PVA-Assisted Fabrication of PrCoO ₃ Cubic Perovskites for Advanced Hybrid Energy Storage

Rare-earth binary oxides are emerging as versatile functional materials, where compositional tuning and structural tailoring strongly govern their electrochemical energy storage behavior. In this work, praseodymium cobaltite (PrCoO3) perovskites were synthesized through a PVA-assisted route, followed by controlled thermal treatment. The Pr/Co ratio played a decisive role in directing the formation of ultrathin nanosheets, crystallinity, and perovskite phase stability. Subtle lattice contraction/expansion induced by stoichiometric variation altered sheet dimensions and aspect ratios, while calcination conditions further modulated the morphology. These synergistic structural evolutions translated into distinct improvements in electrochemical performance. The pseudocapacitive behavior of PrCoO3-based electrodes (PC-1, PC-2, and PC-3) was systematically evaluated. Pr/Co composites synthesized at varying molar ratios (PC-1, PC-2, and PC-3) were comprehensively characterized by using XRD, FTIR, Raman, XPS, UV–Vis, SEM, AFM, TEM, VSM, WCA analysis, BET surface area measurements, and TGA to investigate their structural, optical, morphological, surface wettability, and thermal properties. The binary metal oxide with an optimized Pr:Co molar ratio of 0.5:1.5 (PC-3) exhibited a maximum specific capacitance of 398.7 F g–1/ 199.45 C g–1 at 1 A g–1, with a remarkable 99.3% retention after prolonged cycling. Furthermore, molar fraction adjustments and surface modifications resulted in varying crystallite sizes, electrochemical kinetics, and charge storage properties across the PC-1, PC-2, and PC-3 electrodes. The assembled hybrid supercapacitor device exhibited an impressive energy density of 47.47 Wh kg–1 at a power density of 4612 W kg–1, maintaining 99.6% of its initial capacitance with 100% of Coulombic efficiency after 5000 cycles, demonstrating exceptional cycling stability and superior electrochemical efficiency. The PC-asymmetric capacitor device successfully powered an LED, showcasing its potential for low-power electronic applications. Future research on PrCoO3 perovskites will refine composition and surface properties for better charge storage and stability, and integration of conductive nanomaterials may further boost electrochemical performance.