Inert liquid synthesis method and battery formation gas production measurement device and method

Abstract

The invention discloses an inert liquid synthesis method, which comprises the following steps: mixing N, N-dimethylformamide or N, N-dimethylacetamide and 1, 1, 2, 2, 3, 3, 4-heptafluorocyclopentane according to a molar ratio of 2: 1 to obtain a mixed solution; heating the mixed solution to a preset temperature, and stirring for 5-7 hours to obtain an inert liquid; wherein the temperature is raised to 160 DEG C if the mixed solution is N, N-dimethyl formamide and 1, 1, 2, 2, 3, 3, 4-heptafluorocyclopentane, and the temperature is raised to 170 DEG C if the mixed solution is N, N-dimethyl acetamide and 1, 1, 2, 2, 3, 3, 4-heptafluorocyclopentane. The invention also discloses a device and a method for collecting the inert liquid synthesized by using the inert liquid synthesis method and measuring gas produced by battery formation. According to the battery formation gas production measurement method, the inert liquid synthesized by the inert liquid synthesis method is used as a measurement medium, so that the battery formation gas production loss caused by reaction between the battery formation gas production and the medium or absorption of the battery formation gas production by the medium is avoided.

Description

Technical Field

[0001] The invention relates to the field of gas generation detection of soft-pack batteries, and specifically to a method for synthesizing an inert liquid and a device and method for measuring gas generation during battery formation. Background Art

[0002] Battery formation refers to the process of making a series of physical and chemical changes in the battery electrode materials through a specific charge and discharge procedure for a newly assembled battery (usually the first charge activation), so that the battery can achieve the expected performance. Its main purpose is to form a stable and effective solid electrolyte interface film (SEI film) on the surface of the positive and negative electrodes of the battery. This film plays a vital role in battery performance.

[0003] In the formation process, taking lithium-ion batteries as an example, when the battery is charged for the first time, lithium ions are deintercalated from the positive electrode material (such as lithium cobalt oxide, lithium iron phosphate, etc.) and migrate to the negative electrode (such as graphite) through the electrolyte. On the surface of the negative electrode, lithium ions react with the solvent, lithium salt and other components in the electrolyte to form an SEI film. This process is a complex electrochemical process involving redox reactions. For example, ethylene carbonate (a commonly used electrolyte solvent) may undergo a reduction reaction on the surface of the negative electrode to generate some organic lithium compounds, which gradually accumulate to form an SEI film. At the same time, the lithium ion formation process is accompanied by the generation of a large amount of gas, and the gas production volume is closely related to the electrochemical system, including the positive electrode, the negative electrode, the electrolyte composition, the formation conditions, etc.; the formation conditions such as (voltage, current, temperature, pressure, etc.) determine the quality and time of the formation. The analysis of the gas production and composition at each stage of the formation process is of great significance to shorten the production cycle, improve production efficiency and reduce costs. However, the existing battery formation gas production measurement device, such as CN201007766U disclosed on December 10, 2014, a battery formation gas production measurement system, uses organic solvents as the medium for measuring gas volume, but the battery formation gas contains many gases such as methane and chlorine that react with organic solvents or are soluble in organic solvent gases. If organic solvents are used as the medium, the amount of gas collected will be reduced, and the measured results will be inaccurate. In addition, the system determines the measurement results through the reading of the acid burette, and the naked eye reading is inevitably inaccurate, resulting in inaccurate measurement results. Summary of the invention

[0004] In order to overcome the defects in the prior art, the present invention provides a method for synthesizing an inert liquid and a battery formation gas production measurement device and method. The battery formation gas production measurement method uses the inert liquid synthesized by the inert liquid synthesis method as the measurement medium, avoiding the battery formation gas production reaction with the medium or the medium absorbing the battery formation gas production to cause the battery formation gas production loss, thereby ensuring the accuracy of the measurement result.

[0005] To achieve the above object, the technical solution adopted by the present invention is: an inert liquid synthesis method, comprising the following steps:

[0006] Mixing N,N-dimethylformamide and 1,1,2,2,3,3,4-heptafluorocyclopentane at a molar ratio of 2:1, or mixing N,N-dimethylacetamide and 1,1,2,2,3,3,4-heptafluorocyclopentane at a molar ratio of 2:1 to obtain a mixed solution;

[0007] The mixed solution is heated to a preset temperature and stirred for 5 h to 7 h to obtain an inert liquid;

[0008] Among them, if the mixed liquid is N,N-dimethylformamide and 1,1,2,2,3,3,4-heptafluorocyclopentane, the preset temperature is 160°C, and if the mixed liquid is N,N-dimethylacetamide and 1,1,2,2,3,3,4-heptafluorocyclopentane, the preset temperature is 170°C.

[0009] Furthermore, if the mixed liquid is N,N-dimethylformamide and 1,1,2,2,3,3,4-heptafluorocyclopentane, the preset temperature is 160°C, and if the mixed liquid is N,N-dimethylacetamide and 1,1,2,2,3,3,4-heptafluorocyclopentane, the preset temperature is 170°C.

[0010] Since 1,1,2,2,3,3,4-heptafluorocyclopentane as an organic solution will react chemically with methane, the present application adds N,N-dimethylformamide or N,N-dimethylacetamide to 1,1,2,2,3,3,4-heptafluorocyclopentane and heats it to a preset temperature and stirs it, so that the carbon-carbon bond of 1,1,2,2,3,3,4-heptafluorocyclopentane is broken and the ring is opened to generate cycloolefins of various groups, which have high stability and will not react with the gas produced by battery formation.

[0011] A battery formation gas production measurement device using the inert liquid synthesized by the above method, comprising:

[0012] a first container, wherein the inert liquid is disposed in the first container;

[0013] a second container, the second container being used to receive the inert liquid in the first container;

[0014] a first conduit connecting an inner cavity of the first container with an inner cavity of the battery;

[0015] a second conduit, the second conduit connecting the first container and the second container, and the first conduit extending into the inert liquid in the first container;

[0016] A weight sensor is used to measure the weight of the second container.

[0017] Through the above scheme, the inert liquid synthesized by the above inert liquid synthesis method is loaded into the first container as the measuring medium. When the battery formation gas is injected into the first container, it is ensured that the battery formation gas does not react with the medium, thereby avoiding the loss of the battery formation gas, thereby ensuring that the battery formation gas is completely collected in the first container, and at the same time ensuring the accuracy of the measured gas volume.

[0018] Furthermore, the first container includes a conical flask, the upper side of which is provided with a second cover body that can be opened and closed, the second cover body is provided with a through hole that matches the first conduit and the second conduit, the first conduit and the second conduit are inserted in the through hole, and the inner wall surface of the through hole is provided with a sealant. The first conduit is used for the gas generated by the battery formation to flow from the inner cavity of the battery to the first container. The entry pressure of the first container increases due to the lifting, and since the second conduit is inserted into the inert liquid, the liquid enters the second container along the second conduit under the action of pressure. The entire device is sealed by a sealing strip to prevent gas or liquid leakage.

[0019] Furthermore, it also includes a host computer, which is connected to the weight sensor and stores data of the weight sensor. The host computer can record in real time the volume of the inert liquid discharged from the first container due to the gas production pressure of the battery formation, and corresponds to the battery formation time.

[0020] Furthermore, a battery is included, wherein the battery has a first cover, the first cover is provided with a through hole matching the first conduit, the first conduit passes through the through hole of the first cover and is sealed by a sealant. The first conduit is directly connected to the battery to realize in-situ collection of the generated gas.

[0021] A method for measuring battery formation gas production, using the above-mentioned battery formation gas production measuring device to measure battery formation gas production, comprises the following steps:

[0022] The battery is formed to generate gas, and the gas enters the first container through the first conduit;

[0023] Under the action of gas pressure, the inert liquid in the first container flows into the second container along the second conduit;

[0024] The weight of the second container increases as the inert liquid enters, and the weight sensor detects the real-time weight of the second container and records it in the host computer;

[0025] The host computer calculates the volume of gas produced by the battery formation according to the formula V=m / ρ, where: V represents the gas volume, m represents the weight of the inert liquid entering the second container, and ρ represents the density of the inert liquid.

[0026] Furthermore, the host computer records the initial weight of the second container as m1, and the real-time weight of the second container as m t , the weight of the inert liquid in the second container is m=m t -m1, the volume of the inert liquid in the second container:

[0027] V=(m t -m1) / ρ

[0028] Wherein: t represents the time when the volume of gas produced by the battery is calculated, and the volume of gas is equal to the volume of the inert liquid in the second container.

[0029] Furthermore, the host computer calculates the volume of gas produced by battery formation every 0.1s to 1s.

[0030] Furthermore, the host computer stores the volume V of the gas produced by the battery formation and the corresponding time t in the test table. Through this method, the gas production of the battery formation can be recorded in real time, which is helpful for analyzing the electrochemical changes in the formation process in stages.

[0031] By means of the above technical solution, the beneficial effects of the present invention are as follows:

[0032] 1. In the present application, N,N-dimethylformamide or N,N-dimethylacetamide is added to 1,1,2,2,3,3,4-heptafluorocyclopentane, and the temperature is raised to a preset temperature, so that the carbon-carbon bond of 1,1,2,2,3,3,4-heptafluorocyclopentane is broken and the ring is opened to generate cycloolefins of various groups with high stability, so as to avoid the medium from reacting with the battery formation gas or absorbing the battery formation gas;

[0033] 2. The present application measures the weight of the inert liquid in the second container by a cheap gravity sensor, and calculates the volume of the battery formation gas production by the formula V=m / ρ. Compared with the prior art using expensive gas sensors, the battery formation gas production measurement device disclosed in the present application greatly reduces the cost;

[0034] 3. This application automatically calculates the volume of gas produced by battery formation through the host computer, and stores the volume V of gas produced by battery formation and the corresponding time t in the test table, which is convenient for subsequent analysis of gas composition.

[0035] In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 is a flow chart of the inert liquid synthesis method in an embodiment of the present invention;

[0038] Figure 2 is the reaction formula of 1,1,2,2,3,3,4-heptafluorocyclopentane in the embodiment of the present invention;

[0039] Figure 3 is a schematic structural diagram of a battery formation gas production measurement device according to an embodiment of the present invention;

[0040] Figure 4 It is a flow chart of a method for measuring gas production during battery formation in an embodiment of the present invention.

[0041] The figure numbers of the above drawings are: 1. conical flask; 2. inert liquid; 3. cover; 4. first conduit; 5. battery; 6. second conduit; 7. beaker; 8. weight sensor; 9. computer. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] It should be noted that, in the description of the present invention, the terms "first", "second", etc. are only used for descriptive purposes and to distinguish similar objects. There is no order of precedence between the two, and they cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0044] Combination Figure 1-4 As shown, in Example 1, a method for synthesizing an inert liquid is disclosed, comprising the following steps:

[0045] Add N,N-dimethylformamide and 1,1,2,2,3,3,4-heptafluorocyclopentane or N,N-dimethylacetamide and 1,1,2,2,3,3,4-heptafluorocyclopentane in a molar ratio of 2:1 into a 2000 ml stainless steel reactor, wherein the reactor is equipped with an electric heater and a stirring device;

[0046] If the mixed liquid is N,N-dimethylformamide and 1,1,2,2,3,3,4-heptafluorocyclopentane, the mixed liquid is heated to 160°C and stirred for 6 hours by the electric heater of the reactor. If the mixed liquid is N,N-dimethylacetamide and 1,1,2,2,3,3,4-heptafluorocyclopentane, the reactor is heated to 170°C and stirred for 6 hours. After the temperature is raised to the reaction temperature, under the action of N,N-dimethylformamide or N,N-dimethylacetamide, the carbon-carbon bond of the 1,1,2,2,3,3,4-heptafluorocyclopentane is broken and the ring is opened to generate cycloolefins of various different groups with stable structures. Its reaction structure is as follows Figure 2 In the reaction process, the dispersion of N,N-dimethylformamide or N,N-dimethylacetamide in 1,1,2,2,3,3,4-heptafluorocyclopentane can be accelerated without stirring, so as to improve the reaction efficiency and ensure the yield.

[0047] Among them, the reactor is a container for chemical reactions, also known as a reactor. It is usually a closed tank that can withstand a certain pressure and temperature. Its basic structure includes a kettle, a stirring device, a heat transfer device, a sealing device and various interfaces. The kettle is the main part of the reactor, generally made of stainless steel, glass, enamel and other materials, and its shape is diverse, the common ones are cylindrical, spherical, etc. Stainless steel reactors have good corrosion resistance and mechanical strength, and are suitable for a variety of chemical synthesis reactions. The stirring device is mainly used to mix the reaction materials evenly and promote the reaction. It usually includes a stirrer, a stirring shaft and a motor. The function of the heat transfer device is to control the reaction temperature and make the reaction proceed within a suitable temperature range by heating or cooling. The sealing device is used to prevent the reaction materials from leaking and ensure the sealing of the reactor. The reactor also has various interfaces, such as feed port, discharge port, thermometer interface, pressure gauge interface, vent, etc., which are used for material entry and exit, parameter monitoring and safety measures.

[0048] Embodiment 2 discloses a battery formation gas production measurement device, comprising:

[0049] A conical flask 1 is provided with an inert liquid 2 synthesized by the above method. An openable cover 3 is provided at the upper end of the conical flask 1. The cover 3 is provided with two through holes for connecting the inner cavity of the conical flask 1 with the outside.

[0050] A first conduit 4 is inserted into one of the through holes. The first conduit 4 is inserted into the conical flask 1, and a port of the first conduit 4 is located above the liquid level of the inert liquid 2. One end of the first conduit 4 facing away from the conical flask 1 is connected to the inner cavity of the battery 5 to transport the gas generated by the battery 5 into the conical flask 1.

[0051] A second conduit 6 is inserted into the other through hole, and the second conduit 6 is inserted into the conical flask 1, and the port of the second conduit 6 is inserted below the liquid surface of the inert liquid 2. When the battery 5 is formed and the gas enters the conical flask 1 through the first conduit 4, the pressure in the conical flask 1 increases, and the inert liquid 2 in the conical flask 1 flows out of the conical flask 1 from the second conduit 6 under the action of pressure.

[0052] The end of the second conduit 6 facing away from the conical flask 1 is inserted into the beaker 7, and the inert liquid 2 flowing out of the second conduit 6 flows into the beaker 7. The beaker 7 is connected to a weight sensor 8, and the weight sensor 8 is used to detect the weight of the beaker 7 in real time.

[0053] The connection between the first conduit 4 and the through hole of the conical flask 1 and the battery 5 is sealed with epoxy resin AB glue, and the connection between the second conduit 6 and the through hole of the conical flask 1 is sealed with epoxy resin AB glue.

[0054] The weight sensor 8 is connected to a computer 9, and the computer records the weight m measured by the weight sensor 8. t , and record it and the corresponding time t in the test table.

[0055] Through the above scheme, the inert liquid synthesized by the inert liquid synthesis method disclosed in Example 1 is loaded into the conical flask 1 as the measuring medium. When the battery formation gas is injected into the conical flask 1, since the inert liquid is a cyclic olefin of various groups with a stable structure, it is ensured that the battery formation gas will not react with the medium, and the battery formation gas is avoided from being lost, thereby ensuring that the battery formation gas is completely collected in the first container, and at the same time ensuring the accuracy of the measured gas volume.

[0056] Optionally, the battery 5 can be customized, and the battery 5 has a first cover body, and the first cover body is provided with a through hole matching the first conduit 4, and the first conduit 4 passes through the through hole of the first cover body and is sealed by epoxy resin AB glue. This solution directly connects the first conduit 4 to the inner cavity of the battery 5 to realize in-situ collection of the gas produced by the formation. Compared with the traditional solution of first collecting the gas produced by the battery formation in other intermediate containers and then connecting the first conduit 4 through the intermediate container, the multiple transmission of gas increases the risk of leakage.

[0057] The following experiments verify that the inert liquid disclosed in this application will not react with or absorb the gas produced by battery formation:

[0058] Experiment 1:

[0059] Take 1000 ml of inert liquid and transfer it into a sealed container and evacuate it;

[0060] Maintain the temperature in the sealed container at 25°C;

[0061] Take 200 ml of battery gas and measure the gas content M1 by GC-MS;

[0062] Inject 200ml of battery gas into a sealed container and let it stand for 1 hour;

[0063] The gas content M2 of the gas generated by battery formation in 200 ml of the sealed container was measured again by GC-MS.

[0064] Experiment 2:

[0065] Take 500 ml of inert liquid and transfer it into a sealed container and evacuate it;

[0066] Maintain the temperature in the sealed container at 300°C;

[0067] Take 200 ml of battery gas and measure the gas content M3 by GC-MS;

[0068] Inject 200ml of battery gas into a sealed container and let it stand for 1 hour;

[0069] The gas content M4 of the gas generated by battery formation in 200 ml of the sealed container was measured again by GC-MS.

[0070] In the test results, the gas contents in M1 and M2 are the same, and the gas contents in M3 and M4 are the same. Experiments 1 and 2 prove that the inert liquid disclosed in the present application will not react with or absorb the gas produced by the battery formation.

[0071] The commonly used media in the prior art include silicone oil or organic solvents. It is known that the gas produced by battery formation contains at least methane, chlorine and other gases. Silicone oil itself will react with chlorine, resulting in the consumption of battery formation gas, affecting the measurement accuracy, and silicone oil will also react with oxygen to produce explosions under high temperature conditions. Organic solvents are easy to decompose in high temperature environments, and the decomposition produces gases that will interfere with the measurement results of battery formation gas production. Therefore, the battery formation gas production measurement device disclosed in this application uses an inert liquid with a stable structure as the measurement medium to avoid the reaction between the medium and the battery formation gas production, thereby ensuring accurate measurement results.

[0072] Among them, GC-MS, or gas-mass spectrometry, is a combination of gas chromatography and mass spectrometry, and is one of the most powerful tools for separating and detecting complex compounds.

[0073] Gas chromatography has a strong separation ability, but its qualitative ability for unknown compounds is relatively poor; mass spectrometry has a unique identification ability for unknown compounds and is extremely sensitive, but it requires that the detected components are generally pure compounds. Combining gas chromatography with mass spectrometry, i.e., gas-mass spectrometry, can complement each other's strengths and avoid weaknesses. It not only makes up for the shortcoming that gas chromatography is difficult to make reliable qualitative identification of unknown components in complex compounds based on retention time alone, but also utilizes the highly sensitive mass spectrometer as a detector.

[0074] The principle of GC-MS is: the mixture sample is separated by the chromatographic column and then enters the ion source of the mass spectrometer. It is ionized into ions in the ion source. After passing through the mass analyzer and detector, the ions become mass spectrometry signals and are input into the computer. The sample continuously flows into the ion source from the chromatographic column, and the ions continuously enter the analyzer from the ion source and continuously obtain the mass spectrum. As long as the mass range and scanning time of the analyzer are set, the computer can collect mass spectra one by one. The computer can automatically add up all the ion intensities of each mass spectrum and display the total ion intensity. The curve of the total ion intensity changing with time is the total ion chromatogram. The shape of the total ion chromatogram is consistent with the ordinary chromatogram, which can be considered as a chromatogram obtained by using the mass spectrometer as a detector.

[0075] Embodiment 3 discloses a method for measuring battery formation gas production, using the above-mentioned battery formation gas production measuring device to measure battery formation gas production, including the following steps:

[0076] Before the battery 5 is formed, the various devices are connected according to the battery formation gas production measurement device disclosed in the second embodiment;

[0077] The battery 5 undergoes a formation process, and the gas generated during the formation directly enters the conical flask 1 from the first conduit 4. Under the effect of the gas pressure, the inert liquid 2 in the conical flask 1 enters the beaker 7 along the second conduit 6;

[0078] The weight of the beaker 7 increases as the inert liquid 2 enters, and the weight sensor 8 detects the real-time weight of the beaker 7 and records it in the computer 9 .

[0079] The computer 9 records the initial weight of the beaker 7 as m1, and the real-time weight of the beaker 7 as m t , the weight of the inert liquid in the beaker 7 is m=m t -m1, substitute the volume formula V = m / ρ to get:

[0080] V=(m t -m1) / ρ

[0081] Wherein: V represents the gas volume, m represents the weight of the inert liquid entering the beaker 7, ρ represents the density of the inert liquid, and t represents the time for calculating the volume of gas produced by battery formation.

[0082] The computer 9 calculates the volume V of gas produced by the battery every 0.1 second, and stores the volume V of gas produced by the battery and the corresponding time t in the test table.

[0083] The present invention uses specific embodiments to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A method for synthesizing an inert liquid, characterized in that: The following steps are involved: Mixing N,N-dimethylformamide and 1,1,2,2,3,3,4-heptafluorocyclopentane at a molar ratio of 2:1, or mixing N,N-dimethylacetamide and 1,1,2,2,3,3,4-heptafluorocyclopentane at a molar ratio of 2:1 to obtain a mixed solution; The mixed solution is heated to a preset temperature and stirred for 5 h to 7 h to obtain an inert liquid; Among them, if the mixed liquid is N,N-dimethylformamide and 1,1,2,2,3,3,4-heptafluorocyclopentane, the preset temperature is 150℃~170℃; if the mixed liquid is N,N-dimethylacetamide and 1,1,2,2,3,3,4-heptafluorocyclopentane, the preset temperature is 160℃~180℃.

2. The method for synthesizing an inert liquid according to claim 1, characterized in that: If the mixed liquid is N,N-dimethylformamide and 1,1,2,2,3,3,4-heptafluorocyclopentane, the preset temperature is 160°C. If the mixed liquid is N,N-dimethylacetamide and 1,1,2,2,3,3,4-heptafluorocyclopentane, the preset temperature is 170°C.

3. A battery formation gas production measuring device using an inert liquid synthesized by any of the methods of claims 1-2, characterized in that: include: a first container, wherein the inert liquid is disposed in the first container; a second container, the second container being used to receive the inert liquid in the first container; a first conduit connecting an inner cavity of the first container with an inner cavity of the battery; a second conduit, the second conduit connecting the first container and the second container, and the first conduit extending into the inert liquid in the first container; A weight sensor is used to measure the weight of the second container.

4. The battery formation gas generation measuring device according to claim 3, characterized in that: It also includes a host computer, which is connected to the weight sensor and stores data of the weight sensor.

5. The battery formation gas generation measuring device according to claim 4, characterized in that: It also includes a battery, wherein the battery has a first cover body, the first cover body is provided with a through hole matching the first conduit, and a sealant is provided on the wall surface of the through hole.

6. The battery formation gas generation measuring device according to claim 3, characterized in that: The first container comprises a conical flask, an upper side of which is provided with an openable and closable second cover, the second cover is provided with a through hole matching the first conduit and the second conduit, the first conduit and the second conduit are inserted into the through hole, and a sealant is provided on the wall surface forming the through hole.

7. A method for measuring battery formation gas production, using the battery formation gas production measuring device according to any one of claims 3 to 6 to measure battery formation gas production, characterized in that: The following steps are involved: The battery is formed and produces gas, and the gas enters the first container through the first conduit. Under the effect of the gas pressure, the inert liquid in the first container enters the second container along the second conduit, and the weight of the second container increases with the entry of the inert liquid; The weight sensor detects and records the real-time weight of the second container; The volume of gas produced by battery formation is calculated according to the formula V=m / ρ, where: V represents the gas volume, m represents the weight of the inert liquid entering the second container, and ρ represents the density of the inert liquid.

8. The battery formation gas generation measurement method according to claim 7, characterized in that: The host computer records the initial weight of the second container as m1, and the real-time weight of the second container as m t , the weight of the inert liquid in the second container is m=m t -m1, the volume of the inert liquid in the second container: V=(m t -m1) / p Wherein: t represents the time when the volume of gas produced by the battery is calculated, and the volume of gas is equal to the volume of the inert liquid in the second container.

9. The battery formation gas generation measurement method according to claim 8, characterized in that: The host computer calculates the volume of gas produced by battery formation every 0.1s to 1s.

10. The battery formation gas generation measurement method according to claim 9, characterized in that: The host computer stores the volume V of gas produced by the battery and the corresponding time t in the test table.

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