Co3Se4 Nanoparticles Anchored on Inverse-Opal Skeleton as Sulfur Host for High-Performance Li-S Batteries

Abstract

The practical implementation of lithium-sulfur (Li-S) batteries is significantly impeded by notorious polysulfides shuttle effect and sluggish redox kinetics, which severely compromise cycling stability and energy efficiency. Here, we present a novel framework consisting of high-catalytic Co3Se4 nanoparticles embedded in an N-doped carbonized inverse opal (IO) structure (Co3Se4/NC) as an integrated sulfur host for Li-S batteries. Attributed to the ordered hierarchical porous architecture, the sulfur species are physically confined, while the Co3Se4 nanoparticles enhance both adsorption and catalytic activity. Experimental and computational results demonstrate rapid electron/ion transfer and a high ability of Co3Se4/NC to alleviate the shuttle effect and improve the redox kinetics. As a result, the developed Co3Se4/NC based sulfur cathode (Co3Se4/NC/S) exhibits outstanding electrochemical performance, excellent rate performance, and extended cycling stability, preserving a reversible capacity of 649 mAh g⁻¹ over 500 cycles at 1 C, exhibiting an ultra-low capacity fading of 0.065% per cycle. Even under a sulfur loading of 5 mg cm-2 and a low E/S of 7.2 μL mg-1, a marked areal capacity of 5.4 mAh cm-2 is still retained. This work provides novel insights into structure-oriented electrocatalysis in Li-S chemistry through the synergistic modulation of structure and materials.