JPS63298970A - Manufacture of nonaqueous solvent battery - Google Patents

Abstract

PURPOSE:To prevent generation of cavity caused by welding to prevent electrolyte leakage by inserting a plug into a metal pipe, tentatively sealing a specified part of the plug, cleaning the upper part inside the pipe, then welding the pipe by laser welding. CONSTITUTION:A battery is assembled before pouring an electrolyte, and a metal cover 9 to which a metal pipe 7 is sealed through an insulator 11 is welded to the opening of a can 1. An electrolyte is poured inside the can 1 from the pipe 7, then a stainless steel plug 13 is inserted in the pipe 7. A part, which corresponds to the center of the plug 13, of the pipe 7 is shrunk in the radial direction to form a crimped part 14 and to tentatively seal the pipe 7. Then, the inside of the pipe 7 is cleaned by running water, and the crimped part 14 is sealed by laser welding to form the battery. Generation of cavity caused by laser welding is prevented and electrolyte leakage is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a non-aqueous solvent battery using an alkali metal as a negative electrode and an oxyhalide as a positive electrode active material.

[Prior art] Non-aqueous solvent batteries that use lithium, sodium, etc. as the negative electrode have high energy density, excellent storage characteristics, and a wide operating temperature range, and are often used as backup power sources for calculators, watches, and memories. has been done. Among these batteries, batteries that use lithium as the negative electrode, sulfur or phosphorus oxyhalide such as thionyl chloride or sulfuryl chloride as the main positive electrode active material, and a positive electrode consisting of carbon and metal current collectors are particularly energy efficient. It is attracting attention because of its high density.

By the way, since the above-mentioned battery uses a highly corrosive sulfur or phosphorous oxyhalide such as thionyl chloride or sulfuryl chloride as the main positive electrode active material, the oxyhalide may leak out of the battery container and damage the battery. It is necessary to seal the battery container liquid-tight to prevent corrosion of the built-in equipment.

In addition, although the oxyhalide is in liquid form and also serves as an electrolyte, it is highly volatile and highly toxic, so it is important to avoid deterioration of battery characteristics due to the work environment and insufficient capacity of the electrolyte in the container. After housing the power generation elements (negative electrode, separator, positive electrode) in the container, it is necessary to inject and store the electrolytic solution containing the oxyhalide in the container.

For this reason, a nonaqueous solvent battery having the structure shown in FIG. 2 has been known for some time, and such a battery is manufactured by the following method.

First, a negative electrode 2 made of metallic lithium is attached to the inner peripheral surface of a bottomed cylindrical can body 1 made of stainless steel, which also serves as a negative polarity terminal.
Crimp. A positive electrode 3 is housed inside the negative electrode 2 via a separator 4 made of a nonwoven fabric made of glass fiber, for example, and a bottom paper 5, which are arranged over the inside of the negative electrode 2 and the entire bottom surface of the can body 1. This positive electrode 3 usually includes a cylindrical porous carbon body 3a made of acetylene black with 10% by weight of polytetrafluoroethylene as a binder, and a cylindrical porous carbon body 3a.
A metal current collector 3b made of expanded metal made of nickel is disposed on the inner surface of the hollow portion of a. Further, in the positive electrode 3, for example, lithium aluminum tetrachloride (LiA
, ffc), ) is injected and impregnated with a thionyl chloride solution (electrolyte).

Next, a metal pipe 7 for liquid injection, which also serves as a terminal of the other polarity and has a lead wire 6 attached to its lower end, is connected to the metal current collector 3b via the lead wire 6, and then the pipe 7 is connected to the positive electrode 3.
The insulating paper 8 supported above the separator 4 in the upper can body 1 is inserted through the hole.

Next, the metal pipe 7 is inserted through the center hole 10 of the lid 9 made of stainless steel, the lid 9 is fitted into the upper opening of the can 1, and the outer periphery of the lid 9 and the can 1 and the contact point is laser welded and sealed.

Note that a sealing material 11 made of glass, for example, is interposed in the gap between the center hole 10 of the lid 9 and the pipe 7, and the pipe 7 and the lid 9 are hermetically sealed in advance using the sealing material 11. It is. In this way, a battery precursor is assembled without containing an electrolyte.

Next, the electrolytic solution described above is passed through the pipe 7 to the can body 1.
A predetermined amount of the electrolytic solution 12 is injected into the container.

Subsequently, after inserting the stainless steel plug 13 into the pipe 7, the entire contact portion of the plug 13 with the pipe 7 is directly laser welded to integrate and seal the pipe 7 in a liquid-tight manner.

[Problems to be Solved by the Invention However, the above-mentioned method has the following problems.

That is, when laser welding the upper part of a metal pipe and the stopper, the electrolyte that adheres to the inner surface of the pipe during the electrolyte injection process evaporates due to the heat during welding, gasifies, and escapes to the outside. This creates continuous holes called "crows" in the weld. As a result, the liquid tightness of the battery is impaired, leading to leakage of the electrolyte and reducing the yield of products.

In addition, in order to prevent the above-mentioned welding defects, after inserting the plug into the metal pipe, the contact surface between the metal pipe and the plug is temporarily sealed.
A method has also been proposed in which laser welding is performed after a certain period of time. However, even with this method, the electrolytic solution adhering to the metal pipe and the stopper has the same adverse effect as mentioned above during laser welding, and the above-mentioned problem has not yet been solved.

The present invention has been made in order to solve the above-mentioned conventional problems, and it is possible to significantly suppress the generation of "porous holes" that occur when laser welding a plug inserted into a metal pipe, and to make them liquid-tight. The present invention aims to provide a method for manufacturing a non-aqueous solvent battery that can be reliably sealed.

[Means for Solving the Problems] The present invention includes a negative electrode made of an alkali metal and a positive electrode made mainly of porous carbon, which are housed in a bottomed cylindrical metal can that also serves as a polar terminal, with a separator interposed therebetween. , after welding a metal lid to which a metal pipe is sealed in advance through an insulating material to the upper opening of the metal can, an electrolytic solution containing an oxyhalide as a positive electrode active material is passed through the metal pipe to the metal. In manufacturing a non-aqueous solvent battery, the battery is injected and housed in a can body, and then a stopper is inserted into the metal pipe and sealed by laser welding. Manufacturing a non-aqueous solvent battery characterized by temporarily sealing a predetermined part of the plug located in the pipe, and then cleaning the upper part of the metal pipe into which the plug is inserted, and then laser welding it. It's a method.

As the temporary sealing means, any method may be used as long as the temporarily sealed metal pipe and the plug become liquid-tight, but for example, a method of compressing the metal pipe in the radial direction and caulking it is suitable.

The cleaning liquid used for the above cleaning may be any liquid as long as it can wash away the electrolyte well. For example, in the case of an oxyhalide electrolyte, water having good solubility in the electrolyte may be used.

[Function] According to the present invention, the plug is inserted into a metal pipe, a predetermined portion of the plug located inside the metal pipe is temporarily sealed with respect to the pipe, and then the plug is inserted into the metal pipe. By cleaning the upper part of the metal pipe, it is possible to wash away the electrolyte between the metal pipe and the stopper, which will be the welded part. As a result, the electrolyte that adheres to the metal pipe during subsequent laser welding is effectively prevented from evaporating and gasifying due to the heat during welding and creating "crows" in the welded area, and the plug body is attached to the metal pipe. It is possible to obtain a highly reliable non-aqueous solvent battery that can be welded well and is liquid-tightly sealed.

Further, during cleaning, it is possible to prevent the cleaning liquid from entering the inside of the battery by the temporary sealing performed in the step before cleaning, and it is possible to prevent the battery characteristics from deteriorating.

[Embodiments of the Invention] Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1(A) and 1(B). Incidentally, the same members as those shown in FIG. 2 described above are given the same reference numerals and the explanation thereof will be omitted.

First, as described above, after assembling a battery without containing an electrolyte, a thionyl chloride solution containing lithium aluminum tetrachloride (L i A, & C, Il'4) at a concentration of 1.8 mol/min is added. A predetermined amount of (electrolytic solution) was injected into the can body 1 through the metal pipe 7, and the electrolytic solution 12 was contained therein. Subsequently, a stainless steel stopper 13 was inserted into the pipe 7 (as shown in FIG. 1(A)).

Subsequently, a portion of the pipe 7 corresponding to the central portion of the stopper 13 located inside the metal pipe 7 was compressed in the radial direction to form a caulked portion 14, and a temporary seal was performed (as shown in FIG. 3B). Next, after washing the inside of the metal pipe 7 with running water, the entire contact portion of the stopper 13 with the pipe 7 was directly laser welded and sealed, thereby manufacturing a non-aqueous solvent battery.

Comparative Example 1 A non-aqueous solvent battery was manufactured in the same manner as in Example except that temporary sealing and cleaning were not performed before laser welding the stopper to the metal pipe.

Comparative Example 2 A non-aqueous solvent battery was manufactured in the same manner as in Example, except that a stopper was inserted into a metal pipe, temporarily sealed by caulking, and then laser welding was performed without cleaning.

For each of 500 batteries produced in this Example and Comparative Example 1.2, a silver nitrate solution was dropped into the welded seal between the metal pipe and the stopper, and the number of batteries exhibiting white color was determined. As a result, in the battery manufactured by the method of this example, 50
0 pieces did not exhibit a stone color. On the other hand, it was found that 3G out of 500 batteries manufactured in Comparative Example 1 and 16 out of 500 batteries manufactured in Comparative Example 2 exhibited white color.

[Effects of the Invention] As detailed above, according to the method for manufacturing a non-aqueous solvent battery of the present invention, the occurrence of "porosity" that occurs when laser welding a stopper inserted into a metal pipe can be significantly suppressed and eliminated. It can be sealed liquid-tight and reliably, and has remarkable effects such as no electrolyte leakage when the battery is in use, and corrosion to electronic equipment incorporating the battery can be prevented.

[Brief explanation of drawings]

Figures 1 (A) and (B) are cross-sectional views showing the laser welding process of a stopper to a metal pipe in an embodiment of the present invention, and Figure 2 is a cross-sectional view of a non-aqueous solvent battery manufactured by a conventional method. be. ■...Can body, 2...Negative electrode,...Positive electrode, 4...
Separator, 7...pipe, 9...lid, 11...
- Glass sealing material, 12... Electrolyte, 13... Plug body, 14... Caulking part. Applicant's agent Patent attorney Takehiko Suzue (A) Figure 1

Claims (1)

[Claims] A negative electrode made of an alkali metal and a positive electrode made mainly of porous carbon were housed in a bottomed cylindrical metal case that also served as a unipolar terminal, with a separator interposed therebetween, and a metal pipe was sealed in advance with an insulating material interposed therebetween. After welding a metal lid to the upper opening of the metal can, an electrolytic solution containing an oxyhalide as a positive electrode active material is injected and contained in the metal can through the metal pipe, and then continued into the metal pipe. In manufacturing a nonaqueous solvent battery in which a stopper is inserted and sealed by laser welding, the stopper is inserted into the metal pipe, and a predetermined portion of the stopper located inside the metal pipe is attached to the pipe. A method for manufacturing a non-aqueous solvent battery, which comprises temporarily sealing the pipe, cleaning the upper part of the metal pipe into which the plug is inserted, and then laser welding the pipe.