Study of burst mode for enhancing the ps-laser cutting performance of lithium-ion battery electrodes

The demand for lithium-ion batteries (LIBs) has increased significantly, leading to an increased focus on high quality production methods. In response to this growing demand, laser technology has been increasingly used for electrode notching and cutting. In addition, the advent of high-power ultrashort lasers equipped with burst mode capabilities represents a promising option for electrode cutting of LIBs. On the other hand, these types of lasers for this purpose are relatively unexplored in the literature. This study investigates the effect of various parameters, including the number of pulses per burst (ranging from 1 to 8), the pulse repetition rate (200.0, 550.3, and 901.0 kHz), and the burst shape (equal pulse peak and increasing pulse peak), on the laser cutting process of aluminum foil, cathode, copper foil, and anode. The results indicate that increasing the number of pulses per burst and the pulse repetition rate improves productivity and quality for all materials, with a more significant effect observed for metal foil than for cathode and anode materials due to the different laser-material interactions for metal foil and active material. The burst shape with equal pulse peaks was found to be a more suitable temporal distribution for cutting all materials compared to an increasing pulse peak distribution. The ablation efficiency was evaluated as a function of the peak fluence of a single pulse within the burst. The results emphasize that higher productivity at higher average power can be achieved by increasing the pulse repetition rate toward the MHz range with moderate pulse energies.