Electrochemical Characteristics of Single Crystalline Nanowires and Their Driven Mechanism

The electrochemical characteristics of single crystalline SnO₂, ZnO and Si nanowires and their driven mechanism are reported as nanostructural anode materials. As intercalation and deintercalation of Li, Si nanowires are converted to amorphous phases of shorter wire shapes caused by the lattice expansion of the single crystalline Si, resulting in the fading of discharge capacity, although the reversible capacity (2500 mAh/g) in the first cycle is very high. However, oxide nanowires (SnO₂ and ZnO) are transformed from a single crystalline structure into a polycrystalline form consisting of nano-sized metallic particles and Li₂O crystals within the wires, which maintain their discharge capacity. The results of this study imply that the large surface area and high electrochemical activity of nanowires and nano-sized polycrystalline particles can provide a method to develop a new class of one-dimensional anode nanostructures in lithium-ion rechargeable batteries.