JPH0418426B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a non-aqueous solvent battery. [Prior art] Nonaqueous solvent batteries using lithium, sodium, etc. as negative electrode active materials have high energy density, excellent storage characteristics, and a wide operating temperature range, and are used as backup power sources for calculators, watches, and memories. It is often used as. 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 cause damage to the battery. It is necessary to seal the battery container liquid-tight to prevent corrosion of the stored 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. Therefore, after housing the power generating 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, conventionally, when assembling the above-mentioned battery, the power generating element consisting of the negative electrode, separator and positive electrode, which also serves as a unipolar terminal, is housed in a metal case, and then the power generating element, which is made up of a negative electrode, a separator, and a positive electrode, is placed in a metal case that also serves as a unipolar terminal, and then sealed with a glass or ceramic sealant. A metal lid to which a metal pipe for liquid injection, which also serves as a polar terminal, is liquid-tightly fixed is fitted into the upper opening of the metal can, sealed by laser welding, and then the oxyhalogen is passed through the metal pipe. An electrolytic solution containing a compound is injected into the can, a metal stopper is inserted into the metal pipe, and the end of the pipe protruding from the lid is welded to the stopper to make it liquid-tight. Methods have been devised to close the gap. [Problems to be Solved by the Invention] However, in this method, when welding the end of the metal pipe and the metal stopper, the electrolyte attached to the inner surface of the pipe or the electrolyte in the metal case near the lower end of the pipe is It evaporates due to the heat during welding and enters the space between them as a gas, causing welding defects (often pinholes).
There was a problem that led to a decrease in yield. The present invention has been made in order to solve the above-mentioned conventional problems, and includes a liquid-tight metal pipe for liquid injection that also serves as a terminal of the other polarity and is liquid-tightly fixed to a metal lid via an insulating sealant. The purpose of the present invention is to provide a method for manufacturing a non-aqueous solvent battery having a sealed structure. [Means for Solving the Problems] The present invention includes a step of storing a negative electrode made of a light metal and a positive electrode mainly made of porous carbon in a metal case that also serves as a unipolar terminal, with a separator interposed therebetween, and A metal pipe, which also serves as a terminal of the other polarity, is liquid-tightly fixed to the hole through an insulating material so that the upper end side of the pipe protrudes from the lid. a step of fitting and sealing by welding, a step of accommodating an electrolytic solution containing an oxyhalide as a positive electrode active material in the metal can through the metal pipe, and inserting a metal stopper into the metal pipe, In the method for manufacturing a nonaqueous solvent battery, the method includes the step of sealing the upper end of the metal pipe protruding from the lid and the upper end of the plug by welding, the plug being lower than the upper end. This method of manufacturing a non-aqueous solvent battery is characterized in that the metal pipe has a shape that has a bulge that is in close contact with the inner circumferential surface of the metal pipe. [Function] According to the present invention, a metal lid member is provided in which a metal pipe that also serves as a terminal of the other polarity is liquid-tightly fixed to a hole near the center through an insulating material so that the upper end of the pipe protrudes from the upper end of the pipe. , fit into the upper opening of the metal can body,
After sealing by welding and storing the electrolyte in the metal can through the metal pipe, a metal stopper having a bulge below the upper end is press-fitted into the pipe and protrudes from the lid. By welding the upper end of the pipe and the upper end of the stopper, a non-aqueous solvent battery having a good sealing structure that avoids sealing defects of the metal pipe and prevents leakage of electrolyte during use is provided. Can be manufactured. [Example] Hereinafter, an example of the present invention will be described in detail with reference to FIGS. 1 and 2. First, the stainless steel can body 1 which also serves as the negative terminal
After a cylindrical negative electrode 2 made of metallic lithium is crimped onto the inner peripheral surface of the lithium metal lithium, the positive electrode 3 is placed inside the negative electrode 2 and over the bottom surface of the can 1, for example. It was housed through separators 4a and 4b made of nonwoven glass fiber fabric. The positive electrode 3 is
A commercially available polytetrafluoroethylene emulsion was blended with acetylene black at a ratio of 10% by weight, water and ethyl alcohol were added, and the mixture was stirred at room temperature for about 2 hours, then kneaded and formed into a sheet. The sheet was dried under vacuum at 150° C. to form a band-like body having a porous carbon body 6, which was then spirally wound to produce a strip-shaped body. Next, an insulating paper 7 having a hole in the center and supported by the separator 4a was placed in the can 1 above the positive electrode 3. Next, the hole 9 opened in the center
A stainless steel lid 8 is prepared in advance, in which a stainless steel pipe 10 for liquid injection, which also serves as a positive electrode terminal, is liquid-tightly fixed via a glass sealing material 11 so that the upper and lower ends protrude. After connecting the lower end of the pipe 10 fixed to the metal current collector 5 of the positive electrode 3 via a lead wire 12, it was fitted into the upper opening of the can 1 and sealed by laser welding. Next, a thionyl chloride solution (electrolyte) 13 in which, for example, 1.5 mol/LiAlCl ₄ was dissolved was injected into the can body 1 through the pipe 10 and housed therein.
Next, as shown in FIG. 2, a stainless steel stopper 15 having a spherical bulge 14 that is 1.02 mm larger than the inner diameter of the pipe 10 near the center is prepared.
After press-fitting the plug 15 into the stainless steel pipe 10 and bringing the bulge 14 into close contact with the inner peripheral surface of the pipe 10, the upper part of the pipe 10 and the upper part of the plug 15 are laser welded. The non-aqueous solvent battery shown in FIG. 1 was manufactured by sealing the battery. According to the above-described method, before the stainless steel pipe 10 for liquid injection which also serves as a positive electrode terminal and the stainless steel stopper 15 are sealed by welding, the pipe 10 is
In order to bring the bulge 14 of the plug 15 into close contact with the inner circumferential surface of the pipe 10, when sealing is performed by welding, the electrolyte 13 in the can 1 is gasified or liquefied due to the temperature rise during welding and reaches the upper end of the pipe 10. Movement can be prevented by the close contact between the inner circumferential surface of the pipe 10 and the bulging portion 15 of the stopper 16. As a result, pipe 1 to be solved
Since it is possible to prevent the electrolyte from adhering between the upper part of the plug body 15 and the upper part of the stopper body 15, it is possible to obtain a non-aqueous solvent battery that is well sealed without pinholes by laser welding. In fact, a battery manufactured according to this example and a battery (comparative example) manufactured by inserting a stainless steel plug without a bulge into a stainless steel pipe and sealing it by welding the top of the pipe and the top of the plug were combined. 100 each
These batteries were tested for the occurrence of pinholes in the sealing part due to welding. The test was conducted by dropping a silver nitrate solution, which is an indicator for detecting chloride ions, onto the welded part and measuring the number of pieces showing white coloration. As a result, in the comparative example, pinholes (white coloration) were observed in 7 out of 100 batteries. In contrast, in this example, only one out of 100 batteries was found to have pinholes. The diameter of the bulging portion of the plug is preferably 1.01 to 1.03 mm larger than the inner diameter of the pipe. The reason for this is that if the diameter is less than 1.01 mm, sufficient adhesion between the bulge and the inner peripheral surface of the pipe cannot be achieved, whereas if the diameter exceeds 1.03 mm, there is a risk of the pipe being damaged. It is. In the above embodiment, the metal stopper has a shape with a spherical bulge near the center, but it may also have a shape with an inverted conical bulge near the center. It may also have a shape with a spherical or inverted conical bulge at the lower end of the body. [Effects of the Invention] As described in detail above, according to the present invention, a bulge is provided in a metal pipe for liquid injection that also serves as a terminal of the other polarity and is liquid-tightly fixed to a metal lid via an insulating sealant. By inserting a stopper and welding the top of the pipe protruding from the lid to the top of the stopper, the pipe can be sealed liquid-tight, thereby preventing leakage of the electrolyte inside the metal case during use. It is possible to provide a method for producing a non-aqueous solvent battery with a high yield and having a good sealing structure without any problems.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a non-aqueous solvent battery manufactured according to an embodiment of the present invention, and FIG. 2 is a sectional view showing a metal stopper used in manufacturing the non-aqueous solvent battery shown in FIG. 1. . 1... Can body, 2... Negative electrode, 3... Positive electrode, 4a, 4b...
Separator, 8... Lid, 10... Stainless steel pipe, 13... Electrolyte, 14... Swelling part, 15... Stopper.

Claims (1)

[Claims] 1. A step of storing a negative electrode made of a light metal and a positive electrode mainly composed of porous carbon in a metal case that also serves as a unipolar terminal via a separator, and placing a terminal of another polarity in a hole near the center in advance. A metal lid, which is liquid-tightly fixed via an insulating material so that the upper end side of the metal pipe that also serves as a pipe protrudes from the lid, is fitted into the upper opening of the metal can body and welded. a step of accommodating an electrolytic solution containing an oxyhalide as a positive electrode active material in the metal can through the metal pipe; and a step of inserting a metal plug into the metal pipe and protruding from the lid. In the method for manufacturing a non-aqueous solvent battery, the method includes the step of sealing the upper end of the metal pipe and the upper end of the plug by welding. 1. A method for manufacturing a non-aqueous solvent battery, comprising using a battery having a bulge that is in close contact with its peripheral surface. 2. The method for manufacturing a non-aqueous solvent battery according to claim 1, wherein the bulging portion of the metal stopper is spherical. 3. The method for manufacturing a non-aqueous solvent battery according to claim 1, wherein the bulging portion of the metal stopper has an inverted conical shape.