Synthesis and Electrochemical Performance of NiCO₂S₄ as Anode for Lithium-Ion Batteries.

NiCO2S4 with different morphology was controllably fabricated by a facile hydrothermal and solvothermal route. The as-obtained samples were analyzed and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The results reveal that the sample (NCS-1) prepared by hydrothermal method manifest a mixture of nanorods and nanospheres. The sample (NCS-2) synthesized by solvothermal process takes on spherical nanoparticles (NPs). It is found that the morphology of the sample has much influence on the electrochemical property. When applied as anode for lithium-ion batteries (LIBs), the NiCO2S4 NPs (NCS-2) possess the highest reversible discharge capacity of 1469.8 mAh g-1 compared with other two samples at the current density of 100 mA g-1 in the voltage window of 0.01-3 V. Additionally, it remains a specific capacity of 1163.7 mAh g-1 at a current density of 100 mAg-1 after 100 cycles. This excellent electrochemical performance arises from its unique mesoporous structure, which can reduce the transport lengths of both lithium ions and electrons. The mesoporous NiCO2S4 NPs show the great potential development of high-capacity anode materials for LIBs.