JP2636115B2 - Manufacturing method of non-aqueous electrolyte battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved non-aqueous electrolyte battery manufacturing method using lithium or a lithium alloy as a negative electrode active material, manganese dioxide as a positive electrode active material, and an electrolyte containing an ester such as propylene carbonate. About.

[0002]

2. Description of the Related Art As a typical nonaqueous electrolyte battery,
A battery using a nonaqueous electrolyte in which lithium or a lithium alloy is used as a negative electrode active material, manganese dioxide is used as a positive electrode active material, and lithium perchlorate or the like is dissolved in a nonaqueous solvent such as propylene carbonate or dimethoxyethane is known. I have.

In this type of non-aqueous electrolyte battery, as disclosed in Japanese Patent Application Laid-Open No. 55-80276, a part of the battery capacity is discharged immediately after the battery is manufactured (referred to as pre-discharge). Then, it is completed as a product.

If this pre-discharge treatment is not performed, a large amount of gas is generated during storage, causing the battery to expand, possibly causing liquid leakage or increasing the internal impedance of the battery after storage. Discharge performance may be greatly reduced. In addition, during storage, decomposition products of propylene carbonate adhere to lithium and the discharge reaction is inhibited,
Therefore, the battery capacity may be reduced. For the purpose of solving such inconvenience, the above-mentioned preliminary discharge is performed. It is considered that since the active portion in the positive electrode active material (manganese dioxide) is removed by this preliminary discharge, the above-described gas generation reaction and the like can be suppressed.

[0005]

However, in order to prevent gas generation and performance deterioration during storage, a conventional method of performing a preliminary discharge at the final stage of battery production to remove an active portion in the positive electrode active material is used. In addition, specialized equipment for preliminary discharge is required at the last part of the production line, which causes a problem that the production line becomes complicated and cost increases.

In addition, in the preliminary discharge, there is a problem that the active portion in the positive electrode active material of each product cannot be uniformly removed, and the effect of the preliminary discharge is not constant for each product. There is also a problem in that no effect is obtained unless the capacity corresponding to 2% of the substance is discharged, and there is a problem that the product has to be commercialized with the capacity being consumed more than necessary.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a non-aqueous electrolyte battery that does not generate gas during storage or performance degradation without using a conventional means of preliminary discharge. It is to manufacture by a simple method.

[0008]

In order to achieve the above object, the present invention provides an electrolytic solution comprising lithium or a lithium alloy as a negative electrode active material, manganese dioxide as a positive electrode active material, and an ester such as propylene carbonate as a non-aqueous solvent. In a method for producing a non-aqueous electrolyte battery using a liquid, the positive electrode active material after the drying treatment is treated with a metal hydride complex compound composed of aluminum hydride or borohydride and an alkali metal hydride, or borohydride and tetraalkyl hydride. Ammo
It is made to react with a complex compound consisting of nitrogen and then assembled into a battery.

[0009] As the metal hydride complex compound, lithium aluminum hydride, sodium borohydride, lithium borohydride, calcium borohydride, using one or more of the mixture selected from among aluminum hydride sodium c arm be able to.

[0010] More specifically, the metal hydride complex
Alternatively, a method of reacting the metal-hydrogen complex compound or the complex compound with the positive electrode active material by injecting a solution obtained by dissolving the complex compound in an ether solvent into the dried positive electrode active material is adopted. When the metal-hydrogen complex compound or the complex compound is dissolved in a cyclic ether such as tetrahydrofuran, the ether is polymerized upon contact with air. Therefore, it is preferable to use a linear ether as the solvent.

[0011]

In the conventional method of manufacturing this type of battery, when an electrolyte containing an ester such as propylene carbonate is injected into manganese dioxide as a positive electrode active material, a decomposition reaction of propylene carbonate occurs in an active portion of the manganese dioxide. The reaction causes problems such as gas generation during storage and performance degradation.

According to the manufacturing method of the present invention, prior to pouring the electrolytic solution in the positive electrode active material, by reacting the manganese dioxide and metal-hydrogen complex compound or the complex compound, the active portion of the manganese dioxide To prevent the decomposition of esters such as propylene carbonate in the electrolytic solution.

[0013]

Embodiments of the present invention will be described below. However, the present invention is not limited to only the following examples.

Embodiment 1 FIG. Coin type lithium battery CR20
An embodiment in which the present invention is applied to a 32 (outer diameter 20 mm, total height 3.2 mm) will be described in detail with reference to FIG. FIG. 1A shows a state in which a flat disk-shaped positive electrode active material 2 is press-bonded to the inner bottom surface of a stainless steel positive electrode can 1 via a metal net current collector (not shown). . The positive electrode active material 2 was granulated by mixing graphite 1 and Teflon 0.2 (weight ratio) with manganese dioxide 9 heat-treated at 445 ° C. for 5 hours, and formed into a disk having a prescribed size. Things. After the positive electrode active material 2 is pressed on the positive electrode can 1, vacuum drying is performed at 200 ° C. for 5 hours. The weight of the positive electrode active material 2 after the drying treatment was 1 g.

Next, a solution prepared by dissolving lithium aluminum hydride (LiAlH ₄ ) at a rate of 0.5 mol per liter of diethylene glycol dimethyl ether is prepared in advance. Then, as shown in FIG. 1 (B), one of the positive electrode active materials 2 in the positive electrode can 1 after the drying treatment is performed.
100 microliters of the lithium aluminum hydride solution 3 per g was injected and left for 10 minutes. The amount of the metal hydride complex compound is 0.5 mol per 100 mol of manganese dioxide.

Thereafter, as shown in FIG. 1 (C), a separator 4 is set on the positive electrode active material 2, and
Inject 0 microliter of electrolyte 5. This electrolyte is obtained by dissolving 1 mol of lithium perchlorate (LiClO ₄ ) in 1 liter of a mixed solution obtained by mixing propylene carbonate and dimethoxyethane in the same amount. The separator 4 is a nonwoven fabric made of polypropylene.

The subsequent steps are the same as those in the prior art.
As shown in (D), a negative electrode terminal plate 7 to which a negative electrode active material 6 made of 65 mg of metallic lithium was crimped and a sealing gasket 8
And a positive electrode can 1 to assemble a coin-type lithium battery.

FIG. 2 shows the change in the discharge capacity after storage at 60 ° C. for 80 days for each of the batteries treated with various amounts of lithium aluminum hydride added to manganese dioxide. This is because the batteries treated with different amounts were stored under the above conditions, and then stored at 20 ° C.
The measurement result at the time of constant resistance discharge with a 2.7 kΩ load is shown. According to this figure, the region where the discharge capacity is high is 0.3 to 3
It is within the range around mol, and shows a peak especially around 0.5 mol. Therefore, in this embodiment, the addition amount of lithium aluminum hydride is 0.3 to 3
It has been confirmed that mol is a preferable range, and 0.5 mol is the most preferable addition amount.

Embodiment 2 FIG. The manufacturing method is described in Example 1. The procedure is exactly the same as in the case of
The positive electrode was treated using a solution in which sodium borohydride (NaBH ₄ ) was dissolved at a rate of 1 mol per liter of diethyl ether. The amount of the complex compound added is 1 mole per 100 moles of manganese dioxide.

Embodiment 3 FIG. The manufacturing method is described in Example 1. However, after the treatment of the positive electrode with the metal hydride complex compound solution, 1 liter of a mixed solvent in which the same amount of propylene carbonate and dimethoxyethane are mixed as the nonaqueous electrolyte, and trifluoromethanesulfone as the electrolyte An electrolytic solution in which lithium oxide was dissolved at a ratio of 1 mol was used.

This embodiment is an example in which the electrolyte is changed because the perchloric acid as the electrolyte reacts with the metal hydride complex to cause a fire.

Embodiment 4 FIG. Embodiment 3 FIG. But the same electrolyte was used, but as a metal hydride complex solution, lithium borohydride (LiBH
_The positive electrode was treated using a solution in which ₄ ) was dissolved at a ratio of 1 mol. The amount of the complex compound added is 1 mole per 100 moles of manganese dioxide.

COMPARATIVE EXAMPLE A coin-type lithium battery CR2032 was produced in exactly the same manner as described above, except that the positive electrode was not treated with the metal hydride complex solution and the preliminary discharge treatment was not performed.

Next, Embodiment 1 of the present invention. ~ 4. Lithium battery CR2 manufactured by applying the manufacturing method according to the above.
The internal resistance, the number of leaked liquids, and the discharge capacity of the battery No. 032 and the battery of the comparative example after storage at 60 ° C. for 80 days were compared and measured. The results shown in the following Tables 1 and 2 were obtained.

With respect to the internal resistance value, the average value, the maximum resistance value, and the minimum resistance value of 10 samples were measured. The discharge capacity was 2 for 5 samples.
The average value, the maximum value of the discharge capacity (mAh) when discharging under the conditions of 0 ° C., a 2.7 kΩ load, and a final voltage of 2.5 V,
And the minimum value.

[0026]

[Table 1]

[Table 2] As is clear from the results shown in the above table, the internal resistance value of the battery manufactured by applying the present invention is much smaller than that of the battery of the comparative example, and the deviation can be reduced. Also, in the battery manufactured by applying the present invention, there was no liquid leakage and the discharge capacity was increased, and it was confirmed that the performance after storage was extremely excellent. Thus, the small deviation of the internal resistance value and the discharge capacity suggests that a homogeneous battery can be commercialized as compared with the case where the preliminary discharge treatment is performed.

[0027]

As described above in detail, according to the present invention, before the electrolyte is injected into the positive electrode active material, the hydrogenation
Minium or borohydride and alkali metal hydride
Metal hydride complex or borohydride and hydrogenation
By adding a very simple process of reacting a complex compound consisting of tetraalkylammonium with the positive electrode active material, the active portion of manganese dioxide can be removed. However, no decomposition reaction of esters such as propylene carbonate occurs. As a result, gas generation and performance deterioration during storage can be prevented without performing pre-discharge as in the prior art, and the battery production line can be simplified as compared with the case of performing pre-discharge, and the production can be simplified. This provides an excellent effect that the variation in performance of each product can be reduced.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 4 is a view showing a manufacturing process of a coin-shaped lithium battery according to the present invention.

FIG. Of each battery treated at various changes in the amount of lithium aluminum hydride
It is a graph which shows the change of the discharge capacity after storage for 80 days.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 positive electrode can 2 positive electrode active material 3 lithium aluminum hydride solution 4 separator 5 electrolyte 6 negative electrode active material 7 negative electrode terminal plate 8 sealing gasket

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tomohisa Nozue 5-36-11 Shimbashi, Minato-ku, Tokyo Inside Fuji Electric Chemical Co., Ltd. (72) Inventor Goe Yoshioka 5-36-11 Shimbashi, Minato-ku, Tokyo No. Fuji Electric Chemical Co., Ltd.

Claims (3)

(57) [Claims] 1. A method for producing a nonaqueous electrolyte battery using an electrolyte containing lithium or a lithium alloy as a negative electrode active material, manganese dioxide as a positive electrode active material, and an ester such as propylene carbonate as a nonaqueous solvent. The treated positive electrode active material is a metal hydride complex compound composed of aluminum hydride or borohydride and an alkali metal hydride, or borohydride and tetraalkyl hydride.
A method for producing a non-aqueous electrolyte battery, which comprises reacting with a complex compound comprising ammonium and thereafter assembling the battery. Wherein said metal hydrogen complex compound, lithium aluminum hydride, sodium borohydride, lithium borohydride, calcium borohydride, aluminum hydride sodium c one or more of the mixture selected from among beam The method for manufacturing a nonaqueous electrolyte battery according to claim 1, wherein 3. The metal-hydrogen complex compound or the complex compound
The metal hydride complex compound by pouring a solution obtained by dissolving the compound in an ether solvent into the positive electrode active material after the drying treatment.
3. The method for producing a non-aqueous electrolyte battery according to claim 1, wherein the complex compound is reacted with a positive electrode active material.