First-principles design of YGaTe3 for bidirectional catalysis and shuttle suppression in lithium–sulfur batteries

• Nearly metallic YGaTe 3 enables ultrafast electron transport in Li–S cathodes. • Y-side cuts Li 2 S 4 → Li 2 S 2 barrier to accelerate solid–liquid conversion. • Strong Li–Te bonding ensures stable LiPS anchoring and shuttle suppression. • Stable p-band center buffers volume expansion for long-cycle durability. Lithium-sulfur (Li-S) batteries suffer from sluggish redox kinetics and polysulfide shuttle, which hinder their practical applications. Herein, first-principles calculations are employed to design and evaluate YGaTe 3 as a high-performance sulfur host. The Y-side surface exhibits nearly metallic conductivity (band gap = 0.0186 eV), providing efficient electron transport channels. Gibbs free energy profiles reveal uniformly low energy barriers (<0.20 eV) for the stepwise S 8 → Li 2 S conversion on the Y-side, whereas the Ga-side exhibits a 0.45 eV barrier in the Li 2 S 2 → Li 2 S step. Furthermore, the continuous and thermodynamically favorable energy profiles during the charging process ensure the feasibility of LiPS oxidation and the capability of bidirectional catalysis. The NEB results demonstrate that the lower energy barrier on the Y-side (0.43 eV) compared to the Ga-side (0.72 eV) facilitates easier Li 2 S activation and faster decomposition kinetics. The Bader charge analysis and −pCOHP results indicate the enhanced charge transfer and robust Te-Li bonding on the Y-side, while the p-band center calculations show stable and favorable electronic coupling for polysulfide adsorption. This combination of high conductivity, bidirectional catalysis, and shuttle suppression highlights YGaTe 3 as a promising candidate for stable and efficient Li-S batteries.