Fabrication Of Silicon Microwires By A Combination Of Chemical Etching Steps And Their Analysis As Anode Material In Li-Ion Batteries

This work presents a thorough study of Si microwires obtained by a novel combination of chemical etching steps, for their application as anode material in Li-ion batteries. The fabrication process starts with standard photolithography followed by a metal-assisted chemical etching step and anisotropic etching. This process can be performed in any chemical laboratory. The final structures possess a diameter and a length of 1.5 and 24 mu m, respectively. Paste electrodes were prepared using the Si microwires and were tested in half-battery cells. Cyclic voltammetry and impedance spectroscopy evidenced the formation of Li-Si alloys and a solid electrolyte interface. The lithiated wires are mechanically stable upon lithiation, even when they expand to the 256% of their original volume.