Heterostructured WOx /W2 C Nanocatalyst for Li2 S Oxidation in Lithium-Sulfur Batteries with High-Areal-Capacity

Small. 2024 Feb 2:e2310801. doi: 10.1002/smll.202310801. Online ahead of print.

Abstract

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 (Li2 S), and substantial Li2 S 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 WOx /W2 C nanocatalyst synthesized via ultrafast Joule heating is reported, and the resulting heterointerfaces contribute to enhance electrocatalytic activity for Li2 S oxidation, as well as controlled Li2 S deposition. The densely distributed nanoparticles provide abundant binding sites for uniform deposition of Li2 S. The continuous heterointerfaces favor efficient adsorption and promote charge transfer, thereby reducing the activation barrier for the delithiation of Li2 S. These attributes enable Li-S cells to deliver high-rate performance and high areal capacity. This study provides insights into efficient catalyst design for Li2 S oxidation under practical cell conditions.

Keywords: heterostructured nanocatalysts; lithium sulfide oxidation; lithium-sulfur batteries; ultrafast joule heating.