High entropy sulfide nanoparticles as redox catalysts for lithium–sulfur batteries

Abstract

High entropy sulfide (HES) exhibits high catalytic activity and structural stability due to the synergistic effect and high entropy effect of various metals. However, the conventional approach for synthesizing HES typically necessitates elevated temperatures to ensure homogeneous blending of multiple elements, which directly results in nanoparticle agglomeration and unsatisfactory electrochemical performance. Herein, we propose the HES as a novel separator modifier for lithium–sulfur batteries, which overcomes the limited adsorption-catalytic synergy of conventional single metal sulfides. Ultrafine FeCoNiCrMnS₂ nanospheres (HES NSs) are synthesized via a facile template method, where the multi-metal synergy enables simultaneous suppression of polysulfide shuttling and acceleration of redox kinetics. The ultrafine HES nanocrystals can expose a sufficient number of active sites, which serve as an efficient LiPSs barrier to inhibit side reactions and as an additional collector to enhance the polysulfide redox reaction. As a result, the battery employing HES//PP separators exhibits outstanding cycle stability (906.8 mA h g⁻¹ at 1.0 C after 1000 cycles). This study not only showcases the potential application of HES as a separator modifier for Li–S batteries but also provides novel insights into exploring other high-entropy materials.