Hexagonal Scandium Phosphide Monolayer: A High-Performance Anode for Alkali Metal-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Computational Chemistry

Background:

• Two-dimensional (2-D) materials are crucial for advanced alkali metal-ion batteries (AIBs) due to their stability and surface activity.
• Developing high-performance anode materials is key to enhancing AIB technology.

Purpose of the Study:

• To systematically evaluate the potential of hexagonal scandium phosphide (h-ScP) monolayer as an anode material for AIBs.
• To investigate the structural, electronic, and electrochemical properties of h-ScP using first-principles calculations.

Main Methods:

• First-principles calculations were employed to study the properties of the h-ScP monolayer.
• Adsorption energies, charge transfer, diffusion barriers, and theoretical capacities were calculated.
• Ab initio molecular dynamics simulations were used to assess thermal stability and structural reversibility.

Main Results:

• The h-ScP monolayer demonstrated good thermal and dynamic stability with a 1.612 eV bandgap, becoming metallic upon ion adsorption.
• Strong interfacial interactions, ultralow diffusion barriers (0.216 eV for Li, 0.308 eV for K), and high theoretical capacities (>1200 mA h g⁻¹ for K) were observed.
• Low average open-circuit voltages (<0.33 V for Na/K) and validated structural reversibility under operational conditions were confirmed.

Conclusions:

• The h-ScP monolayer exhibits excellent properties, including stability, high capacity, and low ion diffusion barriers.
• These findings position h-ScP as a superior anode candidate for high-performance alkali metal-ion batteries.
• The study highlights the potential of 2-D phosphides for next-generation energy storage applications.