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

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.