JP2008034178A - Flat battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flat battery composed by preventing an electrolyte from leaking to the outside. <P>SOLUTION: This flat battery 10 is provided with: a layered product 16 comprising a pair of electrolyte layers 12, 12, a positive electrode 13 and a negative electrode 14 sequentially arranged by interposing a separator therebetween, and adhesive layers 15 arranged on respective surfaces of the positive electrode 13 and the negative electrode 14 opposite to the surfaces thereof in contact with the electrolyte layers 12 to expose respective connection parts 13b and 14b of the positive electrode 13 and the negative electrode 14; and a wrapping material 17 covering the respective surfaces of the adhesive layers 15 opposite to the surfaces thereof in contact with the positive electrode 13 and the negative electrode 14, and side surfaces 16a of the layered product 16. The flat battery is characterized in that the electrolyte layer 12 has a liquid or gel-like form. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

 The present invention relates to a thin flat battery used by being enclosed in an IC card, an ID card, a postcard or the like.

Conventionally, batteries such as a cylindrical type, a button type, and a flat plate type have been widely used as dry batteries.
These batteries are not only inconvenient to carry due to their thickness and size, but also cannot be applied to thin ones such as IC cards.
Therefore, in order to eliminate these disadvantages, a film-like flat battery has been proposed (for example, see Patent Documents 1 and 2).
An example of a conventional flat battery is one having a structure as shown in FIG.
2A and 2B are schematic views showing an example of a conventional flat battery, in which FIG. 2A is a plan view and FIG. 2B is a cross-sectional view taken along line BB in FIG.
In the flat battery 100 of this example, a positive electrode plate 102 and a negative electrode plate 103 are formed of metal particles or metal foil on one surface 101a of a plastic sheet 101, respectively. The active material is applied to the surface of the negative electrode plate 103. In addition, after applying the liquid or gel electrolyte 104, the plastic sheet 101 is placed so that the positive electrode plate 102 and the negative electrode plate 103 face each other with the separator 105 infiltrated with the electrolyte therebetween. At this time, the connection portion 102a of the positive electrode plate 102 and the connection portion 103a of the negative electrode plate 103 are protruded so as not to overlap from the outer shape of the plastic sheet 101, thereby forming an electrode. Further, the electrolyte 104 and the separator 105 are sealed by an adhesive layer 106 that is arranged from the positive electrode plate 102 to the negative electrode plate 103.
Japanese Patent No. 2832945 Japanese Patent No. 3638765

However, in the structure in which the ends protrude like the connection portion 102a of the positive electrode plate 102 and the connection portion 103a of the negative electrode plate 103, the sealing strength is weak, and the connection portion 102a and the connection portion 103a and the adhesive layer 106 are weak. There is a problem that the electrolyte 104 easily leaks at the interface.
Further, if the electrolyte 104 contains an alkaline solution, there is a problem that liquid leakage occurs due to a creeping phenomenon on the negative electrode.

 The present invention has been made in view of the above circumstances, and an object thereof is to provide a flat battery in which an electrolyte is prevented from leaking to the outside.

 In the flat battery of the present invention, a pair of electrolyte layers and electrodes arranged in order with a separator interposed therebetween, and a connection portion of the electrode exposed on the surface of the electrode opposite to the surface in contact with the electrolyte layer A laminate composed of an adhesive layer arranged in such a manner, and a wrapping material covering a surface of the adhesive layer opposite to the surface in contact with the electrode and a side surface of the laminate, and the electrolyte layer is liquid or It is gel-like.

 In the flat battery of the present invention, the electrolyte layer preferably contains an alkaline solution.

 In the flat battery of the present invention, a pair of electrolyte layers and electrodes arranged in order with a separator interposed therebetween, and a connection portion of the electrode exposed on the surface of the electrode opposite to the surface in contact with the electrolyte layer A laminate composed of an adhesive layer arranged in such a manner, and a wrapping material covering a surface of the adhesive layer opposite to the surface in contact with the electrode and a side surface of the laminate, and the electrolyte layer is liquid or Since it is gel-like, the electrode is covered with the packaging material via the adhesive layer except for the connection portion, so that the bonding area between the electrode and the packaging material via the adhesive layer is large and the connection portion is flat. Since it does not protrude at the end of the battery, the solution constituting the electrolyte layer hardly leaks to the outside. In particular, even if the electrolyte layer contains an alkaline solution, leakage due to creeping can be suppressed.

The best mode of the flat battery of the present invention will be described.
This embodiment is specifically described for better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified.

1A and 1B are schematic views showing an embodiment of a flat battery according to the present invention, in which FIG. 1A is a plan view and FIG. 1B is a cross-sectional view taken along line AA in FIG.
In FIG. 1, reference numeral 10 is a flat battery, 11 is a separator, 12 is an electrolyte layer, 13 is a positive electrode (hereinafter abbreviated as “positive electrode”), and 14 is a negative electrode (hereinafter abbreviated as “negative electrode”). ), 15 is an adhesive layer, 16 is a laminate, and 17 is a packaging material.
The flat electrode 10 according to this embodiment is roughly composed of a separator 11, an electrolyte layer 12, a positive electrode 13, a negative electrode 14, an adhesive layer 15, and a packaging material 17, and its outer shape is a square shape. .

In the flat battery 10, a pair of an electrolyte layer 12 and a positive electrode 13, and an electrolyte layer 12 and a negative electrode 14 are arranged in this order with a separator 11 interposed therebetween.
The electrolyte layer 12 is disposed on almost the entire surface of the separator 11. The positive electrode 13 and the negative electrode 14 are disposed on almost the entire surface opposite to the surface in contact with the separator 11 of the electrolyte layer 12.

 Further, an adhesive layer 15 made of an adhesive is disposed on the surface 13 a opposite to the surface in contact with the electrolyte layer 12 of the positive electrode 13 so as to expose the connection portion 13 b of the positive electrode 13. Similarly, an adhesive layer 15 made of an adhesive is disposed on the surface 14a of the negative electrode 14 opposite to the surface in contact with the electrolyte layer 12 so that the connecting portion 14b of the negative electrode 14 is exposed.

 Further, the surface 15 a of the adhesive layer 15 opposite to the surface in contact with the positive electrode 13, the surface 15 b of the adhesive layer 15 opposite to the surface in contact with the negative electrode 14, the separator 11, the electrolyte layers 12 and 12, the positive electrode 13, and the negative electrode 14. And the packaging material 17 is distribute | arranged so that the side surface 16a of the laminated body 16 which consists of adhesion layers 15 and 15 may be covered. The inner surface of the packaging material 17, the surface 15 a opposite to the surface in contact with the positive electrode 13 of the adhesive layer 15, the surface 15 b opposite to the surface in contact with the negative electrode 14 of the adhesive layer 15, and the side surface 16 a of the laminate 16. Are in close contact.

As the separator 11, a porous film made of a synthetic resin having excellent chemical resistance is used. As such a synthetic resin, for example, a porous film made of a synthetic resin such as polyolefin resin, polyamide resin, vinylon resin, vinylon resin, or a sheet or film made of a fiber material made of these synthetic resins is used. It is done.
The thickness of the separator 11 is not particularly limited, and is appropriately adjusted according to the required battery output. In addition, when the gel with sufficient intensity | strength is used for the electrolyte layer 12, a separator does not need to be.

As the electrolyte layer 12, a liquid or gel electrolyte is used. Among these electrolytes, those containing an alkaline solution are preferable because the output of the battery can be increased.
As the liquid electrolyte, an aqueous solution of an alkali metal hydroxide such as potassium hydroxide (KOH), sodium hydroxide (NaOH), lithium hydroxide (LiOH) or the like is used. The concentration of metal ions such as potassium ions (K ⁺ ), sodium ions (Na ⁺ ), and lithium ions (Li ⁺ ) contained in this aqueous solution is not particularly limited, and the required battery output is required. It is adjusted accordingly.

Moreover, as gel electrolyte, what added said alkaline aqueous solution to synthetic resins, such as potassium polyacrylate (PAAK), polyethylene oxide (PEO), and polyvinyl alcohol (PVA), is used. The concentration of the alkali metal hydroxide contained in the gel electrolyte is not particularly limited, and is appropriately adjusted according to the required battery output.
In order to prepare such a gel electrolyte, a method of directly mixing the alkali metal hydroxide with the synthetic resin, a solution containing the alkali metal hydroxide, A method of synthesizing a synthetic resin by polymerizing a precursor (monomer) of the synthetic resin, a method of impregnating a water-absorbing polymer composed of the synthetic resin with a solution containing the alkali metal hydroxide, and the like are used. It is done.

 Furthermore, the thickness of the electrolyte layer 12 is not particularly limited, and is appropriately adjusted according to the required battery output, thickness, and the like.

As the material of the positive electrode 13, nickel (Ni), iron (Fe), and other parts such as manganese dioxide (MnO ₂ ), silver oxide (Ag ₂ O), and higher nickel oxide are applied to the plated metal foil. And the like.
Examples of the material of the negative electrode 14 include copper (Cu), brass, and other metal foils plated with zinc (Zn).

 The adhesive forming the adhesive layer 15 is not particularly limited as long as it is excellent in alkali resistance and excellent in adhesiveness with the packaging material 17, the positive electrode 13 and the negative electrode 14. A chemical reaction type such as a curable type or an ultraviolet curable type, a hot melt type, a pressure sensitive type, or a rewet type is used.

Examples of room temperature curable adhesives include phenolic adhesives, epoxy adhesives, and silicone adhesives.
Examples of thermosetting adhesives include phenolic adhesives, epoxy adhesives, and silicone adhesives.
Examples of the ultraviolet curable adhesive include an epoxy adhesive and an acrylic adhesive.
Examples of the hot melt adhesive include polyolefin adhesives, modified polyolefin adhesives, polyamide adhesives, and polyester adhesives.
Examples of the pressure-sensitive adhesive include various pressure-sensitive adhesive tapes, rubbers such as ethylene-vinyl acetate copolymers, and polyacrylic acid esters.

As the packaging material 17, a film or sheet made of a synthetic resin excellent in alkali resistance, adhesion to the adhesive layer 15, and hydrogen permeability is processed into a predetermined shape according to the shape of the laminate 16. It is done.
As the synthetic resin forming the packaging material 17, a polyolefin resin such as polyethylene or polypropylene, or a resin film such as nylon or polyvinylidene chloride is used. Moreover, it is more preferable to provide barrier properties by combining two or more types of layers.
Further, the surface of the packaging material 17 may be subjected to surface treatments such as discharge treatment, chemical treatment, primer treatment, vapor deposition treatment, polishing treatment, and washing treatment in order to improve alkali resistance, adhesion, and the like. Good.

Next, a method for manufacturing the flat battery 10 of this embodiment will be described.
First, the electrolyte layer 12 is formed by applying or impregnating a gel-like or liquid electrolyte on both surfaces of the separator 11.
Next, the separator 11 is sandwiched between the positive electrode 13 and the negative electrode 14 through the electrolyte layer 12.
Next, the adhesive layer 15 is provided by, for example, applying an adhesive to the surface 13 a opposite to the surface in contact with the electrolyte layer 12 of the positive electrode 13 so as to expose the connection portion 13 b of the positive electrode 13. Similarly, the adhesive layer 15 is provided by, for example, applying an adhesive to the surface 14a of the negative electrode 14 opposite to the surface in contact with the electrolyte layer 12 so as to expose the connection portion 14b of the negative electrode 14.
Thereby, the laminated body 16 which consists of the separator 11, the electrolyte layers 12 and 12, the positive electrode 13, the negative electrode 14, and the contact bonding layers 15 and 15 is formed.
Next, the inner surface of the packaging material 17 is closely attached to the surface 15 a opposite to the surface in contact with the positive electrode 13 of the adhesive layer 15, the surface 15 b opposite to the surface in contact with the negative electrode 14 of the adhesive layer 15, and the side surface 16 a of the laminate 16. The flat battery 10 is obtained by covering the laminated body 16 with the packaging material 17 except for the connection portions 13b and 14b.

 In the flat battery 10 of this embodiment, the positive electrode 13 and the negative electrode 14 are covered with the packaging material 17 via the adhesive layer 15 except for the connection portion 13b and the connection portion 14b. 13 and the negative electrode 14 and the packaging material 17 are large, and since the connecting portion 13b and the connecting portion 14b do not protrude at the end of the flat battery 10, the solution constituting the electrolyte layer 12 leaks to the outside. hard. In particular, even when the electrolyte layer 12 contains an alkaline solution, the creeping phenomenon and the liquid leakage that occur on the negative electrode can be suppressed.

In addition, in this embodiment, although the flat battery 10 which has not arrange | positioned the adhesive agent to the side surface 16a of the laminated body 16 was illustrated, the flat battery of this invention is not limited to this. In the flat battery of the present invention, an adhesive may be disposed also on the side surface of the laminate composed of the separator, the electrolyte, the positive electrode, the negative electrode, and the adhesive layer.
In this embodiment, the flat battery 10 having a square outer shape is illustrated, but the flat battery of the present invention is not limited to this. The outer shape of the flat battery of the present invention is not limited to a circular shape, a triangular shape, a rectangular shape, a polygonal shape, or the like, and can be an arbitrary shape. Therefore, the flat battery of the present invention is also excellent in design.

It is the schematic which shows one Embodiment of the flat battery of this invention, (a) is a top view, (b) is sectional drawing which follows the AA line of (a). It is the schematic which shows an example of the conventional flat battery, (a) is a top view, (b) is sectional drawing which follows the BB line of (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Flat battery, 11 ... Separator, 12 ... Electrolyte layer, 13 ... Positive electrode, 14 ... Negative electrode, 15 ... Adhesive layer, 16 ... Laminated body, ...・ Packaging materials.

Claims (2)

 A pair of electrolyte layers and electrodes arranged in order with a separator interposed therebetween, and an adhesive layer arranged to expose a connection portion of the electrodes on a surface opposite to the surface in contact with each electrolyte layer of the electrodes And a packaging material covering a surface of the adhesive layer opposite to the surface in contact with the electrode and a side surface of the laminate, and the electrolyte layer is liquid or gel-like. Flat battery. The flat battery according to claim 1, wherein the electrolyte layer includes an alkaline solution.

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