NiCo2S4 Nanosheets Grown on 3D Networks of Nitrogen-Doped Graphene/Carbon Nanotubes: Advanced Anode Materials for Lithium-Ion Batteries

To meet the requirements of high-performance lithium-ion batteries (LIBs), a new class of electrode materials with favorable nanostructures is highly desirable. Recently, metal sulfides have been intensively studied as promising anode materials for LIBs because of their high lithium storage capacity. Among them, ternary metal sulfides can provide much higher electrochemical activity and energy storage performance than binary metal sulfides or their oxide counterparts, which makes them outstanding candidates as anode materials for next-generation LIBs. In this work, hierarchical nanostructured hybrids of NiCo2S4 nanosheets uniformly grown on nitrogen-doped graphene/carbon nanotube networks (NiCo2S4/NGC) have been easily prepared as novel anode materials for LIBs. Benefiting from the synergistic effects between NiCo2S4 nanosheets and conductive NGC networks, the optimized NiCo2S4/NGC hybrid exhibits greatly enhanced electrochemical performance with high initial charge capacity of 1225.4mAhg(-1) at a current density of 0.2Ag(-1) and excellent cycling stability with 89% capacity retention after 100 cycles. Moreover, its capacity can be retained at 574.8mAhg(-1) after 100 cycles even at a current density of 5Ag(-1), demonstrating its exceptionally high rate performance.