Hollow/porous-walled SnO2 via nanoscale Kirkendall diffusion with irregular particles

Abstract

Hollow/porous structured SnO2 nanoparticles were synthesized by simple oxidation of dense metal chalcogenide precursors via nanoscale Kirkendall diffusion effect. First, tin chalcogenide (SnS, SnSe) nanoparticles were synthesized by mechanochemical method, which is considered a facile, scalable, and eco-friendly process. Hollow/porous-walled SnO2 nanoparticles were synthesized by simple oxidation of the prepared Sn chalcogenide precursors, for which the transformation mechanism was verified in detail. Nanoscale Kirkendall diffusion process was thoroughly investigated by morphological, crystallographic, and elemental analyses performed at various oxidation temperatures and times. To examine the morphological effect of hollow/porous-walled SnO2 nanoparticles on the electrochemical performance, the synthesized nanoparticles were applied as anode material in a lithium-ion battery. Anode material showed highly improved electrochemical properties compared to its dense counterpart, with 83% capacity retention from the second cycle at the 400th cycle and capacity of 302 mA h g(-1) at a high current density of 30 A g(-1). (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.