Battery pack

Abstract

The present invention relates to a battery pack, and more particularly, to a battery pack capable of effectively absorbing heat when thermal runaway occurs in the battery pack due to an event (shock, internal / external short circuit, etc. And block a heat transfer path within the battery pack to prevent thermal runaway starting from one battery module from being transferred to the battery pack of the other battery modules. According to the present invention, a battery pack comprises: a plurality of battery modules; a pack case housing the plurality of battery modules therein; the cross beams are arranged among the battery modules in the battery pack shell, and hollow parts are formed in the cross beams; and an absorbing material disposed in the hollow portion of the cross beam and absorbing heat released from the battery module.

Description

Technical Field

[0001] Cross-reference to related applications This application claims the benefit of priority to Korean Patent Application No. 10-2023-0133781, filed on October 6, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to a battery pack, and more specifically, to a battery pack capable of effectively absorbing heat when thermal runaway occurs within the battery pack due to events within the battery pack (impact, internal / external short circuit, etc.), and blocking heat transfer paths within the battery pack to prevent thermal runaway from starting in one battery module from spreading to other battery modules. Background Technology

[0003] In recent years, due to the depletion of fossil fuels, rising energy prices, increased concern about environmental pollution, and the growing demand for eco-friendly alternative energy sources, the demand for such energy is becoming an indispensable factor in future life. Therefore, research into various power generation technologies such as solar, wind, and tidal power continues, and energy storage devices (such as batteries) for more efficient use of the generated electricity are also receiving considerable attention.

[0004] Furthermore, with technological advancements and increasing demand for battery-powered electronic mobile devices and electric vehicles, the demand for batteries as an energy source is rapidly growing. Consequently, numerous studies have been conducted on batteries capable of meeting diverse needs.

[0005] Rechargeable batteries are gaining attention as an energy source for various products such as mobile devices and electric vehicles. They are considered an excellent alternative to existing products that use fossil fuels, and are also recognized as an environmentally friendly energy source because they do not produce byproducts during use.

[0006] Recently, in addition to using secondary batteries as an energy storage source, the demand for battery packs with multi-module structures in which multiple secondary batteries are assembled in series or parallel is increasing due to the need for high-capacity secondary battery structures.

[0007] When a battery pack is configured by connecting multiple battery cells in series or parallel with each other, a battery module is typically configured with at least one battery cell, and a battery pack is formed by adding a battery module assembly in which multiple battery modules are assembled, as well as other components.

[0008] A typical battery pack usually consists of battery modules arranged in multiple rows and a battery pack housing that houses the battery modules. Additionally, the battery pack may include crossbeams that separate the rows of battery modules from each other.

[0009] In conventional battery packs, thermal runaway can occur when an impact occurs within the pack or when an internal or external electrical short circuit occurs. Furthermore, if thermal runaway occurs in one battery module, thermal propagation (TP) can occur in adjacent battery modules.

[0010] In the case of conventional battery packs, major accidents, such as large-scale fires, can occur if thermal runaway and heat propagation are not effectively prevented, which is a problem. Therefore, a method to effectively prevent thermal runaway and heat propagation is needed. Summary of the Invention

[0011] Technical issues The present invention aims to solve the above-mentioned problems. The purpose of the present invention is to provide a battery pack that can effectively absorb heat when thermal runaway occurs in the battery pack due to events (impact, internal / external short circuit, etc.) and block the heat transfer path in the battery pack to prevent thermal runaway from starting from one battery module from spreading to other battery modules.

[0012] Technical solution The battery pack according to the present invention includes: a plurality of battery modules; a battery pack housing configured to house the plurality of battery modules therein; a crossbeam disposed within the battery pack housing between the battery modules and having a hollow portion therein; and an absorbent material disposed within the hollow portion of the crossbeam to absorb heat released from the battery modules.

[0013] The interior of the crossbeam can be configured as an empty tube, and an opening can be formed in the lower surface of the crossbeam facing the bottom surface of the battery pack housing.

[0014] The crossbeam can be attached to the bottom surface of the battery pack housing via connecting components.

[0015] The connecting member may include: a head disposed on the outside of the crossbeam; and a columnar portion extending from the head and through the crossbeam with a width narrower than the head, wherein the lower end of the columnar portion may pass through an opening formed in the lower surface of the crossbeam and be connected to the bottom surface of the battery pack housing.

[0016] The connecting member can be configured to connect the crossbeam to the bottom surface of the battery pack housing at a predetermined distance (G) from the bottom surface of the battery pack housing.

[0017] The absorbent material can be a material that changes from a solid phase to a liquid phase by absorbing the heat released from the battery module.

[0018] The absorbent material can be at least one of paraffin, fatty acid and salt hydrate.

[0019] After the absorbent material changes phase to liquid, it can leave the hollow part of the beam and be discharged to the outside of the beam.

[0020] The absorbent material that has undergone phase transformation into a liquid can be discharged to the outside of the beam through the opening in the beam.

[0021] A device for discharging absorbent material to the outside can be installed in the opening of the crossbeam.

[0022] The device can be configured as a valve, which can open when a specific pressure is reached.

[0023] Beneficial effects The battery pack according to the present invention may include a plurality of battery modules, a battery pack housing therein accommodating the plurality of battery modules, a crossbeam disposed within the battery pack housing between the battery modules and having a hollow portion therein, and an absorbent material disposed within the hollow portion of the crossbeam to absorb heat released from the battery modules. Therefore, when thermal runaway occurs within the battery pack due to an event within the battery pack (impact, internal / external short circuit, etc.), heat can be effectively absorbed to block the heat transfer path within the battery pack, thereby preventing thermal runaway originating from one battery module from being transmitted to other battery modules. Attached Figure Description

[0024] Figure 1 This is a plan view of the battery pack according to Embodiment 1 of the present invention.

[0025] Figure 2 It is along Figure 1 A sectional view taken by line A-A'.

[0026] Figure 3 The battery pack corresponding to Embodiment 2 of the present invention Figure 2 A partial sectional view. Detailed Implementation

[0027] In the following, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings to enable those skilled in the art to readily implement the invention. However, the invention may be implemented in several different forms and is not limited to or construed as follows.

[0028] To clearly explain the invention, detailed descriptions of parts unrelated to the subject matter or known technology that may unnecessarily obscure the main points of the invention have been omitted, and reference numerals have been added to the components in each figure throughout this specification. In this case, the same or similar reference numerals are assigned to the same or similar elements throughout the specification.

[0029] Furthermore, the terms or words used in this specification and claims should not be construed as having a general meaning or a dictionary-based meaning, but should be interpreted as meanings and concepts that are within the scope of this invention, based on the principle that the inventors can appropriately define the concepts of the terms in order to best describe and interpret their invention.

[0030] Example 1 Figure 1 This is a plan view of the battery pack according to Embodiment 1 of the present invention. Figure 2 It is along Figure 1 A sectional view taken by line A-A'.

[0031] In the following text, reference will be made to Figures 1 to 2 The battery pack according to Embodiment 1 of the present invention will be described.

[0032] The battery pack according to Embodiment 1 of the present invention may include a battery module, a battery pack housing, a crossbeam, and an absorbent material.

[0033] The battery module 110 may include multiple secondary batteries (not shown) and a module housing containing the multiple secondary batteries. Multiple battery modules 110 may be arranged within the battery pack housing 120.

[0034] The battery pack housing 120 can be configured to house multiple battery modules 110 therein. The battery modules 110 can be arranged in multiple rows within the battery pack housing 120. That is, referring to… Figure 1 Two battery modules 110 can be arranged in a row, and four rows of battery modules 110 can be arranged in a horizontal direction.

[0035] A crossbeam 130 is provided within the battery pack housing 120 and can be disposed between the battery modules 110. Furthermore, the crossbeam 130 may have a structure defining a hollow portion therein. Specifically, the crossbeam 130 may be in the form of a hollow tube. The crossbeam 130 may have a rectangular cross-section and may be in the form of a tube extending in the length or width direction of the battery modules 110.

[0036] When the battery modules 110 are arranged in multiple rows, a crossbeam 130 can be disposed between the first row of battery modules 110 and the second row of battery modules 110 adjacent to the first row. The crossbeam 130 can be made of a metallic material. The crossbeam 130 can be used to separate rows of battery modules 110 from each other, and can also be used to improve the durability of the battery pack housing 120. In addition, the presence of the crossbeam 130 itself can, to some extent, prevent thermal runaway from being directly transmitted from battery module 110 to battery module 110. However, the present invention can significantly improve the function of preventing thermal runaway.

[0037] Reference Figure 2The absorbent material 150 can be a material disposed within the hollow portion of the crossbeam 130. Furthermore, the absorbent material 150 can be a material that absorbs heat. The absorbent material 150 can be a material that absorbs heat from the battery module 110.

[0038] Therefore, the battery pack 100 with this structure according to Embodiment 1 of the present invention can first absorb heat when thermal runaway occurs within the battery pack 100 due to an event (impact, internal / external short circuit, etc.) within the battery pack 100, and then absorb heat more effectively. Since the crossbeam 130 is disposed adjacent to the battery module 110, the heat generated in the battery module 110 can be directly transferred to the crossbeam 130 and can be effectively absorbed by the absorbent material 150 within the crossbeam 130.

[0039] For example, the absorbent material 150 can be a material that undergoes a phase change when absorbing heat (phase change material (PCM)). Specifically, the absorbent material 150 can be a material that changes from a solid phase to a liquid phase when a certain temperature is reached. In this case, when the absorbent material 150 absorbs heat from the battery module 110, the absorbent material 150 can change from a solid phase to a liquid phase. When a material that undergoes a phase change in this manner is used, the amount of heat absorption can be increased, and therefore, heat absorption can be effectively achieved when thermal runaway occurs in the battery module 110.

[0040] For example, the absorbent material 150 may be at least one of paraffin, fatty acid, and salt hydrate.

[0041] Furthermore, the absorbent material 150 can become liquid, then leave the hollow portion of the crossbeam 130 and be discharged to the outside of the crossbeam 130. The absorbent material 150 can also be used as a material to block heat propagation when it leaves the hollow portion of the crossbeam 130 and is discharged to the outside of the crossbeam 130. Because the absorbent material 150 is in a liquid phase change state, it can be used to block flames, and when a material with a relatively high specific heat is used, it can also be used to effectively block heat propagation.

[0042] Reference Figure 2 The crossbeam 130 can be connected to the bottom surface 121 of the battery pack housing via a connecting member. For example, the connecting member can be a long-axis bolt. Specifically, the connecting member can include a head 141 and a columnar portion 142. The head 141 can be a portion disposed on the outside of the crossbeam 130. Furthermore, the head can be wider or larger than the columnar portion 142.

[0043] The columnar portion 142 can be configured to extend from the head 141 and through the crossbeam 130 with a width narrower than that of the head 141. A through-hole can be formed in the crossbeam 130 to allow the columnar portion 142 to pass through it. The width or diameter of the head 141 can be larger than the diameter of the through-hole formed in the crossbeam 130. Therefore, the head 141 may not need to enter the crossbeam 130.

[0044] The lower end of the columnar portion 142 can be connected to the bottom surface 121 of the battery pack housing by passing through an opening 131 formed in the lower surface 132 of the crossbeam. The method of connecting the lower end of the columnar portion 142 to the bottom surface 121 of the battery pack housing can include threaded connection or bonding using adhesive. The crossbeam 130, which is coupled to the battery pack housing 120 by the coupling member 140, can be used for alignment between the battery modules 110 or as a guide line.

[0045] An opening 131 can be formed in the lower surface 132 of the crossbeam facing the bottom surface 121 of the battery pack housing. The absorbent material 150, which has become liquid, can flow downwards and be discharged to the outside of the crossbeam 130 through the opening 131 formed on the lower side of the crossbeam 130. The absorbent material 150 discharged in this way can flow between battery modules 110. Therefore, the heat transfer path can be blocked. Furthermore, in the event of flame or thermal runaway propagation, the absorbent material 150 can be used to block the propagation of flame or thermal runaway. In this way, the heat transfer path within the battery pack 100 can be blocked to prevent thermal runaway starting from one battery module 110 from being transmitted to other battery modules 110.

[0046] According to Embodiment 1 of the present invention, when the battery pack 100 reaches a specific temperature, as the absorbent material 150 melts, it can first absorb heat. The melted absorbent material 150 can flow downward through the lower discharge structure to block the heat transfer path between the battery modules 110, thereby preventing the propagation of thermal runaway.

[0047] The connecting member 140 can connect the crossbeam 130 to the bottom surface 121 of the battery pack housing at a predetermined distance G. Due to this structure, the absorbent material 150 flowing to the underside of the crossbeam 130 can quickly diffuse to the circumferential surface of the crossbeam 130, thereby quickly blocking the heat transfer path between battery modules 110.

[0048] Example 2 Figure 3 The battery pack corresponding to Embodiment 2 of the present invention Figure 2 A partial sectional view.

[0049] The difference between Embodiment 2 and Embodiment 1 of the present invention is that: a device for discharging absorbent material into the lower opening of the crossbeam is also provided.

[0050] As much as possible, content that overlaps with Embodiment 1 will be omitted, and Embodiment 2 will be described focusing on the differences. That is, obviously, if content not described in Embodiment 2 is required, it can be regarded as content of Embodiment 1.

[0051] Reference Figure 3 The battery pack according to Embodiment 2 of the present invention may include a battery module 110, a battery pack housing 120, a crossbeam 130, and an absorbent material 150 similar to those in Embodiment 1. However, in the battery pack according to Embodiment 2 of the present invention, a device for discharging the absorbent material 150 to the outside may be provided in the opening 131 of the crossbeam 130. This device may be configured as a valve 260. For example, the valve 260 used herein can open when a specific pressure is reached.

[0052] Specifically, at a specific temperature, the pressure within the beam 130 increases as the absorbent material 150 undergoes a phase change from solid to liquid. For example, the absorbent material 150 may be a material whose volume expands with its phase change from solid to liquid. As the absorbent material 150 undergoes a phase change, the internal pressure within the beam 130 increases. As the internal pressure within the beam 130 increases in this manner, the valve 260 can open to allow the absorbent material 150 to pass through the opening 131 of the beam 130 and then be discharged to the outside of the beam 130.

[0053] For example, valve 260 can be a pressure relief valve or a safety valve, but it can also be a valve with a simple membrane or plug shape. That is, in the case of a valve in the form of a simple membrane or plug, the valve can be a valve that fully and irreversibly opens the opening 131 of the crossbeam 130 when a certain pressure is reached. When the valve 260 is open, the entire absorbent material 150 inside the crossbeam 130 can be discharged to the outside of the crossbeam 130 at once. If a valve 260 with a structure that allows the entire absorbent material 150 to be discharged to the outside of the crossbeam 130 at once is used, it can also be used to quickly and effectively block heat transfer.

[0054] Although embodiments of the invention have been described with reference to specific examples, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

[0055] [Explanation of reference numerals in the attached figures] 100: Battery pack 110: Battery Module 120: Battery pack casing 121: Bottom surface of the battery pack casing 130: Crossbeam 131: Opening 132: Lower surface of the crossbeam 140: Connecting components 141: Head 142: Columnar part 150: Absorbent Material 260: Valve G: Pre-determined distance

Claims

1. A battery pack, comprising: Multiple battery modules; A battery pack housing configured to house the plurality of battery modules therein; A crossbeam, disposed within the battery pack housing between the battery modules, and having a hollow interior; and An absorbent material is disposed within the hollow portion of the crossbeam to absorb heat released from the battery module.

2. The battery pack according to claim 1, wherein, The interior of the crossbeam is designed as a hollow tube, and An opening is formed in the lower surface of the crossbeam that faces the bottom surface of the battery pack housing.

3. The battery pack according to claim 2, wherein, The crossbeam is attached to the bottom surface of the battery pack housing via a connecting member.

4. The battery pack according to claim 3, wherein, The connecting component includes: A head, the head being disposed on the outer side of the crossbeam; and A columnar portion, which extends from the head and penetrates the crossbeam with a width narrower than the head. The lower end of the columnar portion passes through the opening formed in the lower surface of the crossbeam and is attached to the bottom surface of the battery pack housing.

5. The battery pack according to claim 3, wherein, The connecting member is configured to connect the crossbeam to the bottom surface of the battery pack housing at a predetermined distance (G) from the bottom surface of the battery pack housing.

6. The battery pack according to claim 2, wherein, The absorbent material is a material that changes from a solid phase to a liquid phase by absorbing the heat released from the battery module.

7. The battery pack according to claim 2, wherein, The absorbent material is at least one of paraffin, fatty acid, and salt hydrate.

8. The battery pack according to claim 6 or 7, wherein, After the absorbent material changes phase to liquid, the absorbent material leaves the hollow portion of the beam and is discharged to the outside of the beam.

9. The battery pack according to claim 8, wherein, The absorbent material, which has undergone phase transformation into a liquid, is discharged to the outside of the crossbeam through the opening in the crossbeam.

10. The battery pack according to claim 8, wherein, A device for discharging the absorbent material to the outside is provided in the opening of the crossbeam.

11. The battery pack according to claim 10, wherein, The device is configured as a valve, and The valve opens when a specific pressure is reached.

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