Gas venting device and battery pack including same

Abstract

To provide a gas venting device capable of discharging a greater flow rate per unit time even with a venting disk of the same area, and a battery module and a battery pack including the same.SOLUTION: The present invention relates to a gas venting device and a battery module and a battery pack including the same, which are capable of discharging a larger flow rate of gas even when using a venting disk of the same area by continuously reducing the cross-sectional area of the flow path along the gas discharge direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a gas venting device for discharging gas from inside a battery module or a battery pack, and a battery pack including the same.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0024304 dated February 23, 2021 and Korean Patent Application No. 10-2022-0021766 dated February 18, 2022, and all contents disclosed in the documents of the relevant Korean patent applications are incorporated herein by reference. [Background technology]

[0003] A battery pack used in an electric vehicle has a structure in which a plurality of battery modules, each including a plurality of secondary batteries, are connected in series or parallel to obtain high output. The secondary battery includes positive and negative electrode current collectors, separators, active materials, and electrolytes, and can be repeatedly charged and discharged through electrochemical reactions between the components.

[0004] A secondary battery may generate gas from inside during repeated charging and discharging, which is called venting gas. For example, when an overcurrent flows, the temperature of the internal secondary battery rises rapidly. This rapid temperature rise can cause the electrolyte to decompose, generating gas. When gas is generated from the internal secondary battery of a battery pack, the gas may be trapped inside the pack, causing the battery pack to explode, or it may enter the interior of a vehicle through the battery pack's cooling ducts. For this reason, battery packs are equipped with a venting device that releases internal gas to the outside and reduces internal pressure.

[0005] A typical venting device has a structure in which a venting disk that can burst due to internal pressure is inserted between an inlet through which gas flows in from inside a battery pack and an outlet through which the gas is discharged. However, because conventional venting devices simply have a cylindrical structure in which the gas inlet and outlet are connected, the pressure between the inlet and outlet is not large, which limits the amount of gas that can be discharged. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Korean Patent Publication No. 10-2018-0039986 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made to solve the above problems, and it is an object of the present invention to provide a gas venting device that can exhaust a larger flow rate per unit time even with a venting disk of the same area, and a battery module and battery pack including the same. [Means for solving the problem]

[0008] The gas venting device according to the present invention includes a first bracket having a through hole formed in the center, a second bracket having a through hole formed in the center communicating with the first bracket and fastened to the first bracket, and a venting disk fastened between the first bracket and the second bracket to cover the through hole, the venting disk being configured to rupture when a predetermined pressure is applied, and a gas exhaust passage is formed in the through hole formed in the first bracket and the second bracket, and the cross-sectional area of ​​the gas exhaust passage decreases continuously or sequentially in the gas exhaust direction.

[0009] In a specific example, the gas venting device according to the present invention includes an exhaust guide member that is inserted into the through holes of the first bracket and the second bracket and has a gas exhaust passage formed in its center, and the cross-sectional area of ​​the gas exhaust passage may decrease continuously or sequentially along the gas exhaust direction.

[0010] In this case, the exhaust guide member includes a first exhaust guide member inserted into a through hole formed in the first bracket and a second exhaust guide member inserted into a through hole formed in the second bracket, and the cross-sectional area of ​​the gas exhaust flow path formed by the first exhaust guide member and the second exhaust guide member may decrease continuously or sequentially along the gas exhaust direction.

[0011] In one example, the gas exhaust channel may be frusto-conical in shape.

[0012] In another example, the gas discharge passage may have a truncated cone shape in which the cross-sectional area is continuously reduced and the inclined surface formed on the inner wall is concave or convex.

[0013] In a specific example, a straight flow path with a constant cross-sectional area may be formed on the outlet side of the gas discharge flow path, following the flow path in the shape of a truncated cone with a concave or convex inclined surface.

[0014] As another example, the gas discharge flow path may be formed by continuously forming a truncated cone-shaped flow path in which the inclined surface formed on the inner wall is curved to be concave as the cross-sectional area continuously decreases, and a truncated cone-shaped flow path in which the inclined surface is curved to be convex.

[0015] As another example, the gas discharge flow path may be formed by continuously reducing the cross-sectional area, thereby continuously forming a truncated cone-shaped flow path in which the inclined surface formed on the inner wall is curved to bulge, and a truncated cone-shaped flow path in which the inclined surface is curved to concave.

[0016] In a specific example, the inner wall of the gas discharge channel may be formed with protrusions having threads, embossings, or linear patterns.

[0017] In one example, a fastening portion protrudes from the outer surface of the discharge guide member for fastening the discharge guide member to a bracket, and the fastening portion may have a fastening hole formed therein for bolting together with the bracket.

[0018] In another example, the first bracket and the second bracket may be fastened to the discharge guide member by a screw fastening method.

[0019] Meanwhile, the venting disc includes an outer disc portion fastened to the first bracket and the second bracket, and an inner disc portion formed integrally with the outer disc portion, covering the through hole, the inner disc portion rupturing when a predetermined pressure is applied, and a notch may be formed in the inner disc portion so that the inner disc portion ruptures when the predetermined pressure is applied.

[0020] The present invention also provides a battery module including the gas venting device as described above.

[0021] The battery module includes a plurality of secondary batteries and a module frame on which the secondary batteries are mounted, and the gas venting device as described above may be fastened to one side of the module frame.

[0022] In one example, the gas venting device can be fastened with the first bracket in contact with the module frame.

[0023] In another example, the first bracket of the gas venting device may be fastened in contact with the inner surface of the module frame, and the second bracket may be fastened in contact with the outer surface of the module frame.

[0024] The present invention also provides a battery pack including a gas venting device as described above.

[0025] The battery pack includes at least one battery module having a plurality of secondary batteries, and a battery pack case including a tray on which the battery module is mounted and a pack cover that covers the battery module, and the gas venting device as described above may be fastened to one side of the battery pack case.

[0026] In one example, the gas venting device may be fastened with the first bracket or the second bracket in contact with the battery pack case.

[0027] In another example, the first bracket of the gas venting device may be fastened in contact with the inner surface of the battery pack case, and the second bracket may be fastened in contact with the outer surface of the battery pack case. [Effects of the Invention]

[0028] The gas venting device and the battery module or battery pack including the same according to the present invention can discharge a larger amount of gas per unit time even when using a venting disk of the same area, thereby improving the safety of the battery module and battery pack. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a perspective view of a gas venting device according to an embodiment of the present invention; [Figure 2] 3 is a perspective view showing a fastening configuration of a bracket and a venting disk in a gas venting device according to an embodiment of the present invention; FIG. [Figure 3] 1 is a cross-sectional view showing the shape of a gas venting device according to an embodiment of the present invention; [Figure 4] 5A and 5B are schematic diagrams illustrating the shape of a discharge guide member. [Figure 5] 10 is a cross-sectional view showing the shape of a gas venting device according to another embodiment of the present invention. [Figure 6] 10 is a cross-sectional view showing the shape of a gas venting device according to still another embodiment of the present invention. [Figure 7] 10 is a cross-sectional view showing the shape of a gas venting device according to another embodiment of the present invention. [Figure 8] 10 is a cross-sectional view showing the shape of a gas venting device according to still another embodiment of the present invention. [Figure 9] 4 is a cross-sectional view showing a fastening state of a bracket and a discharge guide member according to an embodiment of the present invention; FIG. [Figure 10] 10 is a cross-sectional view showing a fastening configuration of a bracket and a discharge guide member according to another embodiment of the present invention; FIG. [Figure 11] 1 is a schematic diagram showing the shape of a venting disk according to the present invention. FIG. [Figure 12] 1 is a schematic diagram showing a coupling structure of a gas venting device in a battery module according to an embodiment of the present invention; [Figure 13] 10 is a schematic diagram showing a coupling structure of a gas venting device in a battery module according to another embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0030] The present invention will be described in detail below. Prior to this, the terms and words used in the specification and claims should not be construed in a limited manner based on their ordinary or dictionary meanings, but should be construed in a manner that is consistent with the technical concept of the present invention, based on the principle that the inventor can appropriately define the concept of the term in order to best describe his or her invention.

[0031] In this application, the use of terms such as "comprise" or "have" is intended to specify the presence of a feature, numeral, step, operation, component, part, or combination thereof described in the specification, but should be understood not to preclude the possibility of the presence or addition of one or more other features, numerals, steps, operations, components, parts, or combinations thereof. Furthermore, when a layer, film, region, plate, or other part is described as being "on" another part, this includes not only the case where it is "directly on" the other part, but also the case where there is another part between them. Conversely, when a layer, film, region, plate, or other part is described as being "under" another part, this includes not only the case where it is "directly under" the other part, but also the case where there is another part between them. Furthermore, in this application, "arranged on" can include not only the case where it is arranged on top, but also the case where it is arranged on bottom.

[0032] The present invention will be described in detail below.

[0033] FIG. 1 is a perspective view of a gas venting device according to an embodiment of the present invention, and FIG. 2 is a perspective view showing a fastening form of a bracket and a venting disk in the gas venting device according to the embodiment of the present invention.

[0034] 1 and 2, a gas venting device 100 according to the present invention includes a first bracket 110 having a through hole formed in the center thereof, a second bracket 120 having a through hole formed in the center thereof communicating with the first bracket 110 and fastened to the first bracket 110, and a venting disk 130 fastened between the first bracket 110 and the second bracket 120 to cover the through hole, the venting disk 130 being configured to burst when a predetermined pressure is applied, and a gas exhaust passage is formed in the through holes formed in the first bracket 110 and the second bracket 120, and the cross-sectional area of ​​the gas exhaust passage decreases continuously or sequentially along the gas exhaust direction.

[0035] Typically, a battery pack is equipped with multiple battery modules, each of which contains multiple secondary batteries. These secondary batteries generate gas through the decomposition reaction of the electrolyte as they are repeatedly charged and discharged. Heat generated during the battery charging and discharging process promotes the generation of gas, causing the gas to expand and increasing the pressure inside the battery module or battery pack. If this process continues, the battery module or battery pack may explode, or the internal gas may enter the interior of the vehicle through a duct or the like. Therefore, a venting device is installed that releases gas by bursting a venting disc when the gas pressure exceeds a certain level.

[0036] Such gases are generally compressible fluids whose volume changes with pressure. When such air flows at high speed, areas with high pressure and density are created, causing the volume of the air to decrease. However, since the gas discharge speed is low during the gas discharge process, it exhibits an incompressible flow phenomenon in which the change in volume due to pressure can be ignored. In such incompressible flow, the total pressure on the fluid is constant, and the pressure and velocity of the fluid are inversely proportional. In other words, as the fluid pressure increases, the flow velocity decreases, and as the fluid pressure decreases, the flow velocity increases.

[0037] As mentioned above, conventional venting devices simply have a cylindrical structure in which a gas inlet and outlet are connected, and therefore the pressure difference between the inlet and outlet is small, which limits the amount of gas that can be discharged.

[0038] In contrast, when the cross-sectional area of ​​the flow path decreases continuously or gradually in the gas discharge direction, as in the present invention, the internal pressure increases as the air velocity decreases at the inlet with a large cross-sectional area, and the internal pressure decreases as the air velocity increases at the outlet with a small cross-sectional area. As a result, the pressure difference between the inlet and outlet increases locally, allowing a greater flow rate of gas to be discharged even using a venting disk of the same area. Therefore, when the internal pressure due to gas generated inside the battery module or battery pack exceeds a standard value, the gas can be quickly discharged, improving the safety of the battery module and battery pack.

[0039] The structure of the gas venting device according to the present invention will be described in detail below.

[0040] Fig. 3 is a cross-sectional view showing the shape of a gas venting device according to one embodiment of the present invention, Fig. 4 is a schematic view showing the shape of an exhaust guide member, and Fig. 5 is a cross-sectional view showing the shape of a gas venting device according to another embodiment of the present invention.

[0041] 3 or 4 together with FIGS. 1 and 2, a gas venting device 100 according to the present invention includes brackets 110 and 120 for fastening a venting disk 130 and discharging gas therein. The venting disk 130 may be fastened between the two brackets 110 and 120, and a through-hole is formed in the center of the brackets 110 and 120 to form a gas discharge passage within the through-hole. In the present invention, the bracket located on the gas inflow side relative to the gas discharge direction of the two brackets 110 and 120 is defined as the first bracket 110, and the bracket located on the gas discharge side is defined as the second bracket 120. The through-hole formed in the center of the second bracket 120 communicates with the through-hole formed in the center of the first bracket 110 to serve as a gas discharge passage. The first bracket 110 and the second bracket 120 may be formed with fastening holes (not shown) into which bolts 150 can be inserted to fasten the venting disk and discharge guide member (described later) together and fasten the gas venting device 100 to a battery module or a battery pack.

[0042] The venting disk 130 is fastened between the first bracket 110 and the second bracket 120 to block the through-hole, but may be configured to burst when a predetermined pressure is applied.

[0043] Meanwhile, gas exhaust passages are formed within the through-holes formed in the first bracket 110 and the second bracket 120. Specifically, the gas venting device 100 according to the present invention includes an exhaust guide member 140 that is inserted into the through-holes of the first bracket 110 and the second bracket 120 and has a gas exhaust passage 141 formed in its center. The gas exhaust passage formed within the through-hole may be formed by the exhaust guide member 140, and in this case, the cross-sectional area of ​​the gas exhaust passage 141 formed in the exhaust guide member 140 decreases continuously or sequentially along the gas exhaust direction.

[0044] That is, in the present invention, the shape of the gas exhaust flow path formed in the brackets 110 and 120 can be formed by molding the shape of the through hole itself, or by inserting a separate exhaust guide member 140 into the brackets 110 and 120 as described above. The exhaust guide member 140 has a detachable or replaceable structure. By using a separate exhaust guide member 140 in the brackets 110 and 120, the present invention facilitates gas exhaust, allows for easy replacement of parts, and allows for easy change of the flow path shape.

[0045] In the present invention, in order to improve gas exhaust efficiency, the length of the gas exhaust passage can be maximized while the cross-sectional area can be varied. In the present invention, since the venting disk 130 is positioned between the first bracket 110 and the second bracket 120, the exhaust guide member 140 can also be inserted into the through-holes formed in the first bracket 110 and the second bracket 120. Specifically, the exhaust guide member 140 includes a first exhaust guide member 140a inserted into the through-hole formed in the first bracket 110 and a second exhaust guide member 140b inserted into the through-hole formed in the second bracket 120. Here, the cross-sectional area of ​​the gas exhaust passage 141 formed by the first exhaust guide member 140a and the second exhaust guide member 140b decreases continuously or gradually along the gas exhaust direction. That is, no step is generated between the first exhaust guide member 140a and the second exhaust guide member 140b, and the gas exhaust passage 141 forms a single continuous surface. This allows the gas that has flowed into the brackets 110 and 120 to be smoothly discharged without being impeded.

[0046] Furthermore, the gas exhaust flow path 141 formed by the exhaust guide member 140 may be designed to be circular, for example, as shown in FIG. 4. In this case, the gas exhaust flow path 141 formed by the exhaust guide member 140 may be shaped like a truncated cone. Referring to FIG. 3 together with FIG. 4, the inlet 142 and outlet 143 of the gas exhaust flow path 141 in the exhaust guide member 140 are circular, and form the lower and upper surfaces of the truncated cone, respectively. That is, the inner wall 144 of the exhaust guide member 140 has a structure in which the cross-sectional area continuously decreases from the inlet where the gas flows in toward the outlet where the gas exits, thereby forming an inclined surface. When the cross-sectional profile of the inner wall 144 of the gas exhaust flow path 141 is formed as a linear inclined surface as shown in FIGS. 3 and 4, the rate of decrease in the cross-sectional area is constant throughout the gas exhaust flow path.

[0047] Although such a cross-sectional profile is linear and simple, it is easy to manufacture. However, when connected to other components such as pipes, angular portions may be generated on the wall of the flow path, which may result in some sections of unstable flow. Furthermore, because the cross-sectional area reduction rate is constant, if, for example, gas with unstable flow flows into the inlet of the flow path, the gas flow instability may not be resolved and may continue to be maintained until the outlet of the flow path. In other words, a flow path with a constant cross-sectional area reduction rate has the disadvantage of reducing the degree of freedom in adjusting flow instability within the corresponding flow path.

[0048] On the other hand, if the cross-sectional area is varied along the flow path, the flow instability can be controlled or managed within the flow path. Figures 5 to 8 show examples of such gas exhaust flow paths.

[0049] Referring to FIG. 5(a), the gas exhaust flow path 141 formed by the exhaust guide member 140 has a cross-sectional area that continuously decreases toward the outlet 143, resulting in a truncated cone shape where the inclined surface formed on the inner wall 144 of the gas exhaust flow path is concavely curved. Here, the concavely curved shape refers to a shape where the slope of the vertical cross section of the flow path decreases toward the outside of the gas exhaust flow path. In this case, the rate of decrease in the cross-sectional area is small near the inlet 142 where gas flows in and increases toward the outlet 143 where gas is discharged. The gas exhaust flow path 141 with this concavely curved cross-sectional profile has a shape where the flow path cross-sectional area on the outlet 143 side decreases rapidly, thereby increasing the pressure difference (differential pressure) between the inlet 142 and the outlet 143 of the flow path. That is, compared to the gas exhaust flow path 141 of the embodiments of FIGS. 3 and 4, which has a linearly sloped surface, the flow path of this embodiment can achieve a larger differential pressure between the inlet and the outlet. This means that a desired differential pressure can be easily obtained even if the length of the flow path is shortened. Therefore, according to this embodiment, when achieving the same differential pressure as the gas exhaust flow path 141 having the linear inclined surface of Figures 3 and 4, it is possible to configure a gas venting device with a flow path of a shorter length.

[0050] Referring to FIG. 5(b), the gas exhaust flow path 141 formed by the exhaust guide member 140 has a truncated cone shape, with the cross-sectional area continuously decreasing toward the outlet 143, resulting in a convex inclined surface formed on the inner wall 144. The convex inclined surface refers to a shape in which the vertical cross section of the flow path is inclined toward the center of the flow path. In this case, the rate of decrease in the cross-sectional area is large near the inlet 142 where gas flows in and decreases toward the outlet 143 where gas is discharged. Similar to the flow path in FIG. 5(a), the gas exhaust flow path 141 with a convex curved cross-sectional profile in FIG. 5(b) also has a larger rate of decrease in cross-sectional area compared to a gas exhaust flow path with a linear inclined surface. Therefore, a larger pressure difference can be achieved between the inlet and outlet, allowing the gas venting device to be constructed with a shorter flow path. In particular, the gas exhaust flow path 141 in FIG. 5(b) has a shape in which the cross-sectional area decreases more gradually toward the outlet 143 than a flow path with a linear inclined surface. A flow channel of this type has the advantage that high flow stability can be achieved because the change in physical quantity inside the flow channel is gradual.

[0051] Meanwhile, as mentioned above, in order to achieve both the effects of increasing the pressure difference between the inlet and outlet and improving flow stability, the cross-sectional profile of the gas exhaust flow path 141 can be configured in a form that combines curves and straight lines as shown in Figure 6.

[0052] 6(a), a straight flow path 146 with a constant cross-sectional area is formed on the outlet 143 side of the gas exhaust flow path 141, following the truncated cone-shaped flow path with a concave inclined surface of the gas exhaust flow path 141. In this embodiment, a larger pressure difference can be achieved by reducing the cross-sectional area of ​​the truncated cone-shaped flow path of the gas exhaust flow path 141, and the straight flow path 146 on the outlet side can stably send out exhaust gas by designing the inclination of the inner wall surface to be parallel to the gas flow direction.

[0053] 6(b), a straight flow path 146 with a constant cross-sectional area is formed on the outlet 143 side of the gas exhaust flow path, following the truncated cone-shaped flow path with a bulging inclined surface of the gas exhaust flow path 141. In this embodiment, too, a larger pressure difference can be achieved by reducing the cross-sectional area of ​​the truncated cone-shaped flow path of the gas exhaust flow path 141, and the straight flow path 146 on the outlet side can stably discharge exhaust gas by designing the inclination of the inner wall surface to be parallel to the gas flow direction.

[0054] 6 has a structure in which the curvature or cross-sectional area of ​​the gas exhaust flow path 141 continuously decreases, ultimately discharging gas through a flow path parallel to the gas flow direction. Therefore, even if the flow of gas initially introduced into the inlet 142 of the flow path is unstable, the flow instability is resolved as the gas passes through the corresponding flow path, allowing the gas to flow stably at the outlet 143.

[0055] 6, the gas exhaust flow path 141 formed on the inner wall of the first exhaust guide member 140a inserted into the through-hole formed in the first bracket 110 may be configured as a truncated cone with a concave inclined surface (see FIG. 6(a)) or a truncated cone with a convex inclined surface (see FIG. 6(b)). Meanwhile, the gas exhaust flow path 141 formed on the inner wall of the second exhaust guide member 140b connected to the gas exhaust flow path 141 may be configured as a composite flow path including both the truncated cone with a concave or convex inclined surface and a linear flow path 146 connected thereto.

[0056] In addition, in order to achieve both the effects of increasing the pressure difference between the inlet and outlet and improving flow stability, the gas discharge flow path 141 can be configured in a form in which curves with different curvatures are combined as shown in Figures 7 and 8.

[0057] 7(a) shows a schematic cross-sectional profile of a compound flow path in which a gas exhaust flow path having a continuously decreasing cross-sectional area is formed, and in which a flow path 144A having a truncated cone shape with a concave slope and a flow path 144B having a truncated cone shape with a convex slope are successively formed. FIG. 7(b) shows a gas venting device 100 having the cross-sectional profile of the compound flow path.

[0058] 7 is basically the same as the previous embodiments in that the cross-sectional area of ​​gas exhaust flow path 141 continuously decreases from inlet 142 to outlet 143. Therefore, compared to conventional gas venting devices in which the cross-sectional area does not decrease, the pressure difference between the inlet and outlet increases locally, allowing a greater flow rate of gas to be exhausted even when using a venting disk of the same area.

[0059] In addition to these effects, the gas exhaust flow path 141 in Figure 7 has a concave slope and a convex slope formed in succession, which further increases the cross-sectional area reduction rate and further increases the pressure difference between the inlet and outlet relative to the same flow path. As a result, the gas exhaust flow rate can be further increased. Also, the outlet 143 side has a flow path with a convex slope with a relatively gentle curve, which improves the stability of the gas flow.

[0060] The dotted line in Figure 7(a) indicates the boundary where the shape of the inclined surface changes, and this boundary may be the boundary between first bracket 110 and second bracket 120, or the portion where venting disk 130 is installed, as shown in Figure 7(b). However, the location of the boundary is not limited thereto. For example, one of first bracket 110 or second bracket 120 may have a flow path with an inclined surface including the boundary line, and the other bracket may have a flow path with an inclined surface of a single curvature. In other words, although not shown, it is also possible for one of the two brackets to form a gas exhaust flow path in a form that includes all of the flow path portions where the curvature changes.

[0061] Figure 8(a) shows a schematic cross-sectional profile of a compound flow path in which a gas exhaust flow path 141 having a continuously decreasing cross-sectional area is formed, and in which a convex truncated cone-shaped flow path 144B and a concave truncated cone-shaped flow path 144A are successively formed. Figure 8(b) shows a gas venting device having the cross-sectional profile of the compound flow path. That is, the gas venting device of Figure 8 has gas exhaust flow paths arranged in the opposite direction to those of Figure 7.

[0062] In the flow path of Figure 8, the cross-sectional area of ​​the gas exhaust flow path decreases continuously from inlet 142 to outlet 143, so the pressure difference between the inlet and outlet increases locally, making it possible to exhaust a larger flow rate of gas even when using a venting disk of the same area.

[0063] 8, the gas exhaust flow path 141 has a convex slope and a concave slope formed successively, which increases the cross-sectional area reduction rate and further increases the pressure difference between the inlet and outlet relative to the same flow path. This further increases the gas exhaust flow rate. Furthermore, the gas exhaust flow path 141 has a flow path with a slope that is relatively gently curved overall, which further improves the stability of the gas flow.

[0064] The dotted line in Figure 8(a) indicates the boundary where the shape of the inclined surface changes, and this boundary may be the boundary between first bracket 110 and second bracket 120 or the portion where venting disk 130 is installed, as shown in Figure 8(b). However, the location of the boundary is not limited thereto. For example, one of first bracket 110 or second bracket 120 may have a flow path with an inclined surface including the boundary line, and the other bracket may have a flow path with an inclined surface of a single curvature. In other words, although not shown, it is also possible for one of the two brackets to form a gas exhaust flow path in a form that includes all of the flow path portions where the curvature changes.

[0065] The venting devices of Figures 7 and 8 have composite flow channels with inclined surfaces of different curvatures. Therefore, even if gas flow stability initially decreases, the curvature can improve gas flow stability at the outlet as the gas passes through the channel. At the same time, the pressure difference between the inlet 142 and the outlet 143 can be increased by varying the curvature of the flow channels. While the composite flow channel of Figure 7 provides a good balance between pressure difference and flow stability, the composite flow channel of Figure 8 can be seen as an example that further considers flow stability. In either case, the gas flow within the corresponding channel can be adjusted, providing the advantage of excellent flexibility in adjusting flow stability.

[0066] In addition to the above, the shape of the flow passage formed inside the discharge guide member can be designed in various forms depending on the safety standards of the battery pack.

[0067] The cross-sectional area of ​​the outlet 143 of the gas exhaust passage 141 can be appropriately selected depending on the structure of the battery module and battery pack or the safety conditions to be achieved, and may be 40% to 80% of the cross-sectional area of ​​the inlet 142. Specifically, the cross-sectional area of ​​the outlet may be 50% to 70%, and more specifically, 55% to 65%, of the cross-sectional area of ​​the inlet. If the cross-sectional area of ​​the outlet is less than 40% of the cross-sectional area of ​​the inlet, the outlet portion becomes excessively narrow. On the other hand, if the cross-sectional area of ​​the outlet exceeds 80% of the cross-sectional area of ​​the inlet, the difference in cross-sectional area between the inlet and outlet becomes excessively small, reducing the pressure difference between the inlet and outlet, and thereby reducing the efficiency of gas venting.

[0068] In addition, a pattern (not shown) for assisting gas discharge may be formed on the inner wall 144 of the gas discharge channel 141. For example, the pattern may be a protrusion having a thread, embossing, or a linear pattern parallel to the gas discharge direction. Specifically, the pattern may be a protrusion having a thread shape that surrounds the inside of the channel along the inner wall of the channel. Such a pattern may facilitate gas discharge.

[0069] Meanwhile, the exhaust guide member is fastened to the bracket, thereby facilitating stable gas exhaust during gas venting.

[0070] FIG. 9 is a cross-sectional view showing a fastening configuration between a bracket and a discharge guide member according to one embodiment of the present invention, and FIG. 10 is a cross-sectional view showing a fastening configuration between a bracket and a discharge guide member according to another embodiment of the present invention.

[0071] In one example, the brackets 110 and 120 and the discharge guide member 140 may be fastened together by bolts. In this case, as shown in Fig. 9, fastening portions 145 protrude from the outer surface of the discharge guide member 140 to fasten the discharge guide member 140 to the brackets 110 and 120. Since the discharge guide member 140 must be inserted into the through-holes in the brackets 110 and 120, its cross section has a shape corresponding to the shape of the through-holes, and the fastening portions 145 are plate-like protrusions protruding along its outer periphery in a shape similar to the outer periphery of the venting disk 130. In the present invention, the discharge guide member 140 includes a first discharge guide member 140a and a second discharge guide member 140b, and the fastening portions 145 may be formed on both the first discharge guide member 140a and the second discharge guide member 140b. The fastening portion 145 has fastening holes (not shown) formed therein for fastening with the brackets 110 and 120 by bolts. The fastening holes formed in the fastening portion 145 are formed at the same positions as the fastening holes formed in the brackets 110 and 120, and are fixed by inserting bolts.

[0072] Meanwhile, the positions at which the fastening portions 145 are formed may be appropriately designed. For example, as shown in Fig. 9, the fastening portions 145 formed on the first discharge guide member 140a and the second discharge guide member 140b may be formed to be positioned between the first bracket 110 and the venting disk 130 and between the second bracket 120 and the venting disk 130, respectively. However, the positions of the fastening portions are not limited thereto, and for example, the fastening portions 145 may be formed to be in contact with the brackets 110 and 120 on the surfaces of the brackets 110 and 120 opposite to the surfaces that contact the venting disk 130.

[0073] In another example, the first bracket 110 and the second bracket 120 may be fastened to the discharge guide member 140 by a screw fastening method. In this case, as shown in FIG. 10 , threads for screw fastening may be formed on the inner walls of the first bracket 110 and the second bracket 120 and the outer surface of the discharge guide member 140, and the first bracket 110 and the second bracket 120 may be fastened to the discharge guide member 140 by a nut and bolt fastening method, respectively. In the present invention, the discharge guide member 140 includes a first discharge guide member 140a and a second discharge guide member 140b, and the threads may be formed on both the first discharge guide member 140a and the second discharge guide member 140b. When the discharge guide member 140 is fastened to the brackets 110 and 120 by a screw fastening method, the insertion of a separate bolt is not required, simplifying the component structure and fastening method, and the discharge guide member 140 may be firmly fixed to the brackets 110 and 120.

[0074] Meanwhile, referring to FIG. 11, the venting disk 130 includes a disk outer circumferential portion 131 fastened to the first bracket 110 and the second bracket 120, and a disk inner circumferential portion 132 integrally formed with the disk outer circumferential portion 131, covering the through-hole, and rupturing when a predetermined pressure is applied.

[0075] The disk outer periphery 131 is a portion for fixing the brackets 110 and 120 to the venting disk 130, and one side contacts the first bracket 110 and the other side contacts the second bracket 120. The disk outer periphery 131 may have bolt through holes 133 along the circumferential direction, and the first bracket 110, the disk outer periphery 131, and the second bracket 120 may be integrally connected by a bolt fastening method, etc. In the case where a fastening portion is formed on the discharge guide member, the discharge guide member may be connected to the brackets and the venting disk.

[0076] The inner periphery of the disk 132 is made of a metal or plastic material that can burst when a predetermined pressure is applied. For example, the inner periphery of the disk 132 may be made of a thin metal or plastic material such as copper, aluminum, or stainless steel. The inner periphery of the disk 132 may be appropriately selected depending on the pressure conditions at the time of bursting, and the scope of the present invention is not limited thereto.

[0077] Under normal conditions, the disk inner circumference 132 prevents moisture or foreign matter from penetrating into the battery module or battery pack by blocking the through holes formed in the first bracket 110 and the second bracket 120. However, if a large amount of gas is generated in the battery module or battery pack, the internal pressure increases, and this pressure acts as a force that can rupture the disk inner circumference 132. At this time, because the pressure inside the battery module or battery pack is higher than the external air pressure, the internal gas can be discharged to the outside of the battery module or battery pack due to negative pressure.

[0078] The inner periphery 132 of the disk is formed with a notch 134 so that it ruptures when a predetermined pressure is applied. The notch 134 is formed by cutting a portion of the surface of the venting disk 130 in the thickness direction. The shape of the notch 134 may be cross-shaped, circular, rectangular, U-shaped, elliptical, arc-shaped, etc., and the cross section of the notch 134 may be trapezoidal, V-shaped, square, arc-shaped, etc. The shape of the notch 134 formed in the inner periphery 132 of the disk is not limited thereto and may have various other shapes. For example, the notch 134 may be X-shaped as shown in FIG. 2. In this case, even if the inner periphery 132 of the disk ruptures, the ruptured fragments may not completely separate from the inner periphery 132 of the disk and may remain attached to the outer periphery 131 of the disk. If the ruptured fragments of the inner periphery of the disk are completely separated from the venting disk, they are difficult to remove and may damage other components.

[0079] In addition, a disc pad (not shown) may be interposed between the first bracket 110 and the venting disc 130 and / or between the second bracket 120 and the venting disc 130. The disc pad may be annular or ring-shaped and may correspond to the disc outer periphery 131. The disc pad serves to improve airtightness between the first bracket 110 and the venting disc 130 or between the second bracket 120 and the venting disc 130 and to prevent damage to the disc outer periphery 131. For example, the disc pad may be made of an elastic rubber material.

[0080] The present invention also provides a battery module including the gas venting device described above.

[0081] Figure 12 is a schematic diagram showing the connection structure of a gas venting device in a battery module according to one embodiment of the present invention, and Figure 13 is a schematic diagram showing the connection structure of a gas venting device in a battery module according to another embodiment of the present invention.

[0082] Referring to Figures 12 and 13, the battery module 200 according to the present invention includes a plurality of secondary batteries (not shown) and a module frame 210 on which the secondary batteries are mounted, and has a structure in which the gas venting device 100 as described above is fastened to one side of the module frame 210.

[0083] Specifically, the secondary battery has a structure in which an electrode assembly, in which a positive electrode, a negative electrode, and a separator are alternately stacked, is mounted in a cell case together with an electrolyte. The structure of such a secondary battery is obvious to those skilled in the art, and therefore a detailed description thereof will be omitted.

[0084] In one example, the gas venting device 100 may be fastened with the first bracket 110 or the second bracket 120 in contact with the module frame 210 as shown in Fig. 12. In this case, the first bracket 110 may be fastened with the outer surface of the module frame 210 as shown in Fig. 12(a), or the second bracket 120 may be fastened with the inner surface of the module frame 210 as shown in Fig. 12(b). In the present specification, the inner surface of the module frame 210 refers to the surface of the module frame 210 facing the internal space where the secondary battery is mounted, and the outer surface refers to the surface exposed to the outside of the module frame 210. Module frame 210 has holes formed therein corresponding to fastening holes formed in fastening portions (not shown) of first bracket 110, second bracket 120, and discharge guide member 140 and bolt through holes of venting disk 130, so that first bracket 110, venting disk 130, discharge guide member 140, and second bracket 120 can be fixed to module frame 210 by fastening the bolts once. Furthermore, module frame 210 has through holes formed in brackets 110 and 120 or holes of a size corresponding to the inlet of gas discharge passage 141 formed in discharge guide member 140, so that gas generated within the module can be discharged.

[0085] In another example, in the battery module 200, the gas venting device 100 may be fastened with the module frame 210 interposed between the first bracket 110 and the second bracket 120. Specifically, as shown in Fig. 13, the first bracket 110 of the gas venting device 100 may be fastened to the inner surface of the module frame 210, and the second bracket 120 may be fastened to the outer surface of the module frame 210. In this case, there is no particular limitation on the position of the venting disk 130, and it may be fastened between the first bracket 110 and the module frame 210 or between the second bracket 120 and the module frame 210. In the case where a fastening portion is formed on the discharge guide member, the venting disk is located between the fastening portion and the module frame.

[0086] Meanwhile, the battery module 200 may further include a sealing member (not shown) that seals the gap between the module frame 210 and the outer periphery of the gas venting device 100. The sealing member may be a rubber ring or silicone resin, and is installed in the gap between the gas venting device and the module frame to seal the battery module.

[0087] The present invention also provides a battery pack including the gas venting device described above.

[0088] The battery pack according to the present invention includes a battery module having a plurality of secondary batteries, a battery pack case including a tray on which the battery module is mounted and a pack cover that covers the battery module, and the gas venting device as described above may be fastened to one side of the battery pack case.

[0089] In this case, the gas venting device can be fastened to the battery pack case in the same manner as described above.

[0090] In one example, the gas venting device may be fastened with a first bracket in contact with the battery pack case. In this case, the battery pack case may be fastened with the first bracket in contact with the surface opposite the surface in contact with the venting disk. The battery pack case may have holes formed therein that correspond to fastening holes formed in fastening portions of the first bracket, the second bracket, the venting disk, and the discharge guide member, so that the first bracket, the venting disk, the discharge guide member, and the second bracket may be fastened to the battery pack case by fastening with a single bolt. Furthermore, the battery pack case may have holes formed therein that correspond in size to the through holes formed in the brackets, thereby serving as passages for discharging gas generated within the module.

[0091] In another example, the gas venting device may be fastened with the battery pack case interposed between a first bracket and a second bracket. Specifically, the first bracket of the gas venting device may be fastened in a state in which it contacts the inner surface of the battery pack case, and the second bracket may be fastened in a state in which it contacts the outer surface of the battery pack case. In this case, the position of the venting disc is not particularly limited, and it may be fastened between the first bracket and the battery pack case or between the second bracket and the battery pack case. In a configuration in which a fastening portion is formed on the discharge guide member, the venting disc is positioned between the fastening portion and the battery pack case.

[0092] Similarly, the battery pack may include a sealing member that seals the gap between the battery pack case and the outer periphery of the gas venting device. Specifically, the sealing member may be a rubber ring or a silicone resin, and is installed in the gap between the gas venting device and the battery pack case to seal the battery pack. That is, in the battery pack according to the present invention, when the internal pressure exceeds a reference value while the interior is sealed, the venting disk ruptures to discharge gas from the battery pack to the outside, and the cross-sectional area of ​​the flow path continuously or sequentially decreases in the gas discharge direction, allowing a larger flow rate of gas to be discharged.

[0093] The above description merely exemplifies the technical concept of the present invention, and various modifications and variations may be made by a person skilled in the art without departing from the essential characteristics of the present invention. Therefore, the drawings disclosed in the present invention are for explanation purposes, not for limiting the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by such drawings. The scope of protection of the present invention should be interpreted by the following claims, and all technical concepts within the equivalent range should be interpreted as being within the scope of the present invention.

[0094] Meanwhile, although terms indicating directions such as up, down, left, right, front, and back are used in this specification, it is obvious that these terms are used merely for convenience of explanation and may vary depending on the position of the object in question, the position of the observer, etc. [Explanation of symbols]

[0095] 100: Gas venting device 110: First bracket 120: Second bracket 130: Venting disc 131: Outer periphery of disc 132: Inner circumference of the disc 133: Bolt through hole 134: Notch 140: Discharge guide member 141: Gas exhaust flow path 142:Entrance 143:Exit 144:Inner wall 144A: A channel with a concave inclined surface 144B: A channel with a bulging slope 146: Straight channel 145: Fastening part 150: Bolt 200: Battery module 210: Module frame

Claims

1. a first bracket having a through hole formed in the center thereof; a second bracket having a through hole formed in a center thereof and communicating with the first bracket, the second bracket being fastened to the first bracket; a venting disk fastened between the first bracket and the second bracket to cover the through hole, the venting disk being configured to burst when a predetermined pressure is applied; a gas discharge passage is formed in the through hole formed in the first bracket and the second bracket, and a cross-sectional area of ​​the gas discharge passage is continuously reduced along a gas discharge direction; A gas venting device, wherein the rate of decrease in cross-sectional area of ​​the gas exhaust flow path varies along the gas exhaust flow path.

2. A gas venting device as described in claim 1, wherein the rate of reduction in the cross-sectional area of ​​the gas exhaust flow path is small near the inlet where the gas flows in and becomes larger toward the outlet side where the gas is exhausted.

3. A gas venting device as described in claim 1, wherein the rate of reduction in the cross-sectional area of ​​the gas exhaust flow path is large near the inlet where the gas flows in and becomes smaller toward the outlet side where the gas is exhausted.

4. a discharge guide member that is inserted into the through holes of the first bracket and the second bracket and has the gas discharge flow path formed in a center portion thereof; 4. The gas venting device according to claim 1, wherein the cross-sectional area of ​​the gas exhaust flow path decreases continuously along the gas exhaust direction.

5. The discharge guide member is a first discharge guide member inserted into a through hole formed in the first bracket; a second discharge guide member inserted into a through hole formed in the second bracket, 5. The gas venting device according to claim 4, wherein a cross-sectional area of ​​the gas exhaust flow path formed by the first exhaust guide member and the second exhaust guide member decreases continuously along a gas exhaust direction.

6. A gas venting device as described in any one of claims 1 to 5, wherein a linear flow path with a constant cross-sectional area is formed on the outlet side of the gas exhaust flow path, following the flow path with a continuously decreasing cross-sectional area.

7. 7. The gas venting device according to claim 1, wherein the inner wall of the gas exhaust passage is formed with protrusions having a thread, embossing, or linear pattern.

8. a fastening portion protruding from an outer surface of the discharge guide member for fastening the discharge guide member to the first bracket and the second bracket; 6. The gas venting device according to claim 4, wherein the fastening portion has fastening holes formed therein for fastening the first bracket and the second bracket together with a bolt.

9. 6. The gas venting apparatus according to claim 4, wherein the first bracket, the second bracket and the exhaust guide member are fastened together by a screw fastening method.

10. The venting disc is an outer peripheral portion of a disk fastened to the first bracket and the second bracket; a disk inner peripheral portion that is integrally formed with the disk outer peripheral portion and that blocks the through-hole, the disk inner peripheral portion rupturing when a predetermined pressure is applied thereto; 10. The gas venting device according to claim 1, wherein a notch is formed in the inner periphery of the disk so as to burst when the predetermined pressure is applied.

11. A plurality of secondary batteries; a module frame on which the secondary battery is mounted, A battery module having the gas venting device according to any one of claims 1 to 10 fastened to one side of the module frame.

12. The battery module of claim 11 , wherein the gas venting device is fastened with the first bracket or the second bracket in contact with the module frame.

13. The battery module of claim 11 , wherein the first bracket of the gas venting device is fastened to the module frame in contact with an inner surface thereof, and the second bracket is fastened to the module frame in contact with an outer surface thereof.

14. The battery module according to claim 11 , further comprising a sealing member for sealing between the module frame and the outer periphery of the gas venting device.

15. at least one battery module including a plurality of secondary batteries; a battery pack case including a tray on which the battery module is mounted and a pack cover that covers the battery module, A battery pack having the gas venting device according to any one of claims 1 to 10 fastened to one side of the battery pack case.

16. The battery pack according to claim 15 , wherein the gas venting device is fastened with the first bracket or the second bracket in contact with the battery pack case.

17. The battery pack according to claim 15 , wherein the first bracket of the gas venting device is fastened to the battery pack case in contact with an inner surface thereof, and the second bracket is fastened to the battery pack case in contact with an outer surface thereof.

18. 18. The battery pack according to claim 15, further comprising a sealing member that provides a seal between the battery pack case and the outer periphery of the gas venting device.

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