Facile spray drying synthesis of porous structured ZnFe2O4 as high-performance anode material for lithium-ion batteries

摘要

Porous ZnFe2O4 nanorods have been successfully prepared by a simple spray-drying process followed by sintering. The structure and morphology of the samples were characterized by X-ray diffraction, field emission scanning electron microscopy and transmission electron microscopy. The porous structured ZnFe2O4 materials are successfully used as potential anode material for lithium-ion batteries. Electrochemical results show that the anodes exhibit good cycling performance and rate capability. The anode exhibits initial discharge capacity of approximately 1459 mAh g?1 with an initial coulombic efficiency of 77.8% at a constant density of 100 mA g?1. The discharge capacity of the ZnFe2O4 retained 1458 mA h g?1 after 120 cycles at the current rate of 100 mA g?1 and 456 mA h g?1 could be obtained at the current density of 5000 mA g?1 after 200 cycles. The discharge capacities can still be as high as 778 mAh g?1 at a high rate of 3000 mA g?1. Such remarkable electrochemical properties could be ascribed to the unique porous morphology with large surface area and porosity that were beneficial to facilitate the diffusion of Li ions and electrolyte into the electrodes, meanwhile prevent volume expansion/contraction during lithiation/dislithiation processes.