Tailoring the structural and electrochemical properties of bismuth metal oxide-based materials for energy storage...

This study highlights Bi₃SbO₇ (BSO) as a high-performance electrode with superior pseudocapacitance, enhanced charge storage, and faster redox kinetics compared to Bi₂Mn₄O₁₀ (BMO), demonstrating its promise for advanced energy storage applications. XRD analysis confirms that BSO exhibits higher crystallinity, lower dislocation density, and larger interplanar spacing than BMO, facilitating faster ion transport and improved electrochemical kinetics. FTIR spectra verify phase purity and the formation of characteristic metal-oxygen bonds (Bi-O, Sb-O, and Mn-O), while BET analysis reveals a higher specific surface area (48 m² g^-1) and larger pore radius for BSO. TGA demonstrates the superior thermal stability of BSO, which retained 82.1% residual weight at 500 °C compared with 78.3% for BMO. SEM and EDX analyses reveal a highly porous interconnected morphology, homogeneous elemental distribution, and excellent phase purity, which promote efficient electrolyte penetration and charge transport. Both materials exhibit distinct faradaic redox behavior in cyclic voltammetry, although BSO shows a larger surface-controlled contribution and faster charge-storage kinetics. Galvanostatic charge-discharge measurements deliver a higher specific capacitance of 754 F g^-1 for BSO compared with 302 F g^-1 for BMO at 0.8 A g^-1. Electrochemical impedance spectroscopy further confirms the lower charge-transfer resistance (13.82 Ω), lower solution resistance (1.98 Ω), and enhanced ion diffusion of BSO. These findings demonstrate that the superior structural stability, porous architecture, and homogeneous elemental distribution of BSO collectively contribute to its excellent electrochemical performance, making it a promising electrode material for next-generation hybrid supercapacitors.