JPS6010558A - Nonaqueous electrolyte cell - Google Patents

Abstract

PURPOSE:To reduce initial voltage drop and deterioration of capacity after storage in a nonaqueous electrolyte cell, by adding metal sulfide reactable with alkali metal ion to form inter-layer compound to a positive pole containing CuO as main active substance. CONSTITUTION:In a cell having a negative pole employing light metal such as Li, Na as active substance, positive pole employing CuO as main active substance and nonaqueous electrolyte, metal sulfide such as TiS2 which is reactable with alkali metal ion such as Li, Na to form inter-layer compound is added to CuO. In this cell, production of metallic copper is suppressed during preliminary discharge. Since the surface of negative pole is coated with thin sulfur film to be liberated through decomposition of metal sulfide, passive state of negative pole and self discharge are suppressed even upon production of metal copper resulting in improvement of cell performance.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of industrial application The present invention provides a negative electrode using light metals such as lithium and sodium as an active material, a positive electrode using cupric oxide as a living material, and a non-aqueous electrolyte. The present invention relates to a non-aqueous electrolyte battery, and particularly to improvements in the positive electrode.

(Ex) Conventional technology In this type of battery, 3V batteries that use manganese dioxide or carbon fluoride as the positive electrode active material have already been put into practical use.On the other hand, when copper oxide or copper sulfide is used as the positive electrode active material, the Since it has a discharge voltage of 1.5V, a non-aqueous electrolyte battery that is compatible with general-purpose manganese dry batteries and alkaline dry batteries can be obtained.

Many non-aqueous electrolyte batteries, although various factors can be considered, generally exhibit a high voltage at the time of open circuit and initial discharge, and only show the desired discharge voltage after a certain period of time. Are known.

The time required to reach the desired discharge voltage from the high voltage depends on how the battery is used and can range from several hours to several days. However, this phenomenon is a significant disadvantage when used in electronic equipment that requires a nearly constant voltage power supply for its proper operation; This will have a negative impact on the electronic components.

In order to solve the above problem, attempts have been made to pre-discharge a portion of the battery capacity to the shipped vIT after battery assembly.

This is based on the idea that the high voltage portion during initial discharge is removed by preliminary discharge.

However, when preliminary discharge is performed in a non-aqueous electrolyte battery using cupric oxide as the positive electrode active material, metallic copper is generated as a discharge product, and the metallic copper during this nascent stage is very active and does not interact with the electrolyte. It reacts or becomes ions, diffuses to the negative electrode side, and precipitates on the negative electrode surface, resulting in passivation of the negative electrode.Electric ff at the beginning of discharge: Capacity decrease after battery storage due to N inclusion and self-discharge. invite.

(c) Object of the Invention The object of the present invention is to provide an improved non-aqueous electrolyte battery that exhibits less voltage drop at the beginning of discharge and less capacity loss after battery storage even after pre-discharge treatment.

(2) Structure of the Invention The present invention is designed to achieve the objects mentioned in 1.
The gist is that it is equipped with a negative electrode made of a light metal such as lithium or sodium as an active material, a positive electrode made of cupric oxide as a living material, and a non-aqueous electrolyte. A nonaqueous electrolyte battery is characterized in that a metal sulfide that reacts with metal ions to form an intercalation compound is added.

Here, the metal sulfide is titanium disulfide (TiS2),
Niobium trisulfide (Nb'S3) or molybdenum trisulfide
Mo53).

(E) Examples Example 1 3% by weight of titanium disulfide (T r 32 >) is added to commercially available cupric oxide (Cu0) as an active material and mixed in a mortar.Then, water in this mixture is removed. The fired product is then ground in a mortar and passed through a 400-mesh sieve.

The resulting mixture was mixed with graphite powder as a conductive agent and fluororesin powder as a binder at a stacking ratio of 80:15:5 and molded at a pressure of 3 tons/cIT12.
The positive electrode was subjected to vacuum heat treatment at 0°C for 1 hour.

The negative electrode used was a punched metal lithium plate of a specified thickness, and the electrolyte was prepared by dissolving lithium perchlorate at a concentration of 1 molar in a mixed solvent of propylene carbonate and 1.2 dimethoxyethane.・Outer diameter 11.5m, thickness 3.4m
A button type battery of 1.5 m was obtained. This battery is referred to as (A).

Example 2 A battery (B) was produced in the same manner as in Example 1, except that niobium trisulfide (NbS3) was added as an additive to the positive electrode instead of titanium disulfide.

Example 3 A battery (C) was prepared by the component force method in the same manner as in Example 1, except that molybdenum trisulfide (MoSa) was added as an additive to the positive electrode instead of titanium disulfide.

In addition, for comparison, a comparative battery (D>
It was created.

After these batteries are assembled, they are pre-discharged at IKΩ for 5 hours to form completed batteries.

Figures 1 and 2 show these batteries at 20°C.
6 shows the discharge characteristics under an Ω load, FIG. 1 shows the initial characteristics, and FIG. 2 shows the discharge characteristics after storage at 60° C. for 3 months.

(f) Effect of the invention As is clear from FIGS. 1 and 2, the battery of the invention (A
, > (B) and (C), compared to the comparative battery <D>, there is no drop in voltage at the initial stage of discharge, and it can be seen that the decrease in capacity after storage is suppressed.

Considering the reason for this, the positive electrode in the battery of the present invention contains a metal sulfide that reacts with alkali metal ions to form an intercalation compound. As the reaction with the active material progresses, the production of metallic steel, which is a discharge product due to the main reaction, is suppressed, and even if metallic copper is produced, the negative electrode surface is coated with a thin film of sulfur that can be liberated by decomposition of the metallic sulfide. It is thought that the precipitation of metal steel on the surface of the negative electrode is suppressed by the addition of τ, thereby suppressing passivation and self-discharge of the negative electrode, thereby improving battery performance.

[Brief explanation of the drawing]

1 and 2 show comparison diagrams of discharge characteristics between the battery of the present invention and a comparative battery, with FIG. 1 showing the initial characteristics and FIG. 2 showing the discharge characteristics after storage. (A>(B)(C)・Battery of the present invention, (D)・Comparative battery. Applicant: Sanyo Electric Co., Ltd. Agent Patent attorney: Shizuo Sano

Claims (1)

[Claims] ■ Equipped with a negative electrode that uses light metals such as lithium and sodium as an active material, a positive electrode that uses cupric oxide as a living material, and a non-aqueous electrolyte, the positive electrode reacts with alkali metal ions such as lithium and sodium to generate electricity in the living room. A nonaqueous electrolyte battery characterized by adding a metal sulfide that forms a compound.