Magnetic-field-induced enhanced electrochemical energy storage performance of nickel cobalt phosphide

Abstract

In this work, NiCoP nanorods were synthesized using a combination of hydrothermal and phosphorization techniques. The carbon paper coated with NiCoP (NiCoP/CP) exhibited outstanding supercapacitive properties, achieving a specific capacitance of 264.528 F g⁻¹ at a current density of 0.1 A g⁻¹, with 100% coulombic efficiency in both the absence and presence of a 400 G magnetic field. This enhancement was attributed to the alignment of magnetic dipoles caused by the Lorentz effect. The supercapacitor exhibited a peak specific energy density of 72.01 W h kg⁻¹ and a maximum specific power density of 4219.92 W kg⁻¹, maintaining 57% of its initial capacitance after 5000 cycles under a 400 G magnetic field. Additionally, under the magnetic field, the reduced charge transfer resistance (R_ct) facilitated faster ion diffusion in the electrode, thereby enhancing its performance. Consequently, the bimetallic NiCoP/CP electrode prepared in this manner shows significant potential for energy storage and high-performance supercapacitor applications.