## 1 Introduction  
Lithium-ion batteries, which are secondary rechargeable batteries, have a higher energy density than other secondary batteries such as Ni-Cd batteries and Pd batteries if compared under the same conditions. Therefore, they can be used for energy storage devices, electronic devices, and electric vehicles, and demand for them has increased significantly [1]. The lithium-ion manufacturing process can be categorized into two parts: (1) electrode coating and (2) cell assembly [2]. During this manufacturing process, electrode cutting is one of the most important processes since poor cut quality leads to performance degradation. Moreover, defects such as burr and dress result in separator protrusion and local electric stress concentration. This may, eventually, lead to malfunction of lithium-ion batteries or explosion [3]. Currently, die cutting or rotary knife cutting is used to cut electrodes. Since this process is a contact process, tools can be worn out and process instability can be observed with high possibility. Hence, this process instability has more chance to result in poor cut quality with defects such as burr and delamination. Furthermore, the lack of a standardized battery cell design leads to frequent changes in manufacturing specification, whenever the cell design is changed. Therefore, these frequent tool and design changes cause unexpected additional manufacturing cost. These disadvantages observed with current manufacturing methods can be improved by a laser cutting process due to its many advantages, such as being a noncontact process, with a high energy concentration, fast processing time, and higher flexibility for manufacturing design change. Laser cutting has been applied with high popularity compared to other laser-aided manufacturing processes [4; 5; 6; 7; 8; 9]. Recently, laser cutting was applied to cut electrodes of lithium-ion batteries [10]. The first laser technology using cost-efficient nanosecond laser cutting of electrodes was applied and successfully transferred to industry [10]. [PERSON] et al. [2; 11; 12; 13; 14; 15; 16; 17; 18; 19; 20] investigated physical phenomena during laser electrode cutting theoretically and experimentally with a continuous single-mode fiber laser. [PERSON] et al. [21; 22] used a continuous(CW) and pulsed laser to cut lithium iron phosphate battery electrodes. They characterized the process efficiency and quality. They found that the cutting efficiency increases with shorter pulses, higher velocity, and shorter wavelength. [PERSON] et al. [23] investigated a comparative study on cutting electrodes for lithium-ion batteries with lasers. They compared a CW and pulsed laser to evaluate the cut quality by defining frazzing and clearance widths. They concluded that due to the high power range of the CW laser cutting system, it is advantageous in terms of cutting speed. In addition, the pulsed laser cutting system provides more opportunities for further improvements of the cutting quality. [PERSON] et al. [24] compared the cut quality of laser cutting of lithium-ion electrodes with green (\(\lambda\) = 532 nm, \(\tau\) = 1 ns) and infrared (\(\lambda\) = 1064 nm, \(\tau\) = 250 ns) pulsed lasers. They found that the green laser provided a clearance width below 20 \(\upmu\)m. In addition, the infrared laser met the high-productivity criterion with laser power of 54 W and a cutting speed of 30 m/min. While many physical phenomena occur during laser cutting, conventional parameters have been still used for the analysis of laser cutting, such as kerf width and penetration depth. Therefore, this study proposes specific parameters such as melting width, top width, and kerf width to analyze multiphysical phenomena more intuitively during the laser cutting of electrodes in addition to the conventional parameters. Moreover, the relationship between laser parameters and multiphysical phenomena with the proposed specific widths are investigated with cutting efficiency. This study is composed as follows. First, experimental setup and material used are explained.