Heterostructured WO/WC Nanocatalyst for LiS Oxidation in Lithium-Sulfur Batteries with High-Areal-Capacity.

Lithium-sulfur (Li-S) batteries show extraordinary promise as a next-generation battery technology due to their high theoretical energy density and the cost efficiency of sulfur. However, the sluggish reaction kinetics, uncontrolled growth of lithium sulfide (LiS), and substantial LiS oxidation barrier cause low sulfur utilization and limited cycle life. Moreover, these drawbacks get exacerbated at high current densities and high sulfur loadings. Here, a heterostructured WO/WC nanocatalyst synthesized via ultrafast Joule heating is reported, and the resulting heterointerfaces contribute to enhance electrocatalytic activity for LiS oxidation, as well as controlled LiS deposition. The densely distributed nanoparticles provide abundant binding sites for uniform deposition of LiS. The continuous heterointerfaces favor efficient adsorption and promote charge transfer, thereby reducing the activation barrier for the delithiation of LiS. These attributes enable Li-S cells to deliver high-rate performance and high areal capacity. This study provides insights into efficient catalyst design for LiS oxidation under practical cell conditions.