TECHNICAL FIELD
The present disclosure relates to a battery module having a cooling structure using
insulating oil and a battery pack and a vehicle including the battery module, and more
10 particularly, to a battery module having a structure in which insulating oil introduced into a
module housing flows through a space between an edge of a battery cell and the module
housing to cool battery cells, and a battery pack and a vehicle including the battery module.
The present application claims priority to Korean Patent Application No. 10-2020-
0153016 filed on November 16, 2020 in the Republic of Korea, the disclosures of which are
15 incorporated herein by reference.
BACKGROUND ART
In the case of a battery module using an indirect water cooling method using cooling
water, because cooling water does not directly contact a battery cell but indirectly contacts
20 the battery cell through a module housing in which the battery cell is accommodated, there
is a limit to its cooling performance. Also, because a cooling device such as a separate heat
sink should be provided outside the module housing to form a passage for cooling, a volume
of the battery module is inevitably increased, which may cause loss in terms of energy
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density.
In order to solve the problems of the indirect water cooling method, there is a need
to develop a battery module having a cooling structure in which insulating oil for cooling
may be directly introduced into a module housing and may directly contact a battery cell.
5 In the case of a battery module having a direct cooling structure using insulating oil,
it is very important to secure a fluid passage structure for efficient cooling, and maintain
airtightness so that insulating oil does not leak to the outside of a module housing and an end
plate.
10 DISCLOSURE
Technical Problem
The present disclosure is designed to solve the problems of the related art, and
therefore the present disclosure is directed to securing a path through which insulating oil
introduced into a module housing passes through a bus bar frame assembly, smoothly moves
15 toward a cell stack assembly, and smoothly flows in a longitudinal direction of a battery
module.
However, the technical purpose to be solved by the present disclosure is not limited
to the above, and other objects not mentioned herein will be clearly understood by one of
ordinary skill in the art from the following disclosure.
20
Technical Solution
In one aspect of the present disclosure, there is provided a battery module including:
a sub-module including a cell stack assembly including a plurality of battery cells and a
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cooling fin located between adjacent battery cells, a front bus bar frame assembly coupled
to a side of the cell stack assembly in a longitudinal direction of the cell stack assembly, and
a rear bus bar frame assembly coupled to the other side of the cell stack assembly in the
longitudinal direction of the cell stack assembly; a module housing in which the sub-module
5 is accommodated; a front sealing plate covering an opening portion formed on a side of the
module housing in a longitudinal direction of the module housing and including an insulating
oil inlet; and a rear sealing plate covering an opening portion formed on the other side of the
module housing in the longitudinal direction of the module housing and including an
insulating oil outlet.
10 The cooling fin may include: a body contact portion located between adjacent
battery cells; and an edge cover portion bent at any one of an upper end and a lower end of
the body contact portion to cover an edge of the battery cell.
The front bus bar frame assembly and the rear bus bar frame assembly may include
a plurality of insulating oil holes formed at positions corresponding to insulating oil passages
15 formed between the module housing and an edge of the battery cell and between the edge
cover portion and an edge of the battery cell.
Insulating oil introduced through the insulating oil inlet into the module housing
may pass through the insulating oil hole formed in the front bus bar frame assembly and may
be introduced into the insulating oil passage.
20 The insulating oil passing through the insulating oil passage may pass through the
insulating oil hole formed in the rear bus bar frame assembly, and may be discharged to
outside of the module housing through the insulating oil outlet.
The front bus bar frame assembly and the rear bus bar frame assembly may include
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guide ribs respectively formed at an upper end and a lower end and extending toward the
cell stack assembly.
The cooling fin may further include a pair of fixing portions each having a shape
corresponding to the guide rib, formed on both end portions of the edge cover portion in a
5 longitudinal direction of the edge cover portion, and each coupled to the guide rib.
The battery module may further include a pair of terminal assemblies each including
an external terminal located outside the front sealing plate, and a stud passing through the
front sealing plate and configured to electrically connect the external terminal to the battery
cell.
10 The front bus bar frame assembly may include: a bus bar frame; a plurality of bus
bars fixed to the bus bar frame, and connected to an electrode lead of the battery cell; and a
pair of internal terminals each fixed to the bus bar frame, and connected to an electrode lead
of the battery cell located at an outermost position from among the battery cells provided in
the cell stack assembly.
15 The terminal assembly may further include a terminal spacer inserted into a terminal
hole formed in the front sealing plate, wherein the stud is fixed to the internal terminal and
passes through the terminal spacer.
The terminal assembly may further include a fastening nut fastened to the stud
passing through the terminal spacer and the external terminal and configured to closely fix
20 the external terminal to the terminal spacer.
The terminal assembly may further include a first O-ring covering an outer
circumferential surface of the terminal spacer and located between an inner surface of the
front sealing plate and the internal terminal.
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The stud may be press-fitted by passing through the internal terminal, wherein the
terminal assembly further includes a second O-ring located around the stud and located
between the internal terminal and the bus bar frame.
In another aspect of the present disclosure, there are also provided a battery pack
5 and a vehicle including the battery module.
Advantageous Effects
According to an aspect of the present disclosure, insulating oil introduced into a
module housing may pass through a bus bar frame assembly, may smoothly move toward a
10 cell stack assembly, and may smoothly flow in a longitudinal direction of a battery module
in the module housing. Also, according to an aspect of the present disclosure, leakage of
insulating oil flowing inside a module housing may be effectively prevented.
DESCRIPTION OF DRAWINGS
15 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 features of the present disclosure, and thus, the present disclosure is not
construed as being limited to the drawing.
FIG. 1 is a perspective view illustrating a battery module according to an
20 embodiment of the present disclosure.
FIG. 2 is an exploded perspective view illustrating the battery module according to
an embodiment of the present disclosure.
FIG. 3 is a cross-sectional view taken along line A-A’ of FIG. 1.
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FIG. 4 is a view illustrating a state where a front end plate and a front sealing plate
are removed in the battery module of FIG. 1.
FIGS. 5 and 6 are views illustrating a flow of insulating oil for cooling.
FIGS. 7 and 8 are views illustrating a coupling relationship between a cooling fin
5 and a battery cell according to the present disclosure.
FIG. 9 is a perspective view illustrating a cooling fin according to the present
disclosure.
FIG. 10 is a view illustrating a coupling structure between a bus bar frame assembly
and a cooling fin according to the present disclosure.
10 FIGS. 11 and 12 are views illustrating a structure of a terminal assembly according
to the present disclosure.
BEST MODE
Hereinafter, preferred embodiments of the present disclosure will be described in
15 detail with reference to the accompanying drawings. Prior to the description, it should be
understood that the terms used in the specification and the appended claims should not be
construed as limited to general and dictionary meanings, but interpreted based on the
meanings and concepts corresponding to technical aspects of the present disclosure on the
basis of the principle that the inventor is allowed to define terms appropriately for the best
20 explanation. Therefore, the description proposed herein is just a preferable example for the
purpose of illustrations only, not intended to limit the scope of the disclosure, so it should
be understood that other equivalents and modifications could be made thereto without
departing from the scope of the disclosure.
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Referring to FIGS. 1 and 2, a battery module according to an embodiment of the
present disclosure includes a sub-module 100, a module housing 200, a front sealing plate
300, a rear sealing plate 400, and a pair of terminal assemblies 700, and may further include
a front end plate 500 and a rear end plate 600.
5 Referring to FIGS. 2 through 9, the sub-module 100 includes a cell stack assembly
110, a front bus bar frame assembly 120A, and a rear bus bar frame assembly 120B.
The cell stack assembly 110 includes a plurality of battery cells 111 and a plurality
of cooling fins 112 located between adjacent battery cells 111, and may further include at
least one buffer pad 113 located between adjacent battery cells 111. The battery cell 111,
10 the cooling fin 112, and the buffer pad 113 are stacked upright in a direction perpendicular
to the ground (surface parallel to an X-Y plane) to constitute one cell stack assembly 110.
The battery cell 111 may be a pouch-type battery cell including a pair of electrode
leads 111a drawn out in opposite directions in a longitudinal direction (direction parallel to
an X-axis).
15 Referring to FIGS. 7 through 9, the cooling fin 112 includes a body contact portion
112a located between adjacent battery cells 111 and an edge cover portion 112b bent at any
one of an upper end and a lower end of the body contact portion 112a to cover an edge of
the battery cell 111. Edges of the battery cell 111 refer to both side surfaces of a body of
the battery cell 111 in a width direction, that is, in a height direction (direction parallel to a
20 Z-axis) of the battery module. Also, the cooling fin 112 may further include a pair of fixing
portions 112c formed on both end portions of the edge cover portion 112b in a longitudinal
direction (direction parallel to the X-axis) of the edge cover portion 112b.
The body contact portion 112a is located between bodies of a pair of adjacent battery
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cells 111 and directly contacts the bodies of the battery cells 111. The body contact portion
112a is configured to rapidly conducts heat generated from a body of the battery cell 111,
that is, a region where an electrode assembly (not shown) is accommodated, in a width
direction of the cooling fin 112, that is, the height direction (direction parallel to the Z-axis)
5 of the battery module, toward the edge cover portion 112b. As such, the heat conducted
toward the edge cover portion 112b moves in a longitudinal direction (direction parallel to
the X-axis) of the battery module due to insulating oil flowing through an insulating oil
passage P formed between the edge of the battery cell 111 and the edge cover portion 112b
and is discharged to the outside of the battery module.
10 The edge cover portion 112b may not only form the insulating oil passage P as
described above but also, when external impact is applied and the cell stack assembly 110
moves in a vertical direction (direction parallel to the Z-axis) in the module housing 200,
may absorb the external impact.