Ultrathin Honeycomb-like Carbon as Sulfur Host Cathode for High Performance Lithium–Sulfur Batteries

Abstract

Lithium–sulfur (Li–S) batteries have attracted great interest because of its high theoretical capacity (1675 mA h g–1). However, the low electrical conductivity of sulfur, dissolution of polysulfides, and structural collapse of electrode limit its practical application. Here an ultrathin honeycomb-like porous carbon derived from loofah sponge and doped with nitrogen (PCLSN) is prepared as a stable host for sulfur nanoparticles. Attributed to the integrated honeycomb structure, hierarchical porosity, ultrathin honeycomb walls, and synergistic effects between physical and chemical adsorption of polysulfides, the developed PCLSN@S cathode achieves a high initial specific capacity of 1379 mA h g–1 at 0.1 C, outstanding cyclability with a small capacity decay rate of 0.044% per cycle over 970 cycles at 2 C, excellent rate performance with a high capacity of 664 mA h g–1 at 3 C, and high sulfur content of PCLSN@S up to 76.1%. Our approach provides a promising route to design other 3D porous structures for high ...