Synergistic Restriction to Polysulfides by a Carbon Nanotube/Manganese Sulfide-Decorated Separator for Advanced Lithium–Sulfur Batteries
Sreekala Kunhi Kannan, Haritha Hareendrakrishnakumar, Jithu Joseph, Mary Gladis Joseph
Abstract
Polysulfide dissolution and shuttling limit the capacity output and cycle life of lithium–sulfur batteries to a great extent. Separator modification using polar materials exploiting the ability to entrap polysulfides has been demonstrated as an effective approach to deal with the conundrum of polysulfide shuttling. Herein, a carbon nanotube/manganese sulfide nanocomposite is designed as a separator modifier in lithium–sulfur batteries for the first time. Furthermore, the carbon nanotube network provides a continuous network for rapid electronic conduction, imparts structural stability, and acts as a secondary barrier for polysulfides. Consequently, the cell displays an initial discharge capacity of 876 mAh g–1 at 0.5 C and sustains excellent stability with a retained capacity of 76% after 500 cycles. The self-discharge of the cell is also conspicuously reduced, maintaining a constant voltage for 100 h under open-circuit conditions. The electrochemical results represent an effective strategy to realize better performing Li–S batteries.