Ion Kinetics and Capacity Tailoring in Stacked Graphdiyne by Functionalization.

Area of Science:

• Materials Science
• Electrochemistry
• Computational Chemistry

Background:

• Stacked two-dimensional (2D) materials offer practical advantages over monolayers for Li-ion battery anodes.
• Geometric constraints in stacked 2D materials often hinder ion kinetics and capacity.
• Graphdiyne (GDY) is a promising 2D material for energy storage applications.

Purpose of the Study:

• To investigate the anode performance of stacked graphdiyne (GDY) using first-principles calculations.
• To explore the effect of functionalization on the interlayer structure and ion storage properties of stacked GDY.
• To determine if functionalization can mitigate performance degradation in stacked 2D materials.

Main Methods:

• First-principles calculations were employed to simulate and analyze the properties of monolayer and stacked GDY.
• Density of states calculations were used to assess electronic conductivity.
• Lithium-ion diffusion barriers and theoretical capacities were computed for pristine and functionalized stacked GDY.

Main Results:

• Monolayer GDY exhibits a low diffusion barrier (0.315 eV) and high capacity (LiC3).
• Pristine stacked GDY shows reduced capacity (LiC6) and increased diffusion barriers (0.638–0.922 eV) due to geometric constraints.
• Functionalized stacked GDY demonstrates significantly improved ion storage properties, comparable to monolayer GDY, with good electronic conductivity.

Conclusions:

• Functionalization is a viable strategy to enhance the anode performance of stacked 2D materials like GDY.
• Intercalating functional groups effectively enlarges interlayer distance, optimizing ion transport and storage.
• This study provides insights into designing advanced anode materials for high-performance Li-ion batteries.