A lithium ion battery temperature monitoring tool

Abstract

The utility model belongs to the field of battery especially a kind of lithium ion battery temperature monitoring tool, it includes lithium ion battery main body, this lithium ion battery temperature monitoring tool further includes: three-section type clamp assembly, three-section type clamp assembly includes collar and connecting rod, collar is equipped with three, connecting rod is equipped with six, three collars are welded by six connecting rods, the inside of collar and the surface of lithium ion battery main body are set;Temperature measurement unit, temperature measurement unit is equipped with four groups, four groups of temperature measurement unit are evenly distributed on the surface of lithium ion battery main body, in the utility model, the present application provides a kind of new temperature measuring device paradigm, by mechanical design, fundamentally solve the core pain point of prior art in measurement comprehensiveness, reliability and accuracy, especially suitable for the research and development, test and online monitoring of electric vehicle, large-scale energy storage system and other fields with extremely high battery thermal safety requirements.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a lithium-ion battery temperature monitoring fixture. Background Technology

[0002] With the widespread application of lithium-ion batteries in electric vehicles, energy storage systems, consumer electronics and other fields, the safety performance of batteries has received widespread attention. Among them, temperature is one of the most important indicators in battery safety performance testing. In the prior art, Chinese patent document with application number: 202421309110.1 discloses a lithium-ion battery temperature control tooling.

[0003] However, due to structural defects, the above technical solution still has the following problems: 1. Poor fixation reliability: Traditional solutions use thermally conductive adhesive to attach the sensor or screws to lock it in place, which can easily cause it to fall off due to vibration; 2. Insufficient temperature measurement accuracy: Single-point monitoring cannot capture local hot spots, and external temperature measurement (such as infrared thermal imaging) is greatly affected by environmental interference and has a slow response. 3. Weak thermal runaway protection: Conventional materials (such as FR4 circuit boards and PTFE cables) have a temperature limit of <800℃ and cannot withstand the impact of flames at >1000℃ and the spray of molten metal during thermal runaway; 4. Size and cost issues: Multi-cell monitoring requires a large number of sensors, which takes up space and is costly; Currently, most lithium-ion battery temperature monitoring uses single-point contact temperature measurement, which cannot fully reflect the temperature distribution on the battery surface. During the charging and discharging process of cylindrical batteries, due to the uneven internal structure and differences in heat dissipation conditions, obvious circumferential and axial temperature gradients will form on the surface of the casing. In existing technologies, the temperature probe is mostly fixed by adhesive or strapping, which has problems such as poor contact, high thermal resistance, and easy loosening. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies, such as instability, limited monitoring points, poor accuracy, and inconvenient operation, by proposing a lithium-ion battery temperature monitoring fixture.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A lithium-ion battery temperature monitoring fixture includes a lithium-ion battery body, and the lithium-ion battery temperature monitoring fixture further includes: The three-section clamp assembly includes clamp rings and connecting rods. There are three clamp rings and six connecting rods. The three clamp rings are welded together by the six connecting rods. The inner side of the clamp rings is fitted onto the surface of the lithium-ion battery body. The temperature measuring unit consists of four groups, which are evenly distributed circumferentially on the surface of the lithium-ion battery body. Each group of temperature measuring units includes three axially distributed temperature probes and three temperature sensing lines. The temperature probes are electrically connected to the temperature sensing lines. The surface of the temperature probes is covered with an Inconel 600 alloy cover, and the insulating filler is high-purity magnesium oxide powder. The screw bar clamping mechanism has twelve parts. The screw bar clamping mechanism includes a locking nut, a threaded cylinder, a compression spring, and a slide. The inner side of the locking nut is threadedly connected to the surface of the threaded cylinder. The inner end of the threaded cylinder is welded to one end of the compression spring. The other end of the compression spring is welded to the side of the slide. The slide is welded to the temperature probe. The device includes three fixing mechanisms connected to a retaining ring. This application is not a simple improvement on existing technologies, but rather provides a completely new paradigm for temperature measurement devices. Through mechanical design, it fundamentally solves the core pain points of existing technologies in terms of measurement comprehensiveness, reliability, and accuracy. It is particularly suitable for research, testing, and online monitoring in fields such as electric vehicles and large-scale energy storage systems where battery thermal safety requirements are extremely high.

[0006] As a preferred embodiment of this utility model, the fixing mechanism includes a fixing bolt and a fixing nut, the surface of the fixing bolt is connected to the internal thread of the fixing nut, and the fixing nut is embedded inside the retaining ring.

[0007] Furthermore, by rotating the fixing bolt, which engages with the fixing nut, the fixing bolt can be moved closer to the lithium-ion battery body for positioning during the rotation of the fixing bolt.

[0008] In a preferred embodiment of this utility model, the retaining ring is fixedly connected to the lithium-ion battery body through a fixing mechanism, and a protective pad is rotatably connected to the end of the fixing bolt near the lithium-ion battery body.

[0009] Furthermore, the retaining ring is fixed to the surface of the lithium-ion battery body by retaining bolts and nuts, thus ensuring stability.

[0010] In a preferred embodiment of this utility model, the end of the temperature sensing wire away from the temperature probe passes through the holes of the slide, the compression spring, and the threaded cylinder in succession, and the temperature sensing wire extends to the outside of the retaining ring.

[0011] Furthermore, holes are provided inside the slide, compression spring, and threaded cylinder to facilitate the connection of the temperature sensing wire to the multi-channel temperature acquisition module.

[0012] As a preferred embodiment of this utility model, the surface of the retaining ring is provided with a temperature measuring groove, and the surface of the locking nut is rotatably sleeved with the opening on the outside of the temperature measuring groove.

[0013] Furthermore, the locking nut is rotatably mounted on a bearing and a temperature measuring groove to ensure the smooth rotation of the locking nut and facilitate the force exerted by the locking nut on the threaded cylinder.

[0014] As a preferred embodiment of this utility model, both the threaded cylinder and the slide block are integrally machined with slide bars around their perimeters, and both the threaded cylinder and the slide block are slidably connected to the sliding opening of the temperature measuring groove through the slide bars.

[0015] Furthermore, the threaded cylinder and slide are guided by a slider to the temperature measuring groove, facilitating the smooth movement of the threaded cylinder and slide.

[0016] As a preferred embodiment of this utility model, the front end of the temperature probe is a spherical contact surface, and the four temperature probes on the retaining ring are evenly distributed circumferentially. The axial distribution points of the temperature probes on the three retaining rings are located 10 mm from the end of the lithium-ion battery body and at the center position.

[0017] Furthermore, the spherical contact surface can be matched with the surfaces of various battery models, allowing for a clear and comprehensive view of the temperature at every location on the battery surface. This is crucial for identifying local hot spots caused by internal defects, uneven cooling, and other reasons, which are precursors to thermal runaway. Beneficial effects

[0018] 1. From single-point blind testing to full-field perception: Existing technologies can only measure the temperature at one point and cannot monitor the overall temperature of the battery. This application can clearly and comprehensively see the temperature of every location on the battery surface. This is crucial for identifying local hot spots caused by internal defects, uneven cooling, etc., and local hot spots are a precursor to thermal runaway. 2. From unreliable contact to stable contact: The reliability of existing adhesives decreases with time, temperature and environmental changes. The contact pressure provided by the screw bar clamping mechanism of this application is a preset and maintainable "constant". This not only ensures the consistency of each measurement, but also ensures the reliability of the device under long-term use and harsh working conditions. 3. Upgrade from disposable consumables to reusable tools: Existing adhesive probes are basically single-use, resulting in high testing costs and environmental pollution. This application, as a robust tooling, can be repeatedly used for tens of thousands of battery tests. The probe can be individually calibrated and replaced, greatly reducing the cost of long-term use and ensuring the long-term comparability of data. In this utility model: This application is not a simple improvement on the prior art, but provides a brand-new paradigm of temperature measurement device. Through mechanical design, it fundamentally solves the core pain points of the prior art in terms of measurement comprehensiveness, reliability and accuracy. It is particularly suitable for research, testing and online monitoring in fields such as electric vehicles and large-scale energy storage systems where battery thermal safety requirements are extremely high. Attached Figure Description

[0019] Figure 1 This is a three-dimensional view of a lithium-ion battery temperature monitoring fixture proposed in this utility model; Figure 2 A three-dimensional view of the retaining ring of a lithium-ion battery temperature monitoring fixture proposed in this utility model; Figure 3 This is a three-dimensional view of the fixing bolt of a lithium-ion battery temperature monitoring fixture proposed in this utility model; Figure 4 A perspective view of a threaded cylinder for a lithium-ion battery temperature monitoring fixture proposed in this utility model; Figure 5 This is a line graph comparing the dynamic response speed of a lithium-ion battery temperature monitoring fixture proposed in this utility model.

[0020] In the diagram: 1. Lithium-ion battery body; 2. Clamping ring; 3. Connecting rod; 4. Temperature probe; 5. Temperature sensing wire; 6. Locking nut; 7. Threaded cylinder; 8. Compression spring; 9. Slide; 10. Fixing bolt; 11. Fixing nut; 12. Protective pad; 13. Temperature measuring groove; 14. Slide bar. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Example

[0022] Reference Figure 1-5 A lithium-ion battery temperature monitoring fixture includes a lithium-ion battery body 1, and the lithium-ion battery temperature monitoring fixture further includes: The three-section clamp assembly includes clamp rings 2 and connecting rods 3. There are three clamp rings 2 and six connecting rods 3. The three clamp rings 2 are welded together by the six connecting rods 3. The inner side of the clamp rings 2 is sleeved on the surface of the lithium-ion battery body 1. The temperature measuring unit consists of four groups, which are evenly distributed circumferentially on the surface of the lithium-ion battery body 1. Each group of temperature measuring units includes three axially distributed temperature measuring probes 4 and three temperature sensing lines 5. The temperature measuring probes 4 and temperature sensing lines 5 are electrically connected. The surface of the temperature measuring probes 4 is covered with an Inconel 600 alloy cover, and the insulating filler is high-purity magnesium oxide powder. The screw rod clamping mechanism has twelve parts, including a locking nut 6, a threaded cylinder 7, a compression spring 8, and a slide 9. The inner side of the locking nut 6 is threadedly connected to the surface of the threaded cylinder 7. The inner end of the threaded cylinder 7 is welded to one end of the compression spring 8. The other end of the compression spring 8 is welded to the side of the slide 9. The slide 9 is welded to the temperature probe 4. The fixing mechanism has three parts, which are connected to the retaining ring 2. This application is not a simple improvement on the existing technology, but provides a brand-new temperature measurement device paradigm. Through mechanical design, it fundamentally solves the core pain points of the existing technology in terms of measurement comprehensiveness, reliability and accuracy. It is particularly suitable for research and development, testing and online monitoring in fields such as electric vehicles and large-scale energy storage systems where battery thermal safety requirements are extremely high.

[0023] To be larger than card circle 2, such as Figure 3 As shown, the fixing mechanism includes a fixing bolt 10 and a fixing nut 11. The surface of the fixing bolt 10 is connected to the internal thread of the fixing nut 11. The fixing nut 11 is embedded inside the retaining ring 2. When the fixing bolt 10 is rotated, the fixing bolt 10 and the fixing nut 11 cooperate. During the rotation of the fixing bolt 10, the fixing nut 11 can be used to limit the bolt to move closer to the lithium-ion battery body 1.

[0024] In order to fix the card ring 2, such as Figure 3 As shown, the retaining ring 2 is fixedly connected to the lithium-ion battery body 1 through a fixing mechanism. The end of the fixing bolt 10 near the lithium-ion battery body 1 is rotatably connected to a protective pad 12. The retaining ring 2 is fixed to the surface of the lithium-ion battery body 1 by the fixing bolt 10 and the fixing nut 11, thus ensuring stability.

[0025] To facilitate temperature measurement, such as Figure 4 As shown, the end of the temperature sensing wire 5 away from the temperature probe 4 passes through the holes of the slide 9, compression spring 8 and threaded cylinder 7 in succession. The temperature sensing wire 5 extends to the outside of the retaining ring 2. Holes are opened inside the slide 9, compression spring 8 and threaded cylinder 7 to facilitate the connection of the temperature sensing wire 5 to the multi-channel temperature acquisition module after it passes through.

[0026] To facilitate the rotation of the locking nut 6, such as Figure 3 As shown, the surface of the retaining ring 2 is provided with a temperature measuring groove 13. The surface of the locking nut 6 is rotatably connected to the opening on the outside of the temperature measuring groove 13. The locking nut 6 is rotatably set with the temperature measuring groove 13 through the bearing, which ensures the smooth rotation of the locking nut 6 and facilitates the locking nut 6 to generate a force for moving the threaded cylinder 7.

[0027] To guide the threaded cylinder 7 and the slide 9, such as Figure 4 As shown, both the threaded cylinder 7 and the slide block 9 are integrally machined with slide bars 14. The threaded cylinder 7 and the slide block 9 are slidably connected to the sliding opening of the temperature measuring groove 13 through the slide bars 14. The threaded cylinder 7 and the slide block 9 are guided to the temperature measuring groove 13 through the slide bars 14, which facilitates the smooth movement of the threaded cylinder 7 and the slide block 9.

[0028] To facilitate temperature measurement by temperature probe 4, such as Figure 2As shown, the front end of the temperature probe 4 is a spherical contact surface. The four temperature probes 4 on the retaining ring 2 are evenly distributed around the circumference. The axial distribution points of the temperature probes 4 on the three retaining rings 2 are located 10 mm from the end of the lithium-ion battery body 1 and at the center. The spherical contact surface can match the surface of various battery models. It can clearly and comprehensively see the temperature of every position on the battery surface. This is crucial for identifying local hot spots caused by internal defects, uneven cooling, etc., and local hot spots are a precursor to thermal runaway.

[0029] The working principle of this utility model is as follows: The three-section clamp assembly consisting of the retaining ring 2 and the connecting rod 3 is fitted onto the surface of the lithium-ion battery body 1. When it is necessary to fix the three-section clamp assembly, the fixing bolt 10 is rotated. The fixing bolt 10 cooperates with the fixing nut 11. During the rotation of the fixing bolt 10, the cooperation of the fixing nut 11 can drive the protective pad 12 closer to the lithium-ion battery body 1. The fixing bolt 10 abuts against the lithium-ion battery body 1 through the protective pad 12, thereby fixing the retaining ring 2 and the connecting rod 3. The locking nut 6 is rotated. The locking nut 6 is rotated with the retaining ring 2 through the bearing to ensure the smooth rotation of the locking nut 6. The threaded cylinder 7 is limited. The rotation of the locking nut 6 can drive the threaded cylinder 7 to move towards the lithium-ion battery body 1 through the thread. The threaded cylinder 7 can squeeze the compression spring 8. The compression spring 8 can squeeze the slide 9. The slide 9 can drive the temperature probe 4 to be close to the surface of the lithium-ion battery body 1. After the installation is completed, the temperature sensing wire 5 is connected to the multi-channel temperature acquisition module. Implementation Case: Comparative Experiment of 3C Rate Discharge Temperature Measurement of Lithium-ion Battery Main Body 1 Using a 32140 Type Lithium-ion Battery: Verify the superiority of this "screw-bar clamping distributed temperature measurement device" over "traditional single-point adhesive temperature measurement" in capturing battery surface temperature gradients, response speed, and local overheating early warning. Experimental setup: Test battery: 32140 type lithium-ion battery with a capacity of 15000mAh; Environmental conditions: Room temperature 25°C, natural convection; Discharge conditions: 3C constant current discharge 45A to cutoff voltage; Comparison of options: Option A, the traditional method: A PT1000 temperature sensor is attached to a single point in the middle of the battery casing and secured with high-temperature tape; Option B of this application: Install the device of this application on the battery to activate all 12 temperature probes; Experimental Results and Data Analysis:

[0030] After discharge, the time required for the battery temperature to drop to 35°C under both methods during natural cooling was monitored. The temperature measurement curve of this application is always ahead of the traditional method, reaching 35°C about 10 seconds earlier. This indicates that the thermal response time of this application is shorter and can more accurately reflect the actual temperature change of the battery surface. Mechanical reliability verification: Contact stability test: After vibration test at a frequency of 10-55Hz and an acceleration of 10g on a vibration table; Solution A (traditional): A visible gap appears between the sensor and the housing, the contact resistance increases from 0.5Ω to 15Ω, and the temperature measurement function is basically ineffective.

[0031] Option B of this application: The structure is intact, the contact resistance of all probes changes by less than 0.1Ω, and the temperature measurement data is stable.

[0032] Case Conclusion: This simulation experiment, through detailed data comparison, fully demonstrates the significant advancements of this application compared to traditional temperature measurement methods. Comprehensiveness: It successfully captured the axial temperature gradient of 5.2°C and the circumferential temperature gradient of 4.1°C, which could not be detected by traditional methods, and located the actual highest temperature point, avoiding the underestimation of 3.5°C. Accuracy: Thanks to the screw-bar clamping structure, the thermal response is faster, providing more accurate temperature data during dynamic processes, and the response delay is reduced by about 10 seconds compared to traditional methods; Reliability: In mechanical vibration environments, the contact stability and measurement consistency are far superior to adhesive fixing methods.

[0033] In summary, this device provides a more comprehensive, faster, and more reliable solution for monitoring the surface temperature of cylindrical lithium-ion batteries, which can provide a high-quality data foundation for battery thermal safety management and state assessment, and effectively reduce the risk of thermal runaway.

[0034] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A lithium ion battery temperature monitoring tool comprising a lithium ion battery body (1), characterized in that, The lithium-ion battery temperature monitoring fixture also includes: The three-section clamp assembly includes clamp rings (2) and connecting rods (3). There are three clamp rings (2) and six connecting rods (3). The three clamp rings (2) are welded together by the six connecting rods (3). The inner side of the clamp rings (2) is fitted onto the surface of the lithium-ion battery body (1). Temperature measuring unit, the temperature measuring unit is provided in four groups, the four groups of temperature measuring units are evenly distributed circumferentially on the surface of the lithium-ion battery body (1), each group of temperature measuring units includes three axially distributed temperature measuring probes (4) and three temperature sensing lines (5), the temperature measuring probes (4) are electrically connected to the temperature sensing lines (5), the surface of the temperature measuring probes (4) is covered with an Inconel600 alloy cover, and the insulating filler is high-purity magnesium oxide powder; The screw bar clamping mechanism has twelve screw bars. The screw bar clamping mechanism includes a locking nut (6), a threaded cylinder (7), a compression spring (8), and a slide (9). The inner side of the locking nut (6) is threadedly connected to the surface of the threaded cylinder (7). The inner end of the threaded cylinder (7) is welded to one end of the compression spring (8). The other end of the compression spring (8) is welded to the side of the slide (9). The slide (9) is welded to the temperature probe (4). The fixing mechanism has three parts, and the fixing mechanism is connected to the retaining ring (2).

2. The temperature monitoring tool for lithium ion battery according to claim 1, wherein, The fixing mechanism includes a fixing bolt (10) and a fixing nut (11). The surface of the fixing bolt (10) is connected to the internal thread of the fixing nut (11), and the fixing nut (11) is embedded inside the retaining ring (2).

3. The temperature monitoring tool for lithium ion battery according to claim 2, wherein, The retaining ring (2) is fixedly connected to the lithium-ion battery body (1) through a fixing mechanism, and a protective pad (12) is rotatably connected to one end of the fixing bolt (10) near the lithium-ion battery body (1).

4. The temperature monitoring tool for lithium ion battery according to claim 1, wherein, The end of the temperature sensing wire (5) away from the temperature probe (4) passes through the holes of the slide (9), the compression spring (8) and the threaded cylinder (7) in succession, and the temperature sensing wire (5) extends to the outside of the retaining ring (2).

5. The temperature monitoring tool for lithium ion battery of claim 1, wherein, The surface of the retaining ring (2) is provided with a temperature measuring groove (13), and the surface of the locking nut (6) is rotated and sleeved with the opening on the outside of the temperature measuring groove (13).

6. The temperature monitoring tool for lithium ion battery according to claim 5, wherein, The threaded cylinder (7) and the slide block (9) are both integrally machined with slide bars (14), and the threaded cylinder (7) and the slide block (9) are slidably connected to the sliding opening of the temperature measuring groove (13) through the slide bars (14).

7. The temperature monitoring tool for lithium ion battery of claim 1, wherein, The front end of the temperature probe (4) is a spherical contact surface. The four temperature probes (4) on the retaining ring (2) are evenly distributed around the circumference. The axial distribution points of the temperature probes (4) on the three retaining rings (2) are located 10 mm from the end of the lithium-ion battery body (1) and at the center.

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