JP2001093497A - Storage case for flat battery and battery pack using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a storage case for a flat battery, which is thin and can be increase in the capacity, and to provide a battery pack which uses the case. SOLUTION: A case for storing a flat battery has a split structure such that a first case 6 and a second case 8 are combined, wherein at least a part of the first case and the second case is made of metal plates 2a and 2b. Resin- made frame bodies 4a and 4b are arranged in one body with the metal plates 2a and 2b of the first case 6 and/or the second case 8. The case 6 and the case 8 are joined together through the frame bodies 4a and 4b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flat battery storage case and a battery pack using the same.

[0002]

2. Description of the Related Art In recent years, the reduction in size and weight of electronic devices such as mobile phones has been rapidly progressing, and accordingly, there has been a demand for the reduction in size and weight of batteries, which are driving power supplies for these devices. Conventionally, a Li-ion secondary battery having a high capacity and a high energy density has been used as a battery that satisfies such demands. However, recently, devices such as mobile phones have been required to be thinner. Thinning is a new challenge.

In this Li-ion secondary battery, since a non-aqueous solvent-based electrolyte is used as an electrolyte, the electrodes and the electrolyte are sealed in a battery can to manufacture the battery. It is necessary to prevent liquid leakage. Therefore, in order to reduce the thickness of the Li-ion secondary battery (for example, 4 mm or less), it is necessary to reduce the overall thickness of the battery can.
It is difficult to integrally form such a thin can by drawing. Further, when a thin can is manufactured by welding, it is necessary to perform seam welding, which is not preferable in terms of production efficiency and manufacturing cost.

[0004] For these reasons, a flat battery using a solid electrolyte or a polymer electrolyte instead of the above-mentioned electrolyte has attracted attention. This flat battery, for example, in the case of a Li-ion secondary battery, has a structure as shown in FIG.
In FIG. 10, a film-like gel electrolyte 60 in which a Li salt electrolyte solution is supported in a cross-linked structure of a polymer has a positive electrode 61.
And a negative electrode 62, which form a laminate 64. The positive electrode 61 is formed by applying a mixture containing an active material such as LiCoO ₂ to an Al foil, and a tongue-shaped positive electrode lead 61a extends from one side thereof. The negative electrode 62 is formed by applying a mixture containing a carbon material to a Cu foil, and similarly, a tongue-shaped negative electrode lead 62b extends from one side thereof. Then, Al laminated films 66 and 68 are disposed on the upper and lower surfaces of the laminated body 64, respectively.
By flattening the peripheral edges 66a, 68a of the 68 together, a flat battery 70 in which the whole is sealed is manufactured. In addition, the positive electrode lead 61a and the negative electrode lead 62b are exposed in parallel from one side of the bonded portion of the Al laminated films 66 and 68. As described above, since the flat battery uses the polymer electrolyte, there is no problem of leakage of the electrolytic solution, and the battery can be made unnecessary and the battery can be made thin (for example, 3.6 mm in thickness).

[0005] In this flat battery, since the Al laminate film itself as the exterior material does not have sufficient strength, when the flat battery is used in a bare state,
The battery may be bent or a sharp object may penetrate the battery, causing a safety problem. Therefore, in actual use of the flat battery, it is considered preferable to use the flat battery in the form of a battery pack containing the flat battery in a case having appropriate strength. At present, as such an accommodating case, a case of a two-part structure including an upper case and a lower case made of (synthetic) resin is known.

[0006]

However, when the above-mentioned case made of synthetic resin is applied to a flat battery,
In order to ensure proper strength characteristics, it is necessary to increase the thickness of each case, which causes a problem that the thickness of the entire battery pack increases. In other words, the thickness of the battery pack is equal to the thickness of the flat battery described above, and the thickness of the housing case provided above and below the flat battery (one surface and the other flat surface of the flat battery). However, in the case made of resin, it is necessary to make the thickness about 0.4 mm in terms of strength. Even if the thickness of the flat battery is, for example, 3.6 mm, the thickness of the entire battery pack is set to the target. Significantly exceeds (4 mm or more).

The present invention solves the above-mentioned problem in the conventional flat battery housing case in which both the upper case and the lower case are made of resin, and reduces the thickness of the case in the thickness direction of the flat battery to reduce the battery pack. An object of the present invention is to provide a flat battery storage case that can be made thinner as a whole and a battery pack using the same.

[0008]

In order to achieve the above object, a flat battery storage case according to the present invention as set forth in claim 1 is characterized in that at least a part thereof includes a first case made of a metal plate and a first case. And a metal plate in the first case and / or the second case,
It is characterized in that a resin frame is integrally attached, and the respective cases are united through the frame.

Preferably, a plurality of ribs or openings are formed on the surface of the metal plate in the first case and / or the second case (claim 2). It is preferable that the frame is provided with a connection terminal or an opening for exposing the connection terminal (claim 3).
Further, it is preferable that the frame body extends on a surface of the first case and / or the second case to form an insulating region (claim 4).

[0010] Further, there is provided a flat battery storage case having a configuration in which the metal plate in the first case and / or the second case is insert-molded in the frame. Furthermore, the first case or the second case is made of a metal plate having a side edge, and the side edge is provided with a flat battery housing case having a configuration fitted to the frame. (Claim 6).

It is preferable that a locking portion is formed on the side edge portion so as to be expanded after being fitted to the frame and to come into close contact with the frame. The case for accommodating a flat battery according to the present invention described in claim 8 is characterized by comprising the first case described in claim 5 and the second case described in claim 6 or 7.

The constituent material of the frame is a resin composition comprising a thermoplastic resin and a glass component (claim 8), the thermoplastic resin is a polycarbonate or a liquid crystal polymer, and the glass component is glass. It is a fiber chop or a glass bead (Claim 9), and in that case, the blending amount of the glass component is preferably 10 to 25% by volume (Claim 9).

According to a ninth aspect of the present invention, there is provided a battery pack according to any one of the first to eighth aspects, wherein the flat battery and the protection circuit are housed inside the flat battery housing case. Features.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a flat battery accommodating case according to an embodiment of the present invention will be described with reference to the drawings.
Note that the storage case of the present invention may have at least a two-part structure including the first case and the second case. In the following embodiments, the first case has a flat surface of a flat battery. An aspect in which the second case is disposed outside one surface and the second case is disposed outside the other flat surface of the flat battery will be described. Then, for convenience, the first case is referred to as an “upper case”, and the second case is referred to as a “lower case”. However, the present invention is not limited thereto. The first case may be regarded as a “lower case”, and the second case may be regarded as a “lower case”.

[0015] As shown in FIG.
An upper case 6 composed of an aluminum metal plate (thickness 0.2 mm) 2a and a resin (synthetic resin) frame (thickness 0.8mm, height about 2.1mm) 4a integrated with the periphery of the metal plate. , And a lower case 8 composed of a metal plate 2b and a frame 4b integrated with a peripheral portion of the metal plate. The divided structure is, for example, a long side 67 mm and a short side 37 m as a whole.
It is formed in a thin box shape with a thickness of 4.2 mm and a thickness of 4.2 mm. In addition,
The dimensions of the flat battery 10 housed in the housing case 1 are, for example, a long side of 65 mm (including a bonding portion of an exterior film), a short side of 35 mm, and a thickness of 3.6 mm.

Each of the metal plates 2a and 2b is formed in a rectangular shape.
The upper and lower surfaces of the storage case 1 are configured. On the other hand, the frame bodies 4a and 4b integrally attached to the peripheral edges of the metal plates 2a and 2b are combined at the opposing surfaces to constitute the side surface of the housing case 1, and the distance between the metal plates 2a and 2b is fixed. To be held. In the lower case 8, the frame 4b extends to the front and back surfaces on the short side of the lower case 8 to form an insulating region 4i, and covers a part of the metal plate 2b. The insulating region 4i prevents conduction between the protection circuit 12 and the metal plate 2b when assembling a battery pack described later. Further, three openings 8a are formed in the insulating region 4i in parallel in the short side direction of the lower case 8,
A connection terminal 12a protruding from the lower surface of the protection circuit 12 is exposed from this portion.

As shown in FIG. 2, side edges 2c and 2d are formed on the periphery of each of the metal plates 2a and 2b at right angles to the plane direction, and each of the frames 4a and 4b is formed with each side edge 2c. It is integrally formed with the side edge so as to surround 2d. In this case, each metal plate 2a, 2b is insert-molded into the frame 4a, 4b, respectively, and as a result, each side edge 2c, 2d
Are molded in the frames 4a and 4b. here,
Insert molding is a process in which an object (metal plate) is placed inside a mold, and then the resin is poured into the mold to embed the metal plate in the molded resin and integrate the two. Say. Further, the above-described insulating region 4i and opening 8
Similarly, a is integrally formed by insert molding. When forming the opening 8a, a hole larger than the opening 8a is provided in the metal plate 2b in advance, and the end face 2e of the hole is molded with a resin, thereby forming the opening 8a.
a is formed. By doing so, conduction between the connection terminal 12a inserted into each opening 8a and the metal plate 2b can be prevented.

The upper case 6 and the lower case 8 are united by joining the frames 4a and 4b on the surfaces facing each other. Here, a step portion 40 is formed on the fitting surface of the upper frame member 4a, and a step portion 42 is formed on the fitting surface of the lower frame member 4b. The positions are reversed. Then, the convex portion of the step portion 40 is
The concave portion of the step portion 40 is fitted to the convex portion of the step portion 42. The fitting surface of the concave portion and the convex portion is welded by, for example, ultrasonic waves, and the upper case 6 and the lower case 8 are united. . In order to facilitate the welding, welding ribs 44 are protruded from the projections of the steps 40 and 42, respectively. The welding rib 44 may be provided on one of the steps 40 and 42.

In this way, the flat battery 10 is
Is accommodated. In this case, as shown in FIG. 3, the metal plates 2a and 2b are arranged in parallel with the direction of the flat surface of the flat battery 10 and substantially in close contact with the flat battery 10. And the metal plates 2a, 2b
Has an appropriate strength even if its thickness is thin, so that the overall thickness of the battery pack can be reduced while maintaining the strength characteristics, as compared to a housing case made entirely of thick resin. . Also, the upper case 6 and the lower case 8 are each framed 4a,
4b, but since the frame is made of resin, a step portion or the like for positioning can be easily formed on the fitting surface, and the union of the upper case 6 and the lower case 8 can be formed. It can be done easily.

The flat battery 1 is stored in the storage case 1.
0 and the protection circuit 12 are housed and constitute a battery pack as a whole. The flat battery 10 is fixed to the lower case 8 with, for example, an adhesive tape, and the protection circuit 12 is disposed on the insulating region 4i of the lower case 8. The protection circuit 12 is provided with an element for detecting the charge / discharge state and temperature of the battery on a substrate and sealed with a resin, and is connected to the flat battery 10 to prevent overcharging and overheating of the battery. It is. Then, the protection circuit 12 is connected to the flat battery 1 on the positive electrode lead 10a side.
The positive electrode lead 10a and the negative electrode lead 10b are accommodated under the bonded portion
Connected to each other. Further, three connection terminals 12a (a positive terminal, a negative terminal, and a terminal for temperature measurement) protruding from the lower surface of the protection circuit 12 are respectively inserted into the openings 8a and exposed from the rear surface of the lower case 8. ing.

Next, another embodiment of the flat battery accommodating case according to the present invention will be described with reference to FIG. FIG.
In the storage case 20, an upper case 26 formed of a rectangular stainless steel plate 22a (0.1 mm thick) and a stainless steel plate 22b (0.1 mm thick) are formed on a frame 24. It is formed by uniting a lower case 28 having a square shape (height of about 4.0 mm) formed by insert molding. A side edge 22c is formed on the periphery of the metal plate 22a at right angles to the surface direction. The outer shape of the lower case 28 is
It is slightly larger than the periphery of the metal plate 22a.

Then, as shown in a sectional view of FIG.
A stepped portion 24a is formed on the inner edge of the slab and extends outward. The side edge 22c is fitted to the stepped portion 24a by, for example, press-fitting. The distance between the inner surface of the upper case 26 and the inner surface of the lower case 28 is maintained at 3.8 mm,
The thickness of the entire storage case 20 is defined as 4.0 mm. A label 16 is appropriately attached to the outer surface of the upper case 26. In this embodiment, the two can be combined simply by press-fitting the upper case into the lower case, so that work such as welding is not required.

Next, still another embodiment of the flat battery storage case according to the present invention will be described with reference to FIG. In FIG. 6, the storage case 30 includes an upper case 36 made of a metal plate 32a similarly to the storage case 20 described above.
And a lower case 38 formed by insert-molding a metal plate 32b into a frame (thickness 0.8 mm) 34.
However, in this embodiment, the side edge 32c of the metal plate 32a is expanded after being fitted to the frame 34 and the frame 3
A plurality of locking portions (spikes) 32s for making close contact with 4 are formed at appropriate intervals. The metal plate 32b of the lower case 38 is provided with a large number of ribs 32r that have a wave shape when the storage case 30 is viewed from the short side direction.

Then, as shown in the sectional view of FIG.
A concave portion 34a having a width of 0.2 mm is formed on the end surface of the frame body 3 and the side edge portion 32c is fitted therein, and the locking portion 32s is formed on the frame body 3.
4, so that it is in close contact with the inner wall. By doing so, the metal plate 32a and the frame 34 can be more firmly combined. Further, since the ribs 32r are formed on the metal plate 32b, the metal plate can be made thinner while securing the strength characteristics, and the weight of the entire storage case can be reduced.

Further, another embodiment of the flat battery storage case according to the present invention will be described with reference to FIG. 8, the storage case 50 includes an upper case 56 made of a metal plate 52a, similarly to the storage cases 20 and 30 described above.
And a lower case 58 formed by insert-molding the metal plate 52b into the frame 54. However, in this embodiment, a flange 52f is further formed on the side edge 52c of the metal plate 52a, and a plurality of holes 52h are formed on the flange 52f at appropriate intervals. A welding rib 54t is formed on the upper end surface of the frame 54 in the lower case 58 at a position corresponding to the hole 52h.

Then, as shown in a sectional view of FIG.
The upper case 56 and the lower case 58 are united by inserting the welding rib 54t formed on the end surface of the upper case 56 into the hole 52h of the upper case 56 and welding and crushing the head of the welding rib 54t by, for example, ultrasonic waves. I have. The case for accommodating the flat battery according to the present invention is not limited to the above-described embodiment. First, as for a mode in which the first case and the second case are combined, for example, a pair of metal plates are arranged to face each other, a frame is attached therebetween, and one side of the frame is opened to open the first case.
Is formed, and one side surface of the flat battery is accommodated through the opening of the first case. Then, the other side surface portion of the flat battery already housed in the first case is housed in the second case through the opening of the second case formed in the same manner, and at the center of the flat battery. The open ends of the cases may be combined.

The cross-sectional shape of the rib formed on the metal plate is not limited to a waveform, and may be, for example, a trapezoidal shape.
The same effect can be obtained by embossing the surface of the metal plate in place of the rib. Furthermore, it is possible to further reduce the weight by providing a plurality of openings on the surface of the metal plate while keeping the thickness of the metal plate. Here, a thermoplastic resin can be generally used as the resin for the insert mode in each of the above-described embodiments. For example, it is a thermoplastic resin such as polycarbonate, a liquid crystal polymer, a compound of polycarbonate and acrylic butadiene styrene rubber, polypropylene, polybutylene terephthalate, and polyphenylene sulfide.

In this case, each of these thermoplastic resins may be used alone. However, if a glass component such as glass fiber chops or glass beads is mixed with the thermoplastic resin, such a resin composition becomes Since the dimensional shrinkage after molding is small, the frame obtained after insert molding with a metal plate is suitable because the target dimensions are secured and at the same time the strength is increased.

In particular, the above resin composition using a polycarbonate or a liquid crystal polymer as the thermoplastic resin is preferable because the above effects are exhibited. In preparing such a resin composition, it is preferable to mix 10 to 25% by volume of a glass component such as a glass fiber chop or a glass bead. When the amount is less than 10% by volume, the strength of the molded frame is not so high, so that when an external force is applied, the frame may be warped or twisted. Also, if the amount is more than 25% by volume,
Insufficient molding tends to occur at the time of insert molding, and the flexibility of the frame after molding deteriorates.

The thickness of the frame integrated with the side edge of the metal plate is preferably about 0.6 to 1.5 mm when the thickness of the metal plate is 0.1 mm. . Further, a metal plate having a thickness of 0.05 to 0.25 mm is used. For example, a stainless steel plate having a thickness of about 0.05 to 0.15 mm or an aluminum plate having a thickness of about 0.1 to 0.2 mm can be used. And, for example, an aluminum alloy plate, a magnesium alloy plate, a cold rolled steel plate, a hot rolled steel plate, or the like can also be used.

In this case, as shown in FIG. 2, it is necessary to form the metal plate 2a (2b) as a side edge 2c (2d) that enables the insert molding described above. As a forming method, bending, drawing, or the like can be applied. In particular, it is preferable to apply drawing, since warping and twisting do not occur in the processed metal plate.

Further, in the above-described embodiment, the case where the connection terminal protruding from the protection circuit is exposed through the opening provided in the flat battery housing case has been described.
A connection terminal may be formed in the housing case of the flat battery in advance, and the connection terminal and the protection circuit may be connected inside the case. Then, the surface of the metal plate serving as the inner surface of the case may be appropriately covered with a resin sheet or the like to insulate the internal flat battery or the protection circuit.

In addition to the above, the manner in which the frame is integrally attached to the metal plate is not limited to the insert mold described above, and the metal plate may be fitted to the frame.
Both may be adhered.

[0034]

As is apparent from the above description, the flat battery housing case according to the present invention is a thin metal plate whose surface parallel to the flat surface direction of the flat battery housed therein. As a result, the thickness of the case in the thickness direction of the flat battery can be reduced while securing the overall strength characteristics, as a result, compared to the housing case entirely made of synthetic resin. The thickness can be reduced.

Further, since the frame for combining the first case and the second case is made of resin, a step portion or the like for positioning can be easily formed on the fitting surface. And the second case can be easily combined.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a flat battery storage case according to the present invention.

FIG. 2 is a partially enlarged sectional view taken along line II-II of FIG.

FIG. 3 is a view showing a state where a flat battery is housed in a flat battery housing case according to the present invention.

FIG. 4 is a perspective view showing another embodiment of the flat battery storage case according to the present invention.

FIG. 5 is a sectional view taken along line VV of FIG. 4;

FIG. 6 is a perspective view showing still another embodiment of the flat battery accommodating case according to the present invention.

FIG. 7 is a partially enlarged cross-sectional view along the line VII-VII in FIG. 6;

FIG. 8 is a perspective view showing another embodiment of the flat battery storage case according to the present invention.

FIG. 9 is a partially enlarged sectional view taken along line IX-IX of FIG. 6;

FIG. 10 is a diagram showing a configuration of a flat battery.

[Explanation of symbols]

1, 20, 30, 50 (for flat batteries) storage case 2a, 2b, 22a, 22b, 32a, 32b, 52
a, 52b Metal plate 4a, 4b, 24a, 24b, 34a, 34b, 54
a, 54b frame 6, 26, 36, 56 Upper case (first case) 8, 28, 38, 58 Lower case (second case) 10 Flat battery

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Mitsuhiro Hoshino 3-4-10 Minamishinagawa, Shinagawa-ku, Tokyo Inside Toshiba Battery Corporation (72) Noriko Seki 3-4-10 Minamishinagawa, Shinagawa-ku, Tokyo Toshiba Battery Corporation (72) Inventor Ryuta Takeishi 3-4-10 Minamishinagawa, Shinagawa-ku, Tokyo Toshiba Battery Corporation F-term (reference) 5H011 AA00 BB03 CC02 CC05

Claims (12)

[Claims] 1. A flat battery housing case having a divided structure obtained by combining a first case and a second case at least partially formed of a metal plate, wherein the first case and / or the A housing case for a flat battery, wherein a frame made of resin is integrally attached to a metal plate in the second case, and the cases are united through the frame. 2. The flat battery according to claim 1, wherein a plurality of ribs or openings are formed on a surface of the metal plate in the first case and / or the second case. Storage case. 3. The flat battery housing case according to claim 1, wherein the frame body is provided with a connection terminal or an opening for exposing the connection terminal. 4. The apparatus according to claim 1, wherein the frame body extends on a surface of the first case and / or the second case to form an insulating region. A storage case for the flat battery according to the above. 5. The flat battery according to claim 1, wherein the metal plate in the first case and / or the second case is insert-molded in the frame. Storage case. 6. The device according to claim 1, wherein the first case or the second case is made of a metal plate having a side edge, and the side edge is fitted to the frame. 5. The case for accommodating a flat battery according to any one of claims 4 to 4. 7. The frame according to claim 6, wherein a locking portion is formed on the side edge portion so as to be expanded after being fitted to the frame and to come into close contact with the frame. Flat battery storage case. 8. The flat battery housing case according to claim 1, wherein a constituent material of the frame is a resin composition comprising a thermoplastic resin and a glass component. 9. The flat battery housing case according to claim 8, wherein the thermoplastic resin is a polycarbonate or a liquid crystal polymer, and the glass component is a glass fiber chop or a glass bead. 10. The compounding amount of the glass component is 10 to 25.
The storage case for a flat battery according to claim 9, which is in volume%. 11. A flat battery housing case comprising: the first case according to claim 5; and the second case according to claim 6 or 7. 12. A battery pack comprising a flat battery and a protection circuit housed inside the flat battery storage case according to any one of claims 1 to 11.