Further improvement of battery performance via charge transfer enhanced by solution-based antimony doping into tin dioxide nanofibers

Abstract

We synthesized antimony (Sb)-doped tin dioxide (SnO₂) nanofibers by a one-pot solution doping electrospinning process, and demonstrated that the electrical and lithium (Li)-ion conductivities of SnO₂ nanofibers can substantially be increased by such a facile doping process. Owing to improved conductivities, our Sb-doped SnO₂ nanofibers exhibited greatly facilitated charge transport features as battery anodes. The current study on the effect of dopant concentration revealed that 10 at.% doping produced optimized electrical and Li-ion conductivities from current–voltage characteristics and Nyquist plots. The Sb-doped SnO₂ nanofibers retained over 95% Coulombic efficiency at all variable current rates from a low current rate of 100 mA g⁻¹ to a high current rate of 1000 mA g⁻¹, while pure SnO₂ nanofibers had lower Coulombic efficiency values around 85% at the low current rate of 100 mA g⁻¹. Especially, doped nanofibers exhibited a much more stable capacity retention during 100 cycles than undoped SnO₂ nanofibers. We herein confirmed that the increase in charge transport properties by the facile solution doping can directly lead to the further improved performance of Li-ion batteries with one-dimensional nanofiber electrodes.