Morphology-controlled synthesis and electrochemical performance of NiCo sub(2)O sub(4) as anode material in lithium-ion battery application

Mixed-valence oxide precursors were synthesized by a solvothermal method using NiSO sub(4), CoSO sub(4), and NH sub(4)HCO sub(3) as raw materials. The precursors were heat-treated in a muffle furnace at 500 degree C to obtain the products (NiCo sub(2)O sub(4)). 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 NiCo sub(2)O sub(4) were successfully synthesized by changing the volume of solvent and solvothermal temperature. The NiCo sub(2)O sub(4) microspheres (prepared at 180 degree C with 30 ml solvent) as anode material for lithium-ion battery, exhibit a reversible discharge capacity of 1160 mAh g super(-1) and good cycling stability (729 mAh g super(-1) after 50 cycles) at a constant current of 100 mA g super(-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.