From Bulk to Nanosheet: How Tellurene Can Influence the Performance of Li‐S Batteries on Both Electrodes

Abstract In the face of growing environmental challenges and the need for alternative energy storage, lithium‐sulfur (Li‐S) batteries stand out for their high theoretical energy density and sulfur's eco‐friendliness. However, the practical application of Li‐S batteries faces significant obstacles, particularly at the cathode and anode. This study explores the transformative impact of 2D tellurene, focusing on how its dimensional variations influence Li‐S battery performance. At the cathode, tellurene not only improves the conductivity and sulfur utilization but also accelerates the conversion of lithium polysulfides (LiPSs). Its reduced size, compared to the bulk counterpart, offers numerous active sites for efficient Li‐ion migration and promotes LiPSs decomposition. At the anode, the protective polytellurosulfides are formed, thereby establishing a stable solid‐electrolyte interphase (SEI) and enhancing reversible lithium deposition. Diminishing the dimensions of tellurene improves its catalytic interface, leading to faster polysulfide conversion kinetics at the cathode and robust SEI formation at the anode. Li‐S batteries equipped with ultra‐thin tellurene‐modified separators demonstrate exceptional performance, exhibiting high areal capacity and significantly reduced capacity decay. Computational simulations further validate the advantages of optimizing tellurene dimensions, confirming its essential role in LiPSs decomposition and overall battery efficiency.