Bifunctional Role of High-Entropy Selenides in Accelerating Redox Conversion and Modulating Lithium Plating towards Lithium-Sulfur Batteries.

Abstract

Lithium-sulfur (Li-S) batteries, recognized as one of the most promising next-generation energy storage systems, are still limited by the "shuttle effect" of soluble polysulfides (LiPSs) on the cathode and the uncontrolled growth of lithium dendrites on the anode. These issues are critical obstacles to their practical application. Currently, many researchers have addressed these challenges from a unilateral perspective. Herein, we propose bifunctional hosts based on high-entropy selenides (HE-Se) to simultaneously tackle the persistent problems on both the positive and negative electrodes of Li-S batteries. On the one hand, HE-Se interacts with polysulfides to promote their conversion, effectively mitigating the shuttle effect. On the other hand, HE-Se provides multiple lithophilic sites during the initial nucleation of Li+, which reduces overpotential and exhibits excellent lithophilicity and cyclic stability. As a result, Li-S batteries incorporating the HE-Se hosts demonstrate outstanding performance in terms of rate capability and cycling stability. Additionally, the porous lithophilic HE-Se structure offers sufficient nucleation sites, inhibits the growth of dendritic lithium, and accommodates volume changes during charging and discharging cycles. This study highlights the potential of sulphophilic/lithophilic high-entropy materials in designing advanced Li-S batteries and encourages further exploration in this area.