Prussian Blue: A Potential Material to Improve the Electrochemical Performance of Lithium–Sulfur Batteries

The Prussian blue, as a potential adsorbent of polysulfides to suppress the dissolution and shuttle of polysulfides for lithium–sulfur batteries, has been studied in this work. Our results show that Prussian blue improves the electrochemical reaction kinetics during discharge/charge processes. More importantly, the cathode with Prussian blue exhibits better cycling stability and higher discharge capacity retention (722 mAh g–1 at 0.2 A g–1 after 100 cycles) than the one without Prussian blue (151 mAh g–1). These improvements of electrochemical performances are ascribed to the fact that Prussian blue is very effective in suppressing the dissolution of polysulfides into liquid electrolyte by chemical adsorption.