A scalable solution-based method for fabricating carbon-coated Ni-Si nanocomposites for use as anode materials in Li-ion batteries is reported. This facile process involves a one-pot synthesis using an electrical pulse technique in oleic acid containing Si nanoparticles at room temperature and a subsequent carbonization route. In these nanocomposites, the Si nanoparticles are individually and separately coated with a carbon shell with a nanoscale thickness. Furthermore, the nanocomposites have a large specific surface area with a spherical complex-structure in which Ni nanoparticles and carbon layers play various pivotal roles, as a mechanically supporting barrier against the aggregation of Si nanoparticles and as an electronic pathway between the active Si nanoparticles. Because of these favorable features, the obtained nanocomposites exhibit not only better cycling performances, but also rate capability, in comparison with bare Si anode materials.