JP2002063948A - Cylindrical air cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air cell superior in an anti-leakage property after discharging wherein an opposing area of an air electrode to a gel zinc negative electrode is made to be increased and a utilization factor of the negative electrode is improved by a gel electrolytic solution containing no zinc powder filled up in the cylindrical cell having a cylindrical air electrode. SOLUTION: It is possible to obtain a cylindrical air cell which contains no zinc powder, which is superior in discharging and also superior in leakage after discharging because the opposing area of the air electrode to the gel zinc negative electrode is increased and the utilization factor of the negative electrode is improved by the gel electrolytic solution 23 filled beforehand into a part opposing an inner side of a metal inner cap 17 inside a separator 8 constituted and inserted inside the cylindrical air electrode 4. In addition, the cylindrical air electrode of a three-layered structure consists of a catalytic layer 1, a current collector layer 2 and a water-repellent fluororesin porous membrane layer 3, and its lower part is inserted into a resin mold 19 coated with a sealer 18 and sealed by an positive electrode can 11 being pressurized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical air battery, and more particularly to a cylindrical air battery having improved high-rate discharge and improved liquid leakage resistance after discharge.

[0002]

2. Description of the Related Art A conventional cylindrical air battery is disclosed in
In consideration of the volume expansion of the negative electrode zinc after discharge as seen in, for example, No. 1770, the negative electrode active material and the alkaline electrolyte are filled at a filling rate of 75 to 85% with respect to the fillable inner volume of the negative electrode active material. To prevent leakage of the alkaline electrolyte to the outside after battery discharge.

[0003]

When a battery is constructed by the above-mentioned conventional method, sufficient characteristics can be obtained with respect to leakage resistance after discharge. However, when the area of the positive electrode is equal to the area of the negative electrode facing the positive electrode as much as possible, the utilization rate of the negative electrode during discharge increases. As can be seen from the above filling ratio, the facing ratio of the negative electrode to the positive electrode is 75 to 8
Therefore, the negative electrode utilization rate is as low as 35 to 55% in the high rate discharge of the cylindrical air battery. In the conventional cylindrical air battery, when the state of the negative electrode filled inside the battery after discharge is analyzed, the negative electrode zinc filled inside the inner cup remains undischarged, which also indicates the negative electrode utilization rate. It is causing the decline.

An object of the present invention is to solve the above-mentioned problems in the conventional method, and to provide a cylindrical air battery having excellent resistance to liquid leakage after discharge and excellent high-rate discharge performance.

[0005]

In order to achieve the above object, a cylindrical air battery according to the present invention has a cylindrical air electrode in which one side of an open end is closed by a metal outer cup and an inner cup. And a cylindrical air battery having a separator formed in a cylindrical shape with a bottom in the cylindrical air electrode, wherein the negative electrode is not contained in a portion of the separator facing the inside of the inner cup inside the separator. It is characterized by being filled with an electrolytic solution and filling the remaining part with a gelled zinc negative electrode.

[0006]

According to the present invention, with respect to the negative electrode to be filled in the battery, a portion of the inside of the separator facing the inside of the metal inner cup is filled with a gel electrolyte containing no negative electrode, and Is filled with a gelled negative electrode, so that the negative electrode that was filled inside the conventional inner cup and not used for discharging is eliminated, and all the negative electrodes in the battery face the positive electrode to increase the facing ratio. That means
A cylindrical air battery excellent in high-rate discharge and leakage resistance after discharge can be obtained.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a cylindrical air battery according to the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 1A shows a half cross-sectional view of the structure of an AA type zinc-air battery to which the present invention is applied. FIG.
4A is a cylindrical air electrode having a three-layer structure.
As shown in (B), the catalyst layer 1, the current collector layer 2,
It comprises a water-repellent fluororesin porous film layer 3. In this air electrode, a catalyst sheet is pressed by a press onto a current collector layer, which is a nickel-plated stainless steel wire mesh. This catalyst sheet is prepared by mixing activated carbon, manganese oxide, acetylene black, and fluororesin powder, adding ethyl alcohol to the mixed mixture, kneading the mixture, and extruding to form a flat band-shaped mixture. The agent was rolled through two heated rollers to form a 0.6 mm sheet. Next, a dispersion liquid containing fine fluororesin powder is applied to the current collector layer side, and dried at 230 ° C. Finally, a water-repellent fluororesin porous membrane having gas permeability is pressed on the side to which the fluororesin fine powder dispersion is applied by pressing to form a catalyst layer, a current collector layer and a fluororesin porous membrane layer. A flat plate air electrode having a layer structure is manufactured.
The air electrode of the flat plate produced in this manner is curved so that the catalyst layer side is on the inside, and the catalyst layer and a part of both ends of the fluororesin porous membrane are overlapped to form a cylindrical shape. Next, the catalyst layer in the overlapped portion and a part of the fluororesin porous film were removed, and the exposed current collector layer was spot-welded, and a non-hermetic weld was filled with a synthetic rubber-based adhesive to repair the hermetic seal. I do. Through the above steps, a cylindrical air electrode having a three-layer structure is formed. This 3
The upper part of the cylindrical air electrode having a layer structure is sandwiched between an outer cup 16 and an inner cup 17 made of metal plated with nickel on a steel plate and sealed. After sealing the upper part of the positive electrode in this way, current is collected and conducted by spot welding the projection part provided at three places on the bottom of the outer cup and the bottom of the positive electrode can. After the cylindrical separator 8 and the dish bottom paper 15 are sequentially inserted into the cylindrical shape, a gel-like material containing no zinc negative electrode is first provided so as to have a filling rate of 75% with respect to the internal volume that can be filled with the negative electrode active material. The portion facing the inner cup 17 is filled with the electrolytic solution 23, and then the gelled zinc negative electrode 9 is filled. Next, a resin molded body 19 having a concave portion coated with a synthetic rubber-based sealant 18 is inserted below the cylindrical air electrode, and a metal ring 22 is inserted into the inner peripheral side of the resin molded body. Further, the resin-molded sealing body 19 ′ into which the current collector 21 to which the bottom plate 20 is welded is inserted is fitted, and the positive electrode can 11 is mechanically pressed to bring the concave portion of the resin molded body into close contact with the air electrode side to seal. The lower portion of the cylindrical air electrode is inserted into a concave portion of a resin molded body 19 having an annular concave portion to which a synthetic rubber-based sealant 18 has been applied, and is sealed with the resin molded body and the positive electrode can 11. In the drawing, 10 is an air diffusion paper, 12 is an insulating tube, 13 is an air intake hole, which is sealed with a hermetic seal 14 until the battery is used.

(Conventional Example 1) The filling rate of the negative electrode active material is 75%
Thus, a battery constructed in the same manner as in Example 1 using only the gelled zinc negative electrode is manufactured as a conventional example.

Comparative Example 1 A filling rate of the negative electrode active material was 95%.
Thus, a battery constructed in the same manner as in Example 1 using only the gelled zinc negative electrode is manufactured as a comparative example.

Using the batteries of Example 1, Conventional Example 1, and Comparative Example 1, an initial discharge test was performed. Table 1 shows the details of the negative electrode filled in the battery, and Table 2 shows the results of the discharge test.

[0012]

[Table 1]

[0013]

[Table 2]

In the batteries of Example 1 and Conventional Example 1, the structure of the negative electrode to be filled is the same as that of 4.1 g of zinc powder and 2.8 g of a gel electrolyte. Example 1 at a discharge current of ~ 1000 mA
Has a larger discharge capacity. In Example 1, the utilization rate of the zinc negative electrode is almost the same as that of Comparative Example 1, but no liquid leakage after discharge is observed. On the other hand, in Comparative Example 1, since the negative electrode was filled without taking into account the expansion of the negative electrode after discharge, liquid leakage after discharge was observed in all the evaluated current regions.

As described above, in the case of the battery having the configuration according to the present invention, it is possible to obtain a battery that prevents leakage after discharge and has excellent negative electrode utilization in high-rate discharge.

[0016]

As is apparent from the above description, according to the present invention, the gel electrolysis which does not contain the negative electrode in the part facing the inside of the metal inner cup inside the separator inserted in the air electrode. Since the liquid is filled and the remaining part is filled with the gelled negative electrode, it is possible to provide a cylindrical air battery having excellent leakage resistance after discharge and improved utilization of the negative electrode in high-rate discharge.

[Brief description of the drawings]

1A is a half sectional view of a cylindrical air battery according to a first embodiment of the present invention; FIG. 1B is a partially enlarged sectional view of a cylindrical air electrode used in the air battery of FIG. 1A;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Catalyst layer 2 Current collector 3 Fluororesin porous film 4 Cylindrical air electrode 5 Nickel plating layer 6 Polytetrafluoroethylene particles 7 Stainless steel current collector 8 Separator 9 Gelled negative electrode zinc 10 Air diffusion paper 11 Positive electrode can 12 Insulating tube DESCRIPTION OF SYMBOLS 13 Air intake hole 14 Sealing seal 15 Dish bottom paper 16 Metal outer cup 17 Metal inner cup 18 Sealant 19 Resin molded body 19 'Resin molded sealing body 20 Bottom plate 21 Current collector 22 Metal ring 23 Gel electrolyte

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tomoya Watanabe 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Isao Kubo 1006 Kadoma Kadoma, Kadoma City Osaka Pref. 72) Inventor Shigeo Kobayashi 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture F-term in Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] 1. One end of an open end has a cylindrical air electrode closed by a metal outer cup and an inner cup, and a bottomed cylindrical separator is provided in the cylindrical air electrode. In the cylindrical air battery, a portion facing the inside of the inner cup inside the separator is filled with a gel electrolyte containing no negative electrode, and the remaining portion is filled with a gel zinc negative electrode. A cylindrical air battery characterized by the following.