Electrostatic self-assembly of 2-dimensional MXene-wrapped sulfur composites for enhancing cycle performance of lithium-sulfur batteries

For lithium-sulfur (Li-S) batteries to be used in practical applications, the low conductivity of elemental sulfur and the shuttle phenomenon need to be overcome together with the preparation of cathode material of a high sulfur content. Herein, we report a two-dimensional (2D) delaminated MXene-wrapped sulfur composite (S@d-MXene) synthesized via facile electrostatic self-assembly. The ultrathin and flexible 2D MXene wrapping of sulfur particles provides a pathway for lithium-ion transport and electron transfer while suppressing the shuttle phenomenon. In addition, the gap between sulfur particle and the D-MXene sheets wrapping its surface provides a buffering space for the volume expansion of the sulfur particle. The Li-S battery with a high sulfur content of 83.8% in S@d-MXene composite provides a capacity of similar to 506 mAh g(-1) after 500 cycles at a current density of 1C, with a Coulombic efficiency of 99% and an extremely low capacity decay rate (0.047% per cycle). (C) 2021 Elsevier Ltd. All rights reserved.