Abstract

This study presents a phase-characterised optical set-up for shaped-beam femtosecond laser processing of double-sided lithium-ion battery anodes. The phase response was found to be power-independent, with consistent phase scaling across applied powers and a 2π phase shift completed at approximately 220–225 grey levels (GL). The measured modulation visibility stayed high. The generated beam profiles were in good agreement with MATLAB simulations, confirming reliable wavefront control. Under identical processing conditions, wavefronts carrying different orbital angular momentum (OAM) produced distinct kerf morphologies: at 30 overscans, m=0 gave a deeper cut with a taper angle of 16.5±1.1°, while m=1 gave a shallower groove with a less steep angle of 26.3±1.9°, indicating different Cu-layer interaction and ejecta behaviour. When the overscan number was increased to 45 at the same average power, both m=0 and m=1 achieved through-cuts. However, the m=1 condition produced a cleaner cut edge, a more vertical kerf wall, and reduced graphite delamination and heat-affected damage compared with the Gaussian beam. These results demonstrate the potential of wavefront engineering for laser processing of layered battery anodes, where improved cut confinement and edge quality can be achieved through beam shaping under relatively low-energy, moderate-overscan, and tight-focusing conditions.

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