Heterostructured WO_x/W₂C Nanocatalyst for Li₂S 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 (Li₂S), and substantial Li₂S 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_x/W₂C nanocatalyst synthesized via ultrafast Joule heating is reported, and the resulting heterointerfaces contribute to enhance electrocatalytic activity for Li₂S oxidation, as well as controlled Li₂S deposition. The densely distributed nanoparticles provide abundant binding sites for uniform deposition of Li₂S. The continuous heterointerfaces favor efficient adsorption and promote charge transfer, thereby reducing the activation barrier for the delithiation of Li₂S. These attributes enable Li-S cells to deliver high-rate performance and high areal capacity. This study provides insights into efficient catalyst design for Li₂S oxidation under practical cell conditions.