Ti-doped SnOx encapsulated in Carbon nanofibers with enhanced lithium storage properties

Hybrid nanocomposites composed of carbon nanofibers and Ti-doped SnOx nanoparticles with varied molar ratios of Ti/Sn (=0.05, 0.1 and 0.2) have been prepared through electrospinning technique and subsequent thermal treatments. High-resolution transmission electron microscopy showed that the Ti-doped SnOx nanoparticles with a very small particle size of 2∼4 nm were uniformly encapsulated in the carbon nanofibers (CNFs). Among the as-prepared samples, the electrode with the Ti/Sn molar ratio of 0.1 delivered the best reversible capacity of 670.7 mAh g−1 at the 60th cycle, which was 17.9% higher than that of the pristine SnOx/CNFs (SOC). What is more, the optimal electrode presented good rate performance (302.1 mAh g−1 at 2 A g−1). The enhanced lithium storage properties of Ti-doped SnOx/CNFs (TSOC) can be attributed to the uniform encapsulation of ultrafine SnOx nanoparticles in the conductive CNFs as well as the doping with Ti4+.