Uniform Nano-SnO2/C Composite Anodes from Coal Tar Pitch for Sodium-Ion Batteries

Because of the superiority in high theoretical capacity and environmental friendliness, SnO2 as an ideal anode material exhibits an application prospect in sodium-ion batteries. Nevertheless, its practical use is restricted by the poor electro-conductivity and huge volume expansion. To solve these difficulties, a maneuverable and effective strategy is introduced to synthesis SnO2/C composites in this work. For the operation, the composites are prepared via a one-pot hydrothermal technique. For the effect, SnO2 particles disperse uniformly on the pitch-derived carbon matrix in nanometer size. The impacts of the pyrolysis temperature and SnO2 content are investigated in detail. It is surprising that the diameter of the SnO2 particle is similar to 5 nm observed by high-resolution transmission electron microscopy, and the Sn-O-C bond exists, confirmed by X-ray photoelectron spectroscopy. In comparison to the carbonaceous substrate and pure SnO2, the composite shows higher storage capacity and greater cycle performance that SnO2/C-2 delivers a charge specific capacity of 311.8 mAh g(-1) at 100 mA g(-1) initially and a residual capacity of 144.2 mAh g(-1) after 1000 cycles at 500 mA g(-1). The remarkable electrochemical performance benefits from the nanosized SnO2 particles with high dispersion as well as the tight link between SnO2 and the carbon matrix.

Automated summary

This work introduces a strategy to synthesize SnO2/C composites via a hydrothermal technique, resulting in nanometer-sized SnO2 particles with high dispersion. The composites exhibit higher storage capacity and greater cycle performance compared to pure SnO2, attributed to the tight link between SnO2 and the carbon matrix.