JPS61264679A - Organic electrolyte battery - Google Patents

Abstract

PURPOSE:To suppress increase in internal impedance in high temperature storage and increase storage performance by adding a specified crystallized zeolite in a battery. CONSTITUTION:0.003-0.06mg, per 1mg of electrolyte, of a substance indicated in the chemical formula of Na12[(AlO2)12(SiO2)12] (its trade name is Molecular Sieve) is added in a battery. A negative active material 3 is lithium and press- bonded in a sealing plate 2. A positive mix 5 is formed by molding in a pellet form the mixture of 100pts.wt. poly carbon fluoride serving as active material, 10pts.wt. acetylene black, and 14pts.wt. fluorine resin binder. By adding the appropriate amount of the Molecular Sieve, the Molecular Sieve adsorbs or decomposes impurities represented by peroxides. The surface of lithium is kept active and increase in internal impedance in high temperature storage is suppressed and storage performance is increased.

Description

[Detailed description of the invention] Industrial applications The present invention relates to improvements in organic electrolyte batteries.

Conventional technology organic electrolyte batteries have high energy density, storage stability,
Due to its excellent leakage resistance, it has come to be used in a variety of electronic devices, including small electronic devices such as watches and calculators, as well as cameras and computers.

When an organic electrolyte battery contains moisture or other impurities, gas generation, a decrease in battery capacity, and an increase in internal resistance occur. In particular, batteries that use lithium as a negative electrode active material use an organic electrolyte prepared by dissolving a lithium-based electrolyte such as LiBF4 in an organic solvent, so the above impurities cannot be removed. desired.

From this point of view, conventional methods have been used, such as treating the organic solvent with a molecular sieve before preparing the organic electrolyte or vacuum drying the lithium-based electrolyte. Impurities and moisture contained in it are removed as much as possible. However, after these treatments, the organic electrolyte is prepared by mixing the above-mentioned solvent and electrolyte, and before it is stored in the battery, it is possible that impurities and moisture in the air may get mixed in. . Further, impurities such as peroxide may remain in this organic electrolyte. It is thought that these impurities act to form a passive film on the surface of lithium, which is the negative electrode active material, and become a resistor. Despite the above treatment, the battery performance was not sufficiently improved.

Problems to be Solved by the Invention With such a conventional configuration, batteries using lithium as the negative electrode active material may have impurities or water remaining in the organic electrolyte, especially when stored at high temperatures. However, there was a problem in that the impurities act on the surface of lithium and form an immobile film that becomes a resistor, increasing the internal impedance of the battery.

The present invention solves these problems, and aims to suppress the increase in internal impedance during high-temperature storage and improve storage performance.

Means for Solving the Problem In order to solve this problem, the present invention provides an N&1 in the battery.
2 [(mu#02)12(SiO2)12], preferably in an amount of 0.003 q-0.06 mg per 1η of electrolytic solution.

Effect With this configuration, impurities represented by peroxide contained in the organic electrolyte e''+2((io2)+z(Si
The substance represented by the chemical formula O2)12] is adsorbed or decomposed to keep the surface of lithium, which is the negative electrode active material, active, suppressing the increase in internal resistance during high-temperature storage, and improving storage performance.

EXAMPLES Examples of the present invention will be described below with reference to FIGS. 1 to 3.

Figure 2 shows a flat organic electrolyte battery of lithium-fluorocarbon yarn according to the present invention. In the figure, 1 is a battery case made of stainless steel, and 3 is a sealing plate made of the same material.
is press-bonded to the sealing plate 2 with lithium, which is a negative electrode active material. Reference numeral 4 denotes a positive electrode current collector made of titanium, which is spot welded to the inner surface of the case 1. 5 is a positive electrode mixture, which contains 100 parts by weight of fluorocarbon as an active material, 7127210 parts by weight of acetylate,
This product was prepared by mixing 14 parts by weight of a fluororesin binder and molding it into a pellet. 6 is a separator made of polypropylene nonwoven fabric. The electrolyte contains propylene carbonate and 1.
A, O'q for 300q of lithium borofluoride dissolved at a ratio of 1 mol/l in an equal volume mixed solvent with 2-dimethoxyethane.

B, 0.6q, C, 1,2q, D, 2.4q,
E, 3.61'.

F, 48W “12 C(AlO2)12(5i02
)12) (trade name: Molecular Sieve, manufactured by Union Carbide) was added and used. After each of the negative electrode fixed to the sealing plate and the positive electrode fixed to the case are impregnated with an electrolytic solution, the peripheral edge of the separator is placed under the polypropylene insulating backing 7 and caulked together with the sealing plate to form a battery. This battery has a total height of 2.5 ff
, an outer diameter of 23 m, and a capacity of 165 mAh.

In this example, carbon fluoride was used as the positive electrode active material, but molybdenum oxide and manganese dioxide, which are also known as active materials for organic electrolyte batteries, may also be used.

Any product formed by mixing silver chromate or the like with a conductive material and a binder can be similarly applied.

Next, as the conventional example, the amount of electrolyte is 1, as shown in the present example.
Per mg B, 0.00211p, C, 0,00
4W.

D, 0.008111, X, 0.012q,
F, 0.016 jllp molecular sieve added, each internal resistance immediately after manufacture I, 80'
After storage for 0.20 days, measurements were made under the conditions (3), and the results were as shown in the following table.

In addition, Figure 2 shows the initial characteristics when these six types of batteries were discharged at 120'C immediately after manufacture with a 16Ω resistor as a load, and the discharge characteristics when discharged after being stored at 80'C for 20 days. are shown in Figure 3.

As shown in Figure 2, battery E discharges normally, whereas battery F has too large an amount of added molecular sheep, so the molecular sheep becomes a resistor, inhibiting the discharge action, and causing discharge characteristics. Deterioration was observed. In addition, as shown in Figure 3, when comparing the initial discharge characteristics of the battery C-F, the discharge duration at a final voltage of 2.6V at 16Ω after 20 days of storage at 80'C is 95% or more. On the other hand, for battery person B, the battery was significantly degraded to less than 80%.

In addition, when batteries A to B were disassembled after being stored at 180°C, the lithium surface of batteries M and B formed a thin pink film, but the lithium surface of batteries C and F was disassembled. It was normal, exhibiting a silvery white color similar to the color of lithium before storage. This thin pink film is thought to be a passive film formed by the action of impurities such as peroxide, and in order to make the lithium surface inactive, 80%
'C increases the internal impedance of the battery after storage.

On the other hand, in battery C-2, since an appropriate amount of molecular sheep is added, the molecular sheep adsorbs or decomposes impurities such as peroxide, so the lithium surface remains activated. This suppresses the increase in internal impedance.

Effects of the Invention As is clear from the above explanation, a substance represented by the chemical formula ``12 ((person(lo2)+z(5i02)12))'' is contained in the battery in an amount of o,oo3111g to 0 per cape of electrolyte solution.
．． The battery of the present invention constructed by adding o131v is s N'
12 ((muno2), z(Si02)+z)
The substance represented by the chemical formula adsorbs or decomposes impurities such as peroxide contained in the organic electrolyte, maintains the activation of the lithium surface, suppresses internal impedance during high-temperature storage, and improves storage performance. You can get the effect that you can.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a flat battery according to an example of the present invention, and FIGS. 2 and 3 are diagrams showing a comparison of discharge characteristics. 1...Case 12...Sealing plate, 3...
...Negative electrode, 4...Positive electrode current collector, 6...
...Positive electrode, 6... Separator, 7...
Insulated backing. Name of agent: Patent attorney Toshio Nakao and 1 other person
1. Figure 2. Viewed by Saitama) Figure 3. Shima C.

Claims (2)

[Claims] (1) A battery that uses an alkali metal as the negative electrode active material, a metal oxide or carbon fluoride as the positive electrode active material, and an organic solvent as the electrolyte, with Na_1_2 [( AlO_2)_1_2(SiO_
2) An organic electrolyte battery characterized by adding a substance represented by the chemical formula _1_2]. (2) Chemical formula Ni_1_2 [(Al
The amount of the substance represented by O_1_2)_1_2(SiO_2)_1_2] is 0.003 mg to 0 per 1 mg of electrolyte.
．． 013 mg of the organic electrolyte battery according to claim 1.