Abstract:
Transition metal selenides have recently become a more favorable material for energy
storage applications owing to their exceptional electrochemical activity, high theoretical
capacities, conductivity, and non-toxic nature. Herein, we have synthesized different
compositions of copper and manganese-based selenide nanocomposites embedded over
multi-wall carbon nanotubes (MWCNTs) through hydrothermal technique. The proper
synthesis of the materials has been validated through different morphological and
structural characterizations. All the electrodes in a three-electrode assembly were tested
and the Cu0.50Mn0.50Se2/MWCNTs sample displays outstanding electrochemical
performance. The optimum sample displayed exceptional specific capacities of 1437.4
C/g at 5 mV/s (and 1365.3 C/g at 1 A/g), which exceeded the reference sample by 3 to 6
times, respectively. Furthermore, the Cu0.50Mn0.50Se/MWCNTs || AC supercapattery
device was fabricated which resulted in energy density (Ed) and power density (Pd) of 68.3
Wh/kg and 8.5 kW/kg, respectively. The device was also tested for 8000 cycles,
maintaining 82.3 % of its preliminary capacity and excellent Coulombic efficiency of 99.5
%. The hybrid nature was confirmed through Power’s law and Dunn’s model of
Cu0.50Mn0.50Se/MWCNTs || AC device. This work demonstrates that selenide-based
nanocomposites have the potential to be considered as battery-grade material in hybrid
supercapacitors.
