How to detect the permeability and wettability of lithium battery separators?

A method to measure the air permeability of lithium battery separators The air permeability of the lithium battery separator detection method adopts air permeability measurement technology. Its characteristics are: fix the battery diaphragm, apply air pressure on one side of the diaphragm, measure the air pressure drop and test the separation The time it takes for the air permeability of the device. In the case of fixing the lithium battery diaphragm, a certain pressure is applied to one side of the diaphragm. Due to the micropores in the diaphragm, the pressure will gradually decrease until it is equal to the atmospheric pressure. By comparing the time required for the pressure to drop from the initial pressure to the end pressure, the permeability of the diaphragm can be known. By comparing the pressure drop time of different diaphragms, you can compare their air permeability. The shorter the pressure drop time, the better the air permeability. The whole experiment process is simple and fast, and the data can directly reflect the air permeability of the diaphragm, which has significant practicability. In the whole process, pay attention to: 1. Ensure that the sealing and sealing process of the detection device will not damage the diaphragm. 2 The initial pressure should not be too large, so as not to damage the diaphragm. Third, when detecting different lithium battery diaphragms, there should be a certain initial and final pressure value, so that the recorded time has a comparative significance. The permeability, surface density, and alkali absorption rate of lithium battery separators are related to each other. If the air permeability of the membrane is high, the surface density of the membrane will decrease, which will have a certain impact on the performance of the battery. If other parameters reach the ideal range, the air permeability of the diaphragm is not good, which will also affect the performance of the battery. Therefore, it is necessary to detect the air permeability of the diaphragm. Detection method for the wettability of lithium battery diaphragms As the electrolyte of lithium batteries uses ethylene carbonate as the solvent, ethylene carbonate is often used for quantitative decomposition in the detection of the wettability of lithium battery diaphragms. Previously, the wettability of the diaphragm was critically adopted by the immersion solvent visual method. Due to the influence of human factors and environmental factors, the consistency and reproducibility of the test results were poor; during the test process, the sample solution was relatively rough, which led to the test As a result, there is a large human error. The wettability and wetting speed of the separator are critical to the operation of lithium batteries. In order to effectively transfer lithium ions, the diaphragm between the positive and negative materials must be in complete contact with the electrolyte and have a long-lasting electrolyte retention capacity. Otherwise, the internal resistance of the battery will increase and the performance will decrease. Generally, the wettability of the diaphragm is related to the properties of the material. The wettability of hydrophilic materials is better than that of hydrophobic materials. Therefore, a contact angle detector can be used to measure the contact angle between the surface of the diaphragm and the electrolyte. The size of the contact angle is straight to compare its wettability. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous post: What is the important difference between power lithium battery and general lithium battery