Rational designing and prospecting iron-based compounds as efficient host materials for lithium–sulfur batteries

Known for its high theoretical capacity and low cost, the commercialization of Li–S batteries is hindered by the notorious shuttle behavior of the intermediate lithium polysulfides in liquid electrolyte and the sluggish kinetics of the liquid-to-solid reaction. Recently, to improve the electrochemical performance, iron-based compounds with well-designed nanostructures have been developed and applied as host material for sulfur because they have strong chemisorption of polar polysulfide molecules and could reduce the nucleation energy of solid Li₂S. Here, we have reviewed the latest research progresses (in the last three years) of various iron-based compounds as sulfur host materials and prospected the designing principles of efficient host materials with multiple functionalities to address the issues in sulfur cathode.