New approach for the high electrochemical performance of silicon anode in lithium-ion battery: A rapid and large surface treatment using a high-energy pulsed laser

Abstract

Silicon nanoparticle based anode is effective to extend cycle life by reducing pulverization of silicon particles during lithiation and de-lithiation. However, it is hard to handle nano-scale materials during a series of manufacturing processes in the industry. Particularly, during the drying process, inhomogeneous material distribution within electrode is prone to form a dense surface region by agglomeration of the nanoparticles, causing degradation of electrochemical performances. In this work, we report the effects of laser surface treatment on the dense surface region formed by heterogeneous distribution of materials within the silicon anode based on nanoparticles during the drying process. Laser surface treatment enhanced the cycle life (laser-treated, 1000 mAh g−1 vs. original, 250 mAh g−1 at 200 cycles), rate capability and columbic efficiency considerably. From mechanism study on physicochemical changes at the surface region during laser surface treatment, it is revealed that the characteristics of the laser-treated surface contributes to the reduction of internal resistances and thickness of the solid electrolyte interphase layer, and improves diffusion characteristics.