Process temperature measurement during nanosecond pulse laser micromachining of Li-Ion battery electrodes

Surface functionalization as well as the microstructure modification of electrodes by laser material processing has become increasingly important in recent years. Short and ultra-short pulsed lasers, which enable high-precision processing, are used for this purpose. However, the process mechanisms, such as the surface temperatures that emerge during the process are not fully understood yet. New infrared high-speed detectors and their application allow to close this gap. In the present study, the infrared emissions of the selective ablation process of Li-ion battery electrodes are investigated experimentally. The electrode consists of graphite active material embedded in a carbon/binder domain. Due to the compaction of high-energy electrodes, pore clogging occurs, which hinders its fast-charging capability and the electrolyte wettability. The selective ablation of the surface binder phase significantly improves these two properties. The investigation of pure graphite material results in lower heat accumulation values but comparable peak values in comparison to the compacted electrode.