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 costeffective production procedure.

Automated summary

In recent years, there has been a growing interest among researchers in exploiting stable and high-performance electrode materials for clean, efficient, and sustainable energy storage devices. This study successfully synthesized NiFe2O4@CoFe2O4 core-shell nanoflake arrays on a flexible stainless steel mesh using a simple and low-cost two-step chemical bath deposition method. The resulting electrode exhibited a quick electron/ion transfer and higher electrical conductivity due to the synergistic influence between NiFe2O4 and CoFe2O4 nanoflakes. The NiFe2O4@CoFe2O4 core-shell nanoflake array electrode demonstrated superior electrochemical performance, including a capacitance of 1459.4 F g-1 at a current density of 4 mA cm-2, excellent cycling stability with 85% retention over 5000 cycles at a high current density of 20 mA cm-2, and a high energy density of 21.15 W h kg-1 at a power density of 0.466 k W kg-1. The unique hierarchical structure of this novel integrated nanoarchitecture enables efficient ion and electron transport, a high number of active sites, and a synergistic impact, making it a promising candidate for improved electrodes in high-performance supercapacitors.