TECHNICAL FIELD
[0002] The present invention relates to a secondary battery
sealing process for improving a sealing force of a sealing
portion in a pouch and a secondary battery manufacturing method
15 comprising the same.
BACKGROUND ART
[0003] In generally, secondary batteries refer to chargeable
and dischargeable batteries unlike primary batteries that are
not chargeable, and such a secondary battery is being widely
20 used in the high-tech electronic fields such as phones, laptop
computers, and camcorders.
[0004] The secondary batteries are classified into a can-type
secondary battery, in which an electrode assembly is stored in
a metal can, and a pouch-type secondary battery, in which an
25 electrode assembly is stored in a pouch. Also, the pouch-type
2
secondary battery comprises an electrode assembly having an
electrode tab, an electrode lead coupled to the electrode tab,
and a battery case accommodating the electrode assembly in a
state in which a front end of the electrode lead is drawn to
5 the outside. Also, the battery case comprises an accommodation
portion for accommodating the electrode assembly and a sealing
portion formed along an edge surface of the accommodation
portion.
[0005] Meanwhile, the sealing portion of the battery case in
10 the secondary battery is sealed by using a sealing apparatus
for a secondary battery, and the sealing apparatus for a
secondary battery seals the sealing portion of the battery
case by using ultrasonic waves.
[0006] However, a sealing apparatus for a secondary battery
15 according to the related art has a limitation in uniformly
sealing the sealing portion of the battery case. That is, in
the sealing apparatus for a secondary battery according to the
related art, heat is non-uniformly applied to the sealing
portion of the battery case, causing failed welding.
20 DISCLOSURE OF THE INVENTION
TECHNICAL PROBLEM
[0007] The present invention has been made to solve the above
problems. An object of the present invention is to provide a
secondary battery sealing process capable of uniformizing heat
25 applied to the sealing portion of the battery case by setting
3
optimal welding conditions when sealing the sealing portion of
the battery case, and as a result, welding failures may be
prevented. Also, a secondary battery manufacturing method
comprising the same is provided.
5 TECHNICAL SOLUTION
[0008] To achieve the object described above, a sealing
process for a secondary battery of the present invention, which
is to thermally fuse and seal a sealing portion that extends
along an edge surface of a battery case, comprises: an
10 arrangement operation of disposing the sealing portion of the
battery case between an anvil and a horn; a first region-fixing
operation of pressing and fixing a first region of the sealing
portion through the anvil and the horn; and a first regionprimary
sealing operation of applying an ultrasonic wave to
15 the first region of the sealing portion through the horn at a
set frequency and a set amplitude for a set time, thereby
thermally fusing the first region of the sealing portion.
[0009] The set frequency may be 10 kHz to 40 kHz, the set
amplitude may be 5 μm to 50 μm, and the set time may be 0.1
20 seconds to 2.0 seconds.
[0010] The sealing portion may have a stack structure that
comprises a coating layer, a metal layer, and an insulating
layer in a direction from the inside of the battery case toward
the outside, and a thickness of the coating layer may be 30 μm
25 to 85 μm.
4
[0011] After the first region-primary sealing operation, a
first region-secondary sealing operation may be further
performed to secondarily thermally fuse the first region of
the sealing portion by secondarily applying an ultrasonic wave
5 to the first region of the sealing portion through the horn,
wherein the first region-secondary sealing operation is
performed under the same ultrasonic wave frequency and set
time as the first region-primary sealing operation but under
an amplitude reduced by 40% to 60%.
10 [0012] The horn may be rotatable left or right toward the
sealing portion and installed to a converter comprising a
booster, and may press the entirety of the first region of the
sealing portion with a uniform pressure.
[0013] The sealing process may further comprise, after the
15 first region-primary sealing operation: a second region-fixing
operation of pressing and fixing a second region of the sealing
portion, which is spaced apart from the first region, through
the anvil and the horn; and a second region-sealing operation
of applying an ultrasonic wave to the second region of the
20 sealing portion through the horn at a set frequency and a set
amplitude for a set time, thereby thermally fusing the second
region of the sealing portion.
[0014] The second region-sealing operation may be set to the
same ultrasonic wave frequency, amplitude, and time as the
25 first region-primary sealing operation.
5
[0015] The sealing process may further comprise, after the
second region-sealing operation: a third region-fixing
operation of pressing and fixing a third region of the sealing
portion, which is positioned between the first region and the
5 second region, through the anvil and the horn; and a third
region-sealing operation of applying an ultrasonic wave to the
third region of the sealing portion through the horn at a set
frequency and a set amplitude for a set time, thereby thermally
fusing the third region of the sealing portion.
10 [0016] An ultrasonic wave frequency, amplitude, and time of
the third region-sealing operation may be set to differ from
the ultrasonic wave frequency, amplitude, and time of the first
region-primary sealing operation.
[0017] The ultrasonic wave frequency, amplitude, and time of
15 the third region may be set to be higher than the ultrasonic
wave frequency, amplitude, and time of the first region-primary
sealing operation.
[0018] Meanwhile, a method for manufacturing a secondary
battery of the present invention comprises: a manufacturing
20 process of manufacturing an electrode assembly by stacking an
electrode and a separator; an accommodating process of
accommodating the electrode assembly in a pouch-type battery
case; and a sealing process of thermally fusing and sealing a
sealing portion that extends from an edge surface of the
25 battery case, wherein the sealing process comprises: an
6
arrangement operation of disposing the sealing portion, which
extends along the edge surface of the battery case, between an
anvil and a horn; a first region-fixing operation of pressing
and fixing a first region of the sealing portion through the
5 anvil and the horn; and a first region-primary sealing
operation of applying an ultrasonic wave to the first region
of the sealing portion through the horn at a set frequency and
a set amplitude for a set time, thereby thermally fusing the
first region of the sealing portion.
10 [0019] The set frequency may be 10 kHz to 40 kHz, the set
amplitude may be 5 μm to 50 μm, and the set time may be 0.1
seconds to 2.0 seconds.
[0020] The sealing process may further comprise a first
region-secondary sealing operation of secondarily applying an
15 ultrasonic wave to the first region of the sealing portion
through the horn after the first region-primary sealing
operation, wherein the first region-secondary sealing
operation is performed under the same ultrasonic wave frequency
and set time as the first region-primary sealing operation but
20 under an amplitude reduced by 40% to 60%.
[0021] The sealing process may further comprise, after the
first region-primary sealing operation: a second region-fixing
operation of pressing and fixing a second region of the sealing
portion, which is spaced apart from the first region, through
25 the anvil and the horn; and a second region-sealing operation
7
of applying an ultrasonic wave to the second region of the
sealing portion through the horn at a set frequency and a set
amplitude for a set time, thereby thermally fusing the second
region of the sealing portion.
5 [0022] The sealing process may further comprise, after the
second region-sealing operation: a third region-fixing
operation of pressing and fixing a third region of the sealing
portion, which is positioned between the first region and the
second region, through the anvil and the horn; and a third
10 region-sealing operation of applying an ultrasonic wave to the
third region of the sealing portion through the horn at a set
frequency and a set amplitude for a set time, thereby thermally
fusing the third region of the sealing portion.
ADVANTAGEOUS EFFECTS
15 [0023] The sealing process for the secondary battery of the
present invention comprises the arrangement operation, the
first region-fixing operation, and the first region-primary
sealing operation. The first region-primary sealing operation
applies the ultrasonic wave to the first region of the sealing
20 portion, which is provided in the battery case, at the set
frequency and the set amplitude for the set time, thereby
thermally fusing the first region of the sealing portion. Here,
the set frequency may be 10 kHz to 40 kHz, the set amplitude
may be 5 μm to 50 μm, and the set time may be 0.1 seconds to
25 2.0 seconds. Thus, the optimal sealing conditions may be set
8
when the first region of the sealing portion included in the
battery case is sealed. Accordingly, the uniformity in heat
transfer to the first region of the sealing portion may be
enhanced, and as a result, the first region of the sealing
5 portion may be sealed without a failure.
[0024] Also, in the sealing process for the secondary battery
of the present invention, the first region-secondary sealing
operation is further performed. The first region-secondary
sealing operation has the same sealing conditions as the first
10 region-primary sealing operation, but is performed in a state
in which only the amplitude is reduced by 50%. Thus, air
bubbles generated in the sealing portion of the battery case
during the first region-primary sealing operation may be
effectively discharged and eliminated, and accordingly, the
15 occurrence of failures may be significantly reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a cross-sectional view illustrating a
secondary battery according to a first embodiment of the
present invention.
20 [0026] FIG. 2 is a perspective view illustrating a sealing
apparatus for a secondary battery according to the first
embodiment of the present invention.
[0027] FIG. 3 is a cross-sectional view illustrating the
sealing apparatus for a secondary battery according to the
25 first embodiment of the present invention.
9
[0028] FIG. 4 is a flowchart showing a sealing process for a
secondary battery according to the first embodiment of the
present invention.
[0029] FIG. 5 is a perspective view showing an arrangement
5 operation of the sealing process for a secondary battery
according to the first embodiment of the present invention.
[0030] FIG. 6 is a side view showing a first region-fixing
operation of the sealing process for a secondary battery
according to the first embodiment of the present invention.
10 [0031] FIG. 7 is a side view showing a first region-sealing
operation of the sealing process for a secondary battery
according to the first embodiment of the present invention.
[0032] FIG. 8 is a cross-sectional view showing a state in
which air bubbles are generated in a sealing portion in the
15 sealing process for a secondary battery according to the first
embodiment of the present invention.
[0033] FIG. 9 is a cross-sectional view showing a state in
which the air bubbles are eliminated in the sealing portion in
the sealing process for a secondary battery according to the
20 first embodiment of the present invention.
[0034] FIG. 10 is a flowchart showing a secondary battery
manufacturing method according to a second embodiment of the
present invention.
[0035] FIG. 11 is a plan view illustrating a secondary battery
25 sealing process according to a third embodiment of the present
10
invention.
[0036] FIG. 12 is a table showing experimental examples of a
sealing apparatus for a secondary battery of the present
invention.
5 [0037] FIG. 13 is a picture in which an image of experimental
results of Comparative Example 1 of FIG. 12 is captured.
[0038] FIG. 14 is a picture in which an image of experimental
results of Preparation Example 1 of FIG. 12 is captured.
[0039] FIG. 15 is a picture in which an image of experimental
10 results of Preparation Example 2 of FIG. 12 is captured.
[0040] FIG. 16 is a picture in which an image of experimental
results of Comparative Example 2 of FIG. 12 is captured.
MODE FOR CARRYING OUT THE INVENTION
[0041] Hereinafter, embodiments of the present invention will
15 be described in detail with reference to the accompanying
drawings so as to be easily carried out by a person skilled in
the art to which the present invention pertains. However, the
present invention may be embodied in various different forms,
and is not limited to the embodiments described herein. Also,
20 in the drawings, parts irrelevant to the description will be
omitted to clearly describe the present invention, and similar
elements will be designated by similar reference numerals
throughout the specification.
[0042] [Secondary battery according to a first embodiment of
25 the present invention]
11
[0043] As illustrated in FIG. 1, a secondary battery according
to a first embodiment of the present invention comprises an
electrode assembly 10 having an electrode tab, an electrode
lead 20 coupled to the electrode tab, and a battery case 30
5 accommodating the electrode assembly 10 in a state in which a
front end of the electrode lead 20 is drawn to the outside.
[0044] Also, the battery case 30 comprises an upper case and
a lower case. As an accommodation groove of the upper case is
connected to an accommodation groove of the lower case, an
10 accommodation portion 31 for accommodating the electrode
assembly 10 is formed. As a sealing surface of the upper case
is connected to a sealing surface of the lower case, a sealing
portion 32 for sealing the accommodation portion 31 is formed.
[0045] That is, the battery case 30 comprises the
15 accommodation portion 31, which accommodates the electrode
assembly 10, and the sealing portion 32, which extends along
an edge surface of the accommodation portion 31 and seals the
accommodation portion 31.
[0046] Also, referring to FIG. 8, each of the upper case and
20 the lower case has a stack structure in which a coating layer
30a, a metal layer 30b, and an insulating layer 30c are
sequentially stacked from the inside of the battery case toward
the outside.
[0047] Here, the sealing portion of the battery case is sealed
25 by the sealing apparatus for a secondary battery according to
12
the first embodiment of the present invention. Particularly,
the sealing apparatus for a secondary battery according to the
first embodiment of the present invention thermally fuses and
seals the sealing portion of the battery case by using
5 ultrasonic waves. Here, the sealing apparatus for a secondary
battery according to the first embodiment of the present
invention sets optimal conditions when generating an
ultrasonic wave, and thus may seal the sealing portion of the
battery case without failures.
10 [0048] Hereinafter, the sealing apparatus for a secondary
battery according to the first embodiment of the present
invention will be described in detail with reference to the
accompanying drawings.
[0049] [Sealing apparatus for a secondary battery according
15 to the first embodiment of the present invention]
[0050] As illustrated in FIGS. 2 and 3, a secondary battery
sealing apparatus 100 according to the first embodiment of the
present invention comprises an anvil 110, on which the sealing
portion 32 of the battery case 30 is disposed, and a horn 120,
20 which heats and seals the sealing portion 32 disposed on the
anvil 110 while the sealing portion is subjected to pressure.
[0051] That is, in the secondary battery sealing apparatus
100 according to the first embodiment of the present invention,
the sealing portion 32 of the battery case 30 is disposed
25 between the anvil 110 and the horn 120, and then, the sealing
13
portion 32 is subjected to pressure and fixed through the anvil
110 and the horn 120. Next, when the ultrasonic wave is
applied to the sealing portion 32 through the horn 120, a
portion of the coating layer included in the sealing portion
5 32 is thermally fused. Accordingly, the sealing portion may
be sealed.
[0052] As one example, the secondary battery sealing
apparatus 100 according to the first embodiment of the present
invention applies the ultrasonic wave to the first region A of
10 the sealing portion 32 through the horn 120 at a set frequency
and a set amplitude for a set time. Accordingly, uniformity
of heat generated in the first region A of the sealing portion
32 may increase, and as a result, the first region A of the
sealing portion 32 may be sealed without a failure.
15 [0053] Here, when the thickness of the coating layer 30a
provided in the sealing portion 32 is 30 μm to 85 μm, the set
frequency may be 10 kHz to 40 kHz, the set amplitude may be 5
μm to 50 μm, and the set time may be 0.1 seconds to 2.0 seconds.
[0054] As described above, when the secondary battery sealing
20 apparatus 100 according to the first embodiment of the present
invention seals the coating layer included in the sealing
portion 32, the coating layer may be sealed without a failure
by setting the ultrasonic welding conditions.
[0055] Meanwhile, the secondary battery sealing apparatus 100
25 according to the first embodiment of the present invention
14
comprises a converter 130 having a booster 131 that transfers
thermal energy to the horn 120. Here, the center of the horn
120 is rotatably coupled to the booster 131 through a hinge
121, and accordingly, both ends of the horn 120 rotate about
5 the hinge 121. That is, as the horn 120 rotates when the
sealing portion 32 is subjected to pressure through the anvil
110 and the horn 120, the entirety of the sealing portion 32
may be uniformly subjected to pressure through the anvil 110
and the horn 120, and as a result, the uniform ultrasonic wave
10 may be applied to the entirety of the sealing portion. Thus,
the sealing force may increase.
[0056] Hereinafter, a sealing process using the secondary
battery sealing apparatus 100 according to the first embodiment
of the present invention will be described.
15 [0057] [Sealing process for a secondary battery according to
the first embodiment of the present invention]
[0058] As illustrated in FIGS. 4 to 9, a secondary battery
sealing process (S30) according to the first embodiment of the
present invention, which is to thermally fuse and seal the
20 sealing portion 32 that extends along an edge surface of the
battery case 30, comprises an arrangement operation (S31), a
first region-fixing operation (S32), a first region-primary
sealing operation (S33), and a first region-secondary sealing
operation (S34).
25 [0059] Arrangement operation
15
[0060] In the arrangement operation (S31), the first region
A defined in the sealing portion 32 of the battery case 30 is
disposed between the anvil 110 and the horn 120 of the sealing
apparatus 100 for a secondary battery.
5 [0061] First region-fixing operation
[0062] In the first region-fixing operation (S32), the first
region A of the sealing portion 32 is pressed and fixed through
the anvil 110 and the horn 120. Here, the horn 120 is coupled
to the converter 130 so as to be rotatable left and right about
10 the hinge 121. Accordingly, the horn 120 rotates according to
an arrangement angle of the anvil 110, and as a result,
pressure on the entire pressing surfaces of the anvil 110 and
the horn 120 may be uniformized. Through this, the entire
surface of the sealing portion 32 fixed between the anvil 110
15 and the horn 120 may be pressed with uniform force.
[0063] First region-primary sealing operation
[0064] In the first region-primary sealing operation (S33),
the ultrasonic wave is generated in the first region A of the
sealing portion 32 through the horn 120, and the first region
20 A of the sealing portion 32 is thermally fused. Particularly,
in the first region-primary sealing operation (S33), as the
ultrasonic wave is applied through the horn 120 at the set
frequency and the set amplitude for the set time, the first
region A of the sealing portion 32 is thermally fused. That
25 is, the horn 120 applies the ultrasonic wave to the coating
16
layer included in the sealing portion 32. As a portion of the
coating layer is melted and then solidified, the sealing
portion 32 is sealed.
[0065] Meanwhile, the battery case 30 comprises an upper case
5 and a lower case. As the accommodation groove of the upper
case is connected to the accommodation groove of the lower
case, the accommodation portion 31 for accommodating the
electrode assembly 10 is formed. As the sealing surface of
the upper case is connected to the sealing surface of the lower
10 case, the sealing portion 32 for sealing the accommodation
portion 31 is formed. Also, each of the upper case and the
lower case has a structure in which the coating layer 30a, the
metal layer 30b, and the insulating layer 30c are sequentially
stacked from the inside of the battery case toward the outside.
15 [0066] Here, when the thickness of the coating layer 30a
included in the sealing portion 32 is 30 μm to 85 μm, the set
frequency, which is a first condition, may be 10 kHz to 40 kHz,
the set amplitude, which is a second condition, may be 5 μm to
50 μm, and the set time, which is a third condition, may be
20 0.1 seconds to 2.0 seconds. Here, the amplitude of 5 μm to 50
μm is considered as 100%.
[0067] Meanwhile, when the frequency, which is the first
condition, is less than or equal to 10 kHz, a large amount of
time is required to melt the coating layer 30a included in the
25 sealing portion 32. Also, when the frequency is greater than
17
or equal to 40 kHz, the coating layer 30a included in the
sealing portion 32 may be rapidly melted, but damage to the
coating layer may also occur.
[0068] Also, when the set amplitude, which is the second
5 condition, is equal to or less than 5 μm, the coating layer
30a included in the sealing portion 32 is not melted, or a
large amount of time is required. Also, when the set amplitude
is greater than or equal to 50 μm, the coating layer 30a
included in the sealing portion 32 may be rapidly melted, but
10 damage to the coating layer may also occur.
[0069] Also, when the set time, which is the third condition,
is less than or equal to 0.1 seconds, the coating layer 30a
included in the sealing portion 32 is not melted because the
time for which the ultrasonic wave is applied thereto is short.
15 Also, when the set time is greater than or equal to 2.00
seconds, the coating layer 30a included in the sealing portion
32 may be rapidly melted, but damage to the coating layer may
also occur.
[0070] As one example, in a case where the thickness of the
20 coating layer 30a included in the sealing portion 32 is 35 μm
to 80 μm, when the ultrasonic wave frequency is set to 10 kHz
or 40 kHz, the amplitude is set to 100%, and the time is set
to 0.1 seconds or 2.0 seconds, a sealing effect of the sealing
portion becomes excellent (see experimental pictures of FIGS.
25 14 and 15). Meanwhile, when the ultrasonic wave frequency is
18
15 kHz, the amplitude is 100%, and the time is less than or
equal to 0.1 seconds, heat is not uniformly transferred to the
coating layer of the sealing portion 32, and thus, the coating
layer is not sufficiently melted. Accordingly, sealing
5 failure may occur (see an experimental picture of FIG. 13).
Meanwhile, when the ultrasonic wave frequency is 35 kHz, the
amplitude is 50%, and the time is 0.1 seconds, heat is not
uniformly transferred to the coating layer of the sealing
portion 32, and thus, the coating layer is not sufficiently
10 melted (see an experimental picture of FIG. 16).
[0071] Thus, in the first region-primary sealing operation
(S33), the set frequency, which is the first condition, is set
to 10 kHz to 40 kHz, the set amplitude, which is the second
condition, is set to 5 μm to about 50 μm, and the set time,
15 which is the third condition, is set to 0.1 seconds to 2.0
seconds. Accordingly, the uniformity of heat transfer may be
enhanced, and as a result, the first region A of the sealing
portion 32 may be uniformly sealed without failure.
[0072] Here, as illustrated in FIG. 8, air bubbles C are
20 generated in the sealing portion 32 as the coating layer 30a
of the sealing portion 32 is melted in the first region-primary
sealing operation (S33). The first region-secondary sealing
operation (S34) may be further performed to eliminate the air
bubbles C generated in the coating layer 30a of the sealing
25 portion 32.
19
[0073] That is, after the first region-primary sealing
operation (S33), the first region-secondary sealing operation
(S34) is further performed to secondarily apply an ultrasonic
wave to the first region A of the sealing portion 32 through
5 the horn 120.
[0074] First region-secondary sealing operation
[0075] As illustrated in FIG. 9, the first region-secondary
sealing operation (S34) is to secondarily seal the sealing
portion, and at the same time, to eliminate the air bubbles
10 generated in the sealing portion in the first region-primary
sealing operation. That is, in the first region-secondary
sealing operation (S34) after the first region-primary sealing
operation (S33), the ultrasonic wave is secondarily applied to
the first region A of the sealing portion 32 through the horn
15 120, and the first region A of the sealing portion 32 is
secondarily thermally fused.
[0076] Here, the first region-secondary sealing operation
(S34) is performed under the same ultrasonic wave frequency
and set time as the first region-primary sealing operation
20 (S33) but under an amplitude reduced by 40% to 60%, preferably,
50%.
[0077] That is, in the first region-secondary sealing
operation (S34), the ultrasonic wave frequency, which is the
first condition, is set to 10 kHz to 40 kHz, the set amplitude,
25 which is the second condition, is set to 40% to 60% of the
20
amplitude set in the first region-primary sealing operation
(S33), and the set time, which is the third condition, is set
to 0.1 seconds to 2.0 seconds.
[0078] As described above, in the first region-secondary
5 sealing operation (S34), optimal sealing conditions comprising
the first to third conditions are set. Next, the ultrasonic
wave is used to generate frictional heat in the sealing portion
32. Thus, the air bubbles C generated in the sealing portion
32 are guided and gradually discharged to the outside, and as
10 a result, the air bubbles C generated in the sealing portion
32 may be effectively eliminated.
[0079] Thus, the secondary battery sealing process (S30)
according to the first embodiment of the present invention
comprises the arrangement operation (S31), the first region15
fixing operation (S32), the first region-primary sealing
operation (S33), and the first region-secondary sealing
operation (S34), and thus, the optimal sealing conditions may
be set. Accordingly, the uniformity of heat transferred to
the sealing portion may be enhanced, and as a result, the
20 sealing portion may be sealed without failure. Particularly,
the air bubbles generated in the sealing portion may be
effectively eliminated, and thus, the productivity may
increase.
[0080] Hereinafter, in describing another embodiment of the
25 present invention, components having the same functions as
21
those in the foregoing embodiment are given the same reference
numerals, and their duplicated description will be omitted.
[0081] [Secondary battery manufacturing method according to
a second embodiment of the present invention]
5 [0082] As illustrated in FIG. 10, a secondary battery
manufacturing method according to a second embodiment of the
present invention comprises: a manufacturing process (S10) of
stacking an electrode and a separator and manufacturing an
electrode assembly 10; an accommodating process (S20) of
10 coupling an electrode lead 20 to an electrode tab of the
electrode assembly 10 and accommodating the electrode assembly
10 in a pouch-type battery case 30 in a state in which a front
end of the electrode lead 20 is drawn to the outside; and a
sealing process (S30) of thermally fusing and sealing a sealing
15 portion 32 that extends from an edge surface of the battery
case 30.
[0083] Here, the sealing process (S30) comprises: an
arrangement operation (S31) of disposing the sealing portion
32, which extends along the edge surface of the battery case
20 30, between an anvil 110 and a horn 120; a first region-fixing
operation (S32) of pressing and fixing a first region A of the
sealing portion 32 through the anvil 110 and the horn 120; and
a first region-primary sealing operation (S33) of applying an
ultrasonic wave to the first region A of the sealing portion
25 32 through the horn 120 at a set frequency and a set amplitude
22
for a set time, thereby thermally fusing the first region A of
the sealing portion 32.
[0084] Meanwhile, the set frequency may be 10 kHz to 40 kHz,
the set amplitude may be 5 μm to 50 μm, and the set time may
5 be 0.1 seconds to 2.0 seconds.
[0085] Meanwhile, after the first region-primary sealing
operation (S33), a first region-secondary sealing operation
(S34) is further provided to secondarily apply an ultrasonic
wave to the first region of the sealing portion through the
10 horn. The first region-secondary sealing operation is
performed under the same ultrasonic wave frequency and set
time as the first region-primary sealing operation but under
an amplitude reduced by 40% to 60%.
[0086] Meanwhile, the sealing process (S30) has the same
15 processes as the secondary battery sealing process (S30)
described above according to the first embodiment of the
present invention, and accordingly, duplicated descriptions
will be omitted.
[0087] Thus, the secondary battery manufacturing method
20 according to the second embodiment of the present invention
may manufacture a secondary battery having improved sealing
force.
[0088] [Sealing process for a secondary battery according a
third embodiment of the present invention]
25 [0089] In a secondary battery sealing process (S30) according
23
to the third embodiment of the present invention, an operation
of further sealing a second region B of the sealing portion 32
included in the battery case 30 is further performed after the
first region-primary sealing operation or the first region-
5 secondary sealing operation of the secondary battery sealing
process (S30) described above according to the first embodiment
of the present invention is completed. Accordingly, sealing
force of the sealing portion 32 included in the battery case
30 may significantly increase.
10 [0090] As one example, the secondary battery sealing process
(S30) according to the third embodiment of the present
invention comprises an arrangement operation (S31), a first
region-fixing operation (S32), a first region-primary sealing
operation (S33), a first region-secondary sealing operation
15 (S34), a second region-fixing operation (S35), and a second
region-sealing operation (S36).
[0091] Here, the arrangement operation (S31), the first
region-fixing operation (S32), the first region-primary
sealing operation (S33), and the first region-secondary
20 sealing operation (S34) have been described in detail in the
secondary battery sealing process (S30) according to the first
embodiment, and thus, detailed description thereof will be
omitted herein.
[0092] Meanwhile, in the secondary battery sealing process
25 (S30) according to the third embodiment of the present
24
invention, the sealing portion 32 included in the battery case
30 is divided into three regions along the width direction of
the sealing portion as illustrated in FIG. 11, and sealing is
performed. That is, a first region A inside the sealing
5 portion 32 is sealed firstly, a second region B outside the
sealing portion 32 is sealed secondly, and a third region C
between the first region A and the second region B is sealed
finally.
[0093] Here, the first region A and the second region B are
10 sealed under the same setting, and the third region C is sealed
at a higher temperature and for a longer time than the first
region A and the second region B.
[0094] Second region-fixing operation
[0095] In the second region-fixing operation (S35), the
15 second region B of the sealing portion 32, which is spaced
apart from the first region A, is disposed on the anvil 110
and the horn 120, and then, the second region B of the sealing
portion 32 is pressed and fixed through the anvil 110 and the
horn 120.
20 [0096] Second region-sealing operation
[0097] In the second region-sealing operation (S36), as an
ultrasonic wave is applied to the second region B of the
sealing portion 32 through the horn 120 at a set frequency and
a set amplitude for a set time, the second region B of the
25 sealing portion 32 is thermally fused. Accordingly, the second
25
region B of the sealing portion 32 may be sealed.
[0098] Here, the second region-sealing operation (S36)
comprises a second region-primary sealing operation and a
second region-secondary sealing operation.
5 [0099] The second region-primary sealing operation primarily
seals the second region of the sealing portion at the same
conditions as the first region-primary sealing operation (S33)
described above. That is, with regard to the sealing
conditions of the second region-primary sealing operation, the
10 set frequency is 10 kHz to 40 kHz, the set amplitude is 5 μm
to 50 μm, and the set time is 0.1 seconds to 2.0 seconds.
[00100] The second region-secondary sealing operation
secondarily seals the second region B of the sealing portion
at the same conditions as the first region-secondary sealing
15 operation (S34) described above. Here, the second regionsecondary
sealing operation has the same sealing conditions as
the second region-primary sealing operation with regard to the
ultrasonic wave frequency and set time, but is performed under
an amplitude reduced by 40% to 60%, preferably, 50%. Here,
20 air bubbles generated in the second region B of the sealing
portion may also be eliminated together, and as a result, the
second region of the sealing portion may be sealed without
failure.
[00101] Thus, in the secondary battery sealing process (S30)
25 according to the third embodiment of the present invention,
26
the first and second regions of the sealing portion may be
sealed without failure, and as a result, the sealing force of
the secondary battery may increase.
[00102] Meanwhile, the secondary battery sealing process (S30)
5 according to the third embodiment of the present invention
further comprises a third region-fixing operation (S37) and a
third region-sealing operation (S38).
[00103] Third region-fixing operation
[00104] In the third region-fixing operation (S37), the third
10 region C of the sealing portion positioned between the first
region A and the second region B is pressed and fixed through
the anvil 110 and the horn 120 after the second region-sealing
operation.
[00105] Third region-sealing operation
15 [00106] In the third region-sealing operation (S38), as an
ultrasonic wave is applied to the third region C of the sealing
portion 32 through the horn 120 at a set frequency and a set
amplitude for a set time, the third region C of the sealing
portion 32 is thermally fused.
20 [00107] Here, the ultrasonic wave frequency, amplitude, and
time of the third region-sealing operation (S38) are set to
differ from the ultrasonic wave frequency, amplitude, and time
of the first region-primary sealing operation.
[00108] That is, the ultrasonic wave frequency, amplitude, and
25 time of the third region-sealing operation (S38) are set to be
27
higher than the ultrasonic wave frequency, amplitude, and time
of the first region-primary sealing operation. Accordingly,
the third region of the sealing portion, which is positioned
between the first region and the second region, may be
5 effectively melted, and thus, the sealing force may increase.
[00109] Particularly, in the third region-sealing operation
(S38), the ultrasonic wave time of the third region is set to
1 second to 2 seconds. Accordingly, the entirety of the third
region may be stably melted, and as a result, the sealing force
10 may increase.
[00110] Thus, in the secondary battery sealing process (S30)
according to the third embodiment of the present invention,
the third region of the sealing portion is further sealed, and
thus, the sealing force of the secondary battery may
15 significantly increase.

CLAIMS
1. A sealing process for a secondary battery, which
thermally fuses and seals a sealing portion that extends along
5 an edge surface of a battery case, wherein the sealing process
comprises:
an arrangement operation of disposing the sealing portion
of the battery case between an anvil and a horn;
a first region-fixing operation of pressing and fixing a
10 first region of the sealing portion through the anvil and the
horn; and
a first region-primary sealing operation of applying an
ultrasonic wave to the first region of the sealing portion
through the horn at a set frequency and a set amplitude for a
15 set time, thereby thermally fusing the first region of the
sealing portion.
2. The sealing process of claim 1, wherein the set
frequency is 10 kHz to 40 kHz,
20 the set amplitude is 5 μm to 50 μm, and
the set time is 0.1 seconds to 2.0 seconds.
3. The sealing process of claim 2, wherein the sealing
portion has a stack structure that comprises a coating layer,
25 a metal layer, and an insulating layer in a direction from the
33
inside of the battery case toward the outside, and
a thickness of the coating layer is 30 μm to 85 μm.
4. The sealing process of claim 1, wherein, after the
5 first region-primary sealing operation, a first regionsecondary
sealing operation is further performed to
secondarily thermally fuse the first region of the sealing
portion by secondarily applying an ultrasonic wave to the first
region of the sealing portion through the horn,
10 wherein the first region-secondary sealing operation is
performed under the same ultrasonic wave frequency and set
time as the first region-primary sealing operation but under
an amplitude reduced by 40% to 60%.
15 5. The sealing process of claim 1, wherein the horn
is rotatable left or right toward the sealing portion and
installed to a converter comprising a booster, and presses the
entirety of the first region of the sealing portion with a
uniform pressure.
20
6. The sealing process of claim 1, further comprising,
after the first region-primary sealing operation: a second
region-fixing operation of pressing and fixing a second region
of the sealing portion, which is spaced apart from the first
25 region, through the anvil and the horn; and
34
a second region-sealing operation of applying an
ultrasonic wave to the second region of the sealing portion
through the horn at a set frequency and a set amplitude for a
set time, thereby thermally fusing the second region of the
5 sealing portion.
7. The sealing process of claim 6, wherein the second
region-sealing operation is set to the same ultrasonic wave
frequency, amplitude, and time as the first region-primary
10 sealing operation.
8. The sealing process of claim 6, further comprising,
after the second region-sealing operation:
a third region-fixing operation of pressing and fixing a
15 third region of the sealing portion, which is positioned
between the first region and the second region, through the
anvil and the horn; and
a third region-sealing operation of applying an
ultrasonic wave to the third region of the sealing portion
20 through the horn at a set frequency and a set amplitude for a
set time, thereby thermally fusing the third region of the
sealing portion.
9. The sealing process of claim 8, wherein an
25 ultrasonic wave frequency, amplitude, and time of the third
35
region-sealing operation are set to differ from the ultrasonic
wave frequency, amplitude, and time of the first region-primary
sealing operation.
5 10. The sealing process of claim 9, wherein the
ultrasonic wave frequency, amplitude, and time of the third
region are set to be higher than the ultrasonic wave frequency,
amplitude, and time of the first region-primary sealing
operation.
10
11. A method for manufacturing a secondary battery, the
method comprising:
a manufacturing process of manufacturing an electrode
assembly by stacking an electrode and a separator;
15 an accommodating process of accommodating the electrode
assembly in a pouch-type battery case; and
a sealing process of thermally fusing and sealing a
sealing portion that extends from an edge surface of the
battery case,
20 wherein the sealing process comprises:
an arrangement operation of disposing the sealing portion,
which extends along the edge surface of the battery case,
between an anvil and a horn;
a first region-fixing operation of pressing and fixing a
25 first region of the sealing portion through the anvil and the
36
horn; and
a first region-primary sealing operation of applying an
ultrasonic wave to the first region of the sealing portion
through the horn at a set frequency and a set amplitude for a
5 set time, thereby thermally fusing the first region of the
sealing portion.
12. The method of claim 11, wherein the set frequency
is 10 kHz to 40 kHz,
10 the set amplitude is 5 μm to 50 μm, and
the set time is 0.1 seconds to 2.0 seconds.
13. The method of claim 11, wherein the sealing process
further comprises a first region-secondary sealing operation
15 of secondarily applying an ultrasonic wave to the first region
of the sealing portion through the horn after the first regionprimary
sealing operation,
wherein the first region-secondary sealing operation is
performed under the same ultrasonic wave frequency and set
20 time as the first region-primary sealing operation but under
an amplitude reduced by 40% to 60%.
14. The method of claim 11, wherein the sealing process
further comprises, after the first region-primary sealing
25 operation:
37
a second region-fixing operation of pressing and fixing
a second region of the sealing portion, which is spaced apart
from the first region, through the anvil and the horn; and
a second region-sealing operation of applying an
5 ultrasonic wave to the second region of the sealing portion
through the horn at a set frequency and a set amplitude for a
set time, thereby thermally fusing the second region of the
sealing portion.
10 15. The method of claim 14, wherein the sealing process
further comprises, after the second region-sealing operation:
a third region-fixing operation of pressing and fixing a
third region of the sealing portion, which is positioned
between the first region and the second region, through the
15 anvil and the horn; and
a third region-sealing operation of applying an
ultrasonic wave to the third region of the sealing portion
through the horn at a set frequency and a set amplitude for a
set time, thereby thermally fusing the third region of the
20 sealing portion.