In situ grown Nb4N5 nanocrystal on nitrogen-doped graphene as a novel anode for lithium ion battery

The metal-rich niobium nitride of Nb4N5 has higher conductivity than Nb3N5 and a higher theoretical specific capacity than NbN. To rationally design a metal-rich anode material, Nb4N5 nanocrystals coated by nitrogen-doped graphene (N-G) have been successfully synthesized by a facile in situ ice bathing method with subsequent annealing in NH3. The use of these as an anode material is reported for the first time. The discharge capacity is 487 mA h g−1 at the current density of 0.1 A g−1 (0.0819 mA cm−2) after 200 cycles and the high rate discharge capacity is 125 mA h g−1 at a current density of 5 A g−1 (4.0926 mA cm−2). Specially, the discharge capacity is still enhanced after 200 cycles at 0.1 A g−1 (0.0819 mA cm−2). The Nb4N5/N-G hybrid could be a promising anode material for LIBs with a high rate performance and long cycle life.