JPH0654665B2 - Non-aqueous electrolyte battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a non-aqueous electrolyte battery containing 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 disclosed in, for example, Japanese Patent Publication Sho 59.
-33935, the battery voltage is about 1.4 V, so that it has an advantage that it can be used interchangeably with a silver oxide battery or a mercury battery that is widely used as a power source for electronic devices.

However, in this type of battery, during storage, cupric oxide as the positive electrode active material is decomposed and metallic copper is dissolved in the electrolytic solution, and the metallic copper is deposited on the surface of the lithium negative electrode to increase the internal resistance of the battery. There is a problem that the discharge capacity is lowered, and although it is compatible with 1.5 V type batteries such as silver oxide batteries and mercury batteries, the voltage is slightly low, so that the improvement of voltage is desired.

(C) Problems to be Solved by the Invention The present invention aims to improve the storage characteristics and battery voltage of 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. It is intended.

(D) Means for Solving the Problems The present invention provides a non-aqueous electrolytic solution comprising a negative electrode using lithium or a lithium alloy as an active material, a non-aqueous electrolytic solution, and a positive electrode using cupric oxide as an active material. A battery is characterized in that a two-component additive comprising molybdenum trisulfide, cupric sulfide and iron disulfide is added to the positive electrode in an amount of 5 to 40% by weight based on cupric oxide.

(E) Working Addition of molybdenum trisulfide and cupric sulfide to the positive electrode that uses cupric oxide as the active material suppresses the decomposition of cupric oxide and reduces the amount of molybdenum trisulfide and cupric sulfide. It is possible to prevent the sulfur produced by melting the part from depositing as a film on the lithium negative electrode surface and depositing metallic copper on the lithium negative electrode surface.

Further, addition of iron disulfide can increase the battery voltage as compared with the case of using cupric oxide alone.

(F) Examples Hereinafter, examples of the present invention will be described in detail.

85% by weight of a positive electrode mixture prepared by mixing 5% by weight of molybdenum trisulfide, 10% by weight of cupric sulfide and 15% by weight of iron disulfide with commercial grade cupric oxide, acetylene black and graphite as conductive agents 10% by weight and 5% by weight of fluororesin powder as a binder were added and mixed well, and the mixture was mixed with about 2
A molded body having a diameter of 15.0 mm and a thickness of 1.1 mm is obtained by pressure molding at a pressure of ton / cm ² , and this molded body is heat-treated at a temperature of 200 to 300 ° C. to obtain a positive electrode.

The negative electrode is obtained by rolling a lithium plate to a thickness of about 0.6 mm and punching this rolled lithium plate to a diameter of 15.0 mm. The electrolyte is a mixed solvent of propylene carbonate and 1.2 dimethoxyethane in which 1 mol / mol of lithium perchlorate is dissolved and used by impregnating the separator with a diameter of 20.0 mm and a thickness of 2.5 m.
A battery (A) of m was prepared.

FIG. 1 shows a longitudinal sectional view of a battery of the present invention, (1) is a positive electrode containing cupric oxide as an active material and molybdenum trisulfide, cupric sulfide and iron disulfide are added, (2) is a lithium negative electrode, (3) is a separator impregnated with an electrolytic solution. Also, (4) is the positive ring,
(5) is a positive electrode current collector, (6) is a negative electrode current collector, (7) and (8) are positive and negative electrode outer cans, and (9) is an insulating packing.

Then, in order to investigate the superiority of the battery of the present invention, a comparative battery similar to the battery of the present invention except that molybdenum trisulfide, cupric sulfide and iron disulfide were not added to the cupric oxide positive electrode.
(B) was created.

FIG. 2 shows changes with time in internal resistance when these batteries were stored at a temperature of 60 ° C. and a humidity of 90%.

In addition, Fig. 3 shows the discharge characteristics of these batteries when discharged at a constant load of 5.6 kl at 20 ° C. The solid line shows the initial characteristics, and the broken line shows the battery after assembly.
The discharge characteristics after storage for 20 days at a temperature of 60 ° C and a humidity of 90% are shown.

2 and 3, the battery (A) of the present invention has improved storage characteristics under high temperature and high humidity as compared with the comparative battery (B).
Moreover, it can be seen that the battery voltage is increased.

Considering this reason, when molybdenum trisulfide and cupric sulfide are added to the positive electrode having cupric oxide as an active material in the battery of the present invention, decomposition of cupric oxide is suppressed and molybdenum trisulfide and sulfide are suppressed. Sulfur produced by dissolving a part of cupric acid is deposited as a film on the lithium negative electrode surface, so even if cupric oxide is decomposed and metal copper is dissolved in the electrolytic solution, metal is still present on the lithium negative electrode surface. Since copper can be prevented from precipitating, it is considered that the increase in internal resistance is suppressed and the storage characteristics are improved. Since the sulfur film is easily destroyed by discharge, it does not adversely affect the discharge characteristics.

Although the reason why the battery voltage is increased by adding iron disulfide is not clear, iron disulfide has a higher intrinsic potential due to cupric oxide, so the battery voltage is higher than that of cupric oxide alone. It is supposed to be high.

(G) Effect of the invention As described above, in the non-aqueous electrolyte battery provided with the positive electrode using cupric oxide as the active material, the positive electrode is a three-component additive consisting of molybdenum trisulfide, cupric sulfide and iron disulfide. Is added to the cupric oxide in an amount of 5 to 40% by weight, a non-aqueous electrolyte battery having excellent storage characteristics and high voltage can be obtained, and its industrial value is extremely large. .

[Brief description of drawings]

FIG. 1 is a vertical cross-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 discharge characteristic 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 outer can, (9) …… Insulating packing, ( A) ... Invention battery, (B) ... Comparison battery.

Claims (1)

[Claims] 1. A negative electrode using lithium or a lithium alloy as an active material, a non-aqueous electrolytic solution, and a positive electrode using cupric oxide as an active material, wherein the positive electrode is molybdenum trisulfide or sulfide. A non-aqueous electrolyte battery, characterized in that a ternary additive comprising dicopper and iron disulfide is added to the cupric oxide in an amount of 5 to 40% by weight.