Novel bimetallic tin-manganese oxides-carbon nanotube nanocomposite and their charge storage properties

Abstract

The synthesis of CNTs/(Sn+Mn)Ox nanocomposites were first attempted through combining the hydro-oxidation of SnCl2 to SnO2 and the reduction of KMnO4 to MnO2 onto CNTs in this work. The reducing presence of SnCl2 accelerated the deposition of MnO2 from 7 days to a day. Subsequently, CNTs/(Sn+Mn)Ox nanocomposites were characterised by X-ray diffraction, scanning and transmission electron microscopy, cyclic voltammetry, and galvanostatic charge-discharge. These microstructure and electrochemical results indicated that this nanocomposite showed synergetic effect in term of specific capacitance, charge storage capacities and exceptional cycling stability. All these enhanced electrochemical properties were attributed to increased surface area, increased utilisation of co-deposited cassiterite-type SnO2 nanoparticulates and birnessite MnO2 monolayer. Additionally, their improved electronic conductivity facilitated better mass transport of ions during charging and discharging process. Based on the findings above, CNTs/(Sn+Mn)Ox nanocomposite will be served as promising and affordable positive electrode materials for high performance supercapacitors.