JPH0586626B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a non-aqueous electrolyte battery using cupric oxide as a positive electrode active material.

(b) Prior art A non-aqueous electrolyte battery using cupric oxide as a positive electrode active material and lithium or a lithium alloy as a negative electrode active material is known, for example, from Japanese Patent Publication No. 59-33935, and the battery voltage is approximately Since it has a voltage of about 1.4V, it has the advantage of being compatible with silver oxide batteries and mercury batteries that are commonly used as power sources for electronic devices.

However, when this type of battery is stored, the cupric oxide as the positive electrode active material decomposes and metallic copper is dissolved in the electrolyte, and this metallic copper is deposited on the surface of the lithium negative electrode, increasing the internal resistance and causing the battery to deteriorate. There was a problem that the discharge capacity of the battery decreased.

(c) Problems to be solved by the invention The purpose of the present invention is to improve the storage characteristics of a non-aqueous electrolyte battery that uses cupric oxide as a positive electrode active material and lithium or a lithium alloy as a negative electrode active material. It is something.

(d) Means for solving the problems The present invention is characterized in that molybdenum trisulfide is added to a positive electrode that uses cupric oxide as an active material.

Here, the amount of molybdenum trisulfide added is preferably in the range of 1 to 20% by weight based on the positive electrode active material.

(e) Effect When molybdenum trisulfide is added to a positive electrode that uses cupric oxide as an active material, the decomposition of cupric oxide is suppressed, and the sulfur produced by dissolving a part of molybdenum trisulfide becomes lithium. It exists as a film on the surface of the negative electrode, and can suppress the precipitation of metallic copper on the surface of the lithium negative electrode.

(f) Examples Examples of the present invention will be described in detail below.

85% by weight of positive electrode mixture made by mixing 95% by weight of commercially available special grade cupric oxide with 5% by weight of molybdenum trisulfide.
After adding 10% by weight of acetylene black and graphite as conductive agents and 5% by weight of fluororesin powder as a binder and mixing thoroughly, this mixture was
Pressure molded at ton/ml pressure, diameter 15.0mm, thickness
A 1.1 mm molded body is obtained, and this molded body is heat-treated at a temperature of 200 to 300°C to form a positive electrode.

The negative electrode is made by rolling a lithium plate to a thickness of approximately 0.6 mm.
This lithium rolled plate was punched to a diameter of 15.0 mm. The electrolyte was one mole of lithium perchlorate dissolved in a mixed solvent of propylene carbonate and 1.2 dimethoxyethane, and the separator was made of polypropylene nonwoven fabric with a diameter of 20.0 mm and a thickness of
A 2.5mm battery A was created.

FIG. 1 shows a longitudinal cross-sectional view of the battery of the present invention, where 1 is a positive electrode using cupric oxide as an active material and molybdenum trisulfide is added, 2 is a lithium negative electrode, and 3 is a separator impregnated with an electrolyte. Further, 4 is a positive electrode ring, 5 is a positive electrode current collector, 6 is a negative electrode current collector, 7 and 8 are positive and negative electrode exterior cans, and 9 is an insulating packing.

Next, in order to investigate the superiority of the battery of the present invention, a comparative battery B was prepared which was the same as the battery of the present invention except that molybdenum trisulfide was not added to the cupric oxide positive electrode.

Figure 2 shows the change in internal resistance over time when these batteries were stored at a temperature of 60°C and a humidity of 90%.

Figure 3 shows the discharge characteristics of these batteries at 20℃ and 5.6KΩ constant load discharge, where the solid line shows the initial characteristics and the broken line shows the discharge after 20 days of storage at a temperature of 60℃ and 90% humidity. Show characteristics.

From FIGS. 2 and 3, it can be seen that the storage characteristics of the battery A of the present invention, especially under high temperature and high humidity conditions, are improved compared to the comparative battery B.

Considering the reason for this, in the battery of the present invention,
When molybdenum trisulfide is added to a positive electrode that uses cupric oxide as an active material, the decomposition of cupric oxide is suppressed, and the sulfur produced when a portion of molybdenum trisulfide dissolves forms a film on the surface of the lithium negative electrode. Therefore, even if cupric oxide decomposes and metallic copper dissolves in the electrolyte, it can suppress the precipitation of metallic copper on the surface of the lithium negative electrode, suppressing the increase in internal resistance and improving storage characteristics. It is thought that this will be improved.

Note that the sulfur film is easily peeled off by discharge, so it does not adversely affect the discharge characteristics.

(g) Effects of the invention As mentioned above, in a non-aqueous electrolyte battery using a positive electrode containing cupric oxide as an active material, the storage characteristics can be improved by adding molybdenum trisulfide to the positive electrode. Yes, and its industrial value is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of the battery of the present invention, FIG. 2 is a diagram showing the relationship between internal resistance and storage period, and FIG. 3 is a diagram showing the discharge characteristics of the battery. 1...Positive electrode, 2...Negative electrode, 3...Separator,
4...Positive electrode ring, 5...Positive electrode current collector, 6...Negative electrode current collector, 7, 8...Positive and negative electrode exterior can, 9...Insulating packing, A...Battery of the present invention, B...Comparison battery .

Claims (1)

[Claims] 1. It comprises a negative electrode using lithium or a lithium alloy as an active material, a non-aqueous electrolyte, and a positive electrode using cupric oxide as an active material, characterized in that molybdenum trisulfide is added to the positive electrode. non-aqueous electrolyte battery.