Nanosecond laser structuring for improving rate capability of lithium iron phosphate cathode

Abstract

LiFePO₄ cathode's low-capacity retention at high current rates is due to its low electrical conductivity. To address this, a three-dimensional cathode was fabricated using a nanosecond laser. Its performance was studied based on groove aspect ratios (0.39, 0.96) and pitch distances (112 μm, 224 μm). Groove morphology varied with laser parameters. Cathodes with higher aspect ratios exhibited lower internal resistance. However, capacity decreased as groove pitch distance narrowed. The normalized specific capacity of the 3D cathode with an aspect ratio of 0.36 and a pitch distance of 224 μm was 6% higher than that of an unstructured cathode at a 2C rate.