Synthesis

The blank electrolyte consists of 1 M lithium bis(trifluoromethanesulfone)imide (LiTFSI) in a mixture of 1,2-dimethoxyethane (DME) and 1,3-dioxolane (DOL) at a 1:1 volume ratio, with 0.1 M LiNO₃ as an additive. To prepare the polysulphide catholyte, sulphur powder (Alfa Aesar) and lithium sulphide (Alfa Aesar) in fixed ratio were added to the blank electrolyte to achieve 1 M sulphur concentration in the form of Li₂S₆. The catholyte was heated at 45 °C for 24 h. A designated amount of cobaltocene was prepared at room temperature after stirring for 12 h. All processes were performed in an Ar-filled glove box.

Sulphur loaded commercial carbon non-woven layer (GDL, Toray) was prepared by dropping sulphur dissolved CS₂ solution onto GDL electrode.