JPH0629013A - Dry cell - Google Patents

Abstract

PURPOSE:To provide a dry cell having good heavy load pulse discharge characteristics during light load discharging by suppressing increase in the internal resistance during light load discharging without bringing about drop of the heavy load discharge characteristics. CONSTITUTION:A dry cell concerned includes zinc chloride as the main electrolyte, in which the weight of ammonium ions contained in electrolyte is no more than 2% of the weight of electrolyte with which the inside of the battery is filled, wherein ammonium chloride is included in glue 2b for a separator 2, which is arranged between a negative electrode zinc 1 and positive electrode black mix 4, in an amount 1-10g per 1m<2> separator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zinc chloride type dry battery, and more particularly to improvement of a separator thereof.

[0002]

2. Description of the Related Art In a so-called zinc chloride type dry battery using zinc chloride as a main electrolyte, a separator such as kraft paper coated with processed starch or the like as a paste material is generally used. Then, in the battery, this separator has a negative electrode zinc (that is,
It is arranged so as to come into contact with a negative electrode composed of zinc).

Further, in this zinc chloride type dry battery, ammonium chloride is added to the electrolytic solution in order to prevent the precipitation of zinc hydroxide caused by the hydrolysis of zinc chloride.

However, when the amount of ammonium chloride in the electrolytic solution is large, dichlorodiamine zinc [Zn (NH
₃ ) ₂ ] Cl ₂ is deposited in a large amount, increasing the internal resistance and deteriorating the heavy load discharge characteristics.

Therefore, it is necessary to suppress the addition amount of ammonium chloride in the electrolytic solution so that the weight of ammonium ions is 2% or less with respect to the weight of the electrolytic solution to prevent deterioration of heavy load discharge characteristics.

[0006]

However, in a battery in which the weight of ammonium ions is suppressed to 2% or less with respect to the weight of the electrolytic solution as described above, the internal resistance increases at the time of light load discharge, and for example, at light load discharge. There is a problem that the heavy load pulse characteristic is significantly deteriorated when the heavy load pulse discharge is superposed therein.

Therefore, the present invention solves the problems of the conventional zinc chloride type dry cell at the time of light load discharge, and reduces the internal resistance at light load discharge without deteriorating the heavy load discharge characteristics. It is an object of the present invention to provide a dry battery having good characteristics such as heavy load pulse discharge characteristics during light load discharge by suppressing the increase of the battery.

[0008]

The present invention provides a separator paste material in a dry battery in which the main electrolyte is zinc chloride and the weight of ammonium ions contained in the electrolytic solution is 2% or less based on the weight of the electrolytic solution. The above object was achieved by adding ammonium chloride therein.

The reason why it is possible to suppress the increase in the internal resistance during light load discharge by adding ammonium chloride to the paste material as described above is considered to be as follows.

First, the cause of the increase in internal resistance during light load discharge was examined. The increase in internal resistance during light load discharge may be caused by a large amount of basic zinc chloride being deposited on the surface of the negative electrode zinc. found.

Therefore, in the present invention, the amount of ammonium ions in the electrolytic solution is kept within the same range as in the prior art to prevent the deterioration of the heavy load discharge characteristics and to be necessary for diffusing zinc ions during light load discharge. By adding an amount of ammonium chloride to the paste material of the separator, zinc ions are diffused as diammine complex ions into the positive electrode mixture to prevent the formation of basic zinc chloride on the surface of the negative electrode zinc. The increase in internal resistance during light load discharge was suppressed without deteriorating the load discharge characteristics.

By suppressing the increase in internal resistance during light load discharge as described above, the heavy load pulse discharge characteristic during light load discharge is improved.

The paper used as the base material of the separator is, for example, kraft paper or the like, and the paste material is, for example, processed starch, sodium acrylate, carboxymethyl cellulose or the like.

The amount of ammonium chloride added to the paste material of the separator is 1 per m ² of the separator.
About 10 g is preferable. That is, when the amount of ammonium chloride added is less than the above range, the effect of suppressing the increase in internal resistance during light load discharge is reduced, and when the amount of ammonium chloride added is more than the above range, the heavy load discharge characteristics deteriorate. Because you will be able to do it.

In the present invention, since ammonium chloride is added to the paste material of the separator as described above, it is possible not to add ammonium chloride to the electrolytic solution at all.

[0016]

【Example】

Example 1 Kraft paper that is coated with ammonium chloride of processing starch and 1 m ² per 5g of 1 m ² per 40 g (However, when coating a paste, after coating, drying) using as a separator, electrolytic manganese dioxide 28 g of powder and 5 g of acetylene black powder were mixed, and a concentration of 27 g was added to this mixture.
A 2% by weight zinc chloride aqueous solution was added and mixed to prepare a positive electrode mixture, which was used to assemble a single-cell dry battery having the structure shown in FIG.

Explaining the battery shown in FIG. 1, 1 is negative electrode zinc, 2 is separator, 3 is bottom paper, 4 is positive electrode mixture,
5 is an upper lid paper, 6 is a carbon rod, 7 is a sealing body, 8 is a negative electrode terminal plate, 9 is an insulating ring, 10 is a heat-shrinkable resin tube, 1
Reference numeral 1 is a positive electrode terminal plate, 12 is a resin ring, and 13 is a metal outer can.

The negative electrode zinc 1 is a cup-shaped zinc can, and the separator 2 is a kraft paper coated with a paste material containing ammonium chloride. The details of the structure are as shown in FIG. In FIG. 2, 2a is a paper, and in this embodiment, kraft paper is used as the paper 2a. 2b is a paste material, ammonium chloride is added to the paste material 2b, and the separator 2 is made of the paste material 2b.
Are arranged between the positive electrode mixture 4 and the negative electrode zinc 1 so as to contact the negative electrode zinc 1.

The above positive electrode mixture 4 was prepared as described above, and an aqueous solution containing 27% by weight of zinc chloride dissolved therein (without addition of ammonium chloride) was used for this battery. However, the amount of the electrolytic solution filled in the battery is 23.3 g.

The above battery was assembled as follows. First, the separator 2, the bottom paper 3 and the positive electrode mixture 4 are inserted into the negative electrode zinc 1 formed of a cup-shaped zinc can, the electrolyte solution is injected, and then the upper lid paper 5 is placed on the positive electrode mixture 4. After the preliminary pressing, the carbon rod 6 was inserted into the positive electrode mixture 4 through the through hole provided in the center of the upper lid paper 5.

Next, after curling the opening edge of the negative electrode zinc 1 inward, the sealing body 7 having a through hole in the center is fitted to the carbon rod 6, and the negative electrode terminal plate 8 is arranged at the bottom of the negative electrode zinc 1. Then, after arranging the paper ring 9 on the peripheral portion of the negative electrode terminal plate 8, the heat shrinkable resin tube 10 made of vinyl chloride resin is placed on the side surface of the negative electrode zinc 1 and heated to heat the heat shrinkable resin tube 10 described above. Side of the negative electrode zinc 1 and the negative electrode zinc 1
The peripheral portion of the sealing body 7 arranged on the bottom of the paper ring 9 and on the anode zinc 1 was covered.

Next, the positive electrode terminal plate 11 is attached to the head of the carbon rod 6.
The resin ring 1 on the outer peripheral edge of the positive electrode terminal plate 11.
After arranging No. 2, each constituent member was axially tightened with a metal outer can 13 and was externally attached to obtain a battery having a structure shown in FIG.

[0023] except that used was coated with ammonium chloride of processing starch and 1 m ² per 10g of 1 m ² per 40g kraft paper as in Example 2 the separator, making a single-1 type batteries in the same manner as in Example 1 did.

[0024] except that used was coated with ammonium chloride of processing starch and 1 m ² per 1g of 1 m ² per 40g kraft paper as in Example 3 a separator, in the same manner as in Example 1, a single 1 type batteries It was made.

Comparative Example 1 A size 1 battery was prepared in the same manner as in Example 1 except that as the separator, kraft paper coated with 40 g of processed starch per 1 m ² without addition of ammonium chloride was used.

Comparative Example 2 Kraft paper coated with 40 g of processed starch per m ² was used as a separator, and an aqueous solution containing 27% by weight of zinc chloride and 10% by weight of ammonium chloride was used as an electrolytic solution. Others are the same as in Example 1,
A single type dry battery was produced.

Batteries of Examples 1 to 3 and Comparative Examples 1 to 1
2 batteries 25 ℃, 2Ω continuous discharge duration and 200Ω
The change in internal resistance during continuous discharge was investigated. Table 1 shows the 2Ω continuous discharge duration. FIG. 3 shows changes in internal resistance during continuous discharge of 200Ω.

[0028]

[Table 1]

As shown in Table 1, the batteries of Examples 1 to 3 have almost the same discharge duration as the battery of Comparative Example 1, and as shown in FIG. Is Comparative Example 1
The increase in internal resistance was less than that of the battery. As is clear from the results shown in Table 1 and FIG. 3, the batteries of Examples 1 to 3 of the present invention can suppress an increase in internal resistance during light load discharge while maintaining good heavy load discharge characteristics.

On the other hand, although the battery of Comparative Example 1 in which ammonium chloride was not added to the paste material of the separator had good heavy load discharge characteristics, as shown in FIG. 3, the internal resistance increased during light load discharge. In addition, the battery of Comparative Example 2 in which a large amount of ammonium chloride was added to the electrolytic solution could suppress the increase in internal resistance during light load discharge as shown in FIG. The load discharge characteristic was deteriorated. Since the battery of Example 2 and the battery of Comparative Example 2 showed almost the same increase in internal resistance, they are shown as one curve in FIG.

[0031]

As described above, in the present invention, by adding ammonium chloride to the paste material of the separator, the internal resistance at the time of light load discharge can be increased without causing the deterioration of the heavy load discharge characteristics. I was able to suppress it.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing an example of a dry battery of the present invention.

FIG. 2 is an enlarged view of part A in FIG.

FIG. 3 is a diagram showing changes in internal resistance of the batteries of Examples 1 to 3 and the batteries of Comparative Examples 1 and 2 during continuous discharge of 200Ω.

[Explanation of symbols]

 1 Negative electrode zinc 2 Separator 2a Paper 2b Paste material 4 Positive electrode mixture

Claims (1)

[Claims] 1. The main electrolyte is zinc chloride, and the weight of ammonium ions contained in the electrolytic solution is 2% or less with respect to the weight of the electrolytic solution filled in the battery.
Is a paper 2a coated with a paste material 2b, and the separator 2 has a space between the negative electrode zinc 1 and the positive electrode mixture 4 and the paste material 2b.
In the dry battery arranged on the side in contact with the negative electrode zinc 1, ammonium chloride is added to the paste material 2b of the separator 2 described above.