What is the test method for lithium-ion battery separator technology?

What is the test method for lithium battery diaphragm technology? 1. Thickness Li-ion battery diaphragm thickness online control technology has two important ones, one is MD (longitudinal) control and CD (transverse) control; the other is diaphragm online machine vision testing technology. The so-called MD control and CD control refer to the closed-loop control of the thickness in the MD direction by controlling the speed of the feeding screw or the traction speed; and the data measurement through the scanning frame, and finally the closed-loop control of the data in the CD direction. 2. Curvature is also called arched by some companies, which refers to the arc formed after slitting the lithium-ion battery separator. When the arc is distinct, the laminations will be uneven, and vortices will be formed during winding, causing the pole pieces to be exposed and short-circuited. The detection method is to flatten the diaphragm strip on the desktop and compare the parallelism with the edge of the steel ruler to obtain the curvature of the diaphragm. 3. The time required for a certain volume of air to pass through the diaphragm under certain conditions, which is also called Gurley value. Its size has a certain influence on the performance of lithium-ion batteries, and ASTM detection method is generally used. 4. Porosity The ratio of the void volume to the entire volume. The detection methods include liquid absorption calculation method and detection method. The liquid absorption calculation method is to immerse the lithium battery diaphragm in a known solvent, and calculate the diaphragm by measuring the mass difference before and after the diaphragm is infiltrated. For the void volume occupied by liquid, the mercury intrusion detection method uses external force to apply pressure to the diaphragm to press mercury into the pores of the diaphragm, and then calculate the porosity of the diaphragm by measuring the volume of mercury injected, and take the uniform value after multiple measurements .