JPS6065457A - non-aqueous electrolyte battery - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (a) Field of Industrial Application The present invention relates to a negative electrode using light metals such as lithium and sodium or alloys thereof as an active material, a positive electrode using manga dioxide as an active material, and a non-aqueous electrolytic The present invention relates to a non-aqueous electrolyte battery comprising a liquid, and particularly to improvements in a positive electrode.

(b) Conventional technology Although various materials have been proposed as positive electrode active materials for non-aqueous electrolyte batteries, manganese dioxide is seen as promising because it is an abundant resource, inexpensive, and has excellent stability, and has not been put into practical use. There is.

By the way, manganese dioxide is roughly divided into electrolytic manganese dioxide and chemical manganese dioxide. Comparing the properties of the two after heat treatment, it is clear from Table 1 below that although chemical manganese dioxide is superior in terms of surface area, electrolytic manganese dioxide is superior in terms of packing density. In general! Decomposed manganese dioxide is used.

However, as described above, the FC electrolyte manganese dioxide has a small surface area, so the liquid content on the surface of the electrode plate is small, and as a result, there is a problem that ions of the negative electrode active material are difficult to diffuse smoothly into the inside of the positive electrode.

(c) Purpose of the Invention The present invention aims to improve the problems of the conventional batteries and improve the battery characteristics.

B) Structure of the Invention The present invention comprises a negative electrode using a light metal such as lithium or sodium or an alloy thereof as an active material, a positive electrode using manganese dioxide as an active material, and a non-aqueous electrolyte,
a molded body in which the positive electrode is mainly made of electrolytic manganese dioxide;
The non-aqueous electrolyte is characterized by comprising a layer mainly composed of chemical mangaka dioxide, which is integrally disposed on at least the surface facing the negative electrode of the molded body.

(19 examples An embodiment of the present invention will be described in detail below.

In preparing the positive electrode, first, electrolytic manganese dioxide and chemical manganese dioxide are prepared by heat-treating them at a temperature of 350 to 430° C. for 5 hours.

Next, 1 part of acetylene black as a conductive agent and 5 types of fluororesin powder as a binder are mixed with 85'M part of heat-treated electrolytic manganese dioxide to form a first positive electrode mixture. .

On the other hand, similarly heat-treated chemical manganese dioxide 85 M
, k (parts of acetylene black as a conductive agent)
0 parts by weight and fluororesin powder SMjlt as a binder
A second positive electrode mixture is prepared by mixing the two parts.

Then, the second positive electrode mixture was pressure-molded into a current collector ring with a diameter of 20ψ at a molding pressure of 500 Q/m, and then the first positive electrode mixture was filled thereon and pressed at a molding pressure of 6 tons/-. Press mold. Thereafter, it is dried at 300° C. to form a positive electrode.

The negative electrode used was a rolled lithium plate punched out to a diameter of 20ψ, and the electrolyte was a solution of 1 mol/l of lithium perchlorate in a mixed solvent of equal volumes of propylene carbonate and 12 dimethoxyethane. A separator made of a polypropylene nonwoven fabric was impregnated with the separator to prepare a battery of the present invention cA)'6. In addition, the battery dimensions are outer diameter 25
The thickness was 2.8jI#.

Figure 1 shows a longitudinal cross-sectional view of the battery of the present invention, in which (1) is a lithium negative electrode plate, which is crimped to the inner bottom of the electrode can (2). (3) is a plate to a manganese dioxide positive 4 It consists of an electrolytic manganese dioxide molded body 13 with a layer c (1) mainly composed of chemical manganese dioxide disposed on the surface facing the negative electrode plate (11) via a separator (4), and a positive electrode can (5). ) is pressed against the inner bottom surface of the current collector ring (6).
1) is an insulating backing.

Next, in order to investigate the superiority of the battery of the present invention, a comparative battery 0 using a positive electrode formed by pressure molding only the above-mentioned first positive electrode mixture mainly consisting of U-dissolved manganese dioxide, and a chemical manganese dioxide Comparative battery 0 was prepared using a positive electrode formed by pressure molding only the above-mentioned second positive electrode bulk material mainly composed of .

FIG. 2 is a comparison diagram of the discharge characteristics of these batteries, showing the 560Ω constant load discharge characteristics at room temperature.

(f) Effects of the Invention As is clear from FIG. 1, the battery according to the present invention (c) has improved battery performance compared to the comparative battery (average, Q).

Considering the effects of the present invention, as shown in Table 1, the surface area of chemical manganese dioxide is larger than that of electrolytic manganese dioxide (1) The surface area after heat treatment is more than twice as large. The liquid content of electrolytic manganese dioxide is 0.5 cc/cc, which is much higher than that of electrolytic manganese dioxide. The result will be inferior.

Therefore, in the battery of the present invention, it is thought that a synergistic effect can be obtained by providing a layer of chemical manganese dioxide on top of electrolytic manganese dioxide.

In other words, in positive electrodes that use fluororesin as a binder, the binder is liquid repellent and covers the positive electrode surface to some extent, so electrolytic manganese dioxide, which has a small surface area, is suppressed from being absorbed into the positive electrode. Since the diffusion from the inside of the positive electrode to the inside of the positive electrode is suppressed, when high rate discharge is performed, the battery voltage is 1''
descend.

However, by providing a layer of chemical manganese dioxide on the surface of the positive electrode facing the negative electrode as in the battery of the present invention, although the binder is similarly coated, chemical manganese dioxide has a large surface area, so the liquid absorption on the surface of the positive electrode is difficult. However, as a result, lithium ions were diffused smoothly from the surface of the positive electrode into the interior of the positive electrode, and it is thought that the discharge characteristics were improved. It is also believed that if the discharge progresses to a certain extent, lithium ions will diffuse into the electrolytic manganese dioxide and the positive electrode will swell, making it possible to discharge to the inside of the positive electrode.

Table 1 The thickness of the chemical manganese dioxide layer is the total thickness of the positive electrode 5
~15% is good; if it is less than that, the effect is small; on the other hand, if it is more than that, the characteristics deteriorate due to a decrease in the packing density.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of the battery of the present invention, and FIG. 2 is a comparison diagram of discharge characteristics between the battery of the present invention and a comparative battery. (1)...Negative electrode, (2)...Negative electrode mill, (3)...
Positive electrode, C3... chemical manganese dioxide layer, C4...
・Molded body of electrolytic manganese dioxide, 14)... Separator, +57-... Positive electrode can, (6)... Conductive ring, (
7)...Insulating backing. Applicant Sanyo Electric Co., Ltd. Representative Patent Attorney Shizuo Sano

Claims (1)

[Claims] ■ A negative electrode whose active material is a light metal such as lithium or sodium or an alloy thereof, a positive electrode whose active material is manganese dioxide, and a non-aqueous electrolyte, the positive electrode mainly consisting of electrolytic manganese dioxide. 1. A non-aqueous electrolyte battery comprising: a molded body; and a layer mainly composed of chemical manganese dioxide, which is integrally disposed on at least a surface of the molded body facing a negative electrode.