JPS5810365A - Organic solvent battery - Google Patents

Abstract

PURPOSE:To realize an excellent sealing performance of an organic solvent battery by providing blown-asphalt films on the surface of an insulating gasket, and on contacts between a battery case, a battery lid and the said gasket so as to make the asphalt films to be in close contact with each other by mechanical pressure. CONSTITUTION:The symbol 1 represents a battery case which is made of a stainless member and also serves as a positive terminal. The symbol 2 represents a positive mixture which is prepared by adding a graphite used as a conductive agent to manganese dioxide used as an active material before the mixture is molded. The symbol 3 represents a separator, the symbol 4 represents a negative lihium electrode, and the symbol 5 represents a battery lid with which an opening 6 is sealed and which also serves as a negative terminal. In such a lithium battery, blown-asphalt films which are stable to an organic solvent used as an electrolyte are provided on the surface of the gasket 7, and on contacts between the gasket 7, the lid 5 and the case 6. As a result, the battery has an excellent preservation characteristic, and has a small deterioration in discharge capacity caused during the preservation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the sealing of organic solvent batteries, and aims to prevent evaporation of organic solvents and improve the storage characteristics of batteries by improving the sealing method.

In order to improve heavy load characteristics at low temperatures, organic solvent batteries use single solvents such as dimethoxyethane and γ-butyrolactone, which are organic solvents with low viscosity and volatility, or so-called mixed solvents (mixtures of these with other solvents). It is common to use a solution of double solute.

Conventionally, in order to prevent volatile solvents from evaporating from the sealing part to the outside during storage of organic solvent batteries, an insulating backing made of a material such as polypropylene or a copolymer of propylene and ethylene has been bonded to the insulating backing. Batteries were sealed using Alfalt, which has good properties, as a sealant.

However, when an organic solvent battery is manufactured in this way, mechanical pressure forms a tight bond between the asphalt on the surface of the insulating backing and the metal material of the battery container and battery lid. Because of this, it was not possible to obtain good sealing properties, and the organic solvent inside the battery evaporated, making it impossible to prevent the battery's discharge capacity from deteriorating.

An object of the present invention is to eliminate such conventional drawbacks and provide an organic solvent battery with extremely low evaporation of organic solvent and excellent storage characteristics.

Hereinafter, an organic solvent battery which is an example of the present invention will be described based on the drawings.

FIG. 1 shows the structure of a coin-type lithium-manganese dioxide battery according to an embodiment of the present invention, in which numeral 1 denotes a battery container made of stainless steel, which also serves as a positive terminal. 2 is a positive electrode mixture formed by adding graphite as a conductive agent to a manganese dioxide active material. 3 is a separator, 4 is a lithium negative electrode, 5
1 is a battery lid that also serves as a negative electrode terminal and seals the opening 6 of the battery container 1, and is made of stainless steel. Reference numeral 7 denotes an insulating packing that insulates and seals the gap between the battery container 1 and the battery lid 5, and the battery is constructed by bending the opening 6 of the battery container 1 inward. Incidentally, on the surface of the insulating backing 7 and the portions of the battery container 6 and the battery lid 5 that are in contact with the insulating backing 7, a coat 8.8' of blown asphalt, which is stable to the organic solvent used in the electrolytic solution, is formed.

Next, in the battery of the present invention having such a configuration, a polypropylene insulating backing is used, and a prepared asphalt coating is formed on the surface of the insulating packing and the surfaces of the battery container and the battery lid in contact with the insulating backing.
The 6-type lithium battery of the present invention (A) and the conventional product CB), which was manufactured in the same manner except that a blown asphalt film was formed only on the surface of the polypropylene insulating backing, were tested at 60'0
After storage, the battery was discharged at 25°0° with a 30KQ resistor and the deterioration of the discharge capacity was measured. The results are shown in Section IJ. Further, FIG. 3 shows the weight loss of the batteries of the present invention product (A) and the conventional product CB) during storage at 60'O.

As is clear from Figure 2, the uninvented product [A] shows less deterioration in discharge capacity after storage and has better storage characteristics than the conventional product CB), which has a blown asphalt film formed only on the insulating backing surface. There is. According to FIG. 3, the product of the present invention (
The weight loss of the battery due to storage of A) was much smaller than that of the conventional product CB), which is thought to be due to less evaporation of the solvent to the outside of the battery.

Therefore, the storage characteristics of the battery of the present invention are good because a blown asphalt film is formed on the surface of the insulating backing and on the parts of the battery container and the battery lid that contact the insulating backing. Since close contact is obtained by applying pressure, extremely good sealing properties are obtained, and evaporation of the solvent to the outside of the battery is thereby prevented.

As described above, according to the present invention, it is possible to provide an organic solvent battery with good storage characteristics by improving the degree of sealing of the sealing part and preventing evaporation of the organic solvent in the electrolyte.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a coin-type lithium battery which is an embodiment of the present invention, and Fig. 2.3 is a cross-sectional view of a coin-type lithium battery that is an embodiment of the present invention.
) and the conventional product CB) and a comparison diagram of the discharge capacity retention rate and battery weight reduction. 7・・・・・・・・・・・・Insulating backing 8.8′・
... Name of coating patent applicant (,0'C Toge Tsume θ

Claims (1)

[Claims] In a battery that uses a negative electrode made of an alkali metal as a negative electrode active material, a positive electrode made of a positive electrode active material and a conductive agent, and an organic solvent as an electrolyte, the surface of the insulating backing interposed between the battery container and the battery lid, and the battery An organic solvent battery, characterized in that a stable Gaalfalt film is formed in the organic solvent on the surface of the container and the part of the battery lid that contacts the insulating backing, and the battery is sealed.