FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10, rule 13)
“BATTERY MODULE”
LG CHEM, LTD., of 128, Yeoui-daero, Yeongdeungpo-gu, Seoul
07336, Republic of Korea
The following specification particularly describes the invention and the manner in which it is to
be performed.
1
【DESCRIPTION】
【Invention Title】
BATTERY MODULE
【Technical Field】
The present specification claims benefit of priority based 5 on Korean Patent
Application No. 10-2015-0028505 (Feb. 27, 2015), and all contents disclosed in the
corresponding Korean patent document are included as a part of the present
specification.
【Background Art】
10 Secondary batteries include nickel cadmium, nickel hydride, nickel zinc,
lithium secondary batteries, and the like, and the typical battery is the lithium
secondary battery.
A lithium oxide and a carbon material are widely used as a positive active
material and a negative active material of the lithium secondary battery, respectively.
15 The lithium secondary battery includes an electrode assembly in which positive and
negative plates respectively coated with the positive active material and the negative
active material are disposed with a separator interposed therebetween and an exterior
material that seals and accommodates the electrode assembly with an electrolyte and
can be classified into a can type secondary battery and a pouch type secondary
20 battery according to the shape of the exterior material. In the present specification,
a single secondary battery can be referred to as a battery cell.
When the secondary batteries are used for medium and large equipment such
as vehicles or power storage systems, many battery cells are electrically connected to
each other to form a battery module or a battery pack to increase capacity and output.
2
To form battery modules or battery packs in which the plurality of battery
modules are connected, various coupling elements or cooling devices are required.
Accordingly, such coupling elements or cooling devices lead to an increase in
manufacturing cost, volume, and weight of the battery modules or the battery packs
and lead to a decrease in output for the increased 5 volume and weight.
【Disclosure】
【Technical Problem】
The present invention is directed to providing a battery module.
【Technical Solution】
10 One aspect of the present invention provides a battery module including a
module case and a battery cell. The battery case may be accommodated in the
module case. One or more battery cells may be provided in the module case, and a
plurality of battery cells may be accommodated in the module case. The number of
battery cells is adjusted according to use and the like and is not specifically limited.
15 The battery cells accommodated in the module case may be electrically connected to
each other.
The module case may include at least a sidewall and a lower plate forming an
inside space in which the battery cell is accommodated. The module case may
further include an upper plate that seals the inside space. The sidewall, the lower
20 plate, and the upper plate may be integrally formed or the separate sidewall, lower
plate, and/or upper plate may be assembled to form the module case. The shape and
size of such a module may not be specifically limited and may be suitably selected
according to the use, shape, and number of battery cells accommodated in the inside
space
3
FIG. 1 is a schematic view illustrating an example of a module case (10) in a
box shape including one lower plate (10a) and four sidewalls. The module case
(10) may further include an upper plate (10c) that seals the inside space of the
module case (10).
FIG. 2 is a schematic top view illustrating the module case 5 (10) shown in FIG.
1, in which battery cells (20) are accommodated.
Holes may be formed in the lower plate, the sidewall, and/or the upper plate
(hereinafter may be referred to as the lower plate and the like). Such holes may be
formed in the lower plate and the like in contact with a resin layer that will be
10 described below and may be formed in the lower plate and the like in contact with
the resin layer with a contact area that is 80 % or more of the area of the lower plate
and the like to be described below. As described below, the holes may be injection
holes through which a material for forming the resin layer (a resin composition) is
injected when the resin layer is formed by an injection process. Here, the shapes,
15 number, and positions of the holes may be adjusted in consideration of the injection
efficiency of the material for forming the resin layer. As one example, the holes
may be formed at least in the lower plate.
As one example, the holes may be formed at a position that is between
approximately one-third and three-fourth, between approximately three-fourth and
20 seven-eighth, or at approximately the central portion of the entire length of the
sidewall, the lower plate, or the upper plate. By injecting the resin composition
through the injection holes formed at the above-described positions, the resin layer
may have a large contact area. For example, the one-fourth, three-fourth, threeeighth,
or seven-eighth is a ratio of a distance (A) at which the holes are formed to
25 the entire length (L) measured from any one end surface (E) of the lower plate and
4
the like as illustrated in FIG. 3. In addition, the end (E) from which the length (L)
and the distance (A) is measured may be an arbitrary end (E) as long as the length
(L) and the distance (A) is measured from the same end (E). In FIG. 3, injection
holes (50a) are positioned at approximately the central portion of the lower plate 10a.
The size and shape of each injection hole may not be specifically 5 limited and
may be formed by considering the injection efficiency of the material of the resin
layer that will be described below. For example, the holes may have a circular
shape, an oval shape, a polygonal shape such as a triangular or tetragonal shape, or
an amorphous shape. The number of the injection holes and gaps therebetween
10 may not be specifically limited and may be adjusted so that the resin layer may have
a large contact area with the lower plate and the like as described above.
Observation holes (for example, 50b in FIG. 3) may be formed at an end
portion of the lower plate and the like in which the injection holes are formed. For
example, such observation holes may be for observing whether an injected material
15 is sufficiently injected to reach the end of the corresponding sidewall, lower plate, or
upper plate when the material of the resin layer is injected through the injection holes.
The positions, shapes, sizes, and number of the observation holes are not limited as
long as the observation holes are formed to allow determining whether the injected
material was suitably injected.
20 The module case may be a thermally conductive case. The term “thermally
conductive case” refers to a case having an overall thermal conductivity of 10 W/mk
or more or to a case at least including a portion having the above-described thermal
conductivity. For example, at least one of the sidewall, the lower plate, and the
upper plate may have the above-described thermal conductivity. As another
25 example, at least one of the sidewall, the lower plate, and the upper plate may
5
include a portion having the above-described thermal conductivity. In the another
example, the thermal conductivity may be 20 W/mk or more, 30 W/mk or more, 40
W/mk or more, 50 W/mk or more, 60 W/mk or more, 70 W/mk or more, 80 W/mk or
more, 90 W/mk or more, 100 W/mk or more, 110 W/mk or more, 120 W/mk or more,
130 W/mk or more, 140 W/mk or more, 150 W/mk or more, 160 5 W/mk or more, 170
W/mk or more, 180 W/mk or more, 190 W/mk or more, or 195 W/mk or more. The
higher the thermal conductivity values are, the more advantageous it is for the
thermal dissipation properties aspect and the like of the module, and thus an upper
limit is not specifically limited. For example, the thermal conductivity may be
10 approximately 1,000 W/mK or less, 900 W/mk or less, 800 W/mk or less, 700 W/mk
or less, 600 W/mk or less, 500 W/mk or less, 400 W/mk or less, 300 W/mk, or 250
W/mK or less but may not be limited thereto. A material having the abovedescribed
thermal conductivity is not specifically limited and includes, for example,
a metal material such as aluminum, gold, pure silver, tungsten, copper, nickel, or
15 platinum. The entirety of the module case may be formed of the above-described
thermally conductive material, or at least a portion of a part may be formed of the
thermally conductive material. Accordingly, the module case may have thermal
conductivity in the above-described range or may include a portion having thermal
conductivity in the above-described range.
20 In the module case, the portion having the thermal conductivity in the abovedescribed
range may be a contact portion in contact with the resin layer and/or an
insulating layer that will be described below. In addition, the portion having the
thermal conductivity may be a portion in contact with a cooling medium such as
cooling water. According to such a structure, a structure that may effectively
25 dissipate heat generated from battery cells to the outside may be implemented.
6
Meanwhile, when a measured temperature has an influence on materials
properties among the materials properties described in the present specification and
as long as not otherwise specifically described, the materials properties may be
materials properties measured at room temperature. In the present specification, the
term “room temperature” may refer to any one temperature 5 of in a range of
approximately 10 to 30 °C and, for example, may refer to a temperature of
approximately 25 °C, 23 °C, or 20 °C.
The kind of battery cell accommodated in the module case is not specifically
limited, and all various known battery cells may be applied. For example, the
10 battery cell may be a pouch type. Referring to FIG. 4, a pouch type battery cell
(100) may generally include an electrode assembly, an electrolyte, and a pouch type
exterior material.
FIG. 4 is an exploded perspective view schematically illustrating a
configuration of an exemplified pouch type cell, and FIG. 5 is a combined
15 perspective view illustrating the configuration shown in FIG. 4.
An electrode assembly (110) included in the pouch type cell (100) may be
provided in a form in which one or more positive plates and one or more negative
plates are disposed with a separator interposed therebetween. The electrode
assembly (110) may be classified into a wound type in which one positive plate and
20 one negative plate are wound together with the separator, a stacked type in which a
plurality of positive plates and a plurality of negative plates are alternately stacked
with a separator therebetween, or the like.
For example, a pouch exterior material (120) may be provided in a form
including an outer insulating layer, a metal layer, and an inside adhesive layer. To
25 protect the inside elements such as the electrode assembly (110) and electrolyte and
7
in consideration of strengthening the electro-chemical properties against the
electrode assembly and the electrolyte and thermal dissipation properties, such an
exterior material (120) may include a metal thin film formed of aluminum. Such a
metal thin film may be interposed between insulating layers formed of an insulating
material for an electrical insulation from elements such as the 5 electrode assembly
(110) and the electrolyte or other external elements of the battery (100).
In an example, the exterior material (120) may include an upper pouch (121)
and a lower pouch (122), and a concave inside space (I) may be formed in at least
one of the upper pouch (121) or the lower pouch (122). The electrode assembly
10 (110) may be accommodated in an inside space (I) of such a pouch. Sealing
portions (S) are provided at perimetric surfaces of the upper and lower pouches (121
and 122), and the sealing portions (S) are bonded to each other so that the inside
space in which the electrode assembly (110) is accommodated may be sealed.
Electrode taps may be respectively provided at electrode plates of the
15 electrode assembly (110), and one or more electrode taps may be connected to
electrode leads. The electrode leads may serve as electrode terminals of the
secondary battery (100) by being interposed between the sealing portions of the
upper pouch (121) and the lower pouch (122) and being exposed to the outside of the
exterior material (120).
20 The form of the pouch type cell is one example, and the battery cell applied
to the present invention is not limited to the above-described types. In the present
invention, various known pouch type cells or other types of batteries may be applied
as the battery cell.
The battery module according to the present invention may further include a
25 resin layer. The term “resin layer” refers to a layer including a resin component and,
8
in one example, the resin layer may be an adhesive layer. For example, the battery
module may include the case and battery cells and may be in contact with any one of
the sidewall, the lower plate, or the upper plate. Here, the sidewall, the lower plate,
or the upper plate may be a sidewall, lower plate, or upper plate with the abovedescribed
thermal conductivity. Meanwhile, in the above 5 description, the term
“contact” may refer to a thermal contact. That is, The above-described “contact”
may refer to a state in which the resin layer is in direct contact with the lower plate
and the like, or, even though other elements, such as an insulating layer that will be
described below, may exist between the resin layer and the lower plate and the like,
10 the other elements do not interfere with the thermal transmission between the resin
layer and the lower plate and the like. In the above description, the thermal
transmission not being interfered refers to a case in which an entire thermal
conductivity between the other elements and the resin layer is in a range of
approximately 1.5 W/mK or more, 2 W/mK or more, 2.5 W/mK or more, 3 W/mK or
15 more, 3.5 W/mK or more, or 4 W/mK or more even when the other elements (for
example, the insulating layer or a guiding portion that will be described below) is
provided between the resin layer and the lower plate and the like, or an overall
thermal conductivity of the resin layer and the lower plate and the like in contact
therewith is in the above-described range even when the other elements are provided.
20 The thermal conductivity of the thermal contact may be 50 W/mK or less, 45 W/mk
or less, 40 W/mk or less, 35 W/mk or less, 30 W/mk or less, 25 W/mk or less, 20
W/mk or less, 15 W/mk or less, 10 W/mK or less, 5 W/mK or less, 4.5 W/mK or less,
or approximately 4.0 W/mK or less. Such a thermal contact may be obtained by
controlling the thermal conductivity and/or the thickness of another element when
25 another element is provided.
9
The resin layer may be in contact with the lower plate and the like and may
also be in contact with the battery cells. The contact between the battery cells and
the resin layer is also the above-described thermal contact. In the present invention,
by adopting the above-described structure, the number of various coupling parts, a
cooling apparatus of the module or the like conventionally required 5 when a general
battery module or a battery pack that is a group of such general battery modules is
formed may be dramatically decreased, thermal dissipation properties may be
obtained, and a module in which more battery cells are accommodated per unit
volume may be implemented. Accordingly, the present invention may provide a
10 small sized, light, and high output battery module.
FIGS. 6 and 7 are cross-sectional views illustrating an example of the battery
module and, for example, the module may have a form including a case (10)
including a sidewall (10b) and a lower plate (10a), a plurality battery cells (20)
accommodated in the case (10), and a resin layer (30) in contact (thermal contact)
15 with all of the battery cells (20) and the case (10).
In the above-described structure, the lower plate and the like in contact with
the resin layer (30) may be a thermally conductive lower plate as described above.
The contact area between the resin layer and the lower plate and the like may
be approximately 70 % or more, 75 % or more, 80 % or more, 85 % or more, 90 %
20 or more, or 95 % or more of the entire area of the lower plate and the like. An
upper limit of the contact area is not specifically limited and, for example, may be
100 % or less or under approximately 100 %.
When the lower plate and the like include a thermally conductive portion, the
contact area may be a contact area with the thermally conductive portion, that is, may
25 be a ratio of the contact area to the entire area of the thermally conductive portion.
10
As described above, the thermally conductive portion or the thermally
conductive lower plate and the like may be a portion in contact with a cooling
medium such as cooling water. That is, as schematically illustrated in FIG. 6, heat
(H) may be easily dissipated through the lower plate and the like, and the heat may
be easily dissipated even in the further simplified structure by having 5 the lower plate
and the like being in contact with a cooling medium (CW).
The resin layer may have a form having a relatively thin layer as illustrated in
FIG. 6 or may fill the inside space of the case (10) as illustrated in FIG. 7. In the
above-described case, the battery cells (20) may be provided having been inserted in
10 the resin layer. In the case of a structure shown in FIG. 6, for example, the
thickness of the resin layer may be in a range of approximately 100 μm to 5 mm or in
a range of approximately 200 μm to 5 mm. In a structure of the present invention,
when the resin layer is thin, dissipating heat is advantageous, and when the resin
layer is thick, insulating heat is advantageous. Accordingly, by considering the
15 above properties, a suitable thickness of the resin layer may be set. The thickness
may be the thickness of the most thin portion, the thickness of the most thick portion,
or the average thickness of the resin layer.
As illustrated in FIGS. 6 or 7, a guiding portion (10d) that guides the
accommodated battery cells (20) may also exist on at least one inside surface of the
20 module case (10), for example, an area (10a) in contact with the resin layer (30).
Here, a shape of the guiding portion (10d) may not be specifically limited and may
be suitably adopted in consideration of a shape of the applied battery cells and the
like. The guiding portion (10d) may be integrally formed with the lower plate and
the like or may be additionally attached thereto. The guiding portion (10d) may be
25 formed of a metal material such as aluminum, gold, pure silver, tungsten, copper,
11
nickel, platinum in consideration of thermal contact. In addition, although not
illustrated in drawings, an interleaving paper or an adhesive layer may be provided
between the accommodated battery cells (20). The interleaving paper may serve as
a buffer when the battery cells are charged and discharged.
The resin layer or the battery module to which the resin 5 layer is applied may
have at least one or more materials properties among materials properties that will be
described below. The materials properties that will be described below are
independent of each other, and materials properties do not take priority over other
materials properties. The resin layer may meet at least one of the materials
10 properties requirements that will be described below.
For example, the resin layer may be a thermally conductive resin layer and
may have thermal conductivity of approximately 1.5 W/mK or more, 2 W/mK or
more, 2.5 W/mK or more, 3 W/mK or more, 3.5 W/mK or more, or 4 W/mK or more.
The thermal conductivity may be 50 W/mK or less, 45 W/mk or less, 40 W/mk or
15 less, 35 W/mk or less, 30 W/mk or less, 25 W/mk or less, 20 W/mk or less, 15 W/mk
or less, 10 W/mK or less, 5 W/mK or less, 4.5 W/mK or less, or approximately 4.0
W/mK or less. When the resin layer is a thermally conductive resin layer as
described above, the lower plate and the like to which the resin layer is attached may
be a portion having the above-described thermal conductivity of 10 W/mK or more.
20 Here, a portion of the module case having the above-described thermal conductivity
may be a portion in contact with a cooling medium, e.g., cooling water. For
example, the thermal conductivity of the resin layer is a value measured based on
ASTM D5470 or ISO 22007-2 standard. The method of adjusting the thermal
conductivity of the resin layer in the above-described range is not specifically limited.
25 For example, the thermal conductivity of the resin layer may be adjusted through the
12
type of resin used for the resin layer and/or use of a filler. For example, an acrylic
based resin, a urethane based resin, and a silicone based resin among resin materials
generally known to be used as an adhesive have similar properties of thermal
conductivity, the epoxy based resin have a relatively higher thermal conductivity
than the others, and it is known that an olefin based resin 5 has a higher thermal
conductivity than the epoxy based resin. Accordingly, a resin having excellent
thermal conductivity may be adopted among the variety of resins as necessary.
However, since it is difficult to obtain a target thermal conductivity only with a resin
material, a method to be described below of adding a filler having excellent thermal
10 conductivity to the resin layer at a suitable ratio may also be applied.
In a battery module, a thermal resistance of the resin layer or the battery
module in which the resin layer is applied may be 5 K/W or less, 4.5 K/W or less, 4
K/W or less, 3.5 K/W or less, 3 K/W or less, or approximately 2.8 K/W or less.
When the resin layer or the battery module in which the resin module is applied is
15 adjusted to have the thermal resistance in the above-described range, excellent
cooling efficiency or heat dissipation efficiency may be obtained. The method of
measuring the thermal resistance is not specifically limited. For example, the
thermal resistance may be measured based on ASTM D5470 or ISO 22007-2
standard.
20 The resin layer may have suitable adhesion strength in consideration of
effective immobilizing of the battery cells, shock resistance, and vibration resistance
in using the module. For example, the resin layer may have adhesion strength of
approximately 1,000 gf/10mm or less, approximately 950 gf/10mm or less,
approximately 900 gf/10mm or less, approximately 850 gf/10mm or less,
25 approximately 800 gf/10mm or less, approximately 750 gf/10mm or less,
13
approximately 700 gf/10mm or less, approximately 650 gf/10mm or less, or
approximately 600 gf/10mm or less. As another example, the resin layer may have
adhesion strength of approximately 50 or more, approximately 70 gf/10mm or more,
approximately 80 gf/10mm or more, or approximately 90 gf/10mm or more. The
above-described adhesion strengths may be values measured at a 5 delamination speed
of approximately 300 mm/min and a delamination angle of 180°. In addition, the
adhesion strength may be adhesion strength to the module case in contact with the
resin layer. For example, when an insulating layer is formed between the lower
plate and the like and the resin layer in the module case as described below, adhesion
10 strength to the module case may be adhesion strength to a module case in which the
insulating layer is formed. When the above-described adhesion strength is obtained,
excellent adhesion strength to various materials of a case included in the battery
module and the battery cells may be obtained for example. When the adhesion
strength is obtained in the above-described range, delamination and the like due to a
15 change in the volume during charging and discharging the battery cells, a change in
the operating temperature of the battery module, contraction due to curing of the
resin layer, or the like are prevented in the battery module, and thus excellent
durability may be obtained. Such adhesion strength may be obtained by using the
resin layer as an adhesive layer for example. That is, since adhesion strengths of
20 known adhesive materials are well known, a material may be adopted in
consideration of such adhesion strength.
A resin layer may be required to withstand a thermal shock test, for example,
consisting of repeating 100 cycles of being maintained at the low temperature of
approximately -40 °C for 30 minutes, raising the temperature to 80 °C, and being
25 maintained for 30 minutes and to afterwards show no detachment or delamination
14
from the module case or the battery cells of the battery module or generation of
cracks. For example, when the battery module is applied to a product such as a
vehicle that requires a long warranty period (in the case of the vehicle, approximately
15 years or more), the level of performance as described above may be required.
The resin layer may be an electrically insulating resin layer. 5 In the abovedescribed
structure, by the resin layer being electrically insulating, performance of
the battery module may be maintained and safety may be guaranteed. The
electrically insulating resin layer may have an insulation breakdown voltage of
approximately 3 kV/mm or more, approximately 5 kV/mm or more, approximately 7
10 kV/mm or more, 10 kV/mm or more, 15 kV/mm or more, or 20 kV/mm or more
measured based on ASTM D149. Although a higher value of the insulation
breakdown voltage refers to the resin layer having excellent insulation properties, the
insulation breakdown voltage is not specifically limited, and when formation and the
like of the resin layer are considered, the insulation breakdown voltage may be
15 approximately 50 kV/mm or less, 45 kV/mm or less, 40 kV/mm or less, 35 kV/mm
or less, or 30 kV/mm or less. Such an insulation breakdown voltage may be
controlled by adjusting the insulation properties of resin materials of the resin layer
and, for example, the insulation breakdown voltage may be adjusted by applying an
insulating filler in the resin layer. A ceramic filler that will be described below has
20 been generally known as a material that may provide insulation properties among
thermally conductive fillers.
A flame retardant resin layer may be applied as the resin layer in
consideration of safety. The term “flame retardant resin layer” in the present
invention may refer to a resin layer having a grade V-0 based on UL 94 V Test
15
(vertical burning test). Thus, the safety against fire and other accidents that may
occur in the battery module may be obtained.
The resin layer may have a specific gravity of 5 or less. As another example,
the specific gravity may be 4.5 or less, 4 or less, 3.5 or less, or 3 or less. The resin
layer having a specific gravity in the above-described range 5 is advantageous for
manufacturing lighter battery modules. Since a lower value of the specific gravity
is advantageous for making the module lighter, a lower limit is not specifically
limited. For example, the specific gravity may be approximately 1.5 or more or 2
or more. Materials added to the resin layer may be adjusted so that the resin layer
10 has a specific gravity in the above-described range. For example, when a thermally
conductive filler is added, a method of adding a filler having a relatively low specific
gravity through which a target thermal conductivity is obtained, that is, a filler of
which gravity itself is low or a filler for which a surface treatment has been
performed may be used.
15 A resin layer that does not include a volatile material is suitable, if possible.
For example, the resin layer may include a nonvolatile material at 90 wt% or more,
95 wt% or more, or 98 wt% or more. The above-described nonvolatile material and
a ratio may be defined by a method below. That is, a nonvolatile portion may be
defined as the residue material after the resin layer is maintained at 100 °C for an
20 hour, and accordingly, the ratio may be measured based on the initial weight of the
resin layer and the weight after being maintained at 100 °C for an about hour.
In addition, the resin layer may be required to provide safety against
chemically reacting to a surface of the battery case or battery cells even when the
resin layer has excellent necessary resistance against degradation.
16
In addition, a lower contraction rate of the resin layer during or after a curing
process may be advantageous for the resin layer. Thus, delamination or a gap that
may be generated in manufacturing or using a module may be prevented. The
contraction rate may be suitably adjusted in a range in which the above-described
effect is obtained and, for example, may be under 5%, under 5 3%, or approximately
under 1%. Since a lower value of the contraction rate is advantageous, a lower limit
thereof is not specifically limited.
A lower coefficient of thermal expansion (CTE) may be advantageous for the
resin layer. Thus, delamination or a gap that may be generated in manufacturing or
10 using a module may be prevented. The CTE may be suitably adjusted in a range in
which the above-described effect is obtained and, for example, may be under 300
ppm/K, under 250 ppm/K, under 200 ppm/K, under 150 ppm/K, or approximately
under 100 ppm/K. Since a lower value of the CTE is advantageous, a lower limit
thereof is not specifically limited.
15 Since tensile strength of the resin layer may be suitably adjusted, excellent
shock resistance is thus obtained, and the module having a suitable durability may be
provided. For example, the tensile strength may be adjusted in a range of
approximately 1.0 MPa or more.
Since the elongation of the resin layer may be suitably adjusted, the excellent
20 shock resistance thereof is thus obtained, and providing a module having a suitable
durability may be possible. For example, the elongation may be adjusted in a range
of approximately 10 % or more or approximately 15 % or more.
A suitable hardness may also be advantageous for the resin layer. For
example, when the hardness of the resin layer is excessively high, the resin layer may
25 become too brittle and have a bad influence on reliability. In addition, by adjusting
17
hardness of the resin layer, shock and vibration resistance may be obtained, and the
product durability may be obtained. For example, a shore A hardness of the resin
layer may be less than 100, 99 or less, 98 or less, 95 or less, or 93 or less, or a shore
D hardness thereof may be less than approximately 80, approximately 70 or less,
approximately 65 or less, or approximately 60 or less. A lower limit 5 of the hardness
is not specifically limited. For example, a shore A hardness may be 60 or more, or
a shore OO hardness may be 5 or more or approximately 10 or more. The hardness
of the resin layer generally depends on the type or a ratio of a filler included in the
resin layer of the filler, and when an excessive amount of the filler is included, the
10 hardness is generally increased. However, a resin component included in the resin
layer has an influence on the hardness similar to a silicone based resin having
hardness that is lower than that of other resins such as an epoxy or urethane based
resin.
The temperature corresponding to the 5 % weight loss of the resin layer may
15 be 400 °C or more, or the amount of residue of the resin layer at 800 °C may be 70
wt% or more based on thermogravimetric analysis (TGA). Through these
properties, safety of the battery module may be further improved at a high
temperature. As another example, the amount of residue at 800 °C may be
approximately 75 wt% or more, approximately 80 wt% or more, approximately 85
20 wt% or more, or approximately 90 wt% or more. As still another example, the
amount of residue at 800 °C may be approximately 99 wt% or less. The TGA may
be performed in an environment of N2 provided at 60 cm3/min, temperature ramp up
speed at 20 °C/min, and in a temperature range of 25 °C to 800 °C. The result of
the TGA may be obtained by adjusting composition of the resin layer. For example,
25 the amount of residue at 800 °C depends on the type or a ratio of a filler included in
18
the resin layer, and when an excessive amount of filler is included, the amount of
residue is increased. However, since a silicone based resin generally has a thermal
resistance higher than that of other resins such as an epoxy or urethane based resin,
the amount of residue is larger, and accordingly, a resin material included in the resin
layer has an influence on the 5 hardness thereof.
The type of the resin layer may not be specifically limited and all of known
curable resin materials may be used as long as the battery cell may be effectively
immobilized, and the above-described materials properties are obtained as necessary.
Materials that may be used may be an acrylic based resin, an epoxy based resin, a
10 urethane based resin, an olefin based resin, an ethylene vinyl acetate (EVA) based
resin, a silicone based resin, or the like, and accordingly, the resin layer may include
the above-described resins. The resin layer may include the above-described resins
as a main material among resin materials. That is, the acrylic based resin, epoxy
based resin, urethane based resin, olefin based resin, EVA based resin, silicone based
15 resin, or the like in all resin materials included in the resin layer may be
approximately 70 % or more, approximately 75 % or more, approximately 80 % or
more, approximately 85 % or more, or approximately 90 % or more based on weight.
The ratio may be approximately 99 % or less or approximately 95 % or less.
A material forming the resin layer, that is, a resin composition, may be an
20 adhesive material as described above and may be a solvent, a water based material,
or solvent free material, but it may be suitable that the resin layer is the solvent free
resin layer in consideration of convenience and the like of a manufacturing process
that will described below.
A material of the resin layer may be an active energy-ray curing type, wet
25 curing type, a thermal curing type, a room temperature curing type, or the like, and it
19
may be suitable that the material be the room temperature curing type in
consideration of the convenience and the like of the manufacturing process that will
described below.
The resin layer may include a filler in consideration of the above described
thermal conductivity, insulation properties, thermal resistance 5 (measured by TGA),
specific gravity, or the like. By using a suitable filler, the resin layer in the abovedescribed
range may include the filler in consideration of the above described
thermal conductivity, insulation properties, thermal resistance (measured by TGA),
specific gravity, or the like. By using a suitable filler, thermal conductivity of in the
10 above-described range may be obtained. For example, the filler may be a thermally
conductive filler. The term “thermally conductive filler” refers to a material having
thermal conductivity of approximately 1 W/mK or more, approximately 5 W/mK or
more, approximately 10 W/mK or more, or approximately 15 W/mK or more. The
thermally conductive filler has thermal conductivity of approximately 400 W/mK or
15 less, approximately 350 W/mK or less, or approximately 300 W/mK or less.
Although the type of the filler that may be used is not specifically limited, a ceramic
filler may be used in consideration of the insulation properties. For example,
particles of a ceramic such as alumina, aluminum nitride (AlN), boron nitride (BN),
silicon nitride, ZnO, SiC, or BeO. In addition, as long as the insulation properties
20 of the resin layer are obtained, use of a carbon filler such as graphite may be
considered. The shape or ratio of the filler included in the resin layer is not
specifically limited and may be selected in consideration of viscosity of the resin
layer, possibility of sinking in the resin layer, a target thermal resistance or thermal
conductivity, insulation properties, filling effect or dispersion properties, and the like.
25 Generally, as the size of filler particles becomes larger, viscosity of a resin
20
composition becomes higher, and a possibility of a filler to sink in the resin layer
becomes higher. In addition, as the size of the filler particles becomes smaller, the
thermal resistance tends to be higher. Accordingly, a suitable filler may be selected
in consideration of the above-described aspect, and two or more types of fillers may
be used as necessary. In addition, although it is advantageous to 5 use a round shaped
filler in consideration of a filled amount, a filler in a needle shape, plate shape, or the
like may also be used in consideration of forming a network, conductivity, or the like.
For example, the resin layer may include the thermally conductive filler having an
average particle diameter in a range of 0.001 to 80 μm. As another example, an
10 average particle diameter of the filler may be 0.01 μm or more, 0.1 μm or more, 0.5
μm or more, 1 μm or more, 2 μm or more, 3 μm or more, 4 μm or more, 5 μm or
more, or approximately 6 μm or more. As still another example, an average particle
diameter of the filler may be approximately 75 μm or less, approximately 70 μm or
less, approximately 65 μm or less, approximately 60 μm or less, approximately 55
15 μm or less, approximately 50 μm or less, approximately 45 μm or less,
approximately 40 μm or less, approximately 35 μm or less, approximately 30 μm or
less, approximately 25 μm or less, approximately 20 μm or less, approximately 15
μm or less, approximately 10 μm or less, or approximately 5 μm or less.
A ratio of the filler included in the resin layer may be selected to obtain the
20 above-described properties, for example, thermal conductivity and insulation
properties in consideration of the properties of the resin layer. For example, the
filler may be included at in the range of approximately 50 to 2,000 parts by weight
with respect to the resin material of the resin layer of 100 parts by weight. As
another example, the filler may have 100 parts by weight or more, approximately 150
25 parts by weight or more, approximately 200 parts by weight or more, approximately
21
250 parts by weight or more, approximately 300 parts by weight or more,
approximately 350 parts by weight or more, approximately 400 parts by weight or
more, approximately 500 parts by weight or more, approximately 550 parts by
weight or more, approximately 600 parts by weight or more, or approximately 650
parts 5 by weight or more.
The resin layer may further include a viscosity regulator, for example, a
thixotropic additive, a diluent, a dispersant, a surface treatment agent, or a coupling
agent for adjusting viscosity, for example, to raise or lower the viscosity, or for
adjusting the viscosity according to shearing force.
10 The thixotropic additive may adjust the viscosity according to the shearing
force of the resin composition for effectively performing a manufacturing process of
the battery module. For example, fumed silica may be used as a thixotropic
additive.
The diluent or dispersant is generally used for lowering the viscosity of the
15 resin composition, and various types of known diluents or dispersants in the field
may be used without limitation as long as the diluents or dispersants have the abovedescribed
functions.
The surface treatment agent is for surface treatment of the filler included in
the resin layer, and various types of surface treatment agents known in the field may
20 be used without limitation as long as the surface treatment agents have the abovedescribed
functions.
The coupling agent is used for improving the dispersion properties of the
thermally conductive filler, and, for example, alumina and various types of coupling
agents known in the field may be used without limitation as long as the coupling
25 agents have the above-described function.
22
The resin layer may further include a flame retardant, a flame retardant
supplement agent, or the like. Such a resin layer may form a flame retardant resin
layer. Various known flame retardants may be applied without a specific limitation.
For example, a solid phase flame retardant in a filler type, a liquid phase flame
retardant, or the like may be applied. For example, the flame retardant 5 may include
an organic flame retardant such as melamine cyanurate or an inorganic flame
retardant such as magnesium hydroxide but may not be limited thereto.
When an amount of filler that fills the resin layer is large, a liquid phase
flame retardant material (triethyl phosphate (TEP), Tris(2-chloroethyl) phosphate
10 (TCPP), tris (1,3-chloro-2-propyl) phosphate, or the like) may be used. In addition,
a silane coupling agent that functions as a flame retardation promoter may be added.
The resin layer may include at least one of the above-described components.
As one example, the battery module may further include an insulating layer
between the module case and the battery cells or the resin layer and the module case.
15 FIG. 8 is a schematic view illustrating an insulating layer (40) formed between a
resin layer (30) and a guiding portion (10d) formed on a lower plate (10c) of a case.
By adding the insulating layer, problems of an electrical short phenomenon,
occurrence of fire, or the like due to a contact between cells and the case due to a
shock during use may be prevented. The insulating layer may be formed by using
20 an insulation sheet having high insulation properties and thermal conductivity, or by
coating with or injecting a material having insulation properties. For example, in a
method of manufacturing the battery module, a process for forming the insulating
layer may be performed before a resin composition is injected. A so-called thermal
interface material (TIM) and the like may also be applied to form the insulating layer.
25 As another method, the insulating layer may be formed of an adhesive material that,
23
for example, may be formed by using a resin layer in which an amount of thermally
conductive filler is small or a thermally conductive filler is not provided. Although
a resin material used for forming the insulating layer may be, for example, an acrylic
resin, an olefin resin such as poly vinyl chloride (PVC) and polyethylene (PE), an
epoxy resin, a silicone, or a rubber material such as ethylene 5 propylene diene
monomer (EPDM) rubber but may not be limited thereto. The insulating layer may
have an insulation breakdown voltage of approximately 5 kV/mm or more,
approximately 10 kV/mm or more, approximately 15 kV/mm or more, 20 kV/mm or
more, 25 kV/mm or more, or 30 kV/mm or more measured based on ASTM D149.
10 A higher value of the insulation breakdown voltage refers to excellent insulation
properties, and the insulation breakdown voltage is not specifically limited. For
example, the insulation breakdown voltage of the insulating layer may be
approximately 100 kV/mm or less, 90 kV/mm or less, 80 kV/mm or less, 70 kV/mm
or less, or 60 kV/mm or less. The thickness of the insulating layer may be set to a
15 suitably range in consideration of insulation properties, thermal conductivity, or the
like and may be, for example, approximately 5 μm or more, approximately 10 μm or
more, 20 μm or more, 30 μm or more, 40 μm or more, 50 μm or more, 60 μm or
more, 70 μm or more, 80 μm or more, or 90 μm or more. In addition, the upper
limit of the thickness is not specifically limited and may be, for example,
20 approximately 1 mm or less, approximately 200 μm or less, 190 μm or less, 180 μm
or less, 170 μm or less, 160 μm or less, or 150 μm or less.
Another aspect of the present invention also provides a method of
manufacturing a battery module, e.g., the above-described battery module.
24
The method in the present invention may include injecting a resin
composition in the above-described module case; accommodating a battery cells in
the module case; and curing the resin composition to form the resin layer.
Order of injecting of the resin composition in the module case and
accommodating of the battery cells in the module case is not 5 specifically limited.
For example, the resin composition may be first injected in the module case and the
battery cells may be accommodated therein, or the battery module may be first
accommodated in the module case and the resin composition may be injected therein.
The term “resin composition” in the present invention may refer to a state of
10 the resin layer before curing, and the term “resin layer” may refer to a state of the
resin layer after the curing.
The method of injecting of the resin composition in the module case may not
be specifically limited, and known methods may be applied thereto. For example, a
method of injecting the resin composition by pouring the resin composition through
15 an opening of the module case, injecting the resin composition through the opening
formed in the module case, spraying the resin composition on both of the battery
cells and the battery module, or the like may be applied. The injecting process may
also be performed while the battery module or the battery cells are constantly being
vibrated for suitable immobilizing.
20 The type of injected resin composition is not specifically limited and may be
suitably selected when meeting target materials properties requirements.
For example, the above-described injected resin composition may be a resin
composition that may meet materials properties requirements such as the abovedescribed
thermal conductivity or may form a resin layer that includes a material for
25 meeting the materials properties requirements.
25
Such a resin composition may be a solvent based resin composition, a water
based resin composition, or solvent free resin composition, and it may be suitable
that the resin composition be the solvent free resin composition.
In addition, the resin composition may be an active energy-ray curing type, a
wet curing type, a thermal curing type, a room temperature curing 5 type, or the like,
and it may be suitable that the resin composition be the room temperature curing type.
The resin composition may be a resin composition that includes one or more
among various additives such as the above-described thermally conductive fillers.
Such a resin composition may be a single-component type, a two-component
10 type, a three-component type, or the like.
The accommodating of the battery cells in the module case in which the resin
composition has been injected or in the module case before the resin composition is
injected is not specifically limited.
The accommodating of the battery cells may be performed by disposing the
15 battery cells at a suitable position in the module case in consideration of target
disposition and the like. In addition, when a cartridge structure is provided, the
above-described process may be performed by positioning the battery cells at a
suitable position in the cartridge structure, or inserting the cartridge structure on
which the battery cells are positioned into the module case.
20 Bonding between the battery cells or between the battery cells and the
module case may be accomplished by curing the injected resin composition after the
battery cells are accommodated. The curing of the resin composition is not
specifically limited.
For example, the above-described process may be performed by a method of
25 emitting active energy-rays such as ultraviolet rays to the resin composition when the
26
resin composition is the active energy-ray curing type, maintaining under a suitable
humidity when the resin composition is the wet curing type, applying suitable heat
when the resin composition is the thermal curing type, or maintaining the resin
composition under at room temperature when the resin composition is the room
temperature curing 5 type, and the like.
In addition, the resin composition may be heated for a short time before or
during curing or before or during the accommodating of the battery cells to be, for
example, in a range of approximately 40 °C to 50 °C under a condition in which
safety of the battery cells is not influenced in terms of of tack time and processing
10 characteristics.
Still another aspect of the present invention also provides a resin composition
that may be used for the method of manufacturing the same or forming the battery
module having the above-described structure.
As described above, the resin composition is not specifically limited, and all
15 known resin compositions may be used as long as the battery cells may be effectively
immobilized to the module case and the above-described materials properties
requirements may be obtained as necessary.
Such a resin composition may include an acrylic based resin composition, an
epoxy based resin composition, an urethane based resin composition, an olefin based
20 resin composition, an EVA based resin composition, a silicone based resin
composition, or the like but may not be limited thereto.
The resin composition may be a solvent based resin composition, a water
based resin composition, or solvent free resin composition, but it may be suitable that
the resin composition be the solvent free resin composition.
27
The resin composition may have a resin composition that is active energy-ray
curing type, a wet curing type, a thermal curing type, a room temperature curing type,
or the like, and it may be suitable that the resin composition be the room temperature
curing type resin composition.
For example, in consideration of target materials properties, 5 the resin
composition prepared by adding suitable amounts of additives such as the abovedescribed
fillers and the like to the resin composition that may form an acrylic based
adhesive, an epoxy based adhesive, an urethane based adhesive, an olefin based
adhesive, an EVA based adhesive, or a silicone based adhesive may be applied to the
10 above-described method.
The above-described resin composition may include a radical initiator and a
catalyst for the radical initiator in consideration of the room temperature curing
properties and the like. For example, the resin composition may include an acyl
peroxide initiator such as a benzoyl peroxide and the like and a catalyst such as a
15 toluidine compound for the initiator, and accordingly, a suitable curing system may
be implemented.
The resin composition may further include various materials in addition to the
above-described materials as necessary.
Yet another aspect of the present invention also provides a battery pack, for
20 example, a battery pack including two or more of the above-described battery
modules. In the battery pack, the battery modules may be electrically connected.
The method of forming of the battery pack by connecting two or more battery
modules is not specifically limited, and all of known methods may be applied.
Yet another aspect of the present invention also provides equipment including
25 the battery module or the battery pack. A vehicle such as an electrical vehicle may
28
be exemplified as the apparatus, but the apparatus is not limited thereto. All uses
that need an output of the secondary battery may be included in the equipment. For
example, the method of forming of the vehicle using the battery module or the
battery pack is not specifically limited, and a general method may be applied thereto.
【5 Advantageous Effects】
According to embodiment of the present invention, a battery module
manufactured with a simple process and low cost but having excellent output,
thermal dissipation properties, and the like for its size, a method manufacturing the
same, and a resin composition applied to the method of manufacturing the same are
10 provided.
【Description of Drawings】
FIG. 1 is a schematic view illustrating an example of a module case that may
be applied to the present invention.
FIG. 2 is a view illustrating battery cells accommodated in the module case.
15 FIG. 3 is a view illustrating an example of a lower plate in which injection
holes and observation holes are formed.
FIGS. 4 and 5 are schematic views illustrating examples of battery pouches
which may be used as the battery cells.
FIGS. 6 to 8 are schematic views illustrating examples of structures of the
20 battery module.
【Reference Numerals】
10: MODULE CASE
10A: LOWER PLATE
10B: SIDEWALL
29
10C: UPPER PLATE
10D: GUIDING PORTION
20: BATTERY CELL
30: RESIN LAYER
50A: 5 INJECTION HOLE
50B: OBSERVATION HOLE
40: INSULATING LAYER
100: POUCH TYPE CELL
110: ELECTRODE ASSEMBLY
10 120: EXTERIOR MATERIAL
121: UPPER POUCH
122: LOWER POUCH
S: SEALING PORTION
【Modes of the Invention】
15 Hereinafter, although the present invention will be described with reference
to examples and comparative examples, the scope of the present invention is not
limited to the scope that will be described below.
1. Method of measuring thermal conductivity of resin layer
20 Thermal conductivity of a resin layer was measured based on ASTM D5470
standard. That is, based on ASTM D5470 standard, a thermal equilibrium state
(temperature change is approximately 0.1 °C or less in five minutes) was reached by
positioning the resin layer between two copper bars, having one of the two copper
bars be in contact with a heater, having the other be in contact with a cooler,
30
maintaining the heater at a constant temperature, and adjusting the capacity of the
cooler. The temperature of each copper bar was measured in the thermal
equilibrium state, and thermal conductivity K (unit: W/mK) was evaluated using the
following equation. During evaluating the thermal conductivity, pressure applied to
the resin layer was adjusted to be approximately 11 Kg/2 5 5 cm2, and when the
thickness of the resin layer was changed during measurement, the thermal
conductivity was calculated based on a final thickness.

K = (Q × dx) / (A × dT)
10 In Equation of thermal conductivity, K denotes thermal conductivity (W/mK),
Q denotes heat that transfers per unit time (unit: W), dx denotes a thickness of the
resin layer (unit: m), A denotes a cross-sectional area of the resin layer (unit: m2),
and dT denotes a temperature difference of the copper bars (unit: K).
15 2. Method for evaluating specific gravity
Specific gravity of the resin layer was measured based on ASTM D792
standard. For example, the weight of the resin layer is measured based on the
standard, the weight is then measured again in water, and density and specific gravity
may be calculated using the difference between the measured weights, or a
20 predetermined amount of power or pellet (for example, approximately 5 g) is put into
a premeasured volume with a pyrometer, and the specific gravity may be calculated
using differences of the weight and volume thereof at 73.4 °F.
3. Method of thermogravimetric analysis (TGA).
31
TGA was performed using an instrument, TA400 made by TA Instruments.
The analysis was performed using a resin layer of approximately 10 mg, at a
temperature in a range of 25 °C to 800 °C, at heating speed of 20 °C/min, and under
an N2 atmosphere of 60 cm3/min.
5
4. Measurement of insulation breakdown voltage
An insulation breakdown voltage of the resin layer was evaluated based on
ASTM D149 standard. The insulation breakdown voltage refers to a voltage
applied up to the moment at which a material loses insulation properties, the
10 insulation properties disappear as conductivity is rapidly increased at a high voltage
of a certain level or more. The breakdown voltage refers to a minimum voltage
required for causing an insulation breakdown, and the insulation properties are
generated by completely generating an arc through a specimen. A voltage gradient
may be obtained by dividing a voltage at the moment at which a breakdown occurs
15 by an insulation thickness. The insulation breakdown voltage was measured using
an instrument, PA70-1005/202 made by Backman Industrial Co., and here, the
thickness of the specimen (resin layer) was approximately 2 mm, and the diameter
was approximately 100 mm.
20 5. Measurement of adhesion strength
A lower plate of a module case formed of aluminum in which an insulation
film (epoxy and/or polyester based insulating layer) and a polyethylene terephthalate
(PET) film were attached using a resin layer, and here, the width of attachment was
approximately 10 mm. Here, the thickness of the resin layer was approximately 1
25 mm. The attachment was performed by loading an uncured resin composition
32
between the insulation film and the PET film and curing the resin composition.
Next, adhesion strength was measured while the PET film was being delaminated at
speed of approximately 300 mm/min and a delamination angle of 180°.
6. Measurement 5 of hardness
Hardness of a resin layer was measured based on ASTM D 2240, and JIS K
6253 standards. ASKER, a durometer hardness instrument, was used for measuring
the hardness. Initial hardness was measured by applying a weight of 1 Kg or more
(approximately 1.5 Kg) to a flat sample (the resin layer), and hardness was evaluated
10 by confirming a stable measurement value after 15 seconds.
7. Reliability evaluation of battery module.
Reliability of a battery module was evaluated by measuring thermal
conductivity and a withstand voltage of the module. The withstand voltage is
15 measured for checking the highest applied voltage up to which the battery module
tolerates without breaking down. In below examples and comparative examples,
the withstand voltage was measured while an applied voltage was started from
approximately 1.2 kV and increased. The thermal resistance of the battery module
was evaluated by positioning the module between upper and lower blocks of the
20 measurement instrument, executing DynTIM Tester software on a controlling
computer, determining and inputting a heating current and measurement time in the
software, completing setting of parameters such as the measurement pressure and
measurement condition of the thermal resistance, and measuring the thermal
resistance depending on the measurement conditions by using a T3Ster and DynTIM
33
tester controlled by software. Reliability according to each evaluation result was
classified based on below reference.

Good: Withstand voltage is 2 kV or more.
Fair: Withstand voltage is less than 2 kV and 5 0.5 kV or more.
Poor: Withstand voltage is less than 0.5 kV.

Good: Thermal resistance is 2 K/W or less
Fair: Thermal resistance is greater than 2 K/W and 6 K/W or less.
10 Poor: Thermal resistance is greater than 6 K/W.
Example 1.
Resin composition preparation
A resin composition with viscosity of approximately 250,000 cP at room
15 temperature was prepared by mixing an amount of alumina (particle size distribution:
1 to 60 μm) into a two-component urethane based adhesive composition (main
material: HP-3753 (KPX Chemical Co., Ltd) and hardener: TLA-100 (AsshiKASEI))
such that the two-component urethane based adhesive composition has thermal
conductivity of approximately 3 W/mK after curing (in a range of approximately 600
20 to 900 parts by weight with respect to 100 parts by weight of the total twocomponents
solid content), and the resin composition was applied to preparing a
battery module.
Battery module manufacturing
34
A battery module was formed using a module case that is in the shape shown
in FIG. 1 and includes a lower plate, a sidewall, and an upper plate formed of
aluminum. A guiding portion that guides installation of battery cells was formed on
an inside surface of the lower plate of the module case. Injection holes for injecting
a resin composition were formed at a regular gap in a central 5 portion of the lower
plate of the module case. Observation holes were formed at end portions of the
lower plate. A bundled pouch in which a plurality of battery pouches were stacked
was accommodated in the module case. Then, the top surface of the module case
was covered by the upper plate. Next, the prepared resin composition was injected
10 until it was confirmed that the resin composition reached the observation holes, and
then the battery module was manufactured by curing the resin composition.
Example 2.
Resin composition preparation
15 A resin composition with viscosity of approximately 130,000 cP at room
temperature was prepared by mixing an amount of alumina (particle size distribution:
1 to 60 μm) into a two-components silicone based adhesive composition (main
material: SL5100A (KCC Corporation), hardener: SL5100B (KCC Corporation))
such that the two-component silicone based adhesive composition had thermal
20 conductivity of approximately 3 W/mK after curing (in a range of approximately 800
to 1200 parts by weight with respect to 100 parts by weight of the total twocomponents
solid content), and the resin composition was applied to manufacturing
the following battery module.
25 Battery module manufacturing
35
A battery module was used that had the same structure as that of the Example
1 however in which an injection hole and an observation hole for injecting a resin
composition were not formed. The battery module was manufactured by coating a
front surface of an inside surface of the corresponding case with the prepared resin
composition with a thickness of approximately 500 μm, accommodating 5 the same
battery cells as that of the Example 1, covering an upper plate, and curing a layer of
the resin composition.
Example 3.
10 A battery was identically manufactured with that of the Example 1 except
using a resin composition whose viscosity was adjusted to approximately 350,000 cP
at room temperature by mixing an amount of alumina (particle size distribution: 1 to
60 μm) into a two-component urethane based adhesive composition (main material:
PP-2000(KPX Chemical), hardener: TLA-100 (AsshiKASEI)) such that the two15
components urethane based adhesive composition had thermal conductivity of
approximately 3.5 W/mK after curing (in a range of approximately 600 to 900 parts
by weight with respect to of 100 parts by weight of the total two-components solid
content).
20 Example 4.
A battery was identically manufactured with that of the Example 1 except
using a resin composition whose viscosity was adjusted to approximately 500,000 cP
at room temperature by mixing an amount of alumina (particle size distribution: 1 to
60 μm) into an adhesive composition having an epoxy based room temperature
25 curing type made by KUKDO Chemical Co., Ltd such that the adhesive composition
36
had thermal conductivity of approximately 3 W/mK after curing (in a range of
approximately 600 to 900 parts by weight with respect to 100 parts by weight of the
total two-components solid content).
5 Example 5.
A battery was identically manufactured with that of the Example 2 except
using a resin composition whose viscosity was adjusted to approximately 2,000,000
cP at room temperature by mixing an amount of graphite into a two-component
silicone based adhesive composition (main material: SL5100A (KCC Corporation),
10 hardener: SL5100B (KCC Corporation)) such that the two-component silicon based
adhesive composition had thermal conductivity of approximately 1.5 W/mK after
curing (in a range of approximately 100 to 300 parts by weight with respect to 100
parts by weight of the total two-components solid content).
15 Example 6.
A battery was identically manufactured with that of the Example 2 except
using a resin composition whose viscosity was adjusted to approximately 100,000 cP
at room temperature by mixing an amount of alumina (particle size distribution: 1 to
60 μm) into a two-component silicone based adhesive composition (main material:
20 SL5100A (KCC Corporation), hardener: SL5100B (KCC Corporation)) such that the
adhesive composition had thermal conductivity of approximately 1.5 W/mK after
curing (in a range of approximately 300 to 500 parts by weight with respect to of the
total two-components solid content 100 parts by weight of the total two-components
solid content).
25
37
Example 7.
A battery was identically manufactured with that of the Example 1 except
using a resin composition whose viscosity was adjusted to approximately 150,000 cP
at room temperature by mixing an amount of alumina (particle size distribution: 1 to
60 μm) into a two-component urethane based adhesive composition 5 (main material:
PP-2000(KPX Chemical), hardener: TLA-100 (AsshiKASEI)) such that the twocomponent
urethane based adhesive composition had thermal conductivity of
approximately 2 W/mK after curing (in a range of approximately 400 to 900 parts by
weight with respect to 100 parts by weight of the total two-components solid content)
10 to the two-components urethane based adhesive composition.
Comparative example 1.
A battery module was identically manufactured with that of the Example 2
except an adhesive composition was not used, that is, did not form a resin layer.
15
Materials properties of the resin layers and reliabilities of the battery modules
from the above examples and comparative examples were measured, summarized,
and input in table 1 below.
【table 1】
Examples
Comp
arativ
e
exam
ple
1 2 3 4 5 6 7 1
38
Resin
layer
Thermal
conductivi
ty (W/mK)
3 3 3.5 3 1.5 1.5 2 -
Specific
gravity
3.1 3.1 3.2 3.2 2 2 2.6 -
Residue at
800 °C
(wt%)
>80 >80 >80 >80
about
60
about
60
about
50
-
Adhesion
strength
(gf/10mm)
500 100 450 600 80 90 500 -
hardness
(shore A)
90 60 90 100 40 40 70 -
Insulation
breakdown
voltage
(kV/mm)
15 11 10 < 8 2 5 4 -
Reliability
(withstand voltage) good good good fair fair fair fair poor
Reliability (thermal
resistance) good good good fair fair fair fair poor
It is apparent from the result of table 1 that materials properties of a resin
layer are influenced by the type and ratio of resin used for the resin layer, and
accordingly reliability of a module is also influenced.
For example, it is apparent from a comparison between Examples 5 1, 2, and 4
that when alumina is added to obtain the same level of thermal conductivity,
adhesion strength is higher in the order of an epoxy base resin layer, an urethane
39
based resin layer, and a silicone based resin layer, hardness is higher in the order of
an epoxy based resin layer, an urethane based resin layer, and a silicone based resin
layer, and specific gravities and TGA results of thermal resistance were adjusted to a
similar level. It is apparent that hardness in the case of Example 4 is slightly higher
than those of Examples 1 and 2, and, accordingly, reliability result 5 is slightly lowered.
In addition, in is apparent from a comparison among Examples 2, 5, and 6 or
among Examples 1, 3, and 7 that when the same material based resins are used,
thermal conductivity, specific gravity, TGA result for thermal resistance, hardness,
and the like were changed according to the type and amount of a filler. For
10 example, in the case of Example 7, by applying an amount of filler less than those of
the cases of Examples 1 and 3, values of thermal conductivity and specific gravity
were slightly low, TGA result for thermal resistance was also slightly lower,
although adhesion strength was at a similar level, hardness was slightly lowered, and
particularly, an insulation breakdown voltage was lowered due to lowering of a ratio
15 of the filler that influenced obtaining insulation properties. Accordingly, it is
apparent that reliability evaluation result of Example 7 is slightly lower than those of
Examples 1 and 3.
40
【CLAIMS】
【Claim 1】
A battery module comprising:
a module case including a lower plate and a sidewall forming an inside space;
a plurality of battery cells provided in the inside space 5 of the module case;
and
a resin layer provided in the inside space of the module case,
wherein the resin layer is in contact with the plurality of battery cells and also
in contact with the lower plate or the sidewall of the module case.
10 【Claim 2】
The battery module of claim 1, wherein an injection hole through which a
resin composition is injected is formed in the lower plate or the sidewall in contact
with the resin layer.
【Claim 3】
15 The battery module of claim 2, wherein an observation hole is formed in the
lower plate or the sidewall in which the injection hole is formed.
【Claim 4】
The battery module of claim 1, wherein the sidewall or the lower plate in
contact with the resin layer includes a thermally conductive region.
20 【Claim 5】
The battery module of claim 4, wherein a contact ratio of the resin layer to
the thermally conductive region is 80 % or more of the entire area of the thermally
conductive region.
【Claim 6】
41
The battery module of claim 1, wherein the resin layer has thermal
conductivity of 1.5 W/mK or more.
【Claim 7】
The battery module of claim 1, wherein the resin layer has an insulation
breakdown voltage of 5 10 kV/mm or more.
【Claim 8】
The battery module of claim 1, wherein the resin layer has adhesion strength
of 1,000 gf/10 mm or less.
【Claim 9】
10 The battery module of claim 1, wherein the resin layer has a specific gravity
of 5 or less.
【Claim 10】
The battery module of claim 1, wherein a shore A hardness of the resin layer
is less than 100 or a shore D hardness is 70 or less.
15 【Claim 11】
The battery module of claim 1, wherein, in a thermogravimetric analysis
(TGA), the amount of residue of the resin layer at 800 °C is 70 wt% or more.
【Claim 12】
The battery module of claim 1, wherein the resin layer includes an acrylic
20 resin, an epoxy resin, an urethane resin, an olefin resin, an ethylene vinyl acetate
(EVA) resin, or a silicone resin.
【Claim 13】
The battery module of claim 1, wherein the resin layer includes a filler.
【Claim 14】
42
The battery module of claim 13, wherein the filler includes ceramic particles
or a carbon based filler.
【Claim 15】
The battery module of claim 1, wherein the resin layer includes a thixotropic
additive, a diluent, a dispersant, a surface treatment agent, a flame 5 retardant, or a
coupling agent.
【Claim 16】
The battery module of claim 1, wherein the resin layer has a thickness in a
range of 100 μm to 5 mm.
10 【Claim 17】
A method of manufacturing a battery module, comprising:
injecting a resin composition into a module case including a lower plate and a
sidewall forming an inside space;
accommodating a battery cell in the module case; and
15 curing the resin composition to form a resin layer.
【Claim 18】
The method of claim 17, wherein an injection hole through which the resin
composition is injected is formed in the lower plate or the sidewall and the resin
composition is injected after the accommodating of the battery cell.
20 【Claim 19】
A battery pack comprising two or more battery modules, each of which is the
battery module of claim 1, electrically connected to each other.
【Claim 20】
43
A vehicle comprising the battery module of claim 1 or the battery pack of
claim 20.