High Performance Nitrogen-Doped Si/C as the Anode Material of Lithium-Ion Batteries

Abstract The large-scale synthesis of electrode materials in the field of lithium ion batteries (LIBs) is highly depending on the synthetic technique. In this paper, we developed a facile route to synthesize N-doped carbon coated silicon (Si/C) materials. In that, commercial Si flakes were ball-milled with asphalt as a carbon source and dopamine as a nitrogen source, followed by carbonization in inert atmorsphere to obtain N-doped Si/C materials. As a result, the N-doped Si/C material achieved better cycling stability and slightly higher initial charging capacity of 2265.1 mA h g–1 than that of undoped Si/C at the current density of 200 mA g–1. After 50 cycles, a charge capacity of 1359.1 mA h g–1 was retained, representing 36.7% capacity enhancement compared with that of the Si/C sample (994.4 mA h g–1). Moreover, the rate performance of the Si-based material was also effectively improved by the N-doping. It can be explained that the N-doped carbon layer can facilitate the Li-ions diffusion. Overall, the N-doped Si/C material obtained by a simple technique is promising for the high energy density LIBs application as the anode material.