JPS6111434B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a battery having an air electrode using oxygen as an active material, and provides an air battery with high voltage, large capacity, and excellent storage performance by using a sulfamate aqueous solution as the electrolyte and lead as the negative electrode. . Conventional air batteries use oxygen as the positive electrode active material and zinc as the negative electrode, and the electrolyte is a 30-40% caustic alkali aqueous solution such as caustic soda or caustic potash saturated with zinc oxide.Furthermore, CMC, polyacrylic Add viscosity with a glue such as acid soda and thickly cover the surface of the air electrode to prevent the oxygen reduction ability from decreasing.
In addition, the battery was miniaturized and sealed to prevent leakage from the air supply hole in the positive electrode can. Conventional air batteries use an alkaline electrolyte such as caustic potash, and during storage or discharge, a large amount of carbon dioxide gas flows in in addition to oxygen from the air supply hole, so the electrolyte comes into contact with carbon dioxide gas, causing caustic potassium to form in the liquid. The reaction produced a large amount of potassium carbonate. As a result, the alkaline concentration of the electrolyte decreased, resulting in a decrease in electrical conductivity and a decrease in the discharge operating voltage of the battery. Furthermore, the alkaline electrolyte dissolved zincate ions produced by the discharge reaction of zinc to near saturation, and when a large amount of carbon dioxide gas flowed in, it reacted with the carbonate ions in the solution, producing a large amount of zinc carbonate.
Zinc acid ions have low solubility in the electrolytic solution and deposit on the surface of zinc, reducing the discharge reaction area, resulting in drawbacks such as a decrease in discharge operating voltage and discharge capacity. As an improvement to this, in large air batteries, the electrolyte was circulated using a pump, etc., and the alkali carbonate was regenerated into new alkali using calcium hydroxide, but this required large equipment and was difficult to miniaturize the battery. It was hot. The present invention uses an acidic electrolyte consisting of an aqueous sulfamate solution and a negative electrode body consisting of lead.
The purpose is to obtain a high voltage, large capacity air battery with excellent storage performance. Embodiments of the present invention will be described based on the drawings. Reference numeral 1 denotes a positive electrode can that also serves as a positive electrode terminal, and has an air supply hole 2 at the bottom. The air electrode 3 is made of cobalt phthalocyanine and activated carbon, and is in contact with the separator paper 4, which is a lyophilic semipermeable membrane. 5 is an electrolyte holding material that holds an acidic electrolyte of sulfamate;
It is a nonwoven fabric or porous body with excellent liquid retention and acid resistance, and is in contact with the negative electrode body 6 made of lead powder. 7 is a paper with excellent air permeability, and is in contact with the air electrode 3 through a Teflon air permeable membrane 8 having many micropores.
The other surface is in contact with the bottom of the positive electrode can 1 where the air supply hole 2 is provided. 9 is the negative electrode can and gasket 10
The battery is sealed by bending the opening of the positive electrode can 1 through the opening. Numeral 11 is a polyvinyl chloride sheet sealing material that seals the air supply hole 2, and a pressure-sensitive adhesive 12 seals the air supply hole 2 at the bottom of the positive electrode can 1. Since the battery of the present invention uses an acidic electrolyte of sulfamate, there is no generation of carbonates due to large amounts of carbon dioxide gas other than oxygen flowing in from the air supply hole of the positive electrode can, so the electrolyte deteriorates due to carbonates. This eliminates the drop in battery discharge operating voltage, and since no zinc is used, there is no zinc carbonate precipitate, so there is no decrease in discharge capacity, resulting in an air battery with high voltage, large capacity, and excellent storage performance. It will be done. Furthermore, when a sulfamate aqueous solution with a pH of 1 is used as the electrolyte for the battery of the present invention, the logical reduction potential of oxygen is +1.23V with respect to the hydrogen electrode, and the oxidation potential of lead is -0.4V, and the battery The theoretical potential difference is
1.63V, and the operating voltage becomes approximately 1.5V due to polarization due to discharge. This is because the oxygen reduction potential in an alkaline electrolyte of PH15 is +0.40V, the oxidation potential of zinc is -1.32V, the theoretical potential difference of the battery is 1.72V, and the discharge operation voltage is approximately 1.3V due to polarization. The voltage increases by 0.2V, and an air battery with high voltage and large capacity can be obtained by that increase. Next is an example battery according to the present invention, which is a button-shaped air battery with a diameter of 11.5 mm and a height of 5.2 mm, using an acidic electrolyte of a sulfamate aqueous solution with pH = 1 and a negative electrode body of lead powder. Invention product [A] and PH15
10 each of the conventional product [B], which is the same type of air battery using an alkaline electrolyte of aqueous caustic potassium solution and a negative electrode body of zinc powder, were discharged at a constant current of 1.5 mA at 25°C, and the discharge curve was The discharge capacity is summarized in Figure 2 and Table 1. In addition, 20 pieces of the present invention [A] and 20 pieces of the conventional product [B] were stored at 25°C, and in the 6th and 12th months, 10 pieces each were discharged at 25°C with a constant current of 1.5 mA. The results are summarized in Table 1.

[Table] From FIG. 2 and Table 1, it can be seen that the product [A] of the present invention has a high discharge operating voltage and excellent storage performance. In addition, since the air battery of the present invention has an operating voltage of 1.5V, it can be used as an alkaline manganese battery, a silver oxide battery, or
It is compatible with nickel zinc batteries, etc. As described above, the air battery of the present invention includes an air electrode, an acidic electrolyte consisting of an aqueous sulfamate solution, and a lead negative electrode body inserted into a positive electrode can having an air supply hole, and sealed with a gasket and a negative electrode can. It has a high discharge operating voltage, greatly improves discharge capacity and storage performance, and has great industrial value.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an air battery according to an embodiment of the present invention.
Figure 2 shows the inventive product [A] and the conventional product [B] at 25°C.
It is a comparison diagram of the discharge curve of 1.5mA constant current. DESCRIPTION OF SYMBOLS 1... Positive electrode can, 2... Air supply hole, 3... Air electrode, 5... Electrolyte holding material, 6... Negative electrode body.

Claims (1)

[Claims] 1. An air battery consisting of an air electrode, an acidic electrolyte made of an aqueous sulfamate solution, and a negative electrode body made of lead.