Ultrafast laser ablation of lithium manganese iron phosphate for 3D lithium-ion batteries

In recent years, laser structuring has emerged as a promising approach to enhance fast charging and discharging capabilities of lithium-ion batteries and to shift the onset of lithium plating to higher C-rates. In this study, different laser strategies were applied to LiMn$_{0.7$Fe$_{0.3}$PO$_4$ (LMFP) cathodes to enhance their electrochemical performance. The ablation behavior of LMFP cathodes was investigated in single pulse and GHz burst mode with different burst lengths in the range of 50 ns to 500 ns. The resulting groove morphologies were analyzed by evaluating the ablation width and depth, and the laser processing rate under different laser parameters was calculated. In addition, to assess whether high-quality laser ablated microstructures could be achieved while simultaneously maintaining high processing speed, scanning electron microscopy is employed to analyze the structured electrode and identify potential laser-induced thermal modifications of the active material resulting from high average laser power. Finally, the electrochemical performance of unstructured and structured LMFP cathodes was analyzed in half-cell configurations.