Electrospun ZnO–SnO2 composite nanofibers with enhanced electrochemical performance as lithium-ion anodes

Abstract

ZnO–SnO2 composite nanofibers with different structures were synthesized by a simple electrospinning approach with subsequent calcination at three different temperatures using polyacrylonitrile as the polymer precursor. The electrochemical performance of the composites for use as anode materials in lithium-ion batteries were investigated. It was found that the ZnO–SnO2 composite nanofibers calcined at 700°C showed excellent lithium storage properties in terms of cycling stability and rate capability, compared to those calcined at 800 and 900°C, respectively. ZnO–SnO2 composite nanofibers calcined at 700°C not only delivered high initial discharge and charge capacities of 1450 and 1101mAhg−1, respectively, with a 75.9% coulombic efficiency, but also maintained a high reversible capacity of 560mAh g−1 at a current density of 0.1Ag−1 after 100 cycles. Additionally, a high reversible capacity of 591mAhg−1 was obtained when the current density returned to 0.1Ag−1 after 50 cycling at a high current density of 2Ag−1. The superior electrochemical performance of ZnO–SnO2 composite nanofibers can be attributed to the unique nanofibrous structure, the smaller particle size and smaller fiber diameter as well as the porous structure and synergistic effect between ZnO and SnO2.