Spraying Coagulation-Assisted Hydrothermal Synthesis of MoS2/Carbon/Graphene Composite Microspheres for Lithium-Ion Battery Applications

Composite microspheres consisting of molybdenum disulfide, amorphous carbon, and reduced graphene oxide (named MoS2-AC-RGO) were prepared by using a hydrothermal approach combined with the spraying coagulation process and calcinations step. Intercalation compound cellulose-MoS2 was obtained after the spraying coagulation-assisted hydrothermal treatment, which then converts to MoS2-AC-RGO after calcination. Graphene oxide and cellulose were utilized as the precursors of RGO and AC, respectively. Thiourea was adopted as both the species for cellulose dissolution and the sulfur precursor for MoS2. The suspension of GO and sodium molybdate also played the role of the coagulation bath. The influence of cellulose on the structure, morphology, and electro-chemical performance of the resultant MoS2-AC-RGO microspheres was investigated based on XRD, SEM, TEM, Raman spectra, TGA, and N-2 adsorption-desorption technique as well as electrochemical measurements. The composite microspheres show superior electrochemical properties as anode materials for lithium-ion batteries and exhibit a high reversible capacity of 910 mAhg(-1) at a current density of 200 mAg(-1), excellent rate capability, and superior cyclic stability with a capacity of 86% after 70 cycles. The roles of the graphene and the cellulose in improving the electrochemical properties of the MoS2-AC-RGO composites are discussed based on the morphology, structure, phase, and electrochemical performance studies.