In Situ Carbon-Coated Yolk-Shell V2O3 Microspheres for Lithium-Ion Batteries

摘要

Metal oxide-based materials with yolk-shell morphology have been intensively investigated as important anodes for Li-ion batteries due to their large ion storage ability, high safety, and excellent cycling stability. In this work, in situ carbon-coated yolk-shell V2O3 microspheres were synthesized via a template-free polyol solvothermal method. The growth of yolk-shell microspheres underwent coordination and polymerization, followed by an inside-out Ostwald-ripening process and further calcination in N-2 atmosphere. The thin amorphous carbon layers coating on the microspheres' surface came from polyol frameworks which could protect V2O3 during the charge-discharge process and led to a better stability in Li-ion batteries. The in situ carbon-coated yolk-shell V2O3 microspheres showed a capacity of 437.5 mAh center dot g(-1) after 100 cycles at a current density of 0.1 A center dot g((-1)), which was 92.6% of its initial capability (472.5 mAh center dot g(-1)). They were regarded as excellent electrode materials for lithium-ion batteries and exhibit good electrochemistry performance and stability.