To reduce the use of fossil fuels, the adoption of battery electric vehicles (BEVs) using lithium-ion batteries has been increasing in internal combustion engine alternatives. Accordingly, significant efforts have been made to improve the manufacturing process of lithium-ion batteries within electric vehicles. In particular, the cutting process of lithium-ion batteries has been actively discussed as it is closely related to battery performance. Laser-based cutting enables a more precise and sustainable manufacturing process. The laser ablation threshold has been investigated in many studies to achieve high-precision laser processing. While laser parameters and ambient conditions have been examined to determine the laser ablation threshold, studies focusing on the effect of relative humidity remain insufficient. Thus, this study investigated the laser ablation threshold of aluminum foil under varying relative humidity conditions. First, a laser interaction chamber was fabricated to control the relative humidity during experiments. A scanning electron microscope (SEM) was then used to observe laser ablation craters and analyze the threshold. The variation of the laser ablation threshold with relative humidity revealed changes in the interaction between the laser and aluminum foil depending on the humidity level.

Micro-hole perforation on stainless steel is essential for various industrial applications. However, achieving precise hole geometry, high aspect ratio, and excellent surface quality remains challenging with conventional drilling methods. In this study, we employed a single circular path trepanning technique using a femtosecond laser to drill micro-holes in 316L stainless steel with diameters less than 90 µm. Process parameters, including pulse energy, repetition rate, scan speed, and number of scans, were systematically varied. Resulting hole morphology and cross-sectional profiles were characterized using a confocal microscope and a scanning electron microscope. Our findings demonstrated that optimized femtosecond laser drilling could minimize recast layers, sputter deposition, and heat-affected zones, thereby achieving high-quality micro-holes suitable for demanding industrial applications.

Many countries are trying to overcome global warming due to greenhouse gas emissions, such as CO₂. In particular, the regulation on CO₂ emissions of internal combustion engine vehicles has become strictly important. Thus, the automobile companies are putting more effort for improving the manufacturing of the battery, which is the main power supply of electrical vehicles. In the electrode cutting process, laser cutting has been actively discussed to solve problems originating from the conventional electrode cutting processes. However, there is a lack of research considering the effect of thickness of the active material on laser cutting. In this paper, the effect of thickness of the active material on laser cutting of electrodes is analyzed. First, the cut electrodes are observed through a scanning electron microscope (SEM). Next, the kerf width and clearance width of the electrodes are measured and compared at the same laser parameter. The kerf width and clearance width of relatively thick electrodes are narrowly formed. Finally, the cutting quality of the electrode is compared. A uniform cut edge is observed as the scanning speed increases.