Battery module

Abstract

A battery module according to an embodiment of the present invention may include a module frame; a plurality of pouch-type battery cells arranged side by side within the module frame; and a plurality of vent holes formed through one surface of the module frame. The pouch-type battery cells may include an electrode assembly including an electrode lead; a battery case including a receiving portion that receives the electrode assembly, a short-side sealing portion located on a portion of the periphery of the receiving portion and from which the electrode leads protrude, and a long-side sealing portion located on another portion of the periphery of the receiving portion and folded toward the receiving portion; and a plurality of fixing members attached to the battery case and arranged at intervals along the length of the long-side sealing portion to fix the long-side sealing portion in a folded state. Each of the vent holes may have an area that does not overlap with the fixing member that is larger than an area that overlaps with the fixing member.

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims the benefit of priority based on Korean Patent Application No. 10 - 2022 - 0160853 filed on November 25, 2022 and Korean Patent Application No. 10 - 2023 - 0165914 filed on November 24, 2023, and all the contents disclosed in the Korean patent applications are included as part of this specification.

[0002] The present invention relates to a battery module including a pouch - type battery cell.

Background Art

[0003] Unlike primary batteries, secondary batteries can be charged and discharged and can be applied to various fields such as digital cameras, mobile phones, notebook computers, and hybrid vehicles. Examples of secondary batteries include nickel - cadmium batteries, nickel - metal hydride batteries, nickel - hydrogen batteries, and lithium secondary batteries.

[0004] Among such secondary batteries, many studies on lithium secondary batteries having high energy density and discharge voltage are in progress. Recently, lithium secondary batteries are manufactured as flexible pouch - type battery cells, and multiple of them are connected and configured in a module form for use.

[0005] A pouch - type battery cell is a method using a pouch as an exterior material that wraps an electrode assembly. The electrode assembly has a structure in which a positive electrode plate and a negative electrode plate to which an electrode active material is applied, and a separator interposed between the positive electrode plate and the negative electrode plate are laminated. A positive electrode tab is formed on one side of the positive electrode plate, and a negative electrode tab is formed on one side of the negative electrode plate. The tabs are each connected to an electrode lead to be connected to an external circuit. Such an electrode assembly is sealed by a pouch which is an exterior material.

[0006] The pouch includes a storage section for housing the electrode assembly and a sealing section located around the storage section to seal the electrode assembly. The electrode leads protrude from a portion of the sealing section, while the other portion can be folded to form a wing-folding section to increase energy density. For example, the wing-folding section may be formed by double-side folding (DSF). Since the wing-folding section may not maintain its folded state after a certain period of time and a portion may unfold and protrude to the outside, the wing-folding section can be secured using a fixing member such as tape to prevent this.

[0007] However, if a pouch-type battery cell malfunctions and generates flames or gases, the aforementioned fixing member prevents the flames or gases from being discharged from the wing-folding portion, instead causing them to be discharged from the electrode leads.

[0008] If flames or gases generated in any one pouch-type battery cell within a battery module or battery pack are discharged towards the electrode leads, the flames can rapidly propagate to the surrounding area, potentially inducing continuous thermal runaway in adjacent battery cells. Therefore, a solution to this problem is required. [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] One problem that the present invention aims to solve is to provide a battery module that delays the venting of flames and gases generated within a pouch-type battery cell toward the electrode leads, thereby allowing the flames and gases vented within the pouch-type battery cell to be smoothly vented to the outside. [Means for solving the problem]

[0010] An embodiment of the present invention may include a module frame; a plurality of pouch-type battery cells arranged side by side within the module frame; and a plurality of vent holes formed through one surface of the module frame. The pouch-type battery cell may include an electrode assembly provided with electrode leads; a battery case including a housing for the electrode assembly, a short-side sealing portion located on part of the periphery of the housing and from which the electrode leads protrude, and a long-side sealing portion located on another part of the periphery of the housing and folded toward the housing; and a plurality of fixing members attached to the battery case to fix the long-side sealing portion in a folded state and arranged to be spaced apart from each other in the longitudinal direction of the long-side sealing portion. Each of the vent holes may have a larger area that does not overlap with the fixing member than the area that overlaps with the fixing member.

[0011] The value obtained by subtracting the total length of the multiple fixing members from the length of the long side sealing portion may be greater than or equal to the total length of the short side sealing portion.

[0012] The spacing between the plurality of fixing members may be greater than the length of the fixing member.

[0013] The spacing between the plurality of fixing members may be greater than the length of each of the short-side sealing portions.

[0014] The outermost of the plurality of fixing members can be positioned to correspond to the end of the storage section.

[0015] The total length of the plurality of fixing members may be 20% or less of the length of the long side sealing portion.

[0016] The total length of the plurality of fixing members may be 17% or less of the length of the long side sealing portion.

[0017] The total length of the plurality of fixing members may be 10% or more of the length of the long side sealing portion.

[0018] Each length of the fixing member may be 3% to 6% or less of the length of the long-side sealing portion.

[0019] The vent hole may be formed long in a direction parallel to the pouch-type battery cell and have a length longer than that of the fixing member.

[0020] The length of the vent hole may be 3 times or more the length of the fixing member.

[0021] The area where the plurality of fixing members overlap the plurality of vent holes may be 1 / 3 or less of the total area of the plurality of vent holes.

[0022] For each of the vent holes, the area where it overlaps the fixing member may be 1 / 3 or less of the area where it does not overlap the fixing member.

[0023] The plurality of vent holes may include a first vent hole that does not overlap the fixing member and a second vent hole that partially overlaps the fixing member.

[0024] The plurality of vent holes are arranged to form a plurality of columns parallel to the stacking direction of the plurality of pouch-type battery cells, and the interval between the plurality of vent holes in the length direction of the pouch-type battery cell may be equal to or greater than the length of the fixing member.

[0025] Both ends of the vent hole may be formed to be convex and rounded outward.

Advantages of the Invention

[0026] According to a preferred embodiment of the present invention, when a fire occurs inside a pouch-type battery cell, gas and flames can be preferentially bent at the long-side sealing portion rather than the short-side sealing portion where the electrode lead protrudes. Thereby, the time taken until gas or flames are bent at the short-side sealing portion can be maximally delayed, and the rapid propagation of the flames to the surroundings and the induction of continuous thermal runaway of adjacent battery cells can be minimized.

[0027] Also, during the normal operation of the pouch-type battery cell, the long-side sealing portion can be reliably maintained in a folded state by a fixing member.

[0028] In addition, the gas and flames bent at the long-side sealing portion of the pouch-type battery cell can be smoothly discharged to the vent hole of the module frame.

[0029] In addition, effects that can be easily predicted by those skilled in the art from the configuration according to the preferred embodiment of the present invention can be included.

Brief Description of the Drawings

[0030] The following drawings attached to this specification illustrate the preferred embodiments of the present invention and serve to further understand the technical idea of the present invention together with the detailed description of the invention to be described later. Therefore, the present invention should not be construed as being limited only to the matters described in such drawings. [Figure 1] It is a perspective view of a pouch-type battery cell included in a battery module according to an embodiment of the present invention. [Figure 2] It is a partial cross-sectional view taken along A-A' of FIG. 1. [Figure 3] It is a front view of the pouch-type battery cell shown in FIG. 1. [Figure 4] It is a front view showing a modified example of the pouch-type battery cell shown in FIG. 1. [Figure 5a] It is a front view of a pouch-type battery cell according to a comparative example. [Figure 5b] It is a front view of a pouch-type battery cell according to a comparative example. [Figure 5c] This is a front view of a pouch-type battery cell as an example. [Figure 5d] This is a front view of a pouch-type battery cell as an example. [Figure 6] This is a perspective view of a battery module according to one embodiment of the present invention. [Figure 7] Figure 6 is an exploded perspective view of the battery module shown. [Figure 8] Figure 6 is a plan view of the battery module shown. [Figure 9a] This is a diagram illustrating the inside of a battery module based on an experimental example. [Figure 9b] This is a diagram illustrating the inside of a battery module based on an experimental example. [Modes for carrying out the invention]

[0031] In the following, preferred embodiments of the present invention will be described in detail with reference to the attached figures, so that they can be easily implemented by a person with ordinary skill in the art to which the present invention pertains. However, the present invention may be embodied in a variety of different forms and is not limited to or restricted by the following embodiments.

[0032] In order to clearly explain the present invention, detailed descriptions of related prior art that are irrelevant to the description or that could unnecessarily obscure the gist of the invention have been omitted. In this specification, when assigning reference numerals to components in each figure, the same or similar reference numerals are assigned to components that are the same or similar throughout the specification.

[0033] Furthermore, terms and words used in this specification and in the claims shall not be interpreted in a manner limited to their ordinary and lexicographical meanings, but rather in a manner consistent with the technical idea of ​​the present invention, in accordance with the principle that inventors may define the concepts of terms as appropriate to best describe their invention.

[0034] Figure 1 is a perspective view of a pouch-type battery cell included in a battery module according to one embodiment of the present invention, Figure 2 is a partial cross-sectional view of the section A-A' in Figure 1, Figure 3 is a front view of the pouch-type battery cell shown in Figure 1, and Figure 4 is a front view showing a modified example of the pouch-type battery cell shown in Figure 1.

[0035] The pouch-type battery cell 100 (hereinafter referred to as "battery cell") described below may be included in a battery module according to one embodiment of the present invention. The battery cell 100 may include an electrode assembly 110, a battery case 120, and a fixing member 130.

[0036] The electrode assembly 110 may be formed with a separator membrane interposed between alternating positive and negative electrodes. That is, the electrode assembly 110 may include a plurality of electrodes and a separator membrane interposed between the plurality of electrodes to insulate them from each other. The electrode assembly 110 may be housed together with the electrolyte in the battery case 120, or in a storage section 121 which will be described in more detail later.

[0037] The electrode assembly 110 can be of various types, including stack type, jelly roll type, and stack-and-fold type, and the type of electrode assembly 110 is not limited.

[0038] The electrode assembly 110 may include electrode tabs connected to a positive electrode and a negative electrode, respectively, which can act as pathways through which electrons can move between the inside and outside of the electrode assembly 110. The electrode tabs may include a positive electrode tab connected to the positive electrode and a negative electrode tab connected to the negative electrode. The positive electrode tab and the negative electrode tab may, but are not limited to, protrude from the electrode assembly 110 in different directions, and may be formed to protrude in various directions, such as protruding side by side from one side in the same direction.

[0039] The electrode assembly 110 may be provided with electrode leads 111. The electrode leads 111 can electrically connect the electrode assembly 110 to the outside.

[0040] More specifically, the electrode lead 111 may be connected to the electrode tab of the electrode assembly 110 by spot welding or the like. A portion of the electrode lead 111 may be surrounded by an insulating material. The insulating material can be positioned to correspond to the short-side sealing portion 122 of the battery case 120, which will be described later. Thus, the insulating material can insulate the electrode lead 111 from the short-side sealing portion 122 and maintain the sealing of the short-side sealing portion 122. Generally, insulating tape that adheres easily to the electrode lead 111 and is relatively thin is often used as the insulating material, but it is not limited to this.

[0041] The electrode lead 111 may have one end connected to the electrode tab and the other end protruding outside the battery case 120. The electrode lead 111 may include a positive lead connected to the positive electrode tab and a negative lead connected to the negative electrode tab. Since the positive electrode tab and the negative electrode tab are formed to protrude in various directions, the positive electrode lead and the negative electrode lead may also extend in various directions.

[0042] The battery case 120 may be formed by molding a laminate sheet and can house the electrode assembly 110 inside.

[0043] The battery case 120 may include a pair of cases connected by a bridge, either before sealing or after the sealing has been released, wherein at least one of the pair of cases may have a recessed storage section 121, and the area surrounding the storage section 121 may form a terrace. When the bridge is folded with the electrode assembly 110 housed in the storage section 121, the terraces of the pair of cases may come into contact with each other, and three sides may be sealed by heat fusion. In this case, the bridge may form a folding section 124, and the terraces may form sealing sections 122, 123.

[0044] However, the pair of cases may be separate components. In this case, the terraces of the pair of cases can touch each other, and all four sides can be sealed by heat fusion. Such a cell case configuration is well known and should be easily understood by those skilled in the art.

[0045] The battery case 120 may include a storage section 121 for housing the electrode assembly 110, a short-side sealing section 122 located on part of the perimeter of the storage section 121 from which the electrode leads 111 protrude, and a long-side sealing section 123 located on the other part of the perimeter of the storage section 121 that folds toward the storage section 121.

[0046] The storage section 121 may have a pocket shape, and the electrode assembly 111 may be stored inside it.

[0047] The short-side sealing portion 122 can be located on a portion of the perimeter of the storage portion 121. For example, the short-side sealing portion 122 can be located on both sides of the storage portion 121 in the overall length direction and may extend in the overall width direction. The electrode leads 111 may protrude to the outside of the battery case 120 through the short-side sealing portion 122.

[0048] The long-side sealing portion 123 can be located on another part of the perimeter of the storage portion 121. For example, the long-side sealing portion 123 can be located on one side in the width direction of the storage portion 121 and may extend in the length direction. The long-side sealing portion 123 can connect both short-side sealing portions 122. The long-side sealing portion 123 can be located on the opposite side of the folding portion 124. The long-side sealing portion 123 may be the portion where the electrode lead 111 does not protrude.

[0049] In the manufacturing process of the battery case, the long-side sealing portion 123 is sealed after the short-side sealing portion 122, so the corners of the sealing portions 122 and 123 may be included in the long-side sealing portion 123.

[0050] The long side sealing section 123 may be folded at least once toward the storage section 121. Preferably, the long side sealing section 123 may be DSF (Double Side Folding).

[0051] The fixing member 130 may be attached to the battery case 120 so as to fix the long-side sealing portion 123 in a folded state. In other words, the fixing member 130 can fix the long-side sealing portion 123 in a folded state. For example, the fixing member 130 may be adhesive tape.

[0052] Multiple fixing members 130 may be provided. Multiple fixing members 130 may be arranged so as to be at a predetermined distance from each other in the longitudinal direction of the long side sealing portion 123.

[0053] More specifically, the plurality of fixing members 130 may include a pair of outermost fixing members and at least one intermediate fixing member located between the pair of outermost fixing members. However, it is not limited to this, and as shown in Figure 4, the plurality of fixing members 130 may also include only a pair of outermost fixing members.

[0054] The lengths L of the multiple fixing members 130 may be the same, but are not limited to this.

[0055] On the other hand, if ignition occurs in the battery cell 100, or more specifically, the electrode assembly 110, the battery case 120 may be damaged, causing gas to be released along with sparks and particles. In this case, if the gas is released towards the electrode lead 111, there is a risk that heat and flames will spread rapidly to other surrounding battery cells 100, so a configuration is needed to minimize such concerns.

[0056] In the long-side sealing portion 123, the portion to which the fixing member 130 is attached does not swell, and gas venting is difficult. On the other hand, in the long-side sealing portion 123, the portion to which the fixing member 130 is not attached gradually expands as the internal pressure of the battery case 120 increases, and the internal volume of the battery case 120 increases. As a result, the time required for gas venting to occur can be delayed, and gas can be vented preferentially.

[0057] Furthermore, the portion of the long-side sealing portion 123 to which the fixing member 130 is not attached may be provided with a weakly sealed portion or an unsealed portion that is preferentially broken. However, it is not limited to this.

[0058] The value obtained by subtracting the sum of the lengths L of the multiple fixing members 130 from the length L2 of the long side sealing portion 123 may be greater than or equal to the total length of the short side sealing portion 122. That is, the total length of the portion of the long side sealing portion 123 to which the fixing members 130 are not attached may be greater than or equal to the total length of the short side sealing portion 122. The total length of the short side sealing portion 122 may be the sum of the lengths L1 of each part of the short side sealing portion 122.

[0059] For example, as shown in Figure 3, if the short-side sealing portion 122 is formed on both sides of the storage portion 121 and three fixing members 130 are attached to the long-side sealing portion 123, the condition L2-3L≧2L1 can be satisfied.

[0060] As a result, the portion of the long-side sealing section 123 to which the fixing member 130 is not attached expands as the internal gas pressure increases, delaying gas venting. Furthermore, since the gas is more likely to be preferentially vented through the aforementioned portion, the venting of the gas toward the short-side sealing section 122 can be sufficiently delayed.

[0061] The spacing between the multiple fixing members 130 may be greater than the length L of each fixing member 130. The spacing between the multiple fixing members 130 may be greater than the length L1 of each short-side sealing portion 122. As a result, when the internal pressure of the battery case 120 increases, the portion of the long-side sealing portion 123 located between the multiple fixing members 130 will easily bulge, allowing gas to be vented preferentially over the short-side sealing portion 122.

[0062] The outermost of the multiple fixing members 130 can be positioned to correspond to the end of the storage section 121. The end of the storage section 121 can mean the end in the overall length direction. More specifically, the outermost fixing member 130 may be attached to the end of the storage section 121 or attached adjacent to the end of the storage section 121. This allows the portion of the gas vented in the second sealing section 123 to be spaced apart from the first sealing section 122, thereby more reliably delaying the spread of the flame to the electrode lead 111.

[0063] The total length L of the multiple fixing members 130 may be 20% or less, preferably 17% or less, of the length L2 of the long-side sealing portion 123. If the total length L of the multiple fixing members 130 is greater than 20% of the length L2 of the long-side sealing portion 123, there is a problem that the time until the gas is vented at the short-side sealing portion 122 may not be sufficiently delayed.

[0064] Furthermore, the sum of the lengths L of the multiple fixing members 130 may be 10% or more of the length L2 of the long-side sealing portion 123. If the sum of the lengths L of the multiple fixing members 130 is less than 10% of the length L2 of the long-side sealing portion 123, there is a problem in that it is difficult to sufficiently fix the long-side sealing portion 123 in the folded state.

[0065] Furthermore, the length L of each fixing member 130 may be 6% or less of the length L2 of the long-side sealing portion 123. This allows the portion of the long-side sealing portion 123 to which the fixing member 130 is not attached to easily expand due to the increase in internal pressure of the battery case 120, and a uniform area for gas venting can be formed.

[0066] Furthermore, the length L of each fixing member 130 may be 3% or more of the length L2 of the long-side sealing portion 123. This ensures that the adhesive force of each fixing member 130 prevents the fixing member 130 from separating due to the restoring force of the folded long-side sealing portion 123.

[0067] Figures 5a to 5d are front views of pouch-type battery cells according to comparative examples.

[0068] As shown in Figure 5a, in the first comparative example, the fixing member 130a of the battery cell 100a is attached to the entire long-side sealing portion 123. Therefore, if a fire occurs inside the battery cell 100a, the gas may be vented almost immediately at the short-side sealing portion 122, minimizing the effect of venting delay.

[0069] As shown in Figure 5b, in the second comparative example, the fixing member 130b of the battery cell 100b is formed with relatively long lengths, so the length of the portion where the fixing member 130b is not attached in the long-side sealing portion 123 may not be sufficient. In this case, it is difficult to sufficiently delay the venting of gas in the short-side sealing portion 122.

[0070] As shown in Figure 5c, although the fixing members 130c of the battery cell 100c in the third comparative example are relatively short in length, the number of fixing members 130c is relatively large, so the length of the portion where the fixing members 130c are not attached in the long-side sealing portion 123 may not be sufficient. In addition, because the spacing between the fixing members 130c is short, the portion between the fixing members 130c in the long-side sealing portion 123 does not easily bulge, making it difficult for gas to be vented. In this case, it is even more difficult to sufficiently delay the venting of gas in the short-side sealing portion 122.

[0071] As shown in Figure 5d, the battery cell 100d according to the fourth comparative example may not have a fixing member provided in the long-side sealing portion 123. In this case, it is difficult to maintain the folded state of the long-side sealing portion 123.

[0072] The following explanation will refer to Figures 3, 4, and 5a through 5d to describe the experimental examples.

[0073] The inventors attached a heating pad to the center of one side of the storage section 121 of the battery cell 100 and heated it, measuring the time it took from the moment gas venting occurred until the gas was vented at the short-side sealing section 122 (hereinafter referred to as "delay time"). The long-side sealing section of the battery case used in each experimental example was treated with DSF (Double Side Folding) at 270 degrees, and the length of the long-side sealing section was 548 mm. Fixing tape was used as a fixing member.

[0074] In the case of the battery cell in the first experimental example, the entire long-side sealing portion was secured using a single fixing tape with a length of 548 mm (see Figure 5a). As a result, the gas was vented first at the short-side sealing portion 122, and the delay time was measured to be 0 seconds. That is, it can be confirmed that there is no effect on flame delay.

[0075] In the case of the battery cell in the second experimental example, fixing tape with a length of 183 mm was attached to both ends of the long-side sealing section, which was divided into three equal parts (see Figure 5b). As a result, the delay time was measured to be 4 seconds, confirming that it had a flame delay effect on a battery cell basis. However, there is a problem in that it is disadvantageous to guide the flame and gas into the vent holes formed on the upper surface of the module frame, which will be described later.

[0076] In the case of the battery cell used in the third experimental example, two fixing tapes, each 30 mm long, were attached 31.2 mm away from both ends of the long-side sealing section (see Figure 4). As a result, the delay time was measured to be 8 seconds, confirming that it had a flame delay effect on a battery cell basis. However, the central part of the long-side sealing section bulges excessively, which poses a risk of damage to the battery cell due to interference with the module frame described later.

[0077] In the case of the battery cell in the fourth experimental example, two of the three fixing tapes, each 30 mm long, were attached 31.2 mm away from both ends of the long-side sealing section, and the remaining tape was attached to the center of the long-side sealing section (see Figure 3). As a result, the delay time was measured to be 4 seconds, confirming that it had a flame delay effect on a battery cell basis.

[0078] In the case of the battery cell according to the fifth experimental example, two of the six fixing tapes, each 30 mm long, were attached 31.2 mm away from both ends of the long-side sealing section, and the remaining four were attached at equal intervals (see Figure 5c). As a result, the gas was vented first at the short-side sealing section 122, and the delay time was measured to be 0 seconds. In other words, it can be confirmed that there is no effect of flame delay.

[0079] In the case of the battery cell used in the sixth experimental example, the fixing tape was not attached to the long-side sealing portion (see Figure 5d). As a result, the delay time was measured to be 10 seconds, confirming that it had a flame delay effect on a per-battery cell basis. However, there is a problem in that the long-side sealing portion is not fixed.

[0080] These experimental examples confirm that the battery cell 100 according to one embodiment of the present invention can minimize side effects while having a flame delay effect (Experimental Example 4). Furthermore, it can be confirmed that modified versions of the battery cell 100 are also useful when used alone (Experimental Example 3).

[0081] Figure 6 is a perspective view of a battery module according to one embodiment of the present invention, Figure 7 is an exploded perspective view of the battery module shown in Figure 6, and Figure 8 is a plan view of the battery module shown in Figure 6.

[0082] A battery module 10 according to one embodiment of the present invention may include a plurality of battery cells 100 and a module frame 200.

[0083] Multiple battery cells 100 may be housed in a module frame 200. Multiple battery cells 100 may be arranged side by side.

[0084] Multiple battery cells 100 may be stacked on top of each other. Multiple stacked battery cells 100 can form a battery cell stack 140. The battery cell stack 140 may also be provided with at least one heat dissipation pad 150. The heat dissipation pad 150 can dissipate heat from the battery cells 100. The heat dissipation pad 150 may be placed between the multiple battery cells 100 or to cover the outermost battery cell 100.

[0085] The module frame 200 can form the external appearance of the battery module 10. The module frame 200 can be made of a metal material with high strength.

[0086] The structure of the module frame 200 can be diverse. For example, the module frame 200 may be a monoframe. The monoframe may be a metal plate material with an integrated top surface, bottom surface, and both sides. As another example, the module frame 200 may have a structure in which a U-shaped frame and an upper plate (top surface) are joined together. The U-shaped frame may be a metal plate material with a lower plate (bottom surface) and side plates (both sides) joined together or integrated. In addition, the structure of the module frame 200 may be provided as a structure in which L-shaped frames are joined together, and it should be possible to provide a variety of structures not described in the examples above.

[0087] The module frame 200 may have an internal space in which a battery cell stack 140 may be housed. More specifically, the module frame 200 may include a top surface, a bottom surface, and both sides. The module frame 200 may have open ends in the overall length direction and may be covered by end plates 400, which will be described later.

[0088] Multiple vent holes 240 may be formed on one side 210 of the module frame 200, preferably the upper surface. If ignition occurs in the battery cell 100 within the module frame 200, gas and flames can be quickly discharged into the vent holes 240.

[0089] Each vent hole 240 may be formed to be elongated in a direction parallel to the battery cell 100.

[0090] Both ends of each vent hole 240 may be formed with a rounded, convex shape on the outside. This reduces stress concentration near the corners of the vent hole 240 while increasing the open area of ​​the vent hole 240.

[0091] Multiple vent holes 240 may be arranged in multiple rows parallel to the stacking direction of multiple pouch-type battery cells 100. For example, as shown in Figure 8, multiple vent holes 240 may be arranged in five rows parallel to the stacking direction of the pouch-type battery cells 100. Thus, a predetermined gap d can be formed between two adjacent rows of vent holes 240 with respect to the length direction of the pouch-type battery cell 100.

[0092] The battery module 10 may further include a busbar frame 300 and an end plate 400.

[0093] The busbar frame 300 may be arranged on both sides along the entire length of the battery cell stack 140. The busbar frame 300 may have at least one busbar 310 attached to it, and each busbar 310 may be connected to the electrode leads 111 of the battery cell 100. The busbars 310 may be configured to electrically connect multiple battery cells 100 to an external device.

[0094] The end plate 400 may be positioned outside the busbar frame 300. That is, the busbar frame 300 may be positioned between the battery cell stack 120 and the end plate 400.

[0095] The end plate 400 may be coupled to the module frame 200. The end plate 400 can cover both open ends of the module frame 200. An opening 400H is formed in the end plate 400, and the busbar 310 can be electrically connected through the opening 400H. That is, the busbar 310 of one battery module 10 can be electrically connected to other battery modules 10 or BDUs (Battery Disconnect Units) through the opening 400H.

[0096] On the other hand, there is a risk that the multiple fixing members 130 of the battery cell 100 may obstruct the discharge of gas through the vent holes 240. To resolve this concern, the area of ​​each vent hole 240 that is not overlapped with the fixing members 130 may be even larger than the area that is overlapped with the fixing members 130. In other words, each vent hole 240 may not overlap with the fixing members 130, or less than half of its area may overlap with the fixing members 130. This allows the gas vented in the battery cell 100 to be smoothly vented through the vent holes 240.

[0097] More specifically, the area over which the multiple fixing members 130 overlap with the multiple vent holes 240 may be 1 / 3 or less of the total area of ​​the multiple vent holes 240. In other words, the fixing members 130 may overlap with only 1 / 3 or less of the total area of ​​the multiple vent holes 240.

[0098] More specifically, the area of ​​each vent hole 240 that overlaps with the fixing member 130 may be less than one-third of the area that does not overlap with the fixing member 130. That is, only less than one-third of the area of ​​each vent hole 240 may overlap with the fixing member 130. This prevents some of the vent holes 240 from being blocked by the fixing member 130, ensuring that all vent holes 240 are opened evenly and improving the reliability of gas venting.

[0099] The vent hole 240 can have a length longer than the fixing member 130. Preferably, the length of the vent hole 240 may be three times or more the length L of the fixing member 130. This increases the ease of designing and manufacturing the battery cell 100 because the position where the fixing member 130 is attached to the battery case 120 is not constrained by the position of the vent hole 240.

[0100] The spacing d between the multiple vent holes 240 in the longitudinal direction of the battery cell 100 may be greater than or equal to the length L of the fixing member 30. This reduces the proportion in which the fixing member 130 attached to any position on the battery case 120 overlaps with the vent holes 240, thereby maintaining high rigidity of the module frame 200.

[0101] The multiple vent holes 240 may include a first vent hole 241 that overlaps with the fixing member 130 and a second vent hole 242 that does not overlap with the fixing member 130. That is, some of the multiple vent holes 240 may overlap with the fixing member 130, while other parts may not overlap with the fixing member 130. This makes it possible to maintain a certain degree of smooth gas venting through the multiple vent holes 240 while preventing the multiple vent holes 240 from being formed excessively wide in the module frame 200, thereby preventing the rigidity of the module frame 200 from becoming too low.

[0102] However, the invention is not limited thereto, and in other embodiments, it is also possible for a plurality of vent holes 240 to include only the first vent hole 241 or only the second vent hole 242 through an appropriate arrangement of the plurality of vent holes 240.

[0103] Figures 9a and 9b illustrate the internal structure of a battery module based on an experimental example.

[0104] The experimental conditions for the battery module described below are the same as those for the battery cell described above.

[0105] In the battery module of the first experimental example, two of the four fixing tapes, each 30 mm long, were attached 31.2 mm away from both ends of the long-side sealing section, and the remaining two were attached at equal intervals. In addition, a module frame with three vent holes was used, so that more than half of the outermost two vent holes overlapped with the fixing tapes (see Figure 9a). As a result, the delay time was measured as 0 seconds in the first test and as 4.7 seconds in the second test, confirming that the flame delay effect appears randomly.

[0106] In the case of the battery module in the second experimental example, two of the three 30mm long fixing tapes were attached 31.2mm away from both ends of the long-side sealing section, and the remaining one was attached to the center of the long-side sealing section. In addition, a module frame with two vent holes was used so that the entire vent hole did not overlap with the fixing tape (see Figure 9b). As a result, the delay time was measured at 5.2 seconds in the first trial and at 10.4 seconds in the second trial, confirming that it had a flame delay effect.

[0107] These experimental examples confirm that the battery module 10 according to one embodiment of the present invention has a reliable flame delay effect (second experimental example).

[0108] The above description is merely illustrative of the technical concept of the present invention, and a person with ordinary skill in the art to which the present invention belongs could make various modifications and variations without departing from the essential characteristics of the present invention.

[0109] Therefore, the embodiments disclosed in this invention are for illustrative purposes only, and not to limit the technical concept of the invention, and the scope of the technical concept of the invention is not limited by such embodiments.

[0110] The scope of protection of this invention shall be interpreted in accordance with the following claims, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of the rights of this invention. [Explanation of Symbols]

[0111] 10 Battery Modules 100 pouch-type battery cells 110 Electrode assembly 111 Electrode Leads 120 Battery Case 121 Storage compartment 122 Short side sealing section 123 Long side sealing section 124 Folding section 130 Fixing member 200 Module Frames 210 (One side of the module frame) 240 vent holes

Claims

1. Module frame; Multiple pouch-type battery cells arranged in a row within the module frame; and The module frame includes a plurality of vent holes formed through one surface, The aforementioned pouch-type battery cell is Electrode assembly equipped with electrode leads; A battery case including a storage section for housing the electrode assembly, a short-side sealing section located in part of the periphery of the storage section from which the electrode leads protrude, and a long-side sealing section located in another part of the periphery of the storage section and folded toward the storage section; and It includes a plurality of fixing members attached to the battery case so as to fix the long side sealing portion in a folded state, and arranged so as to be spaced apart from each other in the longitudinal direction of the long side sealing portion, A battery module in which each of the vent holes has a larger area that does not overlap with the fixing member than the area that overlaps with the fixing member.

2. The battery module according to claim 1, wherein the value obtained by subtracting the total length of the plurality of fixing members from the length of the long side sealing portion is greater than or equal to the total length of the short side sealing portion.

3. The battery module according to claim 1, wherein the spacing between the plurality of fixing members is greater than the length of the fixing member.

4. The battery module according to claim 1, wherein the spacing between the plurality of fixing members is greater than the length of each of the short-side sealing portions.

5. The battery module according to claim 1, wherein the outermost fixing member among the plurality of fixing members is positioned to correspond to the end of the storage section.

6. The battery module according to claim 1, wherein the total length of the plurality of fixing members is 20% or less of the length of the long side sealing portion.

7. The battery module according to claim 1, wherein the total length of the plurality of fixing members is 17% or less of the length of the long side sealing portion.

8. The battery module according to claim 6 or 7, wherein the total length of the plurality of fixing members is 10% or more of the length of the long side sealing portion.

9. The battery module according to claim 1, wherein the length of each of the fixing members is 3% to 6% or less of the length of the long side sealing portion.

10. The battery module according to claim 1, wherein the vent hole is formed to be elongated in a direction parallel to the pouch-type battery cell and has a length longer than the fixing member.

11. The battery module according to claim 10, wherein the length of the vent hole is three times or more the length of the fixing member.

12. The battery module according to claim 1, wherein the area in which the plurality of fixing members overlap with the plurality of vent holes is 1 / 3 or less of the total area of ​​the plurality of vent holes.

13. The battery module according to claim 1, wherein the area of ​​each of the vent holes that overlaps with the fixing member is 1 / 3 or less of the area that does not overlap with the fixing member.

14. The aforementioned multiple vent holes are, A first vent hole overlapping the aforementioned fixing member; and The battery module according to claim 1, further comprising a second vent hole that does not overlap with the aforementioned fixing member.

15. The plurality of vent holes are arranged in a plurality of rows parallel to the stacking direction of the plurality of pouch-type battery cells. The battery module according to claim 1, wherein the spacing between the plurality of vent holes in the longitudinal direction of the pouch-type battery cell is greater than or equal to the length of the fixing member.

16. The battery module according to claim 1, wherein both ends of the vent hole are formed in a rounded shape that is convex outwards.

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