Gas venting device and battery pack including the 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 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, filed on February 23, 2021, and Korean Patent Application No. 10-2022-0021766, filed on February 18, 2022, and all the contents disclosed in the corresponding Korean patent applications are included as part of this specification.

Background Art

[0003] A battery pack applied to an electric vehicle or the like has a structure in which a plurality of battery modules including a plurality of secondary batteries are connected in series or in parallel to obtain high output. And, the secondary battery includes a positive electrode and a negative electrode current collector, a separator, an active material, an electrolyte, etc., and can be repeatedly charged and discharged by an electrochemical reaction between components.

[0004] During repeated charging and discharging of the secondary battery, gas may be generated inside at any time during use, which is called venting gas. For example, when an overcurrent flows, the temperature of the internal secondary battery rises rapidly. Such a rapid rise in temperature can cause a decomposition reaction of the electrolyte and generate gas. When gas is generated from the internal secondary battery in the battery pack, such gas may be collected inside the pack and cause the battery pack to explode, or may flow into the interior of a vehicle or the like through a cooling duct of the battery pack. Therefore, the battery pack is provided with a venting device that discharges the internal gas to the outside to reduce the internal pressure.

[0005] The venting device generally has a structure in which a venting disk that can be ruptured by internal pressure is inserted between an inlet through which gas inside the 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 the gas inlet and outlet are simply connected, the pressure between the inlet and the outlet is not large, so there is a limit to the flow rate of the gas that can be discharged.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The present invention was devised to solve the above problems, and an object thereof is to provide a gas venting device that can discharge a larger 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 Problems

[0008] The gas venting device according to the present invention includes a first bracket having a through hole formed in a central portion thereof, a second bracket having a through hole formed in a central portion thereof that communicates with the first bracket and being fastened to the first bracket, and a venting disk fastened between the first bracket and the second bracket to shield the through hole, the venting disk being configured to rupture when a predetermined pressure is applied. A gas discharge flow path is formed in the through holes formed in the first bracket and the second bracket, and the cross-sectional area of the gas discharge flow path continuously or sequentially decreases along the gas discharge direction.

[0009] In a specific example, the gas venting device according to the present invention includes a discharge guide member inserted into the through holes of the first bracket and the second bracket, and a gas discharge flow path is formed in the central portion, and the cross-sectional area of the gas discharge flow path may continuously or sequentially decrease along the gas discharge direction.

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

[0011] In one example, the gas discharge flow path may be in the shape of a frustum of a cone.

[0012] In another example, the gas discharge flow path may be in the shape of a frustum of a cone in which an inclined surface formed on the inner wall is curved in a concave or convex manner as the cross-sectional area continuously decreases.

[0013] In a specific example, following the frustum-shaped flow path in which the inclined surface is curved in a concave or convex manner, a linear flow path with a constant cross-sectional area may be formed on the outlet side of the gas discharge flow path.

[0014] As another example, the gas discharge flow path may be such that a frustum-shaped flow path in which an inclined surface formed on the inner wall is curved in a concave manner as the cross-sectional area continuously decreases and a frustum-shaped flow path in which the inclined surface is curved in a convex manner are continuously formed.

[0015] As yet another example, the gas discharge flow path may be such that a frustum-shaped flow path in which an inclined surface formed on the inner wall is curved in a convex manner as the cross-sectional area continuously decreases and a frustum-shaped flow path in which the inclined surface is curved in a concave manner are continuously formed.

[0016] In a specific example, a thread, an embossing, or a protrusion having a linear pattern may be formed on the inner wall of the gas discharge passage.

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

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

[0019] On the other hand, the venting disk includes a disk outer peripheral portion fastened to the first bracket and the second bracket, and a disk inner peripheral portion formed integrally with the disk outer peripheral portion and shielding the through hole, the disk inner peripheral portion being a disk inner peripheral portion that ruptures when a predetermined pressure is applied, and notches may be formed in the disk inner peripheral portion so as to rupture 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 may 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 in contact with the inner surface of the module frame, and the second bracket may be in contact with the outer surface of the module frame and fastened.

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

[0025] The battery pack includes at least one 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 covering the battery module, and a gas venting device as described above can be fastened to one side of the battery pack case.

[0026] In one example, the gas venting device can 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 can be fastened in contact with the inner surface of the battery pack case and the second bracket in contact with the outer surface of the battery pack case.

Advantages of the Invention

[0028] The gas venting device according to the present invention and the battery module or battery pack including the same can improve the safety of the battery module and battery pack by discharging a larger flow rate per unit time even when using a venting disk of the same area.

Brief Description of the Drawings

[0029]

Figure 1

Figure 2

Figure 3

Figure 4

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Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Mode for Carrying Out the Invention

[0030] Hereinafter, the present invention will be described in detail. Prior to this, terms or words used in this specification and the claims should not be construed as being limited to their ordinary or dictionary meanings, and should be construed in accordance with the meaning and concept that conforms to the technical idea of the present invention in accordance with the principle that the inventor can appropriately define the concept of the terms in order to explain his invention in the best way.

[0031] In this application, terms such as "comprising" or "having" are intended to specify the presence of the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and should not be construed as precluding the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof. Also, when a part such as a layer, film, region, or plate is said to be "on" another part, this includes not only the case where it is directly on the other part but also the case where there are other parts in between. Conversely, when a part such as a layer, film, region, or plate is said to be "under" another part, this includes not only the case where it is directly under the other part but also the case where there are other parts in between. Also, in this application, being "disposed on" can include being disposed not only on the upper part but also on the lower part.

[0032] Hereinafter, the present invention will be described in detail.

[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 an embodiment of the present invention.

[0034] Referring to FIGS. 1 and 2, a gas venting device 100 according to the present invention includes a first bracket 110 having a through hole formed in a central portion, a second bracket 120 having a through hole formed in a central portion and 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 shield the through hole, the venting disk 130 being configured to rupture when a predetermined pressure is applied. A gas discharge flow path 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 discharge flow path continuously or sequentially decreases along the gas discharge direction.

[0035] Generally, a battery pack is equipped with a plurality of battery modules, and each battery module contains a plurality of secondary batteries. As these secondary batteries repeatedly charge and discharge, they generate gas through decomposition reactions of the electrolyte solution and the like. The heat generated during the charging and discharging process of the battery promotes the generation of gas, causing the gas to expand and increase the pressure inside the battery module or the battery pack. If this process continues, the battery module or the battery pack may explode, or the internal gas may flow into the interior of a vehicle or the like through a duct or the like. Therefore, when the gas pressure reaches a certain magnitude or more, a venting device that discharges the gas by rupturing a venting disk is attached.

[0036] Such gas is generally a compressible fluid whose volume changes with respect to pressure. When such air flows at high speed, regions with high pressure and density are generated in some areas, resulting in a decrease in the volume of the air. However, since the gas discharge speed is small during the gas discharge process as described above, it exhibits an incompressible flow phenomenon in which the volume change 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. That is, when the pressure of the fluid increases, the flow velocity decreases, and when the pressure of the fluid decreases, the flow velocity increases.

[0037] As described above, the conventional venting device has a cylindrical structure in which the gas inlet and outlet are simply connected. Therefore, since the pressure difference between the inlet and the outlet is small, there is a limit to the gas flow rate that can be discharged.

[0038] In contrast, when the cross-sectional area of the flow path is made to continuously or sequentially decrease in the gas discharge direction as in the present invention, at the inlet with a large cross-sectional area, the internal pressure increases as the air velocity decreases, and at the outlet with a small cross-sectional area, the internal pressure decreases as the air velocity increases. Along with this, the pressure difference between the inlet and the outlet will locally increase further, and even with the use of a venting disk of the same area, a larger flow rate of gas can be discharged. Therefore, when the internal pressure due to the gas generated inside the battery module or the battery pack exceeds the reference value, the safety of the battery module and the battery pack can be improved by quickly discharging the gas.

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

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

[0041] Referring to FIG. 3 or FIG. 4 together with FIGS. 1 and 2, the gas venting device 100 according to the present invention includes brackets 110 and 120 for fastening a venting disk 130 and discharging internal gas. The venting disk 130 can be fastened while being interposed between the two brackets 110 and 120, and through holes are formed in the central portions of the brackets 110 and 120, and a gas discharge flow path is formed in the through holes. In the present invention, among the two brackets 110 and 120, the bracket located on the side where gas relatively flows in based on the gas discharge direction 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 central portion of the second bracket 120 communicates with the through hole formed in the central portion of the first bracket 110 and serves as a gas discharge flow path. The first bracket 110 and the second bracket 120 may be fastened together with a venting disk and a discharge guide member described later, and fastening holes (not shown) into which bolts 150 for fastening the gas venting device 100 to a battery module or a battery pack can be inserted may be formed.

[0042] The venting disk 130 is fastened while being interposed between the first bracket 110 and the second bracket 120 to shield the through hole, but may be configured to rupture when a predetermined pressure is applied.

[0043] On the other hand, a gas discharge flow path 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 a discharge guide member 140 inserted into the through holes of the first bracket 110 and the second bracket 120 and having a gas discharge flow path 141 formed in the central portion. The gas discharge flow path formed in the through hole may be formed by the discharge guide member 140, and at this time, the cross-sectional area of the gas discharge flow path 141 formed in the discharge guide member 140 continuously or sequentially decreases along the gas discharge direction.

[0044] That is, in the present invention, the shape of the gas discharge flow path formed in the brackets 110 and 120 can be formed by molding the shape of the through hole itself, but as described above, it is also possible to form by inserting a separate discharge guide member 140 into the brackets 110 and 120. The discharge guide member 140 has a detachable or replaceable structure. The present invention makes the gas discharge smooth by using a separate discharge guide member 140 for the brackets 110 and 120, enables easy replacement of parts, and can easily change the shape of the flow path.

[0045] In the present invention, in order to improve the gas discharge efficiency, it is possible to maximize the length of the gas discharge flow path while showing a change in the cross-sectional area. Since the venting disk 130 is located between the first bracket 110 and the second bracket 120 in the present invention, the discharge guide member 140 can also be inserted into the through holes formed in the first bracket 110 and the second bracket 120, respectively. Specifically, the discharge guide member 140 includes a first discharge guide member 140a inserted into the through hole formed in the first bracket 110 and a second discharge guide member 140b inserted into the through hole formed in the second bracket 120. Here, the cross-sectional area of the gas discharge flow path 141 formed by the first discharge guide member 140a and the second discharge guide member 140b decreases continuously or sequentially along the gas discharge direction. That is, no step is generated between the first discharge guide member 140a and the second discharge guide member 140b, and the gas discharge flow path 141 forms a continuous single surface. As a result, the gas flowing into the brackets 110 and 120 can be discharged smoothly without being obstructed.

[0046] Further, the gas discharge channel 141 formed by the discharge guide member 140 can be designed to be circular as shown in FIG. 4, for example. In this case, the gas discharge channel 141 formed by the discharge guide member 140 can be in the shape of a frustum of a cone. Referring to FIG. 3 and FIG. 4 together, the shapes of the inlet 142 and the outlet 143 of the gas discharge channel 141 in the discharge guide member 140 are circular, and respectively constitute the lower surface and the upper surface of the frustum of the cone. That is, the inner wall 144 of the discharge guide member 140 has a structure in which an inclined surface is formed by the cross-sectional area continuously decreasing from the inlet where the gas flows in to the outlet where the gas escapes. As shown in FIGS. 3 and 4, when the cross-sectional profile of the inner wall 144 of the gas discharge channel 141 is formed by a linear inclined surface, the reduction rate of the cross-sectional area is constant throughout the gas discharge channel.

[0047] Since such a cross-sectional profile is linear and simple, it is easy to manufacture. However, when connected to other components such as pipes, a squared portion may occur on the wall surface of the flow path, so there may be a section where part of the flow is unstable. Also, since the reduction rate of the cross-sectional area is constant, for example, when gas with unstable flow enters at the inlet of the flow path, it is highly likely that the flow instability of the gas cannot be eliminated and is maintained until the outlet of the flow path. That is, a flow path with a constant cross-sectional area reduction rate has the disadvantage that the degree of freedom to adjust the flow instability within the corresponding flow path decreases.

[0048] On the other hand, when the reduction rate of the cross-sectional area is changed along the flow path, there is an advantage that the above-described flow instability can be adjusted or managed within the flow path. FIGS. 5 to 8 illustrate embodiments related to such a gas discharge channel.

[0049] Referring to Fig. 5(a), the gas discharge channel 141 formed by the discharge guide member 140 has a frustum of a cone shape in which the inner wall 144 of the gas discharge channel is bent so that the inclined surface formed thereon is recessed by the cross-sectional area continuously decreasing toward the outlet 143. Here, the shape in which the inclined surface is bent so as to be recessed means a shape in which the inclination drops toward the outside of the gas discharge channel in the vertical cross-section of the channel. 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 discharge channel 141 having such a concave curved cross-sectional profile is a shape that rapidly reduces the cross-sectional area of the channel on the outlet 143 side, so that the pressure difference (differential pressure) between the inlet 142 and the outlet 143 of the channel can be increased. That is, compared with the gas discharge channels 141 of the embodiments of Figs. 3 and 4 having straight inclined surfaces, the channel of this embodiment can achieve a larger differential pressure between the inlet and the outlet. This means that even if the length of the channel is shortened, the desired differential pressure can be easily obtained. Therefore, according to this embodiment, when achieving the same differential pressure as the gas discharge channels 141 having straight inclined surfaces of Figs. 3 and 4, the gas venting device can be configured with a shorter channel length.

[0050] Also, referring to FIG. 5(b), the gas discharge channel 141 formed by the discharge guide member 140 has a frustum of a cone shape in which the inner wall 144 is curved such that the inclined surface formed thereon bulges as the cross-sectional area continuously decreases toward the outlet 143. Here, the shape that is curved such that the inclined surface bulges means a shape in the vertical cross-section of the channel where the inclination protrudes toward the center of the channel. In this case, the rate of decrease of the cross-sectional area is large near the inlet 142 where the gas flows in, and becomes smaller as it goes toward the outlet 143 side where the gas is discharged. The gas discharge channel 141 having the bulging curved cross-sectional profile in FIG. 5(b) also has a larger cross-sectional area reduction rate compared to the gas discharge channel having a straight inclined surface, similar to the channel in FIG. 5(a). Therefore, since a larger differential pressure can be achieved between the inlet and the outlet, the gas venting device can be configured with a shorter length of the channel. In particular, the gas discharge channel 141 in FIG. 5(b) is in a form in which the cross-sectional area decreases relatively gently on the outlet 143 side compared to the channel with a straight inclined surface. Such a channel has the advantage of achieving high flow stability because the change in physical quantities inside the channel becomes gentle.

[0051] On the other hand, as described above, in order to achieve all the effects of increasing the pressure difference between the inlet and the outlet and enhancing the flow safety, the cross-sectional profile of the gas discharge channel 141 can be configured in a form in which a curve and a straight line are used in combination as shown in FIG. 6.

[0052] Referring to FIG. 6(a), following the frustum-shaped channel of the gas discharge channel 141 in which the inclined surface is concave, a straight channel 146 with a constant cross-sectional area is formed on the outlet 143 side of the gas discharge channel 141. In this embodiment, a larger pressure difference can be achieved by the decrease in the cross-sectional area in the frustum-shaped channel of the gas discharge channel 141 where the inclined surface is concave, and the discharged gas can be stably sent out by designing the inclination of the inner wall surface to be parallel to the gas flow direction in the straight channel 146 on the outlet side.

[0053] Referring to FIG. 6(b), following the frustum-shaped channel where the inclined surface of the gas discharge channel 141 bulges, a linear channel 146 with a constant cross-sectional area is formed on the outlet 143 side of the gas discharge channel. In this embodiment as well, a larger pressure difference can be achieved by reducing the cross-sectional area in the frustum-shaped channel where the gas discharge channel 141 bulges. In the linear channel 146 on the outlet side, the exhaust gas can be stably sent out by designing the inclination of the inner wall surface to be parallel to the gas flow direction.

[0054] Particularly, the gas venting device 100 equipped with the exhaust guide member 140 of the embodiment of FIG. 6 has a structure in which the curvature or cross-sectional area of the gas discharge channel 141 continuously decreases and finally the gas is discharged through a channel parallel to the gas flow direction. Therefore, even when the flow of the gas initially introduced into the inlet 142 of the channel is unstable, the flow instability is eliminated while passing through the corresponding channel, and the gas can flow stably at the outlet 143.

[0055] In the embodiment of FIG. 6, the gas discharge channel 141 formed on the inner wall of the first exhaust guide member 140a inserted into the through hole formed in the first bracket 110 can be configured in the shape of a frustum with a concave inclined surface (see FIG. 6(a)) or a frustum with a convex inclined surface (see FIG. 6(b)). On the other hand, the gas discharge channel 141 formed on the inner wall of the second exhaust guide member 140b following the gas discharge channel 141 can be configured as a composite channel including all of a frustum-shaped channel with a concave or convex inclined surface and a subsequent linear channel 146.

[0056] Also, in order to achieve all the effects of increasing the pressure difference between the inlet and outlet and enhancing the flow safety, the gas discharge channel 141 can be configured in a form where curves with different curvatures are used in combination as shown in FIGS. 7 and 8.

[0057] FIG. 7(a) shows a schematic cross-sectional profile of a composite flow path in which a gas discharge flow path with a continuously decreasing cross-sectional area is formed as a whole, and a frustum-shaped flow path 144A with a concave inclined surface and a frustum-shaped flow path 144B with a convex inclined surface are continuously formed. FIG. 7(b) discloses a gas venting device 100 having the cross-sectional profile of the composite flow path.

[0058] The flow path in FIG. 7 is basically the same as that of the above-described embodiment in that the cross-sectional area continuously decreases from the inlet 142 to the outlet 143 of the gas discharge flow path 141. Therefore, compared with a conventional gas venting device in which the cross-sectional area does not decrease, the pressure difference between the inlet and the outlet locally increases, and even when using a venting disk of the same area, a larger flow rate of gas can be discharged.

[0059] In addition to such an effect, since the gas discharge flow path 141 in FIG. 7 is formed by continuously following a concave inclined surface and a convex inclined surface, 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 path. Accordingly, the gas discharge flow rate can be further increased. Further, since the outlet 143 side has a flow path with a convex inclined surface having a relatively gentle curve, the flow stability of the gas can be improved.

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

[0061] FIG. 8(a) shows a schematic cross-sectional profile of a composite flow path in which a gas discharge flow path 141 with a continuously decreasing cross-sectional area is formed, and a frustum-shaped flow path 144B with a bulging inclined surface and a frustum-shaped flow path 144A with a concave inclined surface are continuously formed. FIG. 8(b) discloses a gas venting device having the cross-sectional profile of the composite flow path. That is, the gas venting device of FIG. 8 has a gas discharge flow path arranged opposite to that of FIG. 7.

[0062] Since the flow path of FIG. 8 also has a continuously decreasing cross-sectional area from the inlet 142 to the outlet 143 of the gas discharge flow path, the pressure difference between the inlet and the outlet locally increases, and even using a venting disk of the same area, a larger flow rate of gas can be discharged.

[0063] In addition, since the gas discharge flow path 141 of FIG. 8 is formed by successive bulging and concave inclined surfaces, the rate of decrease in the cross-sectional area can be increased, and the pressure difference between the inlet and the outlet can be further increased based on the same flow path. Accordingly, the gas discharge flow rate can be further increased. Also, since the gas discharge flow path 141 generally has a flow path with a relatively gentle curved inclined surface, the flow stability of the gas can be further improved.

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

[0065] The bending devices of FIGS. 7 and 8 are provided with a composite flow path having inclined surfaces with different curvatures. Therefore, for example, even if the gas flow stability initially decreases, the gas flow stability can be improved at the outlet due to the curvature while passing 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 FIG. 7 takes into account the pressure difference and flow stability in a well-balanced manner, the composite flow path of FIG. 8 can be regarded as an example that further considers the flow stability. In any case, since the gas flow can be adjusted within the corresponding flow path, it has the advantage of excellent freedom for adjusting the flow stability.

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

[0067] Also, the cross-sectional area of the outlet 143 of the gas discharge flow path 141 can be appropriately selected according to the structure of the battery module and the battery pack or the safety conditions to be achieved, but it can be 40% to 80% of the cross-sectional area of the inlet 142. Specifically, the cross-sectional area of the outlet is 50 to 70% of the inlet cross-sectional area, and more specifically, it can be 55 to 65%. If the cross-sectional area of the outlet is less than 40% of the inlet cross-sectional area, the outlet part becomes excessively narrow. On the contrary, if the cross-sectional area of the outlet exceeds 80% of the inlet cross-sectional area, the cross-sectional area difference between the inlet and the outlet decreases excessively, and the pressure difference between the inlet and the outlet decreases, resulting in a decrease in the efficiency of gas venting.

[0068] Also, a pattern (not shown) for assisting gas discharge can be formed on the inner wall 144 of the gas discharge flow path 141. For example, the pattern can be a thread pattern, an embossing, or a protrusion having a straight line pattern parallel to the gas discharge direction. Specifically, the pattern can be a protrusion in the form of a thread pattern surrounding the inside of the flow path along the inner wall of the flow path. Such a pattern can promote gas discharge.

[0069] On the one hand, the discharge guide member can promote stable gas discharge even during gas venting by being fastened to the bracket.

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

[0071] In one example, the brackets 110, 120 and the discharge guide member 140 can 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, 120 protrudes from the outer surface of the discharge guide member 140. Since the discharge guide member 140 must be inserted into the through holes in the brackets 110, 120, its cross-section 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 peripheral portion in a shape similar to the outer peripheral portion 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 can be formed on both the first discharge guide member 140a and the second discharge guide member 140b. The fastening portion 145 is formed with fastening holes (not shown) for bolt fastening together with the brackets 110, 120. The fastening holes formed in the fastening portion 145 are formed at the same positions as the fastening holes formed in the brackets 110, 120 and are fixed through the insertion of bolts.

[0072] On the other hand, the position where the fastening portion 145 is formed can 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 can 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 to this. For example, the fastening portion 145 may be formed on the surface of the brackets 110, 120 opposite to the surface in contact with the venting disk 130 so as to contact the brackets 110, 120.

[0073] In another example, the first bracket 110, the second bracket 120, and the discharge guide member 140 can be fastened by a screw fastening method. In this case, as shown in FIG. 10, threads for screw fastening can 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. Accordingly, the first bracket 110, the second bracket 120, and the discharge guide member 140 can be fastened in such a manner that nuts and bolts are fastened 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 can be formed on all of 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 in this way, separate insertion of bolts is not required, so that the structure of the components and the fastening method are simplified, and the discharge guide member 140 can be firmly fixed to the brackets 110 and 120.

[0074] On the other hand, referring to FIG. 11, the bending disk 130 includes a disk outer peripheral portion 131 fastened to the first bracket 110 and the second bracket 120, and a disk inner peripheral portion 132 formed integrally with the disk outer peripheral portion 131 and shielding the through hole, the disk inner peripheral portion 132 being ruptured when a predetermined pressure is applied.

[0075] The disk outer peripheral portion 131 is a portion for fixing the brackets 110 and 120 and the bending disk 130. One surface is in contact with the first bracket 110, and the other surface is in contact with the second bracket 120. The disk outer peripheral portion 131 can be provided with bolt through holes 133 along the circumferential direction, and the first bracket 110, the disk outer peripheral portion 131, and the second bracket 120 can be integrally coupled through 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 can be coupled to the bracket and the bending disk.

[0076] When a predetermined pressure is applied to the inner peripheral portion 132 of the disk, it is made of a metal or plastic material that can be ruptured. For example, the inner peripheral portion 132 of the disk can be formed of a metal or plastic material such as thin copper, aluminum, or stainless steel. The inner peripheral portion 132 of the disk can be appropriately selected according to the pressure conditions at the time of rupture, and the scope of the rights of the present invention is not limited thereto.

[0077] The inner peripheral portion 132 of the disk 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 under normal conditions. However, when a large amount of gas is generated in the battery module or battery pack, the internal pressure rises, and such pressure acts as a force to rupture the inner peripheral portion 132 of the disk. At this time, since the pressure inside the battery module or battery pack is higher than the external atmospheric pressure, the internal gas can be discharged to the outside of the battery module or battery pack by negative pressure.

[0078] Notches 134 are formed in the inner peripheral portion 132 of the disk so as to rupture when a predetermined pressure is applied. Such notches 134 are formed by partially cutting from the surface of the bending disk 130 in the thickness direction. The shape of the notch 134 can be designed in shapes such as a cross shape, a circular shape, a square shape, a U shape, an elliptical shape, and an arc shape, and the cross section of the notch 134 can be in shapes such as a trapezoidal shape, a V shape, a square shape, and an arc shape. The shape of the notch 134 formed in the inner peripheral portion 132 of the disk is not necessarily limited thereto, and can have various shapes. For example, the shape of the notch 134 can be an X shape as shown in FIG. 2. In this case, even if the inner peripheral portion 132 of the disk ruptures, the fragments of the ruptured inner peripheral portion 132 of the disk do not completely separate and can be coupled to the outer peripheral portion 131 of the disk. It is difficult to remove the fragments of the ruptured inner peripheral portion of the disk when they are completely separated from the bending disk, and other components may be damaged.

[0079] Further, a disk pad (not shown) may be interposed between at least one of between the first bracket 110 and the bending disk 130 and between the second bracket 120 and the bending disk 130. Such a disk pad is in a form corresponding to the outer peripheral portion 131 of the disk and may be provided in an annular or ring shape. The disk pad is for enhancing the airtightness between the first bracket 110 and the bending disk 130 or between the second bracket 120 and the bending disk 130 and preventing damage to the outer peripheral portion 131 of the disk. For example, the disk pad may be formed of an elastic rubber material or the like.

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

[0081] FIG. 12 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, and FIG. 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.

[0082] Referring to FIGS. 12 and 13, a 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 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 shape in which an electrode assembly in which a positive electrode, a negative electrode, and a separator are alternately laminated is mounted in a cell case together with an electrolytic solution. Since the configuration of such a secondary battery is obvious to a person skilled in the art to which the present invention pertains, a more detailed description thereof will be omitted.

[0084] In one example, the gas venting device 100 can 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, it can be fastened with the first bracket 110 in contact with the outer surface of the module frame 210 as shown in FIG. 12(a), or fastened with the second bracket 120 in contact with the inner surface of the module frame 210 as shown in FIG. 12(b). In the specification of the present invention, the inner surface of the module frame 210 means the surface facing the internal space where the secondary battery is mounted in the module frame 210, and the outer surface means the surface exposed to the outside of the module frame 210. The module frame 210 is formed with fastening holes formed at the fastening portions (not shown) of the first bracket 110, the second bracket 120, and the discharge guide member 140, and holes corresponding to the bolt through-holes of the venting disk 130. The first bracket 110, the venting disk 130, the discharge guide member 140, and the second bracket 120 can be fixed to the module frame 210 through a single bolt fastening. Consequently, the module frame 210 is formed with holes having a size corresponding to the through-holes formed in the brackets 110 and 120 or the inlet of the gas discharge passage 141 formed in the discharge guide member 140, so that the gas generated in the module can be discharged.

[0085] In another example, in the battery module 200, the gas venting device 100 can 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 can be in contact with the inner surface of the module frame 210, and the second bracket 120 can be 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 can 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 the fastening portion is formed in the discharge guide member, the venting disk will be located between the fastening portion and the module frame.

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

[0087] In addition, the present invention provides a battery pack including the gas venting device described above.

[0088] The battery pack according to the present invention includes a 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 covering the battery module, and the gas venting device as described above can 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 can be fastened with the first bracket in contact with the battery pack case. In this case, it can be fastened with the battery pack case in contact with the surface of the first bracket opposite to the surface in contact with the venting disk. The battery pack case is formed with holes corresponding to the fastening holes formed in the 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 can be fixed to the battery pack case through a single bolt fastening. As a result, the battery pack case is formed with holes having a size corresponding to the through holes formed in the bracket, so that it can act as a passage for discharging the gas generated in the module.

[0091] In another example, the gas venting device can be fastened with the battery pack case interposed between the first bracket and the second bracket. Specifically, the first bracket of the gas venting device can be fastened in contact with the inner surface of the battery pack case, and the second bracket can be fastened in contact with the outer surface of the battery pack case. At this time, there is no particular limitation on the position of the venting disk, and it can 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 disk will be located between the fastening portion and the battery pack case.

[0092] Similarly, the battery pack can include a sealing member for sealing the space between the battery pack case and the outer periphery of the gas venting device. Specifically, the sealing member can be a rubber ring or a silicon resin, and can 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 the reference value while the inside is sealed, the venting disk ruptures and the gas inside the battery pack is discharged to the outside. However, by continuously or sequentially reducing the cross-sectional area of the flow path in the gas discharge direction, a larger flow rate of gas can be discharged.

[0093] The above description merely exemplarily explains the technical idea of the present invention, and those with ordinary knowledge in the technical field to which the present invention pertains can make various modifications and deformations without departing from the essential characteristics of the present invention. Therefore, the drawings disclosed in the present invention are for the purpose of explanation rather than for 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 protection scope of the present invention should be interpreted according to the following claims, and all technical ideas within the equivalent scope should be construed as being included in the scope of rights of the present invention.

[0094] On the one hand, terms indicating directions such as up, down, left, right, front, and back are used in this specification, but such terms are merely for convenience of explanation and it is obvious that they can vary depending on the position of the object in question, the position of the observer, etc.

Explanation of Signs

[0095] 100: Gas venting device 110: First bracket 120: Second bracket 130: Venting disk 131: Disk outer peripheral part 132: Disk inner peripheral part 133: Bolt through-hole 134: Notch 140: Exhaust guide member 141: Gas exhaust flow path 142: Inlet 143: Outlet 144: Inner wall 144A: Flow path with a concave inclined surface 144B: Flow path with a convex inclined surface 146: Linear flow path 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 decreases continuously or sequentially along a gas exhaust direction.

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 or sequentially along the 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 apparatus 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 decreases continuously or sequentially along a gas exhaust direction.

4. 4. The gas venting apparatus according to claim 1, wherein the gas exhaust passage is shaped like a truncated cone.

5. The gas venting device according to any one of claims 1 to 3, wherein the gas exhaust flow path has a truncated cone shape in which a cross-sectional area is continuously reduced such that an inclined surface formed on an inner wall is concave or convex.

6. 6. The gas venting device according to claim 5, 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.

7. 4. The gas venting device according to claim 1, wherein the gas exhaust flow path is formed by continuously reducing a cross-sectional area, and continuously forming 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.

8. 4. The gas venting device according to claim 1, wherein the gas exhaust flow path is formed by continuously reducing a cross-sectional area, and is successively formed with a flow path having a truncated cone shape in which an inclined surface formed on an 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.

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

10. 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.

11. 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.

12. 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; 12. 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.

13. 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 12 fastened to one side of the module frame.

14. The battery module of claim 13 , wherein the gas venting device is fastened with the first bracket or the second bracket in contact with the module frame.

15. The battery module according to claim 13 , 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.

16. The battery module according to any one of claims 13 to 15, further comprising a sealing member for sealing between the module frame and an outer periphery of the gas venting device.

17. 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 12 fastened to one side of the battery pack case.

18. The battery pack according to claim 17 , wherein the gas venting device is fastened with the first bracket or the second bracket in contact with the battery pack case.

19. The battery pack according to claim 17 , 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.

20. The battery pack according to any one of claims 17 to 19, 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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