For this very sensitive battery manufacturing process the use of a desiccant dehumidifier is essential. Pure lithium reacts violently with water. Even normal levels of relative levels or humidity cause quality control problems in the lithium battery manufacturing process. Therefore the processing takes place in dry rooms, where the dewpoint temperature is typically controlled at a very low humidity level. The safety of employees and property is of utmost importance.
The quality of the end product is also extremely important. Recent research demonstrates that ambient moisture present in the manufacturing room can degrade the "memory" characteristic of the lithium and also the newer advances polymer-based batteries.
Dry rooms, or environmental chambers, are generally built to house the manufacturing areas for batteries. Because of the reactive nature of the moisture in the air during the lithium battery manufacturing, most lithium battery, and lithium polymer battery process, require a dry room dew point of -40 to -50 degrees Fahrenheit or lower, (i.e., 0.6 to 0.3 gr/# respectively). Taking into consideration that there could be a moisture migration into the dry room, even with an airlock entry way, and there could be a slight latent gain within the room due to the workers, the supply air moisture level may be required to be -60 to - 100 degrees Fahrenheit dewpoint (0.1 to 0.0 gr/#. respectively).