Cleanliness is crucial for the production process of lithium-ion batteries, especially for the anode and cathode coatings. As the materials cannot come into contact with each other, cleaning needs to be carried out in two separate clean rooms. Electrolyte filling must also be carried out in a dry environment to prevent lithium hexafluoride from reacting with water vapor in the air to form hydrogen. Most manufacturers will conduct the entire assembly process in a clean and controllable environment.

Generally speaking, the ambient air in production environments needs to be drier than -30 ° Cdp (or 1.4% RH at 23 ° C).

Due to the large number of people involved in battery production, it is necessary to continuously circulate the air in the production environment through a rotary dryer to remove the moisture emitted by personnel.

Part of the process may be carried out in a glove box, possibly under pressure close to vacuum, and the humidity can be reduced to a lower dew point temperature, typically as low as -65 ° C dew point (about 3 ppmV, or 0.01% RH).

What is the best choice for measuring low humidity environments in battery production?

It is crucial to use highly sensitive and extremely reliable measuring instruments under these challenging conditions.

The accuracy of the cold mirror hygrometer is ± 0.15 ° C or higher. Because they measure the actual temperature at which condensation forms, they have almost no drift over time, making them one of the reliable and practical instruments in this application. The measurement range varies for different models, but for truly low humidity levels - below -30 ° C dew point - cold mirrors are the best choice.

The cold mirror hygrometer is used to sample the environmental humidity at key locations in the manufacturing area. Connect it to the Supervisory Control and Data Acquisition (SCADA) system to enable direct control of the dehumidifier, maximizing energy efficiency. When the room humidity exceeds the specified value, an alarm is crucial for providing immediate indication.

Recommended products for monitoring trace humidity in battery production

Mixier S8000 RS - Suitable for very dry applications

• Reliable coverage of the key low dew point measurement range for dry battery production applications - precise measurement of dew points as low as -90 ° C;

• Compact and lightweight (19 "x 4U rack mounted, 22.4 kg);

• Easy to install, no need for additional cooling;

• Ethernet and USB connections can be integrated with SCADA.





Mixier S8000- suitable for applications with a dew point of around -40 ° C.

• Specially designed for industrial environments, it can accurately measure dew points as low as -60 ° C. This series is suitable for most battery production applications.

• Like the S8000 RS, it is compact in structure, lightweight, and offers the same wide range of connectivity options.





Michiel Optidew - Ideal for measuring humidity in lower specification factories or dew points as low as -30 ℃

• Affordable humidity measurement with almost no drift and an accuracy of 0.15 ° C dew point;

• Wide range of communication methods, including Modbus TCP, Ethernet, USB, and RS485;

• Quick response: Stable measurement within 1 minute.