Facile synthesis of flower-like Cu3BiS3 hierarchical nanostructures and their electrochemical properties for lithium-ion batteries

Flower-like hierarchical nanostructures with Cu3BiS3 nanosheets as building blocks formed by in situ corrosion of matrix Cu3BiS3 microspheres were synthesized via a facile hydrothermal method. Their morphology, microstructure, and crystalline phase were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD), respectively. Pore-size distribution analysis indicated that both mesopores and micropores existed in the as-obtained product, which are favourable for increasing the surface-to-volume ratio. The optical band gap of the hierarchical Cu3BiS3 nanostructures was estimated to be ∼1.2 eV by UV-vis spectroscopy. Electrochemical measurements were also used to investigate the electrochemical Li+ intercalation performance for the flower-like Cu3BiS3 nanostructures. The results showed that the initial discharge capacity of the nanosheet based Cu3BiS3 hierarchical structures is 676 mA h g−1 which is larger than the theoretical value of Bi2S3 (625 mA h g−1), but it degraded quickly during subsequent cycles, and further improvement in cyclic stability is still needed for practical application in lithium-ion batteries.