New carbon–nitrogen–oxygen compounds as high energy density materials

Abstract

Molecular crystals are complex systems exhibiting various crystal structures, and accurately modeling the crystal structures are essential for understanding their physical behaviors under high pressure. Here, we have performed an extensive structure searches of ternary carbon-nitrogen-oxygen (CNO) compound under high pressure by CALYPSO method and first principles calculations and successfully identified three polymeric CNO compounds with $ Pbam $,$ C2/m $ and $ I\bar{4}m2 $ symmetries under 100 GPa. Most interestingly, these structures are also dynamically stable at ambient pressure, and are potential high energy density materials (HEDMs). The energy densities of $ Pbam $, $ C2/m $ and $ I\bar{4}m2 $ phases of CNO are about 2.30 kJ/g, 1.37 kJ/g and 2.70 kJ/g, respectively, with the decompositions of graphitic carbon and molecular carbon dioxide and $\alpha$-N (molecular $ \rm N_2 $) at ambient pressure. The present results offer in-depth insights into the structural evolution and physical properties of CNO compounds under high pressures, which offer crucial insights for the design and synthesis of novel HEDMs.

Effect of strain on structure and electronic properties of monolayer C4N4

“…Two-dimensional (2D) materials including graphene, silicene, metal oxides, transition-metal dichalcogenides, and transition-metal carbides, have received much attention in the fields of physics, chemistry, and materials science, especially in battery materials, because of their outstanding physical and chemical properties, such as high surface-volume ratio and unique electronic band structure, charge carrier mobility, and mechanical properties. [1][2][3][4][5][6][7] Lithium-sulfur (Li-S) battery has potential wide-ranging applications as the next-generation energy storage devices but the shuttle effect adversely influences battery longevity and performance. [8] Graphene, as the best known 2D carbon-based material, is hindered by the relatively low adsorption energy to be a high-performance anchoring material restraining the shuttle effect.…”