JPS6151749A - Nonaqueous electrolyte battery - Google Patents

Abstract

PURPOSE:To produce a nonaqueous electrolyte battery with long duration of discharge by performing indium plating on the inner bottom surface of the exterior can touching the positive electrode. CONSTITUTION:Iron disulfide is combined with graphite and a fluorine resin powder and then the thus prepared mixture is thoroughly mixed before being subjected to compression molding to obtain a positive pellet. A positive electrode 1 is made by sintering the positive pellet. A negative electrode 2 is prepared from a lithium plate by stamping, and is fixed to a negative cap 4 by pressure. A liquid electrolyte is prepared by dissolving 1mol of lithium borofluoride in a solvent mixture composed of propylene carbonate and 1,2-dimethoxyethane. A positive can 3 is plated using an In plate as the counter electrode in an indium plating bath after the entire surface of the positive can 3 other than its inner bottom surface is masked. Since no positive current collectors are used, this battery has an increased internal volume and therefore the charging amount of the positive electrode can be increased. Furthermore, the electric contact between the positive electrode and the inner bottom surface of the positive can plated with indium is improved, thereby achieving good discharge characteristics without using any positive current collector.

Description

[Detailed description of the invention] (b) Industrial application field The present invention relates to a non-aqueous electrolyte battery with excellent discharge characteristics.

(b) Conventional technology A non-aqueous electrolyte battery comprising a negative electrode using a light metal as an active material, a corresponding positive electrode, an outer case that also serves as a positive electrode terminal, and a non-aqueous electrolyte consisting of a solute and a solvent has a high battery voltage and high energy. It has many advantages such as high density and low self-discharge. Recently, 1.5V non-aqueous electrolyte batteries, which are compatible with conventional batteries, have been attracting attention especially as power sources for small electronic devices, and improvements in their battery characteristics have been desired.

(c) Problems to be Solved by the Invention The present invention was made in view of the above-mentioned circumstances, and particularly aims to provide a non-aqueous electrolyte battery with a long discharge duration.

(d) Means for Solving the Problems This invention provides a non-aqueous electrolyte comprising a negative electrode using a light metal as an active material, a corresponding positive electrode, an outer can that also serves as a positive electrode terminal, and a non-aqueous electrolyte comprising a solvent and a solute. The present invention provides a non-aqueous electrolyte battery characterized in that the inner bottom surface of the outer can that contacts the positive electrode is plated with indium.

In the battery of this invention, a light metal such as lithium or sodium is used as the negative electrode active material, and a metal oxide, sulfide or chloride, or a halogen carbon compound is used as the positive electrode active material. The electrolytic solution used is one in which a solute such as lithium perchlorate, lithium aluminum chloride, or lithium fluoroborate is dissolved in an organic solvent such as propylene carbonate, T-butyrolactone, or 1,2-dimethoxyethane.

Stainless steel or the like is used as the outer case which also serves as the positive electrode terminal of the battery of the present invention, and the inner bottom surface which comes into contact with the positive electrode is indium plated by a conventional method. For example, as an indium plating bath, In(SO+>260g/1
, an aqueous solution of NazSO310g/1 is used as the electrolyte, and an indium plate is used as the counter electrode.

(E) Function According to the present invention, a non-aqueous electrolyte battery that does not require a positive electrode current collector and has a long discharge duration can be obtained.

(f) Examples This invention will be explained by examples, but the invention is not limited to them.

To commercially available iron disulfide, 10wL% of graphite as a conductive agent and 5ivt% of fluororesin powder as a binder were added and mixed thoroughly, and then pressure molded at a pressure of about 2 tons/d to form a diameter of 11m/m.
, to obtain a positive electrode pellet with a thickness of 0.45 m/m. This positive electrode pellet is fired 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 0.7 m/m.
This rolled plate is punched out to a diameter of 7 m/m and crimped onto a negative electrode cap. The electrolyte is propylene carbonate and 1,2
- A mixture of 1 mole of lithium borofluoride in a mixed solvent of dimethoxyethane was used.

The positive electrode can was masked except for the inner bottom surface, and then placed in an indium plating bath (In2(SO4) 360g/l 5Na2s
The counter electrode was plated using an In plate.

A battery A according to an embodiment of the present invention was prepared as described above, and a cross-sectional view thereof is shown in FIG.

In Figure 1, (1) is the positive electrode, (2) is the negative electrode, (3) is the outer can that also serves as the positive electrode terminal, (4) is the negative electrode can, (5) is the separator, (6) is the insulating backing, (7) is the negative electrode current collector.

The inner bottom surface QQ) of the outer can (3) is plated with indium.

A battery B (comparative example) similar to the battery shown in Figure 1 except that a positive electrode current collector (stainless wire mesh plated with indium) was used instead of the indium plating on the inner bottom of the outer can was manufactured, and its cross-sectional view is shown in Figure 1. It is shown in Figure 2. In Figure 2 (
11) is a positive electrode, (12) is a negative electrode, (13) is an exterior can that also serves as a positive electrode terminal, (14) is a negative electrode can, (15) is a separator,
(16) is an insulating backing, (17) is a negative electrode current collector, (
20) is the above positive electrode current collector.

The discharge characteristics of Battery A according to the embodiment of the present invention and Comparative Example Battery I under constant load discharge of 5.6 Ω at 20° C. were measured and are shown in the graph of FIG.

From FIG. 3, it is clear that battery A has a longer discharge duration than comparative battery B. This advantage is thought to be due to the fact that, compared to battery B, battery A did not use a positive electrode current collector, so the internal volume of the battery increased and the amount of positive electrode filled could be increased. Furthermore, since the electrical contact between the indium-plated inner bottom surface of the positive electrode and the positive electrode was good, it is thought that excellent discharge characteristics were obtained even without using a positive electrode current collector.

(G) Effects of the Invention According to the present invention, a non-aqueous electrolyte battery with a long discharge duration can be obtained. Also, by coating the inside of the battery with indium metal, the following effects can be obtained. In other words, since both the moisture inside the battery and the adsorbed oxygen are consumed by the reaction between hydroxyl groups on the surface of the positive electrode and indium, eliminating such impurity species can lower the open circuit voltage and at the same time reduce the amount of impurities that are present on the surface of the negative electrode during storage. It has the effect of suppressing the formation of a conductive film.

[Brief Description of the Drawings] Fig. 1 is a longitudinal cross-sectional view of a non-aqueous electrolyte battery (A) according to an embodiment of the present invention, and Fig. 2 is a longitudinal cross-sectional view of a non-aqueous electrolyte battery (B) according to a comparative example. , FIG. 3 is a graph showing the discharge characteristics of batteries (A) and (B). (1) (11)...Positive electrode, (2) ('12)
... Negative electrode, (31031 ... External can that also serves as positive electrode terminal, +4) (141 ... Negative electrode can,
+5) (15+... Separator, (61(1
6) Insulating backing, (7) Rib...
・Negative electrode current collector, 001...Indium-plated outer can inner bottom surface, (20)...Positive electrode east heavy body.

Claims (1)

[Claims] 1. A negative electrode using a light metal as an active material, a corresponding positive electrode,
A non-aqueous electrolyte battery comprising an outer case that also serves as a positive electrode terminal and a non-aqueous electrolyte consisting of a solvent and a solute, the battery being in contact with the positive electrode.
A non-aqueous electrolyte battery, wherein the inner bottom surface of the outer can is indium plated.