Functionalized M2CT2 (M = Ti, V, Cr, Mn; T = O, S, Se) MXenes as anchoring materials for lithium-sulfur batteries

The dissolving of soluble lithium polysulfides (LiPSs) in electrolytes severely hinders the practical applications of Li-S batteries, anchoring material (AM) as a cathode additive restrains the dissolution of LiPSs. The -O/-S/-Se functionalized M 2 C (M = Ti, V, Cr, Mn) MXenes were comparative studied as AMs by first-principles calculations. We have studied the relationship between the anchoring effect and the valence electrons’ number (Ne) of metal elements in MXenes. Oxygen functional group MXene has drawbacks such as too strong interaction or semiconductor conductivity. However, for sulfur and selenium functional group M 2 C (M = V, Cr, Mn) MXenes, the moderate interaction of LiPSs and MXenes make them suitable as AMs. For Ti-based MXene, Ti 2 CS 2 and Ti 2 CSe 2 have better electrical conductivity than Ti 2 CO 2 . • We study how the intrinsic properties of metal elements (M) in M 2 CT 2 (T = O, S, Se) MXenes influence the electrochemical performance of Li-S batteries anchoring material. • We investigated the electrical conductivity of MXenes with three functional groups before and after adsorption of LiPSs. • How TM in M 2 CT 2 (T = O, S, Se) MXenes influences the binding energy and decomposition barriers. • We explain the periodicity of electrochemical performance by the analysis of Bader charge and ratio for vdW interaction. The dissolving of soluble lithium polysulfides (LiPSs) in electrolytes severely hinders the practical applications of Li-S batteries, anchoring material (AM) as a cathode additive restrains the dissolution of LiPSs. The -O/-S/-Se functionalized M 2 C (M = Ti, V, Cr, Mn) MXenes were comparative studied as AMs by first-principles calculations. We have studied the relationship between the anchoring effect and the valence electrons’ number (Ne) of metal elements in MXenes. Oxygen functional group MXene has drawbacks such as too strong interaction or semiconductor conductivity. However, for sulfur and selenium functional group M 2 C (M = V, Cr, Mn) MXenes, the moderate interaction of LiPSs and MXenes makes them suitable as AMs. For Ti-based MXene, Ti 2 CS 2 and Ti 2 CSe 2 have better electrical conductivity than Ti 2 CO 2 .