Graphitic carbon nanofibers were synthesized by chemical vapor deposition of methane and acetylene on the γ-alumina-supported nickel catalyst. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption/desorption, X-ray diffraction (XRD), and Raman spectroscopy were used to examine the structure and the graphitic degree of carbons. The results show that carbons derived from methane consist of a more graphitic structure compared to acetylene-based carbons. The temperature and the catalyst loading affected the graphitic structure further; i.e., the higher the temperature and the catalyst loadings, the better the graphitic structure. The electrochemical performance of synthesized carbons in 1 M H2SO4 revealed that the methane-based carbons show very stable charge/discharge performance in the whole range of investigated current loadings (viz., 0.05 and 3 A g−1), owing to the graphitic structure and thus resulting from the good charge propagation, particularly at high loads...