Exceptionally stable electrochemical supercapacitor devices based on V2O5@MnO2 nanocomposite functional anode materials

The performance of supercapacitor devices is mainly limited by the ability to identify anode materials with fair stability and activity. Herein, we demonstrate the efficient synthesis of V2O5@MnO2 nanocomposites. The XRD, XPS, EDS, FESEM, and N-2-physisorption techniques are carried out to clarify the crystallinity, elemental composition, morphology, and surface structure associated with the V2O5@MnO2 nanocomposites. Upon use as negative electrodes in supercapacitor devices, the fabricated V2O5@MnO2 nanocomposite displayed excellent specific capacitance over an outstanding operating voltage window (0 to -1 V). Moreover, the constructed symmetric supercapacitor (V2O5@MnO2//V2O5@MnO2) device revealed ultrahigh specific energy (Es) of 69 Wh kg(-1) with 1200 W kg(-1) under 1.5 A g(-1), and an exceptional cell potential of 1.6 V (almost equal to that of an asymmetric device) with remarkable cycling stability. The device retains an exceptional efficiency (similar to 100 %) over 32,000 consecutive galvanostatic charging/discharging (GCD) cycles. These findings demonstrate the ability of the synthesized nanocomposite for use as viable negative/positive material for high performance devices.