JPS6243060A - Silver oxide battery - Google Patents

Abstract

PURPOSE:To prevent potential drop in high rate discharge by fitting a current collector made of an alkali resistant metal on the surface of a sheet-like silver oxide electrode of a bipolar electrode in electrolyte circulation type lithium-silver oxide battery. CONSTITUTION:An electrode of electrolyte circulation type lithium-silver oxide battery which is used by supplying and circulating electrolyte at starting has a bipolar construction formed by bonding together a silver oxide sheet 6 serving as positive electrode and a lithium plate 7 serving as negative electrode to a conductive substrate 8. The positive electrode 6 is formed in such a way that a mixture of silver peroxide powder and Teflon binder is kneaded and formed in a sheet, and its surface is covered with a current collector 9 comprising nickel net, then the net is welded to the substrate 8 at a spot-welding point 10. Thereby, electric resistance is reduced and electrons are uniformly supplied to the whole reaction surface to increase discharge performance.

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Usage Meter The present invention dispenses 1 AM liquid at 1! This relates to silver oxide mm, such as lithium/silver oxide batteries and aluminum/silver oxide batteries, which use an electrolyte that is supplied and circulated in a wm type electrolyte.

Conventional technology and the V-point electrolyte VA The positive and negative electrodes of cyclic lithium-silver oxide batteries and aluminum-silver oxide batteries have a so-called bipolar structure in which a conductive substrate is usually sandwiched between them. This Bypira 1! A battery is constructed by alternately stacking a required number of electrodes and separators. Conventionally, the following two methods have been typical for producing silver oxide electrodes used as positive electrodes in batteries of this type.

■Chemical formation method: A method in which silver powder is pressed and sintered onto a substrate such as a silver net or expanded net, and then charged and discharged in an alkaline electrolyte to form a silver oxide electrode.

■Sheet type...Silver peroxide (Age) or silver liquefaction (
A method in which Teflon is added as a binder to powder of Ag2O) or a mixed powder of both, and the mixture is mixed and molded to obtain a porous, sheet-like silver oxide electrode.

The sheet type (■) requires less effort and has the advantage of being lower in cost than the chemical formula (■). Fig. 1 is a plan view of a conventional bipolar electrode for a tallithium/silver oxide battery using a silver oxide electrode formed by a sheet-type manufacturing method, and Fig. 2 is a plan view of a conventional bipolar electrode for a thallium/silver oxide battery.
FIG.

Bipolar T&5 has a structure in which a silver oxide sheet 1 and a lithium plate 2 are integrated via a conductive substrate 3, but since the lithium plate 2 and the conductive substrate 6 are crimped together, there is no conductivity between them. However, since the silver oxide sheet 1 itself has high electrical resistance and is only placed on the conductive substrate 3, the contact resistance between the silver oxide sheet 1 and the conductive substrate 3 is also high. Therefore, in order to impart electrical conductivity, tin oxide sheet 1
It was necessary to create a large number of small through-holes and pour the conductive resin 4 thereinto.

Therefore, the electrons (e-) involved in the discharge reaction of the silver oxide electrode shown by the following formulas (1) and (9) are supplied from the conductive substrate 3 to the conductive resin 4 to the reaction surface.

2A90 + H2O+ 2e-→Ag2O+ 2OH
-(1) AP2O + H2O+ 2e-→2 A9+
2OH--(2) However, the above-mentioned conventional silver oxide electrode had a drawback in that the initial potential drop during high rate discharge was extremely large. this is! ! This is due to the conductive resin, and this type of commercially available conductive resin originally has weak adhesion.
Since the specific resistance value is about 100 times that of metal and there is no adhesive strength, the contact with the conductive substrate 5 tends to be unstable, resulting in a large electrical resistance.

That is, the highly conductive A9 produced by the reaction of the above formula (2)
The output of the battery is apparently suppressed until the layer penetrates from the reaction surface of the electrode to the conductive substrate 3 along the opaque edge of the conductive resin 4.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned drawbacks, and aims to provide a silver oxide electrode that exhibits a stable potential with a small drop in potential at the initial stage of discharge.

Formulation of the invention The present invention utilizes peroxide (A90) powder or silver oxide (A90) powder or silver oxide (A90) powder.
2O) In a silver oxide battery using a sheet-shaped oxidized I1 frame formed by mixing powder or a mixed powder of both with Teflon added as a binder and molding the MA active material as a positive electrode, the reaction surface of the silver oxide electrode is This is a silver oxide battery equipped with a current collector made of an alkali-resistant metal.

Example An embodiment of the present invention will be described in detail based on the drawings.

FIG. 6 is a plan view of a bipolar electrode of a circulating electrolyte lithium/silver oxide battery equipped with a silver oxide electrode used in the present invention, and FIG. 4 is a cross-sectional view taken along the line B-B' in FIG. .

6 is a silver oxide sheet, 7 is a lithium plate, 8 is a conductive substrate, and 6, 7.8 have an integrated structure similar to the conventional example (FIG. 1). Reference numeral 9 denotes a current collector formed of a net or expanded net of alkali-resistant gold 1 such as nickel or silver, which is placed or embedded in the silver oxide sheet 6 and fixed to the substrate 8 by spot welding parts 10. , an electrical connection is made. Further, the mesh size, wire diameter, etc. of the net 9 can be arbitrarily selected depending on the use of the battery, such as high rate discharge or low rate discharge.

In such a structure, the electrons (e-) required in the reactions of formulas (1) and (2) are transferred to the conductive substrate 8.
From there, the electrons (6-) are supplied to the reaction surface of the silver oxide sheet 6 through the spot welding net 101 net or the expanded net 9, but since the electrical resistance is lower than in the conventional example and its variation is also small, the electrons (6-) are uniform over the entire reaction surface. will be supplied to

FIG. 5 is a diagram showing the relationship between the initial silver oxide electrode potential during high rate discharge of the battery of the present invention and the conventional battery. Note that the discharge current is 1A/. It is glossy. As is clear from FIG. 5, the battery of the present invention has a small potential drop at the initial stage of discharge.

Effects of the Invention Since the present invention has the structure as described in the claims, it is possible to prevent the potential drop of the silver oxide electrode during high rate discharge, and its industrial value is great.

[Brief explanation of the drawing]

Figure 1 is a plan view of a conventional bipolar electrode, and Figure 2 is a top view of a conventional bipolar electrode.
3 is a polar plan view of the biwheeler used in the present invention, FIG. 4 is a sectional view taken along BB' in FIG. 5, and FIG. FIG. 3 is a diagram showing the relationship between discharge time and silver oxide electrode potential of an inventive battery and a conventional battery.

Claims (1)

[Claims] Silver peroxide (AgO) powder or silver oxide (Ag_2O)
In a silver oxide battery that uses a sheet-shaped silver oxide electrode as a positive electrode, which is made by kneading and molding an electrode active material consisting of a powder or a mixed powder of the two and adding Teflon as a binder, an alkali-resistant metal is coated on the reaction surface of the silver oxide electrode. A silver oxide battery characterized by being equipped with a current collector formed of.