RESUMO
Carbon-SnO x composites are obtained by impregnating acetylacetone-treated, delignified wood fibers with tin precursor and successively carbonizing at 1000 °C in 95% argon and 5% oxygen. Scanning electron microscopy and nitrogen sorption studies (Brunauer-Emmett-Teller) show that acetylacetone treatment stabilizes the wood fiber structure during carbonization at 1000 °C and preserves the porous structural features. X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy studies show that the small amount of oxygen introduced in inert atmosphere passivates the surface of tin nanoparticles. The passivation process yields thermally and electrochemically stable SnO x particles embedded in carbon matrix. The resultant carbon-SnO x material with 16 wt% SnO x shows excellent electrochemical performance of rate capability from 0.1 to 10 A g-1 and cycling stability for 1000 cycles with Li-ion storage capacity of 280 mAh g-1 at a current density of 10 A g-1. The remarkable electrochemical performance of wood-derived carbon-SnO x composite is attributed to the reproduction of structural featured wood fibers to nanoscale in carbon-SnO x composite and controlled passivation of tin nanoparticles to yield SnO x nanoparticles.