Morphology-controlled synthesis and electrochemical performance of NiCo2O4 as anode material in lithium-ion battery application

Mixed-valence oxide precursors were synthesized by a solvothermal method using NiSO4, CoSO4, and NH4HCO3 as raw materials. The precursors were heat-treated in a muffle furnace at 500 degrees C to obtain the products (NiCo2O4). The samples were characterized by X-ray diffractometer, thermogravimetric, energy-dispersive spectroscopy, scanning electron microscopy, and transmission electron microscopy. The results show that dumbbells, microspheres, and particle-like NiCo2O4 were successfully synthesized by changing the volume of solvent and solvothermal temperature. The NiCo2O4 microspheres (prepared at 180 degrees C with 30 ml solvent) as anode material for lithium-ion battery, exhibit a reversible discharge capacity of 1160 mAh g(-1) and good cycling stability (729 mAh g(-1) after 50 cycles) at a constant current of 100 mAh g(-1) in the voltage range of 0.01-3.0 V due to its high crystallinity and uniform porous morphology. Hence, the synthetic method could be extended to other high-capacity ternary metal oxide materials for lithium-ion battery application.