JPS6038831B2 - How to detect the lifespan of alkaline batteries - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for detecting the lifespan of an alkaline battery.

In general, for alkaline batteries such as nickel-zinc batteries, zinc-air batteries, alkaline manganese batteries, mercury oxide batteries, silver oxide batteries, and silver peroxide batteries, the discharge voltage is kept constant from the beginning of battery use, and the discharge voltage is kept constant at the end of discharge. Lasts until.

Therefore, in conventional Alka IJ batteries, it is extremely difficult to know the lifespan of the battery before the battery active material is exhausted, and it is difficult to know when to replace the battery.

In addition, if it is incorporated into an extremely important device in which human life is involved, such as an artificial heart stimulator, from the standpoint of safety, even if the battery host material still remains and can be used continuously, it may be used for a certain period of time. There was a drawback that it had to be replaced after that. Generally, methods for knowing when to replace a battery include a method of attaching a label indicating the approximate replacement time to the device being used, or a method of detecting a voltage drop at the end of battery life using a circuit. For example, most electronic wristwatches currently use the latter method, but silver oxide batteries, silver peroxide batteries, mercury oxide batteries, etc. normally maintain a constant voltage, but at the end of their lifespan, the voltage suddenly increases. Since it has a built-in battery that causes a voltage drop, it has the disadvantage that there is no time to replace the battery. In the case of a silver oxide battery, a clock is normally driven at a constant voltage of 1.5 V, but when the voltage reaches about 0.9 to 1.2 V, a typical clock stops. Therefore, if you set the battery life detection voltage level to a low level (for example, about 1.35V), the clock will stop after a few days even if the battery life is detected, and if you set the battery life detection voltage level to a high level (for example, about 1.5V), the clock will stop after a few days. When set, it is very common for the life detection circuit to operate due to a drop in battery voltage at low temperatures or when additional clock mechanisms (lamps, buzzers, etc.) are activated, even though the life has not yet come to an end. It's happening. According to the present invention, the voltage at the end of discharge of a battery, which rapidly drops, can be controlled by two methods that prevent a watch, etc. from stopping.
All of the above-mentioned drawbacks can be solved by a completely new method of detecting this flat low potential by creating a stepped potential.

Hereinafter, examples in which the present invention is applied to silver oxide batteries will be described.
This will be explained with reference to the figures.

FIG. 1 is a sectional view of a JISGS-12 type (diameter 11.6 mm, t4.2 side) silver oxide battery used in the present invention.

1 is an anode can that also serves as an anode terminal, and is made of monovalent silver oxide (Ag20
) and graphite or silver divalent oxide (Ago
), a separator 3, a plastic ring 4, and an electrolyte impregnated material 5 are housed therein.

A cathode can 7 also serves as a cathode terminal, and houses a cathode composite material 6 that has been pressure-molded or gelled.

8 is an insulating packing between the two poles.

Next, how to make the cathode mixture 6 will be described.

After mixing 2 parts by weight of tin powder with 8 parts by weight of mercury,
The tin powder was dissolved and amalgamated by shaking at room temperature for 3 hours. After adding 40 parts by weight of 60 to 120 mesh zinc powder to the bundled tin powder, the zinc powder was also bundled by shaking for 4 hours. It is thought that this zinc powder was expressed by excess mercury in the bundled zinc powder. Thereafter, the mixture was aged at 60 qo for 6 minutes to produce a mixture of bundled tin powder and springified zinc powder.
The mixture of bundled tin powder and bundled zinc powder thus produced is uniformly mixed with one or two gelling agents such as carboxymethyl cellulose, sodium polyacrylate, polyethylene glycol, and polyvinyl alcohol. Thereafter, it was press-molded or gelled with an alkaline electrolyte and used as a cathode mixture.

7. Assemble a battery as shown in FIG. 1 using the cathode mixture 6 of the present invention prepared as described above; When Uta-Q constant resistance discharge was performed, as shown in Figure 2, tin silver monoxide (A
Since a potential of 1.25 V was generated at g20), it was possible to predict the consumption of zinc powder, which is the main active material of the cathode, and to know that the life of the battery was approaching.

Furthermore, Figure 2 shows the difference between the battery used in the present invention and the conventional battery.
．． It is a diagram showing a comparison of constant resistance discharge characteristics.

In the figure, A is a battery used in the present invention, and B is a conventional battery. Between a and b, the main cathode active material zinc-valent silver oxide (A
g20), and shows a constant voltage of 1.56V. The voltage between c and d is the voltage associated with the combined discharge of tin monovalent silver oxide (Ag20), which is the sub-cathode active material, and shows a constant voltage of 1.25V. Further, the duration between c and d can be arbitrarily set by changing the amount of tin metal, which is a subcathode host material, relative to the amount of zinc. This example describes a silver oxide battery, but a nickel-oxide battery that uses zinc for the cathode
It can also be applied to alkaline batteries such as zinc batteries, zinc air batteries, alkaline manganese batteries, and mercury oxide batteries.

As described above, in the present invention, after zinc and silver oxide undergo a complete battery reaction, tin and silver oxide, whose potential is more base than zinc, undergo a battery reaction, and the discharge potential ranges from 1.5V to 1.2V. The life of the battery can be determined by detecting the potential at the end of discharge.

Therefore, according to the present invention, the battery can be replaced before the device is stopped, making it ideal for use in various electronic devices that require reliability, such as electronic wristwatches that use batteries as an energy source.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of an iron oxide battery to which the present invention is applied;
The figure is a diagram showing a comparison of the discharge characteristics of a battery of the present invention and a conventional battery. 1...Anode can, 2...Anode mixture, 3...
...Separator, 4...Plastic sling, 5
... Electrolyte impregnated material, 6 ... Cathode mixture, 7 ...
...Cathode can, 8...Insulating packing. Figure 1 Figure 2

Claims (1)

[Claims] 1. In a method for detecting the life of an alkaline battery using zinc as the main cathode active material, the cathode mixture of the alkaline battery is composed of a mixture of zinc oxide powder, tin oxide powder, and a gelling agent, and the auxiliary cathode active material is A method of detecting the lifespan of an alkaline battery by detecting the potential associated with the discharge of tin and the anode active material.