Pulsed Laser Ablation of Lithium Ion Battery Electrodes

Lithium ion battery electrodes have been exposed to 1064nm nanosecond pulsed laser irradiation with pulse energy in the range 8μJ - 1mJ and fluence in the range 3:2 -395J=cm2. Experiments have been executed at translational velocities of 100mm=s and 1m=s, allowing individual characterization of the graphite and lithium metal oxide coatings of the copper anode and aluminum cathode, respectively, as well as that of the complete multi-layer structures. A 3D optical profiler has been utilized to measure the incision depth of all samples and allow observation of the process quality. At high velocity, partial or complete removal of the upper coating layers was achieved with little or no impact on the underlying metallic layers. At low velocity, complete cuts were possible under certain conditions, with process efficiency found to be almost entirely governed by the response of the metallic layers. While the coating layers of each electrode exhibited different responses than the metallic layer, the influence of the latter was found to be dominant for cutting operations. Shorter pulses with fluence in the range 30-60J=cm2 were found to lead to optimum process outcomes with the employed laser source.