Terminal hollowed Fe2O3@SnO2 heterojunction nanorods anode materials with enhanced performance for lithium-ion battery

Abstract

By the simply mediated concentration of Na2SnO3 and the solvothermal reaction time, a novel terminal hollowed Fe2O3@SnO2 (TH-Fe2O3@SnO2) heterojunction nanorods are synthesized by the inside-out ostwald ripening of SnO2 nanoparticles. For comparison, olive-like Fe2O3 nanorods covered with SnO2 nanoparticles core-shell heterogeneous composites (Fe2O3@SnO2) are also synthesized by a facile hydrothermal treatment method. The structure and morphology of the TH-Fe2O3@SnO2 are investigated by X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). It is found that the shells with 20–25 nm thickness of TH-Fe2O3@SnO2 are composed of tetragonal SnO2 particles (with an average diameter 10 nm), and the core of TH-Fe2O3@SnO2 are formed of the corroded Fe2O3 nanorods with 100 nm length and 50 nm widths. The formation mechanism of TH-Fe2O3@SnO2 has also been studied on the basis of investigation of the concentration of Na2SnO3 and the solvothermal reaction time. By comparison with single Fe2O3 nanorods and Fe2O3@SnO2, the TH-Fe2O3@SnO2 exhibits a higher reversible specific capacity of 570.7 mAh g−1 at the current density of 200 mA g−1 after 100 cycles. The unique terminal hollowed structure and synergetic effect of Fe2O3 and SnO2 can benefit to enhance the Li storage performance and are responsible for the enhanced electrochemical performances.