Gas venting device and battery pack including same

Abstract

The present invention relates to a gas venting device and a battery module and a battery pack including the same, which can discharge 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.

Description

[Technical field]

[0001] The present invention relates to a gas venting device for discharging gas 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, a separator, an active material, an electrolyte, etc., and can be repeatedly charged and discharged through electrochemical reactions between the components.

[0004] A secondary battery may generate gas from inside at any time during use as it is repeatedly charged and discharged, and this is called venting gas. For example, when an overcurrent flows, the temperature of the internal secondary battery rises rapidly. This rapid rise in temperature can cause a decomposition reaction of the electrolyte, generating gas. When gas is generated from the internal secondary battery of a battery pack, the gas may be trapped inside the pack and cause the battery pack to explode, or may flow into the inside of a vehicle through the cooling duct of the battery pack. For this reason, a venting device is provided in the battery pack to release the internal gas to the outside and reduce the internal pressure.

[0005] Generally, a 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 inside a battery pack flows in and an outlet through which the gas is discharged. However, since the conventional venting device has a simple cylindrical structure in which a gas inlet and outlet are connected, the pressure between the inlet and outlet is not large, and there is a limit to 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 an object of the present invention is to provide a gas venting device that can exhaust 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. [Means for solving the problem]

[0008] The gas venting device according to the present invention includes a first bracket having a through hole formed at the center, a second bracket having a through hole formed at 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 burst when a predetermined pressure is applied, a gas exhaust passage is formed in the through hole formed in the first bracket and the second bracket, and a cross-sectional area of ​​the gas exhaust passage decreases continuously or sequentially along the gas exhaust direction.

[0009] In a specific example, the gas venting device of 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 passage may be frusto-conical in shape.

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

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

[0014] As another example, the gas exhaust flow path may be formed by continuously reducing the cross-sectional area, so that a flow path having a truncated cone shape in which the inclined surface formed on the inner wall is curved in a concave manner, and a flow path having a truncated cone shape in which the inclined surface is curved in a convex manner.

[0015] As yet another example, the gas exhaust flow path may be formed by continuously reducing the cross-sectional area, so that a flow path having a truncated cone shape in which the inclined surface formed on the inner wall is curved to bulge, and a flow path having a truncated cone shape in which the inclined surface is curved to concave are continuously formed.

[0016] In a specific example, the inner wall of the gas exhaust passage may be formed with protrusions having a thread, embossing, or linear pattern.

[0017] In one example, a fastening portion protrudes from an 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 being fastened together with the bracket by a bolt.

[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 disk includes an outer disk portion fastened to the first bracket and the second bracket, and an inner disk portion formed integrally with the outer disk portion and blocking the through hole, the inner disk portion rupturing when a predetermined pressure is applied thereto, and a notch may be formed in the inner disk portion so that the inner disk portion ruptures when the predetermined pressure is applied thereto.

[0020] The present invention also provides a battery module including a 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 apparatus may be fastened with the first bracket in contact with the module frame.

[0023] In another example, the first bracket of the gas venting apparatus may be fastened to an inner surface of the module frame and the second bracket to an 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 covering 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 a state in contact with an inner surface of the battery pack case, and the second bracket may be fastened in a state in contact with an outer surface of the battery pack case. Effect 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 flow rate 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 description of the drawings]

[0029] [Figure 1] 1 is a perspective view of a gas venting apparatus according to an embodiment of the present invention; [Diagram 2] 4 is a perspective view showing a fastening manner of a bracket and a venting disk in a gas venting device according to an embodiment of the present invention; FIG. [Diagram 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. [Diagram 5] FIG. 4 is a cross-sectional view showing the shape of a gas venting device according to another embodiment of the present invention. [Figure 6] FIG. 4 is a cross-sectional view showing the shape of a gas venting device according to still another embodiment of the present invention. [Figure 7] FIG. 4 is a cross-sectional view showing the shape of a gas venting device according to another embodiment of the present invention. [Figure 8] FIG. 4 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 mode of a bracket and a discharge guide member according to an embodiment of the present invention; FIG. [Figure 10] 11 is a cross-sectional view showing a fastening form of a bracket and a discharge guide member according to another embodiment of the present invention. FIG. [Figure 11] FIG. 2 is a schematic diagram showing the shape of a venting disk according to the present invention. [Figure 12] 2 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] 13 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; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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 interpreted in a limited manner based on their ordinary or dictionary meanings, but should be interpreted in a meaning and concept that corresponds to the technical idea 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 / her invention.

[0031] In this application, the terms "comprise" or "have" are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, and should be understood as not precluding the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof. In addition, 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 in between. 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 in between. In addition, in this application, "on" may include not only the case where it is located on the top, but also the case where it is located on the 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 at the center, a second bracket 120 having a through hole formed at the center 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 a cross-sectional area of ​​the gas exhaust passage decreases continuously or sequentially along the gas exhaust direction.

[0035] Generally, a battery pack is equipped with a number of battery modules, each of which contains a number of secondary batteries. These secondary batteries generate gas due to the decomposition reaction of the electrolyte as they are repeatedly charged and discharged. Heat generated during the charging and discharging process of the battery promotes the generation of gas, which expands and increases 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 flow into the inside of a vehicle through a duct, etc., so a venting device is attached that releases gas by bursting a venting disk 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 generated in some regions, causing the volume of the air to decrease. However, since the gas discharge speed is low during the gas discharge process, it shows an incompressible flow phenomenon in which the change in volume due to pressure can be ignored. In such an 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 pressure of the fluid increases, the flow velocity decreases, and as the pressure of the fluid decreases, the flow velocity increases.

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

[0038] In contrast, when the cross-sectional area of ​​the flow passage is continuously or sequentially decreased 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 the outlet increases locally, and a larger flow rate of gas can 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 reference value, the gas can be quickly discharged, thereby improving the safety of the battery module and battery pack.

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

[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 FIG. 1 and FIG. 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 side where gas flows in relative to the gas discharge direction among the two brackets 110 and 120 is defined as the first bracket 110, and the bracket located on the side where gas is discharged 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 act 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 for fastening a venting disk and an exhaust guide member, which will be described later, together and fastening 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 cover the through hole, but may be configured to burst when a certain pressure is applied.

[0043] Meanwhile, a gas exhaust passage is formed in 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 the center thereof. The gas exhaust passage formed in the through holes 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 passage formed in the brackets 110 and 120 can be formed by molding the shape of the through hole itself, or it can be formed 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 the separate exhaust guide member 140 in the brackets 110 and 120, the present invention facilitates gas exhaust, allows easy replacement of parts, and allows the shape of the flow passage to be easily changed.

[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 changed. Since the venting disk 130 is located between the first bracket 110 and the second bracket 120 in the present invention, 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 sequentially 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 one continuous surface. This allows the gas that has flowed into the brackets 110 and 120 to move unhindered and be discharged smoothly.

[0046] Also, the gas exhaust passage 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 passage 141 formed by the exhaust guide member 140 may be in the shape of a truncated cone. Referring to FIG. 3 together with FIG. 4, the inlet 142 and the outlet 143 of the gas exhaust passage 141 in the exhaust guide member 140 are circular in shape, and respectively form the lower and upper surfaces of the truncated cone shape. That is, the inner wall 144 of the exhaust guide member 140 has a structure in which a cross-sectional area is continuously reduced from the inlet where the gas flows in to the outlet where the gas exits, thereby forming an inclined surface. As shown in FIG. 3 and FIG. 4, when the cross-sectional profile of the inner wall 144 of the gas exhaust passage 141 is formed as a linear inclined surface, the reduction rate of the cross-sectional area is constant throughout the gas exhaust passage.

[0047] Although such a cross-sectional profile is linear and simple and easy to manufacture, when it is connected to other parts such as piping, angular parts may be generated on the wall of the flow path, which may cause some sections to have unstable flow. Also, since the reduction rate of the cross-sectional area is constant, for example, when gas with unstable flow flows into the inlet of the flow path, the instability of the gas flow is likely to be maintained until the outlet of the flow path without being resolved. In other words, a flow path with a constant reduction rate of the cross-sectional area has a disadvantage in that the degree of freedom to adjust the flow instability within the corresponding flow path is reduced.

[0048] On the other hand, when the rate of reduction of the cross-sectional area is changed along the flow path, it is possible to adjust or control the flow instability in the flow path. Figures 5 to 8 show an embodiment of such a gas exhaust flow path.

[0049] Referring to FIG. 5(a), the gas exhaust flow passage 141 formed by the exhaust guide member 140 has a truncated cone shape in which the cross-sectional area is continuously reduced toward the outlet 143, and the inclined surface formed on the inner wall 144 of the gas exhaust flow passage is curved in a concave manner. Here, the shape of the inclined surface curved in a concave manner means a shape in which the inclination is lowered toward the outside of the gas exhaust flow passage in the vertical cross section of the flow passage. In this case, the reduction rate of the cross-sectional area is small near the inlet 142 where the gas flows in, and becomes larger toward the outlet 143 side where the gas is discharged. The gas exhaust flow passage 141 having such a concave curved cross-sectional profile is a shape in which the flow passage cross-sectional area on the outlet 143 side is rapidly reduced, so that the pressure difference (differential pressure) between the inlet 142 and the outlet 143 of the flow passage can be increased. That is, compared to the gas exhaust flow passage 141 of the embodiment of FIG. 3 and FIG. 4 having a linear inclined surface, the flow passage of this embodiment can achieve a larger differential pressure between the inlet and the outlet. This means that the desired differential pressure can be easily obtained even if the length of the flow passage 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 in FIG. 3 and FIG. 4, it is possible to configure a gas venting device with a flow path having a shorter length.

[0050] Also, referring to FIG. 5(b), the gas exhaust flow passage 141 formed by the exhaust guide member 140 has a truncated cone shape in which the cross-sectional area is continuously reduced toward the outlet 143, and the inclined surface formed on the inner wall 144 is curved to bulge. Here, the shape of the curved inclined surface means a shape in which the inclination is protruding toward the center of the flow passage in the vertical cross section of the flow passage. In this case, the reduction rate of the cross-sectional area is large near the inlet 142 where the gas flows in, and becomes smaller toward the outlet 143 side where the gas is discharged. The gas exhaust flow passage 141 having a curved cross-sectional profile with a bulge in FIG. 5(b) also has a larger cross-sectional area reduction rate than the gas exhaust flow passage having a linear inclined surface, as in the flow passage of FIG. 5(a). Therefore, a larger pressure difference can be achieved between the inlet and outlet, and the gas venting device can be configured with a flow passage of a shorter length. In particular, the gas exhaust flow passage 141 of FIG. 5(b) has a shape in which the cross-sectional area of ​​the flow passage on the outlet 143 side decreases relatively gradually compared to the flow passage having a linear inclined surface. A flow channel of this type has the advantage that a high flow stability can be achieved since the change in physical quantity inside the flow channel is gradual.

[0051] Meanwhile, as described above, in order to achieve the effects of increasing the pressure difference between the inlet and outlet and improving the 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 passage 146 with a constant cross-sectional area is formed on the outlet 143 side of the gas exhaust flow passage 141, following the truncated cone-shaped flow passage with a concave inclined surface of the gas exhaust flow passage 141. In this embodiment, a larger pressure difference can be achieved by reducing the cross-sectional area in the truncated cone-shaped flow passage of the gas exhaust flow passage 141, and the straight flow passage 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 passage 146 with a constant cross-sectional area is formed on the outlet 143 side of the gas exhaust flow passage, following the truncated cone-shaped flow passage with a bulging inclined surface of the gas exhaust flow passage 141. In this embodiment, too, a larger pressure difference can be achieved by reducing the cross-sectional area of ​​the truncated cone-shaped flow passage of the gas exhaust flow passage 141, and the straight flow passage 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.

[0054] 6 has a structure in which the curvature or cross-sectional area of ​​the gas exhaust flow passage 141 is continuously reduced, and the gas is finally exhausted through a flow passage parallel to the gas flow direction. Therefore, even if the flow of gas initially introduced into the inlet 142 of the flow passage is unstable, the flow instability is eliminated as the gas passes through the corresponding flow passage, and the gas can flow stably at the outlet 143.

[0055] 6, the gas exhaust flow passage 141 formed in 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 shape with a concave inclined surface (see FIG. 6(a)) or a truncated cone shape with a convex inclined surface (see FIG. 6(b)). Meanwhile, the gas exhaust flow passage 141 formed in the inner wall of the second exhaust guide member 140b connected to the gas exhaust flow passage 141 may be configured as a composite flow passage including both a truncated cone shape with a concave or convex inclined surface and a linear flow passage 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 exhaust flow path 141 can be configured in a form in which curves with different curvatures are used in combination, as shown in Figures 7 and 8.

[0057] 7(a) shows a schematic cross-sectional profile of a composite 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 concave truncated cone shape and a flow path 144B having a convex truncated cone shape are continuously formed. FIG. 7(b) shows a gas venting device 100 having the cross-sectional profile of the composite flow path.

[0058] 7 is basically the same as the above-mentioned embodiment in that the cross-sectional area of ​​the gas exhaust flow path 141 continuously decreases from the inlet 142 to the outlet 143. Therefore, compared to a conventional gas venting device in which the cross-sectional area does not decrease, 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.

[0059] In addition to these effects, the gas exhaust flow passage 141 in Fig. 7 has a concave inclined surface and a convex inclined surface formed in succession, so that the cross-sectional area reduction rate can be further increased, and the pressure difference between the inlet and the outlet can be further increased based on the same flow passage. As a result, the gas exhaust flow rate can be further increased. Also, the outlet 143 side has a flow passage with a convex inclined surface with a relatively gentle curve, so that the stability of the gas flow can be improved.

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

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

[0062] In the flow passage of FIG. 8, the cross-sectional area of ​​the gas exhaust flow passage decreases continuously from inlet 142 to outlet 143, so that 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 passage 141 has a convex slope and a concave slope formed in succession, so that the cross-sectional area reduction rate can be increased, and the pressure difference between the inlet and the outlet can be further increased based on the same flow passage. As a result, the gas exhaust flow rate can be further increased. Also, since the gas exhaust flow passage 141 has a flow passage with a slope that is a relatively gentle curve overall, the gas flow stability can be further improved.

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

[0065] The venting devices of Figures 7 and 8 have a composite flow path having inclined surfaces with different curvatures. Therefore, even if the gas flow stability is initially reduced, the gas flow stability at the outlet can be improved by the curvature as the gas passes through the flow path. 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 path. If the composite flow path of Figure 7 is an example that takes into account the pressure difference and flow stability in a well-balanced manner, the composite flow path of Figure 8 can be seen as an example that takes flow stability into further consideration. In any case, the gas flow can be adjusted within the corresponding flow path, which has the advantage of excellent freedom in adjusting flow stability.

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

[0067] In addition, the cross-sectional area of ​​the outlet 143 of the gas exhaust passage 141 may be appropriately selected depending on the structure of the battery module and the battery pack or the safety conditions to be achieved, and may be 40% to 80% of the cross-sectional area of ​​the inlet 142. In particular, the cross-sectional area of ​​the outlet may be 50% to 70%, more particularly, 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 cross-sectional area difference between the inlet and the outlet becomes excessively small, and the pressure difference between the inlet and the outlet decreases, 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 passage 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 passage along the inner wall of the passage. 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 form between a bracket and an ejection guide member according to one embodiment of the present invention, and FIG. 10 is a cross-sectional view showing a fastening form between a bracket and an ejection 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 by bolt fastening. In this case, as shown in Fig. 9, a fastening portion 145 for fastening the discharge guide member 140 to the brackets 110 and 120 protrudes from the outer surface of the discharge guide member 140. The discharge guide member 140 must be inserted into the through holes in the brackets 110 and 120, so the cross section of the discharge guide member 140 has a shape corresponding to the shape of the through holes, and the fastening portion 145 is a plate-like protrusion 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 portion 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) for fastening with the brackets 110 and 120 by bolts, and 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 position where the fastening portion 145 is formed may be appropriately designed. For example, as shown in Fig. 9, the fastening portion 145 formed on the first discharge guide member 140a and the second discharge guide member 140b may be formed to be located between the first bracket 110 and the venting disk 130 and between the second bracket 120 and the venting disk 130, respectively. However, the position of the fastening portion is not limited thereto, and for example, the fastening portion 145 may be formed to be in contact with the brackets 110 and 120 on the surface of the brackets 110 and 120 opposite to the surface in contact with the venting disk 130.

[0073] In another example, the first bracket 110 and the second bracket 120 and the discharge guide member 140 may be fastened 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 accordingly, the first bracket 110 and the second bracket 120 and the discharge guide member 140 may be fastened by a nut and bolt fastening method, respectively. In the present invention, the discharge guide member 140 includes the first discharge guide member 140a and the second discharge guide member 140b, and the threads may be formed on all of the first discharge guide member 140a and the second discharge guide member 140b. In this case, when the discharge guide member 140 is fastened to the brackets 110 and 120 by a screw fastening method, since there is no need to insert a separate bolt, the structure and fastening method of the parts are simplified, 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 periphery 131 fastened to the first bracket 110 and the second bracket 120, and a disk inner periphery 132 formed integrally with the disk outer periphery 131 to cover the through hole, the disk inner periphery 132 being ruptured 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 of the disk outer periphery 131 contacts the first bracket 110 and the other side of the disk outer periphery 131 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 coupled to each other by a bolt fastening method or the like. In the case of a structure in which a fastening portion is formed on the discharge guide member, the discharge guide member may be coupled to the brackets and the venting disk.

[0076] The inner circumference 132 of the disk is made of a metal or plastic material that can burst when a certain pressure is applied. For example, the inner circumference 132 of the disk may be made of a metal or plastic material such as thin copper, aluminum, or stainless steel. The inner circumference 132 of the disk may be appropriately selected according to the pressure conditions when it bursts, 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, when 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 bursts the disk inner circumference 132. At this time, since the pressure inside the battery module or battery pack is higher than the external air pressure, the internal gas may be discharged to the outside of the battery module or battery pack by the negative pressure.

[0078] The inner circumference 132 of the disk is formed with a notch 134 so as to burst when a predetermined pressure is applied. The notch 134 is formed by cutting out a part of the surface of the venting disk 130 in the thickness direction. The shape of the notch 134 may be designed to be a cross, a circle, a square, a U-shape, an ellipse, an arc, etc., and the cross section of the notch 134 may be a trapezoid, a V-shape, a square, an arc, etc. The shape of the notch 134 formed in the inner circumference 132 of the disk is not necessarily limited thereto, and may have various shapes. For example, the shape of the notch 134 may be an X-shape as shown in FIG. 2. In this case, even if the inner circumference 132 of the disk bursts, the broken pieces of the inner circumference 132 of the disk may not completely separate from the inner circumference 132 of the disk and may be attached to the outer circumference 131 of the disk. If the broken pieces of the inner circumference of the disk are completely separated from the venting disk, it is difficult to remove them and may damage other parts.

[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 provided in an annular or ring shape in correspondence with the disc outer periphery 131. The disc pad is intended to increase 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] FIG. 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 FIG. 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] 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 an electrode assembly in which a positive electrode, a negative electrode, and a separator are alternately stacked, and the electrode assembly is mounted in a cell case together with an electrolyte. The configuration of such a secondary battery is obvious to those skilled in the art to which the present invention pertains, and therefore will not be described in detail here.

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

[0085] In another example, in the battery module 200, the gas venting device 100 may be fastened in a state in which the module frame 210 is 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 in a state in which it is in contact with the inner surface of the module frame 210 and the second bracket 120 is fastened in contact with the outer surface of the module frame 210. At this time, 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) for sealing 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 a 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, and a battery pack case including a tray on which the battery module is mounted and a pack cover covering 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 a battery pack case. In this case, the battery pack case may be fastened with a surface of the first bracket opposite to the surface in contact with the venting disk. The battery pack case may have holes formed therein corresponding to fastening holes formed in fastening portions of the first bracket, the second bracket, the venting disk, and the discharge guide member, and the first bracket, the venting disk, the discharge guide member, and the second bracket may be fixed to the battery pack case by fastening with a single bolt. Furthermore, the battery pack case may have holes formed therein with a size corresponding to the through holes formed in the brackets, thereby acting as a passage 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 is in contact with an inner surface of the battery pack case, and the second bracket may be fastened in a state in which it is in contact with an 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 the case where a fastening portion is formed on the discharge guide member, the venting disc is located between the fastening portion and the battery pack case.

[0092] Similarly, the battery pack may include a sealing member for sealing 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 may be 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 in a sealed state, the venting disk bursts to discharge the gas inside the battery pack to the outside, but the cross-sectional area of ​​the flow path is continuously or sequentially reduced in the gas discharge direction, so that a larger flow rate of gas can be discharged.

[0093] The above description is merely illustrative of the technical idea of ​​the present invention, and various modifications and variations may be made by a person having ordinary knowledge in the technical field to which the present invention belongs, without departing from the essential characteristics of the present invention. Therefore, the drawings disclosed in the present invention are for the purpose of explanation, not for the purpose of limiting the technical idea of ​​the present invention, and the scope of the technical idea of ​​the present invention is not limited by such drawings. The scope of protection of the present invention should be interpreted according to the following claims, and all technical ideas within the equivalent range should be interpreted as being included in 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 such terms are used merely for convenience of explanation and may change depending on the position of the target object, the position of the observer, etc. [Explanation of symbols]

[0095] 100: Gas venting equipment 110: First bracket 120: Second bracket 130: Venting disc 131: Outer periphery of disc 132: Inner circumference of the disk 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 inclined surface 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 thereto; a gas exhaust passage is formed in the through hole formed in the first bracket and the second bracket, and a cross-sectional area of ​​the gas exhaust passage is continuously reduced along a gas exhaust direction; The gas exhaust passage has a cross-sectional area that is continuously reduced, and thus the inclined surface formed on the inner wall has a truncated cone shape that is concave or convex.

2. 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; 2. The gas venting apparatus according to claim 1, wherein the cross-sectional area of ​​the gas exhaust passage decreases continuously along a gas exhaust direction.

3. The discharge guide member is a first discharge guide member that is inserted into a through hole formed in the first bracket; a second discharge guide member that is inserted into a through hole formed in the second bracket, 3. The gas venting device according to claim 2, wherein a cross-sectional area of ​​the gas exhaust flow passage formed by the first exhaust guide member and the second exhaust guide member continuously decreases along a gas exhaust direction.

4. 4. The gas venting device according to claim 1, wherein a straight flow path having a constant cross-sectional area is formed on the outlet side of the gas exhaust flow path, following the flow path having a truncated cone shape with the inclined surface being concave or convex.

5. A first bracket having a through hole formed in the center; 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 thereto; a gas exhaust passage is formed in the through hole formed in the first bracket and the second bracket, and a cross-sectional area of ​​the gas exhaust passage is continuously reduced along a gas exhaust direction; The gas exhaust flow path has a cross-sectional area that is continuously reduced, so that a flow path having a truncated cone shape in which the inclined surface formed on the inner wall is curved in a concave manner and a flow path having a truncated cone shape in which the inclined surface is curved in a bulging manner are continuously formed.

6. A first bracket having a through hole formed in the center; 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 thereto; a gas exhaust passage is formed in the through hole formed in the first bracket and the second bracket, and a cross-sectional area of ​​the gas exhaust passage is continuously reduced along a gas exhaust direction; The gas exhaust flow path has a cross-sectional area that is continuously reduced, so that a flow path having a truncated cone shape in which the inclined surface formed on the inner wall is curved so as to bulge, and a flow path having a truncated cone shape in which the inclined surface is curved so as to be concave are continuously formed.

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

8. a fastening portion for fastening the discharge guide member to the first bracket and the second bracket protrudes from an outer surface of the discharge guide member; The gas venting apparatus according to claim 2 , wherein the fastening portion is formed with fastening holes for fastening the first bracket and the second bracket together with a bolt.

9. 3. The gas venting apparatus according to claim 2, wherein the first bracket and the second bracket are fastened to the exhaust guide member by a screw fastening method.

10. The venting disk is an outer circumferential portion of a disk fastened to the first bracket and the second bracket; a disk inner peripheral portion that is integral with the disk outer peripheral portion and that blocks the through hole, the disk inner peripheral portion being ruptured when a predetermined pressure is applied thereto; 10. The gas venting device according to claim 1, wherein a notch is formed in an inner periphery of the disk so that the disk ruptures 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, comprising: a module frame having a 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 of the module frame, and the second bracket is fastened to the module frame in contact with an outer surface of the module frame.

14. The battery module according to any one of claims 11 to 13, further comprising a sealing member for sealing between the module frame and an 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, comprising the gas venting device according to any one of claims 1 to 11 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 in a state of contacting an inner surface of the battery pack case, and the second bracket is fastened in a state of contacting an outer surface of the battery pack case.

18. The battery pack according to any one of claims 15 to 17, further comprising a sealing member for sealing between the battery pack case and an outer periphery of the gas venting device.

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