Pyrite FeS2 as an efficient adsorbent of lithium polysulphide for improved lithium–sulphur batteries

Abstract

Pyrite FeS₂ chemically combines lithium polysulphide (Li₂S_n) to form active Li₂FeS_2+n complexes that substantially reduce the out-diffusion of dissolved Li₂S_n from sulphur cathodes and consequently improve the cycling performance of lithium–sulphur batteries. The same functions are also applicable to other transition metal sulphides, which opens a new direction for polysulphide sequestration in lithium–sulphur batteries.