CoS₂ Hollow Spheres: Fabrication and Their Application in Lithium-Ion Batteries

Abstract

Uniform hollow spheres of CoS2 have been successfully synthesized via a facile solvothermal method and electrochemically investigated as anode material for lithium-ion batteries. The key strategy is that sulfur powder is used as the sulfur source, while absolute ethanol (EtOH) serves as the solvent and reducing agent simultaneously. X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) patterns demonstrate the high purity of the product. SEM images display that the hollow spheres are about 2−3 μm in diameter and 300 nm in shell thickness. The mechanism for the formation of the final hollow structure is discussed. Temperature and reaction concentrations are found to be the key factors in controlling the morphologies. Meanwhile, electrochemical measurements reveal that the as-prepared CoS2 delivers high discharge capacity (1210 mAh g−1) and good cycle stability, indicating that it might find possible application as anode material for lithium-ion batteries in the long term.