Regulating the catalytic behaviour of iron oxyhydroxide by introducing Ni sites for facilitating polysulfide anchoring and conversion.

Abstract

The sluggish conversion kinetics and notorious shuttle effect of polysulfides are critical hindrances to practical implementation of lithium-sulfur batteries. Herein, bimetallic oxyhydroxide (FeNiOOH) as a functional sulfur host is proposed to overcome these obstacles. The introduction of Ni sites can modulate the electronic structure of the active sites to implement strong soluble polysulfide species immobilization and accelerate the conversion reaction kinetics of polysulfides, resulting in improved sulfur utilization and reduced polarization during the electrochemical reaction process. Benefiting from these advantages, FeNiOOH enables the sulfur cathode to deliver superior rate capability and cycling stability.