Invasion of Zinc in BiFeO<sub>3</sub>/Bi<sub>25</sub>FeO<sub>40</sub> Perovskite-Structured Material as an Efficient Electrode for Symmetric Supercapacitor
Yogapriya Selvaraj, Kiruthika Paramasivam, Manik Clinton Franklin, Karthick Sivalingam Nallathambi, Vijayakumar Elayappan, Hemalatha Kuzhandaivel
Abstract
BiFeO 3 /Bi 25 FeO 40 (BFO) and zinc-substituted BiFeO 3 /Bi 25 FeO 40 /Bi 38 ZnO 58 (BFZO1, BFZO2, and BFZO3) were successfully synthesized by a hydrothermal method at different concentrations of Zn:Fe. The BFZO1 showed the highest electrochemical behavior than other composites. The X-ray diffraction and Raman analyses of BFZO1 confirmed the formation of zinc-substituted BiFeO 3 /Bi 25 FeO 40 /Bi 38 ZnO 58 . The structural analysis confirmed the agglomerated flake-like morphology from field emission scanning electron microscopy and transmission electron microscopy. BFZO1 showed a high surface area of 56.59 m 2 g –1 and a high pore diameter of 6.71 nm, offering a higher specific capacitance of 1087 F g –1 at a current density of 1 A g –1 in 3 M KOH as an electrolyte. Furthermore, the symmetric device fabricated from BFZO1 showed the highest specific capacitance of 236 F g –1, a specific energy of 32 W h kg –1, and a specific power of 1000 W kg –1 at a current density of 0.5 A g –1 . The reversibility and cyclic stability of the device showed capacitance retention of 84% and Coulombic efficiency of 91% up to 10,000 cycles at a current density of 3 A g –1 . The resulting BFZO1 delivers excellent electrochemical performance in supercapacitor applications.