FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)
TITLE OF INVENTION:
HEAT SINK AND BATTERY MODULE INCLUDING THE SAME

APPLICANT:
LG CHEM, LTD.
A Company incorporated in South Korea
Having address:
128, Yeoui-daero Yeongdeungpo-gu Seoul 07336
Republic of Korea
The following specification describes the invention and the manner in which it is
to be performed.

CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY
The present application claims priority from PCT application Number
PCT/KR2016/013088 filed on November 14, 2016 further claims priority from
Korean Patent Application No. 10-2015-0163174 filed on November 20, 2015 in
the Republic of Korea, the disclosures 5 of which are incorporated herein by
reference.
The present disclosure relates to a heat sink having improved space utilization and
a battery module including the same.

BACKGROUND ART
10 A secondary battery which has ease with applicability for various product groups and
good electric characteristics such as high energy density is universally applied not
only to portable devices but also electric vehicles (EV), hybrid electric vehicles
(HEV), energy storage systems or the like, which are driven by an electric source.
The secondary battery has a primary advantage of greatly reducing the use of fossil
15 fuels and a secondary advantage of generating no byproduct after the use of energy,
and thus the secondary battery receives attention as a new energy source which is
environment-friendly and promotes energy efficiency.
A battery pack applied to an electric vehicle or the like includes a plurality of cell
assembly connected in series, each cell assembly having a plurality of unit cells, in
20 order to obtain high output. In addition, the unit cell includes positive and negative
electrode current collectors, a separator, active materials, an electrolyte or the like
and is capable of being repeatedly charged and discharged by means of
electrochemical reactions among the components.
Meanwhile, recently, as the necessity for a large-capacity structure to be utilized as
25 an energy storage is increasing, the demand for a battery pack having a multimodule
structure in which a plurality of modules are aggregated is also increasing.
In the battery pack of a multi-module structure, a plurality of secondary batteries is
densely arranged in a narrow space, and thus it is important to easily emit heat
generated from each battery module.
In order to cool the battery pack, an indirect water-cooling method is used.
The indirect water-cooling method is used for preventing a battery module from
generating heat by using a heat sink with a cooling channel, and 5 in general case, a
single heat sink is coupled to a lower end of the battery module to absorb heat of the
battery module.
FIGS. 1 and 2 are diagrams showing an existing heat sink applied for the indirect
water-cooling method.
10 Referring to FIGS. 1 and 2, the existing heat sink 1 is coupled to a lower surface of a
cell assembly 2 to cool the cell assembly 2. A cooling channel is formed in the heat
sink 1, and a coolant inflow tube 3 and a coolant outlet tube 4 are also formed
thereat. If a coolant flows into the coolant inflow tube 3, the coolant circulates
along the cooling channel formed in the heat sink 1 to cool the cell assembly 2 and
15 flows out through the coolant outlet tube 4.
However, the existing heat sink using the indirect water-cooling method has a
problem in that its structure increases the entire height of a battery pack. In other
words, since the upper surface of the existing heat sink 1 is closely coupled to a
lower surface of the cell assembly 2, the entire height of the battery pack increases.
20 In addition, if the upper surface of the heat sink 1 is coupled to the lower surface of
the cell assembly 2, a differential pressure increases at the coolant inflow tube 3 and
the coolant outlet tube 4. In detail, since the heat sink 1 is closely coupled to the
lower surface of the cell assembly 2, the coolant inflow tube 3 and the coolant outlet
tube 4 are respectively bent twice, and due to such a bending structure, a differential
25 pressure increases at the bent portions. In other words, the coolant inflow tube 3
and the coolant outlet tube 4 are firstly bent from a vertical direction to a horizontal
direction and then secondly bent from the horizontal direction to the vertical
direction, and due to such several bent portions, a differential pressure increases at
the coolant inflow tube 3 and the coolant outlet tube 4.
DISCLOSURE
5 Technical Problem
The present disclosure is designed to solve the problems of the related art, and
therefore the present disclosure is directed to providing a heat sin which may have
improved space utilization, and a battery module including the same.
In addition, the present disclosure is also directed to providing a heat sink which
10 may have a reduced differential pressure by minimizing bending of a coolant
inflow tube and a coolant outlet tube, and a battery module including the same.
These and other objects and advantages of the present disclosure may be
understood from the following detailed description and will become more fully
apparent from the exemplary embodiments of the present disclosure. Also, it
15 will be easily understood that the objects and advantages of the present disclosure
may be realized by the means shown in the appended claims and combinations
thereof.
Technical Solution
In one aspect of the present disclosure, there is provided a heat sink for cooling a
20 cell assembly including at least one unit cell, the heat sink comprising: a first heat
sink coupled to one side of the cell assembly and having a first cooling channel
through which a coolant passes; and a second heat sink coupled to the other side
of the cell assembly and having a second cooling channel through which the
coolant passes.
25 The second heat sink may include a coolant inflow tube connected to one end of
the second cooling channel, and the first heat sink may include a coolant outlet
tube connected to one end of the first cooling channel. The other end of the
second cooling channel may be connected to a coolant connection tube, and the
other end of the first cooling channel may be connected to the coolant connection
tube.A second connection port may be formed at the other end of the second cooling
channel so that the other end of the second cooling channel is connected to the
5 coolant connection tube through the second connection port.
Also, a first connection port may be formed at the other end of the first cooling
channel so that the other end of the first cooling channel is connected to the
coolant connection tube through the first connection port.
The coolant flowing in through the coolant inflow tube may pass through the
10 second cooling channel, the coolant connection tube and the first cooling channel,
and then flow out through the coolant outlet tube.
The coolant inflow tube and the coolant outlet tube may be bent downwards, so
that a coolant inlet and a coolant outlet are formed at adjacent locations.
In an embodiment, the coolant outlet tube may extend horizontally toward the
15 second heat sink and be bent downwards at a point adjacent to the second heat
sink.
In another embodiment, the coolant inflow tube may extend horizontally toward
the first heat sink and be bent downwards at a point adjacent to the first heat sink.
20 Advantageous Effects
In the present disclosure, since heat sinks are coupled to both sides of a cell
assembly, a Z-axial space of a battery pack may be ensured without increasing the
height of the battery pack.
In particular, in the present disclosure, since a plurality of heat sinks is designed to
25 commonly use a single coolant inflow tube and a single coolant outlet tube, it is
possible to further enhance space utilization of the battery module and reduce
manufacture costs of the battery module.
In addition, in the present disclosure, since the cell assembly is cooled by means
of a plurality of heat sinks installed at both sides thereof, it is possible to improve
the cooling efficiency of the battery module in comparison to an existing indirect
5 water-cooling method.
Further, in the present disclosure, since bending of the coolant inflow tube and the
coolant outlet tube is minimized, it is possible to reduce a differential pressure
occurring in the coolant inflow tube and the coolant outlet tube.
10 DESCRIPTION OF DRAWINGS
The accompanying drawings illustrate a preferred embodiment of the present
disclosure and together with the foregoing disclosure, serve to provide further
understanding of the technical spirit of the present disclosure, and thus, the
present disclosure is not construed as being limited to the drawing.
15 FIGS. 1 and 2 are diagrams showing an existing heat sink using an indirect watercooling
method.
FIG. 3 is an exploded view showing a cell assembly and a heat sink according to
an embodiment of the present disclosure.
FIG. 4 is a diagram showing a battery module to which the cell assembly and the
20 heat sink are coupled according to an embodiment of the present disclosure.
BEST MODE
The above objects, features and advantages of the present disclosure will become
apparent from the following descriptions of the embodiments with reference to the
25 accompanying drawings, from which it will be deemed that a person having
ordinary skill can easily practice the technical features of the present disclosure.
Also, any explanation of the prior art known to relate to the present disclosure
may be omitted if it is regarded to render the subject matter of the present
disclosure vague. Hereinafter, an embodiment of the present disclosure will be
described in detail with reference to the accompanying drawings.
FIG. 3 is an exploded view showing a cell assembly 5 and a heat sink according to
an embodiment of the present disclosure.
FIG. 4 is a diagram showing a battery module to which the cell assembly and the
heat sink are coupled according to an embodiment of the present disclosure.
Referring to FIGS. 3 and 4, a battery module 100 according to the present
10 disclosure includes a cell assembly 110 and a plurality of heat sinks 120, 130.
The cell assembly 110 is a module in which a plurality of unit cells 111 are
stacked laterally and connected in series or in parallel, and electrode leads may be
exposed at its sides.
The unit cell 111 is configured so that cells, each having a negative electrode plate,
15 a separator and a positive electrode plate, are repeatedly stacked.
The cell assembly 110 includes at least one unit cell 111, and the kind of the unit
cell is not specially limited. Each unit cell 111 may be configured with a lithium
ion battery cell, a lithium polymer battery cell, a nickel cadmium battery cell, a
nickel hydrogen battery cell, a nickel zinc battery cell or the like, which is
20 rechargeable and also needs to consider a charge or discharge voltage. In
addition, the number of unit cells 111 included in the cell assembly 110 may be
set variously depending on a demanded output voltage or charge/discharge
capacity. However, the present disclosure is not limited by the kind, output
voltage, charge/discharge capacity or the lie of the unit cell 111. In addition, the
25 present disclosure is not limited by an electric connection method of the unit cell
111. Each of the heat sinks 120, 130 is used for cooling the cell assembly 110 in an
indirect water-cooling method and is made of a material with excellent thermal
conductivity (for example, aluminum or the like). Also, cooling channels 122,
132 serving as passages of the coolant are formed in the heat sinks 120, 130.
The cooling channels 122, 132 formed in each 5 of the heat sinks 120, 130 may be
shaped as shown in FIGS. 3 and 4 in the heat sinks 120, 130, or cooling channels
122, 132 of various shapes may also be formed in each of the heat sinks 120, 130.
In addition, cooling channels of different shapes may be formed in the first heat
sink 120 and the second heat sink 130.
10 A plurality of through holes 121 is formed in the first heat sink 120 so that a
coupling member such as a bolt may be inserted therein, and if the coupling
member is inserted into and coupled to the through hole 121, the first heat sink
120 is closely coupled to one side of the cell assembly 110. The first heat sink
120 is coupled to one side of the cell assembly 110 to absorb and dissipate heat
15 energy generated at the unit cell 111 of the cell assembly 110 by means of the
coolant flowing through the cooling channel 122.
A coolant outlet tube 124 is formed at one end of the cooling channel 122 of the
first heat sink 120, and a connection port 123 is formed at the other end of the
cooling channel 122.
20 The coolant outlet tube 124 may be designed with a pipe shape of a predetermined
length, and has a space therein so that the coolant may flow. One end of the
coolant outlet tube 124 is connected to one end of the cooling channel 122, and a
coolant outlet b is formed at the other end of the coolant outlet tube 124.
In addition, one end of the coolant outlet tube 124 may also be connected to one
25 end of the cooling channel 122 by means of welding, coupling or the like. In
addition, the coolant outlet tube 124 and the cooling channel 122 may also be
integrally fabricated.
The connection port 123 formed at the other end of the cooling channel 122 of the
first heat sink 120 is coupled to the coolant connection tube 140 by means of
welding, coupling or the like, thereby forming a passage for the coolant between
the cooling channel 122 and the coolant connection tube 140. The coolant
transferred through the coolant 5 connection tube 140 flows into the cooling
channel 122 of the first heat sink 120.
The coolant outlet tube 124 extends horizontally toward the second heat sink 130,
and is bent in a vertical direction at a point adjacent to the second heat sink 130
and then extends again, so that the coolant outlet b is adjacent to a coolant inlet a.
10 Since the coolant outlet b and the coolant inlet a are located adjacent to each other,
it is easier to control flowing-in and flowing-out of the coolant. In addition,
since the coolant outlet tube 124 is bent once in a downward direction, the number
of bending is reduced in comparison to an existing heat sink, and thus a
differential pressure in the coolant outlet tube 124 is also reduced.
15 By means of the connection structure of the coolant outlet tube 124 and the
cooling channel 122 of the first heat sink 120, the coolant circulating through the
cooling channel 122 of the first heat sink 120 flows out through the coolant outlet
tube 124.
Similarly, a plurality of through holes 131 is formed in the second heat sink 130
20 so that a coupling member such as a bolt may be inserted therein, and if the
coupling member is inserted into and coupled to the through hole 131, the second
heat sink 130 is closely coupled to the other side of the cell assembly 110. The
first heat sink 120 is coupled to one side of the cell assembly 110, and the second
heat sink 130 is coupled to the other side of the cell assembly 110, which is
25 opposite to one side thereof, to absorb and dissipate heat energy generated at the
unit cell 111 of the cell assembly 110 by means of the coolant flowing through the
cooling channels 122, 132.
A coolant inflow tube 134 is formed at one end of the cooling channel 132 of the
second heat sink 130, and a connection port 133 is formed at the other end of the
cooling channel 132.
The coolant inflow tube 134 may be designed with a pipe shape of a
predetermined length, and has a space therein so that the coolant may flow. One
end of the coolant inflow tube 134 is coupled to one end of the cooling channel
132, and a coolant inlet a is formed 5 at the other end of the coolant inflow tube 134.
One end of the coolant inflow tube 134 may be connected to one end of the
cooling channel 132 by means of welding, coupling or the like. In addition, the
coolant inflow tube 134 and the cooling channel 132 may also be integrally
fabricated.
10 The connection port 133 formed at the other end of the cooling channel 132 of the
second heat sink 130 is coupled to the coolant connection tube 140 by means of
welding, coupling or the like, thereby forming a passage for the coolant between
the cooling channel 132 and the coolant connection tube 140 and also providing
the coolant circulating through the cooling channel 132 to the coolant connection
15 tube 140.
The coolant inflow tube 134 is bent into a vertical downward direction and
extends so that the coolant inlet a is formed downwards. In particular, since the
coolant inflow tube 134 is bent just once, the number of bending is reduced in
comparison to an existing heat sink, and thus a differential pressure in the coolant
20 outlet tube 134 is also reduced.
By means of the connection structure of the coolant inflow tube 134, the cooling
channel 132 of the second heat sink 130 and the coolant connection tube 140, the
coolant flowing in through the coolant inlet a passes through the cooling channel
132 of the second heat sink 130 and the coolant connection tube 140.
25 In addition, by means of the connection structure of the first heat sink 120, the
second heat sink 130 and the coolant connection tube 140, the battery module 100
including a plurality of heat sinks 120, 130 has just a single coolant inlet a, a
single coolant inflow tube 134, a single coolant outlet b and a single coolant outlet
tube 124. In other words, a single coolant inlet a, a single coolant inflow tube
134, a single coolant outlet b and a single coolant outlet tube 124 are commonly
used for the first heat sink 120 and the second heat sink 130.
The coolant flowing into the coolant inflow tube 134 absorbs heat of the unit cells
111 while passing through the cooling 5 channel 132 of the second heat sink 130,
the coolant connection tube 140, and the cooling channel 122 of the first heat sink
120, and then flows out through the coolant outlet tube 124.
Meanwhile, in the above embodiment, it has been described that the coolant outlet
tube 124 extends horizontally toward the second heat sink 130 and is bent into a
10 vertical downward direction at a point adjacent to the second heat sink 130 so that
the coolant outlet b and the coolant inlet a are adjacent to each other. However,
it is also possible that the coolant inflow tube 134 extends horizontally toward the
first heat sink 120, and is bent into a vertical downward direction at a point
adjacent to the first heat sink 120 and vertically extends downwards.
15 In other words, as another embodiment, the coolant outlet tube 124 may be
directly bent into a vertical downward direction without extending horizontally,
and also the coolant inflow tube 134 may extends horizontally toward first heat
sink 120 and is bent into a vertical downward direction at a point adjacent to the
first heat sink 120. In another embodiment, the coolant inlet and the coolant
20 outlet may be located adjacent to the first heat sink 120. In still another
embodiment, both the coolant outlet tube 124 and the coolant inflow tube 134 may extend horizontally and are then bent into a vertical downward direction at a specific point (for example, an intermediate point between the first heat sink and the second heat sink) and extends, so that the coolant inlet and the coolant outlet
25 are located adjacent to each other.
The battery module 100 according to an embodiment of the present disclosure
may be used as a component of a battery pack including a plurality of battery
modules and a battery management system for controlling charge/discharge of the
battery modules. The battery pack according to an embodiment of the present
disclosure may be used as a component of a battery-driven system including the
battery pack and a load which is supplied with power from the battery pack.
The battery-driven system may be an electric vehicle (EV), a hybrid electric
vehicle (HEV), an electric bike (E-Bike), a power tool, an energy storage system,
an uninterrupted power supply, a 5 portable computer, a portable phone, a portable
audio device, a portable video device or the like. The load may be a motor for
giving a rotational force by the power supplied from the battery pack or a power
conversion circuit for converting the power supplied from the battery pack into a
power necessary to various circuit components.
10 As described above, in the battery module 100 according to an embodiment of the
present disclosure, since the heat sinks 120, 130 are coupled to both sides of the
cell assembly 110, a Z-axial space of a battery pack may be ensured without
increasing the height of the battery pack. In addition, in the battery module 100
according to an embodiment of the present disclosure, since a plurality of heat
15 sinks 120, 130 is designed to commonly use a single coolant inflow tube 134 and
a single coolant outlet tube 124, it is possible to further enhance space utilization
and reduce manufacture costs of the battery module. Moreover, since the cell
assembly 110 of the battery module 100 is cooled by means of the plurality of
heat sinks 120, 130 installed at both sides thereof, it is possible to improve the
20 cooling efficiency in comparison to an existing indirect water-cooling method.
Further, in the battery module 100, since bending of the coolant inflow tube 134
and the coolant outlet tube 124 is minimized, it is possible to reduce a differential
pressure occurring in the coolant inflow tube 134 and the coolant outlet tube 124.
It should be understood by those skilled in the art that many adaptations,
25 modifications and changes may be made to the present disclosure without
departing from the technical aspects of the present disclosure, and the present
disclosure described hereinabove is not limited by the disclosed embodiments and
the accompanying drawings.

WE CLAIM:
1. A heat sink for cooling a cell assembly including at least one unit cell, the
heat sink comprising:
a first heat sink coupled to one side of the 5 cell assembly and having a first
cooling channel through which a coolant passes; and a second heat sink coupled to the other side of the cell assembly and having a
second cooling channel through which the coolant passes.
10 2. The heat sink according to claim 1,
wherein the second heat sink includes a coolant inflow tube connected to one
end of the second cooling channel,
wherein the first heat sink includes a coolant outlet tube connected to one end
of the first cooling channel, and
15 wherein the other end of the second cooling channel is connected to a coolant
connection tube, and the other end of the first cooling channel is connected to
the coolant connection tube.
3. The heat sink according to claim 2,
20 wherein a second connection port is formed at the other end of the second
cooling channel so that the other end of the second cooling channel is connected to the coolant connection tube through the second connection port, and wherein a first connection port is formed at the other end of the first cooling 25 channel so that the other end of the first cooling channel is connected to the
coolant connection tube through the first connection port.
4. The heat sink according to claim 2,
wherein the coolant flowing in through the coolant inflow tube passes
30 through the second cooling channel, the coolant connection tube and the first
cooling channel, and then flows out through the coolant outlet tube.
5. The heat sink according to claim 2,
wherein the coolant inflow tube and the coolant outlet tube are bent
downwards, so that a coolant inlet and a coolant outlet are formed at adjacent
locations.
6. The heat sink according to claim 5,
wherein the coolant outlet tube extends horizontally toward the second heat
sink and is bent downwards at a point adjacent to the second heat sink.
10 7. The heat sink according to claim 5,
wherein the coolant inflow tube extends horizontally toward the first heat
sink and is bent downwards at a point adjacent to the first heat sink.
8. A battery module, comprising:
15 a first heat sink coupled to one side of a cell assembly and having a first
cooling channel through which a coolant passes;
a second heat sink coupled to the other side of the cell assembly and having a
second cooling channel through which the coolant passes; and the cell assembly to both sides of which the first heat sink and the second heat
20 sink are coupled, respectively.