Electrochemical performances of asymmetric aqueous supercapacitor based on porous Cu3Mo2O9 petals and La2Mo3O12 nanoparticles fabricated through a simple co-precipitation method

Abstract

Present work shows the electrochemical performances of asymmetric aqueous supercapacitor device based on Cu3Mo2O9 and La2Mo3O12 as a positive and a negative electrode respectively. The Cu3Mo2O9 and La2Mo3O12 were prepared by a simple co-precipitation route within 20 min and post annealing method. Crystalline phase purity of the electrodes is confirmed with powder X-ray diffraction, Raman and X-ray photoelectron spectroscopy techniques. The agglomerated nanoparticles and porous petals-like microstructures are observed for La2Mo3O12 and Cu3Mo2O9 respectively. The specific capacity of La2Mo3O12 and Cu3Mo2O9 is found to be 195.85 and 71.94 C g−1 at 2.5 A g−1 respectively. Charge storage mechanism of the electrodes is elucidated via Dunn’s and Trasatti’s approaches. The asymmetric supercapacitor (ASC) device exhibits a specific capacitance of 61.45 F g−1 at 2 A g−1. The ASC shows retention of 119.4% of initial specific capacitance after 5000 charging and discharging cycles and exhibits coulombic efficiency of 95.5% throughout the 5000 cycles. The ASC stores energy density of 21.84 Wh kg−1 at power density of 1.61 kW kg−1 and sustains the energy density as 2.92 Wh kg−1 at high power density of 10.86 kW kg−1.