On-line testing device and method for thermal runaway jet mass of battery

Abstract

The invention discloses an on-line testing device and method for the mass of a battery thermal runaway sprayed matter, and belongs to the technical field of battery energy storage safety, and the device comprises a weighing platform which is used for supporting a to-be-tested battery and horizontally placing a battery pressure release valve port; the digital weighing sensor is arranged on the weighing platform and is used for measuring the mass change of the battery in real time; the battery clamp is used for fixing the battery and preventing the battery from displacing in the thermal runaway process; a pressure sensor is arranged on the battery clamp and is used for monitoring deformation and expansion of the battery; the rectifying tube is fixed at a nozzle of the battery pressure release valve and is used for guiding electrolyte steam to be horizontally sprayed out; the power line supporting platform comprises a base supporting platform and two horizontal pipes and is used for supporting a power line to eliminate interference of mechanical deformation on the weighing platform; according to the invention, the mass of the thermal runaway sprayed substance of the battery can be accurately measured on line, and the interference of mechanical deformation and external acting force on the weighing device is eliminated.

Description

Technical Field

[0001] The present invention relates to an online testing device and method for the quality of battery thermal runaway ejecta, belonging to the technical field of battery energy storage safety. Background Art

[0002] In battery energy storage systems, thermal runaway poses a serious threat to system safety. When a battery experiences thermal runaway, various substances are ejected. Accurately measuring the mass of these ejected substances is crucial for gaining a deeper understanding of the thermal runaway mechanism, assessing battery safety, and developing effective protective measures.

[0003] Currently, existing testing equipment has many shortcomings when measuring the mass of battery thermal runaway ejecta. For example, during thermal runaway, improper battery placement can exert a downward force on the weighing device below, resulting in inaccurate battery mass loss measurements and an inability to truly reflect the mass of the thermal runaway ejecta. Furthermore, during overcharge experiments, when a battery bulges and experiences thermal runaway, the power line exerts additional force on the weighing device. Changes in the length and position of the power line can also affect the weighing device, causing the measurement results to deviate significantly from the actual value, making it impossible to provide reliable data support for battery energy storage safety research.

[0004] In battery energy storage safety research, thermal runaway is a key factor in causing safety accidents. When thermal runaway occurs within a battery, high-temperature gases, electrolyte vapor, and other substances are ejected. Accurately measuring the mass of these ejected substances is essential for in-depth analysis of the underlying mechanisms of thermal runaway, scientifically evaluating battery safety performance, and developing targeted protection strategies.

[0005] However, the current testing devices available on the market have many defects when measuring the mass of battery thermal runaway ejecta. On the one hand, during thermal runaway, the traditional battery placement method causes the battery to exert an additional downward force on the weighing device below, resulting in large errors in the measured battery mass loss data, which cannot truly reflect the actual mass of the thermal runaway ejecta. On the other hand, in overcharge experiments, once the battery bulges and thermal runaway occurs, the power line will generate additional force on the weighing device due to changes in position and length, which will seriously affect the accuracy of the measurement results, causing the measured data to deviate significantly from the actual value, making it difficult to meet the demand for high-precision data in battery energy storage safety research. In addition, when thermal runaway gas is produced, the direction and force of the electrolyte vapor ejection will also interfere with the weighing device, further reducing the reliability of the measurement. Summary of the Invention

[0006] The purpose of the present invention is to overcome the deficiencies in the prior art and provide an online testing device and method for the mass of battery thermal runaway ejecta, which can accurately measure the mass of battery thermal runaway ejecta online and eliminate the interference of mechanical deformation and external forces on the weighing device.

[0007] To achieve the above object, the present invention is implemented by adopting the following technical solutions: In a first aspect, the present invention provides an online testing device for the mass of ejecta during thermal runaway of a battery, comprising: Weighing platform, used to support the battery to be tested and place the battery pressure relief valve port horizontally; A digital weighing sensor, installed on the weighing platform, for measuring the change in battery mass in real time; A battery fixture, used to secure the battery and prevent it from shifting during thermal runaway; the battery fixture is provided with a pressure sensor for monitoring battery deformation and expansion; The rectifier tube is fixed to the nozzle of the battery pressure relief valve and is used to guide the electrolyte vapor to spray out horizontally; The power line support platform includes a base support platform and two horizontal pipes, which are used to support the power line to eliminate the interference of mechanical deformation on the weighing platform; The remote monitoring device is connected to the digital weighing sensor and pressure sensor for automatically storing and analyzing the data after receiving it, generating a curve showing the battery mass loss over time and a deformation curve, and combining the two curves to calculate the mass of the thermal runaway ejecta.

[0008] Furthermore, the data acquisition frequency of the digital weighing sensor is not less than 10 Hz.

[0009] Furthermore, the remote monitoring device is connected to the digital weighing sensor and the pressure sensor via a 485 communication module.

[0010] Furthermore, the rectifier tube is fixed by a magic clip, and the magic clip is made of high-temperature resistant material.

[0011] Furthermore, the pressure sensor has a measuring range of 0-1 t and an accuracy of 0.3% FS.

[0012] Furthermore, the horizontal tube of the power line support platform is made of corrosion-resistant material and its height is aligned with the battery tab.

[0013] Furthermore, the weighing platform includes a base steel plate and an upper plane, which are fixed by screws.

[0014] Furthermore, the remote monitoring device includes a control computer and a data storage module, which is used to store the data through the data storage module after receiving the data, and analyze the data through the control computer to generate a curve of battery mass loss over time and a deformation curve, and combine the two curves to calculate the mass of thermal runaway ejecta.

[0015] Furthermore, the rectifier tube is made of high-strength, high-temperature resistant material, the shape of its tube mouth is consistent with the shape of the experimental battery pressure relief valve, and the size of the tube mouth is larger than the setting range of the battery pressure relief valve mouth.

[0016] In a second aspect, the present invention provides a method for online testing the mass of battery thermal runaway ejecta according to any of the aforementioned devices, comprising: Fix the experimental battery in the battery fixture to ensure that the battery does not move during thermal runaway; Pass the battery power line through the two horizontal tubes of the power line support platform, adjust the position of the horizontal tube so that it is parallel to the large surface of the battery, and the height is aligned with the battery tabs on the weighing device; Fix the rectifier tube to the nozzle of the battery pressure relief valve, ensuring that the nozzle of the rectifier tube is horizontally aligned with the nozzle of the pressure relief valve and does not hinder the normal opening of the pressure relief valve; Place the weighing platform on a stable workbench, connect the digital weighing sensor and remote monitoring equipment, and perform system calibration; Overcharging the battery through the charger / discharger triggers thermal runaway until the safety valve opens and charging stops; During thermal runaway, digital weighing sensors collect battery quality data in real time, while pressure sensors simultaneously monitor battery deformation and expansion, transmitting the data to remote monitoring equipment in real time. After receiving the data, the remote monitoring device automatically stores and analyzes the data, generates a curve showing the battery mass loss over time and a deformation curve, and combines the two curves to calculate the mass of the thermal runaway ejecta.

[0017] Compared with the existing technology, the beneficial effects achieved by the present invention are: The present invention provides an online testing device and method for the mass of battery thermal runaway ejecta. By setting a weighing platform, a digital weighing sensor, a battery fixture, a rectifier tube, a power line support platform and a remote monitoring device, the mass of battery thermal runaway ejecta is accurately measured online, and the interference of mechanical deformation and external force on the weighing device is eliminated. This solves the problem of inaccurate measurement of battery thermal runaway ejecta mass in the prior art, solves the problem of uncertain gas production direction during battery thermal runaway and interference of mechanical deformation and external force on the weighing device, and realizes accurate online measurement of mass loss during battery thermal runaway. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is an expanded view of the weighing platform structure provided by an embodiment of the present invention; Figure 2 This is an expanded view of the battery preload fixture structure provided by an embodiment of the present invention; Figure 3 This is an overall diagram of a device for online testing the mass of ejecta from a battery experiencing thermal runaway, provided in an embodiment of the present invention; Figure 4 This is a flow chart of a method for online testing the mass of battery thermal runaway ejecta provided by an embodiment of the present invention; Figure 5 This is an original waveform diagram of battery quality measured under overcharge conditions provided by an embodiment of the present invention; Figure 6 This is a graphical diagram of an embodiment of the present invention after an overcharge condition occurs through the device and method of this patent. DETAILED DESCRIPTION

[0019] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0020] Example 1. This example introduces an online testing device for the mass of battery thermal runaway ejecta, comprising: a weighing platform, a digital weighing sensor, a battery fixture, a rectifier tube, a power line support platform, and a remote monitoring device, wherein: the weighing platform is used to support the battery to be tested and to place the battery pressure relief valve port horizontally; the digital weighing sensor is installed on the weighing platform for real-time measurement of battery mass changes; the battery fixture is used to fix the battery and prevent it from displacing during thermal runaway; the battery fixture is provided with a pressure sensor for monitoring battery deformation and expansion; the rectifier tube is fixed to the battery pressure relief valve nozzle for guiding the horizontal ejection of electrolyte vapor; the power line support platform includes a base support platform and two horizontal tubes for supporting the power line to eliminate the interference of mechanical deformation on the weighing platform; the remote monitoring device is communicatively connected to the digital weighing sensor and the pressure sensor for automatically storing and analyzing the data after receiving the data, generating a curve of battery mass loss over time and a deformation curve, and combining the two curves to calculate the mass of the thermal runaway ejecta.

[0021] The following describes the contents involved in the above embodiment in conjunction with a preferred embodiment.

[0022] Figure 1 This is a diagram of the weighing platform structure of an online testing device and method for the mass of battery thermal runaway ejecta provided by an embodiment of the present invention, which is intended to illustrate one of the structural designs of the device and point out the functions of each structure, including: The base 201 of the weighing platform is composed of four nuts, screws and a steel plate, which is used to provide stable and firm support when measuring battery mass loss; The digital weighing sensor 202 is fixed to the base and upper surface of the weighing platform by screws and is used to measure the mass loss of the battery during thermal runaway online; The upper plane 203 of the weighing platform is used to support the measuring cell and the fixture; Figure 2 This is a structural expansion diagram of a 280 Ah battery preload fixture for an online battery thermal runaway ejecta mass testing device and method provided by an embodiment of the present invention. It is intended to illustrate one of the structural designs of the device and point out the functions of each structure, including: The lower base 301 of the 280 Ah battery preload fixture is made of 20 mm thick 304 stainless steel and is fully welded in the grooves. It is used to fix and support the battery 302 to prevent left and right displacement. The battery 302 is a 280 Ah battery. The top surface 303 of the 280 Ah battery preload fixture is made of 20 mm thick 304 stainless steel and is used to fix the battery 302 and support the pressure sensor 304; The pressure sensor 304 is used to calibrate the initial preload force of the experimental battery and to monitor and collect the deformation and expansion of the battery during the experiment; The top surface 305 of the 280 Ah battery preload fixture is made of 20 mm thick 304 stainless steel and is used to fix the pressure sensor so that the force is evenly distributed; The 280 Ah battery preload clamp fixing bolt 306 and the 280 Ah battery preload clamp fixing nut 307 cooperate with each other to fix the entire clamp.

[0023] Figure 3 This is a general diagram of an online test device and method for the mass of ejecta from a battery experiencing thermal runaway, provided in an embodiment of the present invention. It is intended to illustrate one structural design of the device and point out the functions of each structure, wherein: The magic clamp 401 is made of high-strength, high-temperature resistant material and is used to fix the rectifier tube to ensure that the rectifier tube will not loosen or move during the entire measurement process; The rectifier tube 402 is used to allow the electrolyte vapor to be ejected horizontally when the battery experiences thermal runaway; The battery power line 403 and the power line support tube 404 cooperate with each other to provide support when the battery pack is thermally runaway, so as to prevent the power line from affecting the weighing device; The support platform 405 is used to provide support for the power line support tube.

[0024] Figure 4 This is a flow chart of an online testing device and method for battery thermal runaway ejecta mass provided by an embodiment of the present invention.

[0025] Specific implementation steps in the experiment: S1: Place the experimental battery on the battery fixture to ensure that the battery is firmly fixed and will not move; S2: Pass the power line of the battery through the two horizontal tubes of the power line support platform, and adjust the position of the horizontal tubes so that the horizontal tubes are parallel to the large surface of the battery and the height is consistent with the height of the battery tabs on the weighing device; S3: Use a magic clip to fix the rectifier tube to the battery pressure relief valve nozzle position, ensuring that the rectifier tube nozzle is level with the battery pressure relief valve nozzle and the rectifier tube is firmly installed; S4: Place the weighing platform on a stable workbench, connect the digital weighing sensor and the data transmission module, and ensure normal data transmission; S5: Check whether the weighing platform, preload sensor, power line and other lines are connected correctly to reduce safety hazards during the experiment; S6: Overcharging the battery through the charger and discharger, causing the battery to thermal runaway until it reaches complete thermal runaway; S7: During the entire thermal runaway process, the digital weighing sensor collects battery quality data in real time and transmits the data to the remote monitoring device via 485 communication; S8: Receive the quality data transmitted remotely, organize and analyze the data, and draw a curve showing the change of battery quality loss over time; S9: Analyze the rules and characteristics of mass loss during battery thermal runaway based on the curve, calculate the mass of the battery thermal runaway ejecta, and provide data support for battery energy storage safety research.

[0026] In the experiment, the battery was overcharged with a current of 0.5 C until thermal runaway occurred in the battery, and the battery safety valve opened to release the pressure. Charging was stopped until the battery completely thermally ran away. Experimental data was recorded until the end of the test.

[0027] like Figure 5 As shown, in the overcharge condition, as the battery is charged differently, during the 500-1500 s overcharge stage, the battery begins to bulge, and the power line shifts upward, causing the overall mass of the weighing platform to slowly increase. At 1750 s into the experiment, the battery safety valve opens, the battery casing deforms, and the battery power line is too rigid, exerting a downward force on the weighing platform. After the valve is opened, the mass first decreases, releasing a large amount of gas, and then rapidly increases. Around 2000 s, the battery experiences thermal runaway, with violent gas production. Due to the lack of a rectifier tube, gas is ejected from the pressure relief valve port, exerting a downward force on the weighing platform, causing the mass measured on the weighing platform to increase, resulting in significant mass fluctuations. like Figure 6As shown in the figure, under the same overcharge conditions, the waveform obtained by the weighing device and method provided by the present invention shows an overall downward trend. There is no significant fluctuation in mass during the 500-1000 s overcharge period, and the curve is flat. Even after the battery valve is opened for 1750 s, there is no significant fluctuation.

[0028] In summary, the present invention is based on the battery mass loss and designs a set of methods to solve the mechanical error of the weighing device and the battery deformation. Through careful design, the accurate measurement of the experimental battery mass loss is achieved.

[0029] Example 2: This example provides an online testing method for the mass of battery thermal runaway ejecta according to the device described in any one of Example 1, comprising: Fix the experimental battery in the battery fixture to ensure that the battery does not move during thermal runaway; Pass the battery power line through the two horizontal tubes of the power line support platform, adjust the position of the horizontal tube so that it is parallel to the large surface of the battery, and the height is aligned with the battery tabs on the weighing device; Fix the rectifier tube to the nozzle of the battery pressure relief valve, ensuring that the nozzle of the rectifier tube is horizontally aligned with the nozzle of the pressure relief valve and does not hinder the normal opening of the pressure relief valve; Place the weighing platform on a stable workbench, connect the digital weighing sensor and remote monitoring equipment, and perform system calibration; Overcharging the battery through the charger / discharger triggers thermal runaway until the safety valve opens and charging stops; During thermal runaway, digital weighing sensors collect battery quality data in real time, while pressure sensors simultaneously monitor battery deformation and expansion, transmitting the data to remote monitoring equipment in real time. After receiving the data, the remote monitoring device automatically stores and analyzes the data, generates a curve showing the battery mass loss over time and a deformation curve, and combines the two curves to calculate the mass of the thermal runaway ejecta.

[0030] The application process of the online testing method for the mass of battery thermal runaway ejecta provided in this embodiment specifically involves the following steps: S1: Place the experimental battery on the battery fixture to ensure that the battery is firmly fixed and will not move; the battery fixture is made of high-strength, high-temperature resistant materials to ensure that the measuring device can be used multiple times and operates safely during the measurement process; the battery fixture is equipped with a pressure sensor with a range of 0-1 t, an accuracy of 0.3% FS, and a 485 digital output for remote monitoring and data acquisition, for initial preload calibration of the experimental battery, and for monitoring and collecting battery deformation and expansion during the experiment; S2: Pass the power line of the battery through the two horizontal tubes of the power line support platform, adjust the position of the horizontal tube so that the horizontal tube is parallel to the large surface of the battery and the height is consistent with the height of the battery tab on the weighing device; the power line support platform in S2 is made of corrosion-resistant material, including a base support platform and two horizontal tubes to support the power line and ensure that the power line and the battery tab are kept level; the two horizontal tubes are made of corrosion-resistant and high-temperature resistant materials, and the power line of the battery passes through the horizontal tubes. The horizontal tubes are parallel to the large surface of the battery and the height is consistent with the height of the battery tab on the weighing device, which is used to provide support for the power line when the battery bulge is thermally runaway, so as to avoid the power line affecting the weighing device; S3: Use a magic clip to fix the rectifier tube at the position of the battery pressure relief valve nozzle to ensure that the nozzle of the rectifier tube is level with the battery pressure relief valve nozzle and the rectifier tube is firmly installed; the magic clip in S3 is made of high-strength, high-temperature resistant material to fix and support the rectifier tube to ensure that the rectifier tube will not loosen or displace during the entire measurement process; the rectifier tube is made of high-strength, high-temperature resistant material, and the shape of its nozzle is consistent with the shape of the experimental battery pressure relief valve. The nozzle size is slightly larger than the battery pressure relief valve nozzle and does not affect the normal opening of the experimental battery; the rectifier tube is installed at the position of the battery pressure relief valve nozzle, and its nozzle is level with the battery pressure relief valve nozzle, so that the electrolyte vapor is ejected horizontally when the battery thermal runaway produces gas, without generating downward force to interfere with the weighing device, and does not affect the normal opening of the battery pressure relief valve and the ejection of electrolyte vapor; S4: Place the weighing platform on a stable workbench, connect the digital weighing sensor and the data transmission module to ensure normal data transmission; the digital weighing sensor samples data at a frequency of not less than 10 Hz to ensure the accuracy of the measurement data; S5: Check whether the weighing platform, preload sensor, power line and other lines are connected correctly to reduce safety hazards during the experiment; S6: Overcharging the battery through the charger and discharger, causing the battery to thermal runaway until it reaches complete thermal runaway; S7: During the entire thermal runaway process, the digital weighing sensor collects the battery quality data in real time and transmits the data to the control computer of the remote monitoring device through 485 communication; S8: The control computer receives the quality data transmitted remotely, organizes and analyzes the data, and draws a curve of battery quality loss over time; S9: Analyze the rules and characteristics of mass loss during battery thermal runaway based on the curve, calculate the mass of the battery thermal runaway ejecta, and provide data support for battery energy storage safety research.

[0031] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An online testing device for the quality of battery thermal runaway ejecta, characterized in that: include: Weighing platform, used to support the battery to be tested and place the battery pressure relief valve port horizontally; A digital weighing sensor, installed on the weighing platform, for measuring the change in battery mass in real time; A battery fixture, used to secure the battery and prevent it from shifting during thermal runaway; the battery fixture is provided with a pressure sensor for monitoring battery deformation and expansion; The rectifier tube is fixed to the nozzle of the battery pressure relief valve and is used to guide the electrolyte vapor to spray out horizontally; The power line support platform includes a base support platform and two horizontal pipes, which are used to support the power line to eliminate the interference of mechanical deformation on the weighing platform; The remote monitoring device is connected to the digital weighing sensor and pressure sensor for automatically storing and analyzing the data after receiving it, generating a curve showing the battery mass loss over time and a deformation curve, and combining the two curves to calculate the mass of the thermal runaway ejecta.

2. The battery thermal runaway ejecta mass online testing device according to claim 1, characterized in that: The data acquisition frequency of the digital weighing sensor is not less than 10 Hz.

3. The battery thermal runaway ejecta mass online testing device according to claim 1, characterized in that: The remote monitoring device is connected to the digital weighing sensor and the pressure sensor via a 485 communication module.

4. The battery thermal runaway ejecta mass online testing device according to claim 1, characterized in that: The rectifier tube is fixed by a magic clip, and the magic clip is made of high-temperature resistant material.

5. The battery thermal runaway ejecta mass online testing device according to claim 1, characterized in that: The pressure sensor has a measuring range of 0-1 t and an accuracy of 0.3% FS.

6. The battery thermal runaway ejecta mass online testing device according to claim 1, characterized in that: The horizontal tube of the power line support platform is made of corrosion-resistant material and its height is aligned with the battery tab.

7. The battery thermal runaway ejecta mass online testing device according to claim 1, characterized in that: The weighing platform includes a base steel plate and an upper plane, which are fixed by screws.

8. The battery thermal runaway ejecta mass online testing device according to claim 1, characterized in that: The remote monitoring device includes a control computer and a data storage module, which is used to store data through the data storage module after receiving data, and analyze the data through the control computer to generate a curve of battery mass loss over time and a deformation curve, and combine the two curves to calculate the mass of thermal runaway ejecta.

9. The battery thermal runaway ejecta mass online testing device according to claim 1, characterized in that: The rectifier tube is made of high-strength, high-temperature resistant material, and the shape of its tube mouth is consistent with the shape of the experimental battery pressure relief valve, and the size of the tube mouth is larger than the setting range of the battery pressure relief valve mouth.

10. An online testing method for the mass of battery thermal runaway ejecta according to the device according to any one of claims 1 to 9, characterized in that: include: Fix the experimental battery in the battery fixture to ensure that the battery does not move during thermal runaway; Pass the battery power line through the two horizontal tubes of the power line support platform, adjust the position of the horizontal tube so that it is parallel to the large surface of the battery, and the height is aligned with the battery tabs on the weighing device; Fix the rectifier tube to the nozzle of the battery pressure relief valve, ensuring that the nozzle of the rectifier tube is horizontally aligned with the nozzle of the pressure relief valve and does not hinder the normal opening of the pressure relief valve; Place the weighing platform on a stable workbench, connect the digital weighing sensor and remote monitoring equipment, and perform system calibration; Overcharging the battery through the charger / discharger triggers thermal runaway until the safety valve opens and charging stops; During thermal runaway, digital weighing sensors collect battery quality data in real time, while pressure sensors simultaneously monitor battery deformation and expansion, transmitting the data to remote monitoring equipment in real time. After receiving the data, the remote monitoring device automatically stores and analyzes the data, generates a curve showing the battery mass loss over time and a deformation curve, and combines the two curves to calculate the mass of the thermal runaway ejecta.

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