Flower‐like Fe(OH)₃ as Sulfur Hosts for High‐Performance Lithium–Sulfur Batteries

Abstract

Lithium‐sulfur batteries are considered one of the next generation potential candidates for electrochemical energy storage devices owing to their high energy density. However, their practical application presents several challenges that need to be addressed. In this study, a flower‐like Fe(OH)3 was obtained using a simple and environmentally friendly one‐step injection method, intended to be used as sulfur host in lithium‐sulfur batteries. The polar hydroxyl groups in Fe(OH)3 capture free polysulfides in the electrolyte via chemisorption and the unique structure of the material physically entraps polysulfides, thus preventing the shuttle effect. Benefiting from functional group and spatial shape advantages, the resultant S@FH electrode yielded an initial capacity of 1187.6 mAh g−1 at 0.1 C. When the batteries are tested for 100 cycles, the reversible capacity remained at 635.2 mAh g−1 and the coulomb efficiency was nearly 100 %.