JPS5868878A - Organic electrolyte cell - Google Patents

Abstract

PURPOSE:To prevent oxidation of electrolyte and improve the storage performance without deteriorating the discharge performance, in the organic electrolyte cell containing lithium as cathode activating substance. CONSTITUTION:Salicylic acid ester is added into electrolyte. Phyenyl salicylate, p-octylphenyl salicylate etc. are used as salicylic acid ester. It is preferably to add salicylic acid ester in 0.02-0.05% by weight into electrolyte, because when the addition amount of salicylic acid ester is less than 0.02%, the oxidation preventing effect of electrolyte is not sufficient, and when the addition amount exceeds 0.5%, an increased oxidation preventing effect is obtained, but deterioration of the electric discharge performance, for example lowering of the closed circuit voltage is generated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvement of an organic electrolyte battery using lithium as a negative electrode active material, and aims to improve storage performance.

In organic electrolyte batteries that use an organic solvent for the electrolyte, there is a problem in that the electrolyte is oxidized by the positive electrode active material during storage, resulting in a decrease in discharge performance after storage.

In view of such circumstances, the present invention has been developed to prevent oxidation of the electrolyte without causing a decrease in discharge performance by adding salicylic acid ester to the electrolyte in an organic electrolyte battery using lithium as a negative electrode active material. This improves storage performance.

In the present invention, as the salicylic acid ester, for example, phenyl salicylate, 1]-octylphenyl salicylate, etc. are used. These salicylic acid esters are used during electrolysis (1, rl 2 to 0.5% (by weight,
The same applies below) is preferably added. This is because if the addition of salicylic acid ester is less than 0.02%, the oxidation prevention effect of the electrolyte is not sufficient, and if it exceeds 0.5%, the oxidation prevention effect increases, but the closed circuit voltage decreases, etc.
This is because a decrease in IfJlf (hi) occurs.

In the organic electrolyte battery of the present invention, as the 11-7 active material, for example, manganese dioxide, valent iron, copper sulfide, copper oxide, carbon fluoride, chromium I'W silver, etc. are used, and as the electrolyte, for example, Dissolve an electrolyte such as lithium perchlorate or lithium borofluoride in a solvent such as propylene carbonate-7-phthyrolactone, tetrahydrofuran, 1,2-dimethoxyethane, l, JJ~diogysolan, etc. alone or in a mixture of two or more of them. The one that was made is used.

Next, the present invention will be explained with reference to Examples.

Figure 1 is a cross-sectional view of a JII flat organic electrolyte battery. In the drawing, (1) is an il-CM, (2) is a stainless steel mesh, and (3) also serves as a positive terminal. It is a positive electrode can. (4) is a separator made of polypropylene nonwoven fabric or the like, and (5) is a negative electrode can that also serves as a negative electrode terminal. (6) is a stainless steel mesh spot welded to the inner surface of the negative electrode can (5), (7) is the negative electrode, and the mesh (
6) There is a soil layer. (8) is an annular gasket made of synthetic resin such as polypropylene.

The positive electrode (1) was made of 100 parts of manganese dioxide (the same amount hereinafter) heat-treated at 400°C for 4 hours,
A mold was filled with 290 Mf, a mixture consisting of 1 part of phosphorous graphite and 2 parts of polytetrafluoroethylene.
After preforming at /l*2, a stainless steel mesh (2) is placed on the preformed layer, and the diameter is 16jE at 7[/α2.
The negative electrode (7) is made of a lithium plate with a diameter of 14 mm and a thickness of 0.2 mm, and ta is a diameter of 20 mm and a thickness of 1.6 mm.
j! It is.

Electrolyte solution: perchlorine in a mixed medium of propylene carbonate and 1,2-dimethoxyethane with a volume ratio of 1:1.
1 mol/e of lithium was dissolved in the same electrolyte, and the batteries were injected with phenyl salicylate added in the amount shown in Table 1, and the amount of fE was 75 μl for each battery. Table 1 shows the results of determining the internal resistance (internal rs1X resistance at 20°C) of these batteries at the initial stage and after storage for 20 μl at 60°C.

Also, ``2HU2tun WIJ (However, the mold before storage)
) of 80 release '+((at time -10°C18001
Table 1 also shows the results of measuring the closed circuit "ton field" after discharging for 5 seconds at J.

Table 1 As shown in Table 1, the addition of phenyl salicylate reduces the increase in internal resistance due to storage, and the effect of adding phenyl salicylate is obvious.

is preferred.

[Brief explanation of drawings]

It is a diagram. (7)...Negative electrode

Claims (1)

[Claims] 1. An organic electrolyte battery using lithium as a negative electrode active material, characterized in that a salicylic acid ester is added to the electrolyte. 2. The organic electrolyte battery according to claim 1, which has a capacitance of 0.02 to 0.5 before adding the salicylic acid ester.