JPS5991673A - Button type alkaline manganese battery - Google Patents

Abstract

PURPOSE:To increase battery performance by specifying the total amount of electrolyte in a button type alkaline manganese battery. CONSTITUTION:In a button type alkaline manganese battery, a pellet of a positive mix 2 containing MnO2 and a negative material 6 containing amalgamated zinc are placed in a positive can 1 and a negative can 7 respectively. An alkali hydroxide electrolyte is impregnated in the electrode materials 2 and 6. The ratio of the total electrolyte quantity A in the battery to the theoretical capacity B mAh of zinc active material is specified to meet the following indefinite equation; 0.8<A/B<1.1. Thereby, discharge capacity and leakage resistance of the battery is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a button-type alkaline manganese battery, and aims to improve battery performance by appropriately regulating the total amount of electrolyte.

In recent years, button-type alkaline manganese batteries, which are used in many electronic products such as calculators, cameras, and game watches, use manganese dioxide, a cheaper raw material than conventional expensive silver batteries. The quantity used is rapidly increasing. However, compared to a silver battery which has a stable discharge voltage, an alkaline manganese battery has a disadvantage in that the voltage decreases as discharge progresses, resulting in a smaller discharge capacity. This is also shown by the performance of a silver battery, which can only provide a capacity of about 60 cm when the lowest voltage at which the equipment is operated is 1.2V.

Conventional button-type alkaline batteries are designed to be filled with the maximum amount of positive and negative electrode active materials in order to maximize the discharge capacity, and as a result, it is necessary to reduce the amount of electrolyte jIi injected into the battery. Ta. Alkaline manganese batteries consume water due to a stain pond reaction, which is different from silver batteries (M n 02 +', 4Zn + V2H * o - + M
Therefore, it is known that there is a close relationship between the amount of electrolytic solution and the utilization rate of the active material.

On the other hand, in a study of alkaline solution concentration, it was pointed out that the electrolyte becomes concentrated due to water consumption due to battery reaction, and when the concentration exceeds about 55%, KOH solids are generated, which has an adverse effect on battery performance. Please advise at the end of the KOH
The amount of electrolyte that does not produce solids and the amount of electrolyte that corresponds to the theoretical capacity of zinc have been proposed. The active material utilization rate of conventional button-type alkaline batteries designed based on these findings is 90%.
It had the disadvantage of being below 1.

The present invention eliminates such conventional drawbacks and appropriately regulates the amount of electrolyte, thereby improving the utilization rate of active materials and improving battery performance.

The present invention will be explained below with reference to Examples.

FIG. 1 is a cross-sectional view of a battery based on an example.

It is a button type battery with a diameter of 11.6 m and a height of 5.4116 m, 1 is a positive electrode can, 2 is a manganese dioxide positive electrode mixture containing graphite and Teflon resin, 3 is a separator, 4 is an impregnating material, 5 is a backing, 6 is a gel compound of frozen zinc containing 10% mercury, and 7 is a camellia can.

As the positive electrode mixture 2, 650q was used (Belen) which was molded at a pressure of 4t/d. The negative electrode mixture 6 was 165q and had a theoretical zinc capacity of 120 mAh. The electrolytic solution is partially impregnated into the positive electrode mixture 2 in advance, and a part is injected into the negative electrode mixture side, so that the total electrolytic solution is 90.10°C; 110°C.
Batteries were manufactured at six levels: 120, 150, and 140 μ2. The electrolyte used was 9 M/ItKOH solution with 5
It is made by electrolyzing nO.

The battery was discharged with a discharge capacity iih and a load resistance of 7.5 KΩ, and the discharge time was measured when the final voltage was set to 1.2V.

Table 1 and Figure 24C, percentage of discharge capacity (utilization rate) of zinc theoretical capacity and 2
The rate of occurrence of leakage defects after being left for 000 hours is shown.

From this result, it was found that as the amount of electrolyte injected into the battery increased, the utilization rate of negative electrode zinc increased. However, regarding leakage resistance, the amount of electrolyte is 130μ
[It was confirmed that the battery deteriorates when the battery is exceeded, and it was found that excellent battery characteristics could be obtained by regulating the electrolysis and liquid volume in consideration of the utilization rate of negative electrode zinc and leakage resistance.

The reason why leakage resistance worsens when the amount of electrolyte is increased is that filling material beyond the limited battery capacity deforms the battery shape and weakens the sealing performance of the battery seal. . This can be easily determined by measuring the dimensions of the leaking battery.In addition, for the above-mentioned batteries, other battery characteristics such as electrical characteristics and self-discharge rate, as well as discharge capacity and leakage resistance, can be determined. The evaluation results confirmed that there was no difference from the previous level.

As described above, according to the present invention, a high-performance button-type alkaline manganese battery can be manufactured by appropriately regulating the amount of electrolyte relative to the theoretical capacity of negative electrode zinc. Furthermore, in electronic devices using button-type alkaline manganese batteries, there are effects such as extending the battery life and reducing the troublesome battery replacement for the user.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a button-type alkaline manganese battery according to an example, and FIG. 2 is a graph showing the utilization rate of negative electrode zinc and leakage rate with respect to changes in the amount of electrolyte based on the example. 2...Positive electrode 3...Separator 6...Negative electrode and above Applicant Daini Seikosha Co., Ltd.

Claims (1)

[Claims] A button-type alkaline battery using manganese dioxide as a positive electrode, frozen zinc as a negative electrode, and an alkaline hydroxide solution as an electrolyte, characterized in that the electrolyte is regulated so as to satisfy the following inequality: Button type alkaline manganese battery. 0.8<A/B<1.1 A: Total electrolyte amount of battery e1 (μμ) B: Theoretical capacity of zinc active material (mAh)