Silkworm Excrement Derived In‐situ Co‐doped Nanoporous Carbon as Confining Sulfur Host for Lithium Sulfur Batteries

Abstract

AbstractLithium sulfur batteries (Li−S) are widely proposed as the next generation energy storage systems due to their super high energy density. However, one of the challenges remains in the “shuttle effects” of polysulfides, which hinders the practical application of Li−S. To address the above issue, herein, we propose an innovative design strategy of in‐situ co‐doped nanoporous carbon (ICPC) derived from silkworm excrement to achieve the strong chemical bonding and strict physical confinement of sulfur. As a result, the migration of polysulfides might be suppressed by the synergistic effects of physical and chemical interactions, which is helpful for the significant improvement of electrochemical performance. After 100 stable cyclic discharge‐charge tests at the current density of 0.2 C, the reversible capacity of the as obtained ICPC−S composite cathode still maintains around 500 mAh g−1, corresponding to 67% capacity retention. More importantly, high Coulombic efficiency of nearly 100% can be realized, suggesting the greatly avoided “shuttle effects”. Such a novel design of in‐situ co‐doped nanoporous carbon opens up new possibilities for high performance lithium sulfur batteries.