Microwave-assisted hydrothermal synthesis of SnO2/reduced graphene-oxide nanocomposite as anode material for high performance lithium-ion batteries

Abstract

Surfactant and organic solvents free SnO2 nanospheres and SnO2/reduced graphene oxide (SnO2/rGO) nanocomposite were prepared by microwave assisted hydrothermal method. X-ray diffraction (XRD) and Raman spectroscopy results confirm the formation of pure nanocrystalline rutile phase of SnO2 and nanostructured rutile phase of SnO2 over the amorphous structured rGO. FE-SEM, EDX and HR-TEM results showed the formation of spherical shape SnO2 nanoparticles and the formation of spherical shape SnO2 nanoparticles over the crumpled nanosheets like morphology of rGO. The electrochemical measurements of lithium-ion batteries fabricated using pure spherical shape SnO2 nanoparticles and crumpled nanosheets like morphology of SnO2/rGO nanocomposite as an anode material showed the good initial discharge–charge capacity of 2128 and 1718 mA h g−1 respectively. The capacity retention after 50 cycles is found to be 349 mAh g−1 at a current density of 500 mA g−1 for the lithium-ion battery fabricated using pure spherical shape SnO2 nanoparticles and the capacity retention after 300 cycles is found to be 318 mAh g−1 at a current density of 500 mA g−1 for the lithium-ion battery fabricated using SnO2/rGO nanocomposite, which is much better than the reported values. The observed better electrochemical performance of the lithium-ion battery is attributed to the formation of spherical shape SnO2 nanoparticles over the crumpled nanosheets like morphology of highly porous graphene and also increased electronic conductivity of SnO2/rGO nanocomposite. Hence, the crumpled nanosheets like morphology of highly porous of SnO2/rGO nanocomposite prepared by microwave hydrothermal method can be a high-performance anode material for a lithium-ion battery application.