High-entropy metal phosphide nanoparticles for accelerated lithium polysulfide conversion

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.