Battery pack

Abstract

The present invention relates to a battery pack, and more particularly to a battery pack that can effectively absorb heat when thermal runaway occurs within the battery pack due to an event within the battery pack (such as an impact or an internal / external short circuit), and can block the heat transfer path within the battery pack to prevent thermal runaway that started in one battery module from spreading to other battery modules.

Description

Technical Field

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0133781 filed on October 6, 2023, the entire contents disclosed in the documents of said Korean Patent Application are incorporated herein as part of the present specification.

[0002] The present invention relates to a battery pack, which can effectively absorb heat when thermal runaway occurs inside the battery pack caused by events (such as impact, internal and external short circuits, etc.) within the battery pack, and can block the heat transfer path inside the battery pack to prevent thermal runaway that starts from one battery module from being transmitted to other battery modules.

Background Art

[0003] In recent years, along with the rise in prices of energy sources due to the depletion of fossil fuels and the growing concern over environmental pollution, the demand for environmentally friendly alternative energy sources has become an essential and indispensable factor for future life. Accordingly, research on various power generation technologies such as solar power, wind power, and tidal power is ongoing, and great interest continues to be directed toward power storage devices such as batteries for using the electric energy generated in such a manner more efficiently.

[0004] In addition, as technological development and demand for electronic mobile devices and battery electric vehicles that use batteries increase, the demand for batteries as an energy source is rising sharply, and accordingly, a great deal of research on batteries that can meet various requirements is being conducted.

[0005] Secondary batteries have received much attention as an energy source in a group of products such as various mobile devices and electric vehicles. Such secondary batteries are excellent energy resources that can replace the use of existing products that use fossil fuels, and do not generate by-products from the use of energy, so they are attracting attention as an environmentally friendly energy source.

[0006] Recently, with the increasing need for large-capacity secondary battery structures, including their use as energy storage sources, there has been a growing demand for multi-module battery packs, which are collections of battery modules in which multiple secondary batteries are connected in series or parallel.

[0007] On the other hand, when configuring a battery pack by connecting multiple battery cells in series or parallel, it is common to configure a battery module consisting of at least one battery cell, and then to configure a battery pack by adding a battery module assembly, which is formed by combining multiple such battery modules, and other components.

[0008] Conventional battery packs typically include battery modules arranged in multiple rows and a pack housing that accommodates the multiple battery modules. They may also further include crossbeams that separate the rows of battery modules from each other.

[0009] In conventional battery packs, thermal runaway could occur if an impact occurred within the battery pack or if an electrical short circuit occurred internally or externally. Furthermore, if thermal runaway occurred in one battery module, thermal propagation (TP) could occur to adjacent battery modules.

[0010] In conventional battery packs, the inability to effectively block thermal runaway and its propagation has been a problem, as it can lead to major accidents such as large fires. Therefore, there is a need for methods to effectively block such thermal runaway and its propagation. [Overview of the project] [Problems that the invention aims to solve]

[0011] The present invention was devised to solve the above-mentioned problems, and the object 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 an event inside the battery pack (such as shock or internal / external short circuit), and can block the heat transfer path inside the battery pack to prevent thermal runaway that started in one battery module from being transmitted to other battery modules. [Means for solving the problem]

[0012] The battery pack according to the present invention includes a plurality of battery modules, a pack housing that houses the plurality of battery modules inside, a crossbeam positioned between the battery modules within the pack housing and having a hollow inside, and an absorbing material located within the hollow of the crossbeam that absorbs heat emitted from the battery modules.

[0013] The crossbeam is provided in the form of a hollow tube, and an opening may be formed on the lower surface of the crossbeam facing the bottom surface of the pack housing.

[0014] The crossbeam may be attached to the bottom surface of the pack housing by fastening members.

[0015] The fastening member includes a head portion located on the outside of the crossbeam and a column portion extending from the head portion with a narrower width than the head portion and penetrating the crossbeam. The lower end of the column portion may pass through an opening formed in the lower surface of the crossbeam and be connected to the bottom surface of the pack housing.

[0016] The fastening member may connect the crossbeam to the bottom surface of the pack housing while the crossbeam is separated from the bottom surface of the pack housing by a predetermined distance (G).

[0017] The absorbing material may be a substance that absorbs heat emitted from the battery module and undergoes a phase change from solid to liquid.

[0018] The absorbing material may be at least one of paraffins, fatty acids, and salt hydrates.

[0019] After undergoing a phase change to a liquid, the absorbing material may exit from the hollow interior of the cross beam and be discharged to the outside of the cross beam.

[0020] The absorbing material that has undergone a phase change to a liquid may be discharged to the outside of the cross beam through an opening of the cross beam.

[0021] The opening of the cross beam may be provided with a means for discharging the absorbing material to the outside.

[0022] As the means, a valve may be provided, and the valve may be configured to open when a specific pressure is reached. [Effects of the Invention]

[0023] The battery pack according to the present invention includes a plurality of battery modules, a pack housing that accommodates the plurality of battery modules therein, a cross beam disposed between the battery modules inside the pack housing and having a hollow interior formed therein, and an absorbing material located within the hollow interior of the cross beam to absorb heat emitted from the battery modules, whereby heat can be effectively absorbed when thermal runaway occurs in the battery pack due to events (impact, internal or external short circuits, etc.) inside the battery pack, and the heat transfer path within the battery pack is blocked to prevent thermal runaway starting from one battery module from propagating to other battery modules. [Brief Description of the Drawings]

[0024] [Figure 1] This is a plan view showing the battery pack according to Embodiment 1 of the present invention. [Figure 2] This is a cross-sectional view taken along line A-A' of Figure 1. [Figure 3] This is a cross-sectional view showing a portion corresponding to Figure 2 in a battery pack according to Embodiment 2 of the present invention. [Mode for Carrying Out the Invention]

[0025] Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail so that those skilled in the art to which the present invention pertains can easily carry out the invention. However, the present invention can be implemented in various different forms, and is not restricted or limited to the following embodiments.

[0026] To clearly describe the present invention, detailed descriptions of parts not related to the description or related known technologies that may obscure the gist of the present invention are omitted. In assigning reference numerals to the constituent members of each drawing in the present specification, the same or similar reference numerals are assigned to the same or similar constituent members throughout the entire specification.

[0027] It should be noted that the terms and words used in the present specification and claims should not be construed as being limited to their ordinary or dictionary meanings, and in accordance with the principle that the inventor can appropriately define the concept of terms in order to explain his or her invention in the best way, they should be interpreted to have the meaning and concept consistent with the technical idea of the present invention.

[0028] Embodiment 1 Figure 1 is a plan view showing a battery pack according to Embodiment 1 of the present invention. Figure 2 is a cross-sectional view taken along line A-A' of Figure 1.

[0029] Hereinafter, the battery pack according to Embodiment 1 of the present invention will be described with reference to Figure 1 and Figure 2.

[0030] The battery pack according to Embodiment 1 of the present invention may include a battery module, a pack housing, a cross beam, and an absorbent material.

[0031] The battery module 110 may include a plurality of secondary batteries (not shown) and a module case containing the plurality of secondary batteries. A plurality of the battery modules 110 may be contained within the pack housing 120.

[0032] The pack housing 120 may be configured to house multiple battery modules 110 inside. The battery modules 110 may be arranged in multiple rows within the pack housing 120. That is, referring to Figure 1, the battery modules 110 may form rows of two, and four such rows of battery modules 110 may be arranged horizontally.

[0033] The crossbeam 130 may be positioned between the battery modules 110 within the pack housing 120. The crossbeam 130 may also have a hollow interior. Specifically, the crossbeam 130 may be provided in the form of a hollow tube. The crossbeam 130 may have a square cross-section and may be provided in the form of a tube extending in the length or width direction of the battery module 110.

[0034] If the battery modules 110 are arranged in multiple rows, a crossbeam 130 may be placed between the first row of battery modules 110 and the second row of the adjacent battery modules 110. The crossbeam 130 may include a metallic material. The crossbeam 130 can also serve to demarcate the rows of battery modules 110 and improve the durability of the pack housing 120. Furthermore, the mere presence of the crossbeam 130 can, to some extent, block the direct propagation of thermal runaway from one battery module 110 to the other. However, the present invention can further enhance such a blocking role.

[0035] Referring to Figure 2, the absorbing material 150 may be a material located within the hollow of the crossbeam 130. Furthermore, the absorbing material 150 may be a material that absorbs heat. The absorbing material 150 may be a material that absorbs heat emitted from the battery module 110.

[0036] Therefore, the battery pack 100 according to Embodiment 1 of the present invention, having such a configuration, can temporarily absorb heat when thermal runaway occurs within the battery pack 100 due to an event within the battery pack 100 (such as an impact or an internal / external short circuit), and can absorb it more effectively. Because the crossbeam 130 is positioned adjacent to the battery module 110, the heat generated from the battery module 110 is immediately transferred to the crossbeam 130 and effectively absorbed by the absorbing material 150 within the crossbeam 130.

[0037] The absorbent material 150 may be, for example, a material that undergoes a phase change when it absorbs heat (PCM, Phase Change Material). In particular, it may be a material that undergoes a phase change from solid to liquid when it reaches a specific temperature. In that case, when the absorbent material 150 absorbs the heat emitted from the battery module 110, it undergoes a phase change from solid to liquid. When a material that undergoes such a phase change is used, the amount of heat absorbed can be increased, so heat can be effectively absorbed when thermal runaway occurs in the battery module 110.

[0038] For example, the absorbing substance 150 may be at least one of the following substances: paraffins, fatty acids, and salt hydrates.

[0039] Furthermore, after the absorbent material 150 undergoes a phase change to a liquid, it may detach from the hollow of the crossbeam 130 and be discharged to the outside of the crossbeam 130. When the absorbent material 150 detaches from the hollow of the crossbeam and is discharged to the outside of the crossbeam 130, it can also function as a material that blocks heat propagation. Since the absorbent material 150 is in a liquid phase change state, it can also play a role in blocking flames, and if a material with a relatively high specific heat is used, it can also effectively block heat propagation.

[0040] Referring to Figure 2, the crossbeam 130 may be connected to the bottom surface 121 of the pack housing by fastening members. The fastening members may, for example, be long-shaft bolts. Specifically, the fastening members may include a head portion 141 and a column portion 142. The head portion 141 may be located on the outside of the crossbeam 130. It may also be wider or larger than the column portion 142.

[0041] The column portion 142 may extend from the head portion 141 with a narrower width than the head portion 141 and penetrate the cross beam 130. A through-hole may be formed in the cross beam 130 so that the column portion 142 can penetrate the cross beam 130. The width or diameter of the head portion 141 may be even larger than the diameter of the through-hole formed in the cross beam 130. This prevents the head portion 141 from entering the cross beam 130.

[0042] The lower end of the column portion 142 may pass through an opening 131 formed in the lower surface 132 of the crossbeam and be connected to the bottom surface 121 of the pack housing. The method by which the lower end of the column portion 142 is connected to the bottom surface 121 of the pack housing may be by screwing or adhesive, and various connection methods can be used. The crossbeam 130 fastened to the pack housing 120 by the fastening member 140 can align the positions of the battery modules 110 or serve as a guideline.

[0043] An opening 131 may be formed in the lower surface 132 of the crossbeam facing the bottom surface 121 of the pack housing. The absorbent material 150, which has undergone a phase change to a liquid, is discharged to the outside of the crossbeam 130 through the opening 131 formed on the lower side of the crossbeam 130 in a manner that flows downward. The absorbent material 150 thus discharged flows into the space between the battery modules 110. This blocks the heat transfer path. Furthermore, in situations where there is a risk of flame or thermal runaway propagation, the absorbent material 150 can play a role in blocking the propagation of such flame or thermal runaway. In this manner, the heat transfer path within the battery pack 100 can be blocked, preventing thermal runaway that started in one battery module 110 from being transmitted to other battery modules 110.

[0044] In the battery pack 100 according to Embodiment 1 of the present invention, when a specific temperature is reached, the absorbent material 150 melts and temporarily absorbs heat, and the melted absorbent material 150 flows downward through the lower drain structure, thereby blocking the heat transfer path between the battery modules 110 and preventing the propagation of thermal runaway.

[0045] On the other hand, the fastening member 140 can connect the crossbeam 130 to the bottom surface 121 of the pack housing while maintaining a predetermined distance G from the bottom surface 121 of the pack housing. With such a structure, the absorbent material 150 that flows out to the underside of the crossbeam 130 spreads rapidly across the main surface of the crossbeam 130, thereby quickly blocking the heat propagation path between the battery modules 110.

[0046] Embodiment 2 Figure 3 is a cross-sectional view showing the portion of the battery pack according to Embodiment 2 of the present invention that corresponds to Figure 2.

[0047] Embodiment 2 of the present invention differs from Embodiment 1 in that it further comprises means for discharging an absorbent material into the lower opening of the crossbeam.

[0048] This explanation will focus on the differences between Embodiment 2 and Embodiment 1, omitting as much common information as possible. In other words, it goes without saying that any information not described in Embodiment 2 can be supplemented by the information in Embodiment 1.

[0049] Referring to Figure 3, the battery pack according to Embodiment 2 of the present invention may include a battery module 110, a pack housing 120, a crossbeam 130, and an absorbent material 150, similar to Embodiment 1. However, in the battery pack according to Embodiment 2 of the present invention, the opening 131 of the crossbeam 130 may be provided with means for discharging the absorbent material 150 to the outside. Such means may include a valve 260. Here, the valve 260 used may, for example, be one that opens when a certain pressure is reached.

[0050] Specifically, when the absorbent material 150 undergoes a phase change from solid to liquid upon reaching a certain temperature, the pressure inside the crossbeam 130 increases. For example, the absorbent material 150 may be a substance whose volume expands upon phase change from solid to liquid. When the absorbent material 150 undergoes a phase change, the internal pressure inside the crossbeam 130 increases. When the internal pressure inside the crossbeam 130 increases in this way, the valve 260 opens, allowing the absorbent material 150 to pass through the opening 131 of the crossbeam 130 and be discharged to the outside of the crossbeam 130.

[0051] Valve 260 may be, for example, a relief valve or a safety valve, but it may also be a simple membrane or cap-shaped valve. That is, a simple membrane or cap-shaped valve may be a valve that irreversibly and completely opens the opening 131 of the crossbeam 130 when a certain pressure is reached. When such a valve 260 is opened, all of the absorbent material 150 inside the crossbeam 130 can be discharged to the outside of the crossbeam 130 at once. When a valve 260 is used that is designed to discharge all of the absorbent material 150 to the outside of the crossbeam 130 at once, it can also serve to quickly and effectively block heat transfer.

[0052] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and various implementations are possible within the equivalent scope of the technical concept of the present invention and the appended claims by persons with ordinary skill in the art to which the present invention pertains. [Explanation of Symbols]

[0053] 100 Battery Pack 110 Battery Modules 120 Pack Housing 121 Pack Housing Bottom 130 Crossbeam 131 Aperture 132 Underside of the crossbeam 140 Fastening members 141 Head section 142 Column section 150 absorbent substances 260 valves G predetermined interval

Claims

1. Multiple battery modules, A pack housing that houses the aforementioned multiple battery modules inside, A crossbeam is positioned between the battery modules within the pack housing and has a hollow interior. A battery pack characterized by including an absorbing material located within the hollow of the crossbeam and absorbing heat emitted from the battery module.

2. The aforementioned crossbeam is provided in the form of a hollow tube, The battery pack according to claim 1, characterized in that an opening is formed on the lower surface of the cross beam facing the bottom surface of the pack housing.

3. The battery pack according to claim 2, characterized in that the crossbeam is connected to the bottom surface of the pack housing by a fastening member.

4. The fastening member is The head portion located on the outside of the aforementioned crossbeam, It includes a column portion that extends from the head portion with a width narrower than the head portion and penetrates the cross beam, The battery pack according to claim 3, characterized in that the lower end of the column portion passes through the opening formed in the lower surface of the crossbeam and is connected to the bottom surface of the pack housing.

5. The battery pack according to claim 3, characterized in that the fastening member connects the crossbeam to the bottom surface of the pack housing while the crossbeam is separated from the bottom surface of the pack housing by a predetermined distance (G).

6. The battery pack according to claim 2, characterized in that the absorbing material is a material that absorbs the heat emitted from the battery module and undergoes a phase change from solid to liquid.

7. The battery pack according to claim 2, characterized in that the absorbing substance is at least one of paraffins, fatty acids, and salt hydrates.

8. The battery pack according to claim 6 or 7, characterized in that the absorbing material undergoes a phase change to the liquid, and then detaches from the hollow of the crossbeam and is discharged to the outside of the crossbeam.

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

10. The battery pack according to claim 8, characterized in that the opening of the crossbeam is provided with means for discharging the absorbent material to the outside.

11. The means includes a valve, The battery pack according to claim 10, characterized in that the valve is opened when a specific pressure is reached.

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