Structural Engineering of V2O5 Nanobelts for Flexible Supercapacitors

• V 2 O 5 nanobelts have been prepared in a green and scalable method. • V 2 O 5 nanobelts have excellent capacitive performance. • The V 2 O 5 -based supercapacitor has an energy density of 13.9 Wh kg −1 . • The flexible supercapacitor has high capacitance retention. Vanadium pentoxide (V 2 O 5 ) nanobelts were synthesized from powder type V 2 O 5 in an environmentally friendly method with high efficiency which is suitable for large-scale production. Electrochemical properties of the synthesized products were studied using cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) and Nyquist plots. The symmetric solid-state supercapacitor devices have been assembled with V 2 O 5 -1MNa nanobelts as both electrodes. Benefiting from the 1D structure, V 2 O 5 nanobelts interweaved electrodes can be assembled into supercapacitors without binder materials. V 2 O 5 -1MNa nanobelts-based symmetric supercapacitors have a window potential of 2.5 V and an energy density of 13.9 Wh kg −1 when the power density is 1250 W kg −1 .