Important detection method of lithium battery diaphragm

　　Author ：Iflowpower – Portable Power Station Supplier

How to detect the thickness of the lithium ion battery diaphragm? As one of the four major raw materials of lithium electricity, the diaphragm is functionally used for the safety, cycle life, discharge ratio of lithium-ion batteries, but its technical threshold is high, so many investors are still. Even if the lithium-ion battery diaphragm has been domesticated, there are still many technical barriers to overcome. For example, almost all diaphragm thick equipment in China has only detecting the detection function, and it is very few closed-loop control of the diaphragm thickness.

The uniformity of the thickness of the lithium-ion battery diaphragm includes uniform longitudinal thickness, but in turn, the uniformity of lateral thickness is more important, generally must be controlled within 1 um. First, single-frame X-rays ensure that the thickness of the diaphragm thickness online detection is important to convert the radiation through the diaphragm to the diaphragm thickness. This means that the accuracy and stability of the detection must be guaranteed during the testing process.

Second, the online control technology of the diaphragm thickness The lithium-ion battery diaphragm thickness is important for two, one is MD (longitudinal) control and CD (horizontal) control; one is a diaphragm online machine visual detection technology. 1) MD control and CD control so-called MD control and CD control refer to the thickness closed loop control of the MD direction by controlling the upper screw speed or traction speed; and performs data closure control in the CD direction by the scanner. The key technique of which is the banner of the CD, that is, the detection data of the scanning frame must be accurately opposed to the position of the full-scale die.

In addition, consider the shrinkage factors of the membrane, only the case is accurate, can control Okay. 2) The visual detection technique of diaphragm online machinery is understood that the lithium-ion battery diaphragm is very critical is the identification of pinholes. It has introduced pinhole recognition techniques for diaphragm detection, which is a technique of differential needles and bright spots through multi-channel imaging exposure.

In addition to the pinhole recognition, there are other intelligent classification functions, which is the algorithm of intelligent classification. Through intelligent classification, comprehensive flaw analysis data can help companies improve equipment and technology, improve product quality. Thickness testing of lithium-ion battery diaphragm can also be made by non-contact thickness gauge.

However, although the measurement speed is fast, the sample is not damaged, but due to the multi-optical principle, the diaphragm is measured, and the film is very large. Instead, it is more detrimental to the measurement of thickness uniformity. The function of the lithium-ion battery diaphragm is in the structure of a lithium ion battery, and the diaphragm is one of the key innermost components.

The performance of the diaphragm determines the interface structure, internal resistance, etc. of the lithium ion battery, directly affects the capacity, cycle, and safety performance of the battery. Excellent diaphragm is important to improve the overall performance of the battery.

First, provide safety protection for lithium ion batteries. The diaphragm material must first have good insulation to prevent the positive and negative contact short circuit or the short circuit that occurs by burrs, particles, and dendritic thorns. Therefore, the diaphragm has a certain stretch, puncture strength, not easy to tear.

And basically maintain the stability of the size under the high temperature conditions of the burst, and the large area short circuit and thermal out of the battery will not be melted. The second is to supply the lithium-ion battery to achieve charge and discharge function, and the micro-hole passage of the magnification performance.