Bifunctional functionalized two-dimensional transition metal borides for fast reaction redox kinetics in lithiumesulfur batteries

• Ti2BS2 and Ti2BSe2 exhibit strong adsorption toward soluble lithium polysulfides, effectively suppressing the shuttle effect in Li-S batteries. • These functionalized 2D transition metal borides significantly accelerate the redox kinetics of lithium polysulfides, enhancing battery performance. • Low decomposition energy barrier for Li2S and low Li-ion diffusion barrier indicate excellent catalytic activity for Li2S oxidation. • Metallic conductivity maintained throughout charge/discharge cycles, ensuring efficient electron transport and high-rate capability.