Enhanced performance of charge storage supercapattery by dominant oxygen deficiency in crystal defects of 2-D MoO3-x nanoplates

Abstract

Different colors of partially reduced 2-D MoO3-x-S(1-4)-C nanoplates, converted from the pristine fully oxidized MoO3-S(1-4), were successfully prepared by varying the stirring temperatures followed by constant calcination temperature (x, S, and C indicates oxygen vacancy, stirring temperature, and calcination temperature, respectively). Among these parameters, the reduced 2-D MoO3-x-S4-C nanoplates exhibit the most dominant oxygen deficiency and crystal defects due to the presence of NH4+ as reducing agents in AHM precursor at stiring temperature (100 °C) with calcination temperature (300 °C). The dominant oxygen vacancy concentration of 2-D MoO3-x-S4-C nanoplates presents an extraordinary interlayer spacing and thereby electrical conductivity is improved in electrode materials. In addition, the 2-D MoO3-x-S4-C nanoplates are demonstrated to promote faster charge-storage kinetics and significantly improve the electrochemical activity by exhibiting 573.7 Ahg−1 at 1 Ag−1 and the 93% of capacitance retention at 5 mVs−1 after 10,000 cycles. The solid state asymmetric supercapattery of 2-D MoO3-x-S4-C//RGO device exhibits maximum operating potential windows up to 1.6 V, the energy density 129.6 Wh kg−1 at a power densities of 11.6 kW kg−1, and 98.6% capacity retention over 10 000 cycles at a scan rate of 50 mV s−1 in 6 M KOH electrolyte solution.