Phosphorus-doped tin oxides/carbon nanofibers webs as lithium-ion battery anodes With enhanced reversible capacity

Phosphorus-doped tin oxides/carbon nanofibers (P-SnOx/CNFs) composite materials are prepared via electrospinning of a mixed solution composed of polyacrylonitrile (PAN), N,N-dimethyl formamide (DMF), tin tetrachloride, ethylene glycol and phosphoric acid as well as subsequent thermal treatments. The P-SnOx/CNFs samples with tunable P-doping contents are directly used as anodes for lithium-ion batteries without any binders and conductors, exhibiting enhanced reversible capacities and cycling stabilities in comparison with pristine undoped SnOx/CNFs (0P-SnOx/CNFs). In a controlled experiment, the 0.25P-SnOx/CNFs anode with the atomic ratio of P:Sn = 0.25:1 shows the highest specific reversible capacity of 676 mA h g(-1) at 200 mA g(-1) after 100 cycles. Even at a higher current density of 2000 mA g(-1), it still maintains a superior specific reversible capacity of 288 mA h g(-1). The improved electrochemical performances are attributed to the P-doping effects such as inducement of a stable structural protection for tin particles, and enhancement of lithium ion diffusion coefficient and electron kinetics of electrode materials. (C) 2014 Elsevier B.V. All rights reserved.