Production: paint technical analysis

As we all know, the negative electrode of lithium battery is aluminum foil, and the negative electrode is copper foil. After coating, the anode coil and anode coil are made for further processing. The quality of the electrodes determines certain functions of the battery, and the coating of the substrate is a very important part of the entire battery manufacturing process!

From the original dip coating coating method, the most advanced double-sided coating is extruded to improve the quality and function table of the coating. Some domestic economic strength units, in order to make the solid-state lithium battery function, introduce a large amount of expensive foreign Pole piece coating machine.

Coating general process: The coating machine release device coats the substrate (foil). The first layer and the last layer of the substrate are connected by a splicing platform to form a continuous strip, which is then fed into the coating device by the tension adjustment device and the active correction device through the tension device. According to the coating amount and the length of the blank, the patch is performed on the coating equipment. In the double-sided coating, the length of the pre-coating and coating blanks are actively tracked. The coated wet electrode is sent into the boring slot for boring, and the boring temperature is set according to the coating speed and coating thickness. After boring plate tension adjustment and active correction, the next winding process is carried out.

Pole piece coating thickness, coating quantity, dry load. Hot air impact drilling is now widely used. The positive electrode substrate is aluminum foil, which has very active chemical properties and is easily oxidized. In the process of making aluminum foil, a thin oxide film is formed to prevent further oxidation of the aluminum foil. Because the oxide film is thin, porous and soft, it has good adsorption performance, but high temperature and high humidity will destroy the oxide film and accelerate the oxidation reaction. The most important thing now is the single-sided coating method. On the other hand, when the first coating is completely exposed to the air, the coating (oil), the dry hot air is about 130°C, if the water content of the hot air is not Useful control will add aluminum oxide foil and affect the anode material and aluminum foil glue, and even form water droplets in serious cases.

American and Japanese coating organization manufacturers have developed double-sided coating technology for single-layer coating function and aluminum foil oxidation, which completely solves the problem of aluminum foil coating oxidation. However, the price of double-sided coating machine is not affordable by ordinary battery manufacturers.