JPS6059706B2 - Manufacturing method of small silver peroxide battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a small silver peroxide battery.

Batteries using silver peroxide as the positive electrode active material have a high energy density per unit volume and unit weight, so they are particularly advantageous because they can provide a large capacity when made into small button-shaped batteries. . Silver peroxide batteries have the advantage of high battery capacity, but the discharge voltage can be reduced to two different voltage levels, approximately 1. Voltage level at 8V (first stage voltage level) and discharging from silver oxide to silver 1
．． Because it has the disadvantage of discharging at a voltage level of 5V (second voltage level), it discharges at almost a single voltage level for many small battery applications, especially for powering hearing aids, watches, etc. Therefore, it was necessary to remove the first stage voltage level. Methods to eliminate such drawbacks include providing a continuous layer of silver oxide in physical and electrical contact with the silver peroxide pellets, or adding an oxidizable metal layer between the silver peroxide pellets and the positive electrode, e.g. A structure in which a discontinuous metal layer such as zinc is provided, and a method in which silver peroxide is predischarged have been proposed. However, although it is possible to discharge a silver peroxide battery at a single voltage level using these methods, the open circuit voltage of this battery is 1.6V, which is approximately the same voltage level when the battery is discharged with a constant resistance. During battery manufacturing, even if attempts are made to check for battery capacity shortages due to partial internal short-circuits or poor quality of active materials by detecting open-circuit voltage, open-circuit voltage and discharge The pressure was the same, which caused a quality control problem. The present invention eliminates the above-mentioned conventional drawbacks, and consists of a positive electrode based on silver peroxide powder, a zinc negative electrode, and an alkaline electrolyte.
The present invention provides a method for manufacturing a small silver peroxide battery that has an open circuit voltage of 1.85V and a discharge voltage value of 1.5 to 1.6V when discharged at a current of 10 μA or more.

FIG. 1 is a longitudinal cross-sectional view of a small silver peroxide battery according to the present invention, in which 1 is a positive electrode mainly composed of silver peroxide, 2 is a zinc negative electrode, and 3 is a negative electrode made of zinc.
is a separator made of vinylon nonwoven fabric and cellophane.

4 is a positive electrode can, 5 is a negative electrode cap, and 6 is a packing, and the separator is impregnated with a 28% caustic soda aqueous solution as an electrolyte.

The open circuit voltage of this battery is 1.85V, and if this battery is discharged as it is at, for example, 6500Ω, 1.85V.
It is discharged through a first voltage level of V and a second voltage level of 1.55V.

Therefore, since the discharge shows two stages of discharge, it does not reach a single discharge level. In other words, the battery has an open circuit voltage of 1.85V.
And 1.5 to 1.6V when discharged with a current of 10μA or more
For example, if a preliminary discharge is used, a constant resistance of Ω is used to have a discharge pressure in the range of 57! It is sufficient to pre-discharge between the FRs and further discharge for 24Tf with a constant resistance of 160KΩ.

Next, we made 40 prototype batteries as shown in Figure 1, performed the preliminary discharge described above, and when discharged with an open circuit voltage of 1.85V and a current of 10pA or more, the voltage ranged from 1.5 to 1.6V. 26 when the battery of the present invention is used, and the open circuit voltage is 1.
A discharge test was conducted on 20 conventional batteries which had been partially subjected to preliminary discharge treatment (discharged at 5KΩ for 3 days) so as not to exhibit 85V.

After the discharge is stored for two months after the manufacturing method, the open circuit voltage and 65
The discharge time was checked by continuous discharge with a constant resistance of 00Ω (corresponding to a discharge current of about 10 pA). The results are shown in Table 18. Of the 40 batteries of the present invention, 14 had an open circuit voltage of 1.8 V or less, and 11 had an open circuit voltage of 1.8 V or less.
It was excluded because it showed the first stage voltage level (1.85V) during pA current discharge.

Further, Table 1 above is the average value of 26 values for the batteries of the present invention, and the maximum and minimum values are shown in parentheses to show the range of variation between batteries. The above results show that the battery of the present invention has almost no variation in performance, and is utilized to its fullest from the beginning of the second stage voltage level, so the battery capacity can be utilized to its maximum, compared to conventional batteries. and the same amount of active material. It is possible to maintain a large battery capacity. Furthermore, regarding the battery having the above configuration, FIGS. 2 and 3
To explain with the characteristic diagram shown in the figure, Fig. 2 shows the characteristics of the above embodiment.
-1 characteristic diagram, and when the discharge current is 10 μA or less, 1
．． The battery is manufactured to exhibit a voltage value of 1.5 to 1.6 V or less when the discharge current value is increased at a voltage of 5 to 1.6 V or more and 10 μA or more. Figure 3 shows the discharge characteristics of this battery. Curve a shows a high voltage value for an initial short period of time when the battery was discharged with a constant resistance of 6500 Ω, but it soon discharged to a value of about 1.5 to 1.6 V. For example, if the open circuit voltage of the battery is measured at time T1, it shows a voltage value of about 1.85 cm as shown by the dotted curve b. Further, at time T2, the open circuit voltage also shows around 1.6. A battery having such characteristics was manufactured by the method described in the above embodiment. In addition, the fact that there is a voltage difference between the open circuit voltage value and the closed circuit voltage value means that the manufactured battery has an open circuit voltage value of 1.85.
If it shows V, it is a normal battery, and if it is less than that, it is determined to be a defective battery, and even if the battery has been left unattended, it can be determined whether it has a lot of self-discharge by checking the open circuit voltage value. A battery with excellent quality control can be obtained. In addition, when discharging at an open circuit voltage of 1.85■ and a current of 10pA or more, the voltage is 1.5
In order to obtain a battery of the present invention with a discharge voltage in the range of ~1.6V, preliminary discharge was performed using a constant resistance in the above example, but the method is not limited to this method. Alternatively, a battery may be produced structurally to achieve the above values by adjusting the number of continuous layers of silver oxide brought into electrical contact or the oxidizable metal layer provided between the silver peroxide pellets and the positive electrode.

As described above, the present invention utilizes the property that silver peroxide discharges from the first voltage level to the second voltage level, and at the beginning of the second voltage level, the open circuit voltage of the battery is equal to the first voltage level. Show the same 1.85V, 10μA
In other words, if the voltage is set to 1.5 to 1.6 V immediately when the battery is discharged with a current under normal use, the open circuit voltage and the discharge (closed circuit) voltage with a current of 10 pA or more will be different. The capacity of the battery can be checked by this method, and it is possible to provide a battery with extremely stable and uniform performance, which is of great industrial value.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a small silver peroxide battery according to an embodiment of the present invention, FIG. 2 is a V-1 characteristic diagram of the battery of the present invention, and FIG. 3 is a discharge characteristic diagram of the battery of the present invention. 1... Positive electrode based on silver peroxide, 2...
... Zinc negative electrode, 3 ... Separator, 4 ...
...Positive electrode can, 5...Negative electrode cap.

Claims (1)

[Claims] 1. In the manufacturing method of a silver peroxide battery consisting of a positive electrode based on silver peroxide powder, a zinc negative electrode, and an alkaline electrolyte, the discharge pressure value when discharging at an open circuit voltage of 1.85 V and a current of 10 μA or more A method for producing a small silver peroxide battery with a voltage of 1.5 to 1.6V.