Co3Se4 nanoparticles anchored on an inverse-opal skeleton as a sulfur host for high-performance Li–S batteries

Abstract

The practical implementation of lithium–sulfur (Li–S) batteries is significantly impeded by the notorious polysulfide shuttle effect and sluggish redox kinetics, which severely compromise cycling stability and energy efficiency. Here, we present a novel framework consisting of highly 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 the remarkable 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 mA h g⁻¹ over 500 cycles at 1C and 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 mA h cm⁻² is still retained. This work provides novel insights into structure-oriented electrocatalysis in Li–S chemistry through the synergistic modulation of structures and materials.