Cylindrical battery module and device including same

Abstract

A cylindrical battery module according to an embodiment of the present invention comprises: a plurality of plate-shaped battery cells each having electrode leads protruding from both ends; a central shaft to which side surfaces of the plurality of plate-shaped battery cells are fixed; and a cylindrical case accommodating the plurality of plate-shaped battery cells and the central shaft, wherein the plurality of plate-shaped battery cells are fixed radially around the central shaft, the central shaft includes a circular tube and a passage inside the circular tube, and the circular tube has therein a plurality of venting doors which respectively correspond to the plurality of plate-shaped battery cells and through which gases generated from the plurality of plate-shaped battery cells are discharged.

Description

Cylindrical battery module and device including the same

[0001] Cross-citation with related application(s)

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0154613 filed November 4, 2024, and all contents disclosed in the document of said Korean patent application are incorporated herein as part of this specification.

[0003] The present invention relates to a cylindrical battery module and a device including the same, and more specifically, to a cylindrical battery module and a device including the same in which cooling efficiency is improved and safety is enhanced by implementing the cylindrical module with plate-shaped battery cells.

[0004] Rechargeable batteries are attracting significant attention as an energy source for various product categories, including mobile devices and electric vehicles. As a promising energy resource capable of replacing conventional products that use fossil fuels, these batteries are gaining prominence as an eco-friendly energy source because they do not generate byproducts during use.

[0005] Recently, with the increasing need for high-capacity secondary battery structures, including their utilization as energy storage sources, there is a growing demand for battery packs with a multi-module structure that aggregates battery modules in which multiple secondary batteries are connected in series or parallel.

[0006] Meanwhile, when configuring a cylindrical battery module by connecting multiple battery cells in series or parallel, it is common practice to configure a battery module consisting of at least one battery cell and to configure a battery pack by adding other components using this at least one battery module.

[0007] When configuring a battery module using multiple battery cells, the module is generally constructed in the shape of a rectangular prism due to design issues such as battery pack layout, busbar structure, or busbar length efficiency. In this case, plate-shaped battery cells are stacked in one direction to form a rectangular prism shape. When applying a cooling path to cool the battery cells arranged in this way, the path must be placed on the outermost surfaces, such as the top, bottom, and sides of the rectangular prism. However, in this arrangement, there is a problem in that it is difficult to efficiently cool battery cells located far from the cooling path. Furthermore, because the battery cells are densely packed in close proximity, not only is it difficult to increase cooling efficiency, but heat propagation between battery cells also occurs easily. Consequently, if a high temperature occurs in one battery cell, heat and gas rapidly propagate to adjacent battery cells.

[0008] Furthermore, in order to vent gases generated from the battery cells, a venting hole or venting channel must be configured separately from the cooling path, which can complicate the structure of the battery module or battery pack and increase costs. Therefore, a new batch of battery modules is required to achieve more efficient cooling of the battery cells and exhaust of venting gases.

[0009] The problem to be solved by the present invention is to provide a new batch of battery modules capable of efficiently achieving cooling of the battery cell and exhaust of venting gas.

[0010] The problems of the present invention are not limited to those mentioned above, and other unmentioned problems will be clearly understood by those skilled in the art from the description below.

[0011] A cylindrical battery module according to an embodiment of the present invention for realizing the above objective comprises a plurality of plate-shaped battery cells, each having an electrode lead protruding from both ends, a central axis to which the sides of the plurality of plate-shaped battery cells are fixed, and a cylindrical case that accommodates the plurality of plate-shaped battery cells and the central axis, wherein the plurality of plate-shaped battery cells are fixed radially around the central axis, and the central axis comprises a circular tube and a passage inside the circular tube, and the circular tube has a plurality of venting doors formed therein corresponding to each of the plurality of plate-shaped battery cells to discharge gas generated from the plurality of plate-shaped battery cells.

[0012] A cooling plate may be inserted between adjacent plate-shaped battery cells among the plurality of plate-shaped battery cells mentioned above.

[0013] The above passage may be a cooling path through which a refrigerant supplied from the outside passes by communicating with the outside.

[0014] The above venting door may include a door portion that opens inwardly into the circular tube by external pressure, and a hinge portion that fixes the door portion to the circular tube.

[0015] Each of the above plurality of plate-shaped battery cells may include a venting guide formed at a position corresponding to the venting door.

[0016] Each of the above-mentioned plurality of plate-shaped battery cells includes an electrode assembly and a pouch case that accommodates the same, and the pouch case includes a sealing portion formed along at least a portion of the edge of the pouch case and formed by heat-sealing the pouch case, and the venting guide may be formed in the sealing portion.

[0017] At both ends of the above cylindrical case, a donut-shaped terminal cover connected to the electrode lead may be disposed.

[0018] The polarity of the terminal covers disposed at each of the above two ends may be different from each other.

[0019] The above refrigerant may be an insulating fluid with fire extinguishing performance.

[0020] A device according to another embodiment of the present invention may include the cylindrical battery module.

[0021] According to a cylindrical battery module and a device including the same according to one embodiment of the present invention, cooling of the battery cell and discharge of venting gas can be achieved efficiently.

[0022] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description in the claims.

[0023] FIG. 1 is a perspective view showing a cylindrical battery module according to one embodiment of the present invention.

[0024] Figure 2 is a drawing showing the state in which the cylindrical case and terminal cover have been removed from the cylindrical battery module of Figure 1.

[0025] Figure 3 is a drawing showing a cross-section along III-III' of Figure 1.

[0026] Figure 4 is a diagram showing the battery cell and the central axis in Figure 2.

[0027] Figure 5 is a cross-sectional view showing an enlarged view of the venting door portion of the central axis in Figure 4.

[0028] Figure 6 is a drawing to explain how the terminal cover is combined in Figure 2.

[0029] The embodiments described below are presented as examples to aid in understanding the invention, and it should be understood that the invention may be implemented with various modifications different from the embodiments described herein. However, in describing the invention, detailed descriptions and specific illustrations of related known functions or components are omitted if it is determined that such detailed descriptions or specific illustrations might unnecessarily obscure the essence of the invention. Furthermore, the attached drawings are not drawn to actual scale to aid in understanding the invention, and the dimensions of some components may be exaggerated.

[0030] The first and second terms used in this application may be used to describe various components, but the components should not be limited by the terms. The terms are used solely for the purpose of distinguishing one component from another.

[0031] Furthermore, the terms used in this application are used merely to describe specific embodiments and are not intended to limit the scope of the rights. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as “comprising,” “consisting of,” or “consisting of” are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0032] Hereinafter, the configuration of a cylindrical battery module according to an embodiment of the present invention will be described with reference to FIGS. 1 to 6.

[0033] FIG. 1 is a perspective view showing a cylindrical battery module according to an embodiment of the present invention, FIG. 2 is a drawing showing the state in which the cylindrical case and terminal cover are removed from the cylindrical battery module of FIG. 1, FIG. 3 is a drawing showing a cross-section along III-III' of FIG. 1, FIG. 4 is a drawing showing the battery cell and the central axis in FIG. 2, FIG. 5 is a cross-sectional view showing an enlarged view of the venting door portion of the central axis in FIG. 4, and FIG. 6 is a drawing for explaining the connection of the terminal cover in FIG. 2.

[0034] Referring to FIGS. 1 to 6, a cylindrical battery module (10) according to one embodiment of the present invention comprises a plurality of plate-shaped battery cells (100), a central axis (300) to which the plurality of plate-shaped battery cells are fixed, a cylindrical case (200) that accommodates the plurality of plate-shaped battery cells (100) and the central axis, and end covers (210, 220) that are coupled to both ends of the cylindrical case (200).

[0035] A plurality of plate-shaped battery cells (100) may be configured as secondary batteries, such as pouch-shaped secondary batteries. These plate-shaped battery cells (100, which may also be simply referred to as battery cells (100) below) may include an electrode assembly, a pouch case that accommodates the electrode assembly, and an electrode lead (110) protruding from the electrode assembly.

[0036] The electrode assembly may be a stacked electrode assembly in which a plurality of anodes and cathodes cut into units of a certain size are sequentially stacked with a separator interposed therebetween, but is not limited thereto, and may also be a wound-type assembly in which a structure in which anodes and cathodes are stacked with a separator interposed therebetween is wound.

[0037] The electrode leads (110) can be electrically connected to the electrode assembly. These electrode leads (110) may be provided in a pair. Parts of the pair of electrode leads (110) may each protrude outward from the pouch case at the front and rear (both ends in the longitudinal direction of the electrode assembly) of the pouch case. The configuration of the plate-shaped battery cell (100) described above is one example, and the shape of the battery cell (100) can be varied in many ways.

[0038] As shown in FIG. 4, a venting guide (121) may be formed in the plate-shaped battery cell (100). The pouch case of the plate-shaped battery cell (100) may be formed by folding a sheet-shaped pouch in half so that an electrode assembly is accommodated inside, and forming a sealing portion (120) through heat fusion on three sides excluding the folded line. At this time, the venting guide (121) may be formed on the sealing portion (120) formed on one side where the electrode lead (110) does not protrude. The venting guide (121) may act as a vent for gas generated when the temperature rises inside the pouch case. To induce gas and rapidly destroy it to discharge the gas, the venting guide (121) may be formed to have a smaller sealing width in the sealing portion (120) compared to other parts. Alternatively, it may be implemented by having the same width but with a weaker sealing strength, and is not particularly limited. In addition, when the battery cell (100) expands, it is preferable that it be formed corresponding to the center of the electrode assembly in the longitudinal direction, which is the part where deformation and expansion occur the most.

[0039] As described below, this venting guide (121) is positioned to correspond to a venting door (321) formed on the central axis (300), thereby allowing the venting gas generated from the battery cell (100) to be discharged into a passage (CP) inside the central axis (300).

[0040] Referring to FIG. 2, a plurality of plate-shaped battery cells (100) can be fixed radially around a central axis (300). At this time, the sides of the battery cells (100) can be fixed to the central axis (300) so that the electrode leads (110) of the battery cells (100) are each positioned toward the end in the longitudinal direction of the central axis (300). In addition, among the sides of the battery cells (100), a venting guide (121) as described above can be positioned and fixed to correspond to the venting door (321) of the central axis (300). By fixing a plurality of plate-shaped battery cells (100) radially along the circumference of a pipe-shaped central axis (300), a cylindrical battery cell assembly can be realized as shown in FIG. 2.

[0041] A battery cell assembly formed by fixing a plurality of plate-shaped battery cells (100) radially to a central axis (300) is housed in a cylindrical case (200). The cylindrical case (200) may be formed of a metal material having rigidity to protect the battery cells (100) inside, but is not specifically limited. The cylindrical case (200) may have a cylindrical shape with both ends open, and may be arranged so that electrode leads (110) are exposed at both open ends. Additionally, terminal covers (210, 220) may be attached to both ends.

[0042] As shown in FIGS. 2 and 3, a cooling plate (400) may be disposed between a plurality of plate-shaped battery cells (100) arranged radially. The cooling plate (400) can absorb heat emitted from the battery cells (100) to prevent a rapid rise in temperature of the battery cells (100). In cross-section, as shown in FIG. 3, it may be a fan shape in which the width increases as it extends outward from the center of the central axis (300) to correspond to the shape of the space between the battery cells (100). By disposing of such a cooling plate (400), the space between the radially arranged battery cells (100) can be filled and supported, thereby allowing the battery cells (100) to be fixed more effectively.

[0043] The material of the cooling plate (400) can be appropriately selected from the material of the cooling plate (400) placed between battery cells in a conventional battery module, and is not particularly limited.

[0044] The central axis (300) includes a circular tube (310) and a passage (CP) inside the circular tube. As described above, the side of the battery cell (100) can be fixed around the circumference of the circular tube (310). Various fixing methods may be applied, and for example, as shown in FIG. 4, a protrusion may be formed to partition the part where the battery cell (100) is fixed. Alternatively, the battery cell (100) may be fixed through an adhesive means, or the battery cell (100) may be fixed by providing a separate gripping means or a groove, and is not particularly limited.

[0045] The passage (CP) inside the circular tube (310) may be a cooling channel. That is, it may be configured to communicate with the outside so that a refrigerant flows through the passage (CP). Through this configuration, a uniform cooling effect can be obtained for the battery cells (100) fixed radially on the central axis (300). In conventional rectangular battery modules, cooling of the battery cells was achieved by placing a cooling plate with a cooling channel applied to a part of the outer surface of the rectangular prism; however, in this case, there was a problem that cooling of battery cells far from the cooling plate could not be achieved effectively compared to other cells. However, as in the present invention, by circulating a refrigerant through the passage (CP) inside the central axis (300) of the center where the battery cells (100) are fixed radially to form a cooling channel, efficient and uniform large-area cooling can be achieved for all battery cells. At this time, a material having insulating and fire-extinguishing properties may be used as the refrigerant, and is not particularly limited. In addition, to increase cooling efficiency, a material with high thermal conductivity can be used as a circular tube (310) that is in direct contact with the battery cell (100).

[0046] In the circular tube (310), a venting door (320) may be formed corresponding to the part where the battery cell (100) is fixed. That is, a plurality of venting doors (320) may be formed corresponding to a plurality of battery cells (100). More specifically, a venting door (320) is formed corresponding to the part where the venting guide (121) of the battery cell (100) is fixed. When a thermal event occurs in the battery cell (100) and high-temperature flame or gas is generated from the battery cell (100), it can be guided into the interior of the circular tube (310), i.e., the passage (CP), through the venting door (320). By doing so, even if a thermal event occurs in some of the battery cells (100), the high-temperature flame or gas is directly guided into the passage (CP), thereby minimizing the impact of the flame on other injection molded parts or components within the cylindrical battery module (10). In addition, beyond minimizing the influence of flame between battery cells (100) within a cylindrical battery module (10), even when multiple cylindrical battery modules (10) are arranged, heat propagation and flame propagation between neighboring modules can be delayed or minimized.

[0047] This venting door (320) may include a door portion (321) configured to open inwardly into a circular tube (310) by external pressure, and a hinge portion (322) that fixes the door portion (321) to the circular tube (310). The hinge portion (322) may be configured so that the door portion (321) can be elastically opened only inwardly by means of a spring or the like. That is, as shown in FIG. 5, when pressurized by external pressure in the direction of the arrow, i.e., by venting gas discharged from the battery cell (100), the door portion (321) can be opened inwardly by rotating around the hinge portion (322) and open to the position of reference numeral 321', and the venting gas can be introduced into the passage (CP) through this part. Since there is a refrigerant in the passage (CP), the flame can be directly extinguished by this, or discharged to the outside along the passage (CP).

[0048] In this way, a venting door (320) is positioned in correspondence with a venting guide (121) formed in a battery cell (100), and when a thermal event occurs, high-temperature gas and flames are guided through the venting door (320) to a passage (CP) through which a refrigerant flows, thereby suppressing heat propagation from inside the cylindrical battery module (10) to another battery cell (100), protecting internal components from flames, and also suppressing heat transfer to the outside as much as possible, thereby improving the safety of the battery module.

[0049] Meanwhile, referring to FIG. 6, terminal covers (210, 220) attached to both ends of a cylindrical case (200) can be directly attached to electrode leads (110) and used as external terminals themselves. That is, in a conventional battery module of a rectangular shape, a busbar is provided to electrically connect the electrode leads internally, and an electrical connection with the outside can be achieved by electrically connecting the busbar and the terminal busbar. On the other hand, in the present invention, electrical connections between electrode leads can be achieved without a separate busbar by directly welding the electrode leads (110). For example, electrical connections can be achieved by folding the electrode leads (110) in the direction of arrow A in FIG. 6 so that the electrode leads come into contact with each other and then welding them. Afterward, the terminal covers (210, 220) can be directly welded to the electrode leads (110) to be used as terminal busbars. At this time, by arranging electrode leads (110) of different polarities at both ends in the longitudinal direction of the cylindrical structure, the two terminal covers (210, 220) can be configured to have different polarities. By configuring it in this way, it can be designed so that positive and negative poles are formed in both directions, as in a conventional battery. However, it is not limited to this, and various electrical connections can be achieved through various arrangements of the electrode leads and terminal covers.

[0050] The terminal covers (210, 220) may each be formed in a donut shape to correspond to the area where the electrode lead (110) is placed, and may be formed of an electrically conductive material, and are not particularly limited.

[0051] Meanwhile, the cylindrical battery module according to the present embodiment may have a structure in which a battery management system (BMS) that manages the temperature or voltage of the cylindrical battery module and a cooling device are added and packed.

[0052] The above-described cylindrical battery module can be applied to various devices. Such devices may include means of transportation such as electric bicycles, electric vehicles, and hybrid vehicles, but the present invention is not limited thereto and can be applied to various devices capable of using the battery module, and this also falls within the scope of the present invention.

[0053] Although preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above. It is understood that various modifications can be made by those skilled in the art without departing from the essence of the invention as claimed in the claims, and such modifications should not be understood individually from the technical spirit or perspective of the present invention.

[0054] [Explanation of the symbol]

[0055] 10: Cylindrical battery module

[0056] 100: Plate-type battery cell

[0057] 110: Electrode lead

[0058] 120: Sealing part

[0059] 121: Venting Guide

[0060] 200: Cylindrical case

[0061] 210, 220: Terminal cover

[0062] 300: Central axis

[0063] 310: Circular tube

[0064] CP: Passage

[0065] 320: Venting door

[0066] 400: Cooling plate

Claims

1. Multiple plate-shaped battery cells with electrode leads protruding from each of their ends, A central axis to which the sides of the plurality of plate-shaped battery cells are fixed, and It includes the above-mentioned plurality of plate-shaped battery cells and a cylindrical case accommodating the central axis, The plurality of plate-shaped battery cells are fixed radially around the central axis, and The above central axis includes a circular tube and a passage inside the circular tube, and A cylindrical battery module having a plurality of venting doors formed in the above circular tube, corresponding to each of the plurality of plate-shaped battery cells, through which gas generated from the plurality of plate-shaped battery cells is discharged.

2. In Paragraph 1, A cylindrical battery module in which a cooling plate is inserted between adjacent plate-shaped battery cells among the plurality of plate-shaped battery cells.

3. In Paragraph 1, The above passage is a cylindrical battery module that is in communication with the outside and is a cooling channel through which a refrigerant supplied from the outside passes.

4. In Paragraph 1, The above venting door is a cylindrical battery module comprising a door portion that opens inwardly into the circular tube by external pressure and a hinge portion that fixes the door portion to the circular tube.

5. In Paragraph 1, Each of the above plurality of plate-shaped battery cells is a cylindrical battery module including a venting guide formed at a position corresponding to the venting door.

6. In Paragraph 5, Each of the above plurality of plate-shaped battery cells includes an electrode assembly and a pouch case that accommodates the same, and The above pouch case is formed along at least a portion of the edge of the pouch case and includes a sealing portion formed by heat-sealing the pouch case. The above venting guide is a cylindrical battery module formed in the above sealing portion.

7. In Paragraph 1, A cylindrical battery module having donut-shaped terminal covers connected to the electrode leads disposed at both ends of the cylindrical case.

8. In Paragraph 7, Cylindrical battery modules having different polarities of the terminal covers disposed at each of the two ends.

9. In Paragraph 3, The above refrigerant is an insulating fluid with fire extinguishing performance, in a cylindrical battery module.

10. A device comprising a cylindrical battery module according to claim 1.

Images