JPS58178955A - Alkaline cell - Google Patents

Abstract

PURPOSE:To obtain an alkaline cell hardly suffering from deterioration due to storage and excellent in preservation property by limitting inner diameter of the positive pole while employing the positive pole pedestal made of a steel plate having thickness of 0.05-0.2m/m. CONSTITUTION:The relation among the inner diameter (a) of a horizontal part of the positive pole pedestal 1, the inner diameter (b) of the horizontal tip part of a sealing ring 4 and the inner diameter (c) of a horsehoe-shaped turning back point of the negative pole sealing plate 6 is defined to be b<a<c, while the material thereof is selected. When considering the strength and workability, of the positive pole pedestal, the steel plate is the best material. In the case of a>b, reaction of an alkaline solution reduces remarkably and there is no generation of voltage failure. The suitable thickness of said positive pole pedestal is 0.05-0.2m/m. That is to say, when being thinner than 0.05m/m, strength of the pedestal becomes insufficient to stand the pressure occurring at the time of sealing process, thus generating its deformation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an alkaline battery, particularly a battery having a button-type or flat-type anode pedestal, in which the storage characteristics of the alkaline battery are improved by improving the anode pedestal.

Recent alkaline batteries are required not only to have a long discharge life, but also to have leakage resistance and storage stability. In particular, with regard to improving storage stability, various studies have been carried out as described below, and although significant improvements have not been made, the situation is still not satisfactory. The main items to be considered for improvement are as follows: ■ Consideration of materials for separators and impregnating materials ■ Distribution ratio of anode mixture, purity of raw materials, molding density ■ Mixing ratio of cathode mixture, purity of raw materials ■ Prescription of electrolyte solution, purity of raw materials Purity (6) Various conditions during the manufacturing and assembly process, such as the absorption time of electrolyte and the influence of CO2 gas absorption■ Anode pedestal,
As of now, the materials and purity of the cathode sealing plate, anode case, sealing ring, various raw materials, two-part materials, etc. have been examined.

The object of the present invention is to improve the anode pedestal to reduce the deterioration in the storage performance of alkaline batteries and to improve the storage characteristics.

The invention was based on the results of previous studies, and was further studied from a completely different angle, and it was decided that the dimensions of the anode pedestal would be specified as shown below, and the storage characteristics would be significantly improved and stabilized. Everything you need to know is what you found.

Hereinafter, silver oxide battery 5R44 (diameter 1
The present invention will be fully explained using an example of 1.61ffll+, height 6.4 mm).

In the figure, reference numeral 1 denotes an anode pedestal having an inverted cross-section, which is loaded into an anode case 3 together with an anode mixture 2 mainly composed of silver oxide gzO, and supports an insulating sealing ring 4. 5
F/: A gel cathode agent consisting mainly of zinc powder and a small amount of thickener and alkaline electrolyte, and a cathode sealing plate 6
It is housed within. 7 is a separator, and 8 is an impregnated material impregnated with an alkaline electrolyte. 1 and 2 are enlarged sectional views of essential parts of the same battery, and the present invention focuses on the inner diameter a of the horizontal part of the anode pedestal 1, the inner diameter of the horizontal end of the sealing ring 4, and the U-shaped folding of the cathode sealing plate 6. The relationship between the base point and the inner diameter C has been fully specified, and the materials have been selected.

The following table shows the results of various dimensional relationships and battery storage characteristics.

As is clear from this table, in the case of a and b, as the difference between a and b increases, the rate of occurrence of voltage defects increases rapidly. The reason for this is that if the inner periphery of the horizontal part of the anode pedestal protrudes inward beyond the sealing ring through the separator, the distance between the anode pedestal and the cathode mixture becomes shorter, and the contact area with the alkaline electrolyte decreases. For example, if the anode pedestal is made of stainless steel, the stainless steel will be gradually corroded by the alkaline electrolyte, and the iron ions of the n1 component will dissolve and completely penetrate the separator, causing the cathode to become icy. When it reacts with lead, an admixture of mercury and iron is generated, which eventually causes a short circuit phenomenon, resulting in voltage failure and deterioration. Therefore, with an anode pedestal made of synthetic resin, etc., which does not react with alkaline solutions,
- Voltage failure does not occur even in the case of range a (b). However, if the anode pedestal is made of a material such as synthetic resin within the above range, the contact area between the anode and cathode becomes small, and the current There are also disadvantages such as less extraction and unsuitability for strong discharge use.Other strengths of the anode pedestal 2
Considering workability, steel plate is the optimal material. Conversely, if a) and b are used, the above-mentioned reactions will be significantly reduced, and voltage failures will almost never occur. However, a) b)
Moreover, under the condition a) C, the force applied to the lowest point B of the U-shaped folding base of the sealing plate at the time of sealing does not affect the pedestal function on the anode side because the anode pedestal is not located directly below it. It is weak and deforms, and the force of inserting the separator II between the sealing ring and the anode mixture decreases. Therefore 60
When stored at high temperatures such as ℃, the separator shrinks and becomes a circle with a small diameter, which loses its ability to isolate the anode and cathode, eventually causing a short circuit and causing a voltage failure. Also, since the pedestal function of the sealing ring is weakened, the pressure bonding at the AB portion of the sealing ring is weakened, and the leakage performance is also deteriorated.

A suitable thickness of the steel plate for this anode pedestal is 0.06 to 0.2χ. In other words, when it is thinner than 0.06t, it becomes weak in strength and cannot withstand the pressure during sealing, causing deformation and the same phenomenon as in A2.C, resulting in voltage failure, liquid leakage, etc. Occur. On the other hand, if the thickness is made thicker than 0.2 m4n, the amount of anode active material decreases by that amount due to the volume, resulting in a decrease in capacity.

The inner diameter of the anode pedestal is b −, −,,: a <:
By using the entire anode pedestal made of a steel plate with a thickness of 0.05 to 0.2χ, it is possible to supply all alkaline batteries with excellent storage characteristics with little storage deterioration. It is a monkey.

[Brief explanation of drawings]

FIG. 1 is a half-cut side view of a button-type alkaline battery, and FIG. 2 is an enlarged sectional view of the main part of the battery. 1... Anode pedestal, 2... Anode mixture, 3...
... Anode case, 4 ... Sealing 1] ring,
6... cathode mixture, 6... cathode sealing plate,
a... Inner diameter of the anode pedestal, B... Inner diameter of the sealing cylinder, C... Inner diameter of the U-shaped folding base portion of the cathode sealing plate. Name of agent: Patent attorney Toshio Nakao and 1 other person @1
figure

Claims (1)

[Claims] The anode pedestal, which is loaded into the anode case together with the anode mixture, has an inverted-shaped cross section, and the inner diameter a of the horizontal part of the pedestal has an inner diameter bx at the tip of the horizontal part of the sealing ring, which has an inverted-shaped cross-section. The alkaline battery has a diameter smaller than the inner diameter C of the U-shaped fold base of the cathode sealing plate, and is made of a steel plate with a thickness of 0.06 to 0.2 mm.