Facile synthesis of carbon particles composed of N-doped carbon nanotube and their application in lithium-ion batteries

The synthesis of N-doped carbon materials plays an important role in improving electrochemical performance for lithium-ion batteries. The synthesis of N-doped carbon materials with special morphology and structure remains a challenge, because it is difficult to achieve both goals simultaneously. Carbon particles composed of N-doped carbon nanotubes have been successfully prepared via a simple method using Ni²⁺ salt, melamine-formaldehyde resin microspheres and ethanolamine as the raw materials. The as-synthesized carbon particles possess a stable reversible capacity of 445.5 mAh g⁻¹ at 1 C after 100 cycles. Even at 10 C and 20 C, the reversible capacities could also reach 200.1 and 109.8 mAh g⁻¹. The excellent electrochemical performance of the carbon particles can be attributed to both unique structure and N-doping. The high surface area and long carbon nanotube can provide more active area and facilitate the electron transport. Moreover, N-doping can increase the electrical conductivity and create the defects for carbon materials, which are favorable for Li⁺ adsorption.