Electrodeposited Iron‐Incorporated Cobalt Phosphide for Improved Supercapacitor Applications

Supercapacitors have gained significant attention for energy storage due to their high power density and long cycle life. In this context, transition metal phosphides are particularly promising electrode materials for supercapacitors, owing to their high theoretical capacitance and rich redox chemistry. However, they require harsh synthesis conditions and prolonged processing time. Herein, a simple, one‐step electrodeposition method is presented for the synthesis of Fe‐incorporated CoP on Ni foam (NF), offering a rapid and scalable approach. By optimizing the precursor molar ratio of Fe:Co, the electrode material, Fe–CoP (10:20)/NF achieves a high specific capacitance of 920.3 F g −1 at 1 A g −1 with a high‐rate performance of 298.9 F g −1 at 50 A g −1 and retains 78.4% of its capacitance after 10 000 cycles at 30 A g −1 . An asymmetric supercapacitor fabricated using Fe–CoP (10:20)/NF as the positive electrode and activated carbon as the negative electrode delivers an energy density of 16.37 Wh kg −1 at a power density of 799.98 W kg −1 , with 73.8% capacitance retention after 2000 cycles at 5 A g −1 . The enhanced electrochemical performance of CoP is attributed to the Fe incorporation, demonstrating an efficient strategy for advanced supercapacitor development.