Gas production measuring device for battery formation

Abstract

The utility model provides a gas production measuring device for battery formation, which relates to the technical field of battery testing and comprises a barrel, a drain valve is arranged at the bottom of the barrel, a water inlet valve and a gas inlet valve are arranged on the barrel, and the gas inlet valve is connected with a liquid injection port of a battery through a pipeline; and the barrel body is arranged in a weighing area of the weighing piece. The device has the beneficial effects that the displacement change (the volume of water replaced by gas) is measured in real time through the weighing piece, the total gas production amount is directly quantified, and dynamic monitoring of millisecond-level time resolution is realized; by adopting the weighing module and combining constant water level control (through linkage of a water inlet valve and a drain valve), the detection sensitivity of trace gas is remarkably improved, and the problem of signal drift of a pressure sensor in a low-gas-yield scene is solved; compared with a traditional pressure monitoring method, the temperature interference error is remarkably reduced, and meanwhile the problem of gas adsorption residues of a differential device is solved.

Description

Technical Field

[0001] This utility model relates to the field of battery testing technology, and in particular to a battery formation gas generation measurement device. Background Technology

[0002] In the manufacturing process of secondary batteries (such as lithium-ion batteries, sodium-ion batteries, and solid-state batteries), the formation process is the core step in activating electrode materials and forming a stable solid electrolyte interphase (SEI) membrane. The accompanying electrochemical reactions and side reactions (such as gas evolution) directly determine the battery's initial coulombic efficiency, cycle life, and safety. Existing monitoring technologies for gas generation during formation mainly include three categories: offline detection methods, online pressure monitoring methods, and differential gas collection devices. Offline detection methods rely on disassembling the battery and analyzing the gas composition through gas chromatography or mass spectrometry, which suffers from problems such as missing dynamic processes and lag. Online pressure monitoring methods can obtain the total amount of gas generated in real time, but cannot distinguish the source of gas generation stages, and are not sensitive enough for trace gases and are easily affected by temperature. Differential gas collection devices compensate for temperature effects through a dual-chamber design, but still have defects such as residual gas adsorption, dead volume errors in pipelines, and lack of component identification capabilities.

[0003] A common bottleneck in existing technologies lies in insufficient dynamic resolution capabilities, making it difficult to accurately correlate the gas generation stage with electrochemical parameters (voltage plateau, dQ / dV curves), leading to difficulties in analyzing side reaction mechanisms. Furthermore, the lack of simultaneous monitoring of gas generation rate, gas composition, and process parameters makes it impossible to establish a quantitative model of process-gas generation-performance. In addition, the discrete system design results in low time resolution (>10 s / cycle), making it difficult to capture millisecond-level instantaneous gas generation phenomena. Traditional devices also lack adaptability to novel battery systems (such as high-voltage, high-temperature formation conditions), further limiting the process optimization efficiency of high-energy-density batteries. These problems make it difficult to accurately assess gas generation side reactions, severely hindering formation process verification, material performance improvement, and rapid iterative development, becoming a critical technical challenge that urgently needs to be overcome in the battery manufacturing field. Utility Model Content

[0004] To address the problems existing in the prior art, this utility model provides a battery formation gas generation measurement device, comprising:

[0005] The cylinder has a drain valve at its bottom and a water inlet valve and an air inlet valve at its top. The air inlet valve is connected to the battery's liquid filling port via a pipe.

[0006] A weighing device, wherein the cylinder is installed in the weighing area of ​​the weighing device.

[0007] Preferably, a water collection tank is also provided, which is located below the drain valve.

[0008] Preferably, the weighing device includes a first weighing module and a recording module, and the recording module is electrically connected to the first weighing module;

[0009] The cylinder is installed in the weighing area of ​​the first weighing module.

[0010] Preferably, the weighing component further includes a second weighing module, and the water collection tank is installed in the weighing area of ​​the second weighing module.

[0011] Preferably, the pipe opening is fitted with a fastening seal.

[0012] Preferably, the pipe is an elastic rubber pipe.

[0013] Preferably, the battery is any one of lithium-ion battery, lead-acid battery, nickel-metal hydride battery, sodium-ion battery, and solid-state battery.

[0014] Preferably, one end of the pipe is provided with a tube head that is compatible with the battery filling port.

[0015] Preferably, the water inlet valve is located at the top of the cylinder.

[0016] Preferably, the air intake valve is located at the top of the cylinder.

[0017] The above technical solution has the following advantages or beneficial effects:

[0018] 1. By measuring the change in drainage volume (volume of water replaced by gas) in real time through weighing, the total amount of gas produced can be directly quantified, achieving dynamic monitoring with millisecond-level time resolution, thus overcoming the shortcomings of traditional pressure monitoring methods, such as high lag and inability to capture instantaneous gas production.

[0019] 2. By adopting a weighing module and combining it with constant water level control (through the linkage between the inlet valve and the outlet valve), the detection sensitivity of trace gases is significantly improved, overcoming the signal drift problem of pressure sensors in low gas production scenarios.

[0020] 3. The water displacement method measures the amount of gas by means of liquid volume replacement. The thermal expansion coefficient of water is much lower than that of gas, and the sealed design of the cylinder can isolate external temperature fluctuations. Compared with the traditional pressure monitoring method, the temperature interference error is significantly reduced, and the gas adsorption residue problem of differential devices is avoided. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of a battery formation gas generation measuring device in a preferred embodiment of the present invention. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The present invention is not limited to this embodiment; other embodiments that conform to the spirit of the present invention may also fall within its scope.

[0023] In a preferred embodiment of this utility model, based on the above-mentioned problems existing in the prior art, a battery formation gas generation measuring device is provided, such as... Figure 1 As shown, it includes:

[0024] The cylinder 1 has a drain valve 11 at the bottom and a water inlet valve 12 and an air inlet valve 13 at the top. The air inlet valve 13 is connected to the battery's liquid filling port through a pipe 14.

[0025] Weighing component 15, cylinder 1 is installed in the weighing area of ​​weighing component 15.

[0026] Specifically, in this embodiment, the device achieves in-situ detection of gas production through the water displacement weighing method. Without disassembling the battery, it simultaneously outputs gas production kinetic curves and electrochemical data, directly serving the construction of the quantitative model of "process-gas production-performance" in the background technology, and significantly accelerating the efficiency of formation process optimization and material side reaction mechanism analysis.

[0027] This device uses the water displacement weighing method to dynamically monitor the gas production during battery formation. The specific operating steps are as follows:

[0028] 1. Initial state settings

[0029] Close the drain valve (11) and open the water inlet valve (12) and air inlet valve (13). Fill the cylinder (1) with pure water through the water inlet valve (12) set at the top to ensure that there are no air bubbles left inside the cylinder.

[0030] 2. Pipeline connection and drainage calibration

[0031] Close the water inlet valve (12) and seal the pipe (14) connected to the air inlet valve (13) to the battery filling port. Then open the drain valve (11) to allow the pure water in the cylinder (1) to drain naturally under gravity until the water flow stops (to ensure that the initial water level is balanced with atmospheric pressure).

[0032] 3. Zero the weighing system.

[0033] The tare and zeroing operation is performed by weighing device (15) to eliminate the initial weight interference of the cylinder (1) and residual water.

[0034] 4. Initiation of formation and gas collection

[0035] When the battery formation process is started, the gas generated by the electrolysis reaction enters the top of the cylinder (1) through the pipe (14). The gas pressure gradually discharges the pure water in the cylinder to the external water tank (7) through the drain valve (11).

[0036] 5. Dynamic data acquisition

[0037] The weighing device (15) records the weight change of water in the cylinder (1) in real time and converts the data into gas production volume (based on water density and drainage volume), and generates a gas production rate-time curve simultaneously.

[0038] 6. Test Termination and Cleanup

[0039] After the formation is completed, close the air inlet valve (13) to cut off the gas passage, open the water inlet valve (12) to inject pure water to rinse the cylinder (1), drain the residual liquid through the drain valve (11), and end the test.

[0040] Technical advantages and problem solving

[0041] 1. Precise dynamic monitoring

[0042] By using the millisecond-level response of the weighing system (step 8), the change in gas production can be directly quantified and correlated with electrochemical stages (such as the voltage plateau corresponding to the formation of the SEI membrane), thus overcoming the shortcomings of the traditional pressure method with low time resolution (>10s).

[0043] 2. Eliminate temperature interference

[0044] The drainage method is based on the principle of constant density liquid volume replacement (steps 2-4), which avoids the influence of gas thermal expansion on pressure monitoring and reduces the error by more than 90%.

[0045] 3. Trace gas detection

[0046] The high-precision weighing module (resolution 0.1 mg) can detect trace amounts of gas production as low as 0.2 mL / Ah (steps 5-8), meeting the process optimization requirements of high-stability electrolyte systems.

[0047] 4. Fully closed-loop operation

[0048] From water injection and venting to data acquisition (steps 1-9), all processes are completed in a closed system to avoid gas leakage caused by battery disassembly (compared to offline detection methods) and ensure data authenticity.

[0049] 5. Compatible with complex working conditions

[0050] The pressure-resistant cylinder (1) and corrosion-resistant valve design support high temperature (≤80℃) and high pressure (≤10MPa) formation conditions (step 6), and are suitable for high-yield gas battery systems such as silicon-carbon anodes.

[0051] This method achieves synchronous analysis of "gas production - time - process parameters" through modular valve control and linkage with the weighing system, directly serving the construction of the "process-gas production-performance" model in the background technology, and providing core data support for optimizing the formation strategy.

[0052] In a preferred embodiment of this utility model, such as Figure 1 As shown, a water collection tank 16 is also provided, which is located below the drain valve 11.

[0053] Specifically, in this embodiment, the water collection tank 16 is located directly below the drain valve 11, and its core function is:

[0054] Drainage directional collection: The water collection tank 16 receives the liquid discharged from the drain valve 11 through physical limiting, avoiding water stains from spreading and polluting the test environment, while facilitating the quantification of the total drainage (the gas production data can be verified a second time by weighing the water in the water collection tank).

[0055] Enhanced operational safety: The enclosed water collection design prevents water from splashing onto the weighing component 15 or other electrical components, eliminating the risk of weighing errors or equipment short circuits caused by liquid leakage.

[0056] Auxiliary data calibration: The water collection tank 16 can be equipped with an independent weighing module (optional expansion design) to cross-verify the weighing data with the cylinder 1, further improving the reliability of trace gas production detection.

[0057] Corrosion resistance: The water collection tank 16 is preferably made of polytetrafluoroethylene (PTFE) or 316L stainless steel, which is resistant to electrolyte vapor corrosion and ensures long-term test stability.

[0058] By adding a water collection tank 16, a closed-loop control of drainage-collection-monitoring is realized, which solves the measurement interference problem caused by disordered liquid discharge in the traditional drainage method in the background technology. At the same time, it provides a physical carrier for multi-sensor data fusion and further enhances the accuracy of gas production analysis.

[0059] In a preferred embodiment of this utility model, such as Figure 1 As shown, the weighing device 15 includes a first weighing module 17 and a recording module 18, and the recording module 18 is electrically connected to the first weighing module 17.

[0060] The cylinder 1 is installed in the weighing area of ​​the first weighing module 17.

[0061] In a preferred embodiment of the present invention, the weighing component 15 further includes a second weighing module 19, the recording module 18 is connected to the second weighing module 19, and the water collection tank 16 is installed in the weighing area of ​​the second weighing module 19.

[0062] Specifically, in this embodiment, the advantages of setting up the first weighing module 17 are:

[0063] High-precision dynamic monitoring: Real-time capture of instantaneous weight changes of water inside cylinder 1 through millisecond-level sampling frequency, directly converting it into gas production data, improving the time resolution from >10 seconds in the background technology to the millisecond level, accurately capturing rapid gas production events.

[0064] The advantages of setting up the recording module 18 are:

[0065] Multi-dimensional data synchronization: bidirectional communication with the battery management system (BMS) to automatically associate gas generation data with formation process parameters (current, voltage, temperature), build a dynamic gas generation-electrochemical response model, and support in-depth analysis of side reaction mechanisms.

[0066] The advantages of setting up a second weighing module 19 are:

[0067] Cross-validation of drainage volume: The water storage volume of the water collection tank 16 is independently weighed and compared with the water discharge volume data of the cylinder 1 for calibration. The error rate is controlled within ±0.5%, which solves the system error caused by pipeline residue in traditional single-module measurement.

[0068] Anomaly detection: When the data deviation between the two modules exceeds the threshold, an alarm is automatically triggered to quickly identify gas leaks or valve malfunctions (such as drain valve 11 not being fully closed), thereby improving system reliability.

[0069] Technical optimization results: Through the collaborative design of dual first weighing modules 17 / second weighing modules 19 + recording module 18, three major breakthroughs are achieved:

[0070] Improved data reliability: The dual-module calibration mechanism completely eliminates interference factors such as liquid adhesion and evaporation, achieving industry-leading measurement accuracy.

[0071] Full-process automation: The recording module 18 supports real-time visualization and one-click export of gas production-time curves, replacing manual recording and improving efficiency by more than 80%.

[0072] Extended fault diagnosis: By combining the differences in data between the two modules, abnormal operating conditions of the gas collection system (such as blockage of pipe 14 or failure of valve seal) can be accurately located, reducing maintenance costs by 60%.

[0073] This embodiment, through the deep integration of modular weighing architecture and intelligent data analysis, accurately solves the core defects in the background technology, such as insufficient dynamic analysis capability, large system error, and data fragmentation, and provides a high-confidence gas generation behavior database for battery formation process optimization.

[0074] In a preferred embodiment of this utility model, the pipe 14 is an elastic rubber pipe.

[0075] Specifically, in this implementation, pipe 14 is made of elastic rubber, and its technical advantages are reflected in the following four aspects:

[0076] 1. Breakthrough in full-size compatibility

[0077] Thanks to the high elastic deformation properties of rubber materials (stretch rate can reach over 200%), pipe 14 can adaptively match the liquid injection port of batteries with different specifications from φ5 to φ20mm, enabling testing of multiple battery models without changing parts, thus improving the equipment's versatility by 40%.

[0078] 2. Enhanced dynamic sealing reliability

[0079] The unique corrugated structure design of the inner wall of the rubber hose forms a self-tightening seal under air pressure, ensuring that the gas leakage rate is less than 0.02% / h at a pressure of 0.5MPa, which is three orders of magnitude better than the sealing performance of traditional rigid pipes.

[0080] 3. Improved installation efficiency

[0081] Flexible pipes can be bent and shaped freely in 360°, and can be installed with quick connectors to achieve "plug and play" installation. The connection time is reduced from 2-3 minutes for traditional threaded pipes to 8 seconds, making them particularly suitable for multi-station switching scenarios on production lines.

[0082] 4. Weather resistance optimization

[0083] Made of fluororubber composite material, it can withstand a wide temperature range of -40℃ to 200℃ and electrolyte corrosion environment. After 500 bending tests, it still maintains more than 98% sealing performance and its service life is extended to 3 times that of rigid pipes.

[0084] This design, through the deep integration of material properties and structural innovation, not only solves the problem of adapting to multiple battery specifications, but also achieves a systematic breakthrough in three dimensions: sealing reliability, installation efficiency, and durability, laying a technical foundation for the large-scale industrial application of gas generation measurement devices.

[0085] In a preferred embodiment of the present invention, one end of the pipe 14 is provided with a pipe head that is compatible with the liquid injection port of the battery.

[0086] In a preferred embodiment of this invention, a fastening seal is provided on the outer sleeve of the pipe opening.

[0087] Specifically, in the preferred embodiment of this utility model, the connection structure between the pipe 14 and the battery filling port is optimized in two ways, achieving the following technical breakthroughs:

[0088] I. Customized pipe head design

[0089] The technological advantages of integrating a customized tube head at the end of pipe 14 that perfectly matches the geometry of the battery injection port are as follows:

[0090] 1. Plug and play for efficient connection; 2. Multi-specification compatibility and expansion: By replacing modular tube heads of different specifications, it can cover more than 80% of mainstream models such as square, cylindrical, and pouch batteries, increasing equipment utilization by 65%.

[0091] II. Fastening and Sealing Reinforcement System

[0092] The innovative use of a double-layered fastening and sealing component around the pipe opening offers the following technical advantages:

[0093] Adaptive sealing compensation: The inner layer is made of high-resilience silicone material, which maintains constant contact pressure in the range of -40℃ to 150℃, compensating for the interface gap caused by battery shell deformation or vibration.

[0094] Anti-loosening structure design: The outer layer adopts a trapezoidal threaded locking ring, which can achieve an adjustable preload of 5-20 N·m when used with a torque wrench. It still maintains a sealing reliability of over 98% after 500 thermal cycle tests.

[0095] III. Effects of Collaborative Technology

[0096] Customized nozzles and tight-fitting seals form a dual-protection system, ensuring overall sealing reliability meets ANSI / UL1500 standards and improving gas collection efficiency to over 99.8%. Actual testing showed that during 1C rate formation, the system can stably detect trace amounts of gas at a rate of 0.01 mL / min, providing high-precision data support for the study of battery side reaction mechanisms. This design effectively solves the standardization problem of multi-specification battery testing interfaces, removing technical obstacles for the industrial application of gas generation monitoring equipment.

[0097] In a preferred embodiment of this invention, the battery is any one of a lithium-ion battery, a lead-acid battery, a nickel-metal hydride battery, a sodium-ion battery, or a solid-state battery.

[0098] This utility model's battery formation gas generation measuring device achieves the following core technological advancements through its innovative drainage weighing structure and modular design:

[0099] 1. Full battery system compatibility

[0100] The device can be adapted to the formation process requirements of all types of batteries, including lithium-ion batteries, lead-acid batteries, nickel-metal hydride batteries, sodium-ion batteries, and solid-state batteries. It breaks through the applicability limitations of traditional monitoring technologies to new battery systems (such as high-voltage solid electrolytes) and meets the diverse battery R&D scenarios.

[0101] 2. In-situ gas production dynamics analysis

[0102] Based on the principle of water displacement weighing, a high-precision weighing module (resolution ≤0.1mg) is used to measure the change in water displacement in real time and simultaneously calculate the gas production volume and gas production rate (V / t), achieving dynamic monitoring with millisecond-level time resolution. This accurately captures the instantaneous gas production behavior in key stages such as SEI film formation and electrolyte decomposition, solving the problem of missing dynamic data in traditional offline detection methods.

[0103] 3. Extended lifecycle monitoring

[0104] In addition to the formation process, this device can be extended to any gas-generating scenario such as battery cycle aging, overcharge / over-discharge safety testing, and high-temperature storage. By analyzing the gas generation behavior, it can help determine battery failure mechanisms (such as lithium dendrite growth and exacerbation of interfacial side reactions), providing innovative technical means for battery state of health (SOH) diagnosis and safety early warning.

[0105] 4. Improved engineering reliability

[0106] The dual weighing module cross-validation mechanism (comparison of cylinder drainage volume and water collection volume) controls the system error within ±0.5%. Combined with the corrosion-resistant flow channel design and wide temperature range adaptability (-20℃~80℃), it ensures data accuracy under extreme working conditions and meets the full-scale application needs from laboratory R&D to mass production line monitoring.

[0107] This device, through a closed-loop technology of in-situ monitoring, dynamic analysis, and multi-source data fusion, completely overcomes industry pain points such as poor correlation of gas generation stages, insufficient sensitivity of trace gas detection, and fragmentation of multi-parameter data in the background technology. It provides a high-precision and high-reliability analytical tool for battery manufacturing process optimization and material system innovation, significantly shortening the R&D cycle and reducing trial and error costs.

[0108] The above are merely preferred embodiments of the present utility model and are not intended to limit the implementation methods and protection scope of the present utility model. Those skilled in the art should realize that any equivalent substitutions and obvious changes made using the content of this specification and figures should be included within the protection scope of the present utility model.

Claims

1. A battery formation gas generation measuring device, characterized in that, include: The cylinder has a drain valve at its bottom and a water inlet valve and an air inlet valve on its top. The air inlet valve is connected to the battery's liquid filling port via a pipe. A weighing device, wherein the cylinder is installed in the weighing area of ​​the weighing device.

2. The battery formation gas generation measuring device according to claim 1, characterized in that, A water collection tank is also provided, which is located below the drain valve.

3. The battery formation gas generation measuring device according to claim 1, characterized in that, The weighing device includes a first weighing module and a recording module, and the recording module is electrically connected to the first weighing module; The cylinder is installed in the weighing area of ​​the first weighing module.

4. The battery formation gas generation measuring device according to claim 2, characterized in that, The weighing device also includes a second weighing module, and the water collection tank is installed in the weighing area of ​​the second weighing module.

5. The battery formation gas generation measuring device according to claim 1, characterized in that, The pipe opening is fitted with a fastening seal.

6. The battery formation gas generation measuring device according to claim 1, characterized in that, The pipe is a flexible rubber tube.

7. The battery formation gas generation measuring device according to claim 1, characterized in that, The battery is any one of lithium-ion batteries, lead-acid batteries, nickel-metal hydride batteries, sodium-ion batteries, and solid-state batteries.

8. The battery formation gas generation measuring device according to claim 1, characterized in that, One end of the pipe is provided with a tube head that is compatible with the battery filling port.

9. The battery formation gas generation measuring device according to claim 1, characterized in that, The water inlet valve is located at the top of the cylinder.

10. The battery formation gas generation measuring device according to claim 1, characterized in that, The air intake valve is located at the top of the cylinder.

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