[Technical Field]
The present invention relates to a gas venting 5 device for discharging gas inside a
battery module or battery pack, and a battery pack including the same.
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 the entire contents of the Korean patent applications
10 are incorporated herein by reference.
[Background Art]
Battery packs applied to electric vehicles and the like have 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. In addition, the secondary batteries can be
15 repeatedly charged and discharged by an electrochemical reaction between components
including positive and negative current collectors, separators, active materials, electrolytes,
and the like.
A secondary battery may generate gas from the inside thereof at any time while
repeatedly charged and discharged, and the generated gas is called venting gas. For example,
20 when an overcurrent flows, a temperature of the secondary battery inside the battery pack is
rapidly increased. Such a rapid increase in temperature may cause a decomposition reaction
of an electrolyte to generate gas. When the gas is generated from the secondary battery
2
inside the battery pack, the gas may be collected inside the pack and the battery pack may
explode, or the gas may be introduced into the interior of a vehicle or the like through a
cooling duct of the battery pack or the like. Accordingly, a venting device capable of
reducing the pressure in a battery pack by discharging gas inside the battery pack to the
5 outside is provided in the battery pack.
Generally, a venting device has a structure in which a venting disc that can rupture
according to internal pressure is inserted between an inlet through which gas inside a battery
pack is introduced and an outlet through which the gas is discharged. However, since the
conventional venting device has a simple cylindrical structure in which an inlet and outlet of
10 gas are connected, the pressure between the inlet and the outlet is not large, and thus there is a
limit to the flow rate of the gas that can be discharged.
[Document of Related Art]
[Patent Document]
Korean Laid-open Patent Application No. 10-2018-0039986
15 [Disclosure]
[Technical Problem]
An object of the present invention is to provide a gas venting device capable of
discharging a larger flow amount per hour even with a venting disc having the same area, and
a battery module and battery pack including the same.
20 [Technical Solution]
The present invention is directed to providing a gas venting device including a first
bracket having a through hole formed in a central portion thereof, a second bracket in which a
3
through hole communicating with the first bracket is formed in a central portion thereof and
which is fastened to the first bracket, and a venting disc which is fastened between the first
bracket and the second bracket to shield the through holes and is configured to rupture when a
predetermined pressure is applied, wherein a gas discharge flow path is formed in the through
holes formed in the first bracket and the second bracket, and 5 a cross-sectional area of the gas
discharge flow path is continuously or gradually reduced in a gas discharge direction.
In a specific example, the gas venting device according to the present invention
include a discharge guide member which is inserted into the through holes of the first bracket
and the second bracket and has a gas discharge flow path formed in a central portion thereof,
10 wherein a cross-sectional area of the gas discharge flow path may be continuously or
gradually reduced in the gas discharge direction.
In this case, the discharge guide member may include 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, wherein a cross-sectional
15 area of the gas discharge flow path formed by the first discharge guide member and the
second discharge guide member may be continuously or gradually reduced in the gas
discharge direction.
In an example, the gas discharge flow path may have a truncated conical shape.
In another example, the gas discharge flow path may have a truncated conical shape
20 in which an inclined surface formed on an inner wall thereof is concavely or convexly curved,
as the cross-sectional area thereof is continuously reduced.
In a specific example, a straight flow path having a constant cross-sectional area may
4
be formed on the outlet side of the gas discharge flow path so as to follow the truncated coneshaped
flow path in which the inclined surface is concavely or convexly curved.
As another example, in the gas discharge flow path, a truncated conical-shaped flow
path, in which an inclined surface formed on an inner wall thereof is concavely curved, and a
truncated cone-shaped flow path, in which an inclined surface 5 is convexly curved, may be
consecutively formed, as the cross-sectional area thereof is continuously reduced.
As still another example, in the gas discharge flow path, a truncated conical-shaped
flow path, in which an inclined surface formed on an inner wall thereof is convexly curved,
and a truncated cone-shaped flow path, in which an inclined surface is concavely curved, may
10 be consecutively formed, as the cross-sectional area thereof is continuously reduced.
In a specific example, a protrusion having a screw thread, an embossing, or a straightline
shaped pattern may be formed on an inner wall of the gas discharge flow path.
In an example, a fastening portion for fastening the discharge guide member to the
first and second brackets may protrude from an outer surface of the discharge guide member,
15 and a fastening hole for bolt fastening with the first and second brackets may be formed in the
fastening portion.
In another example, the first bracket and the second brackets may be fastened to the
discharge guide member in a screw fastening manner.
Meanwhile, the venting disc may include a disc outer peripheral portion fastened to
20 the first bracket and the second bracket, and a disc inner peripheral portion which is integrally
formed with the disc outer peripheral portion as one body, shields the through holes, and
ruptures when a predetermined pressure is applied, wherein a notch may be formed in the disc
5
inner peripheral portion so as to rupture when the predetermined pressure is applied.
Further, the present invention provides a battery module including the gas venting
device as described above.
The battery module may include a plurality of secondary batteries, and a module
frame on which the secondary batteries are mounted, wherein 5 the gas venting device as
described above may be fastened to one side of the module frame.
In an example, the gas venting device may be fastened to the module frame that is in
a state of being in contact with the first bracket. In another example, the gas venting device
may be fastened to the module frame in a state in which the first bracket is in contact with an
10 inner surface of the module frame and the second bracket is in contact with an outer surface of
the module frame.
Further, the present invention provides a battery pack including the gas venting
device as described above.
The battery pack may include at least one battery module including a plurality of
15 secondary batteries, and a battery pack case including a tray on which the battery module is
mounted and a pack cover that covers the battery module, wherein the gas venting device as
described above may be fastened to one side of the battery pack case.
In an example, the gas venting device may be fastened to the battery pack case that is
in a state of being in contact with the first bracket or the second bracket.
20 In another example, the gas venting device may be fastened to the battery pack case
in a state in which the first bracket is in contact with an inner surface of the battery pack case
and the second bracket is in contact with an outer surface of the battery pack case.
6
[Advantageous Effects]
According to a gas venting device according to the present invention and a battery
module or battery pack including the same, a larger flow amount can be discharged per hour
even when a venting disc having the same area is used, and thus the safety of the battery
5 module and battery pack can be improved.
[Brief Description of the Drawings]
FIG. 1 is a perspective view of a gas venting device according to an embodiment of
the present invention.
FIG. 2 is a perspective view illustrating a form in which brackets and a venting disc
10 are fastened in a gas venting device according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view illustrating a shape of a gas venting device according
to an embodiment of the present invention.
FIG. 4 is a schematic view illustrating a shape of a discharge guide member.
FIG. 5 illustrates cross-sectional views illustrating a shape of a gas venting device
15 according to another embodiment of the present invention.
FIG. 6 illustrates cross-sectional views illustrating a shape of a gas venting device
according to still another embodiment of the present invention.
FIG. 7 illustrates cross-sectional views illustrating a shape of a gas venting device
according to another embodiment of the present invention.
20 FIG. 8 illustrates cross-sectional views illustrating a shape of a gas venting device
according to still another embodiment of the present invention.
FIG. 9 is a cross-sectional view illustrating a form in which brackets and a discharge
7
guide member are fastened according to an embodiment of the present invention.
FIG. 10 is a cross-sectional view illustrating a form in which brackets and a discharge
guide member are fastened according to another embodiment of the present invention.
FIG. 11 is a schematic view illustrating a shape of a venting disc according to the
5 present invention.
FIG. 12 is a schematic views illustrating a coupling structure of a gas venting device
in a battery module according to an embodiment of the present invention.
FIG. 13 is a schematic view illustrating a coupling structure of a gas venting device in
a battery module according to another embodiment of the present invention.
10 [Detailed Description of the Preferred Embodiments]
Hereinafter, the present invention will be described in detail with reference to the
accompanying drawings. Terms and words used in this specification and claims should not
be construed as being limited to commonly used meanings or meanings in dictionaries and
should be construed with meanings and concepts which are consistent with the technological
15 scope of the present invention based on the principle that the inventors have appropriately
defined concepts of terms in order to describe the present invention in the best way.
It should be understood that the terms “comprise,” “comprising,” “include,” and/or
“including,” when used herein, specify the presence of stated features, integers, steps,
operations, elements, parts, and/or combinations thereof, but do not preclude the presence or
20 addition of one or more other features, integers, steps, operations, elements, parts, and/or
combinations thereof. In addition, when a layer, film, region, or plate is referred to as being
"formed on" another element, it includes a case in which the layer, film, region, or plate is
8
formed directly on another element and a case in which the other layer, film, region, or plate
is formed on another element with still another element therebetween. In contrast, when a
layer, film, region, or plate is referred to as being "formed below" another element, it includes
a case in which the layer, film, region, or plate is formed directly below another element and a
case in which the other layer, film, region, or plate 5 is formed below another element with still
another element therebetween. In addition, in the present invention, when an element is
referred to as being located “on” another element, it includes a case in which an element is
disposed above another element and a case in which an element is disposed under another
element.
10 Hereinafter the present invention will be described in detail.
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 illustrating a form in which brackets
and a venting disc are fastened in the gas venting device according to the embodiment of the
present invention.
15 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
thereof, a second bracket 120 in which a through hole communicating with the first bracket
110 is formed in a central portion thereof and which is fastened to the first bracket 110, and a
venting disc 130 fastened between the first bracket 110 and the second bracket 120 to shield
20 the through holes and configured to rupture when a predetermined pressure is applied,
wherein a gas discharge flow path 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 discharge flow path is
9
continuously or gradually reduced in a gas discharge direction.
Generally, a plurality of battery modules are mounted in a battery pack, and a
plurality of secondary batteries are embedded in each battery module. The secondary
batteries generate gas due to a decomposition reaction of an electrolyte or the like as the
secondary batteries are repeatedly charged and discharged. 5 Heat generated during the
charging and discharging process of the batteries promotes gas generation and expands the
gas, thereby increasing the pressure inside the battery module or battery pack. When such a
process continues, the battery module or the battery pack may explode or the gas inside the
battery module or battery pack may be introduced into the interior of a vehicle through a duct
10 or the like. Therefore, a venting device, in which a venting disc ruptures to discharge gas
when the pressure of the gas is a predetermined value or higher, is attached.
Such gas is generally a compressible fluid whose volume changes with respect to
pressure. When air flows at a high speed, pressure and density are increased in some regions,
and a volume of the air is reduced. However, in the process of discharging the gas as
15 described above, a discharging rate of the gas is small, and thus an incompressible flow
phenomenon in which a change in volume according to pressure is negligible occurs. In the
incompressible flow, a total pressure on a fluid is constant, and the pressure and flow rate of
the fluid are inversely proportional. That is, when the pressure of the fluid increases, a flow
rate decreases, and when the pressure of the fluid decreases, the flow rate increases.
20 As described above, since the conventional venting device has a simple cylindrical
structure in which an inlet and outlet of gas are connected, the pressure between the inlet and
the outlet is not large, and thus there is a limit to the flow rate of the gas that can be
10
discharged.
In contrast, when the cross-sectional area of the gas discharge flow path is
continuously or gradually reduced in the gas discharge direction as in the present invention, as
the flow rate of air decreases at the inlet having a large cross-sectional area, the internal
pressure increases, and as the flow rate of air increases 5 at the outlet having a small crosssectional
area, the internal pressure decreases. Accordingly, a difference in pressure
between the inlet and the outlet is further increased locally, and a larger amount of gas can be
discharged even when a venting disc having the same area is used. Therefore, when the
internal pressure due to the gas generated inside the battery module or battery pack exceeds a
10 reference value, the safety of the battery module and battery pack can be improved by rapidly
discharging the gas.
Hereinafter, a structure of the gas venting device according to the present invention
will be described in detail.
FIG. 3 is a cross-sectional view illustrating a shape of the gas venting device
15 according to the embodiment of the present invention, and FIG. 4 is a schematic view
illustrating a shape of a discharge guide member. FIG. 5 illustrates cross-sectional views
illustrating a shape of a gas venting device according to another embodiment of the present
invention.
Referring to FIG. 3 or 4 together with FIGS. 1 and 2, the gas venting device 100
20 according to the present invention includes brackets 110 and 120 for fastening a venting disc
130 and discharging gas therein. The venting disc 130 may be fastened between the two
brackets 110 and 120, and through holes are each formed in one of central portions of the
11
brackets 110 and 120 to form a gas discharge flow path in the through holes. In the present
invention, among the two brackets 110 and 120, a bracket positioned at a side through which
gas is introduced relative to a gas discharge direction is defined as a first bracket 110, and a
bracket positioned at a side through which the gas is discharged is defined as a second bracket
120. The through hole formed 5 in the central portion of the second bracket 120
communicates with the through hole formed in the central portion of the first bracket 110 to
act as a gas discharge flow path. The venting disc and a discharge guide member, which will
be described below, are both fastened to the first bracket 110 and the second bracket 120, and
fastening holes (not illustrated) into which bolts 150 for fastening the gas venting device 100
10 to the battery module or the battery pack may be inserted may be formed.
The venting disc 130 may be fastened between the first bracket 110 and the second
bracket 120 to shield the through holes and may be configured to rupture when a
predetermined pressure is applied.
Meanwhile, the gas discharge flow path is formed in the through holes formed in the
15 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 which is inserted
into the through holes of the first bracket 110 and the second bracket 120 and has a gas
discharge flow path 141 formed in a central portion thereof. The gas discharge flow path
formed in the through holes may be formed by the discharge guide member 140, and in this
20 case, a cross-sectional area of the gas discharge flow path 141 formed in the discharge guide
member 140 is continuously or gradually reduced in the gas discharge direction.
That is, in the present invention, the shape of the gas discharge flow path formed in
12
the brackets 110 and 120 may be formed by forming the shape of the through hole itself, but it
is possible to insert a separate discharge guide member 140 into the brackets 110 and 120 to
form the gas discharge flow path as described above. The discharge guide member 140 has
a detachable/attachable or replaceable structure. In the present invention, by using a separate
discharge guide member 140 for the brackets 5 110 and 120, the gas can be smoothly
discharged, parts can be easily replaced, and the shape of the flow path can be easily changed.
In the present invention, in order to improve the efficiency of gas discharge, the
cross-sectional area may be changed while maximizing a length of the gas discharge flow
path. In the present invention, since the venting disc 130 is positioned between the first
10 bracket 110 and the second bracket 120, the discharge guide member 140 may also be
inserted into the through holes formed in the first bracket 110 and the second bracket 120.
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
15 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 is continuously or gradually
reduced in the gas discharge direction. That is, there is no step difference between the first
discharge guide member 141a and the second discharge guide member 140b, and the gas
discharge flow path 141 is formed with one continuous surface. Accordingly, movement of
20 the gas introduced into the brackets 110 and 120 may not be hindered and the gas can be
smoothly discharged.
Further, the gas discharge flow path 141 formed by the discharge guide member 140
13
may be designed, for example, to have a circular shape, as illustrated in FIG. 4. In this case,
the gas discharge flow path 141 formed by the discharge guide member 140 may have a
truncated conical shape. Referring to FIGS. 3 and 4 together, an inlet 142 and an outlet 143
of the gas discharge flow path 141 in the discharge guide member 140 each have a circular
shape, and have lower and upper surfaces forming a 5 truncated conical shape. That is, an
inner wall 144 of the discharge guide member 140 has a structure in which a cross-sectional
area is continuously reduced from the inlet through which the gas is introduced toward the
outlet through which the gas is discharged so as to form an inclined surface. When a crosssectional
profile of the inner wall 144 of the gas discharge flow path 141 is formed as a
10 straight inclined surface as illustrated in FIGS. 3 and 4, a reduction rate of the cross-sectional
area is constant throughout the gas discharge flow path.
Such a straight cross-sectional profile is simple, and thus it is easy to manufacture the
cross-sectional profile, but when the cross-sectional profile is connected to other parts such as
a pipe and the like, an angular portion may be formed on the wall of the flow path, and thus
15 some sections in which the flow is unstable may be generated. Further, since the reduction
rate of the cross-sectional area is constant, for example, when a gas whose flow is unstable is
introduced from the inlet of the flow path, flow instability of the gas cannot be resolved and is
highly likely to be maintained up to the outlet of the flow path. That is, the flow path having
a constant reduction rate in cross-sectional area has a disadvantage in that a degree of freedom
20 to adjust flow instability within the corresponding flow path is reduced.
On the other hand, when the reduction rate of the cross-sectional area is changed
along the flow path, there is an advantage in that the above-described flow instability may be
14
adjusted and managed within the flow path. FIGS. 5 to 8 illustrate embodiments of the gas
discharge flow path.
Referring to FIG. 5A, the gas discharge flow path 141 formed by the discharge guide
member 140 has a truncated conical shape in which an inclined surface, formed on the inner
wall 144 of the gas discharge flow path is concavely curved, 5 as the cross-sectional area
thereof is continuously reduced toward the outlet 143.
Here, the shape in which the inclined surface is concavely curved refers to a shape
in which the inclined surface is recessed toward the outside of the gas discharge flow path in a
vertical cross section of the flow path. In this case, a reduction rate of the cross-sectional
10 area is small near the inlet 142 through which the gas is introduced, and is increased toward
the outlet 143 through which the gas is discharged. Since the gas discharge flow path 141
having the cross-sectional profile of the concave curved shape as described above has a shape
in which the cross-sectional area of the flow path on the outlet 143 side is rapidly reduced, a
difference in pressure (differential pressure) between the inlet 142 and the outlet 143 of the
15 flow path may be increased. That is, as compared to the gas discharge flow path 141 of the
embodiment of FIGS. 3 and 4 having the straight inclined surface, the flow path of the present
embodiment may achieve a greater differential pressure between the inlet and the outlet.
This means that even when a length of the flow path is shortened, a desired differential
pressure may be easily obtained. Therefore, according to the present embodiment, when the
20 same differential pressure as the gas discharge flow path 141 having the straight inclined
surface of FIGS. 3 and 4 is achieved, the gas venting device may be configured with a flow
path having a shorter length than that of the embodiment of FIGS. 3 and 4.
15
Further, referring to FIG. 5B, the gas discharge flow path 141 formed by the
discharge guide member 140 has a truncated conical shape in which an inclined surface
formed on the inner wall 144 is convexly curved, as the cross-sectional area thereof is
continuously reduced toward the outlet 143.
Here, the shape in which the inclined surface is convexly 5 curved refers to a shape
in which the inclined surface protrudes toward the center of the flow path in a vertical cross
section of the flow path. In this case, a reduction rate of the cross-sectional area is large near
the inlet 142 through which the gas is introduced, and is reduced toward the outlet 143
through which the gas is discharged. The gas discharge flow path 141 having the cross10
sectional profile of the convex curved shape of FIG. 5B also has a cross-sectional area
reduction rate, which is greater than that of the gas discharge flow path having the straight
inclined surface, similar to the flow path of FIG. 5A. Therefore, since a greater differential
pressure may be achieved between the inlet and the outlet, the gas venting device may be
configured with a shorter length of the flow path. In particular, in the gas discharge flow
15 path 141 of FIG. 5B, the flow path on the outlet 143 side has a shape in which the crosssectional
area is relatively gently reduced as compared to the flow path of the straight inclined
surface. The flow path having such a shape has an advantage of achieving high flow
stability because a change in physical quantity inside the flow path is gentle.
Meanwhile, as described above, in order to achieve both effects of increasing the
20 difference in pressure between the inlet and the outlet and increasing flow stability, the crosssectional
profile of the gas discharge flow path 141 may be configured in a form in which a
curve and a straight line are combined as illustrated in FIG. 6.
16
Referring to FIG. 6A, a straight flow path 146 having a constant cross-sectional area
is formed on the side of the outlet 143 of a gas discharge flow path 141, which follows a
truncated conical-shaped flow path in which an inclined surface of the gas discharge flow
path 141 is concave. In the present embodiment, in the concave truncated conical-shaped
flow path of the gas discharge flow path 141, a larger pressure 5 difference may be achieved
due to a reduction in cross-sectional area, and in the straight flow path 146 on the outlet side,
the discharge gas may be stably discharged by designing a slope of an inner wall to be parallel
to the gas flow direction.
Referring to FIG. 6B, a straight flow path 146 having a constant cross-sectional area
10 is formed on the side of the outlet 143 of the gas discharge flow path, which follows the
truncated conical-shaped flow path in which the inclined surface of the gas discharge flow
path 141 is convex. As above, in the present embodiment, in the convex truncated conicalshaped
flow path of the gas discharge flow path 141, a larger pressure difference may also be
achieved due to a reduction in cross-sectional area, and in the straight flow path 146 on the
15 outlet side, the discharge gas may be stably discharged by designing a slope of an inner wall
to be parallel to the gas flow direction.
In particular, the gas venting device 100 having the discharge guide member 140 of
the embodiment of FIG. 6 has a structure in which the gas is finally discharged through the
flow path parallel to the gas flow direction while a curvature or cross-sectional area of the gas
20 discharge flow path 141 is continuously reduced. Therefore, even when the flow of the gas
introduced into the inlet 142 of the flow path is initially unstable, the flow instability of the
gas may be resolved while the gas passes through the corresponding flow path, and thus the
17
gas may stably flow at the outlet 143.
In the embodiment of FIG. 6, the gas discharge flow path 141 formed on the inner
wall of the first discharge guide member 140a inserted into the through hole formed in the
first bracket 110 may have the inclined surface having the concave truncated conical shape of
(see FIG. 6A) or the inclined surface having the convex 5 truncated conical shape of (see FIG.
6B). Meanwhile, the gas discharge flow path 141 formed on the inner wall of the second
discharge guide member 140bmay have a complex type flow path including both of the
concave or convex truncated conical-shaped inclined surface and the straight flow path 146
connected thereto.
10 Further, in order to achieve both effects of increasing the difference in pressure
between the inlet and the outlet and increasing flow stability, the gas discharge flow path 141
may be configured in a form in which curves having different curvatures are combined, as
illustrated in FIGS. 7 and 8.
In FIG. 7A, a schematic cross-sectional profile of a complex flow path is illustrated in
15 which a gas discharge flow path having a continuously reduced overall cross-sectional area is
formed, and a truncated conical-shaped flow path 144A, in which an inclined surface is
concave, and a truncated conical-shaped flow path 144B, in which an inclined surface is
convex, are consecutively formed. In FIG. 7B, a gas venting device 100 having the crosssectional
profile of the complex flow path is disclosed.
20 The flow path of FIG. 7 is basically the same as the above-described embodiment in
that the cross-sectional area is continuously reduced from the inlet 142 toward the outlet 143
of the gas discharge flow path 141. Therefore, as compared to the conventional gas venting
18
device in which the cross-sectional area is not reduced, a difference in pressure between the
inlet and the outlet is increased locally, and thus a larger amount of gas can be discharged
even when a venting disc having the same area is used.
In addition to the above effects, since the gas discharge flow path 141 of FIG. 7 has
the concave inclined surface and the convex inclined surface 5 which are consecutively formed,
a reduction rate of the cross-sectional area may be further increased, and thus the difference in
pressure between the inlet and the outlet may be further increased based on the same flow
path. Accordingly, it is possible to further increase the discharge flow rate of the gas.
Further, since the outlet 143 has a flow path having a convex inclined surface with a relatively
10 gentle curve, it is possible to improve the flow stability of the gas.
A dotted line of FIG. 7A indicates a boundary line at which the shape of the inclined
surface is changed, and the boundary line may become a boundary between the first bracket
110 and the second bracket 120, or become a portion in which the venting disc 130 is installed,
as illustrated in FIG. 7B. However, a position of the boundary line is not limited thereto, and
15 for example, one bracket of the first bracket 110 and the second bracket 120 may have a flow
path having an inclined surface including a boundary line, and the other bracket may have a
flow path having an inclined surface of a single curvature. That is, although not illustrated,
it is also possible to form a gas discharge flow path in such a way that one of the two brackets
includes all of the flow path portions with varying curvatures.
20 In FIG. 8A, a schematic cross-sectional profile of a complex flow path is illustrated in
which a gas discharge flow path 141 having an overall continuously reduced cross-sectional
area is formed, and a truncated conical-shaped flow path 144B in which an inclined surface is
19
convex, and a concave truncated conical-shaped flow path 144A in which an inclined surface
is concave, are consecutively formed. In FIG. 8B, a gas venting device having the crosssectional
profile of the complex flow path is disclosed. That is, the gas venting device of
FIG. 8 includes a gas discharge flow path with an arrangement opposite to that of FIG. 7.
Since the cross-sectional area of the flow path 5 of FIG. 8 is also continuously reduced
from the inlet 142 toward the outlet 143 of the gas discharge flow path, a difference in
pressure between the inlet and the outlet is increased locally, and thus a larger amount of gas
can be discharged even when a venting disc having the same area is used.
Further, since the gas discharge flow path 141 of FIG. 8 has the convex inclined
10 surface and the concave inclined surface which are consecutively formed, a reduction rate of
the cross-sectional area may be increased, and thus the difference in pressure between the
inlet and the outlet may be further increased based on the same flow path. Accordingly, it is
possible to further increase the discharge flow rate of the gas. Further, since the gas
discharge flow path 141 has a flow path having an inclined surface with a relatively gentle
15 curve as a whole, it is possible to further improve the flow stability of the gas.
A dotted line of FIG. 8A indicates a boundary line at which the shape of the inclined
surface is changed, and the boundary line may become a boundary between the first bracket
110 and the second bracket 120, or become a portion in which the venting disc 130 is installed,
as illustrated in FIG. 8B. However, a position of the boundary line is not limited thereto, and
20 for example, one bracket of the first bracket 110 and the second bracket 120 may have a flow
path having an inclined surface including a boundary line, and the other bracket may have a
flow path having an inclined surface of a single curvature. That is, although not illustrated,
20
it is also possible to form a gas discharge flow path in such a way that one of the two brackets
includes all of the flow path portions with varying curvatures.
The venting devices of FIGS. 7 and 8 include a complex flow path having inclined
surfaces with different curvatures. Therefore, for example, even when the flow stability of
the gas is initially reduced, the flow stability of 5 the gas can be improved at the outlet
according to a curvature while the gas passes through the flow path. At the same time, the
difference in pressure between the inlet 142 and the outlet 143 may be increased by varying
the curvature of the flow path. The complex flow path of FIG. 7 may be an example in
which a pressure difference and flow stability are considered in good balance, whereas the
10 complex flow path of FIG. 8 may be an example in which flow stability is further considered.
In any case, since the flow of the gas may be adjusted in the corresponding flow path, there is
an advantage in that the degree of freedom for adjusting flow instability is excellent.
In addition to the above, in the discharge guide member, the shape of the flow path
formed therein may be designed in various forms according to safety standards of battery
15 packs.
Further, the cross-sectional area of the outlet 143 of the gas discharge flow path 141
may be appropriately selected according to structures of the battery module and a battery pack
or safety conditions to be achieved, but may range from 40% to 80% of the cross-sectional
area of the inlet 142. Specifically, the cross-sectional area of the outlet may range from 50
20 to 70% of the cross-sectional area of the inlet, and more specifically, may range from 55 to
65%. When the cross-sectional area of the outlet is less than 40% of the cross-sectional area
of the inlet, the outlet is too narrow. On the other hand, when the cross-sectional area of the
21
outlet exceeds 80% of the cross-sectional area of the inlet, a difference in cross-sectional area
between the inlet and the outlet is excessively reduced and a pressure difference between the
inlet and the outlet is reduced, and thus the efficiency of gas venting is reduced.
Further, a pattern (not illustrated) for assisting gas discharge may be formed on the
inner wall 144 of the gas discharge flow path 141. For 5 example, the pattern may have a
shape of a protrusion having a screw thread, an embossing, or a straight-line shaped pattern
parallel to the gas discharge direction. Specifically, the pattern may be formed in the form
of a screw thread protrusion surrounding the inside of the flow path along the inner wall of the
flow path. Such a pattern may promote the discharge of the gas.
10 Meanwhile, since the discharge guide member is fastened to the brackets, stable gas
discharge may be promoted even during gas venting.
FIG. 9 is a cross-sectional view illustrating a form in which brackets and a discharge
guide member are fastened according to an embodiment of the present invention, and FIG. 10
is a cross-sectional view illustrating a form in which brackets and a discharge guide member
15 are fastened according to another embodiment of the present invention.
In an example, brackets 110 and 120 and a discharge guide member 140 may be
fastened by bolt fastening. In this case, as illustrated in FIG. 9, fastening portions 145 for
fastening the discharge guide member 140 to the brackets 110 and 120 protrude from an outer
surface of the discharge guide member 140. Since the discharge guide member 140 should
20 be inserted into the through holes in the brackets 110 and 120, a cross section of the discharge
guide member 140 has a shape corresponding to a shape of the through hole, and the fastening
portions 145 have a plate-like protrusion shape that protrudes along an outer periphery thereof
22
in a shape similar to an outer periphery of the venting disc 130. In the present invention, the
discharge guide member 140 includes a first discharge guide member 140a and a second
discharge guide member 140b, and the fastening portions 145 may be formed in both of the
first discharge guide member 140a and the second discharge guide member 140b. Fastening
holes (not illustrated) for bolt fastening with the 5 brackets 110 and 120 are formed in the
fastening portions 145, and the fastening holes formed in the fastening portions 145 are
formed at the same positions as the fastening holes formed in the brackets 110 and 120, and
are fixed by bolt insertion.
Meanwhile, positions at which the fastening portions 145 are formed may be
10 appropriately designed. For example, as illustrated in FIG. 9, the fastening portions 145
formed in the first discharge guide member 140a and the second discharge guide member
140b may be formed to be disposed between the first bracket 110 and the venting disc 130
and between the second bracket 120 and the venting disc 130, respectively. However, the
positions of the fastening portions are not limited thereto, and for example, the fastening
15 portions 145 may be formed so that the brackets 110 and 120 are in contact with a surface
opposite to a surface in contact with the venting disc 130.
In another example, the first bracket 110 and the second bracket 120 may be fastened
to the discharge guide member 140 in a screw fastening manner. In this case, as illustrated
in FIG. 10, screw threads for screw fastening may be formed on the inner walls of the first
20 bracket 110 and the second bracket 120 and on the outer surface of the discharge guide
member 140, and accordingly, the first and second brackets 110 and 120 may be fastened to
the discharge guide member 140 in the same way as a nut and a bolt are fastened. In the
23
present invention, the discharge guide member 140 includes the first discharge guide member
140a and the second discharge guide member 140b, and the screw threads may be formed on
both of the first discharge guide member 140a and the second discharge guide member 140b.
In this way, when the discharge guide member 140 is fastened to the brackets 110 and 120 in
a screw fastening manner, the insertion of a separate 5 bolt is not required, and thus a structure
and fastening method of parts may be simplified and the discharge guide member 140 may be
firmly fixed to the brackets 110 and 120.
Meanwhile, referring to FIG. 11, the venting disc 130 includes a disc outer peripheral
portion 131 which is fastened to the first bracket 110 and the second bracket 120, and a disc
10 inner peripheral portion 132 which is integrally formed with the disc outer peripheral portion
131 as one body, shields the through holes, and ruptures when a predetermined pressure is
applied.
The disc outer peripheral portion 131 is a portion for fixing the brackets 110 and 120
and the venting disc 130, and has one surface in contact with the first bracket 110 and the
15 other surface in contact with the second bracket 120. The disc outer peripheral portion 131
may include bolt through holes 133 in a circumferential direction, and the first bracket 110,
the disc outer peripheral portion 131, and the second bracket 120 may be integrally coupled
through a bolt fastening method. When the discharge guide member has a structure in which
the fastening portion is formed, the discharge guide member may be coupled to the brackets
20 and the venting disc.
The disc inner peripheral portion 132 is made of a metal or plastic material that can
rupture when a predetermined pressure is applied. For example, the disc inner peripheral
24
portion 132 may be formed of a thin metal or plastic material such as copper, aluminum, or
stainless steel. The disc inner peripheral portion 132 may be appropriately selected
according to pressure conditions at the time of rupture, and the scope of the present invention
is not limited thereto.
The disc inner peripheral portion 132 prevents 5 moisture or foreign substances from
penetrating into the battery module or the 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 from the battery module or the battery pack, the pressure
inside the battery module or the battery pack is increased, and the pressure acts as a force to
10 rupture the disc inner peripheral portion 132. In this case, since the pressure inside the
battery module or the battery pack is higher than an atmosphere pressure outside, the gas
inside the battery module or the battery pack may be discharged to the outside of the battery
module or the battery pack due to a negative pressure.

[Claim 1]
A gas venting device comprising:
a first bracket having a through hole formed in a central portion thereof;
a second bracket in which a through 5 hole communicating with the first bracket is
formed in a central portion thereof and which is fastened to the first bracket; and
a venting disc which is fastened between the first bracket and the second bracket to
shield the through holes and is configured to rupture when a predetermined pressure is
applied,
10 wherein a gas discharge flow path is formed in the through holes formed in the first
bracket and the second bracket, and a cross-sectional area of the gas discharge flow path is
continuously or gradually reduced in a gas discharge direction.
[Claim 2]
15 The gas venting device of claim 1, further comprising a discharge guide member
which is inserted into the through holes of the first bracket and the second bracket and has a
gas discharge flow path formed in a central portion thereof,
wherein a cross-sectional area of the gas discharge flow path is continuously or
gradually reduced in the gas discharge direction.
20
[Claim 3]
The gas venting device of claim 2, wherein the discharge guide member includes:
a first discharge guide member inserted into the through hole formed in the first
bracket; and
25 a second discharge guide member inserted into the through hole formed in the second
bracket,
32
wherein a cross-sectional area of the gas discharge flow path formed by the first
discharge guide member and the second discharge guide member is continuously or gradually
reduced in the gas discharge direction.
5 [Claim 4]
The gas venting device of claim 2, wherein the gas discharge flow path has a
truncated conical shape.
[Claim 5]
10 The gas venting device of claim 2, wherein the gas discharge flow path has a
truncated conical shape in which an inclined surface formed on an inner wall thereof is
concavely or convexly curved, as the cross-sectional area thereof is continuously reduced.
15 [Claim 6]
The gas venting device of claim 5, wherein a straight flow path having a constant
cross-sectional area is formed on an outlet side of the gas discharge flow path so as to follow
the truncated conical-shaped flow path in which the inclined surface is concavely or convexly
curved.
20
[Claim 7]
The gas venting device of claim 2, wherein, in the gas discharge flow path, a
truncated conical-shaped flow path, in which an inclined surface formed on an inner wall
33
thereof is concavely curved, and a truncated conical-shaped flow path, in which an inclined
surface is convexly curved, are consecutively formed, as the cross-sectional area thereof is
continuously reduced.
5 [Claim 8]
The gas venting device of claim 2, wherein, in the gas discharge flow path, a
truncated cone-shaped flow path, in which an inclined surface formed on an inner wall thereof
is convexly curved, and a truncated conical-shaped flow path, in which an inclined surface is
concavely curved, are consecutively formed, as the cross-sectional area thereof is
10 continuously reduced.
[Claim 9]
The gas venting device of claim 2, wherein a protrusion having a screw thread, an
embossing, or a straight-line shaped pattern is formed on an inner wall of the gas discharge
15 flow path.
[Claim 10]
The gas venting device of claim 2, wherein:
a fastening portion for fastening the discharge guide member to the first and second
20 brackets protrudes from an outer surface of the discharge guide member; and
a fastening hole for being bolt fastening with the first and second brackets is formed
in the fastening portion.
34
[Claim 11]
The gas venting device of claim 2, wherein the first bracket and the second brackets
are fastened to the discharge guide member in a screw fastening manner.
5
[Claim 12]
The gas venting device of claim 1, wherein the venting disc includes:
a disc outer peripheral portion fastened to the first bracket and the second bracket;
and
10 a disc inner peripheral portion which is integrally formed with the disc outer
peripheral portion as one body, shields the through holes, and ruptures when a predetermined
pressure is applied,
wherein a notch is formed in the disc inner peripheral portion so as to rupture when
the predetermined pressure is applied.
15
[Claim 13]
A battery module comprising:
a plurality of secondary batteries; and
a module frame on which the secondary batteries are mounted,
20 wherein the gas venting device according to any one claim of claims 1 to 12 is
fastened to one side of the module frame.
35
[Claim 14]
The battery module of claim 13, wherein the gas venting device is fastened to the
module frame that is in a state of being in contact with the first bracket or the second bracket.
5 [Claim 15]
The battery module of claim 13, wherein the gas venting device is fastened to the
module frame in a state in which the first bracket is in contact with an inner surface of the
module frame and the second bracket is in contact with an outer surface of the module frame.
10 [Claim 16]
The battery module of claim 13, further comprising a sealing member configured to
seal a gap between the module frame and an outer periphery of the gas venting device.
[Claim 17]
15 A battery pack comprising:
at least one battery module including a plurality of secondary batteries; and
a battery pack case including a tray on which the battery module is mounted and a
pack cover that covers the battery module,
wherein the gas venting device according to any one claim of claims 1 to 12 is
20 fastened to one side of the battery pack case.
[Claim 18]
36
The battery pack of claim 17, wherein the gas venting device is fastened to the battery
pack case that is in a state of being in contact with the first bracket or the second bracket.
[Claim 19]
The battery pack of claim 17, wherein the 5 gas venting device is fastened to the battery
pack case in a state in which the first bracket is in contact with an inner surface of the battery
pack case and the second bracket is in contact with an outer surface of the battery pack case.
[Claim 20]
10 The battery pack of claim 17, further comprising a sealing member configured to seal
a gapbetween the battery pack case and an outer periphery of the gas venting device.