Induction vs. laser heating: A comparative study on innovative electrode drying technologies on pilot-scale
Max‐Wolfram von Horstig, Chao Zhang, Gabriela Ventura Silva, Peter Michalowski, Christoph Herrmann, Arno Kwade
Abstract
This study evaluates the drying performance and electrode quality of lithium-ion battery anodes, coated from a water-based slurry, and subjected to induction and laser heating within a pilot-scale roll-to-roll convective dryer. Structural and electrochemical assessments show both methods produce high-quality electrodes with comparable structural integrity. However, drying rates above specific thresholds degrade electrode performance. Adhesion, surface color value, surface roughness, and electrochemical impedance spectroscopy reveal that higher drying rates cause binder and carbon black to accumulate at the electrode surface, likely obscuring surface pores, lengthening ionic pathways, increasing ionic resistance and accelerating aging and capacity loss during electrochemical cycling. While induction heating achieves a 33% higher electrical-to-thermal conversion efficiency, this effects overall energy demand only slightly. Furthermore, increasing drying rates by additional heating increases the specific drying energy demand per kWh of battery produced in all cases. A reduction in energy demand was achieved by reducing the dryer air temperature. Ultimately, the study emphasizes the need for optimization between throughput, energy demand, and electrode quality. While both technologies offer the potential to increase of the throughput, additional research is needed to refine their applications and develop strategies for maximizing performance. • Radiative and inductive heat input contribute to similar increase in the drying rate. • High drying rates lead to accumulation of inactive components at electrode surface. • Particle segregation leads to reduction of surface roughness and ionic conductivity. • Reduction of energy demand by 63% when dryer air heating is turned off.