Hierarchical Porous Carbon Material with Multifunctionalities Derived from Honeycomb as a Sulfur Host and Laminate on the Cathode for High-Performance Lithium–Sulfur Batteries

Lithium–sulfur batteries (LSBs) received worldwide attention because of its high theoretical capacity of sulfur, 1675 mA h g^–1. However, the low electrical conductivity of sulfur, dissolution of polysulfides (PS) in the electrolyte, and PS shuttle toward the Li anode restricted its reach to the market. In this paper, we present a porous carbon material with multifunctionalities derived from honeycomb (HC) used as a conductive host for sulfur for the first time. Honeycomb derived carbon−sulfur composite with 80% of sulfur [HCS (80%)] gives a high reversible capacity of 1101 mA h g^–1 at the 0.1 C rate after 200 cycles with 82% capacity retention. The coating of HC onto the cathode film [HCS (80%)] yielded 92% capacity retention, where sulfur is sandwiched between the two conductive hosts. Therefore, the HCS (80%) composite electrode with coating of HC [HCS (80%)–HC] exhibits good improvement in both cycling performance and rate capability compared to bare cathode HCS, even though the sulfur content of the HCS composite is as high as 80%. Thus, HCS (80%)–HC would be a potent combination for high-performance LSBs.