The high vacuum drying system is a key equipment in the production of lithium-ion batteries, mainly used to thoroughly remove trace amounts of moisture and solvent residues inside the battery cells (or electrodes). Its working effect directly determines the cycle life and safety performance of the battery.

The standard workflow includes the following three stages:

Loading and pre vacuuming: Load the battery cells to be dried (usually sealed before injection) into the material rack of the drying oven, close and lock the oven door. System startup, first perform pre vacuuming to quickly reduce the pressure inside the box to a lower vacuum level, creating a low-pressure environment for subsequent deep dehydration.

Heating and deep drying: Under the condition of maintaining a high vacuum degree (usually better than -0.095MPa), start the heating system and heat the battery cells in a stepwise manner according to the preset process curve. Under the synergistic effect of high vacuum and high temperature (usually 80-120 ℃), the moisture and volatile substances inside the battery cell and the micropores of the electrode plate quickly vaporize and are continuously pumped away by the vacuum pump group, achieving deep and efficient dehydration.

Cooling and Vacuum Breaking: After the drying process is completed, stop heating and introduce cooling medium (such as cooling water) to cool the box and materials. After the temperature drops to a safe range (such as below 40 ℃), fill the box with high-purity dry inert gas (such as nitrogen) to restore normal pressure, that is, "break the vacuum". Finally, open the box door, remove the dried and qualified battery cells, and immediately transfer them to the low dew point drying room for subsequent operations to prevent moisture absorption again.

The core value of this system lies in the synergy of high vacuum and heating, which greatly reduces the boiling point of water, allowing it to be quickly and thoroughly removed at a lower temperature without damaging the battery cell. It can strictly control the water content of the battery cell at an extremely low PPM level, which is the cornerstone of ensuring the consistency and safety of the battery's final performance.