U.S. patent number RE43,063 [Application Number 12/944,713] was granted by the patent office on 2012-01-03 for integrated cap assembly of a secondary battery and fabricating method thereof.
This patent grant is currently assigned to Samsung SDI Co., Ltd.. Invention is credited to Young Taek Kim.
United States Patent |
RE43,063 |
Kim |
January 3, 2012 |
Integrated cap assembly of a secondary battery and fabricating
method thereof
Abstract
An integrated cap assembly of a secondary battery. A cap
lamination forms a top portion of the secondary battery and serves
as a connection terminal while the secondary battery is charged or
discharged. A gasket is molded integrally with the cap lamination
in such a manner that a peripheral portion of the cap lamination is
inserted in the gasket, the gasket insulating the cap lamination
from a can of the secondary battery and sealing a gap between the
cap lamination and the can.
Inventors: |
Kim; Young Taek (Yongin-si,
KR) |
Assignee: |
Samsung SDI Co., Ltd.
(Yongin-si, KR)
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Family
ID: |
36567748 |
Appl.
No.: |
12/944,713 |
Filed: |
November 11, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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10966905 |
May 27, 2008 |
7378187 |
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Reissue of: |
11227957 |
Sep 14, 2005 |
7727668 |
Jun 1, 2010 |
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Foreign Application Priority Data
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Oct 15, 2003 [KR] |
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2003-0071948 |
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Current U.S.
Class: |
429/185; 429/62;
429/53; 429/174 |
Current CPC
Class: |
H01M
50/578 (20210101); H01M 50/3425 (20210101); H01M
50/166 (20210101); H01M 50/171 (20210101); B29C
45/14467 (20130101); B29C 45/14811 (20130101); H01M
50/30 (20210101); H01M 50/183 (20210101); B29C
45/14336 (20130101); Y10T 29/49114 (20150115); Y02P
70/50 (20151101); B29L 2031/3468 (20130101); H01M
2200/106 (20130101); B29L 2031/265 (20130101); Y02E
60/10 (20130101); Y10T 29/4911 (20150115) |
Current International
Class: |
H01M
2/08 (20060101) |
Field of
Search: |
;429/185,174,53,62,186,180 ;220/366.1,367.1 ;277/628,641 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1374711 |
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Oct 2002 |
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CN |
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1374711 |
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Oct 2002 |
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CN |
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10-2002-0071179 |
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Sep 2002 |
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KR |
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2002-0071179 |
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Sep 2002 |
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KR |
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Other References
English translation of Chinese Office action dated Dec. 8, 2006,
for CN 2004100836749, 2 pages. cited by other .
Korean Patent Abstract for Korea Publication No. 1020020071179 A,
dated Sep. 9, 2002. cited by other.
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Primary Examiner: Alejandro; Raymond
Attorney, Agent or Firm: Christie, Parker & Hale,
LLP
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATION
This is a continuation-in-part application of application Ser. No.
10/966,905, now U.S. Pat. No. 7,378,187, issued May 27, 2008 and
filed Oct. 14, 2004, which claims priority to and the benefit of
Korea Patent Application No. 10-2003-0071948 filed on Oct. 15, 2003
in the Korean Intellectual Property Office, the entire content of
both of which is incorporated herein by reference.
Claims
What is claimed:
1. An integrated cap assembly of a secondary battery, the
integrated cap assembly comprising: a cap lamination assembly
having a safety vent, a contact plate connectable to an electrode
lead of an electrode assembly in the secondary battery, and an
insulating plate forming a connection between the safety vent and
the contact plate at an electric connection portion; and a gasket
formed integrally with the cap lamination assembly, a peripheral
portion of at least one of the safety vent, the contact plate and
the insulating plate of the cap lamination assembly being inserted
in the gasket, the gasket insulating the cap lamination assembly
from a can of the secondary battery and sealing a gap between the
cap lamination assembly and the can, wherein a lowermost layer of
the cap lamination assembly has a hole between an end and the
center of the lowermost layer, and a portion of the gasket is
inserted into the hole.
2. The integrated cap assembly of claim 1, wherein the cap
lamination assembly further comprises a positive thermal
coefficient element and an electrode cap.
3. The integrated cap assembly of claim 1, wherein the cap
lamination assembly comprises an electrode cap, and wherein the
electrode cap, the safety vent, the insulating plate, and the
contact plate are layered from top down in the cap lamination
assembly and are inserted in the gasket.
4. The integrated cap assembly of claim 3, wherein a peripheral
portion of at least one of the electrode cap, the safety vent, the
insulating plate, and the contact plate protrudes more deeply into
the gasket as compared with others of the electrode cap, the safety
vent, the insulating plate, and the contact plate.
5. The integrated cap assembly of claim 3, wherein the contact
plate has a protruding portion along a contact plate peripheral
defining positions of the electrode cap, the safety vent, and the
insulating plate.
6. The integrated cap assembly of claim 1, wherein the cap
lamination assembly comprises an electrode cap, the safety vent,
the insulating plate, the contact plate, and the electrode cap, the
safety vent, the insulating plate, and the contact plate are
layered, and the electrode cap, the safety vent, and the insulating
plate are inserted in the gasket, the insulating plate being
attached both to the safety vent and the contact plate, sealing the
space between the safety vent and the contact plate.
7. The integrated cap assembly of claim 1, wherein the cap
lamination assembly and the gasket are integrated with each other
through injection-molding.
8. The integrated cap assembly of claim 1, wherein the hole is
formed at the contact plate.
9. The integrated cap assembly of claim 8, wherein the hole
narrowingly tapers from a surface contacting the insulating
plate.
10. The integrated cap assembly of claim 3, wherein the contact
plate is bent upward at about 90 degrees.
11. The integrated cap assembly of claim 3, wherein the contact
plate is bent downward at about 90 degrees.
12. The integrated cap assembly of claim 1, wherein the hole
comprises an inlet portion and a rear portion, and the rear portion
comprises a larger sectional area than that of the inlet portion in
the direction filled by the gasket.
.Iadd.13. An integrated cap assembly of a secondary battery, the
integrated cap assembly comprising: a cap lamination assembly
having a safety vent, a contact plate connectable to an electrode
lead of an electrode assembly in the secondary battery, and an
insulating plate forming a connection between the safety vent and
the contact plate at an electric connection portion; and a gasket
formed with the cap lamination assembly, a peripheral portion of at
least one of the safety vent, the contact plate and the insulating
plate of the cap lamination assembly being inserted in the gasket,
the gasket insulating the cap lamination assembly from a can of the
secondary battery and sealing a gap between the cap lamination
assembly and the can, wherein a lowermost layer of the cap
lamination assembly has a hole between an end and the center of the
lowermost layer, and a portion of the gasket is inserted into the
hole..Iaddend.
.Iadd.14. The integrated cap assembly of claim 13, wherein the cap
lamination assembly has a groove, and wherein another portion of
the gasket is inserted into the groove..Iaddend.
.Iadd.15. The integrated cap assembly of claim 13, wherein the
lowermost layer of the cap lamination assembly is the contact plate
or the safety vent..Iaddend.
.Iadd.16. The integrated cap assembly of claim 13, wherein the cap
lamination assembly further comprises a positive electrode cap, and
wherein the positive electrode cap is layered above the safety
vent, the insulating plate, and the contact plate and is also
inserted in the gasket..Iaddend.
.Iadd.17. A secondary battery comprising: an electrode assembly
comprising an electrode lead; a can for receiving the electrode
assembly; an integrated cap assembly comprising: a cap lamination
assembly having a safety vent, a contact plate connectable to the
electrode lead of the electrode assembly, and an insulating plate
forming a connection between the safety vent and the contact plate
at an electric connection portion; and a gasket formed with the cap
lamination assembly, a peripheral portion of at least one of the
safety vent, the contact plate and the insulating plate of the cap
lamination assembly being inserted in the gasket, the gasket
insulating the cap lamination assembly from the can and sealing a
gap between the cap lamination assembly and the can, wherein a
lowermost layer of the cap lamination assembly has a hole between
an end and the center of the lowermost layer, and a portion of the
gasket is inserted into the hole..Iaddend.
.Iadd.18. The secondary battery of claim 17, wherein the electrode
lead of the electrode assembly is a positive electrode
lead..Iaddend.
.Iadd.19. The secondary battery of claim 17, wherein the lowermost
layer of the cap lamination assembly is the contact plate or the
safety vent..Iaddend.
.Iadd.20. The secondary battery of claim 17, wherein the cap
lamination assembly has a groove, and wherein another portion of
the gasket is inserted into the groove..Iaddend.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a secondary battery, and more
particularly, to a structure of a cap assembly forming a top of a
secondary battery and a method of fabricating the same.
2. Description of the Related Art
As is generally known in the art, secondary batteries are
rechargeable and can be fabricated in a smaller size with a larger
capacity than primary batteries. Secondary batteries may be
classified into nickel-hydrogen (Ni-MH) batteries, lithium (Li)
batteries, lithium ion (Li-ion) batteries, and polymer lithium
(PLI) batteries according to the materials of the secondary
batteries, or into cylinder type batteries and square type
batteries according to their appearances.
According to a typical method of fabricating a secondary battery,
an electrode assembly including a positive electrode plate, a
negative electrode plate and a separator is seated in a can
generally made from aluminum or an aluminum alloy. Electrolyte is
injected into the can, and the can assembly is then sealed. Each
can has an electrode terminal which is formed at an upper portion
of the can and is insulated from the can. The electrode terminal
has a positive or negative polarity determining a polarity of the
can. In addition, each can includes a positive temperature
coefficient (PTC) element, a thermal fuse, and a protection circuit
module (PCM).
The secondary battery employs an electrode structure in a
"jelly-roll" configuration formed by winding a positive electrode
plate, a negative electrode plate, and a separator interposed
between the positive electrode plate and the negative electrode
plate, together. The shape of the battery determines the shape of
the jelly-roll employed by the battery. That is, a cylinder type
battery employs a jelly-roll wound in a cylindrical shape, and a
square type battery employs a jelly-roll wound in a polygonal shape
having angular corners and flat sides.
FIG. 1 is a sectional view of a conventional secondary battery
having a typical construction. As shown in FIG. 1, a cylinder type
secondary battery includes electrode assembly 110 for generating
potential difference, cylinder-type can 120 for receiving electrode
assembly 110, cap assembly 130 assembled with a top of
cylinder-type can 120, so as to prevent electrode assembly 110 from
being separated from cylinder-type can 120, and electrolyte 140
injected in cylinder-type can 120, so as to enable movement of ions
between electrodes of electrode assembly 110. Cap assembly 130 has
various safety devices provided at cap assembly 130.
Cylinder-type can 120 has clamp portion 121 bent inward so as to
push cap assembly 130 inward and a bead portion 122 depressed
inward so as to push cap assembly 130 upward.
Cap assembly 130 includes conductive safety vent unit 131, printed
circuit board 132, PTC element 133, and positive electrode cap 134.
Conductive safety vent unit 131 has a bottom welded to a positive
electrode lead 111 and has a convex portion which is inverted when
the battery is excessively charged or abnormally heated. Printed
circuit board 132 is disposed above and is electrically and
mechanically connected to conductive safety vent unit 131. Printed
circuit board 132 has a circuit which is cut off when the convex
portion of conductive safety vent unit 131 is inverted. PTC element
133 is disposed above and is electrically and mechanically
connected to printed circuit board 132. PTC element 133 is
electrically cut off when heated exceeding a predetermined
temperature. Positive electrode cap 134 is disposed above and is
electrically and mechanically connected to PTC element 133.
Positive electrode cap 134 allows current to flow to the exterior.
Insulating gasket 135 surrounds circumferential portions of
conductive safety vent unit 131, current breaker 132, PTC element
133, and positive electrode cap 134, stacked on each other, and
insulates them from cylinder-type can 120.
However, in cap assembly 130 of the conventional cylinder-type
secondary battery, conductive safety vent unit 131, printed circuit
board 132, PTC element 133, and positive electrode cap 134 are
simply stacked on each other, and central portion 135a, lower dip
portion 135b, and upper dip portion 135c of insulating gasket 135
are simply in contact with the circumferential portion of cap
assembly 130 including conductive safety vent unit 131, printed
circuit board 132, PTC element 133 and positive electrode cap 134,
stacked on each other. Therefore, insulating gasket 135 cannot
sufficiently seal the gap between the interior and the exterior of
the can and may allow internal gas of the can to leak through a nip
between cap assembly 130 and insulating gasket 135 when the
internal pressure has excessively increased.
SUMMARY OF THE INVENTION
In accordance with the present invention an integrated cap assembly
of a secondary battery and a method of fabricating the same is
provided wherein the cap assembly includes a cap lamination and an
insulating gasket surrounding and clamping the cap lamination with
an increased tightness, the cap lamination may include a conductive
safety vent unit, a printed circuit board, a PTC element, and a
positive electrode cap, the safety vent unit may include a safety
vent, contact plate connected to an electrode lead of electrode
assembly in the secondary battery and an insulating plate which
makes the safety vent and the contact plate meet only at an
electric connection portion.
Also in accordance with the present invention an integrated cap
assembly of a secondary battery and a method of fabricating the
same is provided which can simplify the process of fabricating the
secondary battery, thereby increasing the productivity and reducing
the manufacturing cost
Further in accordance with the present invention an integrated cap
assembly of a secondary battery is provided which includes a cap
lamination and a gasket integrated with each other through
injection-molding in a state that a peripheral portion of the cap
lamination is inserted in the gasket, wherein the cap lamination
may include a conductive safety vent unit, a printed circuit board,
a PTC element, and a positive electrode cap. In an exemplary
embodiment a groove and/or a hole is formed at a portion of at
least one element of the cap lamination being inserted in the inner
side of an insulating gasket, the portion may be a peripheral
portion of a lowermost element of the cap lamination, so that a
portion of the insulating gasket is inserted in the hole or the
groove, thereby enhancing the assembling force between the cap
lamination and the insulating gasket.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of a conventional cylinder-type
secondary battery.
FIG. 2 is a sectional view of a cap assembly according to an
exemplary embodiment of the present invention.
FIG. 3 is a sectional view of a cap assembly according to another
embodiment of the invention.
FIG. 4 is a sectional view of a cap assembly according to yet
another embodiment of the invention.
FIG. 5 is a sectional view of a cap assembly according to still
another embodiment of the invention.
FIG. 6 is a sectional view of a cap assembly according to yet
another embodiment of the invention.
FIG. 7 is a flowchart showing a process for integrally molding a
cap assembly according to an exemplary embodiment of the present
invention.
DETAILED DESCRIPTION
Referring now to FIG. 2, an exemplary embodiment of a cap assembly
according to the present invention includes a cap lamination and
insulating gasket 235. The cap lamination includes conductive
safety vent unit 231, printed circuit board 232, PTC element 233,
and positive electrode cap 234.
Conductive safety vent unit 231 seals a can of the secondary
battery and can be bent outward (upward in the drawing) by a
pressure generated in the secondary battery. Conductive safety vent
unit 231 has a central portion which is deformed or convex inward
(downward in the drawing) in a normal state. The downward convex or
deformed portion of conductive safety vent unit 231 is electrically
connected with a positive electrode tab extending from a positive
electrode plate of an electrode assembly placed in the can of the
secondary battery.
Printed circuit board/current breaker 232 is disposed above
conductive safety vent unit 231 and transfers electric current
supplied from the positive electrode tab to positive electrode cap
234. Printed circuit board/current breaker 232 has a
current-interrupting means which is broken and interrupts electric
current flow by the deformation of conductive safety vent unit 231
when the internal pressure of the battery exceeds a predetermined
value due to abnormal operation such as excessive charging, etc.
Printed circuit board/current breaker 232 is usually made from an
epoxy-based resin. Printed circuit board/current breaker 232
includes a traverse extending over and across the deformed portion
of conductive safety vent unit 231 and its ring-shaped member
connected to opposite ends of the traverse. The traverse has a
breakable portion which can be tom by the force applied by the
deformed portion of conductive safety vent unit 231 when the
deformed portion of conductive safety vent unit 231 is inverted.
The breakable portion is a weakened portion having slits formed
through central and end portions of the traverse. The breakable
portion may have either a single kind of at least two slits, or
combination of slits and grooves.
PTC element 233 is a current regulator which instantly increases
the resistance to regulate or interrupt current flow when the
temperature of the battery increases beyond a safety limit. PTC
element 233 is optional in a cap assembly of a secondary battery
according to the present invention.
Positive electrode cap 234 has a plurality of pores. Positive
electrode cap 234 is an element which may come into contact with an
external terminal.
The cap lamination including the elements as described above is
assembled with insulating gasket 235. In order to assemble the cap
lamination with insulating gasket 235, the cap lamination is
inserted in and is integrally formed with insulating gasket 235
when insulating gasket 235 is molded. Then, a portion of the edges
of the cap lamination is inserted into insulating gasket 235. Edges
of each element of the cap lamination integrally molded in
insulating gasket 235, i.e., each of conductive safety vent unit
231, Printed circuit board/current breaker 232, PTC element 233,
and positive electrode cap 234, are individually integrated with
insulating gasket 235. Therefore, the cap lamination and insulating
gasket 235 are completely integrated with each other without any
gap between them. Here, when some elements such as PTC element 233
are omitted in the cap lamination, only the other elements of the
cap lamination are stacked on each other and then inserted in
insulating gasket 235 while insulating gasket 235 is molded.
Further, groove H, which in exemplary embodiments may be an annular
through-hole or a recess, is formed at a peripheral portion of
Printed circuit board/current breaker 232, which is the lowermost
element of the cap lamination. As a result, when insulating gasket
235 is molded, a portion of insulating gasket 235 is inserted in
groove H, thereby enhancing the assembling force between the cap
lamination and insulating gasket 235. In one exemplary embodiment,
groove H is wedge shaped having an upper or rear portion wider than
a lower or inlet portion thereof. Here, groove H may have not only
a frusto-conical shape but also various shapes including shapes of
polygonal prisms, such as triangular prisms, rectangular prisms,
pentagonal prisms, etc. Further, although FIG. 2 shows groove H
formed at the lowermost element of the cap lamination, a groove,
hole or recess may be formed in and/or through the lower two
elements or all the elements of the cap lamination.
FIG. 3 to FIG. 6 are sectional views of a cylinder-type cap
assembly according to other exemplary embodiments of the present
invention.
FIG. 3 shows a contact plate 336 which has a through-hole 3361 and
is connected to an electrode lead (not shown) of an electrode
assembly, placed at the lowermost layer of the cap assembly.
Conductive safety vent unit 331 has a ring-shaped peripheral
portion separated from the contact plate 336 by the insulating
plate 337. The conductive safety vent unit 331, which is placed
above the contact plate 336, also has a central portion formed
downward convexly so that it is contact with the contact plate
336.
PTC 333 and a positive electrode cap 334 are mounted above
conductive safety vent unit 331.
The cap lamination assembly may be integrally formed with a gasket
335, its peripheral portion of the cap lamination assembly being
covered by the gasket when the gasket is formed through
injection-molding.
Also, the cap lamination assembly and the gasket 335 are integrally
inserted in the upper portion of a can and become part of the
cylinder-type secondary battery through a crimping process.
In the gasket injection process, a portion of the gasket 335 is
directed into a wedge-shaped through-hole 3363 formed in the
contact plate 336 and solidified, thereby enhancing the physical
assembling force between the gasket and the cap lamination
assembly.
The through-hole 3363 may be formed such that the diameter of its
upper part is the same as the diameter of its lower part.
Alternatively, the through-hole 3363 may have a conical shape.
If heating in the interior of the secondary battery raises the
interior pressure of the battery to an abnormal level, the pressure
on the through-hole 3361 will push the downward convex portion of
conductive safety vent unit 331 upward to cut off contact between
the conductive safety vent and the contact plate 336. Thus electric
current between an electrode lead (not shown) and the positive
electrode cap 334 will be interrupted.
Additionally, PTC 333 works independently of conductive safety vent
unit 331 to turn off the electric current between the electrode
lead (not shown) and the positive electrode cap 334.
FIG. 4 shows an exemplary embodiment of a cap assembly similar to
the cap assembly shown in FIG. 3. However, the conductive safety
vent unit .[.331.]. .Iadd.431 .Iaddend.has an extension part 4311
formed on a peripheral portion thereof, the extension part
extending around a lower contact plate 436. The extension part 4311
may be deeply embedded in the interior part of an insulating gasket
435 in the exemplary embodiment of FIG. 4.
A hole 4363 for strengthening contact between a cap assembly and
the insulating gasket 435 is formed in the peripheral portion of
the contact plate 436.
If the extension part 4311 is bent inward, the extension part may
form a groove together with the lower side of the peripheral
portion of the contact plate 436, and the interior of the groove
can be filled with the insulating gasket 435.
The exemplary embodiment of a cap lamination assembly as shown in
FIG. 5 is similar to the exemplary embodiment of FIG. 3.
However, a peripheral portion of a contact plate 536 having a
through-hole 5361 at the lowermost layer of a cap lamination
assembly and being connected to an electrode lead (not shown) of an
electrode assembly is bent upward. A peripheral portion of an
insulating plate 537 above the contact plate 536 is also convexed
upward.
Conductive safety vent unit 531, which has a peripheral portion not
in contact with the contact plate 536, and a central portion formed
convexly so as to contact the contact plate is placed above the
insulating plate.
A positive electrode cap 534 are mounted above conductive safety
vent unit 531, and a PTC 533 may be mounted there as well.
In this exemplary embodiment, the insulating plate 536, conductive
safety vent unit 531, PTC 533, and the positive electrode cap 534
are placed in a fixed position above the contact plate 536 and the
insulating plate 537 of the lowermost layer.
The cap lamination assembly is also integrally formed with a gasket
535, its peripheral portion being covered by the gasket when the
gasket is formed through injection-molding as described above.
Also, the cap lamination assembly and the gasket 535 inserted in
the upper portion of the can, and become part of the cylinder-type
secondary battery through the crimping process.
The exemplary embodiment of FIG. 6 is also substantially similar to
the cap assembly of FIG. 3.
However, a contact plate 636 and an insulating plate 637 are formed
so as to correspond to and be attachable to the central portion of
conductive safety vent unit 631. Thus, the thickness of the
lamination assembly and the length of the secondary battery may be
reduced.
Also, a peripheral portion of conductive safety vent unit 631
itself has holes 6313 for strengthening assembly with an insulating
gasket 635. Additionally, the contact plate 636 has a hole 6361
allowing it to operate with conductive safety vent unit 631.
As a positive electrode cap 634, PTC 633, the contact plate 636,
and conductive safety vent unit 631 having the insulating plate 637
are laminated and the gasket 635 is injected therein, a portion of
the gasket becomes embedded in hole 6313 and solidifies. Thus, the
lamination assembly becomes integrally formed with the insulating
gasket 635.
An electrode lead (not shown) of an electrode assembly is welded to
the contact plate 636, and the lamination assembly is inserted into
the upper part of the cylinder-type cap through crimping to
complete assembly of the secondary battery.
FIG. 7 is a flowchart showing a process for integrally molding a
cap assembly according to an exemplary embodiment of the present
invention. As shown in FIG. 7, the method of injection-molding a
cap assembly according to the present invention includes: aligning
and stacking elements of a cap lamination on each other (S31);
picking up and transferring the cap lamination (S32); inserting and
supporting the cap lamination in a mold (S33); injecting a molding
material, thereby injection-molding a gasket with the cap
lamination (S34); and taking the cap assembly out of the mold
(S35).
In the element aligning and stacking step (S31), conductive safety
vent unit 231, printed circuit board 232, PTC element 233, and
positive electrode cap 234, which constitute the cap lamination,
are aligned and sequentially stacked one after another. Then, the
aligned and stacked cap lamination is supported and held by a
holder, such as a pneumatically-operated forced pin, etc. Here, the
forced pin may have a shape of a dip and may be preferably from the
same material as that of the gasket.
In the cap lamination pick up and transfer step (S32), the cap
lamination having been supported and held by a forced pin, etc., is
picked up and held by a dual pin, tweezers, etc., of an inserting
jig and is then moved to the mold by a robot control operation.
In the cap lamination inserting and supporting step (S33), the cap
lamination moved to the mold is inserted into the mold and is then
held by a holding pin, etc., in order to perform injection-molding
of the gasket. Here, the holding pin may be made from comparable
material as that of the gasket.
In the injection-molding step (S34), the gasket is injection-molded
in such a manner that edges of the gap lamination inserted and held
in the mold are partially inserted in the gasket. Here, a hole or
recess is formed at a lower element the cap lamination, and the
molten gasket is inserted in the hole or recess during the
injection-molding, thereby enhancing the assembling force between
the cap lamination and the gasket. The gasket may be made from
polymer resin, which is an insulating material, such as
polypropylene, etc.
In the step of the cap assembly take-out step (S35), the cap
assembly including the cap lamination and the gasket, which are
integrally injection-molded, is taken out of the mold and is then
dropped on an outputting conveyer.
As described above, the present invention provides an integrated
cap assembly for a secondary battery, thereby highly increasing
tightness between a cap lamination of the cap assembly, including
conductive safety vent unit 131, printed circuit board 132, PTC
element 133, and positive electrode cap 134, and an insulating
gasket surrounding and clamping the cap lamination. Further, a
process of forming a cap assembly of a secondary battery according
to the present invention enables the secondary battery to be
assembled by only one apparatus, thereby greatly reducing the
number of necessary apparatuses, the manufacturing time, the
manufacturing cost, etc., for the fabrication of the secondary
battery, and thereby increasing productivity.
Although exemplary embodiments of the present invention have been
described for illustrative purposes, those skilled in the art will
appreciate that various modifications, additions and substitutions
are possible, without departing from the scope and spirit of the
invention as disclosed in the accompanying claims.
* * * * *