JPH065621B2 - Method for manufacturing non-aqueous solvent battery - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for manufacturing a non-aqueous solvent battery, and more particularly to a method for manufacturing a non-aqueous solvent battery with improved post-treatment after battery assembly.

[Technical background of the invention and its problems] A non-aqueous solvent battery using a light metal such as lithium, sodium, and aluminum as a negative electrode active material has a large energy density, excellent storage characteristics, and a wide operating temperature range. Since it has it, it is often used as a backup battery for calculators, watches, and memories. Among them, batteries using lithium for the negative electrode and sulfur oxyhalides such as thionyl chloride (SOCl ₂ ) and sulfuryl chloride (SO ₂ Cl ₂ ) as the positive electrode active material are attracting attention because of their particularly high energy density. Such a battery has a positive electrode composed of carbon and a metal current collector, and generally dissolves a Lewis acid such as aluminum chloride (AlCl ₃ ) or aluminum bromide (AlBr ₃ ) and a Lewis base such as lithium chloride or lithium bromide. Liquid sulfur oxyhalide is used as the electrolyte.
Therefore, the liquid oxyhalide serves both as the positive electrode active material and the electrolytic solution, and by using a positive electrode having an appropriate shape, a battery having excellent high rate discharge characteristics can be expected.

By the way, in the battery described above, the oxyhalide of sulfur, which is the positive electrode active material, is in direct contact with lithium of the negative electrode, so that a LiCl film, which is a reaction product, is formed on the surface of the negative electrode lithium. This LiCl film has a function of preventing direct contact between the negative electrode lithium and the oxyhalide, and plays a role of preventing deterioration of the battery capacity during storage. But,
It acts as a resistance component during discharge and causes a voltage drop at the beginning of discharge. The extent of this voltage drop is so small that it can be ignored when the discharge current is very small on the order of μA, but it cannot be ignored in the case of large current discharge, and especially when it is stored at high temperature for a long time and LiCl is stored.
There is a problem that a considerable voltage drop occurs at the start of discharge after the film has grown considerably or during discharge at a low temperature, and it takes a considerable time to recover to a predetermined voltage.

[Object of the Invention]

The present invention has a small voltage drop even at the beginning of large current discharge,
In addition, it is an object of the present invention to provide a method for manufacturing a non-aqueous solvent battery having a short voltage recovery time.

[Outline of Invention]

The present invention stores a negative electrode made of a light metal such as lithium and a positive electrode in a battery container via a separator, and also stores an electrolyte solution that also serves as a positive electrode active material containing oxyhalide of sulfur in the container as a main component. In manufacturing a non-aqueous solvent battery having a structure, 0.5 to 10% of the total discharge capacity of the battery is discharged as a post-treatment within 10 days after the battery is assembled. According to such a method of the present invention, it is possible to obtain a non-aqueous solvent battery which does not show a large voltage drop even if a large current discharge is performed after storage and has a short voltage recovery time. It is considered that such excellent characteristics can be exhibited because the discharge reaction product has an inhibitory effect on the growth of the LiCl film on the lithium negative electrode. Also,
By carrying out the above-mentioned post-treatment, an effect that a battery having stable characteristics in which the voltage value and the current value are uniform can be supplied can be expected.

The reason why the discharge capacity during the post-treatment is limited is that if the discharge capacity is less than 0.5% of the pre-discharge capacity of the battery, the effect of suppressing the voltage drop due to the post-treatment cannot be sufficiently exerted. This is because when the discharge capacity exceeds 10%, the above effect does not increase and the battery life becomes negative. The reason why such post-treatment is carried out within 10 days after assembling the battery is that if the post-treatment is carried out after a long number of days exceeding 10 days, the effect of suppressing the voltage effect cannot be sufficiently exerted.

Example of Invention

Next, embodiments of the present invention will be described in detail with reference to the drawings.

Examples 1 to 4 First, a cylindrical negative electrode 2 made of metallic lithium was pressure-bonded into a stainless steel bottomed cylindrical can body 1 whose upper surface also serving as a negative electrode terminal was opened. Next, the negative electrode 2 of the can 1
A positive electrode 3 inside the negative electrode 2 and a separator 41 made of glass fiber non-woven fabric disposed on the inner surface of the negative electrode 2 and the bottom surface of the can body ₁ .
It is disposed over the 4 _2. This positive electrode 3 is a metal current collector composed of a cylindrical porous carbon body 5 made of carbon black with polytetrafluoroethylene as a binder, and a cylindrical wire mesh arranged inside the hollow portion of the porous carbon body 5. It is composed of a body 6. Such a positive electrode 3 may be obtained, for example, by adding a commercially available polytetrafluoroethylene emulsion to acetylene black 10
It is blended in a proportion of wt%, water and ethyl alcohol are added, and the mixture is stirred at room temperature for 2 hours, then kneaded, and the metal current collector 6 made of a nickel wire mesh is pressure bonded, and the current collector 6 becomes the inside. As described above, it is formed into a tubular body, and further dried under vacuum at 150 ° C. to form a kneading sheet into a porous carbon body 5, which is produced.

Then, the insulating paper 7 having a hole in the center on top of the separator 4 ₁ of the can body 1 housed and supported. Next, there is prepared a stainless lid 11 having a hole 8 in the center and a positive electrode terminal 10 made of a stainless pipe for liquid injection inserted therein through a metal-glass sealing material 9. Lid 1
The lead wire 12 is connected to the lower end of the positive electrode terminal 10 of No. 1 and the other end of the lead wire 12 is connected to the metal current collector 6 in the can body 1, and then the lid body 11 is opened at the upper opening of the can body 1. Fitted to the part.
Subsequently, the upper end opening in the can body 1 and the fitted lid body 11 were welded by laser welding or the like, and the lid body 11 was liquid-tightly sealed.

Next, the electrolytic solution was injected from the pipe-shaped positive electrode terminal 10 of the lid body 11 to store the electrolytic solution 13 in the can body 1. As the electrolytic solution, thionyl chloride (SOCl ₂ ) in which aluminum chloride (AlCl ₃ ) and lithium chloride (LiCl) were dissolved at 1.5 mol / mol, respectively was used. Subsequently, the needle body 14 made of stainless steel is inserted into the pipe-shaped positive electrode terminal 10 and the tip of the positive electrode terminal 10 and the needle body 14 are laser-welded to each other to form the terminal 1.
A battery was assembled by sealing the 0 hole.

Then, four batteries obtained within 10 days after assembly were set in a constant current discharge device, and 0.5%, 2.5%, 5%, 10% of the total discharge capacity of the current was obtained by constant current discharge of 50 mA. %, And four types of batteries were manufactured.

Comparative Example A battery having the same structure as that of the example was manufactured except that after the battery was assembled, no post-treatment was performed by discharging.

Then, regarding the batteries of Examples 1 to 4 and Comparative Example,
After storage at 25 ° C. for 3 months after manufacture, constant resistance discharge of 30Ω was performed, and after the start of discharge, the time until the voltage recovered to 3.0 V was measured, and the results shown in the following table were obtained. In the table, as Reference Examples 1 and 2, after battery assembly, discharge of 0.2% and 12%, respectively, of the total discharge capacity of the battery using the constant current discharge device similar to the embodiment. The battery manufactured by the above is also described.

As is clear from the above table, the batteries of Examples 1 to 4 and Reference Examples 1 and 2 which were subjected to the post-treatment by discharging after the battery was assembled were compared with the batteries which were not subjected to the post-treatment (comparative example). You can see that it will be shorter. Further, when the discharge capacity is set to 0.5% to 10% as in this example, the recovery time is within 5 seconds, which is remarkably excellent as compared with Reference Example 1. The battery having a discharge capacity of 12% (Reference Example 2) had a discharge capacity of 10%.
%, The recovery time of the voltage is equal to that of the battery of Example 4,
It can be seen that the battery of Reference Example 2 is disadvantageous in terms of life even if the discharge exceeds 10% without changing the voltage recovery time.

The voltage drop at the start of discharge is 0.9 for the battery of the comparative example.
While it drops to V, this Example 2 (discharge ratio 2.5
It was found that the battery of (%) dropped only to 2.55 V and the voltage drop was small.

〔The invention's effect〕

As described above in detail, according to the present invention, it is possible to provide a method for manufacturing a non-aqueous solvent battery having excellent initial discharge characteristics such as suppressing the voltage drop even in the initial stage of large current discharge and shortening the voltage recovery time.

[Brief description of drawings]

The drawing is a cross-sectional view of a non-aqueous solvent battery assembled in an embodiment of the present invention. 1 ... can body, 2 ... negative electrode, 3 ... positive electrode, _{4 1,} 4 2 _... separator, 5 ... porous carbon material, 6 ... metal current collector, 10 ... pipe-like positive electrode terminal, 11 ... lid 13 ... Electrolyte.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kiyoji Kiyasu 1 Komu, Toshiba-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Higashi Koshibaura Electric Co., Ltd. Research Institute (72) Inventor Yuichi Sato Ko, Kawasaki-shi, Kanagawa Muko Toshiba Town No. 1 TOSHIBA CORPORATION Shibaura Electric Co., Ltd. (72) Inventor Yoshiyasu Aoki 3-4-10 Minamishinagawa, Shinagawa-ku, Tokyo Toshiba Battery Co., Ltd. (72) Inventor Kazuya Hiratsuka Shinagawa, Tokyo 3-4-10 Minami-Shinagawa, Toshiba Battery Co., Ltd. (56) Reference JP-A-59-154768 (JP, A) JP-A-58-209067 (JP, A) JP-A-57-199180 (JP, A) JP-A-58-194260 (JP, A)

Claims (1)

[Claims] 1. A battery container stores a negative electrode made of a light metal such as lithium and a positive electrode via a separator, and an electrolytic solution containing sulfur oxyhalide in the container as a main component and also serving as a positive electrode active material. In manufacturing a non-aqueous solvent battery having the above structure, 0.5 to 10% of the total discharge capacity of the battery is discharged as a post-treatment within 10 days after the battery is assembled. Production method.