Hierarchical nanorod-branched structures of NiO prepared via P, Ni co-doping for boosting energy storage properties as electrode materials of supercapacitors

Abstract

The inadequate exposure of active sites in nickel oxide-based energy storage materials fundamentally limits their energy efficiency and cycling stability. Herein, we report a strategy for preparing phosphorus (P) and nickel (Ni) co-doped NiO heterogeneous nanomaterials (P, Ni–NiO/CC), engineered to achieve superior performance for supercapacitors. The elemental analysis confirms a phosphorus doping concentration of 0.91 at%. As expected, the P, Ni–NiO/CC electrodes delivered an outstanding reversible specific capacitance of 50.6 F cm⁻² at 0.2 A cm⁻² and demonstrated remarkable cycling durability with 93% capacity retention after 10 000 cycles at 1 A cm⁻². This enhanced performance is attributed to the synergistic interplay between the unique P doping and the heterogeneous structure, which collectively improve charge transfer and structural stability. These excellent electrochemical performances confirm the great application potential of P, Ni–NiO/CC as electrode materials for aqueous energy storage devices.