JPH10208709A - Enclosure bag for non-aqueous electrolyte batteries - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of separation of a metallic layer from a plastic layer without corroding the metallic layer by attaching one or a plurality of plastic layers provided with an acid transmission preventive means to the metallic layer. SOLUTION: A PET layer 12 which is a plastic layer is attached to an outer surface of an aluminum foil P which is a metallic layer through the adhesive to obtain a sheet. An acid transmission preventive means comprising a thermoplastic resin layer 11 containing carboxylic acid metal salt or metallic oxide in the resin such as polyethylene, polypropylene, of acid modified resin thereof, and ionomer is attached to the inner side of the sheet to obtain a sealing bag for a nonaqueous electrolytic cell. The positive electrode, the negative electrode, the nonaqueous electrolyte, etc., are sealed in the sealing bag, and a conductor 1 of a lead wire between the positive electrode and the negative electrode is taken outside to obtain the nonaqueous electrolyte cell.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealed bag for a non-aqueous electrolyte battery used as a power source for electronic equipment. More specifically, the positive electrode, the negative electrode, and the electrolyte are sealed in an enclosing bag, and the structure has a structure in which the lead wires of the positive electrode and the negative electrode are respectively taken out to the outside, and a structure having high reliability in sealing the electrolyte. It is characterized by.

[0002]

2. Description of the Related Art Along with the miniaturization of electronic devices, there is an increasing demand for miniaturization and weight reduction of batteries as power sources. On the other hand, batteries are also required to have higher energy density and higher energy efficiency, and expectations for secondary batteries such as Li-ion batteries are increasing. In response to such demands, for example, as seen in JP-A-61-240564, a group of electrode plates is inserted into a bag made of an acid-resistant thermoplastic resin, and a large number of the electrode groups are formed into a film or sheet. There has been proposed an attempt to form a sealed lead-acid battery by enclosing it in a bag-like outer body made of a tubular or tubular synthetic resin. Also, Japanese Patent Application Laid-Open No.
As disclosed in Japanese Patent No. 2447 and Japanese Patent Application Laid-Open No. 57-115820, there is also an attempt to improve the sealing performance by forming a structure in which a metal layer is sandwiched between plastic films in a sheet of an enclosing bag.

[0003]

The provision of a metal layer greatly improves the sealing performance, but does not completely prevent the penetration of moisture from the sealing portion. When moisture enters, it reacts with the electrolytic solution to generate hydrofluoric acid, and this hydrofluoric acid may permeate the plastic film layer and corrode the metal layer, or may cause separation between the metal layer and the plastic layer. The present invention provides a sealed bag for a non-aqueous electrolyte battery that does not corrode a metal layer or cause peeling between a metal layer and a plastic film layer even when moisture invades and generates hydrofluoric acid. Aim.

[0004]

The present inventors have conducted intensive studies to achieve the above-mentioned object, and as a result, if at least one of the plastic layers is provided with an acid permeation preventing means, the generation of hydrofluoric acid will be prevented. Without corroding the metal layer,
It has also been found that no delamination occurs between the metal layer and the plastic film layer.

The gist of the present invention is as follows. A bag for enclosing the positive electrode, the negative electrode, the electrolytic solution, and the like constituting the nonaqueous electrolyte battery, taking out the leads of the positive electrode and the negative electrode, respectively, and enclosing these leads as well. An encapsulating bag for a nonaqueous electrolyte battery, comprising a laminated sheet of a multi-layered plastic layer, wherein at least one of the plastic layers is provided with an acid permeation prevention means, As a preventive means, for example, a metal carboxylate or a metal oxide is contained in the resin. As the metal carboxylate or metal oxide, one or more mixtures selected from the group consisting of calcium carbonate, magnesium oxide, hydrotalcites, and calcium stearate are effective.

The problem and the solution will be described in more detail.
As an example of the configuration of the enclosing bag, there can be cited one in which a PET film is attached to the outer surface of an aluminum foil and a thermoplastic resin such as polyethylene is attached to the inner surface. The PET on the outer surface is provided to protect aluminum from external damage, and the polyethylene on the inner surface is provided for heat sealing. When such a conventionally devised material is used, moisture gradually penetrates during long-term storage even when heat-sealing, and the water reacts with the electrolyte solution sealed in the bag. To produce hydrofluoric acid. This hydrofluoric acid has a problem in that it permeates polyethylene and the like and peels off the adhesive interface between aluminum and polyethylene, which is one of the factors that make such a bag-type battery container not practical.

In order to solve this problem, it is possible to develop a material that does not allow moisture to penetrate at all, or to provide a resin layer that does not allow hydrofluoric acid to permeate even if moisture enters to generate hydrofluoric acid. Good. As a result of examining the provision of a resin layer that does not allow hydrofluoric acid to pass therethrough, it was found that the object can be achieved by the above-described method. That is, a method in which an acid generated by adding a metal carboxylate or a metal oxide to a resin is trapped on the way. As the carboxylate metal salt and metal oxide, the above-mentioned calcium carbonate, magnesium oxide, hydrotalcites, calcium stearate and the like are preferable, but other stabilizers for polyvinyl chloride are also effective. The resin containing these is preferably polyethylene, polypropylene, or their acid-modified products, ionomers, and the like, which are hardly attacked by the electrolytic solution. What is necessary is just to provide the resin layer which is hardly attacked.

[0008]

The present invention will be described below with reference to examples and comparative examples. Note that these examples do not limit the present invention. (Example 1) 30 parts by weight of calcium carbonate with respect to 100 parts by weight of maleic anhydride-modified low-density polyethylene were attached to the inner surface of a sheet in which a 12-μm PET film was bonded to the outer surface of a 9-μm aluminum foil via a 5-μm urethane adhesive. A sheet was prepared by laminating a resin composition containing 50 μm. This sheet is made of electrolyte (1 mol / L LiP
1 of ethylene carbonate and diethyl carbonate containing F _6: 1 mixture) and was heat sealed by sealing electrodes attached lead wires to as in FIG. 2, 60 ℃, 9
It was left in a 5% RH constant temperature / humidity bath and the change in appearance was examined.
As a result, no change in appearance was observed after 30 days.

(Example 2) The same results as in Example 1 were obtained by changing calcium carbonate in Example 1 to magnesium oxide.

(Example 3) The same results as in Example 1 were obtained by changing calcium carbonate in Example 1 to hydrotalcite.

(Example 4) The same results as in Example 1 were obtained by changing calcium carbonate in Example 1 to calcium stearate.

(Comparative Example 1) The material from which calcium carbonate was removed in Example 1 was used. However, peeling occurred between the aluminum layer and the resin layer on the third day after being left in a thermo-hygrostat, and the aluminum layer was further removed. Corrosion was observed.

[0013]

As described in the examples, according to the present invention, the encapsulation for a non-aqueous electrolyte battery which does not cause corrosion of the metal layer used in the bag or peeling of the metal layer even after long-term use. Bags can be provided.

[Brief description of the drawings]

FIG. 1 shows a non-aqueous electrolyte battery using a sealed bag and a lead wire of the present invention.

FIG. 2 schematically shows the inside of an enclosing bag.

FIG. 3 shows a cross section of an enclosing bag.

FIG. 4 is an enlarged view of a heat sealing portion of the enclosing bag.

[Explanation of symbols]

 1, 1 ': conductor of lead wire 2, 2': insulation of lead wire 3: sealed bag 4: sealed portion of sealed bag (example) 5, 5 ': electrode 6: diaphragm 7: positive electrode current collector 7': Negative electrode current collector 8: Positive electrode active material 8 ': Negative electrode active material 9: Aluminum foil 10: Insulating outer layer (insulation for electrode lead) 11: Thermoplastic layer 12: PET layer

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Keiichi Tanaka 1-3-1 Shimaya, Konohana-ku, Osaka-shi, Osaka Sumitomo Electric Industries, Ltd. Osaka Works

Claims (3)

[Claims] A positive electrode, a negative electrode, and a non-aqueous electrolyte battery,
A bag for enclosing the electrolyte, etc., taking out the positive and negative electrode leads, and also enclosing these leads. It is composed of a laminated sheet of a metal layer and a plastic layer consisting of one or more layers. A sealing bag for a non-aqueous electrolyte battery, characterized in that at least one of the plastic layers is provided with an acid permeation preventing means. 2. A sealed bag for a non-aqueous electrolyte battery according to claim 1, wherein the means for preventing permeation of the acid is to make the resin contain a metal carboxylate or a metal oxide. . 3. The metal carboxylate or metal oxide is one or a mixture of calcium carbonate, magnesium oxide, hydrotalcites and calcium stearate. 3. The sealed bag for a non-aqueous electrolyte battery according to claim 2.