Open AccessPreparation of Hollow Fe2O3 Nanorods and Nanospheres by Nanoscale Kirkendall Diffusion, and Their Electrochemical Properties for Use in Lithium-Ion Batteries
Author(s) -
Jung Sang Cho,
JinSung Park,
Yun Chan Kang
Publication year - 2016
Publication title -
scientific reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.24
H-Index - 213
ISSN - 2045-2322
DOI - 10.1038/srep38933
Subject(s) - kirkendall effect , materials science , ostwald ripening , chemical engineering , lithium (medication) , nanorod , composite number , nanofiber , nanostructure , nanotechnology , diffusion , electrochemistry , carbon fibers , composite material , electrode , metallurgy , chemistry , medicine , physics , endocrinology , engineering , thermodynamics
A novel process for the preparation of aggregate-free metal oxide nanopowders with spherical (0D) and non-spherical (1D) hollow nanostructures was introduced. Carbon nanofibers embedded with iron selenide (FeSe) nanopowders with various nanostructures are prepared via the selenization of electrospun nanofibers. Ostwald ripening occurs during the selenization process, resulting in the formation of a FeSe-C composite nanofiber exhibiting a hierarchical structure. These nanofibers transform into aggregate-free hollow Fe 2 O 3 powders via the complete oxidation of FeSe and combustion of carbon. Indeed, the zero- (0D) and one-dimensional (1D) FeSe nanocrystals transform into the hollow-structured Fe 2 O 3 nanopowders via a nanoscale Kirkendall diffusion process, thus conserving their overall morphology. The discharge capacities for the 1000 th cycle of the hollow-structured Fe 2 O 3 nanopowders obtained from the FeSe-C composite nanofibers prepared at selenization temperatures of 500, 800, and 1000 °C at a current density of 1 A g −1 are 932, 767, and 544 mA h g −1 , respectively; and their capacity retentions from the second cycle are 88, 92, and 78%, respectively. The high structural stabilities of these hollow Fe 2 O 3 nanopowders during repeated lithium insertion/desertion processes result in superior lithium-ion storage performances.