High speed pulsed laser cutting of anode material for Li-ion battery in burst mode

The bursts of picosecond laser pulses have nanosecond-level short interval delay. These bursts contain a variable number of sub-pulses, which are used for laser cutting of copper current collector and graphite anode material for Li-ion battery anode. The influences of 2–10 sub-pulses on kerf edges were studied and were compared with that of a single pulse. The shapes of anode edge cut under different conditions, obtained using scanning electron microscopy (SEM), revealed that using burst mode would yield a smaller heat-affected zone (HAZ) of the copper current collector and smaller delamination width of graphite anode material. The capability of laser cutting of anode was characterized with maximum single-time cutting speed. Results showed that the cutting efficiency was raised evidently with the increase in the number of pulses in a burst, and the maximum cutting speeds for the copper current collector and graphite anode material could reach 3,800 mm/s and 500 mm/s respectively.