Improvement of Supercapacitor Performance through Enhanced Interfacial Interactions Induced by Sonication
Bhaskar J. Choudhury, Kuldeep Roy, Vijayanand S. Moholkar
Abstract
The capacitance of electrode materials is influenced by the surface area which contributes to the formation of the electric double layer. Herein, we have reported the ultrasound-assisted synthesis and characterization of Fe3O4/reduced graphene oxide (rGO) nanocomposites. The nanocomposite had a large BET surface area of ∼332 m2 g–1 with mesoporous structure and exhibited ferromagnetic behavior. The intense microconvection generated by sonication induced unfolding of rGO with the generation of additional active sites for nucleation of Fe3O4 nanoparticles. These structural features facilitated faster diffusion of electrolyte ions to the core of electrode material. Exfoliated rGO also provided electrochemical stability to Fe3O4 nanoparticles and formed a conductive matrix enhancing capacitive performance. The all-solid-state supercapacitor fabricated with Fe3O4/rGO nanocomposite demonstrated a high capacitance of 169.2 F g–1 at 1 A g–1, with ∼84.5% capacitance retention after 6000 cycles at 5 A g–1. The energy density of the supercapacitor was ∼8.46 Wh kg–1 at a power density of ∼338 W kg–1.