Battery module and battery pack including the same

Abstract

A battery module according to one embodiment of the present invention comprises a plurality of battery cell stacks including a plurality of battery cells, a frame member accommodating the plurality of battery cell stacks, and at least one partition structure disposed between the plurality of battery cell stacks, wherein the partition structure comprises two plate-like members parallel to the battery cells and a venting passage formed by the two plate-like members, and one of the two plate-like members includes a first opening formed to be open toward the battery cell stacks.

Description

Technology Field

[0001] The present invention relates to a battery module and a battery pack including the same, and more specifically, to a battery module and a battery pack including the same with improved safety and venting performance. Background Technology

[0002] With the technological development and increasing demand for mobile devices, the demand for secondary batteries as an energy source is rapidly rising. Accordingly, extensive research is being conducted on secondary batteries capable of meeting various requirements.

[0003] Secondary batteries are attracting significant attention as an energy source not only for mobile devices such as mobile phones, digital cameras, and laptops, but also for power units such as electric bicycles, electric vehicles, and hybrid electric vehicles.

[0004] Recently, with the increasing need for high-capacity secondary battery structures, including their utilization as energy storage sources, there is a growing demand for medium-to-large modular battery packs that aggregate battery modules in which multiple secondary batteries are connected in series or parallel. A battery pack is typically constructed by forming a battery module consisting of at least one battery cell, and by adding other components using that at least one battery module. Since the battery cells constituting the module are rechargeable secondary batteries, such high-output, high-capacity secondary batteries generate a significant amount of heat during the charging and discharging process. In particular, while small mobile devices use only one or two to three battery cells per device, medium-to-large devices such as automobiles require high output and high capacity. Therefore, medium-to-large battery modules comprising multiple electrically connected battery cells are utilized.

[0005] Since it is desirable for medium-to-large battery modules to be manufactured with the smallest possible size and weight, prismatic and pouch-type batteries, which can be stacked with high integration density and have a low weight-to-capacity ratio, are mainly used as battery cells for medium-to-large battery modules.

[0006] In such an integrated state, if some battery modules experience overvoltage, overcurrent, or overheating, the safety and operational efficiency of the battery modules may become problematic. In particular, as battery module capacity is gradually increasing to improve driving range, it is necessary to design a structure that satisfies strengthening safety standards and ensures the safety of the vehicle and the driver.

[0007] FIG. 1 is a perspective view of a conventional battery module.

[0008] As illustrated in FIG. 1, when configuring a battery pack, multiple battery modules (1) are arranged adjacently. At this time, if thermal runaway occurs in one battery module (1) and is not quickly discharged to the outside, the high-temperature gas and flames accumulated inside explode all at once and are transferred to adjacent battery modules (1). As a result, thermal runaway occurs in the battery modules (1) in a chain reaction, and damage to the battery modules (1) is also transferred.

[0009] Therefore, even if thermal runaway occurs, it is necessary to prevent propagation to adjacent modules to minimize damage, and to this end, there is a growing need for a structure that can effectively vent gases and flames generated within some battery modules to minimize such damage. The problem to be solved

[0010] The problem to be solved by the present invention is to provide a battery module capable of rapidly discharging flames and gases to the outside to prevent the transmission of thermal runaway phenomena between battery cells and battery modules even if an ignition phenomenon occurs within the battery module, and a battery pack including the same.

[0011] The problems that the present invention aims to solve are not limited to those described above, and problems not mentioned will be clearly understood by those skilled in the art from this specification and the attached drawings. means of solving the problem

[0012] A battery module according to one embodiment of the present invention comprises a plurality of battery cell stacks including a plurality of battery cells, a frame member accommodating the plurality of battery cell stacks, and at least one partition structure disposed between the plurality of battery cell stacks, wherein the partition structure comprises two plate-like members parallel to the battery cells and a venting passage formed by the two plate-like members, and one of the two plate-like members includes a first opening formed to be open toward the battery cell stacks.

[0013] The above partition structure includes one end in the longitudinal direction of the battery cell stack and the other end located on the opposite side of the one end, the first opening is formed adjacent to the one end, and the other end can be connected to a first outlet communicating with the outside of the battery module.

[0014] The battery cell stack further includes a first end plate and a second end plate covering each of the two ends in the longitudinal direction, and the first end plate may include the first outlet.

[0015] It may further include at least one outer venting passage disposed on the opposite side of one side of the battery cell stack facing the above bulkhead structure.

[0016] The above outer venting passage can be formed integrally with the frame member.

[0017] The above outer venting passage may be formed as an outer venting structure formed separately from the frame member.

[0018] The above outer venting passage may include one end in the longitudinal direction of the battery cell stack and the other end on the opposite side, and may include a second opening formed adjacent to the one end to be open toward the battery cell stack.

[0019] The other end of the above outer venting passage may be connected to a second outlet communicating with the outside of the battery module.

[0020] The second end plate above does not include the first outlet, and the first opening of the venting passage and the outer venting passage can be connected with the space between the end of the battery cell stack and the second end plate.

[0021] A battery pack according to another embodiment of the present invention includes the battery module described above. Effects of the invention

[0022] According to the embodiments, the battery module of the present invention and the battery pack including the same can prevent continuous thermal runaway phenomena inside the battery module and the transfer of thermal runaway to adjacent battery modules by rapidly discharging gas and flames, etc. to the outside of the battery module when an ignition phenomenon occurs inside the battery module.

[0023] The effects of the present invention are not limited to the effects described above, and unmentioned effects will be clearly understood by those skilled in the art from this specification and the accompanying drawings. Brief explanation of the drawing

[0024] FIG. 1 is a perspective view of a conventional battery module. FIG. 2 is a perspective view of a battery module according to an embodiment of the present invention. FIG. 3 is an exploded perspective view of the battery module of FIG. 2. FIG. 4 is a cross-sectional view taken along IV-IV' of FIG. 2. FIG. 5 is a perspective view of a bulkhead structure of FIG. 2. FIG. 6a and FIG. 6b are drawings for explaining the discharge of gas when thermal runaway occurs inside the battery module of FIG. 2. FIG. 7a is a perspective view of an outer venting passage of FIG. 2, and FIG. 7b is a perspective view of a modified example of FIG. 7a. Specific details for implementing the invention

[0025] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0026] To clearly explain the present invention, parts unrelated to the explanation have been omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0027] Furthermore, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, and thus the present invention is not necessarily limited to what is illustrated. Thicknesses have been enlarged in the drawings to clearly represent various layers and regions. Additionally, for convenience of explanation, the thickness of some layers and regions has been exaggerated in the drawings.

[0028] Furthermore, throughout the specification, when a part is described as “comprising” a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0029] Additionally, throughout the specification, "planar" means when the subject part is viewed from above, and "cross-sectional" means when the cross-section obtained by vertically cutting the subject part is viewed from the side.

[0030] Hereinafter, a battery module according to an embodiment of the present invention will be described with reference to FIGS. 2 to 5.

[0031] FIG. 2 is a perspective view of a battery module according to one embodiment of the present invention, FIG. 3 is an exploded perspective view of the battery module of FIG. 2, FIG. 4 is a cross-sectional view taken along IV-IV' of FIG. 2, and FIG. 5 is a perspective view of a venting member of FIG. 2.

[0032] Referring to FIGS. 2 to 4, a battery module (10) according to one embodiment of the present invention comprises a plurality of battery cell stacks (100) including a plurality of battery cells, a frame member (200) that accommodates the lower surface and side surface of the plurality of battery cell stacks (100) and has an open front and rear surface, a partition structure (300) disposed between adjacent battery cell stacks (100) among the plurality of battery cell stacks (100), an end plate (410, 420) that covers the open front and rear surface of the frame member (200) adjacent to the front and rear surface of the battery cell stacks (100), and an upper cover (500) that covers the upper surface of the battery cell stacks (100) and is coupled to the frame member (200). In this description, the front and rear directions may be the + and - directions in the y-axis direction in the drawings, the upper and lower directions may be the + and - directions in the z-axis direction, and the side direction may be the x-axis direction.

[0033] The frame member (200) may be a U-shaped frame that accommodates the lower surface and side of the battery cell stack (100) and has its front and rear surfaces open. Additionally, the upper cover (500) may be configured to cover the upper surface of the battery cell stack (100) and be coupled to the frame member (200). However, the configuration of the frame member (200) and the upper cover (500) is not limited thereto; they may be in the form of a square tube formed integrally, or the configuration covering the lower part of the battery cell stack (100) may be in the form of a flat plate and the configuration covering the upper part may be an inverted U-shaped frame, and are not particularly limited.

[0034] A battery cell stack (100) can be formed by stacking a plurality of battery cells. Here, it is preferable that the battery cell is a pouch-type battery cell. For example, the battery cell can be manufactured by housing an electrode assembly in a pouch case made of a laminate sheet including a resin layer and an inner layer, and then heat-sealing the sealing portion of the pouch case. Additionally, the battery cell can be formed into a rectangular sheet-type structure. Furthermore, the battery cell can be composed of a plurality of cells, and the plurality of battery cells are stacked so as to be electrically connected to each other to form a battery cell stack (100).

[0035] Here, multiple battery cell stacks (100) may be included within a single frame member (200) with partition structures (300) in between. For example, as shown in the drawing, two battery cell stacks (100) may be arranged facing each other side by side. At this time, the multiple battery cell stacks (100) may be battery cell stacks manufactured identically, differing only in position. Additionally, they may be electrically connected to each other within a single frame member (200).

[0036] The end plates (410, 420) are made of the same material as the frame member (200) and may be fixed to the frame member (200) in a manner such as welding. However, they are not limited to this, and any fixing method capable of blocking the interior of the frame member (200) from the external environment may be appropriately applied. Additionally, the end plates (410, 420) are arranged to cover the front and rear surfaces of the battery cell stack (100), for example, the first end plate (410) may be arranged to cover the front surface and the second end plate (420) may be arranged to cover the rear surface. The differences in their respective configurations will be described later.

[0037] Referring to FIGS. 2 through 5, the battery module (10) may include a partition structure (300) disposed between adjacent battery cell stacks (100). As shown in FIG. 5, the partition structure (300) includes a space in which a first plate-shaped member (301) and a second plate-shaped member (301) are arranged facing each other, parallel to the side of the battery cell stack (100), and the space may form a venting passage (320) through which gas and flames generated during thermal runaway pass. The partition structure (300) may be made of the same material as the frame member (200), upper cover (500), end plates (410, 420), etc., and is not particularly limited. Additionally, to prevent flame propagation, it may be made of a flame-retardant material or may include a flame-retardant coating layer.

[0038] The first plate-like member (301) of the bulkhead structure (300) may include a first opening (310) that is open facing the battery cell stack (100) positioned on the left side of the drawing. The first opening (310) may be formed particularly adjacent to one end (A) in the longitudinal direction of the bulkhead structure (300). The first opening (310) is connected to a venting passage (320).

[0039] The other end (B) of the bulkhead structure (300) can be connected to a first outlet (411) formed in the first end plate (410). That is, a venting passage (320) connected to the first opening (310) formed in the first plate-shaped member (301) of the bulkhead structure (300) is configured to extend inward along the length of the bulkhead structure (300) and open at the other end (B), and this venting passage (320) is connected to the first outlet (411) formed in the first end plate (410) so that gas and flames generated during thermal runaway can be discharged to the outside.

[0040] The second plate-shaped member (302) of the partition structure (300) does not include an opening. That is, the second plate-shaped member (302) may have a plate shape that does not include an opening, as shown in FIG. 5. By doing so, two battery cell stacks (100) placed with the partition structure (300) in between can be isolated from each other. In particular, since the second end plate (420) placed at one end (A) of the partition structure (300) does not include an outlet, the battery cell stacks (100) placed on both sides with the partition structure (300) in between can be isolated from each other by the combination of the partition structure (300) and the second end plate (420). Accordingly, even if thermal runaway occurs in one of the battery cell stacks (100), the gas and flames can be discharged outward along the passage within the space where the battery cell stack (100) is placed, and the adjacent battery cell stack (100) can be isolated by the partition structure (300), thereby blocking the propagation of the gas and flames.

[0041] Next, the outer venting passage (211) will be described with reference to FIGS. 4, FIGS. 7a, and FIGS. 7b. FIGS. 7a is a perspective view illustrating the outer venting passage of FIGS. 2, and FIGS. 7b is a perspective view illustrating a modified example of FIGS. 7a.

[0042] Referring to FIG. 4, an outer venting passage (211) may be formed along the side of the frame member (200). The outer venting passage (211) may be in the form of a tube including a second opening (213) that is open toward the facing battery cell stack (100), similar to the venting passage (320) of the bulkhead structure (300) described above. The second opening (213) may be formed adjacent to the rear side of the battery cell stack (100) (i.e., adjacent to one end (A) of the bulkhead structure (300)), and the opposite end along the longitudinal direction, i.e. the end adjacent to the front side of the battery cell stack (100), may form a second outlet (212) that communicates with the outside.

[0043] These outer venting passages (211) can be formed integrally with the frame member (200) as shown in FIG. 7a. That is, the outer venting passages (211) can be formed by forming the side walls of the frame member (200) in a double layer and forming a second opening (213) in the side wall positioned on the inner side. Alternatively, as shown in FIG. 7b, an outer venting passage (211') may be provided that is formed separately from the frame member (200'). That is, the configuration of the outer venting passage (211') may be formed by attaching a structure including a tubular outer venting passage (211') to the side wall of the frame member (200') which is formed in a single layer. At this time, an opening may also be formed in the side wall of the frame member (200') corresponding to the second opening (213') of the outer venting passage (211').

[0044] Next, with reference to FIGS. 6a and FIGS. 6b, the discharge of gas and flames when thermal runaway occurs inside the battery module will be explained.

[0045] Figures 6a and 6b are drawings illustrating the discharge of gas when thermal runaway occurs inside the battery module of Figure 2.

[0046] Since a partition structure (300) having a venting passage (320) is arranged between adjacent battery cell stacks (100) and an outer venting passage (211) formed on the side wall of a frame member (200) is arranged at the outermost side, each of the multiple battery cell stacks (100) faces at least one opening (310, 213). Therefore, when thermal runaway occurs, flames and gases generated in the battery cell stacks (100) can move through these openings (310, 213) to the venting passage (320) or the outer venting passage (211) and be discharged to the outside.

[0047] For example, as illustrated in FIG. 6a, when thermal runaway occurs in a battery cell stack (100) located on the left side of the drawing, that is, in a battery cell stack (100) facing a first plate-shaped member (301) where the first opening (310) of a partition structure (300) is located, the gas and flame generated in the battery cell stack (100) can travel along the venting passage (320) and the outer venting passage (211) through the first opening (310) and the second opening (213) and be discharged to the outside through the first outlet (411) and the second outlet (212). At this time, since it is isolated from the adjacent battery cell stack (100) through the second plate-shaped member (320), the battery cell stack (100) located on the right side of the drawing can be quickly discharged to the outside without propagation of flame and gas, and thus damage to the adjacent battery cell stack (100) can be prevented.

[0048] Additionally, the first opening (310) and the second opening (213) may be connected to each other through the space between the second end plate (420) and the battery cell stack (100). Through this configuration, internal flames and gases can be rapidly moved and discharged to the outside.

[0049] Meanwhile, as illustrated in FIG. 6b, when thermal runaway occurs in the battery cell stack (100) located on the right side of the drawing, that is, in the battery cell stack (100) facing the second plate-shaped member (302) where no opening is located in the partition structure (300), the gas and flame generated in the battery cell stack (100) can travel along the outer venting passage (211) through the second opening (213) and be discharged to the outside through the second outlet (212). At this time, even if thermal runaway occurs only in the battery cell stack (100) located on the right side, it is isolated from the adjacent battery cell stack (100) through the second plate-shaped member (320), so the flame and gas can be quickly discharged to the outside without propagation to the battery cell stack (100) located on the left side of the drawing, and thus damage to the adjacent battery cell stack (100) can be prevented. In addition, as illustrated in FIG. 6b, if thermal runaway occurs in both battery cell stacks (100), flames and gases can be quickly discharged to the outside through the venting passage (320) of the central partition structure (300) and the outer venting passages (211) on both sides.

[0050] In this way, according to the present embodiment, even if thermal runaway occurs in some battery cell stacks (100) within the battery module (10), the generated flame and gas can be quickly discharged to the outside by moving along the venting passage (320) formed in the partition structure (300) and the outer venting passage (211) formed on the side of the frame member (200), thereby suppressing the accumulation of thermal energy inside the battery module (10) and simultaneously blocking the flame and gas from transferring to neighboring battery cell stacks (100) and battery modules.

[0051] One or more battery modules according to the embodiment described above can be mounted together with various control and protection systems, such as a Battery Management System (BMS) and a cooling system, to form a battery pack. In particular, when a battery module according to one embodiment of the present invention is positioned within a battery pack containing multiple battery modules, flames and gases can be rapidly discharged outward, thereby preventing damage from spreading to adjacent battery modules or other components of the battery pack outside the battery module. Furthermore, when positioning the battery module, the exhaust port through which gases and flames are discharged can be positioned adjacent to a location outside the battery pack where damage-prone components are not placed (e.g., the rear of a vehicle), thereby minimizing the impact of thermal runaway.

[0052] The above-mentioned battery module or battery pack can be applied to various devices. Specifically, it can be applied to means of transportation such as electric bicycles, electric vehicles, and hybrids, but is not limited thereto and can be applied to various devices capable of using secondary batteries.

[0053] In this embodiment, terms indicating directions such as front, back, left, right, up, and down have been used; however, these terms are for convenience of explanation only and may vary depending on the location of the object or the observer.

[0054] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention. Explanation of the symbols

[0055] 10: Battery module 100: Battery cell laminate 200: Frame missing 300: Bulkhead structure 310: First opening 320: Venting passage 301: First plate-like member 302: Second plate-like member 211, 211': Outer venting passage 213: Second opening 410: First end plate 420: Second end plate 411: 1st outlet 212: Second outlet

Claims

Claim 1 A battery module comprising a plurality of battery cell stacks including a plurality of battery cells, a frame member accommodating the plurality of battery cell stacks, and at least one partition structure disposed between the plurality of battery cell stacks, wherein the partition structure comprises two plate-like members parallel to the battery cells and one venting passage formed by the two plate-like members, wherein one of the two plate-like members includes a first opening formed to be open toward the battery cell stack, and the other of the two plate-like members does not have an opening formed therein, and the partition structure includes one end in the longitudinal direction of the battery cell stack and the other end located opposite to the one end, wherein the first opening is formed adjacent to the one end, and the other end is connected to a first outlet communicating with the outside of the battery module, and wherein only one of the first openings is formed in the plate-like member having the first opening formed therein. Claim 2 delete Claim 3 A battery module according to claim 1, further comprising a first end plate and a second end plate covering each of the two ends in the longitudinal direction of the battery cell stack, wherein the first end plate includes the first outlet. Claim 4 A battery module further comprising, in paragraph 3, at least one outer venting passage disposed on the opposite side of one side of the battery cell stack facing the bulkhead structure. Claim 5 In paragraph 4, the outer venting passage is a battery module formed integrally with the frame member. Claim 6 In paragraph 4, the battery module is formed such that the outer venting passage is an outer venting structure formed separately from the frame member. Claim 7 In paragraph 4, the outer venting passage comprises one end in the longitudinal direction of the battery cell stack and the other end on the opposite side, and a battery module comprising a second opening formed adjacent to the one end to be open toward the battery cell stack. Claim 8 In paragraph 7, the other end of the outer venting passage is connected to a second outlet communicating with the outside of the battery module. Claim 9 In paragraph 4, the second end plate does not include the first outlet, and the first opening of the venting passage and the outer venting passage are connected with the space between the end of the battery cell stack and the second end plate, forming a battery module. Claim 10 In claim 1, the plate-shaped member in which the opening is not formed is a battery module that isolates the opposing battery cell stack from the venting passage. Claim 11 A battery pack including a battery module according to paragraph 1.

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