KR100711071B1 - Sealed battery and method for manufacturing the same - Google Patents

Abstract

The present invention provides a sealed battery, a method of manufacturing a sealed battery, and a leak detection method of a sealed battery capable of reliably leak testing. After evacuating the sealed battery can except the electrolyte injection hole, the atmospheric pressure is released from the electrolyte injection hole. After pressurizing with the helium-containing gas of the above pressure to inject the electrolyte solution and injecting the electrolyte solution and the helium-containing gas, the electrolyte injection port is sealed, and the helium-containing sealed battery, its manufacturing method and leakage detection Way.

Description

Sealed battery and method for manufacturing the same

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the process of manufacturing the sealed battery of this invention, A figure explaining the apparatus which injects electrolyte solution and helium in a battery can,

2 is a view for explaining the operation of the injection device of the electrolyte and helium of the present invention in order;

3 illustrates a means for preventing deformation of a battery can;

4 is a view for explaining an example of a leak inspection method;

5 is a view for explaining another example of the leak inspection method;

6 is a view for explaining another example of the leak inspection method;

7 is a view for explaining another example of the leak inspection method.

<Explanation of symbols for main parts of drawing>

One … Battery can 2. Battery element

3…. Electrolyte injection hole 4. External electrode extraction terminal

5…. Lid 6. Electrolyte solution device

7. Injection nozzle 8. O-ring

9... Exhaust means 10... Exhaust valve                 

11. Electrolyte port 12. Electrolyte Filling Valve

13. Electrolyte solution 14. Storage means

15... Electrolyte supply means 16. Electrolyte Supply Valve

17. Helium supply means 18... Pressure valve

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetic battery, and relates to a hermetic battery capable of leak test of electrolyte solution, and more particularly to a lithium ion battery capable of a highly sensitive inspection.

In a sealed battery such as a lithium ion battery, after storing the battery element in the battery can, the header provided with an external connection terminal, a safety valve, and an electrolyte injection hole is welded, except for the electrolyte injection hole. After sealing and inject | pouring electrolyte solution from an electrolyte injection hole, the seal structure angle is attached to the electrolyte injection hole, and it seals by laser welding, and manufactures the sealed battery.

The electrolyte may leak or moisture in the outside air may enter the battery due to poor welding during sealing during sealing of the sealed battery, or poor caulking of the external connection terminal portion attached through the insulating member. In a sealed battery with poor sealing, problems such as damage to the device due to leakage of the electrolyte solution may occur along with deterioration of battery performance.

Therefore, the leak test is performed to prevent the defective battery from being shipped. However, the battery which was charged after the sealing was visually inspected, and the external inspection was performed to check the surface contamination by leakage of the electrolyte solution.

However, in the inspection method by the human eye, there is a possibility that nonuniformity due to individual differences of inspectors may occur, and when there are minute sealing defects or the like, the leakage amount is extremely small. It was difficult to find a battery with a defective sealing, which could be a problem.

Therefore, the airtight test method using the airtight test apparatus which does not depend on a human vision etc. is also proposed. For example, Japanese Patent Application Laid-Open No. 9-115555 proposes a method of measuring a pressure change in a sealed container after storing a cell under test in a sealed container and decompressing the gas therein. Moreover, leaky batteries could not be detected accurately.

In Japanese Patent Laid-Open No. 4-25738, in the battery assembly step, after attaching the cap body to the cell tank, hydrogen is pressurized and supplied into the cell tank, and the leaked hydrogen is detected by the semiconductor gas sensor. Although an airtight inspection device is described, there is a problem in terms of safety because it does not leak test the finished product of the sealed battery in which the electrolyte is injected, and also uses an explosive gas such as hydrogen.

Further, Japanese Patent Laid-Open No. 11-307136 attaches a cover to a rolled body, and then attaches a cover to cover the junction between the rolled body and the cover body, supplies helium to the inside of the roll, and draws in air inside the cover. Although an airtight test apparatus for determining airtightness by detecting helium in suction air has been described, it is to inspect the bonding of the precursor and the lid body in the manufacturing process, and to inject the electrolyte solution to perform leakage inspection of the finished product of the sealed battery. It wasn't.

It is an object of the present invention to provide a sealed battery capable of reliably discovering fine, defective sealing parts of a sealed battery, and to provide a method of manufacturing a sealed battery that reliably excludes shipment of a defective battery. It is to be.

The present invention is a sealed battery, wherein a rare gas is contained therein.

The sealed gas is a rare gas of helium.

In the manufacturing method of a sealed battery, after exhausting the inside of a sealed battery can except the electrolyte injection hole, the electrolyte solution injected from the electrolyte injection hole is pressurized by the rare gas containing gas of atmospheric pressure or more, and the electrolyte solution and the rare gas content are contained. It is the manufacturing method of the sealed battery which seals electrolyte injection hole after injecting gas.

When supplying rare gas containing gas, it is a manufacturing method of the sealed type battery which provided the press means which presses the battery can wall surface and prevents deformation of a battery can.

It is a manufacturing method of the said sealed battery whose rare gas is helium.

In the leak test method of a sealed battery, it is a leak detection method of the sealed battery which leak-detects the sealed battery containing a rare gas by measuring a rare gas concentration with a rare gas leak detection apparatus.                         

It is a leak test method of the sealed type battery which leak-detects by storing a sealed type battery in a sealed container, and measuring the density | concentration of the rare gas which leaks from a sealed type battery in the state which pressure-reduced the sealed container inside.

The hermetic type which detects leakage by storing a hermetic battery in a detection tank of a leak detection tray provided with a plurality of detection tanks, and airtightly mounts a leak detection head coupled to a leak detection device in each detection tank to measure the concentration of rare gas leaking from the sealed battery. It is a leak detection method of a battery.

It is a leak detection method of the said sealed battery whose rare gas is helium.

The present invention provides a sealed battery containing helium in a sealed battery after the helium is filled in the sealed battery, and the helium leak detector detects the concentration of helium leaked from the sealed battery. It has been found that it is possible to surely find a sealed battery of defective sealing.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the process of manufacturing the sealed battery of this invention, and is a figure explaining the apparatus which injects electrolyte solution and helium in a battery can.

The battery element 2 is housed in the battery can 1, and the battery rupture or the like is discharged in the upper opening of the battery can 1 when the electrolyte injection hole 3, the external electrode extraction terminal 4, and the pressure inside the battery rise. The injection nozzle 7 of the electrolyte injection device 6 was formed in the lid 5 in the battery can 1 to which the lid 5 having the pressure release valve to prevent, etc. was attached by laser welding or the like. The injection nozzle 7 of the electrolyte injection device 6 is attached to the electrolyte injection hole 3. The injection liquid nozzle 7 has airtight holding means, such as the O-ring 8, and airtight is hold | maintained when crimped | bonded to the wall surface of a lid body.

Moreover, the electrolyte solution pouring apparatus 6 has the exhaust means 9 for exhaust in a battery can, and the exhaust valve 10 which couples the injection nozzle 7 and the exhaust means 9.

An electrolyte port 11 for storing a predetermined amount of electrolyte is coupled to the injection liquid nozzle 7 through an electrolyte injection valve 12, and an electrolyte solution coupled to the storage means 14 of the electrolyte solution 13 is connected to the electrolyte port 11. The supply means 15 are coupled via the electrolyte supply valve 16.

In addition, helium supply means 17 is coupled to the electrolyte port 11 via a pressure valve 18.

2 is a view for explaining the operation of the injection device of the electrolyte solution and helium of the present invention in order.

As shown in Fig. 2A, the battery element is housed in the battery can 1, and the lid 5 having the electrolyte injection hole 3 in the upper opening of the battery can 1 is subjected to laser welding or the like. The battery can 1 attached by the method is hermetically attached to the electrolyte injection hole 3 in which the injection nozzle 7 of the electrolyte injection device 6 is provided in the lid 5. Subsequently, the exhaust means 9 is operated to open the exhaust valve 10 that couples the injection liquid nozzle 7 and the exhaust means 9 to exhaust the inside of the battery can, and at the same time supply the electrolyte solution from the electrolyte supply means 15. The valve 16 injects a predetermined amount of electrolyte into the electrolyte port 11 according to the battery.

Next, as shown in FIG. 2B, the exhaust valve 10 and the electrolyte supply valve 16 are closed to open the electrolyte injection valve 12. Since the electrolyte is decompressed inside the battery can, the pouring of the electrolyte into the battery can starts due to the pressure difference between the battery can and the electrolyte port 11.

When the pouring of the electrolyte in the electrolyte port 11 is started, as shown in Fig. 2C, the pressure valve coupled to the helium supply means 17 is opened, and the electrolyte in the electrolyte port 11 is pressurized by helium. The electrolyte is rapidly injected into the battery can, the helium is dissolved and injected into the electrolyte, and is injected into the electrolyte as a gas from the electrolyte injection port, and the inside of the battery is filled by the helium atmosphere.

In addition, since the battery can is pressurized from the inside at the time of injecting the electrolyte solution and helium, a phenomenon such as the wall surface of the battery can expands and deforms depending on the size and type of the battery can, so that the battery can is pressurized. It is desirable to suppress deformation due to expansion of the battery can.

3 is a view for explaining a means for preventing deformation of the battery can.

After the injection of the electrolyte from the electrolyte injection nozzle 7 is started, the pressure valve 18 is opened to pressurize the electrolyte in the electrolyte port 11 with helium, and at the same time the wall surface of the battery can by the pressing means 20 ( 21 is pressed from both sides to prevent deformation of the wall surface 21 of the battery can 1.

The pressure which presses the wall surface of a battery can is the pressure according to the pressure of the electrolyte solution inject | poured in a battery can, and it is preferable to press at the pressure equivalent to a pressing force.

The electrolyte and helium pouring apparatus of the present invention can be arbitrarily set according to the type of battery active material, the shape of the battery, the structure, etc., but the exhaust of the inside of the battery can is 1.07 kPa to 1.33 kPa for 5 seconds to 7 seconds. After confirming that the decompression degree was maintained for about a second and the vacuum degree was stabilized and there was no leakage, the exhaust valve was closed to start pouring of the electrolyte, and 4 to 10 seconds after the start of pouring of the electrolyte, the pressure valve was opened to helium. Pressurize The pressing force of helium is preferably set to 0.08 MPa to 0.20 MPa in gauge pressure.

For example, according to the electrolyte injection device of the present invention, even a highly viscous non-aqueous electrolyte solution can be injected in 60 seconds from an electrolyte injection hole having a diameter of 1 mm formed in a battery having a length of 48 mm, a width of 30 mm, and a thickness of 6 mm.

In addition, helium may be mixed with other rare gases, or nitrogen, carbon dioxide, or the like may be mixed. However, if the content other than the rare gas is increased, the leak detection ability is lowered. Therefore, the higher the content of rare gas such as helium is preferable. In addition, helium, which has a small molecule, is easy to pass through the minute leakage part in the rare gas.

In the above description, the method of introducing helium into the battery can simultaneously with the injection of the electrolyte by using helium as the pressurizing gas during the injection of the electrolyte, but the injection of the electrolyte and the injection of helium may be performed separately. .

In this case, a method of individually injecting helium from a pouring port into a battery can that has finished pouring of electrolyte solution, installing a battery can that has finished pouring of electrolyte solution in a sealed chamber, exhausting the inside of the sealed chamber, and then depressurizing the sealed chamber It can be injected by a method of filling the inside with helium and injecting the same.                     

Next, the leak test method of the sealed battery containing the helium of this invention is demonstrated.

4 is a view for explaining an example of a leak inspection method.

As shown in FIG. 4 (A), the sealed battery 31 is produced by sealing the electrolyte injection hole 3 formed in the lid of the battery can 1 by the laser welding means 30 to produce an initial charge. 4B, the sealed battery 31 is installed in the leak detection chamber 32, and the helium leak detector 33 sucks the gas in the leak detection chamber 32 to helium concentration. By measuring the leakage of the battery can be detected.

In addition, as shown in Fig. 4C, by connecting the decompression device 34 to the leak detection chamber 32 and decompressing the inside of the leak detection chamber, the difference in air pressure between the inside and outside of the battery to be detected is increased. It is also possible to increase the rate of leakage from the membrane to facilitate leak inspection.

5 is a view for explaining another example of the leak inspection method.

In the leak detection chamber 32, a plurality of sealed cells 31 are stored and installed in the battery tray 35, installed in the leak detection chamber 32, and the leak detection chamber 32 is provided by the helium leak detector 33. The helium concentration is measured by sucking gas inside, and when helium is detected, each of the sealed cells of the detected battery tray is provided in the leak detection chamber 32 in the same manner as shown in FIG. 33), the leak battery can be specified by sucking gas in the leak detection chamber 32 and measuring the helium concentration.                     

6 is a view for explaining another example of the leak inspection method.

The sniffer probe 36 of the helium leak detector 33 is brought close to a part where a leak, such as a welded part around the sealed battery 31, may occur, and the presence or absence of the leak can be confirmed by such a method. have.

7 is a view for explaining another example of the leak detection method, and is a perspective view.

The sealed battery 31 to be leak-detected is housed in a plurality of detection tanks 38 provided in the detection tray 37. The detection tank 40 equipped with the leak detection probe 39 is hermetically attached to the detection tank individually, and the presence or absence of leakage can be detected by measuring the helium concentration in each detection tank. Moreover, after mounting a detection head, a measurement can also be performed by depressurizing the inside of a detection tank.

By attaching a detection head to a conveying means which is movable to any position in the three-axis directions of X, Y, and Z, and providing a means for removing a battery in which leakage has been detected, automation of the detection process of leakage can also be performed.

The helium-containing sealed battery of the present invention can also be applied to nonaqueous electrolyte batteries such as lithium ion batteries, batteries using polymer electrolytes, aqueous electrolyte batteries such as nickel hydride batteries and sealed lead batteries.

The sealed battery containing the helium of the present invention makes it possible to reliably and uniformly measure a leaky part, such as a sealed part of a sealed battery or a blowout part of a conductive connection terminal, by a measuring device. It is possible to eliminate the possibility that the battery is incorrectly shipped, thereby increasing the reliability of the shipped battery.

Claims (12)

A sealed battery, wherein the sealed battery contains a rare gas therein. The sealed battery according to claim 1, wherein the rare gas is helium. In the manufacturing method of a sealed battery, after exhausting the inside of the sealed battery can except the electrolyte injection hole, the electrolyte solution injected from the electrolyte injection hole is pressurized by the rare gas containing gas of the atmospheric pressure or more, and the electrolyte solution and the rare gas content are contained. A method of manufacturing a sealed battery, characterized in that the electrolyte injection port is sealed after gas is injected. The method of manufacturing a sealed battery according to claim 3, wherein the rare gas is helium. 4. The method of manufacturing a sealed battery according to claim 3, wherein pressurizing means for pressing the battery can wall surface to prevent deformation of the battery can is provided when the rare gas-containing gas is supplied. The method of manufacturing a sealed battery according to claim 5, wherein the rare gas is helium. A leak detection method for a sealed battery, wherein the leak type battery containing a rare gas is detected by measuring a rare gas concentration with a rare gas leak detection device. 8. The method for detecting leakage of a sealed battery according to claim 7, wherein the rare gas is helium. The method for detecting leakage of a sealed battery according to claim 7, wherein the sealed battery is contained in the sealed container and leak detection is performed by measuring the rare gas concentration in a reduced pressure in the sealed container. 10. The method for detecting leakage of a sealed battery according to claim 9, wherein the rare gas is helium. The method according to claim 7, wherein a sealed battery is housed in a detection tank of a leak detection tray provided with a plurality of detection tanks, and a leak detection head coupled to a leak detection device is hermetically mounted in each detection tank, thereby reducing the concentration of rare gas leaking from the sealed battery. The leak detection method of the sealed battery characterized by the above-mentioned. The method for detecting leakage of a sealed battery according to claim 11, wherein the rare gas is helium.

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