Effect of Temperature on Carbon-coated Graphene for Lithium-ion Batteries with Improved Performance

Abstract Carbon-coated graphene was synthesized through pyrolysis of a polyaniline–graphite oxide (PANI–GO) precursor by annealing in an Ar and H2 atmosphere at various temperatures. X-ray diffraction, field-emission scanning and high-resolution transmission electron microscopies, X-ray photoelectron spectroscopy, Raman spectra, and thermogravimetric analysis were used to characterize the pyrolyzed PANI–GO at different temperatures. The PANI on the graphene at temperatures above 650 °C was completely converted into a nanocarbon film. Galvanostatic charge–discharge tests revealed that PANI–GO-800 exhibited improved rate and cycle capabilities over that of graphene due to the increased conductivity in the out-of-plane direction.