Coupling Bifunctional Scaffolds with Slow Photon Effect for Synergistically Enhanced Photoassisted Lithium–Sulfur Battery Properties

Abstract

Photoassisted lithium–sulfur (Li–S) batteries offer a promising approach to enhance the catalytic transformation kinetics of polysulfide. However, the development is greatly hindered by inadequate photo absorption and severe photoexcited carriers recombination. Herein, a photonic crystal sulfide heterojunction structure is designed as a bifunctional electrode scaffold for photoassisted Li–S batteries. Inverse opal (IO) structures utilize a slow photon effect that originates from their adjustable photonic band gaps, giving them distinctive optical response characteristics. The incorporation of a SnS/ZnS heterojunction within these IO frameworks further broadens the light absorption spectrum and enhances the charge transfer process. This efficient IO hybrid bifunctional electrode not only enhances the adsorption and conversion of polysulfides at the cathode but also induces uniform Li nucleation at the anode. These contribute the full batteries to output a high reversible capability of 1072 mAh g^–1 and maintain stable cycling for 50 cycles. Additionally, a specific capacity of 698.8 mAh g^–1 is still obtained even under a sulfur loading of up to 4 mg cm^–2. The present strategy on SnS/ZnS IO to enhance photoassisted Li–S battery properties can be extended to rationally construct other energy storage devices.