Lithium battery diaphragm coating

Lithium battery diaphragm coating - Battery energy - YMUS ultrasonic spraying

Lithium battery separator is a thin film material used in lithium-ion batteries, which is mainly used to isolate the positive and negative electrodes to prevent short circuits and allow the transmission of lithium ions in the electrolyte. The diaphragm is usually located between the positive and negative electrodes, acting as a transmission channel for electrolyte ions and preventing internal short circuits in the battery. Common lithium battery diaphragm materials mainly include polypropylene film (PP film) and polyimide film (PI film). These materials can meet the requirements of diaphragm in lithium battery applications, and have good electrochemical properties and thermal stability. With the development of lithium battery, the energy density of lithium ion battery increases year by year, the amount of inactive characteristics is also less and less, the diaphragm is becoming thinner and thinner, the performance of the diaphragm, especially the safety performance requirements are getting higher and higher, which will bring great challenges to the safety of lithium ion battery, diaphragm coating technology has become an effective way to greatly improve the safety performance of the diaphragm.

At present, there are five types of diaphragms:

1. Special alumina coating: The coating of special alumina coating can improve the temperature resistance and oxidation resistance of the base film, and improve the penetration ability of the diaphragm against lithium crystal branches and dust impurities;

2, Boehmite coating: Boehmite coating can improve the temperature resistance and oxidation resistance of the base film;

3, Aramid coating: coating aramid coating can improve the oxidation resistance, electrolyte infiltration, temperature resistance of the base film;

4, Polyvinylidene fluoride or PMMA coating: coating polyvinylidene fluoride or PMMA coating is to play a bond function between the diaphragm and the pole plate, improve the high pressure resistance of the base film;

5, Coated with polyvinylidene fluoride or PMMA and alumina mixed coating: can play a bond function between the film and the pole, improve the high pressure resistance of the base film;

YMUS ultrasonic spraying system

Different coatings have different effects. At present, YMUS ultrasonic sprayed alumina ceramic diaphragm has been stable and mass produced; The performance test of the ceramic diaphragm shows that the ceramic coating significantly improves the liquid absorption and liquid retention of the diaphragm, so it shows good cycling performance. The alumina ceramic coating provides the skeleton for the flexible diaphragm, improves the wear resistance of the diaphragm to prevent the penetration of lithium dendrites, reduces the thermal shrinkage, improves the temperature resistance, and the porosity changes with the temperature stable, which can effectively improve the safety performance of the battery.