Moisture Analysis in Lithium-Ion Batteries

Lithium-ion batteries are used throughout commercial, industrial, and residential applications due to their high capacity capabilities, lightweight properties, and slow self-discharge rates while in storage. A common issue that manufacturers face when creating lithium-ion batteries is the instability of the cell chemistries. Lithium metals are highly reactive to other materials, including oxygen, nitrogen, hydrogen, and water. Performing moisture analysis allows manufacturers to carefully produce batteries while avoiding problems such as thermal runaway and reduced durability.

Problems with Moisture During Production

Battery manufacturing processes go through specific steps in making the battery cells, which include making the cathodes, anodes, and the electrolyte. During the production of the electrodes, moisture is carefully controlled both in the environment and within processes. Moisture may come from various areas, such as the humidity present in the air along the production floor as well as moisture left over from the cathode slurry and anode solution created from the electrode raw materials before drying in a drying oven.

When too much moisture is present, it can react with the lithium to create dangerous situations. This reactivity may reduce charging capacity, product lifespan, and cause the possibility of fire or explosion (thermal runaway). Typically for lithium-ion battery production, the dry content range for materials involves a 60% dry content for cathode slurries and a 10% dry content for anode solutions. To further understand how much moisture is present, analysis equipment and techniques are used to measure the moisture rate.

Performing Moisture Analysis

Moisture analysis allows workers to measure the moisture content and dry content ratios of materials. In the past, these measurements were done using the Karl Fischer titration (KFT) and loss-on-drying (LoD) methods. However, traditional LoD is very time-consuming.

Newer analysis methods such as the METTLER TOLEDO’s halogen heating technology help to speed up the moisture analysis process, reduce errors, and permit the detection of moisture content during the laboratory and production phases of manufacturing operations. The HX204 Halogen Moisture Analyzer’s results are comparable to the drying-oven method yet they come within minutes instead of hours.

Additionally, the HX204 offers an easy-to-use interface and simple to clean sample area The material to be tested, such as the cathode slurry, is selected on the interface along with the temperature and drying program. The interface displays the data analysis quickly and is a repeatable method so that workers can perform quality testing and production adjustments quickly.

Simplifying Lithium-Ion Battery Production

The demand for quality lithium-ion batteries is expected to grow without any slowdowns in the market. This prediction will force manufacturers to introduce more production lines to keep up with market demand. To ensure both the safety of consumers and the quality performance of this battery chemistry, moisture analysis procedures become essential to prevent potential hazards and capacity losses. With the METTLER TOLEDO’s HX204, this analysis method can be done smoothly anytime during the production process to save the company both time and money.