How to detect a gas permeability and wettability of lithium-ion battery diaphragm?

　　Author ：Iflowpower – Portable Power Station Supplier

A gas permeability of the lithium-ion battery separator detection method was measured by a gas permeability of lithium-ion battery separator. His feature is that the fixed battery diaphragm is applied to the side of the diaphragm, and the air pressure drop is measured. Test the time used in gas permeability.

In the case where the lithium ion battery diaphragm is fixed, a certain pressure is applied to the side of the diaphragm. Since the micropore is present on the diaphragm, the pressure will gradually decrease until it is equal to atmospheric pressure. By comparing the time required to fall from the initial pressure to the end pressure, the gas permeability of the separator can be understood.

By comparing the pressure drop time of different diaphragms, they can compare their breathable performance. The smaller the pressure drop time, the better the gas permeability. The whole experiment is simple, fast, data can reflect the gas permeability of the diaphragm, which has significant practicality.

In the whole process, you should pay attention to: 1. Ensure that the detection device seals and sealing processes do not damage the separator. 2 The initial pressure should not be too large, so as not to damage the separator.

Third, when detecting different lithium-ion battery diaphragms, there should be certain initial and final air pressure values, so that the time is more meaningful. The magnetic permeability, surface density and alkali absorption rate of the lithium ion battery diaphragm are associated with each other. If the membrane is high, the surface density of the film will decrease, which has a certain impact on the performance of the battery.

If the other parameters have achieved ideal, the gas permeability of the membrane is not good, and it will affect the performance of the battery, so it is necessary to detect the gas permeability of the diaphragm. The detection method of lithium-ion battery diaphragm wettability Since the electrolyte of the lithium ion battery is a solvent with a vinyl carbonate, a quantitative decomposition is often used in a lithium ion battery diaphragm wettability. Previously, the wettability of the diaphragm was visually immersed in the immersion solvent.

Due to the influence of human factors and environmental factors, the consistency and reproducibility of test results were poor; during the test, the solution solution was rough, resulting in testing The result is a larger human error. The wettability of the diaphragm and the wetting speed are maintained to the lithium ion battery. In order to effectively transfer lithium ions, the diaphragm between the positive and negative materials does not completely contact with the electrolyte, and has a long-lasting electrolyte retention capacity, otherwise, the internal resistance of the battery increases, and the performance is lowered.

Generally, the wettability of the diaphragm is related to the properties of the material, and the hydrophilic material is better than the hydrophobic material, and thus the contact angle between the surface of the separator and the electrolyte can be measured by a contact angle detector. The size of the contact angle is straightforward.