JPH01154456A - Cylindrical mercury battery - Google Patents

Abstract

PURPOSE:To make mass production easy and to increase the performance of a battery by forming a film comprising viscose and methyl cellulose which is an additive on a thin resin cloth which is a separator material. CONSTITUTION:A mixed solution of viscose and methyl cellulose which is an additive is impregnated in alkali resistant resin fibers and dried for a certain time to form a film 4a comprising the viscose and methyl cellulose on the surface of the thin cloth. This thin cloth is used as a separator 4. The film 4a which is more semitransparent and hydrophilic compared with that made of viscose alone is formed on the separator 4, and the film resistance of the separator 4 in an electrolyte is decreased and its absorbency is increased. The high rate discharge performance and productivity of a battery are increased.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a cylindrical mercury battery using mercury oxide as a positive electrode active material.

BACKGROUND OF THE INVENTION Cylindrical mercury batteries have been widely used as power sources for medical equipment and various measuring instruments for a long time. The separator used in this cylindrical mercury battery is made of a thin resin fiber cloth with a viscose film formed on its surface to suppress deterioration of the storage characteristics of the battery. Immediately after being inserted into the hollow part of the battery's positive electrode body, the electrolyte was injected into the separator and absorbed, and then combined with the negative electrode to form the battery.

Problems to be Solved by the Invention In such a conventional configuration, the internal resistance of the battery increases due to the presence of the viscose film, resulting in deterioration of high load discharge performance. There was a problem in that productivity was poor because the time required from injecting the liquid to completely absorbing the liquid was extremely long.

In view of the above problems, the present invention provides a cylindrical mercury battery that can suppress deterioration in battery characteristics and productivity even when a separator having a viscose film is used.

Means for Solving the Problems To achieve this objective, the present invention involves impregnating alkali-resistant resin fibers with a mixed solution consisting of viscose and methyl cellulose as an additive, and then drying the fibers for a certain period of time. A cylindrical mercury battery is used, which is characterized by using a thin cloth on the surface of which a film made of viscose and the above-mentioned additives is formed.

Function: In such a battery, a film is formed on the entire surface of the separator using methylcellulose, which is more semi-permanent and more hydrophilic than when viscose is used alone, and the separator is bonded in the presence of an electrolyte. The membrane folding resistance of the material decreases, and the absorbency improves. Therefore, unlike the conventional method, the high-load discharge performance and productivity of the battery are improved.

EXAMPLES Hereinafter, examples of the present invention will be explained with reference to the drawings. Figure 2 shows a cylindrical mercury battery (height 16, 8 WrM, outer diameter 16.4
m++) is a half cross-sectional view. A general method for manufacturing this battery is to insert a positive electrode mixture 1 into a positive electrode case 2 together with a positive electrode ring 3 and to mold the positive electrode mixture under pressure. After inserting the separator 4 into the hollow part of the molded stop rod mixture 1, a predetermined amount of electrolyte containing potassium hydroxide as a main component is poured into the separator 4.
After absorption, a predetermined amount of a gelled zinc negative electrode 6 made of a mixture of frozen zinc powder, a gelling agent, and an electrolytic solution is filled. Thereafter, a negative electrode terminal cap consisting of a sealing plate 7 to which the current collector 6 is welded and an insulating gasket 8 is loaded, and the opening edge of the positive electrode case 2 is sealed to form a battery.

Of these, the separator is the feature of the present invention, as shown in Figure 1 (&
The separator 4 shown in ) is made by impregnating alkali-resistant resin fibers in a mixed solution consisting of 95% by weight of viscose and 6% by weight of methylcellulose.

The cloth is then dried at 46° C. for 12 hours to form a film 4a made of viscose and methylcellulose on its surface. Cylindrical mercury batteries of Examples were assembled using the above-described separator according to the present invention and the conventional separator. At that time, the time required from the time the electrolyte was poured into the separator until it was completely absorbed was measured. In addition, after the battery was completed, it was aged for 14 days at room temperature (L7), and the continuous discharge duration until the terminal voltage reached 0.9V with a load resistance of 30Ω was tested. It was done. The data on the time required for absorption is the average value of 10 tests, and the data on the duration is the average value of 6 tests.

Next, each feature of the present invention will be described.

The area of the film made of viscose and methylcellulose formed on the surface of the separator is the entire surface of the separator and both surfaces of the thin pick cloth in FIG.
If the coating weight ratio to the separator weight becomes too high, the semipermeability and hydrophilicity will be adversely affected, and reactions such as those caused by the positive electrode mixture will be a strong attack on the separator surface, as shown in Figure 1 (b). ), the film may be formed only on the positive electrode side surface, that is, the surface that becomes the outer side after the thin cloth is bent.

The following is the mixing weight ratio of niviscose and methylcellulose, but it depends on various combinations of manufacturing process conditions and physical property levels of methylcellulose.The separation speed and compatibility of the mixed solution, water-resistant adhesive strength, and semi-transparent surface of the separator in the presence of electrolyte are They differ in their properties and hydrophilicity. Therefore, the A-D4 variety uses methylcellulose that is most suitable for use in alkaline batteries such as mercury batteries, that is, methylcellulose with a degree of substitution of 1.4 to 2°4, which has excellent alkali solubility or water solubility, and has a high production yield. The above-mentioned test was conducted and the results are shown in the table below. The amount of methylcellulose M in the table is the value for 100 viscose.

The number of tests is the same as above, and the data in each column shows the time required for absorption (min) in the upper row, and the duration (min) in the lower row.
hr ) is the average value. If the product is not fully absorbed even after 30 minutes, it is marked as ``Do not absorb J'', and ``Unable to assemble'' is written for the duration.

As the methyl cellulose weight ratio increases for each variety,
The time required for complete absorption becomes shorter, but it becomes longer when the amount exceeds 8% by weight.

Furthermore, the duration becomes longer as the methyl cellulose weight % increases, but this also shows the opposite trend when it exceeds 8 weight %.

Accordingly, it was appropriate that the weight percent of methylcellulose added to the viscose was 8 or less. In addition, when the range of the coating amount of this film was converted into the coating amount per 1R of separator area, it was 4 to 26 g.

Effects of the Invention As described above, the present invention facilitates mass production and improves battery characteristics by forming a film consisting of viscose and methylcellulose as an additive on a thin cloth of resin fiber that is the material of the separator. This is something that can also be improved.

[Brief explanation of the drawing]

FIGS. 1(a) and (b) are sectional views showing a separator according to the present invention, FIG. 2 is a half sectional view showing a conventional battery and a battery according to an embodiment of the present invention, and FIG. 3 is a sectional view showing a conventional separator. It is. 1... Positive electrode mixture, 2... Positive electrode case,
3... Positive electrode ring, 4... Separator, 4a... Film made of viscose and methyl cellulose, 5... Gel-like zinc negative electrode, 6...・
...Collector, 7...Sealing plate, 8...Insulating gasket. Name of agent: Patent attorney Toshio Nakao and 1 other person 4-
11 Yanog Radar 4a - 7 Scose B Film made of methyl cellulose D1 Figure 1 Figure 2 and Figure 3 1 - Positive electrode ring 1 - Gel i big! Forceps Kii. ;・-Electronic collector r-11 lamp opening version 1-1 insulation assgusoto≠

Claims (2)

[Claims] (1) A cylindrical mercury battery characterized by using a separator whose surface is coated with a film made of viscose and methyl cellulose as an additive. (2) The film on the surface of the separator is obtained by impregnating a thin cloth of alkali-resistant resin fiber with a mixed solution of viscose and methylcellulose containing 8% by weight or less of viscose and then drying it for a certain period of time. A cylindrical mercury battery according to claim 1.