Single‐atomic Co‐B2N2 sites anchored on carbon nanotube arrays promote lithium polysulfide conversion in lithium–sulfur batteries

Abstract

Abstract Due to low cost, high capacity, and high energy density, lithium–sulfur (Li–S) batteries have attracted much attention; however, their cycling performance was largely limited by the poor redox kinetics and low sulfur utilization. Herein, predicted by density functional theory calculations, single‐atomic Co‐B2N2 site‐imbedded boron and nitrogen co‐doped carbon nanotubes (SA‐Co/BNC) were designed to accomplish high sulfur loading, fast kinetic, and long service period Li–S batteries. Experiments proved that Co‐B2N2 atomic sites can effectively catalyze lithium polysulfide conversion. Therefore, the electrodes delivered a specific capacity of 1106 mAh g−1 at 0.2 C after 100 cycles and exhibited an outstanding cycle performance over 1000 cycles at 1 C with a decay rate of 0.032% per cycle. Our study offers a new strategy to couple the combined effect of nanocarriers and single‐atomic catalysts in novel coordination environments for high‐performance Li–S batteries.

Keywords

• carbon nanotubes
• coordination environment engineering
• density functional theory calculation
• lithium–sulfur batteries
• single‐atom catalyst