Detection device and detection method for diaphragm rupture temperature and area
By designing a detection device for the temperature control box and CCD defect detector for the diaphragm, the problem of unstable diaphragm rupture temperature testing in the prior art is solved, and fast and accurate rupture temperature and area detection is achieved, satisfying lithium Battery separator production demand.
Patent Information
- Application Number
- CN202411603530.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-11
- Publication Date
- 2025-01-07
AI Technical Summary
The existing diaphragm rupture temperature testing methods are unstable, difficult to meet market demand, and high requirements for instrument performance, making it difficult to achieve accurate rupture temperature and area detection.
A detection device for rupture temperature and area of the diaphragm is designed, including a thermostatic box and a CCD defect detector. The diaphragm sample is heated through the thermostatic box, and the CCD defect detector is used to observe the rupture temperature and area in real time. A simple and easy detection method is adopted.
It realizes fast and accurate film rupture temperature and area detection, improves detection efficiency and quality, reduces costs, and meets the production needs of lithium battery separators.
Smart Images
Figure CN119269397A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an industrial detection device and a detection method, in particular to a detection device and a detection method applied to the production of lithium battery diaphragms, specifically to a detection device and a detection method for diaphragm rupture temperature and area. Background Art
[0002] Lithium batteries are mainly composed of positive electrode materials, negative electrode materials, electrolytes and diaphragms. The main function of the diaphragm is to separate the positive and negative electrodes of the battery to prevent the two electrodes from contacting and short-circuiting. The diaphragm has many microporous structures. When the battery is heated to a certain temperature, the micropores inside the diaphragm will shrink to prevent lithium ions from passing through, ensuring the safety of the battery. The rupture temperature is the limit temperature that causes battery damage. At this temperature, the diaphragm completely melts and ruptures, causing the two electrodes inside the battery to contact and short-circuit. The rupture area can reflect the performance differences between diaphragms to a certain extent. Therefore, the rupture temperature and rupture area of the diaphragm are both important indicators related to the safety performance of lithium batteries. Improving the rupture temperature of the diaphragm is of great significance to improving the safety performance of lithium batteries.
[0003] At present, the most common test method for the membrane rupture temperature of the diaphragm is the resistance test method. This method places the diaphragm in a fixture that can be heated, and adds electrolyte to form a closed conductivity test environment, observes the resistance change brought about by the temperature increase, and finds the resistance mutation point as the closed-pore rupture temperature of the diaphragm. However, the test results of this method are unstable, and the overall performance requirements of the instrument are high, which is difficult to meet market needs.
[0004] Therefore, it is urgently needed to be improved in order to better meet production needs. Summary of the invention
[0005] The purpose of the present invention is to address the deficiencies in the prior art and to provide a device and method for detecting the temperature and area of diaphragm rupture, which has a simple structure and is easy to use. It can observe changes in the diaphragm state in real time, accurately test the rupture temperature and area, and fully meet the production needs of lithium battery diaphragms.
[0006] The technical solution of the present invention is: A device for detecting the temperature and area of diaphragm rupture, comprising a temperature control box, which is box-shaped, capable of heating and temperature control inside, with transparent observation windows and lighting windows provided on the top and bottom respectively, and a storage rack provided inside; the observation window and lighting window correspond to each other; a light source is provided below the lighting window; a detector is provided above the observation window; the storage rack is hollow and is horizontally placed in the middle of the temperature control box, wherein the hollow space corresponds to the observation window and lighting window; and further comprises a sample rack; the sample rack comprises an outer ring and an inner ring, both of which are annular; the outer ring can be tightly fitted on the inner ring so as to clamp the edge of the diaphragm sample laid on the inner ring between the outer ring and the inner ring; the sample rack is movably placed on the storage rack, and the diaphragm is located in the hollow space of the storage rack.
[0007] Furthermore, the storage rack includes straight rod-shaped rack rods; there are two rack rods, which are arranged in parallel horizontally, and the two ends of the rack rods are respectively fixed on the inner walls on both sides of the temperature control box; the distance between the rack rods is adapted to the width of the observation window.
[0008] Furthermore, it also includes a bracket; the bracket is a rectangular frame, and its size is adapted to the temperature-controlled box; the temperature-controlled box is placed on the bracket.
[0009] Furthermore, it also includes a fixing frame in the shape of a "door", which is arranged across the temperature control box and has a lower end connected to the bracket; the lens of the detector is fixed on the fixing frame.
[0010] Furthermore, the outer ring and the inner ring are both in annular shape; an opening is provided on the outer ring, and a bolt pair is provided at the opening so as to adjust the gap of the opening to change the size of the outer ring.
[0011] Furthermore, the light source is an LED light bar, which is arranged inside the bracket and 100mm-150mm away from the lighting window.
[0012] A method for detecting a diaphragm rupture temperature and area, using the diaphragm rupture temperature and area detection device, comprises the following steps: 1) Cut a piece of diaphragm sample into a square and fix it on the sample holder; 2) Place the sample rack on the shelf inside the temperature control box, and place the diaphragm sample in the hollow position of the shelf; 3) The temperature control box starts to heat up, and when the temperature reaches the set temperature, the light source is turned on, and the diaphragm sample is observed by the CCD defect detector; 4) The temperature control box continues to increase the temperature and the observation is maintained until a hole appears on the diaphragm sample, then the temperature is stopped and the observation is ended; then, the temperature and the area of the hole when the diaphragm sample appears are recorded; 5) Repeat steps 1) to 4) above for the same sample and average the results.
[0013] Furthermore, in the step 1), the excess portion of the membrane sample is cut off, and at least 1 cm is left at the edge.
[0014] Furthermore, in step 3), the temperature control box is heated at a rate of 1°C / min; when the temperature reaches 130°C, it is kept at this temperature for 5 minutes for each 1°C increase; the set temperature is 140°C.
[0015] Furthermore, in step 4), the temperature of the temperature-controlled box is increased at a rate of 1°C / min, and each time the temperature is increased by 1°C, the temperature is maintained for 5 minutes.
[0016] Beneficial effects of the present invention: The invention has reasonable design, simple structure, and convenient use. The diaphragm sample is heated by a temperature control box, and the diaphragm is observed in real time by a CCD defect detector, so that the rupture temperature and rupture area are detected quickly and accurately, which greatly improves the detection efficiency and quality. Moreover, the detection method of the invention is simple and easy to implement, effectively reduces the cost, and fully meets the production needs of lithium battery diaphragms. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a structural schematic diagram of the present invention.
[0018] Among them, 1-lens; 2-fixed frame; 3-storage rack; 4-lighting window; 5-bracket; 6-LED light bar; 7-sample rack; 8-temperature control box; 9-observation window. DETAILED DESCRIPTION
[0019] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.
[0020] like Figure 1 As shown, a device for detecting the temperature and area of diaphragm rupture of the present invention comprises a temperature control box 8 and a detector.
[0021] The temperature control box 8 is in the shape of a rectangular box, which can heat and control the temperature inside. A transparent observation window 9 and a lighting window 4 are provided on the top and bottom, respectively. The observation window 9 and the lighting window 4 are both rectangular holes covered with a transparent cover. At the same time, the observation window 9 and the lighting window 4 are of comparable size and are both centered for easy use. Preferably, the temperature control box 8 can be a commercially available blast temperature control box, and a swing door is provided on the front end for easy opening. The temperature control box is equipped with a heating and temperature measuring device, and the heating speed can be set.
[0022] The temperature control box 8 is provided with a shelf 3. The shelf 3 includes two straight rod-shaped racks. The racks are arranged in parallel in the horizontal direction, and the two ends of the racks are respectively fixed on the inner walls of the two sides of the temperature control box 8, and the distance between them is adapted to the observation window.
[0023] A sample rack 7 is movably placed on the storage rack 3. The sample rack 7 includes an outer ring and an inner ring, both of which are in the shape of a ring, and the outer ring is sleeved on the inner ring to form a structure similar to an "embroidery frame". The outer ring is an open ring, and a bolt pair is provided at the opening so as to adjust the gap of the opening and change the size of the outer ring so that it can be tightly sleeved. The diameter of the inner ring is larger than the distance between the rack rods, which is convenient for its placement. When in use, the outer ring and the inner ring are first separated, and then a diaphragm sample larger than the inner ring is laid on the inner ring, and the outer ring is sleeved on the inner ring to fix the edge of the diaphragm sample and make the diaphragm sample flat. Then, the installed sample rack is placed on the storage rack so that the sample diaphragm corresponds to the observation window.
[0024] A bracket 5 is provided below the temperature control box 8. The bracket 5 is a rectangular frame, and its size is adapted to the temperature control box 8. The temperature control box is placed on the upper surface of the bracket for easy operation. An LED light stick 6 is provided inside the bracket 5 as a light source. The wavelength of the LED light stick 6 is 630mm, and its two ends are respectively connected to the two side frames of the bracket 5. At the same time, the light source corresponds to the observation window and is 100mm-150mm away from the lighting window, so as to provide the lighting required for observation in the temperature control box. Preferably, there are two LED light sticks 6, which are arranged in parallel with each other at a distance to make the lighting more sufficient.
[0025] A fixing frame 2 is provided above the support 1. The fixing frame 2 is a "door"-shaped frame, straddling the temperature control box 8, and its lower end is connected to the support 5. The detector is a CCD defect detector, and its lens 1 is fixed on the fixing frame 2. At the same time, the lens 1 is located on the center line of the temperature control box 8 and is about 20 cm away from the observation window 9, so that the diaphragm sample in the temperature control box can be observed through the observation window.
[0026] The present invention provides a method for detecting the temperature and area of diaphragm rupture, using the above detection device, and comprising the following steps: 1) Cut a piece of diaphragm sample into a square and fix it on the sample holder; after fixing, cut off the excess part of the diaphragm sample and leave at least 1 cm on the edge; 2) Place the sample rack on the shelf inside the temperature control box, and place the diaphragm sample in the hollow position of the shelf; 3) The temperature control box starts heating up, first at a rate of 1°C / min; when the temperature reaches 130°C, it is kept at this temperature for 5 minutes for each 1°C increase to avoid affecting the experimental results due to too fast a temperature increase; when the temperature reaches the set temperature of 140°C, the light source is turned on, and the diaphragm sample is observed by the CCD defect detector; 4) The temperature control box continues to increase at a rate of 1°C / min, and each time the temperature increases by 1°C, it is maintained at this temperature for 5 minutes; at the same time, the observation is maintained until the diaphragm sample has a hole, then the temperature is stopped and the observation is ended; then, the temperature and the area of the hole when the diaphragm sample has a hole are recorded; 5) Take another sample of the same type of diaphragm, repeat the above steps 1) to 4), and take the average of the results to eliminate accidental errors and improve the accuracy of the test.
[0027] The present invention uses a temperature control box to heat the diaphragm sample and uses a CCD defect detector to observe the diaphragm in real time, so that the rupture temperature and rupture area can be detected quickly and accurately, greatly improving the detection efficiency and quality. Moreover, the detection method of the present invention is simple and easy to implement, effectively reduces costs, and fully meets the production needs of lithium battery diaphragms.
[0028] The parts not involved in the present invention are the same as the prior art or can be implemented by using the prior art.
Claims
1. A device for detecting the temperature and area of diaphragm rupture, comprising a temperature control box, characterized in that: The temperature control box is box-shaped, and its interior can be heated and temperature-controlled. A transparent observation window and an illumination window are respectively provided on the top and bottom, and a storage rack is provided inside; the observation window and the illumination window correspond to each other; a light source is provided below the illumination window; a detector is provided above the observation window; the storage rack is hollow and is horizontally placed in the middle of the temperature control box, and the hollow part thereof corresponds to the observation window and the illumination window; it also includes a sample rack; the sample rack includes an outer ring and an inner ring, both of which are annular; the outer ring can be tightly fitted on the inner ring so that the edge of the diaphragm sample laid on the inner ring can be clamped between the outer ring and the inner ring; the sample rack is movably placed on the storage rack, and the diaphragm is located in the hollow part of the storage rack.
2. The device for detecting the diaphragm rupture temperature and area according to claim 1, characterized in that: The storage rack includes two straight rod-shaped rack rods, which are arranged in parallel in the horizontal direction, and the two ends of the rack rods are respectively fixed on the inner walls of the two sides of the temperature control box; the distance between the rack rods is adapted to the width of the observation window.
3. The device for detecting the diaphragm rupture temperature and area according to claim 1, characterized in that: It also includes a bracket; the bracket is a rectangular frame, and its size is adapted to the temperature control box; the temperature control box is placed on the bracket.
4. The device for detecting the diaphragm rupture temperature and area according to claim 3 is characterized in that: It also includes a fixing frame in the shape of a "door", which is arranged across the temperature control box and has a lower end connected to the bracket; the lens of the detector is fixed on the fixing frame.
5. The device for detecting the diaphragm rupture temperature and area according to claim 1, characterized in that: The outer ring and the inner ring are both in annular shape; an opening is arranged on the outer ring, and a bolt pair is arranged at the opening so as to adjust the gap of the opening and change the size of the outer ring.
6. The device for detecting the diaphragm rupture temperature and area according to claim 3, characterized in that: The light source is an LED light stick, which is arranged inside the bracket and 100mm-150mm away from the lighting window.
7. A method for detecting the temperature and area of diaphragm rupture, characterized in that: The device for detecting the diaphragm rupture temperature and area according to claims 1 to 6 comprises the following steps: 1) Cut a piece of diaphragm sample into a square and fix it on the sample holder; 2) Place the sample rack on the shelf inside the temperature control box, and place the diaphragm sample in the hollow position of the shelf; 3) The temperature control box starts to heat up, and when the temperature reaches the set temperature, the light source is turned on, and the diaphragm sample is observed by the CCD defect detector; 4) The temperature control box continues to increase the temperature and the observation is maintained until a hole appears on the diaphragm sample, then the temperature is stopped and the observation is ended; then, the temperature and the area of the hole when the diaphragm sample appears are recorded; 5) Repeat steps 1) to 4) above for the same sample and average the results.
8. The method for detecting the diaphragm rupture temperature and area according to claim 7, characterized in that: In the step 1), the excess portion of the membrane sample is cut off, leaving at least 1 cm at the edge.
9. The method for detecting the diaphragm rupture temperature and area according to claim 7, characterized in that: In the step 3), the temperature of the temperature control box is increased at a rate of 1°C / min; when the temperature reaches 130°C, it is increased by 1°C for 5 minutes at this temperature; the set temperature is 140°C.
10. The method for detecting the diaphragm rupture temperature and area according to claim 7, characterized in that: In step 4), the temperature of the temperature control box is increased at a rate of 1°C / min, and each time the temperature is increased by 1°C, the temperature is maintained for 5 minutes.