Two-dimensional (2D) metal-organic frameworks (MOFs) have attracted attention for their high electrical conductivity and tunable structure, making them promising materials for energy storage. For instance, lithium-sulfur (Li-S) batteries often suffer from the polysulfide shuttling effect, leading to poor batteries. However, by integrating 2D conductive MOFs like M₃(HITP)₂ (where M is a metal and HITP is the linker 2,3,6,7,10,11-hexaiminotriphenylene), we can better minimize this problem. These MOFs show potential for use in batteries due to their large surface area and customizable pore size. However, previous studies have shown inconsistencies between predicted and experimental band gaps, indicating the need for further investigation.

Density functional theory (DFT) calculations were used to examine the electronic properties and conductive behavior of M₃(HITP)₂. Computational steps included energy cutoff convergence, k-point sampling, structure relaxation, density of states (DOS) and band structure calculations, which revealed conductive properties.

The initial setup involved optimizing computational parameters through self-consistent field (SCF) convergence tests to ensure accuracy and efficiency. The structure was relaxed to determine its most stable form, and the resulting parameters closely matched experimental values. DOS analysis showed no band gap, indicating metallic or semi metallic behavior, supporting its potential for electronic applications. However, to fully understand its electronic properties, band structure calculations are essential. These calculations will provide a deeper insight into the material's conductive pathways and the relationship between electronic bands and crystal momentum.

Future work will focus on understanding how M₃(HITP)₂interacts with lithium polysulfides to see if it can mitigate the shuttling effect in Li-S batteries. This will involve studying adsorption energies and chemical interactions. Results will help determine if M₃(HITP)₂ is the best choice for Li-S batteries or if modifications in the metal ion used in the M₃(HITP)₂ structure could enhance its electrochemical performance.

Kwangnam Kim

Appearances