A novel modified sulfur cathode to facilitate the adsorption and conversion of polysulfides in lithium–sulfur batteries

Physical confinement through particular nanostructures is inadequate to avoid the shuttle effect in the lithium–sulfur batteries. Electrocatalysts are based on chemisorption to fix polysulfides on the sulfur cathode and catalyze the conversion of polysulfides. Herein, a novel electrocatalyst consisting of iridium and rGO as support was prepared and employed as the additive to the sulfur cathode. Due to selective catalytic property and changes in activation energy, the formation of polysulfides is slightly inhibited and the transformation of polysulfides is accelerated. Finally, the accumulation of polysulfides and shuttle effect are alleviated. Due to the strong interaction between the polysulfide and catalyst, capacity retention and rate performance were greatly improved.