Promising single-atom catalysts for lithium-sulfur batteries screened by theoretical density functional theory calculations

Exploring prominent active centers with high catalytic activity is essential for developing single-atom catalysts (SACs) towards lithium-sulfur batteries (LSBs). Based on density functional theory calculations, a novel pyrrolic-N-incorporated coordination environment is proposed for accommodating 3d transition metal atoms to design high-performance SACs. Compared with the commonly concerned pyridinic-N coordination structure, pyrrolic-N-incorporated coordination displays stronger adsorption of lithium polysulfide (LiPSs) and higher catalytic efficiencies for LiPSs conversion, which can improve the sulfur utilization, cycle stability, and rate capability of LSBs. Hybridization patterns between the p orbitals from sulfur species and d orbitals from the centric metal atom embedded in different coordination environments are disclosed to interpret the origin of higher adsorption strength of LiPSs from pyrrolic-N-incorporated active centers. To further reveal mechanistic factors beneath the catalytic activity, data-driven efforts have been exerted to clarify the relationship between the intrinsic features of active centers and the catalytic efficiencies on LiPSs conversions. Thereby, promising SACs with novel active centers and the underlying mechanisms on modulating the performance of SACs by active centers are unveiled, which offers design strategies for advanced SACs in LSBs.