Phase boundary-enhanced Ni ₃ N-Co ₃ N@CNT composite materials for lithium-ion batteries

Metal nitride materials are considered as promising candidates for next-generation lithium-ion secondary battery anode materials owing to their high electrical conductivity and attractive theoretical capacity. In this paper, we reported a synthesis method to grow ultrafine Ni ₃ N-Co ₃ N nanoparticles on carbon nanotubes (Ni ₃ N-Co ₃ N@CNTs) via a simple hydrothermal reaction and post-ammonization treatment. By virtue of such a unique structure and component, especially the abundant phase boundaries between Ni ₃ N and Co ₃ N, when used as anodes for lithium-ion batteries (LIBs), the resultant composites delivered reversible discharge capacity of 553.26 mA h g ^-1 even after 600 cycles at a current density of 0.4 A g ^-1 . This reversible capacity was remarkably higher than the theoretical capacities of both Ni ₃ N (424.3 mA h g ^-1 ) and Co ₃ N (421.0 mA h g ^-1 ). We believe that this study will provide a new idea to design high-performance anode materials for LIBs via constructing abundant phase boundaries between different components in composites.