【TECHNICAL FIELD】
Cross Citation with Related Application(s)
This application claims the benefit of Korean Patent Application No. 10-2020-0137479
filed on October 27, 2020 with the Korean Intellectual Property Office, the disclosure of which is
incorporated herein by reference in its entirety.
10 The present disclosure relates to a battery module and a battery pack including the same,
and more particularly, to a battery module that effectively delays a heat propagation speed between
battery cells, and a battery pack including the same.
【BACKGROUND ART】
15 As technology development and demands for mobile devices increase, the demand for
batteries as energy sources is rapidly increasing. In particular, a secondary battery has attracted
considerable attention as an energy source for power-driven devices, such as an electric bicycle,
an electric vehicle, and a hybrid electric vehicle, as well as an energy source for mobile devices,
such as a mobile phone, a digital camera, a laptop computer and a wearable device.
20 The middle or large-sized battery module is preferably manufactured so as to have as small
a size and weight as possible. For this reason, a prismatic battery, a pouch-type battery or the like,
which can be stacked with high integration and has a small weight to capacity ratio, is usually used
as a battery cell of the middle or large-sized battery module. Meanwhile, in order to protect the
battery cell stack from external impact, heat or vibration, the battery module may include a module
25 frame in which a front surface and rear surface are opened to house the battery cell stack in an
internal space.
Fig. 1 is a perspective view of a conventional battery module. Fig. 2 is a top view of a
battery cell stack included in a conventional battery module. Fig. 3 (a) is a top view of the region
2 / 27
A of Fig. 2 as viewed from above, and Fig. 3 (b) is a cross-sectional view taken along the cutting
surface B-B of (a).
Referring to Figs. 1 and 2, the conventional battery module includes a battery cell stack 12
in which a plurality of battery cells 11 are stacked in one direction, module frames 30 and 40 for
5 accommodating the battery cell stack 12, an end plate 15 for covering the front and rear surfaces
of the battery cell stack 12. The module frames 30 and 40 include a lower frame 30 for covering
the lower and both side surfaces of the battery cell stack 12, and an upper plate 40 for covering the
upper surface of the battery cell stack 12.
In addition, the battery cell stack 12 includes a fixing member 17 for fixing the plurality of
10 battery cells 11 to each other, and the fixing member 17 is located at the central part and/or the
end part of the battery cell stack 12. Further, a compression pad 20 is located between a pair of
battery cells adjacent to each other in the battery cell stack 12.
Referring to Figs. 2 and 3, the compression pad 20 located in the conventional battery cell
stack is in contact with the upper surface or the lower surface of the battery cells 11. The
15 compression pad 20 can absorb the impact propagated to adjacent battery cells 11. Further, when
the battery cell 11 ignites, the heat propagation speed can be delayed due to the thickness possessed
by the compression pad 20. However, when a swelling phenomenon occurs in the
charging/discharging process of the battery cells 11, pressure and/or heat is applied to the
compression pad 20. At this time, the compression rate of the conventional compression pad 20
20 appears differently in accordance with the position, and thus the physical properties of the
compression pad 20 may be changed. In addition, when the battery cells 110 ignite, secondary
cell ignition may occur due to heat conduction between adjacent battery cells 11 and external heat
conduction caused by flames generated in the battery cells 11. For this reason, it is difficult to
sufficiently perform the role of delaying the heat propagation speed by using only the conventional
25 compression pad 20. Therefore, unlike the conventional one, there is a need to develop a battery
3 / 27
module that effectively delays the heat propagation speed between battery cells even when a
swelling phenomenon occurs.
【DETAILED DESCRIPTION OF THE INVENTION】
5 【Technical Problem】
It is an object of the present disclosure to provide a battery module that effectively delays
a heat propagation speed between battery cells, and a battery pack including the same.
However, the technical problem to be solved by embodiments of the present disclosure is
not limited to the above-described problems, and can be variously expanded within the scope of
10 the technical idea included in the present disclosure.
【Technical Solution】
According to one embodiment of the present disclosure, there is provided a battery module
comprising: a plurality of battery modules including a battery cell stack in which a plurality of
15 battery cells are stacked, and a barrier layer interposed between battery cells adjacent to each other
among the plurality of battery cells, wherein the barrier layer has a different thickness in
accordance with the position.
The thickness of the barrier layer may increase toward the edge with respect to the surface
facing a body part of the battery cell.
20 The barrier layer may include a first barrier part that covers the body part of the battery cell,
and a second barrier part that extends from the first barrier part and covers a top part of the battery
cell.
A thickness of the first barrier part may be larger than a thickness of the second barrier part.
The second barrier part may be formed of a flexible material.
25 The top part of the battery cell may include a first region covered by the second barrier part
and a second region not covered by the second barrier part.
The barrier layer may further include a third barrier part that covers the end part of the battery
cell around the electrode lead protruding from the battery cell.
4 / 27
An opening through which the electrode lead passes may be formed in the third barrier part.
The barrier layer may be formed of a flame retardant member.
The barrier layer may be formed of a silicon foam pad or a mica sheet.
The barrier layer may include at least two or more, and at least two or more battery cells may
5 be located between two adjacent barrier layers among the barrier layers.
The barrier layer may cover one side of both surfaces of the battery cell, extend from an upper
side of the barrier layer and cover a portion of the other side of the battery cell.
The barrier layer may induce the direction of the flame generated in the battery cell due to the
asymmetric structure.
10 According to another embodiment of the present disclosure, there is provided a battery
pack comprising the above-mentioned battery module.
【ADVANTAGEOUS EFFECTS】
According to embodiments of the present disclosure, the barrier layer formed between a
15 pair of battery cells adjacent to each other in the battery cell stack functions as a flame retardant
member, thereby capable of delaying the heat transfer speed between adjacent battery cells when
a battery cell ignites.
Further, the barrier layer is applied not only to the body part of the battery cell but also to
the top part and lead part of the battery cell extending therefrom, thereby capable of delaying the
20 heat transfer speed into a battery cell in which no flame occurs by the cell external flame.
In addition, the barrier layer is formed so as to have a different thickness for each location,
thereby lowering the compressibility of the barrier layer during cell swelling to maximize the
performance as a flame retardant member, and thus effectively delaying the heat propagation time
between the battery cells.
25 The effects of the present disclosure are not limited to the effects mentioned above and
additional other effects not described above will be clearly understood from the description of
the appended claims by those skilled in the art.
5 / 27
【BRIEF DESCRIPTION OF THE DRAWINGS】
Fig. 1 is a perspective view of a conventional battery module;
Fig. 2 is a top view of a battery cell stack contained in a conventional battery module.
Fig. 3 (a) is a top view of the region A of Fig. 2 as viewed from above, and Fig. 3 (b) is a
5 cross-sectional view taken along the cutting surface B-B of (a);
Fig. 4 is a diagram showing a method of forming a battery cell stack according to a
comparative example;
Fig. 5 is a diagram showing a method of forming a battery cell stack included in a battery
module according to an embodiment of the present disclosure;
10 Fig. 6 is a perspective view showing one battery cell included in the battery cell stack of
Fig. 5;
Fig. 7 is a front view showing a barrier layer surrounding one battery cell included in the
battery cell stack of Fig. 5;
Fig. 8 is a perspective view showing a battery cell stack formed by combining the battery
15 cells of Fig. 5;
Fig. 9 is a plan view showing a barrier layer formed on a battery cell body part included in
a battery module according to another embodiment of the present disclosure;
Fig. 10 is a cross-sectional view taken along the cutting line P-P of Fig. 9;
Fig. 11 is a perspective view showing a barrier layer covering a battery cell according to
20 another embodiment of the present disclosure;
Fig. 12 is a perspective view of the battery cell of Fig. 11 as viewed from the surface of
opposite side by rotating 180 degrees;
Fig. 13 is a perspective view showing a battery cell stack formed by using the battery cell
and a barrier layer of Fig. 11; and
25 Fig. 14 is a perspective view showing a path through which a flame is discharged when the
battery cell ignites according to the embodiment of Fig. 11.
6 / 27
【DETAILED DESCRIPTION OF THE EMBODIMENTS】
Hereinafter, various embodiments of the present disclosure will be described in detail with
reference to the accompanying drawings so that those skilled in the art can easily implement them.
5 The present disclosure may be modified in various different ways, and is not limited to the
embodiments set forth herein.
Portions that are irrelevant to the description will be omitted to clearly describe the present
disclosure, and like reference numerals designate like elements throughout the specification.
Further, in the figures, the size and thickness of each element are arbitrarily illustrated for
10 convenience of description, and the present disclosure is not necessarily limited to those illustrated
in the figures. In the figures, the thickness of layers, regions, etc. are exaggerated for clarity. In
the figures, for convenience of description, the thicknesses of some layers and regions are shown
to be exaggerated.
In addition, it will be understood that when an element such as a layer, film, region, or
15 plate is referred to as being "on" or "above" another element, it can be directly on the other element
or intervening elements may also be present. In contrast, when an element is referred to as being
"directly on" another element, it means that other intervening elements are not present. Further,
the word "on" or "above" means disposed on or below a reference portion, and does not necessarily
mean being disposed on the upper end of the reference portion toward the opposite direction of
20 gravity. Further, throughout the specification, when a portion is referred to as "including" a certain
component, it means that the portion can further include other components, without excluding the
other components, unless otherwise stated. Further, throughout the specification, when referred
to as "planar", it means when a target portion is viewed from the upper side, and when referred to
as "cross-sectional", it means when a target portion is viewed from the side of a cross section cut
25 vertically.
Fig. 4 is a diagram showing a method of forming a battery cell stack according to a
comparative example.
7 / 27
Referring to Fig. 4, in the step of stacking the battery cells 11, they can be stacked by
interposing a compression pad 20 between battery cell 11 and battery cell 11 adjacent to each
other. After stacking the compression pad 20, stacking of the battery cells 11 can be continuously
performed again. At this time, the compression pad 20 may have a constant thickness. The
5 compression pad 20 can play a role in preventing cell swirling and can delay heat propagation to
some extent when the cell ignites. The battery cells 11 and the compression pad 20 are stacked
to form a battery cell stack, and subsequently, subjected to a lead welding process and a module
frame process to form a battery module.
Fig. 5 is a diagram showing a method of forming a battery cell stack included in a battery
10 module according to an embodiment of the present disclosure. Fig. 6 is a perspective view
showing one battery cell included in the battery cell stack of Fig. 5. Fig. 7 is a front view showing
a barrier layer surrounding one battery cell included in the battery cell stack of Fig. 5.
Referring to Fig. 5, the battery cell stack included in the battery module according to the
embodiment of the present disclosure is formed by stacking a plurality of battery cells 110, and
15 includes a barrier layer 200 interposed between battery cells 110 adjacent to each other among the
plurality of battery cells 110. The barrier layer 200 is formed of a flame retardant member. At
this time, the barrier layer 200 may be formed of a silicon foam pad or a mica sheet. The battery
module includes at least two barrier layers 200, and although not shown, at least two or more
battery cells 110 may be located between two adjacent barrier layers 200 among the barrier layers
20 200.
The battery cell 110 according to the embodiment of the present disclosure is preferably a
pouch-type battery cell. For example, referring to Fig. 6, the battery cell 110 according to the
embodiment of the present disclosure has a structure in which two electrode leads 111 and 112
face each other and protrude from one end part 114a and the other end part 14b of the battery body
25 113, respectively. The battery cell 110 can be manufactured by adhering both end parts 114a and
114b of a battery case 114 and both side surfaces 114c connecting them in a state in which an
electrode assembly (not shown) is accommodated in the battery case 114. In other words, the
8 / 27
battery cell 110 according to the embodiment of the present disclosure has a total of three sealing
parts 114sa, 114sb, 114sc, and the sealing parts 114sa, 114sb, 114sc has a structure being sealed
by a method such as heat fusion, and the other side part may be formed of a connection part 115.
A direction from end part 114a to end part 114b is defined as a longitudinal direction of the battery
5 cell 110. A direction from one side part 114c, which connects between both end parts 114a and
114b, to the connection part 115 is defined as a width direction of the battery cell 110.
The connection part 115 is a region extending long along one edge of the battery cell 110,
and a protrusion part 110p of the battery cell 110 can be formed at the end part of the connection
part 115 and can protrude in a direction perpendicular to the direction in which the connection part
10 115 extends. The protrusion part 110p may be located between one of the sealing parts 114sa and
114sb of both end parts 114a and 114b of the battery case 114 and the connection part 115.
The battery case 114 generally has a laminate structure of a resin layer/a metal thin film
layer/a resin layer. For example, when the surface of the battery case is formed of an O (oriented)-
nylon layer, it tends to slide easily due to external impact when stacking a plurality of battery cells
15 to form a medium or large-sized battery module. Therefore, in order to prevent this problem and
maintain a stable stacked structure of battery cells, a battery cell stack can be formed by attaching
an adhesive member such as a cohesive-type adhesive such as a double-sided tape or a chemical
adhesive bonded by chemical reaction during adhesion to the surface of the battery case. In the
embodiment of the present disclosure, the battery cell stack 120 can be stacked in the y-axis
20 direction.
Referring to Figs. 5 to 7, the barrier layer 200 according to the embodiment of the present
disclosure may include a first barrier part 200a that covers the body part 110B of the battery cell
110, and a second barrier part 200b that extends from the first barrier part 200a and covers the top
part 110T of the battery cell 110. The body part 110B of the battery cell 110 refers to one surface
25 of the battery cell 110 facing the y-axis direction, which is the direction in which the battery cells
110 are stacked, and the top part 110T of the battery cell 110 may be a portion corresponding to
9 / 27
one side part 114c connecting both end parts 114a and 114b of the battery case 114. In other
words, the top part 110T of the battery cell 110 may refer to the upper end part based on the width
direction of the battery cell 110.
At this time, the thickness of the first barrier part 200a may be larger than the thickness of
5 the second barrier part 200b. The second barrier part 200b can be formed of a flexible material.
The first barrier part 200a can be formed to be relatively thick, thereby increasing the flame
retardant performance of interrupting heat propagation between adjacent battery cells 110, and due
to the second barrier part 200b formed to be relatively thin, the occurrence of a gap between the
module frame accommodating the battery cell stack and the upper end of the battery cell 110 can
10 be minimized. In addition, the second barrier part 200b is formed of a flexible material, so that
the double-side folding structure of the upper end of the battery cell 110 can be closely covered.
Referring to Fig. 7, the barrier layer 200 according to the embodiment of the present
disclosure may further include a third barrier part 200c covering an end part of the battery cell 110
around the electrode leads 111 and 112 protruding from the battery cell 110. An opening 200A
15 through which the electrode leads 111 and 112 pass may be formed in the third barrier part 200c.
Fig. 8 is a perspective view showing a battery cell stack formed by combining the battery
cells of Fig. 5.
Referring to Figs. 5 to 8, the battery module including the battery cell stack according to
the embodiment of the present disclosure includes a first barrier part 200a, so that heat conduction
20 from the ignited battery cell 110 to the adjacent battery cell 110 can be interrupted when the cell
ignites. In addition, in addition to the body part 110B of the battery cell 110, the battery module
includes a second barrier part 200b covering the top part 110T and a third barrier part 200c
covering the end part of the battery cell 110 around the electrode leads 111 and 112, thereby
capable of cancelling the effect of heat conduction to the battery cell 110 in which no flame occurs
25 by the external flame. For example, referring to Fig. 8 , when ignition occurs in the first battery
10 / 27
cell 110a, heat conduction due to an external flame can be cancelled from the second battery cell
110b to which the barrier layer 200 is applied.
Fig. 9 is a plan view showing a barrier layer formed on a battery cell body part included in
a battery module according to another embodiment of the present disclosure. Fig. 10 is a cross5 sectional view taken along the cutting line P-P of Fig. 9.
Referring to Figs. 9 and 10 the barrier layer 200 according to the embodiment of the
present disclosure may have a different thickness in accordance with the position. Specifically,
the thickness of the barrier layer 200 may increase toward the edge with respect to the surface
facing the body portion 110B of the battery cell 110. Conventionally, the cell swelling
10 phenomenon caused by charging of the battery cell 110 has not been considered, and the
compression pad 20 described with reference to Fig. 4 having the same thickness in all regions has
been applied as a barrier layer. When the compression pad is compressed due to the cell swelling
phenomenon, the physical properties of the barrier layer can be changed. On the contrary,
according to the embodiment of the present disclosure, the thickness of the barrier layer 200 can
15 be differently applied for each region in consideration of the cell swelling phenomenon. Therefore,
during the cell swelling phenomenon, the compressibility of the barrier layer 200 can be lowered
to maximize the performance of the flame retardant member, thereby effectively delaying the heat
propagation time between the battery cells 110. The description of the battery cell 110 described
with reference to Figs. 5 to 8 can also be applied to the embodiment of the present disclosure. For
20 example, the thickness of the first barrier part 200a described with reference to Figs. 5 to 8 can be
formed differently in accordance with the position.
Fig. 11 is a perspective view showing a barrier layer covering a battery cell according to
another embodiment of the present disclosure. Fig. 12 is a perspective view of the battery cell of
Fig. 11 as viewed from the surface of opposite side by rotating 180 degrees. Fig. 13 is a perspective
25 view showing a battery cell stack formed by using the battery cell and a barrier layer of Fig. 11.
11 / 27
Fig. 14 is a perspective view showing a path through which a flame is discharged when the battery
cell ignites according to the embodiment of Fig. 11.
Referring to Figs. 11 and 12, the barrier layer 200 can cover one side of both surfaces of
the battery cell 110, extend from the upper side of the barrier layer 200 and cover a portion of the
5 other side of the battery cell 110. At this time, the top part 110T of the battery cell 110 may
include a first region P1 covered by the second barrier part 200b and a second region P2 not
covered by the second barrier part 200b. At this time, the third barrier part 200c may be formed
only at one end of the battery cell 110 adjacent to the first region P1.
Meanwhile, the first region P1 may be a partial region in the longitudinal direction covered
10 by the second barrier part 200b of the top part 110T of the battery cell 110. The first region P1
and the second region P2 may be located at different positions in the longitudinal direction of the
battery cell 110. The first region P1 may be adjacent to one end of the battery cell 110, and the
second region P2 may be adjacent to the other end of the battery cell 110.
The barrier layer 200 according to the embodiment of the present disclosure may induce
15 the direction of the flame generated in the battery cell 110 due to the asymmetric structure. For
example, by forming the top part 110T of the battery cell 110 including the first region P1 and the
second region P2, the flame may be induced in the left direction of the battery cell 110 as shown
in Fig. 14.
As described in the embodiments of Figs. 5 to 7, the thickness of the first barrier part 200a
20 may be larger than the thickness of the second barrier part 200b. The second barrier part 200b
may be formed of a flexible material. The first barrier portion 200a is formed to be relatively
thick, thereby capable of increasing the flame retardant performance of interrupting heat
propagation between adjacent battery cells 110, and due to the second barrier part 200b formed to
be relatively thin, the occurrence of a gap between the upper end of the battery cell 110 and the
25 module frame accommodating the battery cell stack can be minimized. In addition, the second
barrier part 200b can be formed of a flexible material so as to closely cover the double-side folding
12 / 27
structure of the upper end of the battery cell 110. If there is a gap between the second barrier part
200b covering the upper end of the battery cell 110 and the upper end of the module frame,
induction of the flame direction may not be performed well.
Referring to Fig. 13, the battery cell stack 120 according to the embodiment of the present
5 disclosure may include a plurality of battery cells 110 covered by the barrier layer 200. Because
it is difficult to know which of the battery cells 110 is ignited among the stacked battery cells 110,
a plurality of battery cells 110 covered by the barrier layer 200 can be applied to design flame
induction and heat propagation interruption.
Meanwhile, one or more of the battery modules according to embodiments of the present
10 disclosure can be packaged in a pack case to form a battery pack.
The above-mentioned battery module and a battery pack including the same may be applied
to various devices. These devices can be applied to vehicle means such as an electric bicycle, an
electric vehicle, a hybrid vehicle, but the present disclosure is not limited thereto and can be
applied to various devices that can use the battery module and the battery pack including the same,
15 which also belongs to the scope of the present disclosure.
Although the preferred embodiments of the present disclosure have been described in detail
above, the scope of the present disclosure is not limited thereto, and various modifications and
improvements made by those skilled in the art using the basic concepts of the present disclosure
defined in the following claims also belong to the scope of rights.
20 [Description of Reference Numerals]
110: battery cell 110B: body part
110T: top part 120: battery cell stack
200: barrier layer 200a: first barrier part
200b: second barrier part 200c: third barrier part

【CLAIMS】
【Claim 1】
A battery module comprising:
a battery cell stack in which a plurality of battery cells are stacked, and
5 a barrier layer interposed between battery cells adjacent to each other among the plurality of
battery cells,
wherein the barrier layer has a different thickness in accordance with the position.
【Claim 2】
The battery module of claim 1, wherein:
10 the thickness of the barrier layer increases toward the edge with respect to the surface facing
a body part of the battery cell.
【Claim 3】
The battery module of claim 1, wherein:
the barrier layer comprises a first barrier part that covers the body part of the battery cell, and
15 a second barrier part that extends from the first barrier part and covers a top part of the battery cell.
【Claim 4】
The battery module of claim 3, wherein:
a thickness of the first barrier part is larger than a thickness of the second barrier part.
【Claim 5】
20 The battery module of claim 4, wherein:
the second barrier part is formed of a flexible material.
【Claim 6】
The battery module of claim 5, wherein:
the top part of the battery cell comprises a first region covered by the second barrier part and
25 a second region not covered by the second barrier part.
【Claim 7】
The battery module of claim 3, wherein:
the barrier layer further comprises a third barrier part that covers the end part of the battery
14 / 27
cell around the electrode lead protruding from the battery cell.
【Claim 8】
The battery module of claim 7, wherein:
an opening through which the electrode lead passes is formed in the third barrier part.
5 【Claim 9】
The battery module of claim 1, wherein:
the barrier layer is formed of a flame retardant member.
【Claim 10】
The battery module of claim 9, wherein:
10 the barrier layer is formed of a silicon foam pad or a mica sheet.
【Claim 11】
The battery module of claim 1, wherein:
the barrier layer comprises at least two or more, and at least two or more battery cells are
located between two adjacent barrier layers among the barrier layers.
15 【Claim 12】
The battery module of claim 1, wherein:
the barrier layer covers one side of both surfaces of the battery cell, extends from an upper
side of the barrier layer and covers a portion of the other side of the battery cell.
【Claim 13】
20 The battery module of claim 12, wherein:
the barrier layer induces the direction of the flame generated in the battery cell due to the
asymmetric structure.
【Claim 14】
A battery pack comprising the battery module of claim 1.