JPS58671B2 - dry battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the improvement of dry batteries, particularly manganese dioxide dry batteries using a neutral salt electrolyte. By using a copper-stainless steel clad material with an amalgamated body, the electrical contact between the cathode and current collector is stabilized, improving discharge characteristics and improving the cathode current collector. It's about maintaining strength.

Conventionally, in batteries using an alkaline electrolyte, such as silver oxide batteries and mercury oxide batteries, copper is used as the cathode current collector, and it is also known to amalgamate the copper surface.

When using a gelled zinc cathode or a powdered zinc cathode, copper amalgam is used as the current collector.

This is to prevent self-discharge of zinc in an alkaline solution.

That is, when amalgamated negative electrode zinc comes into contact with non-amalgamated copper, a local battery is formed between the zinc and copper, and hydrogen gas is generated in the body part and Zn+++
Two types of cathodic reactions occur: 2e→Zn precipitation reaction, while zinc dissolves and disappears.

However, amalgamated copper can prevent local batteries from forming with amalgamated zinc.

The present invention improves the cathode current collector in a manganese dry battery that uses a neutral salt electrolyte made of zinc perchlorate, zinc sulfamate, zinc chloride, ammonium chloride, etc., instead of such an alkaline electrolyte.

The present inventors have previously proposed that copper can be used in the cathode current collector in a dry battery using a neutral salt electrolyte, such as the electrolyte composition shown in the following table.

In such a neutral salt electrolyte, when copper is used as the cathode current collector, copper has less polarization and gas generation than when other metals such as iron, stainless steel, tin, and gold are used. It is also good, with little leakage during over-discharge as a battery.

However, when copper alone is used as a cathode current collector, the progress of amalgamation cannot be stopped, and when used as a cathode current collector and sealing plate, the mechanical strength is gradually lost, leading to leakage.

The present invention solves these problems and uses a clad material made of copper-stainless steel as a cathode current collector and sealing plate.
The inner body part in contact with the zinc cathode is amalgamated to prevent formation of a local battery even when in contact with the amalgamated zinc cathode, and to maintain sufficient mechanical strength as a sealing plate.

Hereinafter, an example thereof will be explained using a button-type manganese dry battery shown in the figure.

In the figure, numeral 1 is an anode mixture consisting of manganese dioxide, acetylene black, a neutral salt electrolyte, etc., which is filled in a battery case 2 which also serves as an anode terminal.

3 is a separator, 4 is an amalgamated zinc cathode located on the separator, 5 is a sealing plate that also serves as a cathode terminal in contact with this zinc cathode, and copper 6 is located on the inside and stainless steel 7 is located on the outside. It is clad with.

8 is an insulating sealing ring interposed between the peripheral edge of the sealing plate and the battery case.

The feature of the present invention lies in this sealing plate 5, in which the copper 6 located inside is amalgamated with a cladding material made of copper and stainless steel, and this is brought into electrical contact with the amalgamated zinc cathode 4. .

When the amalgamated copper is brought into contact with the zinc cathode which is also amalgamated, the formation of a local battery as described above can be prevented and the discharge characteristics can be stabilized.

Next, in order to confirm the effect of this invention battery, button type dry battery A shown in the example and comparative battery B whose sealing plate was a non-amalgamated copper plate were both 11.6 mm in diameter and 5.3 mm in height. When a load of Ω was connected to the battery and the battery was discharged, the results shown in Figure 2 were obtained.

As is clear from FIG. 2, the discharge characteristics of A are more stable than those of B, and the voltage drop is also smaller.

Although the above example describes a button-type manganese dry battery, the present invention can be similarly applied to a cylindrical manganese dry battery, and in that case as well, the body part is inserted inside the battery of the cladding material that serves as the cathode current collector and sealing plate. Since stainless steel is placed on the outside, this prevents the progress of copper amalgamation and maintains sufficient mechanical strength as a sealing plate, and also exhibits good corrosion resistance properties, making it suitable for sealing plates. It is possible to improve various properties of.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a button-type manganese dry battery according to an embodiment of the present invention, and FIG. 2 shows its discharge characteristics. 1...Anode mixture, 2...Battery case,
4... Zinc cathode, 5... Sealing plate made of clad material, 6... Amalgamated copper,
7...Stainless steel.

Claims (1)

[Claims] 1 A cathode current collector consisting of an anode mixture mainly composed of manganese dioxide, a zinc cathode, a neutral salt electrolyte with a pH of 3.5 to 5.5, and a copper-stainless steel cladding material, with the body section placed inside the battery. 1. A dry battery comprising: a body and a sealing plate; the amalgamated body portion of the cathode current collector and sealing plate is electrically contacted with an amalgamated zinc cathode.