JPS6235451A - Dry battery - Google Patents

Abstract

PURPOSE:To prevent increase of internal pressure of a battery due to generation of corrosion and hydrogen gas resulting from such corrosion by forming a zinc can as the negative electrode with the zinc alloy adding the specified amount of aluminum. CONSTITUTION:A zinc can is manufactured by the impact extruding method using a zinc alloy pellet adding aluminum (for preventing corrosion of zinc) of 0.01-0.1% to the weight of zinc and a dry battery is manufactured without amalgam process. Therefore,a high voltage due to excessive hydrogen at the surface of zinc can is kept for a long period and a dry battery is to be hardly amalgamated without loss of battery discharging performance and stock performance.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a dry battery that has been made battery-free without deteriorating its performance by improving the material of the negative electrode zinc can.

<Prior art> A positive electrode mixture made by adding a zinc chloride solution, an ammonium chloride solution, etc. as an electrolyte to a powder mixture containing manganese dioxide as a main component, and kneading it is passed through a paper separator coated with an electrolyte paste to the negative electrode. Dry batteries that are housed in zinc cans are in high demand because they are cheaper than alkaline batteries and the like.

In such dry batteries, due to impurities contained in the negative electrode zinc can, the zinc can self-discharges and corrodes during stocking or during intermittent discharge, and pitting and corrosion of the zinc can occur when insects are removed. There are disadvantages such as an increase in the rate of leakage due to the increase in internal pressure due to hydrogen gas generation. In order to prevent such performance deterioration caused by zinc can corrosion, dry cell 1
Each piece is subjected to freezing treatment using 3 to 5 mg of mercury.

Such freezing treatment involves adding mercury, for example, mercuric chloride (Hg) to the electrolyte paste applied to the paper separator.
A method has been used to increase the hydrogen overvoltage of zinc by adding it in the form of Cβ2) or in a similar form to the electrolyte mixed in the positive electrode mixture to amalgamate the inside surface of the zinc can. There is.

<Problems to be solved by the invention> However, no matter what method is used, the freezing treatment method does not allow dry batteries to contain mercury, which is extremely harmful to the human body, even if it is only a small amount. Nowadays, with the environmental pollution problem caused by mercury attracting a lot of attention, there is a strong demand for dry batteries to be made sterile-free.

<Means for Solving the Problems> The dry cell of the present invention has a zinc weight of 0.01 to 0.0.
The gist is that a negative electrode zinc can made of a zinc alloy with 1% aluminum added was used.

The reason why the amount of aluminum added is set in the above range is that if the amount added is less than 0.01%, the desired corrosion-preventing effect on zinc cans cannot be obtained, and if the amount is more than 0.1%, there will be no difference in the corrosion-preventing effect. It is based on the knowledge that there is no such thing.

<Function> By using the above means, the aluminum added to the negative electrode zinc can acts to increase the hydrogen overvoltage on the surface of the zinc can, so that the zinc can will not self-discharge and corrode during long-term storage, etc. This can prevent the battery internal pressure from increasing due to hydrogen gas generation.

<Example> 0.1 to 1% lead (for increasing ductility), O
-0.06% cadmium (for increased hardness) and 0.0
Zinc alloy pellets each containing 6% aluminum (for zinc corrosion protection) are made into cans by impact extrusion. Zinc cans are used to make R20 type dry batteries ( A product of the present invention) was produced. On the other hand, an R20 type dry battery (conventional product) was made using a zinc can made from zinc pellets made of the same material except that no aluminum was added, and was treated with the same amount of mercury as the conventional one.
In addition, R20 type dry batteries (comparative quantity) using similar aluminum-free zinc cans and without icing treatment were produced.

Discharge time (final voltage 0.9V) when these three types of dry batteries are continuously discharged with a discharge resistance of 2Ω after manufacture (continuous discharge)
, and when discharging for 4 hours a day with a discharge resistance of 10Ω (
The discharge time (end voltage: 1.OV) of the intermittent discharge is as shown in Table 1.

Table 1 Continuous discharge Intermittent discharge Invention product 282 minutes 40.4 hours Conventional product
280 minutes 40.5 hours Comparative product 280 minutes 4
0.3 hours Also, three similar types of dry batteries were manufactured and heated at 45°C.
Table 2 shows the measurement results of the discharge time when continuous or intermittent discharge was performed under the same conditions after stocking for 3 months, and the corrosion reduction I of the zinc can after stocking. The weight of the zinc can when manufactured is 18
It is 0.

Table 2 Continuous discharge Kokukyouho J Corrosion impairment Invention product 230 minutes 38.0 hours 0.15 (It
Conventional product 232 minutes 38.3 hours 0.131J Comparative product 215 minutes 3760 hours 0.25g When three similar dry batteries were manufactured and stored at air temperature for one year, they were continuously discharged or intermittent discharged under the same conditions. Table 3 shows the measurement results of the discharge time and corrosion loss of zinc cans after stocking.

Table 3 1 Extraction 1 Plate Kyuho 3 Corrosion weight loss Present invention product 253 minutes 38.4 hours 0.119 Conventional product 260 minutes 38.5 hours 0.09 Q comparison product 2
20 minutes 37.2 hours 0.18 (J From Tables 1 to 3 above, the product of the present invention has slightly inferior discharge performance after stocking compared to the conventional product, and although the corrosion loss after stocking is slightly larger, As is clear from the comparison with the comparative amount,
Its performance is sufficient for practical use.

<Effects of the Invention> According to the dry battery of the present invention constructed as described above, the hydrogen overvoltage on the surface of the zinc can is maintained sufficiently high for a long period of time due to the action of aluminum added to the zinc can, resulting in improved battery discharge performance and This has the excellent effect of making dry batteries battery-free with almost no loss in stock performance.

Same as Ara and Tomonosuke Ki

Claims (1)

[Claims] 1. A non-tank dry battery characterized by using a negative electrode zinc can made of a zinc alloy made by adding 0.01 to 0.1% aluminum to the weight of zinc.