Investigating the Influence of Reflux Condensation Reaction Temperature on the Growth of FeCo2O4 Thin Film for Flexible Supercapacitor

Metal oxides are at the forefront for supercapacitors (SCs) applications considering their unique properties like rapid charge transport and ability to provide more active sites. In this respect, FeCo2O4 nanostructures with varying morphology are designed by reaction temperature variations (80, 100, 120, and 140 °C) in facile reflux condensation synthesis. These different structures are grown onto the flexible stainless‐steel mesh (FSSM) and investigated as an electrode in SCs. FeCo2O4 prepared at 120 °C shows good electrochemical performance and offers 106.85 m2/g specific surface area, 0.1531 cc/g pore volume, and demonstrate hierarchical mesoporous construction. FeCo2O4 nanoflakes demonstrate 260 F g−1 specific capacitance at 1 mA cm−2 and 96.16 % retention of capacitance (over 1000 cycles) supporting considerable cycle stability. The asymmetric supercapacitor (ASC) device demonstrates 15.27 Wh kg−1 energy density and promising charge‐discharge stability (80 % retention up to 2000 cycles). Binder‐free reflux condensation method is used to deposit FeCo2O4 thin films on the FSSM substrate at varying temperatures and its influence on growth and electrochemical properties for supercapacitor application is investigated. The device demonstrated maximum energy density of 15.27 Wh kg−1, a power density of 3.25 kW kg−1 and excellent cycle stability (2000 cycles, 80 % capacitance retention).