Porous ZnFe2O4 nanospheres as anode materials for Li-ion battery with high performance.

Transition metal oxides have attracted considerable attention as anode materials of lithium-ion batteries (LIBs). However, poor electrical conductivity and huge volume change hinder their practical application. Porous nanostructure is vital to attain high-performance lithium-ion batteries. Herein, we have designed and fabricated regularly porous ZnFe 2 O 4 nanospheres consisted of small primary nanoparticles via a facile hydrothermal method followed by calcination. The structural properties and morphology of the sample are characterized by powder X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. The composite is then evaluated as anode for Li-ion battery and shows excellent electrochemical properties. The reversible capacity of 868.9 mAh g −1 can be obtained at 200 mA g −1 over 80 cycles. Furthermore, the discharge capacity can still retain 456 mAh g −1 after 600 cycles at a high charge rate of 2 A g −1 . Our findings reveal that ZnFe 2 O 4 sample is a promising anode material for LIBs due to its superior rate capability and long cycle life. [ABSTRACT FROM AUTHOR]