The formation of the battery electrode is the most costly and energy intensive step in Li-ion cell manufacturing. Drying the electrode slurry coating is a production bottleneck created by slow and inefficient heating methods. Laser drying is the smallest footprint, fastest, and most energy efficient slurry drying solution, offering Li-ion battery manufacturers the opportunity to spend significantly less on energy and maintenance than with convection furnaces or infrared lamps.
Contact an E-Mobility expert to learn more about how IPG laser drying solutions can optimize your electrode foil drying application.
IPG Diode Heaters vs. Convection Furnaces
Li-ion battery cell manufacturers are moving away from traditional fossil fuel burning convection furnaces in an effort to reduce their carbon footprint. Besides the environmental and energy cost concerns, convection furnaces suffer from other drawbacks that limit productivity for battery manufacturers.
Size: Diode heaters for electrode slurry drying are up to 6X smaller than convection furnaces, which often reach lengths of 100 m. A single 15 m diode heater can also replace multiple convection furnaces, freeing up factory floor space and infrastructure.
Speed: Infrared light dries the entire slurry simultaneously, enabling web speeds up to 60 m/min. By comparison, convection is a slow, indirect heating method that must heat the electrode slurry through the surface, typically limiting the foil web speed in convection furnaces to 4 m/min or less.
IPG Diode Heaters vs. Infrared Lamps
The drive to move away from convection furnaces to a higher speed solution has led some battery manufacturers to consider infrared lamp solutions. Lamps create infrared light similar to diode laser heaters and deliver similarly fast drying speeds. While infrared lamps are more efficient than convection furnaces, they are still significantly more costly to operate than a diode laser solution.
Data based on the estimated costs of operating a 520 kW furnace for 8,000 hours per year
Heating Efficiency: Lasers direct their energy only at the electrode slurry rather than radiating heat in a larger area. Infrared bulbs reach extremely high temperatures and direct heat imprecisely, generating substantial waste heat that is absorbed by the oven walls rather than the electrode slurry. Flammable electrode slurry solvent vapors are also at risk of being ignited by these bulbs, forcing manufacturers to use electricity to redirect this excess heat.
Maintenance: IPG diode heaters are maintenance free with an expected lifetime of 7+ years. Infrared bulbs last only 1 to 2 years, requiring a regular maintenance cycle and costly replacement.
Process Control: IPG diode heaters are "cold" furnaces that support in situ process monitoring to ensure consistent slurry drying results. Infrared bulbs start degrading from the moment they are turned on and often at varying rates. As a result, maintaining a balanced temperature distribution across the foil web is a challenge, excacerbated by limited process monitoring options inside the hot oven.
High-Efficiency Diode Lasers for Drying Applications
DLS-ECO diode lasers power IPG diode furnaces to offer high drying speeds and a low carbon footprint to provide EV battery manufacturers with an extremely efficient and cost-effective electrode slurry drying solution.
Power: Up to 200 kW per cabinet
Energy Efficiency: >52%
IPG partners with E-Mobility manufacturers throughout the entire production process from research and development to full-scale manufacturing.
Whether you want to demonstrate feasibility with laser-processed parts or just want to bounce design and implementation ideas off an experienced laser application engineer, don’t hesitate to contact us. Even better, visit one of our 32 regional Application Development Labs to learn how IPG can optimize your electrode foil drying application.
