Abstract
We demonstrate the sonochemical synthesis of multiwalled carbon nanotubes (MWCNTs) and MoO3 hybrids for an application in supercapacitor (SC) electrodes. The MoO3 nanodots with the diameter of <10 nm are uniformly deposited on the surfaces of MWCNTs as characterized by TEM and STEM images. The specific capacitance of 103 F g−1 in MoO3/MWCNT hybrids is two times higher than 42 F g−1 of the pristine MWCNTs and four times higher than 22 F g−1 of MoO3. Moreover, hybrid electrodes show a good rate capability of >90% retention up to 2.12 A g−1 and cyclic stability of 80% retention during 1000 cycles of charge/discharge because of the mechanical stability of the MWCNTs and the good contact between the MoO3 and MWCNTs. The energy density of MoO3/MWCNT hybrids is evaluated to be 38.7 Wh kg−1 by using an organic electrolyte. Therefore, the hybridization of MWCNTs and redox-active MoO3 nanodots provides a rational design strategy to overcome the critical challenges of pseudocapacitors such as poor rate and cycle stability, while improving the low specific capacitance of electric double layer capacitors (EDLCs).
► The MoO3 nanodots were uniformly deposited on MWCNTs through a sonochemical method. ► The specific capacitance was significantly improved by the deposition of MoO3. ► MoO3/MWCNT hybrids showed a good rate capability and cyclic stability. ► The energy density of MoO3/MWCNT hybrids was 38.7 Wh/kg using organic electrolyte.