Battery PACK

Abstract

A battery pack according to one embodiment of the present disclosure comprises a plurality of battery modules including a first battery module and a second battery module; a busbar electrically connecting the first battery module and the second battery module; and the first battery module and / or the second battery module may include a vent hole open toward a portion of the busbar.

Description

Technology Field

[0001] The present disclosure relates to a battery pack comprising a plurality of battery modules. Background Technology

[0002] As technology development and demand for mobile devices, electric vehicles, and Energy Storage Systems (ESS) increase, the demand for secondary batteries as an energy source is rapidly growing.

[0003] A battery cell includes an electrode assembly, such as a positive electrode, a negative electrode, a separator, and an electrolyte, which are the main components of a secondary battery, and a cell body member consisting of a multilayer outer material (Laminated Film Case) that protects the same. A battery module composed of multiple battery cells may be mounted on an electric vehicle, etc. The battery module includes a frame that protects the battery cells from external shock, heat, vibration, etc.

[0004] Battery cells can heat up during the charging and discharging processes, and this heat degrades their performance. Furthermore, if this heat generation becomes severe, the internal pressure of the battery cell increases, leading to the problem of the battery cell itself, and ultimately the entire battery module, catching fire.

[0005] In a battery pack equipped with multiple battery modules, if thermal runaway occurs in one of the battery modules, components such as insulating materials (e.g., plastic, coating) that maintain insulation between the battery cells, battery modules, and the battery pack may fail to function properly, causing an overcurrent to flow between adjacent battery modules. This leads to the propagation of fire between the battery modules and poses a risk of damage to the entire battery pack. The problem to be solved

[0006] The purpose of the present disclosure is to provide a means to protect a battery module in event situations such as overheating or short circuits, and even in thermal runaway situations.

[0007] The purpose of the present disclosure is to provide a means to prevent the propagation of fire to other battery modules even in the event of thermal runaway of a specific battery module. means of solving the problem

[0008] A battery pack according to one embodiment of the present disclosure comprises a plurality of battery modules including a first battery module and a second battery module; a busbar electrically connecting the first battery module and the second battery module; and the first battery module and / or the second battery module may include a vent hole open toward a portion of the busbar.

[0009] In one embodiment, the busbar includes a connection blocking portion in a part facing the vent hole, and the connection blocking portion may have a smaller cross-sectional area than other parts of the busbar connected to the connection blocking portion.

[0010] In one embodiment, the busbar includes a connection blocking part in a portion facing the vent hole, and the connection blocking part may be configured to have a greater resistance than other parts of the busbar connected to the connection blocking part.

[0011] In one embodiment, the busbar includes a connection blocking part in a portion facing the vent hole, and the connection blocking part may be structurally weaker than other parts of the busbar connected to the connection blocking part.

[0012] In one embodiment, the connection blocking unit may include a plurality of bridges connecting both ends of the connection blocking unit to each other.

[0013] In one embodiment, the busbar may include a deformation portion that selectively connects both ends of the busbar by being deformed by gas discharged from the vent hole.

[0014] In one embodiment, the busbar includes a first portion connected to the first battery module and a second portion connected to the second battery module, and one end of the deformation portion is fixedly provided to the first portion, and the other end of the deformation portion can be selectively connected to the second portion by gas from the vent hole.

[0015] In one embodiment, the deformation part may include a bimetal.

[0016] In one embodiment, it may further include a detonator mounted on a part of the busbar to break the busbar in response to gas discharged from the vent hole.

[0017] In one embodiment, a trigger unit may be further provided facing the vent hole and detecting gas discharged from the vent hole to detonate the detonator.

[0018] In one embodiment, the busbar includes a connection blocking part in a portion close to the detonator, and the connection blocking part may include a portion that is structurally weaker than other portions of the busbar connected to the connection blocking part.

[0019] In one embodiment, a case accommodating a portion of the detonator and the busbar may be further included. Effects of the invention

[0020] According to one embodiment of the present disclosure, electrical connections between battery modules are disconnected during a thermal runaway situation to prevent heat transfer between battery modules and to ensure the stability and reliability of the battery modules.

[0021] In the event of thermal runaway of a battery module, electrical connections to the positive and negative electrodes can be blocked on both sides to prevent or suppress / delay heat transfer from the battery module to an adjacent battery module. Brief explanation of the drawing

[0022] FIG. 1 illustrates the electrical connection between two battery modules in one embodiment. Figure 2 is a cross-sectional view taken along line I-I' of Figure 1. FIG. 3 illustrates a busbar connection blocking portion in one embodiment. FIG. 4 illustrates a different form of the busbar connection blocking part in one embodiment. FIG. 5 illustrates the electrical connection between battery modules provided inside a battery pack according to one embodiment. FIG. 6 illustrates the connection structure between two battery modules in one embodiment. Figure 7 is a cross-sectional view taken along line II-II' of Figure 6. Specific details for implementing the invention

[0023] Preferred embodiments of the present disclosure are described below with reference to the attached drawings. However, embodiments of the present disclosure may be modified in various other forms, and the scope of the present disclosure is not limited to the embodiments described below. Furthermore, the embodiments of the present disclosure are provided to more fully explain the present disclosure to those skilled in the art. In the drawings, the shapes and sizes of elements may be exaggerated for clearer explanation.

[0024] Additionally, singular expressions in this specification include plural expressions unless the context clearly indicates otherwise, and reference numerals assigned in the same or similar manner throughout the specification are deemed to refer to the same component or corresponding component.

[0026] FIG. 1 illustrates the electrical connection between two battery modules in one embodiment. FIG. 2 is a cross-sectional view taken along line I-I' of FIG. 1.

[0027] Referring to FIGS. 1 and FIGS. 2, battery modules (100, 200) can be electrically connected by a busbar (310).

[0028] A battery module (100, 200) may include a battery case (120, 220) and battery cells (130, 230) provided inside the case (120, 220). A battery cell (130, 230) may include an electrode assembly and a cell body member that encloses the electrode assembly. The electrode assembly is substantially contained within the cell body member and used together with an electrolyte. The electrolyte may contain a lithium salt such as LiPF6, LiBF4, etc., in an organic solvent such as EC (ethylene carbonate), PC (propylene carbonate), DEC (diethyl carbonate), EMC (ethyl methyl carbonate), DMC (dimethyl carbonate), etc. The electrolyte may be in a liquid, solid, or gel form. The cell body member is configured to protect the electrode assembly and contain the electrolyte; for example, the cell body member may be provided as a pouch-type member or a can-type member.

[0029] The positive or negative electrodes of the battery cells (130, 230) may be connected to a busbar (310) via an electrical path (131, 231). For example, the busbar (310) includes a first terminal section (311) and a second terminal section (314), and each terminal section (311, 314) is electrically connected to a first battery module (100) and a second battery module (200), respectively. For example, the first terminal section (311) may be connected to the positive electrode of the first battery module (100), and the second terminal section (314) may be connected to the negative electrode of the second battery module (200). As another example, the first terminal section (311) may be connected to the negative electrode of the first battery module (100), and the second terminal section (314) may be connected to the positive electrode of the second battery module (200). The busbar (310) may include holes in the first terminal portion (311) and the second terminal portion (314). Each battery module (100, 200) may include a terminal that can be inserted into the hole of the busbar (310) in the battery case (120, 220).

[0030] In FIGS. 1 and 2, a busbar (310) responsible for the electrical connection between two battery modules (100, 200) is shown, but this is for convenience of explanation, and another busbar (310) may be connected to one battery module (100 or 200). For example, the first battery module (100) may be electrically connected via a busbar to a separate battery module not shown.

[0032] In one embodiment, the battery module (100, 200) may include a vent hole (121, 221) that is open toward the bus bar (310). Gas (G) generated when the battery cell (130, 230) ignites may be discharged to the outside of the battery module through the vent hole (121, 221) provided in the case (120, 220). In the event of thermal runaway, not only gas (G) but also flames, oil, particles, etc. may be discharged together through the vent hole (121, 221). In the present disclosure, the venting gas (G) may be understood as a concept that includes all flames, particles, etc. discharged toward the bus bar (310) in the event of thermal runaway.

[0033] In one embodiment, the vent hole (121, 221) may be provided so that gas (G) is ejected toward the bus bar (310). In one embodiment, the vent hole (121, 221) may be provided so as to face at least a portion of the bus bar (310). Due to the high pressure and high temperature of the venting gas (G) discharged from the vent hole (121, 221), a portion of the bus bar (310) may be broken, which cuts off the electrical connection between the battery modules (100, 200). Accordingly, even if thermal runaway occurs in one battery module (100 and / or 200), heat transfer to another battery module may be blocked.

[0034] In one embodiment, the busbar (310) may include a connection blocking part (312, 313) in a portion corresponding to the vent hole (121, 221) of the battery module (100, 200). The connection blocking part (312, 313) may be provided to be damaged or deformed by the venting gas (G) discharged from the vent hole (121, 221) to block the electrical connection between the first terminal part (311) and the second terminal part (314).

[0035] For example, the connection blocking part (312, 313) may be structurally weaker than other parts and may be broken by the venting gas (G). As another example, the connection blocking part (312, 313) may be configured to be thermally deformed by the venting gas (G) to release the electrical connection between the first terminal part (311) and the second terminal part (314). Meanwhile, in the present disclosure, the breaking or severing of the connection blocking part (312, 313) may be understood as a concept that includes not only the physical severing of the connection blocking part (312, 313) but also the deformation of the connection blocking part (312, 313) to release the electrical connection between the first terminal part (311) and the second terminal part (314).

[0036] In one embodiment, the busbar (310) connecting two battery modules (100, 200) may include two connection blocking parts (312, 313). When thermal runaway occurs in the first battery module (100), the first connection blocking part (312) may be broken, and when thermal runaway occurs in the second battery module (200), the second connection blocking part (313) may be broken.

[0037] In the illustrated embodiment, the vent hole (121, 221) and the bus bar (310) are provided on the side of the battery module (100, 200), but in other embodiments, the vent hole (121, 221) and the bus bar (310) may be provided on the upper or lower surface of the battery module (100, 200).

[0038] In the illustrated embodiment, the bus bar (310) is in close contact with the battery module (100, 200) at the terminal portions (311, 314), and other portions (e.g., connection blocking portions (312, 313)) are spaced apart from the battery module (100, 200), but this is merely an example. For example, the bus bar (310) is provided in the form of a bar that is substantially unbent, so that when the bus bar (310) is assembled to the battery module (100, 200), the connection blocking portions (312, 313) can be in close contact with the vent holes (121, 221) of the battery module.

[0039] FIG. 3 illustrates the connection blocking portions (312, 313) of the busbar (310) in one embodiment.

[0040] Referring to FIG. 3, the connection blocking portions (312, 313) of the busbar (310) may have various shapes. For example, in FIG. 1, the first connection blocking portion (312, 313) may have shape (a), and the second connection blocking portion (312, 313) may have shape (b). As another example, the connection blocking portion (512) of FIG. 5 may have any one of the shapes shown in FIG. 3.

[0041] The connection blocking portions (312, 313) may be provided to be easily melted or broken by venting gas (G). In one embodiment, the connection blocking portions (312, 313) may have a structure that is more vulnerable to heat, pressure, or shock than other parts. For example, the cross-sectional area of ​​the connection blocking portions (312, 313) may be smaller than the cross-sectional area of ​​other parts. For example, when the bus bar (310) has a constant thickness, the width of the connection blocking portions (312, 313) may be narrower than other parts.

[0042] In one embodiment, the connection blocking part (312, 313) may be provided to have a higher resistance than other parts. For example, the connection blocking part (312, 313) may be provided to have a smaller cross-sectional area than other parts. If the connection blocking part (312, 313) has a high resistance, when a current of a certain magnitude or more flows through the connection blocking part (312, 313), the connection blocking part (312, 313) may heat up and melt more easily than other parts. This can prevent a situation where the battery module (battery module (100, 200) of FIG. 1, or battery module (400) of FIG. 5) is overcharged.

[0043] In one embodiment, the bus bar (310) includes a connection blocking part (312, 313) in a portion facing the vent hole (121, 221), and the connection blocking part (312, 313) may be structurally weaker than other parts of the bus bar (310) extending from its end.

[0044] Additionally or alternatively, the connection blocking part (312, 313) may be provided to have a higher resistance than other parts. The connection blocking part (312, 313) may break relatively easily when an overcurrent flows, thereby severing the electrical connection between the battery modules (100, 200).

[0045] FIGS. 3 (a) to (e) illustrates various examples of connection blocking parts (312, 313) having a structure or higher resistance value than other parts.

[0046] Referring to FIG. 3(a), the connection blocking section (312, 313) may include a plurality of bridges (316a) that connect both ends and are bent upwards. Referring to FIG. 3(b), the connection blocking section (312, 313) may include straight bridges (316b) that connect both ends. Referring to FIG. 3(c), the connection blocking section (312, 313) may include a section (316c) that has a narrower width than other sections. Referring to FIG. 3(d), the connection blocking section (312, 313) may include a plurality of bridges (316d) that connect both ends and are in an arc shape. Referring to FIG. 3(e), the connection blocking section (312, 313) may include a plurality of bridges (316e) that connect both ends and are in a wave shape.

[0047] In FIG. 3 (a), (b), (d), and (e), three bridges (316a, 316b, 316d, 316e) partially constitute the connection blocking section (312, 313), but in other embodiments, the connection blocking section (312, 313) may include four or more bridges.

[0048] The various forms of the connection blocking parts (312, 313) shown in FIG. 3 are merely examples, and in one embodiment, it is sufficient for the connection blocking parts (312, 313) to have a structure that is more vulnerable to high temperature, high pressure, or impact than other parts.

[0050] FIG. 4 illustrates a different form of the connection blocking portion (312, 313) of the busbar (310) in one embodiment.

[0051] Referring to FIG. 4, the connection blocking portion (312, 313) may alternatively be implemented as a switch. The connection blocking portion (312, 313) may include a deformation portion (317) provided such that the end portion (317b) selectively contacts a part (319) of the bus bar (310) located on one side of the connection blocking portion (312, 313).

[0052] In one embodiment, the busbar includes a first part (318) connected to a first battery module (100) and a second part (319) connected to a second battery module (200), and one end (317a) of the deformation part (317) is fixedly provided to the first part (318), and the other end (317b) of the deformation part (317) can be selectively connected to the second part (319) by gas (G) of the vent hole (121, 221).

[0053] In one embodiment, the deformation part (317) may include a bimetal that selectively connects both ends of the connection blocking part (312, 313). The bimetal is a rod-shaped component made by stacking two types of thin metal plates with different coefficients of thermal expansion and welding them together to form a single sheet. Under normal conditions, the deformation part (317) electrically connects both ends of the connection blocking part (312, 313). As the high-temperature venting gas (G) heats the deformation part (317), the deformation part (317) bends to one side, which can release the electrical connection between both ends of the bus bar (310).

[0054] In one embodiment, the connection blocking member (312, 313) may be provided to block the electrical connection between both ends of the connection blocking member (312, 313) by utilizing thermal deformation caused by the venting gas (G) of the metal in addition to the bimetal. In one embodiment, the connection blocking member (312, 313) may include a PCM (phase change material).

[0056] FIG. 5 illustrates the electrical connection between battery modules (100, 200) provided inside a battery pack (600) according to one embodiment.

[0057] Referring to FIG. 5, in one embodiment, the battery pack (600) may include a plurality of battery modules (400) inside the pack housing (610). The plurality of battery modules (400) are electrically connected to each other by busbars (510).

[0058] In one embodiment, each of the battery modules (400) may include vent holes (412) facing a busbar (510) connected to an adjacent battery module. One battery module (400) may include two busbars (510) connected to a positive electrode and a negative electrode, respectively, and extending to an adjacent battery module. The battery module (400) may include vent holes (412) in the case (410) that are open toward a portion of the busbars (510).

[0059] In one embodiment, one battery module (400) In the event of thermal runaway, gas (G) is released through the vent hole (412), and the busbar (510) facing the vent hole (412) may be severed. Accordingly, the electrical connection between the battery module (400) and the neighboring battery module is cut off.

[0060] In one embodiment, the busbar (510) may include a connection blocking part (512) in a portion corresponding to the vent hole (412). The connection blocking part (512) may have a structure that is more susceptible to high temperature, high pressure, or impact than other parts. The connection blocking part (512) may be provided in a form such as, for example, the example of FIG. 3 or FIG. 4.

[0061] The case (410) of the battery module (400) and the housing (610) of the battery pack (600) are generally made of a metal that conducts electricity. Therefore, to provide insulation between the battery module (400) and the battery pack (600), a plastic member or the like is provided between the two. However, if a specific battery module (400) is triggered and causes a thermal runaway, the components responsible for insulation between the battery module (400) and the pack housing (610) may be damaged, and the battery module (400) and the pack housing (610) may become electrically connected. Consequently, an overcurrent may flow through the battery module (400), which may lead to heat transfer to neighboring battery modules and further ignition of the entire battery pack (600).

[0062] According to one embodiment, even if thermal runaway occurs in a specific battery module (400), the gas (G) discharged from the vent hole (412) can rupture the busbar (510), thereby severing the electrical connection with the adjacent battery module. Accordingly, heat transfer to the neighboring battery module is prevented, and the stability and reliability of the battery module (400) and the battery pack (600) can be ensured.

[0064] FIG. 6 illustrates a connection structure between two battery modules (100, 200) in one embodiment. FIG. 7 is a cross-sectional view taken along line II-II' of FIG. 6.

[0065] Referring to FIGS. 6 and 7, a battery module (100, 200) can be connected to an adjacent battery module (100, 200) via a bus bar (310). At this time, a detonator (340) may be mounted on a part of the bus bar (310).

[0066] In one embodiment, the battery module (100, 200) includes a vent hole (121, 221), and the vent hole (121, 221) may be provided at a position corresponding to a detonator (340) provided on a bus bar (310). For example, the vent hole (121, 221) may be open toward the detonator (340).

[0067] In one embodiment, the detonator (340) may include a case (341), a trigger device (342), and a detonator (344). In one embodiment, the trigger device (342) may be configured to detect venting gas (G) and detonate the detonator (344). A wiring (343) for transmitting a signal may be provided between the trigger device (342) and the detonator (344).

[0068] In one embodiment, the detonator (340) may be configured so that gas (G) ejected from the vent hole (121, 221) is directed toward the trigger device (342). For example, the vent hole (121, 221) of the battery module (100, 200) may be opened toward the trigger device (342). Alternatively, the trigger device (342) and the vent hole (121, 221) may be configured to face each other.

[0069] In another embodiment, the trigger device (342) in the detonator (340) may be omitted. For example, the venting gas (G) may be ejected directly toward the detonator (344) inside the case (341) and detonate the detonator (344).

[0070] In one embodiment, the gas (G) discharged from the vent hole (121, 221) primarily detonates the detonator (344) inside the detonator (340), and the busbar (310) may be broken due to the explosion of the detonator (344). The gas (G) coming out of the vent hole (121, 221) may not be sufficient to break the busbar (310), and the detonator (344) detonating inside the case (341) may cause a relatively large impact to the busbar (310) compared to the venting gas (G).

[0071] In one embodiment, the connection blocking portion (312, 313) in the busbar (310) may be positioned adjacent to the detonator (344) of the detonator (340). The connection blocking portion (312, 313) may be provided in one of the various forms shown in FIG. 3 or FIG. 4. For example, the connection blocking portion (312, 313) may be provided structurally weaker than other parts so that it breaks relatively easily due to the explosion of the detonator (344). As another example, the connection blocking portion (312, 313) may be provided in the form of a switch to release the electrical connection between both ends of the busbar (310) due to the explosion of the detonator (344).

[0072] The description in FIGS. 6 and 7 can be likewise applied to the battery module (400) and busbar (510) provided in the battery pack (600) shown in FIG. 5. For example, the detonator (340) of FIG. 6 can be mounted on the connection blocking part (512) of the busbar (510).

[0074] Although the structure and features of the present disclosure have been described above based on embodiments according to the present disclosure, the present disclosure is not limited thereto, and it is obvious to those skilled in the art that various changes or modifications can be made within the spirit and scope of the present disclosure; therefore, it is noted that such changes or modifications fall within the scope of the appended claims. Explanation of the symbols

[0076] 100, 200, 400: Battery Module 310: Busbar 311, 314: Terminal section 312, 313: Connection blocking section 317: Modified part 340: Detonator 600: Battery pack

Claims

Claim 1 A battery pack comprising: a plurality of battery modules including a first battery module and a second battery module; and a busbar electrically connecting the first battery module and the second battery module; wherein the first battery module includes a first vent hole for discharging gas, and the second battery module includes a second vent hole provided to be open toward the first vent hole, and the busbar includes a connection blocking member provided between the first vent hole and the second vent hole, wherein the connection blocking member is broken or deformed by gas discharged from at least one of the first vent hole or the second vent hole to cut off the electrical connection between the first battery module and the second battery module. Claim 2 In claim 1, the connection blocking part is a battery pack having a smaller cross-sectional area than other parts of the busbar connected to the connection blocking part. Claim 3 A battery pack according to claim 1, wherein the connection blocking part is configured to have a resistance greater than that of other parts of the busbar connected to the connection blocking part. Claim 4 In claim 1, the battery pack is structurally weaker than other parts of the busbar connected to the connection blocking part. Claim 5 In paragraph 4, the battery pack comprising a plurality of bridges that connect both ends of the connection blocking unit to each other. Claim 6 A battery pack according to claim 1, wherein the connection blocking part electrically connects both ends of the busbar while gas is not discharged, and includes a deformation part that releases the electrical connection between both ends of the busbar by being deformed by gas discharged from the first vent hole or the second vent hole. Claim 7 A battery pack according to claim 6, wherein the busbar comprises a first portion connected to the first battery module and a second portion connected to the second battery module, wherein one end of the deformation portion is fixedly provided to the first portion and the other end of the deformation portion contacts the second portion in a state where gas is not discharged from the first vent hole or the second vent hole and is separated from the second portion by gas discharged from the first vent hole or the second vent hole. Claim 8 In paragraph 6, the above-mentioned deformation part is a battery pack including a bimetal. Claim 9 A battery pack further comprising, in claim 1, a detonator mounted on a part of the busbar and configured to break the busbar in response to gas discharged from the first vent hole or the second vent hole. Claim 10 A battery pack according to claim 9, wherein the detonator is provided opposite to the first vent hole or the second vent hole, and further comprises a trigger device that detects gas discharged from the first vent hole or the second vent hole and detonates the detonator. Claim 11 In claim 9, the battery pack comprises a connection blocking portion positioned adjacent to the detonator and including a portion of the busbar connected to the connection blocking portion that is structurally weaker than other portions of the busbar. Claim 12 In claim 9, the detonator further comprises a battery pack including a detonator case that accommodates the detonator and a portion of the busbar.

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