Nitrogen-doped Carbon-coated SnxOy (x = 1 and y = 0 and 2) Nanoparticles for Rechargeable Li-Ion Batteries

Abstract

Polyacrylonitrile was used as a precursor to coat N-doped carbon (NC) on SnxOy (x=1 and y=0 and 2) nanoparticles. The effect of NC coating on electrochemical performance of SnxOy anodes was investigated. Fine dispersion of metal nanoparticles coated with carbon was observed from microscopic analysis. Systematic studies were performed to understand the electrochemical behavior as well as Li-ion battery performance of the prepared materials. Noticeable capacity improvements for NC-SnO2 and NC-Sn were achieved over carbon-coated particles reported previously in the literature. Among the investigated materials, 50wt% NC-SnO2 nanoparticles exhibited the best reversible capacity of 621mAhg−1 while 60wt% NC-Sn exhibited the highest capacity of 450mAhg−1 at 100mA/g after 50 cycles. Electrochemical studies revealed that the carbon shell can effectively increase the stability of the active materials and improve the cycling performance for lithium-ion batteries. NC-protected Sn nanoparticles were also synthesized using poly(vinylpyrrolidone) as a precursor and this material exhibited a significantly high discharge capacity of 650mAhg−1 at 100mA/g after 50 cycles. The studies performed on the Sn-based anodes show the potential of carbon content/coating level and metal particle size for improved Li-ion battery performance.