JPH0319672B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to improvements in the production of alkaline batteries,
The purpose is to shorten manufacturing time by accelerating the infiltration of electrolyte into the anode mixture. In alkaline batteries, there is a restriction that the electrolyte on the anode mixture side must be infiltrated into the anode mixture that has already been pressure-molded. Conventionally, a ring-shaped anode mixture is inserted into an anode can, and a pot-shaped separator is placed in contact with the anode mixture. The method used is to inject the solution into the separator, leave it at room temperature for 5 hours or more, allow the electrolyte to infiltrate into the anode mixture through the separator, and remove the remaining excess electrolyte from the anode can by suction. It had been. As a result, battery manufacturing time becomes longer, and a large amount of intermediate products must be stored for a long time, causing problems in securing storage space and management during storage.Furthermore, the electrolyte absorbs carbon dioxide gas from the air. This causes various problems such as variations in capacitance and decreased leakage resistance, and the infiltration of the electrolyte into the anode mixture has been a bottleneck in battery production. In view of these circumstances, the inventors conducted various studies and found that by heating the anode mixture together with the electrolyte, the electrolyte quickly infiltrates the anode mixture, and as a result, the battery The inventors have discovered that the manufacturing time can be greatly shortened and the above-mentioned problems can be easily solved, leading to the completion of this invention. It is not always clear why the electrolyte quickly infiltrates into the anode mixture when the anode mixture is heated together with the electrolyte, but it is possible that the electrolyte is contained in the anode mixture in a compressed state by heating. Gas such as air expands and escapes from the anode mixture, forming pores in the anode mixture that reach the surface from the inside, and the electrolyte whose viscosity has decreased due to heating passes through the pores to the anode. This is thought to be due to penetration into the mixture. When carrying out this invention, heating is preferably carried out at a temperature of 60°C or above and below the boiling point of the electrolytic solution, and although the heating time varies depending on the heating temperature, it is usually preferable to employ 1 to 10 minutes. .
However, there is no problem even if the heating time exceeds 10 minutes. After the heating is completed, it is preferable to allow the electrolyte to cool to room temperature for about 10 minutes, because the depressurizing effect of cooling will further ensure the infiltration of the electrolyte into the anode mixture. In order to shorten the heating time and reduce the viscosity to facilitate handling, it is preferable to heat the electrolytic solution to about 50 to 70° C. before pouring it into the anode can. This invention can be achieved in various ways as follows. (b) After storing the anode mixture in the anode can, pour in an amount of electrolyte in excess of the amount to be infiltrated into the anode mixture, heat the entire assembly to infiltrate the anode mixture with the electrolyte, and then drain the excess. How to remove electrolyte. (b) After storing the anode mixture and separator in the anode can, inject an amount of electrolyte in excess of the amount to be infiltrated into the anode mixture and separator, and heat them all to infiltrate the electrolyte into the anode mixture and separator. How to remove excess electrolyte after (c) After storing the anode mixture in the anode can, heating them, and injecting an electrolyte in excess of the amount to be infiltrated into the anode mixture, and infiltrating the anode mixture with the electrolyte, How to remove excess electrolyte. (d) After storing the anode mixture and separator in the anode can, heat them, inject an amount of electrolyte in excess of the amount to be infiltrated into the anode mixture and separator, and pour the electrolyte into the anode mixture and separator. A method for removing excess electrolyte after infiltrating the Next, one embodiment of the present invention (method (b)) will be described with reference to the drawings. 100 parts by weight of manganese dioxide and 16.8 parts by weight of phosphorous graphite were added to a nickel-plated iron anode can 5 with an inner diameter of 12.5 mm and a height of 44.6 mm and a thickness of 0.3 mm at a rate of 2.5 t/cm ^{2 .}
Pressure molded with inner diameter 8.3 mm, outer diameter 12.3 mm, height 10
4 mm mixture molded bodies are stacked and stored, pressurized to form the anode mixture 1, the opening of the anode can 5 is bent to form a groove 5a near the opening end, and the anode mixture 1 is A cup-shaped separator 3 made of triple-wound vinylon-rayon mixed paper with a thickness of 0.16 mm was inserted in contact with the separator 3, and then 163.0 g of an electrolytic solution heated to 60°C was poured into the separator 3 as shown in Figure 2. The whole was placed in an electric furnace and heated at 90° C. for 5 minutes, and after the heating was completed, it was allowed to cool to room temperature for about 10 minutes to infiltrate the electrolytic solution 16 into the anode mixture 1 and the separator 3. Thereafter, excess electrolyte was removed from inside the separator 3 using a suction nozzle. Note that the surplus electrolyte was 1.4 g. Next, the cathode agent 2 is put into the separator 3 inside the anode can 5, and then the plastic sealing body 6 into which the cathode lead rod 4 and washer 7 are inserted is placed inside the anode can 5.
The opening of the anode can 5 is sealed by tightening the part beyond the groove 5a of the anode can 5 in the radial direction to bring it into close contact with the sealing body 6, and then the resin tube 11 and the paper ring 10 are placed on the cathode side. , the leaf spring 8 and the cathode terminal plate 9 are attached, the resin tube 12 is attached, the anode terminal plate 13 and the resin ring 15 are attached to the anode side, and the outer can 14 is attached to form the LR6 type as shown in FIG. Alkaline manganese battery A was manufactured. The electrolyte in the cathode used was 1.6
g, contains 2.6g of zinc powder. The electrolyte used dissolved 5% by weight of zinc oxide.
It consists of a 35% by weight aqueous caustic potassium solution. For comparison, after storing anode mixture 1 and separator 3 in anode can 5, 3.0 g of electrolyte was injected.
After leaving the electrolyte at room temperature for 5 hours to infiltrate the anode mixture 1 and separator 3, the excess electrolyte was collected by suction, and then an LR6 type alkaline manganese battery B was prepared in the same manner as above. Manufactured. Next, these batteries A and B were subjected to intermittent discharge at low temperature and under heavy load, and the discharge duration was measured. The results are shown in Table 1. In addition, 10 batteries were used for each test, and the discharge was performed at a terminal voltage of
The voltage was discharged for 5 seconds/paused for 5 seconds until the voltage reached 0.9V.

[Table] As shown in Table 1, the short discharge duration and large variations in the discharge duration of Battery B manufactured using the conventional method are due to variations in the molding density of the anode mixture and the thickness of the separator. This is thought to be due to the fact that the amount of electrolyte infiltrated into and retained in the anode mixture and separator fluctuates or changes in quality due to the electrolyte absorbing carbon dioxide gas in the air during storage. In contrast, in the method of the present invention, the electrolyte held in the anode mixture and separator is semi-forced to infiltrate into the anode mixture and separator, so that the infiltration is completed in a short time and the carbon dioxide gas in the electrolyte is As a result, as shown in Battery A in Table 1, a battery with less variation in electric capacity and excellent discharge performance can be obtained. The following Table 2 shows the number of batteries in which leakage occurred when 100 each of the batteries A and B were stored at 60° C. and 90% relative humidity for 5 months.

[Table] As shown in Table 2, Battery A manufactured by the method of the present invention has better leakage resistance than Battery B manufactured by the conventional method. The reason for the poor leakage resistance of Battery B manufactured by the conventional method is that the electrolyte is injected into the separator and left for a long time, so the electrolyte injected into the separator is This is thought to be because the particles crawl up to the open end of the anode can. In contrast, in the method of the present invention, the electrolyte is sealed within a short time after being injected, so there is less leakage of the electrolyte into the opening of the anode can, and as a result, the electrolyte has good leakage resistance. A battery is obtained. As detailed above, according to the present invention, compared to conventional methods, battery manufacturing time can be significantly shortened, battery manufacturing becomes highly efficient, and storage of intermediate products can be greatly reduced. Problems such as securing storage space and management during storage, as well as problems such as variations in electrical capacity and reduced leakage resistance, are almost completely resolved.

[Brief explanation of the drawing]

FIG. 1 is a half-cut sectional view showing an example of a cylindrical alkaline manganese battery manufactured by the method of the present invention, and FIG. 2 is a sectional view showing one step in manufacturing the battery by the method of the present invention. 1... Anode mixture, 3... Separator, 5... Anode can, 16... Electrolyte.

Claims (1)

[Scope of Claims] 1. After storing the anode mixture in the anode can, an excess of electrolyte than the amount to be infiltrated into the anode mixture is injected, and the whole is heated to infiltrate the electrolyte into the anode mixture. A method for producing an alkaline battery, which is characterized by removing excess electrolyte. 2. After storing the anode mixture and separator in the anode can, an excess amount of electrolyte was injected into the anode mixture and separator, and the whole was heated to allow the electrolyte to infiltrate into the anode mixture and separator. A method for producing an alkaline battery, which is characterized by removing excess electrolyte. 3 After storing the anode mixture in the anode can, heat them and inject an amount of electrolyte in excess of the amount to be infiltrated into the anode mixture. A method for producing alkaline batteries characterized by removing liquid. 4. After storing the anode mixture and separator in the anode can, heat them and inject an amount of electrolyte in excess of the amount to be infiltrated into the anode mixture and separator.
A method for producing an alkaline battery, which comprises infiltrating an anode mixture and a separator with an electrolyte and then removing excess electrolyte.