Porous nanofibers comprised of hollow SnO2 nanoplate building blocks for high-performance lithium ion battery anode

Hollow nanoplates-aggregated SnO2 nanofibers were fabricated from electrospinning process and two-step heat treatment. Se particles were dissolved in electrospinning solution and played a critical role in the formation of small-sized SnSe nanoplates during the selenization heat treatment. During the oxidation heat treatment, due to the well-known Kirkendall diffusion process, the dense SnSe nanoplates were transformed into hollow SnO2 nanoplates. Three other SnO2 nanostructures including SnO2 hollow nanoplates, hollow nanofiber with hierarchical SnO2 nanocrystals, and SnO2 hollow nanofibers were prepared as comparison. The capacity of hollow nanoplate-aggregated SnO2 nanofibers after the 700th discharge process was 375 mA h g(-1) when cycled at a high current density of 3 A g(-1), whereas those of the comparison SnO2 nanostructured electrodes in the order listed were 78, 277, and 262 mA h g(-1), respectively. The high structural stability of the synthesized hollow nanoplate-aggregated SnO2 nanofiber during repeated lithiation and delithiation processes resulted in lithiumion battery anode with longer cycle life.