Most battery manufacturers require that a room's humidity/average moisture level be maintained as low as -40°C dew point (0. 5% Relative Humidity at 72°F) and sometimes even lower.
The humidity level in battery manufacturing varies depending on the stage of the process. Typically, during cell assembly, currently, the dew point ranges from -35°C to -45°C, corresponding to an absolute humidity of 0.10555 to 0.2841 grams of water per kg of dry air.
These classes belong to the middle class of cleanliness. But besides the cleanness, the process room in battery manufacturing shall be dry. A dry room is a premises with a controlled low moisture level in the air.
What is a clean and dry room in lithium-ion battery manufacturing?
The core processes in lithium-ion battery manufacturing such as electrode manufacturing and battery cell assembly are performed in the Clean and Dry (C&D) rooms. In this article, we will deeply consider the peculiarity and challenges of clean and dry rooms in battery manufacturing specifically from the HVAC perspective.
The clean rooms for battery manufacturing usually use the following classes of cleanness ISO 8, ISO7, and ISO6 per ISO 14644-1 standard or equivalent classes 100,000; 10,000; and 1,000 per FS209E standard. These classes belong to the middle class of cleanliness. But besides the cleanness, the process room in battery manufacturing shall be dry.
An analysis of the existing lithium-ion battery manufacturing giga-factories shows that the energy consumption of clean and dry room HVAC systems can be 2938% of the total factory energy consumption, depending on the required humidity level and existing loads.
How many steps are there in lithium-ion battery manufacturing process?
For a deeper understanding of the lithium-ion battery manufacturing process, it can be presented in 13 steps: Slurry Mixing. The first step in lithium-ion battery manufacturing is to prepare the electrode slurry.