Measuring device for gas production of battery cell

Abstract

The utility model relates to the technical field of batteries, and provides a measuring device for gas production of a battery cell. The device for measuring the gas produced by the battery comprises a gas guide pipe, a first flow meter, a second flow meter and a gas source, the gas guide pipe comprises a first pipe body and a second pipe body, the first pipe body comprises a gas inlet section, a middle section and a gas outlet section which are arranged in sequence, the gas inlet section and the gas outlet section are equal in pipe diameter, one end of the second pipe body is communicated with the middle section, and the other end is communicated with the interior of the battery cell; the first flow meter is arranged on the gas inlet section to measure the gas flow in the gas inlet section; the second flow meter is arranged on the gas outlet section to measure the gas flow in the gas outlet section; and the gas source is communicated with the gas inlet section and outputs gas with constant flow. After the measurement data of the first flowmeter and the second flowmeter are calculated, the gas production rate and the gas production rate of the battery cell can be obtained in real time, the gas production condition of the battery cell can be monitored and detected for a long period, and the precision of the data obtained by the measurement device is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a measuring device for gas generation in a battery cell. Background Technology

[0002] During battery production and use, the gas generation characteristics of the battery cell are key indicators characterizing the electrochemical reaction process and failure mechanism within the cell. Currently, the commonly used offline gas collection detection method collects the gas generated during cell cycling using an external, sealed gas collection device, and calculates the average gas generation rate based on the ratio of the accumulated gas volume to the test time.

[0003] However, the capacity of the gas collection device in this detection method is limited. When the gas production of the battery cell reaches the capacity threshold of the gas collection device, the test must be interrupted for manual venting or gas cylinder replacement, which disrupts the continuity of the detection. Furthermore, the gas collection device can only perform gas volume calculation after the collection cycle is over, making it impossible for the existing detection method to obtain the gas production and gas production rate of the battery cell in real time. It is also difficult to achieve long-term detection during the gas production process of the battery cell, making it difficult for the obtained data to accurately reflect the reaction and failure principle inside the battery cell, thus affecting the research on the electrochemical reaction process and failure mechanism inside the battery cell. Utility Model Content

[0004] In order to solve the above-mentioned technical problems, or at least partially solve the above-mentioned technical problems, this application provides a measuring device for gas generation in battery cells.

[0005] This application provides a measuring device for gas generation in battery cells, comprising:

[0006] The air duct includes a first tube body and a second tube body. The first tube body includes an air inlet section, a middle section and an air outlet section arranged in sequence. The diameters of the air inlet section and the air outlet section are equal. One end of the second tube body is connected to the middle section, and the other end is used to connect to the inside of the battery cell.

[0007] A first flow meter is installed in the intake section to measure the gas flow rate within the intake section;

[0008] A second flow meter is installed in the outlet section to measure the gas flow rate within the outlet section;

[0009] The gas source is connected to the air intake section and outputs a constant flow rate of gas.

[0010] Optionally, the diameter of the intermediate section is smaller than the diameter of the air inlet section and the air outlet section, and the pipe wall between the intermediate section and the air inlet section is smoothly transitioned, as is the pipe wall between the intermediate section and the air outlet section.

[0011] Optionally, the air inlet section is equipped with a control valve, which is located upstream of the first flow meter, and the control valve can control the flow rate of the gas flowing into the intermediate section.

[0012] Optionally, a barometer is provided on the second tube to measure the air pressure in the second tube.

[0013] Optionally, a sealing ring is fitted at the end of the second tube away from the first tube, the second tube is used to insert into the liquid injection port of the battery cell, and the sealing ring is used to seal the gap between the second tube and the liquid injection port.

[0014] Optionally, the gas generation measuring device of the battery cell further includes two pressure plates and a connector. The two pressure plates are used to clamp and fix the battery cell, and the two pressure plates are connected by the connector.

[0015] Optionally, a dryer is connected to the port of the air intake section away from the middle section, and the air source is connected to the air intake section through the dryer.

[0016] Optionally, the gas outlet section is connected to a gas analyzer to analyze the composition of the gas discharged from the gas outlet section.

[0017] Optionally, the diameter of the second tube is less than or equal to the length of the intermediate section.

[0018] Optionally, the gas production measurement device of the battery cell further includes an analysis module, which is electrically connected to the first flow meter and the second flow meter and is configured to collect the measurement data and measurement duration of the first flow meter and the second flow meter, and calculate the gas production amount and / or gas production rate of the battery cell based on the difference between the measurement data of the second flow meter and the first flow meter and the measurement duration.

[0019] The technical solution provided in this application has the following advantages compared with the prior art:

[0020] The battery cell gas generation measuring device provided in this application delivers a constant flow of gas into the first tube via a gas source, creating a negative pressure environment in the second tube where it connects to the first tube, where the pressure is lower than atmospheric pressure. When the battery cell is not generating gas, the difference between the measurements of the first and second flow meters is zero. When the battery cell generates gas, the generated gas enters the intermediate section under pressure and exits the first tube through the outlet section, increasing the measurement value of the second flow meter. By calculating the difference between the measurements of the second and first flow meters, the flow rate of gas generated by the battery cell can be obtained in real time. Calculations based on the flow rate of gas generated by the battery cell provide the real-time acquisition of the gas generation amount and rate. The gas output from the gas source passes through the first tube and is discharged into the external environment without the need for a gas collection device. As long as the gas source continues to supply gas, the gas generated by the battery cell can be continuously carried out by the incoming gas, allowing the measuring device to continuously monitor the gas generation of the battery cell for extended periods. By cooperating with the gas source, gas guide pipe, first flow meter, and second flow meter, the gas production volume and rate of the battery cell can be obtained in real time based on the measurement data of the first and second flow meters. Furthermore, it is possible to monitor and detect the gas production of the battery cell over a long period of time, thereby improving the accuracy of the data obtained by the measuring device. Using the measuring device to detect the gas production of the battery cell can accurately reflect the reaction and failure principle within the battery cell. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of the measuring device for cell gas generation described in the embodiments of this application;

[0024] Figure 2 This is one of the schematic diagrams of the battery cell gas generation measuring device described in the embodiments of this application detecting the battery cell gas generation status;

[0025] Figure 3 This is a second schematic diagram of the battery cell gas generation measuring device described in the embodiments of this application detecting the battery cell gas generation status;

[0026] Figure 4 This is a partial schematic diagram of the battery cell gas generation measuring device described in the embodiments of this application detecting the battery cell gas generation status;

[0027] Figure 5This is an exploded view of the pressure plate and a battery cell described in an embodiment of this application;

[0028] Figure 6 This is an exploded view of the pressure plate and another type of battery cell described in the embodiments of this application.

[0029] The components are as follows: 1. First pipe body; 11. Inlet section; 12. Intermediate section; 13. Outlet section; 14. Dryer; 2. Second pipe body; 21. Sealing ring; 22. Barometer; 3. First flow meter; 4. Second flow meter; 5. Air source; 6. Battery cell; 61. Liquid injection port; 71. Pressure plate; 72. Connecting parts. Detailed Implementation

[0030] To better understand the above-mentioned objectives, features, and advantages of this application, the solution of this application will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0031] Many specific details are set forth in the following description in order to provide a full understanding of this application, but this application may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of this application, and not all embodiments.

[0032] Reference Figures 1 to 6 As shown, this application embodiment provides a measuring device for gas generation in a battery cell, including a gas guide pipe, a first flow meter 3, a second flow meter 4, and a gas source 5; the gas guide pipe includes a first pipe body 1 and a second pipe body 2, the first pipe body 1 including an inlet section 11, a middle section 12, and an outlet section 13 arranged in sequence, the inlet section 11 and the outlet section 13 have the same diameter, one end of the second pipe body 2 is connected to the middle section 12, and the other end is used to connect to the inside of the battery cell 6; the first flow meter 3 is set in the inlet section 11 to measure the gas flow rate in the inlet section 11; the second flow meter 4 is set in the outlet section 13 to measure the gas flow rate in the outlet section 13; the gas source 5 is connected to the inlet section 11 and outputs a constant flow rate of gas.

[0033] Specifically, the first tube 1 can be a hollow straight tube or a hollow curved tube, as long as the shape of the first tube 1 does not obstruct the passage of gas. Both ends of the first tube 1 have openings. The inlet section 11, the middle section 12, and the outlet section 13 are three regions on the first tube 1, and these sections are arranged sequentially along the axial direction of the first tube 1. One end of the second tube 2 is connected to the middle section 12, and the other end can be used to pierce the outer shell of the battery cell 6 to enter the interior of the battery cell 6, allowing the gas generated by the battery cell 6 to enter the first tube 1 through the second tube 2. Alternatively, the size of the second tube 2 can be the same as the size of the liquid injection port 61 of the battery cell 6, allowing the second tube 2 to be inserted into the liquid injection port 61, enabling the gas generated by the battery cell 6 to enter the second tube 2 through the liquid injection port 61.

[0034] The first tube 1 mentioned above is a plastic tube or a metal tube, which gives the first tube 1 a certain structural strength and makes it less prone to deformation. This avoids the first tube 1 from deforming and changing the diameter of the air inlet section 11 or the air outlet section 13, thus affecting the accuracy of the measurement data of the first flow meter 3 or the second flow meter 4.

[0035] The second tube 2 mentioned above can be a flexible tube to facilitate communication between the second tube 2 and the inside of the battery cell 6. The second tube 2 is used to introduce the gas inside the battery cell 6 into the first tube 1.

[0036] The gas source 5 mentioned above can be a fan or a compressor. The gas source 5 can deliver gas into the first pipe body 1 through the inlet section 11. The gas flow rate delivered by the gas source 5 is constant, that is, the volume of gas delivered per unit time is fixed. The gas will pass through the inlet section 11, the middle section 12 and the outlet section 13 in sequence along the length direction of the first pipe body 1 and be discharged from the first pipe body 1.

[0037] When the gas flows in the intermediate section 12, according to Bernoulli's principle, the greater the flow velocity, the lower the pressure. This makes the pressure at the end of the second tube 2 connected to the intermediate section 12 less than atmospheric pressure. The pressure causes the gas inside the battery cell 6 when it is not working to enter the first tube 1 along with the gas in the second tube 2. After the gas source 5 supplies gas for a certain period of time, the battery cell 6 and the second tube 2 are in a negative pressure state. At this time, the gas generated by the battery cell 6 when it is working will enter the intermediate section 12 through the second tube 2 under the action of gas pressure, and then be discharged from the first tube 1 through the gas outlet section 13.

[0038] Volumetric flow rate is the volume of fluid passing through a cross-section per unit time, often simply called flow rate, denoted by Q. The formula for calculating the volumetric flow rate of a gas is: Q = A * V, where Q represents the gas flow rate, in standard volumetric flow rate (e.g., cubic meters per hour); A represents the cross-sectional area of ​​the gas flow path, in square meters; and V represents the gas velocity, in linear velocity (e.g., meters per second).

[0039] Therefore, the flow rate measured by the first flow meter 3 is the volume of gas passing through the cross-section of the inlet section 11 per unit time, and the flow rate measured by the second flow meter 4 is the volume of gas passing through the cross-section of the outlet section 13 per unit time. The gas source 5 can output gas at a constant flow rate, that is, the volume of gas output by the gas source 5 per unit time is fixed. The gas output by the gas source 5 enters the inlet section 11 and is discharged through the outlet section 13.

[0040] Gas source 5 delivers gas at a constant flow rate. The volume of gas delivered by gas source 5 per unit time is constant. When cell 6 is not producing gas, the volumes of gas passing through inlet section 11 and outlet section 13 per unit time are equal, therefore the volumetric flow rates of gas discharged from inlet section 11 and outlet section 13 are equal. When the first tube 1 is a straight or curved tube, when cell 6 is not producing gas, the volumes of gas passing through inlet section 11 and outlet section 13 per unit time are equal, that is, the gas flow rates of inlet section 11 and outlet section 13 are equal.

[0041] When cell 6 produces gas, the gas enters the intermediate section 12 through the second tube 2 and is then discharged through the outlet section 13. This means the volume of gas passing through the outlet section 13 per unit time is greater than the volume of gas passing through the inlet section 11, resulting in a gas flow rate in the outlet section 13 greater than that in the inlet section 11. When cell 6 produces gas, the measurement value of the second flow meter 4 is greater than the measurement value of the first flow meter 3, facilitating researchers in confirming the start time of gas production by cell 6. The initial volume is the volume of gas supplied by the gas source 5 per unit time, and the volume of gas discharged from the outlet section 13 is the sum of the initial volume and the volume of gas produced by cell 6.

[0042] The formula for calculating the gas velocity inside a pipeline is: Velocity = V` / (T * S). Where V` represents the volume of compressed air discharged per unit time T, and S represents the cross-sectional area of ​​the pipeline.

[0043] Applying the formulas for calculating gas velocity in a pipe and for gas volumetric flow rate to the measuring device of this application, with A and S values ​​equal, substituting the two formulas yields:

[0044] Q`=(V2`-V1`) / T

[0045] Where Q` is the flow rate of gas produced by cell 6, V2` is the total gas volume passing through the outlet section 13 per unit time, and V1` is the gas volume passing through the inlet section 11 per unit time; while the volume of gas passing through the cross section per unit time is V` = QT, the volume of gas passing through the outlet section 13 per unit time is V2` = Q2*T, the volume of gas passing through the inlet section 11 per unit time is V1` = Q1*T, Q1 is the measured value of the first flow meter 3, and Q2 is the measured value of the second flow meter 4.

[0046] Substituting this into Q`=(V2`-V1`) / T, we can calculate Q`=Q2-Q1, which is the difference between the measured values ​​of the second flow meter 4 and the first flow meter 3, representing the flow rate of the gas generated by the battery cell 6.

[0047] A graph is plotted with the measurement time of the testing device as the horizontal axis and the difference between the measured values ​​of the second flow meter 4 and the first flow meter 3 as the vertical axis. The lines formed by connecting multiple points in the graph can represent the relationship between the difference between the measured values ​​of the second flow meter 4 and the first flow meter 3 and time. The distance between the points on the lines in the graph and the horizontal axis representing time is the gas production flow rate of the battery cell 6. The distance between the points on the lines in the graph and the vertical axis representing the difference between the measured values ​​of the second flow meter 4 and the first flow meter 3 is the measurement time of the battery cell 6.

[0048] When cell 6 does not produce gas, the difference between Q2 and Q1 is 0, and the distance between the point on the line in the figure and the horizontal axis representing time is 0. When cell 6 produces gas, the difference between Q2 and Q1 is greater than 0, and the distance between the line in the figure and the horizontal axis representing time is greater than 0. According to the volume of gas passing through the cross-section V` = QT per unit time, the area enclosed by the line in the figure and the horizontal axis representing time can be obtained, which is the gas production volume of cell 6 in the time period corresponding to the line.

[0049] When calculating the gas production volume of cell 6, the initial time is taken as the moment when the difference between Q2 and Q1 is greater than 0, and the ending time is taken as the moment when the difference between Q2 and Q1 returns to 0. The time between the ending time and the initial time is the gas production time. The total gas production of cell 6 can be obtained by calculating the area between the line corresponding to the gas production time in the graph obtained by calculus and the horizontal axis representing time. Within the gas production time, a time interval is selected as the calculation interval. The area between the line corresponding to this time interval in the graph obtained by calculus and the horizontal axis representing time is calculated to obtain the gas production of cell 6 within the calculation interval. Thus, the gas production of cell 6 can be obtained through calculation.

[0050] When calculating the gas production rate of cell 6, according to Q=A*V, we can obtain V=Q / A, which means dividing the difference between the measured values ​​of the second flow meter 4 and the first flow meter 3 at the selected time by the area of ​​the cross-section of the gas outlet section 13, thus obtaining the gas production rate of cell 6 at the selected time. Therefore, the gas production rate of cell 6 can be obtained in real time through calculation.

[0051] In specific use, the battery cell gas production measuring device provided in this application embodiment connects the second tube 2 to the battery cell 6. A gas source 5 continuously supplies a constant flow rate of gas into the first tube 1. The first flow meter 3 and the second flow meter 4 respectively detect the gas flow rates in the inlet section 11 and the outlet section 13. When the battery cell 6 does not produce gas, the difference between the measured values ​​of the second flow meter 4 and the first flow meter 3 is 0. When the battery cell 6 produces gas, a graph is plotted with the difference between the measured values ​​of the second flow meter 4 and the first flow meter 3 as the vertical axis and the measurement time as the horizontal axis. Calculus is used to calculate the gas production volume of the battery cell 6 within the selected time period, and the gas production rate of the battery cell 6 at the selected time is calculated using the cross-sectional area of ​​the outlet section 13.

[0052] The gas generation measuring device for battery cells provided in this application delivers a constant flow of gas into the first tube 1 via a gas source 5, causing the pressure at the connection point between the second tube 2 and the first tube 1 to be less than atmospheric pressure, thus creating a negative pressure environment in the second tube 2. When the battery cell 6 is not generating gas, the difference between the measurement data of the first flowmeter 3 and the second flowmeter 4 is zero. When the battery cell 6 generates gas, the generated gas enters the intermediate section 12 under pressure and exits the first tube 1 through the outlet section 13, increasing the measurement value of the second flowmeter 4. By calculating the difference between the measurement values ​​of the second flowmeter 4 and the first flowmeter 3, the flow rate of gas generated by the battery cell 6 can be obtained in real time. Calculations based on the flow rate of gas generated by the battery cell 6 provide the real-time measurement of the gas generation amount and rate of the battery cell 6. The gas output from the gas source 5 passes through the first tube 1 and is discharged into the external environment without the need for a gas collection device. As long as the gas source 5 continuously delivers gas, the gas generated by the battery cell 6 can be continuously carried out by the incoming gas, allowing the measuring device to continuously monitor the gas generation status of the battery cell 6 for a long time. By cooperating with the gas source 5, the gas guide pipe, the first flow meter 3, and the second flow meter 4, the gas production volume and gas production rate of the battery cell can be obtained in real time based on the measurement data of the first flow meter 3 and the second flow meter 4. Furthermore, it is possible to monitor and detect the gas production of the battery cell 6 over a long period of time, thereby improving the accuracy of the data obtained by the measuring device. Using the measuring device to detect the gas production of the battery cell 6 can accurately reflect the reaction and failure principle within the battery cell 6.

[0053] Reference Figures 1 to 4 As shown, in some embodiments, the diameter of the intermediate section 12 is smaller than the diameter of the air inlet section 11 and the air outlet section 13, and the pipe wall between the intermediate section 12 and the air inlet section 11 is smoothly transitioned, as is the pipe wall between the intermediate section 12 and the air outlet section 13.

[0054] With this configuration, the gas will flow faster when passing through the intermediate section 12, increasing the pressure difference between the gas pressure in the second tube 2 and the atmospheric pressure, thereby improving the extraction effect of the second tube 2 on the gas inside the battery cell 6.

[0055] Specifically, the diameter of the intermediate section 12 is smaller than that of the inlet section 11 and the outlet section 13, making the first tube 1 a tube with a smaller intermediate diameter. When gas flows through the intermediate section 12, the cross-sectional area of ​​the intermediate section 12 decreases. With the flow rate remaining constant, the gas velocity increases, making the gas flow velocity in the intermediate section 12 greater than that in the inlet section 11 and the outlet section 13. Within the tube, the greater the gas flow velocity, the lower the pressure. The higher gas flow velocity in the intermediate section 12 increases the pressure difference between the gas pressure in the second tube 2 and atmospheric pressure, thus improving the effectiveness of the second tube 2 in extracting gas from the inside of the battery cell 6.

[0056] The smooth transition of the pipe wall between the intermediate section 12 and the intake section 11 allows gas to flow smoothly from the intake section 11 into the intermediate section 12, avoiding the generation of eddies; the smooth transition of the pipe wall between the intermediate section 12 and the exhaust section 13 allows gas to flow smoothly from the intermediate section 12 into the exhaust section 13, avoiding the generation of eddies.

[0057] Reference Figures 1 to 4 As shown, in some embodiments, the intake section 11 is equipped with a control valve, which is located upstream of the first flow meter 3. The control valve can control the flow rate of gas flowing into the intermediate section 12. With this configuration, the flow rate of gas flowing through the intake section 11 can be controlled by the control valve, making it convenient for the user to adjust the gas flow rate between the first flow meter 3 and the second flow meter 4.

[0058] Specifically, the control valve can be positioned between the first flow meter 3 and the end of the inlet section 11 furthest from the intermediate section 12, allowing gas to pass through the control valve before entering the intermediate section 12. The control valve can be equipped with a baffle plate that can rotate within the inlet section 11. When the baffle plate completely blocks the space inside the inlet section 11, gas cannot pass through the control valve. When the baffle plate rotates and creates a gap between itself and the inner wall of the control valve, gas can flow through the gap. The size of the gap is controlled by adjusting the rotation angle of the baffle plate. A smaller gap results in a greater resistance coefficient for gas flow, reducing the gas flow rate under the same pressure differential. By adjusting the opening of the control valve, the gas flow rate can be controlled.

[0059] The control valve described above can be installed on the first flow meter 3, with the control valve located on the side of the first flow meter 3 near the gas source 5 at the detection end.

[0060] Reference Figures 1 to 4 As shown, in some embodiments, a barometer 22 is provided on the second tube 2 to measure the gas pressure in the second tube 2. This configuration allows the barometer 22 to monitor the pressure changes in the second tube 2 in real time. When the pressure in the second tube 2 begins to rise, it indicates that the battery cell 6 has begun to produce gas, assisting researchers in confirming the time when the battery cell 6 begins to produce gas.

[0061] Specifically, the detection end of the barometer 22 is connected to the second tube 2, enabling the barometer 22 to detect the air pressure in the second tube 2. When the gas source 5 continuously outputs gas, and the battery cell 6 does not generate gas, the air pressure in the second tube 2 is lower than the atmospheric pressure, and the difference between the air pressure in the second tube 2 and the atmospheric pressure remains stable, and the value measured by the barometer 22 also remains stable. When the battery cell 6 generates gas, the gas passes through the second tube 2, causing the air pressure in the second tube 2 to rise, thus reducing the difference between the second tube 2 and the atmospheric pressure, and the value measured by the barometer 22 to rise.

[0062] Reference Figures 1 to 4 As shown, in some embodiments, a sealing ring 21 is fitted at the end of the second tube 2 away from the first tube 1. The second tube 2 is used to insert into the liquid injection port 61 of the battery cell 6, and the sealing ring 21 is used to seal the gap between the second tube 2 and the liquid injection port 61.

[0063] With this configuration, the second tube 2 can communicate with the inside of the battery cell 6 through the liquid injection port 61 of the battery cell 6 itself, avoiding the need to puncture the outer shell of the battery cell 6 when the second tube 2 communicates with the battery cell 6; the sealing ring 21 can ensure the sealing between the second tube 2 and the liquid injection port 61, and prevent air leakage at the connection between the second tube 2 and the battery cell 6, which would affect the accuracy of the measurement data.

[0064] Specifically, when the battery is working, the cell 6 may generate gas due to electrolyte decomposition, side reactions of electrode materials, and overcharging or over-discharging. The generated gas exists inside the cell 6. During the manufacturing process, electrolyte is injected into the cell 6 through the injection port 61. It is possible to temporarily seal the injection port 61 after injecting electrolyte into the cell 6 so that the second tube 2 can be inserted into the injection port 61.

[0065] The diameter of the second tube 2 matches the diameter of the injection port 61, allowing the second tube 2 to be inserted into the injection port 61. The sealing ring 21 fills the gap between the wall of the second tube 2 and the inner wall of the injection port 61, ensuring a sealed connection between the second tube 2 and the injection port 61. This guarantees that all gas generated inside the battery cell 6 can enter the first tube 1 through the second tube 2. The sealing ring 21 can be a rubber ring or a soft rubber ring. After the second tube 2 is inserted into the injection port 61, the inner wall of the sealing ring 21 tightly abuts against the outer surface of the second tube 2 for a sealed connection, and the outer wall of the sealing ring 21 tightly abuts against the inner wall of the injection port 61 for a sealed connection.

[0066] Reference Figures 2 to 6 As shown, in some embodiments, the gas-generating measuring device for the battery cell further includes two pressure plates 71 and a connector 72. The two pressure plates 71 are used to clamp and fix the battery cell 6, and the two pressure plates 71 are connected by the connector 72. With this configuration, the two pressure plates 71 can compress the battery cell 6, assisting the gas inside the battery cell 6 to enter the second tube 2.

[0067] Specifically, the connector 72 can be selected as multiple bolts and nuts, and the two pressure plates 71 can both be planar plates. The two pressure plates 71 are parallel to each other and attached to the opposite sides of the battery cell 6. Multiple through holes can be provided on the pressure plates 71. Two opposite through holes on the two pressure plates 71 form a mounting group. Bolts are inserted into the two through holes in each mounting group, and nuts are installed on the bolts. Tightening the nuts causes the two pressure plates 71 to move closer to each other, so that the two pressure plates 71 abut against the sides of the battery cell 6. The two pressure plates 71 clamp the battery cell 6, creating a squeezing effect. This squeezing force helps the gas inside the battery cell 6 enter the second tube 2.

[0068] Alternatively, connector 72 can be a spring clip. After the two pressure plates 71 are attached to both sides of the battery cell 6, the spring clip holds the two pressure plates 71, so that the two pressure plates 71 move closer to each other under the elastic force of the spring clip, so that the two pressure plates 71 abut against both sides of the battery cell 6. The two pressure plates 71 exert a squeezing effect on the battery cell 6, so that the squeezing force of the two pressure plates 71 on the battery cell 6 can help the gas inside the battery cell 6 enter the second tube 2.

[0069] Reference Figures 1 to 4 As shown, in some embodiments, the port of the intake section 11 away from the intermediate section 12 is connected to a dryer 14, and the air source 5 is connected to the intake section 11 through the dryer 14.

[0070] With this configuration, the dryer 14 can remove water vapor from the gas entering the intake section 11, preventing water vapor from interfering with the readings of the first flow meter 3 and the second flow meter 4.

[0071] Specifically, the dryer 14 can be a tube structure, with water-absorbing particles inside the tube and filters at both ends of the tube. This allows the gas supplied by the gas source 5 to pass through the water-absorbing particles before entering the air intake section 11. After the gas passes through the water-absorbing particles, the water vapor carried by the gas is adsorbed onto the water-absorbing particles, ensuring that the gas entering the air intake section 11 remains dry.

[0072] Reference Figures 1 to 4 As shown, in some embodiments, the gas outlet section 13 is connected to a gas analyzer to analyze the composition of the gas discharged from the gas outlet section 13.

[0073] With this setup, a gas analyzer is used to detect the composition of the gas discharged from the gas section 13 in order to obtain the composition of the gas produced by the battery cell 6.

[0074] Specifically, the gas outlet section 13 can be connected to a three-way pipe, and the gas analyzer is connected to the three-way pipe, so that the gas can be discharged into the environment through the three-way pipe, and some of the gas can enter the gas analyzer, so that the gas analyzer can detect the composition of the gas discharged from the gas outlet section 13, thereby detecting the composition of the gas generated by the battery cell 6 when the battery cell 6 generates gas.

[0075] The gas analyzer mentioned above can also be selected as an infrared spectrometer, an electrochemical gas analyzer, or an ultraviolet (UV) gas analyzer, etc., to detect the composition of the gas discharged from the gas outlet section 13.

[0076] Reference Figures 1 to 4 As shown, in some embodiments, the diameter of the second tube 2 is less than or equal to the length of the intermediate section 12. This arrangement ensures that all gas entering the intermediate section 12 after passing through the second tube 2 avoids eddies when the gas enters the first tube 1.

[0077] Specifically, the diameter of the second tube 2 is smaller than the length of the middle section 12. That is, in the radial direction of the first tube 1, the projection of the port of the second tube 2 on the first tube 1 is located inside the middle section 12, so that the gas can enter the middle section 12 completely after passing through the second tube 2, avoiding the generation of vortices due to the large opening of the second tube 2.

[0078] In some embodiments, the gas production measurement device for the battery cell further includes an analysis module electrically connected to a first flow meter 3 and a second flow meter 4. The analysis module is configured to collect measurement data and measurement duration from the first and second flow meters 3 and 4, and to calculate the gas production volume and / or gas production rate of the battery cell 6 based on the difference between the measurement data from the second flow meter 4 and the first flow meter 3 and the measurement duration. This configuration allows the analysis module to analyze and process the measurement data from the first and second flow meters 3, and to obtain the gas production volume and rate of the battery cell 6 through calculation, thus improving the convenience for researchers to obtain the gas production volume or rate of the battery cell 6.

[0079] Specifically, the measurement duration is defined as the time from when the gas-generating measuring device for the battery cell is turned on to when it is turned off. This measurement duration can be selected as the time from when the battery cell 6 begins to produce gas until it stops producing gas, or it can be a portion of the elapsed time from when the battery cell 6 begins to produce gas until it stops producing gas. When calculating the gas production of the battery cell 6, the portion of the graph corresponding to the line in the graph corresponding to the measurement duration is integrated to obtain the gas production of the battery cell 6 corresponding to the measurement duration, based on the relationship between the difference in measurement data from the first flowmeter 3 and the second flowmeter 4 and time.

[0080] The aforementioned analysis module can be selected as a computer, chip, or mobile phone. The measurement data of the first flow meter 3 and the second flow meter 4 can be transmitted to the analysis module. After the researcher selects the measurement duration, the analysis module can calculate the corresponding gas production through program integration. After the researcher selects the required time and inputs the cross-sectional area of ​​the gas outlet section 13, the analysis module can calculate the corresponding gas production rate.

[0081] In specific use, the battery cell gas generation measuring device provided in this application embodiment connects the second tube 2 to the battery cell 6. The gas output from the gas source 5 enters the inlet section 11 after passing through the dryer 14 and the control valve. The control valve controls the flow rate of the gas entering the inlet section 11. The first flow meter 3 and the second flow meter 4 detect the gas flow rates in the inlet section 11 and the outlet section 13, respectively. When the battery cell 6 does not generate gas, the difference between the measured values ​​of the second flow meter 4 and the first flow meter 3 is 0. When the battery cell 6 generates gas, the analysis module calculates the gas volume generated by the battery cell 6 corresponding to the measurement time by integration, and calculates the gas generation rate of the battery cell 6 corresponding to the selected time by the cross-sectional area of ​​the outlet section 13.

[0082] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0083] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A measuring device for gas generation in a battery cell, characterized in that, include: The air duct includes a first tube body (1) and a second tube body (2). The first tube body (1) includes an air inlet section (11), an intermediate section (12) and an air outlet section (13) arranged in sequence. The diameters of the air inlet section (11) and the air outlet section (13) are equal. One end of the second tube body (2) is connected to the intermediate section (12), and the other end is used to connect to the inside of the battery cell (6). A first flow meter (3) is installed in the air intake section (11) to measure the gas flow rate in the air intake section (11); A second flow meter (4) is installed in the outlet section (13) to measure the gas flow rate in the outlet section (13); The gas source (5) is connected to the air intake section (11) and outputs a constant flow of gas.

2. The measuring device for gas generation in a battery cell according to claim 1, characterized in that, The diameter of the intermediate section (12) is smaller than the diameter of the air inlet section (11) and the air outlet section (13), and the pipe wall between the intermediate section (12) and the air inlet section (11) is smoothly transitioned, as is the pipe wall between the intermediate section (12) and the air outlet section (13).

3. The measuring device for gas generation in a battery cell according to claim 1, characterized in that, The air intake section (11) is equipped with a control valve, which is located upstream of the first flow meter (3). The control valve can control the flow rate of the gas flowing into the intermediate section (12).

4. The measuring device for gas generation in a battery cell according to claim 1, characterized in that, The second tube (2) is provided with a barometer (22) so that the barometer (22) can measure the air pressure in the second tube (2).

5. The measuring device for gas generation in a battery cell according to claim 1, characterized in that, A sealing ring (21) is fitted on the end of the second tube (2) away from the first tube (1). The second tube (2) is used to insert into the liquid injection port (61) of the battery cell (6). The sealing ring (21) is used to seal the gap between the second tube (2) and the liquid injection port (61).

6. The measuring device for gas generation in a battery cell according to claim 1, characterized in that, The gas generation measuring device of the battery cell also includes two pressure plates (71) and a connector (72). The two pressure plates (71) are used to clamp and fix the battery cell (6), and the two pressure plates (71) are connected by the connector (72).

7. The measuring device for gas generation in a battery cell according to claim 1, characterized in that, A dryer (14) is connected to the port of the air intake section (11) away from the middle section (12), and the air source (5) is connected to the air intake section (11) through the dryer (14).

8. The measuring device for gas generation in a battery cell according to claim 1, characterized in that, The gas outlet section (13) is connected to a gas analyzer to analyze the composition of the gas discharged from the gas outlet section (13).

9. The measuring device for gas generation in a battery cell according to claim 1, characterized in that, The diameter of the second tube (2) is less than or equal to the length of the intermediate section (12).

10. The measuring device for gas generation in a battery cell according to claim 1, characterized in that, The gas production measuring device of the battery cell further includes an analysis module, which is electrically connected to the first flow meter (3) and the second flow meter (4) and is configured to collect the measurement data and measurement duration of the first flow meter (3) and the second flow meter (4), and calculate the gas production amount and / or gas production rate of the battery cell (6) based on the difference between the measurement data of the second flow meter (4) and the first flow meter (3) and the measurement duration.

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