Guoliang Cui

A simple method is developed for the preparation of MoSe₂/MoO₂ composite with a flower-like structure for high-performance lithium-ion batteries (LIBs). MoSe₂ could lead to fast and facile movement of Li⁺ due to its larger interlayer spacing. Meanwhile, MoO₂ could protect the lamellar structure of MoSe₂ from being destroyed in the charging/discharging processes to maintain the required active surface to electrolytes. In addition, the flower-like structure of the composite could effectively alleviate the volume expansion during charging/discharging. As LIBs are anode material, MoSe₂/MoO₂ composite demonstrates an excellent specific discharge capacity of 1042 mAh g⁻¹ after 100 cycles at 0.1 A g⁻¹, which is attributed to the synergistic effects of MoSe₂ and MoO₂ in the composite.

In this paper, the synthesis of the three-dimensional (3D) composite of spherical reduced graphene oxide (RGO) with uniformly distributed CeO₂ particles is reported. This synthesis is done via a facile and large-scalable spray-drying process, and the CeO₂/RGO materials are hydrothermally compounded with sulfur. The morphology, composition, structure, and electrochemical properties of the 3D S/CeO₂/RGO composite are studied using X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), Raman spectra and X-ray photoelectron spectroscopy (XPS), etc. The electrochemical performance of the composites as electrodes for lithium–sulfur batteries is evaluated. The S/CeO₂/RGO composites deliver a high initial capacity of 1054 mAh g⁻¹, and retain a reversible capacity of 792 mAh g⁻¹ after 200 cycles at 0.1 C. Profiting from the combined effect of CeO₂ and RGO, the CeO₂/RGO materials effectively inhibit the dissolution of polysulfides, and the coating of spherical RGO improves the structural stability as well as conductivity.