A DFT study on 18-crown-6-like-N$_8$ structure as a material for metal-ions storage: stability and performance

Abstract: Developing electrode materials with exceptional electrical conductivity, robust chemical stability, rapid charge and discharge rates, and high storage capacity is essential for advancing high-performance metal-ion batteries. This study explores the two-dimensional, 18-crown-6-like N8 structure (2D-N8) as a promising electrode material for next-generation rechargeable post-lithium batteries. We thoroughly investigated the pristine N8 structures, focusing on their stability and performance metrics. Our analysis revealed remarkable structural stability across the board. Additionally, electronic calculations indicated a small band gap of 0.54 eV for the N8 monolayer, suggesting favorable electronic properties for battery applications. When we evaluated a series of metal ions as adsorbates, we found that the pristine N8 monolayer achieved an impressive storage capacity of 1675 mAh/g for sodium (Na) and magnesium (Mg) ions, highlighting its potential for effective ion storage. Our findings suggest that the engineered 2D-N8 structure offers a unique combination of stability and electrochemical performance that could significantly contribute to developing efficient and durable energy storage technologies.