High entropy alloy nanoparticles dual-decorated with nitrogen-doped carbon and carbon nanotubes as promising electrocatalysts for lithium–sulfur batteries

Abstract

Lithium–sulfur (Li–S) batteries have the advantages of high-energy-density, low cost, and environmental friendliness, but the sluggish sulfur redox reactions and the severe shuttle effect of lithium polysulfide (LiPSs) affect their performance. Herein, we developed a highly efficient electrocatalyst (CNT/HEA-NC) consisting of high-entropy alloy (HEA) nanoparticles decorated with nitrogen-doped carbon (NC) and carbon nanotubes (CNTs) conductive networks. In the elaborate nanostructured protocol, the HEA nanoparticles with high catalytic activity accelerate the bidirectional conversion of LiPSs, the NC with strong sulfophilic activity effectively adsorb LiPSs to suppress the shuttle effect, and the CNT conductive network provides a fast electrons/ions transport pathway. Benefiting from the hierarchical confinement, Li–S batteries with CNT/HEA-NC modified separators deliver a discharge specific capacity of 692.0 mA h g−1 after 300 cycles at 1 C with a capacity decay rate of only 0.03 % per cycle. Even at a current density of 5 C, the cell exhibits a superior capacity of 521.1 mAh g−1. This work provides a general strategy for integrating multifunctional electrocatalysts for high-performance Li–S batteries.