Accelerating conversion of LiPSs on strain-induced MXene for high-performance Li-S battery

Abstract

Accelerating the conversion of lithium polysulfides (Li2Sn, n = 2–8) is the key to high-performance lithium-sulfur (Li-S) batteries. Design of versatile strategies is still desperately needed for facilitating the kinetic process of LiPSs conversion. Herein, we report an intuitive method, strain regulation, for improving the electrocatalytic performances of MXene for LiPSs conversion. The imported strain triggers the distortion of TiC3O3 octahedron configuration and the downshift of the d-band center, which facilitates the charge transfer and conversion of LiPSs on MXene. Under the guidance of the simulations, the strain-induced wrinkle flower-shaped MXene is adopted to verify the effect of strains on the conversion efficiency of sulfur. The experiments prove that the conversion rate of LiPSs and the long cycle stability of batteries were enhanced by the strained MXene. Our first-principle simulations and experiments demonstrate that the introduction of strain is viable and capable of providing a new paradigm for developing high-performance Li-S batteries.