JP2002100329A - Sealed type battery and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To supply a solution of an electrolytic solution without installing an exclusive solution supplying port, and fabricate a sealed type battery. SOLUTION: In the sealed type battery wherein a cap body is mounted on an opening part of a battery can and a sealing is made by welding, when a seal is made of a meeting part between surroundings of the cap body and the opening part of the battery can, a gap part is formed leaving a part, and the gap part is sealed after supplying the solution of the electrolytic solution from the gap part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealed battery in which a lid placed on an opening of a battery can is sealed by welding, and more particularly to a sealed battery characterized by injection of an electrolyte and a method of manufacturing the same. .

[0002]

2. Description of the Related Art In a sealed type battery, a lid is attached to the opening of a battery can via a gasket, and the battery is sealed by caulking integrally with the battery can, or the lid is placed on the opening of the battery can. A sealed battery that is sealed by a method such as laser welding is known. As a sealed battery used as a power source of a small electronic device or the like, a square sealed battery capable of effectively utilizing a battery storage space is widely used. For example, a prismatic lithium-ion battery for a small electronic device is one in which a positive electrode and a negative electrode each manufactured by applying an active material to a positive electrode current collector and a negative electrode current collector are laminated with a separator interposed therebetween. After the battery element wound with is wound in the battery can, a lid is placed on the opening of the battery can and sealed, and the electrolyte is injected from the electrolyte injection hole provided on the lid or the battery can. After that, a sealing piece is provided at the electrolyte injection port, and the gap between the sealing piece and the wall surface of the injection port is sealed by welding.

FIG. 9 is a view for explaining an assembly process of a conventional sealed battery. As shown in FIG. 9 (A), the battery element is housed in the battery can 2, and the electrolyte injection port 9, the external electrode outlet terminal 3, and the internal pressure of the battery rise when the pressure inside the battery rises. After the lid 4 having a pressure release valve or the like for preventing the battery from being ruptured is attached by a method such as welding by irradiating a laser 5, as shown in FIG.
The injection nozzle 7 of the electrolyte injection device is attached to the electrolyte injection port 9 provided in the airtight manner while maintaining the airtightness, and the air inside the battery can is exhausted to a predetermined degree of reduced pressure. Is injected. Next, as shown in FIG. 9 (C), a sealing piece 10 is attached to the electrolyte injection port 9 and welding is performed with a laser 5 to seal the electrolyte injection port.

However, in such a sealed battery, in order to seal the electrolyte injection port, an electrolyte injection port is provided.
The step of mounting the sealing pieces of various shapes such as plate, rod, and sphere was indispensable. In addition, there is a problem that the sealing is defective if the sealing piece is not correctly attached to the liquid inlet. Therefore, methods such as temporarily fixing the sealing piece, or adjusting the irradiation direction of the laser irradiating at the time of sealing have been proposed, but it does not solve the problems caused by sealing using the sealing piece. Did not. In particular, in the case of a small battery, the electrolyte injection port is small, and the sealing piece is also small.However, in the automatic conveyance of a small sealing piece such as a pin or a sphere, poor conveyance is liable to occur, and the sealing piece is easily removed. A step of confirming whether or not the liquid was correctly attached to the injection port was also required.

[0005] In addition, after a power generation element or the like is housed in a battery can at the time of manufacturing a battery, the battery is filled with an electrolytic solution, and then a lid to which external connection terminals and the like are attached is placed on the opening of the battery can and laser welding is performed. Although a method of closing the container is conceivable, such a method has not been performed in practice. This is because when the entire surface of the opening of the battery can is sealed by laser welding, the electrolyte may be degraded by a large amount of heat, and the risk of pinholes caused by the attached electrolyte and the lid are determined. If the battery is not placed at the position, the laser is irradiated inside the battery can.If a flammable substance is used as the electrolyte, there is a risk of fire, etc. Was.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a battery in which an electrolyte is injected into a sealed battery, and the electrolyte is injected without providing an electrolyte injection port in a lid or a battery can. To provide a sealed battery that does not require a series of steps such as mounting of a sealing piece to a liquid inlet, confirmation of mounting, and sealing step by welding of the sealing piece, and a method of manufacturing the same. Is the subject.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a sealed battery in which a lid is placed on an opening of a battery can and sealed by welding, and a junction between the periphery of the lid and the opening of the battery can is provided. Other than that, the problem can be solved by a sealed battery having no sealing portion. Further, the above sealed battery uses a non-aqueous electrolyte as an electrolyte. Further, in a sealed battery in which a lid is placed on the opening of the battery can and sealed by welding, after closing the gap with a gap left partially at the junction between the periphery of the lid and the opening of the battery can, the gap is removed. This is a sealed battery in which the gap is closed after the electrolyte is injected from the opening. The lid placed on the opening of the battery can is a sealed battery in which a gap is formed at a specific location between the lid and the inner wall surface of the battery can when placed on the opening of the battery can. Further, in the method for manufacturing a sealed battery in which a lid is placed on the opening of the battery can and sealed by welding, after storing the battery element in the battery can, the lid is placed on the opening of the battery can, This is a method for manufacturing a sealed battery in which after sealing by welding while leaving a gap at the junction between the lid and the opening of the battery can, an electrolytic solution is injected from the gap, and then the gap is sealed by welding. . The injection of the electrolyte is accommodated with the gap positioned at the bottom, and the pressure in the injection chamber is reduced to the atmospheric pressure or less in the injection chamber in which the injection tank containing the electrolyte to be injected is provided. The method for producing a sealed battery according to the above, wherein the pressure is reduced at least once and then maintained at atmospheric pressure or a pressure higher than atmospheric pressure.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a cover which is attached to an opening of a battery can and has a gap formed between the inner wall surface of the battery can and the cover at a specific location of the cover. By using, after sealing the battery can and the lid body by a method such as laser welding while leaving a gap, an electrolytic solution is injected from the unsealed gap, and then the gap is sealed by closing the gap. A battery was manufactured. And, according to the present invention, except for the junction between the opening of the battery can and the lid, a sealed battery having no sealing portion including an electrolyte injection hole sealed by laser welding after injection is provided. Can be provided. Further, the sealed battery of the present invention is provided with a dedicated electrolyte solution injection port in the lid or battery can, and attached with a sealing piece,
It also has the feature that there is no need for a sealing step.

The present invention will be described below with reference to the drawings.
FIG. 1 is a diagram for explaining the manufacturing process of the sealed battery of the present invention. As shown in the perspective view of FIG. 1 (A), a sealed battery 1 of the present invention is provided at an opening of a battery can 2 containing a battery element.
Lid 4 to which conductive connection terminal 3 is attached via an insulating member
When the laser 5 is applied to the junction between the battery can and the lid to form the sealing portion 6, a portion having a gap is provided between the wall surface of the battery can and the lid. The portion is formed as the gap portion 11 without irradiating the laser. Next, as shown in FIG. 1 (B), the electrolytic solution injection head 7 is attached to the gap portion 11 and the electrolytic solution 8 is injected. After the decompression device is connected to the electrolyte injection head 7 and the gas in the battery can is removed by suction,
It is preferable to inject the electrolytic solution, so that the details of the battery element housed in the battery can can be quickly filled with the electrolytic solution. As shown in FIG. 1C, after the electrolyte is injected, the gap 5 is irradiated with the laser 5 to complete the sealing of the sealed battery. In the sealed battery of the present invention, it is preferable to process the battery can or the lid so that a gap is always formed in a certain range between the battery can and the lid. It is preferable that a gap portion is formed by providing a portion having a small width or the like so that a gap portion is formed when the portion is placed in the opening of the battery can.

FIG. 2 is a view for explaining an example of a place where a gap is formed. FIGS. 2A to 2D are plan views in which the size of the lid is partially smaller than the space formed by the inner wall surface of the battery can. Since the gap is always formed at the same position in the meeting portion, that portion can be used as the gap portion 11. Such a lid can be easily manufactured by using a predetermined mold when manufacturing the lid by metal working. The gap forming portion may be any portion, but it is preferable that the gap is always formed at the same location, and that portion is used as the gap portion.

The size (width) of the gap is 10 to 150.
μm is preferable, and when the size of the gap is smaller than 10 μm, it takes time to inject the electrolytic solution from the gap, which is not preferable. At the time of sealing, there is a problem that welding defects such as generation of a pinhole in the sealing portion easily occur. Increasing the size of the gap, that is, the width, is advantageous in that the injection time of the electrolytic solution is increased and the production time can be shortened, which is advantageous.However, when the gap is closed by laser welding, a pinhole is generated. In such a case, after reducing the size of the gap by pressing the gap of the battery can, laser welding is performed, or the gap of the battery can is reduced. By performing laser welding in a state where the portion is pressed, the characteristics of the sealing portion can be improved. In addition, since the length of the gap also affects the rate of injection of the electrolyte, it is preferable that the length of the gap be longer from the viewpoint of the rate of injection of the electrolyte. The length is preferably set to 3 to 10 mm because there is a problem that a portion to be closed after leakage or injection is long.

In the battery of the present invention, the electrolyte is injected by mounting an electrolyte injection head in a gap formed by a gap between the inner wall surface of the battery can and the lid, and depressurizing the inside of the battery can. Can be done after. The electrolyte is injected by positioning the opening in the electrolyte proposed by the present applicant as Japanese Patent Application No. 2000- (the number of the national priority application which has corrected NME77). It is preferable to inject using a liquid injection device by changing the internal pressure. In the conventional method of mounting a liquid injection head, it is necessary to prepare a liquid injection head according to the shape of the gap. However, in this method, the position of the gap where the electrolyte is injected is determined by the level of the electrolyte. If it can be set below, the electrolyte can be injected without depending on the shape of the gap.

FIG. 3 illustrates a method for injecting liquid using an injecting device that injects liquid according to a change in pressure. Electrolyte injection device 2
1 has a liquid injection chamber 24 provided therein with a liquid injection tank 23 having a plurality of unit liquid injection tanks 22, and a pressure adjusting means 25 capable of arbitrarily adjusting the pressure in the liquid injection chamber. Are combined. The pressure adjusting unit 25 includes an exhaust unit 26 that can reduce the pressure in the liquid injection chamber 24 to a pressure equal to or lower than the atmospheric pressure, and an atmosphere release valve 27. After a plurality of the battery cans 2 with the gap 11 left in part are accommodated in the unit injection tank 22 provided in the injection tank 23 containing the electrolytic solution 9 with the gap 11 as the bottom, the liquid is injected. The pressure in the chamber 24 is reduced by operating the exhaust means 26 of the pressure adjusting means 25 to maintain the pressure in the liquid injection chamber 24 for a predetermined time.

Next, after the atmosphere release valve 27 is opened and the pressure in the liquid injection chamber 24 is maintained at atmospheric pressure for a predetermined time,
Further, the pressure in the liquid injection chamber 24 is reduced by operating the exhaust means 26 of the pressure adjusting means 25 to reduce the pressure in the liquid injection chamber 24, and then the atmosphere release valve 27 is opened to increase the pressure in the liquid injection chamber 24. The pressure is maintained for a predetermined time. in this way,
By changing the pressure in the liquid injection chamber 24, the electrolyte is injected from the gap 11 into the decompressed battery can 2.
After the electrolyte is injected, the battery can is taken out of the injection chamber. Since the gap formed in the gap is sufficiently small, the electrolyte does not fall from the gap when the battery can is taken out from the liquid injection tank. Next, the periphery of the gap to which the electrolytic solution has adhered can be washed with an organic solvent, and the gap can be sealed by laser welding. As an organic solvent used for washing, a solvent which does not adversely affect even if mixed in the electrolytic solution and has a high volatilization rate is preferable, and specific examples thereof include diethyl carbonate. In addition, it is preferable to use a solvent having a particularly low water content as these organic solvents.

The degree of pressure reduction in the liquid injection chamber and the holding time under reduced pressure are preferably taken into consideration in accordance with the characteristics of the electrolyte to be injected. When the ratio changes, the holding time in the reduced pressure state is preferably short. It is preferable that the number of times the pressure is released to the reduced pressure and the atmospheric pressure in the injection chamber and maintained at the atmospheric pressure is at least two or more. In the case where the pressure is reduced a plurality of times, the degree of pressure reduction after the second time is set to the first degree.
The pressure may be set lower than the first time, and the decompression rate may be higher than that of the first time, thereby increasing the liquid injection speed. In addition, the holding under the atmospheric pressure is performed because it is necessary to finally take out the container after the injection with the inside of the apparatus being at the atmospheric pressure. A method of changing the pressure in multiple stages, such as returning and removing, may be employed.

FIG. 4 shows another example of an electrolyte injection device. The electrolyte injection device 21 shown in FIG. 4 (A) has an injection chamber 24 having an injection tank 23 including a plurality of unit injection tanks 22 therein. A pressure adjusting means 25 capable of arbitrarily adjusting the indoor pressure is connected. The pressure adjusting unit 25 includes an exhaust unit 26 that can reduce the pressure in the liquid injection chamber 24 to a pressure equal to or lower than the atmospheric pressure, and an atmospheric gas supply unit 28. 2 is housed in an injection tank 23 having a plurality of unit injection tanks 22 containing the electrolytic solution 9 with the gap 11 at the bottom, and then the pressure in the injection chamber 24 is adjusted by the pressure adjusting means 2.
5, the pressure in the liquid injection chamber 24 is reduced by operating the exhaust means 26, and after maintaining the pressure for a predetermined time, the atmospheric gas supply valve 29 is opened to supply a predetermined atmospheric gas into the liquid injection chamber 24. After a predetermined time, the atmosphere gas supply valve 2
Close 9. Further, the pressure in the liquid injection chamber 24 is reduced by operating the exhaust means 26 of the pressure adjusting means 25 to reduce the pressure in the liquid injection chamber 24, and then the atmosphere gas supply valve 29 is opened. By supplying an atmospheric gas into the liquid injection chamber 24 for a predetermined time, the electrolyte is injected into the decompressed battery can. Next, after the atmosphere release valve 27 is opened and the atmospheric gas is replaced with air, the battery can is taken out from the liquid injection chamber with the gap part facing upward, and then the sealing process can be performed.

By using such an electrolyte injection device, it is possible to supply gases such as nitrogen, helium and carbon dioxide from the atmospheric gas supply means to form an atmosphere of these gases. The atmosphere can be filled with these gases, and the problem caused by the liquid coming into contact with air can be solved. In particular, if special gases that can be used for leak detection such as helium are used, leak detection can be performed after sealing the battery without providing a step of filling these gases.

Further, the electrolyte injection device 2 shown in FIG.
Reference numeral 1 denotes a liquid injection chamber 24 having a liquid injection tank 23 having a plurality of unit liquid injection tanks 22 therein, and a pressure adjusting means capable of arbitrarily adjusting the pressure in the liquid injection chamber. 25 are connected. The pressure adjusting unit 25 includes an exhaust unit 26 that can reduce the pressure in the liquid injection chamber 24 to a pressure equal to or lower than the atmospheric pressure.
After storing the battery can 2 having the pressurizing means 30 and sealing the battery can 2 with the gap 11 left, the gap 11 is positioned at the bottom, and the battery can 2 is accommodated in the unit injection tank 22 containing the electrolytic solution 9. Injection chamber 2
After the pressure in the liquid injection chamber 24 is reduced by operating the exhaust means 26 of the pressure adjusting means 25 to reduce the pressure in the liquid injection chamber 24 and maintained for a predetermined time, the pressure in the liquid injection chamber is reduced to the atmospheric pressure by the pressure means 30. By maintaining the above and holding for a predetermined time, the electrolyte is injected into the decompressed battery can. Further, the steps of reducing the pressure in the liquid injection chamber 24 and maintaining the pressure at a predetermined pressure may be repeated. Next, the atmosphere release valve 27
Is opened and the atmosphere gas is replaced with air to make the injection chamber an atmospheric pressure. The battery can into which the liquid has been injected can be taken out in a state where the gap is directed upward, and can be sealed. Further, the pressing means 30 shown in FIG.
The indicated atmosphere gas supply means may be combined to supply a predetermined atmosphere gas at a pressure higher than the atmospheric pressure. By pressurizing the injection chamber at a pressure equal to or higher than the atmospheric pressure, the injection speed of the electrolyte can be increased.

FIG. 5 is a view for explaining an example of the pressure reduction speed and the degree of pressure reduction in the injection chamber of the electrolytic solution injection device due to the pressure change. The vertical axis indicates the pressure and the horizontal axis indicates the elapsed time. FIG. 5 (A)
In the case where the first decompression speed indicated by A is large, the speed of the gas taken out from the container becomes large,
Since the liquid easily overflows from the inside of the container due to the generated bubbles, the pressure reduction rate needs to be determined in consideration of the height of the wall surface of the unit injection tank and the like. First, the pressure is reduced to a predetermined pressure reduction degree B. The degree of pressure reduction B is preferably not lower than the vapor pressure of the electrolyte to be injected at that temperature, and when the degree of pressure reduction is large, the electrolyte is brought into a boiling state and the liquid is lost from the unit injection tank. Next, after reaching a predetermined pressure reduction degree B, the pressure is returned to the atmospheric pressure and maintained at the atmospheric pressure for a predetermined holding time C.

Next, a second decompression operation is performed at a decompression speed D higher than the first decompression speed, and the pressure is reduced to a predetermined decompression degree E lower than the first decompression degree B. In this state, a considerable amount of electrolyte is injected into the battery can. Therefore, if there is a separator, active material, or other liquid that penetrates inside the battery can, even if the degree of decompression is increased or the decompression speed is increased, phenomena such as overflow of the liquid from the unit injection tank will occur. Does not occur. After reaching a predetermined pressure reduction degree E, the pressure is returned to the atmospheric pressure, and after a predetermined holding time F has elapsed, the container is taken out. FIG. 5B shows that the pressure in the depressurized state is maintained for a predetermined time from B1 to B2 after the pressure is reduced, the pressure is returned to the atmospheric pressure for a predetermined time, and then the pressure is reduced again to reduce the degree of decompression more than before. Is increased and is held from E1 to E2. The method of maintaining the reduced pressure state for a predetermined time is particularly effective when the electrolyte injection port is smaller than the size of the battery to be injected or when the viscosity of the electrolyte is high.

FIG. 6 is a perspective view for explaining an electrolyte injection tank. The liquid injection tank 23 preferably has a unit liquid injection tank 22 separated into a plurality of sections by a partition plate 31. A plurality of battery cans may be accommodated in one injection tank, but depending on the state of the injection port, the contact state between the injection port and the wall surface of the injection tank, etc., individual battery cans in the injection process may be included. Since the rate of liquid injection into the inside is not constant, the amount of liquid to be injected is not constant. Therefore, in order to simultaneously inject into a plurality of containers in one injection step, it is preferable to form a unit injection tank 22 partitioned by the partition plate 31. In addition, the unit injection tank 22 formed for each partition of the injection tank 23
With a predetermined amount of electrolyte to be injected inside,
It is necessary to have a size that does not allow the electrolyte to overflow even when the battery can is accommodated, and when the gas in the battery can rises in the electrolyte when the injection chamber is evacuated and depressurized. It is necessary to have a depth such that the electrolytic solution is not lost from the unit injection tank 22 as bubbles.

FIG. 7 is a view for explaining an example of a unit injection tank. FIG. 7A is a diagram showing a cross section of the unit liquid injection tank, and FIG. 7B is a plan view. It is preferable that the bottom 32 of the unit injection tank 22 has a slope toward the center, and the junction 34 with the side wall surface 33 of the unit injection tank 22 forms a curved surface. It is preferable because the residual amount of the liquid is reduced. Further, it is preferable that the bottom portion 32 has a concave portion 35 for receiving a convex portion such as an external connection terminal provided on the battery can when the battery can to be injected is accommodated. The liquid can be reliably injected from the section.

It is preferable that the filling tank is made of a material having low wettability with the electrolyte to be injected. By using a material having low wettability, the amount of liquid remaining in the filling tank can be reduced. Therefore, the amount of loss of the electrolytic solution is reduced. Alternatively, a material having a large strength such as metal may be used for the base material of the liquid injection tank, and only the inner surface of the liquid injection tank may be coated with a material having low wettability with the electrolyte to be injected. As a material having low wettability, a synthetic resin such as polypropylene and a fluororesin can be used, although it differs depending on the electrolytic solution to be injected. Alternatively, these coatings may be formed using a metal material such as stainless steel as a base material.

When the method of injecting the liquid into the battery can by utilizing the pressure change as described above is used, a fixed amount injection having a large number of injection nozzles is provided in an injection tank provided with a large number of unit injection tanks. After injecting a predetermined amount of the electrolytic solution using the liquid means, a large number of battery cans are accommodated by accommodating a large number of battery cans to be injected and performing a predetermined number of operations of reducing the pressure and returning the pressure to the atmospheric pressure. A predetermined amount of liquid can be injected at one time.

[0025]

The present invention will be described below with reference to examples. Example 1 A header having an electrode extraction terminal was attached to an upper opening of a battery can having a long side of 29 mm and a short side of 4.8 mm to form a gap of 70 μm on the long side and 55 μm on the short side. Then, as shown in FIG. 8, a portion where the gap is formed is formed with a cover having a = 0.02 mm and b = 3 mm, and the gap is formed by laser welding except for the region c to form a gap. A battery can was manufactured. Next, the inner size is 50 mm in width, 42 mm in height, and 12 mm in thickness,
In a unit injection tank provided with a 0.8 mm-depth electrode receiving terminal housing at the bottom, diethyl carbonate (DEC), ethylene carbonate (EC) and lithium hexafluorophosphate (LiP) were placed.
After 3.1 g of the electrolytic solution containing F ₆ ) was charged, the battery can was accommodated with the gap between the battery cans facing the bottom, and then mounted in the injection chamber. .005MPa
When the pressure reached, the degree of pressure reduction was maintained for 5 seconds, then the pressure in the liquid injection chamber was maintained at atmospheric pressure and the atmospheric pressure for 5 minutes, and then the battery can was taken out. The electrolyte did not fall from the electrolyte inlet of the battery can. Each one of battery cans filled with electrolyte
The mass before and after the injection of 0 pieces was measured, and as shown in Table 1, an average of 3.00 g of the electrolyte could be injected as shown in Table 1.

Comparative Example 1 Except that a 1 mm electrolyte injection port was provided on the header,
In the same manner as in Example 1, the electrolyte was injected, and the mass of the obtained batteries before and after injection of 10 batteries was measured. The average injection amount was 3.00 g.

[0027]

[Table 1] Injection amount (g) Sample number 1 2 3 4 5 6 7 8 9 10 Average value Example 1 2.98 3.02 2.99 3.01 3.00 2.99 3.01 3.00 3.00 3.00 3.00 Comparative example 1 3.00 3.00 2.99 2.98 3.01 3.02 3.01 2.99 3.00 3.00 3.00

[0028]

According to the sealed battery of the present invention, when the opening of the battery can is sealed, the gap is left with the gap closed, and the formed gap is used for the injection of the electrolyte. There is no need to provide a liquid port. In addition, when the electrolyte injection port is provided, a sealing piece for closing the injection port, which is indispensable at the time of sealing, is not required, which simplifies the sealing process and causes a problem due to improper mounting of the sealing piece. Can also be eliminated. In addition, by applying the electrolyte solution injection method based on pressure fluctuations in the injection chamber, it is possible to inject a large amount of battery cans in a single processing step. Can also be increased.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a production process of a sealed battery according to the present invention.

FIG. 2 is a diagram illustrating an example of a location where a gap is formed.

FIG. 3 illustrates a method of injecting liquid using an injecting device that injects liquid by a change in pressure.

FIG. 4 shows an example of another electrolytic solution injection device.

FIG. 5 is a diagram for explaining an example of a pressure reduction rate and a pressure reduction degree in a liquid injection chamber of an electrolyte liquid injection device due to a pressure change, in which the vertical axis indicates pressure and the horizontal axis indicates elapsed time.

FIG. 6 is a perspective view illustrating an electrolyte injection tank.

FIG. 7 is a diagram illustrating an example of a unit injection tank.

FIG. 8 is a diagram illustrating a place where a gap is formed in the battery according to the embodiment.

FIG. 9 is a diagram illustrating an assembly process of a conventional sealed battery.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sealed battery, 2 ... Battery can, 3 ... Conductive connection terminal, 4 ...
Lid, 5 ... Laser, 6 ... Sealing part, 7 ... Electrolyte injection head, 8 ... Electrolyte, 9 ... Electrolyte injection port, 10 ... Seal piece, 1
DESCRIPTION OF SYMBOLS 1 ... Gap part, 21 ... Electrolyte infusion apparatus, 22 ... Unit injection tank, 23 ... Injection tank, 24 ... Injection chamber, 25 ... Pressure adjustment means, 26 ... Exhaust means, 27 ... Atmospheric release valve, 28 ... Atmospheric gas supply means, 29 ... Atmospheric gas supply valve, 30 ... Pressurizing means, 31 ... Partition plate, 32 ... Bottom part, 33 ... Side wall surface, 34
... Meeting part, 35 ... Recess

Claims (4)

[Claims] 1. A sealed battery in which a lid is placed and sealed in an opening of a battery can has no sealing portion other than a junction between the periphery of the lid and the opening of the battery can. Characteristic sealed battery. 2. A sealed battery in which a lid is placed on an opening of a battery can and sealed by welding, wherein a gap is formed at a part of a junction between the periphery of the lid and the opening of the battery can. A sealed battery characterized in that the gap portion is sealed after the electrolyte is injected from the gap portion after sealing with (1). 3. A method for manufacturing a sealed battery in which a lid is placed on an opening of a battery can and sealed by welding, after the battery element is stored in the battery can, the lid is placed on the opening of the battery can. Is placed, and sealed by welding in a state where a gap is formed at a part of the junction between the lid and the opening of the battery can, and then the electrolyte is injected from the gap, and then the gap is sealed by welding. A method for producing a sealed battery. 4. An injection chamber, in which an electrolyte is injected with a gap positioned at a bottom portion and an injection tank containing an electrolyte to be injected is provided inside the injection chamber. 4. The method for producing a sealed battery according to claim 3, wherein the pressure is reduced to at least once below atmospheric pressure, and then maintained at atmospheric pressure or a pressure higher than atmospheric pressure.