cover a front side of a storage portion (221). The front busbar frame assembly (231) may include a power terminal (231a). The power terminal (231a) may be electrically connected to a plurality of battery cells (220). The power terminals (231a) may be provided in pairs. The power terminals (231a) may be exposed to the outside of the battery unit (200). The power terminal (231a) can be electrically connected to another battery unit (200) or a BMS (Battery Management System).

[0067] The rear busbar frame assembly (232) can be electrically connected to the rear side electrode lead (224) of the battery stack (201). The rear busbar frame assembly (232) can cover the rear side of the storage unit (221).

[0068] FIG. 7 is a drawing showing the combination of the configuration of FIG. 6 and the inner cover (280). Referring to FIGS. 6 and 7, the front insulating cover (241) can cover the front busbar frame assembly (231). The front insulating cover (241) can be combined, fastened, fixed, installed, or attached to the front busbar frame assembly (231). The front insulating cover (241) can include a material having electrical insulation properties. The front insulating cover (241) can expose the power terminal (231a).

[0069] The rear insulating cover (242) may cover the rear busbar frame assembly (232). The rear insulating cover (242) may be coupled, fastened, fixed, installed, or attached to the rear busbar frame assembly (232). The rear insulating cover (242) may include a material having electrical insulating properties.

[0070] FIG. 8 is a drawing showing the configuration of FIG. 7 and the combination of the top cover (260). Referring to FIGS. 7 and 8, the inner cover (280) may be positioned between the top cover (260) and the battery stack (201). The inner cover (280) may have a sheet shape. The inner cover (280) may cover the upper surface of the battery stack (201). The inner cover (280) may be fixed, coupled, fastened, or attached to the upper end of the busbar frame assembly (231, 232). The inner cover (280) may be fixed, coupled, fastened, or attached to the upper end of the insulating cover (241, 242).

[0071] The inner cover (280) may be joined, fastened, attached, or fixed to the lower surface of the top cover (260). The inner cover (280) may include a fire-resistant material. The inner cover (280) may include a heat-resistant material. The inner cover (280) may include a flame-retardant material. For example, the inner cover (280) may include a ceramic material. The inner cover (280) may include a fire-retardant material.

[0072] The inner cover (280) may include a separation line (281). The separation line (281, score line) may be used as a term that includes and collectively refers to a perforated line (281), a notching line (281), a cutting line (281), a shredding line (281), a tear line (281), or a separation line (281). The separation line (281) may be configured to be easily separated by pressure applied to the inner cover (280).

[0073] FIG. 9 is a drawing showing the combination of the configuration of FIG. 8 and the insulating cover (270). Referring to FIGS. 8 and 9, the top cover (260) may be fixed, coupled, fastened, or attached to the top of the busbar frame assembly (231, 232). The top cover (260) may be fixed, coupled, fastened, or attached to the top of the insulating cover (241, 242). The top cover (260) may include a plastic material.

[0074] The fastening member (S) can fasten the top cover (260) to the insulating covers (241, 242). The fastening member (S) can fasten the inner cover (280) to the insulating covers (241, 242). The fastening member (S) can penetrate the top cover (260) and the inner cover (280).

[0075] The top cover (260) may be provided with a first venting hole (261). A plurality of first venting holes (261) may be provided. The first venting hole (261) may face the dividing line (281). The first venting hole (261) may expose the dividing line (281). The dividing line (281) may be provided to correspond one-to-one with the first venting hole (261).

[0076] When a thermal event occurs from the battery cell (220), the venting gas can separate the separation line (281). This allows the inner cover (280) to open. The venting gas can then be discharged to the outside of the battery unit (200) through the first venting hole (261). On the other hand, when the battery unit (200) is exposed to venting gas generated from the outside, the inner cover (280) can prevent the venting gas generated from the outside from flowing into the inside of the battery unit (200). This can suppress or block the propagation of the thermal event.

[0077] FIG. 10 is a drawing showing the combination of the configuration of FIG. 9 and the partition wall (310). Referring to FIGS. 9 and 10, the top part (271) may be provided with a second venting hole (271a). A plurality of second venting holes (271a) may be provided. The plurality of second venting holes (271a) may be provided in a one-to-one correspondence with the plurality of first venting holes (261). The second venting holes (271a) may face the first venting holes (261). The second venting holes (271a) may expose a dividing line (281).

[0078] When a thermal event occurs outside the battery unit (200), the top part (271) can block heat transfer to the battery unit (200). As a result, the propagation of the thermal event can be suppressed or blocked.

[0079] The first side part (272) can be fastened, joined, attached, or fixed to the right insulating sheet (290). The first side part (272) can cover the right insulating sheet (290). When a thermal event occurs from the battery cell (220), the first side part (272) can block heat transfer in the right or +Y-axis direction. As a result, heat transfer to the adjacent battery unit (200) can be suppressed.

[0080] When a thermal event occurs outside the battery unit (200), the first side part (272) can block heat transfer to the battery unit (200). As a result, propagation of the thermal event can be suppressed or blocked.

[0081] The insulating cover (270) may include a second side part (273). The first side part (272) may cover one side of the battery stack (201). The second side part (273) may cover the other side of the battery stack (201). The second side part (273) may cover the left side of the battery stack (201). The top part (271) and the second side part (273) may be formed integrally. The second side part (273) may extend downward from the top part (271) or along the -Z-axis direction.

[0082] The second side part (273) can be fastened, joined, attached, or fixed to the left insulating sheet (290). The second side part (273) can cover the left insulating sheet (290). The battery stack (201) can be positioned between the first side part (272) and the second side part (273). When a thermal event occurs from the battery cell (220), the second side part (273) can block heat transfer in the left or -Y-axis direction. As a result, heat transfer to the adjacent battery unit (200) can be suppressed.

[0083] When a thermal event occurs outside the battery unit (200), the second side part (273) can block heat transfer to the battery unit (200). As a result, propagation of the thermal event can be suppressed or blocked.

[0084] Referring to FIGS. 2 and 10, the first partition wall (311) can cover the first side part (272). The first partition wall (311) can be fastened, joined, attached, or fixed to the base plate (110). The first partition wall (311) can be in contact with the first side part (272). The first partition wall (311) can press the first side part (272).

[0085] The second partition wall (312) can cover the second side part (273). The second partition wall (312) can be fastened, joined, attached, or fixed to the base plate (110). The second partition wall (312) can be in contact with the second side part (273). The second partition wall (312) can press the second side part (273).

[0086] Fig. 11 is a drawing showing a cross-sectional configuration taken along the cutting line A-A' of Fig. 3. Referring to Fig. 11, a fastening member (S) can fasten a top cover (260) and an inner cover (280) to a front busbar frame assembly (231). Since the top cover (260) and the inner cover (280) are fastened to the front busbar frame assembly (231), when a thermal event occurs, venting gas can be discharged only through the first venting hole (261) or the second venting hole (271a). As a result, the thermal event can be suppressed from propagating to an adjacent battery unit (200).

[0087] The battery pack (1000) according to the present invention may further include various other components in addition to the battery unit (200), such as various battery pack components known at the time of application of the present invention, such as a BMS, a bus bar, a relay, a current sensor, etc.

[0088] FIG. 12 is a drawing showing a vehicle (V) according to an embodiment of the present invention. Referring to FIG. 12, the vehicle (V) according to an embodiment of the present invention may include a battery pack (1000) of the present invention. The battery pack (1000) according to the present invention may be applied to a vehicle (V) such as an electric vehicle (V) or a hybrid vehicle (V). That is, the vehicle (V) according to the present invention may include the battery pack (1000) according to the present invention. In addition, the vehicle (V) according to the present invention may further include various other components included in the vehicle in addition to the battery pack (1000). For example, the vehicle (V) according to the present invention may further include a body, a motor, a control device such as an ECU (electronic control unit), etc.

[0089] 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 space inside and has a pack cover; A battery stack positioned inside the case and having a plurality of battery cells; A top cover positioned between the battery stack and the pack cover; and A battery pack comprising an insulating cover having a top part coupled to an upper surface of the top cover and a first side part covering one side of the battery stack.

2. In paragraph 1, The above insulation cover, A second side part covering the other side of the battery stack is included, The above battery stack is, A battery pack positioned between the first side part and the second side part.

3. In paragraph 2, A battery pack in which the top part, the first side part, and the second side part are formed integrally.

4. In paragraph 2, The above case is, including a base plate on which the battery stack is placed; The above battery pack, A battery pack further comprising a first partition wall covering the first side part and fastened to the base plate.

5. In paragraph 4, A battery pack further comprising a second partition wall covering the second side part and fastened to the base plate.

6. In paragraph 1, The above top cover, A battery pack having a first venting hole.

7. In paragraph 6, A battery pack further comprising an inner cover positioned between the top cover and the battery stack.

8. In paragraph 7, The above inner cover, A battery pack having a separation line facing the first venting hole.

9. In paragraph 7, The above top part is, A battery pack having a second venting hole facing the first venting hole.

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

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