U.S. patent application number 10/515316 was filed with the patent office on 2006-03-30 for outer case for non-aqueous electrolyte battery and method of producing the same.
Invention is credited to Masaru Hiratsuka, Masanori Naritomi, Mitsuo Sakamoto.
Application Number | 20060068281 10/515316 |
Document ID | / |
Family ID | 32599274 |
Filed Date | 2006-03-30 |
United States Patent
Application |
20060068281 |
Kind Code |
A1 |
Hiratsuka; Masaru ; et
al. |
March 30, 2006 |
Outer case for non-aqueous electrolyte battery and method of
producing the same
Abstract
An outer casing of a non-aqueous electrolyte battery is capable
of being mass-produced as well as thin and resistant to damage. The
outer casing 4 comprises a casing body 4a and a cover 4b. After
being internally packaged, a non-aqueous electrolyte battery 2,
e.g. a lithium-ion polymer secondary battery, is sandwiched between
the casing body 4a and the cover 4b, which are then joined together
integrally. The cover 4b is formed from a film-shaped sheet
material 4c of a synthetic resin to make the outer casing 4 thin.
The casing body 4a and the cover 4b have a casing body outer
peripheral frame 9 and a cover outer peripheral frame 10,
respectively, formed by injection molding. Joint portions of the
casing body 4a and the cover 4b have stepped portions 9a and 10a,
respectively. The stepped portions ensure the mechanical strength
against shock and impact. With this structure, the outer casing 4
is resistant to damage.
Inventors: |
Hiratsuka; Masaru;
(Shinagawa-ku, JP) ; Sakamoto; Mitsuo;
(Shinagawa-ku, JP) ; Naritomi; Masanori; (Chuo-ku,
JP) |
Correspondence
Address: |
RADER FISHMAN & GRAUER PLLC
LION BUILDING
1233 20TH STREET N.W., SUITE 501
WASHINGTON
DC
20036
US
|
Family ID: |
32599274 |
Appl. No.: |
10/515316 |
Filed: |
December 17, 2002 |
PCT Filed: |
December 17, 2002 |
PCT NO: |
PCT/JP03/16175 |
371 Date: |
November 23, 2004 |
Current U.S.
Class: |
429/185 ;
29/623.4; 429/175; 429/176; 523/134 |
Current CPC
Class: |
Y10T 29/49108 20150115;
H01M 50/209 20210101; Y02E 60/10 20130101; H01M 10/052 20130101;
Y10T 29/4911 20150115; Y10T 29/49114 20150115 |
Class at
Publication: |
429/185 ;
429/175; 429/176; 029/623.4; 523/134 |
International
Class: |
H01M 2/08 20060101
H01M002/08; H01M 2/04 20060101 H01M002/04 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 17, 2002 |
JP |
2002-365773 |
Oct 1, 2003 |
JP |
2003-342769 |
Claims
1. An outer casing for externally packaging a non-aqueous
electrolyte battery, comprising: a rectangular casing body (4a)
formed of a synthetic resin for accommodating said non-aqueous
electrolyte battery, said casing body having a casing body outer
peripheral frame (9) integrally provided on an outer peripheral
edge of a side of said casing body; a cover (4b) including a
film-shaped side panel (4c) formed of a synthetic resin that covers
an open side of said non-aqueous electrolyte battery accommodated
in said casing body (4a), and a cover outer peripheral frame (10)
formed of a synthetic resin that is integrally fixed to an outer
peripheral edge of said side panel (4c); and joint portions for
integrally joining together said casing body outer peripheral frame
(9) and said cover outer peripheral frame (10) in opposed relation
to each other.
2. An outer casing for externally packaging a non-aqueous
electrolyte battery according to claim 1, wherein said joint
portions have positioning means (9a and 10a) for positioning said
casing body outer peripheral frame (9) and said cover outer
peripheral frame (10) relative to each other.
3. An outer casing for externally packaging a non-aqueous
electrolyte battery according to claim 2, wherein said positioning
means (9a and 10a) include a first stepped portion (9a) with a
stair-shaped sectional configuration that is formed on said casing
body outer peripheral frame (9) and a second stepped portion (10a)
with a stair-shaped sectional configuration that is formed on said
cover outer peripheral frame (10), said first stepped portion (9a)
and said second stepped portion (10a) being fitted in opposed
relation to each other and joined together integrally.
4. An outer casing for externally packaging a non-aqueous
electrolyte battery according to claim 1 or 2, wherein said casing
body (4a) has terminal windows (3) in the form of through-holes
that allow contact with input and output terminals of said
non-aqueous electrolyte battery.
5. An outer casing for externally packaging a non-aqueous
electrolyte battery according to claim 3, wherein said first
stepped portion (9a) and said second stepped portion (10a) each
have surfaces differing in height from each other.
6. A production method for an outer casing for externally packaging
a non-aqueous electrolyte battery as defined in claim 1, said
method comprising: forming said casing body (4a) by injection
molding in an injection-molding mold; inserting said side panel
(4c) into an injection-molding mold and injecting a synthetic resin
onto an outer peripheral edge of said side panel (4c) to integrally
fix the cover outer peripheral frame (10) to the outer peripheral
edge of said side panel (4c), thereby forming said cover (4b); and
integrally joining together said casing body outer peripheral frame
(9) and said cover outer peripheral frame (10) in opposed relation
to each other, thereby producing said outer casing (4).
7. A production method according to claim 6, wherein said fixing is
fusion bonding by the molten resin for forming said cover outer
peripheral frame (10) in said injection-molding mold, and said
joining is effected by ultrasonic welding.
8. A production method according to claim 7, wherein welding
portions (22) in the form of projections for said joining are
formed on said casing body outer peripheral frame (9) and/or said
cover outer peripheral frame (10) to effect said ultrasonic
welding.
9. An outer casing for externally packaging a non-aqueous
electrolyte battery, said outer casing comprising: a film-shaped
first side panel (44e) formed of a synthetic resin that covers a
side of said non-aqueous electrolyte battery that is wider than
other sides of said battery; a film-shaped second side panel (44c)
formed of a synthetic resin that covers a side of said non-aqueous
electrolyte battery opposite to said side; a first outer peripheral
frame (44f) formed of a synthetic resin that is integrally fixed to
an outer peripheral edge of said first side panel (44e); a second
outer peripheral frame (44d) formed of a synthetic resin that is
integrally fixed to an outer peripheral edge of said second side
panel (44c); and joint portions for integrally joining together
said first outer peripheral frame (44f) and said second outer
peripheral frame (44d) in opposed relation to each other.
10. An outer casing for externally packaging a non-aqueous
electrolyte battery according to claim 9, wherein said joint
portions have positioning means (49a) for positioning said first
outer peripheral frame (44f) and said second outer peripheral frame
(44d) relative to each other.
11. An outer casing for externally packaging a non-aqueous
electrolyte battery according to claim 10, wherein said positioning
means (49a) include recesses (49a) and projections to be fitted
into said recesses (49a) to effect positioning, said recesses (49a)
and said projections being formed on said first outer peripheral
frame (44f) and said second outer peripheral frame (44d).
12. An outer casing for externally packaging a non-aqueous
electrolyte battery according to claim 9, wherein said first outer
peripheral frame (44f) and/or said second outer peripheral frame
(44d) has terminal windows (43) in the form of through-holes that
allow contact with input and output terminals of said non-aqueous
electrolyte battery.
13. A production method for an outer casing for externally
packaging a non-aqueous electrolyte battery as defined in claim 9,
said method comprising: inserting said first side panel (44e) into
an injection-molding mold and injecting a synthetic resin onto an
outer peripheral edge of said first side panel (44e) to integrally
fix the first outer peripheral frame (44f) to the outer peripheral
edge of said first side panel (44e), thereby forming a first casing
body member (44a); inserting said second side panel (44c) into an
injection-molding mold and injecting a synthetic resin onto an
outer peripheral edge of said second side panel (44c) to integrally
fix the second outer peripheral frame (44d) to the outer peripheral
edge of said second side panel (44c), thereby forming a second
casing body member (44b); and opposing said first casing body
member (44a) and said second casing body member (44b) to each other
and integrally joining together said first outer peripheral frame
(44f) and said second outer peripheral frame (44d).
14. A production method according to claim 13, wherein said fixing
is fusion bonding by the molten resin for forming said first outer
peripheral frame and by the molten resin for forming said second
outer peripheral frame in the respective injection-molding molds,
and said joining is effected by ultrasonic welding.
15. A production method according to claim 14, wherein welding
portions (22) in the form of projections for said joining are
formed on said first outer peripheral frame (44f) and/or said
second outer peripheral frame (44d) to effect said ultrasonic
welding.
Description
TECHNICAL FIELD
[0001] The present invention relates to an outer casing for
externally packaging a non-aqueous electrolyte battery body
packaged in an aluminum laminated film or the like and also relates
to a production method for the outer casing. More particularly, the
present invention relates to an outer casing of a non-aqueous
electrolyte battery that externally packages a non-aqueous
electrolyte battery element with a thin casing body formed of a
synthetic resin or a film-shaped sheet material having a frame
member of a synthetic resin integrally fixed to the outer periphery
thereof. The present invention also relates to a production method
for the outer casing.
BACKGROUND ART
[0002] Conventionally, a lithium-ion battery is housed in a metal
case, e.g. a steel can, or an aluminum can, and a polymer battery
is packaged in an aluminum laminated film. These batteries need to
be further externally packaged to protect them against shock from
dropping or other external impact. There are known methods for
externally packaging the battery body, for example, a method
wherein the battery body is hermetically covered with a case-shaped
member formed of an aluminum sheet, a plastic material, etc., and a
method wherein the outer surface of the battery body is covered
with a thermoplastic resin by injection molding, thereby packaging
the battery body in the molded resin.
[0003] It is also publicly known that heat-shrinkable tubing made
of polyvinyl chloride or the like is used as a heat-shrinkable
synthetic resin material for covering batteries. Stretched tubing
made of a mixed composition consisting essentially of an
olefin-based ionomer resin is also publicly known as an example of
heat-shrinkable tubing [for example, see Japanese Patent
Application Unexamined Publication (KOKAI) No. Hei 11-170365].
[0004] However, the conventional externally packaging methods have
not yet satisfied all the demands but still have many problems to
be solved. Particularly, cellular phones and the like require as
thin a battery as possible, and a battery that meets the
requirement has appeared. If this battery is covered with thin
hear-shrinkable tubing, the tubing may be partially wrinkled.
Therefore, there is a problem in terms of reliability in mass
production of batteries of stable quality. Meanwhile, injection
molding is excellent in mass productivity but disadvantageous for
the following reason. With the conventional injection molding, the
flow of molten resin is deteriorated as the thickness of the molded
part to be produced is reduced. Accordingly, there is a limit to
the reduction of the part thickness.
[0005] Cellular phones and the like require a material having
chemical resistance and fire retardance. To prepare a resin
material satisfying these requirements, PBT (polybutylene
terephthalate) resin may be mixed with a fire retardant consisting
essentially of an inorganic material, for example. In this case, a
part thickness of at least 0.3 mm to 0.4 mm is required because the
flow of molten resin would otherwise be deteriorated. Thus, it is
even more difficult to obtain a thin molded part. Accordingly, the
thickness of injection-molded parts cannot be reduced to less than
a predetermined thickness as long as an injection molding method
based on the presently common technique is employed. Lithium-ion
polymer secondary batteries, in particular, are characterized by
their capability of implementing a thin and lightweight structure.
Therefore, a thick outer casing that would lessen the advantageous
feature of lithium-ion polymer secondary batteries cannot be
adopted.
[0006] The outer casing for lithium-ion polymer secondary batteries
is required to exhibit stable mechanical strength despite the thin
and lightweight structure. Meanwhile, there has been proposed a
method of producing a thin-walled molded part for housing an
electronic component, wherein a thin-walled portion of the molded
part is formed of a film, and a thick-walled portion thereof is
formed by injection molding [Japanese Patent Application Unexamined
Publication (KOKAI) No. 2002-283507]. However, the thin-walled
molded part does not completely cover the outer surface of the
housed component. Therefore, it cannot be employed for the
above-described outer packaging of batteries.
DISCLOSURE OF THE INVENTION
[0007] With the above-described technical background, the present
invention was made to attain the following objects.
[0008] An object of the present invention is to provide an outer
casing of a non-aqueous electrolyte battery in which a side of the
casing is formed from a film-shaped sheet material formed of a
synthetic resin or by injection molding, thereby realizing an
extremely thin external package exhibiting stable mechanical
strength, and also provide a production method for the outer
casing.
[0009] Another object of the present invention is to provide an
outer casing of a non-aqueous electrolyte battery that is easy to
manufacture and suitable for mass production by injection molding
process of high productivity, and also provide a production method
for the outer casing.
[0010] Still another object of the present invention is to provide
an outer casing of a non-aqueous electrolyte battery that allows
implementation of external packaging excellent in design, and also
provide a production method for the outer casing.
[0011] An advantage of the present invention is as follows. An
outer casing of a non-aqueous electrolyte battery is formed by
joining together a casing body and a cover that are different in
configuration from each other, or by joining together a pair of
mating molded pieces of the same configuration. Joint portions for
joining together the two constituent members of the outer casing
are formed integrally on the two constituent members, respectively,
in the form of a stepped structure. Therefore, the outer casing can
be formed thin in thickness, and yet the required mechanical
strength can be ensured satisfactorily.
[0012] Another advantage of the present invention is that the
capacity-volume efficiency and the capacity-weight efficiency of
the battery pack can be improved.
[0013] Still another advantage of the present invention is that the
production method for the outer casing can employ injection molding
process that is simple and capable of mass production.
[0014] A further advantage of the present invention is that because
a part of the outer casing can be formed by injection molding, the
freedom of configuration increases, so that the outer casing can be
formed into a product that is tasteful and excellent in design.
[0015] The present invention adopts the following means to solve
the above-described problems.
[0016] An outer casing for externally packaging a non-aqueous
electrolyte battery according to a first feature of the present
invention is an outer casing (4) characterized by including a
rectangular casing body (4a) formed of a synthetic resin for
accommodating the non-aqueous electrolyte battery. The casing body
has a casing body outer peripheral frame (9) integrally provided on
the outer peripheral edge of a side of the casing body. The outer
casing (4) further includes a cover (4b) including a film-shaped
side panel (4c) formed of a synthetic resin that covers an open
side of the non-aqueous electrolyte battery accommodated in the
casing body (4a). The cover (4b) further includes a cover outer
peripheral frame (10) formed of a synthetic resin that is
integrally fixed to the outer peripheral edge of the side panel
(4c). Further, the outer casing (4) includes joint portions for
integrally joining together the casing body outer peripheral frame
(9) and the cover outer peripheral frame (10) in opposed relation
to each other.
[0017] It should be noted that the term "film-shaped" as used in
the present invention means being in the form of a thin film, a
thin plate, or a sheet, but does not necessarily mean being a
film.
[0018] An outer casing for externally packaging a non-aqueous
electrolyte battery according to a second feature of the present
invention is characterized as follows. In the outer casing
according to the first feature of the present invention, the joint
portions have positioning means (9a and 10a) for positioning the
casing body outer peripheral frame (9) and the cover outer
peripheral frame (10) relative to each other.
[0019] An outer casing for externally packaging a non-aqueous
electrolyte battery according to a third feature of the present
invention is characterized as follows. In the outer casing
according to the second feature of the present invention, the
positioning means (9a and 10a) include a first stepped portion (9a)
with a stair-shaped sectional configuration that is formed on the
casing body outer peripheral frame (9) and a second stepped portion
(10a) with a stair-shaped sectional configuration that is formed on
the cover outer peripheral frame (10). The first stepped portion
(9a) and the second stepped portion (10a) are fitted in opposed
relation to each other and joined together integrally.
[0020] An outer casing for externally packaging a non-aqueous
electrolyte battery according to a fourth feature of the present
invention is characterized as follows. In the outer casing
according to the first or second feature of the present invention,
the casing body (4a) has terminal windows (3) in the form of
through-holes that allow contact with input and output terminals of
the non-aqueous electrolyte battery.
[0021] An outer casing for externally packaging a non-aqueous
electrolyte battery according to a fifth feature of the present
invention is characterized as follows. In the outer casing
according to the third feature of the present invention, the first
stepped portion (9a) and the second stepped portion (10a) each have
surfaces differing in height from each other.
[0022] A production method according to a sixth feature of the
present invention is a method of producing the outer casing for
externally packaging a non-aqueous electrolyte battery according to
the first feature of the present invention. The production method
is characterized in that the casing body (4a) is formed by
injection molding in an injection-molding mold. The side panel (4c)
is inserted into an injection-molding mold, and a synthetic resin
is injected onto the outer peripheral edge of the side panel (4c)
to integrally fix the cover outer peripheral frame (10) to the
outer peripheral edge of the side panel (4c), thereby forming the
cover (4b). Then, the casing body outer peripheral frame (9) and
the cover outer peripheral frame (10) are integrally joined
together in opposed relation to each other, thereby producing the
outer casing (4).
[0023] A production method for an outer casing of a non-aqueous
electrolyte battery according to a seventh feature of the present
invention is characterized as follows. In the production method
according to the sixth feature of the present invention, the
above-described fixing is fusion bonding by the molten resin for
forming the cover outer peripheral frame (10) in the
injection-molding mold, and the above-described joining is effected
by ultrasonic welding.
[0024] A production method for an outer casing of a non-aqueous
electrolyte battery according to an eighth feature of the present
invention is characterized as follows. In the production method
according to the seventh feature of the present invention, welding
portions (22) in the form of projections for the above-described
joining are formed on the casing body outer peripheral frame (9)
and/or the cover outer peripheral frame (10) to effect the
ultrasonic welding.
[0025] An outer casing for externally packaging a non-aqueous
electrolyte battery according to a ninth feature of the present
invention is characterized by including a film-shaped first side
panel (44e) formed of a synthetic resin that covers a side of the
non-aqueous electrolyte battery that is wider than other sides of
the battery. A film-shaped second side panel (44c) formed of a
synthetic resin covers a side of the non-aqueous electrolyte
battery opposite to the above-described side. A first outer
peripheral frame (44f) formed of a synthetic resin is integrally
fixed to the outer peripheral edge of the first side panel (44e). A
second outer peripheral frame (44d) formed of a synthetic resin is
integrally fixed to the outer peripheral edge of the second side
panel (44c). The outer casing further includes joint portions for
integrally joining together the first outer peripheral frame (44f)
and the second outer peripheral frame (44d) in opposed relation to
each other.
[0026] An outer casing for externally packaging a non-aqueous
electrolyte battery according to a tenth feature of the present
invention is characterized as follows. In the outer casing
according to the ninth feature of the present invention, the joint
portions have positioning means (49a) for positioning the first
outer peripheral frame (44f) and the second outer peripheral frame
(44d) relative to each other.
[0027] An outer casing for externally packaging a non-aqueous
electrolyte battery according to an eleventh feature of the present
invention is characterized as follows. In the outer casing
according to the tenth feature of the present invention, the
positioning means (49a) include recesses (49a) and projections to
be fitted into the recesses (49a) to effect positioning. The
recesses (49a) and the projections are formed on the first outer
peripheral frame (44f) and the second outer peripheral frame
(44d).
[0028] An outer casing for externally packaging a non-aqueous
electrolyte battery according to a twelfth feature of the present
invention is characterized as follows. In the outer casing
according to the ninth feature of the present invention, the first
outer peripheral frame (44f) and/or the second outer peripheral
frame (44d) has terminal windows (43) in the form of through-holes
that allow contact with input and output terminals of the
non-aqueous electrolyte battery.
[0029] A production method according to a thirteenth feature of the
present invention is a method of producing the outer casing for
externally packaging a non-aqueous electrolyte battery according to
the ninth feature of the present invention. The production method
is characterized in that the first side panel (44e) is inserted
into an injection-molding mold, and a synthetic resin is injected
onto the outer peripheral edge of the first side panel (44e) to
integrally fix the first outer peripheral frame (44f) to the outer
peripheral edge of the first side panel (44e), thereby forming a
first casing body member (44a). The second side panel (44c) is
inserted into an injection-molding mold, and a synthetic resin is
injected onto the outer peripheral edge of the second side panel
(44c) to integrally fix the second outer peripheral frame (44d) to
the outer peripheral edge of the second side panel (44c), thereby
forming a second casing body member (44b). The first casing body
member (44a) and the second casing body member (44b) are opposed to
each other, and the first outer peripheral frame (44f) and the
second outer peripheral frame (44d) are joined together
integrally.
[0030] A production method for an outer casing for a non-aqueous
electrolyte battery according to a fourteenth feature of the
present invention is characterized as follows. In the production
method according to the thirteenth feature of the present
invention, the above-described fixing is fusion bonding by the
molten resin for forming the first outer peripheral frame and by
the molten resin for forming the second outer peripheral frame in
the respective injection-molding molds, and the above-described
joining is effected by ultrasonic welding.
[0031] A production method for an outer casing of a non-aqueous
electrolyte battery according to a fifteenth feature of the present
invention is characterized as follows. In the production method
according to the fourteenth feature of the present invention,
welding portions (22) in the form of projections for the
above-described joining are formed on the first outer peripheral
frame (44f) and/or the second outer peripheral frame (44d) to
effect the ultrasonic welding.
[0032] It should be noted that the term "non-aqueous electrolyte
battery" as used in the present invention means a battery
containing a non-aqueous electrolyte material in the electrolyte
thereof. Examples of such non-aqueous electrolyte material include
an electrolytic solution, a polymer gel electrolyte, a solid
electrolyte, a polymer electrolyte, and a molten salt electrolyte.
Batteries in the present invention include not only secondary
batteries but also primary batteries. Batteries containing a
non-aqueous electrolyte material include lithium-ion batteries,
lithium-ion secondary batteries, lithium-ion polymer batteries,
etc.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 is an external view showing a lithium-ion polymer
secondary battery.
[0034] FIG. 2 is an exploded view illustrating the lithium-ion
polymer secondary battery.
[0035] FIG. 3 is a sectional view taken along the line X-X in FIG.
1.
[0036] FIG. 4 is a sectional view taken along the line Y-Y in FIG.
1.
[0037] FIG. 5 is a sectional view of an injection-molding mold used
to form a cover.
[0038] FIG. 6 is a sectional view showing the injection-molding
mold when it is closed.
[0039] FIG. 7 is a fragmentary enlarged view of a cover outer
peripheral frame in the injection-molding mold.
[0040] FIG. 8 is a sectional view showing a molten resin injected
into a cavity for the cover outer peripheral frame.
[0041] FIG. 9 is a fragmentary sectional view of an outer casing
after bonding process.
[0042] FIG. 10 is a sectional view showing the way in which the
cover is joined to the casing body by ultrasonic welding.
[0043] FIG. 11 illustrates an example showing another configuration
of a sheet material for forming a side of the casing.
[0044] FIG. 12 is a sectional view of a molten resin injected into
a cavity for an outer peripheral frame, which shows a second
embodiment.
[0045] FIG. 13 is a fragmentary sectional view of a cover after
molding process, which shows the second embodiment.
[0046] FIG. 14 is a sectional view of a thermoforming die for
vacuum forming in a third embodiment.
[0047] FIG. 15 is a sectional view showing an injection-molding
mold when closed in the third embodiment.
[0048] FIG. 16 is a sectional view of a cover after injection
molding process in the third embodiment.
[0049] FIG. 17 is a sectional view showing an injection-molding
mold when closed in a fourth embodiment.
[0050] FIG. 18 is a fragmentary enlarged view of the
injection-molding mold in the fourth embodiment.
[0051] FIG. 19 is a fragmentary enlarged view of a cover after
injection molding process in the fourth embodiment.
[0052] FIG. 20 is a fragmentary enlarged view of a cover after
injection molding process in a fifth embodiment.
[0053] FIG. 21 is a fragmentary enlarged view of a cover after
injection molding process in a sixth embodiment.
[0054] FIG. 22 is a sectional view of an injection-molding mold
used to form a cover in a seventh embodiment.
[0055] FIG. 23 is a sectional view showing the injection-molding
mold when closed in the seventh embodiment.
[0056] FIG. 24 is an external view showing a lithium-ion polymer
secondary battery having another configuration.
[0057] FIG. 25 is an exploded view illustrating the lithium-ion
polymer secondary battery shown in FIG. 24.
BEST MODE FOR CARRYING OUT THE INVENTION
[First Embodiment]
[0058] A first embodiment of the present invention will be
described below. FIG. 1 is an external view of a lithium-ion
polymer secondary battery 1 to which the present invention is
applied. FIG. 2 is an exploded view of the lithium-ion polymer
secondary battery 1. FIG. 3 is a sectional view taken along the
line X-X in FIG. 1. FIG. 4 is a sectional view taken along the line
Y-Y in FIG. 1.
[0059] The lithium-ion polymer secondary battery 1 is a repeatedly
rechargeable battery, which is used as a battery for a cellular
phone or the like. The lithium-ion polymer secondary battery 1 is a
thin and lightweight battery implemented by replacing an
electrolytic solution with a gel-state polymer electrolyte. In this
example, the lithium-ion polymer secondary battery 1 is a thin
battery (e.g. 3.8 mm in thickness) implemented so as to be usable
in a cellular phone or the like.
[0060] An outer casing 4 of the lithium-ion polymer secondary
battery 1 is a synthetic resin casing-produced by a method
described later. The outer casing 4 basically comprises a casing
body 4a and a cover 4b. The casing body 4a of the outer casing 4
has three terminal windows 3 in the form of through-holes through
which an electric current is input and output. FIG. 2 is an
exploded view of the lithium-ion polymer secondary battery. A
battery element 2 is a main body constituting the lithium-ion
polymer secondary battery.
[0061] The battery element 2 is formed by stacking a strip anode
and a strip cathode with a polymer electrolyte layer and/or a
separator interposed therebetween, and winding the stack structure
in the longitudinal direction. In addition, an anode terminal 5 and
a cathode terminal 6 are led out from the anode and the cathode,
respectively. The anode comprises a strip anode current collector
and an anode active material layer formed thereon. Further, a
polymer electrolyte layer is formed on the anode active material
layer. Further, a polymer electrolyte layer is formed on a cathode
active material layer. The anode terminal 5 and the cathode
terminal 6 are joined to the anode current collector and the
cathode current collector, respectively. The materials and
functions of these components are not directly related to the
subject matter of the present invention. Therefore, a detailed
description thereof is omitted.
[0062] The battery element 2 is packaged in an aluminum laminated
film 7. The aluminum laminated film 7 has a laminated structure
formed from a polypropylene (PP) layer, an aluminum layer, a
polyamide layer, etc. stacked in that order from the inner side.
The aluminum layer prevents water from entering the interior of the
battery. The polypropylene layer prevents change in quality of the
polymer electrolyte and also serves as a joint surface of the
aluminum laminated film 7. That is, joining for sealing the
aluminum laminated film 7 is effected by fusion-bonding the opposed
edges of the polypropylene layer.
[0063] The polyamide layer imparts strength and gas barrier
properties to the aluminum laminated film 7. The aluminum laminated
film 7 extends beyond the outer periphery of the rectangular
battery element 2 at three sides thereof. That is, the aluminum
laminated film 7 has a top hem portion 7a corresponding to the top
position of the battery element 2 and side hem portions 7b
corresponding to the side positions of the battery element 2. The
top hem portion 7a and the side hem portions 7b are provided by
forming the fusion-bonded portions of the polypropylene layer with
an extra width at the three sides of the aluminum laminated film 7
to prevent water from entering the interior of the battery element
2 from the outside. As shown in FIG. 2, the side hem portions 7b
are folded in one direction when the battery element 2 is
accommodated in the outer casing 4.
[0064] The elongated strip anode and cathode terminals 5 and 6 are
folded and laminated to the top hem portion 7a. A protective
circuit board 8 is disposed adjacently to the anode terminal 5 and
the cathode terminal 6. The distal ends of the anode and cathode
terminals 5 and 6 are connected to respective terminals on the
protective circuit board 8 by spot welding, ultrasonic welding,
etc., thereby being electrically connected to each other. Because
the protective circuit board 8 is accommodated within the thickness
of the battery element 2, together with the top hem portion 7a, the
lithium-ion polymer secondary battery 1 can be made compact in
size.
[0065] On the protective circuit board 8 are implemented a
protective element, e.g. a thermostat, a PTC, or a temperature
fuse, and/or an electronic circuit for protection (not shown).
Further, input/output terminals 8a are provided on the protective
circuit board 8, which are contact terminals for drawing an
electric current. The input/output terminals 8a are capable of
contacting terminals on the associated equipment that are inserted
from the terminal windows 3. Although in this example the terminal
windows 3 are formed in a side of the casing body 4a, the terminal
windows 3 may be formed in another side that is at 90 degrees to
the above-described side, for example, in the cover 4b.
Alternatively, the terminal windows 3 may be formed in a region
extending over from the casing body 4a to the cover 4b. The battery
element 2 and the protective circuit board 8 are accommodated in
the casing body 4a, which constitutes one casing half, and covered
with the cover 4b, which constitutes the other casing half.
[0066] The first embodiment of the present invention relates to the
above-described outer casing 4. That is, the outer casing 4
comprises the casing body 4a and the cover 4b, which are provided
in the form of two casing halves, and the battery element 2 and the
protective circuit board 8 are sandwiched between the two casing
halves, thereby being packaged. The completed lithium-ion polymer
secondary battery 1 is a product in which the battery element 2 and
the protective circuit board 8 are packaged and integrated with the
casing body 4a and the cover 4b. The product name, the manufacturer
name, etc. are indicated on the surface of the outer casing 4 by
using a label or the like.
[0067] Conventionally, a synthetic resin plastic molded casing has
been used, as stated above. The synthetic resin casing can be
produced with a complicated configuration by injection molding.
However, there is a limit to the reduction in thickness of the
conventional synthetic resin casing. In contrast to this, the first
embodiment of the present invention can fabricate a lightweight and
thin outer casing having a complicated configuration because of the
use of a sheet material or a combination of a sheet material and
injection molding process. Further, the first embodiment of the
present invention has the advantage that the mold structure is
simplified, as will be explained later.
[0068] The outer casing 4 according to the present invention makes
use of the advantageous features of the material. That is, the
casing body 4a for accommodating the lithium-ion polymer secondary
battery 1 comprises a surface portion 9b (side) injection-molded as
thin as possible and a casing body outer peripheral frame 9 with a
stepped portion 9a that forms the outer peripheral edge of the
surface portion 9b. The cover 4b opposed to the casing body 4a
comprises a sheet material 4c (side) in the form of a film (thin
film) of a synthetic resin and a cover outer peripheral frame 10
with a stepped portion 10a that is formed by injecting a synthetic
resin to cover the outer peripheral edge of the sheet material 4c.
The casing body outer peripheral frame 9 of the casing body 4a and
the cover outer peripheral frame 10 of the cover 4b are opposed and
joined to each other through the stepped portions 9a and 10a,
thereby obtaining an outer casing 4 that is thin and yet
mechanically strong and easy to manufacture.
[0069] An end portion inside the casing body 4a may be integrally
formed with board supporting ribs for supporting the protective
circuit board 8, according to need. In this embodiment, however,
such ribs are not shown in the figure. It is a matter of course
that the lithium-ion polymer secondary battery 1 is placed in the
casing body 4a so as not to be displaced. FIGS. 3 and 4 show the
structure of the outer casing 4 accommodating the battery element
2, which is a non-aqueous electrolyte battery, as stated above.
[Production Method for Outer Casing 4]
[0070] Next, a production method for the outer casing 4 will be
described. In this embodiment, the casing body 4a has an integral
structure formed by injection molding. That is, the surface portion
9b for accommodating the battery element 2 and the casing body
outer peripheral frame 9 are simultaneously injection-molded in the
same cavity to form an integral structure. The casing body outer
peripheral frame 9 of the casing body 4a is formed with a stepped
portion 9a having a stair-shaped sectional configuration. The
stepped portion 9a may be provided with an undercut for fitting. In
this case, injection molding is performed by a publicly known
method capable of removal from the mold by splitting the mold or
making use of elastic deformation.
[0071] The injection molding method is based on a common method.
Therefore, a description thereof is omitted. The surface portion 9b
for accommodating the battery element 2 is made as thin as possible
within the range in which the mechanical strength required for the
outer casing 4 can be ensured. Meanwhile, the surface portion of
the cover 4b that covers the battery element 2 is formed of a sheet
material 20 (stock for the sheet material 4c) in the form of a film
(0.1 mm in thickness in this example) of a synthetic resin, as
shown in FIG. 5. One surface of the sheet material 20 may be
previously printed with the specifications, trademark, etc. of the
product or labeled to show such information.
[0072] Because the stock of the sheet material 20 is flat with a
plane surface, the sheet material 20 before forming process can be
easily printed with information indicating model name, capacity,
place of manufacture, etc. or labeled to indicate such information
instead of printing. The sheet material 20 is formed of a synthetic
resin. Examples of usable synthetic resins are PBT (polybutylene
terephthalate), ABS resin, PC (polycarbonate), PET (polyethylene
terephthalate), etc. In the first embodiment, a sheet material 20
with a thickness of the order of from 0.02 mm to 0.3 mm is used. As
shown in FIG. 5, the rectangular sheet material 20 is placed on a
stationary mold member 11 of an injection-molding mold by vacuum
holding or other similar means.
[0073] Thereafter, a movable mold member 12 is moved toward the
stationary mold member 11 to press the sheet material 20, thereby
plastically deforming it as shown in FIGS. 6 and 7. The plastically
deformed sheet material 20 is in the shape of a box with a tapered
portion 21 around the outer periphery thereof. The deformation of
the tapered portion 21 of the sheet material 20 may cause wrinkle
in the corner thereof. However, the wrinkled portion is softened
and drawn to become unwrinkled by injection of a molten resin to
form the cover outer peripheral frame 10, as described later.
Therefore, there will be no problem.
[0074] As shown in FIGS. 6 and 7, a molten resin is injected into a
sprue 13 from the nozzle tip of an injection molding machine to
form the cover outer peripheral frame 10. The injected molten resin
flows through a runner 14 and a gate 15 to fill a cavity 16 for
forming the cover outer peripheral frame 10. The filling of the
injected molten resin causes the tapered portion 21 to extend and
come in close contact with the cavity surface of the movable mold
member 12 as shown in FIG. 8. Thus, the cover outer peripheral
frame 10 is constructed. The synthetic resin for forming the cover
outer peripheral frame 10 is the same material as that of the sheet
material 20. That is, one of the above-described resins, i.e. PBT,
ABS, PC, PET, etc. is used. It is preferable to use a resin
material that is excellent in chemical resistance and has a
coefficient of thermal expansion close to that of the aluminum
laminated film 7 constituting the battery element 2. The reason for
this is to allow the cover outer peripheral frame 10 to follow a
change in size of the battery element 2 even if the latter shrinks
by heat.
[0075] As the result of filling the molten resin into the cavity
16, the molten resin and the sheet material 20 fusion-bond to each
other to form the cover outer peripheral frame 10, as has been
stated above. To effect the desired fusion bonding, it is
preferable to use the same resin material for the cover outer
peripheral frame 10 and the sheet material 20. It should be noted
that injection molding as stated above is generally carried out for
a plurality of products simultaneously from the viewpoint of
improving productivity. Therefore, in actual practice, the molten
synthetic resin is simultaneously injected into not only the cavity
16 but also a plurality of other cavities (not shown) through
respective runners 14. Thus, a plurality of covers 4b are
simultaneously produced by injection molding.
[0076] The casing body 4a has a thickness close to that of the
battery element 2. The casing body outer peripheral frame 9 of the
casing body 4a is provided with terminal windows 3. Further, an end
portion of the casing body outer peripheral frame 9 of the casing
body 4a is provided with a positioning hole A or a positioning
projection (cylinder) B. If the projection B is provided on the
casing body outer peripheral frame 9 of the casing body 4a, the
hole A is provided in the cover outer peripheral frame 10 of the
cover 4b. As has been stated above, the casing body outer
peripheral frame 9 and the cover outer peripheral frame 10 are
molded on the respective outer peripheral edges of the casing body
4a and the cover 4b. The joint portions of the casing body outer
peripheral frame 9 and the cover outer peripheral frame 10 have the
stepped portions 9a and 10a, respectively. The casing body 4a and
the cover 4b are joined to each other through the stepped portions
9a and 10a.
[0077] The stepped portions 9a and 10a formed on the joint portions
increase the mechanical strength of the outer casing 4. FIG. 9 is a
fragmentary sectional view showing the casing body 4a and the cover
4b after they have been joined to each other. As shown in FIG. 9,
when a load F is applied to the cover 4b, because the joint
portions have the stepped portions 9a and 10a, respectively, the
mating casing body 4a also receives the load F through the stepped
portions 9a and 10a.
[0078] Accordingly, the load F is borne at the joint portions and
also borne at mutually abutting portions 9c of the stepped portions
9a and 10a. Therefore, the joint strength is further increased in
comparison to a joint structure having joint portions that are flat
over the entire surfaces, for example. The structure according to
the present invention is free from the likelihood of breakage of
the outer casing 4, e.g. separation of the cover 4b from the casing
body 4a, even if an impacting load is applied to the outer casing 4
when it is dropped, for example.
[0079] Welding portions (ridges) 22 for ultrasonic welding may be
formed along the stepped portion 10a of the cover outer peripheral
frame 10 of the cover 4b, according to need. The welding portions
(ridges) 22 formed on the joint portion increase the strength of
joining with the mating member and facilitate the joining. The
welding portions 22 may be provided on the joint portion of the
mating member. The joint portions can be joined together by fusion
bonding even if they are flat. However, a joint portion with an
uneven surface configuration is capable of enhancing the joint
strength.
[0080] Further, positioning of the casing body 4a and the cover 4b
during joining process can be effected by fitting the stepped
portions 9a and 10a of the respective joint portions to each other.
However, it is preferable to employ a positioning structure in
which pins (not shown) formed on the casing body 4a are inserted
into positioning holes formed in the protective circuit board 8 or
the cover 4b to join the casing body 4a and the cover 4b to each
other. With this structure, the casing body 4a and the cover 4b,
including the protective circuit board 8, can be positioned with
respect to each other.
[0081] FIG. 10 is a sectional view illustrating ultrasonic welding.
The casing body 4a molded by the above-described method is inserted
into a predetermined positioning recess 26 in a holder (fixing jig)
25, thereby being positioned. The battery element 2 is mounted in
the casing body 4a. Further, the cover 4b is placed over the
battery element 2 so as to face the casing body 4a across the
battery element 2.
[0082] In this state, a tool horn 27 secured to the distal end of a
stationary horn 28, which is driven by an ultrasonic oscillator
(not shown) of an ultrasonic welding machine, moves downward to
press a portion of the cover 4b corresponding to the cover outer
peripheral frame 10. Ultrasonic welding is based on the principle
that ultrasonic vibration is applied to the joint surfaces of two
synthetic resins to weld them together by frictional heat.
[0083] More specifically, when the tool horn 27 being
ultrasonically vibrated is brought into contact with one of two
synthetic resin molded pieces to be welded together, ultrasonic
vibration energy transmitted from the distal end of the tool horn
27 to the molded piece changes into mechanical vibration at the
joint surfaces of the two molded pieces (this is known as
"hammering effect"). Consequently, frictional heat is generated
from the entire surfaces of the joint portions, causing the heated
portions to be melted. Thus, the joint surfaces are welded together
instantaneously.
[0084] The welding portions 22 of the casing body 4a are portions
to be welded, which are known as "ridges". If ultrasonic energy is
concentrated on the welding portions 22, the rise in temperature of
the joint surface of the cover outer peripheral frame 10 is
accelerated. Consequently, complete welding can be
accomplished.
[0085] Thus, as shown in FIG. 10, the casing body 4a and the cover
4b are butted against each other in the direction of the arrows,
and the stepped portions 9a and 10a of the joint portions of the
casing body outer peripheral frame 9 and the cover outer peripheral
frame 10 are joined to each other. The ultrasonic welding provides
a beautifully finished joint and requires a short welding time.
Ultrasonic welding can be effectively applied to the outer casing 4
of the present invention because it can be applied to small-sized
products and carried out efficiently. With the ultrasonic welding,
once the casing body 4a and the cover 4b have been butt-joined
together, they cannot be disassembled. In actual practice,
therefore, after the battery element 2, the protective circuit
board 8 and so forth have been incorporated, the casing body 4a and
the cover 4b are butt-joined to form an integral structure. FIG. 9
is a fragmentary sectional view of the butt-joint portion of the
outer casing 4 after the bonding process.
[0086] The figures illustrating the first embodiment are
schematically drawn for explanatory purposes. In actuality, the
sheet material 20 and the cover outer peripheral frame 10 are
extremely thin and very light in weight. External packaging by the
outer casing 4 according to the present invention is mechanically
strong because the outer casing 4 has the casing body outer
peripheral frame 9 and the cover outer peripheral frame 10 and is
provided with the stepped portions 9a and 10a. The outer casing 4
also exhibits superior effects in terms of design. Accordingly, the
lithium-ion polymer secondary battery 1 can be offered as a product
that is robust and exhibits a quality appearance.
[0087] Further, because labeling, printing, etc. can be easily
performed on the cover 4b even when it is in the stage of the sheet
material 20, various designs can be given to the outer casing 4.
Moreover, productivity can be increased. Although the sheet
material 20 of the cover 4b has its outer peripheral edge folded
during injection molding, as stated above, the sheet material 20
may be previously formed into a foldable configuration. FIG. 11
illustrates an example showing such a configuration of the sheet
material. That is, the figure shows the original configuration of a
sheet material 4c for forming a side of the outer casing 4. The
sheet material 4c has cut portions 23 at four corners and further
has fold lines 24 thereon.
[0088] Because the cut portions 23 and the fold lines 24 have been
formed on the sheet material 20a before it is inserted into the
injection-molding mold, the sheet material 20a is easy to deform at
the time of molding. Accordingly, it is possible to mold the outer
casing 4 accurately. Further, in this embodiment, the cover member
has its outer peripheral portion folded as shown in the figures.
However, the cover member may be a plane sheet without being
subjected to forming process. Next, an embodiment in which the
cover member is a plane sheet will be described.
[Second Embodiment (Another Production Method for Outer Casing
4)]
[0089] FIG. 12 is a diagram showing a second embodiment, which is a
fragmentary sectional view of an injection-molding mold used to
mold a cover 4b in the second embodiment. In the foregoing first
embodiment, after the sheet material 20 has been plastically
deformed, the cover outer peripheral frame 10 is injection-molded.
In the second embodiment shown in FIG. 12, the sheet material 20
does not extend to the outer peripheral portion of the cover outer
peripheral frame 10. Accordingly, there is practically no
deformation of the sheet material 20 in a cavity 30. The second
embodiment does not need trimming of the sheet material 20 after
the injection molding process and hence facilitates manufacture.
FIG. 13 is a fragmentary sectional view of the cover 4b after the
molding process.
[Third Embodiment (Thermoforming of Sheet Material)]
[0090] In either of the foregoing first and second embodiments, the
sheet material 4c of the cover 4b for forming a side of the outer
casing 4 is formed into a predetermined shape in the
injection-molding mold. In this embodiment, the sheet material is
thermoformed before it is inserted into the injection-molding mold.
FIG. 14 is a sectional view of a thermoforming die 25a for vacuum
forming. As shown in FIG. 14, a sheet material 20b, which is a
thermoplastic sheet, is fixed on the thermoforming die 25a and
heated to soften with a heater 34. The softened sheet material 20b
is sucked onto the thermoforming die 25a through a vacuum circuit
35 communicating with a vacuum device, thereby forming the sheet
material 20b.
[0091] Thereafter, the outer periphery of the thermoformed sheet
material 20b is trimmed with a cutting device (not shown). As shown
in FIG. 15, the thermoformed and trimmed sheet material 20b is
inserted into an injection-molding mold. Then, a molten resin is
injected to flow through a runner 14 and a gate 15 and filled in a
cavity 36 for molding a cover outer peripheral frame 10 in the same
way as in the foregoing embodiments.
[0092] Thereafter, as shown in FIG. 16, an unnecessary portion at
the outer periphery of the sheet material 20b is cut off with a
cutting edge 29 to complete the cover 4b. It should be noted that
the above-described thermoforming process is vacuum forming, and
the forming pressure is not more than 1 atmospheric pressure.
However, the thermoforming process may be pressure forming process
wherein the sheet material is formed by using compressed air of the
order of from 2 to 8 atmospheric pressures.
[Fourth Embodiment] (Thermoforming of Sheet Material)
[0093] A fourth embodiment is the same as the third embodiment in
that the sheet material is thermoformed before it is inserted into
an injection-molding mold. The fourth embodiment is also the same
as the third embodiment in that the outer periphery of the
thermoformed sheet material 20c is trimmed with a cutting device
(not shown). As shown in FIG. 18, however, the thermoformed and
trimmed sheet material 20c has burr 31 occurring on the cut surface
as a result of the cutting process.
[0094] It is necessary to carry out a deburring step of removing
the burr 31 before or after ultrasonic welding performed with an
ultrasonic welding apparatus after the above-described injection
molding. This embodiment enables the deburring step to be omitted.
An outer peripheral portion 32 of the sheet material 20c
constituting the cover outer peripheral frame 10 is cut shorter
than the thickness h (see FIG. 19) of the cover outer peripheral
frame 10.
[0095] The outer peripheral portion 32 is positioned in a cavity 33
of an injection-molding mold shown in FIG. 17. When a molten resin
is injected into the cavity 33, the outer peripheral portion 32 of
the sheet material 20c softens and fusion-bonds to the molten resin
into an integral structure (as shown in FIG. 19). Even if the sheet
material 20c and the cover outer peripheral frame 10 are formed of
different resin materials, the boundary between the sheet material
20c and the cover outer peripheral frame 10 is indiscernible with
the naked eye, provided that the same coloring matter is used.
Accordingly, the forming method according to the fourth embodiment
eliminates the need for the trimming operation otherwise required
after the injection molding process and hence allows the number of
steps to be reduced, advantageously.
[Fifth Embodiment] (Another Configuration of Stepped Portion)
[0096] FIG. 20 shows an example in which the stepped portion 9a or
10a at the joint portion of the casing body 4 or the cover 4b of
the outer casing 4 has a plurality of joint portions of different
heights provided in a stair-shaped configuration. The figure shows
an example in which the cover 4b has a stair-shaped stepped portion
10a. However, the casing body 4a may also have a stair-shaped
stepped portion 9a. With this arrangement, the joint area is
enlarged, and the joint strength is increased. An external force
applied to the cover outer peripheral frame 10 can also be borne by
the casing body outer peripheral frame 9 of the casing body 4a in
the same way as the above. Therefore, the outer casing 4 can be
reinforced effectively.
[Sixth Embodiment] (Still Another Configuration of Stepped
Portion)
[0097] FIG. 21 shows an example in which the stepped portion 9a or
10a of the joint portion of the outer casing 4 has a slant surface.
The figure shows an example in which the cover 4b has a stepped
portion 10a with a slant surface. However, the casing body 4a may
also have a stepped portion 9a with a slant surface. The slant
surface is a special example of the configuration of the stepped
portions 9a and 10a. However, an external force applied to the
cover outer peripheral frame 10 can also be borne by the casing
body outer peripheral frame 9 of the casing body 4a in the same way
as the above-described example. Therefore, the outer casing 4 can
be reinforced effectively.
[Seventh Embodiment] (Thermoforming for Obtaining Rounded Sheet
Material)
[0098] In the thermoforming of the sheet material in the first
embodiment shown in FIGS. 5 to 8, the sheet material 20 is
plastically deformed with a rather large size in consideration of
the fact that the whole deformed portion of the tapered portion 21
is fusion-bonded to the outer peripheral frame, as shown in FIGS. 5
to 8. In contrast to the first embodiment, the sheet material 20 in
this seventh embodiment, as shown in FIG. 22, has a smaller size
than that of the sheet material 20 shown in FIG. 5.
[0099] Another feature of this embodiment resides in that a corner
12a of a movable mold member 12 is intentionally rounded. When the
sheet material 20 vacuum-held to a stationary mold member 11 is
pressed between the stationary and movable mold members 11 and 12
so as to be plastically deformed, the sheet material 20 becomes as
shown in FIG. 23. After the plastic deformation, the outer
peripheral portion 21a of the sheet material 20 is within the
movable mold member 12 and will not extend outward of the frame.
The outer peripheral portion 21a is rounded in conformity to the
corner 12a of the movable mold member 12.
[0100] A molten resin injected from a gate 15 through a sprue 13
and a runner 14 is fusion-bonded to the outer peripheral portion
21a in such a manner that the injected resin covers the whole outer
peripheral portion 21a along the round profile of the corner 12a of
the movable mold member 12 and has a stepped configuration. The
outer peripheral portion 21a constitutes a corner of the outer
casing 4 when completed and hence provides a smoothly curved round
configuration. With the round configuration, the mechanical
strength of the outer casing 4 can be enhanced. In terms of design
also, the round configuration gives effectively a smooth and soft
appearance to the outer casing 4.
[Eighth Embodiment] (Another Lithium-Ion Polymer Secondary
Battery)
[0101] FIG. 24 is an external view of a lithium-ion polymer
secondary battery 40 to which the present invention is applied.
FIG. 25 is an exploded view of the lithium-ion polymer secondary
battery 40. The above-described casing body 4a shown in FIGS. 1 to
4 has the surface portion 9b for accommodating the battery element
2 and the casing body outer peripheral frame 9, which are
simultaneously molded into an integral structure in the same cavity
by injection molding.
[0102] The lithium-ion polymer secondary battery 40 shown in FIGS.
24 and 25 has an outer casing 44 comprising a first casing body
member 44a and a second casing body member 44b prepared as a pair
of casing body halves that are joined together into an integral
structure. The first casing body member 44a and the second casing
body member 44b are produced by substantially the same production
method as that for the casing body 4a in the above-described first
to eighth embodiments. Therefore, a repeated description of the
structure and projection method concerning the first and second
casing body members 44a and 44b is omitted.
[0103] The first casing body member 44a has a thin-walled,
film-shaped first side panel 44e formed of a synthetic resin as
stated above. A first outer peripheral frame 44f of a synthetic
resin is molded on the outer peripheral edge of the first side
panel 44e by the above-described injection molding method and
integrally fixed to the first side panel 44e in the mold.
Similarly, the second casing body member 44b has a film-shaped
second side panel 44c formed of a synthetic resin. A second outer
peripheral frame 44d of a synthetic resin is integrally formed on
the outer peripheral edge of the second side panel 44c by injection
molding.
[0104] The first outer peripheral frame 44f and the second outer
peripheral frame 44d are opposed to each other and joined together
into an integral structure by ultrasonic welding, adhesive or other
similar means. The first casing body member 44a of the outer casing
40 has three terminal windows 43 in the form of through-holes,
through which an electric current is input and output. The second
casing body member 44b is formed with board supporting ribs 49,
positioning holes 49a, etc. Positioning pins of the second casing
body member 44b are inserted into the positioning holes 49a at the
time of assembling. Therefore, the first casing body member 44a and
the second casing body member 44b can be assembled with high
accuracy.
[0105] A battery element 42, a protective circuit board 48, an
anode terminal 45, a cathode terminal 46, etc. each have
substantially the same structure and function as in the case of the
foregoing lithium-ion polymer secondary battery 1. Therefore, a
description thereof is omitted.
[Other Embodiments]
[0106] In the foregoing first to seventh embodiments, the sheet
material 20 is provided to extend outside the outer peripheral
frame as a skin. However, the sheet material 20 does not always
need to be disposed outside the outer peripheral frame but may be
disposed inside it.
INDUSTRIAL APPLICABILITY
[0107] The foregoing embodiments of the outer casing of the
non-aqueous electrolyte battery according to the present invention
are applied to a polymer battery packaged in an aluminum laminated
film. However, the outer casing of the present invention is also
applicable to external packaging for a metal case, e.g. a steel
can, or an aluminum can, which houses a lithium-ion battery.
* * * * *