High-entropy metal phosphide nanoparticles for accelerated lithium polysulfide conversion

Abstract

To overcome the persistent challenges of sluggish lithium polysulfide (LiPS) conversion kinetics and the shuttle effect in Li–S batteries, this work introduces a novel, cost-effective thermal treatment strategy for synthesizing high-entropy metal phosphide catalysts using cation-bonded phosphate resins. For the first time, we successfully fabricated single-phase high-entropy Fe_0.20Co_0.62Ni_0.14Cu_0.23Mn_0.38P nanoparticles anchored on a porous carbon network (HEP/C). HEP/C demonstrates enhanced electronic conductivity and superior LiPS adsorption capability, substantially accelerating its redox kinetics. These catalytic improvements arise from (1) synergistic electronic modulation by the five constituent metals, which elevates d-band electron energy levels, and (2) lattice distortion induced by atomic radius mismatches, collectively generating a dense array of highly active catalytic sites. The HEP/C@S cathode delivers an ultrahigh initial specific capacity of 1402.18 mA h g⁻¹ at 0.2C, outstanding cycling stability with merely 0.05% capacity decay per cycle over 1000 cycles at 5C, and a remarkable initial energy density of 455 Wh kg⁻¹ in practical pouch cells. This work not only presents an efficient synthesis strategy for high-entropy materials but also provides fundamental insights into the design principles of advanced LiPS conversion catalysts for high-performance Li–S batteries.