Anchoring and Catalytic Performance of Co@CN Monolayer for Rechargeable Li-SeS Batteries: A First-Principles Calculations

SeS composite cathode materials, which offer superior theoretical capacity compared to pure selenium and improved electrochemical properties relative to pure sulfur, have aroused considerable interest in recent decades on account of their applications in electric vehicles and energy storage grids. In the current work, the feasibility of a Co@CN monolayer as a promising host candidate for the cathode material of Li-SeS batteries has been evaluated using first-principles calculations, and particular efforts have been devoted to underscoring the anchoring mechanism and catalytic performance of the Co@CN monolayer. The pronounced synergistic effects of Co-S and Li-N bonds lead to increased anchoring performance for LiSeS/SeS clusters on the surface of Co@CN monolayer, which effectively inhibit the shuttle effect. The charge density difference and Mulliken charge analysis underscores a substantial charge transfer from the LiSeS and SeS clusters to the Co@CN monolayer, which indicates a noticeable chemical interaction between them. Further electronic property calculations show that the Co@CN monolayer can improve the electrical conductivity of cathode materials for Li-SeS batteries by maintaining semi-metallic characteristics after anchoring of LiSeS/SeS clusters. Additionally, the catalytic performance of the Co@CN monolayer is evaluated in terms of the reduction pathway of Se and the decomposition energy barrier of the LiSeS cluster, which highlights the catalytic role of the Co@CN monolayer in the formation and decomposition of the LiSeS cluster during the cycle processes. Overall, the Co@CN monolayer emerges as a promising host material and catalyst for Li-SeS batteries with remarkable anchoring and catalytic performance.