Rational design of binder free NiFe2O4@CoFe2O4 core–shell nanoflake arrays synthesized by chemical bath deposition for supercapacitor application

In recent years, exploiting stable and high-performance electrode materials has attracted researchers interest as the demand for clean, efficient, and sustainable energy storage devices grows. In this study, facile NiFe2O4@CoFe2O4 core-shell nanoflake arrays grown on flexible stainless steel mesh (FSSM) were synthesized by a simple, low-cost two-step chemical bath deposition (CBD) method. The synergistic influence between NiFe2O4 nanoflake arrays and CoFe2O4 nanoflakes in the mesh form electrode that show a quick electron/ion transfer and a higher electrical conductivity. The NiFe2O4@CoFe2O4 core-shell nanoflake array electrode has shown a capacitance of 1459.4 F g−1 at a current density of 4 mA cm−2, which is significantly higher than the capacitances of the pristine NiFe2O4 and CoFe2O4 electrode. The NiFe2O4@CoFe2O4 core-shell nanoflake array electrode shows superb cycling stability with 85 % retention over 5000 cycles at a high current density of 20 mA cm−2. Furthermore, the NiFe2O4@CoFe2O4 core-shell nanoflake array symmetric device demonstrated a high energy density of 21.15 W h kg−1 at a power density of 0.466 k W kg−1. The improved electrochemical performance is attributed to its unique hierarchical structure, which allows for efficient ion and electron transport, a high number of active sites, and a synergistic impact. This novel integrated nanoarchitecture could hold significant promise as improved electrodes for high-performance supercapacitors due to its remarkable electrochemical performance and cost-effective production procedure. •Binder-free NiFe2O4@CoFe2O4 core-shell nanoflake arrays are prepared via a simple chemical bath deposition method.•The electrode shows a specific capacitance of 1459.4 F g−1 at 4 mA cm−2.•Assembled FSSM device delivers a high specific energy of 21.15 W h kg−1 and excellent cyclic performance.