Venting delay device for Battery cell

Abstract

A venting delay device for a battery cell according to a first embodiment of the present invention comprises a battery cell that accommodates an electrode assembly inside and includes a sealing portion at one end or the other end having a first tab or a second tab formed therein, wherein the sealing portion is coupled to the sealing portion at one end or the other end of the battery cell, and wherein the sealing portion has a terrace portion which is a non-adhesive portion and a fusion portion which is an adhesive portion formed therein, and includes a slit into which the fusion portion is inserted and an inner guide surface that disperses the expansion force of the terrace portion. The effect according to one embodiment of the present invention is to effectively disperse the expansion force caused by the increase in internal pressure due to gas generation inside the battery cell, thereby effectively preventing and delaying battery cell venting.

Description

Technology Field

[0001] One embodiment of the present invention relates to a venting delay device for a battery cell. Background Technology

[0002] Pouch-type rechargeable batteries can be exposed to harsh environments, such as high temperatures or humidity, as well as repeated charging and discharging cycles, during manufacturing and use; these conditions generate gas within the battery. The gas generated inside the battery increases the pressure within the pouch, and if the pressure exceeds the critical threshold that the pouch can withstand, the weakest point of the seal breaks, resulting in damage to the pouch-type rechargeable battery. As such, the pressure resistance performance of pouch-type rechargeable batteries is a key factor related to their lifespan and stability.

[0003] Conventionally, technologies regarding sealing methods have been developed to improve the sealing portion, which is the weak point of a pouch's sealing. However, even when sealing technology is optimized, there are limitations based on the characteristics of the material being sealed. Furthermore, since the optimization of sealing technology has already progressed significantly, the reality is that the improvement in pressure resistance achievable by improving the sealing technology is minimal. Prior art literature

[0004] (Patent Document 0001) KR 10-2016-0080559 A The problem to be solved

[0005] The objective according to one embodiment of the present invention is to provide a battery cell venting delay device capable of delaying the venting time of a battery cell caused by internal expansion pressure of the battery cell and ensuring the safety of the battery cell operation.

[0006] In addition, considering the expansion characteristics at the battery cell tab, this is intended to effectively ensure the electrical reliability of the battery cell by effectively dispersing the expansion force caused by more stable internal pressure, thereby effectively delaying venting caused by battery cell expansion. means of solving the problem

[0008] A venting delay device for a battery cell according to one embodiment of the present invention comprises a battery cell having a sealing portion at one end or the other end that accommodates an electrode assembly inside and has a first tab or a second tab formed therein, wherein the sealing portion is coupled to the sealing portion at one end or the other end of the battery cell, the sealing portion having a non-adhesive terrace portion and an adhesive fusion portion formed therein, and includes a slit into which the fusion portion is inserted and an inner guide surface that disperses the expansion force of the terrace portion.

[0009] Here, the inner guide surface may include an upper guide surface having an inner curved surface of a predetermined curvature facing the expansion direction of the upper terrace portion of the first tab or the second tab, and a lower guide surface having an inner curved surface of a predetermined curvature facing the expansion direction of the lower terrace portion of the first tab or the second tab.

[0010] Additionally, the upper guide surface may have a curved surface extended to cover the bent edge portion of the battery cell above the first tab or the second tab, and the lower guide surface may include a curved surface extended to cover the bent edge portion of the battery cell below the first tab or the second tab.

[0011] In addition, it may include an upper cover covering the upper surface of the sealing portion of one end or the other end of the battery cell, a lower cover covering the lower surface of the sealing portion of one end or the other end of the battery cell, and side covers covering both sides of the upper cover and the lower cover.

[0013] A venting delay device for a battery cell according to a second embodiment of the present invention comprises a battery cell having a sealing portion at one end or the other end that accommodates an electrode assembly inside and has a first tab or a second tab formed therein, wherein the sealing portion is coupled to the sealing portion at one end or the other end of the battery cell, the sealing portion having a terrace portion which is a non-adhesive portion and a fusion portion which is an adhesive portion formed therein, and a slit into which the fusion portion is inserted and an inner expansion guide portion that disperses the expansion force of the terrace portion.

[0014] Here, the expansion guide portion may include an upper expansion guide portion having a symmetric curved surface with a curvature greater than the curvature of the expanding curved surface of the upper terrace portion, facing the direction in which the upper terrace portion of the first tab or the second tab expands and protrudes with a predetermined curvature, and a lower expansion guide portion having a symmetric curved surface with a curvature greater than the curvature of the expanding curved surface of the lower terrace portion, facing the direction in which the lower terrace portion of the first tab or the second tab expands and protrudes with a predetermined curvature.

[0015] Additionally, the upper expansion guide portion may include an upper guide surface in which the inner surface contacting the expansion surface of the terrace portion forms a curved surface protruding outward by a predetermined curvature, and the lower expansion guide portion may include a lower guide surface in which the inner surface contacting the expansion surface of the terrace portion forms a curved surface protruding outward by a predetermined curvature.

[0016] Additionally, the upper guide inclined surface may have a curved surface extended to cover the bent edge portion of the battery cell above the first tab or the second tab, and the lower guide inclined surface may have a curved surface extended to cover the bent edge portion of the battery cell below the first tab or the second tab.

[0018] The features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings.

[0019] Prior to this, terms and words used in this specification and claims should not be interpreted in their ordinary and dictionary senses, but should be interpreted in a sense and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention. Effects of the invention

[0020] The effect according to one embodiment of the present invention is to effectively disperse the expansion force caused by the increase in internal pressure due to gas generation inside the battery cell, thereby effectively preventing and delaying battery cell venting.

[0021] In addition, by effectively regulating and controlling the expansion force caused by the internal pressure of the battery cell, the internal pressure characteristics of the battery cell are effectively secured, thereby effectively improving the performance and operational reliability of the battery cell.

[0022] In addition, by bringing the folded corner portion, which is the corner portion of the battery cell that expands due to the internal pressure of the battery cell, into contact with the inner curved surface, the expansion pressure of the corner portion can be effectively dispersed and prevented.

[0023] In addition, by designing and combining a venting delay device that effectively considers the expansion pattern of specific parts requiring electrical stability in the battery cell tab, it is possible to improve the safety and reliability of the electrical characteristics of the battery cell tab.

[0024] In addition, by considering the expansion shape of the battery cell tab section as it swells into a curved form, and by using an expansion guide section having a greater curvature to the curved surface, the expansion of specific areas is suppressed and the expansion force is effectively dispersed in the lateral direction, thereby improving the stability of the battery cell tab sealing and further enhancing the electrical performance and reliability of the tab section. Brief explanation of the drawing

[0026] FIG. 1 is a schematic diagram of the combination of a venting delay device of a battery cell according to a first embodiment of the present invention; FIG. 2 is a cross-sectional view of one side of a battery cell according to a first embodiment of the present invention; FIG. 3 is a perspective view of a venting delay device of a battery cell according to a first embodiment of the present invention. FIG. 4 is a cross-sectional perspective view along dotted line A of FIG. 3. FIG. 5 is a perspective view of one side of a battery cell assembled according to a first embodiment of the present invention. FIG. 6 is a schematic diagram of the front and rear operation of a battery cell venting delay device according to the first embodiment of the present invention. FIGS. 7A and 7B are schematic plan views of expansion at the battery cell tab portion due to internal expansion of the battery cell. Figure 8 is a schematic diagram of the expansion pattern at the tab portion during internal expansion of the battery cell. FIG. 9 is a perspective view of a venting delay device of a battery cell according to a second embodiment of the present invention. FIG. 10 is a cross-sectional perspective view along the dotted line C of FIG. 9. FIG. 11 is a plan view of FIG. 10 FIG. 12 is a perspective view of one side of a venting delay device of a battery cell according to a second embodiment of the present invention. FIGS. 13a and 13b are front and rear operation plan views of a venting delay device of a battery cell according to a second embodiment of the present invention. FIG. 14 is a perspective view of a battery cell venting delay device according to a modified example of the second embodiment of the present invention. FIG. 15 is a cross-sectional perspective view along the dotted line D of FIG. 14. FIG. 16 is a cross-sectional perspective view along the dotted line E of FIG. 14. FIG. 17 is a plan view of FIG. 16 Specific details for implementing the invention

[0027] The purpose, advantages, and features of an embodiment of the present invention will become more apparent from the following description of the embodiment in conjunction with the accompanying drawings. It should be noted that in assigning reference numerals to the components of each drawing in this specification, identical components are given the same number as much as possible, even if they are shown in different drawings. Furthermore, terms such as "one side," "other side," "first," and "second" are used to distinguish one component from another, and the components are not limited by these terms. In the following description of an embodiment of the present invention, detailed descriptions of related known technologies that may unnecessarily obscure the essence of the embodiment of the present invention are omitted.

[0029] Hereinafter, an embodiment of the present invention will be described in detail with reference to the attached drawings.

[0031] FIG. 1 is a schematic diagram of the assembly of a venting delay device of a battery cell according to the first embodiment of the present invention, FIG. 2 is a cross-sectional view of one side of a battery cell according to the first embodiment of the present invention, FIG. 3 is a perspective view of the venting delay device of a battery cell according to the first embodiment of the present invention, FIG. 4 is a cross-sectional perspective view along the dotted line A of FIG. 3, FIG. 5 is a perspective view of the assembly of one side of a battery cell according to the first embodiment of the present invention, and FIG. 6 is a schematic diagram of the front and rear operation of the battery cell venting delay device according to the first embodiment of the present invention.

[0033] A venting delay device (20) of a battery cell (10) according to the first embodiment of the present invention is a battery cell (10) that accommodates an electrode assembly (14) inside and includes a sealing portion (13) at one end or the other end having a first tab (11) or a second tab (12) formed thereon, wherein the sealing portion (13) is coupled to the sealing portion (13) at one end or the other end of the battery cell (10), wherein the sealing portion (13) has a non-adhesive terrace portion (13a) and an adhesive fusion portion (13b) formed thereon, and includes a slit (21) into which the fusion portion (13b) is inserted and an inner guide surface that disperses the expansion force of the terrace portion (13a).

[0035] As illustrated in FIG. 1, in the first embodiment of the present invention, a first tab (11) and a second tab (12) are formed at both ends of a battery cell (10), and a venting delay device (20) can be coupled on the sealing portion (13) of the first tab (11) or the second tab (12).

[0036] Here, the first tab (11) and the second tab (12) collectively refer to the electrode tabs or electrodes of the battery cell (10), and it is obvious that the first tab (11) and the second tab (12) are formed such that the positive and negative electrodes are mutually complementary to form an electrical connection of the battery cell (10). In the illustrated drawings of the present invention, the first tab (11) and the second tab (12) are shown formed on opposite sides of one end and the other end of the battery cell (10), but it is obvious that the arrangement of the first tab (11) and the second tab (12) can be appropriately modified in consideration of the application of the venting delay device according to the embodiment of the present invention.

[0037] The venting delay device (20) is coupled to the sealing part (13) to effectively prevent and delay venting, such as the rupture of the sealing part (13), which occurs when the pressure inside the battery cell increases due to causes such as gas generation inside the battery cell (10).

[0038] Although the first embodiment of the present invention illustrates a connection to either the first tab (11) or the second tab (12) of the battery cell (10) or to the sealing portion (13) at both ends, it is obvious that a venting delay device (20) of the same type can also be connected or applied to the sealing portion (13) on the other side of the battery cell (10).

[0039] However, the present specification will focus on the embodiment illustrated in FIG. 1.

[0041] As shown in FIG. 2, the sealing portion (13) of the battery cell (10) is typically formed to accommodate an electrode assembly (14) inside by means of a pouch outer material. By joining, i.e., sealing, the outer surface of the pouch outer material, the electrode assembly (14) inside the battery cell (10) can be stably accommodated, and the stacking and electrical connection of a plurality of battery cells (10) can be stably performed.

[0042] As illustrated in FIG. 2, the sealing portion (13) may be composed of a bonded fusion portion (13b) at the end of the sealing portion (13) and a terrace portion (13a) at the tip of the fusion portion (13b) in which an internal space is formed without bonding an exterior material.

[0043] Venting of the battery cell (10) can commonly occur when the adhesion of the fused portion (13b) of the sealing portion (13) is broken by the internal pressure of the battery cell (10). To prevent this, the internal pressure transmitted to the fused portion (13b) of the sealing portion (13) can be minimized by effectively blocking and dispersing the expansion force during the process in which the internal pressure of the battery cell (10) is transmitted from the terrace portion (13a) of the sealing portion (13). Through this, the breaking of the fused portion (13b) of the sealing portion (13) can be prevented and delayed as much as possible.

[0045] As illustrated in FIGS. 3 and 4, the venting delay device (20) of the battery cell (10) according to the first embodiment of the present invention may be formed so that the sealing portion (13) of the battery cell (10) is inserted. A slit (21) may be formed into which the sealing portion (13) of the battery cell (10) is inserted and the fused portion (13b) of the battery cell (10) is fitted and joined. When the fused portion (13b) of the battery cell (10) is joined to the slit (21), the terrace portion (13a) of the sealing portion (13) may be joined to the space inside the venting delay device (20). Inner guide surfaces (22, 23) are formed on the inner side of the venting delay device (20), so that when the terrace portion (13a) of the sealing portion (13) expands due to the internal pressure of the battery cell (10), the expansion direction and expansion force can be effectively dispersed through the contact surface with the terrace portion (13a).

[0047] The inner guide surface (22, 23) may include an upper guide surface (22) having an inner curved surface of a predetermined curvature facing the expansion direction of the upper terrace portion (13a) of the first tab (11) or the second tab (12), and a lower guide surface (23) having an inner curved surface of a predetermined curvature facing the expansion direction of the lower terrace portion (13a) of the first tab (11) or the second tab (12).

[0048] Specifically, the upper guide surface (22) may be formed to have an inner curved surface of a predetermined curvature so as to guide the direction of the expansion surface and disperse the expansion force when the terrace portion (13a) above the sealing portion (13) fusion portion (13b) expands. Specifically, as shown in FIG. 3, the inner curved surface is formed to form a convex curved surface from one corner outward, and when the upper terrace portion (13a) expands, it comes into contact with the surface and naturally disperses the expansion force forward along the curved surface, thereby effectively preventing the concentration of expansion force in a specific area. By doing so, venting caused by the internal pressure of the battery cell (10) can be stably prevented and delayed.

[0049] The lower guide surface (23) can also be formed to have a mutually symmetrical shape and an outwardly convex curved surface, similar to the upper guide surface (22). When the lower terrace portion (13a) expands, the expansion force is effectively dispersed forward through the curved surface of the lower guide surface (23), and venting caused by the expansion of the battery cell (10) can be delayed.

[0051] FIGS. 5 and 6 are schematic diagrams illustrating the coupling of the venting delay device (20) of the first embodiment of the present invention and the venting delay action of the battery cell (10) by the coupling of the venting delay device (20).

[0052] First, as shown in the first drawing in FIG. 6, the fused portion (13b) of the sealing portion (13) of the battery cell (10) is joined to the slit (21) of the venting delay device (20), and the terrace portion (13a) is naturally inserted into the venting delay device (20).

[0053] Next, as shown in the second illustrated drawing, when the terrace portion (13a) swells up due to the internal expansion force of the battery cell (10), the upper terrace portion (13a) and the lower terrace portion (13a) expand outward and come into contact with the upper guide surface (22) and the lower guide surface (23).

[0054] When the terrace portion (13a) is expanded in contact with the upper guide surface (22) and the lower guide surface (23), the expansion force can be transmitted to the front of the battery cell (10) along the curved surface of the upper guide surface (22) and the lower guide surface (23). By doing so, the expansion force of the terrace portion (13a) is dispersed forward, and venting caused by the rupture of the fused portion (13b) of the battery cell (10) sealing portion (13) due to increased internal pressure of the battery cell (10) can be prevented as much as possible.

[0055] In particular, the upper guide surface (22) and the lower guide surface (23) can be formed with an extended curved surface to cover the edge surface of the bent corner portion (15) of the battery cell (10). By doing so, the expansion force of the vulnerable part during the expansion of the battery cell (10) can be effectively dispersed.

[0057] Additionally, the venting delay device (20) may include an upper cover (24) covering the upper surface of the sealing portion (13) at one end or the other end of the battery cell (10), a lower cover (25) covering the lower surface of the sealing portion (13) at one end or the other end of the battery cell (10), and side covers (26) covering both sides of the upper cover (24) and the lower cover (25).

[0058] By effectively supporting the sealing part (13) inserted into the venting delay device (20) through the upper cover (24), lower cover (25), and side cover (26), and by wrapping the upper, lower, and side parts, the venting of the battery cell (10) caused by the internal expansion force of the battery cell (10) can be effectively prevented and delayed.

[0060] FIGS. 7a and 7b are schematic plan views of expansion at the battery cell tab portion due to internal expansion of the battery cell, FIG. 8 is a schematic view of the expansion shape at the tab portion when the battery cell expands internally, FIG. 9 is a perspective view of a venting delay device of a battery cell according to a second embodiment of the present invention, FIG. 10 is a cross-sectional perspective view along the dotted line C of FIG. 9, FIG. 11 is a plan view of FIG. 10, FIG. 12 is a perspective view of one side of the venting delay device of a battery cell according to a second embodiment of the present invention, and FIG. 13a and 13b are front and rear operation plan views of the venting delay device of a battery cell according to a second embodiment of the present invention.

[0062] A venting delay device (30) according to a second embodiment of the present invention may include a battery cell (10) having a sealing portion (13) at one end or the other end that accommodates an electrode assembly (14) inside and has a first tab (11) or a second tab (12) formed therein, and may be coupled to the sealing portion (13) at one end or the other end of the battery cell (10), wherein the sealing portion (13) has a non-adhesive terrace portion (13a) and an adhesive fusion portion (13b) formed therein, and may include a slit (31) into which the fusion portion (13b) is inserted and an expansion guide portion (32, 33) that disperses the expansion force of the terrace portion (13a).

[0064] The venting delay device (30) according to the second embodiment of the present invention is an embodiment that applies a structure for more effective delaying of battery cell (10) venting by considering the expansion shape of the sealing part (13) at the part where the first tab (11) or the second tab (12) of the battery cell (10) is formed.

[0066] As shown in FIGS. 7a and 7b, when the internal pressure of the battery cell (10) increases due to gas or the like at one end where the first tab (11) of the battery cell (10) is formed, it can be seen that the terrace portion (13a) of the first tab (11) of the battery cell (10) expands to form a curved surface shape with a predetermined curvature that is convex forward. This can also be confirmed by looking at the schematic diagram of FIG. 8, which shows the shape of expansion in the direction where the first tab (11) of the battery cell (10) is formed due to actual internal expansion of the battery cell (10).

[0068] The venting delay device (30) according to the second embodiment of the present invention may include an expansion guide part (32, 33) capable of effectively dispersing the forward expansion force of the slit (31) into which the fusion part (13b) is inserted and the terrace part (13a).

[0069] The second embodiment of the present invention can effectively perform venting delay of the battery cell (10) through the shape of the expansion guide part (32, 33).

[0070] That is, as illustrated in FIGS. 9 to 11, the expansion guide portion (32, 33) may include an upper expansion guide portion (32) which faces the direction in which the upper terrace portion (13a) of the first tab (11) or the second tab (12) expands and protrudes with a predetermined curvature, and has a curved surface of greater curvature symmetrical to the curved surface of the expanding curvature of the upper terrace portion (13a); and a lower expansion guide portion (33) which faces the direction in which the lower terrace portion (13a) of the first tab (11) or the second tab (12) expands and protrudes with a predetermined curvature, and has a curved surface of greater curvature symmetrical to the curved surface of the expanding curvature of the lower terrace portion (13a).

[0071] As illustrated in FIG. 12, the venting delay device (30) may include an expansion guide section (32, 33) having a larger curvature and symmetrical to a convex curved surface of a predetermined curvature that expands in the direction of the first tab (11) or the second tab (12) of the battery cell (10), an upper expansion guide section (32) above the first tab (11), and a lower expansion guide below the first tab (11). Of course, the same structure and coupling structure may also be applied to the second tab (12).

[0073] The predetermined curvature of the expansion guide portion (32, 33) can be formed to have a greater curvature than the predetermined curvature of the expansion shape of the first tab (11) or second tab (12) portion of the battery cell (10). By doing so, the expansion force protruding from the center of the battery cell (10) can be smoothly distributed to both sides, thereby effectively dispersing the expansion force.

[0074] As illustrated in FIGS. 13a and 13b, the expansion guide portions (32, 33) are formed with mutually complementary curvatures, that is, mutually symmetrical curvatures, to form an expansion force of a predetermined curvature protruding in the direction of the first tab (11) of the battery cell (10), and the expansion guide portions (32, 33) have a curvature greater than the expanding curvature of the battery cell (10). By doing so, the expansion shape in the direction of the first tab (11) of the battery cell (10) spreads smoothly to both sides through the expansion guide portions (32, 33), thereby simultaneously realizing the dispersion of the expansion force.

[0075] In addition, as in the first embodiment of the present invention described above, the sealing portion (13) of the battery cell (10) can be more stably accommodated and coupled by including the upper cover (34), lower cover (35), and side cover (36) of the venting delay device (30).

[0077] FIG. 14 is a perspective view of a battery cell (10) venting delay device (30) according to a modified example of the second embodiment of the present invention, FIG. 15 is a cross-sectional perspective view along the dotted line D of FIG. 14, FIG. 16 is a cross-sectional perspective view along the dotted line E of FIG. 14, and FIG. 17 is a plan view of FIG. 16.

[0079] As illustrated in FIGS. 14 and 15, a modified example of the venting delay device (30) according to the second embodiment of the present invention may form the front surface of the expansion guide portion (32, 33) to be convex with a predetermined curvature, such as the inner guide surface (22, 23) of the first embodiment of the present invention.

[0080] By doing so, when the battery cell (10) expands to a predetermined curvature in the direction of the first tab (11), the expansion force is effectively dispersed not only in the lateral direction but also in the front direction at the same time, thereby preventing and delaying the overall venting of the battery cell (10) sealing part (13).

[0081] As shown in FIGS. 16 and 17, the expansion force toward the first tab (11) or second tab (12) of the battery cell (10) can be effectively dispersed in all directions, both forward and sideways, through deformation of the outer surface shape of the curved surface of the expansion guide part (32, 33) having a predetermined curvature.

[0083] The present invention has been described in detail through specific embodiments. These embodiments are intended to specifically explain the invention, but the invention is not limited thereto. It will be apparent that modifications or improvements can be made by those skilled in the art within the technical scope of the invention.

[0084] All simple variations or modifications of the present invention fall within the scope of the present invention, and the specific scope of protection of the present invention will be clarified by the appended claims. Explanation of the symbols

[0086] 10: Battery cell 11: First tab 12: Second tab 13: Sealing part 13a: Terrace part 13b: Fusion part 14: Electrode assembly 15: Bending edge part 20: Venting delay device 21: Slit 22: Upper guide surface 23: Lower guide surface 24: Upper cover 25: Lower cover 26: Side cover 30: Venting delay device 31: Slit 32: Expansion guide part 33: Expansion guide part 32a: Upper guide surface 32b: Lower guide surface 34: Upper cover 35: Lower cover 36: Side cover

Claims

Claim 1 A battery cell comprising a sealing portion at one end or the other end having a first tab or a second tab formed therein, which accommodates an electrode assembly inside, wherein the sealing portion is coupled to the sealing portion at one end or the other end of the battery cell, the sealing portion having a terrace portion which is a non-adhesive portion and a fusion portion which is an adhesive portion formed therein, and a slit into which the fusion portion is inserted and an inner guide surface that disperses the expansion force of the terrace portion, wherein the inner guide surface includes an upper guide surface having an inner curved surface of a predetermined curvature facing the expansion direction of the upper terrace portion of the first tab or the second tab, and a lower guide surface having an inner curved surface of a predetermined curvature facing the expansion direction of the lower terrace portion of the first tab or the second tab, wherein the upper guide surface has a curved surface extended to cover a folded edge portion of the battery cell above the first tab or the second tab, and the lower guide surface has a curved surface extended to cover a folded edge portion of the battery cell below the first tab or the second tab. Claim 2 delete Claim 3 delete Claim 4 A venting delay device for a battery cell according to claim 1, comprising: an upper cover covering the upper surface of a sealing portion at one end or the other end of the battery cell; a lower cover covering the lower surface of a sealing portion at one end or the other end of the battery cell; and side covers covering both sides of the upper cover and the lower cover. Claim 5 delete Claim 6 A battery cell comprising a sealing portion at one end or the other end having a first tab or a second tab formed therein, which accommodates an electrode assembly inside, wherein the sealing portion is coupled to the sealing portion at one end or the other end of the battery cell, the sealing portion having a non-adhesive terrace portion and an adhesive fusion portion formed therein, and a slit into which the fusion portion is inserted; and an expansion guide portion that disperses the expansion force of the terrace portion, wherein the expansion guide portion comprises an upper expansion guide portion having a symmetric curved surface with a curvature greater than the curvature of the expanding curved surface of the upper terrace portion, which faces the direction in which the upper terrace portion of the first tab or the second tab expands and protrudes with a predetermined curvature, and a lower expansion guide portion having a symmetric curved surface with a curvature greater than the curvature of the expanding curved surface of the lower terrace portion, which faces the direction in which the lower terrace portion of the first tab or the second tab expands and protrudes with a predetermined curvature. Claim 7 A battery cell venting delay device according to claim 6, wherein the upper expansion guide part includes an upper guide surface in which the inner surface contacting the expansion surface of the terrace part forms a curved surface protruding outward by a predetermined curvature, and the lower expansion guide part includes a lower guide surface in which the inner surface contacting the expansion surface of the terrace part forms a curved surface protruding outward by a predetermined curvature. Claim 8 A battery cell venting delay device according to claim 7, wherein the upper guide surface has a curved surface extended to cover the bent edge portion of the battery cell above the first tab or the second tab, and the lower guide surface has a curved surface extended to cover the bent edge portion of the battery cell below the first tab or the second tab.

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