The drying process in the production of lithium-ion batteries refers to the key process of completely removing moisture from battery components (such as cells, electrodes) or the entire production environment. Moisture can cause side reactions with electrolytes, seriously affecting battery life, safety, and consistency. Therefore, drying is the core prerequisite for ensuring battery quality.

The workflow is mainly divided into the following stages:

Pre processing and transportation: The bare cells (not filled with liquid) after winding or stacking are quickly transferred from a normal environment to a low dew point (usually required to be ≤ -40 ℃) drying room through a drying cabinet or vacuum glove box to prevent them from adsorbing moisture in the air during transportation.

Vacuum high-temperature baking: Place the battery cells in a vacuum baking oven and bake them for a long time under high temperature (usually 80 ℃ -120 ℃) and high vacuum degree (such as -0.09MPa or above) conditions. High temperature provides energy to evaporate water, while a high vacuum environment can quickly remove the evaporated water vapor from the box, achieving efficient and deep dehydration.

Cooling and storage: After baking, cool the battery cells to room temperature under the protection of vacuum or dry inert gas (such as nitrogen). The cooled battery cells should be immediately transferred to a drying room or cabinet for temporary storage, ensuring that they are always in an ultra-low humidity environment before injection to avoid moisture absorption again.

The core value of this process lies in precisely controlling temperature, vacuum degree, and time to ensure that the moisture content inside the battery cell is reduced to extremely low levels (such as PPM level), laying a solid foundation for the subsequent liquid injection process and fundamentally ensuring the stability and safety of the battery's final performance.