JP2002313437A - Method and device for measuring gas quantity in sealed battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure components of gas generated in a sealed battery at high precision even when the sealed battery is of a small type. SOLUTION: The sealed battery 7 is contained in a vacuum container 1, the vacuum container 1 is set vacuum, and a pressure P1 in the vacuum container is measured. In this state, a through hole is bored in a case of the sealed battery 7, and a pressure P2 in the vacuum container 1 is measured again. Using a following expression (1), quantity (a mole number) n of gas contained in the sealed battery is determined. n=(P2.V2-P1.V1)/RT...(1) In the expression, R is a gas constant, and T is an absolute temperature in the vacuum container. V1 is volume of space in the vacuum container 1 containing the sealed battery 7 before boring the through hole. V2 is volume of space in the vacuum container l after boring the through hole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the amount of gas in a sealed battery, a device capable of performing the method, and a system for determining gas in a sealed battery.

[0002]

2. Description of the Related Art When a gas is generated inside a sealed battery (a battery in which a battery structure is housed and sealed in an outer package) during charging / discharging or storage, the gas may swell or leak, or This may cause deterioration of battery capacity and cycle performance. Therefore, for the purpose of ensuring the safety and electrical performance of the sealed battery, materials such as an electrode, a separator, and an electrolytic solution and a structure have been conventionally improved. Along with this, it is required to produce a large number of different samples and measure the amount and components of gas generated in the sealed battery by charging and discharging and storage with high accuracy.

As a conventional method, for example, as shown in FIG. 4, a pressure gauge or an analyzer 60 is directly connected to an outer package 9 of a sealed battery, and the pressure in the sealed battery and the gas generated in the sealed battery are connected. It has been performed to analyze the amount and composition of the components.

[0004]

However, in the above-mentioned conventional method, it is difficult to connect an analyzer or the like directly to the outer case if the outer case is small, so that the outer case needs to be enlarged to some extent. In addition, if a small battery internal member (such as a laminate of an electrode plate and a separator) is contained in a large exterior body, the space inside the battery becomes large, and the amount of gas originally existing in this space increases. Therefore, it becomes difficult to measure the small amount of gas generated by the test with high accuracy. For this reason, it is necessary to increase the size of the battery inner member to some extent according to the size of the outer package.

Therefore, when conducting a test for improving a battery by the above-mentioned conventional method, it is necessary to prepare a large number of large internal battery members and a large number of large exterior members having different configurations to prepare a large number of different samples. There is, however, a lot of work involved in this task. The present invention has been made in view of such problems of the prior art, and enables the measurement of the amount and components of gas generated in a sealed battery to be performed easily and with high accuracy using a small sealed battery. It is an object of the present invention to reduce the labor required for a test for improving a battery.

[0006]

In order to solve the above-mentioned problems, the present invention provides a method for measuring the amount of gas in a sealed battery characterized by the following. This method is defined as the first method of the present invention. The sealed battery is housed in a vacuum container, and the inside of the vacuum container is depressurized until a predetermined degree of vacuum (for example, a pressure of 0.1 kPa) is reached, and then the pressure P1 in the vacuum container is measured.

Next, in this state, a through-hole is formed in the outer casing of the sealed battery in the vacuum vessel, and the pressure P2 in the vacuum vessel is measured again. These pressure measurement values P1 and P2, the volume V1 of the space in the vacuum container before the sealed battery is housed and the through hole is opened, and the vacuum container after the sealed battery is opened and the through hole is opened From the volume V2 of the inner space, the amount (mole number) n of the gas contained in the sealed battery is calculated using the following equation (1).

N = (P2 · V2−P1 · V1) / RT (1) (where R is a gas constant and T is the absolute temperature of the gas in the vacuum vessel.) When a through hole is opened in the outer casing of the sealed battery in the process, the gas in the sealed battery is released into a vacuum container having a predetermined degree of vacuum, so even when the amount of gas contained in the sealed battery is small, this gas Is diffused into the vacuum vessel, so that the pressure in the vacuum vessel rises significantly. In the step (3), the amount of gas contained in the sealed battery is calculated based on the pressure increase amount. Therefore, according to this method, even in a small sealed battery, the gas amount in the sealed battery can be measured with high accuracy.

According to this method, the smaller the inner volume of the vacuum vessel, the greater the degree of pressure increase in the step.
The accuracy of gas measurement in a sealed battery is improved. However, in this method, in order to measure the pressure P1 under a high vacuum in the step, a pressure measuring device capable of measuring the pressure under a high vacuum is used, but if the degree of pressure increase in the step is too large, When measuring P2, there is a concern that the measurement limit of the pressure gauge will be exceeded.

[0010] To cope with this, it is preferable to change the inner volume of the vacuum container in accordance with the assumed value of the contained gas amount for each sealed battery to be measured. For this purpose, it is preferable to use a vacuum container having a mechanism for inserting a spacer in the vacuum container or changing the internal volume. The above (1)
The equation is derived from the equation of state of the gas as follows.

Before the sealed battery is housed and a through-hole is formed in the vacuum container, there is a gas remaining even if the pressure is reduced.
This gas is present in the volume V1 and its quantity n1 is
It is expressed by the following equation (4) using the measured pressure value P1. n1 = P1 · V1 / RT (4) The residual gas and the gas existing in the sealed battery are present in the vacuum vessel after the through hole is formed in the sealed battery, and the amount thereof is (N1 + n) is expressed by the following equation (5) using the measured pressure value P2.

N1 + n = P2 / V2 / RT (5) Here, when the temperature T of the gas in the vacuum vessel is constant,
Equation (1) is derived from equations (4) and (5). Therefore, in order to increase the measurement accuracy, it is necessary to keep the temperature of the gas in the vacuum vessel constant. The present invention also provides
The present invention provides a method for measuring the amount of gas in a sealed battery, characterized by the following. This method is defined as the second method of the present invention.

[0013] The sealed battery is housed in a vacuum container, the pressure in the vacuum container is reduced until a predetermined degree of vacuum is reached, and the pressure P3 in the vacuum container is measured. Next, an inert gas at a pressure Pi is introduced into the vacuum container at a volume Vi, and then the pressure P4 in the vacuum container is measured. From these pressure measurement values P3 and P4 and the pressure Pi and volume Vi of the introduced inert gas, the vacuum in a state before the sealed battery is housed and a through hole is opened using the following equation (2). The volume V1 of the space in the container is calculated.

V1 = Pi · Vi / (P4−P3) (2) After measuring the pressure P4, the pressure inside the vacuum vessel is reduced to a predetermined degree of vacuum, and then the pressure P1 inside the vacuum vessel is measured. . Next, in this state, after a through-hole is formed in the exterior body of the sealed battery in the vacuum container, the pressure P2 in the vacuum container is measured again.

After measuring the pressure P2, the pressure inside the vacuum vessel is reduced to a predetermined degree of vacuum, and then the pressure P5 inside the vacuum vessel is measured. Next, the pressure P
After introducing the inert gas of j in volume Vj, the pressure P6 in the vacuum vessel is measured. These pressure measurements P5, P
6 and the pressure Pj and the volume Vj of the introduced inert gas, the following formula (3) is used to calculate the volume V2 of the space in the vacuum vessel after the through-hole is opened in the sealed battery. I do.

V2 = Pj · Vj / (P6-P5) (3) From the pressure measurement values P1 and P2 and the volume measurement values V1 and V2 of the space in the vacuum vessel, the following equation (1) is used. Then, the amount (number of moles) n of the gas contained in the sealed battery is calculated. n = (P2 · V2−P1 · V1) / RT (1) (where R is a gas constant, and T is an absolute temperature in the vacuum vessel.) Here, as shown in FIG. Assuming that the volume inside the vacuum container 1 before storing the sealed battery 7 is Va, the volume (outer volume) of the sealed battery 7 is VB, and the volume inside the sealed battery 7 with the through hole 70 opened is Vb, Volumes V1 and V of the space in the vacuum vessel before and after the battery is stored and the through hole is opened
2, V1 = (Va−VB), V2 = (Va−VB + V)
b).

When the amount of gas in the sealed battery is calculated from the above equation (1) using previously prepared values (average value, representative value, etc.) as the volume values V1 and V2, the measured values are measured. The variation in the external volume VB of each sealed battery is ignored. On the other hand, according to the second method of the present invention, the volume V
1, V2 is measured each time the gas amount in the sealed battery is measured, and the gas amount in the sealed battery is calculated using the measured value, so that the gas amount is measured with higher accuracy.

In the first and second methods of the present invention, it is preferable that the method for forming a through hole in the outer package of the sealed battery is a mechanical drilling method. According to this method,
No gas is generated when a through-hole is formed in the exterior body of the sealed battery, and no temperature change occurs. As a method of forming a through hole in the exterior body of a sealed battery, in addition to a mechanical perforation method such as drilling with a nail-like object or cutting with an edge-like object, a chemical method such as a method of dissolving the exterior body using a chemical reaction. There are also physical methods such as a method and a method of fusing with a laser. These methods are not preferable because gas is generated as the holes are made, and the gas is present in the closed container.

Further, when a through hole is formed in the exterior body of the sealed battery by a mechanical drilling method, the exterior body may come into contact with a member such as an electrode inside the battery or press the member to cause an electrical short circuit. Must be avoided. When an electric short circuit occurs, heat is generated and the temperature inside the vacuum vessel rises, or due to the generation of new gas by electrochemical reaction,
The accuracy of gas measurement in a sealed battery by the method of the present invention is reduced.

The present invention also provides a vacuum container for accommodating a sealed battery, a decompression mechanism for reducing the pressure in the vacuum container until a predetermined degree of vacuum is reached, and a penetrating through the exterior of the sealed battery contained in the vacuum container. Provided is an apparatus for measuring the amount of gas in a sealed battery, comprising: an opening mechanism for making a hole; and a pressure measuring device for measuring the pressure in the vacuum vessel. According to this device, the first method of the present invention can be performed.

As an embodiment of the gas amount measuring device of the present invention, there is provided a gas amount measuring device provided with a gas introduction mechanism for introducing an inert gas of a predetermined pressure in a predetermined volume into a vacuum vessel containing a sealed battery. No. According to this device, the second method of the present invention can be performed. The gas introduction mechanism preferably includes a mass flow meter and a mass flow controller.

In the gas amount measuring device of the present invention, it is preferable that the opening mechanism is a mechanism for mechanically piercing the exterior body of the sealed battery. In order to prevent an electric short circuit from occurring, it is preferable to provide a stopper mechanism for preventing the perforated end from contacting an electrode or the like. In order to measure the gas amount in the sealed battery with high accuracy by the method of the present invention, it is necessary to measure the pressure with high accuracy in a high vacuum area. Further, it is necessary to prevent a temperature change in the vacuum vessel from occurring during the pressure measurement. It is not preferable to use a pressure measuring device in which the pressure detecting mechanism utilizes heat conduction characteristics, because a temperature change in the vacuum vessel occurs. Further, it is necessary to prevent the composition of the gas in the vacuum vessel from changing due to the pressure measurement.

Therefore, in the gas amount measuring device of the present invention, the pressure measuring device preferably detects pressure by a mechanical mechanism (converts pressure into displacement or force by elastic deformation of the pressure detecting element). . Examples of such a pressure measuring device include a Bourdon tube type, a bellows type, and a diaphragm type pressure gauge. According to such a pressure measuring device, a change in pressure can be detected without significantly changing the temperature in the vacuum vessel or affecting the composition of the gas in the vacuum vessel during the pressure measurement according to the method of the present invention.

In particular, it is a diaphragm type pressure gauge,
It is preferable to use a pressure gauge that converts the amount of elastic deformation of the diaphragm into an electric signal by a strain gauge method, a silicon piezo resistance method, a thin film resistance method, or the like. The present invention also provides a gas quantitative system in a sealed battery, wherein the vacuum vessel of the gas amount measuring device of the present invention is connected to an analyzer for performing qualitative analysis and quantitative analysis of gas. In this system, the analyzer is preferably a gas chromatograph, a mass spectrometer, or a combination of a gas chromatograph and a mass spectrometer. Further, a plurality of gas chromatographs and mass spectrometers may be connected according to the purpose.

According to this system, all gases present in the vacuum vessel after opening the sealed battery ((a) gases contained in the sealed battery immediately after production, (b) removal by the decompression step Gas remaining in the vacuum vessel that was not applied, (c) gas generated inside the battery by conducting a charge / discharge test, etc.)
Can be analyzed at once. In the case where the volumes V1 and V2 are measured by introducing an inert gas into the vacuum vessel, the inert gases (a) to (c) are introduced by introducing an inert gas which is not assumed as a gas. The gas of c) can be accurately determined.

[0026]

Embodiments of the present invention will be described below. FIG. 1 is a schematic configuration diagram showing a gas determination system in a sealed battery corresponding to one embodiment of the present invention. This system includes a vacuum vessel 1, a vacuum evacuation device (decompression mechanism) 2, a mechanical perforation device (opening mechanism) 3, a diaphragm-type pressure gauge (pressure measurement device) 4, and a gas introduction device (gas introduction mechanism). ) 5 and a gas chromatograph-mass spectrometer (GC
-MS) 6.

The mechanical piercing device 3 is used to make a through-hole in the outer package of a coin-type battery (sealed battery) 7 housed in the vacuum container 1, and has a rod-shaped member 31 and a stopper 32. The rod-shaped member 31 is inserted into the inside of the vacuum vessel 1 from the upper outside, and has a nail-like tip made of molybdenum steel. By screwing the rod-shaped member 31 into the vacuum container 1, the nail-shaped tip is pierced into the upper lid 71 of the coin-type battery 7 to open a through hole. In addition, it is preferable that the tip of the rod-shaped member 31 is formed to be sharper and have higher hardness, and preferable materials include hard metal, artificial diamond, and the like, in addition to molybdenum steel.

As shown in FIG. 2, the coin-type battery 7 includes an upper lid 71, a container 72, a positive electrode 73, a separator 74, and a negative electrode 7.
5, an electrode pressing plate 76, an electrode pressing spring 77, and a packing 78. The coin-type battery 7
The rod-shaped member 31 is disposed in the vacuum vessel 1 such that the rod-shaped member 31 is disposed at the peripheral portion of the upper lid 71 (a position where there is a space between the upper lid 71 and the electrode pressing spring 77). Then, the tip of the rod-shaped member 31 is moved to the top cover 71 of the coin-type battery 7 by the stopper 32.
Only the holes are mechanically pierced so as to reach only the position not in contact with the electrode pressing plate 76.

The gas introducing device 5 includes a flow meter 51 and a mass flow controller 52 for introducing a predetermined volume of nitrogen gas (inert gas) into the vacuum vessel 1 in a predetermined volume.
And The vacuum vessel 1 and the gas introduction device 5 are connected by a pipe 81. The vacuum vessel 1 and the evacuation device 2 are connected by a pipe 82. The vacuum vessel 1 and the analyzer 6 are connected by a pipe 83. Each piping 81-8
3 is provided with valves 81a to 83a.

Using this system, the amount of gas inside the coin-type battery 7 can be measured by the following method.
First, the coin-type battery 7 is housed in the vacuum vessel 1, and the valve 81a on the gas introducing device 5 side and the valve 8 on the analyzer 6 side.
Close 2a. The valve 83a on the side of the evacuation apparatus 2 is opened, and the evacuation apparatus 2 operates to a predetermined degree of vacuum (0.1 kPa
(Approximately), the pressure inside the vacuum vessel 1 is reduced. Next, the valve 83a is also closed, and the pressure P3 in the vacuum vessel 1 is measured by the pressure gauge 3.

Next, the valve 81a is opened, and nitrogen gas is supplied from the nitrogen supply source to the gas introducing device 5 at the pressure Pi. The nitrogen gas is introduced into the vacuum vessel 1 by the gas introduction device 5 at a constant flow rate (for example, 1 sccm: 1 cm ³ per minute) adjusted by the mass flow controller 52. The introduction of the nitrogen gas is performed when the pressure in the vacuum vessel 1 is, for example, about 1
The operation is performed until the pressure becomes 00 kPa, and the volume Vi of the introduced nitrogen gas is measured by the mass flow meter 51. Thus, the nitrogen gas at the pressure Pi is introduced into the vacuum vessel 1 in a volume Vi. Next, the valve 81a is closed and the vacuum vessel 1 is closed.
The internal pressure P4 is measured.

From the measured pressure values P3 and P4, the pressure Pi of the introduced nitrogen gas and the volume Vi (measured value by the mass flow meter 51), the volume V1 (coin type battery) is calculated using the following equation (2). 7 is stored, and the volume of the space in the vacuum vessel 1 before opening the through-hole is calculated. This state is shown in FIG. V1 = Pi · Vi / (P4-P3) (2) After measuring the pressure P4, the pressure inside the vacuum vessel 1 is reduced to a predetermined degree of vacuum (about 0.1 kPa) in the same manner as described above, and then the vacuum is applied. The pressure P1 in the container 1 is measured. Next, in this state, a through hole is formed by pressing the tip of the rod-shaped member 31 against the upper cover (outer body) 71 of the coin-type battery 7 in the vacuum container 1. Next, the pressure P2 in the vacuum vessel is measured again.

After the measurement of the pressure P2, in the same manner as described above,
After the pressure inside the vacuum vessel 1 is reduced to a predetermined degree of vacuum (about 0.1 kPa), the pressure P5 inside the vacuum vessel 1 is measured. Next, in the same manner as described above, a nitrogen gas having a pressure Pj is introduced into the vacuum vessel 1 at a volume Vj from the gas introducing device 5, and then the pressure P6 in the vacuum vessel 1 is measured. From these pressure measured values P5 and P6, the pressure Pj of the introduced nitrogen gas and the volume Vj (measured by the mass flow meter 51), the volume V2 (penetrating through the coin-type battery 7) is calculated using the following equation (3). The volume of the space in the vacuum vessel 1 after the hole 70 is formed is calculated. This state is shown in FIG.

V2 = Pj · Vj / (P6-P5) (3) These pressure measurement values P1, P2 and volume measurement values V1, V2
Then, the amount (mole number) n of the gas contained in the coin-type battery 7 is calculated using the following equation (1). n = (P2 · V2−P1 · V1) / RT (1) (where R is a gas constant, and T is an absolute temperature in the vacuum container). The gas volume is measured.

Next, the valve 83a is opened and the vacuum vessel 1 is opened.
By introducing the gas inside the analyzer 6 and operating the analyzer 6, all the gases present in the vacuum vessel 1 after the through-hole 70 is opened in the coin-type battery 7 are analyzed at once. . Note that the control computer is provided with the analyzer 6,
Mass flow meter 51, mass flow controller 52,
By connecting the valves 81a to 83a and the pressure gauge 4 to form a system for controlling the operation of each device with a predetermined control circuit, the amount and composition of gas in the coin-type battery 7 can be automatically analyzed. Can be.

In this embodiment, the analyzer 6
A configuration in which the gas introduction device 5 and the analysis device 6 are removed corresponds to a gas amount measurement device in a sealed battery. In this embodiment, a coin-type battery 7 is used as a sealed battery. Examples of the form of the sealed battery include batteries such as a cylindrical battery, a square battery, and a laminated battery in addition to the coin-shaped battery. For any of these batteries, if it is possible to make a through hole in the exterior body by any method (preferably a mechanical perforation method), the internal gas amount can be measured by the method of the present invention. it can.

[0037]

EXAMPLES Using the system of the above embodiment, the gas present in the vacuum vessel 1 after the through-hole 70 was opened in the coin-type battery 7 was analyzed by the above-described method. First, as a coin-type battery 7 to be measured, a lithium ion secondary battery having the following configuration was manufactured in an argon box. This battery has a diameter of 20 mm and a height of 3.2 mm.

The active material of the negative electrode is carbon. The separator is a polyethylene microporous membrane. The active material of the positive electrode is lithium cobalt oxide. The electrolytic solution is obtained by dissolving 1 mol of lithium hexafluorophosphate in a solvent obtained by mixing ethyl carbonate and ethyl methyl carbonate at a ratio of 1: 2. After leaving the battery at room temperature for 24 hours, 0.6
After charging for 1 hour with a current of mA, the battery is charged into the vacuum vessel 1 and the pressure measurement in the vacuum vessel 1 and operations such as perforation of the coin-type battery 7 are performed by the above-described procedure, and the analyzer (GC-MS)
6 was obtained. Meanwhile, the temperature of the nitrogen gas introduced from the gas introduction device 5 and the temperature in the vacuum
C. was maintained.

Here, Pi = 101.0 kPa and Vi =
5.724 cm ³ , P3 = 1.0 kPa, P4 = 101.
It was 0 kPa. Using these values, V1 was calculated by the equation (2), and as a result, V1 = 5.781 cm ³ .
Pj = 101.0 kPa, Vj = 6.070c
m ³ , P5 = 1.0 kPa, and P6 = 101.0 kPa. Using these values, V2 was calculated according to equation (3), whereupon V2 = 6.13 cm ³ . In addition, the measured pressure value P1 = 1.350 kPa, and P2 = 7.875.
kPa. From the calculated values V1, V2 and the measured pressure values P1, P2, the amount n of the gas contained in the coin-type battery 7 was calculated by the equation (1).
It was 650 × 10 ⁻⁶ mol.

As a result of the analysis, argon, carbon monoxide, carbon dioxide, and ethylene were detected. Of these, argon was mixed into the battery at the time of manufacturing the battery, and the amount was 1.361 × 10 ⁻⁶ mol. From this result, it was found that this battery was 0.6 m
By charging for 1 hour with the current of A, carbon monoxide,
Carbon dioxide and ethylene are generated, and the total amount is 2.89.
× 10 ^-7 mol was found.

[0041]

As described above, according to the method of the present invention, even in a small sealed battery, the gas amount in the sealed battery can be measured with high accuracy. Therefore, by employing the method of the present invention, a small sealed battery can be used as a sample when a test for improving the battery is performed, so that the labor required for the sample preparation operation is reduced.

In particular, according to the second method of the present invention, every time the gas amount in the sealed battery is measured, the volume used in the equation for calculating the gas amount in the sealed battery is measured, and the measurement is performed. Since the gas amount in the sealed battery is calculated using the value, the gas amount measurement is performed with higher accuracy. According to this method, the volume measurement can be easily performed by connecting the gas introduction device to a vacuum container used for measuring the amount of gas in the sealed battery.

According to the gas amount measuring device of the present invention, the method of the present invention can be easily implemented. According to the gas determination system of the present invention, all gases present in the vacuum vessel after opening the sealed battery ((a) gas contained in the sealed battery immediately after production, (b) even in the decompression step The residual gas in the vacuum vessel that has not been removed, (c) the gas generated inside the battery by performing a charge / discharge test, etc.) can be analyzed at one time. The gas generated at the time can be accurately identified. In addition, there is also an effect that a gas component generated in the sealed battery can be easily measured with high accuracy for many different samples.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a gas determination system in a sealed battery corresponding to one embodiment of the present invention.

FIG. 2 is a diagram illustrating an opening position of a battery exterior body by an opening mechanism.

FIG. 3 is a diagram illustrating the volume of a space in a vacuum container when a sealed battery is placed in the vacuum container and when the battery is opened.

FIG. 4 is a diagram illustrating a conventional method for analyzing the pressure in a sealed battery and the gas generated in the sealed battery.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Vacuum container 2 Vacuum exhaust device (decompression mechanism) 3 Mechanical perforation device (opening mechanism) 31 Bar-shaped member 32 Stopper 4 Diaphragm-type pressure gauge (pressure measuring device) 5 Gas introduction device (gas introduction mechanism) 6 Gas chromatograph-mass Analysis device 60 Pressure gauge or analysis device 7 Coin-type battery (sealed battery) 70 Through hole 71 Top lid (exterior body) 72 Container (exterior body) 73 Positive electrode 74 Separator 76 Negative electrode 76 Electrode pressing plate 77 Electrode pressing spring 78 Packing 81 to 81 83 Piping 81a to 83a Valve 9 Outer body Va Volume in vacuum container before storing sealed battery VB Volume of sealed battery (outer volume) Vb Volume in sealed battery with through hole opened V1 Store sealed battery Of the gas in the vacuum container before opening the through-hole V2 and the volume of the gas in the vacuum container after opening the through-hole in the sealed battery n1 Amount (moles) of gas remaining in the vacuum vessel even after pressure reduction n Amount of gas (moles) in sealed battery

Continuation of the front page F term (reference) 5H025 AA09 BB18 BB20 CC31 CC39 MM01 5H030 AA00 FF31

Claims (10)

[Claims] 1. A sealed battery is housed in a vacuum container, the pressure in the vacuum container is reduced until a predetermined degree of vacuum is reached, and the pressure P1 in the vacuum container is measured. After making a through hole in the exterior body of the sealed battery inside, the pressure P2 in this vacuum vessel was measured again, and these pressure measurement values P1 and P2 and the state before the sealed battery was stored and the through hole was made Of the space in the vacuum vessel at V
1 and the volume V2 of the space in the vacuum vessel after the through-hole is opened in the sealed battery, the amount of gas contained in the sealed battery (using the following equation (1)) A method for measuring the amount of gas in a sealed battery, wherein the number of moles (n) is calculated. n = (P2 · V2−P1 · V1) / RT (1) (where R is a gas constant and T is an absolute temperature in the vacuum vessel.) 2. The sealed battery is housed in a vacuum container, and the inside of the vacuum container is decompressed until a predetermined degree of vacuum is reached. Then, the pressure P3 in the vacuum container is measured, and then the pressure inside the vacuum container is measured. After introducing an inert gas of Pi in a volume Vi, the pressure P4 in this vacuum vessel is measured, and these pressure measurement values P
3, P4 and pressure Pi and volume V of the inert gas introduced
From Equation (1), the volume V1 of the space in the vacuum vessel before the sealed battery is housed and the through hole is opened is calculated using the following equation (2), and V1 = Pi · Vi / (P4 -P3) (2) After measuring the pressure P4, the inside of the vacuum vessel is depressurized to a predetermined degree of vacuum, and then the pressure P1 in the vacuum vessel is measured. After making a through hole in the outer casing of the sealed battery, the pressure P
After measuring the pressure P2, the pressure inside the vacuum vessel is reduced to a predetermined degree of vacuum, and then the pressure P5 inside the vacuum vessel is measured. After the gas was introduced at a volume Vj, the pressure P6 in the vacuum vessel was measured. From these pressure measured values P5 and P6 and the pressure Pj and the volume Vj of the introduced inert gas, the following equation (3) was obtained. Calculate the volume V2 of the space in the vacuum vessel after the through-hole is opened in the sealed battery using: V2 = Pj · Vj / (P6-P5) (3) Pressure measurement values P1, P2 And calculating the amount (mole number) n of the gas contained in the sealed battery from the volume measurement values V1 and V2 of the space in the vacuum container using the following equation (1). Method for measuring the amount of gas in a sealed battery. n = (P2 · V2−P1 · V1) / RT (1) (where R is a gas constant and T is an absolute temperature in the vacuum vessel.) 3. The method for measuring the amount of gas in a sealed battery according to claim 1, wherein a through hole is formed in the exterior body of the sealed battery by mechanical perforation. 4. A vacuum container for accommodating a sealed battery, a pressure reducing mechanism for reducing the pressure in the vacuum container until a predetermined degree of vacuum is achieved, and a through hole is formed in an outer package of the sealed battery contained in the vacuum container. A gas amount measuring device in a sealed battery, comprising: an opening mechanism; and a pressure measuring device for measuring a pressure in the vacuum vessel. 5. The gas amount in a sealed battery according to claim 4, further comprising a gas introduction mechanism for introducing an inert gas of a predetermined pressure in a predetermined volume into a vacuum container containing the sealed battery. measuring device. 6. The gas amount measuring device in a sealed battery according to claim 5, further comprising a mass flow meter and a mass flow controller as a gas introduction mechanism. 7. The gas amount measuring device in a sealed battery according to claim 4, wherein the opening mechanism is a mechanism for mechanically piercing an exterior body of the sealed battery. 8. The gas amount measuring device in a sealed battery according to claim 4, wherein the pressure measuring device converts pressure into displacement or force by elastic deformation of the pressure detecting element. 9. A sealed battery, wherein the vacuum container of the gas amount measuring device according to claim 4 is connected to an analyzer for performing qualitative analysis and quantitative analysis of gas. Gas quantification system inside. 10. The system according to claim 9, wherein the analyzer is a gas chromatograph, a mass spectrometer, or a combination of a gas chromatograph and a mass spectrometer.