Design of WO2.83-WN Heterostructure Bidirectional Catalyst for High-Performance Lithium-Sulfur Batteries

The lithium-sulfur (Li-S) batteries are regarded as a promising candidate for next-generation energy storage devices owing to their high theoretical specific capacity and energy density. Nonetheless, the "shuttle effect" induced by lithium polysulfides (LiPSs) migrating between cathode and anode can result in capacity degradation. To address this issue, a catalyst has been introduced into Li-S batteries to effectively inhibit the "shuttle effect". A bidirectional catalyst with both high adsorption ability and catalytic activity is required to achieve fast transformation of LiPSs. In this context, a heterostructure design of WO2.83-WN is proposed, which has both high adsorptive capacity and excellent catalytic properties for smooth capture-diffusion-conversion of LiPSs. The WO2.83-WN/CC heterostructured electrode demonstrates exceptional electrochemical performance owing to the synergistic effect between its components. It delivers an initial discharge capacity of 1510 mA h g(-1) at a low current density of 0.1 C. Impressively, after 400 cycles at a high rate of 1 C, it retains a discharge capacity of 943 mA h g(-1) with a negligible capacity decay rate of only 0.021% per cycle. Excellent cycle stability is also achieved at high sulfur loading.