Immobilisation of sulphur on cathodes of lithium-sulphur batteries via B-doped atomic-layer carbon materials

Developing new host materials for cathodes and exploring their binding mechanisms in lithium-sulphur batteries are crucial issues since the present host materials exhibit low sulphur entrapment properties, thus resulting in the rapid decay of overall performance. In this work, we systematically investigated B-doped atomic-layer carbon materials as the cathode hosts of lithium-sulphur batteries via density functional theory calculations. Based on the analysis of optimised molecular structures, binding energies and surface charge densities, we found that B-doping can help materials suppress the dissolution of sulphides during cycles, further improving the performance of lithium-sulphur batteries. Additionally, we concluded that the internal interactions among multiple Li2Sn-adsorbed structures facilitate the capture of Li2Sn. Furthermore, we found that B-doped graphdiyne is a promising host material since it exhibits a stronger attraction to Li2Sn than other selected materials and an outstanding sulphur loading of B70 wt%.