Morphology-controllable synthesis of bimetallic oxide Bi2Fe4O9 as novel electrode materials for high-performance supercapacitors

Abstract

Supercapacitors have grabbed a lot of limelight and have been under extensive scrutiny by researchers for their advantages over competitors, such as high power density, long-term cycle life, accelerated charging and discharging, security, and environmental sustainability. Herein, the hydrothermal combination with co-precipitation approach is effectively used to create Bi2Fe4O9 particles with various morphologies through controlling the concentrations of NaOH, and they show significant discrepancies in their electrochemical characteristics. The chamfered square plate-like Bi2Fe4O9 particles (Bi2Fe4O9–3) obtained at a NaOH concentration of 12 M demonstrate pseudocapacitive or battery-like behavior in a three-electrode system and exhibited optimum electrochemical properties, displaying a mass-specific capacitance of 443.8 F g−1 at 1.0 A g−1. In terms of electrochemical characteristics and long-term cycling stability, the Bi2Fe4O9–3 sample also displays an extraordinary Coulombic efficiency of 98.87 % and capacitance retention rate of 142 % after completing 5000 cycles of galvanostatic charge-discharge. Moreover, the self-assembled asymmetric supercapacitor device has an energy density of 21.11 Wh kg−1 at a power density of 424.26 W kg−1. Bi2Fe4O9–3 has been meticulously fabricated as an innovative and inimitable electrode material that manifests brilliant electrochemical properties, rendering it prospective for progressive application in the supercapacitors realm by researchers in the future.