Electrochemical performance of SnO2 rods and SnO2/rGO, SnO2/MWCNTs composite materials as an anode for lithium-ion battery application-A comparative study

Abstract

Surfactant and organic solvents-based SnO2 rods and SnO2/rGO, SnO2/MWCNTs composite materials were synthesized by microwave-assisted hydrothermal process. Powder X-ray diffraction analysis revealed the rutile phase formation. Surface morphology of the prepared samples and their chemical compositions were investigated by SEM and EDS, respectively. Lithium ion batteries (LIBs) were fabricated from synthesized SnO2 rods and composites SnO2/rGO, SnO2/MWCNTs as anode materials and it revealed promising initial discharge capacity of 1426 mAh g−1 and 1575 mAh g−1, 1189 mAh g−1 respectively. Electrochemical studies showed that the discharge capacities retained even after 100th cycle were found to be 171 mAh g−1, 351 mAh g−1 and 214 mAh g−1 even at a high current density of 500 mA g−1, with high coulombic efficiency for SnO2 rods and SnO2/rGO, SnO2/MWCNTs composites, respectively. These findings are better than the commercially used graphite as anode material. Further, electrochemical impedance spectra of the fabricated LIBs having SnO2/rGO and SnO2/MWCNTs composites used as anode material showed less charge transfer resistance as compared to bare SnO2 rods. Due to low charge transfer resistance, improved electrical conductivity and the large surface area of rGO nanosheets, the SnO2/rGO composite exhibited better electrochemical performance when compared with the bare SnO2 rods and SnO2/MWCNTs composite.