Coupling highly dispersed Sb2S3 nanodots with nitrogen/sulfur dual-doped porous carbon nanosheets for efficient immobilization and catalysis of polysulfides conversion

Abstract

• Ultrafine Sb 2 S 3 nanodots serve as adsorbents and catalysts for lithium polysulfides. • Highly N/S Dual-doped carbon matrix guarantees the high conductivity. • Tiny Sb 2 S 3 nanodots guide the Li 2 S to uniformly deposit on carbon matrixes. • The S-NSCNLs@Sb 2 S 3 cathodes exhibit enhanced cyclic stability. Low cost and high energy density lithium-sulfur batteries show great promise for powering next-generation energy storage system. However, the practical application is greatly hindered by the poor cathode conductivity and the shuttle effect of soluble lithium polysulfides. Herein, a leaf-like nanosheets composing of highly dispersed Sb 2 S 3 nanodots embedded in highly nitrogen (18.9%) and sulfur dual-doped porous carbon skeleton (NSCNLs@Sb 2 S 3 ) is designed for efficient immobilization and catalysis of polysulfides conversion by a facile approach. The conductive carbon matrix effectively enhances the conductivity. Nitrogen/sulfur doping species and Sb 2 S 3 nanodots provide abundant stable active sites to anchor lithium polysulfides. Moreover, a series of fundamental experiments reveal that the Sb 2 S 3 nanodots can boost the redox reaction kinetics and guide the polysulfide to uniformly deposit on carbon matrixes, leading to a stable electrode structure. Benefiting from the unique design of the structure and rational componential selection, the S-NSCNLs@Sb 2 S 3 electrodes deliver a stable capacity after 800 cycles with a capacity fade rate of 0.029% per cycle at 1.0 C and an excellent rate capacity of 567 mAh g −1 at 4.0 C. This present work with facile synthetic process may provide a new sight for the designing and practical application of carbon-based sulfur storage materials.