Battery pack

Abstract

The present invention relates to a battery pack and, more particularly, to a battery pack which can effectively absorb heat when thermal runaway occurs in the battery pack due to an event (impact, internal or external short circuit, etc.) in the battery pack and can block a heat transfer path in the battery pack to prevent the thermal runaway starting from one battery module from being transferred to another battery module. According to the present invention, the battery pack comprises: multiple battery modules; a pack housing in which the multiple battery modules are accommodated; a crossbeam disposed between the battery modules in the pack housing, the crossbeam having a hollow portion formed therein; and an absorption material positioned in the hollow portion of the cross beam to absorb heat emitted from the battery modules.

Description

battery pack

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority from Korean Patent Application No. 10-2023-0133781, filed October 6, 2023, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] The present invention relates to a battery pack, and more particularly, to a battery pack capable of effectively absorbing heat when thermal runaway occurs within the battery pack due to an event (impact, internal / external short circuit, etc.) within the battery pack, and blocking a heat transfer path within the battery pack to prevent thermal runaway starting from one battery module from being transmitted to other battery modules.

[0005] In recent years, rising energy prices due to the depletion of fossil fuels and growing concerns about environmental pollution have made the demand for eco-friendly alternative energy sources essential for future living. Research is continuing into various power generation technologies, such as solar, wind, and tidal power. Furthermore, significant interest is being focused on power storage devices, such as batteries, to more efficiently utilize the generated electricity.

[0006] Moreover, with the technological development and increasing demand for battery-powered electronic mobile devices and electric vehicles, the demand for batteries as an energy source is rapidly increasing, and accordingly, much research is being conducted on batteries that can meet various needs.

[0007] Secondary batteries are attracting significant attention as an energy source for a variety of products, including mobile devices and electric vehicles. These batteries are an excellent energy source that can replace the use of existing fossil fuel-powered products. Furthermore, they are gaining recognition as an eco-friendly energy source because they produce no byproducts from energy use.

[0008] Recently, as the need for large-capacity secondary battery structures has increased, including the use of secondary batteries as energy storage sources, the demand for battery packs with multi-module structures that assemble battery modules in which multiple secondary batteries are connected in series or parallel is increasing.

[0009] Meanwhile, when configuring a battery pack by connecting multiple battery cells in series / parallel, it is common to configure a battery module composed of at least one battery cell, and then configure a battery pack by adding a battery module assembly formed by assembling multiple such battery modules and other components.

[0010] A conventional battery pack typically includes battery modules arranged in multiple rows and a pack housing that accommodates the multiple battery modules. The pack may further include a crossbeam that separates the rows of battery modules.

[0011] In conventional battery packs, thermal runaway can occur when an impact occurs within the battery pack or when an internal or external electrical short occurs. Furthermore, if this thermal runaway occurs in a single battery module, it can propagate to nearby battery modules through thermal propagation (TP).

[0012] Conventional battery packs have been problematic because failure to effectively block thermal runaway and thermal runaway propagation can lead to major accidents, including large-scale fires. Therefore, a method to effectively block thermal runaway and thermal runaway propagation was urgently needed.

[0013] The present invention has been devised to solve the above problems, and the task of the present invention is to provide a battery pack that can effectively absorb heat when thermal runaway occurs within a battery pack due to an event (impact, internal / external short circuit, etc.) within the battery pack, and can block a heat transfer path within the battery pack to prevent thermal runaway starting from one battery module from being transmitted to other battery modules.

[0014] A 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 that is arranged between battery modules in the pack housing and has a hollow space formed therein, and an absorbent material that is positioned within the hollow space of the cross beam and absorbs heat from the battery modules.

[0015] The cross beam is formed in the form of a hollow tube, and an opening may be formed on the lower surface of the cross beam facing the bottom surface of the pack housing.

[0016] The crossbeam can be joined to the bottom surface of the pack housing by a fastening member.

[0017] The fastening member includes a head portion located on the outside of the crossbeam, and a pillar portion extending from the head portion with a narrower width than the head portion and penetrating the crossbeam, and a lower end of the pillar portion can pass through an opening formed on the lower surface of the crossbeam and be coupled to the bottom surface of the pack housing.

[0018] The fastening member can connect the crossbeam to the bottom surface of the pack housing at a predetermined distance (G) from the bottom surface of the pack housing.

[0019] The absorbent material may be a material that absorbs heat from the battery module and changes phase from solid to liquid.

[0020] The absorbent material may be at least one of paraffins, fatty acids, and salt hydrates.

[0021] After the absorbent material changes into a liquid, it can leave the hollow space of the crossbeam and be discharged to the outside of the crossbeam.

[0022] The absorbent material that has changed into a liquid phase can be discharged to the outside of the crossbeam through the opening of the crossbeam.

[0023] The opening of the crossbeam may be provided with means for discharging the absorbent material to the outside.

[0024] The means may be provided with a valve, which may be opened when a certain pressure is reached.

[0025] A battery pack according to the present invention comprises a plurality of battery modules, a pack housing that accommodates the plurality of battery modules therein, a cross beam that is arranged between battery modules in the pack housing and has a hollow interior, and an absorbent material that is positioned within the hollow interior of the cross beam and absorbs heat from the battery modules, thereby effectively absorbing heat when thermal runaway occurs within the battery pack due to an event (impact, internal / external short circuit, etc.) within the battery pack, and blocking a heat transfer path within the battery pack, thereby preventing thermal runaway that started in one battery module from being transmitted to other battery modules.

[0026] FIG. 1 is a plan view illustrating a battery pack according to Example 1 of the present invention.

[0027] Figure 2 is a cross-sectional view taken along line A-A' of Figure 1.

[0028] FIG. 3 is a cross-sectional view showing a portion corresponding to FIG. 2 in a battery pack according to Embodiment 2 of the present invention.

[0029] Hereinafter, with reference to the attached drawings, preferred embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the invention. However, the present invention may be implemented in various different forms and is not limited or restricted by the following examples.

[0030] In order to clearly explain the present invention, a detailed description of a part that is irrelevant to the description or a related known technology that may unnecessarily obscure the gist of the present invention has been omitted, and when adding reference signs to components of each drawing in this specification, the same or similar reference signs are attached to the same or similar components throughout the specification.

[0031] In addition, terms and words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical idea of ​​the present invention based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best way.

[0032]

[0033] Example 1

[0034] Fig. 1 is a plan view illustrating a battery pack according to Embodiment 1 of the present invention. Fig. 2 is a cross-sectional view taken along line A-A' of Fig. 1.

[0035] Hereinafter, a battery pack according to Example 1 of the present invention will be described with reference to FIGS. 1 and 2.

[0036] A battery pack according to Example 1 of the present invention may include a battery module, a pack housing, a cross beam, and an absorbent material.

[0037] A battery module (110) may be formed by including a plurality of secondary batteries (not shown) and a module case including a plurality of secondary batteries. A plurality of battery modules (110) may be included within a pack housing (120).

[0038] The pack housing (120) may be configured to accommodate a plurality of battery modules (110) therein. The battery modules (110) may be arranged in a plurality of rows within the pack housing (120). That is, referring to FIG. 1, the battery modules (110) form a row of two each, and these rows of battery modules (110) may be arranged in four rows in the horizontal direction.

[0039] A crossbeam (130) may be placed between battery modules (110) within a pack housing (120). Furthermore, the crossbeam (130) may have a hollow interior. Specifically, the crossbeam (130) may be formed in a hollow tube shape. The crossbeam (130) may have a rectangular cross-section and may be formed in a tube shape extending in the lengthwise or widthwise direction of the battery module (110).

[0040] When the battery modules (110) are arranged in multiple rows, a crossbeam (130) may be arranged between the first row of battery modules (110) and the second row of adjacent battery modules (110). The crossbeam (130) may include a metal material. The crossbeam (130) may serve to partition between rows of battery modules (110) and may also serve to improve the durability of the pack housing (120). In addition, the presence of the crossbeam (130) itself may block to some extent the direct propagation of thermal runaway from one battery module (110) to another battery module (110). However, the present invention can significantly improve this blocking function.

[0041] Referring to FIG. 2, the absorbent material (150) may be a material positioned within the hollow space of the crossbeam (130). The absorbent material (150) may be a material that absorbs heat. The absorbent material (150) may be a material that absorbs heat from the battery module (110).

[0042] Therefore, the battery pack (100) according to Embodiment 1 of the present invention having such a configuration can primarily 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 can absorb it more effectively. Since the cross beam (130) is arranged immediately adjacent to the battery module (110), the heat generated in the battery module (110) is directly transferred to the cross beam (130) and can be effectively absorbed by the absorbent material (150) within the cross beam (130).

[0043] The absorbent material (150) may be, for example, a phase change material (PCM) that changes phase when absorbing heat. In particular, it may be a material that changes phase from solid to liquid when a certain temperature is reached. In this case, the absorbent material (150) may change phase from solid to liquid when absorbing heat from the battery module (110). When a material that changes phase in this way is used, the amount of heat absorption can be increased, so that heat absorption can be effectively achieved when thermal runaway occurs in the battery module (110).

[0044] For example, the absorbent material (150) may be at least one of paraffins, fatty acids, and salt hydrates.

[0045] In addition, the absorbent material (150) can be discharged to the outside of the cross beam (130) after the phase change into a liquid, leaving the hollow space of the cross beam (130). When the absorbent material (150) is discharged to the outside of the cross beam (130) after leaving the hollow space of the cross, it can also function as a material that blocks heat transmission. Since the absorbent material (150) is in a state of phase change into a liquid, it can play a role in blocking flames, and when a material with a relatively high specific heat is used, it can also play a role in effectively blocking heat transmission.

[0046] Referring to FIG. 2, the crossbeam (130) may be connected to the bottom surface (121) of the pack housing by a fastening member. The fastening member may be, for example, a long-axis bolt. Specifically, the fastening member may include a head portion (141) and a pillar portion (142). The head portion (141) may be a portion located on the outside of the crossbeam (130). And, it may be larger or wider than the pillar portion (142).

[0047] The pillar portion (142) may be configured to extend from the head portion (141) with a width narrower 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 pillar portion (142) may penetrate the cross beam (130). The width or diameter of the head portion (141) may be larger than the diameter of the through hole formed in the cross beam (130). Accordingly, the head portion (141) may not enter the cross beam (130).

[0048] The lower end of the pillar portion (142) can be coupled to the bottom surface (121) of the pack housing by passing through the opening (131) formed in the lower surface (132) of the cross beam. The method by which the lower end of the pillar portion (142) is coupled to the bottom surface (121) of the pack housing may be a screw connection or an adhesive connection, and various coupling methods may be used. The cross beam (130) coupled to the pack housing (120) by the fastening member (140) can align the positions between the battery modules (110) or serve as a guide line.

[0049] An opening (131) may be formed on the lower surface (132) of the crossbeam facing the bottom surface (121) of the pack housing. The absorbent material (150) that has changed into a liquid phase may flow downward and be discharged to the outside of the crossbeam (130) through the opening (131) formed on the lower surface of the crossbeam (130). The absorbent material (150) discharged in this way may flow between the battery modules (110). Accordingly, the heat transfer path may be blocked. In addition, in a situation where a flame or thermal runaway is about to propagate, the absorbent material (150) may play a role in blocking the propagation of such flame or thermal runaway. In this way, by blocking the heat transfer path within the battery pack (100), it is possible to prevent a thermal runaway that started in one battery module (110) from being transmitted to another battery module (110).

[0050] The battery pack (100) according to Example 1 of the present invention can primarily absorb heat as the absorbent material (150) melts when a specific temperature is reached, and the melted absorbent material (150) can flow down through the lower drain structure, thereby blocking the heat transfer path between the battery modules (110) and preventing the propagation of thermal runaway.

[0051] Meanwhile, the fastening member (140) can connect the cross beam (130) to the bottom surface (121) of the pack housing at a predetermined distance (G) from the bottom surface (121) of the pack housing. With this structure, the absorbent material (150) flowing out from the lower side of the cross beam (130) can quickly spread to the main surface of the cross beam (130), thereby quickly blocking the heat transfer path between the battery modules (110) and the battery modules (110).

[0052]

[0053] Example 2

[0054] FIG. 3 is a cross-sectional view showing a portion corresponding to FIG. 2 in a battery pack according to Embodiment 2 of the present invention.

[0055] Embodiment 2 of the present invention differs from Embodiment 1 in that it further provides means for discharging an absorbent material into the lower opening of the cross beam.

[0056] We will explain Example 2 focusing on the differences, omitting as much of the common content as possible with Example 1. In other words, it is self-evident that if there is content not explained in Example 2, it can be supplemented through the content of Example 1.

[0057] Referring to FIG. 3, a battery pack according to Embodiment 2 of the present invention may include a battery module (110), a pack housing (120), a cross beam (130), and an absorbent material (150) similar to Embodiment 1. However, in the battery pack according to Embodiment 2 of the present invention, a means for discharging the absorbent material (150) to the outside may be provided in the opening (131) of the cross beam (130). This means may be provided as a valve (260). The valve (260) used here may be, for example, opened when a specific pressure is reached.

[0058] Specifically, when a certain temperature is reached, if the absorbent material (150) undergoes a phase change from a solid to a liquid, the pressure within the crossbeam (130) may increase. For example, the absorbent material (150) may be a material whose volume expands as it undergoes a phase change from a solid to a liquid. When the absorbent material (150) undergoes a phase change, the internal pressure within the crossbeam (130) may increase. When the internal pressure within the crossbeam (130) increases in this way, the valve (260) may open, 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).

[0059] The valve (260) may be, for example, a relief valve or a safety valve, but may also be a valve in the form of a simple membrane or plug. That is, in the case of a valve in the form of a simple membrane or plug, it may be a valve that irreversibly completely opens the opening (131) of the crossbeam (130) when a certain pressure is reached. When this valve (260) is opened, all of the absorbent material (150) within the crossbeam (130) can be discharged to the outside of the crossbeam (130) at once. If a valve (260) having a structure in which all of the absorbent material (150) is discharged to the outside of the crossbeam (130) at once is used, it can also play a role in quickly and effectively blocking heat transfer.

[0060]

[0061] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and various embodiments are possible within the scope equivalent to the technical idea of ​​the present invention and the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

[0062] [Explanation of symbols]

[0063] 100: Battery pack

[0064] 110: Battery module

[0065] 120: Pack Housing

[0066] 121: Bottom surface of pack housing

[0067] 130: Crossbeam

[0068] 131: Opening

[0069] 132: Lower side of crossbeam

[0070] 140: Absence of a binding

[0071] 141: Head

[0072] 142: Pillar

[0073] 150: Absorbent material

[0074] 260: Valve

[0075] G: a certain interval

Claims

1. Multiple battery modules; A pack housing accommodating the plurality of battery modules therein; A cross beam disposed between the battery modules within the pack housing and having a hollow space formed therein; and A battery pack characterized in that it includes an absorbent material positioned within the hollow portion of the crossbeam and absorbing heat from the battery module.

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

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

4. In claim 3, The above decision absence is, a head portion located on the outside of the crossbeam; and Including a pillar portion extending from the head portion to a narrower width than the head portion and penetrating the cross beam, A battery pack characterized in that the lower part of the pillar part passes through the opening formed on the lower surface of the cross beam and is coupled to the bottom surface of the pack housing.

5. In claim 3, A battery pack characterized in that the fastening member connects the crossbeam to the bottom surface of the pack housing at a predetermined distance (G) from the bottom surface of the pack housing.

6. In claim 2, A battery pack characterized in that the above absorbent material is a material that absorbs the heat from the battery module and changes phase from solid to liquid.

7. In claim 2, A battery pack characterized in that the above absorbent material is at least one of paraffins, fatty acids, and salt hydrates.

8. In claim 6 or claim 7, A battery pack characterized in that the absorbent material changes into the liquid and then leaves the hollow space of the cross beam and is discharged to the outside of the cross beam.

9. In claim 8, A battery pack characterized in that the absorbent material that has changed into a liquid phase is discharged to the outside of the cross beam through the opening of the cross beam.

10. In claim 8, A battery pack characterized in that the opening of the cross beam is provided with a means for discharging the absorbent material to the outside.

11. In claim 10, The above means is provided with a valve, A battery pack characterized in that the valve opens when a specific pressure is reached.

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