Single step fabrication of nanostructured Cr2O3-MoO2 composite flexible electrode for top-notch asymmetric supercapacitor

[Display omitted] •Nanostructured Cr2O3-MoO2 electrode is fabricated on flexible SS304 by sputtering.•The Cr2O3-MoO2 electrode exhibits a high specific capacitance of 340.8 Fg−1.•The Cr2O3-MoO2//C flexible asymmetric supercapacitor device developed.•Cr2O3-MoO2//C FASC shows excellent capacitance retention of 91.7% for 20,000 cycles. Herein, a high performing flexible asymmetric supercapacitor (FASC) has been constructed by using Cr2O3-MoO2 composite film as positive electrode and carbon film as negative electrode. These thin film electrodes were synthesized by using DC magnetron sputtering technique on the flexible stainless steel (SS 304) current collector. Further, electrochemical kinetics of the prepared thin film electrodes were examined in 1 M Na2SO4 aqueous electrolyte solution. The Cr2O3-MoO2 composite thin film electrode offered high specific capacitance of 340.8 Fg−1 at the current density of 2 mAcm−2. Cr2O3-MoO2 composite electrode surplus Cr2O3 electrode in aspect of their electrochemical properties and cyclability. The structural integrity of both electrodes for (Cr2O3-MoO2//C) FASC device construction facilitated excellent electrochemical performance, operated at prolonged working voltage of +1.9 V and accomplished specific capacitance of 74.5 Fg−1 at 2 mAcm−2. FASC device delivered competitive specific energy of (37.35 Whkg−1) at specific power of (9708 Wkg−1) with excellent capacitance retention of (91.7%) even after 20,000 discharging cycles. Moreover, FASC displayed high capacitance retention (86.1%) in 80° bend state for the same number of charging cycles. These tremendous electrochemical properties and excellent cyclic stability of design FASC device, suggests it to be a promising candidate for energy storage and flexible electronic devices.