U.S. patent application number 12/876053 was filed with the patent office on 2010-12-30 for rechargeable battery with electrolyte injection opening sealing member.
Invention is credited to Ki-Ho Kim, Yong-Sam Kim, Sang-Won Lee, Hong-Sup Lim.
Application Number | 20100330417 12/876053 |
Document ID | / |
Family ID | 36617379 |
Filed Date | 2010-12-30 |
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United States Patent
Application |
20100330417 |
Kind Code |
A1 |
Kim; Yong-Sam ; et
al. |
December 30, 2010 |
RECHARGEABLE BATTERY WITH ELECTROLYTE INJECTION OPENING SEALING
MEMBER
Abstract
A rechargeable battery having an electrolyte sealing member
covering and sealing the electrolyte injection opening. An
electrode assembly includes a positive electrode, a negative
electrode and a separator wound in a jelly roll configuration. A
case houses the electrode assembly. A cap assembly is combined with
the case to seal the case, the cap assembly including a positive
terminal connected to the positive electrode and a negative
terminal connected to the negative electrode. An electrolyte
injection opening is formed on the case or the cap assembly. A
groove is formed along a periphery of the electrolyte injection
opening. An electrolyte sealing member engages the groove.
Inventors: |
Kim; Yong-Sam; (Yongin-si,
KR) ; Kim; Ki-Ho; (Yongin-si, KR) ; Lim;
Hong-Sup; (Yongin-si, KR) ; Lee; Sang-Won;
(Yongin-si, KR) |
Correspondence
Address: |
CHRISTIE, PARKER & HALE, LLP
PO BOX 7068
PASADENA
CA
91109-7068
US
|
Family ID: |
36617379 |
Appl. No.: |
12/876053 |
Filed: |
September 3, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11434637 |
May 15, 2006 |
7799456 |
|
|
12876053 |
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Current U.S.
Class: |
429/185 |
Current CPC
Class: |
Y02E 60/10 20130101;
H01M 50/60 20210101; H01M 50/3425 20210101; H01M 50/636 20210101;
H01M 50/155 20210101; H01M 10/04 20130101 |
Class at
Publication: |
429/185 |
International
Class: |
H01M 2/04 20060101
H01M002/04 |
Foreign Application Data
Date |
Code |
Application Number |
May 16, 2005 |
KR |
10-2005-0040590 |
Claims
1. A rechargeable battery comprising: an electrode assembly
including a positive electrode, a negative electrode and a
separator interposed therebetween; a case for housing the electrode
assembly; a cap assembly combined with the case to seal the case,
the cap assembly including a cap plate having a positive terminal
connected to the positive electrode and a negative terminal
connected to the negative electrode; an electrolyte injection
opening formed on the cap assembly; a groove formed around a
periphery of the electrolyte injection opening; and an electrolyte
sealing member engaged with the groove, the electrolyte sealing
member covering and sealing the electrolyte injection opening.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 11/434,637, filed May 15, 2006, which claims
priority to and the benefit of Korean Patent Application No.
10-2005-0040590, filed May 16, 2005, the entire content of both of
which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a rechargeable battery.
More particularly, the present invention relates to a rechargeable
battery with an improved sealing structure of an electrolyte
injection opening.
[0004] 2. Description of the Related Art
[0005] Distinct from a primary battery, a secondary (rechargeable)
battery can be repeatedly charged and discharged. Recently,
researchers are developing high-power rechargeable batteries using
non-aqueous electrolyte which has a high energy density.
[0006] Low-capacity batteries having a single battery pack are used
as a power source for various portable electronic devices such as
mobile phones and laptop computers. High-capacity rechargeable
batteries formed using tens of battery cells connected to each
other may be used as a power source for driving a motor in a device
requiring high power, such as an electric vehicle.
[0007] A rechargeable battery includes an electrode assembly of a
shape such as a jelly-roll configuration having a positive
electrode and a negative electrode with a separator interposed
between them, a case having a space for housing the electrode
assembly, a cap plate combined with the case to seal the case, and
a positive terminal and a negative terminal protruding toward the
cap plate and electrically connected to the positive electrode and
the negative electrode, respectively.
[0008] Rechargeable batteries are manufactured in diverse shapes,
such as cylindrical shapes and prismatic shapes which are selected
and used according to device requirements for a rechargeable
battery.
[0009] The cap plate is welded onto the case to seal the case and
an electrolyte injection opening is formed in the cap plate through
which electrolyte solution is injected into the case. To prevent
the electrolyte solution from leaking out of the case, an
electrolyte sealing member is mounted on the electrolyte injection
opening.
[0010] In conventional rechargeable batteries, a spherical
electrolyte sealing member having a diameter larger than that of
the electrolyte injection opening is mounted and pressed onto the
circular electrolyte injection opening and fixed onto the cap plate
by laser welding.
[0011] However, when the spherical electrolyte sealing member seals
the electrolyte injection opening, as used in conventional
rechargeable batteries, it is difficult to securely weld the
electrolyte sealing member onto the cap plate because the upper
surface of the electrolyte sealing member may not form an exact
circle. Thus, a laser used for welding is not well irradiated onto
the junction face. Further, when the electrolyte sealing member is
inserted into the electrolyte injection opening and welded thereto,
a portion between the electrolyte injection opening and the
electrolyte sealing member may be smeared with electrolyte
solution, thus deteriorating the weld. Poor welding may allow the
electrolyte solution to leak out along the electrolyte injection
opening causing a short-circuit.
SUMMARY OF THE INVENTION
[0012] One embodiment of the present invention provides a
rechargeable battery having an improved sealing structure for an
electrolyte injection opening by improving the structure of the
electrolyte injection opening and an electrolyte sealing member for
closing the electrolyte injection opening.
[0013] According to the embodiment of the present invention, a
rechargeable battery is provided that includes a groove formed
along a circumference of the electrolyte injection opening, and an
electrolyte sealing member engaged with the groove and covering and
sealing the electrolyte injection opening.
[0014] More specifically, a rechargeable battery is provided having
an electrolyte sealing member covering and sealing the electrolyte
injection opening. An electrode assembly includes a positive
electrode, a negative electrode and a separator wound in a jelly
roll configuration. A case houses the electrode assembly. A cap
assembly is combined with the case to seal the case, the cap
assembly including a positive terminal connected to the positive
electrode and a negative terminal connected to the negative
electrode. An electrolyte injection opening is formed on the case
or the cap assembly. A groove is formed along a periphery of the
electrolyte injection opening. An electrolyte sealing member
engages the groove.
[0015] The electrolyte sealing member is welded to the cap plate at
an edge of the groove distal from the electrolyte injection hole.
The electrolyte injection opening may be formed to have a circular
cross section.
[0016] The groove may be formed apart from the electrolyte
injection opening by a predetermined distance, and the groove may
be formed to contact the electrolyte injection opening.
[0017] The brim of the electrolyte sealing member may come on a
same plane as the upper surface of the cap assembly.
[0018] The groove may be formed consecutively to have a loop
structure.
[0019] The electrolyte sealing member may include a cover for
closing the electrolyte injection opening and a rib which is
protruded from the entire surface of the cover and engaged with the
groove.
[0020] The rib may be formed consecutively along circumference of
the cover.
[0021] The rib may be formed to have an external diameter
corresponding to the external diameter of the groove.
[0022] The electrolyte sealing member may be press-fit into the
groove.
[0023] The electrolyte sealing member may be engaged with the
groove and the electrolyte sealing member may be fixed onto the
case or the cap assembly by welding.
[0024] One side of the electrolyte sealing may be slanted from the
upper surface of the electrolyte sealing member to a height
corresponding to the case or the cap plate to form a slant
face.
[0025] A welding part having a height corresponding to the depth of
the groove may be formed to be extended outward from the side of
the electrolyte sealing member.
[0026] A slant face may be formed along the side of the electrolyte
sealing member from the upper surface of the electrolyte sealing
member to the welding part.
[0027] A vent broken at a predetermined pressure may be formed in
the electrolyte sealing member.
[0028] The vent may be formed in a depressed structure.
[0029] The rechargeable battery may be used for driving a
motor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 is a cross sectional view showing a rechargeable
battery in accordance with an exemplary embodiment of the present
invention.
[0031] FIG. 2 is a partial perspective cross-sectional view showing
a sealing structure of an electrolyte injection opening of the
rechargeable battery in accordance with an exemplary embodiment of
the present invention.
[0032] FIG. 3 is a perspective view showing a structure of an
exemplary electrolyte sealing member of the present invention.
[0033] FIG. 4 is a cross-sectional view illustrating a sealed
electrolyte injection opening of a rechargeable battery in
accordance with an exemplary embodiment of the present
invention.
[0034] FIG. 5 is a partial perspective cross-sectional view showing
a sealing structure of an electrolyte injection opening of a
rechargeable battery in accordance with another exemplary
embodiment of the present invention.
[0035] FIG. 6 is a cross-sectional view illustrating a sealed
electrolyte injection opening of a rechargeable battery in
accordance with another exemplary embodiment of the present
invention.
[0036] FIG. 7 is a partial perspective cross-sectional view showing
a sealing structure of an electrolyte injection opening of a
rechargeable battery in accordance with yet another exemplary
embodiment of the present invention.
[0037] FIG. 8 is a block diagram schematically showing a
rechargeable battery as a power source for driving a motor.
DETAILED DESCRIPTION
[0038] Referring to FIG. 1, a rechargeable battery 100 includes an
electrode assembly 10 having a positive electrode 11 and a negative
electrode 12 with a separator 13 interposed between them, a
prismatic case 14 for housing the electrode assembly 10, a cap
assembly 30 mounted on an opening of the case 14 and sealing the
case 14, and a positive terminal 31 and a negative terminal 32
which are electrically connected to the positive electrode 11 and
the negative electrode 12, respectively, through tabs 15. The
positive and negative electrode taps protrude to the outside of the
cap assembly 30.
[0039] The cap assembly 30 includes a safety vent 20 for exhausting
gas generated by the rechargeable battery 100, an electrolyte
injection opening 34 through which electrolyte solution is injected
into the case 14, and an electrolyte sealing member 40 for sealing
the electrolyte injection opening 34 to seal the case 14. The
electrolyte injection opening 34 may be formed at one side of the
cap assembly 30.
[0040] The case 14 may be formed of conductive metal such as
aluminum, aluminum alloy and nickel-plated steel in the shape of
hexahedron having an internal space for housing the electrode
assembly 10 or another shape.
[0041] The present invention will be described by using a
rechargeable battery having a prismatic shape as an example.
However, the present invention is not limited to a prismatic shape,
but rather, the present invention may be applied to rechargeable
batteries of other shapes, such as a cylindrical shape.
[0042] The electrode assembly 10 is formed in the shape of a jelly
roll by stacking the positive electrode 11 and the negative
electrode 12 with the separator 13 and winding them together. Both
the positive electrode 11 and the negative electrode 12 include a
current collector coated with an active material.
[0043] An uncoated region 11a of the positive electrode and an
uncoated region 12a of the negative electrode are positioned at
either end of the electrode assembly 10 such that the uncoated
regions 11a, 12a, one located on either side end of the case 14
when the cap assembly 30 are disposed in a vertical direction as
shown in FIG. 1.
[0044] The positive terminal 31 and the negative terminal 32 are
electrically connected to the uncoated region 11a of the positive
electrode (positive uncoated region) and the uncoated region 12a of
the negative electrode (negative uncoated region), respectively,
through tabs 15 or current collecting plates.
[0045] The cap assembly 30 includes a cap plate 33 mounted on the
upper part of the case 14. The positive terminal 31 and the
negative terminal 32 mounted on either sides of the cap plate
33.
[0046] A safety vent 20 may be mounted on the cap plate 33 and the
electrolyte injection opening 34 is spaced from the safety vent 20
by a predetermined distance.
[0047] The electrolyte injection opening 34 is sealed by the
following structure in the present embodiment.
[0048] As shown in FIG. 2, the electrolyte injection opening 34 is
formed in the cap plate 33 and a cross section of the electrolyte
injection opening 34 is generally circular.
[0049] In an external surface of the cap plate 33, a groove 35 is
formed around the periphery of the electrolyte injection opening
34, the groove being spaced a predetermined distance from the
electrolyte injection opening 34. The groove 35 may be formed
continuously to have a loop cross section. The size and the depth
of the groove 35 may vary.
[0050] Referring to FIG. 3, an electrolyte sealing member 40 for
sealing the electrolyte injection opening 34 includes a covering
disc 41 for covering the electrolyte injection opening 34, and a
rib 42 protruding from the periphery of the covering disc 41
perpendicularly to the covering disc 41. The rib 42 is integrated
with the covering disc 41 and it is formed continuously along the
circumference of the covering disc 41 to have a loop cross section.
The rib 42 may have a diameter corresponding to a diameter of the
groove 35 and is adapted to be inserted into the groove 35. A rib
42 formed to be wider than the width of the groove 35 may be
press-fitted into the groove 35.
[0051] Even when the groove 35 and the rib 42 have different
widths, the external diameter of the rib 42 may correspond to the
external diameter of the groove 35. Thus, when the rib 42 is
engaged with the groove 35, the circumferential surface of the
groove 35 closely contacts the external circumferential surface of
the rib 52.
[0052] As described above, the electrolyte sealing member 40 may be
easily disposed in the electrolyte injection opening 34 since the
rib 42 fits into the groove 35 formed along the circumference of
the electrolyte injection opening 34. The electrolyte injection
opening 42 is thus sealed when the rib 42 of the electrolyte
sealing member 40 closes the electrolyte injection opening 34 and
its circumference.
[0053] The material that forms the electrolyte sealing member 40 is
not specifically limited and it may be the same material as that of
the cap plate 33.
[0054] Referring to FIG. 4, laser welding is carried out along the
boundary (P) between the rib 42 and the cap plate 33 when the rib
42 is engaged with the groove 35 of the cap plate 33 to firmly fix
the electrolyte sealing member onto the cap plate 33.
[0055] The boundary (P) may be spaced from the electrolyte
injection opening 34 by a predetermined distance to prevent the
weld from being degraded even if electrolyte solution is smeared
onto the electrolyte injection opening 34. Thus, the electrolyte
sealing member becomes firmly fixed onto the cap plate 33 and seals
the electrolyte injection opening 34.
[0056] FIGS. 5 and 6 illustrate a rechargeable battery in
accordance with another exemplary embodiment of the present
invention. Referring to FIGS. 5 and 6, the rechargeable battery of
the present embodiment improves a weld by locating the welding
surface between an electrolyte sealing member 50 and the cap plate
33 on the same plane.
[0057] More specifically, a groove 35' is formed as a loop along
the circumference of the electrolyte injection opening 34 on the
cap plate 33, and the groove 35' is formed spaced from the
electrolyte injection opening 34 by a predetermined distance.
[0058] The electrolyte sealing member 50 engageable with the groove
35 includes a covering disc 51 for covering the electrolyte
injection opening 34, and a rib 52 protruding along the entire
external circumferential surface of the covering disc 51 and
engageable with the groove 35.
[0059] This embodiment illustrates an electrolyte sealing member 50
having a covering disc 51 for sealing the electrolyte injection
opening 34 having a circular cross section. However, the present
invention is not limited to a circular shape, but rather the
covering disc may be formed in diverse shapes depending on the
cross-sectional shape of the electrolyte injection opening.
[0060] The rib 52 includes a welding portion 54 formed having a
height generally corresponding to a depth of the groove 35 and
extending from a side of the rib 52 to contact a side of the groove
35. The welding portion 54 has an external diameter corresponding
to the external diameter of the groove 35. Thus, when the rib 52 is
engaged with the groove 35, the external circumferential surface of
the welding portion 54 contacts the surface of the groove 35.
[0061] The height of the welding portion 54 corresponds to the
depth of the groove 35. Thus, when the rib 52 is engaged with the
groove 35, laser welding may be performed easily along the boundary
(P) between the rib 52 and the groove 35 which meet on the same
plane. Also, the electrolyte sealing member 50 may be formed to be
slanted at a predetermined angle from the upper part of the
covering disc 51 to the welding portion 54 to provide a slanted
face 53. Since the slanted face 53 more distinctly exposes the
boundary (P) between the welding portion 54 and the cap plate 33,
the laser welding may be performed more precisely.
[0062] Referring to FIG. 7, the electrolyte injection opening 34 is
formed in the cap plate 33. A groove 37 is formed in contact with
the electrolyte injection opening 34 along the circumference of the
electrolyte injection opening 34.
[0063] An electrolyte sealing member 60 is mounted on the groove 37
to seal the electrolyte injection opening 34. The electrolyte
sealing member 60 is formed in the shape of a disc such that the
external diameter of the electrolyte sealing member 60 is the same
as or slightly larger than the diameter of the groove 37. Thus,
when the electrolyte sealing member 60 is engaged with the groove
37, the groove 37 contacts the surface of the electrolyte sealing
member 60.
[0064] The electrolyte sealing member 60 has a height about equal
to the depth of the groove 37. When the electrolyte sealing member
60 is engaged with the groove 37, the electrolyte sealing member 60
and the cap plate 33 are on the same plane. Thus, the electrolyte
sealing member 60 may be easily welded to the groove.
[0065] A vent 61 is formed on the surface of the electrolyte
sealing member 60. The vent 61 is formed to have a lower shear
strength than the electrolyte sealing member 60. Thus, the vent may
be fractured at a predetermined pressure when the pressure
increases inside the rechargeable battery. Since the vent 61 is
recessed, it is thinner than the rest of the electrolyte sealing
member 60. The vent 61 may be formed to have a cross section of a
wedge or a notch. As stress is converged into the edge of the
wedge, the vent 61 is easily fractured at the predetermined
pressure.
[0066] FIG. 8 is a block diagram schematically showing a state in
which the rechargeable battery 100 shown in FIG. 1 is connected to
a motor 70.
[0067] According to the above-described embodiments of the present
invention, the electrolyte sealing member may be easily mounted on
the electrolyte injection opening. The technology of the present
invention simplifies the process of fabricating a rechargeable
battery and increases the output.
[0068] Also, the technology of the present invention improves the
sealing of rechargeable batteries by more securely combining the
electrolyte injection opening to the electrolyte sealing
member.
[0069] When the boundary between the electrolyte sealing member and
the groove are on the same plane as the cap plate, the electrolyte
sealing member and the groove may be easily welded. Also, when the
vent is mounted to the electrolyte sealing member, there is no need
to form an additional vent member, thus simplifying the
rechargeable battery fabrication process.
[0070] The rechargeable batteries described above may be
effectively used as batteries for hybrid electric vehicles
requiring high power and high capacity. However, the usage of the
rechargeable batteries is not limited to batteries for hybrid
electric vehicles.
[0071] While this invention has been described in connection with
what is presently considered to be exemplary embodiments, it will
be understood that the invention is not limited to the disclosed
embodiments, but, rather is intended to cover various modifications
and equivalent arrangements included within the spirit and scope of
the appended claims.
* * * * *