JPS61107661A - Nonaqueous electrolyte battery - Google Patents

Abstract

PURPOSE:To improve storage life of a battery by adding molybdenum trisulfide to a positive electrode using cupric oxide as active material. CONSTITUTION:95wt% cupric oxide and 5wt% molybdenum trisulfide are mixed to prepare a positive mix. 85wt% positive mix, 10wt% the mixture of acetylene black and graphite and 5wt% fluorine resin powder which serves as a binder are mixed and pressed to mold a pellet measuring 15.0mm diameter and 1.1mm thickness. The pellet is heated to obtain a positive electrode 1. An about 0.6mm thick lithium sheet is punched in a 15.0mm diameter disk to form a negative electrode 2. Thereby, deposit of metallic copper on the surface of lithium negative electrode is suppressed, and storage life of a battery is increased.

Description

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

(b) Conventional technology 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, for example,
It is known from Japanese Patent No. 9-53935, and since its battery voltage is approximately t4V, it has the advantage that it can be used interchangeably with commonly used silver oxide batteries and mercury batteries as power sources for electronic devices.

However, when this type of battery is stored, the cupric oxide (iE positive electrode active material) decomposes in the electrolyte (-metallic copper dissolves, and this metallic copper precipitates on the lithium negative electrode surface (2), increasing the internal resistance. There was a problem in that the battery's discharge capacity decreased.

(c) Problems to be solved by the invention The purpose of the present invention is to improve the storage characteristics of a nonaqueous 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.

B) Means for Solving the Problems The present invention is characterized in that molybdenum trisulfide is added to a positive electrode containing 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 is Lithium negative electrode surface fleas exist as a film on the lithium negative electrode surface;
Precipitation of metallic copper can be suppressed.

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

95% by weight of commercially available special grade cupric oxide (mixed with 5% by weight of molybdenum trisulfide to make a positive electrode mixture of 85% by weight,
After adding and thoroughly mixing 10% by weight of acetylene black and graphite as conductive agents and 5% by weight of fluororesin powder as a binder, this mixture was pressure-molded at a pressure of about 2 tons/- to form a diameter of 15. .0sm.

A molded body with a thickness of 1.1 mm was obtained, and this molded body was
A positive electrode is obtained by heat treatment at a temperature of 0°C.

The negative electrode was made by rolling a lithium plate to a thickness of about 0.6 cm.

This lyticum rolled plate was made with a diameter of 15. (It is punched into 1 m. Electrolytic G is a mixed solvent of propylene carbonate and t2 dimethoxyethane (1 mol of diperchloric acid is dissolved), and the separator is made of polypropylene nonwoven fabric with a diameter of 1 t6. ■, 3.4 m thick battery (4
)It was created.

Figure 181 shows a longitudinal cross-sectional view of the battery of the present invention, (1) shows a positive electrode using cupric oxide as an active material and adding molybdenum trisulfide;
(2) is a lyticum negative electrode, and (3) is a separator impregnated with an electrolyte. Also, (4) is a positive electrode ring, (511/
i is a positive electrode current collector, (6) is a negative electrode current collector, (71 (81 is a positive and negative electrode exterior can, and (9) is an insulating puffing.

Next, in order to investigate the superiority of the battery of the present invention, a comparative battery (B) similar to the battery of the present invention except that no cupric chloride positive electrode (molybdenum ditrisulfide was added) was prepared.

FIG. 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° C.

In addition, Figure 3 shows the discharge characteristics of these batteries at 20°C and a constant load of 5.6 Ω, with the solid line representing the initial characteristics.

The broken line shows the discharge characteristics after storage for 20 days under conditions of a temperature of 60° C. and a humidity of 90° C.

It can be seen from FIG. 2 and '#IIs that the battery according to the present invention has improved storage characteristics, especially under high temperature and high humidity conditions, compared to the comparison battery.

The reason for this will be considered (=, considering the present invention battery C2).

Positive electrode C that uses cupric oxide as an active material; When molybdenum trisulfide is added, the decomposition of cupric oxide is suppressed, and the sulfur generated by dissolving a part of molybdenum trisulfide is absorbed onto the surface of the lithium negative electrode ζ Because it exists as a two-layer film, even if cupric oxide decomposes and metal steel dissolves in the electrolyte, it suppresses the precipitation of the two-metal steel on the lithium negative electrode surface, suppressing the increase in internal resistance. It is believed that the storage properties are improved.

Note that the sulfur film easily peels off due to discharge, so it does not adversely affect the discharge characteristics.

(g) Effects of the invention As mentioned above, non-aqueous electrolyte batteries using a positive electrode containing cupric oxide as an active material (2) The positive electrode (improving storage characteristics by adding molybdenum ditrisulfide) It is possible to do this, and its industrial value is extremely large.

[Brief explanation of the drawing]

Figure 1 is a longitudinal cross-sectional view of the battery of the present invention, Figure 2 is a diagram showing the relationship between internal resistance and storage period, and Figure 3 is a diagram showing the discharge characteristics of the battery. (1)...Positive electrode, (21...Negative electrode, (3)...Separator, (4)...Positive electrode ring, (5)...Positive electrode current collector, (6)...Negative electrode Current collector, (7) (8)...
Positive and negative electrode outer can, (9)... Insulating backing, (4).
...Battery of the present invention, ■)...Comparison battery.

Claims (1)

[Claims] (1) A device comprising 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, wherein molybdenum trisulfide is added to the positive electrode. Characteristics of non-aqueous electrolyte batteries.