Kinetic matching and P-vacancy enrichment of amorphous Ni/Mo-P via central atom modulation in carbon nanospheres for enhanced sodium-ion storage in hybrid capacitors

Amorphous materials, characterized by disordered geometric and electronic configurations, offer abundant active sites and isotropic ion-transport pathways, yet their full potential in sodium-ion hybrid capacitors (SIHCs) remains constrained by insufficient kinetic matching and limited defect engineering. Herein, we propose a bimetallic-modulated amorphous phase in carbon nanospheres (Ni/Mo-P@NC) through atomic microenvironment regulation. The disordered architecture of amorphous Ni/Mo-P facilitates P-vacancy enrichment and enables unrestricted Na+ diffusion, overcoming the sluggish kinetics and rigid atomic arrangements inherent to crystalline counterparts. Synergistic electronic interactions between Ni/Mo atoms induce charge redistribution, generating additional P-vacancies that enhance electrochemical activity and ion-transport efficiency. As an anode, Ni/Mo-P@NC exhibits a 35.5% increase in reversible capacity (up to 335.5 mAh g- 1) at 2.0 A g- 1 after 2000 cycles, relative to Mo-P@NC, while the long cycling stability is achieved due to distinctive plastic deformability of the amorphous phase. In the practicality of hybrid capacitors, Ni/Mo-P@NC delivers both high energy/power densities. This study highlights the benefits of disordering strategy and bimetallic atom modulation, offering important insights for designing high-performance SIHC anodes.