Lithium-Ion-Engineered Interlayers of V2C MXene as Advanced Host for Flexible Sulfur Cathode with Enhanced Rate Performance.

A flexible free-standing S@lithium-ion-intercalated V2C MXene/rGO-CNT (S@V2C-Li/C) electrode was rationally prepared to address the neglected issue of Li-ion transport for high-rate lithium-sulfur batteries. In this unique nanoarchitecture, rGO and CNTs serve as a flexible skeleton with high conductivity, whereas V2C-Li MXene plays a vital role in both the chemical absorption of polysulfides and the enhanced transport of lithium ions due to its high polarity and enlarged interlayer distance. Benefiting from the synergistic effect of strong chemical absorption capability and fast lithium-ion migration and exchange, the as-prepared S@V2C-Li/C electrode demonstrates long-term cycling stability with small capacity decay rates of 0.053 and 0.051% per cycle over 500 cycles at 1 and 2 C, respectively.