Pulsed Laser Ablation of Oxygen deficiency Enriched Superlattice Vanadium Pentoxide (V 2 O 5 ) Ultrathin Nextrode aiming for Flexible Binder-less Tandem Energy Harvesting Devices.

For the initial instance, oxygen deficiency-enriched vanadium pentoxide (O─V 2 O 5 @500) thin film electrodes are tuned by the Pulsed Laser Ablation technique. The O─V 2 O 5 @500 thin film electrode shows remarkable electrochemical performances confirming the greater potential window of -0.4 to 0.9 V versus Hg/HgO in an alkaline electrolyte; also, the O─V 2 O 5 @ 500 thin film electrode exhibits a noteworthy volumetric capacity of 167.7 mAh cm -3 (areal capacity of 73.3 µAh cm -2 ). Additionally, Density Functional Theory (DFT) theory calculations are carried out for oxygen-deficient V 2 O 5 . From the partial density of states (pDOS) and partial charge density analysis, it is clear that oxygen vacancy improves the electrical conductivity due to the higher degree of electron delocalization of V─O─V near the vacancy and enhances the redox properties due to the formation of in-gap states. Further, it is reported that a O─V 2 O 5 @ 500 ||PVA-KOH|| Bi 2 O 3 A-650 thin film supercapbattery (TFSCB) device attains an exceptional discharge volumetric capacitance of 182.85 F cm -3 (equal volumetric capacity of 124.5 mAh cm -3 ). Furthermore, the TFSCB device exhibits an extraordinary maximum volumetric energy (power) density of 14.28 mWh cm -3 (1.66 W cm -3 ); TFSCB succeeds in supreme capacity retention of 86% with outstanding coulombic efficiency of 94.4% after 21 000 cycles.