Ni–Fe–P nanorods via self-sacrificial template as high-performance anodes for sodium-ion batteries

Abstract Ni–Fe Prussian blue analogue (PBA) nanorods were successfully synthesized using an innovative one-dimensional molybdate template method, followed by the preparation of Ni–Fe–P nanorods through a phosphating process. These nanorods are meticulously constructed from two metal phosphides, Ni₅P₄ and FeP. As an anode material for sodium-ion batteries (SIBs), the self-sacrificial template synthesis of Ni–Fe–P nanorods demonstrates remarkable electrochemical performance, achieving a reversible specific capacity of up to 678.8 mAh g⁻¹ at a current density of 0.1 A g⁻¹, and retaining 108.0 mAh g⁻¹ even at a high rate of 10 A g⁻¹. The unique nanorod morphology, synergistic interactions among components, and optimized electron/ion transport pathways contribute to the significant enhancement of the electrochemical properties of Ni–Fe–P nanorods. This study confirms the viability of using molybdate as a template for the synthesis of bimetallic PBAs and subsequent rephosphating to create complex nanostructured phosphide materials, offering a novel approach for the development of high-performance anode phosphide nanomaterials for SIBs.