Wood‐Derived Carbon Fibers Embedded with SnO(x) Nanoparticles as Anode Material for Lithium‐Ion Batteries

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.